JP2022074622A - Polarizer and image display device - Google Patents

Abstract

To provide a polarizer which is thin even though the polarizer has a low resistance adhesive layer, which is excellent in the durability, suppresses the poor appearance and suppresses a crack in the deformation.SOLUTION: A polarizer according to an embodiment of the present invention comprises: a polarizer; a protective layer which is provided on one side of the polarizer; an iodine transmission suppression layer which is provided on the other side of the polarizer; and an adhesive layer which is provided on the side opposite to the polarizer of the iodine transmission suppression layer. The iodine transmission suppression layer is a solidified object or thermally-cured object of a coating film of an organic solvent solution of a resin. An adhesive composition constituting the adhesive layer includes a base polymer and an anti-static agent. The base polymer has the glass transition temperature equal to or less than -50°C and the dielectric constant at 100 kHz equal to or greater than 5.0. The surface resistance value of the adhesive layer is equal to or less than 1.0×109 Ω/sq.SELECTED DRAWING: Figure 1

Description

The present invention relates to a polarizing plate and an image display device using the same.

Image display devices represented by liquid crystal displays and electroluminescence (EL) display devices (for example, organic EL display devices and inorganic EL display devices) are rapidly becoming widespread. In an image display device, a polarizing plate is typically attached to a display panel via an adhesive layer. In recent years, with the narrowing of the frame of an image display device and the development of a so-called in-cell type image display device in which a conductive layer for a touch panel is incorporated in a display panel, improvement of the antistatic performance of the image display device is required. As a result, it is required to improve the antistatic performance of the pressure-sensitive adhesive layer and reduce the resistance. However, in a polarizing plate using such an adhesive layer, there are problems such as deterioration of the durability of the polarizing plate, poor appearance, and generation of cracks when the polarizing plate is processed into a deformed shape other than a rectangle.

JP-A-2015-193371

The present invention has been made to solve the above-mentioned conventional problems, and its main purpose is to have a low resistance pressure-sensitive adhesive layer, yet it is thin, has excellent durability, suppresses appearance defects, and has a low resistance pressure-sensitive adhesive layer. It is an object of the present invention to provide a polarizing plate in which cracks are suppressed during irregular shape processing.

式中、Ｒ^１はアルキル基であり、ｎは１～１５の整数である。
１つの実施形態においては、上記ベースポリマーは、モノマー成分としてヒドロキシル基含有モノマーをさらに含む。
１つの実施形態においては、上記粘着剤組成物における上記帯電防止剤の含有量は、上記ベースポリマー１００重量部に対して１０重量部以下である。
１つの実施形態においては、上記帯電防止剤はリチウムビス（トリフルオロメタンスルホニル）イミド、１－エチル－３－メチルイミダゾリウムビス（フルオロスルホニル）イミドまたはトリブチルメチルアンモニウムビス（トリフルオロメタンスルホニル）イミドを含む。
１つの実施形態においては、上記粘着剤組成物は、シランカップリング剤をさらに含む。１つの実施形態においては、上記粘着剤組成物は、酸化防止剤をさらに含む。
１つの実施形態においては、上記粘着剤層のガラスに対する粘着力は１．０Ｎ／２５ｍｍ以上である。
１つの実施形態においては、上記ヨウ素透過抑制層を構成する樹脂は、５０重量部を超える（メタ）アクリル系単量体と０重量部を超えて５０重量部未満の式（１）で表される単量体とを含むモノマー混合物を重合することにより得られる共重合体を含む：

（式中、Ｘはビニル基、（メタ）アクリル基、スチリル基、（メタ）アクリルアミド基、ビニルエーテル基、エポキシ基、オキセタン基、ヒドロキシル基、アミノ基、アルデヒド基、および、カルボキシル基からなる群より選択される少なくとも１種の反応性基を含む官能基を表し、Ｒ^１およびＲ^２はそれぞれ独立して、水素原子、置換基を有していてもよい脂肪族炭化水素基、置換基を有していてもよいアリール基、または、置換基を有していてもよいヘテロ環基を表し、Ｒ^１およびＲ^２は互いに連結して環を形成してもよい）。
１つの実施形態においては、上記偏光板は、総厚みが６０μｍ以下である。
本発明の別の局面によれば、画像表示装置が提供される。この画像表示装置は、上記の偏光板を備える。 The polarizing plate according to the embodiment of the present invention has a polarizing element, a protective layer provided on one side of the polarizing element, an iodine permeation suppressing layer provided on the other side of the polarizing element, and the iodine permeation. It has a pressure-sensitive adhesive layer provided on the opposite side of the polarizing layer of the inhibitory layer. The iodine permeation suppressing layer is a solidified product or a thermosetting product of a coating film of an organic solvent solution of a resin. The pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer contains a base polymer and an antistatic agent, and the base polymer has a glass transition temperature of −50 ° C. or lower and a dielectric constant of 5.0 or higher at 100 kHz. Yes, the surface resistance value of the pressure-sensitive adhesive layer is 1.0 × ¹⁰⁹ Ω / □ or less.
In one embodiment, the base polymer comprises an alkoxy group-containing monomer as a monomer component. In one embodiment, the base polymer contains 20 parts by weight to 99 parts by weight of the alkoxy group-containing monomer with respect to 100 parts by weight of all the monomer components. In one embodiment, the alkoxy group-containing monomer is represented by the following formula:

In the formula, R ¹ is an alkyl group and n is an integer of 1 to 15.
In one embodiment, the base polymer further comprises a hydroxyl group-containing monomer as a monomer component.
In one embodiment, the content of the antistatic agent in the pressure-sensitive adhesive composition is 10 parts by weight or less with respect to 100 parts by weight of the base polymer.
In one embodiment, the antistatic agent comprises a lithium bis (trifluoromethanesulfonyl) imide, a 1-ethyl-3-methylimidazolium bis (fluorosulfonyl) imide or a tributylmethylammonylbis (trifluoromethanesulfonyl) imide.
In one embodiment, the pressure-sensitive adhesive composition further comprises a silane coupling agent. In one embodiment, the pressure-sensitive adhesive composition further comprises an antioxidant.
In one embodiment, the adhesive force of the pressure-sensitive adhesive layer on the glass is 1.0 N / 25 mm or more.
In one embodiment, the resin constituting the iodine permeation inhibitory layer is represented by the formula (1) of more than 50 parts by weight of the (meth) acrylic monomer and more than 0 parts by weight and less than 50 parts by weight. Contains a copolymer obtained by polymerizing a monomer mixture containing a monomer:

(In the formula, X is a group consisting of a vinyl group, a (meth) acrylic group, a styryl group, a (meth) acrylamide group, a vinyl ether group, an epoxy group, an oxetane group, a hydroxyl group, an amino group, an aldehyde group, and a carboxyl group. Representing a functional group containing at least one reactive group selected, R ¹ and R ² each independently have a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, and a substituent. Represents an aryl group which may have a substituent or a heterocyclic group which may have a substituent, and R ¹ and R ² may be linked to each other to form a ring).
In one embodiment, the polarizing plate has a total thickness of 60 μm or less.
According to another aspect of the present invention, an image display device is provided. This image display device includes the above-mentioned polarizing plate.

According to the embodiment of the present invention, in a polarizing plate having a low resistance pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer has a specific configuration, so that the polarizing plate is thin, has excellent durability, and has a poor appearance (typically, a polarizing plate). It is possible to realize a polarizing plate in which partial expansion of the protective layer and cracks of the functional layer contained in the above are suppressed, and cracks during irregular shape processing are suppressed.

It is a schematic sectional drawing of the polarizing plate by one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

A. Overall Configuration of Polarizing Plate FIG. 1 is a schematic cross-sectional view of the polarizing plate according to one embodiment of the present invention. The polarizing plate 100 of the illustrated example includes a polarizing element 11, a protective layer 12 provided on one side of the polarizing element 11, an iodine permeation suppressing layer 40 provided on the other side of the polarizing element 11, and iodine permeation. It has a pressure-sensitive adhesive layer 30 provided on the opposite side of the polarizing element 11 of the suppression layer 40. The iodine permeation suppressing layer 40 is a solidified product or a thermosetting product of a coating film of an organic solvent solution of a resin. Another protective layer (not shown) may be provided between the polarizing element 11 and the iodine permeation suppressing layer 40. Preferably, as shown in the illustrated example, the protective layer 12 is provided only on one side of the polarizing element 11. In this case, the iodine permeation suppressing layer 40 is directly provided on the polarizing element 11 on the other side of the polarizing element 11. As used herein, the term "directly provided on the polarizing element" means that it is directly formed on the surface of the polarizing element without interposing an adhesive layer (typically, an adhesive layer or an adhesive layer). do. The pressure-sensitive adhesive layer 30 is provided as an outermost layer, and the polarizing plate can be attached to an image display device (substantially, an image display panel). Practically, it is preferable that a release film is temporarily attached to the surface of the pressure-sensitive adhesive layer 30 until the polarizing plate is used. By temporarily attaching the release film, the pressure-sensitive adhesive layer can be protected and a roll of the polarizing plate can be formed.

In the embodiment of the present invention, the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer 30 contains a base polymer and an antistatic agent. The base polymer has a glass transition temperature of −50 ° C. or lower and a dielectric constant of 5.0 or higher at 100 kHz. By using such a base polymer, it is possible to realize a pressure-sensitive adhesive layer having a small surface resistance value even though the content of the antistatic agent is small. That is, in the embodiment of the present invention, the surface resistance value of the pressure-sensitive adhesive layer is 1.0 × while the content of the antistatic agent in the pressure-sensitive adhesive composition is less than 10 parts by weight with respect to 100 parts by weight of the base polymer. It can be 10 ⁹ Ω / □ or less. As a result, it is possible to realize a polarizing plate that is thin, has excellent durability, suppresses poor appearance of the functional layer (for example, iodine permeation suppressing layer) contained in the polarizing plate, and suppresses cracks during irregular shape processing. be able to.

The polarizing plate according to the embodiment of the present invention may further include a functional layer other than the iodine permeation suppressing layer. A typical example of such a functional layer is a retardation layer. The optical characteristics (for example, refractive index characteristics, in-plane retardation, Nz coefficient, photoelastic coefficient), thickness, arrangement position, and the like of the retardation layer can be appropriately set according to the purpose.

The polarizing plate according to the embodiment of the present invention may be single-wafered or elongated. As used herein, the term "long" means an elongated shape having a length sufficiently long with respect to the width, and for example, an elongated shape having a length of 10 times or more, preferably 20 times or more with respect to the width. include. The long polarizing plate can be wound in a roll shape.

The polarizing plate according to the embodiment of the present invention may have a variant shape other than a rectangle. As used herein, the term "having a variant other than a rectangle" means that the planar view shape of the polarizing plate has a shape other than a rectangle. The irregular shape is typically a deformed portion that has been deformed. Therefore, the "polarizing plate having a deformed shape other than the rectangle" is not only when the entire polarizing plate (that is, the outer edge defining the planar view shape of the film) is other than the rectangle, but also from the outer edge of the rectangular polarizing plate to the inside. It also includes the case where a deformed portion is formed in a separated portion. When a pressure-sensitive adhesive layer (low-resistance pressure-sensitive adhesive layer) having a small surface resistance value is used, the added antistatic agent acts as a plasticizer, which causes the polarizing plate to shrink in such a deformed portion in a high-temperature environment. Where cracks are likely to occur in the polarizing element, such cracks can be remarkably suppressed according to the embodiment of the present invention. Examples of the deformed portion (deformed portion) include a through hole, chamfering of a corner portion, and a machined portion that becomes a concave portion when viewed in a plan view. Typical examples of the recess include a shape similar to a ship shape, a shape similar to a bathtub, a V-shaped notch, and a U-shaped notch. Another example of the irregular shape (deformed portion) is a shape corresponding to the instrument panel of an automobile. The shape includes a portion in which the outer edge is formed in an arc shape along the rotation direction of the meter needle and the outer edge is V-shaped (including a round shape) convex inward in the plane direction. The irregular shape is not limited to the above example, and any appropriate shape according to the purpose can be adopted. For example, as the shape of the through hole, a circle, an ellipse, a triangle, a quadrangle, a pentagon, a hexagon, or an octagon can be adopted. Further, the through hole is provided at an arbitrary appropriate position according to the purpose. As shown in FIG. 2, the through hole may be provided at a substantially central portion of the longitudinal end portion of the rectangular polarizing plate, or may be provided at a predetermined position at the longitudinal end portion of the polarizing plate. It may be provided at a corner; it may be provided at the lateral end of a rectangular polarizing plate; it may be provided at the center of a polarizing plate having an entirely irregular shape. The deformed portion may be formed by combining the above-exemplified forms. For example, the through hole may be formed by combining a V-shaped notch and / or a U-shaped notch.

The total thickness of the polarizing plate is preferably 60 μm or less, more preferably 55 μm or less, still more preferably 50 μm or less, and particularly preferably 40 μm or less. The lower limit of the total thickness can be, for example, 28 μm. According to the embodiment of the present invention, in a configuration having a low resistance pressure-sensitive adhesive layer and having a protective layer on only one side of the polarizing element, the same effect as a configuration having protective layers on both sides of the polarizing element can be obtained. Obtainable. As a result, one of the protective layers can be omitted, so that remarkable thinning can be realized. When the total thickness of the polarizing plate is within such a range, the generation of bubbles, so-called delay bubbles, can be remarkably suppressed. The delay bubble is a bubble generated in the following situations. For example, when a polarizing plate having a through hole is attached to the visible side of an image display panel, a cover glass may be attached to the visible side of the polarizing plate. The cover glass is attached by vacuum laminating via a predetermined adhesive. At this time, the through hole may be filled with the adhesive. Immediately after vacuum laminating, there are often no recognizable bubbles in the filled portion, but bubbles may be generated in the subsequent heating durability test of the image display device. Such bubbles can typically be generated by the contraction stress of the polarizing plate applied to the filled portion. Such bubbles are called delay bubbles. The delay bubble is not a fine one, but a large one that occupies a certain percentage or more of the plan view area of the through hole, and from the viewpoint of appearance and the camera performance of the camera unit provided at the position corresponding to the through hole. It is unacceptable. Therefore, suppressing the delay bubble has high industrial value. The total thickness of the polarizing plate means the total thickness of the polarizing element, the protective layer, the iodine permeation suppressing layer, and the adhesive layer or the pressure-sensitive adhesive layer for laminating them (that is, the total thickness of the polarizing plate is defined as the total thickness of the polarizing plate. Does not include the thickness of the pressure-sensitive adhesive layer 30 and the release film that can be temporarily attached to its surface).

Hereinafter, the components of the polarizing plate will be described in more detail.

B. Polarizer The splitter is typically composed of a resin film containing a dichroic substance (typically iodine). As the resin film, any suitable resin film that can be used as a polarizing element can be adopted. The resin film is typically a polyvinyl alcohol-based resin (hereinafter referred to as “PVA-based resin”) film. The resin film may be a single-layer resin film or a laminated body having two or more layers.

Specific examples of the polarizing element composed of a single-layer resin film include those obtained by subjecting a PVA-based resin film to a dyeing treatment with iodine and a stretching treatment (typically, uniaxial stretching). The dyeing with iodine is performed, for example, by immersing a PVA-based film in an aqueous iodine solution. The draw ratio of the uniaxial stretching is preferably 3 to 7 times. The stretching may be performed after the dyeing treatment or may be performed while dyeing. Further, it may be dyed after being stretched. If necessary, the PVA-based resin film is subjected to a swelling treatment, a crosslinking treatment, a cleaning treatment, a drying treatment and the like. For example, by immersing the PVA-based resin film in water and washing it with water before dyeing, it is possible not only to clean the dirt and blocking inhibitor on the surface of the PVA-based film, but also to swell the PVA-based resin film to cause uneven dyeing. Etc. can be prevented.

Specific examples of the polarizing element obtained by using the laminate include a laminate of a resin base material and a PVA-based resin layer (PVA-based resin film) laminated on the resin base material, or a resin base material and the resin. Examples thereof include a polarizing element obtained by using a laminate with a PVA-based resin layer coated and formed on a base material. The ligand obtained by using the laminate of the resin base material and the PVA-based resin layer coated and formed on the resin base material is, for example, a resin base material obtained by applying a PVA-based resin solution to the resin base material and drying the resin base material. It is produced by forming a PVA-based resin layer on top of the PVA-based resin layer to obtain a laminate of a resin base material and a PVA-based resin layer; obtain. In the present embodiment, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is preferably formed on one side of the resin base material. Stretching typically involves immersing the laminate in an aqueous boric acid solution for stretching. Further, stretching may further comprise, if necessary, stretching the laminate in the air at a high temperature (eg, 95 ° C. or higher) prior to stretching in boric acid aqueous solution. In addition, in the present embodiment, preferably, the laminate is subjected to a drying shrinkage treatment in which the laminate is shrunk by 2% or more in the width direction by heating while being conveyed in the longitudinal direction. Typically, the production method of the present embodiment includes subjecting the laminate to an aerial auxiliary stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment in this order. By introducing the auxiliary stretching, even when PVA is applied on the thermoplastic resin, the crystallinity of PVA can be enhanced and high optical characteristics can be achieved. At the same time, by increasing the orientation of PVA in advance, it is possible to prevent problems such as deterioration of PVA orientation and dissolution when immersed in water in a subsequent dyeing step or stretching step, and high optical characteristics. Will be possible to achieve. Further, when the PVA-based resin layer is immersed in a liquid, the disorder of the orientation of the polyvinyl alcohol molecule and the decrease in the orientation can be suppressed as compared with the case where the PVA-based resin layer does not contain a halide. This makes it possible to improve the optical characteristics of the polarizing element obtained through a treatment step of immersing the laminate in a liquid, such as a dyeing treatment and a stretching treatment in water. Further, the optical characteristics can be improved by shrinking the laminated body in the width direction by the drying shrinkage treatment. The obtained resin base material / polarizing element laminate may be used as it is (that is, the resin base material may be used as a protective layer for the polarizing element), and the resin base material is peeled off from the resin base material / polarizing element laminate. Then, an arbitrary appropriate protective layer according to the purpose may be laminated on the peeled surface and used. Details of the method for producing such a polarizing element are described in, for example, Japanese Patent Application Laid-Open No. 2012-73580 and Japanese Patent No. 6470455. The entire description of these publications is incorporated herein by reference.

The thickness of the splitter is preferably 1 μm to 10 μm, more preferably 1 μm to 8 μm, and further preferably 2 μm to 5 μm. If the thickness of the polarizing element is within such a range, it can greatly contribute to the thinning of the polarizing plate.

The splitter preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The simple substance transmittance of the polarizing element is preferably 41.5% to 46.0%, more preferably 43.0% to 46.0%, still more preferably 44.5% to 46.0%. be. The degree of polarization of the polarizing element is preferably 97.0% or more, more preferably 99.0% or more, and further preferably 99.9% or more.

C. Protective Layer The protective layer 12 (and another protective layer, if any) is formed of any suitable film that can be used as a protective layer for the stator. Specific examples of the material that is the main component of the film include cellulosic resins such as triacetylcellulose (TAC), polyesters, polyvinyl alcohols, polycarbonates, polyamides, polyimides, polyethersulfones, and polysulfones. , Polyester-based, polynorbornene-based, polyimide-based, (meth) acrylic-based, acetate-based transparent resins and the like. Further, thermosetting resins such as (meth) acrylic, urethane, (meth) acrylic urethane, epoxy, and silicone, or ultraviolet curable resins can also be mentioned. In addition to this, for example, glassy polymers such as siloxane-based polymers can also be mentioned. Further, the polymer film described in JP-A-2001-343529 (WO01 / 37007) can also be used. As the material of this film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain. Can be used, and examples thereof include a resin composition having an alternating copolymer composed of isobutene and N-methylmaleimide and an acrylonitrile / styrene copolymer. The polymer film can be, for example, an extruded product of the above resin composition.

When the polarizing plate is arranged on the visible side of the image display device, the protective layer 12 is typically arranged on the visible side thereof. In this case, the protective layer 12 may be subjected to surface treatment such as hard coat treatment, antireflection treatment, sticking prevention treatment, and antiglare treatment, if necessary.

The thickness of the protective layer is preferably 10 μm to 50 μm, more preferably 15 μm to 35 μm. When the surface treatment is applied, the thickness of the outer protective layer is the thickness including the thickness of the surface treatment layer.

D. Iodine Permeation Suppressing Layer In the embodiment of the present invention, by providing the iodine permeation suppressing layer, it is possible to suppress an increase in the surface resistance value of the pressure-sensitive adhesive layer in a high temperature environment and / or a high temperature / high humidity environment. Moreover, it is possible to suppress cracks during irregular shape processing. As described above, the iodine permeation suppressing layer is a solidified product or a thermosetting product of a coating film of an organic solvent solution of a resin. With such a configuration, the thickness can be made very thin (for example, 10 μm or less). The thickness of the iodine permeation inhibitory layer is preferably 0.05 μm to 10 μm, more preferably 0.08 μm to 5 μm, still more preferably 0.1 μm to 1 μm, and particularly preferably 0.2 μm to 0.7 μm. Is. Further, with such a configuration, the iodine permeation inhibitory layer can be formed directly on the polarizing element (that is, without the intervention of the adhesive layer or the pressure-sensitive adhesive layer). According to the embodiment of the present invention, as described above, the polarizing element and the iodine permeation suppressing layer are very thin, and the adhesive layer or the pressure-sensitive adhesive layer for laminating the iodine permeation suppressing layer can be omitted. The total thickness of the polarizing plate can be made extremely thin. Further, such an iodine permeation suppressing layer has an advantage that it is excellent in humidification durability because it has a smaller hygroscopicity and moisture permeability than a solidified water-based coating film such as an aqueous solution or an aqueous dispersion. As a result, it is possible to realize a polarizing plate having excellent durability, which can maintain optical characteristics even in a high temperature and high humidity environment. Further, such an iodine permeation suppressing layer can suppress an adverse effect on a polarizing plate (polarizer) due to ultraviolet irradiation as compared with, for example, a cured product of an ultraviolet curable resin. The iodine permeation inhibitory layer is preferably a solidified coating film of an organic solvent solution of a resin. The solidified product has a smaller shrinkage during film molding than the cured product, and since it does not contain residual monomers, deterioration of the film itself is suppressed, and the polarizing plate (polarizer) caused by the residual monomers is suppressed. The adverse effect can be suppressed.

The glass transition temperature (Tg) of the resin constituting the iodine permeation suppressing layer is typically 85 ° C. or higher, preferably 90 ° C. or higher, more preferably 100 ° C. or higher, still more preferably 110 ° C. or higher. It is particularly preferably 120 ° C. or higher. The upper limit of Tg can be, for example, 200 ° C. The weight average molecular weight Mw of the resin is typically 25,000 or more, preferably 30,000 or more, more preferably 35,000 or more, and further preferably 40,000 or more. The upper limit of Mw can be, for example, 150,000. When the Tg and Mw of the resin are in such a range, the iodine permeation inhibitory layer is very effective due to the synergistic effect with the effect of forming the solidified or thermosetting film of the coating film of the organic solvent solution of the resin. Despite its thinness, the transfer of iodine in the polarizing element to the image display panel can be significantly suppressed. As a result, when the polarizing plate is applied to the image display device, corrosion of the metal member of the image display device can be remarkably suppressed.

As the resin constituting the iodine permeation suppressing layer, any suitable thermoplastic resin or thermosetting resin can be used. A thermoplastic resin is preferable. Examples of the thermoplastic resin include acrylic resins and epoxy resins. Acrylic resin and epoxy resin may be used in combination. Hereinafter, typical examples of the acrylic resin and the epoxy resin that can be used for the iodine permeation suppressing layer will be described.

The acrylic resin typically contains a repeating unit derived from a (meth) acrylic acid ester-based monomer having a linear or branched structure as a main component. As used herein, (meth) acrylic refers to acrylic and / or methacrylic. The acrylic resin may contain repeating units derived from any suitable copolymerized monomer depending on the intended purpose. Examples of the copolymerized monomer (copolymerized monomer) include a carboxyl group-containing monomer, a hydroxyl group-containing monomer, an amide group-containing monomer, an aromatic ring-containing (meth) acrylate, and a heterocyclic ring-containing vinyl-based monomer. By appropriately setting the type, number, combination, copolymerization ratio, etc. of the monomer unit, an acrylic resin having the above-mentioned predetermined Mw can be obtained.

（式中、Ｘはビニル基、（メタ）アクリル基、スチリル基、（メタ）アクリルアミド基、ビニルエーテル基、エポキシ基、オキセタン基、ヒドロキシル基、アミノ基、アルデヒド基、および、カルボキシル基からなる群より選択される少なくとも１種の反応性基を含む官能基を表し、Ｒ^１およびＲ^２はそれぞれ独立して、水素原子、置換基を有していてもよい脂肪族炭化水素基、置換基を有していてもよいアリール基、または、置換基を有していてもよいヘテロ環基を表し、Ｒ^１およびＲ^２は互いに連結して環を形成してもよい）。 <Boron-containing acrylic resin>
In one embodiment, the acrylic resin is a (meth) acrylic monomer having more than 50 parts by weight and a monomer represented by the formula (1) having more than 0 parts by weight and less than 50 parts by weight (hereinafter,). , May be referred to as a copolymerized monomer) and a copolymer obtained by polymerizing a monomer mixture (hereinafter, may be referred to as a boron-containing acrylic resin).

(In the formula, X is a group consisting of a vinyl group, a (meth) acrylic group, a styryl group, a (meth) acrylamide group, a vinyl ether group, an epoxy group, an oxetane group, a hydroxyl group, an amino group, an aldehyde group, and a carboxyl group. Representing a functional group containing at least one reactive group selected, R ¹ and R ² each independently have a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, and a substituent. Represents an aryl group which may have a substituent or a heterocyclic group which may have a substituent, and R ¹ and R ² may be linked to each other to form a ring).

（式中、Ｒ^６は任意の官能基を表し、jおよびｋは１以上の整数を表す）。 The boron-containing acrylic resin typically has a repeating unit represented by the following formula. By polymerizing a monomer mixture containing the copolymerized monomer represented by the formula (1) and the (meth) acrylic monomer, the boron-containing acrylic resin has a substituent containing boron in the side chain (for example,). It has a repeating unit of k in the following formula). As a result, when the iodine permeation suppressing layer is arranged adjacent to the polarizing element, the adhesion to the polarizing element can be improved. The boron-containing substituent may be continuously (that is, in a block shape) contained in the boron-containing acrylic resin, or may be randomly contained.

(In the equation, R ⁶ represents an arbitrary functional group, and j and k represent integers of 1 or more).

<(Meta) acrylic monomer>
Any suitable (meth) acrylic monomer can be used as the (meth) acrylic monomer. For example, a (meth) acrylic acid ester-based monomer having a linear or branched structure and a (meth) acrylic acid ester-based monomer having a cyclic structure can be mentioned.

Examples of the (meth) acrylic acid ester-based monomer having a linear or branched structure include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and (meth) acrylic acid. Examples thereof include isopropyl, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, methyl 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate and the like. .. Preferably, methyl (meth) acrylate is used. As the (meth) acrylic acid ester-based monomer, only one kind may be used, or two or more kinds may be used in combination.

Examples of the (meth) acrylate-based monomer having a cyclic structure include cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, 1-adamantyl (meth) acrylate, and ( Dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, biphenyl (meth) acrylate, o-biphenyloxyethyl (meth) acrylate, o-biphenyloxyethoxy Ethyl (meth) acrylate, m-biphenyloxyethyl acrylate, p-biphenyloxyethyl (meth) acrylate, o-biphenyloxy-2-hydroxypropyl (meth) acrylate, p-biphenyloxy-2-hydroxypropyl (meth) acrylate , M-biphenyloxy-2-hydroxypropyl (meth) acrylate, N- (meth) acryloyloxyethyl-o-biphenyl = carbamate, N- (meth) acryloyloxyethyl-p-biphenyl = carbamate, N- (meth) Examples thereof include biphenyl group-containing monomers such as acryloyloxyethyl-m-biphenyl = carbamate and o-phenylphenol glycidyl ether acrylate, terphenyl (meth) acrylate, and o-terphenyloxyethyl (meth) acrylate. Preferably, 1-adamantyl (meth) acrylate and dicyclopentanyl (meth) acrylate are used. By using these monomers, a polymer having a high glass transition temperature can be obtained. Only one kind of these monomers may be used, or two or more kinds thereof may be used in combination.

Further, instead of the above-mentioned (meth) acrylic acid ester-based monomer, a silsesquioxane compound having a (meth) acryloyl group may be used. By using the silsesquioxane compound, an acrylic polymer having a high glass transition temperature can be obtained. The silsesquioxane compound is known to have various skeleton structures such as a cage-type structure, a ladder-type structure, and a random structure. The silsesquioxane compound may have only one of these structures, or may have two or more of these structures. Only one kind of silsesquioxane compound may be used, or two or more kinds may be used in combination.

As the silsesquioxane compound containing a (meth) acryloyl group, for example, MAC grade and AC grade of Toagosei Co., Ltd. SQ series can be used. The MAC grade is a silsesquioxane compound containing a methacryloyl group, and specific examples thereof include MAC-SQ TM-100, MAC-SQ SI-20, and MAC-SQ HDM. The AC grade is a silsesquioxane compound containing an acryloyl group, and specific examples thereof include AC-SQ TA-100 and AC-SQ SI-20.

The (meth) acrylic monomer is used in an amount of more than 50 parts by weight with respect to 100 parts by weight of the monomer mixture.

<Copolymerization monomer>
As the copolymerization monomer, a monomer represented by the above formula (1) is used. By using such a copolymerized monomer, a substituent containing boron is introduced into the side chain of the obtained polymer. Only one type of copolymerization monomer may be used, or two or more types may be used in combination.

The aliphatic hydrocarbon group in the above formula (1) may have a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, and may have a substituent and may have 3 to 3 carbon atoms. Examples thereof include a cyclic alkyl group of 20 and an alkenyl group having 2 to 20 carbon atoms. Examples of the aryl group include a phenyl group having 6 to 20 carbon atoms which may have a substituent, a naphthyl group having 10 to 20 carbon atoms which may have a substituent, and the like. Examples of the heterocyclic group include a 5-membered ring group or a 6-membered ring group containing at least one heteroatom which may have a substituent. In addition, R ¹ and R ² may be connected to each other to form a ring. R ¹ and R ² are preferably a hydrogen atom or a linear or branched alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom.

The reactive group contained in the functional group represented by X is a vinyl group, a (meth) acrylic group, a styryl group, a (meth) acrylamide group, a vinyl ether group, an epoxy group, an oxetane group, a hydroxyl group, an amino group, an aldehyde group, and the like. And at least one selected from the group consisting of carboxyl groups. Preferably, the reactive group is a (meth) acrylic group and / or a (meth) acrylamide group. By having these reactive groups, the adhesion to the polarizing element can be further improved when the iodine permeation suppressing layer is arranged adjacent to the polarizing element.

In one embodiment, the functional group represented by X is preferably a functional group represented by ZZ. Here, Z is selected from the group consisting of a vinyl group, a (meth) acrylic group, a styryl group, a (meth) acrylamide group, a vinyl ether group, an epoxy group, an oxetane group, a hydroxyl group, an amino group, an aldehyde group, and a carboxyl group. Represents a functional group containing at least one reactive group, where Y represents a phenylene group or an alkylene group.

Specifically, the following compounds can be used as the copolymerization monomer.

The copolymerized monomer is used in an amount of more than 0 parts by weight and less than 50 parts by weight with respect to 100 parts by weight of the monomer mixture. It is preferably 0.01 parts by weight or more and less than 50 parts by weight, more preferably 0.05 parts by weight to 20 parts by weight, still more preferably 0.1 parts by weight to 10 parts by weight, and particularly preferably 0. It is 5 parts by weight to 5 parts by weight.

<Acrylic resin containing lactone ring, etc.>
In another embodiment, the acrylic resin has a repeating unit including a ring structure selected from a lactone ring unit, a glutaric anhydride unit, a glutarimide unit, a maleic anhydride unit and a maleimide (N-substituted maleimide) unit. You may be doing it. Only one type of the repeating unit including the ring structure may be contained in the repeating unit of the acrylic resin, or two or more types may be contained. The content ratio of the repeating unit including the ring structure in the acrylic resin is preferably 1 mol% to 50 mol%, more preferably 10 mol% to 40 mol%, and further preferably 20 mol% to 30 mol%. The acrylic resin contains the above-mentioned (meth) acrylic monomer-derived repeating unit as the main repeating unit.

<Epoxy resin>
As the epoxy resin, an epoxy resin having an aromatic ring is preferably used. By using an epoxy resin having an aromatic ring as the epoxy resin, the adhesion to the polarizing element can be improved when the iodine permeation suppressing layer is arranged adjacent to the polarizing element. Further, when the pressure-sensitive adhesive layer is arranged adjacent to the iodine permeation suppressing layer, the anchoring force of the pressure-sensitive adhesive layer can be improved. Examples of the epoxy resin having an aromatic ring include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin and other bisphenol type epoxy resins; phenol novolac epoxy resin, cresol novolak epoxy resin, hydroxybenzaldehyde phenol novolac. Novolak type epoxy resin such as epoxy resin; polyfunctional epoxy resin such as tetrahydroxyphenylmethane glycidyl ether, tetrahydroxybenzophenone glycidyl ether, epoxidized polyvinylphenol, naphthol type epoxy resin, naphthalene type epoxy resin, biphenyl type Epoxy resin and the like can be mentioned. Preferably, a bisphenol A type epoxy resin, a biphenyl type epoxy resin, and a bisphenol F type epoxy resin are used. Only one type of epoxy resin may be used, or two or more types may be used in combination.

The iodine permeation inhibitory layer can be formed by applying an organic solvent solution of a resin as described above to form a coating film, and solidifying or thermosetting the coating film. Any suitable method and condition may be adopted as the coating method, solidification or curing conditions.

The iodine permeation suppressing layer (substantially, the organic solvent solution of the above resin) may contain any suitable additive depending on the purpose. The type, number, combination, amount of additive, etc. of the additive can be appropriately set according to the purpose.

E. Adhesive layer The surface resistance value of the adhesive layer 30 is 1.0 × 10 ⁹ Ω / □ or less, preferably 5.0 × 10 ⁸ Ω / □ or less, more preferably 1.0 as described above. It is × 10 ⁸ Ω / □ or less, more preferably 7.0 × 10 ⁷ Ω / □ or less, and particularly preferably 1.0 × 10 ⁷ Ω / □ or less. The lower limit of the surface resistance value may be, for example, ^5.0 × 105 Ω / □ or less. As described above, according to the embodiment of the present invention, it is possible to realize a pressure-sensitive adhesive layer having a small surface resistance value even though the content of the antistatic agent is small.

The adhesive strength of the pressure-sensitive adhesive layer to the glass is preferably 1.0 N / 25 mm or more, more preferably 1.5 N / 25 mm or more, and further preferably 2.0 N / 25 mm or more. When the adhesive strength is within such a range, the adhesiveness to the image display panel is excellent and the reworkability is excellent. The upper limit of the adhesive force may be, for example, 6.0 N / 25 mm.

The thickness of the pressure-sensitive adhesive layer is preferably 2 μm to 55 μm, more preferably 2 μm to 30 μm, still more preferably 5 μm to 25 μm, and particularly preferably 10 μm to 20 μm.

The pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer contains a base polymer and an antistatic agent as described above. The glass transition temperature (Tg) of the base polymer is −50 ° C. or lower, preferably −52 ° C. or lower, and more preferably −55 ° C. or lower, as described above. The lower limit of Tg of the base polymer can be, for example, −75 ° C. The dielectric constant of the base polymer at 100 kHz is 5.0 or more, preferably 5.5 or more, more preferably 6.0 or more, still more preferably 6.5 or more, and particularly preferably 6.5 or more, as described above. Is 7.0 or higher. The upper limit of the dielectric constant of the base polymer can be, for example, 10.0. By using such a base polymer, it is possible to realize a pressure-sensitive adhesive layer having a small surface resistance value even though the content of the antistatic agent is small. The Tg of the base polymer can be calculated as the Tg of the polymer converted from the Tg of each monomer component using the polymerization ratio.

Examples of the base polymer include (meth) acrylic polymers, urethane-based polymers, silicone-based polymers, and rubber-based polymers. A (meth) acrylic polymer is preferable. In the present specification, the (meth) acrylic polymer as the base polymer may be referred to as a (meth) acrylic base polymer.

式中、Ｒ^１はアルキル基であり、例えばメチル基またはエチル基であり、ｎは１～１５の整数である。上記式から明らかなように、アルコキシ基は好ましくは直鎖状である。直鎖状アルコキシ基であれば、得られる（メタ）アクリル系ベースポリマーのＴｇを上記所望の範囲とすることができ、当該ベースポリマーの誘電率を上記所望の範囲とすることができる。環構造を有するモノマーを含むベースポリマーは、Ｔｇが過度に高くなる、および／または、誘電率が過度に小さくなる場合がある。アルコキシ基含有モノマーの具体例としては、メトキシエチル（メタ）アクリレート、エトキシエトキシエチル（メタ）アクリレート、メトキシトリエチレングリコール（メタ）アクリレート、メトキシポリエチレングリコール（メタ）アクリレートが挙げられる。これらは、単独で用いてもよく２種以上を組み合わせて用いてもよい。モノマー成分としてアルコキシ基含有モノマーを用いることにより、所望のＴｇおよび誘電率を有するベースポリマーを得ることができる。その結果、帯電防止剤の含有量が少ないにもかかわらず表面抵抗値が小さい粘着剤層を実現することができる。ベースポリマーにおけるアルコキシ基含有モノマーの含有量は、全モノマー成分１００重量部に対して、好ましくは３０重量部～９９重量部である。アルコキシ基含有モノマーの含有量は、例えば３０重量部～６０重量部であってもよく、また例えば３０重量部～５０重量部であってもよく、また例えば５０重量部～９９重量部であってもよく、また例えば６０重量部～９９重量部であってもよい。 The (meth) acrylic base polymer preferably contains an alkoxy group-containing monomer as a monomer component. Examples of the alkoxy group-containing monomer include a monomer represented by the following formula:

In the formula, R ¹ is an alkyl group, for example a methyl group or an ethyl group, and n is an integer of 1 to 15. As is clear from the above formula, the alkoxy group is preferably linear. If it is a linear alkoxy group, the Tg of the obtained (meth) acrylic base polymer can be in the above-mentioned desired range, and the dielectric constant of the base polymer can be in the above-mentioned desired range. The base polymer containing the monomer having a ring structure may have an excessively high Tg and / or an excessively small dielectric constant. Specific examples of the alkoxy group-containing monomer include methoxyethyl (meth) acrylate, ethoxyethoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, and methoxypolyethylene glycol (meth) acrylate. These may be used alone or in combination of two or more. By using an alkoxy group-containing monomer as the monomer component, a base polymer having a desired Tg and dielectric constant can be obtained. As a result, it is possible to realize a pressure-sensitive adhesive layer having a small surface resistance value even though the content of the antistatic agent is small. The content of the alkoxy group-containing monomer in the base polymer is preferably 30 parts by weight to 99 parts by weight with respect to 100 parts by weight of all the monomer components. The content of the alkoxy group-containing monomer may be, for example, 30 parts by weight to 60 parts by weight, for example, 30 parts by weight to 50 parts by weight, and for example, 50 parts by weight to 99 parts by weight. It may be 60 parts by weight to 99 parts by weight, for example.

The (meth) acrylic base polymer preferably contains a hydroxyl group-containing monomer as a monomer component. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and 8-hydroxyoctyl ( Examples thereof include meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, and (4-hydroxymethylcyclohexyl) -methyl acrylate. From the viewpoint of improving the durability of the pressure-sensitive adhesive layer, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are preferable, and 4-hydroxybutyl (meth) acrylate is more preferable. The content of the hydroxyl group-containing monomer in the base polymer is preferably 1 part by weight to 5 parts by weight, and more preferably 1 part by weight to 3 parts by weight with respect to 100 parts by weight of all the monomer components.

The (meth) acrylic base polymer may contain an alkyl (meth) acrylate as a monomer component. Examples of the alkyl (meth) acrylate include linear or branched alkyl groups having 1 to 18 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an amyl group, a hexyl group, a cyclohexyl group, a heptyl group, a 2-ethylhexyl group, an isooctyl group, a nonyl group and a decyl group. , Isodecyl group, dodecyl group, isomiristyl group, lauryl group, tridecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group and the like. Alkyl (meth) acrylates can be used alone or in combination. The average number of carbon atoms of the alkyl group is preferably 3 to 8, and more preferably 3 to 6. The content of the alkyl (meth) acrylate in the base polymer can be arbitrarily set as the balance of the monomer components other than the alkyl (meth) acrylate.

The (meth) acrylic-based base polymer may further contain other monomer components (copolymerization monomer), if necessary. Typical examples of copolymerized monomers include aromatic hydrocarbon group-containing monomers (eg, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, benzyl (meth) acrylate), and carboxyl group-containing monomers (eg, (meth) acrylic). Acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid), amino group-containing monomer (eg, N, N-dimethylaminoethyl (meth) acrylate), amide Group-containing monomers (eg, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide), nitrile group-containing monomers (eg, (meth) acrylonitrile), polyfunctional monomers (eg, (meth) acrylonitrile) For example, hexanediol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate), epoxy group-containing monomer (eg, glycidyl (meth) acrylate), Examples include heterocyclic-containing monomers (eg, acryloylmorpholin). The type, number, combination, and blending amount (content) of the copolymerizable monomer can be appropriately set according to the purpose.

The weight average molecular weight Mw of the (meth) acrylic base polymer is preferably 1 million to 3 million, more preferably 2 million to 3 million, and further preferably 2 million to 2.8 million. If the weight average molecular weight Mw is less than 1 million, crack suppression may be insufficient. If the weight average molecular weight Mw exceeds 3 million, an increase in viscosity and / or gelation during polymer polymerization may occur.

Typical examples of the antistatic agent include inorganic cation salts and organic cation salts.

The inorganic cation salt is specifically an inorganic cation-anion salt. Typical examples of the cation constituting the cation portion of the inorganic cation salt include alkali metal ions. Specific examples include lithium ion, sodium ion, and potassium ion. Lithium ion is preferred. Therefore, the preferred inorganic cation salt is a lithium salt.

Examples of the anions constituting the anion portion of the inorganic cation salt include ^Cl- , Br- ^, I- ^, AlCl _4- ^, Al ₂ Cl _7- ^, BF _4- ^, PF _6- ^, ClO _4- ^, NO _3- ^, and so on. CH ₃ COO- ^, CF ₃ COO- ^, CH ₃ SO _3- ^, CF ₃ SO _3- ^, (CF ₃ SO ₂ ) ₃ C- ^, AsF _6- ^, SbF _6- ^, NbF _6- ^, TaF _6- ^, (CN) ) ₂ N- ^, C ₄ F ₉ SO _3- ^, C ₃ F ₇ COO- ^, (CF ₃ SO ₂ ) (CF ₃ CO) N ^- , ^- O ₃ S (CF ₂ ) ₃ SO _3- ^, and the following General formulas (1) to (4)
(1): (C _n F _{2n + 1} SO ₂ ) ₂ N- ⁽ n is an integer from 1 to 10),
(2): CF ₂ (C _m F _2m SO ₂ ) ₂ N- ⁽ m is an integer of 1 to 10),
(3) ^: -O ₃ S (CF ₂ ) _l SO _3- ⁽ l is an integer of 1 to 10),
(4): (C _p F _{2p + 1} SO ₂ ) N- ⁽ C _q F _{2q + 1} SO ₂ ), (p, q are integers of 1 to 10),
Examples thereof include anions represented by. Fluorine-containing anions are preferred, and fluorine-containing imide anions are more preferred.

Examples of the fluorine-containing imide anion include an imide anion having a perfluoroalkyl group. Specific examples include the above (CF ₃ SO ₂ ) (CF ₃ CO) N ⁻ and the general formulas (1), (2) and (4).
(1): (C _n F _{2n + 1} SO ₂ ) ₂ N- ⁽ n is an integer from 1 to 10),
(2): CF ₂ (C _m F _2m SO ₂ ) ₂ N- ⁽ m is an integer of 1 to 10),
(4): (C _p F _{2p + 1} SO ₂ ) N- ⁽ C _q F _{2q + 1} SO ₂ ), (p, q are integers of 1 to 10),
Examples thereof include anions represented by. It is preferably a (perfluoroalkylsulfonyl) imide represented by the general formula (1) such as (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , and more preferably (CF ₃ ). SO ₂ ) _A bis (trifluoromethanesulfonyl) imide represented by 2N ⁻ . Therefore, a preferred inorganic cationic salt that can be used in embodiments of the present invention is lithium bis (trifluoromethanesulfonyl) imide.

The organic cation salt is specifically an organic cation-anion salt. Typical examples of the cation constituting the cation portion of the organic cation salt include organic onium in which onium ions are formed by substitution with an organic group. Examples of onium in organic onium include nitrogen-containing onium, sulfur-containing onium, and phosphorus-containing onium. Nitrogen-containing onium and sulfur-containing onium are preferable. Examples of nitrogen-containing oniums include ammonium cations, piperidinium cations, pyrrolidinium cations, pyridinium cations, pyrrolin skeleton cations, pyrrole skeleton cations, imidazolium cations, tetrahydropyrimidinium cations, and dihydropyrimidinium cations. Examples thereof include pyrazolium cations and pyrazolinium cations. Examples of the sulfur-containing onium include a sulfonium cation. Examples of the phosphonium-containing cation include a phosphonium cation. Examples of the organic group in organic onium include an alkyl group, an alkoxyl group, and an alkenyl group. Specific examples of preferred organic onium include tetraalkylammonium cations (eg, tributylmethylammonium cations), alkylpiperidinium cations, and alkylpyrrolidinium cations. The anions constituting the anion portion of the organic cation salt are as described with respect to the anions constituting the anion portion of the inorganic cation. Preferred organic cation salts that can be used in the embodiments of the present invention are 1-ethyl-3-methylimidazolium bis (fluorosulfonyl) imide, trimethylbutylammonium bis (trifluoromethanesulfonyl) imide.

Inorganic cation salts and organic cation salts may be used in combination.

The content of the antistatic agent in the pressure-sensitive adhesive composition is less than 10 parts by weight, preferably 7 parts by weight or less, and more preferably 5 parts by weight or less with respect to 100 parts by weight of the base polymer. , More preferably 3 parts by weight or less. According to the embodiment of the present invention, it is possible to realize a pressure-sensitive adhesive layer having a small surface resistance value even though the content of the antistatic agent is so small. The lower limit of the content of the antistatic agent may be, for example, 0.5 parts by weight. If the content of the antistatic agent is too small, the desired surface resistance value may not be obtained.

The pressure-sensitive adhesive composition typically contains a silane coupling agent, a cross-linking agent, and / or an antioxidant. Typical examples of the silane coupling agent include a functional group-containing silane coupling agent. Examples of the functional group include an epoxy group, a mercapto group, an amino group, an isocyanate group, an isocyanurate group, a vinyl group, a styryl group, an acetoacetyl group, a ureido group, a thiourea group, a (meth) acrylic group, a heterocyclic group and an acid. Anhydrous groups and combinations thereof can be mentioned. The functional group-containing silane coupling agent can be used alone or in combination. Examples of the cross-linking agent include isocyanate-based cross-linking agents and peroxide-based cross-linking agents. Crosslinkers can also be used alone or in combination. The following advantages can be obtained by containing a silane coupling agent. Since the pressure-sensitive adhesive composition using the base polymer containing the alkoxy group-containing monomer has high polarity, the adhesiveness to the non-polar adherend may be insufficient. By containing the silane coupling agent, sufficient adhesive force can be obtained for various adherends, and peeling can be suppressed. In addition, the following advantages can be obtained by containing an antioxidant. The base polymer containing the alkoxy group-containing monomer has a low Tg and becomes soft. By containing the antioxidant, it is possible to suppress shrinkage due to oxidative deterioration from the end face of the polarizing plate and the end face of the pressure-sensitive adhesive layer.

The pressure-sensitive adhesive composition may contain an additive. Specific examples of additives include powders such as colorants and pigments, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, light stabilizers, and ultraviolet rays. Absorbents, polymerization inhibitors, inorganic or organic fillers, metal powders, particulates, foils and the like. Further, a redox system to which a reducing agent is added may be adopted within a controllable range. The type, number, combination, content, etc. of additives can be appropriately set according to the purpose.

F. Image display device The polarizing plate according to the above items A to E can be applied to an image display device. Therefore, an embodiment of the present invention includes an image display device using such a polarizing plate. Typical examples of the image display device include a liquid crystal display device and an electroluminescence (EL) display device (for example, an organic EL display device and an inorganic EL display device). In one embodiment, the image display device is a narrow frame (preferably bezelless) image display device or an in-cell image display device. In such an image display device, the effect of the embodiment of the present invention is remarkable.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. The measurement method of each characteristic is as follows. Unless otherwise specified, "parts" and "%" in Examples and Comparative Examples are based on weight.

(1) Thickness The thickness of 10 μm or less was measured using an interference film thickness meter (manufactured by Otsuka Electronics Co., Ltd., product name “MCPD-3000”). Thicknesses exceeding 10 μm were measured using a digital micrometer (manufactured by Anritsu, product name “KC-351C”).

(2) Surface resistance value The resistance value on the surface of the pressure-sensitive adhesive layer of the polarizing plate (polarizing plate with pressure-sensitive adhesive layer) obtained in Examples and Comparative Examples was measured using MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd. The initial resistance value was used. Further, the polarizing plate with the pressure-sensitive adhesive layer was subjected to a reliability test under two different conditions (500 hours in an environment of 85 ° C. and 500 hours in an environment of 60 ° C. and 95% RH), and then in the same manner as above. The resistance value was measured. The resistance value increase rate was calculated by the following formula.
Resistance value increase rate (%) = {(resistance value after reliability test-initial resistance value) / initial resistance value} x 100
Furthermore, it was evaluated according to the following criteria.
◯: Resistance value increase rate is less than 50% Δ: Resistance value increase rate is 50% or more and less than 1000% ×: Resistance value increase rate is 1000% or more

(3) ESD Test The polarizing plates (polarizing plates with an adhesive layer) obtained in Examples and Comparative Examples were cut out to a size of 70 mm × 150 mm and bonded to a liquid crystal panel via the adhesive layer. Next, silver paste was applied to the side surface portion of the bonded polarizing plate with the pressure-sensitive adhesive layer so as to cover the entire side surface portion of the polarizing plate with the pressure-sensitive adhesive layer in the thickness direction, and connected to the ground electrode from the outside. Next, using an electrostatic discharge device ESD (ESD-8012A, manufactured by SANKI) on the surface of the polarizing plate with an adhesive layer (applied voltage 15 kV), every second so as to draw a circle in the polarizing plate surface. A total of 10 shots (applications) were made to distort the orientation of the liquid crystal in the liquid crystal panel. The time until the white spot disappeared by electricity was measured and evaluated according to the following criteria.
◯: White spots disappeared within 5 seconds Δ: White spots disappeared within 10 seconds ×: White spots remained for 10 seconds or more

(4) Delay Bubble A through hole having a diameter of 3.9 mm was formed in the corner of the polarizing plate obtained in Examples and Comparative Examples using an end mill. This polarizing plate was attached to a glass plate via an adhesive layer to obtain a polarizing plate / glass plate laminate A. On the other hand, a normal optical adhesive sheet was bonded to a cover glass (manufactured by Matsunami Glass Co., Ltd., thickness 0.8 mm) with a roll laminator to obtain a cover glass / optical adhesive laminate B. The polarizing plate of the laminated body A and the optical pressure-sensitive adhesive of the laminated body B were brought into close contact with each other by using a vacuum laminator, and the through holes were filled with the optical pressure-sensitive adhesive. In this way, a product compatible with the image display device was produced. The obtained image display device compatible product was subjected to a heating test (85 ° C., 24 hours) after being autoclaved, and the state of bubbles after the test was observed visually or with an optical microscope and evaluated according to the following criteria.
◯: No air bubbles were found in the filling part ×: Bubbles were found in the filling part

(5) Color loss From the polarizing plates obtained in Examples and Comparative Examples, test pieces (50 mm × 50 mm) having two opposite sides in the absorption axis direction and the directions orthogonal to the absorption axis direction were cut out. The test piece was attached to a glass plate via the pressure-sensitive adhesive layer, and the test piece was left in an oven at 65 ° C. and 90% RH for 120 hours to be humidified. The state of color loss at the end of the later polarizing plate (substantially, the polarizing element) was examined with a microscope. Specifically, the magnitude of color loss (color loss amount: μm) from the end of the polarizing element was measured. A MX61L manufactured by Olympus was used as a microscope, and the amount of color loss at the corners was measured from an image taken at a magnification of 10 times.

(6) Appearance The polarizing plates (cut out to a size of 50 mm × 50 mm) obtained in Examples and Comparative Examples were subjected to a reliability test (72 hours in an environment of 65 ° C. and 90% RH), and then the appearance (appearance). The appearance of the entire polarizing plate including the expansion of the protective layer and the state of the iodine permeation inhibitory layer) was visually observed and evaluated according to the following criteria.
◯: No swelling, peeling, cracks or foreign matter was observed Δ: Expansion, peeling, cracks or foreign matter were found in several places ×: Many swelling, peeling, cracks or foreign matter were found throughout.

(7) Cracks in the deformed portion A through hole having a diameter of 3.9 mm was formed in the corner of the polarizing plate obtained in Examples and Comparative Examples using an end mill. A polarizing plate having through holes was attached to a glass plate via an adhesive layer to prepare a test sample. This test sample was subjected to a heat shock test in which holding at 85 ° C. for 30 minutes and then at -40 ° C. for 30 minutes was repeated for 300 cycles, and the appearance of the through-hole portion after the test was visually observed, and the following criteria were used. evaluated. In each of the Examples and Comparative Examples, glue chipping (a phenomenon in which the end portion of the pressure-sensitive adhesive layer was chipped) did not occur.
◯: No crack was found ×: Crack was found

[Production Example 1: Preparation of (meth) acrylic base polymer A1]
39 parts of butyl acrylate (BA), 60 parts of methoxyethyl acrylate (MEA), and 1 part of 4-hydroxybutyl acrylate (4HBA) in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler. A monomer mixture containing the above was charged. Further, to 100 parts of this monomer mixture, 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator is charged together with 100 parts of ethyl acetate, and nitrogen gas is introduced while gently stirring to introduce nitrogen. After the substitution, the liquid temperature in the flask was maintained at around 55 ° C. and the polymerization reaction was carried out for 8 hours to prepare a solution of the (meth) acrylic base polymer A1. Table 1 shows the Tg and the dielectric constant of the (meth) acrylic base polymer A1. The dielectric constant was measured by a conventional method. For Tg, a value converted from Tg of each monomer using the polymerization ratio was calculated.

[Production Example 2: Preparation of (meth) acrylic base polymer A2]
A solution of the (meth) acrylic base polymer A2 was prepared in the same manner as in Production Example 1 except that 60 parts of ethoxyethoxyethyl acrylate (EEEA) was used instead of 60 parts of MEA. Table 1 shows the Tg and the dielectric constant of the (meth) acrylic base polymer A2.

[Production Example 3: Preparation of (meth) acrylic base polymer A3]
A solution of the (meth) acrylic base polymer A3 was prepared in the same manner as in Production Example 1 except that 60 parts of methoxytriethylene glycol acrylate (MTGA) was used instead of 60 parts of MEA. Table 1 shows the Tg and the dielectric constant of the (meth) acrylic base polymer A3.

[Production Example 4: Preparation of (meth) acrylic base polymer A4]
A solution of the (meth) acrylic base polymer A4 was prepared in the same manner as in Production Example 1 except that a monomer mixture containing 99 parts of MTGA and 1 part of 4HBA was used. Table 1 shows the Tg and the dielectric constant of the (meth) acrylic base polymer A4.

[Production Example 5: Preparation of (meth) acrylic base polymer A5]
A solution of the (meth) acrylic base polymer A5 was prepared in the same manner as in Production Example 1 except that a monomer mixture containing 49 parts of BA, 50 parts of MTGA and 1 part of 4HBA was used. Table 1 shows the Tg and the dielectric constant of the (meth) acrylic base polymer A5.

[Production Example 6: Preparation of (meth) acrylic base polymer A6]
A solution of the (meth) acrylic base polymer A6 was prepared in the same manner as in Production Example 1 except that a monomer mixture containing 69 parts of BA, 30 parts of MTGA and 1 part of 4HBA was used. Table 1 shows the Tg and the dielectric constant of the (meth) acrylic base polymer A6.

[Production Example 7: Preparation of (meth) acrylic base polymer A7]
A solution of the (meth) acrylic base polymer A7 was prepared in the same manner as in Production Example 5 except that 50 parts of methoxypolyethylene glycol acrylate (MPEA) was used instead of 50 parts of MTGA. Table 1 shows the Tg and the dielectric constant of the (meth) acrylic base polymer A7.

[Production Example 8: Preparation of (meth) acrylic base polymer A8]
A solution of the (meth) acrylic base polymer A8 was prepared in the same manner as in Production Example 1 except that a monomer mixture containing 79 parts of BA, 20 parts of MEA and 1 part of 4HBA was used. Table 1 shows the Tg and the dielectric constant of the (meth) acrylic base polymer A8.

[Production Example 9: Preparation of (meth) acrylic base polymer A9]
A solution of the (meth) acrylic base polymer A9 was prepared in the same manner as in Production Example 5 except that 50 parts of phenoxyethyl acrylate (PEA) was used instead of 50 parts of MTGA. Table 1 shows the Tg and the dielectric constant of the (meth) acrylic base polymer A9.

[Production Example 10: Preparation of (meth) acrylic base polymer A10]
A solution of the (meth) acrylic base polymer A10 was prepared in the same manner as in Production Example 5 except that 50 parts of tetrahydrofurfuryl acrylate was used instead of 50 parts of MTGA. Table 1 shows the Tg and the dielectric constant of the (meth) acrylic base polymer A10.

[Production Example 11: Preparation of (meth) acrylic base polymer A11]
Similar to Production Example 5, the (meth) acrylic base polymer A11 was used in the same manner as in Production Example 5 except that 50 parts of (2-methyl-2-ethyl-1,3-dioxolane-4-yl) methyl acrylate was used instead of 50 parts of MTGA. Solution was prepared. Table 1 shows the Tg and the dielectric constant of the (meth) acrylic base polymer A11.

[Production Example 12: Preparation of (meth) acrylic base polymer A12]
A solution of the (meth) acrylic base polymer A12 was prepared in the same manner as in Production Example 5 except that 50 parts of (3-ethyloxetane-3-yl) methyl acrylate was used instead of 50 parts of MTGA. Table 1 shows the Tg and the dielectric constant of the (meth) acrylic base polymer A12.

[Production Example 13: Preparation of (meth) acrylic base polymer A13]
A solution of the (meth) acrylic base polymer A13 was prepared in the same manner as in Production Example 5 except that 50 parts of cyclic trimethylolpropane formal acrylate was used instead of 50 parts of MTGA. Table 1 shows the Tg and the dielectric constant of the (meth) acrylic base polymer A13.

[Production Example 14: Preparation of (meth) acrylic base polymer A14]
Except for using a monomer mixture containing 80.3 parts of BA, 0.2 parts of acrylic acid (AA), 16 parts of PEA, 3 parts of N-vinylpyrrolidone (NVP) and 0.5 parts of 4HBA. A solution of the (meth) acrylic base polymer A14 was prepared in the same manner as in Production Example 1. Table 1 shows the Tg and the dielectric constant of the (meth) acrylic base polymer A14.

[Production Example 15: Preparation of (meth) acrylic base polymer A15]
A solution of the (meth) acrylic base polymer A15 was prepared in the same manner as in Production Example 1 except that a monomer mixture containing 99 parts of BA and 1 part of 4HBA was used. Table 1 shows the Tg and the dielectric constant of the (meth) acrylic base polymer A15.

[Manufacturing Example 16: Fabrication of Polarizing Plate P1]
1. 1. Preparation of Polarizer As the thermoplastic resin base material, an amorphous isophthal copolymer polyethylene terephthalate film (thickness: 100 μm) having a long shape, a water absorption of 0.75%, and a Tg of about 75 ° C. was used. One side of the resin base material was corona-treated.
100 weight of PVA-based resin in which polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gosefimer Z410") are mixed at a ratio of 9: 1. A PVA aqueous solution (coating solution) was prepared by dissolving 13 parts by weight of potassium iodide in water.
The PVA aqueous solution was applied to the corona-treated surface of the resin base material and dried at 60 ° C. to form a PVA-based resin layer having a thickness of 13 μm, and a laminate was prepared.
The obtained laminate was stretched 2.4 times in the longitudinal direction (longitudinal direction) between rolls having different peripheral speeds in an oven at 130 ° C. (aerial auxiliary stretching treatment).
Next, the laminate was immersed in an insolubilizing bath at a liquid temperature of 40 ° C. (a boric acid aqueous solution obtained by blending 4 parts by weight of boric acid with 100 parts by weight of water) for 30 seconds (insolubilization treatment).
Next, in a dyeing bath having a liquid temperature of 30 ° C. (an aqueous iodine solution obtained by mixing iodine and potassium iodide in a weight ratio of 1: 7 with respect to 100 parts by weight of water), the polarizing element finally obtained is charged. It was immersed for 60 seconds while adjusting the concentration so that the single transmittance (Ts) became a predetermined value (staining treatment).
Then, it was immersed in a cross-linked bath having a liquid temperature of 40 ° C. (a boric acid aqueous solution obtained by blending 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with respect to 100 parts by weight of water) for 30 seconds. (Crossing treatment).
Then, while immersing the laminate in a boric acid aqueous solution (boric acid concentration 4.0% by weight, potassium iodide concentration 5% by weight) at a liquid temperature of 70 ° C., the rolls having different peripheral speeds are vertically (longitudinal). The uniaxial stretching was performed so that the total stretching ratio was 5.5 times (underwater stretching treatment).
Then, the laminate was immersed in a washing bath having a liquid temperature of 20 ° C. (an aqueous solution obtained by blending 4 parts by weight of potassium iodide with 100 parts by weight of water) (cleaning treatment).
Then, while drying in an oven kept at 90 ° C., the sauce was brought into contact with a heating roll made of SUS whose surface temperature was kept at 75 ° C. for about 2 seconds (dry shrinkage treatment). The shrinkage rate in the width direction of the laminated body by the dry shrinkage treatment was 5.2%.
In this way, a substituent having a thickness of 5 μm was formed on the resin substrate.

2. 2. Preparation of Polarizing Plate An HC-TAC film as a protective layer was attached to the surface of the polarizing element obtained above (the surface opposite to the resin substrate) via an ultraviolet curable adhesive. Specifically, the curable adhesive was coated so as to have a total thickness of 1.0 μm, and bonded using a roll machine. Then, UV light was irradiated from the protective layer side to cure the adhesive. The HC-TAC film is a film in which a hard coat (HC) layer (thickness 7 μm) is formed on a triacetyl cellulose (TAC) film (thickness 25 μm), and the TAC film is attached so as to be on the splitter side. I matched it. Next, the resin base material was peeled off to form an iodine permeation suppressing layer (thickness 0.3 μm) on the peeled surface. The iodine permeation inhibitory layer was formed as follows.
Methyl methacrylate (MMA, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name "methyl methacrylate monomer") 97.0 parts, 3.0 parts of copolymerized monomer represented by the above general formula (1e), polymerization started. 0.2 part of the agent (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name "2,2'-azobis (isobutyronitrile)") was dissolved in 200 parts of toluene. Next, a polymerization reaction was carried out for 5.5 hours while heating at 70 ° C. under a nitrogen atmosphere to obtain a boron-containing acrylic resin solution (solid content concentration: 33%). The Tg of the obtained boron-containing acrylic polymer was 110 ° C., and the Mw was 80,000. 20 parts of this boron-containing acrylic polymer was dissolved in 80 parts of methyl ethyl ketone to obtain a resin solution (20%). This resin solution is applied to the peeled surface of the resin base material using a wire bar, the coating film is dried at 60 ° C. for 5 minutes, and iodine permeation is formed as a solidified coating film of the organic solvent solution of the resin. An inhibitory layer was formed.
In this way, a polarizing plate P1 having a structure of a protective layer (HC layer / TAC film) / adhesive layer / polarizing element / iodine permeation suppressing layer was obtained.

[Production Example 17: Fabrication of Polarizing Plate P2]
A 30 μm-thick polyvinyl alcohol film was stretched up to 3 times while being dyed in an iodine solution at 30 ° C. and a 0.3% concentration for 1 minute between rolls having different speed ratios. Then, the total stretch ratio was stretched to 6 times while being immersed in an aqueous solution containing boric acid at 60 ° C. and a concentration of 4% and potassium iodide at a concentration of 10% for 0.5 minutes. Then, it was washed by immersing it in an aqueous solution containing potassium iodide having a concentration of 1.5% at 30 ° C. for 10 seconds, and then dried at 50 ° C. for 4 minutes to obtain a polarizing element having a thickness of 12 μm. An HC-TAC film was bonded to one side of the polarizing element in the same manner as in Production Example 15. Further, an acrylic film having a lactone ring structure (thickness 20 μm) was bonded to the other surface of the polarizing element via an ultraviolet curable adhesive (thickness 1.0 μm). Further, an iodine permeation suppressing layer (thickness 0.3 μm) was formed on the surface of the acrylic film in the same manner as in Production Example 16. In this way, a polarizing plate P2 having a structure of a protective layer (HC layer / TAC film) / adhesive layer / polarizing element / adhesive layer / protective layer (acrylic film) / iodine permeation suppressing layer was obtained.

[Production Example 18: Fabrication of Polarizing Plate P3]
A polarizing plate P3 was obtained in the same manner as in Production Example 17 except that a cyclic olefin resin (COP) film (thickness 13 μm) was used instead of the acrylic film.

[Example 1]
1. Preparation of adhesive composition 3 parts of antistatic agent (trade name: LiTFSi30EA, manufactured by Mitsubishi Materials Co., Ltd.) with respect to 100 parts of the solid content of the solution of the (meth) acrylic base polymer A1 obtained in Production Example 1. , Benzoyl peroxide as a cross-linking agent (trade name: Niper BMT 40SV, manufactured by Nippon Oil & Fats Co., Ltd.) 0.3 parts, isocyanate-based cross-linking agent (trade name: Takenate D110N, manufactured by Mitsui Chemicals Co., Ltd.) 0.2 parts , Rework improver (trade name: Cyril SAT10, manufactured by Kaneka) 0.03 part, antioxidant (trade name: Irganox 1010, hindered phenol type, manufactured by BASF Japan) 0.3 part, and silane coupling A solution of an acrylic pressure-sensitive adhesive composition was prepared by blending 0.2 parts of an agent (trade name: A-100, manufactured by Soken Kagaku Co., Ltd., silane coupling agent containing an acetoacetyl group).

2. 2. Preparation of Platelet with Adhesive Layer A polyethylene terephthalate film (manufactured by Mitsubishi Chemical Polyester Film, trade name "MRF38", separator film) in which the solution of the acrylic pressure-sensitive adhesive composition obtained above is treated with a silicone-based release agent. The pressure-sensitive adhesive layer was applied to one side of the film so that the thickness of the pressure-sensitive adhesive layer after drying was 15 μm, and 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 onto the surface of the iodine permeation-suppressing layer of the polarizing plate P1 produced in Production Example 16 to prepare a polarizing plate with a pressure-sensitive adhesive layer. The obtained polarizing plate with an adhesive layer was subjected to the evaluations (2) to (7) above. The results are shown in Table 1.

[Examples 2 to 24 and Comparative Examples 1 to 12]
A polarizing plate with a pressure-sensitive adhesive layer was prepared by combining the polarizing plate and the pressure-sensitive adhesive layer shown in Table 1. The results are shown in Table 1. The abbreviations of antistatic agents in Table 1 are as follows.
LiTFSI: Lithium bis (trifluoromethanesulfonyl) imide EMI-FSI: 1-ethyl-3-methylimidazolium bis (fluorosulfonyl) imide TBMA-TFSI: tributylmethylammonyl bis (trifluoromethanesulfonyl) imide

[evaluation]
As is clear from Table 1, the polarizing plate of the embodiment of the present invention shows good results in the ESD test and maintains a low surface resistance value even after the reliability test. Further, the polarizing plate of the embodiment of the present invention has good suppression of delay bubbles, color loss during humidification, poor appearance after reliability test, and cracks during irregular shape processing.

The polarizing plate of the present invention is suitably used for an image display device such as a liquid crystal display device, an organic EL display device, and an inorganic EL display device.

11 Polarizer 12 Protective layer 30 Adhesive layer 40 Iodine permeation suppression layer 100 Polarizing plate

Claims (13)

A polarizing element, a protective layer provided on one side of the polarizing element, an iodine permeation suppressing layer provided on the other side of the polarizing element, and an iodine permeation suppressing layer on the opposite side of the polarizing element. With an adhesive layer provided,
The iodine permeation suppressing layer is a solidified product or a thermosetting product of a coating film of an organic solvent solution of a resin.
The pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer contains a base polymer and an antistatic agent.
The base polymer has a glass transition temperature of −50 ° C. or lower and a dielectric constant of 5.0 or higher at 100 kHz.
The surface resistance value of the pressure-sensitive adhesive layer is 1.0 × ¹⁰⁹ Ω / □ or less.
Polarizer. The polarizing plate according to claim 1, wherein the base polymer contains an alkoxy group-containing monomer as a monomer component. The polarizing plate according to claim 2, wherein the base polymer contains 20 parts by weight to 99 parts by weight of the alkoxy group-containing monomer with respect to 100 parts by weight of all the monomer components. The polarizing plate according to claim 3, wherein the alkoxy group-containing monomer is represented by the following formula:

In the formula, R ¹ is an alkyl group and n is an integer of 1 to 15. The polarizing plate according to claim 4, wherein the base polymer further contains a hydroxyl group-containing monomer as a monomer component. The polarizing plate according to any one of claims 1 to 5, wherein the content of the antistatic agent in the pressure-sensitive adhesive composition is 10 parts by weight or less with respect to 100 parts by weight of the base polymer. 6. The polarizing plate described in Crab. The polarizing plate according to any one of claims 1 to 7, wherein the pressure-sensitive adhesive composition further contains a silane coupling agent. The polarizing plate according to any one of claims 1 to 8, wherein the pressure-sensitive adhesive composition further contains an antioxidant. The polarizing plate according to any one of claims 1 to 9, wherein the pressure-sensitive adhesive layer has an adhesive force with respect to glass of 1.0 N / 25 mm or more. The resin constituting the iodine permeation suppressing layer contains a (meth) acrylic monomer exceeding 50 parts by weight and a monomer represented by the formula (1) exceeding 0 parts by weight and less than 50 parts by weight. The polarizing plate according to any one of claims 1 to 10, which comprises a copolymer obtained by polymerizing a monomer mixture:

(In the formula, X is a group consisting of a vinyl group, a (meth) acrylic group, a styryl group, a (meth) acrylamide group, a vinyl ether group, an epoxy group, an oxetane group, a hydroxyl group, an amino group, an aldehyde group, and a carboxyl group. Representing a functional group containing at least one reactive group selected, R ¹ and R ² each independently have a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, and a substituent. Represents an aryl group which may have a substituent or a heterocyclic group which may have a substituent, and R ¹ and R ² may be linked to each other to form a ring). The polarizing plate according to any one of claims 1 to 11, wherein the total thickness is 60 μm or less. An image display device comprising the polarizing plate according to any one of claims 1 to 12.

Images