JPH034511A - Electrolyte for driving electrolytic capacitor - Google Patents

Abstract

PURPOSE:To lower the changing rate of electrostatic capacitance to about -1.2%, and also to bring the change of tangent of loss angle to almost nil by a method wherein an electrolyte for driving of an electrolytic capacitor is composed of an organic polarity solvent and 2,2-bis(4-carboxyphenyl) hexafluoropropane. CONSTITUTION:An electrolyte is composed of ethylene glycol, an organic polarity solvent such as gamma-butyl lactone and the like, 2,2-bis(4-carboxyphenyl) hexafluoropropane and the like as a main electrolyte. At this point, the desirable quantity of propane is within the range of 5 to 25wt.%, and this composition is indicated by the formula separately indicated. If the propane is used as above- mentioned, the conductivity of 2000muS/cm or higher can be maintained, and tan delta does not become higher even when propane is used for the electrolytic capacitor. Also, sparking voltage becomes 250V or higher, and the electrolyte suitable for a medium voltage electrolytic capacitor can be obtained.

Description

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

[Conventional technology and its problems l As a driving electrolyte for an aluminum electrolytic capacitor for high temperature [105°C] and long life [2000 hours], 85'w t% ethylene glycol and 7w ammonium borate were used.
t%, adipine 1113 wt% and water 5 wt
% (hereinafter referred to as conventional example) is well known.

However, the high temperature load test (10
Looking at the results at 5°C for 2000 hours.

The rate of change in capacitance is large, and the tangent of loss angle is also large, so it is still insufficient as an electrolytic solution for driving electrolytic capacitors for high temperatures and long life.

CObject of the Invention 1 However, the present invention provides an electrolytic solution for driving an intermediate voltage aluminum electrolytic capacitor which has characteristics superior to those of the above-mentioned conventional example.

[Configuration of the Invention] The electrolytic solution according to the present invention contains an organic polar solvent such as ethylene glycol or γ-butyrolactone and 2.2- as the main electrolyte.
bis(4-carboxyphenyl)hexafluoropropane, and the amount of 2.2-bis(4-carboxyphenyl)hexafluoropropane is 5 to 25 wt%.
A range of is preferred.

2) 2-bis(4-carboxyphenyl) according to the present invention
Hexafluoropropane is represented by the following formula (1).

If it exceeds 5wt%, the spark voltage will be 250v or less,
It can no longer be used as a medium voltage electrolytic capacitor.

[Example] The composition of the electrolytic solution (40°C) according to the present invention is shown in Table 1 together with the conventional example. This example uses ethylene glycol as the organic polar solvent, showing the relationship between quantity and conductivity and spark voltage for polar solvents.
The liquid temperature was 40°C.

When the amount of 2.2-bis(4-carboxyphenyl)hexafluoropropane is less than 5 wt%, the electrical conductivity becomes 2000 μS/cm or less.

When used in an electrolytic capacitor, the tan δ becomes high, and the amount of 2.2-bis(4-carboxyphenyl)hexafluoropropane is Among them, electrolytic capacitors (rated 180V-56
OL! Table 2 shows the basic characteristics (average values) for each of the 50 pieces of 'F) (+30x302).

Next, among the electrolytes shown in Table 1, conventional examples.

Electrolytic capacitor (rated 200V-820uF) using the electrolytes of Example 2 and Example 3 (4) 30X40β
Temperature 105℃, rated voltage applied 2 for each 50m of
Table 3 shows the results of the 000-hour high-temperature load test, and each value of the initial and post-test characteristics is the average value of 350 electrolytic capacitors.

Although ammonium salts have been described as electrolytes in the examples, amine salts and quaternary ammonium salts can also be used.

[Effect of the invention 1 As can be seen from Table 3, in the conventional example, after the high temperature load test, the rate of change in capacitance with respect to the initial value was approximately -4%.
The change in the tangent of the loss angle is as large as approximately 2.5 times. On the other hand, in the embodiment, the rate of change in capacitance is as low as about -1.2%, and there is almost no change in the tangent of the loss angle.

Therefore, according to the electrolytic solution according to the present invention, an aluminum electrolytic capacitor with high temperature and long life can be provided.

[Brief explanation of the drawing]

FIG. 1 is a characteristic diagram showing the relationship between the amount of 2) 2-bis(4-carboxyphenyl)hexafluoropropane, electrical conductivity, and spark voltage according to the present invention.

Claims (2)

[Claims] (1) Organic polar solvent and 2,2-bis( as main electrolyte)
An electrolytic solution for driving an electrolytic capacitor consisting of 4-carboxyphenyl)hexafluoropropane. (2) In claim (1), 2.2-bis(
An electrolytic solution for driving an electrolytic capacitor, characterized in that the amount of 4-carboxyphenyl)hexafluoropropane is 5 to 25 wt%.