JP2007172984A - Organic conductive film, transparent organic conductive film, and coordinate input device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic conductive film with reduced contact resistance due to contact with a foreign conductor. <P>SOLUTION: This transparent organic conductive film is provided with a transparent base material 12 and an organic conductive film 11 formed on a transparent base material. The organic conductive film 11 is provided with an organic conductive polymer and metal ions contained in the organic conductive polymer. Since the organic conductive polymer contains the metal ions, contact resistance with an ITC film or another type of organic conductive film is reduced greatly. For including the metal ions in the organic polymer, an ionizable metal compound or metal is added to a suspension/solution solvent before film formation of the organic conductive polymer material, and the metal ions are included in the organic conductive film when the organic conductive film is formed and dried. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a coordinate input device using a touch panel used for a portable information terminal and the like, and an organic conductive film and a transparent organic conductive film suitable for forming the transparent electrode.

  In recent years, with the spread and progress of portable information devices, centering on electronic notebooks and PDAs (Personal Digital Assistants), mobile phones, PHS, calculators, watches, GPS (Global Positioning System), bank ATMs Coordinate input device having excellent man-machine interface performance for inputting information by touching the screen with a pen or a finger in data input in a high function device such as a system, vending machine, POS (Point Of Sales) system, etc. It has been adopted and its application in many fields is expanding.

  These high-performance devices have been made smaller and more multifunctional due to advances in semiconductor elements, and in particular, miniaturization of portable information terminals such as mobile phones, PDAs, and notebook personal computers has become remarkable. The volume ratio of the coordinate input device and the display element in the main body is relatively large, and the coordinate input device is also required to be downsized.

  As described in Patent Document 1, the coordinate input device has a structure in which two transparent conductive plates having transparent electrodes on the surface are arranged in parallel at a predetermined interval so that the transparent electrodes face each other. The drive detection circuit alternately applies a voltage in the X direction to one of the opposing transparent electrodes and a voltage in the Y direction to the other. Since the transparent electrode acts as a resistance film, each part of the transparent electrode becomes a voltage corresponding to the position when a voltage is applied.

  At this time, when a part of the two transparent conductive plates is pressed and the transparent electrodes come into contact with each other, the contact portion of the transparent electrode on the side where the voltage is not applied (second) is also applied to the side where the voltage is applied (first Therefore, the position of the contact portion of the transparent electrode on the side to which the voltage is applied (first) is determined by detecting the voltage by the drive detection circuit. Similarly, the position of the contact portion of the first transparent electrode can be determined with a voltage applied to the second transparent electrode.

  The transparent electrode acting as a resistance film generally uses an ITO film obtained by evaporating In and Sn, but has a problem of high manufacturing cost. Further, at least the transparent conductive plate on the pressing side needs to be partially deformed by pressing, and is formed of a polymer material film. Since the ITO film is a hard thin film and fragile, when it is formed on a flexible polymer film, cracks are generated by continuous writing, the resistance of the resistance film changes, and the coordinate position reading accuracy decreases. There was a problem of durability. Therefore, a resistance film using an organic conductive material that solves these problems and is easier to manufacture and inexpensive has been developed. Patent Document 2 describes an organic conductive film in which conductivity is improved by dispersing conductive particles. However, since conductive particles are dispersed, there is a problem that transparency is insufficient.

Japanese Patent Laid-Open No. 2001-154805 Japanese Patent Laid-Open No. 2004-185914

  The organic conductive film has better durability than the ITO film, but has a problem that the surface resistivity is higher and the light transmittance is lower than the ITO film. For this reason, it is desirable to form the transparent electrode not on the pressure side with an ITO film and the counter electrode with an organic conductive film. In this case, however, the contact resistance greatly increases due to different conductor contact, resulting in a decrease in input sensitivity and a delay in coordinate input time. Problems occur. This problem also occurs when two opposing transparent electrodes are formed of different organic conductive films.

  The present invention solves these problems, and reduces contact resistance due to different conductor contact when an organic conductive film is used for one transparent electrode and a transparent electrode made of a material different from that of the organic conductive film is used for the counter electrode. An organic conductive film in which an increase in contact resistance is small even when an organic conductive film is used as one of the electrodes, and problems such as input sensitivity and input time delay do not occur, a transparent organic conductive film having such an organic conductive film, And it aims at realization of the coordinate input device using such a transparent organic conductive film.

  In order to achieve the above object, according to the present invention, metal ions are contained in the organic conductive film to reduce the contact resistance due to the connection of different conductors.

  That is, the organic conductive film of the present invention comprises an organic conductive polymer and metal ions contained in the organic conductive polymer.

  Since the organic conductive film of the present invention contains metal ions in the organic conductive polymer, the contact resistance with the ITO film and other types of organic conductive films is remarkably reduced.

  In order to contain metal ions in the organic conductive polymer, a metal compound or metal that is ionized with respect to the dispersion or dissolution solvent before film formation of the organic conductive polymer material is added, and the organic conductive film is added to the organic conductive film when the organic conductive film is dried. Contain metal ions.

  As the organic conductive polymer material, organic conductive polymers represented by polyacetylene, polypyrrole, polythiophene, polyphenylene vinylene, and their derivative polymers can be used.

  As metal ions, Na, Mg, K, Al, Mn, Zn, Cr, Fe, Cd, Co, Ni, Sn, Pb, Cu, Hg, Ag, Pt, Au, Ba, Sr, Sb, Bi, Pd One or more of metal elements typified by can be used.

  In addition, the metal ions are supplied by containing a simple metal, an inorganic metal salt, an organic metal salt, an inorganic metal compound, and an organic metal compound in the organic conductive polymer.

  The concentration of the metal ions is preferably 0.01 to 15 wt%, particularly 0.05 to 10 wt% with respect to the solid content concentration of the organic conductive film.

  In the above configuration, the metal ion has a chemical bond obtained by reducing a part of the organic conductive polymer.

  The transparent organic conductive film of the present invention is a transparent organic conductive film comprising a transparent base material and an organic conductive film formed on the transparent base material, wherein the organic conductive film contains the above metal ions. It is an organic conductive film. The production of organic conductive films does not require a vacuum process and can be solution coated on the substrate in the atmosphere, such as microbars, closed edge dies, Meyer bars, blade coaters, and other die coaters, and roll offset offset coaters. It is possible to use a general-purpose coating apparatus capable of solution coating such as a gravure coater such as a micro gravure, a screen printing machine.

  The transparent substrate is a PET film or a glass plate.

  The transparent base material desirably blocks ultraviolet rays.

  The coordinate input device according to the present invention has two transparent conductive plates that are arranged in parallel at predetermined intervals and whose opposite surfaces are transparent electrodes, and voltages in different directions of the transparent electrodes of the two transparent conductive plates, respectively. And a drive detection circuit that electrically detects a position where the transparent electrodes are in contact with each other by pressurizing a part of the two transparent conductive plates. One of the conductive plates is the transparent organic conductive film described above.

  As the other transparent electrode of the two transparent conductive plates, an inorganic transparent electrode typified by an ITO film, for example, a transparent electrode containing ZnO, or an organic conductive film can be used.

  According to the present invention, an organic conductive film with reduced contact resistance due to different conductor contact is realized, and problems such as input sensitivity and input time delay occur by using a transparent organic conductive film having this organic conductive film. Coordinate input device that does not.

  An embodiment when the present invention is applied to a touch panel of a coordinate input device will be described below with reference to the accompanying drawings. The scope of the present invention is not limited to the following embodiments.

  FIG. 1 is a basic configuration diagram of a resistive film type touch panel constituting an input unit of a coordinate input device. As shown in the figure, the touch panel has a structure in which two first and second transparent conductive plates 1 and 2 having transparent electrodes on the surface are arranged in parallel at a predetermined interval so that the transparent electrodes face each other. Drive electrodes 3 and 4 are provided at both ends in the Y direction of the first transparent conductive plate 1, and drive electrodes 5 and 6 are provided at both ends in the X direction of the second transparent conductive plate 2. The drive detection circuit 7 applies a voltage to the drive electrodes 3 and 4 at both ends of the first transparent conductive plate 1 so that each point on the transparent electrode of the first transparent conductive plate 1 is positioned in the Y direction. Depending on the voltage is generated. Similarly, the drive detection circuit 7 applies a voltage to the drive electrodes 5 and 6 at both ends of the second transparent conductive plate 2, so that each point on the transparent electrode of the second transparent conductive plate 2 has X A voltage is generated depending on the position in the direction. The voltage application to the drive electrodes 3 and 4 and the voltage application to the drive electrodes 5 and 6 are alternately performed in a time division manner.

  For example, when a voltage is applied to the drive electrodes 3 and 4 at both ends of the first transparent conductive plate 1, a part of the first transparent conductive plate 1 is pressurized with the input pen 8 to thereby apply the first and first electrodes. When the transparent electrodes of the second transparent conductive plates 1 and 2 are in contact with each other, the contact portion of the transparent electrode of the first transparent conductive plate 1 is also the contact portion of the transparent electrode of the second transparent conductive plate 2 where no voltage is applied. When the drive detection circuit 7 detects this voltage, the position in the Y direction of the contact portion to which the voltage is applied is determined. The contact position in the X direction is also detected in the same manner.

  The above configuration and operation are the same as the configuration and operation of a conventional resistive film type touch panel, and are described in Patent Document 1 and the like.

  In the touch panel of the present embodiment, the second transparent conductive plate 2 is obtained by forming a transparent electrode with an ITO film on a glass support substrate. Since the ITO film has been widely known, description thereof will be omitted. In addition, it is also possible to comprise the transparent electrode of the 2nd transparent conductive plate 2 with other inorganic type transparent electrodes, such as ZnO.

  Furthermore, in the touch panel of the present embodiment, the transparent electrode of the first transparent conductive plate 1 with which the input pen 8 is brought into contact is composed of an organic conductive film containing metal ions.

  FIG. 2 is a diagram illustrating a configuration of the first transparent conductive plate 1 of the touch panel of the present embodiment. As shown in FIG. 2, the 1st transparent conductive plate 1 forms the organic electrically conductive film 11 on the support base material 12 made from polymer films, such as PET film. The support base 12 desirably has a function of blocking ultraviolet rays in order to prevent the organic conductive film 11 from being deteriorated by ultraviolet rays.

  The organic conductive film 11 is obtained by adding metal ions to an organic conductive polymer such as polyacetylene, polypyrrole, polythiophene, polyphenylene vinylene, and organic conductive polymers represented by these derivative polymers. By dispersing and polymerizing a metal compound or metal added to a dispersion or dissolution solvent before film formation of the polymer material on the support substrate 12 by various methods such as coating with a coater, the organic material is dried. Metal ions are contained in the conductive film. Since the organic conductive polymer 11 contains metal ions in the organic conductive polymer, the contact resistance with the opposing ITO film can be remarkably reduced as compared with the case where no metal ions are contained. Further, the organic conductive film 11 containing metal ions has low contact resistance with other types of organic conductive films. In addition, since a general-purpose wet coating apparatus can be applied, mass production is possible, and thus the cost of the film can be reduced.

  As metal ions to be contained, Na, Mg, K, Al, Mn, Zn, Cr, Fe, Cd, Co, Ni, Sn, Pb, Cu, Hg, Ag, Pt, Au, Ba, Sr, Sb, Bi , One or more of metal elements typified by Pd can be used. Further, the metal ions are supplied into the polymer by containing a metal simple substance, an inorganic metal salt, an organic metal salt, an inorganic metal compound, and an organic metal compound in the organic conductive polymer. The metal ion has a chemical bond obtained by reducing a part of the organic conductive polymer.

  The concentration of the metal ions is preferably 0.01 to 15 wt%, particularly 0.05 to 10 wt% with respect to the solid content concentration of the organic conductive film.

  An embodiment of the present invention will be described below with reference to FIG.

As a base material, an organic conductive polymer is coated on a PET film of 188 μm using a bar coater to a wet film thickness of 20 μm, and a heat treatment is performed at a drying temperature of 100 ° C. and a drying time of 3 minutes to produce a transparent organic conductive film having a transmittance of 91%. did. Silver paste is printed by screen printing on the first electrodes 3 and 4 on both ends of the transparent organic conductive film, and the second electrodes 5 and 6 orthogonal to the transparent organic conductive film are screened on both ends of the ITO glass serving as a counter electrode. Silver paste is printed by the printing method, and the two are opposed to each other. In the bonding, there is no particular limitation as long as the first conductor 1 and the second conductor 2 can be bonded together, and can be appropriately selected from known bonding methods, for example, double-sided tape. Adhesive, heating, pressurizing method, etc. can be used. These may be used alone or in combination of two or more. Among these, the following method using the double-sided tape, specifically, a double-sided tape is attached in a frame shape to the outer peripheral portion of the second conductor, holes are provided at both ends of the double-sided tape, A method of bonding the first conductor to the second conductor after dropping the conductive resin into the hole is preferable. In the case of this method, it is advantageous in that electricity can be easily conducted between the first conductor and the second conductor even after bonding.
The conductive resin is not particularly limited as long as it has conductivity, and can be appropriately selected from known conductive resins. Examples thereof include epoxy-based conductive resins. The resistive touch panel shown in FIG. 1 was manufactured using the above steps. The first transparent electrode plate 1 uses a PET film as the support substrate 11, uses a thiophene-based organic conductive film as the organic conductive polymer material, and Al ³⁺ as metal ions is 0 with respect to the solid content concentration of the organic conductive polymer material. It was formed by adding .05 wt%. The second transparent electrode plate 2 was formed by forming ITO having a surface resistivity of 400Ω / □ on a glass support substrate to form a counter electrode.

  With such a resistive film type touch panel, the weight at which the tip was pressed with a 0.8 R stylus to obtain coordinate input was measured. As a result, the minimum input weight capable of coordinate input was 0.4 N.

A panel having the same configuration except that the addition amount of Al ³⁺ which is a metal ion in the panel configuration shown in Example 1 was changed to a solid content concentration of 10 wt% of the organic conductive material, and the same measurement was performed. The input weight was 0.2N.

A panel having the same configuration except that the metal ion was changed to Cu ⁺ in the panel configuration shown in Example 1 and the same measurement was performed. As a result, the minimum input weight was 0.4 N.

A panel having the same configuration except that the metal ion was changed to Na ⁺ in the panel configuration shown in Example 1 was prepared, and the same measurement was performed. As a result, the minimum input weight was 0.4 N.

  In the panel configuration shown in Example 1, a panel having the same configuration was prepared except that the surface resistivity of ITO formed on the glass substrate of the second transparent electrode plate 2 was changed to 1 kΩ / □. As a result, the minimum input weight was 0.4N.

  In order to confirm the effect of the present invention, the following comparative examples were performed.

(Comparative Example 1)
A panel having the same configuration except that no metal ions were added to the organic conductive polymer material in the panel configuration of Example 1, and the same measurement was performed. As a result, the minimum input weight deteriorated to 1N. An input time delay occurred.

(Comparative Example 2)
A panel having the same configuration except that no metal ions were added to the organic conductive polymer material in the panel configuration of Example 5, and the same measurement was performed. As a result, the minimum input weight deteriorated to 9 N, and the input time There was a delay.

(Comparative Example 3)
A panel having the same configuration as the panel configuration shown in Example 1 except that the amount of addition of Al ³⁺ that is a metal ion was set to 20 wt% of the solid content concentration of the organic conductive polymer material was produced, and the same measurement was performed. However, even if a maximum input weight of 50 N is applied, it is impossible to input coordinates.

(Comparative Example 4)
In the panel configuration shown in Example 1, a panel having the same configuration was prepared except that the first transparent electrode plate 1 in which an ITO film having a surface resistivity of 400Ω / □ was formed on the support substrate of the PET film was used. When the same measurement was performed, the minimum input weight was 0.4 N, which was equivalent to Example 1. As described above, the configuration of Comparative Example 4 has a problem in durability.

(Comparative Example 5)
First and second transparent electrode plates 1 and 2 in which the same type of organic conductive film not containing metal ions having a surface resistivity of 700 Ω / □ is formed on a PET film support substrate in the panel configuration shown in Example 1. A panel having the same configuration except that was used and a similar measurement was performed. As a result, the minimum input weight was 0.4 N, which was the same as in Example 1. As described above, the configuration of Comparative Example 5 has a problem that the light transmittance is low.

  In the embodiments and examples of the present invention described above, the transparent electrode of the first transparent conductive plate on the side in contact with the input pen is formed of a transparent organic conductive film in which metal ions are dispersed, and the second transparent electrode facing the transparent electrode. The transparent electrode of the conductive plate is formed of an ITO film. For example, both the transparent electrodes of the first and second transparent conductive plates are formed of a transparent organic conductive film, and at least one transparent organic conductive film contains metal ions. You may make it do.

(Appendix 1)
An organic conductive polymer;
An organic conductive film comprising: metal ions contained in the organic conductive polymer. (1)
(Appendix 2)
The metal ions are Na, Mg, K, Al, Mn, Zn, Cr, Fe, Cd, Co, Ni, Sn, Pb, Cu, Hg, Ag, Pt, Au, Ba, Sr, Sb, Bi, Pd. The organic conductive film according to supplementary note 1, having one or more elements. (2)
(Appendix 3)
The organic conductive film according to appendix 1, wherein the metal ion is formed using a metal simple substance, an inorganic metal salt, an organic metal salt, an inorganic metal compound, or an organic metal compound contained in the organic conductive polymer as a supply source.

(Appendix 4)
The organic conductive film according to supplementary note 1, wherein the concentration of the metal ions is 0.01 to 15 wt% with respect to the solid content concentration of the organic conductive film.

(Appendix 5)
The organic conductive film according to claim 1, wherein the metal ion has a chemical bond obtained by reducing a part of the organic conductive polymer.

(Appendix 6)
A transparent substrate;
An organic conductive film formed on the transparent substrate, and a transparent organic conductive film comprising:
6. The transparent organic conductive film, wherein the organic conductive film is the organic conductive film according to any one of appendices 1 to 5. (3)
(Appendix 7)
The transparent organic conductive film according to appendix 6, wherein the transparent substrate is a PET film.

(Appendix 8)
The transparent organic conductive film according to appendix 6, wherein the transparent substrate is a glass plate.

(Appendix 9)
The transparent organic conductive film according to appendix 6, wherein the transparent substrate blocks ultraviolet rays.

(Appendix 10)
Two transparent conductive plates that are arranged in parallel at a predetermined interval and whose opposing surfaces are transparent electrodes;
A voltage is applied to each of the two transparent conductive plates in different directions of the transparent electrodes, and a part of the two transparent conductive plates is pressed to electrically detect a position where the transparent electrodes are in contact with each other. In a coordinate input device comprising a drive detection circuit that
One of the two transparent conductive plates is the transparent organic conductive film according to any one of supplementary notes 6 to 9, wherein the coordinate input device is characterized in that (4)
(Appendix 11)
The coordinate input device according to appendix 10, wherein the other transparent electrode of the two transparent conductive plates has an ITO film. (5)
(Appendix 12)
The coordinate input device according to appendix 10, wherein the other transparent electrode of the two transparent conductive plates contains ZnO.

  The organic conductive film and the transparent organic conductive film of the present invention are applied to a coordinate input device such as a resistive film type touch panel, but are not limited to this, and the transparent electrode (wiring) is in contact with a different transparent electrode. Applicable if available.

FIG. 1 is a diagram illustrating a basic configuration of a coordinate input device according to an embodiment. FIG. 2 is a cross-sectional view of the transparent organic conductive film of the example. FIG. 3 is a diagram showing measurement results of Examples and Comparative Examples in which the present invention is applied to a touch panel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st transparent conductive plate 2 2nd transparent conductive plate 7 Drive detection circuit 11 Organic conductive film 12 Support base material

Claims (5)

An organic conductive polymer;
An organic conductive film comprising: metal ions contained in the organic conductive polymer.   The metal ions are Na, Mg, K, Al, Mn, Zn, Cr, Fe, Cd, Co, Ni, Sn, Pb, Cu, Hg, Ag, Pt, Au, Ba, Sr, Sb, Bi, Pd. The organic conductive film according to claim 1, comprising one or more elements. A transparent substrate;
An organic conductive film formed on the transparent substrate, and a transparent organic conductive film comprising:
The said organic conductive film is an organic conductive film of Claim 1 or 2, The transparent organic conductive film characterized by the above-mentioned. Two transparent conductive plates that are arranged in parallel at a predetermined interval and whose opposing surfaces are transparent electrodes;
A voltage is applied to each of the two transparent conductive plates in different directions of the transparent electrodes, and a part of the two transparent conductive plates is pressed to electrically detect a position where the transparent electrodes are in contact with each other. In a coordinate input device comprising a drive detection circuit that
One of the said 2 transparent conductive plates is the transparent organic conductive film of Claim 3, The coordinate input device characterized by the above-mentioned.   The coordinate input device according to claim 4, wherein the other transparent electrode of the two transparent conductive plates has an ITO film.

Images