JPH0455321B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD 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 anodic oxide film on its surface and a cathode electrode configured to face the electrode is a manganese dioxide capacitor. Most of them have been used as solid electrolytes. Problems to be Solved by the Invention However, in this method, when forming manganese dioxide on the electrode, it is generally immersed in a manganese nitrate solution and then thermally decomposed, so the anodic oxide film is damaged. The drawback was that the repairability of the anodic oxide film with manganese was poor. Means for Solving the Problems The present invention aims to improve the above-mentioned drawbacks by using organic semiconductors as solid electrolytes, mainly 7, 7, 8,
The present invention aims to provide a solid electrolytic capacitor using a salt of 8-tetracyanoquinodimethane (hereinafter referred to as TCNQ). TCNQ is used as an acceptor material, and donor materials include quinoline (hereinafter referred to as _Qo ), tetrathiafulvalene (hereinafter referred to as TTE), N-methylphenazinium (hereinafter referred to as NMP), and tetraselenafulvalene (hereinafter referred to as TSF). There is,
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. Also
When applying a TCNQ complex consisting of TCNQ and a donor material to an electrolytic capacitor, there is a problem with adhesion to the electrode, so a TCNQ complex with extremely fine crystal grains and good compatibility with metal oxides is desirable. In addition, a TCNQ complex is required that does not change its electrical conductivity much from low to high temperatures and does not easily 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 7, 7, 8, 8, tetracyano, and A solid electrolytic capacitor characterized by using an organic semiconductor compound consisting of quinodimethane and 1,2-di(N-R-4-pyridinium)ethylene having the structural formula shown below. The alkyl group R of the above-mentioned 1,2-di(N-R-4-pyridinium)ethylene has the N-position substituted with a hydrocarbon group and has 1 to 3 carbon atoms. Structural formula Action 1,2-di(N-R-4-pyridinium)ethylene-TCNQ salt (hereinafter referred to as DRPE/TCNQ salt)
is a single crystal with a resistance of (2 to 18) × 10 ² Ω ^-1 cm ^-1 . A pellet-like powder sample is pressurized to form a tablet, silver electrodes are applied to the opposing surfaces, and the resistance between the electrodes is determined. measured, and shows high conductivity of 2 to 5 Ω ^-1 cm ^-1 . In addition, as a result of impregnating DRPE/TCNQ salt and energizing between the anode electrode made of valve metal with an anodic oxide film and the cathode electrode configured to face each other,
It exhibited very low leakage current characteristics. Examples 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 had been subjected to 80V chemical conversion using an ammonium phosphate solution and thoroughly dried. Next, 1,2-di(N-ethyl-4-pyridinium) ethylene (TCNQ) ₂ complex was heated and dissolved in acetonitrile to create a saturated solution, which was applied onto the above electrode and heated at 80 to 90°C. The solvent acetonitrile was removed by scattering. This operation was repeated three times, colloidal carbon was applied and dried as a cathode, and then silver paste was applied and lead wires were soldered to package the capacitor, thereby creating a capacitor sample with a rating of 50 V and 2.2 μF. (Sample Group A) As a conventional example, manganese nitrate was dissolved in water to create a saturated solution, and the above electrode was immersed in it for 50 minutes at 400℃.
A drying process was performed for a minute, and this operation was repeated three times. The cathode and lead wires were attached in the same manner as described above, and a capacitor sample (sample group B) was prepared in the same manner. Initial characteristics of these two types of capacitors and 105℃
Tables 1 and 2 show the results of a high temperature load test in which the rated voltage was applied for 2000 hours in an atmosphere of The capacitance and tan δ are the values at room temperature and 120kHz, and the leakage current is the value at room temperature and after 1 minute of application of the rated voltage.

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[Table] Effects of the invention As described above, the DRPE-TCNQ complex has extremely good bonding properties with electrodes, exhibits excellent properties when used as a solid electrolyte in capacitors, has good reliability, and is suitable for industrial and It has great practical value.

Claims (1)

[Scope of Claims] 1. 7, 7, 8, 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.
8. A solid electrolytic capacitor characterized by using an organic semiconductor compound consisting of tetracyanoquinodimethane and 1,2-di(NR-4-pyridinium)ethylene having the structural formula shown below. Structural formula 2 Claims characterized in that the alkyl group R of the above 1,2-di(N-R-4-pyridinium)ethylene is one in which the N-position is substituted with a hydrocarbon group and has 1 to 3 carbon atoms. The solid electrolytic capacitor according to item 1.