JP2000012400A - Electrode foil for aluminum electrolytic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode foil whose electrostatic capacity per a unit area is high, and whose productivity is high at low costs. SOLUTION: The mixture of at least one kind of metal of Ti, Zr, Hf, Nb, and Al, or at least one kind of fine particles of the oxide, nitride, and carbide of the metal with a binder or solvent containing the binder is applied to an Al foil in this electrode foil for an aluminum electrolytic capacitor. Thus, the electrostatic capacity per a unit area of this electrode foil for an aluminum electrolytic capacitor can be greatly increased, and the effect can be made large.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an electrode foil for an aluminum electrolytic capacitor.

[0002]

2. Description of the Related Art With the recent miniaturization and weight reduction of electric and electronic devices, the demand for miniaturization of aluminum electrolytic capacitors has become stronger. In order to reduce the size of the aluminum electrolytic capacitor, it is necessary to increase the capacitance per unit area of the electrode foil used, and various etching methods have been studied. Since the melting of the parts occurs, it is difficult to dramatically increase the capacitance per unit area.

[0003]

In order to solve the above problems, an attempt has been made to increase the capacity per unit area by coating the surface with an element having a higher dielectric constant than Al by a dry process. Although it is employed, it has drawbacks in that it is difficult to adapt to the anode, that it is expensive and that productivity is low. Therefore, there has been a demand for the development of a low-cost and highly productive electrode foil that dramatically increases the capacitance per unit area.

[0004]

Means for Solving the Problems The present invention has been found as a result of various studies to solve the above problems, and has a high capacitance per unit area and a low cost. It is an electrode foil for aluminum electrolytic capacitors with high productivity. That is, a mixture of at least one kind of metal of Ti, Zr, Hf, Nb, and Al, or at least one kind of fine particles of oxides, nitrides, and carbides of the metal, and a binder or a solvent containing a binder is used. , A
1 is an electrode foil for an aluminum electrolytic capacitor characterized by being applied to a 1 foil. 2. The electrode foil for an aluminum electrolytic capacitor according to claim 1, wherein the foil produced by the above method is pressed.

[0005]

By applying fine particles of Ti, Zr, Hf, Nb, and Al, which are generally called valve metal, onto an Al foil via a binder, the surface area can be increased without performing etching. In the case where fine particles other than Al are used, the effect of the high dielectric constant is taken into consideration, and it is considered that the capacitance per unit area can be dramatically increased. Further, each fine particle is made of Al
Although bonding is performed between foils or fine particles, it is considered that the bonding force can be further increased by applying pressure or heat. Furthermore, this electrode foil manufacturing process does not require special atmosphere control unlike the dry process, and is preferable in terms of cost and productivity.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments including a conventional example will be described below in detail. [Example 1] Zirconium oxide fine particles were mixed with water containing polyvinyl alcohol, and then applied on an Al foil.
Let dry. After that, rolling at a pressure of 1 ton, 500
The sample heat-treated at ℃ was used as a test material. This test material was subjected to a chemical conversion treatment so as to have a film withstand voltage of 22 V. [Example 2] Titanium nitride fine particles were mixed with water containing polyvinyl alcohol, applied to an Al foil, and dried. Thereafter, rolling was performed at a pressure of 1 ton, and heat treatment was performed at 500 ° C. [Conventional Example 1] A predetermined anode etching was performed on a 99.98% aluminum foil, and then a chemical conversion treatment was performed so that the film withstand voltage was 22V. [Conventional example 2] A predetermined cathode etching was performed on a 99.80% aluminum foil. Table 1 shows the results.

[0007]

[Table 1]

[0008] In Table 1, a comparison between Examples 1 and 2 using the method according to the present invention and Conventional Examples 1 and 2, respectively, shows that the capacitance is dramatically increased. The pressure resistance of the coating is the same as that of the coating.

In the above embodiment, the oxide of Zr or the nitrogen of Ti is used. However, Ti, Zr, H
A similar effect can be obtained by using a single metal of f, Nb, or Al, or one kind of fine particles among oxides, nitrides, and carbides of the metal or a combination of two or more kinds of fine particles.

[0010]

The electrode foil for an aluminum electrolytic capacitor according to the present invention can greatly increase the capacitance per unit area, and the effect is great.

Claims (2)

[Claims] At least one metal selected from the group consisting of Ti, Zr, Hf, Nb, and Al, or an oxide or nitride of the metal,
An electrode foil for an aluminum electrolytic capacitor, wherein a mixture of at least one kind of fine particles among carbides and a binder or a solvent containing a binder is applied to an Al foil. 2. The electrode foil for an aluminum electrolytic capacitor according to claim 1, wherein the foil produced by the above method is pressed.