WO2020179510A1

WO2020179510A1 - Liquid crystal display device with built-in touch sensing function and manufacturing method therefor

Info

Publication number: WO2020179510A1
Application number: PCT/JP2020/007127
Authority: WO
Inventors: 悟士山本; 智之木村; 雄祐外山
Original assignee: 日東電工株式会社
Priority date: 2019-03-05
Filing date: 2020-02-21
Publication date: 2020-09-10
Also published as: KR20210134719A; JP2020144200A; CN113661439A; TW202040232A

Abstract

The purpose of the present invention is to provide a liquid crystal display device with a built-in touch sensing function, which is able to hold stable touch sensor sensitivity while preventing occurrence of electrostatic unevenness even when being exposed to a wet heat environment. Provided is a liquid crystal display device with a built-in touch sensing function. This liquid crystal display device is equipped with: a liquid crystal layer including liquid crystal molecules; a touch sensor part; and first and second polarizing films respectively disposed on both sides of the liquid crystal layer. 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 part. A conductive layer is disposed closer to the viewing side than the touch sensor part. Regarding the conductivity layer, a wet heat conductivity change ratio F_HT expressed by the following formula (1) is 2 or less.　F_HT = ΔC(B)/ ΔC(A) ….. (1) (In formula (1), ΔC(B) is a difference between a touch panel current value after a wet heat test and a touch panel base current value, and ΔC(A) is a difference between a touch panel current value before the wet heat test and the touch panel base current value.)

Description

Liquid crystal display device with built-in touch sensing function and manufacturing method thereof

The present invention relates to a liquid crystal display device having a built-in touch sensing function and a method for manufacturing the same.
This application claims priority based on Japanese Patent Application No. 2019-039938 filed on March 5, 2019, the entire contents of which are incorporated herein by reference.

In recent years, liquid crystal display devices with a built-in touch sensing function have been widely used as input-capable image display devices in various fields such as portable electronic devices and vehicles. In this type of liquid crystal display device, measures such as providing an antistatic layer are taken in order to prevent the occurrence of liquid crystal display unevenness (hereinafter, also referred to as "static electricity unevenness") caused by static electricity or the like. .. Static electricity can be generated when the release liner is removed from the polarizing film with an adhesive layer, for example, when the polarizing film is attached to a liquid crystal cell. Patent Document 1 is mentioned as a prior art document that discloses this kind of prior art. In addition, Patent Document 2 discloses a conductive resin composition that can be used for a touch panel of various electronic devices, a transparent electrode for driving a liquid crystal, and the like, and describes that the transparent conductive film contains a conductivity improving agent. ing.

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

Since the capacitance method used in the liquid crystal display device with built-in touch sensing function is an input device that detects and drives the change in capacitance caused by the contact of a finger with the touch panel, the change in capacitance to be detected. However, when it becomes unstable due to the disturbance of the electric field due to the presence of the antistatic layer, the touch panel sensitivity is lowered. Therefore, the antistatic layer used in the built-in touch sensing function is configured to have conductivity that can both prevent the occurrence of static electricity unevenness and the touch sensor sensitivity (Patent Document 1). It is desirable that this conductivity be stable even when used in various environments, from the viewpoint of durability and long life of the device. However, as a result of the study by the present inventors, it has been clarified that the conventional antistatic layer has a possibility that the surface resistance value decreases when used in a high temperature and high humidity environment, and the touch sensor may malfunction.

The present invention has been created in view of the above circumstances, and is a touch sensing function capable of maintaining stable touch sensor sensitivity while preventing the occurrence of static electricity unevenness even when exposed to a moist heat environment. An object is to provide a built-in liquid crystal display device. Another object of the present invention is to provide a method for manufacturing a liquid crystal display device having a built-in touch sensing function.

According to the present specification, a liquid crystal display device having a built-in touch sensing function is provided. The liquid crystal display device includes: a liquid crystal layer containing liquid crystal molecules; a touch sensor unit; and first and second polarizing films arranged on both sides of the liquid crystal layer, respectively. Here, the first polarizing film is arranged on the viewing side of the liquid crystal layer and on the viewing side of the touch sensor unit. Further, in the above liquid crystal display device, the conductive layer is arranged on the viewing side of the touch sensor unit. Then, in some embodiments, the conductive layer is wet heat conductive variation ratio F _HT represented by the following formula (1) is 2 or less.
F _HT =ΔC(B)/ΔC(A) (1)
(In the formula (1), ΔC(B) is the current of the touch panel that flows when the conductive layer after the heat and humidity test performed under the conditions of the temperature of 85° C., the relative humidity of 85% and the 24 hours is arranged on the touch panel for evaluation. It is the difference between the value and the touch panel base current value, and ΔC (A) is the difference between the touch panel current value and the touch panel base current value that flow when the conductive layer before the wet heat test is arranged on the evaluation touch panel. .)

According to the above configuration, the conductive layer of the liquid crystal display device has a moist heat conductivity change ratio _FHT of 2 or less before and after the moist heat test, so that the change in conductivity is suppressed even when exposed to a moist heat environment. Has been done. As a result, it is possible to prevent the occurrence of static electricity unevenness, maintain stable touch sensor sensitivity, and prevent malfunction of the touch sensor. The liquid crystal display device with a built-in touch sensing function has excellent wet and heat durability.

According to the present specification, a liquid crystal display device with a built-in touch sensing function is provided from a different aspect. This liquid crystal display device includes: a liquid crystal layer containing liquid crystal molecules; a touch sensor part; first and second polarizing films respectively arranged on both sides of the liquid crystal layer. Here, the first polarizing film is arranged on the viewing side of the liquid crystal layer and on the viewing side of the touch sensor unit. Further, in the liquid crystal display device, a conductive layer is arranged on the visual side of the touch sensor unit. In some aspects, the conductive layer has a wet heat surface resistance change ratio S/P satisfying the condition: 0.05≦S/P≦10. 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° C., a relative humidity of 85% and 24 hours, and P is a conductive layer before the wet heat test. Surface resistance value [Ω/□]. According to the above configuration, the conductive layer included in the liquid crystal display device has a surface resistance change ratio before and after the wet heat test within a specific range, so that it is possible to achieve both prevention of occurrence of static electricity unevenness and stability of touch sensor sensitivity.

According to the present specification, a liquid crystal display device with a built-in touch sensing function is provided from a different aspect. This liquid crystal display device includes: a liquid crystal layer containing liquid crystal molecules; a touch sensor part; first and second polarizing films respectively arranged on both sides of the liquid crystal layer. Here, the first polarizing film is arranged on the visual side of the liquid crystal layer and on the visual side of the touch sensor unit. Further, in the liquid crystal display device, a conductive layer is arranged on the visual side of the touch sensor unit. In some embodiments, the conductive layer is formed from a conductive composition containing a conductive polymer and a high boiling point compound having a boiling point of 180° C. or higher. According to the conductive layer formed using a high boiling point compound having a boiling point of 180° C. or higher, the conductive stability after being exposed to the moist heat environment (that is, the moist heat conductive stability) is improved. Even if there is, the change in conductivity is suppressed. As a result, it is possible to maintain stable touch sensor sensitivity while preventing the occurrence of static electricity unevenness. That is, in the techniques disclosed herein, the high boiling point compound is not used for improving conductivity, but for touch sensor sensitivity stability in a moist heat environment to improve moist heat durability. .. In this respect, it is essentially different from the conductivity improvement using the conductivity improver in Patent Document 2. In the technique disclosed herein, the target conductivity can be adjusted by the type and amount of the conductive polymer used.

In some aspects of the technology disclosed herein (including a liquid crystal display device with a built-in touch sensing function, an in-cell type liquid crystal display device, and a method for manufacturing the same; the same applies hereinafter), the conductive layer has a moist heat surface resistance change ratio. S / P satisfies the condition: 0.05 ≦ S / P ≦ 10 ;. 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° C., a relative humidity of 85% and 24 hours, and P is a conductive layer before the wet heat test. Surface resistance value [Ω/□]. According to the above configuration, the conductive layer of the liquid crystal display device has a surface resistance change ratio by a wet heat test within a specific range, so that even when exposed to a wet heat environment, good touch sensor sensitivity stability is obtained. Can be demonstrated.

In some 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 within a specific range, the effects of the technique disclosed herein can be preferably exhibited.

In some preferred embodiments, the high boiling point compound has a boiling point of 210 to 290°C. In addition, in some other embodiments, the high boiling point compound is preferably a glycol ether solvent. By selecting an appropriate high-boiling point compound from the boiling point and the chemical structure, it is possible to realize more excellent touch sensor sensitivity stability even when exposed to a humid heat environment.

In some preferred embodiments, the conductive layer comprises a thiophene-based polymer as the conductive polymer. In the configuration in which the thiophene-based polymer is used as the conductive polymer, the moist heat conductive stability improving effect and the touch sensor sensitivity stability improving effect by the technique disclosed here are preferably exhibited.

In some preferred embodiments, the conductive layer comprises a binder. As a result, the film formability of the conductive layer is improved and the conductive layer can be favorably fixed in the liquid crystal display device.

Further, the liquid crystal display device is preferably an in-cell type liquid crystal display device. Unlike the on-cell type, the in-cell type liquid crystal display device does not have a conductive layer such as an ITO layer on the surface of the panel and has a lower resistance as the conductive layer arranged on the viewing side of the touch sensor unit. Can be used. The lower the resistance level, the more difficult it is to eliminate the problem of the touch sensor sensitivity. Therefore, the stability of the resistance value is more important in the in-cell type liquid crystal panel than in the on-cell type. By arranging the conductive layer with improved moist heat conductivity stability in the in-cell liquid crystal display device, the sensitivity of the touch sensor is maintained stably for a long period of time with good durability, and the touch sensor sensitivity in the in-cell liquid crystal display device is stable. Of the device, and thus, the durability of the device can be improved and the life of the device can be extended. The technique disclosed herein may be particularly suitable for in-cell liquid crystal panel applications among various liquid crystal panels.

Further, according to this specification, a method for manufacturing a liquid crystal display device having a built-in touch sensing function is provided. The liquid crystal display device having a built-in touch sensing function manufactured by this method includes a liquid crystal layer containing liquid crystal molecules; a touch sensor unit; and first and second polarizing films arranged on both sides of the liquid crystal layer, respectively. .. Here, the first polarizing film is arranged on the visual side of the liquid crystal layer and on the visual side of the touch sensor unit. This method includes the step of disposing a conductive layer on the viewing side of the touch sensor unit. Then, the conductive layer is formed from a conductive composition containing a conductive polymer and a high boiling point compound having a boiling point of 180° C. or higher. According to this method, by forming a conductive layer using a high boiling point compound having a boiling point of 180 ° C. or higher, the touch sensor sensitivity is stable while preventing the occurrence of static electricity unevenness even when exposed to a moist heat environment. It is possible to obtain a liquid crystal display device having a built-in touch sensing function having excellent properties.

FIG. 3 is a schematic cross-sectional view showing a main part of an in-cell type liquid crystal display device according to one embodiment. FIG. 11 is a schematic cross-sectional view showing a main part of an in-cell type liquid crystal display device according to another embodiment. It is a schematic cross-sectional view which shows the main part of the in-cell type liquid crystal display device which concerns on another embodiment. FIG. 11 is a schematic cross-sectional view showing a main part of an in-cell type liquid crystal display device according to another embodiment. It is a schematic cross-sectional view which shows the main part of the in-cell type liquid crystal display device which concerns on another embodiment. FIG. 11 is a schematic cross-sectional view showing a main part of an in-cell type liquid crystal display device according to another embodiment. FIG. 11 is a schematic cross-sectional view showing a main part of an in-cell type liquid crystal display device according to another embodiment. FIG. 3 is a schematic cross-sectional view showing a main part of a semi-in-cell type liquid crystal display device according to one embodiment. FIG. 3 is a schematic cross-sectional view showing a main part of an on-cell type liquid crystal display device according to one embodiment. It is explanatory drawing which shows typically the measuring method of the difference of the electric current value of a touch panel at the time of arrange|positioning a conductive layer on a touch panel, and a touch panel base electric current value. 6 is a graph showing a correlation between ΔC (Cooked Data (Max-Min)) when a conductive layer is arranged and the surface resistance value [Ω/□] of the conductive layer.

Hereinafter, preferred embodiments of the present invention will be described. Note that matters other than matters particularly referred to in the present specification, which are necessary for carrying out the present invention, are based on the teaching for carrying out the invention described in the present specification and the common general knowledge at the time of filing. Can be understood by those skilled in the art. The present invention can be implemented based on the contents disclosed in this specification and the common general technical knowledge in the field.
In the following drawings, members / parts having the same function may be described with the same reference numerals, and duplicate description may be omitted or simplified. In addition, the embodiments described in the drawings are schematically illustrated to clearly explain the present invention, and do not accurately represent the sizes and scales of products and parts actually provided.

<Liquid crystal display with built-in touching 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 unit. Further, in the liquid crystal display device, a conductive layer is arranged on the visual side of the touch sensor unit. Further, the liquid crystal display device may typically have a polarizing film (first polarizing film) arranged on the visual side of the liquid crystal layer and on the visual side of the touch sensor unit. Such a liquid crystal display device may be one in which first and second polarizing films are arranged on both sides of a 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 aspects, the touch sensor unit (for example, a detection electrode and a drive electrode forming the touch sensor unit) is It is arranged between the first polarizing film and the liquid crystal layer. In some other aspects, a part of the touch sensor unit (for example, the detection electrode) is arranged between the first polarizing film and the liquid crystal layer.

Examples of liquid crystal display devices with a built-in touch sensing function include devices that include an in-cell liquid crystal panel as shown in FIGS. 1 to 7. The in-cell liquid crystal panel is simply a liquid crystal cell including a liquid crystal layer and two transparent substrates sandwiching the liquid crystal layer, in the liquid crystal cell (that is, inside the two transparent substrates). It has a configuration including a touch sensing electrode unit related to the touch sensing function. A complete in-cell liquid crystal panel is one in which both the detection electrode and the drive electrode related to the touch sensing function are arranged in the liquid crystal cell.

FIGS. 1 to 7 are schematic cross-sectional views showing a configuration example of a main part (in-cell type liquid crystal panel) of the liquid crystal display device 1 with a built-in touch sensing function. The in-cell type liquid crystal panel 101 shown in FIG. 1 includes a liquid crystal cell (in-cell type liquid crystal cell) 120 and a first polarizing film 111 arranged on the visual side of the liquid crystal cell 120.

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

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

In the in-cell type liquid crystal panel 101, on the viewing side of the liquid crystal cell 120, the first adhesive layer 112, the conductive layer 113, and the first polarizing film 111 are provided in this order from the first transparent substrate 141 toward the viewing side. Specifically, they are laminated. Although not particularly limited, 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 visible side in the form of the polarizing film with a conductive layer 110. It is attached. In the polarizing film 110 with a conductive layer, the conductive layer 113 is provided on one surface of the first polarizing film 111, and the first polarizing layer 113 is placed on one surface of the conductive layer 113 (the surface opposite to the first polarizing film 111 side). It has a structure in which the pressure-sensitive adhesive layer 112 is arranged. The first pressure-sensitive adhesive layer 112 is arranged and fixed on the outer surface of the first transparent substrate 141 without a conductive layer. The first polarizing film 111 is arranged on the viewing side of the liquid crystal layer 125 so that the transmission axes (or absorption axes) of the polarizers thereof are orthogonal to each other. In this configuration example, the surface treatment layer 114 is arranged on the back surface side of the first polarizing film 111.

On the other hand, in the in-cell type liquid crystal panel 101, the second polarizing film 151 is arranged on the opposite side to the viewing 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 the second adhesive layer 152. The second polarizing film 151 is arranged on the back surface side of the liquid crystal layer 125 so that the transmission axis (or absorption axis) of the polarizer is orthogonal to each other. Although not particularly limited, 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. The polarizing film with a conductive layer 150 has a configuration in which the second adhesive layer 152 is disposed on one surface of the second polarizing film 151.

In addition, in the in-cell type liquid crystal panel 101, a conductive structure 170 made of a conductive material is provided on the side surfaces of the conductive layer 113 and the first adhesive layer 112. Thereby, the potential can be released from the side surface of the conductive layer 113 and the first pressure-sensitive adhesive layer 112 to other places, and the electrostatic charge can be reduced or prevented. The conductive structure 170 may be provided on the entire side surface (end surface) of the conductive layer 113 and the first pressure-sensitive adhesive layer 112, or may be provided on a part of the side surface. When the conductive structure 170 is provided in a part, in order to secure the conductivity on the side surface, approximately 1% or more, preferably approximately 3% or more of the total area of the side surface of the conductive layer 113 and the first pressure-sensitive adhesive layer 112, The conductive structure 170 can be provided at an area ratio of preferably about 10% or more, more preferably about 50% or more. 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 treatment layer 114.

The liquid crystal display device 2 with a built-in touch sensing function shown in FIG. 2 is a modified example of the structure shown in FIG. 1, and the layer structure on the viewing side of the liquid crystal cell 120 is different from the structure shown in FIG. Specifically, in the in-cell type liquid crystal panel 102, the conductive layer 113, the first adhesive layer 112, and the first polarizing film 111 are provided on the viewing side of the liquid crystal cell 120 from the first transparent substrate 141 toward the viewing side. The point that they have in order (specifically, that they are laminated) is different from the configuration example of FIG. Although not particularly limited, 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 polarizing films with a conductive layer. In the form of 110, it is attached to the conductive layer 113 formed on the outer surface of the first transparent substrate 141 on the viewing side. The polarizing film 110 with a conductive layer has a configuration in which the first pressure-sensitive adhesive layer 112 is arranged on one surface of the first polarizing film 111. Note that, in FIG. 2, the surface treatment layer 114 and the

conductive structures

170 and 171 on the back side of the first polarizing film 111 are omitted for convenience of description.

The liquid crystal display device 3 with a built-in touch sensing function shown in FIG. 3 is also a modified example of the configuration shown in FIG. 1, and the layer configuration on the visual side of the liquid crystal cell 120 is different from the configuration shown in FIG. Specifically, in the in-cell type liquid crystal panel 103, the first adhesive layer 112, the first polarizing film 111, and the conductive layer 113 are provided on the viewing side of the liquid crystal cell 120 from the first transparent substrate 141 toward the viewing side. The point that they have in order (specifically, that they are laminated) is different from the configuration example of FIG. Although not particularly limited, 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 on the visible side of the first transparent substrate 141 in the form of a polarizing film 110 with a conductive layer. It is attached. In the polarizing film 110 with a conductive layer, the first pressure-sensitive adhesive layer 112 is arranged on one surface of the first polarizing film 111, and the other surface of the first polarizing film 111 (opposite side of the surface on which the first pressure-sensitive adhesive layer 112 is formed). The surface is provided with the conductive layer 113. The conductive layer 113 may be formed on the back surface of the first polarizing film 111 after laminating the first polarizing film 111 on the visible side of the liquid crystal cell 120. Also in FIG. 3, for convenience of explanation, the surface treatment layer 114 on the back surface side of the first polarizing film 111 and the

conductive structures

170 and 171 are omitted.

The liquid crystal display device 4 with a built-in touch sensing function shown in FIG. 4 is a modified example of the configuration shown in FIG. 1, and in the in-cell type liquid crystal panel 104, the touch sensing electrode portion 130 as a touch sensor portion has a liquid crystal layer 125 and a second portion. The structure is different from that shown in FIG. 1 in that it is arranged between the transparent substrate 142 and the transparent substrate 142. That is, the touch sensing electrode unit 130 including the detection electrode 131 and the drive electrode 132 is arranged on the backlight side (back side) with respect to the liquid crystal layer 125. The liquid crystal display device 5 with a built-in touch sensing function shown in FIG. 5 is also a modified example of the structure shown in FIG. 1, and in the in-cell type liquid crystal panel 105, the touch sensing electrode portion 130 in which the detection electrode and the drive electrode are integrally formed is used. The point is different from the configuration shown in FIG. The liquid crystal display device 6 with a built-in touch sensing function shown in FIG. 6 is a combination of the configurations of FIGS. 4 and 5, and in the in-cell liquid crystal panel 106, a touch sensing electrode portion in which a detection electrode and a drive electrode are integrally formed. The configuration differs from that shown in FIG. 1 in that the 130 is used and that the touch sensing electrode unit 130 as the touch sensor unit is arranged on the backlight side (back side) of the liquid crystal layer 125.

Further, in the liquid crystal display device 7 with a built-in touch sensing function shown in FIG. 7, in the in-cell liquid crystal panel 107, the detection electrode 131 and the drive electrode 132 of the touch sensing electrode part 130 as a touch sensor part are separated on both sides of the liquid crystal layer 125. It is different from the configuration shown in FIG. Specifically, in the in-cell type liquid crystal panel 107, the detection electrode 131 is arranged between the liquid crystal layer 125 and the first transparent substrate 141, and the drive electrode 132 is located between the liquid crystal layer 125 and the second transparent substrate 142. It is located in. Since the other configurations of the modified examples shown in FIGS. 2 to 7 are basically the same as those of the in-cell type liquid crystal panel shown in FIG. 1, overlapping description will be omitted.

As described above, the in-cell type liquid crystal panel has a touch sensing electrode portion inside the liquid crystal cell, not outside the liquid crystal cell. In such a configuration, an electrode such as an ITO layer (usually, a surface resistance value of 1 × 10 ¹³ Ω / □ or less) is not provided on the outer surface of the first transparent substrate of the liquid crystal cell. By arranging the conductive layer disclosed here on the visual side of the first transparent substrate of the liquid crystal cell of such an in-cell type liquid crystal panel, it was exposed to a moist heat environment based on the improved moist heat conductivity stability. Even in such a case, it is possible to exhibit touch sensor sensitivity stability and achieve excellent durability. The effects of the techniques disclosed herein (effects of improving wet and heat conductive stability, thereby improving durability of good touch sensor sensitivity and maintaining long-term stability) can be preferably exhibited in the in-cell type.

Further, as another example of the liquid crystal display device with a built-in touch sensing function disclosed here, a device provided with a semi-in-cell type liquid crystal panel can be mentioned. Briefly, the semi-in-cell type liquid crystal panel has a liquid crystal cell including a liquid crystal layer and two transparent substrates sandwiching the liquid crystal layer, and a detection electrode and a drive constituting a touch sensing electrode portion related to a touch sensing function. Only one of the electrodes is arranged inside the liquid crystal cell, and the other of the electrodes is arranged outside the liquid crystal cell (typically on the outer surface of the transparent substrate).

FIG. 8 is a schematic cross-sectional view showing a configuration example of a device including a semi-in-cell type liquid crystal panel. In the liquid crystal display device 8 with a built-in touch sensing function shown in FIG. 8, in the semi-in-cell type liquid crystal panel 201, a part of the touch sensing electrode part 130 as a touch sensor part is arranged in the liquid crystal cell 120, and the touch sensing electrode part 130 is provided. The other part is arranged outside the liquid crystal cell 120 (specifically, outside the viewing side of the liquid crystal cell 120), which is different from the in-cell type shown in FIGS. Specifically, the detection electrode 131 forming the touch sensing electrode unit 130 is provided on the outer surface of the first transparent substrate 141, and the drive electrode 132 forming the touch sensing electrode unit 130 is arranged in the liquid crystal cell 120. ing. In this configuration example, the drive electrode 132 is arranged between the liquid crystal layer 125 and the second transparent substrate 142. From the visual side, the semi-incell type liquid crystal panel 201 has 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 driving electrode 132, and a second transparent. The substrate 142 has a laminated structure arranged in this order. Further, a surface treatment layer 114 is provided further on the viewing side of the first polarizing film 111. Further, the second pressure-sensitive adhesive layer 152 and the second polarizing film 151 are arranged in this order on the outside of the second transparent substrate 142. In the liquid crystal panel 201, the detection electrode 131 of the touch sensing electrode portion 130 is arranged outside the first transparent substrate 141 and is in contact with the adhesive layer 112.

Another example of the liquid crystal display device with a built-in touch sensing function disclosed herein is a device including an on-cell liquid crystal panel. Briefly, the on-cell type liquid crystal panel has a liquid crystal cell including a liquid crystal layer and two transparent substrates sandwiching the liquid crystal layer, and a touch sensor function is provided on an outer surface of the transparent substrate of the liquid crystal cell. Say.

FIG. 9 is a schematic cross-sectional view showing a configuration example of a device including an on-cell liquid crystal panel. In the liquid crystal display device 9 with a built-in touch sensing function shown in FIG. 9, in the on-cell type liquid crystal panel 202, the detection electrodes 131 and the drive electrodes 132 related to the touch sensing electrode portion 130 as the touch sensor portion have the liquid crystal cell 120 as an electrode pattern. The outside is different from the in-cell type shown in FIGS. 1 to 7. In this configuration, a touch sensor function is provided outside the liquid crystal cell 120 (specifically, outside the first transparent substrate 141 and the second transparent substrate 142). More specifically, the drive electrode 132 is arranged on the outer surface of the first transparent substrate 141 of the liquid crystal cell 120, and the detection electrode 131 is arranged on the drive electrode 132. The on-cell type liquid crystal panel 202 includes 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, and a drive electrode 134 from the viewer side. The second transparent substrate 142 has a laminated structure arranged in this order. Further, a surface treatment layer 114 is provided further on the viewing side of the first polarizing film 111. Further, the second pressure-sensitive adhesive layer 152 and the second polarizing film 151 are arranged 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 sensing electrode unit 130 is arranged outside the first transparent substrate 141 and is in contact with the first adhesive layer 112. Further, a drive electrode 134 is arranged in the liquid crystal cell 120. The drive electrode 134 is arranged between the liquid crystal layer 125 and the second transparent substrate 142.

In addition to the above, the liquid crystal panel described above and the liquid crystal display device provided with the liquid crystal panel are arranged with each component according to the application and purpose as long as the effects of the techniques disclosed herein are not impaired. The configuration can be changed, or another configuration can be additionally adopted as appropriate. As an example, the design can be changed such that the color filter substrate is provided on the liquid crystal cell (for example, the first transparent substrate 141 in FIG. 1).

Further, in the in-cell type liquid crystal panel shown in FIGS. 1, 4 and 7, the detection electrode is arranged closer to the first transparent substrate side (viewing side) than the drive electrode. The configuration of the panel is not limited to this, and the drive electrodes can be arranged on the first transparent substrate side (viewing side) with respect to the detection electrodes.

In the liquid crystal display device with a built-in touch sensing function shown in FIGS. 4 to 9, the laminated structure on the viewing side of the liquid crystal cell has the first polarizing film, the conductive layer, and the first adhesive layer arranged in this order from the viewing side. However, as shown in FIG. 2, for example, these structures are formed into a laminated structure in which the first polarizing film 111, the first adhesive layer 112, and the conductive layer 113 are arranged in this order from the visual side. You may change it. Alternatively, as shown in FIG. 3, the laminated structure on the viewing side of the liquid crystal cell of the liquid crystal display device with a built-in touch sensing function shown in FIGS. 4 to 9 is arranged from the viewing side to the conductive layer 113, the first polarizing film 111, and the first polarizing film 111. You may change into the laminated structure which 1 adhesive layer 112 was arrange|positioned in this order.

In the semi-in-cell type liquid crystal panel shown in FIG. 8, the detection electrodes are arranged outside the liquid crystal cell (specifically, outside the first transparent substrate), and the drive electrodes are arranged inside the liquid crystal cell (specifically, Although it is arranged between the first transparent substrate and the second transparent substrate), the present invention is not limited to this, and the technique disclosed here is that the detection electrode is arranged in the liquid crystal cell and the drive electrode is the liquid crystal. It can be applied to a semi-in-cell type liquid crystal panel arranged outside the cell.

Further, in the above configuration example, a polarizing film with an adhesive layer substantially composed of a second adhesive layer and a second polarizing film was used on the back surface side of the liquid crystal cell, which is disclosed here. The technique is not limited to this, and it is also possible to use the polarizing film with a conductive layer as used in the configuration example of FIG. 1 on the back side of the liquid crystal panel. In that case, the polarizing film with a conductive layer disclosed here can be arrange|positioned on both sides of a liquid crystal cell. As the polarizing film that can be arranged on the side opposite to the viewing side, the same polarizing film as that arranged on the viewing side may be used, or a different polarizing film may be used. Alternatively, a known optical film with a pressure-sensitive adhesive layer may be arranged on the back side of the liquid crystal cell.

As the pressure-sensitive adhesive layer arranged on the back side of the liquid crystal panel, the pressure-sensitive adhesive layer disclosed here or a known or commonly used pressure-sensitive adhesive layer can be used depending on the application and purpose. The pressure-sensitive adhesive layer may be the same as or different from the pressure-sensitive adhesive layer disposed on the viewer side. When the pressure-sensitive adhesive layer arranged on the side opposite to the visible side is formed from a known or common pressure-sensitive adhesive, the thickness of the pressure-sensitive adhesive layer is not particularly limited, and is preferably about 1 to 100 μm, It is 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-mentioned layers (polarizing film, adhesive layer, conductive layer, arbitrary surface treatment layer), a polarizing film and a conductive layer are formed on the visible side and the back side of the liquid crystal cell of the liquid crystal display device having a built-in touch sensing function. An easy-adhesion layer can be provided between them, and various easy-adhesion treatments such as corona treatment and plasma treatment can be performed.

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

Next, the components of the liquid crystal display device with a built-in touch sensing function will be described.

<Polarizing film>
The polarizing films disclosed herein (including the first and second polarizing films; the same shall apply hereinafter unless otherwise specified) are also referred to as polarizing plates, and are usually a polarizing element and at least one surface of the polarizing element (the same applies hereinafter). It may include a transparent protective film arranged on both sides). The polarizer is not particularly limited, and for example, a hydrophilic polymer film in which a dichroic substance such as iodine or a dichroic dye is adsorbed and uniaxially stretched is used. Examples of the hydrophilic polymer film include polyvinyl alcohol (PVA) film, partially formalized PVA film, ethylene/vinyl acetate copolymer partially saponified film and the like. As the polarizer, a polyene-based alignment film such as a dehydrated product of PVA or a dehydrochlorinated product of polyvinyl chloride can also be used. Of these, a polarizer made of a PVA-based film and a dichroic substance such as iodine is preferable.

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

As a material constituting the transparent protective film, for example, a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture blocking property, isotropic property, etc. is preferably used. Specific examples of such a thermoplastic resin include cellulose resins such as triacetyl cellulose (TAC), polyester resins, polyether sulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylics. Examples thereof include resins, cycloolefin resins (typically norbornene resins), polyarylate resins, polystyrene resins, PVA resins, and mixtures of two or more thereof. In a preferred embodiment, a transparent protective film made of a thermoplastic resin such as TAC is arranged on one surface of the polarizer, and a cycloolefin resin (typically norbornene resin) or ( A configuration in which a transparent protective film made of a (meth)acrylic resin is arranged can be adopted. In another preferred embodiment, a transparent protective film made of a thermoplastic resin such as TAC is arranged on one surface of the polarizer, and a (meth)acrylic-based, urethane-based, acrylic-based acrylic resin is used on the other surface as a transparent protective film. A urethane-based, epoxy-based, silicone-based, or other thermosetting resin or an ultraviolet curable resin can be used. These transparent protective films can be laminated on the polarizer via an adhesive such as PVA. The transparent protective film may contain one or more kinds of any appropriate additive depending on the purpose.

The adhesive used for laminating the polarizer and the transparent protective film is not particularly limited as long as it is optically transparent, and various types of water-based, solvent-based, hot-melt-based, radical-curable and cation-curable types are used. be able to. Of these, water-based adhesives or radical curable adhesives are preferable.

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

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

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

When the technique disclosed here is carried out in a manner including a surface treatment layer, the surface treatment layer can be provided with a conductive agent to impart conductivity. As the conductive agent, a conductive agent or a conductive component described below can be used without particular limitation. Therefore, the surface treatment layer can be the conductive layer disclosed herein. Incidentally, when the surface treatment 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 treatment layer may be arranged between the polarizing film and the conductive layer. A conductive layer may be provided between the layers.

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

<Conductive layer>
The conductive layer disclosed here is a layer that is arranged on the visual side of the touch sensor unit to increase the conductivity on the visual side of the liquid crystal display device and prevent the occurrence of electrostatic unevenness. The conductive layer may be formed from a conductive composition containing various conductive agents such as organic or inorganic conductive substances. In the embodiment in which the pressure-sensitive adhesive layer is arranged on the conductive layer, it may function as an anchor layer that enhances the adhesion between the pressure-sensitive adhesive layer and the polarizing film.

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

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 and chromium. , Titanium, iron, cobalt, copper iodide, ITO (indium oxide/tin oxide), ATO (antimony oxide/tin oxide) and the like. As such an inorganic conductive substance, one type may be used alone, or two or more types may be used in combination.

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

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

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

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

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

Examples of commercial products of the above polythiophene aqueous solution include the product name “Denatron” manufactured by Nagase Chemtech and the product name “Clevios” manufactured by Heraeus. Further, as a commercial product of the polyaniline sulfonic acid aqueous solution, a product name “aqua-PASS” manufactured by Mitsubishi Rayon Co., Ltd. is exemplified.

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

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

(High boiling point compound)
The conductive layer disclosed herein may typically be formed from a conductive composition comprising a high boiling point compound having a boiling point of 180 ° C. or higher. The conductive layer formed using the high boiling point compound exhibits improved wet heat conductive stability. The liquid crystal display device constructed with the conductive layer can maintain stable touch sensor sensitivity while preventing the occurrence of static electricity unevenness even when exposed to a moist heat environment. The high-boiling compounds can be used alone or in combination of two or more. The high boiling point compound may not remain due to volatilization when the conductive layer is formed, but the formed conductive layer preferably satisfies the moist heat surface resistance change ratio and the moist heat surface resistance reduction rate, and the moist heat conductivity change ratio _FHT is preferable. Can be satisfied. The high boiling point compound is a compound having a boiling point of 180° C. or higher, and is a solid or liquid at room temperature (23° C.). As the high boiling point compound that is solid at room temperature, it is preferable to use a compound that is easily dissolved in the solvent (for example, water) of the conductive composition described later. Such a high-boiling compound may have a solubility in, for example, 100 mL of a solvent (eg, water) at room temperature of about 1 g or more (typically about 3 g or more, for example, about 10 g or more, further about 20 g or more). Further, from the viewpoint of forming the conductive layer, the high boiling point compound is preferably a compound which is liquid at a temperature of 20 to 50° C. (and thus has a melting point of 20° C. or less). Such compounds are also referred to as high boiling point solvents. The term "solvent" as used herein refers to a liquid medium contained in the conductive composition. For convenience, the term "solvent" is a concept that includes the solvent and the dispersion medium.

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

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

In some embodiments, the boiling point of the high boiling point compound contained in the conductive composition is preferably about 200 ° C. or higher, more preferably about 210 ° C. or higher, still more preferably about 220 ° C. or higher from the viewpoint of wet-heat conductive stability. Particularly preferably, it is about 230°C or higher (for example, about 240°C or higher). The upper limit of the boiling point of the high boiling point compound is appropriately set in consideration of the film forming property of the conductive layer, the drying efficiency, etc., and is not limited to a specific range. The boiling point of the high boiling point compound is usually about 400° C. or lower, and about 320° C. or lower is appropriate, and adhesion with a layer adjacent to the conductive layer (eg, adhesive layer, first polarizing film, first transparent substrate) From the viewpoint of properties, it is preferably about 300 ° C. or lower (for example, about 290 ° C. or lower), more preferably about 280 ° C. or lower, still more preferably about 260 ° C. or lower, and particularly preferably about 250 ° C. or lower.

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

Although not particularly limited, a compound having a hydroxyl group is preferably 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 when added to an aqueous solvent, for example, can take a good volatile behavior that brings about improvement in wet heat conductivity stability. In some preferred embodiments, the high boiling point compound contains 2 or more hydroxyl groups, for example 3 or more. Further, for example, those containing an ether structure can be preferably used.

The content of the high boiling point compound in the conductive composition disclosed herein is appropriately set so as to achieve the target wet heat conductive stability, and thus the wet heat durability of the liquid crystal display device, and is not limited to a specific range. The content of the high boiling point compound in the conductive composition is preferably about 0.1% by weight or more, preferably about 0.5% by weight or more, from the viewpoint of obtaining the effect of improving the moist heat conductivity stability. It is preferably about 1% by weight or more, more preferably about 2% by weight or more, and may be about 5% by weight or more (for example, about 8% by weight or more). Further, the upper limit of the content of the high boiling point compound in the conductive composition can be, for example, about 50% by weight or less, and about 30% by weight or less (for example, about 25% by weight or less) is suitable for the conductive layer. From the viewpoint of adhesion to an adjacent layer (for example, an adhesive layer, a first polarizing film, a first transparent substrate), it is preferably about 15% by weight or less, more preferably about 10% by weight or less, still more preferably about 7% by weight. % Or less, particularly preferably about 5% by weight or less (typically 4% by weight or less).

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

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

(Binder)
In some embodiments, the conductive layer comprises a binder. When the conductive layer contains a binder, the film-forming property of the conductive layer is improved, and the adhesion to a layer adjacent to the conductive layer (for example, an adhesive layer, a first polarizing film, a first transparent substrate) is improved. The binder is not particularly limited, and includes oxazoline group-containing polymers, urethane-based polymers, acrylic-based polymers, polyester-based polymers, polyether-based polymers, cellulose-based polymers, vinyl alcohol-based polymers, epoxy group-containing polymers, and vinylpyrrolidone-based polymers. One or more of styrene polymers, polyethylene glycol, pentaerythritol and the like may be used. Suitable examples include oxazoline group-containing polymers and urethane-based polymers (typically polyurethane).

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

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

In some embodiments, a urethane polymer is used as the binder. The use of the urethane polymer tends to improve the adhesiveness with the layer adjacent to the conductive layer (for example, the pressure-sensitive adhesive layer, the first polarizing film, the first transparent substrate). Examples of urethane-based polymers include polyurethanes such as ether-based polyurethanes, ester-based polyurethanes and carbonate-based polyurethanes; urethane (meth)acrylates and acryl-urethane copolymers in which alkyl (meth)acrylates are copolymerized. The urethane polymer may be used alone or in combination of two or more. In some embodiments, it is preferable to use the oxazoline group-containing polymer and the urethane-based polymer in combination as the binder.

The content of the binder in the conductive layer is not particularly limited, and for example, it is suitable that it is about 3% by weight or more. From the viewpoint of adhesion and the like, 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. It may be about 70% by weight or more (for example, about 80% by weight or more). The upper limit of the binder content is usually about 99% by weight or less, and about 95% by weight or less is appropriate in consideration of the action of other components such as a conductive polymer, for example, about 90% by weight or less ( For example, about 80% by weight or less).

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

(Method of forming conductive layer)
The conductive layer is preferably prepared by a method including applying to the polarizing film a liquid conductive composition in which the conductive agent or the high boiling point compound, and the additives used as necessary are dispersed or dissolved in a suitable solvent. Can be formed. For example, a method of applying the above-mentioned conductive composition to one surface of a polarizing film, drying it, and performing a curing treatment (heat treatment, ultraviolet treatment, etc.) as necessary can be preferably adopted. Alternatively, in the embodiment in which the conductive layer is formed on the outer surface of the first transparent substrate, the conductive composition is subjected to a roll coating method, a bar coating method, a dip coating method, a spin coating method, a casting method, a die coating method, or a gravure coating method. , Spray coating method, spray printing method, screen printing method, inkjet printing method, offset printing method, etc. are applied to the surface of the first transparent substrate, and if necessary, dried and cured to form a conductive layer. can do. The solid content concentration (NV) of the conductive composition can be, for example, 5% by weight or less (typically 0.05 to 5% by weight), and is usually 3% by weight or less (typically 0%). 10 to 3% by weight) is suitable. When forming a thin conductive layer, the NV of the conductive composition is preferably 0.05 to 0.50 wt% (eg 0.10 to 0.30 wt%). By using such a low NV conductive composition, a more uniform conductive layer can be formed.

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

(Wet heat surface resistance change ratio)
The conductive layer disclosed herein has, in some embodiments, the surface resistance value S [Ω/□] of the conductive layer after a heat and humidity test performed at a temperature of 85° C., a relative humidity of 85%, and a condition of 24 hours. It is characterized in that the ratio with respect to the surface resistance value P [Ω/□] of the conductive layer before the wet heat test (wet heat surface resistance change ratio S/P) satisfies the condition: 0.05≦S/P≦10. Can be. The conductive layer satisfying the moist heat surface resistance change ratio S / P exhibits improved moist heat conductive stability, and can exhibit good touch sensor sensitivity stability even when exposed to a moist heat 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 further preferably about 0.8 or more (for example, about 1 or more). The above S/P is preferably about 3 or less, more preferably about 1.5 or less, further 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 Examples below. The liquid crystal display device with a built-in touch sensing function disclosed in the present specification includes a mode in which the wet heat surface resistance change ratio S/P is not limited. It is not limited to those having the above characteristics.

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

(Wet heat conductivity change ratio F _HT )
Conductive layer disclosed herein, in some embodiments, is characterized in that moist heat conductive variation ratio is expressed by the following equation _{(1) F HT (Hygro-} thermal factor) is 2 or less obtain.
F _HT =ΔC(B)/ΔC(A) (1)
In the above formula (1), ΔC(B) is the current of the touch panel that flows when the conductive layer after the heat and humidity test performed under the conditions of the temperature of 85° C., the relative humidity of 85% and the 24 hours is placed on the touch panel for evaluation. It is the difference between the value and the touch panel base current value, and ΔC (A) is the difference between the touch panel current value and the touch panel base current value that flow when the conductive layer before the wet heat test is arranged on the evaluation touch panel. .. A conductive layer that satisfies this property maintains stable conductivity even when exposed to a moist heat environment, while maintaining stable touch sensor sensitivity while preventing the occurrence of static electricity unevenness. It is possible to prevent malfunction. From such a viewpoint, the _FHT is preferably about 1.7 or less, more preferably about 1.5 or less, still more preferably about 1.3 or less, and particularly preferably about 1.1 or less (for example, 1.0). Below). Since the technique disclosed herein may relate to suppressing a decrease in surface resistance (increase in conductivity) when exposed to a moist heat environment, the decrease in conductivity (that is, a decrease in _FHT ) after a moist heat test is not particularly limited. However, the _FHT is usually about 0.1 or more (for example, about 0.3 or more), about 0.5 or more is appropriate, preferably about 0.6 or more, and more preferably about 0.7. The above is more preferably about 0.8 or more, and particularly preferably about 0.9 or more (typically 0.95 or more, for example, 0.99 or more). The _FHT is measured by the method described in Examples described later. Incidentally, the touch sensing function-equipped liquid crystal display device disclosed herein encompasses the unrestricted mode of the above wet heat conductive variation ratio F _HT, in such embodiments, the touch sensing function-equipped liquid crystal display device described above It is not limited to those having characteristics.

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

<Adhesive layer>
The liquid crystal display device with a built-in touch sensing function disclosed herein includes a pressure-sensitive adhesive layer (including first and second pressure-sensitive adhesive layers, for the purpose of fixing the first polarizing film to the liquid crystal cell and the like. The same shall apply hereinafter). The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is, for example, one selected from various pressure-sensitive adhesives such as acrylic, rubber, urethane, silicone, vinylalkyl ether, vinylpyrrolidone, acrylamide, and cellulose. It may be an adhesive layer composed of two or more kinds. 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 cellulosic polymer or the like. Among them, acrylic adhesives are preferable from the viewpoints of transparency, appropriate wettability, adhesive properties such as cohesiveness and adhesiveness, weather resistance, heat resistance and the like. Hereinafter, the techniques disclosed herein will be described in more detail by taking the configuration in which the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer as a main example, but the intention is to limit the pressure-sensitive adhesive layer to one made of an acrylic pressure-sensitive adhesive. is not.

(Acrylic adhesive)
The acrylic pressure-sensitive adhesive used in some preferred embodiments means an acrylic polymer as a base polymer (a main component among polymer components contained in the pressure-sensitive adhesive, that is, a component contained in an amount of more than 50% by weight). Refers to an adhesive. Further, the "acrylic polymer" means a monomer having at least one (meth)acryloyl group in one molecule (hereinafter, this may be referred to as "acrylic monomer") as a main constituent monomer component (monomer). Of 50% by weight or more of the total amount of the monomers constituting the acrylic polymer). The above-mentioned "(meth) acryloyl group" has a meaning that comprehensively refers to an acryloyl group and a methacryloyl group. Similarly, the term “(meth)acrylate” is meant to mean acrylate and methacrylate inclusively.

(Acrylic polymer)
The acrylic polymer, which is the base polymer of the acrylic pressure-sensitive adhesive, is typically a polymer containing an alkyl (meth) acrylate as a main constituent monomer component. As the alkyl (meth)acrylate, for example, a compound represented by the following formula (1) can be preferably used.
CH ₂ = C (R ¹ ) COOR ² (1)
Here, R ¹ in the above formula (1) is a hydrogen atom or a methyl group. R ² is an alkyl group having 1 to 20 carbon atoms (meaning to include a chain alkyl group and an alicyclic alkyl group). Excellent since the adhesive can be easily obtained on the adhesive characteristics, R ² is 1 to 18 carbon atoms (hereinafter sometimes representing such number range of carbon atoms and C _1-18.) A chain alkyl An alkyl(meth)acrylate which is a group (meaning to include a linear alkyl group and a branched alkyl group) is preferable, and an alkyl(meth)acrylate having a C _1-14 chain alkyl group is more preferable. Specific examples of the chain alkyl group of C _1-14 include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-pentyl group, and the like. Isoamyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, isooctyl group, 2-ethylhexyl group, n-nonyl group, isononyl group, n-decyl group, isodecyl group, n-undecyl group, Examples thereof include n-dodecyl group, n-tridecyl group and n-tetradecyl group. Examples of the alicyclic alkyl group that can be selected as R ² include a cyclohexyl group and an isobornyl group.

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

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

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

As the acrylic polymer in the technology disclosed herein, those obtained by copolymerizing a functional group-containing monomer can be preferably used. Preferable examples of the functional group-containing monomer include a carboxy group-containing monomer, an acid anhydride group-containing monomer, and a hydroxyl group-containing monomer. These may be used alone or in combination of two or more. The functional group-containing monomer can serve as a cross-linking point in the pressure-sensitive adhesive layer, and can improve the cohesive force and heat resistance of the pressure-sensitive adhesive. In addition, the adhesion between the conductive layer and the pressure-sensitive adhesive layer can be improved. By using an appropriate amount of the functional group-containing monomer, it is also possible to adjust the glass transition temperature (Tg) of the acrylic polymer and adjust the adhesive properties.

Examples of the carboxy group-containing monomer include ethylenically unsaturated monocarboxylic acids such as acrylic acid (AA), methacrylic acid (MAA), carboxyethyl (meth) acrylate, and carboxypentyl (meth) acrylate; itaconic acid, maleic acid, and fumaric acid. , Ethylenically unsaturated dicarboxylic acids such as crotonic acid, isocrotonic acid and citraconic acid;
Examples of the acid anhydride group-containing monomer include acid anhydrides such as maleic anhydride, itaconic anhydride, and the above ethylenically unsaturated dicarboxylic acid.
As the hydroxyl group-containing monomer, 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, (4) Hydroxyalkyl (meth)acrylates such as -hydroxymethylcyclohexyl)methyl (meth)acrylate; alkylene glycol (meth)acrylates such as polyethylene glycol mono (meth)acrylate and polypropylene glycol mono (meth)acrylate; vinyl alcohol, Unsaturated alcohols such as allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether; and the like.
These functional group-containing monomers may be used alone or in combination of two or more.

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

Amide group-containing monomers: For example, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, N- Methoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide.
Amino group-containing monomer: For example, aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, t-butylaminoethyl (meth) acrylate.
Monomers having a nitrogen atom-containing ring: for example, N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazin, N-vinyl. Pyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholin, N-vinylcaprolactam, N- (meth) acryloylmorpholine, N- (meth) acryloylpyrrolidone.
Among the monomers having a nitrogen atom-containing ring, for example, N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylcaprolactum, N- (meth) acryloylmorpholin, N- (meth) acryloylpyrrolidone, etc. Needless to say, there are also amide group-containing monomers. 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, and about 30% by weight, of the total amount of the monomers used for synthesizing the base polymer (typically an acrylic polymer). The following is appropriate, and from the viewpoint of adhesive properties and the like, it is preferably about 20% by weight or less, more preferably about 15% by weight or less, still more preferably 10% by weight or less (for example, 5% by weight or less). The lower limit of the content of the functional group-containing monomer in the total amount of monomers used for the synthesis of the base polymer is usually about 0.001% by weight or more, and about 0.01% by weight or more is suitable. From the viewpoint of preferably exerting the effect of the monomer copolymerization, it is preferably about 0.1% by weight or more, more preferably about 0.5% by weight or more, still more preferably about 1% by weight or more.

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

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

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

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

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

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

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

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

Base polymer (acrylic polymer) in the art disclosed herein may suitably be GPC weight average molecular weight in terms of standard polystyrene obtained by (Gel Permeation Chromatography) (Mw) is at approximately 10 × 10 ⁴ or more From the viewpoint of durability, heat resistance, etc., preferably about 50×10 ⁴ or more, more preferably about 80×10 ⁴ or more, and further preferably about 120×10 ⁴ or more (for example, about 150×10 ⁴ or more). Is. Further, the Mw is suitably about 500×10 ⁴ or less, and from the viewpoint of coatability at the time of forming the pressure-sensitive adhesive layer, preferably about 300×10 ⁴ or less, more preferably about 250×10 ⁴ or less, more preferably about 200 × 10 ⁴ or less.

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

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

(Alkali metal salt)
As the alkali metal salt, organic salts and inorganic salts of alkali metals can be used. Examples of the alkali metal ion forming the cation part of the alkali metal salt include lithium, sodium and potassium ions. Among these alkali metal ions, lithium ion is preferable.

The anion part of the alkali metal salt may be composed of an organic material or an inorganic material. Examples of the anion portion constituting the organic salt include CH ₃ COO ⁻ , CF ₃ COO ⁻ , CH ₃ SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , C ₄ F ₉ SO ₃ ^{_{_{^{-, C 3 F 7 COO -}}}} , (CF 3 SO 2) (CF 3 CO) N -, (FSO 2) 2 N -, - O 3 S (CF 2) 3 SO 3 -, PF 6 -, CO 3 ^2- and the following general formulas (1) to (4):
(1) (C _n F _2n+1 SO ₂ ) ₂ N ⁻ (where n is an integer of 1 to 10);
(2) CF ₂ (C _m F _2m SO ₂ ) ₂ N ⁻ (where m is an integer of 1 to 10);
^{_{_{(3) - O 3 S (}}} CF 2) l SO 3 - ( provided that, l is an integer of 1 to 10);
(4) (C _p F _{2p + 1} SO ₂ ) N ⁻ (C _q F _{2q + 1} SO ₂ ) (where p and q are integers of 1 to 10); An ionic compound whose anion part contains a fluorine atom is preferably used because it has a good ionic dissociation property. The anionic portion of the ^{^{^{_{^{inorganic, Cl -, Br -, I}}}}} -, AlCl 4 -, Al 2 Cl 7 -, BF 4 -, PF 6 -, ClO 4 -, NO 3 -, AsF 6 -, SbF 6 -, NbF ₆ ⁻ , TaF ₆ ⁻ , (CN) ₂ N ^{− and the} like are used. As the anion portion, (perfluoroalkylsulfonyl) imides such as (CF ₃ SO ₂ ) ₂ N ⁻ and (C ₂ F ₅ SO ₂ ) ₂ N ⁻ are preferable, and are represented by (CF ₃ SO ₂ ) ₂ N ^−. (Trifluoromethanesulfonyl) imide is particularly preferred.

Specific examples of the organic salt of an alkali metal include sodium acetate, sodium alginate, sodium ligninsulfonate, sodium toluenesulfonate, LiCF ₃ SO ₃ , Li(CF ₃ SO ₂ ) ₂ N, Li(CF ₃ SO ₂ _{_{_{_{) 2 N, Li (C 2}}}} F 5 SO 2) 2 N, Li (C 4 F 9 SO 2) 2 N, Li (CF 3 SO 2) 3 C, KO 3 S (CF 2) 3 SO 3 K, _{_{_{LiO 3 S (CF 2) 3}}} SO 3 K , and the like. Among _{_{_{_{them, LiCF 3 SO 3, Li (}}}} CF 3 SO 2) 2 N, Li (C 2 F 5 SO 2) 2 N, Li (C 4 F 9 SO 2) 2 N, Li (CF 3 SO 2) 3 C and the like are preferable, and fluorine-containing lithium imide salts such as Li(CF ₃ SO ₂ ) ₂ N, Li(C ₂ F ₅ SO ₂ ) ₂ N and Li(C ₄ F ₉ SO ₂ ) ₂ N are more preferable, and Perfluoroalkylsulfonyl)imide lithium salts are particularly preferred.
Examples of the inorganic salt of the alkali metal include lithium perchlorate and lithium iodide.
The said alkali metal salt may be used individually by 1 type, and may be used in combination of 2 or more type.

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

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

Examples of the anion component of the organic cation-anion salt include Cl ⁻ , Br ⁻ , I ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , NO ₃ ⁻ , CH ₃ ^{_{^{_{COO -, CF 3 COO -,}}}} CH 3 SO 3 -, CF 3 SO 3 -, (CF 3 SO 2) 3 C -, AsF 6 -, SbF 6 -, NbF 6 -, TaF 6 -, (CN) 2 ^{_{_{_{N -, C 4 F 9 SO}}}} 3 -, C 3 F 7 COO -, (CF 3 SO 2) (CF 3 CO) N -, (FSO 2) 2 N -, - O 3 S (CF 2) 3 SO ₃ ^- or the following general formulas (1) to (4):
(1) (C _n F _2n+1 SO ₂ ) ₂ N ⁻ (where n is an integer of 1 to 10);
(2) CF ₂ (C _m F _2m SO ₂ ) ₂ N ⁻ (where m is an integer of 1 to 10);
^{_{_{(3) - O 3 S (}}} CF 2) l SO 3 - ( provided that, l is an integer of 1 to 10);
(4) (C _p F _{2p + 1} SO ₂ ) N ⁻ (C _q F _{2q + 1} SO ₂ ) (where p and q are integers of 1 to 10); An ionic compound whose anion component contains a fluorine atom is preferably used because it has a good ionic dissociation property. The number of carbon atoms of the perfluoroalkyl group contained in the anion component is preferably 1 to 3, more preferably 1 or 2. These ionic compounds may be used alone or in combination of two or more.

(Other ionic compounds)
Further, as the ionic compound, in addition to the above-mentioned alkali metal salt and organic cation-anionic salt, inorganic salts such as ammonium chloride, aluminum chloride, copper chloride, ferric chloride, ferric chloride and ammonium sulfate can also be used. it can. The ionic compounds disclosed herein also include those generally referred to as ionic surfactants. As the ionic surfactant, a cationic surfactant having a cationic functional group such as quaternary ammonium salt, phosphonium salt, sulfonium salt, pyridinium salt and amino group; carboxylic acid, sulfonate, sulfate, phosphate, phosphite, etc. An anionic surfactant having an anionic functional group; a zwitterionic surfactant such as sulfobetaine and its derivatives, alkylbetaine and its derivatives, imidazoline and its derivatives, alkylimidazolium betaine and its derivatives; and the like. .. The organic cation-anion salt may be used alone or in combination of two or more.

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

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

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

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

(Adhesive composition)
In the technology disclosed herein, the form of the pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer is not particularly limited. For example, a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive component in an organic solvent (solvent-type pressure-sensitive adhesive composition), a pressure-sensitive adhesive composition in which a pressure-sensitive adhesive component is dispersed in an aqueous solvent (water-dispersed pressure-sensitive adhesive composition, typically Is an aqueous emulsion-type pressure-sensitive adhesive composition), a solventless pressure-sensitive adhesive composition (for example, a pressure-sensitive adhesive composition that is cured by irradiation with active energy rays such as ultraviolet rays and electron beams, hot-melt pressure-sensitive adhesive composition). Object) etc. The technique disclosed here can be preferably implemented in an aspect including a pressure-sensitive adhesive layer formed from a solvent-based pressure-sensitive adhesive composition. The organic solvent contained in the solvent-type pressure-sensitive adhesive composition may be, for example, a single solvent consisting of any one of toluene, xylene, ethyl acetate, hexane, cyclohexane, methylcyclohexane, heptane and isopropyl alcohol, and any of these. It may be a mixed solvent containing as a main component.

In the technique disclosed herein, the pressure-sensitive adhesive composition (preferably a solvent-type pressure-sensitive adhesive composition) used for forming the pressure-sensitive adhesive layer is a base polymer (typically an acrylic polymer) contained in the composition. It is possible to preferably employ those configured so that (1) can be appropriately crosslinked. As a specific cross-linking means, a cross-linking base point is introduced into the base polymer by copolymerizing a monomer having an appropriate functional group (hydroxyl group, carboxy group, etc.) and reacts with the functional group to form a cross-linked structure. A method of adding a compound (crosslinking agent) capable of reacting to the base polymer to cause a reaction can be preferably adopted.

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

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

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

(Method of forming the adhesive layer)
The pressure-sensitive adhesive layer is formed, for example, by directly applying the pressure-sensitive adhesive composition as described above to the polarizing film, or by applying it on the conductive layer provided on the polarizing film and then drying or curing it (direct method). can do. Alternatively, the pressure-sensitive adhesive composition is 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 is attached to a polarizing film, or It may be formed by a method of transferring the pressure-sensitive adhesive layer by bonding it to the surface of the conductive layer provided on the polarizing film (transfer method). In applying (typically applying) the pressure-sensitive adhesive composition, various methods such as a roll coating method and a gravure coating method can be appropriately adopted. The pressure-sensitive adhesive composition can be dried under heating if necessary. As a means for curing the pressure-sensitive adhesive composition, ultraviolet rays, laser rays, α rays, β rays, γ rays, X rays, electron rays and the like can be appropriately adopted.

(Surface resistance value of adhesive layer)
The surface resistance value of the adhesive layer is not particularly limited. In some preferred embodiments, the pressure-sensitive adhesive layer is configured to have conductivity in addition to the conductive layer, so that higher conductivity can be imparted to the visual side of the liquid crystal display device. In such an embodiment, the surface resistance value of the pressure-sensitive adhesive layer is appropriately about 1×10 ¹² Ω/□ or less from the viewpoint of antistatic properties. When the pressure-sensitive adhesive layer whose surface resistance value is limited to a predetermined value or less is applied to a liquid crystal panel (for example, in-cell type liquid crystal panel) application, static electricity unevenness is preferably prevented due to its conductivity. Further, from the viewpoint of touch sensor sensitivity and durability, the lower limit of the surface resistance value is preferably about 1×10 ⁷ Ω/□ or more. From the above viewpoint, for example, when applied to the on-cell type liquid crystal cell described later, the surface resistance value is preferably about 1 × 10 ¹⁰ Ω / □ to 1 × 10 ¹² Ω / □. When applied to a semi-in-cell type liquid crystal cell described later, the surface resistance value is preferably about 1×10 ⁹ Ω/□ to 1×10 ¹² Ω/□. Further, when applied to an in-cell type liquid crystal cell described later, the surface resistance value is preferably about 1 × 10 ⁷ Ω / □ to 1 × 10 ¹² Ω / □, and from the viewpoint of durability, it is about. It is more preferably 1×10 ⁸ Ω/□ to 1×10 ¹⁰ Ω/□. The surface resistance value of the pressure-sensitive adhesive layer is measured by the method described in Examples below.

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

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

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

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

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

The material forming the transparent substrate (including the first and second transparent substrates) includes, for example, glass or polymer film. Therefore, the transparent substrate can be a glass substrate or a polymer substrate. The glass used for the transparent substrate is not particularly limited, and various glass materials can be used. Examples of the polymer film include polyethylene terephthalate (PET), polycycloolefin, polycarbonate and the like. When the transparent substrate is mainly formed of a glass plate, its thickness is, for example, about 0.1 mm to 1 mm. When the transparent substrate is mainly formed of a polymer film, its thickness is, for example, about 10 μm to 200 μm. The transparent substrate may have an easy adhesion layer or a hard coat layer on its surface.

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

In the liquid crystal panel, as the optical film of the pressure-sensitive adhesive layer-attached optical film arranged on the side opposite to the viewing side, a polarizing film or a known or common optical film different from the polarizing film is used depending on the application or purpose. be able to. Examples of such an optical film include a retardation film (also referred to as a retardation plate, including a wavelength plate), an optical compensation film, a brightness enhancement film, a light diffusion film, a reflection film, an anti-transmission film and the like. They can be used alone or in combination of two or more.

<Use>
The application of the liquid crystal display device with a built-in touch sensing function (also referred to as a touch panel type liquid crystal display device) disclosed herein is not particularly limited, and can be used for various purposes such as for portable electronic devices and for vehicles. The technology disclosed herein may be particularly suitable for a vehicle-mounted touch panel type liquid crystal display device that is easily exposed to a harsh environment and is required to have a wet heat durability higher than a predetermined level. By applying the techniques disclosed herein to the above applications, excellent durability can be obtained based on the improved wet and heat conductive stability and the like.

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

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

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

[Moist heat conductivity change ratio _FHT ]
(1) Preliminary evaluation (correlation with surface resistance value)
Five samples of the polarizing film with a conductive layer having different surface resistance values were prepared, and each polarizing film sample with a conductive layer was set in a touch panel evaluation kit (Product name “TouchKit” manufactured by Shurter). This evaluation kit has a PCAP (projection capacitive type) touch panel on which a cover glass is laminated, an IC (integrated circuit) substrate, and software, and the current value of the touch panel is connected to the touch panel. It is possible to record and process with the above software from the terminal through the IC substrate. Specifically, as shown in FIG. 10, the polarizing film sample with a conductive layer is set on the cover glass 304 of the touch panel 302 of the evaluation kit 300, and the surface of the pressure-sensitive adhesive layer of the polarizing film sample S with a conductive layer. Was attached so as not to cause floating. The touch panel 302 is horizontally placed on an insulator (not shown). As the insulator, for example, a plate-shaped resin or a frame-shaped rubber body can be used. Then, the software activated on the PC acquires the capacitance data map in the plane of the touch panel 302 through the terminal T and the IC substrate, and the obtained current value of the touch panel and the touch panel base current value without the polarizing film sample S with the conductive layer. The difference (Cooked Data) of was obtained as ΔC. In this measurement, Cooked Data (Max-Min) calculated from the maximum and minimum values of the difference (Cooked Data) between multiple measured values measured at multiple points on the touch panel surface and the base current value is used as ΔC. doing. FIG. 11 is a graph in which the ΔC (Cooked Data (Max-Min)) measured above is plotted on the vertical axis and the surface resistance value [Ω/□] of the conductive layer is plotted on the horizontal axis. As shown in FIG. 11, since the correlation coefficient R ^{2 of the} regression line between the ΔC and the surface resistance value [Ω/□] showed a high correlation of 0.9701, the ΔC was the same as that of the conductive layer. It can be seen that it can be used as an index of conductivity and change in conductivity. Since the above-mentioned ΔC is a value that has been digitally (8-bit) converted by the software, the unit is bit. The same applies to ΔC(A), ΔC(B) and the wet heat conductivity change ratio F _HT described later.
In the measurement of ΔC(A) and ΔC(B) described later, when the polarizing film sample with a conductive layer is set in the evaluation kit, no floating occurs between the polarizing film sample with a conductive layer and the cover glass 304. As described above, a plurality of insulating sheets (for example, polystyrene sheets) may be superposed on the upper surface (back surface) of the conductive layer-attached polarizing film sample as a weight. Further, when the measurement of ΔC (A) and ΔC (B) described later is carried out by directly setting the conductive layer (for example, a sample in which the conductive layer is formed on the PET film of the insulator) in the evaluation kit, the conductivity is concerned. Place the layer surface so as to contact the cover glass of the evaluation kit, and then place a plurality of insulating sheets (for example, a touch panel) as a weight on the conductive layer so that the conductive layer and the cover glass do not float. 20 sheets of polystyrene sheets (about 10 to 20 g each) having the same size as the above can be superposed, and the measurement can be performed in the same manner as above for the others.
Even when the F _HT of the conductive layer is measured by the evaluation kit through the pressure-sensitive adhesive layer using the polarizing film with the conductive layer as described above, the conductive layer is directly contacted with the cover glass and the F of the conductive layer is measured by the evaluation kit. _{Even when HT} is measured, F _HT takes a value that is almost the same and does not change significantly.
(2) ΔC (A)
The polarizing film with a conductive layer used for manufacturing a liquid crystal display device is set in the evaluation kit 300 by the same method as in (1) above, and from the acquired capacitance data map in the touch panel surface, when the polarizing film with a conductive layer is set. The difference ΔC (Cooked Data) between the touch panel current value and the touch panel base current value is obtained. This is defined as the difference ΔC (A) between the current value of the touch panel and the touch panel base current value that flows when the conductive layer before the moist heat test is arranged on the evaluation touch panel. As described above, ΔC(A) can be measured by directly using the conductive layer instead of the polarizing film with the conductive layer.
(3) ΔC (B)
Further, the polarizing film with a conductive layer used for manufacturing a liquid crystal display device is left for 24 hours in a moist heat environment at a temperature of 85 ° C. and 85% RH (wet heat test). Then, about the thing dried at room temperature for 3 hours, it set to the evaluation kit 300 by the method similar to said (1), and from the acquired capacity data map of the touch panel surface, the current of the touch panel at the time of setting the polarizing film with a conductive layer was set. The difference ΔC (Cooked Data) between the value and the base current value of the touch panel is obtained. This is defined as the difference ΔC (B) between the current value of the touch panel and the touch panel base current value that flows when the conductive layer after the moist heat test is arranged on the evaluation touch panel. As described above, ΔC(B) can be measured by directly using the conductive layer instead of the polarizing film with the conductive layer.
(4) moist heat conductive variation ratio _{F HT} calculated following equation (1), to calculate the wet heat conductivity variation ratio _{F HT.}
F _HT =ΔC(B)/ΔC(A) (1)

[Evaluation of touch sensitivity stability]
Based on the wet heat conductive variation ratio F _HT, it is evaluated according to the following criteria.
(Evaluation criteria)
⊚: F _HT ≦1.5
◯: 1.5<F _HT ≦2
X: 2<F _HT

[ESD (electrostatic discharge) test]
An in-cell type liquid crystal cell is prepared, the release liner is peeled off from the polarizing film with a conductive layer, and the exposed adhesive surface is bonded to the visible side of the in-cell type liquid crystal cell as shown in FIG. Next, a silver paste having a width of 5 mm was applied to the side surface of the polarizing film with a conductive layer attached to the in-cell liquid crystal cell so as to cover all the side surfaces of the hard coat layer, the polarizing film, the conductive layer, and the pressure-sensitive adhesive layer. A liquid crystal display panel is obtained by connecting to a ground electrode from the outside. Under the conditions of 23 ° C. and 55% RH, the liquid crystal display panel was set on the backlight device, and an electrostatic discharge gun (Electro-static Discharge Gun) was fired on the polarizing film surface on the visual side at an applied voltage of 10 kV. Measure the time until the white spot disappears due to electricity (initial evaluation). Further, the same ESD test is also carried out after the liquid crystal display panel is put into a moist heat environment at a temperature of 85 ° C. and 85% RH for 24 hours and then dried at room temperature for 3 hours (evaluation after moist heat). The obtained measurement results are evaluated according to the following criteria.
(Evaluation criteria)
⊚: White unevenness disappears within 3 seconds both in the initial stage and after moist heat. ○: White unevenness disappears within 5 seconds in either the initial stage or after moist heat. ×: Even if it exceeds 5 seconds in both the initial stage and after moist heat. White unevenness does not disappear.

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

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

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

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

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

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

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

(Preparation Example B6)
A conductive composition B6 according to this example was prepared in the same manner as in Preparation example B1 except that N-methylpyrrolidone (boiling point: about 204° C.) was used as the high-boiling compound instead of triethylene glycol.

(Preparation Example B7)
As the high boiling point compound, 5% of dimethyl sulfoxide (boiling point: about 189 ° C.) was used instead of 3% of triethylene glycol, and the amount of water was reduced by that amount, but the conductivity according to this example was the same as in Preparation Example B1. Composition B7 was prepared.

(Preparation Example B8)
A conductive composition B8 according to this example was prepared in the same manner as in Preparation Example B1 except that the high-boiling compound was not used.

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

(Preparation Example B10)
The conductive composition B10 according to this example was prepared in the same manner as in Preparation Example B1 except that diethylene glycol dimethyl ether (boiling point: about 162 ° C.) was used instead of triethylene glycol.

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

With respect to 100 parts of the solid content of the acrylic polymer P1 solution obtained above, 0.4 parts of an isocyanate crosslinking agent (manufactured by Tosoh Corporation, trade name "Coronate L", trimethylolpropane/tolylene diisocyanate adduct), Oxide crosslinking agent (Nippon Yushi Co., Ltd., trade name “Nyper BMT”) 0.1 part and γ-glycidoxypropylmethoxysilane (Shin-Etsu Chemical Co., Ltd. trade name “KBM-403”) 0.2 parts A solution of the acrylic pressure-sensitive adhesive composition C1 was prepared by blending.

(Preparation example C2)
6 parts of a conductive agent is added to 100 parts of the solid content of the acrylic polymer P1 solution, and an isocyanate-based cross-linking agent (manufactured by Toso Co., Ltd., trade name "Coronate L", trimethylolpropane / tolylene diisocyanate adduct) 0. .4 parts, peroxide cross-linking agent (manufactured by Nippon Oil & Fats Co., Ltd., trade name "Niper BMT") 0.1 parts and γ-glycidoxypropylmethoxysilane (manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name "KBM-403") A solution of the acrylic pressure-sensitive adhesive composition C2 was prepared by blending 0.2 parts. Bis(trifluoromethanesulfonyl)imide lithium (Li-TFSI) was used as the conductive agent.

<Examples 1 to 11 and Comparative Examples 1 to 3>
A coating liquid composed of any of the above conductive compositions B1 to B10 is applied to one side of the above polarizing film (the side on which the hard coat layer is not provided) so that the thickness after drying is 50 nm, and at 80 ° C. It was dried for 3 minutes to form a conductive layer.
A solution of any of the above acrylic pressure-sensitive adhesive compositions C1 to C2 was applied to one side of a polyethylene terephthalate (PET) film (release liner, manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., product number “MRF38”) treated with a silicone-based release agent. The film was applied so that the thickness of the pressure-sensitive adhesive layer after drying was 23 μm, and the film was dried at 155 ° C. for 1 minute to form a pressure-sensitive adhesive layer on the surface of the release liner. Then, the pressure-sensitive adhesive layer formed on the release liner was transferred onto the surface of the polarizing film obtained above on the conductive layer side. Thus, the polarizing film with a conductive layer according to each example was produced. These polarizing films with a conductive layer have a structure of polarizing film/conductive layer/adhesive layer, and a hard coat layer is provided on the back side of the polarizing film, and the adhesive surface of the adhesive layer is protected by a release liner. Has been done.

Next, an in-cell type liquid crystal cell was prepared, the release liner was peeled off from the polarizing film with a conductive layer according to each example, and the exposed adhesive surfaces were bonded to both sides of the in-cell type liquid crystal cell as shown in FIG. .. A liquid crystal display device with a built-in touch sensing function according to each example was produced by connecting a routing wiring (not shown) around the transparent electrode pattern inside the in-cell type liquid crystal cell to a controller IC (not shown).

Schematic configuration of the liquid crystal display device with built-in touch sensing function according to each example, surface resistance value [Ω / □] after initial and moist heat test, moist heat surface resistance change ratio, surface resistance value [Ω / □] of adhesive layer, and moist heat. Table 1 shows the conductivity change ratio _FHT (ΔC (B) / ΔC (A)), touch sensitivity stability, and ESD evaluation results. The N,N-dimethylformamide and diethylene glycol dimethyl ether used in Comparative Examples 2 and 3 are not high boiling point compounds, but are described in the item of 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° C. or higher was used for forming the conductive layer, the wet heat surface resistance change ratio of the conductive layer was within the range of 0.05 or more and 10 or less. The touch sensitivity stability evaluation results were all acceptable levels. In these examples, the wet-heat conductivity change ratio _FHT was also 2 or less. In Examples 1 to 5 and 8 to 11 using the high boiling point compounds having a boiling point of 210° C. 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, the evaluation results of ESD were also good in Examples 1 to 11, and particularly excellent results were obtained in Examples 8 to 11 in which the pressure-sensitive adhesive layer contained a conductive agent. In contrast, in Comparative Examples 1 to 3 in which the high boiling point compound having a boiling point of 180° C. or higher was not used, the wet heat surface resistance change ratio of the conductive layer was less than 0.05, and the touch sensitivity stability evaluation result was not good. there were. Moreover, in Comparative Examples 1 to 3, the wet heat conductivity change ratio F _HT also exceeded 2.
From the above results, in the liquid crystal display device with a built-in touch sensing function in which the conductive layer is arranged on the visual side of the touch sensor unit, the moist heat conductivity change ratio _FHT is 2 or less, and the moist heat surface resistance change of the conductive layer. According to the structure having the conductive layer formed by using the conductive polymer and the high boiling point compound having a boiling point of 180° C. or more, the ratio of which is 0.05 to 10, even when exposed to a humid heat environment. It can be seen that stable touch sensor sensitivity can be maintained while preventing the occurrence of static electricity unevenness.

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

1, 2, 3, 4, 5, 6, 7, 8, 9: Liquid crystal display device with a built-in touch sensing function 110: Polarizing film with a conductive layer 111: First polarizing film 112: First adhesive layer 113: Conductive layer 114 :

Surface treatment layer

101, 102, 103, 104, 105, 106, 107: In-cell type liquid crystal panel 201: Semi-in-cell type liquid crystal panel 202: On-cell type liquid crystal panel 120: Liquid crystal cell 125: Liquid crystal layer 130: Touch sensing electrode section (touch) Sensor part)
131: detection electrode 132: drive electrode 141: first transparent substrate 142: second transparent substrate 150: polarizing film with adhesive layer 151: second polarizing film 152: second adhesive layer 170: conductive structure 171: conductive structure 300 : Evaluation kit 302: Touch panel 304: Cover glass S: Polarizing film sample with conductive layer

Claims

With a liquid crystal layer containing liquid crystal molecules;
With the touch sensor section;
First and second polarizing films respectively disposed on both sides of the liquid crystal layer, and the first polarizing film is disposed on the viewing side of the liquid crystal layer and on the viewing side of the touch sensor unit. ;
A liquid crystal display device with a built-in touch sensing function, comprising:
here,
The conductive layer is arranged on the visual side of the touch sensor unit.
The conductive layer is wet heat conductive variation ratio F HT represented by the following formula (1) is 2 or less, a liquid crystal display device.
F HT =ΔC(B)/ΔC(A) (1)
(In the formula (1), ΔC(B) is the current of the touch panel that flows when the conductive layer after the heat and humidity test performed under the conditions of the temperature of 85° C., the relative humidity of 85% and the 24 hours is arranged on the touch panel for evaluation. It is the difference between the value and the touch panel base current value, and ΔC (A) is the difference between the touch panel current value and the touch panel base current value that flow when the conductive layer before the wet heat test is arranged on the evaluation touch panel. .)
With a liquid crystal layer containing liquid crystal molecules;
With the touch sensor section;
First and second polarizing films respectively disposed on both sides of the liquid crystal layer, and the first polarizing film is disposed on the viewing side of the liquid crystal layer and on the viewing side of the touch sensor unit. ;
A liquid crystal display device with a built-in touch sensing function, comprising:
here,
The conductive layer is arranged on the visual side of the touch sensor unit.
The conductive layer satisfies a wet heat surface resistance change ratio S/P satisfying a condition: 0.05≦S/P≦10, where S is a temperature of 85° C., a relative humidity of 85% and a condition of 24 hours. Is a surface resistance value [Ω/□] of the conductive layer after the wet heat test, and P is a surface resistance value [Ω/□] of the conductive layer before the wet heat test.
With a liquid crystal layer containing liquid crystal molecules;
With the touch sensor section;
First and second polarizing films respectively disposed on both sides of the liquid crystal layer, and the first polarizing film is disposed on the viewing side of the liquid crystal layer and on the viewing side of the touch sensor unit. ;
A liquid crystal display device with a built-in touch sensing function, comprising:
here,
The conductive layer is arranged on the visual side of the touch sensor unit.
A liquid crystal display device in which 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 ° C. or higher.
The conductive layer satisfies the condition: wet heat surface resistance change ratio S / P: 0.05 ≦ S / P ≦ 10, where S is carried out under the conditions of temperature 85 ° C., relative humidity 85% and 24 hours. The surface resistance value [Ω / □] of the conductive layer after the moist heat test, and P is the surface resistance value [Ω / □] of the conductive layer before the moist heat test, according to claim 1 or 3. Liquid crystal display device.
The liquid crystal display device according to claim 3, wherein the content of the high boiling point compound in the conductive composition is 0.1 to 10% by weight.
The liquid crystal display device according to claim 3 or 5, wherein the boiling point of the high boiling point compound is 210 to 290 ° C.
The liquid crystal display device according to claim 3, 5 or 6, wherein the high boiling point compound is a glycol ether solvent.
The liquid crystal display device according to any one of claims 1 to 7, wherein the conductive layer contains a thiophene-based polymer as a conductive polymer.
The liquid crystal display device according to any one of claims 1 to 8, wherein the conductive layer includes a binder.
A liquid crystal layer containing liquid crystal molecules; a touch sensor unit; first and second polarizing films arranged on both sides of the liquid crystal layer, respectively, wherein the first polarizing film is a visual side of the liquid crystal layer. Is arranged on the viewing side of the touch sensor unit; and
The step of arranging the conductive layer on the visual side of the touch sensor unit is included.
The manufacturing method, wherein the conductive layer is formed from a conductive composition containing a conductive polymer and a high boiling point compound having a boiling point of 180° C. or higher.