JPS6261312A - Solid 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 [Industrial Application Field] The present invention provides a 7,7°8.8-
The present invention relates to a solid electrolytic capacitor using an ionic radical salt of tetracyanoquinodimethane as a solid electrolyte.

[Prior art and problems] 7.7,8.8-tetracyanoquinodimethane (hereinafter referred to as T
For example, as a solid electrolytic capacitor using an ionic radical salt consisting of CNQ as a solid electrolyte, for example, TCNQ i# salt having quinoline or isoquinoline as a cation and TCNQ as an anion (JP-A-58-191
No. 414) and TCNQ with pyridine as a cation.
It is well known that complex salts (Japanese Unexamined Patent Publication No. 59-61026) are heated and melted, solidified by cooling, and then used as a solid electrolyte.

In addition, in the cation of these TCNQ complex salts, its N
The carbon positions are substituted with an alkyl group selected from carbons 1fi2 to 18.

The method of heating and melting the TCNQ complex salt and cooling and solidifying it is very preferable because the etched aluminum foil or tantalum sintered body can be impregnated with the TCNQ complex salt in a molten state. However, on the other hand, if the melting temperature of TCNQI salt is high or the melting time is long, TCNQI salt, which is an organic semiconductor,
The CN layer decomposes and transforms into an insulator.

For example, quinoline or isoquinoline TCNQ complex salt decomposes without melting, and N-methyl-quinoline TCNQ complex salt, N-methyl-isoquinoline TCNQ complex salt and N-
Both methyl-pyridine TCNQI salts decompose upon melting. N-n-propyluginoline T CN Q
When 31 is a salt, the melting point is 225-235['C]
However, it decomposes after 80 seconds at a melting temperature of 26Q['C1 and 2G seconds at a temperature of 290[''C] to become an insulator.In addition, in the case of the N-n-butyl-pyridine TCNIIt salt, the melting temperature is 260[''C]. After 60 seconds at [t], temperature 2
It decomposes after 19 seconds at 90°C and becomes an insulator. Therefore, it must be impregnated onto TCNQCN and rapidly cooled within this time. Next, we will discuss the specific resistance value when TCNQ salt is melted at 290 [t] and immediately cooled and solidified at 25 [t].
The specific resistance value of propyl-quinoline TCNQ complex salt is 23[Ω
- cml, and the specific resistance value of the Nn-butyl-pyridine TCNQ complex salt is 330 [Ω·crn].

As described above, it is necessary that the melting time of conventional TCNQCN, which functions as an organic semiconductor, is short and that impregnation is performed as quickly as possible. Although the specific resistance value is sufficiently smaller than that of conventional aluminum electrolytic capacitors and tantalum solid electrolytic capacitors, it still shows a large resistance value. Therefore, TCNQ has a longer melting time and a smaller specific resistance value after thermal melting.
It is hoped that such a TCNQ will appear on the CN.
It has been desired to develop a solid electrolytic capacitor that can be used on CN and has excellent temperature characteristics and life characteristics.

[Summary of the Invention] However, the present invention provides a β-naphthoquinoline TCNQ complex salt on TCNQCN which has a long melting time and a low resistivity value, and also provides a β-naphthoquinoline TCNQ complex salt in a solid electrolyte and a monomer. The present invention provides a solid electrolytic capacitor with excellent temperature characteristics.

The basic structure of the solid electrolyte according to the present invention is anodized (
Valve metal (chemical conversion) has an anodized film on its surface.
For example, a solid electrolyte made of TCNQCN is used, with a first @ electrode made of (aluminum, tantalum, titanium, and alloys thereof) and a second electrode (counter electrode) directly or with a separator interposed therebetween. TCNQjlt
As mentioned above, the salt C is β-naphthogynoline TCNQ.
The N-position of β-naphthoquinoline, which is a complex salt and a cation, is substituted with an alkyl group having 1 to 18 carbon atoms (including all isomers such as n- and 1sO-). Here, the structural formula of β-naphthoquinoline TCNQ complex salt is as follows.

Structural formula of β-naphthoquinoline TCNQ complex salt (R is an alkyl group having 1 to 18 carbon atoms 6) Next, a method for synthesizing β-naphthoquinoline TCNQ complex salt will be described. 0.0
1 mol of β-su7toquinoline (i, 79 [gl) and 0.01 mol of methyl iodide (1,42 [gl]) were heated in a flask to about 40-45 ['C] in a water bath to produce P. ? When exposed, a quaternization reaction occurs (yield 90[
%]). Cooling this solution yields a first yellow powder (:
, I-N-methyl-β-naphthoquinoline) of 0,01
Mol (3,21 [gl) is dissolved in acetonitrile at boiling state and mixed with an 80 [''C] acetonitrile solution in which 0.02 mole (4,08 [gl) of TCNQ is dissolved. Then, for about 5 hours. By cooling at room temperature, the desired N-methyl-β-naphthoquinoline T was obtained with a yield of about 98%1.
Oblique crystals of CNQ complex salt are obtained. The crystals were washed with a large amount of acetonitrile, further washed with ethanol until the washing solution was no longer colored, washed with ether, and dried for 5 minutes. Furthermore, it is ground to 400 meshes using a ball mill or the like and applied to solid electrolytic capacitors.

In addition, in this synthesis step, instead of methyl iodide,
When ethyl iodide, propyl iodide, etc. are used, N-ethyl-β-naphthoquinoline TCNQ complex salt, Nn-propyl-β-naphthoquinoline complex salt, etc. are obtained, respectively.

As a representative example, N-methyl-β-naphthoquinoline TCN
The specific resistance value of Qfu salt is 0.7 [Ω・Cm], N-ethyl-
The specific resistance value of β-naphthoquinoline TCNQ complex salt is 0.9[
Ω・Cm], N-n-buυbi-β-naphthoquinoline T
The specific resistance value of CNQi salt is 1.5 [Ω-cm1. N-n-
The specific resistance value of the butyl-β-naphthoquinoline TCNQ&I salt was 1°3[Ω·ClTl'll. In addition, the N-methyl to β-nut quinoline TCNQ complex decomposed at a melting temperature of 255° C. for 105 seconds and then at 290 tl for 25 seconds and became an insulator. , N-ethyl-
β-S”7 Togynoline TCNQ complex has a melting temperature of 260[
After 100 seconds at Tl, it decomposed and became an insulator at a temperature of 290 [Tl for 34 seconds. N-n-propyl- After 110 seconds at a melting temperature of 260 ['C], a temperature of 290
It decomposed in 337 seconds at [t:] and became an insulator. Furthermore, N-n-butyl-β-su1toquinoline TCNQ
The complex salt decomposed at a melting temperature of 260 [T:] for 1135 seconds and at a temperature of 290 [Cl] for 46 seconds and became an insulator. When the specific resistance value was measured after rapid cooling to
The specific resistance value of m salt is 3.1 [Ω・Cm]. N-ethyl-β
The specific resistance value of naphthoquinoline TCNQ complex is 6.6[Ω・
Cm], Nn-propyl-β naphthoquinoline TCN
The specific resistance value of Q complex salt is 7.3 [Ω・Cm3.

The specific resistance value of the N-n-butyl-β naphthoquinoline TCNQ salt was 8.8 [Ω·Cm].

[Example] Next, β-naphthoquinoline TCN obtained as described in Section 5
An example in which Q complex salt is used in an electrolytic capacitor will be described.

40 [mg] of N-methyl-β naphthoquinoline TCNQ complex salt powder was filled into an aluminum case with a diameter of 5 and O [mm], and heated to 290 [tl] in about 10 seconds to dissolve it. A rolled-up aluminum electrolytic capacitor element was immersed therein, and quenched about 15 seconds after immersion. The capacitor element used was an aluminum foil whose surface was subjected to chemical conversion treatment to form an oxide film, and the temperature was raised to 270 [Tl] immediately before impregnation with the organic semiconductor. Due to stiffness, the rating is 4.7 [μF for an anode of 1
], a solid electrolytic capacitor with a loss of 4.6% was obtained.

Solid electrolytic capacitor according to the present invention obtained as described above (rated 25 [v] □ 4.7 [μFl) (
7) In the example and in the capacitor element similar to the example, N −
Conventional Example 1 of a solid electrolytic capacitor of the same rating impregnated with n-propyl-quinoline TCNQ complex salt, and an aluminum electrolytic capacitor of the same rating impregnated with an ethylene glycol-ammonium adipate based electrolyte in a capacitor Af similar to the example. Table 1 shows a comparison of the temperature characteristics of the capacitor with Conventional Example 2, and Table 2 shows a comparison of the characteristics.

In Tables 1 and 2, the capacitance value and the tangent of loss angle are the values at a frequency of 120 [Hz], and the equal series resistance values are the values at a frequency of 100 [KHz]. . Further, the capacitance change rate is based on the capacitance value at a temperature of 25 [° C.]. The leakage current is the rated voltage (2
5 [V]) was applied and measured 30 seconds later.

In the following examples, a case was described in which a rolled aluminum electrolytic capacitor element was impregnated with β-naphthoquinoline TCNQ complex salt, but it is also possible to impregnate an aluminum sintered capacitor element or a tantalum sintered capacitor element. It is possible.

[Effect] β-naphthoquinoline TCN according to the present invention described above
Q complex salt can take a longer melting time to transform from an organic semiconductor to an insulator than the conventional quinoline TCNQ complex salt, so it is very preferable for handling in the impregnation process, etc., and has a low specific resistance value. It is also possible to provide an organic semiconductor with a small value. Furthermore, this β-naphthoquinoline TCNQ! When a salt is used as the electrolyte of a solid electrolytic capacitor, as can be seen from Tables 1 and 2, it is possible to provide a solid electrolytic capacitor that is superior to the conventional example in terms of both temperature characteristics and life characteristics.

Claims (3)

[Claims] (1) A solid electrolytic capacitor characterized in that a β-naphthoquinoline/7,7,8,8-tetracyanoquinodimethane complex salt substituted with a hydrocarbon group at the N position is used as an electrolyte. (2) A solid electrolytic capacitor according to claim (1), characterized in that the N-position of the β-naphthoquinoline is substituted with an alkyl group having 1 to 18 carbon atoms. (3) A solid according to claim (1), characterized in that the solid electrolyte is obtained by heating and melting β-naphthoquinoline/7,7,8,8-tetracyanoquinodimethane complex salt and solidifying it by cooling. Electrolytic capacitor.