KR100328262B1 - A method for preparing electrolytes for aluminum electrolysis condensor for high voltage and the electrolyte prepared therefrom - Google Patents

Abstract

The present invention relates to a method for preparing an electrolytic solution for an aluminum electrolytic capacitor for high pressure, and an electrolyte prepared therefrom.

Solvents of ethylene glycol and benzyl alcohol;

Solutes of ammonium sebacate, ammonium dodecanedioate, ammonium pentaborate and 1,6-decane dicarboxylic acid; And

Room temperature mixing of the additives of mannitol, p-nitrobenzyl alcohol and hypophosphorous acid; And

A method of manufacturing an electrolytic solution for a high pressure aluminum electrolytic capacitor, comprising the step of stirring the mixed solution;

An electrolyte prepared by the above method is provided.

According to the above, by appropriately controlling the composition of the electrolyte used in the high voltage aluminum electrolytic capacitor of the rated voltage 450WV class, by improving the problems such as conductivity, impregnation, poor flow and case vent operation of the electrolyte, As a result, it is possible to improve the characteristics of the aluminum electrolytic capacitor using the electrolyte.

Description

A method for preparing an electrolytic solution for a high pressure aluminum electrolytic capacitor and an electrolyte prepared therefrom {A METHOD FOR PREPARING ELECTROLYTES FOR ALUMINUM ELECTROLYSIS CONDENSOR FOR HIGH VOLTAGE AND THE ELECTROLYTE PREPARED THEREFROM}

The present invention relates to a method for preparing an electrolytic solution for an aluminum electrolytic capacitor for high pressure, and to an electrolyte prepared therefrom, and more particularly, to improve the impregnating property, conductivity property, poor flow rate, and case vent operation of the electrolyte solution. The present invention relates to a method for producing an electrolytic solution for use in a high pressure aluminum electrolytic capacitor having excellent product characteristics, and an electrolytic solution prepared therefrom.

Generally, aluminum electrolytic capacitors are classified into low pressure (less than 100WV), medium pressure (160-350WV), and high pressure (more than 400WV), and the criteria for this classification are generally determined by the electrolyte loaded into the electrolytic capacitor. .

Examples of the electrolyte used in the high pressure aluminum electrolytic capacitors having a rated voltage of 450 WV in the electrolytes classified as described above include, for example, a solvent consisting of 20 to 30% ethylene glycol and 50 to 60% diethylene glycol, 5 to 15%. And an electrolytic solution composed of a solute composed of ammonium sebacate and a hydrogen gas absorbent such as 1 to 5% polynitrobenzyl alcohol. This electrolyte is applied to a mixed solvent of ethylene glycol and diethylene glycol shows a sparking voltage characteristic of 470V or more, it is applied to a high-pressure electrolytic capacitor.

However, the electrolyte solution as described above has a relatively high resistivity of 1000 Ω · c / 25 ° C., which is not good in loss characteristics, and also implies a management problem by manufacturing at high temperature. 55 to 65% by weight of ethylene glycol, 10 to 15% by weight of diethylene glycol, and 5 to 10% by weight of benzyl alcohol (registered Sep. 20, 1999); 1.0-2.5% by weight of ammonium sebacate, 1.0-2.5% by weight of ammonium dodecanedioate, 1.0-2.5% by weight of ammonium pentaborate; The electrolyte solution which consists of 0.5-1.5 weight% of mannitol, 0.1-0.2 weight% of p-nitrobenzyl alcohol, and 0.05-0.2 weight% of hypophosphoric acid was disclosed.

However, the electrolyte solution has also improved the loss characteristics, which are a problem in the related art, but includes problems such as poor liquid leakage and case vent operation. Herein, the term "liquid leakage" refers to a phenomenon in which the electrolyte leaks out under high temperature and high pressure when the aluminum foil and the electrolyte are injected into the aluminum case and the inlet is sealed with a rubber packing. In addition, as used herein, the term "case vent" is intended to prevent explosion, and refers to a safety device that causes the vent in the lower part of the aluminum case to preferentially explode when a product is damaged and an impact is applied.

Therefore, the present invention not only improves the loss characteristics to be applicable to the electrolytic capacitor for high pressure, but also to solve problems such as poor liquid discharge and case vent operation, and adds 1,6-decane dicarboxylic acid instead of diethylene glycol in the conventional composition. It is an object of the present invention to provide a method for producing an electrolyte solution used in an improved high-pressure aluminum electrolytic capacitor.

Another object of the present invention is to provide an electrolyte solution for use in high pressure aluminum electrolytic capacitors that can be used at high temperature as well as low temperature and room temperature by improving the problems such as impregnation, conductivity characteristics and poor liquid leakage, case vent operation. have.

According to one aspect of the invention,

45-50 wt% of ethylene glycol and 20-25 wt% of benzyl alcohol;

Solute of 0.1-0.5% by weight of ammonium sebacate, 0.1-0.5% by weight of ammonium dodecanedioate, 1.0-2.0% by weight of ammonium pentaborate and 20-25% by weight of 1,6-decane dicarboxylic acid; And

Mixing at room temperature an additive of 0.5 to 1.0 wt% of mannitol, 0.1 to 0.2 wt% of p-nitrobenzyl alcohol, and 0.1 to 0.2 wt% of hypophosphorous acid; And

And setting the reactor at 95-105 ° C. and stirring the mixture for 270-330 minutes to raise the temperature to 195-205 ° C ..

According to the second aspect of the present invention,

An electrolytic solution for a high pressure aluminum electrolytic capacitor prepared by the above method is provided.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention is an solvent consisting of ethylene glycol, benzyl alcohol, ammonium sebacate, ammonium dodecanedioate, ammonium pentaborate, solutes of 1,6-decane dicarboxylic acid, mannitol, p-nitrobenzyl alcohol, hypophosphorous acid It relates to an electrolyte consisting of, each content and the reason for limitation are as follows.

The solvent dissolves the solute and plays a role in determining the properties. Among these solvents, when the content of the ethylene glycol is less than 45%, the specific resistance increases due to the decrease of the solubility, and when the content exceeds 50%, the withstand voltage is lowered and the reliability is increased. This is bad. Therefore, in the present invention, it is preferable to limit the content of ethylene glycol to 45 to 50%.

The benzyl alcohol, in particular, reduces the size per molecule to improve the impregnation and improve the conductivity at low temperatures, when the content is less than 20%, the specific resistance is increased, when the content exceeds 25% reliability is lowered do. Therefore, in the present invention, it is preferable to limit the content of benzyl alcohol to 20 to 25%.

The solute acts as an electrolyte. In the solute, the ammonium sebacate has a problem that the resistivity increases when the content is less than 1.0%, and when the solute exceeds 2.0%, the solute is precipitated due to a decrease in solubility. Therefore, in the present invention, it is preferable to limit the content of ammonium sebacate to 1.0 to 2.0%.

When the content of ammonium dodecanedioate is less than 0.1%, the withstand voltage is lowered, and when the content of the ammonium dodecanedioate is more than 0.5%, the solute is precipitated due to the decrease of the solute. Therefore, in the present invention, it is preferable to limit the content of ammonium dodecanedioate to 0.1 to 0.5%.

The ammonium pentaborate has a problem in that when the content thereof is less than 1.0%, the breakdown voltage decreases, and when the content exceeds 2.0%, the specific resistance is increased. Therefore, in the present invention, it is preferable to limit the content of ammonium pentaborate to 1.0 to 2.0%.

The use of such a straight-chain solute has a disadvantage in that the specific resistance also increases when the withstand voltage is improved. In the present invention, by adding a side chain solute such as 1,6-decane dicarboxylic acid, the withstand voltage can be increased and the specific resistance can be reduced. I want to.

The 1,6-decane dicarboxylic acid, in particular, improves the loss characteristics and improves the conductivity at room temperature. When the content is less than 20%, the resistivity increases to increase the loss angle of the electrolytic capacitor. If it exceeds%, there is a problem that the solute precipitates due to the solubility charge.

The additive absorbs hydrogen gas to suppress corrosion and is added in consideration of the breakdown voltage characteristics and reliability, and the mannitol is lower in the breakdown voltage when the content is less than 0.5%, and the reliability is lowered when it exceeds 1.0%. There is a problem. Therefore, in the present invention, it is preferable to limit the content of mannitol to 0.5 to 1.0%.

The p-nitrobenzyl alcohol has a problem that the gas generation increases when the content is less than 0.1%, the reliability is lowered when it exceeds 0.2%. Therefore, in the present invention, it is preferable to limit the content of p-nitrobenzyl alcohol to 0.1 to 0.2%.

The hypophosphite acts to minimize the amount of gas in the product by stabilizing the electrode by protecting the aluminum film, if the content is less than 0.1%, the corrosion resistance is insignificant, if the content exceeds 0.2%, the withstand voltage increases There is a problem. Therefore, in the present invention, it is preferable to limit the content of hypophosphorous acid to 0.1 to 0.2%.

Of solvents of ethylene glycol and benzyl alcohol, ammonium sebacate, ammonium dodecanedioether, ammonium pentaborate, solutes of 1,6-decane dicarboxylic acid, mannitol, p-nitrobenzyl alcohol and hypophosphorous acid having the above contents Additives are mixed at room temperature.

The temperature is not limited thereto, but mixing at room temperature may be attributable to the convenience of the process, and may simplify the manufacturing process.

Then set the reactor to 95-105 ° C. and then stir the mixture for 270-330 minutes to raise the temperature to 195-205 ° C. and complete the preparation of the electrolyte.

It is most preferable from the standpoint of satisfying the specific resistance and the breakdown voltage at the same time to use the reactor within the above temperature range. If the temperature rising range is also low, the withstand voltage is low, and if the temperature is high, the specific resistance is increased.

If it is shorter than the said agitation time, since a solute precipitates, it is unpreferable, and when it exceeds, it will raise a specific resistance, and it is preferable to exist in the said range.

The electrolyte thus prepared must be cooled and used to prevent the aluminum foil and the insulating paper used together from being degraded at a later stage.

The electrolytic solution of the high pressure aluminum electrolytic capacitor manufactured by the method of the present invention has a feature that the poor leakage is improved, it can be used simultaneously at a high temperature of 85 ℃, 105 ℃.

Hereinafter, the present invention will be described through examples. The following examples are intended to illustrate the invention and are not intended to limit the invention thereto.

Example 1 Preparation of Electrolyte

Ethylene glycol and benzyl alcohol were mixed at room temperature to have the composition shown in Table 1, and then ammonium sebacate, ammonium dodecanedioate, ammonium pentaborate, and 1,6-decane dicarboxylic acid were slowly shown in Table 1 without increasing the temperature. Amount was added.

Then, it was visually observed whether the solute of the reactor was completely diluted. After confirming complete dilution, mannitol, p-nitrobenzyl alcohol and hypophosphoric acid were added thereto, and the reaction tank was set at 100 ° C., followed by stirring with a stirrer for an elevated temperature and a stirring time as shown in Table 1 below. Cooled.

The abbreviations used in Table 1 are described below: "EG" for ethylene glycol, "DEG" for diethylene glycol, "BA" for benzyl alcohol, "AS" for ammonium sebacate, and "AD" for ammonium Dodecanedioate, "AP" for ammonium pentaborate, "DA" for 1,6-decane dicarboxylic acid, "MT" for mannitol, "HP" for hypophosphorous acid and "p-NBA" for p Nitrobenzyl alcohol.

In addition, an electrolyte solution (traditional example 1) for foreign imported products (trade name 'H1184SB' manufactured by Yoneyama Japan) was prepared.

Furthermore, by the conventional method, ethylene glycol, diethylene glycol and benzyl alcohol are mixed, and then ammonium sebacate, ammonium dodecanedioate, ammonium pentaborate and mannitol, hypophosphoric acid and p-nitrobenzyl alcohol are added to the electrolyte solution (conventional example). 2) was prepared.

Component Composition of Electrolyte Reaction conditions EG BA DEG AS AD AP DA MT p-NBA HP Elevated Temperature (℃) Stirring time (hours) Inventive Example 45 25.34 - 0.5 0.1 1.5 26.35 1.01 0.1 0.1 100 2 Comparative example 50 25 - 0.5 0.1 1.5 21.7 1.0 0.1 0.1 120 One Conventional Example 1 Import goods Conventional Example 2 60 7.0 12 2.0 2.0 2.0 - 1.0 1.5 0.1 90 2

Specific resistance (loss characteristics), pH, and breakdown resistance (withstand voltage) of the electrolytes prepared in the table were measured, respectively, and the results are shown in Table 2 below.

Each of these physical properties was measured using a commercially available measuring instrument, the specific resistance of the resistivity meter, the pH of the pH meter and the breakdown resistance of the breakdown resistance meter.

Property measurement Specific resistance (Ωm / 25 ℃) pH Breaking resistance (V / 25 ℃) Inventive Example 810 7.0 480 Comparative example 1010 7.5 490 Conventional Example 1 1100 6.6 485 Conventional Example 2 647 6.6 472

As can be seen in Table 2, the electrolyte solution that satisfies the reaction conditions of the present invention can be seen that the specific resistance and breakdown resistance is significantly improved compared to the conventional example.

On the contrary, although the components were the same in the comparative example, but the range was not appropriate, the problem of high specific resistance and loss angle of the electrolyte occurred.

In addition, in the conventional example 2 in which diethylene glycol was added without using 1,6-decane dicarboxylic acid, the specific resistance and the improvement of the loss angle were remarkable, but the leakage current and the ESR value for each frequency were poor.

Example 2-Electrolytic Capacitor Application

The electrolytic solutions of the invention examples, comparative examples and conventional examples prepared in Example 1 were charged with an electrolytic capacitor of 450 WV 330 ㎌ ( 35 * 45) and the product properties were observed. As the initial characteristics, the capacitance, loss angle, leakage current, and frequency-specific ESR were measured, respectively, and the results are shown in Table 3 below.

The capacitance was measured using an LCR meter and the leakage current was measured using a leakage current meter, wherein the term "frequency-specific ESR" means a measurement Hz of an electrolytic capacitor product, and was measured at 120 Hz.

Property measurement Capacitance (μF) Loss angle (Tan δ) Leakage Current (μA) Frequency-specific ESR (Ω) Inventive Example 314 0.06 215 0.179 Comparative example 310 0.09 204 0.217 Conventional Example 1 315 0.09 220 0.246 Conventional Example 2 315 0.05 231 0.167

As can be seen from the table, it was confirmed that the loss angle and the frequency-specific ESR at room temperature are significantly improved.

In addition, after the high temperature load test at 85 ° C. and 450v for 2000 hours, the capacity change rate, loss angle, and leakage current as described above were measured, and the results are shown in Table 4 below.

Capacity change rate (%) Loss angle (Tan δ) Leakage Current Conventional Example 2 -3.7 0.11 241 Inventive Example 2 -1.5 0.07 227

As a result, it was confirmed that the loss angle at high temperature was more improved.

Then, the frequency-specific ESR change was measured and the results are shown in Table 5 below.

120 Hz 1 kHz 10 kHz 100 kHz Conventional Example 2 0.246Ω 0.206Ω 0.183Ω 0.179Ω Inventive Example 2 0.179Ω 0.140Ω 0.132Ω 0.131Ω % Improvement 27.2 31.0 27.9 26.0

As can be seen from the table, the ESR was confirmed to be improved by about 30% based on the equivalent series resistance value.

Furthermore, each appearance state was observed to determine whether the electrolyte leaked out of the aluminum case and whether there was a crack in the lower portion of the aluminum case.

As a result, it was confirmed that only the case of using the electrolytic solution prepared in the present invention is effective in improving the poor discharge and case vent operation.

As described above, the electrolyte used in the high-pressure aluminum electrolytic capacitor of the rated voltage of 450WV prepared according to the present invention can not only reduce the unit cost by 50% compared to the conventional products, but also manufactured using the electrolyte It is possible to improve the conductivity of the condenser, the impregnation, and further, the poor flow at high temperature and high pressure, and the case vent operation problem.

Claims (2)

45-50 wt% of ethylene glycol and 20-25 wt% of benzyl alcohol; Solute of 0.1-0.5% by weight of ammonium sebacate, 0.1-0.5% by weight of ammonium dodecanedioate, 1.0-2.0% by weight of ammonium pentaborate and 20-25% by weight of 1,6-decane dicarboxylic acid; And Mixing at room temperature with 0.5 to 1.0% by weight of mannitol, 0.1 to 0.2% by weight of p-nitrobenzyl alcohol, and 0.1 to 0.2% by weight of hypophosphorous acid; And Setting the reaction tank to 95 to 105 ° C. and stirring the mixture for 270 to 330 minutes to raise the temperature to 195 to 205 ° C .; Electrolyte for high pressure aluminum electrolytic capacitor manufactured by the method of claim 1