JPH0629249B2 - Complex composition for capacitors - Google Patents

Description

TECHNICAL FIELD The present invention relates to a complex composition having excellent properties for electrolytic capacitors.

It is known that the organic cation complex of 7,7,8,8-tetracyanoquinodimethane (TCNQ) has electrical conductivity. Utilizing this characteristic, it has recently been used as an electronic component such as a capacitor. Is being used.

This complex is, for example, an organic cation iodide and TCN.
It is synthesized by the reaction with Q, and the reaction formula is as follows.

^{4TCNQ + 3M + I - ...>} 2M + · TCNQ - · TCNQ + M + I - 3 In other words, TCNQ is reduced to TCNQ anion by iodide, iodine and liberated iodine, it is reacted with an excess of iodide, ▲ I ^- ₃ ▼ anion To generate. The composition of the formed complex with TCNQ can be expressed by the general formula: M ⁺ · TCNQ ⁻ · (TCNQ) mm = 0 to 1.

J.Am.Chem.Soc.84 3374 (1962) reports a complex with m = 0 and a complex with m = 1, but it is difficult to synthesize a pure product. Furthermore, JP-A-50-277
According to the description of Japanese Patent No. 83 (N-methylquinolinium) ⁺
In the synthesis of (TCNQ) ^- (TCNQ) m, the composition of the complex has a different value of m depending on the solvent used during the synthesis, and the following results are obtained, for example.

Synthesis solvent m value Acetonitrile 0.5 Acetone 0.7 Nitromethane 0.9 Dichloromethane 1.0 The value of m tends to fluctuate in the first place due to subtle differences in synthesis conditions. Furthermore, even in the same solvent, the molar ratio of organic cation iodide and TCNQ can be changed. If you get m
The value of changes. Further, the reaction temperature, the reaction method and the like have a delicate influence on the value of m, so that it is extremely difficult to obtain a complex composition having a constant value of m.

Problems to be Solved by the Invention This is a major problem when the complex is to be put to practical use for a specific purpose such as the electrolyte layer of an electrolytic capacitor. For example, the uniformity of the performance of the capacitor, the life, etc. are controlled. However, this is difficult with the conventional complex composition, leading to a delay in practical application.

An object of the present invention is to provide a complex composition having excellent performance uniformity and life when used as an electrolyte of a capacitor.

Means for Solving the Problems As a result of extensive studies on the complex composition having good properties, the present inventors have found that the isopropylisoquinoline TCNQ complex has a certain absorbance when it is dissolved in acetonitrile. It has been found that the complex has excellent properties for capacitors. That is, the present invention provides 393 for 842 nm in acetonitrile solution.
The gist is a (TCNQ) -isopropylisoquinoline complex composition for capacitors, which has an absorbance ratio of nm in the range of 2.1 to 4.0.

If the absorbance ratio is greater than 4.0, the electrical conductivity of the TCNQ complex will deteriorate when used in an organic semiconductor capacitor,
If it is less than 2.1, the initial capacitor characteristics can be obtained, but when used for a long time, the electrical conductivity of the TCNQ complex deteriorates, and the high frequency ESR of the capacitor increases.
In addition, the capacitance becomes small, which is not preferable as an electrolyte for capacitors. The preferred absorbance ratio range is 2.1 to 3.5, more preferably 2.1 to 3.0.

An example of the method for producing the complex used in the present invention is shown below.

TCNQ and isopropylisoquinolinium iodide are charged in a solvent at the same time and reacted, or
It can be produced by adding CNQ and isopropylisoquinolinium iodide as they are or by dissolving them in a solvent and treating them for an appropriate time. Alternatively, the order of addition may be reversed.

The reaction temperature at this time is -30 to 120 ° C, and more preferably 30 to 85 ° C. The molar ratio of isopropyl isoquinolinium iodide and TCNQ is 0.53 ~
The range of 0.65, more preferably 0.55 to 0.63 is good.

As the solvent, various organic solvents are used, and examples thereof include aliphatic ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and acetonitrile. Further, halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,2-trichloroethane and the like can also be used. Acetonitrile and methyl ethyl ketone are particularly preferred.

After the complex is synthesized, it is filtered and washed with an appropriate solvent, for example, acetonitrile, so that a complex composition having a desired performance can be obtained.

Using this complex composition, an electrolytic capacitor can be manufactured as follows.

First, a method for manufacturing an organic semiconductor capacitor using the complex composition of the present invention will be described. FIG. 1 shows an element structure of an organic semiconductor capacitor, and FIG. 2 shows a method of forming the complex composition of the present invention as an electrolyte in this capacitor element.

The capacitor element 1 of FIG. 1 is formed by winding a strip electrode body, and the anode 2 is made of aluminum, tantalum,
It is made of a film-forming metal such as niobium. This anode 2
Is first subjected to etching treatment for surface expansion,
A dielectric oxide film is formed on the surface by anodic oxidation treatment. The strip-shaped anode 2 has collector electrodes 3 having substantially the same area arranged opposite to each other, and a separator 4 slightly wider than the anodes 2 and 3 is narrowed between the anode 2 and the collector electrode 3. The assembled product is wound from one end to form a cylindrical capacitor element 1. It should be noted that tabs 5 and 6 for obtaining electrical connection to the outside are connected to each of the anode 2 and the collecting electrode 3 by means such as welding, and project in parallel from one end face. Further, external leads 7 and 8 are connected to the tips of these tabs by welding.

The capacitor element 1 is not limited to a structure in which foil electrodes are wound, and may be a stack of foil electrodes or a film-forming metal sintered into a porous block. .

FIG. 2 illustrates a method of impregnating the capacitor element 1 with an organic semiconductor. A preheating block 10 is placed on the left side of the figure. This preheating block 1
In No. 0, a heater for heating is embedded inside, and a recess 11 is provided on the upper surface.
The capacitor element 1 is placed inside and preheated to maintain a high temperature state.

Next, an impregnating block 12 is placed on the right side of the figure, the impregnating block 12 also has a heater for heating embedded therein, and a recess 13 is provided on the upper surface. The complex composition or a powder 14 in which an additive is mixed with the complex composition is injected into the recess 13 and the powder 14 is melted by heating. Then, the capacitor element 1 which has been made to stand by in the preheating block 10 is moved to the melted position and immersed for a predetermined time, after which the capacitor element 1 is pulled up from the concave portion 13 and the powder 14 which is melted by natural cooling is solidified to solidify the organic semiconductor layer. Are formed on the surface of the electrode 2.

In this way, the organic semiconductor capacitor is completed by housing the capacitor element 1 having the organic semiconductor layer formed therein in a metal case, or by applying an outer packaging means such as resin sealing.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples.

Example 1 6 g (0.0294 mol) of TCNQ was dissolved in 600 m of acetonitrile at 72 to 76 ° C., and 5.57 g of isopropylisoquinolinium (IPIQ) iodide was added.
What melt | dissolved (0.0186 mol) in 30 m of acetonitrile at 50 degreeC was dripped, and after making it react at 70-76 degreeC for 30 minutes, it cooled to 5 degreeC, continuing stirring.

The formed crystals were filtered, washed 3 times with 30 m of acetonitrile, further washed with 30 m of ether and then dried to obtain a complex. The absorbance ratio A393 / A842 was 2.36.

Example 2 6 g of TCNQ was suspended in 90 m of acetonitrile and stirred at 70 ° C. IPIQ iodide
5.57 g was dissolved in 90 m of acetonitrile at 50 ° C and added dropwise. Including the dropping time, the mixture was gradually cooled after 30 minutes, passed 5 hours later at a temperature of 20 ° C., and then carried out in the same manner as in Example 1 to obtain 6.7 g of a complex. Absorbance ratio A393 / A
842 was 2.25.

Example 3 6 g of TCNQ in 120 m of acetonitrile at 30 ° C
While stirring at, IPIQ Iodide 5.57g
Was dissolved in 60 m of acetonitrile at 50 ° C. and added dropwise. The reaction was carried out at 30 ° C. for 2 hours, the mixture was gradually cooled to 20 ° C., passed through the same procedure as in Example 1, and 6.86 g of a complex was obtained. The absorbance ratio A393 / A842 was 2.26.

Example 4 6 g of TCNQ in 90 m of methyl ethyl ketone at 76 ° C
Then, 5.57 g of IPIQ iodide powder was added together with 90 ml of methyl ethyl ketone. After reacting for 30 minutes, the mixture was gradually cooled to 20 ° C. and then the same procedure as in Example 1 was carried out to obtain 6.92 g of a complex. The absorbance ratio A393 / A842 was 2.29.

Example 5 The amount of IPIQ iodide used was 4.68 g (0.0156 mol).
A complex was obtained in the same manner as in Example 1 except that the complex was changed to.
The absorbance ratio A393 / A842 was 3.30.

Comparative Example 1 6 g of TCNQ was stirred in 600 m of acetonitrile under reflux, and 6.15 g of IPIQ iodide (0.
(0206 mol) dissolved in 30 m of hot acetonitrile was added. After 30 minutes, it was cooled to 5 ° C. Thereafter, the same procedure as in Example 1 was carried out to obtain 6.03 g of a complex. Absorbance ratio A393 /
The A842 was 1.86.

Comparative Example 2 The amount of IPIQ iodide used was 4.0 g (0.0133 mol).
A complex was obtained in the same manner as in Example 1 except that the complex was changed to. The absorbance ratio A393 / A842 was 4.33.

Reference Example 1 An electrolytic capacitor was prepared using the complex compositions of Examples 1 to 5 and Comparative Examples 1 and 2, and the characteristics were compared.

First, as an anode, width 2.2mm, length 10mm, thickness 80μ
Using m high purity aluminum (purity 99.99%), the surface of this anode was expanded by electrolytic etching with an alternating current, and then a derivative oxide film having a withstand voltage of 9 V was formed on the surface by anodization. Next, as a current collecting electrode, aluminum of the same size as the anode (purity 99.94
%), The current collecting electrode and the anode are arranged opposite to each other, an aluminum tab for external drawing is connected to the approximately central portion of both electrodes by cold weld, and a separator paper of Manila hemp fiber mixed paper is interposed. And wound into a cylindrical capacitor element.

Next, this capacitor element is heated to 200 by preheating block.
While keeping the temperature at 0 ° C., 0.5 part by weight of γ-butyrolactone was added to 1 part by weight of each of the complex compositions of Examples 1 to 5 and Comparative Examples 1 and 2 in a melting tank of an impregnating block. It was poured and melted by heating. Then, the capacitor element was moved from the preheating block to the melting tank of the impregnating block, impregnated in the melting tank for 10 seconds, and then pulled up and naturally cooled.

The capacitor element thus formed with the electrolyte layer is housed in an aluminum outer case, the opening is closed with a rubber sealing body, the outer case opening end is wound and sealed, and a rated voltage of 6.3 V, An electrolytic capacitor having a rated capacity of 10 μF was completed. At this time, the outer dimensions of the main body are 3
mm and the length was 5 mm.

The following Table 1 shows the initial values of these electrolytic capacitors and the characteristics after a 2000-hour life test was performed by applying a rated voltage at 85 ° C. The characteristics are capacitance (CA
P), loss tangent (Tan δ), equivalent series resistance (ES
R) was measured.

EFFECTS OF THE INVENTION The TCNQ-isopropylisoquinoline complex composition having a constant absorbance ratio of the present invention, when used as an electrolyte layer of a capacitor, has low conductivity and excellent characteristics as a capacitor, and has characteristics even when used for a long time. Can be maintained. Therefore, it has an excellent effect as a capacitor.

[Brief description of drawings]

FIG. 1 shows an example of an organic semiconductor capacitor element structure, and FIG. 2 shows a method for forming the complex composition of the present invention as an electrolyte on the capacitor element of FIG. DESCRIPTION OF SYMBOLS 1 ... Capacitor element, 2 ... Anode, 3 ... Collection electrode, 4 ... Separator, 5, 6 ... Tab, 7, 8 ... External lead, 10 ... Preheating block, 11, 13 ... Recessed part, 12 ... Impregnation block, 14 ... powder

Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number in the agency FI Technical indication location H01G 9/02 331 7924-5E H01L 29/28 (72) Inventor Takao Maki 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Address: Sanryoh Kasei Kogyo Co., Ltd., Research Institute (72) Inventor Isao Kawakami 1000, Kamoshida-cho, Midori-ku, Yokohama, Kanagawa Sanryo Kasei Kogyo Co., Ltd. (56) Reference JP-A-60-100551 A)

Claims (1)

[Claims] 1. A 7,7,8,8-tetracyanoquinodimethane-isopropylisoquinoline complex composition for capacitors, which has an absorbance ratio at 393 nm to 842 nm in an acetonitrile solution of 2.1 to 4.0.