JP2001102258A - Method for manufacturing conductive polymer film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an easy peeling method of a conductive polymer film which is stuck on a metal plate and a power supply terminal by electrolytic polymerization. SOLUTION: After a metal plate 1 and a counter electrode 2 are dipped in polymeric liquid 3 composed of polymeric monomer and support electrolyte, a DC voltage is applied from a DC power source 20 to a part between the metal plate 1 (anode) and the counter electrode 2 (cathode), and a conductive polymer film 30 on the metal plate 1 is subjected to electrolytic polymerization. The voltage between the metal plate 1 and the opposite electrode 2 is increased, oxygen gas (bubbles 50) is generated from the metal plate 1, and the conductive polymer film 30 is peeled from the surface of the metal plate 1 by the pressure of the oxygen gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a conductive polymer film, and more particularly to a method for producing a conductive polymer film used for a current collector of an electric double layer capacitor or a solid electrolyte of a solid electrolytic capacitor by electrolytic polymerization. It is intended to provide a method of peeling off from an auxiliary electrode or a base after formation.

[0002]

2. Description of the Related Art In recent years, conductive polymers have been used for current collectors of electric double layer capacitors and solid electrolytes of solid electrolytic capacitors.

[0003] As a method for forming a conductive polymer, there are a chemical polymerization method and an electrolytic polymerization method. The former is a method used when the substrate is electrically insulating. For example, a conductive polymer is applied to the surface of the substrate by immersing the substrate in a low-temperature mixed solution of iron p-toluenesulfonate and pyrrole, followed by drying and washing. Of polypyrrole is formed by chemical polymerization. The latter method is used when the substrate is conductive.For example, an auxiliary electrode is brought into contact with a substrate immersed in a mixed aqueous solution of sodium p-toluenesulfonate and pyrrole, and the auxiliary electrode is placed between the auxiliary electrode and the counter electrode. When a DC voltage is applied for a predetermined time so that
The conductive polymer polypyrrole is electrolytically polymerized on the substrate surface. As a substrate for the electrolytic polymerization, a material such as a metal such as stainless steel or a material obtained by pre-coating a conductive polymer film on a porous electrically insulating material such as tantalum oxide by the above-described chemical polymerization method to impart conductivity is used. You.

[0004] The electrolytic polymerization method has been widely used in a method of manufacturing a capacitor because the electrolytic solution is less likely to deteriorate and the film thickness is easily controlled.

A method of forming a conductive polymer film when a conductive polymer is used as a current collector of an electric double layer capacitor will be described with reference to FIG. First, as shown in FIG. 3A, a metal plate 1 of stainless steel or the like (to be an anode electrode) is placed in an electrolytic polymerization solution (for example, a mixed aqueous solution of 30 wt% sodium p-toluenesulfonate and 5 wt% pyrrole) in an electrolytic tank 10. ), And using a DC power supply 20, a DC voltage is applied for a predetermined time using the metal plate 1 as an anode and the counter electrode 2 (a metal electrode such as stainless steel) as a cathode.
The electrode voltage of the metal plate 1 is about 1 V with respect to a standard electrode (hereinafter referred to as a silver / silver chloride standard electrode) in which silver chloride is deposited on the surface of silver. By this electrolysis, the metal plate 1 is placed on the metal plate 1 as shown in FIG.
As shown in (b), the conductive polymer film 30 (polypyrrole) is deposited. Next, after the electrolysis is completed, the conductive polymer film 3
3 is mechanically peeled off from the metal plate 1 by scratching or vibrating as shown in FIG. The peeled conductive polymer film is integrally formed with carbon to form a current collector.

Next, a method of forming a conductive polymer film when a conductive polymer is used for a solid electrolyte of a solid electrolytic capacitor will be described with reference to FIG. First, after anodic oxidation of a valve action metal powder sintered body such as tantalum metal having an anode lead 7 such as a tantalum wire planted thereon, a prepolymer film of a conductive polymer film such as polypyrrole is coated by a chemical polymerization method. A pellet 5 is formed. FIG. 4 (a)
Electrolytic polymerization liquid (for example, 30 wt% p-
(A mixed aqueous solution of sodium toluenesulfonate and 5 wt% pyrrole). Next, using a DC power supply 20, an auxiliary electrode made of a metal material such as stainless steel is brought into contact with the surface of the pellet to make the auxiliary electrode an anode and a counter electrode 2
(A metal electrode such as stainless steel) as a cathode, and a DC voltage is applied for a predetermined time to form a pellet 5 as shown in FIG.
A conductive polymer film 30 is formed on the surface.

[0007]

A method of using the above-mentioned conductive polymer film on a metal plate by electrolytic polymerization and peeling it off from the surface of the metal plate by vibration or scratching to use it as a current collector of an electric double layer capacitor. Has a problem that the conductive polymer film is easily broken when the conductive polymer film is peeled off from the metal surface.

[0008] In the above-mentioned method in which an auxiliary electrode is brought into contact with the pellet to electrolytically polymerize the electrolyte of a solid electrolytic capacitor made of a conductive polymer film, the auxiliary electrode is naturally coated with the conductive polymer film. . Since the auxiliary electrode is used repeatedly, the conductive polymer film deposited on the auxiliary electrode needs to be peeled off before the next use. As a method of peeling the conductive resin film, there is a method of peeling the conductive polymer film for a current collector of the electric double layer capacitor from the metal plate by the same vibration or scratching as the method of peeling the conductive polymer film from the metal plate. The pellets are liable to be scratched, etc., which causes the pellets to be scratched or chipped when used next time.

Japanese Patent Application Laid-Open No. 61-245413 discloses a method of peeling a conductive polymer film from a substrate by laminating a polymer resin film on a conductive polymer film electrolytically polymerized on an electrode surface. Although it is disclosed, when a polymer resin film is laminated, the polymer resin film easily adheres to the electrodes, and one side of the conductive polymer film is insulated by the polymer resin film. It cannot be used for current collectors.

As another method for peeling the conductive polymer film, Japanese Patent Application Laid-Open No. 7-94365 discloses a method in which the conductive polymer film deposited on the anode lead of a solid electrolytic capacitor is decomposed by heat treatment. However, this may be used as a method of removing the conductive polymer film deposited on the auxiliary electrode when the electrolyte of the solid electrolytic capacitor is electrolytically polymerized. In some cases, the surface of the auxiliary electrode is insulated by a film generated by thermal decomposition of the molecular film, and it is necessary to chemically treat the auxiliary electrode in order to use the auxiliary electrode repeatedly.

An object of the present invention is to provide a simple peeling method which solves the above-mentioned problems of the prior art for peeling a conductive polymer film formed by electrolytic polymerization on an auxiliary electrode or a metal plate.

[0012]

According to a first aspect of the method for producing a conductive polymer membrane of the present invention, the first and second electrodes are immersed in a mixed solution of a polymerizable monomer and a supporting electrolyte. Forming a conductive polymer film on the first electrode surface by electrolytic polymerization by performing electrolysis for a predetermined time using the first electrode as an anode and the second electrode as a cathode; Applying a DC voltage generated by oxygen gas between the first electrode and the second electrode to perform electrolysis for a predetermined time, and peeling the conductive polymer film from the surface of the first electrode. It is characterized by the following.

A second structure of the method for producing a conductive polymer film according to the present invention is a processing object for forming a desired conductive polymer film in a mixed solution of a polymerizable monomer and a supporting electrolyte. A step of immersing a first electrode in electrical communication with the object to be processed and a second electrode acting as a counter electrode of the first electrode; and contacting the first electrode with the object to be processed. Using a first electrode as an anode and the second electrode as a cathode, performing electrolysis for a predetermined time, and forming a conductive polymer film on the surface of the object to be processed and the first electrode by electrolytic polymerization; After separating the first electrode from the object to be processed, a DC voltage at which oxygen gas is generated from the first electrode is applied between the first electrode and the second electrode to perform electrolysis for a predetermined time, Forming the conductive polymer film on the first
Separating from the electrode surface.

According to the present invention, as described above, after the conductive polymer film is electrolytically polymerized on the first electrode (anode), and further electrolyzed at an oxygen gas generation potential, the first electrode (anode) is subjected to electrolysis at the generated oxygen gas pressure. The conductive polymer film is separated from the first electrode.

In the present invention, when the conductive polymer film deposited from the first electrode is peeled off by the pressure of oxygen gas, ultrasonic vibration is applied to the first electrode to peel off the conductive polymer film. Can be promoted.

[0016]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view of an electrolytic polymerization apparatus for explaining a method for producing a conductive polymer film according to a first embodiment of the present invention. FIG. 1 shows a method for producing a conductive polymer film when the conductive polymer film electrolytically polymerized on a metal plate is peeled off and used as a current collector such as an electric double layer capacitor.
First, as shown in FIG. 1A, a metal plate 1 made of stainless steel or the like and a counter electrode 2 made of stainless steel or the like are set in an electrolytic cell 10 containing a polymer solution 3, and a counter electrode is set using a DC power supply 20. 2 (to be a cathode) and metal plate 1 (to be an anode)
During this time, a DC voltage is applied for a predetermined time, and the conductive polymer film 30 is electrolytically polymerized on the surface of the metal plate 1 as shown in FIG.
As the polymerization solution, a solution containing a polymerizable monomer of pyrrole, thiophene, furan or a derivative thereof and a supporting electrolyte such as p-toluenesulfonic acid, naphthalenesulfonic acid or benzenesulfonic acid can be used. For example,
A polymerization solution 3 of 0.5 M pyrrole and 0.3 M p-toluenesulfonic acid aqueous solution was used, and the voltage of the metal plate 1 was set to 1.0 V based on a silver / silver chloride standard electrode.

Next, a voltage (for example, the potential of the metal plate 1 is set to 1 with reference to the silver / silver chloride standard electrode) from the metal plate 1 using a DC power source in the same polymerization solution 3 using a DC power supply. 0.5 V) and electrolyze for a predetermined time.
The conductive polymer film 30 was peeled off from the metal plate 1 as shown in FIG. In FIG. 1B, when ultrasonic vibration is applied to the metal plate 1, the conductive polymer film 30 can be more easily separated.
As described above, in the present invention, the conductive polymer film can be easily peeled off from the surface of the metal plate 1 by the pressure of oxygen gas, and the peeled film is integrally formed with carbon to form an electric double layer capacitor. And the like.

Next, a second embodiment of the present invention will be described with reference to FIG.

FIG. 2 is a schematic view of an electrolytic polymerization apparatus for explaining a method for producing a conductive polymer film according to a second embodiment of the present invention. FIG. 2 shows an example of forming an electrolyte of a solid electrolytic capacitor. The valve action metal sintered body composed of Ta and Nb or an etched foil of Al is anodized, and the surface is precoated with a conductive polymer film to make it conductive. This is a case where a conductive polymer film is electrolytically polymerized as a solid electrolyte on the pellet 5 formed. First, an anode lead was embedded in a Ta metal powder compact and sintered by a known technique. This sintered body was anodized to form tantalum oxide on the surface. Further, a conductive polymer film of polypyrrole was precoated on the tantalum oxide surface by chemical polymerization to form pellets 5.

Next, as shown in FIG.
The counter electrode 2 was set in the electrolytic cell 10 containing the polymerization liquid 3, and the stainless steel auxiliary electrode 6 (used as a power supply terminal) was set so as to be in contact with the pellet. Subsequently, a DC voltage is applied between the counter electrode 2 (to be a cathode) and the auxiliary electrode (to be an anode) for a predetermined time by using a DC power source 20 to apply a DC voltage to the surfaces of the auxiliary electrode 6 and the pellet 5 as shown in FIG.
The conductive polymer film 30 is electrolytically polymerized as shown in FIG. As the polymerization solution, a solution containing a polymerizable monomer of pyrrole, thiophene, furan or a derivative thereof and a supporting electrolyte such as p-toluenesulfonic acid, naphthalenesulfonic acid or benzenesulfonic acid can be used. For example,
When a polymerization solution 3 of 0.5 M pyrrole and 0.3 M p-toluenesulfonic acid aqueous solution was used, the voltage of the auxiliary electrode 6 was set to 1.0 V based on the silver / silver chloride standard electrode.

Next, after the auxiliary electrode 6 is separated from the pellet 5, a voltage (for example, the voltage of the auxiliary electrode 6) generated from the auxiliary electrode 5 by using a DC power source in the same polymerization liquid 3 is generated. The potential was 1.5 with respect to the silver / silver chloride standard electrode.
V) and electrolyzed for a predetermined time, and the conductive polymer film 30 was peeled off from the auxiliary electrode 6 (feed terminal) as shown in FIG. In FIG. 2B, when ultrasonic vibration is applied to the auxiliary electrode 61, the conductive polymer film 30 can be more easily separated.

As described above, according to the present invention, the power supply terminal (auxiliary electrode 6) is brought into contact with the pellet, and the conductive polymer film of the electrolyte for the solid electrolytic capacitor is electrolytically polymerized on the pellet. The conductive polymer film can be easily peeled off by the pressure of oxygen gas, so that not only the power supply terminal can be used repeatedly, but also the number of steps for peeling off can be reduced.

[0024]

As described above, in the present invention, an oxygen generation potential is applied to the electrode on which the conductive polymer film is formed, and the conductive polymer film can be effectively peeled off from the electrode by the pressure of the generated oxygen gas. The following effects can be obtained. (1) The conductive polymer film can be peeled off using the same polymer solution formed thereon, and the conductive polymer film can be peeled at a reduced cost.
In addition, the quality of the peeled conductive polymer film can be prevented from lowering as compared with the conventional mechanical peeling method. (2) When a conductive polymer film is formed by electrolytic polymerization as an electrolyte of a solid electrolytic capacitor, the conductive polymer film attached to the power supply terminal (auxiliary electrode) can be easily peeled off, and the power supply terminal can be used repeatedly. .

[Brief description of the drawings]

FIG. 1 is a schematic view of an electrolytic polymerization apparatus for explaining a method for producing a conductive polymer film according to a first embodiment of the present invention.

FIG. 2 is a schematic view of an electrolytic polymerization apparatus for explaining a method for producing a conductive polymer film according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram of an electrolytic polymerization apparatus for explaining an example of a conventional method for producing a conductive polymer film.

FIG. 4 is a schematic diagram of an electrolytic polymerization apparatus for explaining another example of a conventional method for producing a conductive polymer film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal plate 2 Counter electrode 3 Polymerization liquid 5 Pellet 6 Auxiliary electrode 7 Anode lead 10 Electrolyzer 20 DC power supply 30 Conductive polymer film 50 Bubbles

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01B 1/06 H01B 1/12 F 1/12 Z C08L 65:00 H01G 9/02 331H C08L 65:00 9 / 00 301F F term (reference) 4F071 AA58 AA61 AA69 AF37 AG04 AH12 BB12 BC01 4K021 AC24 BA12 BB03 BC07 BC09 CA02 CA03 CA09 CA15 DA13 5G301 CA30 CD01 CD02 CE01 5G323 AA01

Claims (7)

[Claims] After immersing a first electrode and a second electrode in a mixed solution of a polymerizable monomer and a supporting electrolyte, electrolysis is performed for a predetermined time using the first electrode as an anode and the second electrode as a cathode. Forming a conductive polymer film on the surface of the first electrode by electrolytic polymerization, and applying a DC voltage for generating oxygen gas from the first electrode between the first electrode and the second electrode. And electrolyzing for a predetermined time to peel off the conductive polymer film from the surface of the first electrode. 2. A conductive object to form a desired conductive polymer film in a mixed solution of a polymerizable monomer and a supporting electrolyte, a first electrode electrically connected to the object to be processed, and Immersing a second electrode acting as a counter electrode of the first electrode, contacting the first electrode with the object to be processed, and using the first electrode as an anode and the second electrode as a cathode Electrolyzing for a predetermined time, forming a conductive polymer film on the surface of the object to be processed and the first electrode by electrolytic polymerization, and after separating the first electrode from the object to be processed, A DC voltage at which oxygen gas is generated from the first electrode is applied between the first electrode and the second electrode to perform electrolysis for a predetermined time, and the conductive polymer film is separated from the surface of the first electrode. Conducting the conductive material. A method for manufacturing a child film. 3. The method for producing a conductive polymer film according to claim 1, wherein the polymerizable monomer is pyrrole, thiophene, furan or a derivative thereof. 4. The method for producing a conductive polymer film according to claim 2, wherein the object to be processed is a metal or an insulating material on which a conductive polymer chemical polymer film is adhered. 5. The method according to claim 1, wherein the insulating material is Ta, Al or Nb.
5. An anodically oxidized valve metal comprising: a conductive polymer chemical polymer film comprising a polymer of pyrrole, thiophene or a derivative thereof.
A method for producing the conductive polymer film according to the above. 6. The method according to claim 1, wherein said first electrode is made of stainless steel. 7. Applying a DC voltage between the first electrode and the second electrode, and applying ultrasonic vibration to the first electrode when generating oxygen gas from the first electrode. The method for producing a conductive polymer film according to claim 1 or 2, wherein: