阅读说明：本技术 内置有触摸传感功能的液晶显示装置及其制造方法 (Liquid crystal display device with touch sensing function built-in and method for manufacturing the same ) 是由 山本悟士 木村智之 外山雄祐 于 2020-02-21 设计创作，主要内容包括：本发明提供即使在暴露于湿热环境的情况下、也能够防止静电不均的发生、并且保持稳定的触摸传感灵敏度的内置有触摸传感功能的液晶显示装置。另外,提供内置有触摸传感功能的液晶显示装置。该液晶显示装置具备：包含液晶分子的液晶层；触摸传感器部；以及分别配置于液晶层的两侧的第一偏振膜及第二偏振膜,其中,第一偏振膜配置于液晶层的可视侧、且比触摸传感器部更靠近可视侧,在比触摸传感器部更靠近可视侧配置有导电层,下式(1)表示的导电层的湿热导电性变化比F-(HT)为2以下。F-(HT)＝ΔC(B)/ΔC(A)·····(1)(式(1)中,ΔC(B)是湿热试验后的触摸面板电流值与触摸面板基础电流值的差值,ΔC(A)是湿热试验前的触摸面板电流值与触摸面板基础电流值的差值。)。(The invention provides a liquid crystal display device with a built-in touch sensing function, which can prevent the generation of static electricity unevenness and keep stable touch sensing sensitivity even under the condition of being exposed to a damp and hot environment. Further, a liquid crystal display device having a touch sensing function is provided. The liquid crystal display device includes: a liquid crystal layer containing liquid crystal molecules; a touch sensor section; and a first polarizing film and a second polarizing film respectively disposed on both sides of the liquid crystal layerTwo polarizing films, wherein the first polarizing film is disposed on the visible side of the liquid crystal layer and closer to the visible side than the touch sensor unit, the conductive layer is disposed on the visible side than the touch sensor unit, and the moisture-heat conductivity change ratio F of the conductive layer represented by the following formula (1) HT Is 2 or less. F HT Δ c (b)/Δ c (a) · · · · · (1) (in formula (1), Δ c (b) is a difference between a touch panel current value after the wet heat test and a touch panel base current value, and Δ c (a) is a difference between a touch panel current value before the wet heat test and a touch panel base current value).)

1. A liquid crystal display device having a touch sensing function built therein, the liquid crystal display device comprising:

a liquid crystal layer containing liquid crystal molecules;

a touch sensor section; and

a first polarizing film and a second polarizing film respectively disposed on both sides of the liquid crystal layer,

wherein the first polarizing film is disposed on the viewing side of the liquid crystal layer and closer to the viewing side than the touch sensor unit,

a conductive layer is disposed on the visible side of the touch sensor portion,

a change ratio F of wet heat conductivity of the conductive layer represented by the following formula (1)_HTThe content of the compound is less than 2,

F_HT＝ΔC(B)/ΔC(A)·····(1)

in the formula (1), Δ c (b) is a difference between a current value of the touch panel that flows when the conductive layer after the wet heat test is disposed on the touch panel for evaluation and a touch panel base current value, and Δ c (a) is a difference between a current value of the touch panel that flows when the conductive layer before the wet heat test is disposed on the touch panel for evaluation and a touch panel base current value, the wet heat test being performed under conditions of a temperature of 85 ℃, a relative humidity of 85%, and 24 hours.

2. A liquid crystal display device having a touch sensing function built therein, the liquid crystal display device comprising:

a liquid crystal layer containing liquid crystal molecules;

a touch sensor section; and

a first polarizing film and a second polarizing film respectively disposed on both sides of the liquid crystal layer,

wherein the first polarizing film is disposed on the viewing side of the liquid crystal layer and closer to the viewing side than the touch sensor unit,

a conductive layer is disposed on the visible side of the touch sensor portion,

the wet-heat surface resistance change ratio S/P of the conductive layer satisfies the condition: S/P is more than or equal to 0.05 and less than or equal to 10,

wherein S is a surface resistance value [ omega/□ ] of the conductive layer after a wet heat test performed under conditions of a temperature of 85 ℃, a relative humidity of 85% and 24 hours, and P is a surface resistance value [ omega/□ ] of the conductive layer before the wet heat test.

3. A liquid crystal display device having a touch sensing function built therein, the liquid crystal display device comprising:

a liquid crystal layer containing liquid crystal molecules;

a touch sensor section; and

a first polarizing film and a second polarizing film respectively disposed on both sides of the liquid crystal layer,

wherein the first polarizing film is disposed on the viewing side of the liquid crystal layer and closer to the viewing side than the touch sensor unit,

a conductive layer is disposed on the visible side of the touch sensor portion,

the conductive layer is formed of a conductive composition containing a conductive polymer and a high boiling point compound having a boiling point of 180 ℃ or higher.

4. The liquid crystal display device according to claim 1 or 3,

the wet-heat surface resistance change ratio S/P of the conductive layer satisfies the condition: S/P is more than or equal to 0.05 and less than or equal to 10,

wherein S is a surface resistance value [ omega/□ ] of the conductive layer after a wet heat test performed under conditions of a temperature of 85 ℃, a relative humidity of 85% and 24 hours, and P is a surface resistance value [ omega/□ ] of the conductive layer before the wet heat test.

5. The liquid crystal display device according to claim 3,

the content of the high boiling point compound in the conductive composition is 0.1 to 10 wt%.

6. The liquid crystal display device according to claim 3 or 5,

the boiling point of the high boiling point compound is 210-290 ℃.

7. The liquid crystal display device according to claim 3, 5 or 6,

the high boiling point compound is glycol ether solvent.

8. The liquid crystal display device according to any one of claims 1 to 7,

the conductive layer contains a thiophene polymer as a conductive polymer.

9. The liquid crystal display device according to any one of claims 1 to 8,

the conductive layer includes a binder.

10. A method for manufacturing a liquid crystal display device having a touch sensing function built therein, the liquid crystal display device comprising:

a liquid crystal layer containing liquid crystal molecules;

a touch sensor section; and

a first polarizing film and a second polarizing film respectively disposed on both sides of the liquid crystal layer,

wherein the first polarizing film is disposed on the viewing side of the liquid crystal layer and closer to the viewing side than the touch sensor unit,

the method comprises the following steps:

a step of disposing a conductive layer on the visible side of the touch sensor section,

the conductive layer is formed of a conductive composition containing a conductive polymer and a high boiling point compound having a boiling point of 180 ℃ or higher.

Technical Field

The present invention relates to a liquid crystal display device having a touch sensor function built therein and a method for manufacturing the same.

The present application is based on the priority claim of japanese patent application No. 2019-039938 filed on 3/5 of 2019, the entire contents of which are incorporated by reference into the present specification.

Background

In recent years, liquid crystal display devices incorporating a touch sensing function have been widely used as image display devices capable of input in various fields such as portable electronic devices and vehicles. In such a liquid crystal display device, in order to prevent the occurrence of display unevenness (hereinafter, also referred to as "static electricity unevenness") of liquid crystal due to static electricity or the like, countermeasures such as providing an antistatic layer have been taken. Static electricity may be generated, for example, when a polarizing film is attached to a liquid crystal cell or when a release liner is removed from the polarizing film with an adhesive layer. As a prior art document disclosing such a prior art, patent document 1 is cited. Patent document 2 discloses a conductive resin composition that can be used for touch panels of various electronic devices, transparent electrodes for driving liquid crystals, and the like, and describes that a transparent conductive film contains a conductivity enhancer.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2017/057097

Patent document 2: japanese patent application laid-open No. 2015-117367

Disclosure of Invention

Problems to be solved by the invention

The capacitance system used in a liquid crystal display device having a touch sensor function is an input device that detects and drives a change in capacitance due to a touch of a finger on a touch panel, and therefore, when the change in capacitance to be detected is unstable due to an electric field disturbance caused by the presence of an antistatic layer, the sensitivity of the touch panel is lowered. Therefore, the antistatic layer used in the touch sensor function built-in type is configured to have conductivity that can achieve both prevention of occurrence of static unevenness and touch sensor sensitivity (patent document 1). The conductivity is desired to be stable in various environments from the viewpoint of durability and long life of the device. However, the results of the studies conducted by the present inventors indicate that: when the conventional antistatic layer is used in a high-temperature and high-humidity environment, the surface resistance value decreases, and there is a concern that a malfunction of the touch sensor may occur.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal display device with a built-in touch sensing function, which can prevent the occurrence of static electricity unevenness and maintain stable touch sensing sensitivity even when exposed to a hot and humid environment. Another object of the present invention is to provide a method for manufacturing a liquid crystal display device having a touch sensing function.

Means for solving the problems

According to the present specification, a liquid crystal display device incorporating a touch sensing function is provided. The liquid crystal display device includes: a liquid crystal layer containing liquid crystal molecules; a touch sensor section; and a first polarizing film and a second polarizing film respectively disposed on both sides of the liquid crystal layer, wherein the first polarizing film is disposed on a visible side of the liquid crystal layer and on a visible side of the touch sensor unit, and a conductive layer is disposed on a visible side of the touch sensor unit in the liquid crystal display device. In some embodiments, the moisture-heat conductivity change ratio F of the conductive layer represented by the following formula (1)_HTIs 2 or moreThe following steps.

F_HT＝ΔC(B)/ΔC(A)·····(1)

(in the formula (1),. DELTA.C (B) is the difference between the touch panel current value and the touch panel base current value which flow when the conductive layer after the wet heat test is placed on the touch panel for evaluation, and. DELTA.C (A) is the difference between the touch panel current value and the touch panel base current value which flow when the conductive layer before the wet heat test is placed on the touch panel for evaluation, the wet heat test being performed under the conditions of 85 ℃ temperature, 85% relative humidity and 24 hours.)

According to the above configuration, the ratio of change in the wet heat conductivity of the conductive layer of the liquid crystal display device before and after the wet heat test is F_HTSince the ratio is 2 or less, the change in conductivity can be suppressed even when exposed to a moist heat environment. This prevents the occurrence of static electricity unevenness, and prevents malfunction of the touch sensor while maintaining stable touch sensing sensitivity. The liquid crystal display device having a touch sensor function incorporated therein is excellent in humidity and heat durability.

In addition, according to the present specification, a liquid crystal display device having a touch sensing function is provided. The liquid crystal display device includes: a liquid crystal layer containing liquid crystal molecules; a touch sensor section; and a first polarizing film and a second polarizing film respectively disposed on both sides of the liquid crystal layer, wherein the first polarizing film is disposed on a visible side of the liquid crystal layer and on a visible side of the touch sensor unit, and a conductive layer is disposed on a visible side of the touch sensor unit in the liquid crystal display device. In some embodiments, the wet heat surface resistance change ratio S/P of the conductive layer satisfies the following condition: S/P is more than or equal to 0.05 and less than or equal to 10. Wherein S is a surface resistance value [ omega/□ ] of the conductive layer after a wet heat test performed under conditions of a temperature of 85 ℃, a relative humidity of 85% and 24 hours, and P is a surface resistance value [ omega/□ ] of the conductive layer before the wet heat test. According to the above configuration, since the surface resistance change ratio of the conductive layer included in the liquid crystal display device before and after the damp-heat test is within a specific range, it is possible to achieve both prevention of the occurrence of the static electricity unevenness and stability of the touch sensing sensitivity.

In addition, according to the present specification, a liquid crystal display device having a touch sensing function is provided. The liquid crystal display device includes: a liquid crystal layer containing liquid crystal molecules; a touch sensor section; and first and second polarizing films respectively disposed on both sides of the liquid crystal layer, wherein the first polarizing film is disposed on a viewing side of the liquid crystal layer and on a viewing side of the touch sensor unit, and a conductive layer is disposed on a viewing side of the touch sensor unit in the liquid crystal display device. In some embodiments, the conductive layer is formed of a conductive composition containing a conductive polymer and a high boiling point compound having a boiling point of 180 ℃ or higher. According to the conductive layer formed using a high boiling point compound having a boiling point of 180 ℃ or higher, the conductive stability after exposure to a moist heat environment (i.e., moist heat conductive stability) is improved, and therefore, even when exposed to a moist heat environment, the change in conductivity can be suppressed. This prevents the occurrence of static electricity unevenness, and maintains stable touch sensing sensitivity. That is, in the technology disclosed herein, the high boiling point compound is used not for improvement of conductivity but for touch sensing sensitivity stability in a hot and humid environment, improving hot and humid durability. This is fundamentally different from improvement of conductivity by using the conductivity improver in patent document 2. In the technique disclosed herein, the target conductivity can be adjusted by the type, amount, and the like of the conductive polymer.

In some aspects of the technology disclosed herein (including a touch sensor function-incorporating liquid crystal display device, an in-cell liquid crystal display device, and methods for manufacturing the same, hereinafter) the wet-heat surface resistance change ratio S/P of the conductive layer satisfies the condition: S/P is more than or equal to 0.05 and less than or equal to 10. Wherein S is a surface resistance value [ omega/□ ] of the conductive layer after a wet heat test performed under conditions of a temperature of 85 ℃, a relative humidity of 85% and 24 hours, and P is a surface resistance value [ omega/□ ] of the conductive layer before the wet heat test. According to the above configuration, since the surface resistance change ratio of the conductive layer included in the liquid crystal display device in the wet heat test is within a specific range, it is possible to exhibit good touch sensing sensitivity stability even when exposed to a wet heat environment.

In preferred embodiments, the content of the high boiling point compound in the conductive composition is 0.1 to 10% by weight. By setting the content of the high boiling point compound in the conductive composition to a specific range, the effects of the technology disclosed herein can be exhibited appropriately.

In preferred embodiments, the high boiling point compound has a boiling point of 210 to 290 ℃. In some other embodiments, the high boiling point compound is preferably a glycol ether solvent. By selecting an appropriate high boiling point compound according to the boiling point and the chemical structure, even when exposed to a moist heat environment, more excellent stability in touch sensing sensitivity can be achieved.

In some preferred embodiments, the conductive layer contains a thiophene polymer as a conductive polymer. In the configuration using a thiophene-based polymer as a conductive polymer, the effect of improving the wet heat conductivity stability and further the effect of improving the touch sensing sensitivity stability by the technique disclosed herein can be exhibited suitably.

In preferred embodiments, the conductive layer contains a binder. This improves the film formation property of the conductive layer, and enables the conductive layer to be favorably fixed in the liquid crystal display device.

The liquid crystal display device is preferably an in-cell type liquid crystal display device. Unlike the external embedded liquid crystal display device, a conductive layer such as an ITO layer is not provided on the surface of the panel, and a conductive layer having a lower resistance can be used as the conductive layer disposed on the visible side of the touch sensor portion. Since it tends to be difficult to eliminate the disadvantage of the touch sensing sensitivity as the resistance value level is lower, the resistance value stability is more important in the internal-embedded liquid crystal panel than in the external-embedded liquid crystal panel. By disposing the conductive layer having improved thermal and humidity conductivity stability in the embedded liquid crystal display device, the sensitivity of the touch sensor can be stably maintained for a long period of time with good durability, and the stability of the touch sensor sensitivity in the embedded liquid crystal display device, and hence the durability of the device, and the life of the device, can be improved. The technology disclosed herein can be particularly applied to an in-cell type liquid crystal panel application among various liquid crystal panels.

Further, according to the present specification, a method of manufacturing a liquid crystal display device incorporating a touch sensing function is provided. The liquid crystal display device with a built-in touch sensor function manufactured by the method includes: a liquid crystal layer containing liquid crystal molecules; a touch sensor section; and first and second polarizing films respectively disposed on both sides of the liquid crystal layer, wherein the first polarizing film is disposed on a viewing side of the liquid crystal layer and closer to the viewing side than the touch sensor unit. The method includes a step of disposing a conductive layer on a visible side of the touch sensor section. 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 ℃ or higher. According to this method, by forming the conductive layer using a high boiling point compound having a boiling point of 180 ℃ or higher, a liquid crystal display device incorporating a touch sensing function, which can prevent the occurrence of electrostatic unevenness and has excellent touch sensing sensitivity stability even when exposed to a hot and humid environment, can be obtained.

Drawings

Fig. 1 is a schematic cross-sectional view showing a main part of an in-cell type liquid crystal display device according to an embodiment.

Fig. 2 is a schematic sectional view showing a main part of an in-cell type liquid crystal display device of another embodiment.

Fig. 3 is a schematic sectional view showing a main part of an in-cell type liquid crystal display device of another embodiment.

Fig. 4 is a schematic sectional view showing a main part of an in-cell type liquid crystal display device of another embodiment.

Fig. 5 is a schematic sectional view showing a main part of an in-cell type liquid crystal display device of another embodiment.

Fig. 6 is a schematic sectional view showing a main part of an in-cell type liquid crystal display device of another embodiment.

Fig. 7 is a schematic sectional view showing a main part of an in-cell type liquid crystal display device of another embodiment.

Fig. 8 is a schematic cross-sectional view showing a main part of a semi-embedded type liquid crystal display device of one embodiment.

Fig. 9 is a schematic cross-sectional view showing a main part of an external-mount liquid crystal display device according to an embodiment.

Fig. 10 is an explanatory view schematically showing a method of measuring a difference between a current value of the touch panel and a base current value of the touch panel when the conductive layer is disposed on the touch panel.

Fig. 11 is a graph showing a correlation between Δ C (Cooked Data, Max-Min) and the surface resistance value [ Ω/□ ] of the conductive layer when the conductive layer is disposed.

Description of the symbols

1.2, 3,4, 5, 6, 7, 8, 9: liquid crystal display device with built-in touch sensing function

110: polarizing film with conductive layer

111: first polarizing film

112: first adhesive layer

113: conductive layer

114: surface treatment layer

101. 102, 103, 104, 105, 106, 107: embedded liquid crystal panel

201: semi-embedded liquid crystal panel

202: externally-embedded liquid crystal panel

120: liquid crystal cell

125: liquid crystal layer

130: touch sensor electrode part (touch sensor part)

131: detection electrode

132: driving electrode

141: a first transparent substrate

142: a second transparent substrate

150: polarizing film with adhesive layer

151: second polarizing film

152: second adhesive layer

170: conduction structure

171: conduction structure

300: evaluation kit

302: touch panel

304: cover glass

S: polarizing film sample with conductive layer

Detailed Description

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

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

Liquid crystal display device with built-in touch sensor function

The liquid crystal display device with a built-in touch sensing function disclosed herein includes: a liquid crystal layer containing liquid crystal molecules, and a touch sensor portion. In the liquid crystal display device, the conductive layer is disposed on the visible side of the touch sensor section. In the liquid crystal display device, typically, a polarizing film (first polarizing film) may be disposed on the viewing side of the liquid crystal layer and on the viewing side of the touch sensor unit. In such a liquid crystal display device, the first polarizing film and the second polarizing film may be disposed on both sides of the liquid crystal layer. At least a part of the touch sensor unit is disposed between the first polarizing film and the liquid crystal layer, and in some embodiments, the touch sensor unit (for example, a detection electrode and a drive electrode constituting the touch sensor unit) is disposed between the first polarizing film and the liquid crystal layer. In some other embodiments, a part of the touch sensor unit (for example, the detection electrode) is disposed between the first polarizing film and the liquid crystal layer.

Examples of a liquid crystal display device having a touch sensor function built therein include a device having an in-cell liquid crystal panel as shown in fig. 1 to 7. In brief, the in-cell type liquid crystal panel has the following configuration: in a liquid crystal cell including a liquid crystal layer and 2 transparent substrates sandwiching the liquid crystal layer, a touch sensing electrode portion related to a touch sensing function is provided in the liquid crystal cell (i.e., inside the 2 transparent substrates). A liquid crystal panel in which both the detection electrode and the drive electrode related to the touch sensing function are disposed in the liquid crystal cell is referred to as a complete in-cell liquid crystal panel.

Fig. 1 to 7 are schematic cross-sectional views showing a configuration example of a main part (in-cell liquid crystal panel) of a liquid crystal display device 1 incorporating a touch sensing function. The in-cell liquid crystal panel 101 shown in fig. 1 includes: a liquid crystal cell (in-cell liquid crystal cell) 120, and a first polarizing film 111 disposed on the viewing side of the liquid crystal cell 120.

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

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

In the in-cell type liquid crystal panel 101, the first pressure-sensitive adhesive layer 112, the conductive layer 113, and the first polarizing film 111 are provided in this order, specifically, are stacked in this order from the first transparent substrate 141 to the visible side of the liquid crystal cell 120. In this configuration example, the first pressure-sensitive adhesive layer 112, the conductive layer 113, and the first polarizing film 111 are attached to the outer surface of the first transparent substrate 141 on the viewing side in the form of the conductive-layer-attached polarizing film 110, although not particularly limited thereto. The polarizing film with conductive layer 110 has the following configuration: a conductive layer 113 is provided on one surface of the first polarizing film 111, and a first pressure-sensitive adhesive layer 112 is provided on one surface (the surface on the opposite side to the first polarizing film 111) of the conductive layer 113. The first adhesive layer 112 is disposed and fixed on the outer surface of the first transparent substrate 141 without interposing a conductive layer therebetween. The first polarizing film 111 is disposed on the viewing side of the liquid crystal layer 125 so that the transmission axis (or absorption axis) of the polarizer is orthogonal to each other. In this configuration example, the surface treatment layer 114 is disposed on the back surface side of the first polarizing film 111.

On the other hand, in the inline liquid crystal panel 101, the second polarizing film 151 is disposed on the opposite side to the visible side. The second polarizing film 151 is attached to the outer surface of the second transparent substrate 142 of the liquid crystal cell 120 via a second adhesive layer 152. The second polarizing film 151 is disposed on the back surface side of the liquid crystal layer 125 so that the transmission axis (or absorption axis) of the polarizer is orthogonal to the transmission axis. In this configuration example, the second pressure-sensitive adhesive layer 152 and the second polarizing film 151 are attached to the outer surface of the second transparent substrate 141 in the form of the conductive-layer-attached polarizing film 150, although not particularly limited thereto. The polarizing film 150 with a conductive layer has a structure in which a second pressure-sensitive adhesive layer 152 is disposed on one surface of a second polarizing film 151.

In the liquid crystal panel 101 of the inline type, a conductive structure 170 made of a conductive material is provided on the side surfaces of the conductive layer 113 and the first pressure-sensitive adhesive layer 112. This allows the potential to escape from the side surfaces of the conductive layer 113 and the first adhesive layer 112 to other positions, thereby reducing or preventing charging due to static electricity. The conductive structure 170 may be provided on the entire side surfaces (end surfaces) of the conductive layer 113 and the first adhesive layer 112, or may be provided on a part of the side surfaces. When the via structure 170 is provided in a part, the via structure 170 may be provided at an area ratio of about 1% or more, preferably about 3% or more, more preferably about 10% or more, and further preferably about 50% or more of the total area of the side surfaces of the conductive layer 113 and the first adhesive layer 112 in order to ensure conduction of the side surfaces. In the configuration example shown in fig. 1, the conductive structure 171 is also provided on the side surfaces of the first polarizing film 111 and the surface-treated layer 114.

The liquid crystal display device 2 having a touch sensing function incorporated therein shown in fig. 2 is a modification of the configuration shown in fig. 1, and the layer configuration on the visible side of the liquid crystal cell 120 is different from the configuration shown in fig. 1. Specifically, the liquid crystal panel 102 of the inline type differs from the configuration example of fig. 1 in that the conductive layer 113, the first pressure-sensitive adhesive layer 112, and the first polarizing film 111 are provided (specifically, laminated) in this order from the first transparent substrate 141 to the visible side of the liquid crystal cell 120. In this configuration example, the conductive layer 113 is formed on substantially the entire outer surface of the first transparent substrate 141, and the first pressure-sensitive adhesive layer 112 and the first polarizing film 111 are attached to the conductive layer 113 formed on the outer surface of the first transparent substrate 141 on the viewing side in the form of the conductive-layer-attached polarizing film 110. The polarizing film with a conductive layer 110 has a structure in which a first pressure-sensitive adhesive layer 112 is disposed on one surface of a first polarizing film 111. In fig. 2, the surface treatment layer 114 on the back surface side of the first polarizing film 111 and the conductive structures 170, 171 are omitted for convenience of explanation,

The liquid crystal display device 3 having a touch sensor function incorporated therein shown in fig. 3 is also a modification of the configuration shown in fig. 1, and the layer configuration on the viewing side of the liquid crystal cell 120 is different from the configuration shown in fig. 1. Specifically, the liquid crystal panel 103 of the inline type differs from the configuration example of fig. 1 in that the first pressure-sensitive adhesive layer 112, the first polarizing film 111, and the conductive layer 113 are provided (specifically, laminated) in this order from the first transparent substrate 141 to the visible side of the liquid crystal cell 120. In this configuration example, the first pressure-sensitive adhesive layer 112, the first polarizing film 111, and the conductive layer 113 are attached to the outer surface of the first transparent substrate 141 on the viewing side in the form of the polarizing film with a conductive layer 110, although not particularly limited thereto. The polarizing film with a conductive layer 110 has the following configuration: the first pressure-sensitive adhesive layer 112 is disposed on one surface of the first polarizing film 111, and the conductive layer 113 is provided on the other surface (the surface opposite to the surface on which the first pressure-sensitive adhesive layer 112 is formed) of the first polarizing film 111. The conductive layer 113 may be formed on the back surface of the first polarizing film 111 after the first polarizing film 111 is laminated on the viewing side of the liquid crystal cell 120. In fig. 3 as well, the surface treatment layer 114 and the conductive structures 170 and 171 on the back surface side of the first polarizing film 111 are omitted for convenience of description.

The liquid crystal display device 4 having a touch sensor function incorporated therein shown in fig. 4 is a modification of the configuration shown in fig. 1, and differs from the configuration shown in fig. 1 in that: in the in-cell liquid crystal panel 104, the touch sensor electrode portion 130 as a touch sensor portion is disposed between the liquid crystal layer 125 and the second transparent substrate 142. That is, the touch sensor electrode portion 130 having the detection electrode 131 and the drive electrode 132 is disposed on the backlight side (rear surface side) of the liquid crystal layer 125. The liquid crystal display device 5 having a touch sensor function incorporated therein shown in fig. 5 is also a modification of the configuration shown in fig. 1, and differs from the configuration shown in fig. 1 in that: in the in-cell type liquid crystal panel 105, a touch sensor electrode portion 130 in which a detection electrode and a drive electrode are integrally formed is used. The liquid crystal display device 6 with a touch sensing function shown in fig. 6 is a combination of the configurations shown in fig. 4 and 5, and differs from the configuration shown in fig. 1 in that: in the in-cell liquid crystal panel 106, a touch sensor electrode portion 130 in which a detection electrode and a drive electrode are integrally formed and a touch sensor electrode portion 130 which is a touch sensor portion are disposed on the backlight side (rear surface side) of the liquid crystal layer 125 are used.

The liquid crystal display device 7 with a touch sensing function shown in fig. 7 is different from the configuration shown in fig. 1 in that: the detection electrode 131 of the touch sensor electrode portion 130 as a touch sensor portion in the in-cell liquid crystal panel 107 is disposed on both sides of the liquid crystal layer 125 so as to be separated from the drive electrode 132. Specifically, in the in-cell liquid crystal panel 107, the detection electrode 131 is disposed between the liquid crystal layer 125 and the first transparent substrate 141, and the driving electrode 132 is disposed between the liquid crystal layer 125 and the second transparent substrate 142. Other configurations of the modifications shown in fig. 2 to 7 are basically the same as those of the in-cell type liquid crystal panel shown in fig. 1, and therefore, redundant description is omitted.

As described above, the in-cell type liquid crystal panel includes the touch sensor electrode portion not only outside the liquid crystal cell but also inside the liquid crystal cell. In such a configuration, no electrode such as an ITO layer is provided on the outer surface of the first transparent substrate of the liquid crystal cell (usually, the surface resistance value is 1 × 10)¹³Omega/□ or less). By disposing the conductive layer disclosed herein on the viewing side of the liquid crystal cell of such an in-cell liquid crystal panel with respect to the first transparent substrate, the touch sensing sensitivity stability can be exhibited even when exposed to a moist heat environment due to the improved moist heat conductive stability, and excellent durability can be achieved. The effect of the technique disclosed herein (effect of improving the wet heat conductivity stability, and thus improving the durability and long-term stability of the touch sensing sensitivity) can be suitably exhibited in the embedded type.

In addition, as another example of the liquid crystal display device with a touch sensing function incorporated therein disclosed herein, a device provided with a semi-embedded liquid crystal panel is given. In short, a semi-embedded liquid crystal panel is a liquid crystal panel having a liquid crystal cell including a liquid crystal layer and 2 transparent substrates sandwiching the liquid crystal layer, wherein only one of a detection electrode and a drive electrode constituting a touch sensor electrode portion related to a touch sensor function is disposed inside the liquid crystal cell and the other of the electrodes is disposed outside the liquid crystal cell (typically, the outer surface of the transparent substrate).

Fig. 8 is a schematic cross-sectional view showing a configuration example of a device including a semi-embedded liquid crystal panel. The liquid crystal display device 8 having a touch sensing function built therein shown in fig. 8 is different from the built-in type shown in fig. 1 to 7 in that: in the semi-embedded liquid crystal panel 201, a part of the touch sensor electrode portion 130, which is a touch sensor portion, is disposed inside the liquid crystal cell 120, and the other part of the touch sensor electrode portion 130 is disposed outside the liquid crystal cell 120 (specifically, outside the liquid crystal cell 120 on the visible side). Specifically, the detection electrode 131 constituting the touch sensor electrode portion 130 is disposed on the outer surface of the first transparent substrate 141, and the drive electrode 132 constituting the touch sensor electrode portion 130 is disposed in the liquid crystal cell 120. In this configuration example, the driving electrode 132 is disposed between the liquid crystal layer 125 and the second transparent substrate 142. The semi-embedded liquid crystal panel 201 has a laminated structure in which a first polarizing film 111, a conductive layer 113, a first 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 are arranged in this order from the visible side. Further, a surface treatment layer 114 is disposed on the first polarizing film 111 on the side closer to the viewing side. Further, a second pressure-sensitive adhesive layer 152 and a second polarizing film 151 are disposed in this order on the outer side of the second transparent substrate 142. In the liquid crystal panel 201, the detection electrode 131 of the touch sensor electrode portion 130 is disposed outside the first transparent substrate 141 and is in contact with the adhesive layer 112.

In addition, as another example of the liquid crystal display device having a touch sensing function incorporated therein disclosed herein, a device having an externally-embedded liquid crystal panel is given. In short, the externally-embedded liquid crystal panel refers to: the liquid crystal panel includes a liquid crystal cell having a liquid crystal layer and 2 transparent substrates sandwiching the liquid crystal layer, and a touch sensor function is disposed on an outer surface of the transparent substrate of the liquid crystal cell.

Fig. 9 is a schematic cross-sectional view showing a configuration example of a device including an externally-embedded liquid crystal panel. The liquid crystal display device 9 having a touch sensing function built therein shown in fig. 9 is different from the built-in type liquid crystal display device 9 shown in fig. 1 to 7 in that: in the external liquid crystal panel 202, the detection electrodes 131 and the drive electrodes 132 related to the touch sensor electrode portions 130 as touch sensor portions are disposed outside the liquid crystal cell 120 as electrode patterns. In this configuration, the 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 disposed on the outer surface of the first transparent substrate 141 of the liquid crystal cell 120, and the detection electrode 131 is disposed on the drive electrode 132. The externally-embedded liquid crystal panel 202 has a laminated structure in which a first polarizing film 111, a conductive layer 113, a first 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 substrate 142 are arranged in this order from the visible side. In addition, the first polarizing film 111 has a surface treatment layer 114 on the side closer to the visible side. Further, a second pressure-sensitive adhesive layer 152 and a second polarizing film 151 are disposed in this order on the outer side of the second transparent substrate 142. In the liquid crystal panel 202, the detection electrode 131 of the touch sensor electrode portion 130 is disposed outside the first transparent substrate 141 and is in contact with the first pressure-sensitive adhesive layer 112. In addition, a driving electrode 134 is disposed in the liquid crystal cell 120. The driving electrode 134 is disposed between the liquid crystal layer 125 and the second transparent substrate 142.

In addition to the above, the liquid crystal panel and the liquid crystal display device including the liquid crystal panel may be configured such that the arrangement and the configuration of each component are changed or other configurations are appropriately added depending on the application and the purpose within a range not impairing the effects of the technology disclosed herein. For example, a design change such as providing a color filter substrate on a liquid crystal cell (for example, the first transparent substrate 141 in fig. 1) may be performed.

In the in-cell type liquid crystal panel shown in fig. 1,4, and 7, the detection electrode is disposed on the first transparent substrate side (visible side) of the drive electrode, but the configuration of the in-cell type liquid crystal panel disclosed herein is not limited thereto, and the drive electrode may be disposed on the first transparent substrate side (visible side) of the detection electrode.

In the liquid crystal display device with a touch sensor function built therein shown in fig. 4 to 9, the lamination structure of the liquid crystal cell on the viewing side is a lamination structure in which the first polarizing film, the conductive layer, and the first pressure-sensitive adhesive layer are arranged in this order from the viewing side, but these structures may be changed to a lamination structure in which the first polarizing film 111, the first pressure-sensitive adhesive layer 112, and the conductive layer 113 are arranged in this order from the viewing side, for example, as shown in fig. 2. Alternatively, the lamination structure of the liquid crystal cell of the liquid crystal display device with a touch sensor function shown in fig. 4 to 9 on the viewing side may be changed to a lamination structure in which the conductive layer 113, the first polarizing film 111, and the first pressure-sensitive adhesive layer 112 are arranged in this order from the viewing side, as shown in fig. 3, for example.

In the semi-embedded liquid crystal panel shown in fig. 8, the detection electrode is disposed outside the liquid crystal cell (specifically, outside the first transparent substrate), and the drive electrode is disposed inside the liquid crystal cell (specifically, between the first transparent substrate and the second transparent substrate).

In the above configuration example, the polarizing film with an adhesive layer substantially composed of the second adhesive layer and the second polarizing film is used on the back surface side of the liquid crystal cell, but the technique disclosed herein is not limited to this, and a polarizing film with a conductive layer as employed in the configuration example of fig. 1 may be used on the back surface side of the liquid crystal panel. In this case, the polarizing film with a conductive layer disclosed herein may be disposed on both sides of the liquid crystal cell. The polarizing film disposed on the side opposite to the viewing side may be the same polarizing film as the polarizing film disposed on the viewing side, or may be a different polarizing film. Alternatively, a known optical film with an adhesive layer may be disposed on the back side of the liquid crystal cell.

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

In addition to the above-described layers (polarizing film, pressure-sensitive adhesive layer, conductive layer, and optional surface treatment layer), an easy-adhesion layer may be provided between the polarizing film and the conductive layer, or various easy-adhesion treatments such as corona treatment and plasma treatment may be performed on the viewing side and the back side of the liquid crystal cell of the liquid crystal display device incorporating the touch sensor function.

A liquid crystal display device with a touch sensing function is manufactured using the liquid crystal panel (preferably, an in-cell type liquid crystal panel) having the above-described configuration. In the manufacture of the liquid crystal display device, a backlight, a reflection plate, or the like is used for an illumination system, and various members used for the liquid crystal display device can be used by a known or commonly used method. The liquid crystal display device may have a configuration in which a touch panel is disposed outside the polarizing film (for example, a configuration in which a touch panel is provided outside a liquid crystal panel such as an IPS system).

Next, the components of the liquid crystal display device having the touch sensing function built therein will be described.

< polarizing film >

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

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

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

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

Further, a surface treatment layer may be provided on the back surface of the polarizing film. The surface treatment layer may be provided on the above-described transparent protective film used for the polarizing film, or may be separately provided on the polarizing film from the transparent protective film.

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

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

When the technique disclosed herein is implemented to include a surface treatment layer, the surface treatment layer may contain a conductive agent to impart conductivity. As the conductive agent, a conductive agent and a conductive component described later can be used without particular limitation. Thus, the surface treatment layer may be a conductive layer as disclosed herein. When the surface-treated layer and the conductive layer are provided on the back surface of the polarizing film, the arrangement thereof is not particularly limited, and the surface-treated layer may be arranged between the polarizing film and the conductive layer, or the conductive layer may be arranged between the polarizing film and the surface-treated layer.

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

< conductive layer >

The conductive layer disclosed herein is disposed on the viewing side of the touch sensor section, and is a layer that improves the conductivity on the viewing side of the liquid crystal display device and prevents the occurrence of electrostatic unevenness. The conductive layer can be formed of a conductive composition containing various conductive agents such as an organic or inorganic conductive material. In the embodiment in which the pressure-sensitive adhesive layer is disposed on the conductive layer, the pressure-sensitive adhesive layer can function as an adhesion-promoting layer for improving adhesion between the pressure-sensitive adhesive layer and the polarizing film.

Examples of the organic conductive material that can be contained in the conductive composition (and therefore also in the conductive layer, the same applies hereinafter, if not specifically described) include: quaternary ammonium salt, pyridineCationic conductive agents having cationic functional groups such as salts, primary amino groups, secondary amino groups, and tertiary amino groups; anionic conductive agents having anionic functional groups such as sulfonic acid salts, sulfuric acid ester salts, phosphonic acid salts, and phosphoric acid ester salts; amphoteric ion conductive agents such as alkyl betaine and its derivatives, imidazoline and its derivatives, and alanine and its derivatives; nonionic conductive agents such as aminoalcohol and its derivatives, glycerin and its derivatives, polyethylene glycol and its derivatives, and the like; an ion conductive polymer obtained by polymerizing or copolymerizing the above cationic, anionic or zwitterionic monomer having an ion conductive group (for example, a quaternary ammonium salt group). Such conductive agents may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Examples of the inorganic conductive material that can be contained in the conductive layer include: tin oxide, antimony oxide, indium oxide, cadmium oxide, titanium oxide, zinc oxide, indium, tin, antimony, gold, silver, copper, aluminum, nickel, chromium, titanium, iron, cobalt, copper iodide, ITO (indium oxide/tin oxide), ATO (antimony oxide/tin oxide), and the like. Such inorganic conductive materials may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

(conductive Polymer)

In preferred modes, a conductive polymer is used as the conductive agent. By using the conductive polymer, a conductive layer having excellent optical characteristics, appearance, and antistatic effect can be obtained. In addition, the effect of improving the wet heat conductivity stability by the technique disclosed herein tends to be exhibited suitably in a conductive layer containing a conductive polymer. Examples of the conductive polymer include polymers such as polyaniline, polythiophene, polypyrrole, polyquinoxaline, polyethyleneimine, and polyallylamine. Such conductive polymers can be used alone in 1 kind, also can be combined with the use of 2 or more. Among them, polyaniline (aniline polymer) and polythiophene (thiophene polymer) are preferable.

Preferred examples of the conductive polymer include: polythiophene (thiophene polymer) and polyaniline (aniline polymer). In the present specification, polythiophene refers to a polymer of unsubstituted or substituted thiophene. As a suitable example of the substituted thiophene polymer in the art disclosed herein, poly (3, 4-ethylenedioxythiophene) may be mentioned.

As the conductive polymer, an organic solvent-soluble, water-dispersible conductive polymer can be used without particular limitation. In preferred embodiments, the conductive polymer is used for forming the conductive layer in the form of an aqueous solution or an aqueous dispersion. In this embodiment, since the coating liquid containing the conductive composition can be in the form of an aqueous liquid (an aqueous solution or an aqueous dispersion that may contain water and other solvents), the risk of modification of the polarizing film by an organic solvent can be reduced. Conductive polymers such as polyaniline and polythiophene can be used preferably because they can be easily prepared in the form of an aqueous solution or an aqueous dispersion. Among them, polythiophene is more preferable. In preferred modes, an aqueous polythiophene solution is used for the preparation of the conductive composition. The aqueous solution or aqueous dispersion may contain an aqueous solvent in addition to water. For example, 1 or 2 or more kinds of alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-pentanol, isopentanol, sec-pentanol, tert-pentanol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, and cyclohexanol may be used in the form of a mixed solvent (aqueous solvent) with water.

The aqueous solution or aqueous dispersion of the conductive polymer can be prepared, for example, by dissolving or dispersing a conductive polymer having a hydrophilic functional group (which can be synthesized by a method such as copolymerization of a monomer having a hydrophilic functional group in the molecule) in water. Examples of the hydrophilic functional group include a sulfo group, an amino group, an amide group, an imino group, a hydroxyl group, a mercapto group, a hydrazine group, a carboxyl group, a quaternary ammonium group, and a sulfate group (-O-SO)₃H) Phosphate groups (e.g., -O-PO (OH)₂) Etc., the hydrophilic functional group may form a salt.

In some preferred embodiments, a polyanion is used as a dopant (specifically, a dopant of a thiophene-based polymer) in the preparation of the conductive composition. In this manner, the conductive layer may contain a polyanion. As the polyanion, 1 or 2 or more species of 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 in a form in which PSS is added as a dopant to polythiophene) is used. The aqueous solution may contain polythiophene in a weight ratio of 1:1 to 1: 10: PSS. The total content of the polythiophene and the PSS in the aqueous solution may be, for example, about 1 to 5 wt%.

Examples of commercially available products of the above polythiophene aqueous solution include a product name "Denatron" series manufactured by Nagase ChemteX Corporation and a product name "Clevios" series manufactured by Heraeus Corporation. Further, as a commercially available product of the polyaniline sulfonic acid aqueous solution, there can be exemplified MITSUBISHI RAYON co., a product name "aqua-PASS" manufactured by ltd.

From the viewpoint of antistatic properties, the content of the conductive agent (preferably, the conductive polymer) in the conductive composition is suitably about 0.005% by weight or more, and preferably about 0.01% by weight or more. The upper limit of the content of the conductive agent (preferably, the conductive polymer) in the conductive composition is, for example, suitably about 5 wt% or less, preferably about 3 wt% or less, more preferably about 1 wt% or less, and still more preferably about 0.7 wt% or less. From the viewpoint of antistatic properties, the content of the conductive agent (preferably, a conductive polymer) in the conductive layer obtained using the conductive composition is suitably about 1% by weight or more, preferably about 3% by weight 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, a conductive polymer) in the conductive layer is preferably about 90% by weight or less.

In the embodiment using a conductive layer containing a conductive polymer, the conductive layer may contain a conductive component other than the conductive polymer. Examples of such a conductive component include conductive components (other than conductive polymers) exemplified as the above-mentioned organic or inorganic conductive materials, and conductive components contained in a pressure-sensitive adhesive layer described later. These conductive components may be used alone in 1 kind, or may be used in combination in 2 or more kinds. 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 not impairing the effects of the invention. The content thereof is usually about 5% by weight or less, and preferably about 3% by weight or less (for example, about 1% by weight or less, and typically 0.3% by weight or less) in the conductive layer. The technology disclosed herein can be preferably implemented in such a manner that the conductive layer does not substantially contain a conductive component other than the conductive polymer.

(high boiling point compound)

Typically, the conductive layer disclosed herein may be formed of a conductive composition containing a high boiling point compound having a boiling point of 180 ℃ or higher. The conductive layer formed using the above-mentioned high boiling point compound shows improved wet heat conductive stability. Has the conductive layerThe liquid crystal display device of (1) can prevent the occurrence of electrostatic unevenness and maintain stable touch sensing sensitivity even when exposed to a moist heat environment. The high boiling point compound may be used alone in 1 kind, or may be used in combination in 2 or more kinds. The high boiling point compound is not left by volatilization at the time of forming the conductive layer, and the formed conductive layer can suitably satisfy the change ratio of the wet heat surface resistance, the decrease ratio of the wet heat surface resistance, and the change ratio of the wet heat conductivity F_HT. The high boiling point compound has a boiling point of 180 ℃ or higher, and is solid or liquid at ordinary temperature (23 ℃). As the high boiling point compound which is solid at ordinary temperature, a high boiling point compound which is easily dissolved in a solvent (for example, water) of the conductive composition described later is preferably used. The solubility of such a high boiling point compound in 100mL of a solvent (e.g., water) at ordinary temperature may be about 1g or more (typically about 3g or more, for example, about 10g or more, and further about 20g or more). In addition, from the viewpoint of the conductive layer formability, the high boiling point compound is preferably a compound that is liquid at a temperature of 20 to 50 ℃ (therefore, has a melting point of 20 ℃ or lower). Such compounds are also referred to as high boiling solvents. The solvent mentioned here is a liquid medium contained in the conductive composition, and is referred to as a solvent for convenience, and is a concept including a solvent and a dispersion medium.

The reason why the wet heat conduction stability is improved by using a high boiling point compound is considered as follows. For example, when a low boiling point solvent (a solvent having a boiling point of less than 180 ℃) such as water is used as the solvent of the conductive composition, the solvent in the composition is quickly volatilized and dried because the thickness of the conductive layer is thin (for example, the thickness is less than 1 μm). At this time, the arrangement (which may be orientation) of the conductive agent (preferably, a conductive polymer) contained in the same composition in the conductive layer is affected by the drying process. The high boiling point compound appropriately controls the volatilization behavior of the solvent in the drying process when forming the conductive layer, and as a result, the configuration of the conductive agent in the conductive layer can be made good. However, not only this, but also: the high boiling point compound having a boiling point of at least a given value stabilizes the arrangement of the conductive agent in the conductive layer in the drying process, and is less likely to change due to external factors such as environmental changes. The present inventors heated a mixed solvent of water and diethylene glycol (boiling point: about 244 ℃ C.) and a mixed solvent of water and N-methylpyrrolidone (boiling point: about 204 ℃ C.) at 50 ℃ respectively using TOF/MS (time of flight mass spectrometer), measured the amount of volatile components at that time over time, and confirmed that the high boiling point compound slowly volatilizes during the main period of the process if the mixed solvent using a specific high boiling point compound (specifically, boiling point 180 ℃ C. or higher) passed the initial stage of the drying process. It is considered that the above-described volatilization behavior by the use of the high boiling point compound contributes to stable maintenance of the arrangement of the conductive agent, and stable conductivity is brought about even when exposed to a moist heat environment. This effect is considered to be particularly significant in a mode in which a thiophene polymer or an aniline polymer that conducts electrons by pi-pi stacking action is used as a conductive agent (more preferably, a thiophene polymer, for example, a dopant of a thiophene polymer with PSS or the like). The technique disclosed herein is not limited to the above consideration.

The high boiling point compound contained in the conductive composition disclosed herein is also referred to as a conductivity stabilizer due to its effect of stabilizing the wet heat conductivity. The conductivity stabilizer can be defined as an additive that suppresses a change in conductivity (which can be evaluated based on a surface resistance value or the like) of the conductive layer, that is, an additive that contributes to stabilization of conductivity of the conductive layer in a moist heat environment (for example, a temperature of 50 ℃ or more and a relative humidity of 80% or more, typically a temperature of 85 ℃ or 85% RH) for a given period of time (for example, 24 hours) as compared with a case where the conductivity stabilizer is not used.

In some embodiments, the boiling point of the high boiling point compound contained in the conductive composition is preferably about 200 ℃ or higher, more preferably about 210 ℃ or higher, still more preferably about 220 ℃ or higher, and particularly preferably about 230 ℃ or higher (for example, about 240 ℃ or higher), from the viewpoint of the wet heat conductivity stability. 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 preferably about 400 ℃ or lower and about 320 ℃ or lower, and from the viewpoint of adhesion to a layer adjacent to the conductive layer (for example, the adhesive layer, the first polarizing film, and the first transparent substrate), it is preferably about 300 ℃ or lower (for example, about 290 ℃ or lower), more preferably about 280 ℃ or lower, still more preferably about 260 ℃ or lower, and particularly preferably about 250 ℃ or lower.

As the high boiling point compound, for example, a compound having a boiling point of 180 ℃ or higher among the following compounds can be used without particular limitation: lactam compounds (which may be lactam solvents) such as N-methylpyrrolidone; glycol compounds (which may be glycol solvents) such as ethylene glycol, propylene glycol, trimethylene glycol, butanediols (e.g., 1, 3-butanediol and 1, 4-butanediol), pentanediols (e.g., 1, 5-pentanediol), hexanediols (e.g., 1, 6-hexanediol), neopentyl glycol and catechol; glycol ether compounds (which may be glycol ether solvents) such as diethylene glycol, triethylene glycol, tripropylene glycol, diethylene glycol monomethyl ether, and diethylene glycol monoethyl ether; thioglycol compounds (which may be thioglycol solvents) such as β -thiodiglycol; glycerol; sugar alcohol compounds such as mannitol, sorbitol, and xylitol; aromatic alcohol compounds such as 2-phenoxyethanol; amide compounds (which may be amide solvents) such as N-methylformamide, acetamide, N-ethylacetamide, and benzamide; amine compounds (typically cyclic amines) such as pyrazoles; sulfoxide compounds (which may be sulfoxide solvents) such as dimethyl sulfoxide; and so on. These high boiling compounds may be used alone in 1 kind, or may be used in combination in 2 or more kinds. Of these, diol-based compounds having a boiling point of 180 ℃ or higher, diol ether-based compounds, and glycerin are preferred, and diol ether-based compounds having a boiling point of 180 ℃ or higher (typically, diethylene glycol and triethylene glycol) are more preferred.

Although not particularly limited, a compound having a hydroxyl group can be suitably used as the high boiling point compound. It is considered that the high boiling point compound having a hydroxyl group is easily compatible with a solvent (typically an aqueous solvent), and for example, when added to an aqueous solvent, it is possible to obtain a good volatilization behavior which improves the wet heat conductivity stability. In some preferred embodiments, the number of hydroxyl groups contained in the high boiling point compound is 2 or more, and for example, may be 3 or more. Further, for example, a high boiling point compound having an ether structure can be suitably used.

The content of the high boiling point compound in the conductive composition disclosed herein is not limited to a specific range, and may be appropriately set so as to achieve the intended hydrothermal conductive stability and thus the hydrothermal durability of the liquid crystal display device. From the viewpoint of obtaining the effect of improving the wet heat conductivity stability, 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, more preferably about 1% by weight or more, further 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 may be, for example, about 50 wt% or less, and preferably about 30 wt% or less (for example, about 25 wt% or less), and from the viewpoint of adhesion to a layer adjacent to the conductive layer (for example, the pressure-sensitive adhesive layer, the first polarizing film, and the first transparent substrate), it is preferably about 15 wt% or less, more preferably about 10 wt% or less, still more preferably about 7 wt% or less, and particularly preferably about 5 wt% or less (typically 4 wt% or less).

The conductive composition for forming the conductive layer typically contains a solvent and a dispersion medium (hereinafter, collectively referred to as "solvent" for convenience). The solvent is not particularly limited, and a solvent capable of stably dissolving or dispersing the conductive layer forming component can be suitably used. The solvent may be an organic solvent, water, or a mixed solvent thereof. As the organic solvent, for example, 1 or 2 or more selected from the following solvents can be used: esters such as ethyl acetate; ketones such as methyl ethyl ketone, acetone, and cyclohexanone; tetrahydrofuran (THF), bisCyclic ethers such as alkanes; aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as toluene and xylene;aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol and cyclohexanol; glycol ethers such as alkylene glycol monoalkyl ethers (e.g., ethylene glycol monomethyl ether and ethylene glycol monoethyl ether); and so on. The solvent is a liquid at room temperature and has a boiling point of less than 180 ℃.

In some preferred embodiments, the solvent is an aqueous solvent. The aqueous solvent is water or a mixed solvent mainly containing water (for example, a mixed solvent of water and a lower alcohol such as methanol or ethanol). In the technique disclosed herein, an aqueous solvent can be suitably used. This is preferable from the viewpoint of preventing the polarizing film from being modified, for example, in a mode in which the conductive layer is disposed adjacent to the first polarizing film. The proportion of water in the aqueous solvent is preferably about 30% by weight or more, more preferably about 50% by weight or more (typically more than 50% by weight), and may be about 70% by weight or more, and may be about 80% by weight or more (for example, about 90 to 100% by weight).

(Binder)

In several ways, the conductive layer comprises a binder. When the conductive layer contains a binder, film formation properties of the conductive layer are improved, and adhesion to a layer adjacent to the conductive layer (for example, a binder layer, a first polarizing film, and a first transparent substrate) is improved. The binder is not particularly limited, and 1 or 2 or more of the following binders can be used: comprisesOxazoline-based polymers, urethane-based polymers, acrylic polymers, polyester-based polymers, polyether-based polymers, cellulose-based polymers, vinyl alcohol-based polymers, epoxy group-containing polymers, vinyl pyrrolidone-based polymers, styrene-based polymers, polyethylene glycol, pentaerythritol, and the like. As a preferred example, it may includeOxazoline-based polymers, urethane-based polymers (typically polyurethanes).

In preferred several ways, can be usedComprisesThe oxazoline-based polymer acts as a binder. By using a container containingThe oxazoline-based polymer is easy to obtain wettability with respect to the surface of the polarizing film, for example, and tends to improve the anchoring property of the adhesive layer. ComprisesThe oxazoline-based polymer may be used alone in an amount of 1 kind, or may be used in combination with 2 or more kinds. Preferably soluble or dispersible in waterAn oxazoline-based polymer.The oxazolinyl group can be 2-Oxazolinyl, 3-Oxazolinyl, 4-Any group of the oxazoline groups may be preferably used, for example, 2-An oxazoline group. As a containerAs the oxazoline-based polymer, for example: contains a (meth) acrylic skeleton or a styrene skeleton in the main chain and has a side chain in the main chainContaining azolinyl groupsAn oxazoline-based polymer. Preferably several ways includingThe oxazoline-based polymer may be a polymer comprising a main chain having a (meth) acrylic skeleton and having a side chain of the main chainContaining azolinyl groupsAn oxazoline-based (meth) acrylic polymer.

ComprisesThe molecular weight of the oxazoline-based polymer may be appropriately set depending on the purpose, the desired characteristics, and the like. From the viewpoint of coating properties, etc., containThe upper limit of the molecular weight of the oxazoline-based polymer is about 100X 10⁴The following are suitable, and about 50X 10 is preferable⁴Hereinafter, more preferably about 10X 10⁴Hereinafter, more preferably about 5X 10⁴The following. The molecular weight is a number average molecular weight (Mn) in terms of standard polystyrene obtained by GPC (gel permeation chromatography).

In several ways, a urethane-based polymer may be used as the binder. By using the urethane polymer, adhesion to a layer adjacent to the conductive layer (for example, the pressure-sensitive adhesive layer, the first polarizing film, and the first transparent substrate) tends to be improved. Examples of the urethane polymer include polyurethanes such as ether polyurethane, ester polyurethane, and carbonate polyurethane; urethane (meth) acrylate, acrylic acid-urethane copolymer copolymerized with alkyl (meth) acrylate; and so on. The urethane polymer may be used alone in 1 kind, or may be used in combinationMore than 2 kinds of the raw materials are used. Among several embodiments, the binder preferably containsThe oxazoline-based polymer is used in combination with a urethane-based polymer.

The content of the binder in the conductive layer is not particularly limited, and is preferably about 3 wt% or more, for example. The content of the binder is preferably about 10% by weight or more, more preferably about 30% by weight or more, further preferably about 50% by weight or more, particularly preferably about 60% by weight or more, and may be about 70% by weight or more (for example, about 80% by weight or more) from the viewpoint of adhesion and the like. The upper limit of the content of the binder is usually about 99% by weight or less, preferably about 95% by weight or less, for example, about 90% by weight or less (for example, about 80% by weight or less), in consideration of the effect of other components such as the conductive polymer.

Additives may be incorporated into the conductive layer as needed. Examples of the additive include a leveling agent, an antifoaming agent, a thickener, and an antioxidant. The proportion of these additives is usually about 50 wt% or less, preferably about 30 wt% or less (for example, about 10 wt% or less), and may be about 3 wt% or less (for example, less than 1 wt%) in the conductive layer.

(method of Forming conductive layer)

The conductive layer can be formed by a method including applying a liquid conductive composition obtained by dispersing or dissolving the conductive agent, the high boiling point compound, and an additive used as needed in an appropriate solvent to a polarizing film. For example, a method of applying the conductive composition to one surface of a polarizing film, drying the composition, and optionally performing a curing treatment (heat treatment, ultraviolet treatment, or the like) can be preferably employed. Alternatively, in the form of forming the conductive layer on the outer surface of the first transparent substrate, the conductive layer may be formed by applying a conductive composition to the surface of the first transparent substrate by a known method such as a roll coating method, a bar coating method, a dip coating method, a spin coating method, a casting method, a die coating method, a gravure coating method, a spray coating method, an inkjet printing method, a screen printing method, an inkjet printing method, an offset printing method, or the like, and drying and curing as necessary. The solid content concentration (NV) of the conductive composition may be, for example, 5 wt% or less (typically 0.05 to 5 wt%), and usually 3 wt% or less (typically 0.10 to 3 wt%), which is preferable. When a conductive layer having a small thickness is formed, the NV of the conductive composition is preferably 0.05 to 0.50 wt% (e.g., 0.10 to 0.30 wt%), for example. Thus, by using a conductive composition having a low NV, a more uniform conductive layer can be formed.

(surface resistance value)

From the viewpoint of antistatic property, the surface resistance value of the conductive layer is about 1 × 10¹²The following is appropriate for omega/□. If the conductive layer whose surface resistance value is limited to a given value or less is applied to a liquid crystal panel (for example, an in-cell type liquid crystal panel), occurrence of electrostatic unevenness can be prevented based on the conductivity of the conductive layer. In view of touch sensing sensitivity, the lower limit of the surface resistance value is preferably set to about 1 × 10⁶Omega/□ or more. The range of the surface resistance value of the conductive layer may vary depending on whether the first pressure-sensitive adhesive layer is conductive, the type of the liquid crystal cell, the use of the portable electronic device, the use in a vehicle, and the like. For example, when the liquid crystal display device is applied to an in-cell type liquid crystal cell for a portable electronic device, the surface resistance value is preferably about 1 × 10⁸Ω/□～1×10¹⁰Omega/□, from the antistatic point of view, more preferably about 1X 10⁸Ω/□～1×10⁹Omega/□. When applied to an in-cell liquid crystal cell for vehicle use, the liquid crystal cell is preferably about 1 × 10⁶Ω/□～1×10⁹Omega/□, from the antistatic point of view, more preferably about 1X 10⁷Ω/□～5×10⁸Omega/□. When the liquid crystal cell is applied to an externally-embedded liquid crystal cell, the surface resistance value is preferably about 1 × 10¹⁰Ω/□～1×10¹²Omega/□. In addition, in the case of application to a semi-embedded liquid crystal cell, the surface resistance value is preferably about 1 × 10⁹Ω/□～1×10¹²Omega/□. The surface resistance of the conductive layer was measured by the method described in the examples (initial test)Surface resistance value).

(Wet Heat surface resistance Change ratio)

In some embodiments, the ratio (change ratio of wet heat surface resistance S/P) of the surface resistance value S [ Ω/□ ] of the conductive layer after the wet heat test to the surface resistance value P [ Ω/□ ] of the conductive layer before the wet heat test disclosed herein satisfies the following condition: S/P is more than or equal to 0.05 and less than or equal to 10, and the damp-heat test is carried out under the conditions of 85 ℃ of temperature, 85% of relative humidity and 24 hours. The conductive layer satisfying the above-described S/P ratio exhibits improved thermal conductivity stability, and can exhibit good touch sensitivity stability even when exposed to a thermal environment. The wet heat surface resistance change ratio S/P is preferably about 0.1 or more, more preferably about 0.5 or more, and still more 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 wet heat surface resistance change ratio S/P is measured by the method described in the examples described later. The touch sensor function-incorporating liquid crystal display device disclosed in the present specification includes a mode in which the change ratio S/P of the wet heat surface resistance is not limited, and in such a mode, the touch sensor function-incorporating liquid crystal display device is not limited to having the above-described characteristics.

(Wet Heat surface resistance reduction Rate)

In some aspects, the reduction rate of the wet heat surface resistance of the conductive layer can be suppressed to a given value or less. Specifically, the conductive layer is according to the formula: the reduction rate of the wet heat surface resistance determined by (1-S/P). times.100 may be 95% or less. Here, S is the surface resistance value [ Ω/□ ] of the conductive layer after the wet heat test performed under the conditions of a temperature of 85 ℃, a relative humidity of 85% and 24 hours, and P is the surface resistance value P [ Ω/□ ] of the conductive layer before the wet heat test, and S and P are measured by the methods described in the examples described later. The conductive layer satisfying the above-described wet-heat surface resistance reduction rate can favorably suppress a reduction in surface resistance value when exposed to a wet-heat environment. The wet 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. The technique disclosed herein may be related to suppression of decrease in surface resistance in the case of exposure to a moist heat environment, and therefore, the increase in surface resistance value after a moist heat test is not particularly limited, and is, for example, according to the formula: the increase rate of the wet heat surface resistance determined by (S/P-1). times.100 is preferably about 200% or less, and may be less than 150% or less than 130% (for example, 120% or less). S and P in the above formula have the same meanings as S and P of the wet heat surface resistance reduction rate, respectively.

(Wet Heat conductivity Change ratio F_HT)

In some embodiments, the conductive layer disclosed herein has a wet heat conductivity change ratio F represented by the following formula (1)_HT(Hygro-thermal factor) may be 2 or less.

F_HT＝ΔC(B)/ΔC(A)·····(1)

In the above formula (1), Δ c (b) is a difference between a current value of the touch panel flowing when the conductive layer after the wet heat test is disposed on the touch panel for evaluation and a touch panel base current value, and Δ c (a) is a difference between a current value of the touch panel flowing when the conductive layer before the wet heat test is disposed on the touch panel for evaluation and a touch panel base current value, the wet heat test being performed under conditions of a temperature of 85 ℃, a relative humidity of 85%, and 24 hours. The conductive layer satisfying this characteristic can maintain stable conductivity even when exposed to a moist heat environment, prevent occurrence of static electricity unevenness, maintain stable touch sensing sensitivity, and prevent malfunction of the touch sensor. From such a viewpoint, F is_HTPreferably 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 or less). The techniques disclosed herein may be associated with inhibiting a decrease in surface resistance (increase in conductivity) when exposed to a hot and humid environment, and thus, with respect to a decrease in conductivity after a hot and humid test (i.e., F)_HTReduction of (d) is not particularly limited, and F is the above_HTTypically about 0.1 or more (e.g., about 0.3 or more), suitably about 0.5 or more,preferably about 0.6 or more, more preferably about 0.7 or more, still 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). Above F_HTThe measurement was carried out by the method described in the examples described later. The touch sensor function-incorporating liquid crystal display device disclosed in the present specification includes the above-mentioned change ratio F of the wet heat conductivity without limitation_HTIn this aspect, the liquid crystal display device incorporating the touch sensing function is not limited to have the above-described characteristics.

(thickness of conductive layer)

The thickness of the conductive layer in the technique disclosed herein can be set as appropriate in accordance with the required characteristics such as antistatic property and adhesion. The thickness of the conductive layer is usually about 10nm or more, and preferably more than 10 nm. The thickness of the conductive layer is preferably 12nm or more, more preferably 14nm or more, further preferably 15nm or more, and particularly preferably 20nm or more (typically 25nm or more, for example, 30nm or more), from the viewpoint of improving antistatic properties and obtaining a uniform thickness. The thickness of the conductive layer is preferably about 500nm or less. By suppressing the thickness of the conductive layer to about 500nm or less, good optical characteristics (total light transmittance and the like) can be easily obtained. From such a viewpoint, the thickness of the conductive layer is preferably about 100nm or less, and more preferably about 70nm or less. In the configuration including the conductive layer having a small thickness, the effect of using the high boiling point compound disclosed herein (wet heat conductive stability improvement effect) can be suitably exhibited.

< adhesive layer >

The touch sensor function-incorporating liquid crystal display device disclosed herein may include an adhesive layer (including a first adhesive layer and a second adhesive layer, the same applies hereinafter unless otherwise specified) for the purpose of fixing the first polarizing film to the liquid crystal cell or the like. The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer may be a pressure-sensitive adhesive layer containing 1 or 2 or more kinds selected from various pressure-sensitive adhesives such as acrylic, rubber, urethane, silicone, vinyl alkyl ether, vinyl pyrrolidone, acrylamide, and cellulose. Therefore, the polymer constituting the pressure-sensitive adhesive layer may be an acrylic polymer, a rubber polymer, a urethane polymer, a silicone polymer, a vinyl alkyl ether polymer, a vinyl pyrrolidone polymer, an acrylamide polymer, a cellulose polymer, or the like. Among them, acrylic adhesives are preferred from the viewpoint of transparency, suitable wettability, cohesiveness, adhesive properties such as adhesiveness, weather resistance, heat resistance, and the like. The technology disclosed herein will be described in more detail below, mainly with reference to a configuration in which the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer, but the pressure-sensitive adhesive layer is not intended to be limited to being formed of an acrylic pressure-sensitive adhesive.

(acrylic adhesive)

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

(acrylic Polymer)

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

CH₂＝C(R¹)COOR² (1)

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

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

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

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

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

As the acrylic polymer in the technology disclosed herein, an acrylic polymer obtained by copolymerizing a functional group-containing monomer can be suitably used. Preferred examples of the functional group-containing monomer include a carboxyl group-containing monomer, an acid anhydride group-containing monomer, and a hydroxyl group-containing monomer. These monomers may be used alone in 1 kind, or may be used in combination in 2 or more kinds. The functional group-containing monomer serves as a crosslinking point in the pressure-sensitive adhesive layer, and can improve the cohesive force and heat resistance of the pressure-sensitive adhesive. In addition, the adhesion between the conductive layer and the adhesive layer can be improved. The glass transition temperature (Tg) of the acrylic polymer can also be adjusted by using an appropriate amount of the functional group-containing monomer, and the adhesion characteristics can also be adjusted.

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

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

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

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

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

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

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

Monomers having a ring containing a nitrogen atom: such as N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-Vinylpiperazines, N-vinylpyrazines, N-vinylpyrroles, N-vinylimidazoles, N-vinylsOxazole, N-vinyl morpholine, N-vinyl caprolactam, N- (meth) acryloyl morpholine, N- (meth) acryloyl pyrrolidone.

Of the monomers having a ring containing a nitrogen atom, monomers corresponding to amide group-containing monomers such as N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylcaprolactam, N- (meth) acryloylmorpholine, and N- (meth) acryloylpyrrolidone may be used. The same applies to the relationship between the monomer having a nitrogen atom-containing ring and the amino group-containing monomer.

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

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

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

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

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

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

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

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

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

The weight average molecular weight (Mw) of the base polymer (acrylic polymer) in the technique disclosed herein, as measured by GPC (gel permeation chromatography) and converted to standard polystyrene, is about 10 × 10⁴The above is suitable, and is preferably about from the viewpoint of durability, heat resistance and the like50×10⁴Above, more preferably about 80X 10⁴Above, more preferably about 120X 10⁴Above (e.g., about 150 × 10)⁴Above). Further, the Mw is about 500X 10⁴The following is appropriate, and is preferably about 300 × 10 from the viewpoint of coatability and the like when forming the pressure-sensitive adhesive layer⁴Hereinafter, more preferably about 250X 10⁴Hereinafter, more preferably about 200X 10⁴The following.

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

[ measurement conditions of GPC ]

Sample concentration: 0.2 wt% (tetrahydrofuran solution)

Sample injection amount: 100 μ L

Eluent: tetrahydrofuran (THF)

Flow rate (flow velocity): 0.8 mL/min

Column temperature (measurement temperature): 40 deg.C

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

Column size: 90cm each 7.8mm phi x 30cm meter

A detector: differential Refractometer (RI)

Standard sample: polystyrene

(conductive component)

The technology disclosed herein can be preferably implemented in such a manner that the adhesive layer contains a conductive component. As the antistatic component, an ionic compound can be exemplified. A conductive agent that can be contained in the above conductive layer can also be used. These conductive components can be used alone in 1 kind, also can be combined with more than 2 kinds. In preferred embodiments, the adhesive layer contains an ionic compound. The ionic compound is preferably used as a conductive component to improve the conductivity of the adhesive layer. It is possible to preferably use, for example, 1 or 2 or more selected from alkali metal salts, organic cation-anion salts and the like. From the viewpoint of anchorage, organic cation-anion salts are more preferable.

(alkali metal salt)

As the alkali metal salt, organic salts and inorganic salts of alkali metals can be used. Examples of the alkali metal ion constituting the cation portion of the alkali metal salt include lithium, sodium, potassium and the like. Among these alkali metal ions, lithium ions are preferable.

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

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

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

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

(4)(C_pF_2p+1SO₂)N^-(C_qF_2q+1SO₂) (wherein p and q are integers of 1 to 10).

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

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

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

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

(organic cation-anion salt)

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

Specific examples of the cation component constituting the organic cation-anion salt include: pyridine compoundCation, piperidineCation, pyrrolidineCation, cation having pyrroline skeleton, imidazoleCationic, tetrahydropyrimidinesCationic dihydropyrimidinesCationic, pyrazolesCationic pyrazolinesCation, tetraalkylammonium cation, trialkylsulfonium cation, tetraalkylCations, and the like.

Examples of the anion component of the organic cation-anion salt include: cl^-、Br^-、I^-、AlCl₄ ^-、Al₂Cl₇ ^-、BF₄ ^-、PF₆ ^-、ClO₄ ^-、NO₃ ^-、CH₃COO^-、CF₃COO^-、CH₃SO₃ ^-、CF₃SO₃ ^-、(CF₃SO₂)₃C^-、AsF₆ ^-、SbF₆ ^-、NbF₆ ^-、TaF₆ ^-、(CN)₂N^-、C₄F₉SO₃ ^-、C₃F₇COO^-、(CF₃SO₂)(CF₃CO)N^-、(FSO₂)₂N^-、^-O₃S(CF₂)₃SO₃ ^-And anions represented by the following general formulae (1) to (4).

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

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

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

(4)(C_pF_2p+1SO₂)N^-(C_qF_2q+1SO₂) (wherein p and q are integers of 1 to 10).

An ionic compound whose anion component contains a fluorine atom is preferable because it has good ionization properties. The number of carbon atoms of the perfluoroalkyl group contained in the anionic component is preferably 1 to 3, more preferably 1 or 2. These ionic compounds may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

(other Ionic Compound)

In addition, as the ionic compound, in addition to the alkali metal salt and the organic cation-anion salt, inorganic salts such as ammonium chloride, aluminum chloride, copper chloride, ferrous chloride, ferric chloride, and ammonium sulfate can be used. In addition, the ionic compounds disclosed herein generally include compounds referred to as ionic surfactants. Examples of the ionic surfactant include: quaternary ammonium salt,Onium salts, sulfonium salts, pyridineSalts, cationic surfactants having cationic functional groups such as amino groups; anionic surfactants having anionic functional groups such as carboxylic acid, sulfonic acid ester, sulfuric acid ester, phosphoric acid ester, and phosphorous acid ester; sulfobetaine and its derivatives, alkyl betaine and its derivatives, imidazoline and its derivatives, alkyl imidazoleAmphoteric surfactants such as betaine and its derivatives; and so on. The organic cation-anion salt may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The ionic compound includes ionic solids and ionic liquids, and ionic liquids can be preferably used. The ionic liquid is likely to move in the adhesive layer and to be uniformly dispersed in the layer. When an ionic liquid is used as the ionic compound, the effects of the technology disclosed herein tend to be exhibited as appropriate.

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

The content of the ionic compound (preferably, an organic cation-anion salt) in the adhesive layer is not particularly limited, and an appropriate amount capable of imparting a given conductivity to the adhesive layer may be added. The amount of the ionic compound is preferably about 0.01 part by weight or more (for example, about 0.05 part by weight or more) relative to 100 parts by weight of the base polymer (for example, an acrylic polymer), and from the viewpoint of improvement in conductivity, it is preferably about 0.1 part by weight or more, more preferably about 0.3 part by weight or more, further preferably about 0.5 part by weight or more, and particularly preferably about 0.7 part by weight or more. The upper limit of the amount of the ionic compound is preferably about 20 parts by weight or less based on 100 parts by weight of the base polymer, and is preferably about 10 parts by weight or less, more preferably about 5 parts by weight or less, and still more preferably about 3 parts by weight or less (for example, about 2 parts by weight or less) in view of durability, adhesion characteristics, and the like.

The content of the conductive component (the total amount of the conductive component containing the ionic compound) in the adhesive layer is not particularly limited, and an appropriate amount capable of imparting a given conductivity to the adhesive layer may be added. The amount of the conductive component is preferably about 0.01 parts by weight or more relative to 100 parts by weight of the base polymer (for example, acrylic polymer), and is preferably about 0.1 parts by weight or more, more preferably about 0.5 parts by weight or more, from the viewpoint of improvement in conductivity. The upper limit of the amount of the conductive component is preferably about 30 parts by weight or less based on 100 parts by weight of the base polymer, and is preferably about 10 parts by weight or less, more preferably about 5 parts by weight or less, and still more preferably about 3 parts by weight or less in view of durability, adhesion characteristics, and the like. In the embodiment using an ionic compound as the conductive component, the pressure-sensitive adhesive layer may optionally contain a conductive component other than the ionic compound, or may not substantially contain a conductive component other than the ionic compound. The technique disclosed herein may be implemented such 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, the pressure-sensitive adhesive composition may be in the form of a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive component in an organic solvent (solvent-based pressure-sensitive adhesive composition), a pressure-sensitive adhesive composition in the form of a pressure-sensitive adhesive component dispersed in an aqueous solvent (water-dispersed pressure-sensitive adhesive composition, typically aqueous emulsion pressure-sensitive adhesive composition), or a solvent-free pressure-sensitive adhesive composition (e.g., a pressure-sensitive adhesive composition or a hot-melt pressure-sensitive adhesive composition that is cured by irradiation with active energy rays such as ultraviolet rays or electron beams). The technique disclosed herein can be preferably implemented to have an adhesive layer formed of a solvent-based adhesive composition. The organic solvent contained in the solvent-based adhesive composition may be a single solvent composed of any one of toluene, xylene, ethyl acetate, hexane, cyclohexane, methylcyclohexane, heptane, and isopropyl alcohol, or may be a mixed solvent mainly composed of any one of these solvents.

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

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

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

The pressure-sensitive adhesive composition may further contain various conventionally known additives as needed. Examples of the additives include surface lubricants, leveling agents, plasticizers, softeners, fillers, antioxidants, preservatives, light stabilizers, ultraviolet absorbers, polymerization inhibitors, crosslinking accelerators, and silane coupling agents. In addition, a tackifier resin and a release controlling agent, which are known and/or commonly used, may be blended in the adhesive composition containing an acrylic polymer as a base polymer. Further, when the adhesive polymer is synthesized by an emulsion polymerization method, an emulsifier or a chain transfer agent (also referred to as a molecular weight regulator or a polymerization degree regulator) is preferably used. The content of the additive as any of these components may be determined as appropriate depending on the purpose of use. The amount of any of the above additives is usually about 5 parts by weight or less, and preferably about 3 parts by weight or less (for example, about 1 part by weight or less) based on 100 parts by weight of the base polymer.

(method of Forming adhesive layer)

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

(surface resistance value of adhesive layer)

The surface resistance value of the adhesive layer is not particularly limited. In some preferred embodiments, the adhesive layer is configured to have conductivity in addition to the conductive layer, so that higher conductivity can be provided to the visible side of the liquid crystal display device. In the embodiment, the surface resistance value of the pressure-sensitive adhesive layer is about 1 × 10 from the viewpoint of antistatic property and the like¹²The following is appropriate for omega/□. If the surface resistance value is limited to a given value or less of the application of the adhesive layer to a liquid crystal panel (for example, an in-cell type liquid crystal panel), the occurrence of static electricity unevenness can be suitably prevented based on the conductivity. In addition, from the viewpoint of touch sensing sensitivity and durability, the lower limit of the surface resistance value is preferably about 1 × 10⁷Omega/□ or higher is suitable. From the above viewpoint, for example, when the liquid crystal cell is applied to an externally-embedded liquid crystal cell described later, the surface resistance value is preferably about 1 × 10¹⁰Ω/□～1×10¹²Omega/□. When the liquid crystal cell is applied to a semi-embedded liquid crystal cell described later, the surface resistance value is preferably about 1 × 10⁹Ω/□～1×10¹²Omega/□. When the liquid crystal cell is applied to an in-cell liquid crystal cell described later, the surface resistance value is preferably about 1 × 10⁷Ω/□～1×10¹²Omega/□, from the viewpoint of durability, more preferably about 1X 10⁸Ω/□～1×10¹⁰Omega/□. The surface resistance value of the pressure-sensitive adhesive layer was measured by the method described in the examples described later.

(thickness of adhesive layer)

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

< constituent Material of liquid Crystal Panel >

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

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

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

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

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

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

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

In the liquid crystal panel, as the optical film of the optical film with an adhesive layer disposed on the side opposite to the viewing side, a polarizing film, a known or commonly used optical film different from the polarizing film may be used depending on the application and purpose. Examples of such optical films include a retardation film (also referred to as a retardation plate, including a wave plate), an optical compensation film, a brightness enhancement film, a light diffusion film, a reflection film, and a reflection film. These optical films may be used alone in 1 kind, or may be used in a stack of 2 or more kinds.

< use >)

The liquid crystal display device having a touch sensing function (also referred to as a touch panel type liquid crystal display device) disclosed herein is not particularly limited in its application, and may be used for various applications such as a portable electronic device and a vehicle-mounted device. The technology disclosed herein can be particularly applied to a touch panel type liquid crystal display device for vehicle use, which is easily exposed to a severe environment and requires a given or more durability against humidity and heat. By applying the technology disclosed herein to the above-mentioned applications, excellent durability can be obtained based on improved wet heat conductive stability and the like.

Examples

The present invention will be described below with reference to some examples, but the present invention is not intended to be limited to the specific examples shown. In the following description, "part" and "%" are based on weight unless otherwise specified.

< evaluation method >

[ surface resistance value of conductive layer ]

(1) Initial surface resistance value

The polarizing film with a conductive layer used in the production of a liquid crystal display device was measured for its initial surface resistance value [ Ω/□ ] under conditions of an applied voltage of 10V and an applied time of 10 seconds in an atmosphere of 23 ℃ and 50% RH in accordance with JIS K6911. As the resistivity meter, a product of "Hiresta UP MCP-HT450 type" manufactured by Mitsubishi Chemical Analytech co., ltd.) or a product equivalent thereof may be used.

(2) Surface resistance value after damp-heat test

The polarizing film with a conductive layer (before lamination of the adhesive layer) used in the production of a liquid crystal display device was placed in a hot and humid environment at 85 ℃ and 85% RH for 24 hours (hot and humid test). Then, the surface of the conductive layer dried at room temperature for 3 hours was subjected to a wet heat test under a voltage of 10V for 10 seconds in an atmosphere of 23 ℃ and 50% RH in accordance with JIS K6911 to measure a surface resistance value [ omega/□ ]. As the resistivity meter, a product of "Hiresta UP MCP-HT450 type" manufactured by Mitsubishi Chemical Analytech co., ltd.) or a product equivalent thereof may be used.

(3) Wet heat surface resistance change ratio

The change ratio of the wet heat surface resistance was determined from the ratio (S/P) of the surface resistance value S [ omega/□ ] after the wet heat test obtained by the above measurement to the initial surface resistance value P [ omega/□ ].

[ surface resistance value of adhesive layer ]

A pressure-sensitive adhesive layer used in the production of a liquid crystal display device was formed on a release liner, and the surface resistance value [ omega/□ ] of the pressure-sensitive adhesive layer was measured under the conditions of an applied voltage of 250V for 10 seconds in an atmosphere of 23 ℃ and 50% RH in accordance with JIS K6911. As the resistivity meter, a commercially available resistivity meter (for example, a trade name "Hiresta UP MCP-HT450 type" manufactured by Mitsubishi Chemical analysis co., ltd.) or a product equivalent thereof may be used. In table 1 described later, the resistance value exceeding the upper measurement limit is referred to as "OVER".

[ Wet Heat conductivity Change ratio F_HT]

(1) Preliminary evaluation (correlation with surface resistance value)

5 samples of the conductive-layer-attached polarizing films having different surface resistance values were prepared, and each sample of the conductive-layer-attached polarizing film was set in a touch panel evaluation kit (product name "TouchKit" manufactured by Shurter corporation). The evaluation kit has: a PCAP (projected capacitive) touch panel, an IC (integrated circuit) substrate, and software, in which a cover glass is laminated, and a current value of the touch panel can be recorded and processed by the software from a terminal connected to the touch panel via the IC substrate. Specifically, as shown in fig. 10, the surface of the pressure-sensitive adhesive layer of the polarizing film sample S with a conductive layer was adhered to the cover glass 304 of the touch panel 302 of the evaluation kit 300 so as not to be lifted. The touch panel 302 is horizontally placed on an insulator not shown. As the insulator, for example, a flat resin or a frame-shaped rubber body can be used. Further, a capacity data map in the surface of the touch panel 302 was obtained by software activated by a PC through the terminal T and the IC substrate, and a difference (cooked data) between the current value of the obtained touch panel and the base current value of the touch panel of the polarizing film sample S without the conductive layer was obtained as Δ C. In the present measurement, Δ C is measured at a plurality of positions in the touch panel surfaceAnd (Max-Min) calculated from the maximum value and the minimum value of the difference (cooked data) between the plurality of measured values and the base current value. FIG. 11 is a graph in which Δ C (cooked data (Max-Min)) measured as described above is taken as a vertical axis and the surface resistance value [ Ω/□ ] of the conductive layer is taken as a surface resistance value]The horizontal axis represents a graph obtained by plotting the samples. As shown in FIG. 11, it can be seen that Δ C and the surface resistance value [ Ω/□ [ ]]Coefficient of correlation R representing regression line thereof²Since the correlation is high at 0.9701, Δ C can be used as an index of the conductivity of the conductive layer and a change in the conductivity. The Δ C is a value obtained by digital (8-bit) conversion in the software, and therefore has a unit of bit. Δ C (A), Δ C (B) and the wet heat conductivity change ratio F described later_HTThe same applies.

In the measurement of Δ c (a) and Δ c (b) described later, the polarizing film sample with a conductive layer was set in the evaluation kit as follows: a plurality of insulating sheets (for example, polystyrene sheets) were stacked as weights on the upper surface (back surface) of the polarizing film sample with a conductive layer so that the polarizing film sample with a conductive layer did not lift up from the cover glass 304. In addition, when Δ c (a) and Δ c (b) described later were measured by directly providing a conductive layer (for example, a sample in which a conductive layer was formed on a PET film of an insulator) to an evaluation kit, the surface of the conductive layer was disposed so as to be in contact with a cover glass of the evaluation kit, and then a plurality of insulating sheets (for example, about 20 polystyrene sheets (about 1 sheet 10 to 20 g) having a size approximately the same as that of a touch panel) were stacked on the conductive layer as weights so as not to cause lifting between the conductive layer and the cover glass.

F of the conductive layer was measured using the polarizing film via the evaluation kit for adhesive layer as described above_HTIn the case of (1), the conductive layer was directly brought into contact with the cover glass and F of the conductive layer was measured by an evaluation kit_HTIn the case of (A), F_HTAll take on substantially consistent values and do not vary significantly.

(2)ΔC(A)

The polarizing film with a conductive layer used in the manufacture of the liquid crystal display device was set in the evaluation kit 300 by the same method as (1) described above, and the difference Δ C (cooked data) between the current value of the touch panel and the base current value of the touch panel when the polarizing film with a conductive layer was set was obtained from the obtained capacity data map in the touch panel surface. This was set as the difference Δ c (a) between the current value of the touch panel flowing when the conductive layer before the damp-heat test was disposed on the touch panel for evaluation and the base current value of the touch panel. Δ c (a) was measured as described above using the conductive layer without using the polarizing film with a conductive layer.

(3)ΔC(B)

The polarizing film with a conductive layer used in the production of a liquid crystal display device was left in a hot and humid environment at 85 ℃ and 85% RH for 24 hours (hot and humid test). Then, the sample was dried at room temperature for 3 hours, and the obtained sample was set in the evaluation kit 300 by the same method as in (1) above, and the difference Δ C (cooked data) between the current value of the touch panel when the polarizing film with the conductive layer was set and the base current value of the touch panel was obtained from the obtained capacity data map in the touch panel surface. This is defined as a difference Δ c (b) between the current value of the touch panel flowing when the conductive layer after the damp-heat test is disposed on the touch panel for evaluation and the base current value of the touch panel. Δ c (b) was measured as described above using the conductive layer without using the polarizing film with a conductive layer.

(4) Wet heat conductivity change ratio F_HTIs calculated by

The wet heat conductivity change ratio F was calculated from the following formula (1)_HT。

F_HT＝ΔC(B)/ΔC(A)·····(1)

[ evaluation of stability of touch sensitivity ]

Based on the wet heat conductivity change ratio F_HTAnd evaluated according to the following criteria.

(evaluation criteria)

◎：F_HT≤1.5

○：1.5＜F_HT≤2

×：2＜F_HT

[ ESD (Electrostatic discharge) test ]

An embedded liquid crystal cell was prepared, and a release liner was peeled off from the polarizing film with a conductive layer, and the exposed adhesive surface was bonded to the visible side of the embedded liquid crystal cell as shown in fig. 1. Next, a 5mm wide silver paste was applied to the side surface of the polarizing film with a conductive layer attached to the in-cell type liquid crystal cell so as to cover the entire side surface of the hard coat layer, the polarizing film, the conductive layer, and the pressure-sensitive adhesive layer, and connected to an external ground electrode, thereby obtaining a liquid crystal display panel. The liquid crystal display panel was set in a backlight unit under conditions of 23 ℃ and 55% RH, and an electrostatic Discharge Gun (Electro-static Discharge Gun) was applied to the polarizing film surface on the viewing side at a voltage of 10kV, and the time until the portion where white spots were caused by electricity disappeared was measured (initial evaluation). The liquid crystal display panel was put into a hot and humid environment at 85 ℃ and 85% RH for 24 hours, and then dried at room temperature for 3 hours, and then subjected to the same ESD test (post hot and humid evaluation). The obtained measurement results were evaluated according to the following criteria.

(evaluation criteria)

Very good: after the initial and damp-heat treatment, the uneven white color disappears within 3 seconds

O: in both the initial and moist-heat cases, the white unevenness disappeared within 5 seconds in more than 3 seconds

X: after the initial heating and the moist heating, the white unevenness did not disappear even after more than 5 seconds.

[ production of polarizing film ]

Preparation example A1

A long roll of a polyvinyl alcohol (PVA) -based resin film (product name "PE 3000" available from Coly corporation) having a thickness of 30 μm was stretched in one direction in the longitudinal direction by a roll stretcher to 5.9 times, and subjected to swelling, dyeing, crosslinking, washing and drying to obtain a polarizer having a thickness of 12 μm. Specifically, in the swelling treatment, the film was stretched to 2.2 times while being treated with pure water at 20 ℃. In the dyeing treatment, the film was stretched to 1.4 times while being treated in an aqueous solution with the iodine concentration adjusted at 30 ℃ so that the monomer transmittance of the polarizer obtained became 45.0%. In the above aqueous solution, the weight ratio of iodine to potassium iodide was 1: 7. As the crosslinking treatment, two-stage crosslinking treatment was used, and in the first stage crosslinking treatment, the film was stretched to 1.2 times while being treated in an aqueous boric acid/potassium iodide solution at 40 ℃. The boric acid content of the aqueous solution was set to 5.0%, and the potassium iodide content was set to 3.0%. In the second stage of crosslinking treatment, the film was stretched to 1.6 times while being treated in an aqueous boric acid/potassium iodide solution at 65 ℃. The boric acid content of the aqueous solution was set to 4.3%, and the potassium iodide content was set to 5.0%. In the cleaning treatment, an aqueous solution of potassium iodide at 20 ℃ 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 ℃ for 5 minutes.

A cellulose Triacetate (TAC) -HC film having a Hard Coat (HC) layer on one surface thereof and a thickness of 32 μm was bonded to one surface of the polarizer using a PVA adhesive. An acrylic (CAT) film having a thickness of 25 μm was laminated on the other surface of the polarizer using a PVA adhesive to prepare a polarizing film having a TAC protective layer/PVA polarizer/CAT protective layer. A hard coat layer is provided as a surface treatment layer on the TAC protective layer side surface of the polarizing film.

[ preparation of electroconductive composition ]

Preparation example B1

Blending a liquid containing a thiophene polymer (PEDOT/PSS-NH)₄)14.3 parts of a binder solution A (trade name "SUPERFLEX 210" manufactured by first Industrial pharmaceutical Co., Ltd., urethane-containing binder, solid content: 35%) 1 part of a binder solution B (trade name "EPOCROS WS-700" manufactured by Nippon catalyst Co., Ltd., Mn 2 ten thousand and Mw 4 ten thousand-containingOxazoline-based polymer) 4 parts, and triethylene glycol (boiling point: about 287 ℃) and water, an electroconductive composition B1 having a solid content concentration of 1.5% was prepared. The liquid containing the thiophene polymer is prepared by TokyoAn aqueous dispersion (trade name "Clevios P" manufactured by Heraeus corporation) containing PEDOT (poly (3, 4-ethylenedioxythiophene)) and PSS (sodium poly (styrenesulfonate)) was neutralized with 28% aqueous ammonia manufactured by chemical industries, and the solid fraction was 1%. Triethylene glycol was added to the composition so that the content of triethylene glycol was 3%. The obtained composition contained 0.14% of a thiophene polymer, 0.36% of a urethane binder, and1.0% of oxazoline-based polymer.

Preparation example B2

A conductive composition B2 of this example was prepared in the same manner as in preparation example B1, except that diethylene glycol (boiling point: about 244 ℃ C.) was used as the high boiling point compound in place of triethylene glycol.

Preparation example B3

A conductive composition B3 of this example was prepared in the same manner as in preparation example B1, except that catechol (boiling point: about 246 ℃ C.) was used as the high boiling point compound in place of triethylene glycol.

Preparation example B4

An electrically conductive composition B4 of this example was prepared in the same manner as in preparation example B3, except that the amount of the high boiling compound (catechol) added was changed from 3% to 10% and the same amount of water was reduced.

Preparation example B5

A conductive composition B5 of this example was prepared in the same manner as in preparation example B1, except that glycerin (boiling point: about 290 ℃ C.) was used as the high boiling point compound in place of triethylene glycol.

Preparation example B6

A conductive composition B6 of 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 B7

A conductive composition B7 of this example was prepared in the same manner as in preparation example B1, except that dimethyl sulfoxide (boiling point: about 189 ℃ C.) was used in an amount of 5% instead of triethylene glycol 3% as the high boiling point compound and the same amount of water was reduced.

Preparation example B8

An electrically conductive composition B8 of this example was prepared in the same manner as in preparation example B1, except that a high boiling point compound was not used.

Preparation example B9

A conductive composition B9 of this example was prepared in the same manner as in preparation example B1, except that N, N-dimethylformamide (boiling point: about 153 ℃) was used instead of triethylene glycol.

Preparation example B10

A conductive composition B10 of 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 C1

A monomer mixture containing 76.9 parts of Butyl Acrylate (BA), 17 parts of benzyl acrylate (BzA), 5 parts of Acrylic Acid (AA), 1 part of N-vinyl-2-pyrrolidone (NVP) and 0.1 part of 4-hydroxybutyl acrylate (4HBA) was placed in a four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a condenser. Further, 0.1 part of 2, 2' -azobisisobutyronitrile as a polymerization initiator was added together with 100 parts of ethyl acetate to 100 parts of the monomer mixture (solid content), nitrogen gas was introduced while slowly stirring the mixture, and after nitrogen substitution, the liquid temperature in the flask was kept near 55 ℃ to conduct polymerization for 8 hours, thereby preparing an acrylic polymer P1 solution having Mw of 195 ten thousand and Mw/Mn of 3.9.

An acrylic pressure-sensitive adhesive composition C1 was prepared by mixing 0.4 parts of an isocyanate-based crosslinking agent (trade name "Coronate L" manufactured by Tosoh corporation, trimethylolpropane/tolylene diisocyanate adduct), 0.1 parts of a peroxide crosslinking agent (trade name "NYPER BMT" manufactured by Nippon fat and oil Co., Ltd.) and 0.2 parts of gamma-glycidoxypropylmethoxysilane (trade name "KBM-403" manufactured by shin Etsu chemical Co., Ltd.) with respect to 100 parts of the solid content of the acrylic polymer P1 solution obtained above.

Preparation C2

An acrylic pressure-sensitive adhesive composition C2 solution was prepared by mixing 6 parts of a conductive agent, 0.4 parts of an isocyanate-based crosslinking agent (trade name "Coronate L", manufactured by Tosoh corporation, trimethylolpropane/tolylene diisocyanate adduct), 0.1 parts of a peroxide crosslinking agent (trade name "NYPER BMT", manufactured by Nippon fat and oil Co., Ltd.), and 0.2 parts of γ -glycidoxypropylmethoxysilane (trade name "KBM-403", manufactured by shin-Etsu chemical Co., Ltd.) with respect to 100 parts of the solid content of the acrylic polymer P1 solution. As the conductive agent, lithium bis (trifluoromethanesulfonyl) imide (Li-TFSI) was used.

< examples 1 to 11 and comparative examples 1 to 3 >

A coating liquid containing any of the conductive compositions B1 to B10 was applied to one surface (the side not provided with the hard coat layer) of the polarizing film to a thickness of 50nm after drying, and dried at 80 ℃ for 3 minutes to form a conductive layer.

A solution of any of the acrylic pressure-sensitive adhesive compositions C1 to C2 was applied to one surface of a polyethylene terephthalate (PET) film (release liner, model "MRF 38" manufactured by mitsubishi chemical polyester film corporation) treated with a silicone-based release agent so that the thickness of the pressure-sensitive adhesive layer after drying became 23 μm, and the pressure-sensitive adhesive layer was formed on the surface of the release liner by drying at 155 ℃ for 1 minute. Then, the pressure-sensitive adhesive layer formed on the release liner was transferred to the conductive layer-side surface on the polarizing film obtained above. The polarizing films with conductive layers of the respective examples were thus produced. These polarizing films with a conductive layer have a polarizing film/conductive layer/pressure-sensitive adhesive layer structure, and a hard coat layer is provided on the back surface of the polarizing film side, and the pressure-sensitive adhesive layer is protected by a release liner on the adhesive surface.

Next, an in-cell liquid crystal cell was prepared, and the release liner was peeled off from each of the polarizing films with a conductive layer, and the exposed adhesive surfaces were bonded to both sides of the in-cell liquid crystal cell as shown in fig. 1. The lead wires (not shown) around the transparent electrode pattern in the embedded liquid crystal cell were connected to a controller IC (not shown), and liquid crystal display devices incorporating touch sensing functions were fabricated in each example.

The outline of the liquid crystal display device having a touch sensor function in each example, and the surface resistance value [ Ω/□ ] after the initial and moist heat tests]Wet-heat surface resistance change ratio, surface resistance value [ omega/□ ] of adhesive layer]And wet heat conductivity change ratio F_HTTable 1 shows (Δ c (b)/Δ c (a)), touch sensitivity stability, and ESD evaluation results. The N, N-dimethylformamide and diethylene glycol dimethyl ether used in comparative examples 2 and 3 do not belong to the high boiling point compounds, but are described in the high boiling point compounds for convenience.

As shown in table 1, in examples 1 to 11 in which a high boiling point compound having a boiling point of 180 ℃ or higher was used in forming the conductive layer, the wet heat surface resistance change ratio of the conductive layer was in the range of 0.05 or more and 10 or less, and all the touch sensitivity stability evaluation results were of a satisfactory level. In these examples, the wet heat conductivity change ratio F_HTIs also 2 or less. In examples 1 to 5 and 8 to 11 using a high boiling point compound having a boiling point of 210 ℃ or higher, the wet heat surface resistance change ratio of the conductive layer was in a narrower range, and particularly excellent evaluation results were obtained. In addition, in the embodiment 1 ~ 11, ESD evaluation results are also good, in the adhesive layer containing conductive agent in the embodiment 8 ~ 11, can obtain especially excellent results. On the other hand, in comparative examples 1 to 3 in which a high boiling point compound having a boiling point of 180 ℃ or higher was not used, the wet heat surface resistance change ratio of the conductive layer was less than 0.05, and the touch sensitivity stability evaluation result was poor. In comparative examples 1 to 3, the change ratio F of wet heat conductivity_HTAlso exceeds 2.

As can be seen from the above results, in the liquid crystal display device having a touch sensor function in which the conductive layer is disposed on the visible side of the touch sensor portion, the change ratio F of the thermal conductivity to humidity change is provided_HTConductive layer of 2 or less, and wet heat surface resistance of the conductive layerThe composition of the conductive layer with a variation ratio of 0.05-10 and the conductive layer formed by using the conductive polymer and the high boiling point compound with the boiling point of more than 180 ℃ can prevent the generation of static electricity unevenness and maintain stable touch sensing sensitivity even when exposed to a damp and hot environment.

Specific examples of the present invention have been described above in detail, but these are merely examples and do not limit the claims. The techniques recited in the claims also include those obtained by variously modifying or changing the specific examples illustrated above.