Adhesive layer-attached polarizing film, image display panel, and image display device

Abstract

To provide an adhesive-layered polarizing film with irregularly shaped portions, which is capable of preventing cracking of the irregularly shaped portions even when the film is applied to in-cell liquid crystal panels, and offers an antistatic feature that suppresses static irregularity.SOLUTION: An adhesive-layered polarizing film is provided, comprising a polarizing film, consisting of a polarizer and a protective film provided on one or both surfaces of the polarizer, a conductive layer, and an adhesive layer arranged in the described order, and having irregularly shaped portions that are not rectangular. The adhesive layer is made of an adhesive composition containing a (meth)acrylic polymer (A) and an ionic compound (B).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pressure-sensitive adhesive layer-attached polarizing film having irregularly shaped portions other than rectangular, and also to an image display panel and an image display device to which the pressure-sensitive adhesive layer-attached polarizing film is applied. [Background technology]

[0002] Image display panels, such as liquid crystal panels used in liquid crystal display devices, typically have polarizing films laminated on both sides of a liquid crystal cell formed from a liquid crystal layer disposed between a pair of transparent substrates, with a pressure-sensitive adhesive layer interposed therebetween. During the manufacture of image display panels, when the pressure-sensitive adhesive layer-attached polarizing film is attached to the liquid crystal cell, a release film is peeled off from the pressure-sensitive adhesive layer of the pressure-sensitive adhesive layer-attached polarizing film. This peeling of the release film generates static electricity. The static electricity thus generated can affect, for example, the alignment of the liquid crystal layer inside the liquid crystal display panel, resulting in defects. The generation of static electricity can be suppressed, for example, by forming an antistatic layer (conductive layer) on the outer surface of the polarizing film.

[0003] For example, Patent Document 1 discloses a liquid crystal display device with a touch sensing function, in which the surface resistance is set to 1.0×10 9 ~1.0×10 11 It has been proposed to place a polarizing film with an Ω / □ antistatic layer on the viewing side of the liquid crystal layer. It is also known that the generation of static electricity can be suppressed by adding an ionic compound as an antistatic agent to the adhesive layer.

[0004] Meanwhile, in recent years, irregularly shaped in-cell liquid crystal displays have become increasingly common in smartphones and car navigation systems, and irregularly shaped polarizing films are being used to match these displays. Patent Document 2 discloses a method for manufacturing polarizing films having irregular shapes other than rectangular by processing polarizing films. Patent Document 3 proposes that the irregularly shaped punching properties of polarizing films and the crack durability of the irregularly shaped polarizing films after punching in a heat cycle test can be improved by incorporating irregularly shaped inorganic particles into a transparent protective film used for the polarizing films. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-105154 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-151191 [Patent Document 3] Japanese Patent Application Publication No. 2017-097111 Summary of the Invention [Problem to be solved by the invention]

[0006] The polarizing film having an antistatic layer described in Patent Document 1 can suppress static electricity generation. However, even a polarizing film with a pressure-sensitive adhesive layer provided with an antistatic layer or a pressure-sensitive adhesive layer containing an ionic compound cannot sufficiently suppress static unevenness. Furthermore, in the case of a polarizing film with a pressure-sensitive adhesive layer having an irregular shape, a polarizing film with a pressure-sensitive adhesive layer provided with an antistatic layer or a pressure-sensitive adhesive layer containing an ionic compound cannot sufficiently suppress irregular cracks that occur in the irregular shape portion. In particular, when a polarizing film with a pressure-sensitive adhesive layer containing an ionic compound in the pressure-sensitive adhesive layer and having an irregular shape portion is applied to an in-cell type liquid crystal panel, it is necessary to add a large amount of ionic compound to the pressure-sensitive adhesive layer, which has been found to result in worsening irregular cracks that occur in the irregular shape portion.

[0007] The present invention aims to provide a polarizing film with an adhesive layer having an irregularly shaped portion, which has an antistatic function and can suppress the occurrence of irregular cracks and static unevenness even when applied to an in-cell type liquid crystal panel.

[0008] Another object of the present invention is to provide an image display panel and an image display device to which the pressure-sensitive adhesive layer-attached polarizing film is applied. [Means for solving the problem]

[0009] As a result of extensive research into solving the above problems, the present inventors have discovered the following pressure-sensitive adhesive layer-attached polarizing film, and have completed the present invention.

[0010] That is, the present invention is A pressure-sensitive adhesive layer-attached polarizing film having a polarizer and a protective film on one or both sides of the polarizer, a conductive layer, and a pressure-sensitive adhesive layer in this order, The pressure-sensitive adhesive layer-attached polarizing film has irregularly shaped portions other than rectangular, The present invention relates to a pressure-sensitive adhesive layer-attached polarizing film, wherein the pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition containing a (meth)acrylic polymer (A) and an ionic compound (B).

[0011] In the pressure-sensitive adhesive layer-attached polarizing film, the conductive layer preferably contains a conductive polymer.

[0012] In the pressure-sensitive adhesive layer-attached polarizing film, the conductive layer preferably has a thickness of 1 μm or less.

[0013] In the pressure-sensitive adhesive layer-attached polarizing film, the ionic compound (B) preferably has a cationic component with a molecular weight of not more than 210. Furthermore, the cationic component is preferably a lithium ion.

[0014] In the pressure-sensitive adhesive layer-attached polarizing film, the ionic compound (B) is preferably contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the (meth)acrylic polymer (A).

[0015] In the pressure-sensitive adhesive layer-attached polarizing film, it is preferable that the protective film is any one selected from a cellulose resin film and a (meth)acrylic resin film, and the thickness of the polarizer in the polarizing film is preferably 10 μm or less.

[0016] In the pressure-sensitive adhesive layer-attached polarizing film, the polarizing film may be a one-sided protected polarizing film having a polarizer and a protective film on only one side of the polarizer. The one-sided protected polarizing film preferably has the conductive layer on the other side of the polarizer.

[0017] The one-sidedly protected polarizing film may have the conductive layer on the other side of the polarizer via a transparent layer having a thickness of 10 μm or less that is directly formed on the polarizer. The transparent layer may be a cured product of a forming material containing a urethane prepolymer, which is a reaction product of an isocyanate compound and a polyhydric alcohol.

[0018] In the pressure-sensitive adhesive layer-attached polarizing film, the pressure-sensitive adhesive layer preferably has a creep value at 85° C. of 120 μm or less.

[0019] The present invention also relates to an image display panel comprising the pressure-sensitive adhesive layer-attached polarizing film, wherein the pressure-sensitive adhesive layer of the pressure-sensitive adhesive layer-attached polarizing film is bonded to a liquid crystal cell with an integrated touch sensing function, the liquid crystal cell having a liquid crystal layer and a touch sensor section.

[0020] The present invention also relates to an image display device comprising the image display panel. [Effects of the Invention]

[0021] The pressure-sensitive adhesive layer-attached polarizing film of the present invention has a conductive layer between the pressure-sensitive adhesive layer and the polarizing film, and the pressure-sensitive adhesive layer contains an ionic compound, so that both the conductive layer and the pressure-sensitive adhesive layer can improve antistatic performance. Therefore, even if the amount of ionic compound in the pressure-sensitive adhesive layer is reduced, the antistatic function of both layers can suppress static unevenness even when the pressure-sensitive adhesive layer-attached polarizing film is applied to an in-cell liquid crystal panel. Furthermore, although the pressure-sensitive adhesive layer-attached polarizing film of the present invention has irregularly shaped portions other than rectangular, as described above, the amount of ionic compound in the pressure-sensitive adhesive layer can be reduced, thereby suppressing the occurrence of irregular cracks.

[0022] It was also found that the smaller the molecular weight of the cationic component of the ionic compound, the less adverse effect it has on irregular cracking. In particular, it was found that when a lithium salt is used as the cationic component of the ionic compound, the effect of suppressing irregular cracking is excellent. Furthermore, it was also found that the effect of suppressing irregular cracking is advantageous when a one-sided protected polarizing film having a protective film on only one side of the polarizer is used as the polarizing film. A one-sided protected polarizing film is advantageous from the viewpoints of thinning and cost reduction. It was also found that the smaller the molecular weight of the cationic component, the more preferable it is in terms of suppressing static unevenness.

[0023] On the other hand, when a one-sided protected polarizing film is used as the polarizing film as described above, the conductive layer is formed directly on the polarizer, and therefore, in a humid environment, the antistatic agent in the conductive layer penetrates into the polarizer, causing discoloration of the edges of the polarizer, and it has also been found that segregation of the ionic compound contained in the pressure-sensitive adhesive layer to the polarizer may reduce the antistatic function of the pressure-sensitive adhesive layer. When a one-sided protected polarizing film is used in this way, by providing the conductive layer on the polarizer via a transparent layer, the conductive layer is prevented from directly affecting the polarizer, thereby making it possible to suppress discoloration of the edges of the polarizer in a humid environment.

[0024] As described above, the pressure-sensitive adhesive layer-attached polarizing film of the present invention can suppress deterioration of the optical reliability of the polarizer even when a one-sided protected polarizing film is used, and can provide a pressure-sensitive adhesive layer-attached polarizing film that is thin, has good optical reliability, and has excellent antistatic properties over the long term. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a cross-sectional view showing an example of a pressure-sensitive adhesive layer-attached polarizing film of the present invention. [Figure 2] 1 is a cross-sectional view showing an example of a pressure-sensitive adhesive layer-attached polarizing film of the present invention. [Figure 3] 1 is a cross-sectional view showing an example of a pressure-sensitive adhesive layer-attached polarizing film of the present invention. [Figure 4] FIG. 2 is a top view showing an example of an irregularly shaped portion other than a rectangle of the pressure-sensitive adhesive layer-attached polarizing film of the present invention. [Figure 5] 1 is a top view showing a pressure-sensitive adhesive layer-attached polarizing film having an irregularly shaped portion according to an example of the present invention. [Figure 6] 1 is a cross-sectional view showing an example of a liquid crystal panel with a touch-sensing function using a pressure-sensitive adhesive layer-attached polarizing film of the present invention. [Figure 7] 1 is a cross-sectional view showing an example of a liquid crystal panel with a touch-sensing function using a pressure-sensitive adhesive layer-attached polarizing film of the present invention. [Figure 8] 1 is a cross-sectional view showing an example of a liquid crystal panel with a touch-sensing function using a pressure-sensitive adhesive layer-attached polarizing film of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] An example of a pressure-sensitive adhesive layer-attached polarizing film of the present invention is shown in FIG. 1. As shown in FIG. 1, the pressure-sensitive adhesive layer-attached polarizing film 1 includes a polarizing film 11, a conductive layer c, and a pressure-sensitive adhesive layer 21, in this order. FIG. 2 shows a case where a single-protected polarizing film 11A having a protective film b on only one side of the polarizer a is used as the polarizing film 11 of FIG. 1. The single-protected polarizing film 11A includes the pressure-sensitive adhesive layer 21 on the other side of the polarizer a, the side not including the protective film b, via the conductive layer c. Although not shown, a single-protected polarizing film A2 having a protective film b on only one side of the polarizer a can also be a laminate in the order polarizer a / protective film b / conductive layer c / pressure-sensitive adhesive layer 21. FIG. 3 shows a case where the single-protected polarizing film 11A is used and further includes a transparent layer d on the other side of the polarizer a. In FIG. 3, the single-protected polarizing film 11A includes a transparent layer d, a conductive layer c, and a pressure-sensitive adhesive layer 21, in this order. The transparent layer d is preferably provided directly on the polarizer a, since this can prevent an increase in moisture content of the polarizer in a high-temperature, high-humidity environment.

[0027] <Unusual part> The pressure-sensitive adhesive layer-attached polarizing film of the present invention also has irregularly shaped portions other than rectangular. Fig. 4 is a top view of an example of a film having irregularly shaped portions other than rectangular. The irregular shape is not particularly limited, and any shape may be used depending on the application, function, design, etc. of the pressure-sensitive adhesive layer-attached polarizing film. Examples of irregular shapes other than rectangular include a rectangle having a notch or a through-hole.

[0028] The notch is provided on the outer edge of the pressure-sensitive adhesive layer-attached polarizing film. When multiple notches are provided, they may have the same shape or different shapes. Two or more notches may be provided on one side, or one or more notches may be provided on each of two sides. The notch may be provided at one of the four corners of the outer edge of the rectangle, or at two or more notches. The corners of the outer edge where no notch is provided may be angular or rounded. The notch may be formed by a straight line, a curve, or a combination thereof. Figure 4 shows an example of a pressure-sensitive adhesive layer-attached polarizing film 1 having an irregular shape, in which notches 2 of different shapes are provided on both short sides of the rectangle.

[0029] The length of the side W1 of the cutout is adjusted appropriately depending on the intended use of the polarizing film. For example, W1 is preferably adjusted to within a range of approximately 2 to 100 mm. Furthermore, the maximum depth D of the cutout 2 from the side W1 is preferably adjusted to approximately 2 to 100 mm.

[0030] 4 shows a case where the angle θ1 between the two straight lines that define the shape of the notch 2 is 90°, but the angle θ1 is greater than or equal to 90° and less than 180°, and preferably greater than or equal to 90° and less than 135°. If the angle θ1 is outside this range, stress due to expansion and contraction will be concentrated at the part 4 where the two straight lines intersect in a severe thermal shock environment, making the part 4 more susceptible to cracking.

[0031] 4 shows a curve that defines the shape of the notched portion 2, and the radius of curvature R1 of the curve is 0.2 mm or more, preferably 1 mm or more, more preferably 2 mm or more, even more preferably 3 mm or more, and even more preferably 5 mm or more. If the radius of curvature R1 is less than 0.2 mm, stress due to expansion and contraction will be concentrated in the curved portion in a severe environment of thermal shock, making the curved portion more susceptible to cracks.

[0032] The through-hole is provided within the plane of the pressure-sensitive adhesive layer-attached polarizing film. When a plurality of through-holes are provided within the plane of the pressure-sensitive adhesive layer-attached polarizing film, they may have the same shape or different shapes. The through-holes are configured as straight lines, curves, or a combination thereof. Examples of the shape of the through-holes include circles, ellipses (with one axis of symmetry or two axes of symmetry), rounded rectangles, quadrilaterals (squares, rectangles), and polygons with five or more sides.

[0033] Examples of methods for forming the irregularly shaped portion include punching, end milling, laser processing, etc. The irregularly shaped portion is usually formed by the above processing after the layers are stacked.

[0034] <Polarizing film with adhesive layer> First, each component constituting the pressure-sensitive adhesive layer-attached polarizing film of the present invention will be described. The polarizing film used has a polarizer and a protective film on one or both sides of the polarizer.

[0035] The polarizer is not particularly limited, and various types can be used. Examples of polarizers include those obtained by uniaxially stretching a hydrophilic polymer film, such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, or a partially saponified ethylene-vinyl acetate copolymer film, onto which a dichroic substance such as iodine or a dichroic dye has been adsorbed, and polyene-based oriented films, such as dehydrated polyvinyl alcohol or dehydrochlorinated polyvinyl chloride, are also suitable. Among these, polarizers made of a polyvinyl alcohol film and a dichroic substance such as iodine are preferred. The thickness of these polarizers is not particularly limited, but is generally about 80 μm or less.

[0036] Furthermore, a thin polarizer having a thickness of 10 μm or less can be used as the polarizer. From the viewpoint of thinning, the thickness is preferably 1 to 7 μm. Such a thin polarizer has less thickness unevenness, excellent visibility, and excellent durability due to less dimensional change, and is also preferable in that the thickness as a polarizing film can be reduced.

[0037] The material constituting the protective film is, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture blocking properties, isotropy, etc. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, cyclic polyolefin resins (norbornene-based resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. The protective film is usually attached to one side of the polarizer with an adhesive layer, while the other side can be made of a thermosetting resin or ultraviolet-curable resin such as a (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone-based resin.

[0038] The material for the protective film (transparent protective film) is preferably a cellulose resin or a (meth)acrylic resin, since this allows for minimizing fluctuations in the surface resistance of the pressure-sensitive adhesive layer. The (meth)acrylic resin is preferably a (meth)acrylic resin having a lactone ring structure. Examples of (meth)acrylic resins having a lactone ring structure include (meth)acrylic resins having a lactone ring structure described in JP 2000-230016 A, JP 2001-151814 A, JP 2002-120326 A, JP 2002-254544 A, and JP 2005-146084 A. Cellulose resins are particularly preferred because they are more effective than (meth)acrylic resins in suppressing irregular cracks and polarizer cracks, which are problems with single-sided protective polarizing films.

[0039] The protective film may also be a retardation film, a brightness enhancement film, a diffusion film, or the like. Examples of the retardation film include those having a front retardation of 40 nm or more and / or a thickness retardation of 80 nm or more. The front retardation is usually controlled to within a range of 40 to 200 nm, and the thickness retardation is usually controlled to within a range of 80 to 300 nm. When a retardation film is used as the protective film, the retardation film also functions as a polarizer protective film, thereby enabling a thinner film to be achieved.

[0040] A functional layer such as a hard coat layer, an anti-reflection layer, an anti-sticking layer, a diffusion layer or an anti-glare layer may be provided on the surface of the protective film to which the polarizer is not attached.

[0041] The protective film and the polarizer are laminated via an intervening layer such as an adhesive layer, a pressure-sensitive adhesive layer, or an undercoat layer (primer layer). In this case, it is desirable to laminate them without any air gaps by using the intervening layer. The protective film and the polarizer are preferably laminated via an adhesive layer. The adhesive used to bond the polarizer and the protective film is not particularly limited as long as it is optically transparent, and various types such as water-based, solvent-based, hot-melt, radical-curing, and cationic-curing adhesives can be used, but water-based adhesives or radical-curing adhesives are preferred.

[0042] <Conductive layer> The thickness of the conductive layer c is preferably 1 μm or less, more preferably 0.01 to 0.5 μm, more preferably 0.01 to 0.2 μm, and even more preferably 0.01 to 0.1 μm, from the viewpoint of the stability of the surface resistance value and the adhesion to the adhesive layer 21. Furthermore, the surface resistance value of the conductive layer c is 1×10 7 ~1×10 12 Ω / □ is preferred, and 1×10 7 ~1×10 11 Ω / □ is preferable, and 1×10 7 ~1×10 10 It is preferably Ω / □.

[0043] The conductive layer can be formed from various antistatic agent compositions, such as ionic surfactants, conductive polymers, conductive fine particles, and carbon nanotubes.

[0044] Among these antistatic agents, conductive polymers and carbon nanotubes are preferred from the viewpoints of optical properties, appearance, antistatic effect, and stability of the antistatic effect under heat and humidity. Conductive polymers such as polyaniline and polythiophene are particularly preferred. Organic solvent-soluble, water-soluble, and water-dispersible conductive polymers can be used as appropriate, but water-soluble or water-dispersible conductive polymers are preferred. Water-soluble or water-dispersible conductive polymers can be prepared as aqueous solutions or dispersions in the coating liquid used to form the antistatic layer. This coating liquid does not require the use of non-aqueous organic solvents, and deterioration of the optical film substrate due to the organic solvent can be suppressed. The aqueous solutions or dispersions can contain aqueous solvents in addition to water. Examples of the alcohol include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, and cyclohexanol.

[0045] Furthermore, the water-soluble conductive polymer or water-dispersible conductive polymer, such as polyaniline or polythiophene, preferably has a hydrophilic functional group in the molecule. Examples of the hydrophilic functional group include a sulfone group, an amino group, an amide group, an imino group, a quaternary ammonium base, a hydroxyl group, a mercapto group, a hydrazino group, a carboxyl group, a sulfate ester group, a phosphate ester group, or salts thereof. The presence of a hydrophilic functional group in the molecule makes the polymer more soluble in water or more easily dispersible in water in the form of fine particles, making it easier to prepare the water-soluble conductive polymer or water-dispersible conductive polymer.

[0046] An example of a commercially available water-soluble conductive polymer is polyaniline sulfonic acid (manufactured by Mitsubishi Rayon Co., Ltd., weight average molecular weight calculated as polystyrene: 150,000). An example of a commercially available water-dispersible conductive polymer is polythiophene-based conductive polymer (manufactured by Nagase Chemtec Corporation, product name: Denatron series).

[0047] In addition to the antistatic agent, a binder component can also be added to the conductive layer forming material for the purpose of improving the film-forming properties of the antistatic agent and its adhesion to the optical film. When the antistatic agent is a water-soluble or water-dispersible conductive polymer, a water-soluble or water-dispersible binder component is used. Examples of binders include oxazoline group-containing polymers, polyurethane resins, polyester resins, acrylic resins, polyether resins, cellulose resins, polyvinyl alcohol resins, epoxy resins, polyvinylpyrrolidone, polystyrene resins, polyethylene glycol, and pentaerythritol. Polyurethane resins, polyester resins, and acrylic resins are particularly preferred. One or more of these binders can be used depending on the application.

[0048] The amounts of antistatic agent and binder used depend on their types, but are determined so that the surface resistance of the resulting conductive layer is 1×10 7 ~1×10 12 It is preferable to control it so that it becomes Ω / □.

[0049] <Adhesive layer> The pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition containing a (meth)acrylic polymer (A) and an ionic compound (B).

[0050] The (meth)acrylic polymer (A) contains, as a monomer unit, alkyl(meth)acrylate as a main component. Note that, (meth)acrylate refers to acrylate and / or methacrylate, and (meth) in the present invention has the same meaning.

[0051] Examples of the alkyl (meth)acrylate constituting the main skeleton of the (meth)acrylic polymer (A) include linear or branched alkyl groups having 1 to 18 carbon atoms. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl, hexyl, cyclohexyl, heptyl, 2-ethylhexyl, isooctyl, nonyl, decyl, isodecyl, dodecyl, isomyristyl, lauryl, tridecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl groups. These groups may be used alone or in combination. The average carbon number of these alkyl groups is preferably 3 to 9.

[0052] The weight ratio of the alkyl (meth)acrylate, as a monomer unit, is preferably 70% by weight or more of the weight ratio of all constituent monomers (100% by weight) constituting the (meth)acrylic polymer (A). The weight ratio of the alkyl (meth)acrylate can be considered as the remainder of other copolymerizable monomers. Setting the weight ratio of the alkyl (meth)acrylate within the above range is preferable in terms of ensuring adhesiveness.

[0053] In addition to the alkyl (meth)acrylate monomer unit, one or more copolymerizable monomers having a polymerizable functional group with an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group, can be introduced into the (meth)acrylic polymer (A) by copolymerization in order to improve adhesiveness and heat resistance.

[0054] Examples of the copolymerizable monomer include functional group-containing monomers such as carboxyl group-containing monomers, hydroxyl group-containing monomers, and amide group-containing monomers.

[0055] The carboxyl group-containing monomer is a compound that contains a carboxyl group in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Specific examples of the carboxyl group-containing monomer include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Among the carboxyl group-containing monomers, acrylic acid is preferred from the viewpoints of copolymerizability, cost, and adhesive properties.

[0056] The hydroxyl group-containing monomer is a compound that contains a hydroxyl group in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Specific examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate, as well as (4-hydroxymethylcyclohexyl)-methyl acrylate. Among the hydroxyl group-containing monomers, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferred from the viewpoint of durability, with 4-hydroxybutyl (meth)acrylate being particularly preferred.

[0057] When the pressure-sensitive adhesive composition contains a crosslinking agent, the carboxyl group-containing monomer and the hydroxyl group-containing monomer serve as reaction sites with the crosslinking agent. Because the carboxyl group-containing monomer and the hydroxyl group-containing monomer are highly reactive with the intermolecular crosslinking agent, they are preferably used to improve the cohesiveness and heat resistance of the resulting pressure-sensitive adhesive layer. Furthermore, the carboxyl group-containing monomer is preferred in terms of achieving both durability and reworkability, and the hydroxyl group-containing monomer is preferred in terms of reworkability.

[0058] The weight ratio of the carboxyl group-containing monomer is preferably 10% by weight or less, more preferably 0.01 to 8% by weight, even more preferably 0.05 to 6% by weight, and even more preferably 0.1 to 5% by weight. A weight ratio of the carboxyl group-containing monomer of 0.01% by weight or more is preferable from the viewpoint of durability. On the other hand, if it exceeds 10% by weight, it is not preferable from the viewpoint of reworkability.

[0059] The weight ratio of the hydroxyl group-containing monomer is preferably 3 wt% or less, more preferably 0.01 to 3 wt%, even more preferably 0.1 to 2 wt%, and even more preferably 0.2 to 2 wt%. A weight ratio of the hydroxyl group-containing monomer of 0.01 wt% or more is preferable from the viewpoint of crosslinking the pressure-sensitive adhesive layer and in terms of durability and adhesive properties. On the other hand, if it exceeds 3 wt%, it is undesirable from the viewpoint of durability.

[0060] The amide group-containing monomer is a compound that contains an amide group in its structure and also contains a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Specific examples of amide group-containing monomers include acrylamide-based monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropylacrylamide, N-methyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hexyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylol-N-propane(meth)acrylamide, aminomethyl(meth)acrylamide, aminoethyl(meth)acrylamide, mercaptomethyl(meth)acrylamide, and mercaptoethyl(meth)acrylamide; N-acryloyl heterocyclic monomers such as N-(meth)acryloylmorpholine, N-(meth)acryloylpiperidine, and N-(meth)acryloylpyrrolidine; and N-vinyl group-containing lactam-based monomers such as N-vinylpyrrolidone and N-vinyl-ε-caprolactam. Amide group-containing monomers are preferred for suppressing an increase in surface resistance over time (particularly in a humid environment), for ensuring durability, and for suppressing irregular cracking. Among amide group-containing monomers, N-vinyl group-containing lactam monomers are particularly preferred for suppressing an increase in surface resistance over time (particularly in a humid environment), for ensuring durability of the transparent conductive layer (touch sensor layer), and for suppressing irregular cracking.

[0061] As the weight ratio of the amide group-containing monomer increases, the anchoring ability to the optical film tends to decrease, so the weight ratio is preferably 10 wt% or less, and more preferably 5 wt% or less. From the viewpoint of suppressing an increase in surface resistance over time (particularly in a humid environment), the weight ratio of the amide group-containing monomer is preferably 0.1 wt% or more. The weight ratio is preferably 0.3 wt% or more, and more preferably 0.5 wt% or more. The amide group-containing monomer is suitable in relation to the ionic compound (B) contained in the pressure-sensitive adhesive layer of the present invention.

[0062] In the pressure-sensitive adhesive composition used to form the pressure-sensitive adhesive layer, when an amide group is introduced into the side chain of the (meth)acrylic polymer (A) that is the base polymer, the presence of the amide group prevents the surface resistance of the pressure-sensitive adhesive layer, which is adjusted by blending the ionic compound (B), from fluctuating and increasing even in a humid environment, and is preferred for maintaining the surface resistance within a desired range. The presence of the amide group introduced into the side chain of the (meth)acrylic polymer (A) as a functional group of a copolymerization monomer is thought to improve the compatibility between the (meth)acrylic polymer (A) and the ionic compound (B).

[0063] Furthermore, when the (meth)acrylic polymer (A) as the base polymer has an amide group introduced into a side chain, the pressure-sensitive adhesive layer has good durability to both glass and transparent conductive layers (such as an ITO layer), and can suppress peeling, lifting, etc. when attached to a liquid crystal panel. Furthermore, the pressure-sensitive adhesive layer can also satisfy durability in a humid environment (after a humid reliability test).

[0064] As the copolymerizable monomer, for example, an aromatic ring-containing (meth)acrylate can be used. The aromatic ring-containing (meth)acrylate is a compound that contains an aromatic ring structure and a (meth)acryloyl group in its structure. Examples of the aromatic ring include a benzene ring, a naphthalene ring, and a biphenyl ring.

[0065] Specific examples of aromatic ring-containing (meth)acrylates include benzyl (meth)acrylate, phenyl (meth)acrylate, o-phenylphenol (meth)acrylate phenoxy (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxypropyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, ethylene oxide-modified nonylphenol (meth)acrylate, ethylene oxide-modified cresol (meth)acrylate, phenol ethylene oxide-modified (meth)acrylate, 2-hydroxybenzoic acid (meth)acrylate, ... Examples of the acrylate include those having a benzene ring, such as methyl-3-phenoxypropyl (meth)acrylate, methoxybenzyl (meth)acrylate, chlorobenzyl (meth)acrylate, cresyl (meth)acrylate, and polystyryl (meth)acrylate; those having a naphthalene ring, such as hydroxyethylated β-naphthol acrylate, 2-naphthoethyl (meth)acrylate, 2-naphthoxyethyl acrylate, and 2-(4-methoxy-1-naphthoxy)ethyl (meth)acrylate; and those having a biphenyl ring, such as biphenyl (meth)acrylate.

[0066] As the aromatic ring-containing (meth)acrylate, benzyl (meth)acrylate and phenoxyethyl (meth)acrylate are preferred from the viewpoint of adhesive properties and durability, with phenoxyethyl (meth)acrylate being particularly preferred.

[0067] The weight ratio of the aromatic ring-containing (meth)acrylate is preferably 25% by weight or less, more preferably 3 to 25% by weight, even more preferably 10 to 22% by weight, and even more preferably 14 to 20% by weight. A weight ratio of the aromatic ring-containing (meth)acrylate of 3% by weight or more is preferable in terms of suppressing display unevenness. On the other hand, if it exceeds 25% by weight, display unevenness is not sufficiently suppressed, and durability tends to decrease.

[0068] Specific examples of copolymerizable monomers other than those mentioned above include: acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; sulfonic acid group-containing monomers such as allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, and sulfopropyl (meth)acrylate; and phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate.

[0069] Also, alkylaminoalkyl(meth)acrylates such as aminoethyl(meth)acrylate, N,N-dimethylaminoethyl(meth)acrylate, and t-butylaminoethyl(meth)acrylate; alkoxyalkyl(meth)acrylates such as methoxyethyl(meth)acrylate and ethoxyethyl(meth)acrylate; N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, and N-(meth)acryloyl-8-oxyoctadecyloxymethylenesuccinimide; Examples of monomers suitable for modifying purposes include succinimide-based monomers such as methylene succinimide; maleimide-based monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide; and itaconimide-based monomers such as N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, and N-laurylitaconimide.

[0070] Further usable modifying monomers include vinyl monomers such as vinyl acetate and vinyl propionate; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate; glycol (meth)acrylates such as polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate; and (meth)acrylate monomers such as tetrahydrofurfuryl (meth)acrylate, fluorine (meth)acrylate, silicone (meth)acrylate, and 2-methoxyethyl acrylate. Other examples include isoprene, butadiene, isobutylene, and vinyl ether.

[0071] Further, copolymerizable monomers other than those mentioned above include silicon atom-containing silane monomers, etc. Examples of silane monomers include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, and 10-acryloyloxydecyltriethoxysilane.

[0072] Examples of copolymerizable monomers include tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol. Polyfunctional monomers having two or more unsaturated double bonds such as (meth)acryloyl groups or vinyl groups, such as esters of (meth)acrylic acid with polyhydric alcohols, such as hexa(meth)acrylate and caprolactone-modified dipentaerythritol hexa(meth)acrylate, and polyester(meth)acrylates, epoxy(meth)acrylates, urethane(meth)acrylates, etc., in which two or more unsaturated double bonds such as (meth)acryloyl groups or vinyl groups are added as functional groups similar to those of the monomer components to the backbone of polyester, epoxy, urethane, etc., can also be used.

[0073] The proportion of the other copolymerizable monomer in the (meth)acrylic polymer (A) is preferably about 0 to 10% by weight, more preferably about 0 to 7% by weight, and even more preferably about 0 to 5% by weight, based on the weight ratio of all constituent monomers (100% by weight) of the (meth)acrylic polymer (A).

[0074] The (meth)acrylic polymer (A) of the present invention typically preferably has a weight-average molecular weight of 1,000,000 to 2,500,000. Considering durability, particularly heat resistance, the weight-average molecular weight is preferably 1,200,000 to 2,000,000. A weight-average molecular weight of 1,000,000 or more is preferable in terms of heat resistance. Furthermore, if the weight-average molecular weight is greater than 2,500,000, the pressure-sensitive adhesive tends to become hard, making peeling more likely to occur. Furthermore, the weight-average molecular weight (Mw) / number-average molecular weight (Mn), which indicates the molecular weight distribution, is preferably 1.8 to 10, more preferably 1.8 to 7, and even more preferably 1.8 to 5. A molecular weight distribution (Mw / Mn) of more than 10 is undesirable in terms of durability. The weight-average molecular weight and molecular weight distribution (Mw / Mn) are determined by measurement using GPC (gel permeation chromatography) and calculated in terms of polystyrene.

[0075] The (meth)acrylic polymer (A) can be produced by any known production method, such as solution polymerization, bulk polymerization, emulsion polymerization, various radical polymerizations, etc. The (meth)acrylic polymer (A) obtained may be any of a random copolymer, a block copolymer, a graft copolymer, etc.

[0076] In the solution polymerization, for example, ethyl acetate, toluene, etc. are used as a polymerization solvent. In a specific example of solution polymerization, the reaction is carried out under a stream of an inert gas such as nitrogen, adding a polymerization initiator, and usually at about 50 to 70°C for about 5 to 30 hours.

[0077] The polymerization initiator, chain transfer agent, emulsifier, etc. used in the radical polymerization are not particularly limited and can be appropriately selected and used. The weight average molecular weight of the (meth)acrylic polymer (A) can be controlled by the amounts of the polymerization initiator and chain transfer agent used and the reaction conditions, and the amounts used are appropriately adjusted depending on the types of these.

[0078] <Ionic Compound (B)> The ionic compound (B) contained in the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer of the present invention is preferably an alkali metal salt and / or an organic cation-anion salt. The alkali metal salt may be an organic salt or an inorganic salt of an alkali metal. In the present invention, the term "organic cation-anion salt" refers to an organic salt whose cation component is composed of an organic substance, and whose anion component may be either organic or inorganic. An "organic cation-anion salt" is also called an ionic liquid or ionic solid. By incorporating the ionic compound (B) into the pressure-sensitive adhesive layer, the surface resistance of the pressure-sensitive adhesive layer can be reduced, thereby suppressing static electricity generation and preventing light leakage (uneven charging) due to disruption of the alignment of the liquid crystal layer caused by charging.

[0079] <Alkali metal salts> Examples of alkali metal ions constituting the cation component of the alkali metal salt include lithium, sodium, and potassium ions, with lithium ions being preferred among these alkali metal ions.

[0080] The anion component of the alkali metal salt may be composed of an organic substance or an inorganic substance. Examples of the anion component constituting the organic salt include CH3COO - , CF3COO - , CH3SO3 - , CF3SO3 - , (CF3SO2)3C - , C4F9SO3 - , C3F7COO - , (CF3SO2)(CF3CO)N - , - O3S(CF2)3SO3 - , PF6 - , CO3 2- , or the following general formulas (1) to (4): (1):(C n F 2n+1 SO2)2N - (where n is an integer from 0 to 10), (2):CF2(C m F 2mSO2)2N - (where m is an integer from 1 to 10), (3): - O3S(CF2) l SO3 - (where l is an integer from 1 to 10), (4):(C p F 2p+1 SO2)N - (C q F 2q+1 SO2), (where p and q are integers of 1 to 10), etc. are used. In particular, an anion component containing a fluorine atom is preferably used because it can give an ionic compound with good ionic dissociation properties. Examples of an anion component constituting an inorganic salt include Cl - , Br - , I - , AlCl4 - , Al2Cl7 - , BF4 - , PF6 - , ClO4 - , NO3 - , AsF6 - , SbF6 - , NbF6 - , TaF6 - , (CN)2N - , etc. are used as the anion component. - , (C2F5SO2)2N - (Perfluoroalkylsulfonyl)imides represented by the general formula (1) such as (CF3SO2)2N are preferred, and particularly (CF3SO2)2N - Preferred is (trifluoromethanesulfonyl)imide represented by the following formula:

[0081] Specific examples of organic salts of alkali metals include sodium acetate, sodium alginate, sodium lignosulfonate, sodium toluenesulfonate, LiCF3SO3, Li(CF3SO2)2N, Li(CF3SO2)2N, Li(C2F5SO2)2N, Li(C4F9SO2)2N, Li(CF3SO2)3C, K03S(CF2)3SO3K, LiO3S(CF2)3SO3K, and the like. Of these, LiCF3SO3, Li(CF3SO2)2N, Li(C2F5SO2)2N, Li(C4F9SO2)2N, Li(CF3SO2)3C, and the like are preferred. Fluorine-containing lithium imide salts, which are bis(fluorosulfonyl)imide lithium salts such as Li(CF3SO2)2N, Li(C2F5SO2)2N, and Li(C4F9SO2)2N, are more preferred, and (perfluoroalkylsulfonyl)imide lithium salts are particularly preferred. Other examples include 4,4,5,5-tetrafluoro-1,3,2-dithiazolidine-1,1,3,3-tetraoxide lithium salt.

[0082] Examples of inorganic salts of alkali metals include lithium perchlorate and lithium iodide.

[0083] <Organic cation-anion salt> The organic cation-anion salt used in the present invention is composed of a cation component and an anion component, and the cation component is an organic substance. Specific examples of the cation component include pyridinium cation, piperidinium cation, pyrrolidinium cation, cation having a pyrroline skeleton, cation having a pyrrole skeleton, imidazolium cation, tetrahydropyrimidinium cation, dihydropyrimidinium cation, pyrazolium cation, pyrazolinium cation, tetraalkylammonium cation, trialkylsulfonium cation, and tetraalkylphosphonium cation.

[0084] Examples of anion components include Cl - , Br - , I - , AlCl4 - , Al2Cl7- , BF4 - , PF6 - , ClO4 - , NO3 - , CH3COO - , CF3COO - , CH3SO3 - , CF3SO3 - , (CF3SO2)3C - , AsF6 - , SbF6 - , NbF6 - , TaF6 - , (CN)2N - , C4F9SO3 - , C3F7COO - , ((CF3SO2)(CF3CO)N - , - O3S(CF2)3SO3 - , or the following general formulas (1) to (4): (1):(C n F 2n+1 SO2)2N - (where n is an integer from 0 to 10), (2):CF2(C m F 2m SO2)2N - (where m is an integer from 1 to 10), (3): - O3S(CF2) l SO3 - (where l is an integer from 1 to 10), (4):(C p F 2p+1 SO2)N - (C q F 2q+1 SO2), (wherein p and q are integers of 1 to 10), etc. are used. Among these, an anion component containing a fluorine atom is particularly preferably used because it gives an ionic compound with good ionic dissociation properties.

[0085] The organic cation-anion salt is suitably selected from compounds formed by a combination of the above-mentioned cation component and anion component. Specific examples of preferred organic cation-anion salts include methyltrioctylammonium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide, and ethylmethylimidazolium bis(fluorosulfonylimide). Of these, 1-methyl-1-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide and ethylmethylimidazolium bis(fluorosulfonylimide) are more preferred.

[0086] In addition to the alkali metal salts and organic cation-anion salts, examples of the ionic compound (B) include inorganic salts such as ammonium chloride, aluminum chloride, copper chloride, ferrous chloride, ferric chloride, and ammonium sulfate.

[0087] From the viewpoint of suppressing the occurrence of irregular cracks, it is preferable to use an ionic compound (B) in which the molecular weight of the cationic component is 210 or less. The molecular weight of the cationic component is more preferably 150 or less, even more preferably 110 or less, even more preferably 50 or less, and even more preferably 10 or less. The larger the molecular weight of the cationic component, the more likely it is that entanglement of the (meth)acrylic polymers in the pressure-sensitive adhesive layer is inhibited, and the physical properties of the pressure-sensitive adhesive layer tend to become softer. Therefore, the smaller the molecular weight, the less likely the physical properties of the pressure-sensitive adhesive layer become soft, and the occurrence of irregular cracks can be suppressed. Furthermore, the smaller the molecular weight of the cationic component, the more likely it is that the surface resistance value of the pressure-sensitive adhesive layer will decrease, and static unevenness will be suppressed, which is also preferable.

[0088] When the ionic compound (B) is an alkali metal salt, alkali metal ions such as lithium, sodium, and potassium are cationic components with a molecular weight of 210 or less, and therefore alkali metal salts containing these alkali metal ions as cationic components can be preferably used. In particular, from the viewpoint of compatibility with the pressure-sensitive adhesive layer, organic salts of alkali metals, in which the anionic component of the alkali metal salt is composed of an organic substance, are preferred. Furthermore, lithium ions, which have the smallest molecular weight, are preferred as the alkali metal ion. Lithium salts are preferred as the ionic compound (B), and organic salts of lithium are particularly preferred. On the other hand, when the ionic compound (B) is an organic cation-anion salt, a salt having a molecular weight of 210 or less can be selected from the above-listed cationic components. In particular, from the viewpoint of compatibility with the pressure-sensitive adhesive layer, organic cation-anion salts, in which the anionic component is composed of an organic substance, are preferred.

[0089] The proportion of the ionic compound (B) in the pressure-sensitive adhesive composition of the present invention can be appropriately adjusted so as to satisfy the antistatic properties of the pressure-sensitive adhesive layer and the sensitivity of the touch panel. For example, when the surface resistance of the pressure-sensitive adhesive layer is 1.0 × 10 8 ~1.0×10 12 It is preferable to adjust the proportion of the ionic compound (B) according to the type of liquid crystal panel with built-in touch sensing function, taking into consideration the type of protective film of the polarizing film, etc., so that the initial surface resistance is in the range of Ω / □. For example, in the case of an in-cell type liquid crystal panel with built-in touch sensing function shown in Figure 6, the pressure-sensitive adhesive layer has an initial surface resistance of 1 x 10 8 ~1×10 12 It is preferable to control it in the range of Ω / □, and 1×10 8 ~1×10 10 It is more preferable to control the initial surface resistance of the adhesive layer to within the range of 1×10 10 ~1×10 12 It is preferable to control it in the range of Ω / □.

[0090] If the amount of the ionic compound (B) is too high, the ionic compound (B) may precipitate, and furthermore, peeling under humidity may occur. Furthermore, if the amount of the ionic compound (B) is too high, the surface resistance may become too low, resulting in baseline fluctuations (malfunctions caused by touch due to too low surface resistance), which may reduce the sensitivity of the touch panel. The proportion of the ionic compound (B) is, for example, typically preferably 40 parts by weight or less, more preferably 20 parts by weight or less, even more preferably 10 parts by weight or less, and even more preferably 6 parts by weight or less, per 100 parts by weight of the (meth)acrylic polymer (A). If the amount is too low, the antistatic properties may be poor, while if the amount is too high, the touch sensitivity may decrease, the ionic compound may precipitate, and the adhesive may peel under humidity. On the other hand, to improve antistatic performance, it is preferable to use 0.01 parts by weight or more of the ionic compound (B). From this viewpoint, the amount of the ionic compound (B) is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more.

[0091] The pressure-sensitive adhesive composition of the present invention may contain a crosslinking agent (C). Examples of the crosslinking agent (C) include organic crosslinking agents and polyfunctional metal chelates. Examples of organic crosslinking agents include isocyanate crosslinking agents, peroxide crosslinking agents, epoxy crosslinking agents, and imine crosslinking agents. Polyfunctional metal chelates are those in which a polyvalent metal is covalently or coordinately bonded to an organic compound. Examples of polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, and Ti. Examples of atoms in the organic compound that form covalent or coordinate bonds include oxygen atoms, and examples of the organic compound include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds.

[0092] The crosslinking agent (C) is preferably an isocyanate-based crosslinking agent and / or a peroxide-based crosslinking agent.

[0093] The isocyanate crosslinking agent (C) may be a compound having at least two isocyanate groups, such as a known aliphatic polyisocyanate, alicyclic polyisocyanate, or aromatic polyisocyanate, which is generally used in urethanization reactions.

[0094] Any peroxide can be used as long as it generates radical active species upon heating or light irradiation and promotes crosslinking of the base polymer of the pressure-sensitive adhesive composition. Taking into consideration workability and stability, it is preferable to use a peroxide with a 1-minute half-life temperature of 80°C to 160°C, and it is more preferable to use a peroxide with a 1-minute half-life temperature of 90°C to 140°C.

[0095] Examples of peroxides that can be used include di(2-ethylhexyl)peroxydicarbonate (1-minute half-life temperature: 90.6°C), di(4-t-butylcyclohexyl)peroxydicarbonate (1-minute half-life temperature: 92.1°C), di-sec-butylperoxydicarbonate (1-minute half-life temperature: 92.4°C), t-butylperoxyneodecanoate (1-minute half-life temperature: 103.5°C), t-hexylperoxypivalate (1-minute half-life temperature: 109.1°C), t-butylperoxypivalate (1-minute half-life temperature: 110.3°C), dilauroylperoxydicarbonate (1-minute half-life temperature: 111.5°C), diisopropylperoxydicarbonate (1-minute half-life temperature: 112.5°C), diisopropylperoxydicarbonate (1-minute half-life temperature: 113.5°C), diisopropylperoxydicarbonate (1-minute half-life temperature: 114.5°C), diisopropylperoxydicarbonate (1-minute half-life temperature: 115.5°C), diisopropylperoxydicarbonate (1-minute half-life temperature: 116.5°C), diisopropylperoxydicarbonate (1-minute half-life temperature: 117.5°C), diisopropylperoxydicarbonate (1-minute half-life temperature: 118.5°C), diisopropylperoxydicarbonate (1-minute half-life temperature: 119.5°C), diisopropylperoxydicarbonate (1-minute half-life temperature: 120.5°C), diisopropylperoxydicarbonate (1-minute half-life temperature: 121.5°C), diisopropylperoxydicarbonate (1-minute half-life temperature: 122.5°C), diisopropylperoxydicarbonate (1-minute half- peroxide (1-minute half-life temperature: 116.4°C), di-n-octanoyl peroxide (1-minute half-life temperature: 117.4°C), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (1-minute half-life temperature: 124.3°C), di(4-methylbenzoyl)peroxide (1-minute half-life temperature: 128.2°C), dibenzoyl peroxide (1-minute half-life temperature: 130.0°C), t-butylperoxyisobutyrate (1-minute half-life temperature: 136.1°C), 1,1-di(t-hexylperoxy)cyclohexane (1-minute half-life temperature: 149.2°C), and the like. Among these, di(4-t-butylcyclohexyl) peroxydicarbonate (1-minute half-life temperature: 92.1°C), dilauroyl peroxide (1-minute half-life temperature: 116.4°C), dibenzoyl peroxide (1-minute half-life temperature: 130.0°C), etc. are preferably used because of their particularly excellent crosslinking reaction efficiency.

[0096] The amount of crosslinking agent (C) used is preferably 3 parts by weight or less, more preferably 0.01 to 3 parts by weight, even more preferably 0.02 to 2 parts by weight, and even more preferably 0.03 to 1 part by weight, per 100 parts by weight of the (meth)acrylic polymer (A). If the amount of crosslinking agent (C) is less than 0.01 part by weight, the pressure-sensitive adhesive layer may be insufficiently crosslinked, and durability and adhesive properties may not be satisfactory. On the other hand, if the amount is more than 3 parts by weight, the pressure-sensitive adhesive layer may become too hard, and durability may tend to decrease.

[0097] The pressure-sensitive adhesive composition of the present invention may contain a silane coupling agent (D). Use of the silane coupling agent (D) can improve durability. Specific examples of silane coupling agents include epoxy group-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino group-containing silane coupling agents such as 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, and N-phenyl-γ-aminopropyltrimethoxysilane; (meth)acrylic group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane; and isocyanate group-containing silane coupling agents such as 3-isocyanatepropyltriethoxysilane. Of the silane coupling agents exemplified above, epoxy group-containing silane coupling agents are preferred.

[0098] Furthermore, as the silane coupling agent (D), one having multiple alkoxysilyl groups in the molecule can also be used. Specific examples include X-41-1053, X-41-1059A, X-41-1056, X-41-1805, X-41-1818, X-41-1810, and X-40-2651 manufactured by Shin-Etsu Chemical Co., Ltd. These silane coupling agents having multiple alkoxysilyl groups in the molecule are preferred because they are less likely to volatilize and, due to the presence of multiple alkoxysilyl groups, are effective in improving durability. Durability is particularly favorable even when the adherend of the optical film with a pressure-sensitive adhesive layer is a transparent conductive layer (e.g., ITO, etc.), which is less susceptible to reaction with alkoxysilyl groups than glass. Furthermore, silane coupling agents having multiple alkoxysilyl groups in the molecule preferably have epoxy groups in the molecule, and more preferably have multiple epoxy groups in the molecule. Silane coupling agents having multiple alkoxysilyl groups and epoxy groups in the molecule tend to have good durability even when the adherend is a transparent conductive layer (e.g., ITO, etc.) Specific examples of silane coupling agents having multiple alkoxysilyl groups and epoxy groups in the molecule include X-41-1053, X-41-1059A, and X-41-1056 manufactured by Shin-Etsu Chemical Co., Ltd., and X-41-1056, which has a high epoxy group content, is particularly preferred.

[0099] The silane coupling agent (D) may be used alone or in combination of two or more, but the total content is preferably 5 parts by weight or less, more preferably 0.001 to 5 parts by weight, even more preferably 0.01 to 1 part by weight, even more preferably 0.02 to 1 part by weight, and even more preferably 0.05 to 0.6 parts by weight, relative to 100 parts by weight of the (meth)acrylic polymer (A). This is an amount that improves durability.

[0100] The pressure-sensitive adhesive composition of the present invention may further contain other known additives, such as polyether compounds having reactive silyl groups, polyether compounds of polyalkylene glycols such as polypropylene glycol, colorants, powders such as pigments, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, antiaging agents, light stabilizers, UV absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, particulate or foil-like materials, etc., which can be added as appropriate depending on the intended use. Furthermore, a redox system in which a reducing agent is added may be employed within a controllable range. These additives are preferably used in an amount of 5 parts by weight or less, more preferably 3 parts by weight or less, or even 1 part by weight or less per 100 parts by weight of the (meth)acrylic polymer (A).

[0101] The pressure-sensitive adhesive layer can be formed, for example, by applying the pressure-sensitive adhesive composition to a release-treated separator or the like, drying and removing the polymerization solvent, etc. to form a pressure-sensitive adhesive layer, and then transferring the layer to an optical film (polarizing film), or by applying the pressure-sensitive adhesive composition to an optical film (polarizing film), drying and removing the polymerization solvent, etc. to form a pressure-sensitive adhesive layer on the optical film, etc. When applying the pressure-sensitive adhesive, one or more solvents other than the polymerization solvent may be added as appropriate.

[0102] The thickness of the pressure-sensitive adhesive layer is not particularly limited and is, for example, about 1 to 100 μm, preferably 2 to 50 μm, more preferably 2 to 40 μm, and even more preferably 5 to 35 μm.

[0103] The pressure-sensitive adhesive layer used in the pressure-sensitive adhesive layer-attached polarizing film of the present invention preferably has a creep value at 85°C of 120 μm or less, more preferably 100 μm or less, even more preferably 85 μm or less, and particularly preferably 60 μm or less, from the viewpoint of application to irregularly shaped polarizing films. The lower limit of the creep value is preferably 15 μm or more, more preferably 30 μm or more. If the creep value exceeds 120 μm, cracks that occur in irregularly shaped polarizing films may worsen, as described in the Examples. If the creep value is below 15 μm, the stress relaxation property of the pressure-sensitive adhesive layer may be reduced, and peeling of the pressure-sensitive adhesive layer may be more likely to occur in durability tests.

[0104] <Transparent layer> The transparent layer will be described in detail below.

[0105] From the viewpoints of thinning and optical reliability, the thickness of the transparent layer is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less, even more preferably 1.5 μm or less, and even more preferably 1 μm or less. If the transparent layer is too thick, the thickness of the polarizing film will increase, which may further reduce the optical reliability of the polarizer. On the other hand, from the viewpoint of minimizing the fluctuation ratio of the surface resistance value of the pressure-sensitive adhesive layer, the thickness of the transparent layer is preferably 0.1 μm or more, more preferably 0.2 μm or more, and even more preferably 0.3 μm or more.

[0106] The transparent layer may be formed from a material that is transparent and can suppress the influence of the conductive layer on the polarizer, such as a material containing a urethane prepolymer (a) that is a reaction product of an isocyanate compound and a polyhydric alcohol.

[0107] As the isocyanate compound, for example, a polyfunctional isocyanate compound is preferable, and specific examples thereof include a polyfunctional aromatic isocyanate compound, an alicyclic isocyanate compound, an aliphatic isocyanate compound, or a dimer thereof.

[0108] Examples of polyfunctional aromatic isocyanate compounds include phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate, methylene bis-4-phenyl isocyanate, and p-phenylene diisocyanate.

[0109] Examples of polyfunctional alicyclic isocyanate compounds include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-bisisocyanatomethylcyclohexane, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated tetramethylxylylene diisocyanate.

[0110] Examples of polyfunctional aliphatic isocyanate compounds include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.

[0111] Furthermore, examples of polyfunctional isocyanate compounds include those having three or more isocyanate groups, such as tris(6-isocyanatehexyl) isocyanurate.

[0112] Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 1,8-decanediol, octadecanediol, glycerin, trimethylolpropane, pentaerythritol, hexanetriol, and polypropylene glycol.

[0113] In the present invention, the urethane prepolymer (a) preferably has a rigid molecular structure in which cyclic structures (such as benzene rings, cyanurate rings, and isocyanurate rings) account for a large proportion of the structure. For example, the polyfunctional isocyanate compounds can be used alone or in combination of two or more, but aromatic isocyanate compounds are preferred from the viewpoint of preventing moisture from entering the polarizer. Other polyfunctional isocyanate compounds can be used in combination with aromatic isocyanate compounds. Among aromatic isocyanate compounds, it is particularly preferred to use at least one selected from the group consisting of tolylene diisocyanate and diphenylmethane diisocyanate as the isocyanate compound.

[0114] As the urethane prepolymer (a), trimethylolpropane-tri-tolylene isocyanate or trimethylolpropane-tri-diphenylmethane diisocyanate is preferably used. The urethane prepolymer (a) is a compound having a terminal isocyanate group, and can be obtained, for example, by mixing an isocyanate compound with a polyhydric alcohol, stirring the mixture, and allowing it to react. Usually, it is preferable to mix the isocyanate compound with the polyhydric alcohol so that the isocyanate groups are in excess relative to the hydroxyl groups of the polyhydric alcohol.

[0115] The urethane prepolymer (a) may have a terminal isocyanate group protected by a protecting group. Examples of the protecting group include oxime and lactam. When the isocyanate group is protected, the protecting group is dissociated from the isocyanate group by heating, allowing the isocyanate group to react.

[0116] The transparent layer forming material may contain, in addition to the urethane prepolymer (a), a compound (b) having at least two functional groups containing active hydrogen that are reactive with isocyanate groups. Examples of functional groups containing active hydrogen that are reactive with isocyanate groups include hydroxyl groups and amino groups. The more functional groups containing active hydrogen that the compound (b) has, the more reaction sites there are with the isocyanate groups of the urethane prepolymer (a), making it easier to form a cured product. Therefore, the number of functional groups is preferably 3 or more.

[0117] Furthermore, it is preferable that the value obtained by dividing the molecular weight of compound (b) by the number of functional groups is not more than 350. By defining the relationship between the molecular weight and the number of functional groups in this way, it is possible to ensure the reactivity between compound (b) and the isocyanate groups of urethane prepolymer (a).

[0118] The molecular weight of the compound (b) is preferably not more than 1000. Compound (b) having a molecular weight of not more than 1000 is preferred in terms of compatibility when preparing a solution of the forming material together with the urethane prepolymer (a).

[0119] Examples of the compound (b) include polyhydric alcohols, polyhydric amines, and compounds having a hydroxyl group and an amino group in the molecule.

[0120] Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, and 1,8-decanediol. , octadecanediol, polypropylene glycol, and other difunctional alcohols; glycerin, trimethylolpropane, and other trifunctional alcohols; pentaerythritol, hexanetriol, sorbitol, and other tetrafunctional alcohols; and other alkylene oxide (e.g., propylene oxide) adducts of the above polyhydric alcohols, such as polyoxypropylene glyceryl ether, polyoxypropylene trimethylolpropane ether, and polyoxypropylene sorbitol ether.

[0121] Examples of polyvalent amines include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, and dimer diamine.

[0122] Furthermore, examples of compounds having a hydroxyl group and an amino group in the molecule include diamines having a hydroxyl group in the molecule, such as 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, and di-2-hydroxypropylethylenediamine; Examples of the alkanolamines include ethanolamine, diethanolamine, and triethanolamine.

[0123] As the compound (b), it is preferable to use a polyhydric alcohol in order to prevent deterioration of the optical reliability of the polarizer, and in particular, trimethylolpropane is preferable in terms of reactivity with the urethane prepolymer (a).

[0124] The forming material contains the urethane prepolymer (a) as a main component, and the urethane prepolymer (a) preferably accounts for 50% by weight or more of the solid content of the forming material.

[0125] The blending ratio of the compound (b) to the urethane prepolymer (a) is preferably 5% by weight or more, with the total of the urethane prepolymer (a) and the compound (b) being 100% by weight (solid content ratio). From the viewpoint of improving film strength, the blending ratio of the compound (b) is preferably 10% by weight or more. On the other hand, since a high blending ratio of the compound (b) may cause a deterioration in the optical reliability of the polarizer, the blending ratio of the compound (b) is preferably 80% by weight or less, and more preferably 50% by weight or less.

[0126] The forming material can further use a reaction catalyst to increase the reactivity of the isocyanate group. The reaction catalyst is not particularly limited, but a tin-based catalyst or an amine-based catalyst is preferred. One or more reaction catalysts can be used. The amount of reaction catalyst used is usually 5 parts by weight or less per 100 parts by weight of the urethane prepolymer (a). If the amount of reaction catalyst is too large, the crosslinking reaction rate increases, causing foaming of the forming material. Even if the foamed forming material is used, sufficient adhesion cannot be obtained. When a reaction catalyst is used, the amount is usually 0.01 to 5 parts by weight, preferably 0.05 to 4 parts by weight.

[0127] Furthermore, a reaction catalyst can be used to increase the reactivity of the isocyanate group. There are no particular restrictions on the reaction catalyst, but tin-based catalysts or amine-based catalysts are preferred. One or more reaction catalysts can be used. The amount of reaction catalyst used is usually 5 parts by weight or less per 100 parts by weight of urethane prepolymer. If the amount of reaction catalyst is too high, the crosslinking reaction rate increases, causing foaming of the forming material. Even if the foamed forming material is used, sufficient adhesion cannot be obtained. When a reaction catalyst is used, the amount is usually 0.01 to 5 parts by weight, and preferably 0.05 to 4 parts by weight.

[0128] As the tin-based catalyst, either inorganic or organic can be used, but organic catalysts are preferred. Examples of inorganic tin-based catalysts include stannous chloride and stannic chloride. Preferred organic tin-based catalysts are those having at least one organic group, such as an aliphatic group or an alicyclic group, having a skeleton such as a methyl group, an ethyl group, an ether group, or an ester group. Examples include tetra-n-butyltin, tri-n-butyltin acetate, n-butyltin trichloride, trimethyltin hydroxide, dimethyltin dichloride, and dibutyltin dilaurate.

[0129] The amine catalyst is not particularly limited. For example, those having at least one organic group such as an alicyclic group, such as quinoclidine, amidine, or diazabicycloundecene, are preferred. Other examples of the amine catalyst include triethylamine. Other examples of the reaction catalyst include cobalt naphthenate and benzyltrimethylammonium hydroxide.

[0130] The forming material is usually used as a solution containing the urethane prepolymer (a) and the compound (b). The solution may be a solvent-based solution or a water-based solution such as an emulsion, a colloidal dispersion, or an aqueous solution.

[0131] The organic solvent is not particularly limited as long as it does not have a functional group having an active hydrogen reactive with an isocyanate group and can uniformly dissolve the urethane prepolymer (a) and the compound (b) that constitute the forming material. One or more organic solvents can be used in combination. Separate organic solvents can be used for the urethane prepolymer (a) and the compound (b). In this case, the forming material can be prepared by preparing each solution and then mixing the solutions. The viscosity of the forming material can be adjusted by adding an organic solvent to the prepared forming material. Furthermore, in the case of a solvent-based solution in which the material is dissolved in an organic solvent, the following alcohols, water, etc. can also be included as a solvent.

[0132] Examples of organic solvents include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic or alicyclic hydrocarbons such as hexane, cyclohexane, and methylcyclohexane; halogenated alkanes such as 1,2-dichloroethane; ethers such as tert-butyl methyl ether; and ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, and acetylacetone.

[0133] When making it a water-based system, for example, alcohols such as n-butyl alcohol and isopropyl alcohol, and ketones such as acetone can be blended in. When making it a water-based system, a dispersant can be used, or a water-dispersible component such as polyethylene glycol or a functional group that has low reactivity with an isocyanate group, such as a carboxylate, sulfonate, or quaternary ammonium salt, can be introduced into the urethane prepolymer.

[0134] Examples of materials for forming the transparent layer other than the urethane prepolymer include cyanoacrylate-based forming materials, epoxy-based forming materials, and urethane acrylate-based forming materials.

[0135] The formation of the transparent layer can be appropriately selected depending on the type of the forming material. For example, the transparent layer can be formed by applying the forming material to a polarizer or the like and then curing it, and the transparent layer can be obtained as a coated layer. Typically, after the application, the cured layer is formed by drying at about 30 to 100°C, preferably 50 to 80°C, for about 0.5 to 15 minutes. Furthermore, when the forming material contains an isocyanate component, an annealing treatment can be performed at about 30 to 100°C, preferably 50 to 80°C, for about 0.5 to 24 hours to promote the reaction.

[0136] <Image display panel, image display device> The pressure-sensitive adhesive layer-attached polarizing film of the present invention can be applied to various image display panels, and the image display panel can be applied to conventional image display devices. Other configurations of the image display device are the same as those of conventional image display devices. Specific examples of image display devices to which the image display panel can be applied include liquid crystal display devices, electroluminescence (EL) displays, plasma displays (PDs), field emission displays (FEDs), etc.

[0137] The pressure-sensitive adhesive layer-attached polarizing film of the present invention has a small fluctuation ratio of the surface resistance value, and is suitable for application to a liquid crystal panel with a built-in touch sensing function.

[0138] Furthermore, in addition to the above configuration, the liquid crystal panel may be provided with optical films such as a retardation film, a viewing angle compensation film, and a brightness enhancement film as appropriate.

[0139] The liquid crystal layer is not particularly limited, and any type can be used, such as TN type, STN type, π type, VA type, IPS type, etc. The transparent substrate 9 (light source side) may be a transparent substrate, and its material is not particularly limited, but examples thereof include glass and transparent resin film substrates. Examples of transparent resin film substrates include those described above.

[0140] On the light source side of the liquid crystal layer, a polarizing film with a pressure-sensitive adhesive layer that has been conventionally used in this field can be used, and the film described in this specification can also be suitably used.

[0141] Specific examples of the above-mentioned liquid crystal panel with built-in touch sensing function are shown in, for example, Figures 6 to 8. Figures 6 to 8 illustrate a case in which the pressure-sensitive adhesive layer-attached polarizing film 1 shown in Figure 1 (however, the conductive layer c is omitted) is used on the viewing side of a liquid crystal cell as the pressure-sensitive adhesive layer-attached polarizing film of the present invention. That is, the one-sided protected polarizing film 11 and the pressure-sensitive adhesive layer 21 in Figure 1 are shown as the first polarizing film 11 and the first pressure-sensitive adhesive layer 21 in Figures 6 to 8.

[0142] 6 shows a so-called in-cell type liquid crystal panel with built-in touch sensing function, which has a configuration from the viewing side of first polarizing film 11 / first adhesive layer 21 / first transparent substrate 41 / touch sensor section 5 / liquid crystal layer 3 / drive electrode and sensor section 6 / second transparent substrate 42 / second adhesive layer 22 / second polarizing film 12. In the in-cell type liquid crystal panel with built-in touch sensing function of FIG. 6, for example, liquid crystal cell C has touch sensor section 5 and drive electrode and sensor section 6 inside first and second glass substrates 41 and 42 (inside the liquid crystal cell) that sandwich liquid crystal layer 3.

[0143] 7 shows a modified example of a so-called in-cell type (semi-in-cell type) liquid crystal panel with built-in touch sensing function, which has a configuration, from the viewing side, of first polarizing film 11 / first adhesive layer 21 / touch sensor unit 5 / first transparent substrate 41 / liquid crystal layer 3 / drive electrode and sensor unit 6 / second transparent substrate 42 / second adhesive layer 22 / second polarizing film 12. In the in-cell type liquid crystal panel with built-in touch sensing function of Fig. 7, for example, the liquid crystal cell C is on the outside of the first transparent substrate 41, and the touch sensor unit 5 is in direct contact with the first adhesive layer 21, and the drive electrode and sensor unit 6 is located on the side of the second transparent substrate 42 within the first and second glass substrates 41 and 42 (inside the liquid crystal cell) that sandwich the liquid crystal layer 3.

[0144] 8 shows a so-called on-cell type liquid crystal panel with built-in touch sensing function, which has a configuration, from the viewing side, of first polarizing film 11, first adhesive layer 21, touch sensor section 5, drive electrode / sensor section 6, first transparent substrate 41, liquid crystal layer 3, drive electrode 7, second transparent substrate 42, second adhesive layer 22, and second polarizing film 12. In the on-cell type liquid crystal panel with built-in touch sensing function of Fig. 8, for example, liquid crystal cell C has touch sensor section 5 and drive electrode / sensor section 6 on the outside of first transparent substrate 41, touch sensor section 5 is in direct contact with first adhesive layer 21, and has drive electrode 7 on the side of second transparent substrate 42 within first and second glass substrates 41 and 42 (inside the liquid crystal cell) that sandwich liquid crystal layer 3.

[0145] In a liquid crystal panel with built-in touch sensing function, when the touch sensor section 5 of the liquid crystal cell C is in direct contact with the first adhesive layer 21, the antistatic function of the first adhesive layer 21 (containing an ionic compound) is likely to deteriorate, particularly in a humid environment. Therefore, the liquid crystal panel with built-in touch sensing function of the present invention is suitably applied to an in-cell type (modified example) liquid crystal panel with built-in touch sensing function shown in Fig. 7 or an on-cell type liquid crystal panel with built-in touch sensing function shown in Fig. 8, among the above examples.

[0146] The first polarizing film 11, which is disposed on the viewing side of the liquid crystal cell C, and the second polarizing film 12, which is disposed on the opposite side to the viewing side, may be laminated with other optical films depending on the suitability of their respective locations. Examples of the other optical films include optical layers that may be used in forming liquid crystal displays, such as reflectors, anti-transmitting films, retardation films (including half-wave and quarter-wave plates), visual compensation films, and brightness enhancement films. These may be used in one layer or in two or more layers. Even when using these other optical films, it is preferable that the pressure-sensitive adhesive layer closest to the liquid crystal layer 3 be the first pressure-sensitive adhesive layer 21.

[0147] The liquid crystal layer 3 of the liquid crystal cell C is a liquid crystal layer containing liquid crystal molecules that are homogeneously aligned in the absence of an electric field, which is applicable to liquid crystal panels with built-in touch sensing functions. An IPS type liquid crystal layer is preferably used as the liquid crystal layer 3. Alternatively, any type of liquid crystal layer, such as a TN type, STN type, π type, or VA type, can be used as the liquid crystal layer 3. The thickness of the liquid crystal layer is, for example, approximately 1.5 μm to 4 μm.

[0148] In the liquid crystal cell C, the first transparent substrate 41 and the second transparent substrate 42 can sandwich the liquid crystal layer 3 to form a liquid crystal cell. Depending on the form of the liquid crystal panel with built-in touch sensing function, a touch sensor section 5, a drive electrode / sensor section 6, a drive electrode 7, etc. are formed inside or outside the liquid crystal cell. In addition, a color filter substrate can be provided on the liquid crystal cell (first transparent substrate 41).

[0149] Examples of materials for forming the transparent substrate include glass and polymer films. Examples of the polymer films include polyethylene terephthalate, polycycloolefin, and polycarbonate. When the transparent substrate is formed from glass, its thickness is, for example, about 0.3 mm to 1 mm. When the transparent substrate is formed from a polymer film, its thickness is, for example, about 10 μm to 200 μm. The transparent substrate may have an easy-adhesion layer or a hard coat layer on its surface.

[0150] The touch sensor unit 5 (capacitive sensor), the driving electrode / sensor unit 6, and the driving electrode 7 are formed as a transparent conductive layer. The material of the transparent conductive layer is not particularly limited, and examples thereof include metals such as gold, silver, copper, platinum, palladium, aluminum, nickel, chromium, titanium, iron, cobalt, tin, magnesium, and tungsten, as well as alloys of these metals. Examples of materials for the transparent conductive layer include metal oxides of indium, tin, zinc, gallium, antimony, zirconium, and cadmium. Specific examples include metal oxides of indium oxide, tin oxide, titanium oxide, cadmium oxide, and mixtures thereof. Other metal compounds such as copper iodide can also be used. The metal oxides may further contain oxides of metal atoms listed in the above group, if necessary. For example, indium oxide (ITO) containing tin oxide and tin oxide containing antimony are preferably used, with ITO being particularly preferred. ITO preferably contains 80 to 99% by weight of indium oxide and 1 to 20% by weight of tin oxide.

[0151] The touch sensor layer 5 may be formed at any location in the liquid crystal cell C, depending on the configuration of the touch-sensing liquid crystal panel. For example, FIGS. 6 to 8 illustrate a case in which the touch sensor layer 5 is disposed between the first polarizing film 11 and the liquid crystal layer 3. The touch sensor layer 5 may be formed, for example, as a transparent electrode pattern on the first transparent substrate 41. Transparent electrode patterns for the drive electrode / sensor unit 6 and the drive electrode 7 may also be formed according to a conventional method depending on the configuration of the touch-sensing liquid crystal panel. The transparent electrode pattern is typically electrically connected to wiring (not shown) formed at the edge of the transparent substrate, and the wiring is connected to a controller IC (not shown). The transparent electrode pattern may have any shape, such as a comb shape, stripe shape, or diamond shape, depending on the application. The height of the transparent electrode pattern is, for example, 10 nm to 100 nm, and the width is 0.1 mm to 5 mm.

[0152] Furthermore, the liquid crystal panel with built-in touch sensing function can appropriately use components forming a liquid crystal display device, such as a device using a backlight or a reflector as an illumination system. [Example]

[0153] The present invention will be described in detail below using examples, but the present invention is not limited to these examples. In each example, parts and percentages are all by weight. Unless otherwise specified below, the room temperature storage conditions are all 23°C and 65% RH.

[0154] <Measurement of Weight Average Molecular Weight of (Meth)acrylic Polymer (A)> The weight average molecular weight (Mw) of the (meth)acrylic polymer (A) was measured by GPC (gel permeation chromatography). Mw / Mn was also measured in the same manner. Analytical equipment: Tosoh HLC-8120GPC Column: Tosoh G7000H XL +GMH XL +GMH XL Column size: 7.8mm diameter x 30cm each, total 90cm Column temperature: 40℃ ·Flow rate: 0.8mL / min ·Injection volume: 100μL Eluent: tetrahydrofuran Detector: Differential refractometer (RI) Standard sample: Polystyrene

[0155] <Production Example 1> (Preparation of 40 μm TAC film with HC and 25 μm TAC film with HC) A resin solution (DIC Corporation, product name: Unidic 17-806, solids concentration: 80%) containing a UV-curable resin monomer or oligomer primarily composed of urethane acrylate dissolved in butyl acetate was prepared. Five parts of a photopolymerization initiator (BASF Ltd., product name: IRGACURE 907) and 0.1 parts of a leveling agent (DIC Corporation, product name: GRANDIC PC4100) were added per 100 parts of solids in the solution. Cyclopentanone and propylene glycol monomethyl ether were then added to the solution in a 45:55 ratio to achieve a solids concentration of 36%, thereby preparing a hard coat layer-forming material. The prepared hard coat layer-forming material was applied to a TJ40UL (Fujifilm Corporation, raw material: triacetyl cellulose-based polymer, thickness: 40 μm) to form a coating film, resulting in a hard coat layer thickness of 7 μm after curing. The coating was then dried at 90°C for 1 minute and then irradiated with a high-pressure mercury lamp at an integrated light intensity of 300 mJ / cm 2 The coating film was irradiated with ultraviolet light of 1000 kJ / cm, and the coating film was cured to form a hard coat layer (HC), thereby producing a 40 μm TAC film with HC. Similarly, a hard coat layer (HC) with a thickness of 7 μm was formed on TJ25UL (manufactured by Fujifilm, raw material: triacetyl cellulose polymer, thickness: 25 μm) to produce a 25 μm TAC film with HC.

[0156] <Production Example 2> (Preparation of 30 μm acrylic film) A 30-L kettle reactor equipped with a stirrer, temperature sensor, condenser, and nitrogen inlet tube was charged with 8,000 g of methyl methacrylate (MMA), 2,000 g of methyl 2-(hydroxymethyl)acrylate (MHMA), 10,000 g of 4-methyl-2-pentanone (methyl isobutyl ketone, MIBK), and 5 g of n-dodecyl mercaptan. The mixture was heated to 105°C while nitrogen was passed through it. Once refluxed, 5.0 g of t-butylperoxyisopropyl carbonate (Kayacarvone BIC-7, manufactured by Kayaku Akzo Co., Ltd.) was added as a polymerization initiator. At the same time, a solution consisting of 10.0 g of t-butylperoxyisopropyl carbonate and 230 g of MIBK was added dropwise over 4 hours. Solution polymerization was carried out at approximately 105-120°C under reflux, and the mixture was then aged for another 4 hours. To the resulting polymer solution, 30 g of a stearyl phosphate / distearyl phosphate mixture (Phoslex A-18, Sakai Chemical Industry Co., Ltd.) was added, and a cyclization condensation reaction was carried out under reflux at approximately 90 to 120°C for 5 hours. The resulting polymer solution was then introduced into a vent-type twin-screw extruder (φ=29.75 mm, L / D=30) with a barrel temperature of 260°C, a rotation speed of 100 rpm, a vacuum of 13.3 to 400 hPa (10 to 300 mmHg), one rear vent, and four fore vents at a processing rate of 2.0 kg / h (equivalent to resin amount). Further cyclization condensation reaction and devolatilization were carried out in this extruder, and transparent pellets of the lactone ring-containing polymer were obtained by extrusion. Dynamic TG measurement of the resulting lactone ring-containing polymer revealed a mass loss of 0.17% by mass, and the lactone ring-containing polymer had a weight-average molecular weight of 133,000, a melt flow rate of 6.5 g / 10 min, and a glass transition temperature of 131°C. The pellets were mixed and extruded with acrylonitrile-styrene (AS) resin (Toyo ASAS20, manufactured by Toyo Styrene Co., Ltd.) in a mass ratio of 90 / 10 using a single-screw extruder (screw diameter: 30 mm) to obtain transparent pellets. The glass transition temperature of the pellets was 127°C. The pellets were melt-extruded through a 400 mm wide coat hanger-type T-die using a 50 mm diameter single-screw extruder to produce a 120 μm thick film. The film was stretched 2.0 times longitudinally and 2.0 times laterally at 150°C using a biaxial stretching device to produce a 30 μm thick stretched film (30 μm acrylic film). The optical properties of this stretched film were measured, revealing a total light transmittance of 93%, an in-plane retardation Δnd of 0.8 nm, and a thickness direction retardation Rth of 1.5 nm.

[0157] <Preparation of Polarizing Film (1)> A 45 μm-thick polyvinyl alcohol film was stretched 3 times between rolls with different speed ratios while dyeing in a 0.3% iodine solution at 30°C for 1 minute. It was then immersed in an aqueous solution containing 4% boric acid and 10% potassium iodide at 60°C for 0.5 minutes, during which it was stretched to a total stretch ratio of 6 times. The film was then washed by immersion in an aqueous solution containing 1.5% potassium iodide at 30°C for 10 seconds, and then dried at 50°C for 4 minutes to obtain a polarizer with a thickness of 18 μm. A saponified 40 μm TAC film (triacetyl cellulose film side) obtained in Production Example 1 was attached to one side of the polarizer, and a 30 μm acrylic film obtained in Production Example 2 was attached to the other side using a polyvinyl alcohol-based adhesive, to produce a polarized film (1).

[0158] <Preparation of Polarizing Film (2)> (Fabrication of thin polarizer A) One side of an amorphous isophthalic acid copolymerized polyethylene terephthalate (IPA copolymerized PET) film (thickness: 100 μm) substrate with a water absorption rate of 0.75% and a Tg of 75°C was subjected to a corona treatment. An aqueous solution containing polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetoacetyl-modified PVA (degree of polymerization 1200, degree of acetoacetyl modification 4.6%, degree of saponification 99.0 mol% or more, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOHSEFIMER Z200") in a ratio of 9:1 was applied to this corona-treated surface and dried at 25°C to form an 11 μm-thick PVA-based resin layer, producing a laminate. The resulting laminate was uniaxially stretched at its free end to 2.0 times its original size in the machine direction (longitudinal direction) between rolls with different peripheral speeds in an oven at 120°C (auxiliary in-air stretching treatment). Next, the laminate was immersed in an insolubilizing bath (a boric acid aqueous solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 30°C for 30 seconds (insolubilizing treatment). Next, the polarizing plate was immersed in a dye bath at a liquid temperature of 30° C., while adjusting the iodine concentration and immersion time so that the polarizing plate would have a predetermined transmittance. In this example, the polarizing plate was immersed for 60 seconds in an iodine aqueous solution obtained by blending 0.2 parts by weight of iodine and 1.0 part by weight of potassium iodide with 100 parts by weight of water (dyeing treatment). Next, the sample was immersed in a crosslinking bath (a boric acid aqueous solution obtained by blending 3 parts by weight of potassium iodide and 3 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 30°C for 30 seconds (crosslinking treatment). Thereafter, the laminate was immersed in a boric acid aqueous solution (aqueous solution obtained by blending 4 parts by weight of boric acid and 5 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 70°C, and uniaxially stretched in the longitudinal direction (longitudinal direction) between rolls with different peripheral speeds so that the total stretch ratio was 5.5 times (underwater stretching treatment). Thereafter, the laminate was immersed in a cleaning bath (aqueous solution obtained by mixing 4 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 30° C. (cleaning treatment). As a result, an optical film laminate including a polarizer with a thickness of 5 μm was obtained.

[0159] (Preparation of adhesive to be applied to transparent protective film) An ultraviolet-curable adhesive was prepared by mixing 45 parts by weight of acryloylmorpholine, 45 parts of 1,9-nonanediol diacrylate, 10 parts of an acrylic oligomer obtained by polymerizing a (meth)acrylic monomer (ARUFONUP1190, manufactured by Toagosei Co., Ltd.), 3 parts of a photopolymerization initiator (IRGACURE 907, manufactured by BASF), and 1.5 parts of a polymerization initiator (KAYACURE DETX-S, manufactured by Nippon Kayaku Co., Ltd.).

[0160] <Preparation of Polarizing Film (2)> The UV-curable adhesive was applied to the surface of polarizer A of the optical film laminate so that the thickness of the adhesive layer after curing would be 1 μm, and the 25 μm TAC film (triacetyl cellulose film side) with HC obtained in Production Example 1 was laminated thereon. The adhesive was then cured by irradiating with UV rays as active energy rays. The UV irradiation was performed using a gallium-filled metal halide lamp, an irradiation device: Light HAMMER 10 manufactured by Fusion UV Systems, Inc., a V bulb, and a peak irradiance of 1600 mW / cm. 2 , cumulative irradiation dose 1000 / mJ / cm 2 The ultraviolet ray intensity was measured using a Sola-Check system manufactured by Solatell. The amorphous PET substrate was then peeled off to produce a polarized film (2) using a thin polarizer. The optical properties of the resulting polarized film were a single transmittance of 42.8% and a polarization degree of 99.99%.

[0161] <Preparation of transparent layer-attached polarizing film (2)> The transparent layer forming material described below was applied to the polarizer surface of the above polarizing film (2) (the polarizer surface on which the 25 μm TAC film with HC was not provided) using a bar coater, and then heat-treated at 60°C for 12 hours to form a urethane resin layer with a thickness of 3 μm, thereby producing a polarizing film with a transparent layer (2).

[0162] <Transparent layer forming material> As the solution of urethane prepolymer (a), a 75% ethyl acetate solution of urethane prepolymer made of tolylene diisocyanate (TDI) and trimethylolpropane (TMP) (manufactured by Tosoh Corporation, trade name "Coronate L") was used. On the other hand, trimethylolpropane was dissolved in cyclopentanone to a solid content of 10% to prepare a trimethylolpropane solution. The above trimethylolpropane solution was added to 100 parts of a 75% ethyl acetate solution of the above urethane prepolymer (manufactured by Tosoh Corporation, trade name "Coronate L") so that the solids ratio of urethane prepolymer to trimethylolpropane was 90:10, and 0.1 parts of a dioctyltin dilaurate catalyst (manufactured by Tokyo Fine Chemical Co., Ltd., trade name "Envirizer OL-1") was further added, and a forming material (coating liquid) was prepared by adjusting the solids concentration to 10% using methyl isobutyl ketone as a solvent.

[0163] <Preparation of conductive layer forming material> A conductive layer-forming coating solution with a solids concentration of 0.5 wt% was prepared by mixing 8.6 parts of a solution containing 10 to 50 wt% thiophene-based polymer (trade name: Denatron P-580W, manufactured by Nagase ChemteX Corporation), 1 part of a solution containing an oxazoline group-containing acrylic polymer (trade name: Epocross WS-700, manufactured by Nippon Shokubai Co., Ltd.), and 90.4 parts of water. The resulting conductive layer-forming coating solution contained 0.04 wt% polythiophene-based polymer and 0.25 wt% oxazoline group-containing acrylic polymer.

[0164] Example 1 (Preparation of polarizing film with conductive layer) The conductive layer-forming coating liquid was applied to the acrylic film side of the polarizing film (1) so as to have a dry thickness of 0.06 μm, and then dried for 2 minutes at 80° C. to form a conductive layer. The obtained conductive layer contained 8 wt % and 50 wt % of a thiophene-based polymer and an oxazoline group-containing acrylic polymer, respectively.

[0165] (Preparation of Acrylic Polymer (A)) A four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with a monomer mixture containing 78.9 parts of butyl acrylate, 16 parts of phenoxyethyl acrylate, 5 parts of acrylic acid, and 0.1 parts of 4-hydroxybutyl acrylate. Furthermore, 0.1 parts of 2,2'-azobisisobutyronitrile as a polymerization initiator and 100 parts of ethyl acetate were charged to 100 parts of the monomer mixture (solid content). Nitrogen gas was introduced with gentle stirring to replace the atmosphere, and the temperature in the flask was maintained at around 55°C for 8 hours to carry out a polymerization reaction, producing an acrylic polymer solution with a weight average molecular weight (Mw) of 2.2 million and Mw / Mn = 4.0.

[0166] (Preparation of Pressure-Sensitive Adhesive Composition) A solution of an acrylic pressure-sensitive adhesive composition was prepared by blending 1 part of lithium bis(trifluoromethanesulfonyl)imide, 0.6 parts of an isocyanate crosslinking agent (Coronate L, trimethylolpropane tolylene diisocyanate, manufactured by Tosoh Corporation), 0.1 parts of benzoyl peroxide (Niper BMT, manufactured by Nippon Oil & Fats Corporation), and 0.3 parts of an epoxy group-containing silane coupling agent (X-41-1056, manufactured by Shin-Etsu Chemical Co., Ltd.) with 100 parts of the solids content of the acrylic polymer solution obtained above.

[0167] (Preparation of polarizing film with adhesive layer) Next, the solution of the acrylic pressure-sensitive adhesive composition was applied to one side of a polyethylene terephthalate film (separator film: MRF38, manufactured by Mitsubishi Chemical Polyester Film Corporation) treated with a silicone-based release agent so that the thickness of the pressure-sensitive adhesive layer after drying would be 20 μm, and the coating was dried at 155° C. for 1 minute to form a pressure-sensitive adhesive layer on the surface of the separator film. Next, the pressure-sensitive adhesive layer formed on the separator film was transferred to the conductive layer of the polarizing film (1) prepared above, thereby producing a pressure-sensitive adhesive layer-attached polarizing film.

[0168] Examples 2 to 13, Comparative Examples 1 and 2 In Example 1, as shown in Table 1, the types and proportions of the monomers used in preparing the acrylic polymer (A) were changed, and the production conditions were controlled to prepare solutions of the acrylic polymer (A) shown in Table 1.

[0169] Furthermore, pressure-sensitive adhesive layer-attached polarizing films were produced in the same manner as in Example 1, except that the type of polarizing film, whether or not a conductive layer was formed, the type or blending ratio of the ionic compound (B) used in preparing the pressure-sensitive adhesive composition, and the blending amount of the crosslinking agent were changed as shown in Table 1. When the polarizing film (2) was used as the polarizing film, a conductive layer similar to the above was formed on the polarizer surface of the polarizing film (2) (the polarizer surface on which the HC-attached 25 μm TAC film was not provided), and when the transparent layer-attached polarizing film (2) was used, a conductive layer similar to the above was formed on the transparent layer of the transparent layer-attached polarizing film (2). In Comparative Examples 1 and 2, no conductive layer was formed.

[0170] The pressure-sensitive adhesive layer-attached polarizing films obtained in the above Examples, Comparative Examples, and Reference Examples were evaluated as follows. The evaluation results are shown in Table 1.

[0171] <Surface resistance value (Ω / □): Conductive> The surface resistance of the conductive layer was measured on the conductive layer side of the polarizing film with a conductive layer before the pressure-sensitive adhesive layer was formed. The surface resistance of the pressure-sensitive adhesive layer was measured on the surface of the pressure-sensitive adhesive layer formed on the separator film. The measurement was performed using an MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd.

[0172] <Creep value measurement> The upper end portion (10 mm × 10 mm) of a polarizing film with an adhesive layer cut to a size of 10 mm × 30 mm (adhesive layer thickness: 20 μm) was adhered to a SUS plate through the adhesive layer and subjected to autoclave treatment at 50 °C and 5 atm for 15 minutes. A precision hot plate installed so that the heating surface was vertical was heated to 85 °C, and the SUS plate with the polarizing film with the adhesive layer adhered thereto was installed such that the surface without the adhesive layer adhered was in contact with the heating surface of the hot plate. Five minutes after starting to heat the SUS plate at 85 °C, a load of 500 g was applied to the lower end portion of the polarizing film with the adhesive layer, and the displacement width between the polarizing film with the adhesive layer and the SUS plate before and after loading the load was measured when left for 1 hour, and this displacement width was taken as the creep value (μm) at 85 °C.

[0173] <Evaluation of irregular cracks> The produced polarizing film with an adhesive layer was processed into the shape shown in Fig. 5 using a CO2 laser processing machine Spirit (manufactured by GCC, 30 W) under the conditions of a speed of 10, a laser output of 35, and 400 ppi. The irregularly processed polarizing film with an adhesive layer was bonded to a non-alkali glass (manufactured by Corning, product name "EG-XG") with a thickness of 350 mm × 250 mm × 0.7 mm, and then autoclave-treated at 50 °C and 0.5 MPa for 15 minutes to adhere the adhesive layer to the glass. The samples subjected to such treatment were put into a heat cycle test chamber, and the presence or absence of cracks generated in the irregular portions at the 100-cycle and 200-cycle points was visually confirmed. Five identical samples were put in for each condition, and the number of samples with cracks generated was described in Table 1. (Test conditions) Temperature condition: -40 °C (held for 30 minutes) ⇒ 85 °C (held for 30 minutes) is repeated as one cycle. Heating and cooling rate: 10 °C / min

[0174] <ESD test> After peeling the separator film from the adhesive layer-attached polarizing film, it was attached to the viewing side of an in-cell liquid crystal cell to create a liquid crystal panel with built-in touch sensing function. That is, the obtained adhesive layer-attached polarizing film was attached to the first transparent substrate of the in-cell liquid crystal cell shown in Figure 6 to form a first adhesive layer and a first polarizing film. An ESD (electrostatic discharge) gun (10 kV) was fired at the polarizing film surface of the liquid crystal panel, and the time until the electrically whitened areas disappeared was measured and evaluated according to the following criteria. (Evaluation criteria) A: Within 0.5 seconds. B: More than 0.5 seconds to less than 1 second. C: More than 1 second to less than 10 seconds. D: More than 10 seconds.

[0175] <Durability test> The prepared pressure-sensitive adhesive layer-attached polarizing film was cut into a size of 300 × 220 mm so that the absorption axis of the polarizing film was parallel to the long side. The pressure-sensitive adhesive layer-attached polarizing film was laminated to a 350 × 250 mm × 0.7 mm thick alkali-free glass (manufactured by Corning Incorporated, product name "EG-XG") using a laminator. The pressure-sensitive adhesive layer was then autoclaved for 15 minutes at 50 °C and 0.5 MPa to adhere the pressure-sensitive adhesive layer to the glass. The treated sample was then treated in an atmosphere of 95 °C for 500 hours, and then again in an atmosphere of 60 °C / 95% RH for 500 hours. The appearance of the sample was then visually evaluated according to the following criteria. (Evaluation criteria) A: No changes in appearance such as foaming or peeling. B: There is slight peeling or foaming at the edges, but this does not pose any problems for practical use. C: There is peeling or foaming at the edges, but this does not pose a problem for practical use unless it is for special purposes. D: Significant peeling at the edge, causing problems in practical use.

[0176] <Edge color loss evaluation> The pressure-sensitive adhesive layer-attached polarizing films obtained in the Examples and Comparative Examples were cut into 50 mm x 50 mm pieces. After peeling off the separator film, the pieces were attached to 1.2-1.5 mm thick alkali glass (microslide glass, manufactured by Matsunami Glass Co., Ltd.) via the pressure-sensitive adhesive layer to prepare samples. The samples were then stored in a high-temperature, high-humidity environment of 60°C and 90% RH for 500 hours, after which the edge color loss was measured using a differential interference microscope (manufactured by Olympus, product name "MX-61L") under the following conditions. The edge color loss was measured by measuring the distance (μm) between the corner and the diagonal line connecting the point closest to the center of the four corners of the sample that was lighter in color than the center, and the average value of the four corners was recorded as the edge color loss of the sample. Equipment: Olympus MX-61L Measurement conditions Lens magnification: 5x ISO:200 Shutter speed: 1 / 100 Reflected light amount: 0 White balance: Auto Transmitted light controller: LG-PS2 Transmitted light amount: 5 Transmitted light polarization direction: Crossed Nicol direction with respect to the polarizing film transmission axis

[0177] [Table 1]

[0178] In Table 1, BA is butyl acrylate, PEA is phenoxyethyl acrylate, AA is acrylic acid, NVP is N-vinyl-2-pyrrolidone; HBA is 4-hydroxybutyl acrylate, The isocyanate-based materials include an isocyanate crosslinking agent (Tosoh's Coronate L, trimethylolpropane tolylene diisocyanate), BPO is benzoyl peroxide (Niper BMT manufactured by Nippon Oil & Fats Co., Ltd.), Li-TFSI is lithium bis(trifluoromethanesulfonyl)imide; K-Bis(trifluoromethanesulfonyl)imide potassium TMPA-TFSI is trimethylpropylammonium bis(trifluorosulfonylimide), EMP-TFSI is ethylmethylpyrrolidinium bis(trifluorosulfonylimide), TBMA-TFSI is tributylmethylammonium bis(fluorosulfonylimide), MTOA-TFSI represents methyltrioctylammonium bis(trifluorosulfonylimide). [Explanation of symbols]

[0179] 1. Polarized film with adhesive layer 11 Protective polarizing film a Polarizer b. Protective film c conductive layer d transparent layer 21 adhesive layer 2. Chipped part (irregular part) W1 Length of the notched part D Maximum depth of chip from W1 θ1 The angle between two lines R1 Curve radius 11, 12 First and second polarizing films 21, 22 1st and 2nd adhesive layer 3 Liquid crystal layer 41, 42 1st, 2nd transparent substrate 5 Touch sensor section 6. Driving electrode and sensor section 7. Drive electrode C Liquid crystal cell

Claims

1. A pressure-sensitive adhesive layer-attached polarizing film having a polarizer and a protective film on one or both sides of the polarizer, a conductive layer, and a pressure-sensitive adhesive layer in this order, the pressure-sensitive adhesive layer-attached polarizing film has an irregularly shaped portion other than a rectangular shape when viewed from above, the pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition containing a (meth)acrylic polymer (A) and an ionic compound (B); The surface resistance of the conductive layer is 1×10 ７ ~1 x 10 １２ A polarizing film with an adhesive layer, characterized in that the resistance is Ω / □.

2. 2. The pressure-sensitive adhesive layer-attached polarizing film according to claim 1, wherein the conductive layer contains at least one selected from the group consisting of an ionic surfactant, a conductive polymer, and conductive fine particles.

3. A pressure-sensitive adhesive layer-attached polarizing film having a polarizer and a protective film on one or both sides of the polarizer, a conductive layer, and a pressure-sensitive adhesive layer in this order, the pressure-sensitive adhesive layer-attached polarizing film has an irregularly shaped portion other than a rectangular shape when viewed from above, the pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition containing a (meth)acrylic polymer (A) and an ionic compound (B); A pressure-sensitive adhesive layer-attached polarizing film, wherein the conductive layer contains carbon nanotubes.

4. The surface resistance of the conductive layer is 1×10 ７ ~1 x 10 １２ The pressure-sensitive adhesive layer-attached polarizing film according to claim 3, wherein the resistance is Ω / □.

5. The surface resistance value of the pressure-sensitive adhesive layer is 1×10 ８ ~1 x 10 １２ The pressure-sensitive adhesive layer-attached polarizing film according to any one of claims 1 to 4, wherein the resistance is Ω / □.

6. 6. The pressure-sensitive adhesive layer-attached polarizing film according to claim 1, wherein the conductive layer has a thickness of 1 μm or less.

7. 7. The pressure-sensitive adhesive layer-attached polarizing film according to claim 1, wherein the ionic compound (B) is an alkali metal salt and / or an organic cation-anion salt.

8. The pressure-sensitive adhesive layer-attached polarizing film according to any one of claims 1 to 7, characterized in that the (meth)acrylic polymer (A) contains, as monomer units, an alkyl (meth)acrylate and one or more functional group-containing monomers selected from a carboxyl group-containing monomer, a hydroxyl group-containing monomer, and an amide group-containing monomer.

9. 9. The pressure-sensitive adhesive layer-attached polarizing film according to claim 1, wherein the ionic compound (B) has a cationic component with a molecular weight of 210 or less.

10. 10. The pressure-sensitive adhesive layer-attached polarizing film according to claim 9, wherein the cationic component is a lithium ion.

11. The pressure-sensitive adhesive layer-attached polarizing film according to any one of claims 1 to 10, characterized in that it contains 0.1 to 10 parts by weight of the ionic compound (B) per 100 parts by weight of the (meth)acrylic polymer (A).

12. 12. The pressure-sensitive adhesive layer-attached polarizing film according to claim 1, wherein the protective film is any one selected from a cellulose resin film and a (meth)acrylic resin film.

13. The pressure-sensitive adhesive layer-attached polarizing film according to any one of claims 1 to 12, wherein the polarizer has a thickness of 10 µm or less.

14. The pressure-sensitive adhesive layer-attached polarizing film according to any one of claims 1 to 13, wherein the polarizing film is a one-sided protected polarizing film having a polarizer and a protective film on only one side of the polarizer.

15. The pressure-sensitive adhesive layer-attached polarizing film according to claim 14, wherein the one-sided protected polarizing film has the conductive layer on the other side of the polarizer.

16. The polarizing film with a pressure-sensitive adhesive layer according to claim 15, characterized in that the conductive layer is provided on the other side of the polarizer in the one-sided protective polarizing film, via a transparent layer with a thickness of 10 μm or less that is formed directly on the polarizer.

17. 17. The pressure-sensitive adhesive layer-attached polarizing film according to claim 16, wherein the transparent layer is a cured product of a forming material containing a urethane prepolymer, which is a reaction product of an isocyanate compound and a polyhydric alcohol.

18. 18. The pressure-sensitive adhesive layer-attached polarizing film according to claim 1, wherein the pressure-sensitive adhesive layer has a creep value of 120 μm or less at 85° C.

19. An image display panel comprising the pressure-sensitive adhesive layer-attached polarizing film according to any one of claims 1 to 18.

20. 20. The image display panel according to claim 19, wherein the adhesive layer of the adhesive layer-attached polarizing film is bonded to a liquid crystal cell with a built-in touch sensing function, the liquid crystal cell having a liquid crystal layer and a touch sensor portion.

21. An image display device comprising the image display panel according to claim 19 or 20.

Images