JPS601826A - Cathode material for electrolytic condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] This invention relates to cathode materials for electrolytic capacitors.

Conventionally, as a cathode capacitor for electrolytic capacitors, an aluminum foil whose surface area has been expanded by etching has been used. However, the conventional cathode material O'31 has a problem in that its performance as a cathode material, mainly its capacitance, varies depending on the material of the aluminum foil, heat treatment conditions, etching conditions, etc. Furthermore, since etching is a wet process, there is a problem in waste liquid treatment.

The object of the present invention is to provide a cathode material for electrolytic capacitors that solves the above problems.

The cathode capacitor for an electrolytic capacitor according to the present invention has a vapor deposited film made of a Q conductive metal formed on the surface of a base material.

In the above, as the base material, for example, a synthetic resin film such as polyester, conductive metal foil such as aluminum foil, paper, etc. are used. It is preferable to use a synthetic resin film or paper as the base material because it is cheaper than using metal foil.

As conductive metals, Δu, Ag, -1'i, Cr, Z
n1Al, 3i 1Ge, Go, Sn, Ta, Fe
, Cu, pb, Ni 13i, Mn, etc. or alloys thereof, among which Al1゜△q,
Typical examples are Ti and Cr.

Examples of methods for forming a deposited film include an ion blasting method, a sputtering method, and a vacuum deposition method. It is preferable that the deposition film is formed in an atmosphere of an inert gas such as argon or helium. This is because fine recesses are uniformly and densely formed on the surface of the 1q deposited film, expanding the surface V of the cathode spot material and increasing the capacitance. Further, when a non-conductive material such as a synthetic resin film is used as the base material, it is preferable that the thickness of the deposited film is 500 Å or more.

This is because if it is less than 500A, the conductivity will be poor. When forming a vapor deposited film, the distance between the evaporation source and the profiteer is 10~
It is preferable to set it as 100C1ll. Further, the deposition rate is preferably 10 to 5000 A/SeC.

Since the cathode +JE for electrolytic condenser υ according to the present invention is constructed as described above, the capacitance can be increased to a large extent regardless of the quality of the base material.

Moreover, unlike conventional cathode materials, there is no variation in performance, mainly in capacitance. Furthermore, since there is no need to perform etching treatment, there is no problem with waste liquid disposal.

Next, examples of the present invention will be shown together with comparative examples.

Example 1 A polyester film base material with a thickness of 0.1 mm is placed in the upper part of a vacuum chamber maintained at a pressure of 1 x 10" or less. , an evaporation source with a vapor deposition material made of titanium is placed.The distance between the substrate and the evaporation source is 25 cm.Then,
Titanium was evaporated from the evaporation source to form a 1.0 μm thick vapor deposited titanium film on the surface of the substrate at a rate of 30 A/sea. In this way, a cathode material was obtained in which a titanium vapor-deposited film was formed on the surface of a polyester film base material. The surface of the deposited film was smooth.

Example 2 A cathode material 1F1 was prepared by forming a silver vapor deposition film on the surface of a polyester film base material under the same conditions as in Example 1 above, except that silver was used as the vapor deposition substance. The surface of this deposited film was also smooth.

Example 3 A polyester film base material with a thickness of 0.1 mm+ is placed at the top of a vacuum chamber maintained at an argon gas pressure of 9×10' Torr. On the other hand, an evaporation source containing a silver vapor deposition material is placed in the lower part of the vacuum chamber and below the substrate. The distance between the substrate and the evaporation source is 25 cm. Then, a deposited film of silver with a thickness of 1.0 μm was formed on the surface of the base material by an ion-blating method. In this way, 1 q of cathode material is obtained by forming a silver vapor-deposited film on the surface of a polyester film base material. Fine depressions were uniformly and densely formed on the surface of the deposited film.

Example 4 The conditions were the same as in Example 1 above, except that A1100)1 aluminum foil with a J width of 0°1 mm whose surface had been cleaned was used as the base material, and chromium was used as the vapor deposition substance.
A cathode 4J 1lijl was obtained in which a vaporized chromium film was formed on the surface of an aluminum foil base material. The surface of this deposited film was smooth.

Example 5 A with a thickness of 0°1 mm whose surface was cleaned as a base material
A cathode material was obtained by forming a tin vapor deposited film on the surface of an aluminum foil base material under the same conditions as in Example 1 above, except that 1100+-1 aluminum foil was used and tin was used as the vapor deposition substance. . The surface of this deposited film was also smooth.

Example 6 A with a thickness of 0°1 mm whose surface was cleaned for profiteering
A cathode material was obtained by forming a tin vapor deposited film on the surface of an aluminum foil base material under the same conditions as in Example 3 above, except that 11001-11i1 aluminum foil was used and tin was used as the vapor deposition material. Fine depressions were uniformly and densely formed on the surface of this deposited film.

Comparative Example 1 An aluminum foil with a purity of 99.8 wt% and a thickness Q of 1 mm+ was heated to 1]0.20 in a 2 wt% hydrochloric acid solution at a liquid temperature of 60°C.
A cathode material was obtained by etching for 300 seconds at a current density of A150 cm2.

The capacitances of the seven types of cathode materials obtained as described above were each measured in a 10wI% ammonium borate solution at a liquid temperature of 30°C. The results are summarized in the table below.

As is clear from the above results, the electrolytic capacitor cathode material according to the present invention has a larger capacitance than conventional cathode materials.

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Claims (1)

[Claims] A cathode material for electrolytic capacitors in which vaporized @flR made of conductive metal is formed on the surface of a base material.