JPS61234024A - Solid electrolytic capacitor - 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 Field of Industrial Application The present invention relates to an aluminum electrolytic capacitor with an improved solid electrolyte.

Conventional technology A conventional solid electrolytic capacitor in which a solid electrolyte is interposed between an anode electrode made of a valve metal having an anodized film on its surface and a cathode electrode configured to face the electrode is a carbon dioxide Most of them have used manganese as a solid electrolyte.

Problems to be Solved by the Invention However, in this method, when forming manganese dioxide on the electrode, the anodic oxide film is damaged because -a is immersed in a manganese nitrate solution and then thermally decomposed.
In addition, there was a drawback in that the repairability of the anodic oxide film by manganese dioxide was poor.

Means for Solving the Problems In order to improve the above-mentioned drawbacks, the present invention provides a solid electrolyte using an organic semiconductor, mainly a salt of 7.7.8.8 tetracyanoquinodimethane (hereinafter referred to as TCNQ). The aim is to provide an electrolytic capacitor.

TCNQ is used as an acceptor material, and donor materials include quinoline (hereinafter referred to as Q1), tetrathiafulvalene (hereinafter referred to as TTF), and N-methylzenadinium (hereinafter referred to as TTF).
(hereinafter referred to as NMP), tetraselenafulvalene (hereinafter referred to as T
In particular, research into new donor materials is being actively conducted.

Its characteristics as a donor material include a suitably small ionization potential, a large π-electron system, stable ions, and high polarizability.

Satisfying all of these conditions is an important factor in molecular design, but it is extremely difficult to satisfy all of them. Furthermore, when applying a TCNQ complex consisting of TCNQ and a donor material to an electrolytic capacitor, there is a problem of adhesion with electrodes, so it is desirable to use a TCNQ complex that has extremely fine crystal grains and has good compatibility with metal oxides. .

Furthermore, a TCNQ complex is required that does not change its electrical conductivity much from low to high temperatures and is difficult to decompose even at high temperatures.

The present inventors repeated various experiments and found a donor material for TCNQ that satisfies the above requirements.

That is, the present invention uses TCNQ and 1.9- as electrolytes interposed between an anode electrode made of a valve metal having an anodic oxide film and a cathode electrode configured to face the anode electrode.
This is a solid electrolytic capacitor characterized by using an organic semiconductor made of an anthrazoline derivative. The above l,9-anthrazoline derivative has the following structural formula (I
) or (II), and one or both of the N positions are quaternized with a proton and a hydrocarbon group, and the hydrocarbon group has 1 to 18 carbon atoms. When the number of carbon atoms exceeds 19, it becomes thermally unstable and cannot be used as a capacitor.

Structural formula (I) ^1, Blue 2 Effect 1.9-Anthrazoline derivative-TCNQ salt is pellet-shaped (10-''~10-')Ω-'c
It shows high conductivity of ill-'. Furthermore, it exhibits extremely thermally stable properties.

In addition, as a result of impregnating a 1,9-anthrazoline derivative-TCNQ salt between an anode electrode made of a valve metal having an anodized film and a cathode electrode configured to face each other and applying current, extremely low leakage can be achieved. The current characteristics are shown.

Example Specific examples of the present invention will be shown below.

As an electrode, an aluminum foil etched to a surface magnification of about 10 times was used, which was subjected to 80V chemical conversion using an ammonium phosphate solution and thoroughly dried. Next, the N-butyl-anthrasilinium (TCN Q)Z complex was heated and dissolved in acetonitrile to create a saturated solution, which was applied onto the electrode and heated at 80 to 90°C to scatter the solvent acetonitrile. Removed. Repeat this operation three times, apply colloidal carbon as a cathode, dry it, then apply silver paste, solder the lead wire, and package it with a rating of 50.
v.

A 2.2 μF capacitor sample was manufactured. (Sample Group A) As a conventional example, a saturated solution was prepared by dissolving manganese nitrate in water, and the electrode was immersed in the solution and dried at 400° C. for 5 minutes, and this operation was repeated three times. The cathode and lead wires were attached in the same manner as described above, and capacitor samples (sample group B) were produced in the same manner.

Tables 1 and 2 show the initial characteristics of these two types of capacitors and the results of a high temperature load test in which a rated voltage was applied for 2000 hours in an atmosphere of 105°C.

The capacitance and tan δ are the values at room temperature and 120kllz, and the leakage current is the value at room temperature and 1 minute after application of the rated voltage.

Table 2 (High-temperature load test characteristics) Note that the anode electrode of the present invention is not limited to aluminum foil, and can be similarly applied to other valve metals and powder sintered metal electrodes, and is within the technical scope of the present invention. It is included.

Effects of the invention As described above, 1,9-anthrazoline derivative-TCNQ
The complex has extremely good bondability with electrodes, exhibits excellent properties when used as a solid electrolyte of a capacitor, and has good reliability, and is of great industrial and practical value.

Claims (2)

[Claims] (1) 7, 7, 8, 8 tetracyanoquinodimethane as an electrolyte interposed between an anode electrode made of a valve metal having an anodic oxide film and a cathode electrode configured to face the electrode. A solid electrolytic capacitor characterized in that it uses an organic semiconductor compound consisting of a 1,9-anthrazoline derivative and a 1,9-anthrazoline derivative. (2) The above 1,9-anthrazoline derivative has the following structural formula (I) or (II), and one or both of the N positions are quaternized. Solid electrolytic capacitor according to item 1. Structural formula (I) ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼ Structural formula (II) ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼