JPH07192536A - Conductive complex material and manufacture thereof and electrolytic capacitor using it - Google Patents

Abstract

PURPOSE:To provide a low-priced sheet-like complex conductor and an electrolytic capacitor using it which excels in an impedance characteristic in a conductive complex in which a conductor made of a conductive polymer and a manganese oxide is formed in the surface of a sheet-like insulator, and an electrolytic capacitor and the like using it. CONSTITUTION:A sheet-like conductive complex can be easily manufactured in solution at a room temperature with oxidation and reduction reaction of polymerizing monomer and salt permanganate. A conductive polymer obtained and a manganese oxide have a high clad restoration function of a petal metal, so that the conductive complex is used for the separator of an electrolytic capacitor, thereby providing an excellent impedance characteristic without the generation of a short-circuit increased by a leakage current.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-like conductive composite having a conductive layer made of a conductive polymer and manganese oxide formed on the surface of paper, cloth, non-woven fabric or polymer film. The present invention relates to a manufacturing method thereof, and further, the present invention relates to an electrolytic capacitor using the composite conductor as a separator.

[0002]

2. Description of the Related Art Conventionally, many attempts have been made to obtain a conductive composite by subjecting a sheet-shaped insulator such as paper, cloth, non-woven fabric or polymer film to a conductive treatment.

Examples of such methods include a method of adsorbing a surfactant on the surface of a base material, a method of weaving fibers or powders of metal, carbon or the like, and a method of mixing fibers or powders of metal or carbon. , A method of depositing a metal or a conductive metal oxide such as indium oxide, or a method of sputtering a metal or a conductive metal oxide such as indium oxide, and a method of chemically synthesizing a polymerizable monomer such as pyrrole or aniline. A method of forming a conductive polymer on the surface by polymerization (Synthetic Metals, 2
8 C, 823 (1989)) and the like are known.

Further, in the wound type aluminum electrolytic capacitor, in order to improve the loss characteristics and the impedance characteristics, the thickness of the separator is reduced, the density is reduced, the opening diameter is made uniform, and the material is changed from paper to polymer non-woven fabric. Such studies have been made conventionally.

There is also a report that an aluminum electrolytic capacitor using a separator compounded with graphite powder not only improves impedance characteristics but also achieves sound quality distortion (Funkschau, No. 8, 40). P. (1984)).

A structure using a separator made conductive by a conductive polymer is also disclosed in, for example, Japanese Patent Laid-Open No. 1-90517.

[0007]

However, in the above conventional structure, (a) the electrical conductivity is low, or the change over time due to volatilization or the like is relatively large (in the case of surfactant adsorption), (b) If it cannot be made of low density, or it needs to be added in a large amount to obtain high electrical conductivity (in the case of metal, carbon fiber or powder), (c) In the case of fiber such as cloth and non-woven surface Uniform coverage is difficult because the layers are predominantly coated, or they cannot be wound (for metal or metal oxide vapor deposition) due to large changes in the mechanical strength and texture of the substrate, and (d) Since it has little or no chemical conversion, it has problems such as increased leakage current and short defects (in the case of conductive polymer polymerization).

Further, a separator composed of graphite composite
In the case of an electrolytic capacitor using a battery, there is a problem in that the shot generation rate becomes high because it is unavoidable that it falls off or is dispersed in the electrolytic solution.

The present invention has been made to solve the above-mentioned problems of the prior art. A composite conductive layer composed of a conductive polymer and manganese oxide or a conductive layer is formed on the surface of a sheet-shaped insulator such as paper, cloth, non-woven fabric or polymer film. An object of the present invention is to provide a composite conductor provided with a conductive polymer layer, a composite conductive layer composed of a conductive polymer and manganese oxide, and a method for producing the same.

Still another object of the present invention is to provide an electrolytic capacitor which uses the above composite as a separator and has excellent loss coefficient and high frequency impedance characteristics.

[0011]

To achieve the above object, the present invention provides a composite conductive layer comprising a conductive polymer obtained by polymerizing a polymerizable monomer and manganese oxide, or a polymerizable monomer. A conductive layer obtained by polymerizing a conductive polymer and a conductive polymer obtained by polymerizing a polymerizable monomer and a composite conductive layer made of manganese oxide are provided on the surface of a sheet-shaped insulator such as paper, cloth, nonwoven fabric or polymer film. It has a composite structure.

The composite conductive layer is formed by bringing the permanganate adsorbed on the surface of the sheet-shaped insulator into contact with the polymerizable monomer.

Further, the conductive layer obtained from the polymerizable monomer is obtained by reacting the polymerizable monomer with an oxidizing agent selected from ammonium persulfate, iron salts, copper salts and the like.

In order to obtain an electrolytic capacitor having excellent loss characteristics and high frequency impedance characteristics,
A composite conductive layer made of the above conductive polymer and manganese oxide, or a conductive polymer conductive layer obtained from a polymerizable monomer and a composite conductive layer made of a conductive polymer and manganese oxide were sequentially formed on the separator. It has a structure using a composite conductor of paper, cloth, non-woven fabric or a polymer film.

[0015]

The composite conductor according to the above-mentioned structure of the present invention has a high conductivity with manganese oxide mainly composed of manganese dioxide by a redox reaction caused by contact between permanganate and a polymerizable monomer on the surface of the sheet-shaped insulator. Since a composite conductive layer composed of molecules is formed, it can be obtained by an extremely simple process.

Further, the polymerization of the polymerizable monomer can be easily obtained by contact with an oxidizing agent, so that a composite conductor having a conductive layer laminated with the above composite conductor can be easily obtained.

Since the composite conductor thus obtained has a low sheet resistance value, the electrolytic capacitor using these as a separator has improved loss coefficient and high-frequency impedance characteristics.

Further, as can be seen from the fact that manganese oxide is generally used as a solid electrolyte of a tantalum solid electrolytic capacitor, since it has an extremely high valve metal oxide film repairing ability, the composite conductive layer also has a high oxidation. It has a film repairing ability (see Japanese Patent Publication No. 5-48925, etc.), and when the composite conductor having the above-mentioned composite conductive layer is used as a separator, leakage current increases and shorts occur. There is nothing to do.

The conductive polymer conductive layer is provided on the surface of the sheet-shaped insulator, and the composite conductive layer made of the above manganese oxide and the conductive polymer is further laminated on the conductive polymer conductive layer to provide a sheet. It becomes possible to further reduce the resistance value, and by using this as a separator, an electrolytic capacitor having further improved loss characteristics and impedance characteristics can be obtained.

Further, since the change in the mechanical properties and the feel of the sheet-like material of the base material due to the above-mentioned compounding is extremely small,
It can be used by bending and winding as in the case of untreated material.

[0021]

【Example】

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described.

[0022] Manila hemp / synthetic fiber low density separator paper for capacitors (0.3 g / cm ² ) was once dipped in a 0.01 M potassium permanganate aqueous solution and then pulled up,
Immediately, it was immersed in an aqueous solution containing 0.5 M of 0.5 M pyrrole monomer / 0.1 M of sodium triisopropylnaphthalene sulfonate.

Simultaneously with the immersion, the surface of the separator paper turned black, and the progress of the polymerization reaction due to the oxidation of potassium permanganate was observed.

After 5 minutes, the separator paper was pulled up, washed with water and dried, and the sheet resistance value was measured (Table 1).
The results shown in are obtained.

[0025]

[Table 1]

The texture of the obtained conductive composite was almost the same as that before the formation of the conductive layer.

It was observed that the color of the liquid in the monomer solution was extremely small and the reaction predominantly occurred on the surface of the separator paper.

Furthermore, the formation of manganese dioxide was confirmed from the results of X-ray diffraction analysis of the precipitate obtained by mixing the above two solutions.

Comparative Example 1 For comparison, as Comparative Example 1, iron (III) triisopropylnaphthalene sulfonate was used.
After soaking in 0.01M ethanol solution, 0.5M pyro-
An attempt was made to form a conductive layer in the same manner as in Example 1 except that the conductive layer was immersed in an ethanol solution of rumonomer for 1 hour.

Although blackening of the entire solution was observed, the coloration of the separator itself was lighter than in Example 1.

The sheet resistance value was measured in the same manner as in Example 1, and the obtained results are shown in (Table 1).

As can be understood from this (Table 1), the composite conductor having the conductive layer formed on the surface of the conductive polymer and the manganese oxide according to this example can be easily manufactured in a short time, Moreover, an excellent effect is obtained in that the sheet resistance value can be reduced.

As described above, according to this example, a conductive layer made of a conductive polymer obtained from a polymerizable monomer and manganese oxide is formed on the surface of a capacitor separator,
Since the composite conductor is formed, the composite conductor having a small sheet resistance value can be obtained in a short time.

(Example 2) In place of the low density separator used in Example 1, 6-6 nylon cloth (A), polyester nonwoven cloth (B) and porous polypropylene (C) were used as the base materials, respectively. A composite conductor having the same structure as in Example 1 was prepared and the sheet resistance value was measured.

The results are shown in (Table 1). As can be understood from this (Table 1), the composite conductor having a conductive layer formed on the surface of the conductive polymer and manganese oxide according to this example can be easily manufactured in a short time and has a sheet resistance value of An excellent effect can be obtained in that it can be made smaller.

As described above, according to this embodiment, a conductive layer composed of a conductive polymer obtained from a polymerizable monomer and manganese oxide is formed on the surface of a cloth, a non-woven fabric, and a polymer film to form a composite conductor. Since it is formed, a composite conductor having a small sheet resistance value can be obtained in a short time.

(Example 3) In Example 1, instead of an aqueous solution containing 0.5 M of pyrrole monomer / 0.1 M of sodium triisopropylnaphthalene sulfonate, 0.35 M of aniline monomer / 0.1 M of p-toluenesulfonic acid was used. Aqueous solution (A) or thiophene 0.5M / p-
A composite conductor was prepared in the same manner as in Example 1 except that 0.1 M toluene solution of toluenesulfonic acid (B) was used, and the sheet resistance value was measured.

The results are shown in (Table 1). As can be seen from this (Table 1), the composite conductor having a conductive layer formed on the surface of the conductive polymer and manganese oxide according to this example can be easily manufactured in a short time and has a low sheet resistance. An excellent effect can be obtained in that it can be done.

As described above, according to this embodiment, a conductive layer made of a conductive polymer obtained from a polymerizable monomer and manganese oxide is formed on the surface of a cloth, a nonwoven fabric and a polymer film to form a composite conductor. Since it is formed, a composite conductor having a low sheet resistance can be obtained in a short time.

Example 4 Using a low density separator paper (0.3 g / cm ² ) for a capacitor made of Manila hemp and synthetic fiber, it was once immersed in a 0.3 M aqueous solution of pyrrole monomer, and immediately thereafter, iron p-toluenesulfonate ( III) A conductive conductor layer made of polypyrrole was formed by immersing in a 0.5 M ethanol solution, and then a composite conductor was prepared by laminating a composite conductive layer made of polypyrrole and manganese oxide in the same manner as in Example 1 to produce a sheet. The resistance value was measured.

The results are shown in (Table 1). This (Table 1)
As can be understood from the above, the composite conductor obtained by sequentially forming the composite conductive layer made of the conductive polymer and the manganese oxide in addition to the conductive layer made of the conductive polymer according to the present example can be easily manufactured in a short time. An excellent effect can be obtained in that the sheet resistance value can be further reduced.

As described above, according to this embodiment, the conductive layer made of the conductive polymer obtained from the polymerizable monomer and the composite conductive layer made of the conductive polymer and manganese oxide are formed on the surfaces of the cloth, the nonwoven fabric and the polymer film. Since the composite conductor is formed by forming layers, the composite conductor having a small sheet resistance value can be obtained in a short time.

Example 5 The separator prepared in Example 1 and having a conductive layer made of a conductive polymer and manganese oxide was used, and 20% γ-butyrolactone of methyltriethylammonium hydrogen phthalate was used. Using the solution as an electrolyte, a total of 10 wound aluminum electrolytic capacitors with a rated voltage of 35 V were produced, and after aging at 44 V, the capacity and loss coefficient were 1 kHz, the leakage current (value 2 minutes after applying the rated voltage) and 10 kHz. Impedance measurement was performed.

The results are shown in (Table 2). (Comparative Example 2) For comparison, 10 wound aluminum electrolytic capacitors were prepared in the same manner as in Example 5 except that the separator before the formation of the conductive layer was used as Comparative Example 2, and the evaluation was made. went.

The results are shown in (Table 2).

[0046]

[Table 2]

As can be seen from this (Table 2), the capacitor using the electrolyte according to this example has an excellent effect in that the loss and the high frequency impedance can be reduced without deteriorating the leakage current characteristics. It is a thing.

As described above, according to this embodiment, since the conductive separator having the conductive layer composed of the conductive polymer and the manganese oxide is used, the loss coefficient of the aluminum electrolytic capacitor and the high frequency range are reduced. The impedance can be reduced.

Further, since both polypyrrole and manganese oxide have the function of repairing the oxide film dielectric of the valve metal, the leakage current characteristics are not deteriorated.

Example 6 A capacitor was produced in the same manner as in Example 5 except that the conductive composite produced in Example 4 was used as a separator, and the same evaluation as in Example 5 was performed.

The results are shown in (Table 2). (Comparative Example 3) For comparison, as Comparative Example 3, a composite conductive layer in which the conductive polymer of Example 4 and the manganese oxide is not formed, that is, a composite conductive layer having only a polypyrrole conductive layer. A capacitor was manufactured in the same manner as in Example 6 except that was used, and the same evaluation was performed.

The results are shown in (Table 2). As can be seen from (Table 2), the capacitor using the electrolyte according to this example has an excellent effect in that the loss and the high frequency impedance can be reduced without deteriorating the leakage current characteristics.

Particularly, since the conductive layer made of the conductive polymer is interposed in the inner layer, the sheet resistance value is lower than that in the case where only the composite conductive layer made of the conductive polymer and manganese oxide is provided. As a result, a more excellent loss coefficient and high-frequency impedance improving effect can be seen.

As is clear from the comparison with Comparative Example 3, the separator having the composite conductive layer composed of the conductive polymer and the manganese oxide has a large film repairing power, so that the leakage current can be reduced. be able to.

As described above, according to this embodiment, since the conductive separator having the conductive layer composed of the conductive polymer and the manganese oxide is used, the loss coefficient of the aluminum electrolytic capacitor and the high frequency range are reduced. The impedance can be reduced.

In the above embodiment, only the case where the concentration of permanganate is 0.01M has been described.
Other concentrations may be used, and the present invention is not limited to that concentration.

However, even if it is used in an unnecessarily high concentration, the thickness of the conductive layer becomes thick, the texture of the base material changes, and when the base material is paper, cloth, or non-woven fabric, the porosity is small. Is not desirable.

In the above embodiment, the paper is made of Manila hemp / synthetic fiber, the cloth is made of 6-6 nylon, the non-woven fabric is made of polyester, and the polymer film is made of polypropylene. However, the present invention is not limited to that type.

Further, in the fourth embodiment, only the case where the conductive composite material whose base material is Manila hemp / synthetic fiber is used as the separator has been described, but a separator made of other materials may be used. it can.

Further, even when the base material is composed of a polymer film, a material processed so as to have a large number of pores which does not prevent the passage of electrolyte ions can be similarly used.

Furthermore, only the case where the conductive polymer is obtained from a pyrrole monomer has been described, but it goes without saying that aniline and thiophene can be similarly used.

The polymerizable monomer may be not only pyrrole, aniline or thiophene but also a compound containing at least one of these derivatives, and needless to say, the present invention is not limited thereto.

[0063]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a sheet-like conductive material having a composite conductive layer composed of a conductive polymer obtained by a redox reaction of a polymerizable monomer and a permanganate and manganese oxide is formed on the surface. The present invention relates to a composite, a sheet-shaped conductive composite in which a conductive layer made of a conductive polymer is interposed in an inner layer of the composite conductive layer, and an electrolytic capacitor using them as a separator.

The reaction for forming the conductive layer predominantly occurs in the vicinity of the surface of the sheet-shaped substrate at room temperature in the solution, so that the above-mentioned conductive composite can be easily produced.

Further, since both the electroconductive polymer obtained from the polymerizable monomer and the manganese oxide have a high valve metal film repairing function, by using the electroconductive composite as a separator for an electrolytic capacitor, leakage current Also, an electrolytic capacitor having excellent loss characteristics and impedance characteristics can be realized without increasing the occurrence of short circuits.

Claims (13)

[Claims] 1. A conductive material made of any one selected from paper, cloth, non-woven fabric or polymer film, which has a composite conductive layer containing a conductive polymer obtained from a polymerizable monomer and manganese oxide formed on the surface thereof. Sex complex. 2. A paper in which a conductive polymer conductive layer obtained from a polymerizable monomer and a composite conductive layer containing a conductive polymer obtained from a polymerizable monomer and manganese oxide are sequentially formed on the surface. , A conductive composite made of any one selected from cloth, non-woven fabric, and polymer film. 3. The conductive composite according to claim 1, wherein the polymerizable monomer is selected from compounds containing at least one of pyrrole, aniline or thiophene, or derivatives thereof. 4. A conductive composite in which a composite conductive layer containing a conductive polymer and manganese oxide is formed in-situ on any one surface selected from paper, cloth, non-woven fabric or polymer film. Manufacturing method. 5. The method for producing a conductive composite according to claim 4, wherein the composite conductive layer containing a conductive polymer and manganese oxide is formed by a reaction of permanganate and a polymerizable monomer. 6. A step of immersing any one kind of material selected from paper, cloth, non-woven fabric or polymer film in an aqueous solution of permanganate, and a solution containing a polymerizable monomer and an anion which is a dopant. The method for producing a conductive composite according to claim 4 or 5, including a step of immersing. 7. A conductive layer containing a conductive polymer and a composite conductive layer containing a conductive polymer and manganese oxide are provided on paper, cloth,
A method for producing a conductive composite, which is sequentially formed on the surface of any one type selected from a non-woven fabric or a polymer film. 8. A conductive layer containing a conductive polymer is formed by oxidative polymerization of a polymerizable monomer, and a composite conductive layer containing a conductive polymer and manganese oxide is reacted with permanganate and a polymerizable monomer. The method for producing a conductive composite according to claim 7, wherein the conductive composite is formed by: 9. A conductive layer made of a conductive polymer is obtained by immersing any one kind of material selected from paper, cloth, non-woven fabric or polymer film in a solution containing an oxidizing agent and a solution containing a polymerizable monomer. And a step of forming a composite conductive layer composed of a conductive polymer and manganese oxide by immersing in a solution containing an aqueous solution of permanganate, a polymerizable monomer, and an anion that becomes a dopant. 7. The method for producing a conductive composite according to 7 or 8. 10. The method for producing a conductive composite according to claim 4, wherein the polymerizable monomer is selected from compounds containing at least one of pyrrole, aniline, thiophene and derivatives thereof. 11. A composite conductive layer containing a conductive polymer obtained from a polymerizable monomer and manganese oxide is composed of any one selected from paper, cloth, nonwoven fabric or polymer film formed on the surface. An electrolytic capacitor using a conductive composite material as a separator. 12. A conductive layer containing a conductive polymer and a composite conductive layer containing a conductive polymer and manganese oxide formed on the surface of any of paper, cloth, non-woven fabric or polymer film. An electrolytic capacitor using a conductive composite material as a separator. 13. The electrolytic capacitor according to claim 11, wherein the polymerizable monomer contains at least one of pyrrole, aniline, thiophene and derivatives thereof.