阅读说明：本技术 带粘合剂层的光学膜、内嵌型液晶面板及液晶显示装置 (Optical film with adhesive layer, embedded liquid crystal panel and liquid crystal display device ) 是由 山本悟士 藤田昌邦 外山雄祐 于 2019-01-29 设计创作，主要内容包括：本发明提供具有良好的导电性、且粘合剂层的锚固性也优异的带粘合剂层的光学膜。带粘合剂层的光学膜(10)具备：光学膜(11)、设置于光学膜(11)的至少一个表面的抗静电层(13)、以及配置于抗静电层(13)上的粘合剂层(12)。该带粘合剂层的光学膜(10)中,粘合剂层(12)包含作为基础聚合物的聚合物A、和离子性化合物。另外,在粘合剂层(12)中,相对于基础聚合物(100)重量份,离子性化合物的含量为5～20重量份。另一方面,抗静电层(13)包含：导电性聚合物、和聚合物B。另外,聚合物A具有官能团a,聚合物B具有与官能团a相互作用的官能团b。而且,聚合物B的分子内的聚醚单元为10mol％以下。(The invention provides an optical film with an adhesive layer, which has good conductivity and excellent anchoring property of the adhesive layer. An optical film (10) with an adhesive layer is provided with: the antistatic film comprises an optical film (11), an antistatic layer (13) arranged on at least one surface of the optical film (11), and an adhesive layer (12) arranged on the antistatic layer (13). In the optical film (10) with an adhesive layer, the adhesive layer (12) contains a polymer A as a base polymer and an ionic compound. In addition, in the adhesive layer (12), relative to the base polymer (100) weight parts, the content of ionic compound is 5-20 weight parts. On the other hand, the antistatic layer (13) comprises: a conductive polymer, and a polymer B. Further, polymer a has a functional group a, and polymer B has a functional group B that interacts with functional group a. The polyether unit in the molecule of the polymer B is 10 mol% or less.)

1. An optical film with an adhesive layer, comprising: an optical film, an antistatic layer disposed on at least one surface of the optical film, and an adhesive layer disposed on the antistatic layer,

the adhesive layer contains a polymer A as a base polymer and an ionic compound,

in the adhesive layer, the content of the ionic compound is 5 to 20 parts by weight relative to 100 parts by weight of the base polymer,

the antistatic layer comprises a conductive polymer, and a polymer B,

the polymer A has a functional group a, the polymer B has a functional group B that interacts with the functional group a,

the polyether unit in the molecule of the polymer B is less than 10 mol%.

2. The optical film with an adhesive layer according to claim 1,

one of the functional group a and the functional group b is selected fromAt least 1 of carboxyl group, acid anhydride group, hydroxyl group and thiol group, and the other is selected fromAt least 1 of oxazoline group and isocyanate group.

3. The optical film with an adhesive layer according to claim 1 or 2,

the surface resistance values of the antistatic layer and the adhesive layer are both 1 × 10⁸～1×10¹⁰Omega/□.

4. The optical film with an adhesive layer according to any one of claims 1 to 3,

the ionic compound is selected from alkali metal salts and organic cation-anion salts.

5. The optical film with an adhesive layer according to any one of claims 1 to 4,

the ionic compound is an ionic liquid having a melting point of 40 ℃ or lower.

6. The optical film with an adhesive layer according to any one of claims 1 to 5,

the conductive polymer is a thiophene polymer.

7. The optical film with an adhesive layer according to any one of claims 1 to 6,

the polymer A is an acrylic polymer.

8. The optical film with an adhesive layer according to any one of claims 1 to 7,

the polymer B is a polymer containingAn oxazoline-based polymer.

9. The optical film with an adhesive layer according to any one of claims 1 to 8, which is used for a liquid crystal cell.

10. An in-cell liquid crystal panel comprising: a liquid crystal cell, and the optical film with an adhesive layer according to any one of claims 1 to 8,

the liquid crystal cell is an in-cell type liquid crystal cell, and is provided with:

a liquid crystal layer containing liquid crystal molecules;

a first transparent substrate and a second transparent substrate for holding the liquid crystal layer, wherein the first transparent substrate is arranged at the visible side; and

a touch sensing electrode section disposed between the first transparent substrate and the second transparent substrate,

the adhesive layer of the optical film with the adhesive layer is adhered to the surface of the first transparent substrate.

11. A liquid crystal display device comprising the in-cell type liquid crystal panel according to claim 10.

12. An optical film with an adhesive layer for use in an in-cell type liquid crystal cell,

the embedded liquid crystal unit is provided with:

a liquid crystal layer containing liquid crystal molecules;

a first transparent substrate and a second transparent substrate for holding the liquid crystal layer, wherein the first transparent substrate is arranged at the visible side; and

a touch sensing electrode section disposed between the first transparent substrate and the second transparent substrate,

the optical film with an adhesive layer is provided with:

an optical film;

an antistatic layer disposed on at least one surface of the optical film; and

an adhesive layer disposed on the antistatic layer,

the adhesive layer contains a polymer A as a base polymer and an ionic compound,

in the adhesive layer, the content of the ionic compound is 5 to 20 parts by weight relative to 100 parts by weight of the base polymer,

the antistatic layer comprises a conductive polymer, and a polymer B,

the polymer A has a functional group a, the polymer B has a functional group B that interacts with the functional group a,

the polyether unit in the molecule of the polymer B is less than 10 mol%.

13. The optical film with an adhesive layer according to claim 12,

one of the functional group a and the functional group b is at least 1 selected from the group consisting of a carboxyl group, an acid anhydride group, a hydroxyl group and a thiol group, and the other is selected from the group consisting of

14. The optical film with an adhesive layer according to claim 12 or 13,

the surface resistance values of the antistatic layer and the adhesive layer are both 1 × 10⁸～1×10¹⁰Omega/□.

15. The optical film with an adhesive layer according to any one of claims 12 to 14,

the ionic compound is selected from alkali metal salts and organic cation-anion salts.

16. The optical film with an adhesive layer according to any one of claims 12 to 15,

the ionic compound is an ionic liquid having a melting point of 40 ℃ or lower.

17. The optical film with an adhesive layer according to any one of claims 12 to 16,

the conductive polymer is a thiophene polymer.

18. The optical film with an adhesive layer according to any one of claims 12 to 17,

the polymer A is an acrylic polymer.

19. The optical film with an adhesive layer according to any one of claims 12 to 18,

the polymer B is a polymer containingAn oxazoline-based polymer.

Technical Field

The invention relates to an optical film with an adhesive layer, an embedded liquid crystal panel and a liquid crystal display device.

This application is based on the priority claim of japanese patent application No. 2018-025976 filed on 2018, 2, 16, the entire contents of which are incorporated by reference into the present specification.

Background

Optical films such as polarizing plates and retardation films, which are components of liquid crystal display devices, are generally bonded to liquid crystal panel members such as liquid crystal cells via an adhesive. In a typical embodiment, in the production process of a liquid crystal display device, the optical film is treated in the form of an optical film with a pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer on at least one side thereof. Such an optical film with an adhesive layer is advantageous in terms of handling property and productivity because it can constitute a liquid crystal panel only by removing a release liner protecting the adhesive layer and attaching the exposed adhesive surface to an adherend. On the other hand, when the release liner is removed as described above, static electricity is generated. This static electricity affects the alignment of the liquid crystal in the liquid crystal cell, and causes, for example, display unevenness of the liquid crystal (hereinafter also referred to as "static electricity unevenness"). Therefore, countermeasures have been taken such as providing an antistatic layer to an optical film having a pressure-sensitive adhesive layer, or including a conductive agent in the pressure-sensitive adhesive layer.

As for the static electricity countermeasure described above, a method of merely improving the conductivity cannot be adopted depending on the device configuration. For example, in a touch panel-mounted liquid crystal display device that has been put into practical use, the improvement in conductivity can adversely affect the touch sensing sensitivity. The capacitance system used in the touch panel-mounted liquid crystal display device is an input device that detects and drives a change in capacitance due to contact of a finger with the touch panel, and therefore, when the change in capacitance to be detected is unstable due to disturbance of an electric field caused by the presence of the antistatic layer, the sensitivity of the touch panel is lowered. In view of such background, touch panel-mounted types have been designed to have conductivity that can achieve both prevention of occurrence of static electricity unevenness and touch sensing sensitivity. As a prior art document disclosing such a prior art, patent document 1 is cited. Patent document 1 specifically relates to a so-called in-cell type liquid crystal panel in which electrodes related to a touch sensor are arranged inside a liquid crystal cell (i.e., inside a transparent substrate that holds a liquid crystal layer). Patent document 2 discloses an optical film with an adhesive layer in which an adhesion-promoting layer containing a conductive polymer is disposed between the optical film and the adhesive layer.

Disclosure of Invention

Problems to be solved by the invention

For example, in the touch panel-mounted liquid crystal display device as described above, it is required to have a good touch sensing sensitivity and to further improve the conductivity of the liquid crystal panel to prevent the occurrence of the electrostatic unevenness. In particular, in the in-cell type liquid crystal panel, unlike the external cell type liquid crystal panel, a conductive layer such as an ITO layer is not provided on the surface of the panel, and therefore, it is preferable to include not only a conductive agent in the pressure-sensitive adhesive layer but also an antistatic adhesion-promoting layer between the optical film and the pressure-sensitive adhesive layer to improve the conductivity of the entire panel (patent document 1). In such a configuration, if the amount of the conductive agent (typically, an ionic compound) in the pressure-sensitive adhesive layer is increased, further improvement in conductivity can be expected while maintaining good touch-sensing sensitivity. However, it has been clarified that if the amount of the ionic compound in the adhesive layer is increased, the adhesion (i.e., the anchoring property) of the adhesion-promoting layer to the adhesive layer for antistatic property is decreased.

The present invention relates to an improvement in an optical film with an adhesive layer created in view of the above-described circumstances, and an object of the present invention is to provide an optical film with an adhesive layer that has good electrical conductivity and also has excellent anchoring properties of the adhesive layer. Another object of the present invention is to provide an in-cell type liquid crystal panel and a liquid crystal display device having good touch sensitivity and improved antistatic unevenness by providing the optical film with an adhesive layer.

Means for solving the problems

According to the present specification, there is provided an optical film with an adhesive layer, comprising: the optical film comprises an optical film, an antistatic layer arranged on at least one surface of the optical film, and an adhesive layer arranged on the antistatic layer. In the optical film with an adhesive layer, the adhesive layer contains a polymer a as a base polymer and an ionic compound. In addition, in the adhesive layer, relative to the base polymer 100 weight portions, the ionic compound content is 5-20 weight portions. On the other hand, the antistatic layer includes: a conductive polymer, and a polymer B. The polymer a has a functional group a, and the polymer B has a functional group B that interacts with the functional group a. The polyether unit in the molecule of the polymer B is 10 mol% or less.

According to the above configuration, since the antistatic layer contains a conductive polymer and the adhesive layer contains an ionic compound, the conductivity of the laminated film is improved by the two layers of the antistatic layer and the adhesive layer, and good conductivity is obtained. For example, when the optical film with an adhesive layer is used for a liquid crystal panel, the occurrence of electrostatic unevenness can be highly prevented. Further, since the conductivity of the laminated film can be adjusted by the composition of the two layers, i.e., the antistatic layer and the adhesive layer, when the laminated film is used for a touch sensor-mounted liquid crystal panel, for example, the laminated film can be improved in conductivity, prevent the occurrence of static electricity unevenness, and maintain good touch sensing sensitivity. Further, since the polymer a in the adhesive layer and the polymer B in the antistatic layer have the functional group a and the functional group B, respectively, which interact with each other, the antistatic layer and the adhesive layer are easily adhered to each other. Here, the interaction between the two functional groups means a covalent bond, a dipole-dipole interaction, a hydrogen bond, a van der waals force, or the like, an interaction of bonding different molecules to each other, and an interaction of attraction.

In the above configuration, the ionic compound is contained in the pressure-sensitive adhesive layer in an amount of 5 to 20 parts by weight based on 100 parts by weight of the base polymer from the viewpoint of improvement in conductivity, but this may cause reduction in anchoring property. Specifically, the present inventors have conducted analysis and study of a cross section of a laminate of an optical film with an adhesive layer by TOF-SIMS (time of flight secondary ion mass spectrometry), and as a result, have obtained the following findings: if the polymer B contained in the antistatic layer has a polyether unit in addition to the functional group B in a given amount or more, the ionic compound contained in the adhesive layer is attracted to the antistatic layer side to migrate to the interface with the antistatic layer, and this phenomenon is associated with a decrease in anchoring property. Therefore, in the above configuration, a polymer having a polyether unit in a predetermined amount or less is used as the polymer B contained in the antistatic layer. This prevents migration of the ionic compound, which is caused by the polyether unit of the polymer B, to the antistatic layer side, thereby suppressing decrease in the anchoring property. This suppression of the decrease in the anchoring property can be achieved without decreasing the amount of the ionic compound in the adhesive layer, and therefore, can be achieved simultaneously with the improvement in the electrical conductivity.

In short, according to the above configuration, an optical film with an adhesive layer having good conductivity and excellent anchoring properties of the adhesive layer can be realized. When the optical film with an adhesive layer having such a structure is used for, for example, a liquid crystal panel, the antistatic property can be improved. Further, when the touch sensor is applied to a touch sensor mounting type, good touch sensing sensitivity can be exhibited. Further, the excellent anchoring property of the pressure-sensitive adhesive layer improves the workability and reworkability in the production of an optical structure (for example, a liquid crystal panel, and further, a liquid crystal display device) to which the pressure-sensitive adhesive layer-attached optical film is applied, and the structure to which the pressure-sensitive adhesive layer-attached optical film is attached contributes to excellent durability.

In a preferred embodiment of the technology disclosed herein (including an optical film with an adhesive layer, a liquid crystal panel, a touch sensor-mounted liquid crystal panel, an in-cell liquid crystal panel, and a liquid crystal display device, the same applies hereinafter), one of the functional group a and the functional group b is at least 1 selected from a carboxyl group, an acid anhydride group, a hydroxyl group, and a thiol group, and the other is selected from a carboxyl group, an acid anhydride group, a hydroxyl group, and a thiol group

At least 1 of oxazoline group and isocyanate group. In order to allow the functional group a and the functional group b to interact with each other, one of the functional groups is selected from the above-mentioned functional groups. Excellent anchoring properties are easily obtained by the interaction of the functional groups.

In a preferred embodiment of the technology disclosed herein, the antistatic layer and the pressure-sensitive adhesive layer each have a surface resistance of 1 × 10⁸～1×10¹⁰Omega/□, surface resistance of the antistatic layer and the adhesive layer was set to 1 × 10¹⁰Omega/□ or less, for example, in the liquid crystal panel application, based on the conductivity, can highly prevent the static electricity uneven, in addition, through the surface resistance value of the above-mentioned each layer is set to 1 × 10⁸The touch sensor-mounted liquid crystal panel can preferably ensure good touch sensitivity at a value of Ω/□ or more.

In a preferred embodiment of the technology disclosed herein, the ionic compound is selected from the group consisting of alkali metal salts and organic cation-anion salts. Among them, the ionic compound is more preferably an ionic liquid (for example, an organic cation-anion salt) having a melting point of 40 ℃ or lower. By using the ionic compound of the above kind, it is possible to obtain the conductivity of the adhesive layer and suitably suppress the decrease in the anchoring property of the adhesive layer.

In a preferred embodiment of the technology disclosed herein, the conductive polymer is a thiophene polymer. By using a thiophene polymer as the conductive polymer, the antistatic layer can be suitably provided with conductivity suitable for liquid crystal panel (for example, touch panel-mounted liquid crystal panel) applications.

In a preferred embodiment of the technology disclosed herein, the polymer a is an acrylic polymer. By using an acrylic polymer as the base polymer of the pressure-sensitive adhesive layer, the optical film disposed on the back surface thereof can be favorably adhered and fixed to an adherend such as a liquid crystal cell.

In a preferred embodiment of the technology disclosed herein, the polymer B is a polymer containing

An oxazoline-based polymer. By using a container containingThe oxazoline-based polymer can suitably improve the adhesion to the pressure-sensitive adhesive layer as the polymer B contained in the antistatic layer, and can suitably exert an effect of making the polyether unit in the polymer B10 mol% or less.

Further, according to the present specification, there is provided an in-cell type liquid crystal panel including: a liquid crystal cell, and any of the adhesive layer-bearing optical films disclosed herein. In the liquid crystal panel, the liquid crystal cell includes: a liquid crystal layer containing liquid crystal molecules; a first transparent substrate and a second transparent substrate arranged to sandwich the liquid crystal layer (wherein the first transparent substrate is arranged on the visible side of the liquid crystal panel); and a touch sensing electrode portion disposed between the first transparent substrate and the second transparent substrate. The pressure-sensitive adhesive layer of the optical film with a pressure-sensitive adhesive layer is bonded to the surface of the first transparent substrate. In the inline type having no conductive layer on the panel surface, it is necessary to improve the conductivity by an optical film with an adhesive layer. By using the optical film with an adhesive layer disclosed herein for an in-cell type liquid crystal panel, it is possible to maintain good touch sensing sensitivity and to obtain antistatic unevenness due to its high conductivity.

In the present specification, the term "touch sensor electrode portion" is a concept including at least one (preferably both) of a detection electrode and a drive electrode related to touch sensing, and also includes an integrated electrode in which the detection electrode and the drive electrode are integrally formed.

Further, according to the present specification, there is provided a liquid crystal display device including any of the in-cell type liquid crystal panels disclosed herein. The embedded liquid crystal panel highly suppresses the occurrence of static electricity unevenness and has good touch sensing sensitivity. Further, the adhesive layer is excellent in anchoring property, and therefore, is also excellent in processability and durability. Therefore, by using the in-cell type liquid crystal panel disclosed herein, a high-quality liquid crystal display device in which defects are unlikely to occur can be provided.

Drawings

Fig. 1 is a schematic cross-sectional view illustrating an optical film with an adhesive layer according to an embodiment.

Fig. 2 is a schematic cross-sectional view showing an in-cell type liquid crystal panel of one embodiment.

Fig. 3 is a schematic cross-sectional view showing an in-cell type liquid crystal panel of one embodiment.

Fig. 4 is a schematic cross-sectional view showing an in-cell type liquid crystal panel of one embodiment.

Fig. 5 is a schematic cross-sectional view showing an in-cell type liquid crystal panel of one embodiment.

Fig. 6 is a schematic cross-sectional view showing an in-cell type liquid crystal panel of one embodiment.

Fig. 7 is a schematic cross-sectional view showing a semi-inline type liquid crystal panel of one embodiment.

Fig. 8 is a schematic cross-sectional view showing an external-fit liquid crystal panel according to an embodiment.

FIG. 9 is a graph schematically showing the results of TOF-SIMS analysis for a constitution using a polymer B having more than 10 mol% of polyether units.

FIG. 10 is a graph schematically showing the results of TOF-SIMS analysis of a composition using a polymer B having 10 mol% or less of polyether units.

Description of the symbols

10. 110, 210, 310, 410, 510, 610, 710: (first) optical film with adhesive layer

11. 111, 211, 311, 411, 511, 611, 711: (first) optical film

11A: first side of optical film

11B: second side of optical film

12. 112, 212, 312, 412, 512, 612, 712: (first) adhesive layer

13. 113, 213, 313, 413, 513, 613, 713: antistatic layer

14. 114, 214, 314, 414, 514, 614, 714: surface treatment layer

100. 200, 300, 400, 500: embedded liquid crystal panel

600: semi-embedded liquid crystal panel

700: externally-embedded liquid crystal panel

120. 220, 320, 420, 520, 620, 720: liquid crystal cell

125. 225, 325, 425, 525, 625, 725: liquid crystal layer

130. 230, 330, 430, 530, 630, 730: touch sensing electrode section

131. 231, 331, 431, 531, 631, 731: detection electrode

132. 232, 332, 432, 532, 632, 732: driving electrode

141. 241, 341, 441, 541, 641, 741: a first transparent substrate

142. 242, 342, 442, 542, 642, 742: a second transparent substrate

150. 250, 350, 450, 550, 650, 750: second optical film with adhesive layer

151. 251, 351, 451, 551, 651, 751: second optical film

152. 252, 352, 452, 552, 652, 752: second adhesive layer

170. 270, 370, 470, 570, 670, 770: conduction structure

171. 271, 371, 471, 571, 671, 771: conduction structure

Detailed Description

Preferred embodiments of the present invention will be described below. It is to be noted that matters necessary for carrying out the present invention other than the matters specifically mentioned in the present specification can be understood by those skilled in the art based on the teaching about the carrying out of the invention described in the present specification and the technical common knowledge at the time of application. The present invention can be implemented based on the content disclosed in the present specification and the technical common knowledge in the field.

In the following drawings, members and portions that exhibit the same function are sometimes denoted by the same reference numerals, and redundant description thereof may be omitted or simplified. In addition, the embodiments shown in the drawings are illustrated for the purpose of clearly explaining the present invention, and do not necessarily accurately show the size and scale of products and components actually provided.

< composition >

Fig. 1 schematically shows a configuration example of the optical film with an adhesive layer disclosed herein. The optical film with an adhesive layer 10 includes an optical film 11, an antistatic layer 13, and an adhesive layer 12 in this order. Specifically, the antistatic layer 13 is provided on one surface (first surface) 11A of the optical film 11, and the pressure-sensitive adhesive layer 12 is disposed on one surface (surface on the side opposite to the optical film 11 side) of the antistatic layer 13. The optical film 10 with an adhesive layer may have a surface treatment layer 14 on the other surface (second surface, also referred to as back surface) 11B of the optical film 11. The optical film with an adhesive layer 10 is used by attaching the adhesive surface 12A of the adhesive layer 12 to the surface of an object to be adhered (an object to be protected, for example, an optical member such as a transparent substrate on the viewing side of a liquid crystal cell). The optical film with an adhesive layer 10 before use (i.e., before attachment to an adherend) may be in a form in which the adhesive surface (attachment surface to the adherend) 12A of the adhesive layer 12 is protected by a release liner (not shown) having a release surface at least on the adhesive layer 12 side. A surface protective film (not shown) may be provided on the back surface of the optical film 10 with an adhesive layer (the outer surface of the surface treatment layer 14, or the back surface of the optical film 11 in the case where the surface treatment layer 14 is not provided).

< optical film >

The optical film disclosed herein may be an optical film such as a polarizing film (also referred to as a polarizing plate), a phase difference film (also referred to as a phase difference plate including a wave plate), an optical compensation film, a brightness enhancement film, a light diffusion film, a reflection film, or a reflection film, which is used as an optical member in an image display device such as a liquid crystal display device. The optical film of a preferred embodiment is a polarizing film or a retardation film. One of them may be used alone to form an optical film, or 2 or more (typically, stacked) may be used in combination as an optical film. Such an optical film may be formed by laminating a polarizing layer including a polarizing film and another optical layer such as a retardation film. Hereinafter, a polarizing film will be described as a preferred example of the optical film, but the technique disclosed herein is not intended to be limited thereto.

The polarizing film used as a preferred example of the optical film disclosed herein may generally include a polarizer and a transparent protective film disposed on at least one surface (preferably both surfaces) of the polarizer. The polarizer is not particularly limited, and for example, a polarizer obtained by adsorbing a dichroic substance such as iodine or a dichroic dye to a hydrophilic polymer film and uniaxially stretching the film can be used. Examples of the hydrophilic polymer film include a polyvinyl alcohol (PVA) -based film, a partially formalized PVA-based film, and an ethylene-vinyl acetate copolymer-based partially saponified film. As the polarizer, a polyene alignment film such as a dehydrated PVA product or a desalted polyvinyl chloride product may be used. Among them, a polarizer made of a dichroic material such as a PVA-based film and iodine is preferable.

The thickness of the polarizer is not particularly limited, but is generally about 80 μm or less. In addition, from the viewpoint of thickness reduction, a polarizer having a small thickness of about 10 μm or less (preferably about 1 to 7 μm) may be used. The polarizer having a small thickness has excellent durability because it has little variation in thickness, excellent visibility, and little dimensional change. The use of a polarizer having a small thickness also contributes to the reduction in the thickness of the polarizing film.

As a material constituting the transparent protective film, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, and the like can be preferably used. Specific examples of such thermoplastic resins include: cellulose resins such as cellulose Triacetate (TAC), polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, cycloolefin resins (typically norbornene resins), polyarylate resins, polystyrene resins, PVA resins, and mixtures of 2 or more of these resins. In a preferred embodiment, the following configuration may be adopted: a transparent protective film made of, for example, a thermoplastic resin such as TAC is disposed on one surface of the polarizer, and a transparent protective film made of a cycloolefin resin (typically, a norbornene resin) or a (meth) acrylic resin is disposed on the other surface. In another preferred embodiment, a transparent protective film made of a thermoplastic resin such as TAC may be disposed on one surface of the polarizer, and a thermosetting resin or an ultraviolet-curable resin such as (meth) acrylic, urethane, acrylic urethane, epoxy, silicone, or the like may be used as the transparent protective film on the other surface. These transparent protective films may be laminated on the polarizer via an adhesive layer of PVA type or the like. The transparent protective film may contain 1 or more kinds of any appropriate additives depending on the purpose.

The adhesive used for bonding the polarizer and the transparent protective film is not particularly limited as long as it is optically transparent, and various types of adhesives such as aqueous, solvent-based, hot-melt, radical-curable, and cation-curable can be used. Among them, an aqueous adhesive or a radical curing adhesive is preferable.

In addition, a surface treatment layer may be provided on the back surface of the optical film (i.e., the surface opposite to the side on which the antistatic layer is provided). The surface treatment layer may be provided on the above-described transparent protective film used for the optical film, or may be separately provided on the optical film from the transparent protective film.

A preferable example of the surface treatment layer is a hard coat layer. As a material for forming the hard coat layer, for example, a thermoplastic resin, a material which is cured by heat or radiation, or the like can be used. Examples of the material to be used include radiation-curable resins such as thermosetting resins, ultraviolet-curable resins, and electron beam-curable resins. Among them, ultraviolet curable resins are preferred. The ultraviolet curable resin is excellent in processability because a cured resin layer can be efficiently formed by curing treatment by ultraviolet irradiation. The curable resin may be one selected from 1 or 2 or more of polyesters, acrylics, urethanes, amides, silicones, epoxies, melamines, etc., and these may be in the form of monomers, oligomers, polymers, etc. The radiation curable resin (typically, an ultraviolet curable resin) is particularly preferable because it does not require heat (may cause damage to the substrate) and is excellent in processing speed.

Other examples of the surface-treated layer include an antiglare layer and an antireflection layer for the purpose of improving visibility. An antiglare layer or an antireflection layer may be provided on the hard coat layer. The material constituting the antiglare layer is not particularly limited, and for example: radiation curable resins, thermosetting resins, thermoplastic resins, and the like. As the antireflection layer, titanium oxide, zirconium oxide, silicon oxide, magnesium fluoride, or the like can be used. The antireflection layer may have a multilayer structure composed of a plurality of layers. Other examples of the surface treatment layer include an anti-adhesion layer.

When the technique disclosed herein is implemented to include a surface treatment layer, the surface treatment layer may contain an antistatic agent to impart conductivity. As the antistatic agent, a conductive agent described later can be used without particular limitation.

The thickness of the optical film disclosed herein (the total thickness thereof in the case of being composed of a plurality of layers) is not particularly limited, and is, for example, about 1 μm or more, usually about 10 μm or more, and preferably about 20 μm or more. For example, in the case of providing a transparent protective film, the thickness of the optical film is preferably about 30 μm or more, more preferably about 50 μm or more, and still more preferably about 70 μm or more, from the viewpoint of protection and the like. The upper limit of the optical film is not particularly limited, and is, for example, about 1mm or less, usually about 500 μm or less, and preferably about 300 μm or less. From the viewpoint of optical characteristics and thickness reduction, the thickness is preferably about 150 μm or less, more preferably about 120 μm or less, and still more preferably about 100 μm or less.

< adhesive layer >

The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer disclosed herein is not particularly limited as long as the polymer a as a base polymer constituting the pressure-sensitive adhesive layer has the functional group a, and may be, for example, a pressure-sensitive adhesive layer composed of 1 or 2 or more kinds selected from various pressure-sensitive adhesives such as acrylic, rubber, urethane, silicone, vinyl alkyl ether, vinyl pyrrolidone, acrylamide, and cellulose. Therefore, the polymer a as the base polymer constituting the pressure-sensitive adhesive layer may be an acrylic polymer, a rubber polymer, a urethane polymer, a silicone polymer, a vinyl alkyl ether polymer, a vinyl pyrrolidone polymer, an acrylamide polymer, a cellulose polymer, or the like. Among them, acrylic adhesives are preferred from the viewpoint of transparency, suitable wettability, cohesiveness, adhesive properties such as adhesiveness, weather resistance, heat resistance, and the like. The technology disclosed herein will be described in more detail below, mainly with reference to a configuration in which the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer, but the pressure-sensitive adhesive layer is not intended to be limited to being formed of an acrylic pressure-sensitive adhesive.

(acrylic adhesive)

The acrylic pressure-sensitive adhesive used in a preferred embodiment is a pressure-sensitive adhesive containing an acrylic polymer as a base polymer (a main component of the polymer component contained in the pressure-sensitive adhesive, that is, a component having a content of more than 50% by weight). The "acrylic polymer" refers to a polymer having a monomer having at least 1 (meth) acryloyl group in 1 molecule (hereinafter, this may be referred to as "acrylic monomer") as a main constituent monomer component (a component that occupies 50% by weight or more of the total amount of monomers constituting the acrylic polymer, which is a main component of the monomer). The "(meth) acryloyl group" means an acryloyl group and a methacryloyl group. Likewise, "(meth) acrylate" is meant to include both acrylates and methacrylates.

(acrylic Polymer)

The acrylic polymer as the base polymer of the acrylic pressure-sensitive adhesive is typically a polymer containing an alkyl (meth) acrylate as a main constituent monomer component. As the alkyl (meth) acrylate, for example, a compound represented by the following formula (1) can be suitably used.

CH₂＝C(R¹)COOR²(1)

Here, R in the above formula (1)¹Is a hydrogen atom or a methyl group, R²An alkyl group having 1 to 20 carbon atoms (including a chain alkyl group and an alicyclic alkyl group). R is preferably R from the viewpoint of easily obtaining an adhesive excellent in adhesive properties²Is 1 to 18 carbon atoms or less, and the range of the number of carbon atoms may be represented by C_1-18) The alkyl (meth) acrylate having a chain alkyl group (including a linear alkyl group and a branched alkyl group) of (2), more preferably having C_1-14An alkyl (meth) acrylate having a chain alkyl group of (1). As C_1-14Specific examples of the chain alkyl group of (2) include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, isooctyl group, 2-ethylhexyl group, n-nonyl group, isononyl group, n-decyl group, isodecyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, and n-tetradecyl group. For as R²Examples of the alicyclic alkyl group include cyclohexyl and isobornyl.

In a preferred embodiment, R in the total amount of monomers used for synthesizing the acrylic polymer (hereinafter also referred to as "all raw material monomers") is selected from R in the above formula (1)²Is C_1-18Chain alkyl (meth) acrylate (more preferably C)_1-14More preferably C_4-10The chain-like alkyl (meth) acrylate (e.g., one or both of n-Butyl Acrylate (BA) and 2-ethylhexyl acrylate (2 EHA)) occupies about 50% by weight or more, more preferably about 60% by weight or more, for example, about 70% by weight or more. The acrylic polymer obtained from such a monomer composition is preferable because it can easily form an adhesive agent having adhesive properties suitable for the use disclosed herein. C is the amount of the total amount of the above monomers in view of introduction of the functional group a, adjustment of retardation, adjustment of refractive index, and the like_1-18(e.g. C)_1-14Typically preferably C_4-10) The proportion of the chain-like alkyl (meth) acrylate(s) is preferably about 95% by weight or less, more preferably about 90% by weight or less, and still more preferably 85% by weight or less (for example, 80% by weight or less).

In addition, from the viewpoints of adhesion characteristics, durability, adjustment of retardation, adjustment of refractive index, and the like, it is preferable to use (meth) acrylate having an aromatic ring structure as a monomer used for synthesis of the acrylic polymer. Examples of the aromatic ring structure of the (meth) acrylate having an aromatic ring structure include a benzene ring, a naphthalene ring, a thiophene ring, a pyridine ring, a pyrrole ring, and a furan ring. Among them, (meth) acrylates having a benzene ring and a naphthalene ring are preferable. As the (meth) acrylate having an aromatic ring structure, various aryl (meth) acrylates, arylalkyl (meth) acrylates, aryloxyalkyl (meth) acrylates, and the like can be used.

Specific examples of the (meth) acrylate having an aromatic ring structure include: phenyl (meth) acrylate, o-phenylphenol (meth) acrylate, phenoxymethyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxypropyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethylene glycol (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, ethylene oxide-modified nonylphenol (meth) acrylate, ethylene oxide-modified cresol (meth) acrylate, phenol ethylene oxide-modified (meth) acrylate, phenoxy-2-hydroxypropyl (meth) acrylate, methoxybenzyl (meth) acrylate, chlorobenzyl (meth) acrylate, tolyl (meth) acrylate, styrene (meth) acrylate, hydroxyethylated β -naphthol acrylate, 2-naphthyloxyethyl (meth) acrylate, phenyloxyethyl (meth) acrylate, phenoxyethylated β -naphthol acrylate, phenoxyethyl (meth) acrylate, phenoxyethyl (, 2- (4-methoxy-1-naphthyloxy) ethyl (meth) acrylate, phenyl thio (meth) acrylate, pyridyl (meth) acrylate, pyrrolyl (meth) acrylate, and poly (styrene (meth) acrylate). A biphenyl ring-containing (meth) acrylate such as biphenyl (meth) acrylate may also be used. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds. Among them, phenoxyethyl (meth) acrylate and benzyl (meth) acrylate are preferable.

When a (meth) acrylate having an aromatic ring structure is used, the content thereof is appropriately set based on the adhesive property, optical property, and the like. The amount of the (meth) acrylate having an aromatic ring structure is preferably about 5% by weight or more of the total amount of the monomers used for synthesizing the acrylic polymer, and is preferably about 10% by weight or more, more preferably about 15% by weight or more (for example, about 20% by weight or more) from the viewpoint of satisfactorily exerting the effects (improvement in durability, improvement in liquid crystal display unevenness, and the like) of the (meth) acrylate having an aromatic ring structure. The upper limit of the amount of the (meth) acrylate having an aromatic ring structure to be used is suitably about 30% by weight or less, and is preferably less than about 30% by weight, more preferably less than about 25% by weight (for example, less than 22% by weight) in view of the adhesive property, the anchoring property of the adhesive layer, and the like.

Typically, the functional group a of the polymer a (typically, an acrylic polymer) as the base polymer is introduced into the molecule of the polymer a by copolymerizing a monomer having the functional group a. The functional group a interacts with a functional group b contained in an antistatic layer described later, and improves adhesion between the antistatic layer and the adhesive layer. In addition, crosslinking points are formed in the pressure-sensitive adhesive layer, and the cohesive force and heat resistance of the pressure-sensitive adhesive can be improved. The glass transition temperature (Tg) of the polymer a can also be adjusted by using an appropriate amount of a monomer having the functional group a, thereby adjusting the adhesive characteristics. The introduction form of the functional group a is not limited to copolymerization of the monomer containing the functional group a, and may be carried out by adding a compound containing the functional group a to the polymer a by an appropriate chemical reaction at an appropriate timing after polymerization of the polymer a.

The functional group a is not particularly limited as long as it interacts with the functional group b. The functional group a may be selected from the group consisting of a carboxyl group, an acid anhydride group, a hydroxyl group and a thiol group, or fromOxazoline group and isocyanate. The functional group a may be used alone in 1 kind, or may be used in 2 or more kinds. Among them, the functional group a is preferably at least 1 functional group selected from a carboxyl group, an acid anhydride group, a hydroxyl group and a thiol group. Preferred examples of the monomer having the functional group a to be copolymerized in the polymer a (typically, an acrylic polymer) are a carboxyl group-containing monomer, an acid anhydride group-containing monomer, and a hydroxyl group-containing monomer. The thiol group can be introduced by adding a compound containing a thiol group to the polymer a by an appropriate chemical reaction at an appropriate timing after polymerization of the polymer a.

As the carboxyl group-containing monomer, there can be exemplified: ethylenically unsaturated monocarboxylic acids such as Acrylic Acid (AA), methacrylic acid (MAA), carboxyethyl (meth) acrylate, and carboxypentyl (meth) acrylate; ethylenically unsaturated dicarboxylic acids such as itaconic acid, maleic acid, fumaric acid, crotonic acid, methacrylic acid, and citraconic acid.

Examples of the acid anhydride group-containing monomer include maleic anhydride, itaconic anhydride, and anhydrides of the above ethylenically unsaturated dicarboxylic acids.

Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyhexyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, and methyl (meth) acrylate (4-hydroxymethylcyclohexyl) methyl ester; alkylene glycol (meth) acrylates such as polyethylene glycol mono (meth) acrylate and polypropylene glycol mono (meth) acrylate; unsaturated alcohols such as vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether and diethylene glycol monovinyl ether; and so on.

These functional group-containing monomers may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Monomers having functional groups other than those described above may be copolymerized with the acrylic polymer in the art disclosed herein. The monomer can be used for the purpose of, for example, adjusting Tg of the acrylic polymer, adjusting adhesive properties, and the like. Examples of the monomer capable of improving the cohesive force and heat resistance of the adhesive include a sulfonic acid group-containing monomer, a phosphoric acid group-containing monomer, and a cyano group-containing monomer. Examples of the monomer that can introduce a functional group that can serve as a crosslinking group site into the acrylic polymer or can contribute to improvement of adhesion to an adherend such as glass include an amide group-containing monomer, an amino group-containing monomer, an imide group-containing monomer, an epoxy group-containing monomer, a monomer having a ring containing a nitrogen atom, a ketone group-containing monomer, an isocyanate group-containing monomer, and an alkoxysilyl group-containing monomer. Among them, amide group-containing monomers, amino group-containing monomers, and monomers having a ring containing a nitrogen atom, as exemplified below, can be preferably used.

Amide group-containing monomer: such as (meth) acrylamide, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide.

Amino group-containing monomers: for example aminoethyl (meth) acrylate, N-dimethylaminoethyl (meth) acrylate, N-dimethylaminopropyl (meth) acrylate, tert-butylaminoethyl (meth) acrylate.

Monomers having a ring containing a nitrogen atom: such as N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperOxazines, N-vinylpyrazines, N-vinylpyrroles, N-vinylimidazoles, N-vinyls

Oxazole, N-vinyl morpholine, N-vinyl caprolactam, N- (meth) acryloyl morpholine, N- (meth) acryloyl pyrrolidone.

The content of the functional group-containing monomer is not particularly limited, and is usually about 40% by weight or less, preferably about 30% by weight or less, in the total amount of the monomers used for synthesizing the base polymer (typically, an acrylic polymer), and is preferably about 20% by weight or less, more preferably about 15% by weight or less, and still more preferably 10% by weight or less (for example, 5% by weight or less) from the viewpoint of adhesion characteristics and the like. The lower limit of the content of the functional group-containing monomer in the total amount of the monomers used for synthesizing the base polymer is usually about 0.001 wt% or more, and preferably about 0.01 wt% or more, and from the viewpoint of suitably exerting the effect of the functional group-containing monomer on copolymerization, it is preferably about 0.1 wt% or more, more preferably about 0.5 wt% or more, and still more preferably about 1 wt% or more.

The content of the monomer having the functional group a is not particularly limited, and is preferably about 20% by weight or less, more preferably about 15% by weight or less, and even more preferably about 10% by weight or less (for example, about 5% by weight or less), of the total amount of the monomers used for synthesizing the base polymer (typically, the acrylic polymer), from the viewpoint of adhesion properties and the like. The lower limit of the content of the monomer containing the functional group a in the total amount of the monomers used for synthesizing the base polymer is usually about 0.001 wt% or more, and about 0.01 wt% or more is appropriate, and from the viewpoint of suitably exerting the effect of improving the fixing property by the functional group a, the lower limit is preferably about 0.1 wt% or more, more preferably about 0.5 wt% or more, and still more preferably about 1 wt% or more.

In a preferred embodiment, at least one (preferably both) of the carboxyl group-containing monomer and the hydroxyl group-containing monomer is used as the monomer component of the base polymer (typically, an acrylic polymer). When the carboxyl group-containing monomer is used as the monomer component of the acrylic polymer, the amount of the total amount of the monomers used for synthesizing the carboxyl group-containing monomer in the base polymer is usually about 0.001 wt% or more, preferably about 0.01 wt% or more, more preferably about 0.1 wt% or more, still more preferably about 0.2 wt% or more, for example, 1 wt% or more, and may also be 3 wt% or more, from the viewpoint of the cohesive property of the adhesive, the anchoring property, and the like. The upper limit of the amount of the carboxyl group-containing monomer to be used is suitably set in order to obtain desired adhesive properties, and is suitably about 10% by weight or less, preferably about 8% by weight or less, more preferably about 6% by weight or less, for example, about 3% by weight or less, and may be about 1% by weight or less, of the total amount of the monomers used for synthesizing the base polymer.

When a hydroxyl group-containing monomer is used as a monomer component of the base polymer (typically, an acrylic polymer), the amount of the hydroxyl group-containing monomer in the total amount of monomers used for synthesizing the base polymer is usually about 0.001 wt% or more, preferably about 0.01 wt% or more, and more preferably about 0.1 wt% or more, from the viewpoint of cohesiveness of the adhesive, anchoring property, and the like. The upper limit of the amount of the hydroxyl group-containing monomer to be used is suitably set in order to obtain desired adhesive properties, and is suitably about 5% by weight or less, preferably about 3% by weight or less, and more preferably about 1% by weight or less (for example, about 0.5% by weight or less) of the total amount of the monomers used in the synthesis of the base polymer.

As other copolymerizable monomers that can be used in addition to the above-mentioned functional group-containing monomer, there can be mentioned: vinyl ester monomers such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene, substituted styrene (α -methylstyrene, etc.), vinyl toluene, etc.; non-aromatic ring-containing (meth) acrylates such as cyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate, and isobornyl (meth) acrylate; olefin monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene; chlorine-containing monomers such as vinyl chloride and vinylidene chloride; alkoxy group-containing monomers such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate; vinyl ether monomers such as methyl vinyl ether, ethyl vinyl ether and isobutyl vinyl ether; and so on. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds. When such other copolymerizable monomer is used, the amount thereof is not particularly limited, and is usually suitably about 30% by weight or less (e.g., 0 to 30% by weight), preferably about 10% by weight or less (e.g., about 3% by weight or less), of the total amount of the monomers used for synthesis of the base polymer (typically, the acrylic polymer). The technique disclosed herein may be carried out in such a manner that the monomer component used for the synthesis of the base polymer does not substantially contain the other copolymerizable monomer.

As another example of the copolymerizable monomer that can constitute the base polymer (typically, an acrylic polymer), a polyfunctional monomer is cited. Specific examples of the polyfunctional monomer include compounds having 2 or more (meth) acryloyl groups in 1 molecule, such as 1, 6-hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and methylenebisacrylamide. The polyfunctional monomer may be used alone in 1 kind, or may be used in combination in 2 or more kinds. When such a polyfunctional monomer is used, the amount thereof to be used is not particularly limited, and is usually preferably about 2% by weight or less (more preferably about 1% by weight or less) of the total amount of the monomers used for synthesis of the base polymer.

The initiator used in the polymerization may be suitably selected from known or commonly used polymerization initiators. For example, azo polymerization initiators such as 2, 2' -azobisisobutyronitrile can be preferably used. Examples of the polymerization initiator include peroxide initiators (e.g., persulfates such as potassium persulfate, benzoyl peroxide, and hydrogen peroxide); substituted ethane initiators such as phenyl-substituted ethane; an aromatic carbonyl compound; and so on. As still another example of the polymerization initiator, a redox-type initiator based on a combination of a peroxide and a reducing agent can be cited. Examples of the redox initiator include a combination of a peroxide and ascorbic acid (e.g., a combination of hydrogen peroxide and ascorbic acid), a combination of a peroxide and an iron (II) salt (e.g., a combination of hydrogen peroxide and an iron (II) salt), and a combination of a persulfate and sodium bisulfite.

Such polymerization initiators may be used alone in 1 kind, or may be used in combination in 2 or more kinds. The amount of the polymerization initiator to be used may be any amount as long as it is usually used, and may be selected from the range of about 0.005 to 1 part by weight (typically about 0.01 to 1 part by weight) based on 100 parts by weight of the total raw material monomers.

The method for obtaining the base polymer (typically, an acrylic polymer) having such a monomer composition is not particularly limited, and various polymerization methods such as solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization can be employed. From the viewpoint of transparency, adhesive properties, and the like, solution polymerization can be suitably employed. As a method of supplying the monomers in the polymerization, a one-shot feeding method of supplying all the monomer raw materials at once, a continuous supply (dropwise addition) method, a batch supply (dropwise addition) method, and the like can be suitably employed. The polymerization temperature may be suitably selected depending on the kind of the monomer and the solvent used, the kind of the polymerization initiator, and the like, and may be, for example, about 20 ℃ to 170 ℃ (typically about 40 ℃ to 140 ℃). The base polymer to be synthesized may be a random copolymer, a block copolymer, a graft copolymer, or the like. From the viewpoint of productivity and the like, a random copolymer is generally preferred.

As a solvent (polymerization solvent) used in the solution polymerization of a preferred embodiment, for example, aromatic compounds (typically aromatic hydrocarbons) selected from toluene, xylene, and the like; acetic acid esters such as ethyl acetate; aliphatic or alicyclic hydrocarbons such as hexane; halogenated alkanes such as 1, 2-dichloroethane; lower alcohols (e.g., monohydric alcohols having 1 to 4 carbon atoms) such as isopropyl alcohol; ethers such as t-butyl methyl ether; ketones such as methyl ethyl ketone; and any 1 or a mixture of 2 or more of the solvents.

Weight average molecule of base polymer (acrylic polymer) in the technique disclosed herein, in terms of standard polystyrene obtained by GPC (gel permeation chromatography)An amount (Mw) of about 10 × 10⁴The above is preferable, and from the viewpoint of durability, heat resistance and the like, about 50 × 10 is preferable⁴Above, more preferably about 80 × 10⁴Above, more preferably about 120 × 10⁴In addition, the Mw is about 500 × 10⁴The following is preferable, and from the viewpoint of coatability when forming the pressure-sensitive adhesive layer, it is preferably about 300 × 10⁴Less, more preferably about 250 × 10⁴Hereinafter, more preferably about 200 × 10⁴The following.

Specifically, the Mw can be measured under the following conditions using a GPC measurement apparatus under the trade name "HLC-8120 GPC" (manufactured by Tosoh corporation).

[ measurement conditions of GPC ]

Sample concentration: 0.2 wt% (tetrahydrofuran solution)

Sample injection amount: 100 μ L

Eluent: tetrahydrofuran (THF)

Flow rate (flow velocity): 0.8 mL/min

Column temperature (measurement temperature): 40 deg.C

A chromatographic column: G7000H, manufactured by Tosoh corporation_XL+GMH_XL+GMH_XL

Column size: each one ofMeter 90cm

A detector: differential Refractometer (RI)

Standard sample: polystyrene

(Ionic Compound)

The adhesive layer disclosed herein is characterized by containing an ionic compound. The ionic compound as a conductive component improves the conductivity of the adhesive layer. It is possible to preferably use, for example, 1 or 2 or more selected from alkali metal salts, organic cation-anion salts and the like. From the viewpoint of anchorage, organic cation-anion salts are more preferable.

(alkali metal salt)

Examples of the alkali metal ion constituting the cation portion of the alkali metal salt include lithium, sodium, potassium and the like. Among these alkali metal ions, lithium ions are preferable.

The anion portion of the alkali metal salt may be composed of an organic substance or an inorganic substance. Examples of the anion portion constituting the organic salt include: CH (CH)₃COO^-、CF₃COO^-、CH₃SO₃ ^-、CF₃SO₃ ^-、(CF₃SO₂)₃C^-、C₄F₉SO₃ ^-、C₃F₇COO^-、(CF₃SO₂)(CF₃CO)N^-、(FSO₂)₂N^-、^-O₃S(CF₂)₃SO₃ ^-、PF₆ ^-、CO₃ ^2-And anions represented by the following general formulae (1) to (4).

(1)(C_nF_2n+1SO₂)₂N^-(wherein n is an integer of 1 to 10);

(2)CF₂(C_mF_2mSO₂)₂N^-(wherein m is an integer of 1 to 10);

(3)^-O₃S(CF₂)_lSO₃ ^-(wherein l is an integer of 1 to 10);

(4)(C_pF_2p+1SO₂)N^-(C_qF_2q+1SO₂) (wherein p and q are integers of 1 to 10). An ionic compound having a fluorine atom in the anionic portion is preferably used because of its good ionization property. As the inorganic anion portion, Cl may be used^-、Br^-、I^-、AlCl₄ ^-、Al₂Cl₇ ^-、BF₄ ^-、PF₆ ^-、ClO₄ ^-、NO₃ ^-、AsF₆ ^-、SbF₆ ^-、NbF₆ ^-、TaF₆ ^-、(CN)₂N^-And the like. As the anion portion, (CF) is preferable₃SO₂)₂N^-、(C₂F₅SO₂)₂N^-Etc. (perfluoroalkylsulfonyl) imide, particularly preferably (CF)₃SO₂)₂N^-(trifluoromethanesulfonyl) imide.

Specific examples of the organic salt of an alkali metal include: sodium acetate, sodium alginate, sodium lignosulfonate, sodium tosylate, LiCF₃SO₃、Li(CF₃SO₂)₂N、Li(CF₃SO₂)₂N、Li(C₂F₅SO₂)₂N、Li(C₄F₉SO₂)₂N、Li(CF₃SO₂)₃C、KO₃S(CF₂)₃SO₃K、LiO₃S(CF₂)₃SO₃K, and the like. Among them, LiCF is preferable₃SO₃、Li(CF₃SO₂)₂N、Li(C₂F₅SO₂)₂N、Li(C₄F₉SO₂)₂N、Li(CF₃SO₂)₃C, etc., more preferably Li (CF)₃SO₂)₂N、Li(C₂F₅SO₂)₂N、Li(C₄F₉SO₂)₂A fluorine-containing imide lithium salt such as N, and a (perfluoroalkyl sulfonyl) imide lithium salt is particularly preferable.

Examples of the inorganic salt of an alkali metal include lithium perchlorate and lithium iodide.

The alkali metal salt can be used alone in 1, also can be combined with more than 2.

(organic cation-anion salt)

The "organic cation-anion salt" used in the art disclosed herein means an organic salt, and the cation component thereof is composed of an organic substance, and the anion component thereof may be either an organic substance or an inorganic substance.

Specific examples of the cation component constituting the organic cation-anion salt include: pyridine compound

Cation, piperidine

Cation, pyrrolidineCation, cation having pyrroline skeleton, imidazoleCationic, tetrahydropyrimidinesCationic dihydropyrimidinesCationic, pyrazolesCationic pyrazolines

Cation, tetraalkylammonium cation, trialkylsulfonium cation, tetraalkylCations, and the like.

Examples of the anion component of the organic cation-anion salt 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^-、(FSO₂)₂N^-、^-O₃S(CF₂)₃SO₃ ^-And anions represented by the following general formulae (1) to (4).

(1)(C_nF_2n+1SO₂)₂N^-(wherein n is an integer of 1 to 10);

(2)CF₂(C_mF_2mSO₂)₂N^-(wherein m is an integer of 1 to 10);

(3)^-O₃S(CF₂)_lSO₃ ^-(wherein l is an integer of 1 to 10);

(4)(C_pF_2p+1SO₂)N^-(C_qF_2q+1SO₂) (wherein p and q are integers of 1 to 10). An ionic compound whose anion component contains a fluorine atom is preferable because it has good ionization properties. The number of carbon atoms of the perfluoroalkyl group contained in the anionic component is preferably 1 to 3, more preferably 1 or 2. These ionic compounds may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

(other Ionic Compound)

In addition, as the ionic compound, in addition to the alkali metal salt and the organic cation-anion salt, inorganic salts such as ammonium chloride, aluminum chloride, copper chloride, ferrous chloride, ferric chloride, and ammonium sulfate can be used. In addition, the ionic compounds disclosed herein generally include compounds referred to as ionic surfactants. Examples of the ionic surfactant include: quaternary ammonium salt,

Onium salts, sulfonium salts, pyridineSalt,A cationic surfactant having a cationic functional group such as an amino group; anionic surfactants having anionic functional groups such as carboxylic acid, sulfonic acid ester, sulfuric acid ester, phosphoric acid ester, and phosphorous acid ester; sulfobetaine and its derivatives, alkyl betaine and its derivatives, imidazoline and its derivatives, alkyl imidazoleAmphoteric surfactants such as betaine and its derivatives; and so on. The organic cation-anion salt may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The ionic compound includes ionic solids and ionic liquids, and ionic liquids can be preferably used. The ionic liquid is likely to move in the adhesive layer and to be uniformly dispersed in the layer, and on the other hand, is concentrated by a chemical action or the like, and affects the required properties of the adhesive (typically, feline characteristics). When an ionic liquid is used as the ionic compound, the effects of the technology disclosed herein tend to be exhibited as appropriate. When the polymer a is an acrylic polymer, an ionic liquid is particularly preferably used as the ionic compound.

The "ionic liquid" refers to a molten salt that is in a liquid state at 40 ℃ or lower. The ionic liquid can be easily added, dispersed, or dissolved to the binder in a temperature region in which the ionic liquid is in a liquid state, as compared with a solid salt. Further, since the ionic liquid has no vapor pressure (non-volatile), it does not disappear with time and has a characteristic that the antistatic property can be continuously obtained. The ionic liquid used in the technique disclosed herein is preferably a molten salt that is liquid at room temperature (25 ℃) or lower. Among the above ionic compounds, an organic cation-anion salt (an ionic liquid of an organic cation-anion salt) which is in a liquid state at 40 ℃ or lower is preferable, and an organic cation-anion salt (an ionic liquid of an organic cation-anion salt) which is in a liquid state at room temperature (25 ℃) or lower is more preferable.

The adhesive layer contains 5 to 20 parts by weight of an ionic compound per 100 parts by weight of a base polymer (polymer A, for example, an acrylic polymer). When the content of the ionic compound is 5 parts by weight or more, the conductivity of the pressure-sensitive adhesive layer is improved. Further, by setting the content of the ionic compound to 20 parts by weight or less, the decrease in the heating durability can be suppressed. The content of the ionic compound may be, for example, about 5 parts by weight or more based on 100 parts by weight of the base polymer in consideration of the balance of conductivity and the like. The upper limit of the content of the ionic compound is preferably about 17 parts by weight or less, for example, about 15 parts by weight or less, and from the viewpoint of durability against heating, about 10 parts by weight or less, based on 100 parts by weight of the base polymer.

(adhesive composition)

In the technique disclosed herein, the form of the pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer is not particularly limited. For example, the pressure-sensitive adhesive composition may be in the form of a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive component in an organic solvent (solvent-based pressure-sensitive adhesive composition), a pressure-sensitive adhesive composition in the form of a pressure-sensitive adhesive component dispersed in an aqueous solvent (water-dispersed pressure-sensitive adhesive composition, typically aqueous emulsion pressure-sensitive adhesive composition), or a solvent-free pressure-sensitive adhesive composition (e.g., a pressure-sensitive adhesive composition or a hot-melt pressure-sensitive adhesive composition that is cured by irradiation with active energy rays such as ultraviolet rays or electron beams). The technique disclosed herein can be preferably implemented to have an adhesive layer formed of a solvent-based adhesive composition. The organic solvent contained in the solvent-based adhesive composition may be a single solvent composed of any one of toluene, xylene, ethyl acetate, hexane, cyclohexane, methylcyclohexane, heptane, and isopropyl alcohol, or may be a mixed solvent mainly composed of any one of these solvents.

In the technique disclosed herein, as the pressure-sensitive adhesive composition (preferably, solvent-based pressure-sensitive adhesive composition) used for forming the pressure-sensitive adhesive layer, a pressure-sensitive adhesive composition that can be suitably crosslinked with the polymer a (typically, acrylic polymer) contained in the composition as a base polymer can be preferably used. As a specific crosslinking method, the following method can be suitably employed: the reaction can be carried out by introducing a crosslinking group site into the base polymer by copolymerizing a monomer having an appropriate functional group (e.g., a hydroxyl group or a carboxyl group), and adding a compound (crosslinking agent) capable of reacting with the functional group to form a crosslinked structure to the base polymer.

Examples of the crosslinking agent include: isocyanate crosslinking agent, epoxy crosslinking agent,An oxazoline-based crosslinking agent, an aziridine-based crosslinking agent, a melamine-based crosslinking agent, a carboximide-based crosslinking agent, a hydrazine-based crosslinking agent, an amine-based crosslinking agent, an imine-based crosslinking agent, a peroxide-based crosslinking agent (e.g., benzoyl peroxide), a metal chelate-based crosslinking agent (typically a polyfunctional metal chelate), a metal alkoxide-based crosslinking agent, a metal salt-based crosslinking agent, and the like. The crosslinking agent may be used alone in 1 kind, or may be used in combination in 2 or more kinds. Among them, isocyanate crosslinking agents, epoxy crosslinking agents, peroxide crosslinking agents, and metal chelate crosslinking agents are preferable. For example, when an acrylic polymer is used as the base polymer, an isocyanate-based crosslinking agent and a peroxide-based crosslinking agent are preferable, and a combination of an isocyanate-based crosslinking agent and a peroxide-based crosslinking agent is more preferable.

The amount of the crosslinking agent to be used may be appropriately selected depending on the composition and structure (molecular weight, etc.) of the base polymer (for example, acrylic polymer), the use of the optical film with an adhesive layer, and the like. The amount of the crosslinking agent to be used is usually preferably about 0.01 part by weight or more based on 100 parts by weight of the base polymer, and is preferably about 0.02 part by weight or more, more preferably about 0.03 part by weight or more (for example, 0.1 part by weight or more) from the viewpoint of improving the cohesive force of the adhesive. The upper limit of the amount of the crosslinking agent is usually suitably about 10 parts by weight or less based on 100 parts by weight of the base polymer, and from the viewpoint of wettability with an adherend, the amount is preferably about 5 parts by weight or less, more preferably about 3 parts by weight or less, and still more preferably about 1 part by weight or less.

The pressure-sensitive adhesive composition may further contain various conventionally known additives as needed. Examples of the additives include surface lubricants, leveling agents, plasticizers, softeners, fillers, antioxidants, preservatives, light stabilizers, ultraviolet absorbers, polymerization inhibitors, crosslinking accelerators, and silane coupling agents. The pressure-sensitive adhesive layer may optionally contain a conductive component other than the ionic compound, or may not contain it. In addition, a tackifier resin and a release controlling agent, which are known and/or commonly used, may be blended in the adhesive composition containing an acrylic polymer as a base polymer. The pressure-sensitive adhesive layer disclosed herein may or may not contain an alkylene oxide compound such as polypropylene glycol for the purpose of adjusting removability and hygroscopicity. Further, when the adhesive polymer is synthesized by an emulsion polymerization method, an emulsifier or a chain transfer agent (also referred to as a molecular weight regulator or a polymerization degree regulator) is preferably used. The content of the additive as any of these components may be determined as appropriate depending on the purpose of use. The amount of any of the above additives is usually about 5 parts by weight or less, and preferably about 3 parts by weight or less (for example, about 1 part by weight or less) based on 100 parts by weight of the base polymer.

(method of Forming adhesive layer)

The adhesive layer in the technology disclosed herein can be formed by, for example, a method (direct method) of directly applying the adhesive composition as described above on an antistatic layer provided on an optical film and drying or curing it. Alternatively, the pressure-sensitive adhesive layer may be formed on the surface (release surface) of a release liner by applying the pressure-sensitive adhesive composition to the surface and drying or curing the composition, and the pressure-sensitive adhesive layer may be attached to the surface of an antistatic layer provided on an optical film to transfer the pressure-sensitive adhesive layer (transfer method). When the pressure-sensitive adhesive composition is applied (typically, coated), various methods such as a roll coating method and a gravure coating method can be suitably used. The drying of the adhesive composition may be performed under heating as necessary. As a method for curing the adhesive composition, ultraviolet rays, laser rays, α rays, β rays, γ rays, X rays, electron beams, and the like can be suitably used.

(surface resistance value of adhesive layer)

From the viewpoint of antistatic property, the surface resistance value of the adhesive layer was about 1 × 10¹²Omega/□ or less is appropriate, if the surface resistance value is limited to a given value or less is applied to the liquid crystal panel (for example, embedded liquid crystal panel) application, based on the conductivity, can suitably prevent the static electricity uneven, and from the touch sensing sensitivity, durability point of view, the surface resistance value of the lower limit is preferably about 1 × 10⁸Omega/□ or more is preferable from the above viewpoint, for example, in the case of applying to an externally-embedded liquid crystal cell described later, the surface resistance value is preferably about 1 × 10¹⁰Ω/□～1×10¹²Ω/□, when applied to a semi-embedded liquid crystal cell described later, the surface resistance value is preferably about 1 × 10⁹Ω/□～1×10¹²Ω/□, when applied to an in-cell liquid crystal cell described later, the surface resistance value is preferably about 1 × 10⁸Ω/□～1×10¹⁰Omega/□, from the viewpoint of durability, is more preferably about 1 × 10⁹Ω/□～1×10¹⁰Ω/□。

The surface resistance value of the adhesive layer was measured as follows: the surface of the pressure-sensitive adhesive layer formed on the release liner was measured under the conditions of an applied voltage of 250V and an applied time of 10 seconds in accordance with JIS K6911 in an atmosphere of a temperature of 23 ℃ and 50% RH. As the resistivity meter, a commercially available resistivity meter (for example, a trade name "Hiresta UP MCP-HT 450" manufactured by Mitsubishi chemical ANALYTECH Co., Ltd.) can be used. The same method is also used in the embodiment described later.

(thickness of adhesive layer)

The thickness of the pressure-sensitive adhesive layer is not particularly limited, but may be, for example, about 1 μm or more, and is preferably about 3 μm or more. The thickness of the pressure-sensitive adhesive layer is preferably about 5 μm or more, more preferably about 7 μm or more, and further preferably about 10 μm or more, from the viewpoints of antistatic properties, durability, and securing a contact area with a conductive path when the conductive path is provided on the side surface. The thickness may be, for example, about 100 μm or less, and is usually preferably about 50 μm or less (e.g., about 35 μm or less).

< antistatic layer >

The antistatic layer disclosed herein comprises a conductive polymer and a polymer B. Typically, polymer B can function as a binder in the antistatic layer. The antistatic layer is disposed between the optical film and the pressure-sensitive adhesive layer, and not only functions as an adhesion-promoting layer for improving adhesion to the optical film of the pressure-sensitive adhesive layer, but also functions to improve conductivity of the optical film with the pressure-sensitive adhesive layer by having a predetermined conductivity.

(conductive Polymer)

In the technique disclosed herein, a conductive polymer is used as an antistatic agent contained in an antistatic layer. By using the conductive polymer, an antistatic layer having excellent optical characteristics, appearance, antistatic effect, and stability of the antistatic effect during heating and humidification can be suitably obtained. Examples of the conductive polymer include polymers such as polyaniline, polythiophene, polypyrrole, polyquinoxaline, polyethyleneimine, and polyallylamine. Such conductive polymers can be used alone in 1 kind, also can be combined with the use of 2 or more. Among them, polyaniline (aniline polymer) and polythiophene (thiophene polymer) are preferable.

As the conductive polymer which can be preferably used in the technique disclosed herein, polythiophene and polyaniline can be exemplified. In the present specification, polythiophene refers to a polymer of unsubstituted or substituted thiophene. As a suitable example of the substituted thiophene polymer in the art disclosed herein, poly (3, 4-ethylenedioxythiophene) may be mentioned.

As the conductive polymer, a conductive polymer soluble in an organic solvent, water-soluble, or water-dispersible can be used, and there is no particular limitation. In a preferred embodiment, the conductive polymer is used for the antistatic layer formation in the form of an aqueous solution or an aqueous dispersion. Thus, the coating liquid containing the composition for forming an antistatic layer can be made into an aqueous solution or an aqueous dispersion, and thus the risk of modification of the optical film by an organic solvent can be avoided. Conductive polymers such as polyaniline and polythiophene can be used preferably because they can be easily prepared in the form of an aqueous solution or an aqueous dispersion. Among them, polythiophene is more preferable. The aqueous solution or aqueous dispersion may contain an aqueous solvent in addition to water. For example, 1 or 2 or more kinds of alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-pentanol, isopentanol, sec-pentanol, tert-pentanol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, and cyclohexanol may be used in the form of a mixed solvent (aqueous solvent) with water.

The aqueous solution or aqueous dispersion of the conductive polymer can be prepared, for example, by dissolving or dispersing a conductive polymer having a hydrophilic functional group (which can be synthesized by a method such as copolymerization of a monomer having a hydrophilic functional group in the molecule) in water. Examples of the hydrophilic functional group include a sulfo group, an amino group, an amide group, an imino group, a hydroxyl group, a mercapto group, a hydrazine group, a carboxyl group, a quaternary ammonium group, and a sulfate group (-O-SO)₃H) Phosphate groups (e.g., -O-PO (OH)₂) Etc., the hydrophilic functional group may form a salt. As a commercially available product of the polythiophene aqueous solution, a trade name "Dentron" series manufactured by Nagase ChemteX Corporation can be exemplified. Further, as a commercially available product of the polyaniline sulfonic acid aqueous solution, there can be exemplified a product of MITSUBISHI rayonco, a trade name "aqua-PASS" manufactured by ltd.

In a preferred embodiment of the technology disclosed herein, an aqueous solution of polythiophene is used in the preparation of the composition for forming an antistatic layer. An aqueous solution of polythiophene (which may be a polythiophene with PSS as a dopant) of polystyrene sulfonate (PSS). The aqueous solution may contain polythiophene in a weight ratio of 1:1 to 1: 10: PSS. The total content of the polythiophene and the PSS in the aqueous solution may be, for example, about 1 to 5 wt%.

From the viewpoint of antistatic properties, in the antistatic layer-forming composition prepared using a liquid (typically an aqueous solution) containing a conductive polymer such as polythiophene, the content of the conductive polymer in the antistatic layer is suitably about 0.005% by weight or more, and preferably about 0.01% by weight or more. The upper limit of the content of the conductive polymer in the composition for forming an antistatic layer is, for example, suitably about 5 wt% or less, preferably about 3 wt% or less, more preferably about 1 wt% or less, and still more preferably about 0.7 wt% or less. In the antistatic layer obtained using the antistatic layer-forming composition, the content of the conductive polymer is suitably about 1% by weight or more, preferably about 3% by weight or more, more preferably about 5% by weight or more, further preferably about 7% by weight or more, and particularly preferably about 10% by weight or more, from the viewpoint of antistatic properties. The upper limit of the content of the conductive polymer in the antistatic layer is preferably about 90% by weight or less.

(Polymer B)

In addition, the antistatic layer disclosed herein is characterized by comprising a polymer B. Polymer B may be defined as a different polymer from the electrically conductive polymer. When the antistatic layer contains the conductive polymer and the polymer B, film formability, adhesion to an optical film, and the like can be achieved. The polymer B contained in the antistatic layer has a functional group B that interacts with the functional group a of the polymer a, and the polymer a is contained in the adhesive layer as a base polymer. This improves the adhesion between the antistatic layer and the adhesive layer.

The polymer B is characterized in that the polyether unit in the molecule is 10 mol% or less. This can suppress a decrease in the anchoring property of the adhesive layer to the antistatic layer. From TOF-SIMS analysis it can be confirmed: if the polymer B in the antistatic layer has a given amount or more of polyether units, the ionic compound contained in the adhesive layer migrates at the interface with the antistatic layer; when the polyether unit of the polymer B in the antistatic layer is a given value or less, the migration of the ionic compound in the above adhesive layer does not occur, and it is considered that the polyether unit of the polymer B causes a decrease in the anchoring property. It is considered that by limiting the polyether unit in the polymer B having the functional group B to a given amount or less, the decrease in the anchoring property can be effectively suppressed. This effect can be achieved without reducing the amount of ionic compound in the adhesive layer, and therefore, can be achieved simultaneously with the improvement of antistatic property. In this regard, there is no particular limitation to the explanation, but for example, the following is conceivable. That is, the polyether unit of the polymer B in the antistatic layer is present in a state of being introduced into the molecule by copolymerization or the like, and is not dissociated in the layer. It is considered that the polymer B improves adhesion to the adhesive layer by the presence of the functional group B in the antistatic layer at or near the interface with the adhesive layer, and on the other hand, the polymer B having a polyether unit attracts an ionic compound in the adhesive layer, thereby lowering the anchoring property. Here, when the polyether unit is separated from the polymer B having the functional group B, improvement of adhesion by the functional group B is not inhibited (examples 6 to 7 described later). In such a form, it is considered that the compound having a polyether unit may be transferred to the adhesive layer beyond the interface, or the ionic compound in the adhesive layer may be transferred to the antistatic layer containing the compound having a polyether unit beyond the interface, and these compounds do not concentrate in the vicinity of the interface between the adhesive layer and the antistatic layer.

From the viewpoint of suppressing the decrease in the anchoring property, the polyether unit in the molecule of the polymer B is preferably about 5 mol% or less, more preferably about 3 mol% or less, and further preferably about 1 mol% or less (for example, 0.1 mol% or less). The technique disclosed herein can be suitably carried out in such a manner that the polymer B contains substantially no polyether unit in the molecule. The phrase "the polymer B contains substantially no polyether unit in the molecule" means that the polyether unit in the molecule of the polymer B is 0.1 mol% or less. The polyether unit described above is introduced into the polymer B, for example, by polymerizing or copolymerizing a monomer having a polyether unit. Therefore, in the synthesis of the polymer B, by limiting the amount of the monomer having a polyether unit, the polymer B in which the amount of the polyether unit in the molecule is limited can be obtained.

The mol% of the polyether unit in the polymer B is a molar ratio [ mol% ] of the polyether unit in the polymer B when the repeating unit constituting the polymer B is regarded as one molecule. In other words, the mol% of the polyether unit is the ratio of the number of polyether units as repeating units to the total number of repeating units constituting the polymer B.

In addition, the polymer B contained in the antistatic layer has a functional group B that interacts with the functional group a of the polymer a contained in the adhesive layer. The functional group b is not particularly limited as long as it interacts with the functional group a. The functional group b may be selected from the group consisting of a carboxyl group, an acid anhydride group, a hydroxyl group and a thiol group, or may be composed ofAn oxazoline group and an isocyanate group. The functional group b may be 1 kind alone or 2 or more kinds. Wherein the functional group b is preferably selected fromAt least 1 functional group of oxazoline group and isocyanate group. From the viewpoint of film formability and the like, it is particularly preferableAn oxazoline group. In addition, as functional group b

The oxazoline group is easily reacted with the functional group a of the polymer a in the adhesive layer at a relatively low temperature to improve the anchoring property. Typically, the functional group B is introduced into the polymer B by polymerizing or copolymerizing a monomer containing the functional group B.

By reacting monomers containing functional groups b (e.g. containingOxazoline-based monomers) or copolymers of the monomers to give polymers B (e.g. containing

Oxazoline-based polymers) functional groups b (e.g. in the case of oxazoline-based polymers)Oxazolinyl) is introduced into the polymer B,the proportion (which may be a copolymerization proportion) of the total amount of the monomers used in the synthesis of the polymer B in the monomers having the functional group B is [ mol%]The amount is not particularly limited, and is, for example, preferably about 10 mol% or more, and usually about 30 mol% or more. In a preferred embodiment, the proportion of the monomer having the functional group B in the total amount of the monomers used for synthesizing the polymer B is [ mol% ], from the viewpoint of improving the anchoring property of the adhesive layer]The content is about 50 mol% or more, more preferably about 70 mol% or more, still more preferably about 80 mol% or more, and may be, for example, about 90 mol% or more. The polymer B may be a homopolymer of a monomer substantially containing the functional group B. Regarding other characteristics of the polymer B (for example, characteristics as a binder), the proportion (copolymerization proportion) of the monomer having the functional group B may be set to [ mol% ]]Is set to less than about 95 mol%, less than about 90 mol%. In another embodiment, the proportion of the monomer having the functional group b [ mol% ]]Can be less than 70 mol%, or can be less than about 50 mol% (e.g., less than 40 mol%).

The polymer B used in the antistatic layer is not particularly limited as long as it is a polymer having 10 mol% or less of the polyether unit and the functional group B, and various polymers can be used. Specific examples of the polymer B include

Oxazoline-based polymers, urethane-based polymers, acrylic polymers, polyester-based polymers, amide-based polymers, cellulose-based polymers, vinyl alcohol-based polymers, epoxy group-containing polymers, vinyl pyrrolidone-based polymers, styrene-based polymers, and the like. These polymers may be used alone in 1 kind, or may be used in combination of 2 or more kinds. Among them, it preferably contains

Oxazoline-based polymer, urethane-based polymer, acrylic polymer, polyester-based polymer, particularly preferably an acrylic polymerAn oxazoline-based polymer.

In a preferred embodiment, the composition containsAs polymer B, an oxazoline-based polymer. Comprises

The oxazoline-based polymer may be used alone in an amount of 1 kind, or may be used in combination with 2 or more kinds. Preferably soluble or dispersible in waterAn oxazoline-based polymer.The oxazolinyl group can be 2-Oxazolinyl, 3-

Oxazolinyl, 4-Any group of the oxazoline groups may be preferably used, for example, 2-

An oxazoline group.

As a containerExamples of the oxazoline-based polymer include polymers having a (meth) acrylic skeleton or a styrene skeleton in the main chain and having a side chain in the main chain

An oxazoline-based polymer. Preferably one embodiment of the present invention comprisesThe oxazoline-based polymer may be a copolymer comprising (A) and (B)Group) a main chain of an acrylic skeleton and having a side chain of the main chain

Containing azolinyl groups

An oxazoline-based (meth) acrylic polymer. In the range of limiting the polyether unit to 10 mol% or less, the content of the polyether unit

Oxazoline-based polymersIn addition to the oxazoline group, the polyester may have a polyoxyalkylene group or other functional group.

Comprises

The molecular weight of the oxazoline-based polymer may be appropriately set depending on the purpose, the desired characteristics, and the like. From the viewpoint of coating properties, etc., contain

The upper limit of the molecular weight of the oxazoline-based polymer is about 100 × 10⁴The following is appropriate, preferably about 50 × 10⁴Less, more preferably about 10 × 10⁴Hereinafter, more preferably about 5 × 10⁴The following. The Mn is a value in terms of standard polystyrene based on GPC.

Polymer B (preferably containing polymer B) in the antistatic layer

Oxazoline-based polymer) is suitably contained in an amount of about 3% by weight or more. The content of the polymer B is preferably about 5% by weight or more, more preferably about 8% by weight or more, and further preferably about 10% by weight or more, from the viewpoint of anchorage property and the like. The upper limit of the content of the polymer B is usually about 99% by weight or less, and about 90% by weight or less, considering the effect of other components such as a conductive polymerSuitably, it is preferably about 80% by weight or less, more preferably about 70% by weight or less, and still more preferably about 60% by weight or less.

The antistatic layer in the technology disclosed herein may contain a conductive component other than the conductive polymer. Examples of such a conductive component include an ionic compound contained in the pressure-sensitive adhesive layer and another conductive component that may be contained in the pressure-sensitive adhesive layer, and the other conductive component does not correspond to the conductive polymer. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds. In the technique disclosed herein, the content of the conductive component other than the conductive polymer in the antistatic layer can be set within a range that does not impair the effects of the invention. The content of the antistatic layer is usually about 5 wt% or less, and preferably about 3 wt% or less (for example, about 1 wt% or less, and typically 0.3 wt% or less). The technique disclosed herein can be suitably carried out in such a manner that the antistatic layer does not substantially contain a conductive component other than the conductive polymer.

The antistatic layer may optionally contain a polymer C different from the conductive polymer or the polymer B. The polymer C is, for example, a component functioning as a binder in the antistatic layer, does not have the above-mentioned functional group b, or the polymer C does not have the functional group b and may contain1 or more than 2 of oxazoline-based polymer, urethane-based polymer, acrylic polymer, polyester-based polymer, polyether-based polymer, cellulose-based polymer, vinyl alcohol-based polymer, epoxy-containing polymer, vinyl pyrrolidone-based polymer, styrene-based polymer, polyethylene glycol, pentaerythritol, and the like. A preferable example of the polymer C is a urethane polymer (typically, polyurethane). The content of the polymer C in the antistatic layer can be appropriately set within a range not to impair the effects of the invention.

Additives may be blended in the antistatic layer as necessary. Examples of the additive include a leveling agent, an antifoaming agent, a thickener, and an antioxidant. The proportion of these additives is usually about 50% by weight or less in the antistatic layer, and is suitably about 30% by weight or less (for example, about 10% by weight or less).

(method of Forming antistatic layer)

The above antistatic layer can be suitably formed by the following method: the resin component and the additives used as needed are dispersed or dissolved in an appropriate solvent to give the obtained liquid composition (coating material for forming an antistatic layer) to a film substrate (optical film). For example, the following method can be suitably employed: the coating material is applied to the first surface of the film base, dried, and cured (heat treatment, ultraviolet treatment, etc.) as necessary. The solid content concentration (NV) of the coating material may be, for example, 5 wt% or less (typically 0.05 to 5 wt%), and usually 1 wt% or less (typically 0.10 to 1 wt%), which is preferable. In the case of forming an antistatic layer having a small thickness, the NV of the coating material is preferably 0.05 to 0.50 wt% (e.g., 0.10 to 0.30 wt%), for example. By thus using a coating material with low NV, a more uniform antistatic layer can be formed.

(surface resistance value of antistatic layer)

From the viewpoint of antistatic property, the surface resistance value of the antistatic layer was about 1 × 10¹²Omega/□ or less is appropriate, if the surface resistance value is limited to a given value or less antistatic layer applied to liquid crystal panel (for example, embedded liquid crystal panel) application, in addition to the adhesive layer, also based on the antistatic layer conductivity, can prevent static electricity uneven occurrence, and from the touch sensing sensitivity point of view, the surface resistance value of the lower limit is preferably about 1 × 10⁸Omega/□ or more, from the above-mentioned viewpoint, for example, when applied to an externally-embedded liquid crystal cell described later, the surface resistance value is preferably about 1 × 10¹⁰Ω/□～1×10¹²Ω/□, when applied to a semi-embedded liquid crystal cell described later, the surface resistance value is preferably about 1 × 10⁹Ω/□～1×10¹²Omega/□. In addition, when the present invention is applied to an in-cell type liquid crystal cell described later, the above is preferableThe surface resistance value is about 1 × 10⁸Ω/□～1×10¹⁰Omega/□, from the viewpoint of antistatic properties, is more preferably about 1 × 10⁸Ω/□～1×10⁹Ω/□。

The surface resistance value of the antistatic layer was measured as follows: the surface of the antistatic layer-attached optical film before the formation of the pressure-sensitive adhesive layer was measured under conditions of an applied voltage of 10V and an applied time of 10 seconds in accordance with JIS K6911 in an atmosphere of a temperature of 23 ℃ and 50% RH. The resistivity meter used was the same as the measurement of the surface resistance value of the pressure-sensitive adhesive layer. The same method is also used in the embodiment described later.

(thickness of antistatic layer)

The thickness of the antistatic layer in the technology disclosed herein can be set as appropriate in accordance with the required characteristics such as antistatic property and anchoring property. The thickness of the antistatic layer is usually about 10nm or more, and it is appropriate to set it to more than 10 nm. The thickness of the antistatic layer is preferably 12nm or more, more preferably 14nm or more, further preferably 15nm or more, and particularly preferably 20nm or more (typically 25nm or more, for example 30nm or more), from the viewpoint of improving antistatic properties and obtaining a uniform thickness. Further, it is preferable to set the thickness of the antistatic layer to about 500nm or less. By suppressing the thickness of the antistatic layer to about 500nm or less, good optical characteristics (total light transmittance and the like) can be easily obtained. From such a viewpoint, the thickness of the antistatic layer is preferably about 100nm or less, more preferably about 50nm or less.

< Release liner >

The optical film with a pressure-sensitive adhesive layer disclosed herein may be provided in a form in which a release liner (a form of an optical film with a release liner and a pressure-sensitive adhesive layer) is bonded to a pressure-sensitive adhesive surface (a surface of the pressure-sensitive adhesive layer to be bonded to an adherend) for the purpose of protecting the pressure-sensitive adhesive surface as necessary. As a base material constituting the release liner, paper, a synthetic resin film, or the like can be used. A synthetic resin film can be suitably used in view of excellent surface smoothness. For example, various resin films (for example, polyester film) can be preferably used as a substrate of the release liner. The thickness of the release liner may be, for example, about 5 to 200 μm, and is preferably about 10 to 100 μm. The surface of the release liner bonded to the pressure-sensitive adhesive layer may be subjected to release or stain-proofing treatment using a conventionally known release agent (for example, silicone, fluorine, long-chain alkyl, fatty acid amide, etc.) or silica powder.

< other layers, etc. >

The optical film with a pressure-sensitive adhesive layer disclosed herein may be provided with an easy-adhesion layer between the optical film and the antistatic layer, or subjected to various easy-adhesion treatments such as corona treatment and plasma treatment, in addition to the above-described layers (optical film, pressure-sensitive adhesive layer, antistatic layer, and optional surface treatment layer).

< use >)

When the optical film with an adhesive layer disclosed herein is used as a material for a liquid crystal panel, the occurrence of static electricity unevenness in the liquid crystal panel can be highly prevented based on the conductivity of the adhesive layer containing a given amount of an ionic compound and an antistatic layer. Therefore, the pressure-sensitive adhesive composition can be suitably used as an optical film with a pressure-sensitive adhesive layer for a liquid crystal cell, a liquid crystal panel, and a liquid crystal display device. For example, the optical film with an adhesive layer disclosed herein can be suitably used for a liquid crystal cell called an in-cell type liquid crystal cell, a semi-in type liquid crystal cell, or an out-cell type liquid crystal cell described later, and a liquid crystal panel provided with the liquid crystal cell. In addition, in the case where the optical film with an adhesive layer is used for a touch panel type display device, good touch sensing sensitivity can be maintained. Therefore, an optical film with an adhesive layer for a touch panel is also preferable. Further, the optical film with an adhesive layer disclosed herein can be suitably used in a touch sensor-mounted liquid crystal panel (also referred to as a liquid crystal panel with a touch sensing function) and a touch panel-type liquid crystal display device (also referred to as a liquid crystal display device with a touch sensing function) by preventing the occurrence of the static electricity unevenness and the touch sensing sensitivity as described above. By applying the technology disclosed herein to the above-mentioned applications, excellent workability and durability can be obtained based on the improved anchoring properties of the adhesive layer.

As the touch sensor-mounted liquid crystal panel described above, liquid crystal panels having various configurations can be used. For example, the optical film with an adhesive layer disclosed herein can be suitably used for liquid crystal panels called an in-cell type liquid crystal panel and an out-cell type liquid crystal panel. In short, the in-cell type liquid crystal panel has the following constitution: in a liquid crystal cell including a liquid crystal layer and 2 transparent substrates sandwiching the liquid crystal layer, a touch sensing electrode portion related to a touch sensing function is provided in the liquid crystal cell (i.e., inside the 2 transparent substrates). A liquid crystal panel in which both the detection electrode and the drive electrode related to the touch sensing function are disposed in the liquid crystal cell is referred to as a complete in-cell liquid crystal panel. A liquid crystal panel in which only one of the detection electrode and the drive electrode is disposed inside a liquid crystal cell and the other of the electrodes is disposed outside the liquid crystal cell (typically on the outer surface of a transparent substrate) is referred to as a semi-embedded liquid crystal panel. The externally-embedded liquid crystal panel is referred to as a liquid crystal panel in which a touch sensor function is disposed on the outer surface of the transparent substrate of the liquid crystal cell. The effect of improving the conductivity of the optical film with an adhesive layer disclosed herein can be exhibited favorably in an in-cell type that does not have a conductive layer such as an ITO layer on the panel surface. Further, the effects (both prevention of static unevenness and good touch sensing sensitivity) of the technology disclosed herein can be exhibited well in an in-cell liquid crystal panel. Accordingly, the optical film with an adhesive layer disclosed herein may be particularly suitable for use in an in-cell type liquid crystal panel. The optical film with an adhesive layer disclosed herein can be used in a configuration in which a touch panel is disposed outside the optical film (for example, a configuration in which a touch panel is provided outside a liquid crystal panel such as an IPS system), and a liquid crystal display device having the configuration.

< Structure of liquid crystal panel >

Preferred applications of the optical film with an adhesive layer disclosed herein include, for example, in-cell liquid crystal panels as shown in fig. 2 to 6. Fig. 2 to 6 are schematic cross-sectional views showing configuration examples of the in-cell type liquid crystal panel. The in-cell liquid crystal panel 100 shown in fig. 2 includes: a liquid crystal cell (in-cell liquid crystal cell) 120, and an optical film 110 with an adhesive layer disposed on the viewing side of the liquid crystal cell 120. As the optical film with an adhesive layer 110, the optical film with an adhesive layer disclosed herein is used.

The liquid crystal cell 120 includes: a liquid crystal layer 125 including liquid crystal molecules, and a first transparent substrate 141 and a second transparent substrate 142 disposed so as to sandwich the liquid crystal layer 125. The liquid crystal unit 120 includes a touch sensor electrode portion 130 between the first transparent substrate 141 and the second transparent substrate 142. The touch sensing electrode section 130 has a detection electrode 131 and a drive electrode 132. Here, the detection electrode refers to a touch detection (reception) electrode, and functions as an electrostatic capacity sensor. The detection electrodes are also referred to as touch sensor electrodes.

In the touch sensor electrode portion 130, when the liquid crystal cell 120 is viewed as a plane, the detection electrodes 131 and the drive electrodes 132 are formed in a stripe pattern independently in the X-axis direction and the Y-axis direction of the plane, and the two electrodes intersect at right angles to each other. The pattern in which the touch sensor electrodes 130 can be formed is not limited thereto, and the detection electrodes 131 and the driving electrodes 132 can be formed in various patterns as described later.

In the in-cell type liquid crystal panel 100, the optical film 110 with an adhesive layer disposed on the viewing side of the liquid crystal cell 120 is bonded to the outer surface of the first transparent substrate 141 of the liquid crystal cell 120 with the adhesive layer 112. In other words, the optical film with adhesive layer 110 is disposed and fixed on the outer surface of the first transparent substrate 141 without interposing a conductive layer. Hereinafter, in the liquid crystal panel, the optical film with an adhesive layer 110, the optical film 111, and the adhesive layer 112 may be referred to as a first optical film with an adhesive layer, a first optical film, and a first adhesive layer, respectively, for the purpose of distinguishing the optical film with an adhesive layer, the optical film, and the adhesive layer, which are disposed on the side opposite to the viewing side. The optical film 111 of the optical film with an adhesive layer 110 is typically a polarizing film, and is disposed on the viewing side of the liquid crystal layer 125 so that the transmission axis (or absorption axis) of the polarizer is orthogonal to the transmission axis. A surface treatment layer 114 is formed on the back surface side of the optical film 110 with an adhesive layer.

On the other hand, in the inline liquid crystal panel 100, the optical film 150 with an adhesive layer is disposed on the side opposite to the side on which the optical film 110 is disposed. The optical film 151 constituting the optical film 150 with an adhesive layer is attached to the outer surface of the second transparent substrate 142 of the liquid crystal cell 120 via an adhesive layer 152. The optical film 151 is typically a polarizing film, and is disposed on the back side of the liquid crystal layer 125 so that the transmission axis (or absorption axis) of the polarizer is orthogonal to the transmission axis. Hereinafter, the optical film 150 with an adhesive layer, the optical film 151, and the adhesive layer 152 may be referred to as a second optical film with an adhesive layer, a second optical film, and a second adhesive layer, respectively, for the purpose of distinguishing them from those disposed on the visible side of the liquid crystal panel.

In the in-cell liquid crystal panel 100, the antistatic layer 113 and the pressure-sensitive adhesive layer 112 of the pressure-sensitive adhesive layer-attached optical film 110 have a conductive structure 170 made of a conductive material on their side surfaces. This allows the potential to escape from the side surfaces of the antistatic layer 113 and the adhesive layer 112 to other positions, thereby reducing or preventing charging due to static electricity. The conductive structure 170 may be provided on the entire side surfaces (end surfaces) of the antistatic layer 113 and the adhesive layer 112, or may be provided on a part of the side surfaces. When the via structure 170 is provided in a part, the via structure 170 may be provided at an area ratio of about 1% or more, preferably about 3% or more, more preferably about 10% or more, and further preferably about 50% or more of the total area of the side surfaces of the antistatic layer 113 and the adhesive layer 112 in order to secure conduction of the side surfaces. In the configuration example shown in fig. 2, the conductive structure 171 is also provided on the side surfaces of the optical film 111 and the surface treatment layer 114.

The in-cell liquid crystal panel 200 shown in fig. 3 is a modification of the configuration shown in fig. 2, and is different from the configuration shown in fig. 2 in that the touch sensor electrode portion 230 is disposed between the liquid crystal layer 225 and the second transparent substrate 242. That is, the touch sensing electrode portion 230 having the detection electrode 231 and the drive electrode 232 is disposed on the backlight side (rear surface side) of the liquid crystal layer 225. The in-cell liquid crystal panel 300 shown in fig. 4 is also a modification of the configuration shown in fig. 2, and differs from the configuration shown in fig. 2 in that a touch sensor electrode section 330 in which a detection electrode and a drive electrode are integrated is used. The in-cell liquid crystal panel 400 shown in fig. 5 is an in-cell liquid crystal panel in which the configurations shown in fig. 3 and 4 are combined, and is different from the configuration shown in fig. 2 in that a touch sensor electrode portion 430 in which a detection electrode and a drive electrode are integrated is used, and in that the touch sensor electrode portion 430 is disposed on the backlight side (rear surface side) of the liquid crystal layer 425.

The in-cell liquid crystal panel 500 shown in fig. 6 is different from the configuration shown in fig. 2 in that the detection electrodes 531 and the drive electrodes 532 of the touch sensor electrode unit 530 are disposed on both sides of the liquid crystal layer 525 in a spaced manner. Specifically, in the inline liquid crystal panel 500, the detection electrode 531 is disposed between the liquid crystal layer 525 and the first transparent substrate 541, and the drive electrode 532 is disposed between the liquid crystal layer 525 and the second transparent substrate 542. Other configurations of the modifications shown in fig. 3 to 6 are basically the same as those of the in-cell type liquid crystal panel shown in fig. 2, and therefore, redundant description is omitted.

In such a configuration, a conductive layer such as an electrode is not provided on the outer surface of the first transparent substrate of the liquid crystal cell, and here, the conductive layer means a surface resistance value of 1 × 10¹³Layers below Ω/□. By disposing the optical film with an adhesive layer disclosed herein on the viewing side of the liquid crystal cell of the in-cell type liquid crystal panel having such a configuration, the occurrence of electrostatic unevenness can be highly prevented.

In addition, the optical film with an adhesive layer disclosed herein can also be suitably used for a semi-embedded liquid crystal panel. Fig. 7 is a schematic cross-sectional view showing a configuration example of a semi-embedded liquid crystal panel. The semi-inline type liquid crystal panel 600 shown in fig. 7 is different from the inline type shown in fig. 2 to 6 in that a part of the touch sensor electrode portion 630 is disposed inside the liquid crystal cell 620 and the other part of the touch sensor electrode portion 630 is disposed outside the liquid crystal cell 620 (specifically, outside the visible side of the liquid crystal cell 620). Specifically, the detection electrode 631 constituting the touch sensor electrode portion 630 is disposed on the outer surface of the first transparent substrate 641, and the drive electrode 632 constituting the touch sensor electrode portion 630 is disposed in the liquid crystal cell 620. In this configuration example, the driving electrode 632 is disposed between the liquid crystal layer 625 and the second transparent substrate 642. The semi-inline liquid crystal panel 600 has a laminated structure in which an optical film 611, an antistatic layer 613, an adhesive layer 612, a detection electrode 631, a first transparent substrate 641, a liquid crystal layer 625, a drive electrode 632, and a second transparent substrate 642 are arranged in this order from the visible side. In addition, the optical film 611 has a surface treatment layer 614 on the side closer to the visible side. Further, a pressure-sensitive adhesive layer 652 and an optical film 651 are disposed in this order on the outer side of the second transparent substrate 642. In the liquid crystal panel 600, the detection electrode 631 of the touch sensor electrode section 630 is disposed outside the first transparent substrate 641 and is in contact with the adhesive layer 612.

The optical film with an adhesive layer disclosed herein can also be suitably used for an external liquid crystal panel. Fig. 8 is a schematic cross-sectional view showing a configuration example of an externally-embedded liquid crystal panel. The externally-embedded liquid crystal panel 700 shown in fig. 8 is different from the internally-embedded liquid crystal panel shown in fig. 2 to 6 in that both the detection electrodes 731 and the drive electrodes 732 related to the touch sensor electrode portion 730 are arranged outside the liquid crystal cell 720 as electrode patterns. In this configuration, a touch sensor function is provided outside the liquid crystal cell 720 (specifically, outside the first transparent substrate 741 and the second transparent substrate 742). More specifically, the drive electrode 732 is disposed on the outer surface of the first transparent substrate 741 of the liquid crystal cell 720, and the detection electrode 731 is disposed on the drive electrode 732. The externally-embedded liquid crystal panel 700 has a laminated structure in which an optical film 711, an antistatic layer 713, an adhesive layer 712, a detection electrode 731, a drive electrode 732, a first transparent substrate 741, a liquid crystal layer 725, a drive electrode 734, and a second transparent substrate 742 are arranged in this order from the visible side. In addition, the optical film 711 has a surface treatment layer 714 on the side closer to the visible side. Further, a pressure-sensitive adhesive layer 752 and an optical film 751 are disposed in this order on the outer side of the second transparent substrate 742. In the liquid crystal panel 700, the detection electrode 731 of the touch sensor electrode portion 730 is disposed outside the first transparent substrate 741, and is in contact with the adhesive layer 612. In addition, a driving electrode 734 is disposed in the liquid crystal cell 720. The driving electrode 734 is disposed between the liquid crystal layer 725 and the second transparent substrate 742.

In the above configuration example, the optical film with a pressure-sensitive adhesive layer substantially composed of the pressure-sensitive adhesive layer and the optical film is used as the optical film with a pressure-sensitive adhesive layer disposed on the back surface side, but the technique disclosed herein is not limited thereto, and the optical film with a pressure-sensitive adhesive layer disclosed herein may be used on the back surface side of the liquid crystal panel. In this case, the optical film with an adhesive layer disclosed herein may be disposed on both sides of the liquid crystal cell. This makes it possible to exhibit the effects of the technique disclosed herein on both sides of the liquid crystal panel. Alternatively, the optical film with an adhesive layer disclosed herein may be disposed only on the back side, not on the visible side of the liquid crystal panel. In such a configuration, the effects of the technology disclosed herein can also be exhibited.

In the in-cell type liquid crystal panel shown in fig. 2, 3, and 6, the detection electrode is disposed on the first transparent substrate side (visible side) of the drive electrode, but the configuration of the in-cell type liquid crystal panel disclosed herein is not limited thereto, and the drive electrode may be disposed on the first transparent substrate side (visible side) of the detection electrode.

In the semi-embedded liquid crystal panel shown in fig. 7, the detection electrode is disposed outside the liquid crystal cell (specifically, outside the first transparent substrate), and the drive electrode is disposed inside the liquid crystal cell (specifically, between the first transparent substrate and the second transparent substrate).

A liquid crystal display device with a touch sensing function is manufactured using the in-cell type liquid crystal panel having the above-described configuration. In the manufacture of the liquid crystal display device, a backlight, a reflection plate, or the like is used for an illumination system, and various members used for the liquid crystal display device can be used by a known or commonly used method.

< constituent Material of liquid Crystal Panel >

As the liquid crystal layer constituting the liquid crystal cell, a liquid crystal layer containing liquid crystal molecules is used. In a preferred embodiment, the liquid crystal layer includes liquid crystal molecules that are uniformly oriented in the absence of an electric field. As the liquid crystal layer, for example, an IPS liquid crystal layer can be suitably used. Examples of other liquid crystal layers that can be used in the technology disclosed herein include TN type, STN type, pi type, VA type, and the like liquid crystal layers. The thickness of the liquid crystal layer is, for example, about 1.5 μm to 4 μm.

The detection electrode and the drive electrode (including an electrode formed by integrating both electrodes) constituting the touch sensor electrode portion are typically transparent conductive layers (transparent electrodes). The material of these electrodes is not particularly limited, and for example: and 1 or 2 or more metals selected from gold, silver, copper, platinum, palladium, aluminum, nickel, chromium, titanium, iron, cobalt, tin, magnesium, tungsten, and alloys thereof. As the electrode material, 1 or 2 or more kinds of metal oxides of indium, tin, zinc, gallium, antimony, zirconium, and cadmium can be used. Specific examples thereof include metal oxides composed of indium oxide, tin oxide, titanium oxide, cadmium oxide, and mixtures thereof. Other metal compounds containing copper iodide and the like may also be used. The metal oxide may further contain an oxide of the metal atom exemplified above, as necessary. For example, indium oxide (ITO) containing tin oxide, tin oxide containing antimony, or the like can be preferably used, and ITO is particularly preferably used. As ITO, ITO containing about 80 to 99% by weight of indium oxide and about 1 to 20% by weight of tin oxide can be suitably used.

In the in-cell liquid crystal panel, the detection electrode, the drive electrode, and the electrode formed by integrating both of them, which are the touch sensor electrode portion, are usually formed as a transparent electrode pattern on the inner side (the liquid crystal layer side in the liquid crystal cell) of at least one (typically only one) of the first transparent substrate and the second transparent substrate. In the semi-embedded liquid crystal panel, one of the detection electrode and the drive electrode is formed on the inner side of one of the first transparent substrate and the second transparent substrate (on the liquid crystal layer side in the liquid crystal cell), and the other of the detection electrode and the drive electrode is formed on the outer side of the other of the first transparent substrate and the second transparent substrate. In the externally-embedded liquid crystal panel, the detection electrode, the drive electrode, and the electrode formed by integrating the detection electrode and the drive electrode are formed outside the first transparent substrate and the second transparent substrate (outside the liquid crystal cell). The electrode pattern can be formed by a usual method.

The detection electrode, the drive electrode, and the electrode formed by integrating the detection electrode and the drive electrode in the touch sensor electrode portion can simultaneously function as a common electrode for controlling the liquid crystal layer.

The electrode pattern is usually electrically connected to a lead line (not shown) formed at an end of the transparent substrate. The lead line is connected to a controller IC (not shown). The shape of the electrode pattern is not limited to the shape in which the stripe-shaped wirings are orthogonal as in the above configuration example, and may be any shape according to the application, purpose, and the like, such as a comb shape, a diamond shape, and the like, in addition to the stripe shape. Therefore, the detection electrodes and the drive electrodes may have a cross pattern other than a right angle or various other patterns. The electrode pattern may have a height of about 10nm to 100nm and a width of about 0.1mm to 5mm, for example.

Examples of the material for forming the transparent substrate (including the first and second transparent substrates) include: glass or polymer films. Thus, the transparent substrate may be a glass substrate or a polymer substrate. As the glass used for the transparent substrate, various glass materials can be used without particular limitation. Examples of the polymer film include: polyethylene terephthalate (PET), polycycloolefins, polycarbonates, and the like. When the main body of the transparent substrate is formed of a glass plate, the thickness thereof is, for example, about 0.1mm to 1 mm. When the main body of the transparent substrate is formed of a polymer film, the thickness thereof is, for example, about 10 to 200 μm. The transparent substrate may have an easy-adhesion layer, a hard coating layer on its surface.

In the optical film with an adhesive layer, various conductive materials can be used without particular limitation as a material for forming a conductive structure connected to the side surfaces of the adhesive layer and the antistatic layer. For example, a conductive paste such as a metal paste containing 1 or 2 or more kinds of metals such as silver and gold can be suitably used. As another example of the above material, a conductive adhesive can be given. The conductive structure may have a linear shape extending from the side of the antistatic layer, the adhesive layer. The material of the conductive structure that can be provided on the side surface of the optical film or the like can be formed in the same manner as described above.

In the liquid crystal panel, as the optical film of the second pressure-sensitive adhesive layer-attached optical film disposed on the side opposite to the viewing side, the optical film disclosed herein or a known or commonly used optical film may be used depending on the application and purpose. The second optical film may be the same as the first optical film disposed on the viewing side, or may be a different optical film. Similarly, as the second pressure-sensitive adhesive layer constituting the optical film with a second pressure-sensitive adhesive layer, a pressure-sensitive adhesive layer disclosed herein, a known or commonly used pressure-sensitive adhesive layer may be used depending on the application and purpose. The second adhesive layer may be the same adhesive layer as the first adhesive layer disposed on the visible side, or may be a different adhesive layer. When the second adhesive layer is formed by a known or commonly used adhesive, the thickness of the second adhesive layer is not particularly limited, and is suitably about 1 to 100 μm, for example, preferably about 2 to 50 μm, more preferably about 2 to 40 μm, and further preferably about 5 to 35 μm.

Further, as the first optical film disposed on the viewing side of the liquid crystal layer and the second optical film disposed on the opposite side of the viewing side, polarizing films may be used depending on the suitability of the disposition positions thereof, or optical films other than the polarizing film may be used alone, or 2 or more of them may be used in combination, or 1 or 2 or more of other optical films may be used in a stack, other than the polarizing film. The optical film disclosed herein is not described in detail because the materials that can be used as the respective optical layers constituting the optical film are as described above.

In addition to the above, the liquid crystal panel and the liquid crystal display device including the liquid crystal panel may be configured such that the arrangement and the configuration of each component are changed or other configurations are appropriately added depending on the application and the purpose within a range not impairing the effects of the technology disclosed herein. For example, a design change such as providing a color filter substrate on a liquid crystal cell (for example, the first transparent substrate 141 in fig. 2) may be performed.