JPS6085509A - Electrolyte for driving electrolytic condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention is directed to an electrolytic solution for driving electrolytic capacitors, and its purpose is to use it in electrolytic capacitors for medium and high voltages to reduce internal resistance and extend the operating temperature range. The objective is to provide an electrolytic solution that can be expanded.

Conventionally, an electrolytic solution prepared by adding boric acid or a salt thereof to a solvent such as ethylene glycol has been generally used.

However, this yuzu electrolyte has a high specific resistance, which increases capacitor loss, causes heat generation, and accelerates thermal deterioration. In order to improve these drawbacks, an electrolytic solution containing directly saturated dicarboxylic acids or salts thereof such as acelaic acid, separazine acid, and decanedicarboxylic acid as a solute is sometimes used; Since the straight-line saturated diabine has a low solubility S in solvents such as ethylene glycol, the dicarboxylic acid tends to precipitate as crystals at low temperatures, which inevitably causes the deterioration of the low-temperature characteristics of the capacitor. Furthermore, in order to overcome the drawbacks of the above-mentioned linear saturated dicarboxylic acids, saturated dibasic acids or salts thereof having side chains such as 1, butyloctanedioic acid and 1,6-decanedicarboxylic acid are sometimes used as solutes. However, the solubility of these dicarboxylic acids or their salts in solvents such as ethylene glycol is improved compared to that of the saturated dicarboxylic acids or their salts. At present, the characteristics at low temperatures are still insufficient, and further improvement is desired. As a result of intensive research to develop an electrolyte,
We have discovered that when a mixture of two or more polybasic acids with similar structures and side chains is used as a solute, it is difficult to precipitate as crystals even at low temperatures and can be used as a desired electrolytic solution for side movement of electrolytic capacitors. The present invention was finally completed.

That is, the present invention provides a liquid polybasic acid or a salt thereof obtained by removing a substance with a melting point of about 90°C or higher from a polybasic acid mixture of any of The present invention relates to an electrolytic solution for driving an electrolytic capacitor, characterized in that it is dissolved in a solvent.

(8) Polybasic acid mixture obtained by converting peroxides of at least two cyclic ketones selected from cyclopentanone, cyclohexanone, and cycloheptanone (formerly) butadiene, isoprene, acrylic acid, or their cyclopentanone, cyclohexanone and cycloheptanone in the presence of at least one unsaturated compound selected from esters, methacrylic acid or its esters and maleic acid or its esters. A polybasic acid mixture obtained by dimerizing a peroxide of a cyclic ketone and/or a saturated polybasic acid mixture obtained by hydrogenating the mixture (C) A polybasic acid obtained by the above (A) or (B) A polybasic acid mixture formed by mixing two or more types of polybasic acids separated from an acid mixture.The electrolytic solution for driving an electrolytic capacitor of the present invention has a low resistivity and does not cause crystal precipitation even at low temperatures. It can be suitably used as an electrolyte for medium and high voltage electrolytic capacitors.

First, the polybasic acid mixture [(A) to (C
)] will be explained.

As the cyclic ketone used as a starting material for (A), at least two types selected from cyclopentanone, cyclohexanone and cycloheptanone are used. In producing a cyclic ketone peroxide from a cyclic ketone, the cyclic ketone and hydrogen peroxide may be reacted in water-lower alcohol in the presence of an acid catalyst. As acid catalysts used in this reaction, inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, and #acid are used.
These acids are usually 0.01 per mole of cyclic ketone.
mol or more, preferably about 0.02 to 0.05 mol (.1). Examples of lower alcohols include methanol, ethanol, impropatol, n-phthanol,
Examples include tert-butanol. In this reaction, the lower alcohol should be used in amounts of about 4 to 4 moles per 1 mole of the cyclic ketone. Hydrogen peroxide is preferably used in an amount of about 0.5 to 1.5 mol, preferably about 0.7 to 1.27 mol, per mol of cyclic ketone, and water is usually used in an amount of 2 mol or more, preferably It is good to use 10 to 16 moles. When using water, it can also be used in a state mixed with hydrogen peroxide or lower alcohol in advance. For example, a 30-35% hydrogen peroxide solution is used. In this reaction, the reaction is preferably carried out at 60 to 80°C, so that almost all of the cyclic ketone as a raw material is reacted to a peroxide of the cyclic ketone. The above-mentioned peroxide thus produced is dried separately from P and used as a raw material for the next generation reaction. Moreover, since the peroxide is commercially available, a commercially available product can also be used as a raw material for the next dimerization reaction.

The diferrification reaction converts 1 mole of cyclic ketone peroxide into about 8 to 1 mole of cyclic ketone peroxide.
After dissolving or dispersing in 0 mol of organic solvent, it is heated to 60 to 80°C in an autoclave, and a separately diluted ferrous salt bath solution is forced into the autoclave. Ferrous salts include ferrous chloride, ferrous sulfate,
Examples include ferrous acetate. As the organic solvent, lower alcohols such as n-butanol, impropatol, ethanol, methanol, etc. are desirable, and it is preferable to use 2 to 3 moles per mole of the cyclic ketone peroxide. The shorter the injection time, the better the yield, or the rapid generation of reaction heat, so in order to keep the reaction temperature constant, it is necessary to carry out the injection as quickly as possible within a cooling range.

Next, the lower alkyl polybasic acid obtained above is hydrolyzed to a polybasic acid according to a conventional method. This hydrolysis is
An acid or an alkali may be used as a catalyst. For example, an alkali such as potassium hydroxide or sodium hydroxide is added to the lower alkyl polybasic acid and water while heating and stirring, and after continued heating and stirring for several hours, a mineral acid such as sulfuric acid is added to the reaction solution to increase the pH and H of the reaction solution. It is best to add it until it reaches about 3.

The polybasic acid thus produced can be easily isolated by extraction with an aromatic solvent such as benzene or toluene, washing with water, and then distilling off the solvent. The polybasic acid thus obtained is a mixture of yuzu polysalts ah, and in the present invention, such a mixture of polybasic acids is not isolated into individual polybasic acids (
Used as a mixture.

As the cyclic ketone used as a starting material for (B), at least one selected from cyclopentanone, cyclohexanone, and cycloheptanone is used. In producing a cyclic ketone peroxide from a cyclic ketone, the above (A
) can be applied directly to P.

Next, the cyclic ketone peroxide obtained above is dimerized in the presence of an unsaturated compound. Unsaturated compounds include butadiene, isoprene, acrylic acid or its ester,
At least one selected from methacrylic acid or its ester and maleic acid or its ester is used. When using an unsaturated compound, the peroxide of a cyclic ketone is usually used.
0.1 mole to 0.5 mole, preferably 0.1 mole to 0.5 mole.
The amount is preferably 3 moles. The 2-hatching reaction is performed using the above (Al
Similarly, a solution of a ferrous salt dispersed in a lower alcohol may be injected and stirred into a solution of a cyclic ketone and an unsaturated compound. Examples of the ferrous salts that can be used include ferrous sulfate, ferrous chloride, and ferrous acetate. When ferrous chloride is used as the ferrous salt, the oxidized iron compound can be reduced with hydrochloric acid and iron to regenerate ferrous chloride after the reaction is completed, and therefore it can be recovered and recycled. This is advantageous because it can be used. The amount of ferrous salt to be used is usually 1 to 2 mol, preferably 1.2 to 1.5 mol, per 1 mol of cyclic ketone peroxide. Examples of lower alcohols include methanol, ethanol, impropanol, n-butano/l/, and phthanol. The reaction is usually carried out at 30-80°C.
, preferably at 60"C, generally 5~1L
The reaction is completed in about 0 minutes. In this way, a lower alkyl polybasic acid is produced.

The lower alkyl polybasic acid produced above is then hydrolyzed to a polybasic acid according to a conventional method. The conditions for this hydrolysis may be the same as those in (A) above.

Next, as a method for hydrogenating the polybasic acid obtained by the above hydrolysis, conventionally known methods can be widely applied, for example, using a nickel catalyst (approximately 1.0 to 1.5% by weight) at 10 K.
g/cm" at 200° C. for 2 hours.

The polybasic acid obtained above is a mixture of various polybasic acids, and in the present invention, such polybasic acids are used as a mixture. When dimerization is carried out in the presence of the above unsaturated compounds, high-molecular weight polymers may be mixed into the reaction product, but the proportion of this mixture is limited to about 0.5 to 1% of the total. be.

Regarding (C), the above-mentioned compound or the polybasic acid mixture obtained in (B) can be used. The polybasic acids separated in this way are mixed in an arbitrary ratio.

In the present invention, when a substance with a melting point of 90°C or higher is mixed in the polybasic ii2 mixture obtained in any of (8), (B), and (C) above, the high melting point substance is It is removed from the polybasic acid mixture by a conventional method such as a bath crystallization method, converted into a salt form such as an ammonium salt if necessary, and then used as a solute in an electrolytic solution for driving an electrolytic capacitor.

The ratio of the polybasic acid or its salt and ethylene glycol is not particularly limited and can be appropriately selected within a wide range, but the ratio of the former to the latter is usually 5 to 30:95.
It may be used at a ratio of ~70 (W/W). In the present invention, other solvents such as methyl cellosolve may be appropriately added to ethylene glycol as a solvent, and sacric acid, adipic acid, etc. are added to the above-mentioned polybasic acid or its salt as a solute.

It can also be added.

Examples are given below to further clarify the present invention.

Example 1 250 kg of hexano was placed in a high-pressure reaction vessel equipped with a stirrer,
After dissolving 11 kg of cyclohexanone peroxide, 9.3 kg of cyclopentanone peroxide, and 12.5 kg of cycloheptanone peroxide, 0.9 kg of concentrated sulfuric acid was gradually added while maintaining the liquid temperature at 50°C. Next is isoprene 8
Kg, Phtadiene 15Kg and Hymethyl Acrylic)
Add 4 Kg. In a separate reaction vessel, add 30 ml of anhydrous methanol.
Add 100kg of ferrous sulfate (heptahydrate) while blowing in nitrogen gas, mix well, and create both liquids.
This is pressurized into the high pressure reaction vessel. While rapidly removing the reaction heat, the reaction temperature was maintained at 40°C. Pressure injection was completed in about 5 minutes, and after stirring for another 15 minutes, the solvent and unreacted butadiene and isoprene were distilled off, leaving about 210 kg of reaction liquid. get. This is left to stand and separated into two layers, an upper polybasic acid layer and a lower iron salt liquid layer. The polybasic acid layer obtained from the upper layer contains some impurities such as unreacted methyl acrylate and caproic acid and enanthic acid, so it was
mmHg) was sufficiently degassed at 140° C., and since some of the polybasic acids were produced as methyl esters, they were hydrolyzed by a conventional method to obtain 51 kg of a clear light brown polybasic acid mixed solution. Acid value 421, iodine value 118, unsaponifiable matter 0.52
%. In addition, there were 26 samples in total measured by gas chromatograph, indicating that the liquid was a mixture of various polybasic acids.

Example 2 The reaction was carried out in the same manner as in Example 1 except that 2 kg of methyl methacrylate and 1.5 kg of maleic dimethyl were added in place of acrylic acid in Example 1, and the reaction was carried out in the same manner as in Example 1. %, light brown liquid 55.5K
g was obtained.

The peak by gas chromatography is 31.

Example 3 The acid solution obtained in Example 2 was boiled under reflux with methanol to reduce the oxidation temperature to 4.2, then the methanol was recovered and hydrogenated by a conventional method to form an ester mixture with an iodine value of 3.8. was gotten. This is vacuumed to 1mmllmm1 (~24
Distilled at 0°C, cut the first and final distillates, and reduced the middle distillate to about 35
I got %. The acid solution obtained from hydrolysis has an acid value of 398,
The iodine value is 2.9, the unsaponifiable matter is 0.21%, and the peaks determined by gas chromatography are 4 as the main peak and 11 as the minor peak.

The polybasic acid mixtures obtained in Examples 1.2 and 3 were dissolved by heating at about 50°C in 3 times the amount of toluene, and then heated to -20°C.
After cooling slowly for about 8 hours, the precipitated crystals were centrifuged.
Distill toluene. The removed crystals are in the range of about 1-4.5% chopped into the treated polybasic acid mixture.

The polybasic acid mixtures obtained in Examples 112 and 3 from which the crystals were removed are designated as Sample 1, Sample 2, and Sample 3, respectively. Table 1 shows the solubility of these samples in ethylene glycol at 20°C, 1OoC and 0°C. For comparison, Table 1 also shows the solubility of ammonium borate, ammonium sebacate, ammonium dodecanoate, and ammonium butyloctanedioate in ethylene glycol.

Table 1 Next, we will discuss the performance when the above samples 1 to 3 are used as motors for driving electrolytic capacitors. υiJ ethylene glycol 90g! For sample 1, sample 2, sample 3, sebacic acid or butyloctanoic acid (purity 98%) 9.3
When y and ammonia 0.77 were added and the specific resistance (Ωcm) and spark generation voltage (V) at 30°C were subtracted by 2, the results were as shown in Table 2.

Table 2 In addition, after adjusting the concentration of each solute in ethylene glycol to match the specific resistance at 30°C for aluminum electrolytic capacitors of 350 V and 1200 μF, the temperature characteristics of loss were measured, and the results are shown in Table 3 below. was gotten.

Table 3 Electrical properties of electrolyte (above) Procedural amendment written 0 August 10, 1980 1 Case description 1981 Patent Application No. 195019 2 Name of invention Electrolyte for driving electrolytic capacitor Okamura Oil Co., Ltd. 4 Spontaneity of the agent 6 Contents of the amendment in the "Detailed Description of the Invention" section of the specification to be amended 1 In Table 2 on page 17 of the ammonium sebacate column, specific resistance (Ωc+n) term r480
J is corrected to r780J, and in the ammonium butyloctanoate column, the specific resistance (0 cm) term r442J is corrected to r490J.

(that's all)

Claims (1)

[Claims] ■ In the following (5), a liquid polybasic acid or its salt obtained by removing a high melting point substance with a melting point of about 90°C or higher from a polybasic acid mixture of either (Bl or (C1), An electrolytic solution for driving an electrolytic capacitor, characterized in that (5) at least two peroxides of cyclic ketones selected from cyclopentanone, cyclohexanone, and cycloheptanone are dissolved in a solvent serving as a main solvent; a polybasic acid mixture obtained by quantification, ([3) in the presence of at least 13 unsaturated compounds selected from butadiene, isoprene, acrylic acid or its esters, methacrylic acid or its esters, and maleic acid or its esters; : ξ A polybasic acid mixture obtained by dichotomizing at least one peroxide of a cyclic ketone selected from cyclopentanone, cyclohexanone, and cycloheptanone, and/or a polybasic acid mixture obtained by hydrogenating the mixture. (C) A polybasic acid mixture obtained by mixing two or more types of polybasic acids separated from the polybasic acid mixture obtained in the above hole or @).