JPH0394413A - Electrolyte for drive use of electrolytic capacitor - Google Patents

Abstract

PURPOSE:To obtain an aluminum electrolytic capacitor which is resistant to a cleaning agent, whose reliability is high and whose cost is favorable by a method wherein a prescribed amount of nitrophenetole is added to an electrolyte which is prepared by dissolving boric acid and an organic acid or its salt in ethylene glycol, as a main solvent. CONSTITUTION:Nitrophenetole (ethoxynitrobenezene) of 0.5wt.% or higher is added to and dissolved in an electrolyte which is prepared by dissolving boric acid and an organic acid or its salt in ethylene glycol as a main solvent; an electrolyte for drive use of an aluminum electrolytic capacitor is formed. Thereby, even when a halogenated hydrocarbon used as a cleaning agent for the aluminum electrolytic capacitor for medium- and high-pressure use ingresses into a capacitor case, it is possible to prevent chlorine ions from being extricated by a decomposition-suppressing action of an added nitrocompound, to prevent a chlorine-ion concentration of the electrolyte from being increased and to prevent an aluminum electrode from being corroded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention prevents corrosion of capacitor elements caused by halogenated hydrocarbons penetrating into the capacitors when electrolytic capacitors are cleaned with a cleaning agent containing halogenated hydrocarbons. The present invention relates to a driving electrolytic solution (hereinafter referred to as electrolytic solution) for medium-high voltage electrolytic capacitors that improves life characteristics.

BACKGROUND OF THE INVENTION Conventionally, an electrolytic solution prepared by using ethylene glycol as a main solvent and dissolving boric acid and an organic acid or a salt thereof has been used as an electrolytic solution for a 7-luminium electrolytic capacitor.

In addition, electrolytes containing nitrophenol or nitrobenzoic acid have been used to prevent corrosion caused by halogenated hydrocarbons.

Problems to be Solved by the Invention In aluminum electrolytic capacitors, during the cleaning process or the process of removing solder flux used when attaching to a printed circuit board, this may be removed by immersion in a halogenated hydrocarbon used as a cleaning agent or a steam bath. Halogenated hydrocarbons penetrate through the rubber stopper and enter the capacitor, decompose and produce chlorine ions, which sometimes corrode the capacitor element.

Therefore, in order to prevent corrosion caused by halogenated hydrocarbons, electrolytes to which nitrophenol or nitrobenzoic acid has been added have been used.
(lower than V).

Means for Solving the Problems The present invention solves the above-mentioned problems by making it possible to incorporate a cleaning process into electrolytic capacitors without sacrificing the excellent properties obtained from conventional electrolytes. It provides a high-pressure electrolyte solution.

That is, 0,
This is an electrolytic solution for driving an aluminum electrolytic capacitor, characterized in that 5% by weight or more of nitrophenethole (ethoxynitrobenzene) is added and dissolved therein.

Note that the above-mentioned nitrophenetole is characterized in that it is 0-nitrophenetole, m-nitrophenetole, or p-nitrophenetole.

Function: The electrolytic solution of the present invention prevents chlorine ions from forming in aluminum electrolytic capacitors for medium and high voltages even if halogenated hydrocarbons used as cleaning agents enter the capacitor case by inhibiting the decomposition of the added nitro compound. death,
Prevents increase in chlorine ion concentration in electrolyte and prevents corrosion of aluminum electrodes.

Example Examples of the present invention will be described below.

Table 1 shows comparative examples regarding the composition and specific resistance of electrolytes used in electrolytic capacitors of the present invention and conventional electrolytic capacitors. Electrolyte sample symbols A, B%C in Table 1 are conventional examples, sample symbols D, E, F
, G, and H are examples of the present invention.

Table 1 and Table 2 show that using the electrolyte in Table 1, the rating is 250WV, 2
Prototype of 201LF 7 aluminum electrolytic capacitor, 1
, Ll - after immersion in trichloroO ethane, at 105°C2
The results of a high temperature load test for 000 hours are shown.

The electrolyte solution according to the present invention using the electrolyte solution with the symbol D%E%F%G,H does not cause corrosion in the high-temperature load test even if the above-mentioned cleaning solution penetrates into the capacitor element. There were no problems with the characteristics, and an improvement effect was obtained.

Further, the amount of nitrophenethole added is preferably 0.5% by weight or more, and it is not preferable that the amount added exceeds the saturation concentration. Note that the corrosion prevention effect is insufficient when 0.5% by weight of the groove is left ungrooved.

Effects of the Invention As described above, a 7-luminium electrolytic capacitor using the electrolyte of the present invention can withstand cleaning agents, is highly reliable, and is advantageous in terms of cost.
It has great industrial and practical value.

Claims (1)

[Claims] An aluminum electrolytic capacitor characterized in that 0.5% by weight or more of nitrophenethole (ethoxynitrobenzene) is added and dissolved in an electrolytic solution containing ethylene glycol as a main solvent and boric acid and an organic acid or its salt dissolved therein. driving electrolyte.