Polarizing film, optical film, and image display device

Abstract

This invention provides a polarizing film that exhibits excellent humidification reliability even in harsh environments with high temperature and humidity. The polarizing film of this invention comprises an iodine-based polarizer and an adjacent layer disposed on at least one side of the iodine-based polarizer, wherein the HSP distance between the adjacent layer and water is 26 or more. Preferably, the adjacent layer contains a water permeability of 500 g / (m²). 2 A barrier layer of 24h or less. Furthermore, the thickness of the barrier layer is preferably 1μm or more. Additionally, it is preferable that adjacent layers are separated by an adhesive layer that is directly in contact with the iodine-based polarizer, thus providing a barrier layer.

Description

Technical Field

[0001] This invention relates to a polarizing film comprising an iodine-based polarizer and an adjacent layer disposed on at least one side of the iodine-based polarizer. The polarizing film can be used alone to form image display devices such as liquid crystal displays (LCDs), organic EL displays, CRTs, and PDPs, or it can be used as an optical film in which the polarizing film is stacked to form such image display devices. Background Technology

[0002] Polarizing films are used in various image display devices to display images. For example, in liquid crystal display (LCD) devices, from the perspective of its image formation method, it is essential to place polarizing films on both sides of the glass substrate on which the liquid crystal panel surface is formed. In addition, in organic EL display devices, in order to block the specular reflection of external light on the metal electrodes, a circularly polarizing film with a polarizing film and a quarter-wave plate stacked on the visible side of the organic light-emitting layer is placed.

[0003] Generally, the polarizing film used is a protective film bonded to one or both sides of a polarizer using various adhesives. The polarizer is formed from a polyvinyl alcohol film and a dichroic material such as iodine. As an adhesive, for example, a free-radical polymerizable active energy ray-curable adhesive using N-substituted amide monomers as curing components has been proposed (Patent Documents 1 and 2 below). This adhesive exhibits excellent humidification reliability in harsh environments with high humidity and high temperature; however, in the market, there is a demand for adhesives that can further improve humidification reliability.

[0004] In addition, focusing on the SP value (solubility parameter) of the curing component, an active energy ray curing adhesive was proposed (Patent Document 3 below) that can form an adhesive layer with improved humidification reliability by using at least three free radical polymerizable compounds with different SP values ​​in a given composition ratio.

[0005] It should be noted that, sometimes, for polarizing films, not only is humidification reliability required, but also excellent resistance even in harsh environments such as thermal shock (e.g., repeated thermal shock tests at temperatures of -30°C and 80°C). For example, Patent Document 4 describes a polarizing film comprising a polarizing mirror and a protective film layer formed on at least one side of the polarizing mirror, wherein the thickness of the protective film layer is set to be 0.5 μm or less.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2008-287207

[0009] Patent Document 2: Japanese Patent Application Publication No. 2010-078700

[0010] Patent Document 3: Japanese Patent Application Publication No. 2012-144690

[0011] Patent Document 4: International Publication No. 2018-101204 Summary of the Invention

[0012] The problem the invention aims to solve

[0013] If the active energy ray-curing adhesive described in Patent Document 3 is used, the humidification reliability of various transparent protective films used in the manufacture of polarizing films can be met. However, although the polarizing film obtained using the active energy ray-curing adhesive described in Patent Document 3 can meet the water resistance requirement when immersed in warm water at 60°C for 6 hours (warm water immersion test), the market demands humidification reliability in harsher environments with higher temperatures and humidity.

[0014] It should be noted that the polarizing film described in Patent Document 4 was developed to improve thermal shock resistance under the requirement of thinning the polarizing film, and not to improve humidification reliability. Furthermore, Patent Document 4 contains absolutely no description or instruction regarding the mechanism by which the effects of the present invention are manifested, as described later.

[0015] The present invention was developed in view of the above-mentioned actual situation, and its purpose is to provide a polarizing film with excellent humidification reliability even in harsh environments with high temperature and high humidity.

[0016] Problem Solving Methods

[0017] The above-mentioned problem can be solved by the following configuration. That is, the present invention relates to a polarizing film, characterized in that it comprises: an iodine-based polarizer, and an adjacent layer disposed on at least one side of the iodine-based polarizer, wherein the distance between the adjacent layer and the HSP value of water is 26 or more.

[0018] In the above-mentioned polarizing film, preferably the adjacent layer contains a moisture permeability of 500 g / (m²). 2 • A barrier layer of less than 24 hours.

[0019] In the above-mentioned polarizing film, it is preferable that the thickness of the blocking layer is 1 μm or more.

[0020] In the above-mentioned polarizing film, it is preferable that the above-mentioned adjacent layers are separated by an adhesive layer that is directly in contact with the above-mentioned iodine-based polarizing lens, and thus have the above-mentioned blocking layer.

[0021] In the above-mentioned polarizing film, it is preferable that the adjacent layers are separated by an adhesive layer and have the above-mentioned barrier layer, wherein the adhesive layer is formed on an easily bondable layer that is directly in contact with the above-mentioned iodine-based polarizer.

[0022] In the above-mentioned polarizing film, the ratio (Tb / Ta) of the thickness Tb of the barrier layer to the thickness Ta of the adhesive layer is preferably 0.05 to 50.

[0023] In the above-mentioned polarizing film, it is preferable to further include a resin film stacked on one side of the adjacent layer of the above-mentioned iodine-based polarizer.

[0024] In the above-mentioned polarizing film, the moisture permeability of the resin film is preferably 80 g / (m²). 2 ·24h) or more.

[0025] In addition, the present invention relates to an optical film, characterized in that at least one polarizing film as described in any of the above claims is stacked thereon. Furthermore, the present invention also relates to an image display device having a polarizing film as described in any of the above claims, or an optical film as described above.

[0026] The effects of the invention

[0027] The polarizing film of the present invention has an adjacent layer on at least one side of an iodine-based polarizer with an HSP value distance of 26 or more from water. As a result, the polarizing film of the present invention exhibits excellent humidification reliability even in harsh environments with high temperature and high humidity. The reason for obtaining such excellent results is not yet clear, but it can be presumed as follows.

[0028] In polarizing films equipped with iodine-based polarizers, especially under high temperature and high humidity conditions, iodine leaks from the iodine-based polarizer to the outer layer. This tends to increase both the change in the individual transmittance and the change in the degree of polarization of the polarizing film. The inventors, focusing on this tendency, diligently investigated the cause and discovered that, particularly under high temperature and high humidity conditions, when water is immersed in the iodine-based polarizer and leaks outwards, iodine is carried into the water, thus leaking out of the iodine-based polarizer along with the water. The inventors conducted a detailed study of this mechanism and found that by providing an adjacent layer with an HSP distance of 26 or more from the water on at least one side of the iodine-based polarizer, iodine leakage from the iodine-based polarizer can be suppressed, resulting in a significant improvement in humidification reliability even in harsh environments with high temperature and high humidity.

[0029] In particular, in the polarizing film of the present invention, by comprising a moisture permeability of 500 g / (m 2 By using a barrier layer of less than 24h as an adjacent layer, and making the thickness of the barrier layer more than 1μm, iodine leakage from the polarizer can be significantly suppressed, and the humidification reliability can be further improved by leaps and bounds even in harsh environments with high temperature and high humidity.

[0030] The polarizing film of the present invention can have a resin film laminated on one side of the adjacent layer of an iodine-based polarizer. In particular, the moisture permeability of the resin film can be 80 g / (m²). 2 • 24h or more. Water permeability is 80g / (m³). 2 Resin films with a humidity level of 24h or higher are prone to water permeation, especially under high temperature and high humidity conditions. As described above, with conventional polarizing films, iodine leakage from the iodine-based polarizer is likely to occur. However, the polarizing film of the present invention has an adjacent layer with an HSP value distance of 26 or more from water on at least one side of the iodine-based polarizer, thus suppressing iodine leakage from the iodine-based polarizer. Even in harsh environments with high temperature and high humidity, the humidification reliability is significantly improved. Detailed Implementation

[0031] The polarizing film of the present invention comprises: an iodine-based polarizer and an adjacent layer disposed on at least one side of the iodine-based polarizer.

[0032] <Iodine-based polarizer>

[0033] There are no particular limitations on iodine-based polarizers (hereinafter also referred to as "polarizers" or "thin polarizers"), and various iodine-based polarizers can be used. Examples of polarizers include films formed by uniaxial stretching of hydrophilic polymer films such as polyvinyl alcohol films, partially methylated polyvinyl alcohol films, and partially saponified ethylene-vinyl acetate copolymer films, etc., on which iodine is adsorbed. Examples of polarizer thicknesses include 3 to 20 μm.

[0034] However, in this invention, from the viewpoint of improving the reliability of humidification in harsh environments with high temperature and humidity, a thin polarizer with a thickness of 3 μm or more and 15 μm or less is preferred as the polarizer, more preferably 12 μm or less, further preferably 10 μm or less, and particularly preferably 8 μm or less. Such a thin polarizer has less thickness unevenness, excellent visual visibility, and minimal dimensional variation, thus exhibiting excellent durability against thermal shock.

[0035] A polarizing mirror made by dyeing a polyvinyl alcohol (PVA) film with iodine and then unidirectionally stretching it can be manufactured as follows: PVA is dyed by immersing it in an aqueous solution of iodine and then stretched to 3 to 7 times its initial length. Boric acid, zinc sulfate, zinc chloride, etc., can be included as needed, or it can be immersed in an aqueous solution of potassium iodide, etc. Furthermore, the PVA film can be washed with water before dyeing, as needed. Washing the PVA film with water not only removes stains and anti-blocking agents from the surface of the PVA film but also prevents uneven dyeing by causing the PVA film to swell. Stretching can be performed after dyeing with iodine, or during dyeing and stretching, or dyeing with iodine after stretching. Stretching can also be performed in an aqueous solution of boric acid, potassium iodide, etc., or in a water bath.

[0036] From the perspective of tensile stability and humidification reliability, it is preferable that the polarizer contains boric acid. Furthermore, from the viewpoint of suppressing the formation of through-cracks, the boric acid content in the polarizer is preferably 22% by mass or less, and more preferably 20% by mass or less, relative to the total amount of the polarizer. From the viewpoint of tensile stability and humidification reliability, the boric acid content is preferably 10% by mass or more, and more preferably 12% by mass or more, relative to the total amount of the polarizer.

[0037] As a thin polarizer, representative examples include thin polarizers described in the following documents or thin polarizers obtained by the manufacturing methods described in these documents: Japanese Patent No. 4751486, Japanese Patent No. 4751481, Japanese Patent No. 4815544, Japanese Patent No. 5048120, International Publication No. 2014 / 077599, and International Publication No. 2014 / 077636.

[0038] As for the aforementioned thin polarizer, in manufacturing methods including stretching in a laminated state and dyeing, from the viewpoint of being able to stretch to high magnification and thus improve polarization performance, thin polarizers obtained by methods including stretching in a boric acid aqueous solution, as described in Japanese Patent Nos. 4751486, 4751481, and 4815544, are preferred. Thin polarizers obtained by methods including a stretching process in a gas atmosphere prior to stretching in a boric acid aqueous solution, as described in Japanese Patent Nos. 4751481 and 4815544, are particularly preferred. These thin polarizers can be obtained by methods including stretching a polyvinyl alcohol resin (hereinafter also referred to as PVA resin) layer and a stretching resin substrate in a laminated state and dyeing. If this method is used, even if the PVA resin layer is thin, it can be stretched by being supported by a stretched resin substrate without causing defects such as breakage due to stretching.

[0039] <Adjacent Layers>

[0040] The polarizing film of the present invention is characterized in that at least one side of the iodine-based polarizer has an adjacent layer, and the distance between the adjacent layer and water at the HSP value is 26.0 or more. First, the calculation method of the HSP value (solubility parameter) will be explained below.

[0041] (Calculation method of solubility parameter (HSP value distance))

[0042] In this invention, the solubility parameter (HSP value distance) between adjacent layers is obtained based on the Hansen calculation method [using HSPPversion 4.1.07 calculation software]. That is, the Hansen solubility parameter is the value used by Charles M. Hansen in 1967 when predicting the solubility of substances.

[0043] The Hansen solubility parameter consists of the following three parameters.

[0044] ·δD: Energy based on intermolecular dispersion forces

[0045] ·δP: Energy based on intermolecular dipole interactions

[0046] ·δH: Energy based on intermolecular hydrogen bonds

[0047] The above three parameters can be regarded as coordinates in three-dimensional space. The affinity between two substances (such as water and an adjacent layer) can be evaluated based on the distance between the two HSP values ​​(HSP value distance). When the HSP value distance between two substances is small, the affinity can be considered large.

[0048] The HSP value distance used as an indicator in this study is calculated by substituting the three components of Hansen's equations for the two substances into the following formula.

[0049] [Mathematical Expression 1]

[0050] HSP value distance=√(4×(δD1-δD2)^2+2×(δP1-δP2)^2+2×(δH1-δH2)^2)

[0051] In this invention, the HSP distance between the adjacent layers on at least one side of the iodine-based polarizer and water is preferably 26 or more, more preferably 27 or more, and even more preferably 28 or more.

[0052] It should be noted that in this invention, it is possible to have adjacent layers with an HSP distance of 26 or more on only one side of the iodine-based polarizer, but it is particularly preferred to have adjacent layers with an HSP distance of 26 or more on both sides of the iodine-based polarizer, because in this case, the humidification reliability is particularly excellent even in harsh environments with high temperature and high humidity.

[0053] Adjacent layers, for example, may have an adhesive layer on at least one side of the polarizer and a moisture permeability of 500 g / (m²). 2 A barrier layer of 24 hours or less. In this case, for example, a barrier layer can be formed on an adhesive layer that is directly in contact with an iodine-based polarizer. It should be noted that when adjacent layers consist of an adhesive layer and a barrier layer, the HSP distance between the adjacent layers and water can be calculated as follows.

[0054] (Thickness ratio of the adhesive layer to the adjacent layer) × (HSP distance between the adhesive layer and water) + (Thickness ratio of the barrier layer to the adjacent layer) × (HSP distance between the barrier layer and water)

[0055] <Blocking Layer>

[0056] In particular, in the polarizing film of the present invention, by comprising a moisture permeability of 500 g / (m 2 By using a barrier layer of 24h or less as an adjacent layer, and thus making the thickness of the barrier layer 1 μm or more, iodine leakage from the polarizer can be significantly suppressed, and the humidification reliability can be further improved dramatically even in harsh environments with high temperature and high humidity. The resin component constituting the barrier layer is preferably composed of polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate resins; polyarylate resins; amide resins such as nylon and aromatic polyamides; polyolefin polymers such as polyethylene, polypropylene, and ethylene-propylene copolymers; cyclic olefin resins having a cyclic structure or a norbornene structure; (meth)acrylic resins; or mixtures thereof. In particular, in this invention, the resin constituting the barrier layer is preferably a polycarbonate resin, a cyclic polyolefin resin, or a (meth)acrylic resin, and especially preferably a cyclic polyolefin resin.

[0057] Regarding the thickness Tb of the barrier layer, a lower limit of 0.75 μm is particularly preferred, and more preferably 1 μm. By designing the lower limit of the barrier layer thickness as described above, the humidification reliability in harsh environments with high temperature and high humidity can be improved. Regarding the upper limit of the barrier layer thickness, from the viewpoint of the requirement for thinner polarizing films, for example, about 3 μm can be considered, and more preferably about 1 μm.

[0058] <Adhesive layer>

[0059] The adjacent layer with an HSP value distance of 26 or more from water can consist solely of an adhesive layer directly in contact with the iodine-based polarizer, or it can consist of an adhesive layer directly in contact with the iodine-based polarizer with a barrier layer formed thereon, or it can consist of an adhesive layer directly in contact with the iodine-based polarizer with a barrier layer formed thereon, and then an adhesive layer formed thereon. Furthermore, the aforementioned adhesive layer can be formed directly in contact with the iodine-based polarizer, or it can be formed on an easily bonded layer directly in contact with the iodine-based polarizer. The easily bonded layer will be described later.

[0060] Whether the adhesive layer constituting the adjacent layers is a single layer or two or more layers, the average thickness Ta of each adhesive layer is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm.

[0061] From the viewpoint of improving the humidification reliability of the polarizing film by utilizing adjacent layers, the ratio of the thickness Tb of the barrier layer to the thickness Ta of the adhesive layer (Tb / Ta) is preferably 0.05 to 50, more preferably 1 to 10.

[0062] The adhesive composition used as the raw material for the adhesive layer of the present invention contains at least a curing component. Preferably, the curing component is selected such that the HSP value distance between the cured adhesive layer and water is 25 or more and 27 or less.

[0063] As curing components, adhesives can be broadly categorized into electron beam curing, ultraviolet (UV) curing, visible light curing, and thermosetting types. Furthermore, UV-curing and visible light curing adhesives can be further classified into free radical polymerization curing adhesives and cationic polymerization adhesives. In this invention, active energy rays with wavelengths ranging from 10 nm to less than 380 nm are designated as ultraviolet light, and active energy rays with wavelengths ranging from 380 nm to 800 nm are designated as visible light. The curing components of the aforementioned free radical polymerization curing adhesives can be used as curing components of thermosetting adhesives.

[0064] Examples of curing agents include, for instance, free radical polymerizable compounds used in free radical polymerization curing adhesives. Examples of free radical polymerizable compounds include compounds having carbon-carbon double bonds such as (meth)acryloyl or vinyl groups. These curing agents can be any of monofunctional free radical polymerizable compounds or difunctional or multifunctional free radical polymerizable compounds. Furthermore, one of these free radical polymerizable compounds can be used alone, or two or more can be used in combination. Among these free radical polymerizable compounds, compounds having a (meth)acryloyl group are preferred, for example. It should be noted that in this invention, (meth)acryloyl refers to acryloyl and / or methacryloyl, and "(meth)" has the same meaning below.

[0065] Examples of monofunctional free radical polymerizable compounds include (meth)acrylamide derivatives having a (meth)acrylamide group. (meth)acrylamide derivatives are preferred from the perspectives of ensuring adhesion to polarizers and various transparent protective films, as well as fast polymerization speed and excellent productivity. Specific examples of (meth)acrylamide derivatives include: N-methyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-butyl (meth)acrylamide, N-hexyl (meth)acrylamide, and other N-alkyl (meth)acrylamide derivatives; N-hydroxymethyl (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, N-hydroxymethyl-N-propyl (meth)acrylamide, and other N-hydroxyalkyl (meth)acrylamide derivatives; aminomethyl (meth)acrylamide, aminoethyl (meth)acrylamide, and other N-aminoalkyl (meth)acrylamide derivatives; N-methoxymethylacrylamide, N-ethoxymethylacrylamide, and other N-alkoxy (meth)acrylamide derivatives; mercaptomethyl (meth)acrylamide, mercaptoethyl (meth)acrylamide, and other N-mercaptoalkyl (meth)acrylamide derivatives; and so on. In addition, the nitrogen atom, which is a (meth)acrylamide group, forms heterocyclic (meth)acrylamide derivatives, such as N-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine, and N-acryloylpyrrolidine.

[0066] In addition, as monofunctional free radical polymerizable compounds, examples include various (meth)acrylic acid derivatives having a (meth)acryloyloxy group. Specifically, examples include: methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, 2-methyl-2-nitropropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, tert-pentyl (meth)acrylate, 3-pentyl (meth)acrylate, 2,2-dimethylbutyl (meth)acrylate, n-hexyl (meth)acrylate, hexadecyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 4-methyl-2-propylpentyl (meth)acrylate, n-octadecyl (meth)acrylate, and other alkyl esters of (meth)acrylate (1-20 carbon atoms).

[0067] In addition, examples of the aforementioned (meth)acrylic acid derivatives include: cyclohexyl (meth)acrylate, cyclopentyl (meth)acrylate, and other cycloalkyl (meth)acrylates; benzyl (meth)acrylate and other aralkyl (meth)acrylates; 2-isoborneol (meth)acrylate, 2-norborneol methyl (meth)acrylate, 2-norborneol methyl (meth)acrylate, 5-norbornen-2-yl methyl (meth)acrylate, 3-methyl-2-norborneol methyl (meth)acrylate, and (meth)acrylic acid... Polycyclic (meth)acrylates such as dicyclopentenyl ester, dicyclopentenoxyethyl ester, and dicyclopentyl ester; (meth)acrylates containing alkoxy or phenoxy groups such as 2-methoxyethyl ester, 2-ethoxyethyl ester, 2-methoxymethoxyethyl ester, 3-methoxybutyl ester, ethyl carbitol ester, phenoxyethyl ester, and alkylphenoxy polyethylene glycol ester; etc.

[0068] In addition, examples of the above-mentioned (meth)acrylic acid derivatives include: 2-hydroxyethyl (meth)acrylic acid, 2-hydroxypropyl (meth)acrylic acid, 3-hydroxypropyl (meth)acrylic acid, 2-hydroxybutyl (meth)acrylic acid, 4-hydroxybutyl (meth)acrylic acid, 6-hydroxyhexyl (meth)acrylic acid, 8-hydroxyoctyl (meth)acrylic acid, 10-hydroxydecyl (meth)acrylic acid, 12-hydroxylaurate (meth)acrylic acid, etc.; hydroxyalkyl (meth)acrylic acid esters such as [4-(hydroxymethyl)cyclohexyl]methyl acrylate, cyclohexanediol mono(meth)acrylic acid, and 2-hydroxy-3-phenoxypropyl (meth)acrylic acid; glycidyl (meth)acrylic acid, 4-hydroxybutyl (meth)acrylic acid glycidyl ether, etc., containing epoxy groups; 2,2,2-trifluoroethyl (meth)acrylic acid, 2,2-hydroxyethyl (meth)acrylic acid, etc. Halogenated (meth)acrylates such as 2-trifluoroethyl ethyl ester, tetrafluoropropyl (meth)acrylate, hexafluoropropyl (meth)acrylate, octafluoropentyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate, and 3-chloro-2-hydroxypropyl (meth)acrylate; alkyl aminoalkyl (meth)acrylates such as dimethylaminoethyl (meth)acrylate; oxy-heterocyclic butyl (meth)acrylates such as 3-oxetanebutylalkyl (meth)acrylate, 3-methyloxetanebutyl (meth)acrylate, 3-ethyloxetanebutyl (meth)acrylate, 3-butyloxetanebutyl (meth)acrylate, and 3-hexyloxetanebutyl (meth)acrylate; heterocyclic (meth)acrylates such as tetrahydrofurfuryl (meth)acrylate and butyrolactone (meth)acrylate; neopentyl glycol (meth)acrylate adducts of hydroxypentanoic acid; and p-phenylphenol (meth)acrylate.

[0069] In addition, examples of monofunctional free radical polymerizable compounds include: (meth)acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, and other carboxyl-containing monomers.

[0070] In addition, examples of monofunctional free radical polymerizable compounds include: N-vinylpyrrolidone, N-vinyl-ε-caprolactam, methylvinylpyrrolidone, and other lactam vinyl monomers; vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazolium, and vinylpyrrole. Vinyl monomers containing nitrogen-containing heterocycles, such as azoles and vinylmorpholine.

[0071] Furthermore, as a monofunctional radical polymerizable compound, a radical polymerizable compound having an active methylene group can be used. A radical polymerizable compound having an active methylene group is a compound having an active double bond group such as a (meth)acrylate group at the end or in the molecule, and also having an active methylene group. Examples of active methylene groups include acetoacetyl, alkoxymalonyl, or cyanoacetyl. The preferred active methylene group is acetoacetyl. Specific examples of free radical polymerizable compounds containing an active methylene group include, for instance, 2-acetylacetoxyethyl esters of (meth)acrylate, such as 2-acetylacetoxyethyl propyl esters of (meth)acrylate, 2-acetylacetoxyethyl-1-methylethyl esters of (meth)acrylate; 2-ethoxymalonyl ethyl esters of (meth)acrylate, 2-cyanoacetoxyethyl esters of (meth)acrylate, N-(2-cyanoacetoxyethyl)acrylamide, N-(2-propanoylacetoxybutyl)acrylamide, N-(4-acetylacetoxyethylmethylbenzyl)acrylamide, and N-(2-acetylacetylaminoethyl)acrylamide. The preferred free radical polymerizable compound containing an active methylene group is an acetylacetoxyethyl alkyl ester of (meth)acrylate.

[0072] In addition, examples of multifunctional free radical polymerizable compounds with two or more functions include: tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol diacrylate, 2-ethyl-2-butylpropanediol di(meth)acrylate, bisphenol A di(meth)acrylate, bisphenol A ethylene oxide adduct di(meth)acrylate, bisphenol A propylene oxide adduct di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, neopentyl glycol di(meth)acrylate, tricyclodecanediethanol di(meth)acrylate, cyclic trimethylolpropane formal(meth)acrylate, and dimethylolpropane formal(meth)acrylate. Esterifications of methacrylic acid and polyols, such as alkyldiol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and EO-modified diglycerol tetra(meth)acrylate, as well as 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene. Specific examples include ARONIX M-220, M-306 (manufactured by Toa Synthetic Co., Ltd.), LIGHT ACRYLATE 1,9ND-A (manufactured by Kyoeisha Chemical Co., Ltd.), LIGHT ACRYLATE DGE-4A (manufactured by Kyoeisha Chemical Co., Ltd.), LIGHT ACRYLATE DCP-A (manufactured by Kyoeisha Chemical Co., Ltd.), SR-531 (manufactured by Sartomer Co., Ltd.), and CD-536 (manufactured by Sartomer Co., Ltd.). In addition, as needed, examples include: various epoxy (meth)acrylates, urethane (meth)acrylates, polyester (meth)acrylates, and various (meth)acrylate monomers.

[0073] From the perspective of balancing adhesion to polarizers and various transparent protective films, as well as optical durability in harsh environments, it is preferable to use a combination of monofunctional and polyfunctional free radical polymerizable compounds. Typically, a combination of 30–90% by weight of monofunctional free radical polymerizable compounds and 10–70% by weight of polyfunctional free radical polymerizable compounds is preferred, relative to 100% by weight of the free radical polymerizable compound.

[0074] Regarding the polarizing film curable adhesive of the present invention, when the curing component is used as an active energy ray curing component, it can be used as an active energy ray curable adhesive. Furthermore, when the curing component is used as a thermosetting component, it can be used as a thermosetting adhesive. For the above-mentioned active energy ray curable adhesive, when the active energy ray uses an electron beam or the like, the active energy ray curable adhesive does not need to contain a photopolymerization initiator; however, when the active energy ray uses ultraviolet or visible light, it is preferable to contain a photopolymerization initiator. On the other hand, when the curing component of the above-mentioned adhesive is used as a thermosetting component, the adhesive preferably contains a thermopolymerization initiator.

[0075] In the case of using free radical polymerizable compounds, the photopolymerization initiator can be appropriately selected based on the active energy of the radiation. In the case of curing by ultraviolet or visible light, a photopolymerization initiator that undergoes ultraviolet or visible light degradation is used. Examples of such photopolymerization initiators include: benzoyl, benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, and other benzophenone compounds; aromatic ketone compounds such as 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)one, α-hydroxy-α,α′-dimethylacetophenone, 2-methyl-2-hydroxyphenylacetone, α-hydroxycyclohexylphenyl ketone, etc.; acetophenone compounds such as methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one, etc.; and benzoin methyl ether. Benzoin ethers, such as benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, and anisolein methyl ether; aromatic ketals, such as benzoin dimethyl ketal; aromatic sulfonyl chlorides, such as 2-naphthalenesulfonyl chloride; photoactive oximes, such as 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)oxime; thioxanthones, such as 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone; camphorquinone; haloketones; acylphosphine oxides; and acylphosphonates.

[0076] The amount of the photopolymerization initiator is 20 parts by weight or less relative to 100 parts by weight of the total amount of the curing component (free radical polymerizable compound). The amount of the photopolymerization initiator is preferably 0.01 to 20 parts by weight, more preferably 0.05 to 10 parts by weight, and even more preferably 0.1 to 5 parts by weight.

[0077] Furthermore, when using the polarizing film curable adhesive of the present invention in a visible light curable form containing a free radical polymerizable compound as a curing component, it is particularly preferable to use a photopolymerization initiator that is highly sensitive to light above 380 nm. The photopolymerization initiator that is highly sensitive to light above 380 nm will be described later.

[0078] As the above-mentioned photopolymerization initiator, it is preferred to use the compound shown in general formula (1) alone; or to use the compound shown in general formula (1) in combination with the photopolymerization initiator with high sensitivity to light above 380 nm described later.

[0079] [Chemical Formula 1]

[0080]

[0081] (where R is in the formula) 1 and R 2 Represents -H, -CH2CH3, -iPr, or Cl, R 1 and R 2 (These may be the same or different). When using the compound shown in general formula (1), the adhesion is superior compared to using a photopolymerization initiator with high sensitivity to light above 380 nm alone. Among the compounds shown in general formula (1), R is particularly preferred. 1 and R 2 The compound is a diethylthioxanthone with the formula -CH2CH3. The composition ratio of the compound of general formula (1) in the curable resin composition is preferably 0.1 to 5% by weight, more preferably 0.5 to 4% by weight, and even more preferably 0.9 to 3% by weight, relative to the total amount of the curable resin composition.

[0082] In addition, a polymerization initiator is preferably added as needed. Examples of polymerization initiators include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, and isoamyl 4-dimethylaminobenzoate, with ethyl 4-dimethylaminobenzoate being particularly preferred. When using a polymerization initiator, its amount added relative to the total amount of the curable resin composition is typically 0 to 5% by weight, preferably 0 to 4% by weight, and most preferably 0 to 3% by weight.

[0083] In addition, known photopolymerization initiators can be used in combination as needed. Since transparent protective films with UV absorption capabilities do not transmit light below 380 nm, photopolymerization initiators that are highly sensitive to light above 380 nm are preferred. Examples include: 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholino)phenyl]-1-butanone, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and bis(η5-2,4-cyclopentadien-1-yl)bis(2,6-difluoro-3-(1H-pyrrole-1-yl)phenyl)titanium, etc.

[0084] In particular, in addition to the photopolymerization initiator of general formula (1), it is preferable to further use the compound shown in general formula (2) below.

[0085] [Chemical Formula 2]

[0086]

[0087] (where R is in the formula) 3 R 4 and R 5 Represents -H, -CH3, -CH2CH3, -iPr, or Cl, R 3 R 4 and R 5 (They may be the same or different). As the compound represented by general formula (2), 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1-one (trade name: IRGACURE 907, manufacturer: BASF), which is commercially available, can be used appropriately. In addition, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone (trade name: IRGACURE 369, manufacturer: BASF) and 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholino)phenyl]-1-butanone (trade name: IRGACURE 379, manufacturer: BASF) are preferred due to their high sensitivity.

[0088] In the above-described adhesive composition, when a free radical polymerizable compound with an active methylene group is used as the free radical polymerizable compound, it is preferable to use it in combination with a free radical polymerization initiator with hydrogen abstraction activity. According to this configuration, the adhesiveness of the adhesive layer of the polarizing film is significantly improved, especially even immediately after removal from a high humidity environment or water (in a non-dry state). The reason for this is not yet clear, but it is believed to be due to the following: The free radical polymerizable compound with an active methylene group polymerizes together with other free radical polymerizable compounds constituting the adhesive layer, entering the main chain and / or side chain of the base polymer in the adhesive layer to form the adhesive layer. During this polymerization process, if a free radical polymerization initiator with hydrogen abstraction activity is present, the base polymer constituting the adhesive layer is formed, and hydrogen is abstracted from the free radical polymerizable compound with an active methylene group, generating free radicals in the methylene group. Furthermore, the methylene group that generates free radicals reacts with the hydroxyl groups of polarizing lenses such as PVA, forming covalent bonds between the adhesive layer and the polarizing lens. As a result, it is speculated that the adhesive properties of the adhesive layer of the polarizing film are significantly improved, especially even in the non-dry state.

[0089] In this invention, examples of free radical polymerization initiators with hydrogen abstraction effects include thioxanthone-based free radical polymerization initiators and benzophenone-based free radical polymerization initiators. The aforementioned free radical polymerization initiators are preferably thioxanthone-based free radical polymerization initiators. Examples of thioxanthone-based free radical polymerization initiators include compounds represented by the above general formula (1). Specific examples of compounds represented by general formula (1) include thioxanthone, dimethylthioxanthone, diethylthioxanthone, isopropylthioxanthone, and chlorothioxanthone. Among the compounds represented by general formula (1), R is particularly preferred. 1 and R 2 It is a diethylthioxanthone with the form -CH2CH3.

[0090] When the adhesive composition contains a free radical polymerizable compound with an active methylene group and a free radical polymerization initiator with hydrogen abstraction, and the total amount of curable components is set to 100% by mass, it is preferable to contain 1 to 50% by mass of the free radical polymerizable compound with an active methylene group and 0.1 to 10% by mass of the free radical polymerization initiator relative to the total amount of the curable resin composition.

[0091] As described above, in this invention, in the presence of a free radical polymerization initiator with hydrogen abstraction activity, the methylene group of a free radical polymerizable compound with an active methylene group generates a free radical. This methylene group reacts with the hydroxyl groups of polarizing agents such as PVA to form a covalent bond. Therefore, to ensure sufficient formation of this covalent bond by generating a free radical from the methylene group of the free radical polymerizable compound with an active methylene group, when the total amount of the curing component is set to 100% by mass, it is preferable to contain 1 to 50% by mass of the free radical polymerizable compound with an active methylene group, more preferably 3 to 30% by mass. To sufficiently improve water resistance and adhesion in a non-drying state, it is preferable to contain 1% or more of the free radical polymerizable compound with an active methylene group. On the other hand, if it exceeds 50% by mass, poor curing of the adhesive layer may occur. Furthermore, relative to the total amount of the adhesive composition, it is preferable to contain 0.1 to 10% by mass of the free radical polymerization initiator with hydrogen abstraction activity, more preferably 0.3 to 9% by mass. To ensure sufficient hydrogen abstraction reaction, it is preferable to use 0.1% or more of the free radical polymerization initiator. On the other hand, if it is greater than 10% by mass, it may sometimes not dissolve completely in the composition.

[0092] As needed, the adhesive composition used in this invention may further incorporate a compound described in the following general formula (3).

[0093] [Chemical Formula 3]

[0094]

[0095] (Where, X is a functional group containing a reactive group, R...) 6 and R 7 Each group (representing a hydrogen atom, optionally a substituent, aliphatic hydrocarbon group, aryl or heterocyclic group) is independently represented, preferably in combination with the compound described in the following general formula (3').

[0096] [Chemical Formula 4]

[0097]

[0098] (Where Y is an organic group, X' is a reactive group contained in X, and R...) 6 and R 7 (Same as above), and further preferred are compounds described in general formulas (3a) to (3d) as described below.

[0099] [Chemical Formula 5]

[0100]

[0101] When these compounds are incorporated into the adhesive composition, the adhesion to the polarizer and the transparent protective film is sometimes improved, which is therefore preferred. From the viewpoint of improving the adhesion between the polarizer and the transparent protective film and improving water resistance, the content of the compound described in the above general formula (3) in the adhesive composition is preferably 0.001 to 50% by mass, more preferably 0.1 to 30% by mass, and most preferably 1 to 10% by mass.

[0102] In the above general formula (3), examples of aliphatic hydrocarbon groups include linear or branched alkyl groups with optional substituents having 1 to 20 carbon atoms, cyclic alkyl groups with optional substituents having 3 to 20 carbon atoms, and alkenyl groups with 2 to 20 carbon atoms; examples of aryl groups include phenyl groups with optional substituents having 6 to 20 carbon atoms, and naphthyl groups with optional substituents having 10 to 20 carbon atoms; examples of heterocyclic groups include, for example, groups containing at least one heteroatom and optionally substituents, forming 5-membered or 6-membered rings. They can be linked together to form a ring. In general formula (3), as R 6 and R 7 Preferably, it is a straight-chain or branched alkyl group with 1 to 3 carbon atoms, and most preferably a hydrogen atom.

[0103] The compound represented by general formula (3) has a functional group X containing a reactive group, which is a functional group that can react with the curing components that constitute the adhesive layer. Examples of reactive groups contained in X include: hydroxyl, amino, aldehyde, carboxyl, vinyl, (meth)acryloyl, styrene, (meth)acrylamide, vinyl ether, epoxy, oxetyl, α,β-unsaturated carbonyl, mercapto, halogen, etc. When the curable resin composition constituting the adhesive layer is ray-curable, the reactive group contained in X is preferably selected from at least one reactive group selected from vinyl, (meth)acryloyl, styrene, (meth)acrylamide, vinyl ether, epoxy, oxetyl, and mercapto. In particular, when the adhesive composition constituting the adhesive layer is free radical polymerizable, the reactive group contained in X is preferably selected from at least one reactive group selected from (meth)acryloyl, styrene, and (meth)acrylamide. When the compound represented by general formula (1) has a (meth)acrylamide group, the reactivity is high, and the copolymerization rate with the ray-curable resin composition is increased, which is more preferable. In addition, the (meth)acrylamide group has high polarity and excellent adhesion, which is also preferable from the perspective of efficiently obtaining the effects of the present invention. When the curable resin composition constituting the adhesive layer is cationic polymeric, the reactive group contained in X preferably has at least one functional group selected from hydroxyl, amino, aldehyde, carboxyl, vinyl ether, epoxy, oxetyl, and mercapto. In particular, when epoxy is present, the resulting curable resin layer has excellent adhesion to the adherend, and is therefore preferred. When vinyl ether is present, the curability of the curable resin composition is excellent, and is therefore preferred.

[0104] In this invention, the compound represented by general formula (3) can be a compound formed by direct bonding of reactive groups and boron atoms. However, as shown in the specific examples above, the compound represented by general formula (3) is preferably a compound formed by bonding reactive groups and boron atoms through organic groups, that is, a compound represented by general formula (3'). When the compound represented by general formula (3) is, for example, a compound formed by bonding reactive groups through oxygen atoms bonded to boron atoms, there is a tendency for the adhesion and water resistance of the polarizing film to deteriorate. On the other hand, when the compound represented by general formula (3) does not have boron-oxygen bonds, but has boron-carbon bonds through bonding of boron atoms to organic groups, and contains reactive groups (as in general formula (3')), the adhesion and water resistance of the polarizing film is improved, and therefore preferred. The aforementioned organic groups specifically refer to organic groups with 1 to 20 carbon atoms that are optionally substituented. More specifically, examples include: linear or branched alkylene groups with 1 to 20 carbon atoms that are optionally substituented; cyclic alkylene groups with 3 to 20 carbon atoms that are optionally substituented; phenylene groups with 6 to 20 carbon atoms that are optionally substituented; and naphthylene groups with 10 to 20 carbon atoms that are optionally substituented.

[0105] As compounds represented by general formula (3), in addition to the compounds exemplified above, examples of esters formed by (meth)acrylates and boric acid include esters formed by hydroxyethyl acrylamide and boric acid, esters formed by hydroxymethyl acrylamide and boric acid, esters formed by hydroxyethyl acrylate and boric acid, and esters formed by hydroxybutyl acrylate and boric acid.

[0106] As needed, the adhesive composition used in this invention may further contain a bubble inhibitor. A bubble inhibitor is a compound that reduces surface tension by being incorporated into the adhesive composition, thereby reducing air bubbles between the compound and the substrate to be bonded. Examples of bubble inhibitors that can be used include: silicone-based bubble inhibitors having a polysiloxane backbone, such as polydimethylsiloxane; (meth)acrylic-based bubble inhibitors having a (meth)acrylamide backbone, formed by polymerizing (meth)acrylates, etc.; polyether-based bubble inhibitors formed by polymerizing vinyl ethers, cyclic ethers, etc.; fluorinated bubble inhibitors formed from fluorinated compounds having a perfluoroalkyl group; and bubble inhibitors that reduce surface tension when added to the adhesive composition.

[0107] Bubble inhibitors preferably have reactive groups in the compound. In this case, the formation of lamination bubbles can be reduced when the polarizing mirror and the transparent protective film are laminated. Examples of reactive groups in bubble inhibitors include polymerizable functional groups, specifically, free radical polymerizable functional groups with olefinic double bonds such as (meth)acryloyl, vinyl, and allyl; epoxy groups such as glycidyl; oxetyl; vinyl ether; cyclic ether; cyclic thioether; and cationic polymerizable functional groups such as lactone. From the viewpoint of reactivity in the adhesive composition, bubble inhibitors having double bonds as reactive groups are preferred, and bubble inhibitors having (meth)acryloyl groups are more preferred.

[0108] Considering both the bubble suppression effect and the adhesion enhancement effect in lamination, silicone-based bubble inhibitors are preferred among the aforementioned bubble inhibitors. Furthermore, considering the adhesion of the adhesive layer, bubble inhibitors containing urethane bonds or isocyanurate ring structures in the main chain backbone or side chains are preferred. Commercially available silicone-based bubble inhibitors can also be suitable, such as "BYK-UV3505" (manufactured by BYK-Chemie Japan Co., Ltd.), an acryloyl-modified polydimethylsiloxane.

[0109] In order to balance the adhesive strength of the obtained adhesive layer and the reduction of lamination bubbles, when the total amount of the adhesive composition is set to 100% by mass, the content of bubble inhibitor is preferably 0.01 to 0.6% by mass.

[0110] In the adhesive composition used in this invention, in addition to the curing component of the aforementioned free radical polymerizable compound, an acrylic oligomer formed by polymerizing (meth)acrylic acid monomers may also be included. By including this acrylic oligomer in the adhesive composition, the curing shrinkage when the composition is irradiated with active energy rays and cured can be reduced, thereby reducing the interfacial stress between the adhesive and the adhered objects such as polarizers and transparent protective films. As a result, the decrease in adhesion between the adhesive layer and the adhered objects can be suppressed. In order to sufficiently suppress the curing shrinkage of the cured layer (adhesive layer), the content of the acrylic oligomer is preferably 20% by mass or less, more preferably 15% by mass or less, relative to the total amount of the adhesive composition. When the content of the acrylic oligomer in the adhesive composition is too high, the reaction rate when the composition is irradiated with active energy rays decreases sharply, resulting in poor curing. On the other hand, relative to the total amount of the adhesive composition, it is preferable to contain 3% by mass or more, more preferably 5% by mass or more of the acrylic oligomer.

[0111] Considering workability and uniformity during application, a low viscosity adhesive composition is preferred; therefore, acrylic oligomers polymerized from (meth)acrylic acid monomers are also preferably low viscosity. As a low-viscosity acrylic oligomer capable of preventing curing shrinkage of the adhesive layer, its weight-average molecular weight (Mw) is preferably 15,000 or less, more preferably 10,000 or less, and particularly preferably 5,000 or less. On the other hand, to sufficiently suppress curing shrinkage of the cured layer (adhesive layer), the weight-average molecular weight (Mw) of the acrylic oligomer is preferably 500 or more, more preferably 1,000 or more, and particularly preferably 1,500 or more.Examples of (meth)acrylate monomers constituting acrylic oligomers include: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, 2-methyl-2-nitropropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, n-pentyl methacrylate, tert-pentyl methacrylate, 3-pentyl methacrylate, 2,2-dimethylbutyl methacrylate, n-hexyl methacrylate, etc. Cetyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, 4-methyl-2-propylpentyl methacrylate, n-octadecyl methacrylate, and other alkyl methacrylates (1-20 carbon atoms), as well as cycloalkyl methacrylates (e.g., cyclohexyl methacrylate, cyclopentyl methacrylate, etc.), aralkyl methacrylates (e.g., benzyl methacrylate, etc.), polycyclic methacrylates (e.g., 2-isobornyl methacrylate, 2-norbornyl methacrylate, etc.). Borneol methyl ester, 5-norbornen-2-yl methyl methacrylate, 3-methyl-2-norbornol methyl methacrylate, etc.; hydroxyl-containing (meth)acrylates (e.g., hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2,3-dihydroxypropyl methyl butyl methacrylate, etc.); alkoxy or phenoxy (meth)acrylates (2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-methoxymethoxyethyl methacrylate, 3-methoxybutyl methacrylate). Ethyl carbitol acrylate (meth)acrylate, phenoxyethyl acrylate (meth)acrylate, etc.), epoxy-containing (meth)acrylates (e.g., glycidyl acrylate (meth)acrylate, etc.), halogen-containing (meth)acrylates (e.g., 2,2,2-trifluoroethyl acrylate (meth)acrylate, 2,2,2-trifluoroethyl acrylate (meth)acrylate, tetrafluoropropyl acrylate (meth)acrylate, hexafluoropropyl acrylate (meth)acrylate, octafluoropentyl acrylate (meth)acrylate, heptadecafluorodecyl acrylate (meth)acrylate, etc.), alkylaminoalkyl acrylates (e.g., dimethylaminoethyl acrylate (meth)acrylate, etc.). These (meth)acrylates can be used alone or in combination of two or more. Specific examples of acrylic oligomers include "ARUFON" manufactured by Toa Synthetic Co., Ltd., "ACTFLOW" manufactured by Soken Chemical Co., Ltd., and "JONCRYL" manufactured by BASF Japan Ltd.

[0112] The adhesive composition described above may contain a photoacid generator. Compared to the case without a photoacid generator, the water resistance and durability of the adhesive layer can be significantly improved when the adhesive composition contains a photoacid generator. The photoacid generator can be represented by the following general formula (4).

[0113] General formula (4)

[0114] [Chemical Formula 6]

[0115] L + X - (4)

[0116] (where L+ represents any) Cations. Additionally, X - Indicates selection from PF66 - SbF6 - AsF6 - SbCl6 - BiCl5 - SnCl6 - ClO4 - (Dithiocarbamate anion, counter anion in SCN-)

[0117] Next, the counter anion X- in general formula (4) will be explained.

[0118] In principle, there are no special limitations on the counter anion X- in general formula (4), but a non-nucleophilic anion is preferred. When the counter anion X is a non-nucleophilic anion, it is less likely to cause nucleophilic reactions in intramolecularly coexisting cations and various materials used in combination, thereby improving the long-term stability of the photoacid generator represented by general formula (4) and the composition using it. The non-nucleophilic anion referred to here is an anion with a low ability to cause nucleophilic reactions. Examples of such anions include PF6. - SbF6 - AsF6 - SbCl6 - BiCl5 - SnCl6 - ClO4 - Dithiocarbamate anions, SCN-, etc.

[0119] Specifically, “CYRACURE UVI-6992”, “CYRACURE UVI-6974” (manufactured by Dow Chemical Japan Limited), “Adekaoptomer SP150”, “Adekaoptomer SP152”, “Adekaoptomer SP170”, “Adekaoptomer SP172” (manufactured by ADEKA Co., Ltd.), “IRGACURE250” (manufactured by Ciba Specialty Chemicals Inc.), “CI-5102”, “CI-2855” (manufactured by Nippon Soda Co., Ltd.), “San-Aid SI-60L”, “San-Aid SI-80L”, “San-Aid SI-100L”, “San-Aid SI-110L”, “San-Aid SI-180L” (manufactured by Sanshin Chemical Co., Ltd.), “CPI-100P”, “CPI-100A” (manufactured by San-Apro) The following products (manufactured by Wako Pure Chemical Industries, Ltd.) are preferred examples of the photoacid-generating agents of the present invention: “WPI-069”, “WPI-113”, “WPI-116”, “WPI-041”, “WPI-044”, “WPI-054”, “WPI-055”, “WPAG-281”, “WPAG-567”, and “WPAG-596” (manufactured by Wako Pure Chemical Industries, Ltd.).

[0120] The content of the photoacid generator relative to the total amount of the adhesive composition is 10% by mass or less, preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, and particularly preferably 0.1 to 3% by mass.

[0121] Photoalkali-generating agents are compounds that, through irradiation with ultraviolet or visible light, undergo molecular structure changes or molecular cleavage to generate one or more alkaline substances that can function as catalysts for the polymerization reactions of free radical polymerizable compounds and epoxy resins. Examples of alkaline substances include secondary and tertiary amines. Examples of photoalkali-generating agents include the aforementioned α-aminoacetophenone compound, the aforementioned oxime ester compound, and compounds having substituents such as acyloxyimino, N-formylated aromatic amino, N-acylated aromatic amino, nitrobenzylcarbamate, and alkoxybenzylcarbamate. Oxime ester compounds are preferred.

[0122] Examples of compounds containing acyloxyimino groups include, for example, O,O'-benzophenone oxime, O,O'-dinaphthophenone oxime, and benzophenone oxime acrylate-styrene copolymer.

[0123] Examples of compounds having N-formylated aromatic amino groups or N-acylated aromatic amino groups include: di-N-(p-formylamino)diphenylmethane, di-N-(p-acetylamino)diphenylmethane, di-N-(p-benzoamide)diphenylmethane, 4-formylaminostilbene, 4-acetylaminostilbene, 2,4-diformylaminostilbene, 1-formylaminonaphthalene, 1-acetylaminonaphthalene, 1,5-diformylaminonaphthalene, 1-formylaminoanthracene, 1,4-diformylaminoanthracene, 1-acetylaminoanthracene, 1,4-diformylaminoanthraquinone, 1,5-diformylaminoanthraquinone, 3,3'-dimethyl-4,4'-diformylaminobiphenyl, and 4,4'-diformylaminobenzophenone.

[0124] Examples of compounds having nitrobenzylcarbamate or alkoxybenzylcarbamate groups include: bis{{(2-nitrobenzyl)oxy}carbonyl}diaminodiphenylmethane, 2,4-bis{(2-nitrobenzyl)oxy}stilbene, bis{(2-nitrobenzyl)oxy)carbonyl}hexane-1,6-diamine, and o-dimethylaniline{{(2-nitro-4-chlorobenzyl)oxy}amide}.

[0125] The photo-alkali-producing agent is preferably selected from at least one of oxime ester compounds and α-aminoacetophenone compounds, more preferably oxime ester compounds. As an α-aminoacetophenone compound, an α-aminoacetophenone compound having two or more nitrogen atoms is particularly preferred.

[0126] Other photo-alkali-producing agents include WPBG-018 (trade name: 9-anthrylmethyl N,N'-diethylcarbamate), WPBG-027 (trade name: (E)-1-[3-(2-hydroxyphenyl)-2-acryloyl]piperidine), WPBG-082 (trade name: guanidinium 2-(3-benzoylphenyl)propionate), and WPBG-140 (trade name: 1-(anthraquinon-2-yl)ethyl imidazolecarboxylate).

[0127] In the above adhesive composition, a photoacid generator and a compound containing either an alkoxy or an epoxy group may be used in combination.

[0128] When using compounds with one or more epoxy groups within the molecule, or polymers (epoxy resins) with two or more epoxy groups within the molecule, compounds with two or more functional groups that are reactive with epoxy groups can be used in combination. Examples of functional groups reactive with epoxy groups include carboxyl groups, phenolic hydroxyl groups, mercapto groups, and primary or secondary aromatic amino groups. Considering three-dimensional curability, it is particularly preferable that a molecule contains two or more of these functional groups.

[0129] Examples of polymers having one or more epoxy groups within their molecules include epoxy resins, such as bisphenol A type epoxy resins derived from bisphenol A and epichlorohydrin, bisphenol F type epoxy resins derived from bisphenol F and epichlorohydrin, bisphenol S type epoxy resins, phenolic varnish type epoxy resins, cresol phenolic varnish type epoxy resins, bisphenol A phenolic varnish type epoxy resins, bisphenol F phenolic varnish type epoxy resins, alicyclic epoxy resins, diphenyl ether type epoxy resins, hydroquinone type epoxy resins, naphthalene type epoxy resins, biphenyl type epoxy resins, fluorene type epoxy resins, trifunctional epoxy resins, tetrafunctional epoxy resins, and other multifunctional epoxy resins, glycidyl ester type epoxy resins, glycidylamine type epoxy resins, hydantoin type epoxy resins, isocyanurate type epoxy resins, and aliphatic chain epoxy resins. These epoxy resins can be halogenated or hydrogenated. Commercially available epoxy resin products include, for example: JER code 828, 1001, 801N, 806, 807, 152, 604, 630, 871, YX8000, YX8034, YX4000 manufactured by Japan Epoxy Resin; EPICLON830, EXA835LV, HP4032D, HP820 manufactured by DIC Corporation; EP4100 series, EP4000 series, EPU series manufactured by ADEKA Corporation; and Daicel Chemical. Industries, Ltd. produces the CELLOXIDE series (2021, 2021P, 2083, 2085, 3000, etc.), Epolead series, EHPE series, Nippon Steel Chemicals Co., Ltd. produces the YD series, YDF series, YDCN series, YDB series, phenoxy resins (polyhydroxy polyethers synthesized from bisphenols and epichlorohydrin, with epoxy groups at both ends; YP series, etc.), Nagase ChemteX Corporation produces the Denacol series, and Kyoei Chemicals Co., Ltd. produces the Epolight series, etc., but is not limited to these. Two or more of these epoxy resins can be used in combination.

[0130] As for compounds containing alkoxy groups within their molecules, there are no special restrictions as long as the molecule contains one or more alkoxy groups; well-known compounds can be used. Examples of such compounds include melamine compounds, amino resins, and silane coupling agents.

[0131] The amount of the compound containing either alkoxy or epoxy groups is typically 30% by mass or less relative to the total amount of the adhesive composition. Excessive content of the compound in the composition reduces adhesiveness and may sometimes worsen impact resistance in drop weight tests. More preferably, the content of the compound in the composition is 20% by mass or less. On the other hand, from the perspective of water resistance, it is preferable that the composition contains 2% by mass or more, more preferably 5% by mass or more of the compound.

[0132] When the adhesive composition used in this invention is ray-curable, the silane coupling agent is preferably a ray-curable compound, but even if it is not ray-curable, the same water resistance can be imparted.

[0133] Specific examples of silane coupling agents include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, 3-epoxypropoxypropyltriethoxysilane, p-styrenetrimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropyltriethoxysilane, and 3-acryloyloxypropyltrimethoxysilane.

[0134] Preferably, it is 3-methacryloyloxypropyltrimethoxysilane or 3-acryloyloxypropyltrimethoxysilane.

[0135] Specific examples of silane coupling agents that can be cured by inactive energy rays are preferably silane coupling agents containing amino groups. Specific examples of silane coupling agents containing amino groups include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, γ-(2-aminoethyl)aminopropyltriethoxysilane, γ-(2-aminoethyl)aminopropylmethyldiethoxysilane, γ-(2-aminoethyl)aminopropyltriisopropoxysilane, γ-(2-(2-aminoethyl)aminoethyl)aminopropyltrimethoxysilane, and γ-(6-aminohexyl)aminopropyltrimethoxysilane. Aminosilanes such as 3-(N-ethylamino)-2-methylpropyltrimethoxysilane, γ-ureopropyltrimethoxysilane, γ-ureopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-benzyl-γ-aminopropyltrimethoxysilane, N-vinylbenzyl-γ-aminopropyltriethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldiethoxymethylsilane, N-phenylaminomethyltrimethoxysilane, (2-aminoethyl)aminomethyltrimethoxysilane, and N,N'-bis[3-(trimethoxysilyl)propyl]ethylenediamine; and ketimine silanes such as N-(1,3-dimethylbutylene)-3-(triethoxysilyl)-1-propylamine.

[0136] Silane coupling agents containing amino groups can be used in single-component or multi-component combinations. Among these, γ-aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, γ-(2-aminoethyl)aminopropyltriethoxysilane, γ-(2-aminoethyl)aminopropylmethyldiethoxysilane, and N-(1,3-dimethylbutylene)-3-(triethoxysilyl)-1-propylamine are preferred to ensure good adhesion.

[0137] The amount of silane coupling agent incorporated relative to the total amount of the adhesive composition is preferably in the range of 0.01 to 20% by mass, more preferably 0.05 to 15% by mass, and even more preferably 0.1 to 10% by mass. This is because when the amount incorporated is greater than 20% by mass, the storage stability of the adhesive composition deteriorates, and when it is less than 0.1% by mass, it is difficult to fully exert the effect of adhesive water resistance.

[0138] Specific examples of inactive energy-curable silane coupling agents other than those mentioned above include 3-ureopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanate-propyltriethoxysilane, imidazole silane, etc.

[0139] When the adhesive composition used in this invention contains a compound having a vinyl ether group, the adhesion and water resistance between the polarizer and the adhesive layer are improved, which is therefore preferred. The reason for this effect is not yet clear, but one possible reason is that the vinyl ether group of the compound interacts with the polarizer, thereby increasing the adhesion between the polarizer and the adhesive layer. To further improve the adhesion and water resistance between the polarizer and the adhesive layer, the compound is preferably a free radical polymerizable compound having a vinyl ether group. Furthermore, regarding the content of the compound, it is preferable to contain 0.1 to 19% by mass relative to the total amount of the adhesive composition.

[0140] The adhesive composition used in this invention may contain compounds that generate keto-enol tautomerism. For example, in adhesive compositions containing crosslinking agents or adhesive compositions that can be used in conjunction with crosslinking agents, it is preferable to use compounds that generate keto-enol tautomerism. This suppresses excessive viscosity increase, gelation, and microgel formation in the adhesive composition after incorporation with organometallic compounds, thereby extending the pot life of the composition.

[0141] Various β-dicarbonyl compounds can be used as compounds that generate the aforementioned keto-enol tautomerism. Specific examples include: β-diketones such as acetylacetone, 2,4-hexanedione, 3,5-heptanedione, 2-methylhexane-3,5-dione, 6-methylheptane-2,4-dione, and 2,6-dimethylheptane-3,5-dione; acetoacetate esters such as methyl acetoacetate, ethyl acetoacetate, isopropyl acetoacetate, and tert-butyl acetoacetate; propionyl acetate esters such as ethyl propionyl acetate, isopropyl propionyl acetate, and tert-butyl propionyl acetate; isobutyryl acetate esters such as ethyl isobutyryl acetate, isopropyl isobutyryl acetate, and tert-butyl isobutyryl acetate; malonates such as methyl malonate and ethyl malonate; and so on. Among these, acetylacetone and acetoacetate esters are suitable compounds. The compounds that produce ketone-enol tautomerism can be used alone or in combination of two or more.

[0142] The amount of the compound that produces the keto-enol tautomerism can be set to, for example, 0.05 to 10 parts by mass, preferably 0.2 to 3 parts by mass (e.g., 0.3 to 2 parts by mass), relative to 1 part by mass of the organometallic compound. If the amount of the above compound used is less than 0.05 parts by mass relative to 1 part by mass of the organometallic compound, it may be difficult to achieve a sufficient effect. On the other hand, if the amount of the compound used is greater than 10 parts by mass relative to 1 part by mass of the organometallic compound, it may interact excessively with the organometallic compound and become difficult to exhibit the target water resistance.

[0143] The adhesive composition of the present invention may also contain polyrotaxane. The polyrotaxane has a cyclic molecule, a straight-chain molecule penetrating the opening of the cyclic molecule, and sealing groups disposed at both ends of the straight-chain molecule to prevent the cyclic molecule from detaching from the straight-chain molecule. Preferably, the cyclic molecule has functional groups that are radioactive and can be cured by energy radiation.

[0144] As a cyclic molecule, there is no particular limitation as long as its opening is a molecule that encloses a straight-chain molecule in a chain-like manner, can move on the straight-chain molecule, and has a polymerizable group that is active and capable of being polymerized by energy rays. It should be noted that in this specification, "cyclic" in "cyclic molecule" means substantially "cyclic." That is, as long as it can move on the straight-chain molecule, the cyclic molecule may not be completely closed.

[0145] Specific examples of cyclic molecules include cyclic polymers such as cyclic polyethers, cyclic polyesters, cyclic polyetheramines, and cyclic polyamines, as well as cyclodextrins such as α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin. Among these, α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin are preferred because they are relatively easy to obtain and allow for the selection of a wide variety of capping groups. Two or more cyclic molecules may coexist in polyrotaxanes or adhesives.

[0146] In the polyrotaxane used in this invention, the aforementioned cyclic molecules possess reactive energy-ray polymerizable groups. Therefore, by reacting the polyrotaxane with a reactive energy-ray curable component, an adhesive that remains mobile even at the crosslinking points after curing can be obtained. The reactive energy-ray polymerizable groups possessed by the cyclic molecules can be any groups capable of polymerizing with the aforementioned reactive energy-ray curable compound; examples include free radical polymerizable groups such as (meth)acryloyl and (meth)acryloyloxy groups.

[0147] When using cyclodextrin as a cyclic molecule, it is preferable to introduce active energy-ray polymerizable groups onto the hydroxyl groups of the cyclodextrin via any suitable linker. The number of active energy-ray polymerizable groups in one molecule of polyrotaxane is preferably 2 to 1280, more preferably 50 to 1000, and even more preferably 90 to 900.

[0148] Preferably, hydrophobic modifying groups are introduced into the cyclic molecule. By introducing hydrophobic modifying groups, compatibility with active energy ray curable components can be improved. In addition, since hydrophobicity is imparted, when used in polarizing films, water can be prevented from penetrating the interface between the adhesive layer and the polarizing lens, further improving water resistance. Examples of hydrophobic modifying groups include polyester chains, polyamide chains, alkyl chains, oxidized olefin chains, ether chains, etc. As specific examples, the groups described in

[0027] to

[0042] of WO2009 / 145073 can be cited.

[0149] Polarizing films using resin compositions containing polyrotaxane as adhesives exhibit excellent water resistance. The reason for the improved water resistance of the polarizing film is not yet determined, but it is speculated as follows: It is believed that due to the mobility of the cyclic molecules of polyrotaxane, the crosslinking points can move (the so-called pulley effect), thereby imparting flexibility to the cured adhesive and increasing the adhesion to the surface irregularities of the polarizer. As a result, water penetration into the interface between the polarizer and the adhesive layer is prevented. Furthermore, it is believed that by incorporating hydrophobic modifying groups into the polyrotaxane, hydrophobicity can be imparted to the adhesive, which also helps prevent water penetration into the interface between the polarizer and the adhesive layer. The polyrotaxane content is preferably 2% to 50% by mass relative to the resin composition.

[0150] In this invention, cationic polymerizable adhesive compositions can be used to form adhesive layers. Cationic polymerizable compounds used in the cationic polymerizable adhesive compositions can be classified as monofunctional cationic polymerizable compounds having one cationic polymerizable functional group within their molecules, and polyfunctional cationic polymerizable compounds having two or more cationic polymerizable functional groups within their molecules. Since monofunctional cationic polymerizable compounds have lower liquid viscosity, the liquid viscosity of the resin composition can be reduced by including a monofunctional cationic polymerizable compound in the resin composition. Furthermore, monofunctional cationic polymerizable compounds generally have functional groups exhibiting various functions; by including a monofunctional cationic polymerizable compound in the resin composition, various functions can be exhibited in the resin composition and / or the cured resin composition. Polyfunctional cationic polymerizable compounds are preferably included in the resin composition because they can cause three-dimensional crosslinking of the cured resin composition. Regarding the ratio of monofunctional cationic polymeric compounds to polyfunctional cationic polymeric compounds, it is preferable to mix the polyfunctional cationic polymeric compounds in the range of 10 to 1000 parts by mass relative to 100 parts by mass of the monofunctional cationic polymeric compound. Examples of cationic polymeric functional groups include epoxy groups, oxetyl groups, and vinyl ether groups. Examples of compounds containing epoxy groups include aliphatic epoxy compounds, alicyclic epoxy compounds, and aromatic epoxy compounds. Due to their excellent curability and adhesive properties, alicyclic epoxy compounds are particularly preferred as the cationic polymeric adhesive composition of the present invention. Examples of alicyclic epoxy compounds include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, caprolactone-modified versions of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, trimethylcaprolactone-modified versions, and valproic acid-modified versions. Specifically, examples include CELLOXIDE 2021, CELLOXIDE 2021A, CELLOXIDE 2021P, CELLOXIDE 2081, CELLOXIDE 2083, CELLOXIDE 2085 (all manufactured by Celebratory Chemical Industries, Ltd.), Cyracure UVR-6105, Cyracure UVR-6107, Cyracure 30, and R-6110 (all manufactured by Dow Chemical Japan Ltd.). Since compounds containing oxetane are preferred due to their ability to improve the curability of the cationic polymerizable adhesive composition of the present invention and reduce the liquid viscosity of the composition, compounds containing oxetane are preferred.Examples of compounds containing oxetane groups include 3-ethyl-3-hydroxymethyloxetane, 1,4-bis[(3-ethyl-3-oxetane)methoxymethyl]benzene, 3-ethyl-3-(phenoxymethyl)oxetane, di[(3-ethyl-3-oxetane)methyl] ether, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, and phenolic varnish oxetane. Commercially available examples include ARON OXETANE OXT-101, ARON OXETANE OXT-121, ARON OXETANE OXT-211, ARON OXETANE OXT-221, and ARON OXETANE OXT-212 (all manufactured by Toa Synthetic Co., Ltd.). Compounds containing vinyl ether groups are preferred because they improve the curability of the cationic polymerizable adhesive composition of the present invention and reduce the liquid viscosity of the composition. Examples of compounds containing a vinyl ether group include 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, triethylene glycol divinyl ether, cyclohexanediethanol divinyl ether, cyclohexanediethanol monovinyl ether, tricyclodecane vinyl ether, cyclohexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, and pentaerythritol-type tetravinyl ether.

[0151] The cationic polymerizable adhesive composition contains at least one compound selected from the above-described compounds having epoxy groups, oxetyl compounds, and vinyl ether groups as a curing component. These compounds are all substances that cure via cationic polymerization, and therefore a photocationic polymerization initiator is incorporated. This photocationic polymerization initiator generates cationic species or Lewis acids upon irradiation with active energy rays such as visible light, ultraviolet light, X-rays, or electron beams, thereby initiating the polymerization reaction of epoxy groups and oxetyl groups. Photoacid generators and photoalkali generators can be used as photocationic polymerization initiators; photoacid generators described later are suitable. Furthermore, when using the adhesive composition employed in this invention as a visible light curable material, a photocationic polymerization initiator with high sensitivity to light above 380 nm is particularly preferred. However, photocationic polymerization initiators are compounds that typically exhibit maximum absorption in wavelength regions around or shorter than 300 nm. Therefore, by combining them with a photosensitizer that exhibits maximum absorption in wavelength regions longer than 380 nm, specifically wavelengths longer than 380 nm, light of nearby wavelengths can be sensed, promoting the generation of cationic species or acids from the photocationic polymerization initiator. Examples of photosensitizers include anthracene compounds, pyrene compounds, carbonyl compounds, organosulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, and photoreducing pigments; two or more of these can also be used in combination. Anthracene compounds are particularly preferred due to their excellent photosensitizing effect; specific examples include Anthracure UVS-1331 and Anthracure UVS-1221 (manufactured by Kawasaki Chemical Co., Ltd.). The photosensitizer content is preferably 0.1% to 5% by mass, more preferably 0.5% to 3% by mass.

[0152] <Easy-to-bond compositions>

[0153] To further improve the adhesion between the polarizer and adjacent layers, in this invention, an easy-to-adhere composition can be applied to the bonding surface of the polarizer (the bonding surface with the adjacent layer). This easy-to-adhere composition preferably contains a compound represented by the above-described general formula (3). By applying an easy-to-adhere composition containing a boron-containing compound represented by the above-described general formula (3) to the bonding surface of the polarizer, the water-resistant adhesion of the polarizing film is particularly improved, and is therefore preferred. The reason for this effect is not yet clear, but it is presumed to be due to the following reasons.

[0154] In the easy-adhesive composition, the boron-containing compound described in formula (3) above can react with functional groups such as hydroxyl groups possessed by the polarizer. This improves the adhesion between the polarizer and, for example, an adhesive layer, resulting in improved water resistance and adhesion of the polarizing film. In this invention, an easy-adhesive layer can be formed by coating the entire surface of the polarizer on one side of an adjacent layer, or by coating at least a portion of the surface with the easy-adhesive composition.

[0155] Among the compounds represented by the above general formula (3), the compounds represented by the above general formula (3') are preferred, and the compounds (3a) to (3d) are even more preferred.

[0156] In easy-to-bond compositions, when the content of the compound represented by general formula (3) is too low, the proportion of the compound represented by general formula (3) present on the surface of the easy-to-bond layer decreases, and sometimes the easy-to-bond effect becomes lower. Therefore, in easy-to-bond compositions, the content of the compound represented by general formula (3) is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more.

[0157] In addition to the compounds described in general formula (3) above, a solvent may also be included in the easily bondable composition in this invention. Preferably, the solvent that can be included in the easily bondable composition is one capable of stably dissolving or dispersing the compounds represented by general formula (3). This solvent may be an organic solvent, water, or a mixture thereof. Examples of such solvents include: esters such as ethyl acetate, butyl acetate, and 2-hydroxyethyl acetate; ketones such as methyl ethyl ketone, acetone, cyclohexanone, methyl isobutyl ketone, diethyl ketone, methyl n-propyl ketone, and acetylacetone; tetrahydrofuran (THF), diethyl ethyl ketone, ... Cyclic ethers such as alkanes; aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as toluene and xylene; aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol, and cyclohexanol; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and diethylene glycol monoethyl ether; glycol ether acetates such as diethylene glycol monomethyl ether acetate and diethylene glycol monoethyl ether acetate; and so on.

[0158] Furthermore, when using an easy-to-bond composition in this invention, other additives may be included, such as tackifiers, ultraviolet absorbers, antioxidants, heat stabilizers, and other stabilizers.

[0159] <Resin Film>

[0160] The polarizing film of the present invention can have a resin film laminated on one side of an adjacent layer of an iodine-based polarizer. It should be noted that, at a transmittance of 80 g / (m²), 2In existing polarizing films with iodine-based polarizers, where a resin film (with a permeability of 24h or more) is laminated with an adhesive layer, iodine leaks from the polarizer into the resin film. This tends to decrease humidification reliability. However, with the polarizing film of this invention, humidification reliability is improved. In this invention, a permeability of 80 g / (m²) is used. 2 Resin films with a lifespan of 24 hours or more can include specific transparent protective films or phase difference films.

[0161] As a moisture permeability of 80g / (m 2 Transparent protective films with a permeability of 24 hours or more, such as TAC film (1250 g / (m²) moisture permeability), are examples of such films. 2 • 24h)) TAC membrane with hard coating (humidity permeability 420g / (m) 2 ·24h)), polycarbonate membrane (humidity permeability 90g / (m) 2 ·24h)) etc.

[0162] As a moisture permeability of 80g / (m 2 Phase retardation films with a permeability of 24 hours or more can be exemplified by, for example, polycarbonate resin phase retardation films (permeability 90 g / (m²)). 2 • 24h)), a phase retardation film containing a liquid crystal curing layer (humidity permeability 500g / (m) 2 ·24h)) etc.

[0163] Hereinafter, an example of a method for manufacturing the polarizing film of the present invention will be described.

[0164] The polarizing film of the present invention can be manufactured, for example, by the following manufacturing method.

[0165] The method for manufacturing the aforementioned polarizing film is a method for manufacturing a polarizing film comprising an iodine-based polarizer and an adjacent layer disposed on at least one side of the iodine-based polarizer. The adjacent layer comprises an adhesive layer directly in contact with the iodine-based polarizer and a barrier layer on the adhesive layer. The HSP value distance between the adjacent layer and water is 26 or more. The manufacturing method includes: a coating step of applying an adhesive composition, which serves as a raw material for the adhesive layer, to at least one side of the iodine-based polarizer; a bonding step of bonding the barrier layer (which will become a resin layer and a diaphragm, i.e., a barrier layer with a diaphragm) to the coating surface of the adhesive composition of the iodine-based polarizer; and a forming step of peeling off the diaphragm of the barrier layer with a diaphragm to form a polarizer with a barrier layer.

[0166] It should be noted that, for the polarizing film of the present invention, in order to further improve the adhesion between the polarizer and the adjacent layer, an easy-to-adhere composition can be applied to the bonding surface of the polarizer (the bonding surface with the adjacent layer). In this case, the easy-to-adhere composition application step can be provided before the coating step (referred to as the "adhesive composition application step"), which is a step of applying an adhesive composition, which is the raw material for the adhesive layer, to at least one side of the iodine-based polarizer, and the easy-to-adhere composition application step is a step of applying the easy-to-adhere composition to the bonding surface of the polarizer (the bonding surface with the adjacent layer).

[0167] <Coating Process>

[0168] As a method for applying an adhesive composition, or an easily bondable composition and an adhesive composition, to the bonding surface of a polarizer, the appropriate method can be selected based on the viscosity of the composition and the target thickness. From the viewpoint of removing foreign matter from the surface of the iodine-based polarizer and the coating properties, a post-measurement coating method is preferred. Specific examples of post-measurement coating methods include gravure roller coating, forward roller coating, air knife coating, and rod / bar coating. Among these, gravure roller coating is particularly preferred from the viewpoint of removing foreign matter from the surface of the transparent protective film and the coating properties.

[0169] Before the above-described coating process, an easy-to-adhere composition can be applied to the coating surface of the polarizer's adhesive composition. As a method for applying the easy-to-adhere composition to the bonding surface of the polarizer, a post-application measurement method is preferred to achieve the same effect as the above-described coating process.

[0170] In gravure roller coating, various patterns can be formed on the surface of the gravure roller, such as honeycomb patterns, trapezoidal patterns, grid patterns, conical patterns, or diagonal line patterns. To effectively prevent appearance defects in the final polarizing film, a honeycomb pattern is preferred for the surface of the gravure roller. In the case of a honeycomb pattern, to improve the surface finish of the coated surface after applying the easily bondable composition, the unit volume is preferably 1 to 5 cm². 3 / m 2 More preferably 2-3cm 3 / m 2 Similarly, to improve the surface finish of the coated surface after applying the easily bondable composition, the number of lines per unit inch of roller is preferably 200 to 3000 lines per inch. Furthermore, the ratio of the rotational speed of the gravure roller to the travel speed of the polarizing mirror is preferably 100 to 300%.

[0171] <Lamination Process>

[0172] Using the adhesive composition applied as described above, a polarizer and a resin film for forming a blocking layer are bonded together. The bonding of the polarizer and the resin film for forming the blocking layer can be performed using a roller laminator or the like.

[0173] <Forming Process>

[0174] The barrier layer with a diaphragm is preferably formed by casting or extrusion molding. In casting, the barrier layer can be obtained by dissolving the resin that will become the barrier layer in any solvent, coating the resulting solution onto the diaphragm, and then drying the solvent. In extrusion molding, the barrier layer with a diaphragm can be obtained by co-extruding the resin that will become the barrier layer and the resin that will become the diaphragm.

[0175] When a barrier layer is formed by casting, a barrier layer of arbitrary thickness can be formed by appropriately adjusting the thickness of the bar coater (called the number of bars or the number of bars) during the coating solution application, and thus adjusting the concentration of the solid components in the coating solution.

[0176] After the polarizer and the blocking layer are laminated via the adhesive layer, the following steps may be performed as needed: a second coating step of applying the adhesive composition to the blocking layer; a second bonding step of bonding a resin film such as a transparent protective film or a phase retardation film to the coated surface of the adhesive composition; and a bonding step of further irradiating the surface with active energy rays and bonding the iodine-based polarizer and the resin film together via the cured adhesive composition, i.e., the adhesive layer.

[0177] <Adhesion process>

[0178] After the polarizer is bonded to the transparent protective film, it is irradiated with active energy rays (electron beams, ultraviolet light, visible light, etc.) to cure the adhesive composition, or the adhesive composition and the easily bondable composition, thereby forming an adhesive layer. The irradiation direction of the active energy rays (electron beams, ultraviolet light, visible light, etc.) can be any suitable direction. It is preferable to irradiate from the transparent protective film side. If irradiation is performed from the polarizer side, there is a concern that the polarizer may deteriorate due to the active energy rays (electron beams, ultraviolet light, visible light, etc.).

[0179] The irradiation conditions under electron beam irradiation are any conditions that can cure the adhesive composition described above, and any suitable conditions can be used. For example, the accelerating voltage for electron beam irradiation is preferably 5 kV to 300 kV, and more preferably 10 kV to 250 kV. When the accelerating voltage is less than 5 kV, there is a concern that the electron beam may not reach the adhesive, resulting in insufficient curing. If the accelerating voltage is greater than 300 kV, there is a concern that the penetrating force through the sample may be too strong, causing damage to the transparent protective film and the polarizer. The irradiation linear amount is 5 to 100 kGy, and more preferably 10 to 75 kGy. When the irradiation linear amount is less than 5 kGy, the adhesive will not cure sufficiently. If it is greater than 100 kGy, it will damage the transparent protective film and the polarizer, resulting in a decrease in mechanical strength, yellowing, and failure to obtain the desired optical properties.

[0180] Electron beam irradiation is typically carried out in an inert gas environment, but can also be performed in the atmosphere with a small amount of oxygen introduced, depending on the material of the transparent protective film. Depending on the material, it is appropriate to introduce oxygen so that it contacts the surface of the transparent protective film that initially contacts the electron beam. This oxygen barrier prevents damage to the transparent protective film and allows for efficient electron beam irradiation only on the adhesive.

[0181] In the above-described method for manufacturing polarizing films, the active energy rays used are preferably those containing visible light in the wavelength range of 380 nm to 450 nm, especially those containing the highest amount of visible light in the wavelength range of 380 nm to 450 nm. When using ultraviolet light, visible light, and a transparent protective film with ultraviolet absorption capability (UV-opaque transparent protective film), light with wavelengths shorter than 380 nm is absorbed. Therefore, light with wavelengths shorter than 380 nm does not reach the adhesive composition and does not contribute to its polymerization reaction. Furthermore, the light with wavelengths shorter than 380 nm absorbed by the transparent protective film is converted into heat, causing the transparent protective film itself to heat up, which becomes a cause of defects such as curling / wrinkling of the polarizing film. Therefore, in this invention, when using ultraviolet or visible light, it is preferable to use a device that does not emit light with wavelengths shorter than 380 nm as the active energy ray generating device. More specifically, the ratio of cumulative illuminance in the wavelength range of 380–440 nm to cumulative illuminance in the wavelength range of 250–370 nm is preferably 100:0–100:50, more preferably 100:0–100:40. In the method for manufacturing the polarizing film of this invention, gallium-encapsulated metal halide lamps and LED light sources emitting light in the wavelength range of 380–440 nm are preferred as active energy rays. Alternatively, light sources containing ultraviolet and visible light, such as low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, incandescent lamps, xenon lamps, halogen lamps, carbon arc lamps, metal halide lamps, fluorescent lamps, tungsten lamps, gallium lamps, excimer lasers, or sunlight, can be used. Alternatively, ultraviolet light with wavelengths shorter than 380 nm can be blocked using a bandpass filter. To improve the adhesion of the adhesive layer between the polarizer and the transparent protective film and to prevent the polarizing film from curling, it is preferable to use a gallium-encapsulated metal halide lamp and to use active energy rays obtained by passing through a bandpass filter that can block light with a wavelength shorter than 380 nm, or active energy rays with a wavelength of 405 nm obtained by using an LED light source.

[0182] It is preferable to heat the adhesive composition before irradiating it with ultraviolet or visible light (heating before irradiation). In this case, it is preferable to heat it to 40°C or higher, more preferably to 50°C or higher. Alternatively, it is also preferable to heat the active energy ray-curable adhesive composition after irradiating it with ultraviolet or visible light (heating after irradiation). In this case, it is preferable to heat it to 40°C or higher, more preferably to 50°C or higher.

[0183] <Optical film>

[0184] The polarizing film manufactured by the method of the present invention can be used in practical applications as an optical film laminated with other optical layers. There are no particular limitations on the optical layer; examples include: phase retardation films (including half-wave plates, quarter-wave plates, etc.), visual compensation films, brightness enhancement films, reflective plates, anti-transmission plates, and other optical layers sometimes used in the formation of liquid crystal display devices, etc.

[0185] As the aforementioned phase retardation film, a phase retardation film having a frontal phase retardation of 40 nm or more and / or a thickness-direction phase retardation of 80 nm or more can be used. Typically, the frontal phase retardation is controlled in the range of 40–200 nm, and the thickness-direction phase retardation is typically controlled in the range of 80–300 nm.

[0186] Examples of phase retardation films include: birefringent films formed by unidirectional or bidirectional stretching of polymer raw materials; alignment films of liquid crystal polymers; and phase retardation films formed by using a film to support an alignment layer of liquid crystal polymers. The thickness of phase retardation films is not particularly limited, generally ranging from 20 to 150 μm.

[0187] As a phase retardation film, an inverse wavelength dispersion type phase retardation film that satisfies the following equations (1) to (3) can be used.

[0188] 0.70<Re

[450] / Re

[550] <0.97···(1)

[0189] 1.5×10 -3 <Δn<6×10 -3 .··(2)

[0190] 1.13 < NZ < 1.50 ···(3)

[0191] (In the formula, Re

[450] and Re

[550] are the in-plane phase difference values ​​of the phase difference film measured at 23℃ using light with wavelengths of 450nm and 550nm, respectively. Δn is nx-ny, i.e., in-plane birefringence, when the refractive indices of the slow axis and fast axis of the phase difference film are set to nx and ny, respectively. NZ is the ratio of nx-nz to nx-ny when nz is set as the refractive index of the thickness direction of the phase difference film, where nx-nz is the thickness direction birefringence and nx-ny is the in-plane birefringence).

[0192] An adhesive layer for bonding with other components such as liquid crystal cells can also be provided on the aforementioned polarizing film or optical film having at least one polarizing film layer. There are no particular limitations on the adhesive forming the adhesive layer; materials using polymers such as acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyethers, fluorinated polymers, and rubbers as the base polymer can be suitably selected. Materials with excellent optical transparency, moderate wetting, aggregation, and adhesion properties, as well as excellent weather resistance and heat resistance, such as acrylic adhesives, are particularly preferred.

[0193] The adhesive layer can be provided on one or both sides of the polarizing film or optical film in the form of an overlapping layer of layers with different compositions or types. Furthermore, when provided on both sides, adhesive layers with different compositions, types, and thicknesses can be formed on the front and back surfaces of the polarizing film or optical film. The thickness of the adhesive layer can be appropriately determined according to the intended use, adhesion strength, etc., and is typically 1–500 μm, preferably 1–200 μm, and particularly preferably 1–100 μm.

[0194] The exposed surface of the adhesive layer is temporarily covered by an adhesive diaphragm until it is put into actual use to prevent contamination. This prevents contact with the adhesive layer under normal handling conditions. As the diaphragm, suitable diaphragms as previously specified can be used, in addition to the thickness requirements described above, by coating suitable thin materials such as plastic films, rubber sheets, paper, cloth, nonwoven fabrics, meshes, foam sheets, metal foils, and their laminates with suitable release agents such as silicone, long-chain alkyl, fluorine, and molybdenum sulfide as needed.

[0195] <Image display device>

[0196] The polarizing film or optical film of the present invention can be preferably used in the formation of various devices such as liquid crystal display devices. The formation of a liquid crystal display device can be performed in a conventional manner. That is, a liquid crystal display device is typically formed by appropriately assembling liquid crystal cells with polarizing films or optical films, and components such as illumination systems used as needed, and incorporating driving circuitry. In the present invention, there are no particular limitations except for the use of the polarizing film or optical film of the present invention, and conventional methods can be followed. Regarding the liquid crystal cells, any type of liquid crystal cell, such as TN type, STN type, or π type, can be used.

[0197] Suitable liquid crystal display devices can be formed, such as liquid crystal display devices in which polarizing films or optical films are disposed on one or both sides of the liquid crystal cell, and liquid crystal display devices that use backlights or reflectors in the lighting system. In this case, the polarizing film or optical film of the present invention can be disposed on one or both sides of the liquid crystal cell. When polarizing films or optical films are disposed on both sides, they can be the same or different. Furthermore, during the formation of the liquid crystal display device, one or more suitable components such as diffuser plates, anti-glare layers, anti-reflective films, protective plates, prism arrays, lens array sheets, light diffuser plates, and backlights can be disposed at appropriate positions.

[0198] Example

[0199] The following describes embodiments of the present invention, but the implementation of the present invention is not limited to these.

[0200] <Thin polarizer>

[0201] First, a laminate containing a 9 μm thick PVA layer on an amorphous PET substrate is stretched in a gas atmosphere at a stretching temperature of 130°C to form a stretched laminate. Next, the stretched laminate is dyed to form a colored laminate. Then, the colored laminate is stretched integrally with the amorphous PET substrate in a boric acid aqueous solution at a stretching temperature of 65°C to a total stretching ratio of 5.94 times, forming an optical film laminate containing a 5 μm thick PVA layer. Through this two-step stretching process, an optical film laminate containing a 5 μm thick PVA layer (thin polarizer) constituting an iodine-based thin polarizer is obtained. In this iodine-based thin polarizer, the PVA molecules in the PVA layer formed on the amorphous PET substrate exhibit higher-order orientation, and the iodine adsorbed through dyeing also exhibits higher-order orientation in one direction as a polyiodide ion complex.

[0202] <Transparent Protective Film>

[0203] The following film was used as a transparent protective film.

[0204] "TAC": Cellulose triacetate (TAC) membrane (permeability 420g / (m²)) 2 • 24h), HSP distance from water 22.2, thickness 25μm (trade name "Konica Minolta Tac Film KC2UA", manufactured by Konica Minolta Co., Ltd.)

[0205] "PC": Polycarbonate (PC) film (90g / (m²) moisture permeability) 2 (24h), distance from water HSP value 22.2, thickness 13μm)

[0206] “COP”: Cycloolefin polymer (COP) membrane (permeability 8 g / (m³) 2 • 24h), HSP distance from water is 33.3, thickness is 20μm (trade name "ZEONOR Film ZF14", manufactured by Zeon Corporation, Japan)

[0207] <Phase difference film>

[0208] The phase retardation film is manufactured by the following method.

[0209] Polymerization of polyester carbonate resins

[0210] Polymerization was carried out using a batch polymerization apparatus consisting of two vertical reactors equipped with agitators and reflux condensers controlled at 100°C. The feed consisted of 29.60 parts by mass (0.046 mol) of bis[9-(2-phenoxycarbonylethyl)fluorene-9-yl]methane, 29.21 parts by mass (0.200 mol) of isosorbide (ISB), 42.28 parts by mass (0.139 mol) of spirodiol (SPG), 63.77 parts by mass (0.298 mol) of diphenyl carbonate (DPC), and 1.19 × 10⁻⁶ mol of calcium acetate monohydrate as a catalyst. -2 Parts by weight (6.78 × 10) -5 (mol). After purging the reactor with nitrogen under reduced pressure, it was heated with a heat medium, and stirring was started when the internal temperature reached 100°C. Forty minutes after the start of heating, the internal temperature was raised to 220°C, and while maintaining this temperature, pressure was reduced. After 90 minutes, a pressure of 13.3 kPa was reached at 220°C. Phenol vapor, a byproduct of the polymerization reaction, was introduced into a 100°C reflux condenser, returning a certain amount of monomer components contained in the phenol vapor to the reactor, while the uncondensed phenol vapor was recovered in a 45°C condenser. Nitrogen was introduced into the first reactor to temporarily restore atmospheric pressure, and the oligomerized reaction liquid in the first reactor was transferred to the second reactor. Then, heating and depressurization were started in the second reactor, reaching an internal temperature of 240°C and a pressure of 0.2 kPa within 50 minutes. Polymerization was then carried out until the given stirring power was reached. At the moment when the given power is reached, nitrogen is introduced into the reactor to restore the pressure, and the generated polyester carbonate resin is extruded into the water to cut the thread and obtain granules.

[0211] Fabrication of phase retardation film

[0212] After vacuum drying the obtained polyester carbonate resin (granules) at 80°C for 5 hours, a 130 μm thick elongated resin film was produced using a film-forming apparatus equipped with a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder set temperature: 250°C), a T-die (width 200 mm, set temperature: 250°C), a chilled roll (set temperature: 120-130°C), and a winding machine. The obtained elongated resin film was stretched to obtain a given phase difference, resulting in a 48 μm thick phase difference film. The stretching conditions were: stretching temperature 143°C in the width direction and stretching ratio 2.8 times. The obtained phase difference film had a Re(550) of 141 nm, a Re(450) / Re(550) ratio of 0.86, and an Nz coefficient of 1.12.

[0213] The HSP distance between the phase difference membrane and water is 22.7, and the water permeability is 90 g / (m2·24h).

[0214] <Active Energy Rays>

[0215] As an active energy beam, a visible light (gallium-encased metal halide lamp) irradiation device was used: FusionUV Systems, Inc., Light HAMMER10, valve: V valve, peak illuminance: 1600 mW / cm². 2 Cumulative radiation dose 1000 mJ / cm 2 (Wavelength 380–440 nm). It should be noted that the illuminance of visible light was measured using the Sola-Check system manufactured by Solatell.

[0216] <Adhesive layers 1-3>

[0217] Adhesive layers 1 to 3 are formed using the following adhesive compositions 1 to 3 as raw materials.

[0218] "Adhesive Composition 1"; an adhesive composition containing 30 parts by weight of ACMO, 30 parts by weight of 19NDA, and 15 parts by weight of P2HA (the HSP value distance between the adhesive layer 1 obtained after curing adhesive composition 1 and water is 27.0).

[0219] "Adhesive Composition 2"; an adhesive composition containing 36 parts by weight of 19NDA, 12.5 parts by weight of HEAA, 2 parts by weight of M57002, 6 parts by weight of DEAA, and 12.5 parts by weight of HPPA (the HSP value distance between the adhesive layer 2 obtained after curing adhesive composition 2 and water is 25.7).

[0220] "Adhesive Composition 3"; an adhesive composition containing 10 parts by weight of 19NDA, 43.5 parts by weight of P2HA, 10 parts by weight of HEAA, 10 parts by weight of M5700, 10 parts by weight of M220, and 3 parts by weight of DEAA (the HSP value distance between the adhesive layer 3 obtained after curing adhesive composition 3 and water is 25.5).

[0221] In the above-mentioned adhesive compositions,

[0222] "ACMO"; Acryloylmorpholine (trade name "ACMO", manufactured by KJ Chemical Co., Ltd.)

[0223] "19NDA"; 1,9-Nonadiol diacrylate (trade name "LIGHT ACRYLATE 1,9ND-A", manufactured by Kyoeisha Chemical Co., Ltd.)

[0224] "P2HA"; Phenoxy diethylene glycol acrylate (trade name "LIGHT ACRYLATE P2H-A", manufactured by Kyoei Chemical Co., Ltd.)

[0225] "HEAA"; N-(2-hydroxyethyl)acrylamide (trade name "HEAA", manufactured by KJ Chemical Co., Ltd.)

[0226] “M5700”; a reaction product of 2,3-epoxypropylphenyl ether with 2-hydroxy-3-phenoxypropyl acrylate as the main component and acrylic acid (trade name “M5700 M-5700”, manufactured by Toa Synthetic Co., Ltd.)

[0227] “M220”; (Tripropylene glycol diacrylate) (trade name “M5700 M-220”, manufactured by Toa Sangyo Co., Ltd.)

[0228] "DEAA"; (NN-Diethylacrylamide) (trade name "DEAA", manufactured by KJ Chemical Co., Ltd.)

[0229] "HPPA"; (reaction product of neopentyl glycol, hydroxypentyl acid, and acrylic acid) (trade name "LIGHTACRYLATE HPP-A", manufactured by Kyoei Chemical Co., Ltd.)

[0230] Example 1

[0231] A COP solution was prepared by adding 10 g of a cyclic olefin polymer (COP) film (trade name "ZEONOR Film ZF14") to 90 g of a 2:3 mixed solvent of 2,4-trichlorobenzene and toluene. Next, the prepared COP solution was coated onto a PET film (sealant) using a wire-bar coater #5, and then dried in an oven at 60°C for 3 minutes, thereby creating a barrier layer with a 1 μm thick COP film (barrier layer) laminated on the sealant. It should be noted that the moisture permeability of the barrier layer is 480 g / (m²). 2 (24h), the distance from the HSP value of water is 33.3.

[0232] Using an MCD coating machine (manufactured by Fuji Machinery Co., Ltd.) (unit shape: honeycomb, gravure roller line count: 1000 lines / inch, rotation speed 140% / pair line speed), adhesive composition 2 was applied to the side (bonding surface) of an optical film laminate consisting of a thin polarizer and an amorphous PET substrate. This was then bonded to the blocking surface (bonding surface) of a barrier layer with a diaphragm via a roller mill (bonding line speed: 25 m / min). The adhesive composition 2 was then cured by irradiating the barrier layer with a diaphragm with visible light using an active energy irradiation device. Finally, by peeling the diaphragm from the barrier layer with the diaphragm, a laminated film 1 consisting of a thin polarizer (an optical film laminate consisting of a thin polarizer and an amorphous PET substrate) and a barrier layer 1 separated by adhesive layer 2 was obtained. It should be noted that the thickness of the barrier layer 1 and the thickness of the adhesive layer 2 in this laminated film 1 are both 1 μm. The adjacent layer 1 is composed of a barrier layer 1 and an adhesive layer 2, and the distance between the adjacent layer 1 and the water HSP value is 29.4.

[0233] Using an MCD coating machine (manufactured by Fuji Machinery Co., Ltd.) (cell shape: honeycomb, gravure roller line count: 1000 lines / inch, speed 140% / pair line speed), an adhesive composition 1 is applied to the barrier layer 1 side of the laminated film 1 to a thickness of 0.7 μm, and then bonded to the protective film 1 (“TAC”) by a roller mill (bonding line speed: 25 m / min). Then, the adhesive composition 1 is cured by irradiation from the protective film 1 side using an active energy ray irradiation device, thereby obtaining a laminated film 2 with the protective film 1 laminated on the barrier layer 1 through the adhesive layer 1. The thickness of the adhesive layer 1 is 0.9 μm.

[0234] The amorphous PET substrate (the amorphous PET substrate in the optical film laminate formed by stacking a thin polarizer and an amorphous PET substrate) of the obtained laminated film 2 is peeled off to expose the thin polarizer. Next, adhesive composition 2 is applied to one side of the thin polarizer using the same method as described above, and then bonded to the barrier layer (bonding surface) of the barrier layer with a diaphragm using a roller mill (the bonding linear speed is 25 m / min). Then, the adhesive composition 2 is cured by irradiating the barrier layer with a diaphragm using an active energy ray irradiation device. Then, by peeling the diaphragm from the barrier layer with a diaphragm, a laminated film 3 is obtained with a barrier layer 2 stacked on the other side of the thin polarizer, separated by adhesive layer 2. It should be noted that the thickness of barrier layer 2 in this laminated film 3 is 1 μm, and the thickness of adhesive layer 2 is 1 μm. The barrier layer 2 and adhesive layer 2 constitute adjacent layers 2, and the distance between adjacent layers 2 and water HSP value is 29.4.

[0235] The adhesive composition 3 is applied to the barrier layer 2 side of the laminated film 3 using the same method as described above, and then bonded to the panel-side protective film (phase difference film) using a roller mill (the bonding linear speed is 25 m / min). Then, the adhesive composition 3 is cured by irradiating the panel-side protective film side with an active energy ray irradiation device, thereby producing the polarizing film of Example 1 (a polarizing film consisting of "protective film 1" - "adhesive layer 1" - "barrier layer 1" - "adhesive layer 2" - "thin polarizer" - "adhesive layer 2" - "barrier layer 2" - "adhesive layer 3" - "panel-side protective film" stacked sequentially from the visible side).

[0236] It should be noted that the stacking order of "protective film 1", "adhesive layer 1", "barrier layer 1", "adhesive layer 2", "thin polarizer", "adhesive layer 2", "barrier layer 2", "adhesive layer 3" and "panel side protective film" in Example 1 is not limited to the order described above and can be arbitrarily changed.

[0237] Examples 2-5, Comparative Examples 1-3

[0238] The presence or absence of the barrier layer 1 and adhesive layer 1 (or barrier layer 2 and adhesive layer 3), the type of protective film 1, and the thickness of each adhesive layer were changed as described in Table 1. Otherwise, the polarizing film was manufactured by the same method as in Example 1.

[0239] (Transmittance variation test)

[0240] The transmittance Ts of the obtained polarizing film was measured using a UV-Vis spectrophotometer (V-7100, manufactured by Nippon Spectrophotometer Co., Ltd.). The monomer transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc were set as Ts, Tp, and Tc of the polarizing film, respectively. The Y values ​​of Ts, Tp, and Tc were obtained by measuring with a 2-degree field of view (C light source) using a JIS Z8701 spectrophotometer and undergoing visibility correction. It should be noted that the refractive index of the protective layer is 1.50, and the refractive index of the surface of the polarizing film opposite to the protective layer is 1.53. The single-cell transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc measured using a UV-Vis spectrophotometer (V-7100, manufactured by Nippon Spectrophotometer Co., Ltd.) were set as Ts, Tp, and Tc of the polarizing film, respectively. The aforementioned Ts, Tp, and Tc were measured using a 2-degree field of view (C-light source) of JIS Z8701 and the Y values ​​were obtained after visibility correction. It should be noted that the refractive index of the protective layer is 1.50, and the refractive index of the surface of the polarizing film opposite to the protective layer is 1.53. For the polarizing film exposed to 60°C and 95% RH for 240 hours after installation, the transmittance Ts was also measured using the same method, and the transmittance change ΔT(%) was calculated as |(transmittance Ts(%) before installation) - (transmittance Ts(%) after installation)|, with the results shown in Table 1.

[0241] (Determining the reliability of humidifiers)

[0242] The reliability of humidification is determined as follows: cases where the transmittance change ΔT (%) is less than 0.4 are marked as ◎, cases where it is more than 0.4 but less than 0.8 are marked as ○, cases where it is more than 0.8 but less than 1.0 are marked as △, and cases where it is more than 1.0 are marked as ×. The results are shown in Table 1.

[0243]

Claims

1. A polarizing film, comprising: an iodine-based polarizer, and an adjacent layer provided on at least one surface of the iodine-based polarizer, wherein the adjacent layer has a distance of 26 or more from the HSP value of water, and wherein the adjacent layer has the barrier layer via an adhesive layer directly in contact with the iodine-based polarizer, and wherein a ratio (Tb / Ta) of a thickness Tb of the barrier layer to a thickness Ta of the adhesive layer is 0.05 to 1.

2. A polarizing film, comprising: an iodine-based polarizer, and an adjacent layer provided on at least one surface of the iodine-based polarizer, wherein the adjacent layer has a distance of 26 or more from the HSP value of water, and wherein the adjacent layer has the barrier layer via an adhesive layer formed on an easily adhering layer directly in contact with the iodine-based polarizer, and wherein a ratio (Tb / Ta) of a thickness Tb of the barrier layer to a thickness Ta of the adhesive layer is 0.05 to 1.

3. The polarizing film according to claim 1 or 2, wherein the thickness of the barrier layer is 1 μm or more.

4. The polarizing film according to claim 1 or 2, wherein the thickness of the barrier layer is 3 μm or less. The adjacent layer comprises a barrier layer having a moisture permeability of 500 g / (m 2 ·24h) or less, 5. The polarizing film according to claim 1 or 2, further comprising a resin film laminated on a surface of the adjacent layer on the side opposite to the iodine-based polarizer.

6. The polarizing film according to claim 5, wherein the resin film is a polarizing film.

7. An optical film, comprising at least one polarizing film according to any one of claims 1 to 6.

8. An image display device, comprising the polarizing film according to any one of claims 1 to 6 or the optical film according to claim 7. ​ ​ The adjacent layer comprises a barrier layer having a moisture permeability of 500 g / (m 2 ·24h) or less, ​ ​ ​ ​ ​ ​ ​ ​ The moisture permeability of the resin film is 80 g / (m 2 ·24h) or more. ​ ​

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