JP2011108425A - Transparent electrode structure and touch panel using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent conductive film for a transparent electrode of polythiophene-based conductive polymer which can acquire sufficient conductivity, excellent in transparency and flexibility, suitable for mass production, and with possibility of cost reduction, a transparent electrode including the same, a transparent electrode structure in which the transparent electrode is arranged, and a touch panel including the transparent electrode structure. <P>SOLUTION: In the transparent electrode structure and a touch panel including the transparent electrode structure, the transparent electrode structure to be used for electric connection structure includes the transparent electrode arranged on a transparent base material. The transparent electrode at least includes one layer of the transparent conductive film, and the transparent conductive film is the polythiophene-based conductive polymer film containing the polythiophene-based conductive polymer (a), polymer electrolyte (b), and dopant (c) chosen from a group consisting of high-polarity compound and ionic liquid or electrolyte salt. The polythiophene-based conductive polymer film is characterized by having the conductivity in a film thickness direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resistive film type touch panel.

  A touch panel realizes an intuitive and excellent input interface without using a keyboard or a mouse. In recent years, with the widespread use of portable information terminals such as mobile phones, PDAs, and pen input PCs, there is an increasing demand for touch panels that can directly input information to these devices.

  There are various types of touch panels, such as a resistive film method, a capacitance method, an infrared method, an ultrasonic method, an electromagnetic induction method, and an electrostatic coupling method, depending on the position detection method. For the touch panel, a resistive film system is mainly used.

[Conventional resistive touch panel]
ITO (indium tin oxide, mixed sintered body of In ₂ O ₃ and SnO ₂ ) has been mainly used as a material for the transparent conductive film constituting the transparent electrode of the resistive touch panel.

[ITO transparent conductive film]
However, ITO has the following problems.
The first problem is due to the mechanical properties of the ITO transparent conductive film (hereinafter simply referred to as “ITO film”). The ITO film is a fragile ceramic thin film and is less flexible than a PET film or other flexible resin film. Therefore, the transparent conductive film in which the ITO film is formed on the flexible resin film is likely to be cracked or scratched in the ITO film, and is stored or distributed in a bent state, or continuous in the transparent electrode plate manufacturing process. The ITO film may be deteriorated by processing or punching. In addition, there is a problem that the characteristics of the ITO film are degraded due to repeated cracking of the ITO film due to repeated input operations of the touch panel.

  The second problem is that it is difficult to reduce the cost because the sputtering method or other dry process is used to form the ITO film. In response to this, development of a wet process is currently underway.

  The third problem is the depletion of indium resources, which are raw materials for ITO films. Coupled with the increase in demand, it has led to an increase in indium transaction prices. In response to this problem, development of transparent conductive films using materials that do not use indium, such as indium recovery and recycling, and zinc oxide, is currently underway.

  The fourth problem is the toxicity of indium compounds. Conventionally, indium compounds have been considered to be non-toxic, but in recent years there have been health problems that are thought to be caused by dust in the ITO sintered body or indium compounds.

  Since ITO has the above-mentioned problems, there is a possibility that future demand increase and cost reduction may not be met. In order to solve these problems, development of alternative materials, alternative processes, etc. has been activated. Among them, considering the performance, mass productivity, cost, etc., polythiophene conductive polymer has been studied from the viewpoint of performance, mass productivity, cost, etc. as a transparent conductive film material for resistive film type touch panel. ing.

[Polythiophene conductive polymer]
A polythiophene-based conductive polymer typified by poly (3,4-ethylenedioxythiophene) (hereinafter also referred to as “PEDOT”) is known as a polymer having excellent conductivity. Conductive polymers are formed on transparent conductive films, taking advantage of the flexibility and transparency that metal conductors do not have, and are considered to be used mainly as transparent wiring members for display devices such as liquid crystals and touch panels, and as electromagnetic shielding films. Has been. In particular, it is considered that the flexibility and transparency of the conductive polymer can be utilized in the application of conducting from the surface of the transparent conductive film.

  However, the improvement in the conductivity of the polythiophene-based conductive polymer film has hitherto been performed with the aim of the horizontal conductivity of the transparent conductive film composed of the conductive polymer, so that the transparent There has been no consideration of improving the conductivity in the film thickness direction of the conductive film (for example, Patent Documents 1 to 3). Therefore, the conductivity in the film thickness direction of the transparent conductive film is extremely poor, and the application range is limited.

  The polythiophene conductive polymer is added with a large amount of a polymer electrolyte such as polystyrene sulfonic acid (hereinafter also referred to as “PSS”) as a dopant for the purpose of imparting solubility to water, a solvent, and the like. I use it. For example, CLEVIOS P (HC Starck Co.), which is a commercially available PEDOT / PSS aqueous dispersion containing PEDOT and PSS, contains PEDOT / PSS mass ratio = 1 / 2.5, and PEDOT Is a cation and PSS is an anion.

Patent Document 1 discloses a transparent conductive film having improved horizontal conductivity, formed from a conductive polymer composition in which an electrolyte salt such as lithium perchlorate (LiClO ₄ ) is blended with a PEDOT / PSS aqueous dispersion. A membrane and flexible members such as FFC (flexible flat cable) and FPC (flexible printed circuit board) using the membrane are described. However, there is no description about the conductivity in the film thickness direction.

  In Patent Document 2, a transparent conductive film with improved horizontal conductivity formed from a conductive polymer composition in which a PEDOT / PSS aqueous dispersion is mixed with a high polarity compound such as carbonate is used. Flexible members such as FFC (flexible flat cable) and FPC (flexible printed circuit board) are described. However, there is no description about the conductivity in the film thickness direction.

  Patent Document 3 discloses a conductive polymer composition (mixture) whose conductivity is significantly increased by adding 1-butyl-3-methylimidazolium tetrafluoroborate to a PEDOT / PSS aqueous dispersion, A part comprising the composition and a method of manufacturing the part are described. It is described that the surface resistivity (unit: Ω / □) of the polythiophene-based conductive polymer film (coating) is significantly reduced. However, there is no description about the conductivity in the film thickness direction.

  The poor conductivity of the polythiophene-based conductive polymer film in the film thickness direction is due to gravity segregation during the film formation, which is a surface layer that does not substantially contain the polythiophene-based conductive polymer (the “upper layer” or the “PSS layer”). And an inner layer containing the same (also referred to as “lower layer” or “PEDOT layer”) are formed, and the surface layer is a high resistance layer or insulating layer having a very large volume resistivity. It is thought to be due to this.

  That is, since the PSS is smaller than the primary particles of the polythiophene-based conductive polymer, when the polythiophene-based conductive polymer film is formed, a large polythiophene-based conductive polymer precipitates at the bottom of the film, The surface layer is in a PSS rich state in which the polythiophene conductive polymer is substantially absent. Since the conductivity of PSS is extremely low, the surface layer becomes a high resistance layer or an insulating layer. As a result, the conductivity in the film thickness direction of the transparent conductive film is extremely deteriorated (Non-Patent Document 1).

  Under such circumstances, the polythiophene-based conductive polymer film cannot be applied as it is as the transparent electrode of the resistive film type touch panel.

This will be described with reference to FIGS.
The matrix-type resistive touch panel 101 includes an upper transparent resin film 102, an upper transparent electrode 103 formed thereon, a lower transparent glass substrate 105, and a lower transparent electrode 104 formed thereon. The transparent electrode 104 is opposed to the transparent electrode 104 while maintaining a predetermined interval (1 mm or less, usually about 5 to 100 μm), and the upper transparent electrode 103 and the lower transparent electrode 104 are arranged to form a grid ( FIG. 5). When the upper surface of the touch panel, that is, the upper surface of the upper transparent resin film 102 is pressed, the upper transparent electrode 103 and the lower transparent electrode 104 come into contact with each other and become electrically conductive, whereby a current flows and the pressed position on the touch panel is specified. .

  However, when a polythiophene-based conductive polymer film is used as the transparent electrode, as described above, the polythiophene-based conductive polymer-rich polythiophene layer 123 (126) and the PSS-rich PSS layer 124 (125) are formed at the time of film formation. 6), the PSS layer 124 (125) becomes a barrier even when the upper electrode and the lower electrode are in contact with each other as shown in FIG. Electrical continuity was not obtained between the lower electrode and the polythiophene-based conductive polymer film could not be employed as the transparent electrode of the resistive film type touch panel.

  As described above, the surface layer of the conventional polythiophene-based conductive polymer film is a high resistance layer or an insulating layer having an extremely small electric conductivity in the film thickness direction. However, even if there is a PSS-rich low-conductivity surface layer, the conductor that penetrates to the polythiophene-based conductive polymer-rich high-conductivity inner layer is dispersed in the polythiophene-based conductive polymer film. By doing so, high conductivity in the film thickness direction can be obtained.

  For example, Patent Document 4 discloses a transparent conductive film formed from a conductive polymer composition in which a carbon nanotube (hereinafter referred to as “CNT”) is blended in a PEDOT / PSS aqueous dispersion, a transparent conductive film having the same, and A touch panel using it is described. However, CNT dispersion control / fixation requires strict control of concentration and coating method, which is not suitable for mass production and is considered difficult to reduce costs. Further, when the CNT content is increased to increase the conductivity, the transparency of the transparent electrode is adversely affected and the light transmittance of the touch panel may be deteriorated. Furthermore, it has been pointed out that CNTs may cause health problems similar to asbestos.

  There has also been proposed a method of obtaining conductivity in the film thickness direction by physically destroying a part of the surface layer instead of dispersing the conductor penetrating the high-resistance surface layer.

  For example, Patent Document 5 discloses a transparent conductive film formed from a polythiophene-based conductive polymer composition in which a viscosity mineral (inorganic filler) such as montmorillonite is blended in a PEDOT / PSS aqueous dispersion, and a coordinate input device having the same (Touch panel) is described. It is intended to break through the high-resistance PSS layer by providing irregularities on the surface of the transparent conductive film. However, there is a limit to improving the contact resistance due to a decrease in the contact area.

  As described above, Patent Documents 4 and 5 describe obtaining the conductivity in the film thickness direction of the transparent conductive film by breaking through the high-resistance surface layer of the polythiophene-based conductive polymer film. .

  On the other hand, obtaining the electroconductivity of the transparent conductive film in the film thickness direction by improving the electroconductivity of the surface layer in the film thickness direction has also been studied. For example, it is conceivable to form a polythiophene-based conductive polymer film by blending conductive particles (conductive filler) with a PEDOT / PSS aqueous dispersion. However, since a high resistance layer rich in PSS is formed on the surface of the conductive particles, sufficient conductivity cannot be obtained. Further, for example, a method of further forming a conductive film of metal or the like on the surface of the polythiophene-based conductive polymer film is also conceivable. However, since the flexibility and transparency of the polythiophene-based conductive polymer film are remarkably impaired, this is a fall.

JP 2007-96016 A JP 2007-131682 A Special table 2008-535964 JP 2008-50391 A JP 2008-233993 A

Timpanaro, S. and 4 others, “Morphology and conductivity of PEDOT / PSS films studied by scanning-tunneling microscopy”, Chemical Physics Letters, 2004, 394, 339-43

  Therefore, the present invention provides a transparent conductive material for a transparent electrode of a polythiophene-based conductive polymer, which can obtain sufficient conductivity, is excellent in transparency and flexibility, is suitable for mass production, and can be reduced in cost. It is an object to provide a film, a transparent electrode including the film, a transparent electrode structure for a touch panel provided with the transparent electrode, and a touch panel including the transparent electrode structure for the touch panel.

  As a result of intensive studies, the present inventor improves the electrical conductivity of the surface layer itself by using the surface layer containing at least one selected from the group consisting of highly polar compounds, ionic liquids and electrolyte salts. It was found that the conductivity in the film thickness direction of the transparent conductive film of the polythiophene-based conductive polymer can be improved.

That is, the following invention is provided.
[1] A transparent electrode structure used for an electrical connection structure in which a transparent electrode is provided on a transparent substrate,
The transparent electrode includes at least one transparent conductive film,
The transparent conductive film comprises a polythiophene-based conductive polymer (a),
A polymer electrolyte (b);
A polythiophene-based conductive polymer film containing a dopant (c) selected from the group consisting of a highly polar compound, an ionic liquid and an electrolyte salt;
A transparent electrode structure used for an electrical connection structure, wherein the polythiophene-based conductive polymer film has conductivity in a film thickness direction.
[2] A first transparent electrode structure having a transparent substrate and a transparent electrode provided on the transparent substrate, and a second having a transparent substrate and a transparent electrode provided on the transparent substrate. The transparent electrode structure of the first transparent electrode structure and the transparent electrode of the second transparent electrode structure are brought into contact with each other with the transparent electrode structure facing each other through a spacer. In the resistive touch panel that can obtain electrical connection between both transparent electrodes by
A resistive film type touch panel, wherein the first transparent electrode structure is the transparent electrode structure according to [1].
[3] The resistive film type touch panel according to [2], wherein the second transparent electrode structure is the transparent electrode structure according to [1].
[4] An application step of applying a polythiophene-based conductive polymer composition on a transparent substrate;
A film forming step of forming a polythiophene-based conductive polymer film from the polythiophene-based conductive polymer composition in this order while allowing gravity segregation in the film thickness direction;
The polythiophene conductive polymer composition comprises a polythiophene conductive polymer (a),
A polymer electrolyte (b);
A method for producing a transparent electrode structure, which is a polythiophene-based conductive polymer composition containing a dopant (c) selected from the group consisting of a highly polar compound, an ionic liquid, and an electrolyte salt.
[5] An application step of applying a polythiophene conductive polymer composition containing a polythiophene conductive polymer (a) and a polymer electrolyte (b) on a transparent substrate;
A film forming step of forming a polythiophene conductive polymer film from the polythiophene conductive polymer composition while allowing gravity segregation in the film thickness direction;
The manufacturing method of the transparent electrode structure which comprises the doping process which dopes the dopant (c) chosen from the group which consists of a highly polar compound, an ionic liquid, and electrolyte salt in this polythiophene type conductive polymer film in this order.
[6] A transparent electrode structure comprising a polythiophene-based conductive polymer (a), a polymer electrolyte (b), and a dopant (c) selected from the group consisting of a highly polar compound, an ionic liquid and an electrolyte salt A polythiophene-based conductive polymer composition for use,
With respect to 100 parts by mass of the polythiophene conductive polymer (a), 50 parts by mass or more of the polymer electrolyte (b), 1.25 parts by mass or more of a highly polar compound as the dopant (c), ionic liquid 6 .8 × 10 ³ parts by mass or lithium perchlorate 1.2 × 10 ⁴ parts by mass or more, lithium bis (trifluoromethanesulfone) imide 5.5 × 10 ² parts by mass or lithium bis (pentafluoroethanesulfone) imide A polythiophene-based conductive polymer composition for a transparent electrode structure, comprising 2.7 parts by mass or more.
[7] A transparent electrode structure comprising a polythiophene-based conductive polymer (a), a polymer electrolyte (b), and a dopant (c) selected from the group consisting of a highly polar compound, an ionic liquid and an electrolyte salt A polythiophene-based conductive polymer composition for use,
Polythiophene system for transparent electrode structure comprising polythiophene-based conductive polymer (a), polymer electrolyte (b), and dopant (c) selected from the group consisting of highly polar compounds, ionic liquids and electrolyte salts A conductive polymer composition comprising:
The polythiophene-based conductive polymer (a) and the polymer electrolyte (b) are combined at a mass ratio of polythiophene-based conductive polymer (a) / polymer electrolyte (b) ≦ 2, and 1.2 to In the aqueous dispersion containing 1.4% by mass, as the dopant (c), in the composition, 0.01% by mass or more of the highly polar compound, more than 20% by mass of the ionic liquid or 30% by mass of lithium perchlorate Polythiophene conductivity for transparent electrode structure obtained by adding more than 2% by mass of lithium bis (trifluoromethanesulfone) imide or 0.01% by mass or more of lithium bis (pentafluoroethanesulfone) imide Polymer composition.
[8] A resistive film for a resistive film type touch panel obtained by using the polythiophene-based conductive polymer composition for a transparent electrode structure according to [6] or [7].
[9] A transparent electrode for a resistive touch panel, obtained by using the polythiophene-based conductive polymer composition for a transparent electrode structure according to [6] or [7].

  According to the present invention, it is possible to obtain sufficient conductivity, excellent transparency and flexibility, suitable for mass production, and capable of reducing costs. A film, a transparent electrode including the film, a transparent electrode structure for a touch panel provided with the transparent electrode, and a touch panel including the transparent electrode structure for the touch panel are provided.

FIG. 1 is a schematic diagram showing the structure of the transparent electrode structure of the present invention. FIG. 2 is a schematic diagram showing a cross section of the resistive film type touch panel of the present invention. FIG. 3 is a schematic diagram showing a cross section of the resistive touch panel of the present invention when the touch surface of the resistive touch panel of the present invention is touched with a finger (or pen). FIG. 4 is a schematic diagram showing a film thickness direction electric conductivity measuring apparatus used in Examples 1 and 2. FIG. 5 is a schematic diagram showing a matrix type resistive film type touch panel. FIG. 6 is a schematic diagram showing the touch panel in a state where the upper transparent electrode and the lower transparent electrode are not in contact with each other when the touch panel is not pressed. FIG. 7 is a schematic diagram illustrating the touch panel in a state where the upper transparent electrode and the lower transparent electrode are in contact with each other when the touch panel is pressed.

[Transparent electrode structure and resistive touch panel structure]
The structure of the transparent electrode structure and resistive film type touch panel of the present invention will be described.
The transparent electrode structure of the present invention has a structure in which a transparent electrode is provided on a transparent substrate. Moreover, like a well-known transparent electrode structure, you may coat an undercoat or a primer on a transparent base material, and may provide a transparent electrode on it. The transparent electrode provided in the transparent electrode structure of the present invention includes at least one transparent conductive film, and at least one of the transparent conductive films is a polythiophene conductive polymer film formed from a polythiophene conductive polymer composition It is.

  FIG. 1 is a schematic diagram showing the structure of the transparent electrode structure of the present invention. For simplicity, the transparent electrode is expressed as a single polythiophene-based conductive polymer film. The size is not on scale.

The transparent electrode structure of the present invention will be described with reference to FIG.
In the simplest form, the transparent electrode structure 1 of the present invention has a structure in which a polythipolythiophene-based conductive polymer film 5 serving as a transparent electrode is formed on a transparent substrate 4.

  When the polythiophene-based conductive polymer film 5 is formed from the polythiophene-based conductive polymer composition by a wet process, the polythiophene-based conductive polymer film 5 is rich in the polythiophene-based conductive polymer (a) and polymer electrolyte (b) due to gravity segregation. And B layer 3 (also referred to as “lower layer”, “inner layer” or “polythiophene layer”) containing dopant (c), and a polymer electrolyte (b) rich and containing dopant (c), but polythiophene-based conductive A layer 2 (also referred to as “upper layer”, “surface layer”, or “polymer electrolyte layer”) that substantially does not contain the conductive polymer (a).

  The interface between the A layer 2 and the B layer 3 is generally not a plane and is not clear. Gravity segregation occurs as long as it is not performed under zero gravity or microgravity. Therefore, gravity segregation is allowed when a film is formed on the earth without using a special process.

  The presence of the A layer and the B layer can be observed according to the method described in Non-Patent Document 1, for example, using STM (scanning tunneling microscope) and AFM (atomic force microscope). Further, since the thickness of the A layer is from several nm to about ½ of the film thickness at the maximum, the fact that the polythiophene-based conductive polymer is not substantially contained in the A layer indicates that X-ray photoelectron spectroscopy analysis and other composition analysis It can be confirmed by the method.

Next, the structure of the resistive touch panel of the present invention will be described.
FIG. 2 is a schematic diagram showing the structure of the resistive film type touch panel of the present invention. The size is not on scale.

The resistive touch panel of the present invention will be described with reference to FIG.
The resistive film type touch panel 11 has a structure in which an upper electrode plate (movable electrode plate) 12 and a lower electrode plate (fixed electrode plate) 13 are bonded to each other via a spacer (insulating layer) 14. It should be understood by those skilled in the art that the upper part and the lower part do not mean an absolute arrangement.

  The upper electrode plate 12 includes an upper transparent substrate 15 and an upper transparent electrode 16 provided thereon as constituent elements, and the lower electrode plate 13 includes a lower transparent substrate 18 and a lower transparent electrode 17 provided thereon. If necessary, a dot spacer 19 provided on the lower transparent electrode 17 is included as a constituent element. One skilled in the art understands that the dot spacer may not be provided depending on the size of the touch panel.

  The upper electrode plate 12 and the lower electrode plate 13 are bonded to face each other so that the upper transparent electrode 16 and the lower transparent electrode 17 face each other. The distance between the upper and lower electrodes is 1 mm or less, preferably several tens nm to several hundreds nm, more preferably 5 to 300 μm, and further preferably 5 to 100 μm.

  Although the dot spacer 19 can prevent erroneous input or the always-on state, and the presence of the dot spacer 19 does not hinder the image displayed on the panel, the dot spacer 19 may satisfy the conditions for not impairing the function of the touch panel. For example, the height is preferably 5 to 10 μm and the diameter is 50 μm or less.

As the upper transparent substrate 15, it is preferable to use a resin film from the viewpoint of flexibility, and among the resin films, a PET film is preferable.
As the lower transparent base material 18, any of a glass substrate, a plastic substrate and a resin film can be preferably used.

  In the present invention, the upper transparent electrode 16 is preferably a transparent electrode including the polythiophene-based conductive polymer film according to the present invention. The lower transparent electrode 17 may be a transparent electrode including the polythiophene-based conductive polymer film according to the present invention, or may be a transparent electrode including a conventionally known transparent conductive film. As a conventional transparent electrode, for example, an ITO transparent electrode can be preferably exemplified.

  In the matrix (digital detection) type resistive touch panel, it is preferable to provide upper and lower electrodes so that the upper transparent electrode 16 and the lower transparent electrode 17 form a grid. It is preferable that both electrodes are provided over almost the entire “visible region” for displaying an image.

Next, the principle of the resistive film type touch panel of the present invention will be described.
FIG. 2 shows a state where the finger (or pen) 22 is not pressing the touch surface (also referred to as “front surface” or “upper surface”) of the resistive touch panel 11 of the present invention. In this case, since the upper transparent electrode 16 and the lower transparent electrode 17 are separated, there is no electrical continuity between the upper and lower electrodes. Even if the upper electrode plate 12 or the lower electrode plate 13 is bent to some extent, the upper transparent electrode 16 and the lower transparent electrode 17 are kept separated by the dot spacer 19.

  In FIG. 3, the resistive touch panel (when pressed) 21 presses the touch surface (also referred to as “front surface” or “upper surface”) of the resistive touch panel 11 of the present invention with a finger (or pen) 22. It is a schematic diagram showing a state. In this case, the upper transparent electrode 16 and the lower transparent electrode 17 are in contact with each other, and electrical conduction is established between the upper and lower electrodes.

In the matrix (digital detection) type resistive touch panel, the touched coordinates are specified by specifying the electrically conductive electrode. Here, conduction means that the interelectrode resistance is 10 KΩ or less.
On the other hand, in the analog detection type resistive touch panel, the voltage division ratio is measured with respect to the resistance of the upper transparent electrode 16 and the lower transparent electrode 17, and the touched position is calculated.

  The polythiophene-based conductive polymer film of the present invention desirably has an interelectrode resistance of 10 KΩ or less, preferably 1 KΩ or less when pressed with an operating force (ON load) of 1 g or more, preferably 10 g to 250 g.

  The resistive touch panel of the present invention can be used with either finger input or touch pen input, but is preferably used with finger input from the viewpoint of usability.

[Manufacturing method of resistive touch panel]
The outline of the manufacturing process of the resistive touch panel of the present invention will be briefly described.
The resistance film type touch panel of the present invention can utilize a conventionally known resistance film type touch panel manufacturing process with almost no change.

  The manufacturing method of the resistive film type touch panel of the present invention can be summarized as follows: an upper electrode plate (movable electrode plate) is manufactured, a lower electrode plate (fixed electrode plate) is manufactured, and these two are bonded together. is there. One or both of the upper electrode plate and the lower electrode plate is the transparent electrode structure of the present invention.

  The upper electrode plate is an electrode plate that includes an upper transparent substrate and an upper transparent electrode as constituent elements, and is disposed at the upper part of the touch panel. The lower electrode plate is a lower transparent substrate that is disposed at the lower part of the touch panel. And a lower transparent electrode and a dot spacer as constituent elements.

  From the viewpoint of ensuring the flexibility of the touch surface and the flexibility of the upper transparent electrode, the upper electrode plate is preferably a transparent electrode structure of the present invention using a plastic film as a transparent substrate. Although the example of the manufacturing method of the resistive film type touch panel of this invention is demonstrated below, the aspect of a manufacturing method is not limited to this example, It can carry out according to a conventionally well-known manufacturing method.

A preferable manufacturing process of the upper electrode plate will be described.
(A1) A polythiophene conductive polymer composition (liquid or paste) of the present invention is printed or applied on a flexible resin film (PET film is preferred), and is cured by heating to form a polythiophene conductive polymer. A film is formed.
In the matrix detection type, the film is formed so as to form an electrode pattern, and in the analog detection type, the film is formed over almost the entire visible region.
(A2) Silver ink is printed on a portion other than the visible region (portion for displaying an image) to form a parallel circuit and a drawing circuit.
(A3) An insulating ink is printed to cover the formed silver circuit to form an insulating layer.
(A4) The paste for bonding the upper and lower electrode plates is printed, and the outer diameter is punched out by a press machine to obtain the upper electrode plate.

Next, a manufacturing process using a conventionally known ITO / glass substrate for the lower electrode plate will be described. The lower electrode plate may also be the transparent electrode structure of the present invention.
(B1) An ITO film formed on a glass substrate by sputtering or vacuum deposition (ITO / glass substrate) is prepared.
(B2) The ITO etching resist is printed in the same manner as the upper electrode plate.
(B3) Etching is performed to remove the ITO film in the portion of the surrounding silver ink printed circuit.
(B4) A dot spacer is printed and fired.
(B5) A parallel electrode and a drawing circuit are formed in a portion other than the visible region (portion for displaying an image) using silver ink so as to be perpendicular to the direction formed with the ITO / PET film.
(B6) An insulating ink is formed by printing insulating ink.
(B7) An anisotropic conductive paste (ACP) is printed to form an FPC (flexible printed circuit) connection. Thereafter, the ITO / glass substrate is cut into a predetermined size using a scriber to form a lower electrode plate.

Finally, a process for bonding the upper electrode plate and the lower electrode plate will be described.
(C1) By bonding the paste printed on the upper electrode plate and the lower electrode plate, the two electrode plates are joined while being held at a predetermined interval.
(C2) A circuit between the upper and lower electrode plates and the FPC is connected by thermocompression bonding of the FPC for the lead wire to the ACP.
(C3) An inspection is performed.
(C4) The touch panel is completed.

[Composition and film formation method]
<1. Polythiophene-based conductive polymer (a)>
A conventionally well-known thing can be used for a polythiophene type conductive polymer (a). For example, what contains the repeating unit represented by following formula (1) as a main component can be used.

In formula (1), ^{R 1} and ^{R 2} are each independently _hydrogen, C 1 _{-C 20} - alkyl group or alkyloxy group or 1-8 oxygen atoms or _C 1 -C sulfur atom is inserted ₂₀ - alkyl group or alkyloxy group or,, ^{R 1} and ^{R 2,} taken together, may be optionally substituted _C 1 _{-C 20} - dioxyalkylene group or _C 1 _{-C 20} - dioxy arylene Indicates a group.

Wherein _C 1 _{-C 20} - alkyl group is, for example, can be mentioned n- nonadecyl and n- eicosyl.

Wherein _C 1 _{-C 20} - alkyl group is, for example, a methoxy group, an ethoxy group, n- propoxy group, isopropoxy group, n- butoxy group, isobutoxy group, sec- butoxy group, tert- butoxy group, n- pentyl Oxy group, 1-methylbutyloxy group, 2-methylbutyloxy group, 3-methylbutyloxy group, 1-ethylpropyloxy group, 1,1-dimethylpropyloxy group, 1,2-dimethylpropyloxy group, 2 , 2-dimethylpropyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, 2-ethylhexyloxy group, n-nonyloxy group, n-decyloxy group, n-undecyloxy group, n -Dodecyloxy group, n-tridecyloxy group, n-tetradecyloxy group, n-hexadecyloxy group , N-nonadecyloxy group and n-eicosyloxy group.

  Preferably, a polythiophene-based conductive polymer containing a repeating unit represented by the following formula (2) can be used.

In the formula (2), A is an optionally substituted C ₁ -C ₅ -alkylene group or C ₁ -C ₁₂ -arylene group, preferably an optionally substituted C ₂ -C ₃ -arylene. Indicates a group.

In formula (2), R is a linear or branched optionally substituted C ₁ -C ₁₈ -alkyl group, preferably linear or branched optionally substituted. An optionally substituted C ₁ -C ₁₄ -alkyl group, an optionally substituted C ₅ -C ₁₂ -cycloalkyl group, an optionally substituted C ₆ -C ₁₄ -aryl group, optionally substituted An optionally substituted C ₇ -C ₁₈ -aralkyl group or an optionally substituted C ₁ -C ₄ -hydroxyalkyl group, more preferably an optionally substituted C ₁ -C ₂ -hydroxyalkyl group or hydroxyl group Indicates.

  In the formula (2), X represents an integer of 0 to 8, preferably an integer of 0 to 6, more preferably 0 or 1. R may bond X to A when A is an alkylene group or an arylene group. R and A may be the same or different when R is bonded to A.

Examples of the C ₁ -C ₅ -alkylene group include a methylene group, an ethylene group, an n-propylene group, an n-butylene group, and an n-pentylene group.

Examples of the C ₁ -C ₁₂ -arylene group include a phenylene group, a naphthylene group, a benzylidene group, and an anthracenylidene group.

Wherein _C 1 _{-C 18} alkyl group, for example, a methyl group, an ethyl group, n- propyl group, an isopropyl group, n- butyl group, isobutyl group, sec- butyl group, tert- butyl group, n- pentyl group, 1 -Methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylpropyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 2,2-dimethylpropyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-hexadecyl group or An n-octadecyl group can be illustrated.

The C ₅ -C 12 _- cycloalkyl groups, for example, can be exemplified cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, a cyclononyl group and a cyclodecyl group.

The _C 5 _{-C 14} - aryl groups, for example, can be exemplified a phenyl group and naphthyl group.

Examples of the C ₇ -C ₁₈ -aralkyl group include benzyl group, o-tolyl group, m-tolyl group, p-tolyl group, 2,3-xylyl group, 2,4-xylyl group, and 2,5-xylyl group. Examples thereof include 2,6-xylyl group, 3,4-xylyl group, 3,5-xylyl group and methicyl group.

  More preferably, a polythiophene-based conductive polymer containing a repeating unit represented by the following formula (3) can be used.

  In the formula (3), R and X have the same contents as R and X in the formula (2).

  The polythiophene conductive polymer used in the present invention may be a polymer containing one or more types of repeating units represented by the above formulas (1) to (3), and a copolymer containing two or more types of repeating units. It may be.

  Furthermore, the monomer of the poly-based conductive polymer may have one or more optical isomers having optical isomers, racemates, enantiomerically pure or diastereomerically pure compounds, or enantiomers. It may be a concentrated or diastereomerically enriched compound. Moreover, these mixtures may be sufficient.

Particularly preferably, a polythiophene-based conductive polymer (poly (3,4-ethylenedioxythiophene); PEDOT) containing a repeating unit (3,4-ethylenedioxythiophene) represented by the following formula (4) is used. can do.

<2. Polymer electrolyte (b)>
The polymer electrolyte (b) is not particularly limited as long as it is an anionic polymer, and may be a salt or a derivative. Examples thereof include polymer electrolytes having carboxylic acids such as polyacrylic acid, polymethacrylic acid and polymaleic acid, and polymer electrolytes having sulfonic acids such as polystyrene sulfonic acid and polyvinyl sulfonic acid.
The polyelectrolyte having carboxylic acids and sulfonic acids may be a homopolymer composed of one kind of anionic monomer, may be a copolymer composed of two or more kinds of anionic monomers, and May be a copolymer of an anionic monomer and a non-anionic monomer copolymerizable with the anionic monomer. Examples of such non-anionic monomers include acrylate monomers and styrene monomers. When the polymer electrolyte is a copolymer, it is sufficient that at least one kind of anionic monomer is contained as a copolymerization component.

<< 2-1. Polystyrene sulfonic acid or salt or derivative thereof >>
As polystyrene sulfonic acid or a salt or derivative thereof (hereinafter sometimes simply referred to as “polystyrene sulfonic acid”), conventionally known polystyrene sulfonic acid or a salt or derivative thereof can be used.

  A preferred polystyrene sulfonic acid is a polystyrene sulfonic acid containing a repeating unit represented by the following formula (5).

<3. Dopant (c)>
The dopant (c) used for the transparent conductive film according to the present invention is selected from the group consisting of a highly polar compound, an ionic liquid and an electrolyte salt.

<< 3-1. High Polarity Compound >>
Although it does not specifically limit as a highly polar compound, For example, alcohol, glycol, glycerin, carbonate ester, lactam, amide, sulfone, sulfoxide, organic phosphate ester, organic phosphonate, organic phosphamide, urea and urea derivatives, and mixtures thereof Can be illustrated.

  Among the highly polar compounds, isopropyl alcohol (alcohol); ethylene glycol, diethylene glycol, polyethylene glycol (glycol); glycerin (glycerin); propylene carbonate (carbonate ester); N-methyl-2-pyrrolidone, 2-pyrrolidone (lactam); Formamide, dimethylformamide, N, N-dimethylacetamide (amide); tetramethylene sulfone (sulfone); dimethyl sulfoxide (sulfoxide); hexamethylphosphamide (organic phosphamide); and 1,3-dimethyl-2-imidazolidone, N , N, N ′, N′-tetramethylurea (urea derivative) is preferred. These can be used alone or in combination.

  Among these, polyethylene glycol, ethylene glycol, and dimethyl sulfoxide are more preferable high polarity compounds. As the polyethylene glycol, PEG200 (average molecular weight 200) is preferable.

<< 3-2. Ionic liquid >>
Although it does not specifically limit as an ionic liquid, The thing whose cation component of an ionic liquid is an imidazolium ion or its derivative, or an ammonium ion or its derivative is preferable. Here, the derivative is, for example, an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, an ether group, an ester group or an acyl group introduced, and a hydrogen atom is substituted with a fluorine atom. Say things.

The anionic component of the ionic liquid is bromide ion (Br ⁻ ), chloride ion (Cl ⁻ ), perchlorate ion (ClO ₄ ⁻ ), tetrafluoroborate anion (BF ₄ ⁻ ), hexafluorophosphate. Anion (PF ₆ ⁻ ), bis (trifluoromethylsulfonyl) imide anion (TFSI, (CF ₃ SO ₂ ) ₂ N ⁻ ), bis (pentafluoroethylsulfonyl) imide anion (BETI, (C ₂ F ₅ SO ₂ ) ₂ N ⁻ ) or RSO ₃ ^— (R is an aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, ether group, ester group or acyl group, and the hydrogen atom is substituted with a fluorine atom. Is also preferred.

  As the ionic liquid, 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide (EMI-TFSI) is preferable. This is because of the particularly excellent conductivity improving effect among ionic liquids.

<< 3-3. Electrolyte salt >>
Electrolyte salt is not specifically limited, A conventionally well-known thing can be used.

Preferred cation components are alkali metal cations such as Li ⁺ , Na ⁺ and K ⁺ , alkaline earth metal cations such as Ca ²⁺ and Mg ²⁺ , and ammonium ions.

Preferred anion components are bromide ion (Br ⁻ ), chloride ion (Cl ⁻ ), perchlorate ion (ClO ₄ ⁻ ), tetrafluoroborate anion (BF ₄ ⁻ ), hexafluorophosphate anion (PF). ₆ ^-), bis (trifluoromethylsulfonyl) imide anion _{(TFSI, (CF 3 SO 2} ) 2 N -), bis (pentafluoroethyl sulfonyl) imide anion _{(BETI, (C 2 F 5} SO 2) 2 N - ) or RSO 3 - ^_(R is an aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, an ether group, an ester group, or an acyl group, a hydrogen atom may be substituted with a fluorine atom. ).

Examples of the electrolyte salt include lithium perchlorate (LiClO ₄ ), lithium bis (trifluoromethylsulfonyl) imide (LiTFSI, Li (CF ₃ SO ₂ ) ₂ N), or lithium bis (pentafluoroethylsulfonyl) imide (LiBETI, Li (C ₂ F ₅ SO ₂ ) ₂ N) is preferred, and lithium bis (trifluoromethylsulfonyl) imide (LiTFSI, Li (CF ₃ SO ₂ ) ₂ N) or lithium bis (pentafluoroethylsulfonyl) imide (LiBETI, Li (C ₂ F ₅ SO ₂ ) ₂ N) is more preferred. This is because better conductivity can be obtained.

  One electrolyte salt can be used alone, or two or more electrolyte salts can be used in combination.

<4. Polythiophene-based conductive polymer composition>
The polythiophene-based conductive polymer composition for the resistive film type touch panel of the present invention (hereinafter sometimes simply referred to as “composition” or “composition of the present invention”) is, depending on the aspect of the method for producing a transparent electrode,
[I] A polythiophene-based conductive polymer (a), a polymer electrolyte (b), and a dopant (c), or [II] a polythiophene-based conductive polymer (a), and a polymer electrolyte (B) is contained, but the dopant (c) is not contained.

  The composition [II] is used in a production method in which the dopant (c) is doped after the polythiophene-based conductive polymer film is formed. The composition [I] is a polythiophene-based conductive polymer film. Although it can be used in a production method in which the dopant (c) is doped after the molecular film is formed, it is usually used in a production method in which the dopant (c) is not doped after the film formation.

The composition of [I] is not particularly limited as long as it is a solution containing the polythiophene-based conductive polymer (a), the polymer electrolyte (b), and the dopant (c).
The content of the polythiophene conductive polymer (a) and the polymer electrolyte (b) is not particularly limited, but the polythiophene conductive polymer (a) / polymer electrolyte (b) is 2 or less in terms of mass ratio. It is preferable that it is 1/4 or more and 2 or less.

When the dopant (c) is added to the aqueous dispersion containing the polythiophene-based conductive polymer (a) and the polymer electrolyte (b) to constitute the composition of the present invention, The total content of the polythiophene conductive polymer (a) and the polymer electrolyte (b) in the aqueous dispersion is 1.2 to 1.4% by mass, and the polythiophene conductive polymer (a) Assuming that the mass ratio of the polymer electrolyte (b) ≦ 2, when the dopant (c) is a highly polar compound, a minute amount (less than 0.01% by mass) or more, preferably 0.01 % By mass or more, more preferably 0.01% by mass or more and less than 5% by mass. When the dopant (c) is an ionic liquid, it is more than 20% by mass, preferably more than 20% by mass and preferably 70% by mass. Or less, more preferably 25 to 70 mass , More preferably 25 to 40 wt%, more preferably 30 to 40 mass%, in the case a dopant (c) is LiClO ₄ electrolyte salt (lithium perchlorate), than 30 wt%, Preferably, it is 35% by mass or more, more preferably 40% by mass or more. When the dopant (c) is LiTFSI (lithium bis (trifluoromethanesulfone) imide) of an electrolyte salt, it is more than 2% by mass, preferably Is more than 2% by weight and less than 70% by weight, more preferably 40-60% by weight, still more preferably 50% by weight, and the dopant (c) is LiBETI (lithium bis (pentafluoroethanesulfone) imide) as an electrolyte salt. In some cases, a minute amount (less than 0.01% by mass) or more, preferably 0.01% by mass or more, more preferably 5 mass% or more, More preferably, it is 10-70 mass%, More preferably, it is 20-70 mass%, More preferably, it is 25-60 mass%, More preferably, it is 30 mass%.

The composition [I] preferably contains 50 parts by mass or more, more preferably 50 to 400 parts by mass of the polymer electrolyte (b) with respect to 100 parts by mass of the polythiophene-based conductive polymer (a). Further, in the case of a highly polar compound, the dopant (c) is preferably 2.7 parts by mass or more, more preferably 2.7 to 1.4 × 10 ³ parts by mass, and an ionic liquid. Preferably 6.8 × 10 ³ parts by mass or more, more preferably 6.8 × 10 ^{3 to} 6.2 × 10 ⁴ parts by mass, still more preferably 9.0 × 10 ^{3 to} 2.2 × 10 ⁴ parts by mass, More preferably, 1.2 × 10 ^{4 to} 1.8 × 10 ⁴ parts by mass, and the electrolyte salt LiClO ₄ is preferably 1.2 × 10 ⁴ parts by mass or more, more preferably 1.8 × 10 ^4. Part by mass, more preferably 2.2 × 10 ⁴ parts by mass The LiTFSI of the electrolyte salt is preferably 5.5 × 10 ² parts by mass or more, more preferably 5.5 × 10 ^{2 to} 6.2 × 10 ⁴ parts by mass, and even more preferably 1.8 × 10 ^4. ˜4.0 × 10 ⁴ parts by mass, more preferably 2.7 × 10 ⁴ parts by mass, LiBETI of the electrolyte salt is preferably 2.7 parts by mass or more, more preferably 1.4 × 10 ³ mass Parts or more, more preferably 3.0 × 10 ^{3 to} 6.2 × 10 ⁴ parts by mass, even more preferably 6.7 × 10 ^{3 to} 6.2 × 10 ⁴ parts by mass, and even more preferably 9.0 × 10. ^{3 to} 4.0 × 10 ⁴ parts by mass or less, and still more preferably 1.2 × 10 ⁴ parts by mass.

The composition of [II] is not particularly limited as long as it is a solution containing the polythiophene-based conductive polymer (a) and the polymer electrolyte (b).
The content of the polythiophene conductive polymer (a) and the polymer electrolyte (b) is not particularly limited, but the polythiophene conductive polymer (a) / polymer electrolyte (b) is 2 or less in terms of mass ratio. It is preferable that it is 1/4 or more and 2 or less.

  The composition [II] preferably contains 50 parts by mass or more, more preferably 50 to 400 parts by mass of the polymer electrolyte (b) with respect to 100 parts by mass of the polythiophene-based conductive polymer (a). To do.

  The composition of the present invention can be used diluted or concentrated.

  The solvent of the composition of the present invention may be either aqueous or solvent-based, but is preferably aqueous.

  The composition of the present invention can further contain a film-forming binder from the viewpoint of improving the film-forming property. Such binders include water-soluble or water-dispersible hydrophilic polymers (eg gelatin, gelatin derivatives, maleic acid or maleic anhydride copolymers, styrene sulfonates, cellulose derivatives (eg carboxymethylcellulose, hydroxyethylcellulose, acetic acid). Examples thereof include cellulose butyrate, diacetylcellulose, triacetylcellulose), polyethylene oxide, polyvinyl alcohol, poly-N-vinylpyrrolidone), and the like. Other binders include monomers in which ethylene is unsaturated (for example, acrylic acid salts (including acrylic acid), methacrylic acid salts (including methacrylic acid), acrylamide, methacrylamide, and itaconic acid. Aqueous emulsions of addition type homopolymers and copolymers prepared from esters and diesters, styrene (including substituted styrene), acrylonitrile, methacrylonitrile, vinyl acetate, vinyl ether, vinyl halides, vinylidene halides, olefins, polyurethanes And an aqueous dispersion of polyester ionomer.

  The composition of the present invention may further contain an additive that can be blended with a known polythiophene-based conductive polymer composition. Such additives include dopants, catalysts, polymer electrolytes, ion exchange resins, water, alcohols, glycols, amine solvents and other solvents, electrolyte salts, waxes, surfactants, antifoaming agents, coating aids, Antistatic agents, thickeners or viscosity modifiers, anti-adhesive agents, fusion aids, crosslinking agents or curing agents, soluble dyes and / or solid particle dyes, matte beads, inorganic or polymer particles, adhesion promoters, corrosion Examples thereof include an organic solvent, a chemical etching agent, a lubricant, a plasticizer, an antioxidant, a colorant, and other conventionally known additives.

  The mass ratio of the polythiophene-based conductive polymer (a), the polymer electrolyte (b), and the dopant (c) in the composition is such that the polythiophene-based conductive polymer (a), high A molecular electrolyte (b) and a dopant (c) having the same mass ratio as the respective components, wherein the composition of the present invention contains or does not contain a film-forming binder or other additives, or is diluted or concentrated Alternatively, a composition that can be equated with these can achieve the object of the present invention even if the concentration of each component in the composition is different, and is within the technical scope of the present invention as long as the same effect is obtained. Needless to say, it is included.

  The polythiophene-based conductive polymer (a) and the polymer electrolyte (b) are preferably used as an aqueous dispersion, and a dopant (c) and other additives may be added thereto to prepare a composition. preferable. This is from the viewpoint of the stability and convenience of handling of the polythiophene-based conductive polymer (a).

  The composition of the present invention includes, for example, poly (3,4-ethylenedioxythiophene) (PEDOT) and polystyrenesulfonic acid (PSS) as the polythiophene-based conductive polymer (a) and the polymer electrolyte (b), respectively. Is preferably used. In this case, a commercially available PEDOT / PSS aqueous dispersion can be suitably used.

  As such a commercially available PEDOT / PSS aqueous dispersion, for example, CLEVIOS P (HC Starck Co., Ltd., solid content 1.2 to 1.4% by mass, PEDOT / PSS = 1 / 2.5 ( The mass ratio)) can be preferably exemplified. Such an aqueous dispersion may be diluted or concentrated.

<5. Transparent substrate>
As long as the transparent base material used for the transparent electrode structure of the present invention is a transparent base material, either an insulating base material or a conductive base material may be used.

  As the insulating base material, for example, glass, quartz or other inorganic transparent substrates can be used.

  Examples of organic base materials include (meth) acrylic resins, polystyrene, polyvinyl acetate, polyethylene, polypropylene and other polyolefin substrates or films, polyvinyl chloride, polyvinylidene chloride, polyimide, polyamide, polysulfone, polycarbonate, and polyethylene. Organic transparent substrates such as terephthalate (PET), polyethylene naphthalate (PEN), liquid crystal polymer and other polyesters, amino groups, epoxy groups, hydroxyl groups, carbonyl groups and other functional groups or organic transparent substrates such as triacetyl cellulose or organic A transparent film can be used.

  Examples of the conductive substrate include those obtained by applying a transparent conductive coating to the surface of the insulating substrate.

For the pretreatment such as washing and drying of the transparent substrate, a conventionally known technique can be used.
The substrate treatment is preferably performed in advance with an easy adhesion treatment, and conventionally known techniques can be used for this. Examples of such techniques include corona treatment, plasma treatment, and flame treatment.

<6. Method for forming polythiophene-based conductive polymer film>
The following two methods can be used as a method for forming a polythiophene-based conductive polymer film on a transparent substrate.
<< 6-1. Film formation method I >>
A coating step of coating on a transparent substrate using a solution of a composition containing a polythiophene-based conductive polymer (a), a polymer electrolyte (b), and a dopant (c), and a coated composition A polythiophene-based conductive polymer film can be formed on a transparent substrate through a film forming step for drying the product. In addition, it is preferable to give an undercoat or a primer process to the application surface of a transparent base material.

  In the coating step of coating the composition, a conventionally known coating method can be used. Specifically, for example, screen printing method, inkjet printing method, lip direct method, comma coater method, slit reverse method, die coater method, gravure roll coater method, blade coater method, spray coater method, air knife coating method, dip Examples thereof include a coating method and a bar coater method.

  A conventionally known drying method can be used in the film forming step of drying the composition to form a film.

<< 6-2. Deposition Method II >>
A coating step of coating on a transparent substrate using a solution of a composition containing a polythiophene-based conductive polymer (a) and a polymer electrolyte (b) but not containing a dopant (c); A polythiophene-based conductive polymer film containing no dopant (c) (hereinafter referred to as “undoped film”) is formed on a transparent substrate by passing through a film-forming step of drying the applied composition. The polythiophene-based conductive polymer film can be formed on the transparent substrate by performing a doping process of doping the undoped film with the dopant (c). In addition, it is preferable to give an undercoat or a primer process to the application surface of a transparent base material.

  As the coating method and the drying method, the method described in the above-described film forming method I can be used.

  In the doping step of doping the film with the dopant (c), a conventionally known doping method can be used. Specifically, for example, the dopant (c) can be doped by dissolving it in a solvent so as to have a predetermined concentration and bringing it into contact with the surface of the undoped film.

<1. Common operations>
<< 1-1. Substrate cleaning method >>
A glass substrate (glass slide, 25 mm × 38 mm) was used as the transparent substrate. The glass substrate was washed with Piranha (concentrated sulfuric acid: hydrogen peroxide solution (30 v / v%) = 3: 1) for 1 hour, then rinsed 4 times with pure water, and further washed with ultrasonic water in pure water for 10 minutes. Dried in the oven overnight or longer.

<< 1-2. Formation of polythiophene-based conductive polymer film >>
Poly (3,4-ethylenedioxythiophene) (PEDOT) was used as the polythiophene-based conductive polymer (a), and polystyrene sulfonic acid (PSS) was used as the polymer electrolyte (b).
Specifically, a PEDOT / PSS aqueous dispersion (CLEVIOS P, HC Starck, solid content: 1.3% by mass, PEDOT: PSS = 1: 2.5 (mass ratio)) was used.

The dopant (c) is as follows.
Polyethylene glycol (PEG 200, average molecular weight 200), ethylene glycol (EG) or dimethyl sulfoxide (DMSO) was used as the high polarity compound.

  As the ionic liquid, 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide (EMI-TFSI) was used.

As the electrolyte salt, lithium perchlorate (LiClO ₄ ), lithium bis (trifluoromethylsulfonyl) imide (LiTFSI) or lithium bis (pentafluoroethylsulfonyl) imide (LiBETI) was used.

<<<< 1-2-1. Creation method I >>
The dopant (c) was added to the PEDOT / PSS aqueous dispersion, and the mixture was stirred with ultrasonic waves for 10 minutes or more to obtain a conductive polymer composition.
The conductive polymer composition is spin-coated at 3000 rpm on a glass substrate, the glass substrate is heated and dried at 120 ° C. for 30 minutes in the atmosphere, and the conductive polymer film having a thickness of 90 nm is combined with the PSS layer and the PEDOT layer. Was deposited.

<<<< 1-2-2. Creation method II >>
The conductive polymer composition composed of the PEDOT / PSS aqueous dispersion was spin-coated on a glass substrate at 3000 rpm, the glass substrate was heated and dried at 120 ° C. for 30 minutes in the atmosphere, and the PSS layer and the PEDOT layer were 90 nm in total. A conductive polymer film having a thickness (excluding dopant (c)) was formed. Further, the high polar compound, ionic liquid or electrolyte salt is adjusted to a predetermined concentration solution and brought into contact with the surface of the conductive polymer film from which the dopant (c) is removed, and the high polar compound, ionicity is added to the PSS layer. Impregnated with liquid or electrolyte salt. Excessive high polarity compound, ionic liquid or electrolyte salt was removed by nitrogen blowing, and then the glass substrate was dried by heating at 120 ° C. for 30 minutes in the atmosphere.

<Examples 1 and 2 Manufacturing Method>
[Example 1 Production Method I]
{Measurement of electrical conductivity in film thickness direction (load method)}
(Measuring method)
In the film thickness direction conductivity measurement sample, a gold vapor deposition film having a thickness of 0.2 μm is formed on a glass substrate 45 to form a gold electrode 44, and a polythiophene-based conductive polymer film 46 is formed on the gold electrode 44 according to the preparation method I thereon. did.
When the polythiophene-based conductive polymer film 46 was formed, a PSS-rich PSS layer 42 and a PEDOT-rich PEDOT layer 43 were formed by gravity segregation.
As shown in FIG. 4, the film thickness direction electrical conductivity measurement is performed by using the film thickness direction electrical conductivity measuring device 41 to change the electrical resistance in the film thickness direction of the polythiophene-based conductive polymer film 46 to the PSS layer 42. The measurement was performed by measuring between the movable probe 47 and the gold electrode 44 that were in contact with each other and to which pressure could be applied. The load on the PSS layer 42 was increased from 0 g to 100 g, and the resistance value was monitored with an ohmmeter 49. The contact area of the movable probe 47 was about 1 mm ² .

(Measurement result)
In all samples, the resistance value decreased with increasing load.
Since electrical contacts are desired to exhibit low contact resistance due to weak pressing, loads with a certain resistance value were compared.
Table 1 shows the load (unit: g) with resistance values of 0.3Ω and 0.5Ω for each sample.

  In Table 1, “PEDOT” is a comparative sample not containing the dopant (c) in the composition, “EG” is a measurement sample containing 0.5% by mass of ethylene glycol in the composition, “ “EMI-TFSI” is a measurement sample containing 30% by mass of EMI-TFSI in the composition, “LiTFSI” is a measurement sample containing 50% by mass of LiTFSI in the composition, and “LiBETI” is a composition. Samples for measurement containing 50% by mass of LiBETI are respectively represented.

  Summarizing the results, if the dopant (c) was not contained, the resistance value could not be 0.5Ω or 0.3Ω even with a load of 100 g or more, but on the other hand, for measurement containing the dopant (c) In the sample, the resistance value could be 0.5Ω or 0.3Ω under a load of 5 g or less, and a good electric conductivity in the film thickness direction could be obtained.

[Example 2 Production Method II]
The same operation as in Example 1 was performed except that the preparation method II was used.

Summarizing the results, if the dopant (c) was not contained, the resistance value could not be 0.5Ω or 0.3Ω even with a load of 100 g or more, but on the other hand, for measurement containing the dopant (c) In the sample, the resistance value could be 0.5Ω or 0.3Ω under a load of 5 g or less, and a good electric conductivity in the film thickness direction could be obtained.
That is, it was shown that even if the production method II is used instead of the production method I, the film thickness direction conductivity can be obtained.

<Examples 3-9 Surface Layer of Conductive Polymer Film>
However, the film thickness direction conductivity measurement using a probe is simple because it can be measured according to the actual situation of application, but the surface insulation layer was destroyed by the surface shape, or the conductivity of the surface layer was improved. Sometimes it is difficult to discuss separately.
Therefore, in Examples 3 to 9, the thickness of the insulating layer on the surface is measured by measuring a bias voltage necessary for destroying the insulating layer on the surface of the conductive polymer film using a scanning tunneling microscope (STM). The amount was quantified. It shows that the lower the bias voltage, the thinner the insulating layer on the surface or the improved conductivity of the surface layer.

  STM usually has a very sharp and sharp tip close to the surface of a conductive material, observes the atomic state electronic structure and structure of the surface from the flowing tunnel current, and scans the surface. can get. However, in Examples 3-9, the measurement using STM did not scan the surface, but measured an arbitrary place on the substrate surface. That is, in the measurements according to Examples 3 to 9, the probe was held so as to have a constant height from the surface, and the bias voltage between the substrate and the STM probe was gradually increased. The voltage at which current begins to flow is the voltage at which tunnel current begins to flow through the insulating layer on the surface of the conductive polymer. If the insulating layer is the same material, the voltage is proportional to the thickness of the insulating layer, so the thickness of the insulating layer on the surface was compared by comparing the voltage at which the bias current starts to flow.

[Example 3]
As the dopant (c), PEG200, which is a highly polar compound, was used.
The polythiophene-based conductive polymer film was prepared by forming a 0.2 μm-thick gold vapor-deposited film on a glass substrate and performing the production method 1 thereon.
The measurement results using STM are shown in Table 3.

In Table 3, the PEG200 content is expressed as the concentration (unit: mass%) in the mixture of the PEDOT / PSS aqueous dispersion and PEG200.

From the results shown in Table 3, it was confirmed that the addition of PEG200 improved the conductivity in the film thickness direction of the polythiophene-based conductive polymer film. In particular, the maximum conductivity improvement effect was obtained when PEG200 was added at 0.5 mass%.
In this example, since the conductivity improvement effect is obtained even when 0.01% by mass of PEG 200 is added, it is easy to obtain the conductivity improvement effect even if the addition amount is smaller. Can understand.

[Example 4]
As the dopant (c), EG which is a highly polar compound was used.
The production method of the polythiophene-based conductive polymer film and the measurement method using STM are the same as described in Example 3.
The measurement results are shown in Table 4.

  In Table 4, the EG content is represented by the concentration (unit: mass%) in the mixture of the PEDOT / PSS aqueous dispersion and EG.

From the results shown in Table 4, it was confirmed that the addition of EG improved the conductivity in the film thickness direction of the polythiophene-based conductive polymer film. In particular, when the EG was added by 0.5% by mass, the maximum conductivity improvement effect was obtained.
In this example, since the conductivity improvement effect is obtained even when 0.01% by mass of EG is added, it is easy to obtain the conductivity improvement effect even if the addition amount is smaller. Can understand.

[Example 5]
DMSO, which is a highly polar compound, was used as the dopant (c).
The production method of the polythiophene-based conductive polymer film and the measurement method using STM are the same as described in Example 3.
The measurement results are shown in Table 5.

  In Table 5, the DMSO content is expressed as the concentration (unit: mass%) in the mixture of the PEDOT / PSS aqueous dispersion and DMSO.

From the results shown in Table 5, it was confirmed that the addition of DMSO improved the conductivity in the thickness direction of the polythiophene-based conductive polymer film. In particular, the maximum conductivity improvement effect was obtained when DMSO was added at 0.5 mass%.
In this example, since the conductivity improvement effect is obtained even when DMSO is added in an amount of 0.01% by mass, it is easy to obtain the conductivity improvement effect even if the addition amount is smaller. Can understand.

[Example 6]
As the dopant (c), EMI-TFSI which is an ionic liquid was used.
The production method of the polythiophene-based conductive polymer film and the measurement method using STM are the same as described in Example 3.
The measurement results are shown in Table 6.

  In Table 6, the EMI-TFSI content is expressed as the concentration (unit: mass%) in the mixture of the PEDOT / PSS aqueous dispersion and EMI-TFSI.

From the results shown in Table 6, it was confirmed that the addition of EMI-TFSI improved the conductivity in the film thickness direction of the polythiophene-based conductive polymer film. In particular, when EMI-TFSI was added in an amount of 30 to 40% by mass, the maximum conductivity improvement effect was obtained.
In addition, in a present Example, it can be understood easily that the electroconductivity improvement effect will be acquired if EMI-TFSI is added exceeding 20 mass%.

[Example 7]
LiClO ₄ that is an electrolyte salt was used as the dopant (c).
The production method of the polythiophene-based conductive polymer film and the measurement method using STM are the same as described in Example 3.
The measurement results are shown in Table 7.

In Table 7, the LiClO ₄ content is expressed as the concentration (unit: mass%) in the mixture of the PEDOT / PSS aqueous dispersion and LiClO ₄ .

From the results shown in Table 7, it was confirmed that the addition of LiClO ₄ improved the conductivity in the film thickness direction of the polythiophene-based conductive polymer film. In particular, the maximum conductivity improvement effect was obtained when LiClO ₄ was added in an amount of 40% by mass or more.
In this example, it can be easily understood that the effect of improving conductivity can be obtained by adding LiClO ₄ in excess of 30 mass%.

[Example 8]
LiTFSI, which is an electrolyte salt, was used as the dopant (c).
The production method of the polythiophene-based conductive polymer film and the measurement method using STM are the same as described in Example 3.
The measurement results are shown in Table 8.

  In Table 8, the LiTFSI content is represented by the concentration (unit: mass%) in the mixture of the PEDOT / PSS aqueous dispersion and LiTFSI.

From the results shown in Table 8, it was confirmed that the addition of LiTFSI improved the conductivity in the film thickness direction of the polythiophene-based conductive polymer film. In particular, the maximum electrical conductivity improving effect was obtained when 50% by mass of LiTFSI was added.
In addition, in a present Example, it can understand easily that the electroconductivity improvement effect will be acquired if LiTFSI is added exceeding 2 mass%.

[Example 9: Conductivity of polythiophene-based conductive polymer film]
As the dopant (c), LiBETI, which is an electrolyte salt, was used.
The production method of the polythiophene-based conductive polymer film and the measurement method using STM are the same as described in Example 3.
The measurement results are shown in Table 9.

  In Table 9, the LiBETI content is represented by the concentration (unit: mass%) in the mixture of the PEDOT / PSS aqueous dispersion and LiBETI.

From the results shown in Table 9, it was confirmed that the addition of LiBETI improved the conductivity in the film thickness direction of the polythiophene-based conductive polymer film. In particular, the maximum conductivity improvement effect was obtained when LiBETI was added at 30% by mass.
In this example, since the effect of improving the conductivity was obtained even when 10% by mass of LiBETI was added, it is easily understood that the effect of improving the conductivity can be obtained even if the addition amount is smaller. it can.

DESCRIPTION OF SYMBOLS 1 Transparent electrode structure 2 A layer 3 B layer 4 Transparent base material 5 Polythiophene type conductive polymer film 11 Resistive film type touch panel 12 Upper electrode plate (movable electrode plate)
13 Lower electrode plate (fixed electrode plate)
14 Spacer (insulating layer)
15 Upper transparent substrate 16 Upper transparent electrode 17 Lower transparent electrode 18 Lower transparent substrate 19 Dot spacer 20 FPC
21. Resistive touch panel (when pressed)
22 fingers (or pen)
DESCRIPTION OF SYMBOLS 23 Anisotropic conductive sheet 41 Film thickness direction electrical conductivity measuring apparatus 42 PSS layer 43 PEDOT layer 44 Gold electrode 45 Glass substrate 46 Polythiophene type conductive polymer film 47 Movable probe 48 Pressure gauge 49 Resistance meter 50, 51 Lead wire 101 Matrix-type resistive touch panel 102 Upper transparent resin film 103 Upper transparent electrode 104 Lower transparent electrode 105 Lower transparent glass substrate 121 Resistive touch panel (when the upper and lower polythiophene conductive polymer films are not in contact)
122 Transparent resin film 123, 126 Polythiophene layer 124, 125 PSS layer 127 Transparent glass substrate 128 Spacer 129 Dot spacer 130 Finger (or pen)
131 Resistive touch panel (when contacting upper and lower polythiophene conductive polymer film)

Claims (9)

A transparent electrode structure used for an electrical connection structure in which a transparent electrode is provided on a transparent substrate,
The transparent electrode includes at least one transparent conductive film,
The transparent conductive film comprises a polythiophene-based conductive polymer (a),
A polymer electrolyte (b);
A polythiophene-based conductive polymer film containing a dopant (c) selected from the group consisting of a highly polar compound, an ionic liquid or an electrolyte salt;
A transparent electrode structure used for an electrical connection structure, wherein the polythiophene-based conductive polymer film has conductivity in a film thickness direction. A first transparent electrode structure having a transparent substrate and a transparent electrode provided on the transparent substrate, and a second transparent electrode having a transparent substrate and a transparent electrode provided on the transparent substrate The transparent electrode of the first transparent electrode structure and the transparent electrode of the second transparent electrode structure are brought into contact with each other by arranging the structure so that the transparent electrodes face each other with a spacer interposed therebetween. In the resistive touch panel that can obtain the electrical connection of the transparent electrode,
A resistive film type touch panel, wherein the first transparent electrode structure is the transparent electrode structure according to claim 1.   Furthermore, the resistive film type touch panel of Claim 2 whose 2nd transparent electrode structure is the transparent electrode structure of Claim 1. An application step of applying a polythiophene-based conductive polymer composition on a transparent substrate;
A film forming step of forming a polythiophene-based conductive polymer film from the polythiophene-based conductive polymer composition in this order while allowing gravity segregation in the film thickness direction;
The polythiophene conductive polymer composition comprises a polythiophene conductive polymer (a),
A polymer electrolyte (b);
A method for producing a transparent electrode structure, which is a polythiophene-based conductive polymer composition containing a dopant (c) selected from the group consisting of a highly polar compound, an ionic liquid or an electrolyte salt. An application step of applying a polythiophene-based conductive polymer composition containing the polythiophene-based conductive polymer (a) and the polymer electrolyte (b) on a transparent substrate;
A film forming step of forming a polythiophene conductive polymer film from the polythiophene conductive polymer composition while allowing gravity segregation in the film thickness direction;
The manufacturing method of the transparent electrode structure which comprises the doping process which dopes the dopant (c) chosen from the group which consists of a highly polar compound, an ionic liquid, and electrolyte salt in this polythiophene type conductive polymer film in this order. Polythiophene system for transparent electrode structure comprising polythiophene-based conductive polymer (a), polymer electrolyte (b), and dopant (c) selected from the group consisting of highly polar compounds, ionic liquids and electrolyte salts A conductive polymer composition comprising:
With respect to 100 parts by mass of the polythiophene conductive polymer (a), 50 parts by mass or more of the polymer electrolyte (b), 1.25 parts by mass or more of a highly polar compound as the dopant (c), ionic liquid 6 .8 × 10 ³ parts by mass or lithium perchlorate 1.2 × 10 ⁴ parts by mass or more, lithium bis (trifluoromethanesulfone) imide 5.5 × 10 ² parts by mass or lithium bis (pentafluoroethanesulfone) imide A polythiophene-based conductive polymer composition for a transparent electrode structure, comprising 2.7 parts by mass or more. Polythiophene system for transparent electrode structure comprising polythiophene-based conductive polymer (a), polymer electrolyte (b), and dopant (c) selected from the group consisting of highly polar compounds, ionic liquids and electrolyte salts A conductive polymer composition comprising:
The polythiophene-based conductive polymer (a) and the polymer electrolyte (b) are combined at a mass ratio of polythiophene-based conductive polymer (a) / polymer electrolyte (b) ≦ 2, and 1.2 to In the aqueous dispersion containing 1.4% by mass, as the dopant (c), in the composition, 0.01% by mass or more of the highly polar compound, more than 20% by mass of the ionic liquid or 30% by mass of lithium perchlorate Polythiophene conductivity for transparent electrode structure obtained by adding more than 2% by mass of lithium bis (trifluoromethanesulfone) imide or 0.01% by mass or more of lithium bis (pentafluoroethanesulfone) imide Polymer composition.   A resistive film for a resistive film type touch panel obtained by using the polythiophene-based conductive polymer composition for a transparent electrode structure according to claim 6 or 7.   A transparent electrode for a resistive film type touch panel obtained by using the polythiophene-based conductive polymer composition for a transparent electrode structure according to claim 6 or 7.