JPH02112216A - Electrolyte for driving electrolytic capacitor and electrolytic capacitor - Google Patents

Abstract

PURPOSE:To reduce the variation of a capacitance under a high temperature without lowering a spark voltage by a method wherein 1-hydroxyethane-1, 1-diphosphonic acid and/or its salt are contained in electrolytic capacitor driving electrolyte. CONSTITUTION:1-hydroxyethane-1,1-diphosphoric acid and/or its salt are contained in electrolytic capacitor driving electrolyte. The content is preferably 0.001-5wt.% to the weight of the electrolyte. If the content is less than 0.001wt.%, no effect is obtained. If the content exceeds 5wt.%, the spark voltage of the electrolyte is lowered. With this constitution, the spark voltage can be improved without lowering a specific conductivity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electrolytic solution for driving an electrolytic capacitor and an electrolytic capacitor.

Conventional technology 2...-7 As equipment becomes more reliable, there is a strong demand for electrolytic capacitors to have a longer life at high temperatures. However, conventionally, this type of electrolytic capacitor uses a borate or the like as a solute in a solvent mainly composed of ethylene glycol. In this type of electrolyte, the boric acid is esterified when the electrolyte is prepared, and since it contains a large amount of water, it has a high vapor pressure at high temperatures and reacts with the aluminum, which is still an electrode. It was difficult to extend the lifespan of electrolytic capacitors at high temperatures.

As an electrolytic solution to improve this problem, an electrolytic solution is known in which ethylene glycol is used as a solvent, an organic acid such as 1,6-decanedicarboxylic acid is used as a solute, and 8-oxyquinoline or ethylenediaminetetraacetic acid is added. Efforts are being made to improve capacitance changes in capacitors. (for example,
(Japanese Patent Publication No. 628005) Problems to be Solved by the Invention However, when ethylenediaminetetraacetic acid is added to the electrolytic solution as in the past, the spark generation voltage of the electrolytic solution decreases. 7 was difficult.

The present invention solves the conventional problems, and aims to stabilize the characteristics at high temperatures, particularly stabilizing the capacitance, without reducing the spark generation voltage of the electrolytic solution.

Means for Solving the Problems In order to solve the above problems, the present invention provides an electrolytic solution for driving an electrolytic capacitor containing 1-hydroxyethane-1,1-diphosphonic acid represented by the formula (1) and/or its Contains salt.

The content of OHOH0H 1-hydroxyethane 1,1-diphosphonic acid and/or its salt is preferably 01oO1 to 5% by weight relative to the weight of the electrolyte. This is 0.00
This is because if it is less than 1% by weight, there is no effect, and if it exceeds 5% by weight, the spark generation voltage of the electrolytic solution decreases.

Effect 1-Hydroxyethane 1.1-diphosphonic acid has a moderate ability to oleate aluminum, so aluminum! ('/A It is thought that it adsorbs to the foil surface and prevents attack by water, etc.

Example Examples of the present invention will be described below.

Table 1 shows the electrolyte compositions of the examples of the present invention and conventional electrolytes, as well as the specific conductivity and spark generation voltage at room temperature. Compared to the conventional example, the example of the present invention can increase the spark generation voltage without lowering the specific conductivity.

Next, examples will be described in which the electrolytic solutions of the embodiments and conventional examples shown in Table 1 are used in aluminum electrolytic capacitors. The capacitor element used in the experiment has a well-known wound structure and has a rating of 4.
00 V, 220 It F (φ3゜Xg50)
I used the one from As a result, in the case of using the electrolytic solution of Conventional Example 2, a short circuit occurred during aging during sample preparation, and this rated voltage could not be applied.

5 Heno 6...

FIG. 1 shows Example 1. The capacitance changes of electrolytic capacitors using the electrolytes of Example 2 and Conventional Example 1 in a life test in which rated voltage was applied at 105°C are shown. .

As is clear from Figure 1, 1-hydroxyethane-1
, 1-Diphosphonic acid-containing electrolyte solution can improve capacitance changes at high temperatures.

Effects of the Invention As described above, according to the present invention, compared to conventional electrolytes,
It is possible to improve the capacitance change of electrolytic capacitors at high temperatures without lowering the spark generation voltage, and to improve the reliability of medium and high voltage classes.

[Brief explanation of drawings]

Figure 1 shows the rating 4 using the electrolyte of the present invention and the conventional electrolyte.
It is a characteristic curve diagram showing a change in capacitance at 105°C of a Fulmi electrolytic capacitor of 0ov22oIIF (φ30Xg60).

Claims (3)

[Claims] (1) An electrolytic solution for driving an electrolytic capacitor, comprising 1-hydroxyethane-1,1-diphosphonic acid and/or a salt thereof. (2) Claim 1 characterized in that it contains 0.001 to 5% by weight of 1-hydroxyethane-1,1-diphosphonic acid and/or its salt based on the weight of the electrolyte.
Electrolyte solution for driving the electrolytic capacitor described. (3) An electrolytic capacitor characterized by using the electrolytic solution for driving an electrolytic capacitor according to claim 2.