JPS63173314A - 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 a solid electrolytic capacitor using a solid electrolyte.

[Prior Art] A solid electrolytic capacitor has a structure in which a solid electrolyte is attached to a dielectric film-forming metal such as aluminum having an anodized film. Up until now, most capacitors of this type have used manganese dioxide as the solid electrolyte.

[Problems to be Solved by the Invention] However, when manganese dioxide is formed on an electrode, it is generally immersed in a manganese nitrate solution and then hydrolyzed, which causes damage to the anodic oxide film. However, there was a drawback in that the repairability of the anodic oxide film by manganese dioxide was poor.

In order to improve the above drawbacks, organic semiconductors are mainly used as solid electrolytes. , 7,8.8-tetracyanoquinodimethane (TCNQ) (TCNQ complex) has been proposed.

On TCNQCN TCNQ was used as an acceptor material, and quinoline (Qn) and tetrathiafulvalene (
TTF), N-methylphenazine (NMP), and tetraselenafulvalene (TSF) have been studied so far, and research on new donor materials is also being actively conducted, but there are still none that are fully satisfactory. Not obtained.

Especially in terms of heat resistance, TCN
Both have problems with QCN. In other words, solid electrolytic capacitors are often exposed to heat such as soldering during the capacitor manufacturing process, and are placed near transformers in power supply circuits. Although the electrolyte must be thermally stable, conventional TCNQCN all have concerns in this respect. That is, various solid electrolytic capacitors using TCNQCN as a solid electrolyte using, for example, isoquinoline as a donor material have been proposed, but none of them have been able to solve the above problems.

[Object of the Invention] An object of the present invention is to provide a new and useful solid electrolytic capacitor that does not have any of the above-mentioned problems that solid electrolytic capacitors have.

[Summary of the Invention] The present invention provides an electrolyte of the formula (however, , R1, R2 are each independently a hydrogen atom, carbon number 1
~4 alkyl group, cyano group, acetyl group, or halogen atom, R3, R4, R5 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a nitro group. , a trifluoromethyl group, a fluoro group, or a hydroxyl group, and n represents an arbitrary integer of 1 to 3. ) This solid electrolytic capacitor is characterized in that it is used on TCNQCN using a substituted pyridinium cation represented by the following as a donor material.

That is, as a result of extensive research to achieve the above object, the present inventors have developed a TCNQCN-based pyridine derivative using a quaternized pyridine derivative by introducing an aralkyl group such as a Hensyl group or a phenethyl group into the N-position as a donor material. , has excellent heat resistance and stability, and when applied to the solid electrolyte of electrolytic capacitors, it shows excellent temperature characteristics and stability, and is particularly suitable for soldering to printed circuit boards after commercialization. They discovered that glue flow can be performed at high temperatures and completed the present invention.

On the TCNQCN used in the present invention, it is expressed, for example, as follows.

(In the formula, k represents an arbitrary number of 0.5≦≦2.0.

) atoms, such as methyl, ethyl, propyl groups.

A linear or branched alkyl group having 1 to 4 carbon atoms such as a butyl group, a cyano group, an acetyl group, or chlorine.

Indicates a halogen atom such as bromine, fluorine, iodine, etc., R3゜R4
, R5 each independently represents a hydrogen atom, such as a linear or branched alkyl group having 1 to 4 carbon atoms, such as a methyl group, ethyl group, propyl group, or butyl group, such as a methoxy group, ethoxy group, or propoxy group. , a linear or branched alkoxy group having 1 to 4 carbon atoms such as a butoxy group, a nitro group, a fluoro group, a trifluoromethyl group, or a hydroxyl group, where n is 1
Indicates any integer between ~3.

On the TCNQCN according to the present invention, neutral TC can be prepared by a method known per se, for example, with a halide of a substituted pyridinium cation.
This can be easily done by doping NQ, and n is the same as above. ) can be easily obtained by reacting with pyridine or substituted pyridine in the presence of a suitable solvent if necessary;
(+962), J, Org, Chem,, 26.422
0 (1961), J, Chem, Soc, +961,
206, J,Chem,Soc,,11,] 6]
9, J, Chem, Soc,, Part C, plate TO,
1134, Bull, Chem, Soc, Japan,
45.2810 (+972), J, Am, Chen+,
5oc02 dish, 3197 (194B), Be1g, Pa
t, 615349 (1962), J.

Am, Chem, Soc, 85, 567 (1963)
According to the method described in J. Chem. Since it can be easily obtained, it is sufficient to use the one obtained in this way. Moreover, it goes without saying that the TCNQ complex of the present invention can be produced by utilizing the reducing power of iodo ion I-.

Since the TCNQ complex according to the invention is stable up to high temperatures, it provides advantageous advantages in bonding technology with electrodes. That is, it can be dissolved in a highly polar solvent with a high boiling point, and recrystallization occurs extremely quickly on the electrode surface during immersion and drying. It can also be easily impregnated into the finely etched irregularities of electrodes such as those of aluminum electrolytic capacitors.

Although this is a problem due to conditions related to the crystallization rate, it goes without saying that the impregnated state becomes better as the crystals become thinner and denser.

Note that the anode electrode used in the solid electrolytic capacitor of the present invention is not limited to aluminum foil; other valve metals can of course be used, and even if a powder sintered electrode is used, the same result can be obtained. Needless to say, it is effective.

Hereinafter, specific examples of the present invention will be described, but the present invention is not limited thereto.

[Example] Reference Example 1゜The basic physical properties of several typical TCNQ complexes used in the present invention are shown in Tables 1 (1) and (2).

Example 1° (Preparation of Sample Group-①) Of the compounds exemplified in Reference Example 1, complexes A to K were tested using an aluminum electrolytic capacitor element with a rating of 10 WV-33 μF. For impregnation, each complex was supersaturated in a nitrobenzene solution heated to 180°C, and the element was immersed.
It was dried at 10°C. This operation was repeated four times to complete the impregnation and produce a product.

(Preparation of Sample -■) Using Nn-butylisoquinoline TCNQ complex, impregnation and commercialization were carried out according to the preparation method of Sample Group -■.

(Preparation of Sample-■) Using a saturated manganese nitrate aqueous solution, immersion at 220° C. for 60 seconds and heat treatment were repeated six times, and then products were manufactured in the same manner as Sample Group-I.

(Results) The initial characteristics are shown in Table 2. The capacitance and tan δ are the values at room temperature and 120 Hz, and the leakage current is the value at room temperature and 1 minute after application of the rated voltage.

Furthermore, the results of a high temperature load test for up to 2000 hours by applying the rated voltage in an atmosphere of 105°C are shown in Tables 3 (1) to (
3).

Table-2 Table-3(1) (Rated voltage application time: 500hrs) Table-3(2) (Rated voltage application m: 1000hrs) Table-3(3) (Rated voltage application time: 2000hrs) Table-2 and Table -
From the results of 3(1) to (3), it was demonstrated that the electrolytic capacitor using the TCNQ complex according to the present invention is quite stable thermally.

Example 2゜(Preparation of Sample Group-■) Using the complex LR shown in Reference Example 1, Sample Group-■ was prepared according to the method for preparing Sample Group-I of Example 1.

(Results) Using sample group ■ and samples ■ and ■, reflow was performed at 230° C. for 60 seconds and changes in characteristics due to flow were investigated. Table 4 shows the results.

Table 4 As is clear from the results in Table 4, the capacitance of the product using Nn-butylisoquinoline TCNQ complex and the product using manganese dioxide increased significantly, and the capacitance increased significantly during reflow. However, all solid electrolytic capacitors using the complex according to the present invention have stable capacitance, tan δ, and leakage current, and are therefore extremely stable products. I understand.

(Effect of the invention) As described above, the TCNQ complex used in the present invention is
As a solid electrolyte, it is extremely thermally stable and has good bonding properties between the electrode and the solid electrolyte, so the solid electrolytic capacitor of the present invention using this as an electrolyte has significantly improved electrical characteristics compared to conventional ones. It has a remarkable effect in that it is stabilized, and has great industrial and practical value.

Claims (1)

[Claims] (1) As an electrolyte 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, a formula ▲ mathematical formula, chemical formula, table, etc. Yes▼ (However, R^1 and R^2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, an acetyl group, or a halogen atom, and R^3, R^4, R^ Each of 5 is independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or 1 to 4 carbon atoms.
represents an alkoxy group, nitro group, trifluoromethyl group, fluoro group or hydroxyl group, and n represents any integer of 1 to 3. ) A solid electrolytic capacitor characterized by using a TCNQ complex using a substituted pyridinium cation represented by the following as a donor material.