JP2020144199A - Polarizing film with conductive layer and method for manufacturing the same - Google Patents

Abstract

To provide a polarizing film with a conductive layer capable of maintaining stable conductivity to prevent, for example, an erroneous action of a touch sensor even when the film is exposed to a moisture heat environment.SOLUTION: A polarizing film with a conductive film includes a polarizing film, an adhesive layer disposed on at least either a first surface side or a second surface side of the polarizing film, and further a conductive layer. The polarizing film shows a conductivity change ratio FHT in a moisture heat environment, represented by a formula (1) FHT=ΔC(B)/ΔC(A), is 2 or less. In the formula (1), ΔC(B) represents a difference between a current value of a touch panel and a touch panel base current value when the polarizing film with a conductive layer after subjected to a moisture heat test is stuck to an evaluation touch panel, and ΔC(A) represents a difference between a current value of the touch panel and a touch panel base current value when the polarizing film with a conductive layer prior to the moisture heat test is stuck to the evaluation touch panel.SELECTED DRAWING: Figure 1

Description

The present invention relates to a polarizing film with a conductive layer and a method for producing the same.

A polarizing film, also called a polarizing plate, is widely used as a component of a liquid crystal display device, an optical sensor, or the like. For example, a polarizing film used in a liquid crystal display device is usually bonded to a liquid crystal panel component such as a liquid crystal cell via an adhesive. In a typical aspect, the polarizing film is handled in a form having an adhesive layer on at least one surface thereof in a manufacturing process of a liquid crystal display device. The polarizing film in such a form can be arranged on the liquid crystal panel simply by removing the release liner that protects the pressure-sensitive adhesive layer and attaching the exposed adhesive surface to the adherend, so that the handling and productivity are improved. It is advantageous in that. On the other hand, static electricity may be generated when the release liner is removed as described above. Such static electricity affects the orientation 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, measures such as providing an antistatic layer are taken for the polarizing film provided with the pressure-sensitive adhesive layer. Patent Document 1 is mentioned as a prior art document that discloses this kind of prior art. In addition, Patent Document 2 discloses a conductive resin composition that can be used for a transparent electrode for driving a liquid crystal of various electronic devices, and describes that the transparent conductive film contains a conductivity improving agent. ..

International Publication No. 2017/057097 Japanese Unexamined Patent Publication No. 2015-117367

As for the above-mentioned measures against static electricity, it is difficult to adopt a method of simply increasing the conductivity depending on the device configuration. For example, the improvement of conductivity may adversely affect the touch sensor sensitivity in a liquid crystal display device having a built-in touch sensing function. Since the capacitance method used in the liquid crystal display device with built-in touch sensing function is an input device that detects and drives the change in capacitance caused by the contact of a finger with the touch panel, the change in capacitance to be detected. However, when it becomes unstable due to the disturbance of the electric field due to the presence of the antistatic layer, the touch panel sensitivity is lowered. Therefore, the antistatic layer used in the built-in touch sensing function is configured to have conductivity that can both prevent the occurrence of static electricity unevenness and the touch sensor sensitivity (Patent Document 1). It is desirable that this conductivity can be stably maintained even when used in various environments from the viewpoint of durability and long life of the device. However, as a result of the studies by the present inventors, it has been clarified that the conventional polarizing film with a conductive layer has a reduced surface resistance value when used in a high temperature and high humidity environment, which may cause a malfunction of the touch sensor. ..

The present invention has been created in view of the above circumstances, and is a conductive layer capable of maintaining stable conductivity so as not to cause a malfunction of a touch sensor even when exposed to a moist heat environment. It is an object of the present invention to provide a polarizing film with a light beam. Another object of the present invention is to provide a method for producing a polarizing film with a conductive layer.

According to the present specification, a polarizing film with a conductive layer is provided. The polarizing film with a conductive layer includes a pressure-sensitive adhesive layer arranged on at least one of a first surface side and a second surface side of the polarizing film, and further includes a conductive layer. Further, in some embodiments, the polarizing film, wet heat conductive variation ratio F _HT represented by the following formula (1) is 2 or less.
_FHT = ΔC (B) / ΔC (A) ... (1)
(In the formula (1), ΔC (B) flows when a polarizing film with a conductive layer after a moist heat test carried out under the conditions of a temperature of 85 ° C., a relative humidity of 85% and 24 hours is attached to the evaluation touch panel. It is the difference between the current value of the touch panel and the touch panel base current value, and ΔC (A) is the touch panel current value and the touch panel base current that flow when the polarizing film with a conductive layer before the wet heat test is attached to the evaluation touch panel. The difference from the value.)

The polarizing film with a conductive layer exhibits good conductivity by having a conductive layer. By forming the conductive layer in the form of a laminate with a polarizing film, the target conductivity can be imparted to the adherend (typically a liquid crystal panel) with high productivity, and the adherend (typically). After being fixed to the liquid crystal panel), the conductive layer is hard to peel off and can exhibit excellent durability. Further, since the polarizing film with a conductive layer has a moist heat conductivity change ratio _FHT of 2 or less before and after the moist heat test obtained from the current value difference of the touch panel to which the adhesive layer is attached, when exposed to a moist heat environment. Even so, it can maintain stable conductivity. Specifically, when the polarizing film with a conductive layer is used, for example, in a liquid crystal display device with a built-in touch sensing function, a change in conductivity (more specifically, a surface resistance value) that causes a malfunction of the touch sensor. Can be prevented or suppressed.

Further, according to the present specification, a polarizing film with a conductive layer is provided from different aspects. The polarizing film with a conductive layer includes a polarizing film and an adhesive layer arranged on at least one of the first surface side and the second surface side of the polarizing film, and further includes a conductive layer. Further, in some embodiments, the conductive layer satisfies the condition: 0.05 ≦ S / P ≦ 10; in terms of the moist heat surface resistance change ratio S / P. Here, S is the surface resistance value [Ω / □] of the conductive layer after the moist heat test conducted under the conditions of a temperature of 85 ° C., a relative humidity of 85%, and 24 hours, and P is the conductive layer before the moist heat test. Surface resistance value [Ω / □]. The polarizing film with a conductive layer exhibits good conductivity by having a conductive layer, and can be fixed to an adherend (typically a liquid crystal panel) with good durability. Further, since the surface resistance change ratio of the conductive layer before and after the moist heat test is within a specific range, stable conductivity is maintained even when exposed to a moist heat environment, and durability (wet heat durability). Can be excellent.

Further, according to the present specification, a polarizing film with a conductive layer is provided from different aspects. The polarizing film with a conductive layer includes a polarizing film and an adhesive layer arranged on at least one of the first surface side and the second surface side of the polarizing film, and further includes a conductive layer. In some embodiments, the conductive layer may be formed from a conductive composition comprising a conductive polymer and a high boiling point compound having a boiling point of 180 ° C. or higher. The polarizing film with a conductive layer exhibits good conductivity by having a conductive layer, and can be fixed to an adherend (typically a liquid crystal panel) with good durability. Further, according to the conductive layer formed by using a high boiling point compound having a boiling point of 180 ° C. or higher, the conductive stability after being exposed to the moist heat environment (that is, the moist heat conductive stability) is improved, so that the conductive layer is exposed to the moist heat environment. Even in some cases, stable conductivity can be maintained. That is, in the technique disclosed herein, the high boiling point compound is not used for improving conductivity, but for moist heat conductive stability such that the touch sensor functions without malfunction for a long period of time. .. In this respect, it is essentially different from the conductivity improvement using the conductivity improver in Patent Document 2. In the technique disclosed herein, the target conductivity can be adjusted by the type of the conductive polymer, the amount used, and the like.

Some aspects of the technology disclosed herein (including a polarizing film with a conductive layer, a liquid crystal panel, a liquid crystal panel with a built-in touch sensing function, an in-cell type liquid crystal panel, a liquid crystal display device, and a method for manufacturing them. Then, the conductive layer satisfies the condition: 0.05 ≦ S / P ≦ 10; with a moist heat surface resistance change ratio S / P. Here, S is the surface resistance value [Ω / □] of the conductive layer after the moist heat test conducted under the conditions of a temperature of 85 ° C., a relative humidity of 85%, and 24 hours, and P is the conductive layer before the moist heat test. Surface resistance value [Ω / □]. Since the conductive layer included in the polarizing film with a conductive layer has a surface resistance change ratio within a specific range before and after the moist heat test, it can exhibit improved moist heat conductive stability.

In some preferred embodiments, the content of the high boiling point compound in the conductive composition is 0.1-10% by weight. By setting the content of the high boiling point compound in the conductive layer within a specific range, good moist heat conductive stability can be preferably obtained. Further, in the configuration in which the conductive layer is arranged between the polarizing film and the pressure-sensitive adhesive layer, both moist heat conductive stability and anchoring property of the pressure-sensitive adhesive layer can be preferably compatible. It should be noted that the excellent anchoring property of the pressure-sensitive adhesive layer brings about improvement in workability and reworkability at the time of manufacturing a structure (for example, a liquid crystal panel, and thus a liquid crystal display device) to which the polarizing film with a conductive layer is applied, and the conductivity is improved. It also leads to the fact that the structure to which the layered polarizing film is attached has excellent durability.

In some preferred embodiments, the conductive layer comprises a thiophene-based polymer as the conductive polymer. In a configuration in which a thiophene-based polymer is used as the conductive polymer, the effect of improving the wet-heat conductive stability by the technique disclosed herein is preferably exhibited.

In some preferred embodiments, the conductive layer comprises a binder. As a result, the film-forming property of the conductive layer is improved, and in the embodiment in which the conductive layer is formed on the polarizing film, the adhesion between the polarizing film and the conductive layer is preferably improved, and between the polarizing film and the pressure-sensitive adhesive layer. In the embodiment in which the conductive layer is arranged, the anchoring property of the pressure-sensitive adhesive layer can be preferably improved.

In some preferred embodiments, the pressure-sensitive adhesive layer comprises an acrylic polymer. By using the pressure-sensitive adhesive layer containing an acrylic polymer, it is easy to adhere and fix the polarizing film to an adherend such as a liquid crystal device component. It is more preferable that such an acrylic polymer contains an amide group-containing monomer as a monomer unit. According to the acrylic polymer obtained by polymerizing the amide group-containing monomer, the anchoring property tends to be improved.

In some preferred embodiments, the conductive layer is provided on at least one surface of the polarizing film. Further, the pressure-sensitive adhesive layer is arranged on the conductive layer. In such a configuration, the effects of the techniques disclosed herein are preferably exhibited. Further, by arranging the conductive layer between the polarizing film and the pressure-sensitive adhesive layer, the conductive layer can also function as an anchor layer for improving the anchoring property of the pressure-sensitive adhesive layer.

The polarizing film with a conductive layer disclosed herein is preferably used for an in-cell liquid crystal panel because it has improved wet-heat conductive stability. Unlike the on-cell type, the in-cell type liquid crystal panel does not have a conductive layer such as an ITO layer provided on the surface of the panel. Therefore, a polarizing film with a conductive layer having a lower resistance is used. The lower the resistance value level, the more difficult it is to solve the problem of touch sensor sensitivity. Therefore, the resistance value stability is more important in the in-cell type liquid crystal panel than in the on-cell type. Therefore, the advantage of improving the conductive stability including the moist heat conductive stability by utilizing the technique disclosed herein is particularly great in the in-cell type. By using the polarizing film with a conductive layer disclosed here for an in-cell liquid crystal panel, the sensitivity of the touch sensor can be maintained stably and durable for a long period of time by utilizing the effect of improving the moist heat conductive stability. It is possible to realize the stability of the touch sensor sensitivity in the in-cell liquid crystal display device, the durability of the device, and the long life of the device. The polarizing film with a conductive layer disclosed herein may be particularly suitable for in-cell liquid crystal panel applications among various liquid crystal panels.

Further, according to the present specification, a method for producing a polarizing film with a conductive layer is provided. The method comprises: forming a conductive layer on at least one surface of the polarizing film; and providing an adhesive layer on the conductive layer. Further, the conductive layer is formed from a conductive composition containing a conductive polymer and a high boiling point compound having a boiling point of 180 ° C. or higher. According to this method, a polarizing film with a conductive layer having improved moist heat conductive stability can be obtained by forming a conductive layer using a high boiling point compound having a boiling point of 180 ° C. or higher.

It is a schematic cross-sectional view which shows the polarizing film with a conductive layer which concerns on one Embodiment. It is a schematic cross-sectional view which shows the in-cell type liquid crystal panel which concerns on one Embodiment. It is a schematic cross-sectional view which shows the in-cell type liquid crystal panel which concerns on another embodiment. It is a schematic cross-sectional view which shows the in-cell type liquid crystal panel which concerns on another embodiment. It is a schematic cross-sectional view which shows the in-cell type liquid crystal panel which concerns on another embodiment. It is a schematic cross-sectional view which shows the in-cell type liquid crystal panel which concerns on another embodiment. It is a schematic cross-sectional view which shows the semi-in cell type liquid crystal panel which concerns on one Embodiment. It is a schematic cross-sectional view which shows the on-cell type liquid crystal panel which concerns on one Embodiment. It is explanatory drawing which shows typically the method of measuring the difference between the current value of the touch panel to which the polarizing film with a conductive layer is attached, and the touch panel base current value. It is a graph which shows the correlation of ΔC (Cooked Data (Max-Min)) when the polarizing film with a conductive layer is attached, and the surface resistance value [Ω / □] of a conductive layer.

Hereinafter, preferred embodiments of the present invention will be described. Matters other than those specifically mentioned in the present specification and necessary for the implementation of the present invention are based on the teachings regarding the implementation of the invention described in the present specification and the common general knowledge at the time of filing. Can be understood by those skilled in the art. The present invention can be carried out based on the contents disclosed in the present specification and common general technical knowledge in the art.
In the following drawings, members / parts that perform the same action may be described with the same reference numerals, and duplicate description may be omitted or simplified. In addition, the embodiments described in the drawings are schematically for the purpose of clearly explaining the present invention, and do not accurately represent the sizes and scales of the products and parts actually provided.

<Polarizing film with conductive layer>
The polarizing film with a conductive layer disclosed herein includes a polarizing film, an adhesive layer, and a conductive layer. The arrangement of each of these components (each layer) is not particularly limited, and for example, the pressure-sensitive adhesive layer is arranged on at least one of the first surface side and the second surface (the surface opposite to the first surface) side of the polarizing film. Can be done. The conductive layer may also be arranged on at least one of the first surface side and the second surface side of the polarizing film.

FIG. 1 schematically shows a configuration example of the polarizing film with a conductive layer disclosed herein. The polarizing film 10 with a conductive layer has a polarizing film 11, a conductive layer 13, and an adhesive layer 12 in this order. Specifically, a conductive layer 13 is provided on one surface (first surface) 11A of the polarizing film 11, and is provided on one surface of the conductive layer 13 (the surface opposite to the polarizing film 11 side). The pressure-sensitive adhesive layer 12 is arranged. Further, the polarizing film 10 with a conductive layer may have a surface treatment layer 14 on the other surface (also referred to as a second surface or a back surface) 11B of the polarizing film 11. The polarizing film 10 with a conductive layer is used by attaching the adhesive surface 12A of the adhesive layer 12 to the surface of an adherend (for example, an optical component such as a transparent substrate on the visual side of a liquid crystal cell). In the polarizing film 10 with a conductive layer before use (that is, before being attached to the adherend), the adhesive surface (attachment surface to the adherend) 12A of the adhesive layer 12 is at least the peeling surface on the adhesive layer 12 side. It can be in the form protected by a release liner (not shown). A surface protective film (not shown) can be provided on the back surface of the polarizing film 10 with a conductive layer (the outer surface of the surface treatment layer 14 and the back surface of the polarizing film 11 when the surface treatment layer 14 is not provided). ..

The laminated structure of the polarizing film with a conductive layer is not limited to the above configuration example. For example, a conductive layer may be provided on one surface (first surface) of the polarizing film, and an adhesive layer may be provided on the other surface (second surface) of the polarizing film. In this modification, the conductive layer can be the back layer of the polarizing film. Further, as another modification, an adhesive layer is provided on one surface of the polarizing film, and a conductive layer is arranged on one surface of the adhesive layer (the surface opposite to the polarizing film side). Can be mentioned. In this modification, the conductive layer may be partially fused with the pressure-sensitive adhesive layer and the surface of the conductive layer may have a predetermined adhesive force. Specifically, such a fusion may be a fusion due to the transfer of the pressure-sensitive adhesive layer component to the conductive layer or the transfer of the conductive layer component to the pressure-sensitive adhesive layer. Alternatively, in the same layer structure as above, the conductive layer may be partially disposed on the surface of the pressure-sensitive adhesive layer. Even with this configuration, the surface of the polarizing film with a conductive layer on the conductive layer side can have a predetermined adhesive force. In this embodiment, the shape (pattern) of the conductive layer on the surface of the pressure-sensitive adhesive layer is not particularly limited, and may be a shape continuous in at least one direction on one outer surface of the polarizing film with the conductive layer, such as a stripe shape or a lattice shape. ..

The above configuration example and modification can be combined. For example, the conductive layers are arranged on both sides of the polarizing film, one of which is the back layer of the polarizing film and the other of which is arranged between the polarizing film and the pressure-sensitive adhesive layer, or on the pressure-sensitive adhesive layer ( Specifically, the configuration may be arranged on the surface opposite to the polarizing film side). Further, a conductive layer may be arranged between the polarizing film and the pressure-sensitive adhesive layer, and another conductive layer may be arranged on the surface of the pressure-sensitive adhesive layer opposite to the polarizing film side. Therefore, in the polarizing film with a conductive layer disclosed herein, the conductive layer is not limited to one layer, and may be two or three layers that can be arranged separately.

<Moist heat conductivity change ratio _FHT >
Conductive layer with the polarizing film disclosed herein, in some embodiments, wherein the wet heat conductivity change ratio represented by the following formula _{(1) F HT (Hygro-} thermal factor) is 2 or less It can be a thing.
_FHT = ΔC (B) / ΔC (A) ... (1)
In the above formula (1), ΔC (B) flows when a polarizing film with a conductive layer after a moist heat test carried out under the conditions of a temperature of 85 ° C., a relative humidity of 85% and 24 hours is attached to the evaluation touch panel. It is the difference between the current value of the touch panel and the touch panel base current value, and ΔC (A) is the touch panel current value and the touch panel base current that flow when the polarizing film with a conductive layer before the wet heat test is attached to the evaluation touch panel. The difference from the value. A polarizing film with a conductive layer that satisfies this characteristic can maintain stable conductivity even when exposed to a moist heat environment. From such a viewpoint, the _FHT is preferably about 1.7 or less, more preferably about 1.5 or less, still more preferably about 1.3 or less, and particularly preferably about 1.1 or less (for example, 1.0). Below). Since the technique disclosed herein may relate to suppressing a decrease in surface resistance (increase in conductivity) when exposed to a moist heat environment, there is no particular limitation on a decrease in conductivity (that is, a decrease in _FHT ) after a moist heat test. However, the _FHT is usually about 0.1 or more (for example, about 0.3 or more), about 0.5 or more is appropriate, preferably about 0.6 or more, and more preferably about 0.7. As mentioned above, it is more preferably about 0.8 or more, and particularly preferably about 0.9 or more (typically 0.95 or more, for example, 0.99 or more). The _FHT is measured by the method described in Examples described later. The polarization film with a conductive layer as disclosed herein encompasses the unrestricted mode of the above wet heat conductive variation ratio F _HT, in such embodiments, with the conductive layer polarizing film having the above characteristics Not limited to.

<Polarizing film>
The polarizing film disclosed herein is also referred to as a polarizing plate, and may usually include a polarizing element and a transparent protective film arranged on at least one surface (preferably both sides) of the polarizing element. The polarizer is not particularly limited, and for example, one in which a dichroic substance such as iodine or a dichroic dye is adsorbed on a hydrophilic polymer film and uniaxially stretched is 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-based alignment film such as a dehydrated product of PVA or a dehydrochlorinated product of polyvinyl chloride can also be used. Of these, a PVA-based film and a polarizer made of a dichroic substance such as iodine are preferable.

The thickness of the polarizer is not particularly limited, and is generally about 80 μm or less. Further, from the viewpoint of thinning, a thin polarizing element having a thickness of about 10 μm or less (preferably about 1 to 7 μm) can also be used. The thin polarizing element has less uneven thickness and is excellent in visibility, and also has excellent durability because there is little dimensional change. The use of a thin polarizing element also leads to a thinning of the polarizing film.

As a material constituting the transparent protective film, for example, a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture blocking property, isotropic property and the like is preferably used. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose (TAC), polyester resins, polyether sulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, and (meth) acrylics. Examples thereof include resins, cycloolefin resins (typically norbornene resins), polyarylate resins, polystyrene resins, PVA resins, and mixtures of two or more of these. In a preferred embodiment, a transparent protective film made of a thermoplastic resin such as TAC is placed on one surface of the polarizer, and a cycloolefin resin (typically a norbornene resin) or (typically a norbornene resin) is placed on the other surface. A configuration in which a transparent protective film made of a meta) acrylic resin is arranged can be adopted. In another preferred embodiment, a transparent protective film made of a thermoplastic resin such as TAC is arranged on one surface of the polarizer, and a (meth) acrylic-based, urethane-based, or acrylic as the transparent protective film is arranged on the other surface. Thermosetting resins such as urethane-based, epoxy-based, and silicone-based resins or ultraviolet curable resins can be used. These transparent protective films can be laminated on the polarizer via an adhesive such as PVA. The transparent protective film may contain one or more of any suitable additives, depending on the intended 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 forms such as water-based, solvent-based, hot-melt-based, radical-curable, and cationic-curable are used. be able to. Of these, water-based adhesives or radical-curable adhesives are preferable.

Further, a surface treatment layer may be provided on the back surface of the polarizing film (that is, the surface opposite to the side on which the conductive layer is provided). The surface treatment layer can be provided on the above-mentioned transparent protective film used for the polarizing film, or can be separately provided on the polarizing film as a separate body from the transparent protective film.

A preferred example of the surface treatment layer is a hard coat layer. As the material for forming the hard coat layer, for example, a thermoplastic resin or a material that is cured by heat or radiation can be used. Examples of the material used include a radiation curable resin such as a thermosetting resin, an ultraviolet curable resin, and an electron beam curable resin. Of these, an ultraviolet curable resin is preferable. The ultraviolet curable resin is excellent in processability because the cured resin layer can be efficiently formed by the curing treatment by ultraviolet irradiation. As the curable resin, one or more kinds such as polyester type, acrylic type, urethane type, amide type, silicone type, epoxy type and melamine type can be used, and these may contain monomers, oligomers, polymers and the like. It can be in the form of inclusion. A radiation-curable resin (typically an ultraviolet-curable resin) is particularly preferable because it does not require heat (which can cause damage to the base material) and is excellent in processing speed.

Other examples of the surface treatment layer include an antiglare treatment layer and an antireflection layer for the purpose of improving visibility. An antiglare treatment layer or an antireflection layer may be provided on the hard coat layer. The constituent material of the antiglare treatment layer is not particularly limited, and for example, a radiation-curable resin, a thermosetting resin, a thermoplastic resin, or the like can be used. As the antireflection layer, titanium oxide, zirconium oxide, silicon oxide, magnesium fluoride and the like can be used. The antireflection layer may have a multi-layer structure including a plurality of layers. Other examples of the surface treatment layer include a sticking prevention layer and the like.

When the technique disclosed herein is carried out in a manner including a surface treatment layer, the surface treatment layer can be provided with a conductive agent to impart conductivity. As the conductive agent, the conductive agent and the conductive component described later can be used without particular limitation.

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

<Conductive layer>
The conductive layer disclosed herein is a layer that is arranged on at least one of the first surface side and the second surface side of the polarizing film to enhance the conductivity of the polarizing film with the conductive layer. The conductive layer can be formed from a conductive composition containing various conductive agents such as, for example, an organic or inorganic conductive substance. In the embodiment in which the pressure-sensitive adhesive layer is arranged on the surface of the conductive layer, the conductive layer can also function as an anchor layer for enhancing the adhesion between the pressure-sensitive adhesive layer and the polarizing film.

Examples of the organic conductive substance that can be contained in the conductive composition (and therefore also in the conductive layer; the same shall apply hereinafter unless otherwise specified) include a quaternary ammonium salt, a pyridinium salt, a primary amino group, a secondary amino group, and a first. Cationic conductive agent having a cationic functional group such as 3 amino group; Anionic conductive agent having an anionic functional group such as sulfonate, sulfate ester salt, phosphonate salt, phosphoric acid ester salt; Alkylbetaine and its derivative , Imidazoline and its derivatives, alanine and its derivatives and other amphoteric ionic conductors; aminoalcohol and its derivatives, glycerin and its derivatives, polyethylene glycol and its derivatives and other nonionic conductive agents; the above cationic, anionic and amphoteric ions. Examples thereof include an ionic conductive polymer obtained by polymerizing or copolymerizing a monomer having a type ionic conductive group (for example, a quaternary ammonium base). One type of such a conductive agent may be used alone, or two or more types may be used in combination.

Examples of inorganic conductive substances that can be contained in the conductive layer are tin oxide, antimony oxide, indium oxide, cadmium oxide, titanium oxide, zinc oxide, indium, tin, antimony, gold, silver, copper, aluminum, nickel, and chromium. , Titanium, iron, cobalt, copper iodide, ITO (indium oxide / tin oxide), ATO (antimony oxide / tin oxide) and the like. Such an inorganic conductive substance may be used alone or in combination of two or more.

(Conductive polymer)
In some preferred embodiments, a conductive polymer is used as the conductive agent. By using the conductive polymer, a conductive layer having excellent optical properties, appearance, and antistatic effect can be preferably obtained. Further, the effect of improving the moist heat conductive stability by the technique disclosed herein tends to be preferably exhibited in the conductive layer containing the conductive polymer. Examples of the conductive polymer include polymers such as polyaniline, polythiophene, polypyrrole, polyquinoxaline, polyethyleneimine, and polyallylamine. One type of such a conductive polymer may be used alone, or two or more types may be used in combination.

Preferable examples of the conductive polymer include polythiophene (thiophene-based polymer) and polyaniline (aniline-based polymer). In addition, in this specification, polythiophene means a polymer of unsubstituted or substituted thiophene. A preferred example of the substituted thiophene polymer in the technique disclosed herein is poly (3,4-ethylenedioxythiophene).

As the conductive polymer, those which are soluble in organic solvents, water-soluble, and water-dispersible can be used without particular limitation. In some preferred embodiments, the conductive polymer is used to form a conductive layer in the form of an aqueous solution or an aqueous dispersion. In this aspect, since the coating liquid composed of the conductive composition can be in the form of an aqueous liquid (an aqueous solution or an aqueous dispersion liquid which may contain water and another solvent), the risk of alteration of the polarizing film due to the organic solvent can be reduced. Can be done. Conductive polymers such as polyaniline and polythiophene are preferably used because they tend to be in the form of aqueous solutions or aqueous dispersions. Of these, polythiophene is more preferable. In some preferred embodiments, an aqueous polythiophene solution is used to prepare the conductive composition. The aqueous solution or the aqueous dispersion may contain an aqueous solvent in addition to water. For example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 1-ethyl-1. One or more alcohols such as -propanol, 2-methyl-1-butanol, n-hexanol, and cyclohexanol can be used in the form of a mixed solvent with water (aqueous solvent).

The aqueous solution or aqueous dispersion of the conductive polymer is prepared by, for example, adding a conductive polymer having a hydrophilic functional group (which can be synthesized by a method such as copolymerizing a monomer having a hydrophilic functional group in the molecule) to water. It can be prepared by dissolving or dispersing. Examples of the hydrophilic functional group, a sulfo group, an amino group, an amide group, an imino group, a hydroxyl group, a mercapto group, a hydrazino group, a carboxyl group, quaternary ammonium groups, sulfate ester groups (-O-SO 3 _H), phosphorus An acid ester group (for example, -O-PO (OH) ₂ ) and the like are exemplified. Such hydrophilic functional groups may form salts.

In some preferred embodiments, polyanions are used as dopants (specifically, thiophene-based polymer dopants) in the preparation of conductive compositions. In this aspect, the conductive layer may contain polyanions. As the polyanion, one or more polycarboxylic acids such as polyacrylic acid and polysulfonic acids such as polystyrene sulfonate (PSS) can be used. In a particularly preferred embodiment, an aqueous polythiophene solution containing PSS (which may be a form in which PSS is added as a dopant to polythiophene) is used. Such an aqueous solution may contain polythiophene: PSS in a weight ratio of 1: 1 to 1:10. The total content of polythiophene and PSS in the above aqueous solution can be, for example, about 1 to 5% by weight.

Examples of commercially available products of the polythiophene aqueous solution include the trade name "Denatron" series manufactured by Nagase Chemtech and the trade name "Clevios" series manufactured by Heraeus. Further, as a commercially available product of the polyaniline sulfonic acid aqueous solution, the trade name "aqua-PASS" manufactured by Mitsubishi Rayon Co., Ltd. is exemplified.

From the viewpoint of antistatic, the content of the conductive agent (preferably the conductive polymer) in the conductive composition is preferably about 0.005% by weight or more, preferably about 0.01% by weight or more. The upper limit of the content of the conductive agent (preferably the conductive polymer) in the conductive composition is, for example, about 5% by weight or less, preferably about 3% by weight or less, more preferably about 1% by weight or less. More preferably, it is about 0.7% by weight or less. In the conductive layer obtained by using the above conductive composition, the content of the conductive agent (preferably the conductive polymer) is preferably about 1% by weight or more, preferably about 3% by weight, from the viewpoint of antistatic. % Or more, more preferably about 5% by weight or more, still more preferably about 7% by weight or more, and particularly preferably about 10% by weight or more. The upper limit of the content of the conductive agent (preferably the conductive polymer) in the conductive layer is preferably about 90% by weight or less.

In the embodiment in which the conductive layer containing the conductive polymer is used, the conductive layer may contain a conductive component other than the conductive polymer. Examples of such a conductive component include those exemplified as the above-mentioned organic or inorganic conductive substance (other than the conductive polymer) and the conductive component contained in the pressure-sensitive adhesive layer described later. These can be used alone or in combination of two or more. In the technique disclosed herein, the content of the conductive component other than the conductive polymer in the conductive layer can be set within a range that does not impair the effects of the invention. The content thereof is usually about 5% by weight or less in the conductive layer, and it is appropriate that the content is about 3% by weight or less (for example, about 1% by weight or less, typically 0.3% by weight or less). .. The technique disclosed herein can be preferably carried out in a manner in which the conductive layer substantially does not contain a conductive component other than the conductive polymer.

(High boiling point compound)
The conductive layer disclosed herein may typically be formed from a conductive composition comprising a high boiling point compound having a boiling point of 180 ° C. or higher. The conductive layer formed by using the high boiling point compound exhibits improved wet heat conductive stability. The high boiling point compound may be used alone or in combination of two or more. The high boiling point compound may not remain due to volatilization when the conductive layer is formed, but the formed conductive layer preferably satisfies the moist heat surface resistance change ratio and the moist heat surface resistance reduction rate, and is polarized with a conductive layer including the conductive layer. film may satisfy preferably the wet heat conductivity variation ratio F _HT. The high boiling point compound is a compound having a boiling point of 180 ° C. or higher, and is a solid or a liquid at room temperature (23 ° C.). As the high boiling point compound which is solid at room temperature, it is preferable to use a compound which is easily dissolved in a solvent (for example, water) of a conductive composition described later. Such a high boiling point compound can have a solubility in, for example, 100 mL of a solvent (eg, water) of about 1 g or more at room temperature (typically about 3 g or more, for example, about 10 g or more, and even about 20 g or more). Further, from the viewpoint of conductive layer forming property, the high boiling point compound is preferably a compound which is liquid at a temperature of 20 to 50 ° C. (and therefore has a melting point of 20 ° C. or less). Such compounds are also referred to as high boiling point solvents. The solvent referred to here refers to a liquid medium contained in the conductive composition, and is referred to as a solvent for convenience, but is a concept including a solvent and a dispersion medium.

The following can be considered as the reasons why the moist heat conductive stability is improved by using the high boiling point compound. For example, when a low boiling point solvent such as water (solvent having a boiling point of less than 180 ° C.) is used as the solvent of the conductive composition, the conductive layer is thin (for example, less than 1 μm in thickness), so that the solvent in the composition Quickly volatilizes and dries. At this time, the arrangement (orientation) of the conductive agent (preferably the conductive polymer) also contained in the composition in the conductive layer is affected by this drying process. The high boiling point compound moderately controls the volatilization behavior of the solvent in the drying process during the formation of the conductive layer, and as a result, improves the arrangement of the conductive agent in the conductive layer. However, not only that, as a result of the studies by the present inventors, it is difficult for a high boiling point compound having a boiling point of a predetermined value or higher to change the arrangement of the conductive agent in the conductive layer due to external factors such as environmental changes in the drying process. It is thought that it is also stable. The present inventors used a TOF / MS (time-of-flight mass analyzer) with a mixed solvent of water and diethylene glycol (boiling point: about 244 ° C.), and water and N-methylpyrrolidone (boiling point: about 204 ° C.). Each of the mixed solvents in the above was heated at 50 ° C., the amount of volatile components at that time was measured over time, and in the mixed solvent using a specific (specifically, boiling point of 180 ° C. or higher) high boiling point compound, the initial stage of the drying process was started. After that, it has been confirmed that the high boiling point compound slowly volatilizes during the main period of the process. It is considered that the volatilization behavior due to the use of the high boiling point compound contributes to the stable maintenance of the arrangement of the conductive agent, and brings about stable conductivity even when exposed to a moist heat environment. This action is particularly effective in an embodiment in which a thiophene-based polymer or an aniline-based polymer that conducts electrons by the action of π-π stacking is used as a conductive agent (more preferably, a thiophene-based polymer, for example, a thiophene-based polymer and a dopant such as PSS). It is considered to be particularly meaningful. The techniques disclosed herein are not limited to the above considerations.

The high boiling point compound contained in the conductive composition disclosed herein is also referred to as a conductive stabilizer because of its moist heat conductive stabilizing action. The conductive stabilizer is used when exposed to a moist heat environment (for example, temperature 50 ° C. or higher and relative humidity 80% or higher, typically temperature 85 ° C. 85% RH) for a predetermined time (for example, 24 hours). As an agent that suppresses changes in the conductivity of the conductive layer (which can be evaluated from the surface resistance value, etc.) as compared with the case where it is not used, that is, as an agent that contributes to stabilizing the conductivity of the conductive layer in the above environment. Can be defined.

In some embodiments, the boiling point of the high boiling point compound contained in the conductive composition is preferably about 200 ° C. or higher, more preferably about 210 ° C. or higher, still more preferably about 220 ° C. or higher from the viewpoint of wet-heat conductive stability. Particularly preferably, it is about 230 ° C. or higher (for example, about 240 ° C. or higher). The upper limit of the boiling point of the high boiling point compound is appropriately set in consideration of the film forming property of the conductive layer, the drying efficiency and the like, and is not limited to a specific range. The boiling point of the high boiling point compound is usually about 400 ° C. or lower, preferably about 320 ° C. or lower, and preferably about 300 ° C. or lower (for example, about 290 ° C. or lower) from the viewpoint of film forming property of the conductive layer. It is preferably about 280 ° C. or lower, more preferably about 260 ° C. or lower, and particularly preferably about 250 ° C. or lower. By using a high boiling point compound having a boiling point of 180 ° C. or higher and a relatively low boiling point, the adhesion between the polarizing film and the conductive layer is improved in the embodiment of forming the conductive layer on the polarizing film, and the polarizing film and the conductive layer are adhered to each other. In the embodiment in which the conductive layer is arranged between the agent layer and the agent layer, the anchoring property of the pressure-sensitive adhesive layer tends to be improved.

Examples of the high boiling point compound include lactam compounds such as N-methylpyrrolidone (which can be lactam solvents); ethylene glycol, propylene glycol, trimethylene glycol, butanediols (1,3-butanediol, 1,1). 4-butanediol, etc.), pentanediols (1,5-pentanediol, etc.), hexanediols (1,6-hexanediol, etc.), neopentyl glycol, catechol, and other glycol-based compounds (which can be glycol-based solvents). ); Glycol ether compounds such as diethylene glycol, triethylene glycol, tripropylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether (which can be glycol ether solvents); thioglycol compounds such as β-thiodiglycol (. It can be a thioglycol solvent.); Glycerin; Sugar alcohol compounds such as mannitol, sorbitol, xylitol; Aromatic alcohol compounds such as 2-phenoxyethanol; N-methylformamide, acetamide, N-ethylacetamide, benzamide and the like. Amid compounds (which can be amide solvents); amine compounds such as pyrazole (typically cyclic amines); sulfoxide compounds such as dimethyl sulfoxide (which can be sulfoxide solvents); etc. Those having a boiling point of 180 ° C. or higher can be used without particular limitation. These can be used alone or in combination of two or more. Of these, glycol compounds, glycol ether compounds, and glycerin having a boiling point of 180 ° C. or higher are preferable, and glycol ether compounds having a boiling point of 180 ° C. or higher (typically diethylene glycol and triethylene glycol) are more preferable.

Although not particularly limited, as the high boiling point compound, a compound having a hydroxyl group is preferably used. It is considered that the high boiling point compound having a hydroxyl group is easily compatible with a solvent (typically an aqueous solvent), and when added to an aqueous solvent, for example, can take a good volatilization behavior that brings about an improvement in wet heat conductivity stability. In some preferred embodiments, the high boiling point compound contains 2 or more hydroxyl groups, for example 3 or more. Further, for example, one containing an ether structure can be preferably used.

The content of the high boiling point compound in the conductive composition disclosed herein is appropriately set to achieve the desired moist heat conductive stability and is not limited to a specific range. The content of the high boiling point compound in the conductive composition is preferably about 0.1% by weight or more, preferably about 0.5% by weight or more, from the viewpoint of obtaining the effect of improving the moist heat conductivity stability. It is preferably about 1% by weight or more, more preferably about 2% by weight or more, and may be about 5% by weight or more (for example, about 8% by weight or more). The upper limit of the content of the high boiling point compound in the conductive composition can be, for example, about 50% by weight or less, and about 30% by weight or less (for example, about 25% by weight or less) is appropriate, and preferably about 25% by weight. It is 15% by weight or less, more preferably about 10% by weight or less, still more preferably about 7% by weight or less, and particularly preferably about 5% by weight or less (typically 4% by weight or less). By limiting the amount of the high boiling point compound used to a predetermined range, the adhesion between the polarizing film and the conductive layer is improved in the embodiment of forming the conductive layer on the polarizing film, and the space between the polarizing film and the pressure-sensitive adhesive layer is improved. In the embodiment in which the conductive layer is arranged on the surface, the anchoring property of the pressure-sensitive adhesive layer tends to be improved.

The conductive composition for forming the conductive layer typically contains a solvent or a dispersion medium (for convenience, hereinafter collectively referred to as "solvent"). The solvent is not particularly limited, and a solvent capable of stably dissolving or dispersing the conductive layer forming component can be preferably used. Such a solvent can be an organic solvent, water, or a mixed solvent thereof. Examples of the organic solvent include esters such as ethyl acetate; ketones such as methyl ethyl ketone, acetone and cyclohexanone; cyclic ethers such as tetrahydrofuran (THF) and dioxane; aliphatic or alicyclic ethers such as n-hexane and cyclohexane. Hydrocarbons; aromatic hydrocarbons such as toluene and xylene; aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol and cyclohexanol; alkylene glycol monoalkyl ethers (eg, ethylene glycol monomethyl ether) , Ethylene glycol monoethyl ether) and other glycol ethers; one or more selected from the above can be used. The solvent is a liquid at room temperature and has a boiling point of less than 180 ° C.

In some preferred embodiments, the solvent is an aqueous solvent. Here, the aqueous solvent means water or a mixed solvent containing water as a main component (for example, a mixed solvent of water and a lower alcohol such as methanol or ethanol). In the technique disclosed herein, an aqueous solvent is preferably used from the viewpoint of preventing deterioration of the polarizing film. The ratio of water to the aqueous solvent is preferably about 30% by weight or more, preferably about 50% by weight or more (typically more than 50% by weight), may be about 70% by weight or more, and is about 80% by weight. The above (for example, about 90 to 100% by weight) may be used.

(Binder)
In some embodiments, the conductive layer comprises a binder. When the conductive layer contains a binder, the film forming property of the conductive layer is improved. Further, in the embodiment in which the conductive layer is formed on the polarizing film, the adhesion between the polarizing film and the conductive layer is improved, and in the embodiment in which the conductive layer is arranged between the polarizing film and the pressure-sensitive adhesive layer, the anchoring property of the pressure-sensitive adhesive layer is improved. Tends to improve. The binder is not particularly limited, and includes oxazoline group-containing polymers, urethane-based polymers, acrylic-based polymers, polyester-based polymers, polyether-based polymers, cellulose-based polymers, vinyl alcohol-based polymers, epoxy group-containing polymers, and vinylpyrrolidone-based polymers. One or more of styrene-based polymers, polyethylene glycol, pentaerythritol and the like can be used. Preferable examples include oxazoline group-containing polymers and urethane-based polymers (typically polyurethane).

In some preferred embodiments, an oxazoline group-containing polymer is used as the binder. By using the oxazoline group-containing polymer, wettability to the surface of the polarizing film can be easily obtained. Further, in the embodiment in which the conductive layer is arranged between the polarizing film and the pressure-sensitive adhesive layer, the anchoring property of the pressure-sensitive adhesive layer tends to be improved. The oxazoline group-containing polymer may be used alone or in combination of two or more. Oxazoline group-containing polymers that are soluble or dispersible in water are preferred. The oxazoline group may be any of a 2-oxazoline group, a 3-oxazoline group, and a 4-oxazoline group, and for example, one having a 2-oxazoline group can be preferably used. As the oxazoline group-containing polymer, for example, a polymer containing a (meth) acrylic skeleton or a styrene skeleton in the main chain and having an oxazoline group in the side chain of the main chain can be used. The oxazoline group-containing polymer according to some preferred embodiments may be an oxazoline group-containing (meth) acrylic polymer comprising a main chain consisting of a (meth) acrylic skeleton and having an oxazoline group in the side chain of the main chain.

The molecular weight of the oxazoline group-containing polymer can be appropriately set based on the purpose, required characteristics, and the like. The upper limit of the molecular weight of the oxazoline group-containing polymer is preferably about 100 × 10 ⁴ or less, preferably about 50 × 10 ⁴ or less, and more preferably about 10 × 10 ⁴ or less from the viewpoint of coatability and the like. , still more preferably about 5 × 10 ⁴ or less. The molecular weight is a standard polystyrene-equivalent number average molecular weight (Mn) obtained by GPC (gel permeation chromatography).

In some embodiments, urethane-based polymers are used as binders. By using the urethane-based polymer, the anchoring property of the pressure-sensitive adhesive layer tends to be improved in the embodiment in which the conductive layer is arranged between the polarizing film and the pressure-sensitive adhesive layer. Examples of the urethane-based polymer include polyurethanes such as ether-based polyurethanes, ester-based polyurethanes, and carbonate-based polyurethanes; urethane (meth) acrylates and acrylic-urethane copolymers copolymerized with alkyl (meth) acrylates. Urethane-based polymers may be used alone or in combination of two or more. In some embodiments, the binder is preferably used in combination with an oxazoline group-containing polymer and a urethane-based polymer.

The content of the binder in the conductive layer is not particularly limited, and it is appropriate, for example, to be about 3% by weight or more. From the viewpoint of adhesion to the polarizing film, anchoring property, etc., the binder content is preferably about 10% by weight or more, more preferably about 30% by weight or more, still more preferably about 50% by weight or more, and particularly preferably. Is about 60% by weight or more, and may be about 70% by weight or more (for example, about 80% by weight or more). The upper limit of the binder content is usually about 99% by weight or less, and about 95% by weight or less is appropriate in consideration of the action of other components such as a conductive polymer, for example, about 90% by weight or less ( For example, it may be about 80% by weight or less).

Additives can be added to the conductive layer, if necessary. Examples of the additive include a leveling agent, an antifoaming agent, a thickener, an antioxidant and the like. The ratio of these additives is usually about 50% by weight or less in the conductive layer, and it is appropriate to make it about 30% by weight or less (for example, about 10% by weight or less), and about 3% by weight or less (for example, 1% by weight). It may be less than%).

(Method of forming a conductive layer)
For the conductive layer, a liquid conductive composition in which the conductive agent, a high boiling point compound, and an additive used as necessary are dispersed or dissolved in an appropriate solvent is applied to the polarizing film, or provided on the polarizing film. It can be preferably formed by a method such as applying it to the surface of the pressure-sensitive adhesive layer. For example, a method of applying the above-mentioned conductive composition to the first surface of a polarizing film, drying it, and performing a curing treatment (heat treatment, ultraviolet treatment, etc.) as necessary can be preferably adopted. The solid content concentration (NV) of the conductive composition can be, for example, 5% by weight or less (typically 0.05 to 5% by weight), and usually 3% by weight or less (typically 0% by weight). .10 to 3% by weight) is appropriate. When forming a thin conductive layer, the NV of the conductive composition is preferably set to, for example, 0.05 to 0.50% by weight (for example, 0.10 to 0.30% by weight). By using the low NV conductive composition in this way, a more uniform conductive layer can be formed.

(Surface resistance value)
From the viewpoint of antistatic and the like, the surface resistance value of the conductive layer is preferably about 1 × 10 ¹² Ω / □ or less. When a conductive layer having a surface resistance value limited to a predetermined value or less is applied to a liquid crystal panel (for example, an in-cell liquid crystal panel), the occurrence of static electricity unevenness is prevented based on the conductivity of the conductive layer. From the viewpoint of touch sensor sensitivity, the lower limit of the surface resistance value is preferably about 1 × 10 ⁶ Ω / □ or more. The range of the surface resistance value of the conductive layer may differ depending on whether or not the pressure-sensitive adhesive layer of the polarizing film with the conductive layer is conductive, the type of liquid crystal cell, the use of portable electronic devices, the use of vehicles, and the like. For example, when applied to an in-cell liquid crystal cell for a portable electronic device, the surface resistance value is preferably about 1 × 10 ⁸ Ω / □ to 1 × 10 ¹⁰ Ω / □, from the viewpoint of antistatic. Therefore, it is more preferably about 1 × 10 ⁸ Ω / □ to 1 × 10 ⁹ Ω / □. When applied to an in-cell liquid crystal cell for automobiles, it is preferably about 1 × 10 ⁶ Ω / □ to 1 × 10 ⁹ Ω / □, and from the viewpoint of antistatic, it is about 1 × 10 ⁷ Ω / □. More preferably, it is ~ 5 × 10 ⁸ Ω / □. Further, when applied to an on-cell type liquid crystal cell, the surface resistance value is preferably about 1 × 10 ¹⁰ Ω / □ to 1 × 10 ¹² Ω / □. When applied to a semi-in-cell liquid crystal cell, the surface resistance value is preferably about 1 × 10 ⁹ Ω / □ to 1 × 10 ¹² Ω / □. The surface resistance value of the conductive layer is measured by the method (initial surface resistance value) described in Examples described later.

(Moist heat surface resistance change ratio)
The conductive layer disclosed herein has, in some embodiments, a surface resistance value S [Ω / □] of the conductive layer after a moist heat test carried out under the conditions of a temperature of 85 ° C., a relative humidity of 85% and 24 hours. The characteristic is that the ratio (moist heat surface resistance change ratio S / P) of the conductive layer to the surface resistance value P [Ω / □] before the moist heat test satisfies the condition: 0.05 ≦ S / P ≦ 10 ;. Can be something to do. The conductive layer satisfying the moist heat surface resistance change ratio S / P exhibits improved moist heat conductive stability. The moist heat surface resistance change ratio S / P is preferably about 0.1 or more, more preferably about 0.5 or more, and further preferably about 0.8 or more (for example, about 1 or more). The S / P is preferably about 3 or less, more preferably about 1.5 or less, still more preferably about 1.2 or less, and particularly preferably 1.1 or less. The moist heat surface resistance change ratio S / P is measured by the method described in Examples described later. The polarizing film with a conductive layer disclosed in the present specification includes the above-mentioned mode in which the wet-heat surface resistance change ratio S / P is not limited, and in such a mode, the polarizing film with a conductive layer has the above-mentioned characteristics. Not limited to things.

(Moist heat surface resistance reduction rate)
In some embodiments, the conductive layer may have a moist heat surface resistance reduction rate suppressed to a predetermined value or less. Specifically, the conductive layer may have a moist heat surface resistance reduction rate of 95% or less, which is obtained from the formula: (1-S / P) × 100 ;. Here, S is the surface resistance value [Ω / □] of the conductive layer after the moist heat test conducted under the conditions of a temperature of 85 ° C., a relative humidity of 85%, and 24 hours, and P is the conductive layer before the moist heat test. The surface resistance value P [Ω / □], and S and P are measured by the method described in Examples described later. The conductive layer satisfying the moist heat surface resistance reduction rate can well suppress the decrease in the surface resistance value when exposed to a moist heat environment. The moist heat surface resistance reduction rate is preferably about 90% or less, more preferably about 50% or less, still more preferably about 20% or less, and particularly preferably about 0% or less. Since the technique disclosed herein may relate to suppressing the decrease in surface resistance when exposed to a moist heat environment, the increase in the surface resistance value after the moist heat test is not particularly limited, but for example, the formula: (S / P). The moist heat surface resistance increase rate obtained from -1) × 100; is appropriately about 200% or less, may be less than 150%, and may be less than 130% (for example, 120% or less). S and P in the above equation are synonymous with S and P of the moist heat surface resistance reduction rate, respectively.

(Thickness of conductive layer)
The thickness of the conductive layer in the technique disclosed herein can be appropriately set according to the required characteristics such as antistatic property and anchoring property. The thickness of the conductive layer is usually about 10 nm or more, and it is appropriate to make it more than 10 nm. From the viewpoint of improving antistatic properties and obtaining a uniform thickness, the thickness of the conductive layer is preferably 12 nm or more, more preferably 14 nm or more, further preferably 15 nm or more, and particularly preferably 20 nm or more (typically 25 nm or more). , For example, 30 nm or more). Further, it is appropriate that the thickness of the conductive layer is about 500 nm or less. By suppressing the thickness of the conductive layer to about 500 nm or less, good optical characteristics (total light transmittance, etc.) can be easily obtained. From such a viewpoint, the thickness of the conductive layer is preferably about 100 nm or less, more preferably about 70 nm or less. In a configuration including a thin conductive layer, the effect of using the high boiling point compound disclosed herein (effect of improving wet and heat conductive stability) can be preferably exhibited.

<Adhesive layer>
The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer disclosed herein is selected from various pressure-sensitive adhesives such as acrylic, rubber, urethane, silicone, vinyl alkyl ether, vinylpyrrolidone, acrylamide, and cellulose. It may be an adhesive layer composed of one kind or two or more kinds thereof. Therefore, the 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. Of these, acrylic adhesives are preferable from the viewpoints of transparency, appropriate wettability, adhesive properties such as cohesiveness and adhesiveness, weather resistance, and heat resistance. Hereinafter, the techniques disclosed herein will be described in more detail by taking the configuration in which the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer as a main example, but the intention is to limit the pressure-sensitive adhesive layer to one made of an acrylic pressure-sensitive adhesive. is not.

(Acrylic adhesive)
The acrylic pressure-sensitive adhesive adopted in some preferred embodiments uses an acrylic polymer as a base polymer (a main component of the polymer components contained in the pressure-sensitive adhesive, that is, a component contained in an amount of more than 50% by weight). Adhesive. Further, the "acrylic polymer" is a monomer having at least one (meth) acryloyl group in one molecule (hereinafter, this may be referred to as "acrylic monomer") as a main constituent monomer component (monomer). The main component of the above, that is, a component that accounts for 50% by weight or more of the total amount of monomers constituting the acrylic polymer). The above-mentioned "(meth) acryloyl group" has the meaning of comprehensively referring to an acryloyl group and a methacryloyl group. Similarly, "(meth) acrylate" is meant to comprehensively refer to acrylates and methacrylates.

(Acrylic polymer)
The acrylic polymer, which is 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 preferably used.
CH ₂ = C (R ¹ ) COOR ² (1)
Here, R ¹ in the above formula (1) is a hydrogen atom or a methyl group. R ² is an alkyl group having 1 to 20 carbon atoms (which is meant to include chain alkyl groups and alicyclic alkyl group.). Since it is easy to obtain a pressure-sensitive adhesive having excellent adhesive properties, R ² is a chain alkyl having 1 to 18 carbon atoms (hereinafter, such a range of carbon atoms may be referred to as C _1-18 ). An alkyl (meth) acrylate which is a group (meaning including a linear alkyl group and a branched alkyl group) is preferable, and an alkyl (meth) acrylate having a C _1-14 chain alkyl group is more preferable. Specific examples of the chain alkyl group of C _1-14 include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-pentyl group, and the like. Isoamyl 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, Examples thereof include an n-dodecyl group, an n-tridecyl group and an n-tetradecyl group. Examples of the alicyclic alkyl group that can be selected as R ² include a cyclohexyl group and an isobornyl group.

In some preferred embodiments, the total amount of monomers used in the synthesis of the acrylic polymer (hereinafter, also referred to as “total raw material monomers”) is approximately 50% by weight or more, more preferably approximately 60% by weight or more, for example, approximately 70% by weight. % Or more is a chain (meth) acrylate in which R ² in the above formula (1) is C _1-18 (more preferably C _1-14 , still more preferably C _4-10 ). For example, it is occupied by one or more selected from one or both of n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA). An acrylic polymer obtained from such a monomer composition is preferable because it is easy to form a pressure-sensitive adhesive exhibiting pressure-sensitive adhesive properties suitable for the applications disclosed herein. The ratio of the chain alkyl (meth) acrylate of C _1-18 (for example, C _1-14 , preferably C _4-10 ) to the total amount of the above-mentioned monomers can be determined by introducing the functional group a or adjusting the phase difference. From the viewpoint of adjusting the refractive index and the like, it is appropriate to set it to about 95% by weight or less, preferably about 90% by weight or less, and more preferably 85% by weight or less (for example, 80% by weight or less).

Further, from the viewpoints of adhesive properties, durability, adjustment of phase difference, adjustment of refractive index, etc., it is preferable to use (meth) acrylate having an aromatic ring structure as the monomer used for synthesizing 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. Of these, (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, phenoxy (meth) acrylate, phenoxyethyl (meth) acrylate, and phenoxypropyl (meth). Acrylate, benzyl (meth) acrylate, phenoxyethylene glycol (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, ethylene oxide-modified nonylphenol (meth) acrylate, ethyleneoxide-modified cresol (meth) acrylate, phenolethylene oxide-modified (meth) acrylate, Phenoxy-2-hydroxypropyl (meth) acrylate, methoxybenzyl (meth) acrylate, chlorobenzyl (meth) acrylate, cresyl (meth) acrylate, polystyryl (meth) acrylate, hydroxyethylated β-naphthol acrylate, 2-naphthoxyethyl (meth) ) Acrylate, 2- (4-methoxy-1-naphthoxy) ethyl (meth) acrylate, thiophenyl (meth) acrylate, pyridyl (meth) acrylate, pyrrolyl (meth) acrylate, polystyryl (meth) acrylate and the like. Those having a biphenyl ring such as biphenyl (meth) acrylate can also be used. These can be used alone or in combination of two or more. Of these, phenoxyethyl (meth) acrylate and benzyl (meth) acrylate are more preferable.

When a (meth) acrylate having an aromatic ring structure is used, its content is appropriately set based on adhesive properties, optical properties, and the like. It is appropriate that the (meth) acrylate having an aromatic ring structure is about 5% by weight or more of the total amount of the monomers used for synthesizing the acrylic polymer, and the effect of the (meth) acrylate having an aromatic ring structure ( From the viewpoint of satisfactorily exhibiting (improvement of durability, improvement of unevenness of liquid crystal display, etc.), it is preferably about 10% by weight or more, more preferably about 15% by weight or more (for example, about 20% by weight or more). The upper limit of the amount of (meth) acrylate having an aromatic ring structure to be used is about 30% by weight or less, preferably less than about 30% by weight in consideration of adhesive properties, anchoring property of the pressure-sensitive adhesive layer, and the like. It is preferably less than about 25% by weight (for example, less than 22% by weight).

As the acrylic polymer in the technique disclosed herein, one in which a functional group-containing monomer is copolymerized can be preferably used. Preferable examples of the functional group-containing monomer include a carboxy group-containing monomer, an acid anhydride group-containing monomer, and a hydroxyl group-containing monomer. These can be used alone or in combination of two or more. The functional group-containing monomer can serve as a cross-linking point in the pressure-sensitive adhesive layer, and can improve the cohesive force and heat resistance of the pressure-sensitive adhesive. Further, in the embodiment in which the pressure-sensitive adhesive layer and the conductive layer are adjacent to each other, the adhesion between the conductive layer and the pressure-sensitive adhesive layer can be enhanced. It is also possible to adjust the glass transition temperature (Tg) of the acrylic polymer and adjust the adhesive properties by using an appropriate amount of the functional group-containing monomer.

Examples of the carboxy group-containing monomer include ethylenically unsaturated monocarboxylic acids such as acrylic acid (AA), methacrylic acid (MAA), carboxyethyl (meth) acrylate, and carboxypentyl (meth) acrylate; itaconic acid, maleic acid, and fumaric acid. , Crotonic acid, isocrotonic acid, citraconic acid and other ethylenically unsaturated dicarboxylic acids;
Examples of the acid anhydride group-containing monomer include maleic anhydride, itaconic anhydride, and acid anhydrides such as the ethylenically unsaturated dicarboxylic acid.
Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. , 2-Hydroxyhexyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4) -Hydroxyalkyl (meth) acrylates such as hydroxymethylcyclohexyl) methyl (meth) acrylate; alkylene glycol (meth) acrylates such as polyethylene glycol mono (meth) acrylate and polypropylene glycol mono (meth) acrylate; vinyl alcohol, Unsaturated alcohols such as allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether; and the like.
One of these functional group-containing monomers may be used alone, or two or more thereof may be used in combination.

A functional group-containing monomer other than the above may be copolymerized with the acrylic polymer in the technique disclosed herein. Such a monomer can be used, for example, for the purpose of adjusting Tg of an acrylic polymer, adjusting the adhesive performance, and the like. For example, examples of the monomer capable of improving the cohesive force and heat resistance of the pressure-sensitive adhesive include a sulfonic acid group-containing monomer, a phosphoric acid group-containing monomer, and a cyano group-containing monomer. Further, as a monomer capable of introducing a functional group that can serve as a cross-linking base point into an acrylic polymer or contributing to improvement of adhesion to an adherend such as glass, an amide group-containing monomer, an amino group-containing monomer, and an imide group-containing monomer are used. , Epoxy group-containing monomer, monomer having a nitrogen atom-containing ring, keto group-containing monomer, isocyanate group-containing monomer, alkoxysilyl group-containing monomer and the like. Among them, an amide group-containing monomer, an amino group-containing monomer, and a monomer having a nitrogen atom-containing ring as exemplified below are preferably used.

Amide group-containing monomers: For example, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, N- Monomermethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide.
Amino group-containing monomer: For example, aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, t-butylaminoethyl (meth) acrylate.
Monomers having a nitrogen atom-containing ring: for example, N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinyl Pyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholin, N-vinylcaprolactam, N- (meth) acryloylmorpholine, N- (meth) acryloylpyrrolidone.

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

In some preferred embodiments, at least one (preferably both) of a carboxy group-containing monomer and a hydroxyl group-containing monomer is used as the monomer component of the base polymer (typically an acrylic polymer). When a carboxy group-containing monomer is used as the monomer component of the acrylic polymer, the amount of the carboxy group-containing monomer in the total amount of the monomers used for the synthesis of the base polymer is usually determined from the viewpoint of adhesive cohesiveness, anchoring property, etc. Approximately 0.001% by weight or more, approximately 0.01% by weight or more is appropriate, preferably approximately 0.1% by weight or more, more preferably approximately 0.2% by weight or more, for example, 1% by weight or more. It may be 3% by weight or more. The upper limit of the amount of the carboxy group-containing monomer used is appropriately set so as to obtain the desired adhesive properties, and about 10% by weight or less of the total amount of the monomers used in the synthesis of the base polymer is suitable, preferably about 8. By weight% or less, more preferably about 6% by weight or less, for example, about 3% by weight or less, or about 1% by weight or less.

When a hydroxyl group-containing monomer is used as the monomer component of the base polymer (typically an acrylic polymer), the amount of the hydroxyl group-containing monomer in the total amount of the monomers used for the synthesis of the base polymer is the cohesiveness of the pressure-sensitive adhesive, the anchoring property, etc. From the above viewpoint, it is usually about 0.001% by weight or more, about 0.01% by weight or more is appropriate, and preferably about 0.1% by weight or more. The upper limit of the amount of the hydroxyl group-containing monomer used is appropriately set so as to obtain the desired adhesive properties, and about 5% by weight or less of the total amount of the monomers used for synthesizing the base polymer is appropriate, preferably about 3% by weight. % Or less, more preferably about 1% by weight or less (for example, about 0.5% by weight or less).

Other copolymerizable monomers that can be used other than the above functional group-containing monomers include vinyl ester-based monomers such as vinyl acetate and vinyl propionate; aromatics such as styrene, substituted styrene (α-methylstyrene, etc.), and vinyltoluene. Vinyl compounds; non-aromatic ring-containing (meth) acrylates such as cyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate, isobornyl (meth) acrylate; ethylene, propylene, isoprene, butadiene, Olefin-based monomers such as 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-based monomers such as methyl vinyl ether, ethyl vinyl ether and isobutyl vinyl ether. Monomer; etc. These can be used alone or in combination of two or more. When such other copolymerizable monomers are used, the amount used is not particularly limited and is usually approximately 30% by weight of the total amount of the monomers used in the synthesis of the base polymer (typically an acrylic polymer). The following (for example, 0 to 30% by weight) is appropriate, and preferably about 10% by weight or less (for example, about 3% by weight or less). The technique disclosed herein can also be carried out in an embodiment in which the monomer component used for the synthesis of the base polymer does not substantially contain the above-mentioned other copolymerizable monomer.

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

The initiator used for the polymerization can be appropriately selected from known or commonly used polymerization initiators. For example, an azo-based polymerization initiator such as 2,2'-azobisisobutyronitrile can be preferably used. Other examples of polymerization initiators include peroxide-based initiators (persulfates such as potassium persulfate, benzoyl peroxide, hydrogen peroxide, etc.); substituted ethane-based initiators such as phenyl-substituted ethane; aromatic carbonyls. Compounds; and the like. Yet another example of the polymerization initiator is a redox-based initiator that is a combination of a peroxide and a reducing agent. Examples of such redox-based initiators include a combination of a peroxide and ascorbic acid (such as a combination of a hydrogen peroxide solution and ascorbic acid) and a combination of a peroxide and an iron (II) salt (hydrogen peroxide solution). (Combination of iron (II) salt, etc.), combination of persulfate and sodium hydrogen peroxide, etc.

Such a polymerization initiator can be used alone or in combination of two or more. The amount of the polymerization initiator used may be a normal amount, for example, about 0.005 to 1 part by weight (typically 0.01 to 1 part by weight) with respect to 100 parts by weight of the total raw material monomer. You can choose from a range.

The method for obtaining a base polymer (typically an acrylic polymer) having such a monomer composition is not particularly limited, and various polymerization methods such as a solution polymerization method, an emulsion polymerization method, a massive polymerization method, and a suspension polymerization method are used. obtain. Alternatively, photopolymerization performed by irradiating light such as UV (typically performed in the presence of a photopolymerization initiator), radiation polymerization performed by irradiating radiation such as β-rays and γ-rays, etc. Active energy ray irradiation polymerization may be adopted. From the viewpoint of transparency, adhesive performance and the like, the solution polymerization method can be preferably adopted. As a monomer supply method at the time of polymerization, a batch charging method, a continuous supply (dropping) method, a divided feeding (dropping) method, or the like in which all the monomer raw materials are supplied at once can be appropriately adopted. The polymerization temperature can be appropriately selected depending on the type of monomer and solvent used, the type of polymerization initiator, etc., and may be, for example, about 20 ° C. to 170 ° C. (typically 40 ° C. to 140 ° C.). it can. Further, 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 usually preferable.

Examples of the solvent (polymerization solvent) used for solution polymerization include aromatic compounds such as toluene and xylene (typically aromatic hydrocarbons); acetate esters such as ethyl acetate; aliphatic or fats such as hexane. Cyclic hydrocarbons; Alcan halides such as 1,2-dichloroethane; Lower alcohols such as isopropyl alcohol (for example, monohydric alcohols having 1 to 4 carbon atoms); Ethers such as tert-butylmethyl ether Any one solvent selected from the above; ketones such as methyl ethyl ketone; or a mixed solvent of two or more kinds can be used.

Base polymer (acrylic polymer) in the art disclosed herein may suitably be GPC weight average molecular weight in terms of standard polystyrene obtained by (Gel Permeation Chromatography) (Mw) is at approximately 10 × 10 ⁴ or more , and the durability, in view of heat resistance and the like, preferably about 50 × 10 ⁴ or more, more preferably about 80 × 10 ⁴ or more, more preferably about 120 × 10 ⁴ or more (e.g., about 0.99 × 10 ⁴ or more) Is. Further, the Mw is suitably not more about 500 × 10 ⁴ or less, from the viewpoint of coating property at the time of forming an adhesive layer, preferably about 300 × 10 ⁴ or less, more preferably about 250 × 10 ⁴ or less, more preferably about 200 × 10 ⁴ or less.

Specifically, the above Mw can be measured under the following conditions using the trade name "HLC-8120GPC" (manufactured by Tosoh Corporation) as a GPC measuring device.
[GPC measurement conditions]
Sample concentration: 0.2% by weight (tetrahydrofuran solution)
Sample injection volume: 100 μL
Eluent: tetrahydrofuran (THF)
Flow rate (flow velocity): 0.8 mL / min Column temperature (measurement temperature): 40 ° C
Column: Made by Tosoh, G7000H _XL + GMH _XL + GMH _XL
Column size: 7.8 mm φ x 30 cm each 90 cm in total
Detector: Differential Refractometer (RI)
Standard sample: polystyrene

(Conductive component)
The technique disclosed herein can be preferably carried out in a manner in which the pressure-sensitive adhesive layer contains a conductive component. Examples of the antistatic component include ionic compounds. A conductive agent that can be contained in the conductive layer may be used. One of these conductive components may be used alone, or two or more thereof may be used in combination. In some preferred embodiments, the pressure-sensitive adhesive layer comprises an ionic compound. The ionic compound preferably improves the conductivity of the pressure-sensitive adhesive layer as a conductive component. For example, one or more selected from alkali metal salts, organic cation-anionic salts and the like are preferably used. From the viewpoint of anchoring property, an organic cation-anion salt is more preferable.

(Alkali metal salt)
As the alkali metal salt, an organic salt or an inorganic salt of the alkali metal can be used. Examples of the alkali metal ions constituting the cation portion of the alkali metal salt include lithium, sodium, and potassium ions. Among these alkali metal ions, lithium ions are preferable.

The anionic 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 ₃ COO ⁻ , CF ₃ COO ⁻ , CH ₃ SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , C ₄ F ₉ SO ₃ ⁻ , C ₃ F ₇ COO ⁻ , (CF ₃ SO ₂ ) (CF ₃ CO) N ⁻ , (FSO ₂ ) ₂ N ⁻ , ⁻ O ₃ S (CF ₂ ) ₃ SO ₃ ⁻ , PF ₆ ⁻ , CO ₃ ^2- and the following general formulas (1) to (4):
(1) (C _n F _{2n + 1} SO ₂ ) ₂ N ⁻ (where n is an integer of 1 to 10);
_{(2) CF 2 (C m} F 2m SO 2) 2 N - ( however, m is an integer of from 1 to 10);
(3) ⁻ O ₃ S (CF ₂ ) _l SO ₃ ⁻ (where l is an integer of 1 to 10);
(4) (C _p F _{2p + 1} SO ₂ ) N ⁻ (C _q F _{2q + 1} SO ₂ ) (where p and q are integers of 1 to 10); An ionic compound having a fluorine atom in the anion portion is preferably used because it has good ionic dissociation properties. As the inorganic anion part, Cl ⁻ , Br ⁻ , I ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , NO ₃ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , NbF ₆ ⁻ , TaF ₆ ⁻ , (CN) ₂ N ^{− and the} like are used. As the anion portion, a (perfluoroalkylsulfonyl) imide such as (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ is preferable, and it is represented by (CF ₃ SO ₂ ) ₂ N ^−. (Trifluoromethanesulfonyl) imide is particularly preferred.

Specific examples of the organic salt of the alkali metal include sodium acetate, sodium alginate, sodium lignin sulfonate, sodium toluene sulfonate, LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, and Li (CF ₃ SO _2). ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N, Li (C ₄ F ₉ SO ₂ ) ₂ N, Li (CF ₃ SO ₂ ) ₃ C, KO ₃ S (CF ₂ ) ₃ SO ₃ K, Examples thereof include LiO ₃ S (CF ₂ ) ₃ SO ₃ K. Among them, LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N, Li (C ₄ F ₉ SO ₂ ) ₂ N, Li (CF ₃ SO ₂ ) ₃ C and the like are preferable, and fluorine-containing lithium imide salts such as Li (CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N and Li (C ₄ F ₉ SO ₂ ) ₂ N are more preferable. Perfluoroalkylsulfonyl) imide lithium salts are particularly preferred.
Examples of the inorganic salt of the alkali metal include lithium perchlorate and lithium iodide.
As the alkali metal salt, one kind may be used alone, or two or more kinds may be used in combination.

(Organic cation-anion salt)
The "organic cation-anionic salt" used in the technique disclosed herein refers to an organic salt whose cation component is composed of an organic substance, and the anion component may be an organic substance. It may be an inorganic substance.

Specific examples of the cation component constituting the organic cation-anion salt include pyridinium cation, piperidinium cation, pyrrolidinium cation, cation having a pyrroline skeleton, cation having a pyrrole skeleton, imidazolium cation, and tetrahydropyrimidi. Examples thereof include nium cation, dihydropyrimidinium cation, pyrazolium cation, pyrazolinium cation, tetraalkylammonium cation, trialkylsulfonium cation, tetraalkylphosphonium cation and the like.

Examples of the anion component of the organic cation-anion salt include Cl ⁻ , Br ⁻ , I ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , NO ₃ ⁻ , and CH ₃ COO ⁻ , CF ₃ COO ⁻ , CH ₃ SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , NbF ₆ ⁻ , TaF ₆ ⁻ , (CN) ₂ N ⁻ , C ₄ F ₉ SO ₃ ⁻ , C ₃ F ₇ COO ⁻ , (CF ₃ SO ₂ ) (CF ₃ CO) N ⁻ , (FSO ₂ ) ₂ N ⁻ , ⁻ O ₃ S (CF ₂ ) ₃ SO ₃ ^- And the following general formulas (1) to (4):
(1) (C _n F _{2n + 1} SO ₂ ) ₂ N ⁻ (where n is an integer of 1 to 10);
_{(2) CF 2 (C m} F 2m SO 2) 2 N - ( however, m is an integer of from 1 to 10);
(3) ⁻ O ₃ S (CF ₂ ) _l SO ₃ ⁻ (where l is an integer of 1 to 10);
(4) (C _p F _{2p + 1} SO ₂ ) N ⁻ (C _q F _{2q + 1} SO ₂ ) (where p and q are integers of 1 to 10); An ionic compound whose anionic component contains a fluorine atom is preferably used because it has good ionic dissociation properties. The number of carbon atoms of the perfluoroalkyl group contained in the anion component is preferably 1 to 3, more preferably 1 or 2. One of these ionic compounds may be used alone, or two or more thereof may be used in combination.

(Other ionic compounds)
Further, as the ionic compound, in addition to the above-mentioned alkali metal salt and organic cation-anionic salt, inorganic salts such as ammonium chloride, aluminum chloride, copper chloride, ferric chloride, ferric chloride and ammonium sulfate can also be used. it can. In addition, the ionic compounds disclosed herein include those generally referred to as ionic surfactants. Examples of the ionic surfactant include a cationic surfactant having a cationic functional group such as a quaternary ammonium salt, a phosphonium salt, a sulfonium salt, a pyridinium salt and an amino group; carboxylic acid, sulfonate, sulfate, phosphate, phosphite and the like. Anionic surfactants having an anionic functional group of the above; sulfobetaines and derivatives thereof, alkylbetaines and derivatives thereof, imidazolines and derivatives thereof, and amphoteric ionic surfactants such as alkylimidazolium betaines and derivatives thereof; and the like. .. One type of organic cation-anion salt may be used alone, or two or more types may be used in combination.

Examples of the ionic compound include an ionic solid and an ionic liquid, and the ionic liquid is preferably used. The ionic liquid easily moves in the pressure-sensitive adhesive layer and easily disperses uniformly in the layer. When an ionic liquid is used as the ionic compound, the effects of the techniques disclosed herein tend to be preferably exhibited.

The "ionic liquid" refers to a molten salt that is liquid at 40 ° C. or lower. The ionic liquid can be easily added to, dispersed or dissolved in the pressure-sensitive adhesive in the temperature range in which the liquid is exhibited, as compared with the solid salt. Further, since the ionic liquid has no vapor pressure (nonvolatile), it does not disappear with time and has a feature that antistatic property can be continuously obtained. The ionic liquid used in the techniques disclosed herein is preferably a molten salt that is liquid at room temperature (25 ° C.) or lower. Among the above-mentioned ionic compounds, an organic cation-anionic salt (ionic liquid of an organic cation-anion salt) that is liquid at 40 ° C. or lower is preferable, and an organic cation-anionic salt that is liquid at room temperature (25 ° C.) or lower is preferable. (Ionic liquid of organic cation-anionic salt) is more preferable.

The content of the ionic compound (preferably an organic cation-anionic salt) in the pressure-sensitive adhesive layer is not particularly limited, and an appropriate amount that can impart a predetermined conductivity to the pressure-sensitive adhesive layer can be added. It is appropriate that the amount of the ionic compound with respect to 100 parts by weight of the base polymer (for example, acrylic polymer) is about 0.01 parts by weight or more (for example, about 0.05 parts by weight or more), from the viewpoint of improving conductivity. It is preferably about 0.1 parts by weight or more, more preferably about 0.3 parts by weight or more, still more preferably about 0.5 parts by weight or more, and particularly preferably about 0.7 parts by weight or more. The upper limit of the amount of the ionic compound is preferably about 20 parts by weight or less with respect to 100 parts by weight of the base polymer, and preferably about 10 parts by weight or less in consideration of durability and adhesive properties. It is more preferably about 5 parts by weight or less, still more preferably about 3 parts by weight or less (for example, about 2 parts by weight or less).

The content of the conductive component in the pressure-sensitive adhesive layer (total amount of the conductive component including the ionic compound) is not particularly limited, and an appropriate amount capable of imparting predetermined conductivity to the pressure-sensitive adhesive layer can be added. The amount of the conductive component with respect to 100 parts by weight of the base polymer (for example, acrylic polymer) is preferably about 0.01 part by weight or more, and preferably about 0.1 part by weight or more from the viewpoint of improving conductivity. More preferably, it is about 0.5 parts by weight or more. Further, it is appropriate that the upper limit of the amount of the conductive component is about 30 parts by weight or less with respect to 100 parts by weight of the base polymer, and preferably about 10 parts by weight or less in consideration of durability and adhesive properties. It is preferably about 5 parts by weight or less, more preferably about 3 parts by weight or less. In the embodiment in which the ionic compound is used as the conductive component, the pressure-sensitive adhesive layer may optionally contain a conductive component other than the ionic compound in addition to the ionic compound, or may be substantially not contained. The technique disclosed herein can be carried out in such a manner that the pressure-sensitive adhesive layer does not substantially contain a conductive component other than an ionic compound.

(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, a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive component in an organic solvent (solvent-type pressure-sensitive adhesive composition), and a pressure-sensitive adhesive composition in which the pressure-sensitive adhesive component is dispersed in an aqueous solvent (water-dispersed pressure-sensitive adhesive composition, typical). Aqueous emulsion type pressure-sensitive adhesive composition), solvent-free type pressure-sensitive adhesive composition (for example, type of pressure-sensitive adhesive composition that cures by irradiation with active energy rays such as ultraviolet rays and electron beams, and hot-melt type pressure-sensitive adhesive composition. Things) etc. The technique disclosed herein can be preferably carried out in an embodiment comprising a pressure-sensitive adhesive layer formed from a solvent-based pressure-sensitive adhesive composition. The organic solvent contained in the solvent-type pressure-sensitive adhesive composition may be, for example, a single solvent consisting of any one of toluene, xylene, ethyl acetate, hexane, cyclohexane, methylcyclohexane, heptane and isopropyl alcohol, and any of these. It may be a mixed solvent containing hexane as a main component.

In the technique disclosed herein, the pressure-sensitive adhesive composition (preferably a solvent-type pressure-sensitive adhesive composition) used for forming the pressure-sensitive adhesive layer is a base polymer (typically an acrylic polymer) contained in the composition. ) Can be appropriately crosslinked. As a specific cross-linking means, a cross-linking base point is introduced into the base polymer by copolymerizing a monomer having an appropriate functional group (hydroxyl group, carboxy group, etc.) and reacts with the functional group to form a cross-linked structure. A method in which a possible compound (crosslinking agent) is added to the base polymer and reacted can be preferably adopted.

Examples of the cross-linking agent include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, oxazoline-based cross-linking agents, aziridine-based cross-linking agents, melamine-based cross-linking agents, carbodiimide-based cross-linking agents, hydrazine-based cross-linking agents, amine-based cross-linking agents, and imine-based cross-linking agents. Examples thereof include agents, peroxide-based cross-linking agents (for example, benzoyl peroxide), metal chelate-based cross-linking agents (typically polyfunctional metal chelate), metal alkoxide-based cross-linking agents, and metal salt-based cross-linking agents. The cross-linking agent may be used alone or in combination of two or more. Of these, isocyanate-based cross-linking agents, epoxy-based cross-linking agents, peroxide-based cross-linking agents, and metal chelate-based cross-linking agents are preferable. For example, when an acrylic polymer is used as the base polymer, an isocyanate-based cross-linking agent and a peroxide-based cross-linking agent are preferable, and a combination of the isocyanate-based cross-linking agent and the peroxide-based cross-linking agent is more preferable.

The amount of the cross-linking agent used can be appropriately selected depending on the composition and structure (molecular weight, etc.) of the base polymer (for example, acrylic polymer), the usage pattern of the polarizing film with the conductive layer, and the like. Generally, the amount of the cross-linking agent used with respect to 100 parts by weight of the base polymer is appropriately about 0.01 parts by weight or more, and preferably about 0.02 parts by weight or more from the viewpoint of enhancing the cohesive force of the pressure-sensitive adhesive. , More preferably about 0.03 parts by weight or more (for example, 0.1 parts by weight or more). The upper limit of the amount of the cross-linking agent used is usually about 10 parts by weight or less with respect to 100 parts by weight of the base polymer, and preferably about 5 parts by weight from the viewpoint of wettability to the adherend. Hereinafter, it is more preferably about 3 parts by weight or less, still more preferably about 1 part by weight or less.

Various additives can be further added to the pressure-sensitive adhesive composition, if necessary. Examples of such additives include surface lubricants, leveling agents, plasticizers, softeners, fillers, antioxidants, preservatives, light stabilizers, UV absorbers, polymerization inhibitors, cross-linking accelerators, silane couplings. Examples include agents. Further, a known or commonly used tackifier resin or peeling modifier may be blended in the pressure-sensitive adhesive composition using an acrylic polymer as a base polymer. Further, when a tacky polymer is synthesized by an emulsion polymerization method, an emulsifier or a chain transfer agent (also referred to as a molecular weight adjuster or a degree of polymerization adjuster) is preferably used. The content of the additive as an optional component can be appropriately determined according to the purpose of use. The amount of the optional additive used is usually about 5 parts by weight or less with respect to 100 parts by weight of the base polymer, and it is appropriate that the amount is about 3 parts by weight or less (for example, about 1 part by weight or less).

(Method of forming the adhesive layer)
The pressure-sensitive adhesive layer is produced by, for example, a method (direct method) in which the pressure-sensitive adhesive composition as described above is directly applied to a polarizing film or directly applied onto a conductive layer provided on the polarizing film and dried or cured. Can be formed. Alternatively, the pressure-sensitive adhesive composition is applied to the surface (peeling surface) of the release liner and dried or cured to form a pressure-sensitive adhesive layer on the surface, and the pressure-sensitive adhesive layer is bonded to the surface of a polarizing film. Alternatively, it may be formed by a method (transfer method) of transferring the pressure-sensitive adhesive layer by adhering it to the surface of a conductive layer provided on a polarizing film. When applying (typically applying) the pressure-sensitive adhesive composition, various methods such as a roll coating method and a gravure coating method can be appropriately adopted. The pressure-sensitive adhesive composition can be dried under heating, if necessary. As a means for curing the pressure-sensitive adhesive composition, ultraviolet rays, laser rays, α-rays, β-rays, γ-rays, X-rays, electron beams and the like can be appropriately adopted.

(Surface resistance value of the adhesive layer)
The surface resistance value of the pressure-sensitive adhesive layer is not particularly limited. In some preferred embodiments, the polarizing film with a conductive layer has a conductive layer as well as a pressure-sensitive adhesive layer. In such an embodiment, it is appropriate that the surface resistance value of the pressure-sensitive adhesive layer is approximately 1 × 10 ¹² Ω / □ or less from the viewpoint of antistatic and the like. When the pressure-sensitive adhesive layer having a surface resistance value limited to a predetermined value or less is applied to a liquid crystal panel (for example, an in-cell type liquid crystal panel) application, the occurrence of static electricity unevenness is preferably prevented based on its conductivity. Further, from the viewpoint of touch sensor sensitivity and durability, it is appropriate that the lower limit of the surface resistance value is preferably about 1 × 10 ⁷ Ω / □ or more. From the above viewpoint, for example, when applied to the on-cell type liquid crystal cell described later, the surface resistance value is preferably about 1 × 10 ¹⁰ Ω / □ to 1 × 10 ¹² Ω / □. Further, when applied to a semi-incell type liquid crystal cell described later, the surface resistance value is preferably about 1 × 10 ⁹ Ω / □ to 1 × 10 ¹² Ω / □. Further, when applied to an in-cell type liquid crystal cell described later, the surface resistance value is preferably about 1 × 10 ⁷ Ω / □ to 1 × 10 ¹² Ω / □, and from the viewpoint of durability, it is about. More preferably, it is 1 × 10 ⁸ Ω / □ to 1 × 10 ¹⁰ Ω / □. The surface resistance value of the pressure-sensitive adhesive layer is measured by the method described in Examples described later.

(Thickness of adhesive layer)
Although not particularly limited, the thickness of the pressure-sensitive adhesive layer can be, for example, about 1 μm or more, and usually, it is appropriate to be about 3 μm or more. From the viewpoint of antistatic property, durability, and securing the contact area with the conduction path when the conduction path is provided on the side surface, the thickness of the pressure-sensitive adhesive layer is preferably about 5 μm or more, more preferably about 7 μm or more, and further. It is preferably about 10 μm or more. The thickness can be, for example, about 100 μm or less, and is usually preferably about 50 μm or less (for example, about 35 μm or less).

<Peeling liner>
The polarizing film with a conductive layer disclosed herein has a release liner attached to the adhesive surface (the surface of the adhesive layer on the side to be attached to the adherend), if necessary. It may be provided in a combined form (in the form of a release liner and a polarizing film with a conductive layer). Paper, synthetic resin film, or the like can be used as the base material constituting the release liner. A synthetic resin film is preferably used because of its excellent surface smoothness. For example, various resin films (for example, polyester films) can be preferably used as the base material of the release liner. The thickness of the release liner can be, for example, about 5 to 200 μm, and is usually preferably about 10 to 100 μm. A mold release agent (for example, silicone-based, fluorine-based, long-chain alkyl-based, fatty acid amide-based, etc.) or silica powder, which is conventionally known, is used on the surface of the release liner to be bonded to the pressure-sensitive adhesive layer. Alternatively, antifouling treatment may be applied.

<Other layers, etc.>
In the polarizing film with a conductive layer disclosed herein, in addition to the above-mentioned layers (polarizing film, adhesive layer, conductive layer, arbitrary surface treatment layer), an easily adhesive layer is provided between the polarizing film and the conductive layer. It can also be subjected to various easy-adhesion treatments such as corona treatment and plasma treatment.

<Use>
The polarizing film with a conductive layer disclosed herein exhibits improved wet-heat conductive stability, and therefore, when used as a liquid crystal panel material, stable conductivity even when the liquid crystal panel is exposed to a wet-heat environment. Can exert sex. Therefore, it is preferably used as a polarizing film with a conductive layer for a liquid crystal cell, a liquid crystal panel, and eventually a liquid crystal display device. For example, the polarizing film with a conductive layer disclosed herein is preferably used for an in-cell type liquid crystal cell, a semi-in-cell type liquid crystal cell, a liquid crystal cell called an on-cell type liquid crystal cell, and a liquid crystal panel including the liquid crystal cell, which will be described later. Further, when the polarizing film with a conductive layer is used for a touch panel type display device, good touch sensor sensitivity is stably maintained even when the touch panel type display device is exposed to a moist heat environment. Can be done. Therefore, it is also suitable as a polarizing film with a conductive layer for a touch panel. Further, since the polarizing film with a conductive layer according to some preferred embodiments is also excellent in anchoring property of the pressure-sensitive adhesive layer, it can be used as a member having excellent durability in a liquid crystal panel or a touch panel type display device. Then, utilizing the above-mentioned touch sensor sensitivity, the polarizing film with a conductive layer disclosed here is a touch sensor-mounted liquid crystal panel (also referred to as a liquid crystal panel with a touch sensing function), and eventually a touch panel type liquid crystal display device. It is particularly preferably used for (also referred to as a liquid crystal display device with a touch sensing function). The touch panel type liquid crystal display device to which the technology disclosed herein is applied is not particularly limited, and can be used for various purposes such as for portable electronic devices and automobiles. The technology disclosed herein may be particularly suitable for an in-vehicle touch panel type liquid crystal display device which is easily exposed to a harsh environment and requires a predetermined or higher humidity and heat durability. By applying the techniques disclosed herein to the above applications, excellent durability can be obtained based on the improved wet and heat conductive stability and the like.

As the touch sensor-mounted liquid crystal panel as described above, a liquid crystal panel having various structures can be adopted. For example, the polarizing film with a conductive layer disclosed herein is preferably used for a liquid crystal panel called an in-cell type liquid crystal panel or an on-cell type liquid crystal panel. The in-cell type liquid crystal panel is simply a liquid crystal cell including a liquid crystal layer and two transparent substrates sandwiching the liquid crystal layer, in the liquid crystal cell (that is, inside the two transparent substrates). It has a configuration including a touch sensing electrode unit related to the touch sensing function. A completely in-cell liquid crystal panel in which both the detection electrode and the drive electrode related to the touch sensing function are arranged in the liquid crystal cell is called a complete in-cell liquid crystal panel. A semi-in-cell type liquid crystal panel is one in which only one of the detection electrode and the drive electrode is arranged in the liquid crystal cell and the other of the electrodes is arranged outside the liquid crystal cell (typically on the outer surface of the transparent substrate). Further, the on-cell type liquid crystal panel refers to a panel in which a touch sensor function is arranged on the outer surface of the transparent substrate of the liquid crystal cell. The effect of improving the moist heat conductive stability by the polarizing film with a conductive layer disclosed herein, thereby improving the durability of good touch sensor sensitivity and maintaining long-term stability can be preferably exhibited in the in-cell type. Unlike the on-cell type, the in-cell type liquid crystal panel does not have a conductive layer such as an ITO layer provided on the surface of the panel. Therefore, a polarizing film with a conductive layer having a lower resistance is used. The lower the resistance value level, the more difficult it is to solve the problem of touch sensor sensitivity. Therefore, the resistance value stability is more important in the in-cell type liquid crystal panel than in the on-cell type. The polarizing film with a conductive layer disclosed herein is particularly preferably used for an in-cell liquid crystal panel, and can contribute to improving the durability and extending the life of the in-cell liquid crystal display device. The polarizing film with a conductive layer disclosed herein includes a configuration in which a touch panel is arranged on the outside of the polarizing film (for example, a configuration in which a touch panel is provided on the outside of a liquid crystal panel such as an IPS system), or a liquid crystal display having such a configuration. It can be used for devices.

<Structure of liquid crystal panel>
Preferable application targets of the polarizing film with a conductive layer disclosed herein include, for example, an in-cell liquid crystal panel as shown in FIGS. 2 to 6. 2 to 6 are schematic cross-sectional views showing a configuration example of an in-cell liquid crystal panel. The in-cell type liquid crystal panel 101 shown in FIG. 2 includes a liquid crystal cell (in-cell type liquid crystal cell) 120 and a polarizing film 110 with a conductive layer arranged on the visual side of the liquid crystal cell 120. As the polarizing film 110 with a conductive layer, the polarizing film with a conductive layer disclosed herein is used.

The liquid crystal cell 120 includes a liquid crystal layer 125 containing liquid crystal molecules, and a first transparent substrate 141 and a second transparent substrate 142 arranged so as to sandwich the liquid crystal layer 125. Further, the liquid crystal cell 120 includes a touch sensing electrode portion 130 between the first transparent substrate 141 and the second transparent substrate 142. The touch sensing electrode unit 130 has a detection electrode 131 and a drive electrode 132. Here, the detection electrode is a touch detection (reception) electrode and functions as a capacitance sensor. The detection electrode is also called a touch sensor electrode.

In the touch sensing electrode unit 130, when the liquid crystal cell 120 is viewed as a plane, the detection electrode 131 and the drive electrode 132 are independently formed in stripes in the X-axis direction and the Y-axis direction of the plane. Both form a pattern that intersects at right angles to each other. The pattern that the touch sensor electrode 130 can form is not limited to this, and the detection electrode 131 and the drive electrode 132 can be formed so as to have various patterns as described later.

In the in-cell type liquid crystal panel 101, the pressure-sensitive adhesive layer 112 of the polarizing film 110 with a conductive layer arranged on the visible side of the liquid crystal cell 120 is attached to the outer surface of the first transparent substrate 141 of the liquid crystal cell 120. In other words, the polarizing film 110 with a conductive layer is arranged and fixed to the outer surface of the first transparent substrate 141 without a conductive layer. In the polarizing film 110 with a conductive layer, the conductive layer 113 is provided on one surface of the polarizing film 111, and the pressure-sensitive adhesive layer 112 is arranged on one surface of the conductive layer 113 (the surface opposite to the polarizing film 111 side). Has a configured configuration. The polarizing film 111 in the polarizing film 110 with a conductive layer is arranged so that the transmission axis (or absorption axis) of the polarizing element is orthogonal to the viewing side of the liquid crystal layer 125. A surface treatment layer 114 is formed on the back surface side of the polarizing film 110 with a conductive layer.

On the other hand, in the in-cell liquid crystal panel 101, the optical film 150 with an adhesive layer is arranged on the side opposite to the surface on which the polarizing film 110 with a conductive layer is arranged. 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 the adhesive layer 152. When the optical film 151 is a polarizing film, the optical film 151 is arranged on the back surface side of the liquid crystal layer 125 so that the transmission axis (or absorption axis) of the polarizing element is orthogonal to each other.

Further, in the in-cell liquid crystal panel 101, a conductive structure 170 formed of a conductive material is provided on the side surfaces of the conductive layer 113 and the pressure-sensitive adhesive layer 112 of the polarizing film 110 with a conductive layer. As a result, the electric potential can be released from the side surfaces of the conductive layer 113 and the pressure-sensitive adhesive layer 112 to other places, and the charge due to static electricity can be reduced or prevented. The conductive structure 170 may be provided on the entire side surface (end surface) of the conductive layer 113 and the pressure-sensitive adhesive layer 112, or may be provided on a part of the side surface. When the conductive structure 170 is partially provided, in order to ensure continuity on the side surface, the total area of the side surfaces of the conductive layer 113 and the pressure-sensitive adhesive layer 112 is approximately 1% or more, preferably approximately 3% or more, more preferably. The conductive structure 170 can be provided at an area ratio of about 10% or more, more preferably about 50% or more. In the configuration example shown in FIG. 2, the conductive structure 171 is also provided on the side surfaces of the polarizing film 111 and the surface treatment layer 114.

The in-cell type liquid crystal panel 102 shown in FIG. 3 is a modified example of the configuration shown in FIG. 2, and the point that the touch sensing electrode portion 130 is arranged between the liquid crystal layer 125 and the second transparent substrate 142 is shown in FIG. It is different from the configuration shown in 2. That is, the touch sensing electrode portion 130 having the detection electrode 131 and the drive electrode 132 is arranged on the backlight side (back surface side) of the liquid crystal layer 125. The in-cell type liquid crystal panel 103 shown in FIG. 4 is also a modification of the configuration shown in FIG. 2, and the point that the touch sensing electrode portion 130 in which the detection electrode and the driving electrode are integrally formed is used is the configuration shown in FIG. different. The in-cell type liquid crystal panel 104 shown in FIG. 5 is a combination of the configurations of FIGS. 3 and 4, and uses a touch sensing electrode unit 130 in which a detection electrode and a driving electrode are integrally formed, and touch sensing. The configuration is different from that shown in FIG. 2 in that the electrode portion 130 is arranged on the backlight side (back surface side) of the liquid crystal layer 125.

Further, the in-cell type liquid crystal panel 105 shown in FIG. 6 is different from the configuration shown in FIG. 2 in that the detection electrode 131 and the drive electrode 132 of the touch sensing electrode portion 130 are separately arranged on both sides of the liquid crystal layer 125. .. Specifically, in the in-cell liquid crystal panel 105, the detection electrode 131 is arranged between the liquid crystal layer 125 and the first transparent substrate 141, and the drive electrode 132 is located between the liquid crystal layer 125 and the second transparent substrate 142. It is located in. Since the other configurations of the modified examples shown in FIGS. 3 to 6 are basically the same as those of the in-cell type liquid crystal panel shown in FIG. 2, overlapping description will be omitted.

As described above, the in-cell type liquid crystal panel has a touch sensing electrode portion inside the liquid crystal cell, not outside the liquid crystal cell. 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. Here, the conductive layer means a layer having a surface resistance value of 1 × 10 ¹³ Ω / □ or less. Based on the improved moist heat conductive stability by arranging the polarizing film with a conductive layer disclosed here on the visible side of the first transparent substrate of the liquid crystal cell of the in-cell type liquid crystal panel having such a configuration. Excellent durability can be achieved.

Further, the polarizing film with a conductive layer disclosed herein can be preferably used for a semi-incell type liquid crystal panel. FIG. 7 is a schematic cross-sectional view showing a configuration example of a semi-incell type liquid crystal panel. In the semi-incell type liquid crystal panel 201 shown in FIG. 7, a part of the touch sensing electrode portion 130 is arranged inside the liquid crystal cell 120, and the other part of the touch sensing electrode portion 130 is outside the liquid crystal cell 120 (specifically, the liquid crystal). It is different from the in-cell type shown in FIGS. 2 to 6 in that it is arranged outside the cell 120 on the visual side. Specifically, the detection electrode 131 constituting the touch sensing electrode portion 130 is provided on the outer surface of the first transparent substrate 141, and the driving electrode 132 constituting the touch sensing electrode portion 130 is arranged in the liquid crystal cell 120. ing. In this configuration example, the drive electrode 132 is arranged between the liquid crystal layer 125 and the second transparent substrate 142. The semi-incell type liquid crystal panel 201 includes a polarizing film 111, a conductive layer 113, an adhesive layer 112, a detection electrode 131, a first transparent substrate 141, a liquid crystal layer 125, a drive electrode 132, and a second transparent substrate 142 from the visual side. It has a laminated structure arranged in this order. Further, a surface treatment layer 114 is provided on the visible side of the polarizing film 111. Further, an adhesive layer 152 and an optical film 151 are arranged in this order on the outside of the second transparent substrate 142. In the liquid crystal panel 201, the detection electrode 131 of the touch sensing electrode portion 130 is arranged outside the first transparent substrate 141 and is in contact with the adhesive layer 112.

Further, the polarizing film with a conductive layer disclosed herein can be preferably used for an on-cell liquid crystal panel. FIG. 8 is a schematic cross-sectional view showing a configuration example of an on-cell liquid crystal panel. In the on-cell liquid crystal panel 202 shown in FIG. 8, the points that the detection electrode 131 and the drive electrode 132 related to the touch sensing electrode portion 130 are both arranged outside the liquid crystal cell 120 as an electrode pattern are shown in FIGS. 2 to 6. Different from in-cell type. In this configuration, a touch sensor function is provided outside the liquid crystal cell 120 (specifically, outside the first transparent substrate 141 and the second transparent substrate 142). More specifically, the drive electrode 132 is arranged on the outer surface of the first transparent substrate 141 of the liquid crystal cell 120, and the detection electrode 131 is arranged on the drive electrode 132. From the visual side, the on-cell liquid crystal panel 202 has a polarizing film 111, a conductive layer 113, an adhesive layer 112, a detection electrode 131, a drive electrode 132, a first transparent substrate 141, a liquid crystal layer 125, a drive electrode 134, and a second transparent. The substrate 142 has a laminated structure arranged in this order. Further, a surface treatment layer 114 is provided on the visible side of the first polarizing film 111. Further, the adhesive layer 152 and the optical film 151 are arranged in this order on the outside of the second transparent substrate 142. In the liquid crystal panel 202, the detection electrode 131 of the touch sensing electrode portion 130 is arranged outside the first transparent substrate 141 and is in contact with the adhesive layer 112. Further, a drive electrode 134 is arranged in the liquid crystal cell 120. The drive electrode 134 is arranged between the liquid crystal layer 125 and the second transparent substrate 142.

In the above configuration example, the polarizing film with a conductive layer arranged on the visual side of the liquid crystal cell has an adhesive layer, a conductive layer, and a polarizing film in this order, but the present invention is not limited to this. Instead of the polarizing film with a conductive layer having a structure, a polarizing film with a conductive layer having another layer structure having a pressure-sensitive adhesive layer, a conductive layer and a polarizing film can be adopted. Since the specific configuration (layer configuration) that the polarizing film with a conductive layer can have is as described above, the description will not be repeated.

Further, in the above configuration example, as the optical film with an adhesive layer arranged on the back surface side, an optical film with an adhesive layer substantially composed of the adhesive layer and the optical film was used. The disclosed technology is not limited to this, and the polarizing film with a conductive layer disclosed herein can also be used on the back side of the liquid crystal panel. In that case, the polarizing films with conductive layers disclosed herein can be arranged on both sides of the liquid crystal cell. Thereby, the effect of the technique disclosed herein can be obtained on both sides of the liquid crystal panel. Alternatively, the polarizing film with a conductive layer disclosed herein may be arranged only on the back side of the liquid crystal panel, not on the visual side. Even in such a configuration, the effects of the techniques disclosed herein can be exerted.

Further, in the in-cell type liquid crystal panel shown in FIGS. 2, 3 and 6, the detection electrode is arranged on the first transparent substrate side (visual recognition side) of the drive electrode, but the in-cell type liquid crystal disclosed here The configuration of the panel is not limited to this, and the drive electrode can be arranged on the first transparent substrate side (visual recognition side) of the detection electrode.

Further, in the semi-in-cell type liquid crystal panel shown in FIG. 7, the detection electrode is arranged outside the liquid crystal cell (specifically, outside the first transparent substrate), and the drive electrode is inside the liquid crystal cell (specifically, the outside of the first transparent substrate). It was arranged between the first transparent substrate and the second transparent substrate), but the technique disclosed here is that the detection electrode is arranged in the liquid crystal cell and the driving electrode is the liquid crystal. It can be applied to a semi-in-cell type liquid crystal panel having a configuration arranged outside the cell.

A liquid crystal display device with a touch sensing function is manufactured by using a liquid crystal panel having the configuration described above (preferably an in-cell type liquid crystal panel). In the manufacture of such a liquid crystal display device, various members that can be used in the liquid crystal display device, such as using a backlight or a reflector for the lighting system, can be used by a known or conventional method.

<Constituent materials for liquid crystal panels>
As the liquid crystal layer constituting the liquid crystal cell, a liquid crystal layer containing liquid crystal molecules is used. In some embodiments, the liquid crystal layer is a liquid crystal layer containing homogenically oriented liquid crystal molecules in the absence of an electric field. As the liquid crystal layer, for example, an IPS type liquid crystal layer is preferably used. Other examples of the liquid crystal layer that can be used in the techniques disclosed herein include liquid crystal layers such as TN type, STN type, π type, and VA type. The thickness of the liquid crystal layer is, for example, about 1.5 μm to 4 μm.

The detection electrode and the driving electrode (including the one in which both are integrated) constituting the touch sensing electrode portion are typically a transparent conductive layer (transparent electrode). The material of these electrodes is not particularly limited, and examples thereof include metals such as gold, silver, copper, platinum, palladium, aluminum, nickel, chromium, titanium, iron, cobalt, tin, magnesium and tungsten, and alloys of these metals. One kind or two or more kinds can be used. Further, as the electrode material, one or more kinds of metal oxides of indium, tin, zinc, gallium, antimonide, zirconium and cadmium can be used. Specific examples include metal oxides composed of indium oxide, tin oxide, titanium oxide, cadmium oxide, and mixtures thereof. Other metal compounds such as copper iodide may be used. The metal oxide may further contain an oxide of the metal atom exemplified above, if necessary. For example, indium oxide (ITO) containing tin oxide, tin oxide containing antimony, and the like are preferably used, and ITO is particularly preferably used. As the ITO, those containing about 80 to 99% by weight of indium oxide and about 1 to 20% by weight of tin oxide are preferably used.

In the in-cell liquid crystal panel, the detection electrode as the touch sensing electrode portion, the driving electrode, and the electrode integrally formed with both are usually at least one of the first transparent substrate and the second transparent substrate (typically only one). Is formed as a transparent electrode pattern on the inside (on the liquid crystal layer side in the liquid crystal cell). In the semi-in-cell type liquid crystal panel, one of the detection electrode and the driving electrode is formed inside one of the first transparent substrate and the second transparent substrate (the liquid crystal layer side in the liquid crystal cell), and the detection electrode and the driving electrode are formed. The other is formed on the outside of the other of the first transparent substrate and the second transparent substrate. In the on-cell liquid crystal panel, the detection electrode, the driving electrode, and the electrode integrally formed with both are formed on the outside of the first transparent substrate and the second transparent substrate (outside the liquid crystal cell). The electrode pattern can be formed by a conventional method.
The detection electrode and the driving electrode in the touch sensing electrode portion, and the electrode integrally formed with both, may have a function as a common electrode for controlling the liquid crystal layer.

The electrode pattern is usually electrically connected to a routing wire (not shown) formed at the end of the transparent substrate. The routing wire is connected to a controller IC (not shown). The shape of the electrode pattern is not limited to the one in which the striped wiring is orthogonal as in the above configuration example. For example, in addition to the striped shape, an arbitrary shape such as a comb shape or a diamond shape, depending on the application, purpose, etc. Can be taken. Therefore, the detection electrode and the drive electrode may have an intersection pattern other than a right angle and various other patterns. The height of the electrode pattern may be, for example, approximately 10 nm to 100 nm, and the width may be approximately 0.1 mm to 5 mm.

Examples of the material for forming the transparent substrate (including the first and second transparent substrates) include glass or a polymer film. Therefore, the transparent substrate can 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), polycycloolefin, polycarbonate and the like. When the transparent substrate is mainly formed of a glass plate, its thickness is, for example, about 0.1 mm to 1 mm. When the transparent substrate is mainly formed of a polymer film, its thickness is, for example, about 10 μm to 200 μm. The transparent substrate may have an easy-adhesion layer or a hard coat layer on its surface.

Various conductive materials can be used without particular limitation as the material for forming the adhesive layer and the conductive structure connected to the side surface of the conductive layer in the polarizing film with the conductive layer. For example, a conductive paste such as a metal paste containing one or more of silver, gold and other metals is preferably used. Other examples of the above materials include conductive adhesives. The conductive structure may have a linear shape extending from the side surface of the conductive layer or the pressure-sensitive adhesive layer. The same applies to the material having a conductive structure that can be provided on the side surface of the polarizing film or the like, and the shape can be the same as described above.

In the liquid crystal panel, as the optical film of the optical film with an adhesive layer arranged on the side opposite to the viewing side, a polarizing film or a known or commonly used optical film different from the polarizing film is used depending on the application and purpose. be able to. Examples of such an optical film include a retardation film (also referred to as a retardation plate, including a wave plate), an optical compensation film, a brightness improving film, a light diffusing film, a reflective film, and an antitransmissive film. They can be used alone or in combination of two or more. In the embodiment in which the polarizing film is used as the optical film arranged on the side opposite to the viewing side, the same polarizing film as the polarizing film arranged on the viewing side may be used, or a different one may be used.

As the pressure-sensitive adhesive layer constituting the optical film with the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer disclosed here or a known or commonly used pressure-sensitive adhesive layer can be used depending on the application and purpose. As the pressure-sensitive adhesive layer, the same one as the pressure-sensitive adhesive layer arranged on the visual side may be used, or a different one may be used. When the pressure-sensitive adhesive layer arranged on the side opposite to the visual viewing side is formed from a known or conventional pressure-sensitive adhesive, the thickness of the pressure-sensitive adhesive layer is not particularly limited, and is preferably about 1 to 100 μm, for example. , It is preferably about 2 to 50 μm, more preferably about 2 to 40 μm, and even more preferably about 5 to 35 μm.

In addition to the above, the liquid crystal panel described above and the liquid crystal display device provided with the liquid crystal panel are arranged with each component according to the application and purpose within a range that does not impair the effects of the techniques disclosed herein. And the configuration can be changed, and other configurations can be additionally adopted as appropriate. As an example, it is possible to change the design such that a color filter substrate is provided on the liquid crystal cell (for example, the first transparent substrate 141 in FIG. 2).

Hereinafter, some examples related to the present invention will be described, but the present invention is not intended to be limited to those shown in such specific examples. In addition, "part" and "%" in the following description are based on weight unless otherwise specified.

<Evaluation method>
[Surface resistance value of conductive layer]
(1) Initial surface resistance value With respect to the surface of the polarizing film with the conductive layer (before laminating the pressure-sensitive adhesive layer), the applied voltage is 10 V, based on JIS K 6911, under an atmosphere of a temperature of 23 ° C. and 50% RH. The initial surface resistance value [Ω / □] is measured under the condition that the application time is 10 seconds. As the resistivity meter, a trade name "Hiresta UP MCP-HT450 type") manufactured by Mitsubishi Chemical Analytech Co., Ltd. or an equivalent product thereof can be used.
(2) Surface resistance value after moist heat test The polarizing film with a conductive layer (before laminating the adhesive layer) is left in a moist heat environment at a temperature of 85 ° C. and 85% RH for 24 hours (wet heat test). Then, the surface resistance of the conductive layer surface dried at room temperature for 3 hours after a moist heat test under the conditions of an applied voltage of 10 V and an applied time of 10 seconds under an atmosphere of a temperature of 23 ° C. and 50% RH, based on JIS K 6911. Measure the value [Ω / □]. As the resistivity meter, a trade name "Hiresta UP MCP-HT450 type") manufactured by Mitsubishi Chemical Analytech Co., Ltd. or an equivalent product thereof can be used.
(3) Moist heat surface resistance change ratio From the ratio (S / P) of the surface resistance value S [Ω / □] after the moist heat test to the initial surface resistance value P [Ω / □] obtained by the above measurement, the moist heat surface Find the resistance change ratio.

[Surface resistance value of adhesive layer]
The pressure-sensitive adhesive layer is formed on the release liner, and the surface of the pressure-sensitive adhesive layer is subjected to the conditions of an applied voltage of 250 V and an application time of 10 seconds in an atmosphere of a temperature of 23 ° C. and 50% RH according to JIS K 6911. Measure the surface resistance value [Ω / □]. As the resistivity meter, a commercially available resistivity meter (for example, trade name "Hiresta UP MCP-HT450 type" manufactured by Mitsubishi Chemical Analytech Co., Ltd.) or an equivalent product thereof can be used. In Table 1 described later, when the resistance value exceeds the measurement upper limit, it is described as "OVER".

[Moist heat conductivity change ratio _FHT ]
(1) Preliminary evaluation (correlation with surface resistance value)
Five samples of polarizing films with a conductive layer having different surface resistance values were prepared, and each polarizing film sample with a conductive layer was set in a touch panel evaluation kit (product name "TouchKit" manufactured by Shurter). This evaluation kit has a PCAP (projection type capacitance type) touch panel on which a cover glass is laminated, an IC (integrated circuit) board, and software, and the current value of the touch panel is connected to the touch panel. It is possible to record and process with the above software from the terminal via the IC board. Specifically, as shown in FIG. 9, the polarizing film sample with a conductive layer is set on the cover glass 304 of the touch panel 302 of the evaluation kit 300 on the surface of the pressure-sensitive adhesive layer of the polarizing film sample S with a conductive layer. Was pasted so as not to cause floating. The touch panel 302 is placed horizontally on an insulator (not shown). As the insulator, for example, a flat resin or a frame-shaped rubber body can be used. Then, the capacitance data map in the touch panel 302 surface is acquired through the terminal T and the IC board by the software started on the PC, and the obtained touch panel current value and the touch panel base current value without the polarizing film sample S with the conductive layer are used. The difference (Cooked Data) of was obtained as ΔC. In this measurement, Cooked Data (Max-Min) calculated from the maximum and minimum values of the difference (Cooked Data) between multiple measured values measured at multiple points on the touch panel surface and the base current value is used as ΔC. are doing. FIG. 10 is a graph in which the sample is plotted on the vertical axis of ΔC (Cooked Data (Max-Min)) measured above and on the horizontal axis of the surface resistance value [Ω / □] of the conductive layer. As shown in FIG. 10, the ΔC and the surface resistance value [Ω / □] showed a high correlation with the correlation coefficient R ^{2 of the} regression line of 0.9701. Therefore, the ΔC has a conductive layer. It can be seen that it can be used as an index of the conductivity and the change in conductivity of the polarizing film. Since the ΔC is a value digitally (8 bits) converted in the software, the unit is bit. It described later ΔC (A), ΔC (B ) and wet heat conductive variation ratio _{F HT} is similar.
In the measurement of ΔC (A) and ΔC (B) described later, the setting of the polarizing film sample with a conductive layer in the evaluation kit does not cause floating between the polarizing film sample with a conductive layer and the cover glass 304. As described above, a plurality of insulating sheets (for example, polystyrene sheets) may be superposed on the upper surface (back surface) of the polarizing film sample with a conductive layer as a weight. Further, when measuring ΔC (A) and ΔC (B) described later for the polarizing film with a conductive layer whose outermost surface is formed by the conductive layer, the surface of the conductive layer is placed so as to be in contact with the cover glass of the evaluation kit. Next, a plurality of insulating sheets (for example, a polystyrene sheet having the same size as a touch panel (1 to 10 to 20 g)) as a weight on the conductive layer so as not to cause floating between the conductive layer and the cover glass. About 20 sheets) can be superposed, and the other measurements can be performed in the same manner as described above.
Even when the pressure-sensitive adhesive layer of the conductive layer with the polarizing film were measured F _HT by attaching to evaluation kit attached to the cover glass, even when measuring F _HT evaluation kit by contacting the conductive layer directly to the cover glass, F _HT takes almost the same value and does not change significantly.
(2) ΔC (A)
The polarizing film with a conductive layer to be measured is set in the evaluation kit 300 by the same method as in (1) above, and the current of the touch panel when the polarizing film with a conductive layer is set is obtained from the acquired capacitance data map in the touch panel surface. The difference ΔC (Cooked Data) between the value and the touch panel base current value is obtained. This is defined as the difference ΔC (A) between the current value of the touch panel and the touch panel base current value that flows when the polarizing film with a conductive layer before the moist heat test is attached to the evaluation touch panel.
(3) ΔC (B)
Further, the polarizing film with a conductive layer to be measured is left for 24 hours in a moist heat environment at a temperature of 85 ° C. and 85% RH (wet heat test). Then, the product dried at room temperature for 3 hours was set in the evaluation kit 300 by the same method as in (1) above, and the current of the touch panel when the polarizing film with the conductive layer was set was obtained from the acquired capacitance data map in the touch panel surface. The difference ΔC (Cooked Data) between the value and the touch panel base current value is obtained. Let this be the difference ΔC (B) between the current value of the touch panel and the touch panel base current value that flows when the polarizing film with the conductive layer after the moist heat test is attached to the evaluation touch panel.
(4) moist heat conductive variation ratio _{F HT} calculated following equation (1), to calculate the wet heat conductivity variation ratio _{F HT.
FHT} = ΔC (B) / ΔC (A) ... (1)

[Touch sensitivity stability evaluation]
Based on the moist heat conductivity change ratio _FHT , it is evaluated according to the following criteria.
(Evaluation criteria)
⊚: _FHT ≤ 1.5
〇: 1.5 <F _HT ≤ 2
X: 2 <F _HT

[Anchoring power]
The release liner is removed from the polarizing film with a conductive layer, an ITO film (manufactured by Oike Kogyo Co., Ltd., trade name "125 Tetraite OES") is attached to the exposed adhesive surface, and the film is cut to a width of 25 mm to obtain a measurement sample. The measurement sample is set in a tensile tester, the polarizing film with a conductive layer is peeled off from the ITO film at a speed of 300 mm / min in the 180 degree direction, and the peeling force [N / 25 mm] at that time is recorded as an anchoring force.
If the anchoring force is 18N / 25mm or more, it is "◎", if it is 12N / 25mm or more and less than 18N / 25mm, it is "○", if it is 10N / 25mm or more and less than 12N / 25mm, it is "△", and it is less than 10N / 25mm. If so, it can be evaluated as "x".

[Preparation of polarizing film]
(Preparation Example A1)
A long roll of a 30 μm-thick polyvinyl alcohol (PVA) resin film (manufactured by Kuraray, product name “PE3000”) is swelled while being uniaxially stretched by a roll stretching machine so as to be 5.9 times in the longitudinal direction. It was dyed, crosslinked, washed, and finally dried to obtain a polarizer having a thickness of 12 μm. Specifically, in the swelling treatment, the film was stretched 2.2 times while being treated with pure water at 20 ° C. In the dyeing treatment, the film was stretched 1.4 times while being treated at 30 ° C. in an aqueous solution in which the iodine concentration was adjusted so that the simple substance transmittance of the obtained polarizer was 45.0%. In the above aqueous solution, the weight ratio of iodine to potassium iodide was 1: 7. As the cross-linking treatment, a two-step cross-linking treatment was adopted, and in the first-step cross-linking treatment, the film was stretched 1.2 times while being treated in a boric acid / potassium iodide aqueous solution at 40 ° C. The boric acid content of this aqueous solution was 5.0%, and the potassium iodide content was 3.0%. In the second-stage cross-linking treatment, the film was stretched 1.6 times while being treated in a boric acid / potassium iodide aqueous solution at 65 ° C. The boric acid content of this aqueous solution was 4.3%, and the potassium iodide content was 5.0%. In the washing treatment, an aqueous potassium iodide solution at 20 ° C. was used. The potassium iodide content of the aqueous solution for cleaning treatment was set to 2.6%. The drying treatment was carried out at 70 ° C. for 5 minutes.

A TAC-HC film having a thickness of 32 μm having a hard coat (HC) layer on one side of the triacetyl cellulose (TAC) film was attached to one side of the above-mentioned polarizer using a PVA-based adhesive. Further, an acrylic (CAT) film having a thickness of 25 μm is bonded to the other surface of the polarizer using a PVA-based adhesive to form a polarizing film having a TAC protective layer / PVA polarizer / CAT protective layer configuration. Made. A hard coat layer is provided as a surface treatment layer on the surface of the polarizing film on the TAC protective layer side.

[Preparation of conductive composition]
(Preparation Example B1)
14.3 parts of thiophene polymer-containing solution (PEDOT / PSS-NH ₄ ) and binder solution A (trade name "Superflex 210" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., containing urethane binder, solid content 35%). 1 part, binder solution B (manufactured by Nippon Catalyst Co., Ltd., trade name "Epocross WS-700", containing oxazolin group-containing polymer of Mn 20,000, Mw 40,000) and triethylene glycol as a high boiling point compound (boiling point: about 287 ° C.) and water were mixed to prepare a conductive composition B1 having a solid content concentration of 1.5%. As the thiophene-based polymer-containing liquid, an aqueous dispersion containing PEDOT (poly (3,4-ethylenedioxythiophene)) and PSS (poly (styrene sulfonic acid) sodium) (manufactured by Heraeus, trade name "CleviosP") is used. It was neutralized with 28% aqueous ammonia manufactured by Tokyo Chemical Industry Co., Ltd. to have a solid content of 1%. Triethylene glycol was blended so as to be contained in the composition at 3%. The obtained composition contained 0.14% of a thiophene-based polymer, 0.36% of a urethane binder, and 1.0% of an oxazoline group-containing polymer.

(Preparation Example B2)
The conductive composition B2 according to this example was prepared in the same manner as in Preparation Example B1 except that diethylene glycol (boiling point: about 244 ° C.) was used instead of triethylene glycol as the high boiling point compound.

(Preparation Example B3)
The conductive composition B3 according to this example was prepared in the same manner as in Preparation Example B1 except that catechol (boiling point: about 246 ° C.) was used instead of triethylene glycol as the high boiling point compound.

(Preparation Example B4)
The conductive composition B4 according to this example was prepared in the same manner as in Preparation Example B3 except that the amount of the high boiling point compound (catechol) added was changed from 3% to 10% and the amount of water was reduced accordingly.

(Preparation Example B5)
The conductive composition B5 according to this example was prepared in the same manner as in Preparation Example B1 except that glycerin (boiling point: about 290 ° C.) was used instead of triethylene glycol as the high boiling point compound.

(Preparation Example B6)
The conductive composition B6 according to this example was prepared in the same manner as in Preparation Example B2 except that the amount of the high boiling point compound (diethylene glycol) added was changed from 3% to 20% and the amount of water was reduced accordingly.

(Preparation Example B7)
42.9 parts of thiophene-based polymer-containing solution (PEDOT / PSS-NH ₄ ) and binder solution A (trade name "Superflex 210" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., urethane binder containing, solid content 35%) A conductive composition B7 having a solid content concentration of 0.1% was prepared by blending 3.1 parts, diethylene glycol (boiling point: about 244 ° C.) as a high boiling point compound, and water. Diethylene glycol was blended so as to be contained in the composition at 3%. As the thiophene-based polymer-containing liquid, the same solution as in Preparation Example B1 was used. The obtained composition contained 0.03% of a thiophene-based polymer and 0.07% of a urethane binder.

(Preparation Example B8)
The conductive composition B8 according to this example was prepared in the same manner as in Preparation Example B1 except that N-methylpyrrolidone (boiling point: about 204 ° C.) was used instead of triethylene glycol as the high boiling point compound.

(Preparation Example B9)
As the high boiling point compound, 5% of dimethyl sulfoxide (boiling point: about 189 ° C.) was used instead of 3% of triethylene glycol, and the amount of water was reduced by that amount, but the conductivity according to this example was the same as in Preparation Example B1. Composition B9 was prepared.

(Preparation Example B10)
The conductive composition B10 according to this example was prepared in the same manner as in Preparation Example B1 except that the high boiling point compound was not used.

(Preparation Example B11)
The conductive composition B11 according to this example was prepared in the same manner as in Preparation Example B1 except that N, N-dimethylformamide (boiling point: about 153 ° C.) was used instead of triethylene glycol.

(Preparation Example B12)
The conductive composition B12 according to this example was prepared in the same manner as in Preparation Example B1 except that diethylene glycol dimethyl ether (boiling point: about 162 ° C.) was used instead of triethylene glycol.

[Preparation of adhesive composition]
(Preparation Example C1)
Butyl acrylate (BA) 76.9 parts, benzyl acrylate (BzA) 17 parts, acrylic acid (AA) 5 parts, N- in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler. A monomer mixture containing 1 part of vinyl-2-pyrrolidone (NVP) and 0.1 part of 4-hydroxybutyl acrylate (4HBA) was charged. Further, with respect to 100 parts of the above-mentioned monomer mixture (solid content), 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator is charged together with 100 parts of ethyl acetate, and nitrogen gas is added while gently stirring. After the introduction and nitrogen substitution, the liquid temperature in the flask was maintained at around 55 ° C. and the polymerization reaction was carried out for 8 hours to prepare an acrylic polymer P1 solution having Mw 1.95 million and Mw / Mn = 3.9.

1 part of a conductive agent is added to 100 parts of the solid content of the acrylic polymer P1 solution obtained above, and an isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name "Coronate L", trimethylolpropane / tolylene diisocyanate) is further added. Additives) 0.4 parts, peroxide cross-linking agent (manufactured by Nippon Oil & Fats Co., Ltd., trade name "Niper BMT") 0.1 parts and γ-glycidoxypropylmethoxysilane (manufactured by Shinetsu Chemical Industry Co., Ltd., trade name "KBM") −403 ”) 0.2 parts were blended to prepare a solution of the acrylic pressure-sensitive adhesive composition C1. As the conductive agent, bis (trifluoromethanesulfonyl) imide lithium (LiTFSI) was used.

(Preparation Example C2)
An acrylic polymer P2 solution was prepared in the same manner as in the above preparation of the acrylic polymer P1 solution except that the composition of the monomer mixture was BA77.9 parts, BzA17 parts, AA5 parts, and 4HBA0.1 parts. The Mw of the obtained acrylic polymer P2 was 1.6 million and Mw / Mn = 3.7.
For 100 parts of the solid content of the acrylic polymer P2 solution obtained above, 0.4 part of an isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name "Coronate L", trimethylolpropane / tolylene diisocyanate adduct), excess 0.1 part of oxide cross-linking agent (manufactured by Nippon Oil & Fats Co., Ltd., trade name "Niper BMT") and 0.2 parts of γ-glycidoxypropylmethoxysilane (manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name "KBM-403") It was mixed to prepare a solution of the acrylic pressure-sensitive adhesive composition C2.

(Preparation Example C3)
The composition of the monomer mixture was 75.8 parts of BA, 23 parts of phenoxyethyl acrylate (PEA), 0.5 parts of NVP, 0.4 parts of 4HBA, and 0.3 parts of AA, except that the composition was the same as the preparation of the acrylic polymer P1 solution. , Acrylic polymer P3 solution was prepared. The Mw of the obtained acrylic polymer P3 was 1.6 million and Mw / Mn = 3.7. A solution of the acrylic pressure-sensitive adhesive composition C3 was prepared in the same manner as in Preparation Example C1 except that the acrylic polymer P3 solution obtained above was used instead of the acrylic polymer P1 solution.

(Preparation Example C4)
As the conductive agent, 1-ethyl-3-methylimidazolium bis (fluorosulfonyl) imide (EMI-FSI) was used instead of LiTFSI. In the same manner as in Preparation Example C3, the acrylic pressure-sensitive adhesive composition C4 The solution was prepared.

<Examples 1 to 14 and Comparative Examples 1 to 3>
A coating liquid consisting of any of the above conductive compositions B1 to B12 is applied to one side of the above polarizing film (the side on which the hard coat layer is not provided) so that the thickness after drying is 50 nm, and at 80 ° C. It was dried for 3 minutes to form a conductive layer.
A solution of any of the above acrylic pressure-sensitive adhesive compositions C1 to C4 is applied to one side of a polyethylene terephthalate (PET) film (release liner, manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., product number "MRF38") treated with a silicone-based release agent. The film was applied so that the thickness of the pressure-sensitive adhesive layer after drying was 23 μm, and the film was dried at 155 ° C. for 1 minute to form a pressure-sensitive adhesive layer on the surface of the release liner. Then, the pressure-sensitive adhesive layer formed on the release liner was transferred to the surface on the conductive layer side on the polarizing film obtained above. In this way, the polarizing film with a conductive layer according to each example was produced. These polarizing films with a conductive layer have a structure of a polarizing film / a conductive layer / an adhesive layer, a hard coat layer is provided on the back surface on the polarizing film side, and the adhesive surface of the adhesive layer is protected by a release liner. Has been done.

Schematic configuration of the polarizing film with a conductive layer according to each example, surface resistance value [Ω / □] at the initial stage and after the moist heat test, moist heat surface resistance change ratio, surface resistance value [Ω / □] of the pressure-sensitive adhesive layer, and moist heat conductivity. Table 1 shows the evaluation results of the change ratio _FHT (ΔC (B) / ΔC (A)), touch sensitivity stability, and anchoring force [N / 25 mm]. Although N, N-dimethylformamide and diethylene glycol dimethyl ether used in Comparative Examples 2 and 3 do not correspond to high boiling point compounds, they are described in the item of high boiling point compounds for convenience.

As shown in Table 1, in Examples 1 to 14 in which a high boiling point compound having a boiling point of 180 ° C. or higher was used for forming the conductive layer, the wet heat conductivity change ratio _FHT was 2 or less, and the touch sensitivity stability evaluation was performed. All results were pass level. In these examples, the moist heat surface resistance change ratio of the conductive layer was also in the range of 0.05 or more and 10 or less. Further, in Examples 1 to 12 using a high boiling point compound having a boiling point of 210 ° C. or higher, the _FHT was in a narrower range, and particularly excellent evaluation results were obtained. On the other hand, in Comparative Examples 1 to 3 in which the high boiling point compound having a boiling point of 180 ° C. or higher was not used, the _FHT exceeded 2, and the touch sensitivity stability evaluation result was poor. Further, in Comparative Examples 1 to 3, the moist heat surface resistance change ratio of the conductive layer was also less than 0.05.

Further, in Examples 1 to 4, 7, 13 to 14, in which the boiling point of the high boiling point compound was 180 ° C. or higher and lower than 290 ° C. and the amount of the high boiling point compound used was 0.1 to 10%, the anchoring force was 18 N / It was 25 mm or more and had excellent durability. Further, for example, from the comparison between Examples 3 and 8 and the comparison between Examples 9 to 10 and 11 to 12, an acrylic polymer containing an amide group-containing monomer as a monomer unit is used as the polymer contained in the pressure-sensitive adhesive layer. In the case of the above and the example of using an inorganic salt (a salt of an inorganic cation) as the conductive agent contained in the pressure-sensitive adhesive layer, a tendency to improve the anchoring power was observed.

From the above results, it is a polarizing film with a conductive layer including a polarizing film, a conductive layer provided on at least one surface of the polarizing film, and an adhesive layer arranged on the conductive layer, and is moist heat conductive. Those satisfying a change ratio of _FHT 2 or less, those having a wet-heat surface resistance change ratio of a conductive layer in the range of 0.05 or more and 10 or less, a conductive polymer, and a high boiling point compound having a boiling point of 180 ° C. or more. According to the configuration including the conductive layer formed by using and, it can be seen that stable conductivity can be maintained even when exposed to a moist heat environment.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above.

10,110: Polarizing film with conductive layer 11,111: Polarizing film 11A: First surface of polarizing film 11B: Second surface of polarizing film 12,112: Adhesive layer 13,113: Conductive layer 14,114: Surface treatment layer 101, 102, 103, 104, 105: In-cell type liquid crystal panel 201: Semi-in-cell type liquid crystal panel 202: On-cell type liquid crystal panel 120: Liquid crystal cell 125: Liquid crystal layer 130: Touch sensing electrode unit 131: Detection electrode 132: Drive electrode 141: First transparent substrate 142: Second transparent substrate 150: Optical film with adhesive layer 1511: Optical film 152: Adhesive layer 170: Conductive structure 171: Conductive structure 300: Evaluation kit 302: Touch panel 304: Cover glass S: Conductive layer Polarized film sample with

Claims (12)

A polarizing film with a conductive layer, comprising a polarizing film and an adhesive layer arranged on at least one of a first surface side and a second surface side of the polarizing film, and further comprising a conductive layer.
The polarizing film, wet heat conductive variation ratio F _HT represented by the following formula (1) is 2 or less, the polarizing film with a conductive layer.
_FHT = ΔC (B) / ΔC (A) ... (1)
(In the formula (1), ΔC (B) flows when a polarizing film with a conductive layer after a moist heat test carried out under the conditions of a temperature of 85 ° C., a relative humidity of 85% and 24 hours is attached to the evaluation touch panel. It is the difference between the current value of the touch panel and the touch panel base current value, and ΔC (A) is the touch panel current value and the touch panel base current that flow when the polarizing film with a conductive layer before the wet heat test is attached to the evaluation touch panel. The difference from the value.) A polarizing film with a conductive layer, comprising a polarizing film and an adhesive layer arranged on at least one of a first surface side and a second surface side of the polarizing film, and further comprising a conductive layer.
The conductive layer satisfies the condition: wet heat surface resistance change ratio S / P: 0.05 ≦ S / P ≦ 10, where S is carried out under the conditions of temperature 85 ° C., relative humidity 85% and 24 hours. A polarizing film with a conductive layer, which is the surface resistance value [Ω / □] of the conductive layer after the moist heat test, and P is the surface resistance value [Ω / □] of the conductive layer before the moist heat test. A polarizing film with a conductive layer, comprising a polarizing film and an adhesive layer arranged on at least one of a first surface side and a second surface side of the polarizing film, and further comprising a conductive layer.
The conductive layer is a polarizing film with a conductive layer, which is formed of a conductive composition containing a conductive polymer and a high boiling point compound having a boiling point of 180 ° C. or higher. The conductive layer satisfies the condition: wet heat surface resistance change ratio S / P: 0.05 ≦ S / P ≦ 10, where S is carried out under the conditions of temperature 85 ° C., relative humidity 85% and 24 hours. The surface resistance value [Ω / □] of the conductive layer after the moist heat test, and P is the surface resistance value [Ω / □] of the conductive layer before the moist heat test, according to claim 1 or 3. A polarizing film with a conductive layer. The polarizing film with a conductive layer according to claim 3, wherein the content of the high boiling point compound in the conductive composition is 0.1 to 10% by weight. The polarizing film with a conductive layer according to any one of claims 1 to 5, wherein the conductive layer contains a thiophene-based polymer as the conductive polymer. The polarizing film with a conductive layer according to any one of claims 1 to 6, wherein the conductive layer includes a binder. The polarizing film with a conductive layer according to any one of claims 1 to 7, wherein the pressure-sensitive adhesive layer contains an acrylic polymer. The polarizing film with a conductive layer according to claim 8, wherein the acrylic polymer contains an amide group-containing monomer as a monomer unit. The conductive layer is provided on at least one surface of the polarizing film.
The polarizing film with a conductive layer according to any one of claims 1 to 9, wherein the pressure-sensitive adhesive layer is arranged on the conductive layer. The polarizing film with a conductive layer according to any one of claims 1 to 10, which is used for an in-cell liquid crystal panel. With the step of forming a conductive layer on at least one surface of the polarizing film;
The step of providing the pressure-sensitive adhesive layer on the conductive layer;
Is equipped with
A method for producing a polarizing film with a conductive layer, wherein the conductive layer is formed from a conductive composition containing a conductive polymer and a high boiling point compound having a boiling point of 180 ° C. or higher.

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