JPH07165751A - Organic solvent and electrolytic solution - Google Patents

Abstract

PURPOSE:To obtain an organic solvent composed mainly of a compound having a specific structure, having high boiling point and excellent heat-stability and, accordingly, useful as a good solvent for polymers for dissolving the polymer at high temperature or an electrolyte solution for the production of an ionic element, etc. CONSTITUTION:This organic solvent is composed mainly of a compound of formula I [R1 is a 1-12C bivalent hydrocarbon group; R<2> is H or a l-6C alkyl; R<3> is a 1-12C alkyl or group of formula II (R<4> is R<1>); (m) is O or l; (n) is 0-10], e.g. 4-(2,5-dioxahexyl)--1,3-dioxolan-2-one. The compound of formula I can be produced e.g. by reacting a compound of formula III (X is a halogen) such as epichlorohydrin with a compound of formula IV such as ethanol e.g. by mixing an aqueous solution of the compound of formula IV with the compound of formula III, dropping an aqueous solution of NaOH to the mixture in the presence of a phase-transfer catalyst such as n-tetrabutyl ammonium bisulfate, dissolving the obtained glycidyl ether derivative in DMF, etc., and reacting with CO1 under 1atm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic solvent having a high boiling point and an electrolytic solution which can be used for producing an ionic device having excellent heat resistance.

[0002]

2. Description of the Related Art Lithium batteries, electric double layer capacitors,
The electrolytic solution, which is a component of ionic devices such as aluminum electrolytic capacitors, electrochromic devices, and sensors,
It is known to prepare a supporting electrolyte by dissolving it in an organic solvent. The solvent is usually ethylene carbonate, propylene carbonate, γ-butyrolactone,
1,2-dimethoxyethane, tetrahydrofuran, 2-
Methyltetrahydrofuran, dimethylsulfoxide,
1,3-dioxolane, formamide, N, N'-dimethylformamide, dioxolane, acetonitrile, nitromethane, phosphate triester, sulfolane, etc.
Diglymes such as methyl diglyme and methyl triglyme are used.

However, since these organic solvents have a low boiling point, in the electrolytic solution system in which the supporting electrolyte is dissolved in these organic solvents, the use limit temperature in the high temperature range is 60 to 60 due to the relationship between the boiling point and the vapor pressure. There is a drawback that the temperature is about 80 ° C. Therefore, if the device is used at a temperature higher than this, the internal pressure of the device may be increased and the device may be damaged. If the internal pressure is increased, the impedance will be increased and the performance will be degraded.

Further, in recent years, there has been an increasing demand for the use of the ionic element at high temperatures, and it is desired to improve the guaranteed operating temperature. In addition, as electronic devices have become lighter, thinner, shorter, and smaller, the size and weight of electronic components used have been reduced, and therefore there is a strong demand for the development of ionic devices that can withstand the surface mounting process.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an organic solvent having a high boiling point and the like and usable as an electrolytic solution or the like in the production of ionic devices and the like.

Another object of the present invention is to provide an electrolyte having excellent heat resistance and the like, which can be used for producing an ionic element or the like which can withstand the surface mounting process accompanied by miniaturization and weight reduction.

[0007]

According to the present invention, there is provided an organic solvent containing a compound represented by the following general formula 2 (hereinafter referred to as compound A) as a main component.

[0008]

[Chemical 2]

Further, according to the present invention, there is provided an electrolytic solution containing the organic solvent and a supporting electrolyte.

The present invention will be described in more detail below.

The organic solvent of the present invention contains the compound A represented by the general formula 2 as a main component.
In, the carbon number of R ¹ is 1 to 12, preferably 1 to
6, the carbon number of R ² is 1 to 6, preferably 1 to 4,
When R ³ is an alkyl group, it has 1 to 12 carbon atoms,
Preferably 1 to 6 carbon atoms of R ⁴ is from 1 to 12, preferably a 1-6. Further, n is 0 to 10, preferably 0.
It is an integer of 6. At this time, if the carbon number of R ^{1 to} R ⁴ and n exceeds the above upper limit, the production is difficult. Also R ¹ ,
When R ² and R ³ are specifically listed, examples of R ¹ include a methylene group, an ethylene group, a trimethylene group, a propylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group, and R ² and R ³ Preferred examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a tert-pentyl group. You can

In the organic solvent of the present invention, the compound A contained as the main component is, for example, 4- (2,5
-Dioxahexyl) -1,3-dioxolan-2-one, 4- (2,5,8-trioxanonyl) -1,3-
Dioxolan-2-one, 4,4 '-(1,5- (3-
Oxa-pentanediyl) bis (oxymethylene)) bis-1,3-dioxolan-2-one, 4-butyl-
1,3-dioxolan-2-one, 4-hexyl-1,
3-dioxolan-2-one, 4,4 '-(1,8-
(3,6-Dioxaoctanediyl) bis (oxymethylene)) bis-1,3-dioxolan-2-one, 4-
(4-methyl-2,5-dioxahexyl) -1,3-
Dioxolan-2-one, 4- (4,7-dimethyl-
2,5,8-Trioxanonyl) -1,3-dioxolan-2-one, 4,4 ′-(1,8- (2,5,8-trimethyl-3,6-dioxaoctanediyl) bis (Oxymethylene)) bis-1,3-dioxolan-2-one and the like can be mentioned.

To prepare the compound A, for example, a compound represented by the following general formula 3 (hereinafter referred to as compound B)
When,

[0014]

[Chemical 3]

It can be obtained by reacting a compound represented by the following general formula 4 (hereinafter referred to as compound C) or a compound represented by the following general formula 5 (hereinafter referred to as compound D).

[0016]

[Chemical 4]

[0017]

[Chemical 5]

In particular, when the compound A is prepared so that R ³ is an alkyl group having 1 to 12 carbon atoms, the above compound B is used.
When the compound C is reacted with the compound C, and R ³ is a group represented by the following general formula 6, it can be obtained by a method of reacting the compound B with the compound D.

[0019]

[Chemical 6]

Examples of the compound B include general epoxidizing agents such as epichlorohydrin and epibromohydrin.

Examples of the compound C include alcohols such as ethanol, propanol, butanol, pentanol, methoxyethanol, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether and tripropylene glycol monomethyl ether. You can

Examples of the compound D include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-propanediol, 1,4-butanediol and 1,5-pentane. Examples thereof include diol, tetraethylene glycol, tetrapropylene glycol and the like.

The reaction for preparing the compound A will be described in more detail. For example, first, the compound C or the compound D is dissolved in water, and then 1 to 20 mol per mol of the compound C or the compound D is dissolved. A double amount, preferably 2 to 10 mol times, of the compound B is mixed and stirred in the presence or absence of a reaction solvent. Further, an interlayer transfer catalyst such as hydrogen sulfate-n-tetrabutylammonium is preferably added in an amount of 0.01 to 10 mol% relative to the compound C or compound D.
In particular, 0.1 to 5 mol% is added, an aqueous sodium hydroxide solution is added dropwise, and the mixture is reacted to obtain a glycidyl ether derivative. At this time, the reaction temperature is preferably 0 to 150 ° C.,
Particularly, 10 to 100 ° C. is desirable. When a reaction solvent is used, a water-insoluble hydrocarbon solvent such as toluene or xylene can be used. Such glycidyl ether derivatives are described in more detail, for example, in Journal of
Applied Polymer Science Vol. 41 2
301 (1990), the synthesis method described in JP-A-63-154736 and the like.

Then, the obtained glycidyl ether derivative was dissolved in a polar solvent such as N, N'-dimethylformamide, dimethylsulfoxide and 1,4-dioxane, and sodium iodide and triphenylphosphine were added as catalysts. After that, a method of reacting carbon dioxide at 1 atm (Macromolecules, Vol. 25, 4824
(See (1992)) and the like to synthesize compound A.

The amount of the catalyst added is preferably 0.1 to 10 mol%, more preferably 0.5 to 5 mol% based on the glycidyl ether derivative. The reaction temperature is 30 to 2
00 ° C. is preferable, and 50 to 150 ° C. is particularly desirable.

On the other hand, as another method for synthesizing the compound A from the glycidyl ether derivative, a method in which a pentavalent organic antimony compound is used as the catalyst in the glycidyl ether derivative and reacted with carbon dioxide at 50 atm (Journal of Organic chemistry, Vol. 45, 3735 (1980)) and the like can also be used for the synthesis.

As another method for preparing the compound A,
For example, the compound C or the compound D and the compound B are reacted using tin tetrachloride as a catalyst to synthesize a chlorohydrin ether, and then a sodium hydroxide solution is dropped to cause a ring-closing reaction to give glycidyl. An ether derivative is synthesized (see Industrial Chemistry Magazine Vol. 63, 595 (1960)). Next, the glycidyl ether derivative thus obtained was added to a 5% aqueous sulfuric acid solution, and an acid cleavage reaction was carried out at 40 ° C. to synthesize a 1,2-diol compound. Further, a small amount of metallic sodium was added as a catalyst to form an ester with diethyl carbonate. It can be prepared by a method such as an exchange reaction. At this time, the reaction between the 1,2-diol compound and diethyl carbonate can be carried out, for example, by Macromolecules Vol. 11 1067
(1978).

As a method for preparing the compound A using the compound D, for example, a method of reacting ethylene glycol with phosgene or a method of reacting oxiranes with a lactone, as in the widely industrialized method for producing ethylene carbonate. Method of reaction (tetrahedron letter, V
ol. 27, 3741 (1986) and the like.

The organic solvent of the present invention is preferably the compound A alone, but other than the compound A, for example, ethylene carbonate, propylene carbonate, γ-butyrolactone, or 1 may be used as long as it does not adversely affect the desired performance. , 2-dimethoxyethane, tetrahydrofuran,
2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, N, N'-
In addition to dimethylformamide, dioxolane, acetonitrile, nitromethane, phosphoric acid triester, sulfolane and the like, organic solvents such as diglymes such as methyl diglyme and methyl triglyme can be preferably mixed in an amount of 50% by weight or less. However, when used at high temperature, when performing a process at high temperature before and after use, etc., it is particularly preferable not to contain other solvent, and even in the normal use method, do not mix other solvent. Is desirable.

The electrolytic solution of the present invention contains an organic solvent containing the compound A as a main component and a supporting electrolyte.

The supporting electrolyte contained in the electrolytic solution of the present invention is not particularly limited as long as it can be used in a normal organic electrolytic solution, but examples thereof include alkali metal salts and quaternary ammonium salts.

The alkali metal salt is usually a salt of a metal ion of group 1a or 2a of the periodic table, such as LiClO ₄ , LiBF ₄ , LiPF ₆ , LiCF ₃ ,
SO ₃ , LiSCN, LiBr, LiI, LiAsF ₆ ,
_{LiSbF 6, LiB (C 6 H} 5) 4, NaI, NaClO
₄ , NaBF ₄ , NaIPF ₆ , NaCF ₃ SO ₃ , NaS
CN, NaBr, NaAsF ₆ , NaSbF ₆ , NaB
_{(C 6 H 5) 4,} KI, can be preferably exemplified KCF ₃ SO _3, and the like.

Examples of the quaternary ammonium salt include (C ₂ H ₅ ) ₄ NBF ₄ , (C ₃ H ₇ ) ₄ NBF ₄ and (C
₂ H ₅ ) ₄ NClO ₄ , (C ₃ H ₇ ) ₄ NBF ₄ , (C ₂ H ₅ ) ₄
NPF ₆ , (C ₃ H ₇ ) ₄ NPF ₆ , (C ₂ H ₅ ) ₄ NSb
_{F 6, (C 3 H 7} ) 4 NSbF 6, or pyridine ring, pyrrolidine ring, morpholine ring, piperidine ring, piperazine ring, 1,4-diazabicyclo (2,2,2) cyclic or bicyclic, such as octane ring Preferable examples include a quaternary ammonium salt having a structure.

As a supporting electrolyte showing particularly high ionic conductivity and excellent thermal stability, for example, LiCF ₃ S is used.
O ₃ , LiClO ₄ , LiI, NaCF ₃ SO ₃ , NaCl
O ₄ , NaI, KI, KCF ₃ SO _{3 and the} like can be preferably mentioned.

When the electrolytic solution of the present invention is used as a capacitor electrolytic solution, it is preferable to use a quaternary ammonium salt having a higher reduction potential than an alkali metal salt as a supporting electrolyte. Fourth, in particular having a cyclic or bicyclic structure
The high-grade ammonium salt has high resistance to reduction and is most suitable for capacitors.

In the electrolytic solution of the present invention, the mixing ratio of the organic solvent and the supporting electrolyte can be appropriately selected depending on the purpose of use of the electrolytic solution, the composition of the organic solvent, the type of the supporting electrolyte to be used, and the like. Usually, 0.1 to 4 mol / liter is preferable with respect to the organic solvent, and particularly 0.5 to 3
Mol / liter is desirable.

The electrolytic solution of the present invention may appropriately contain an organic auxiliary agent, if necessary. As the organic auxiliary,
For example, ethylene carbonate, propylene carbonate, γ-butyrolactone, 1,2-dimethoxyethane,
Tetrahydrofuran, 2-methyltetrahydrofuran,
Preferred examples include dimethyl sulfoxide, 1,3-dioxolane, formamide, N, N′-dimethylformamide, dioxolane, acetonitrile, nitromethane, phosphoric acid triester, sulfolane, and diglymes such as methyl diglyme and methyl triglyme. be able to.

When the organic auxiliary agent is used, the content ratio is
Usually, 10 to 90 vol% is preferable, and 20 to 80 vol% is particularly preferable with respect to the entire electrolytic solution. When the content ratio of the organic auxiliary agent is less than 10 vol%, the effect of the organic auxiliary agent is not sufficiently obtained, and when the content ratio exceeds 90 vol%, the upper limit of the temperature at which the electrolytic solution can be used becomes too low. It is not preferable.

In order to prepare the electrolytic solution of the present invention, the above-mentioned essential components can be obtained by a method of stirring and mixing above the freezing point and below the boiling point.

[0040]

INDUSTRIAL APPLICABILITY The organic solvent of the present invention has a higher boiling point than conventional organic solvents and is excellent in thermal stability. Can be used as a good solvent for polymers,
For example, it is also suitable as a high boiling point solvent used for polymer coating for the purpose of forming a uniform coating film.

Further, since the electrolytic solution of the present invention contains the above-mentioned specific organic solvent, it has a boiling point higher than that of the conventional one and is excellent in thermal stability, and can be used, for example, in the production of an ionic element at high temperature. is there. It is useful for the development of ionic devices that can withstand the surface mounting process that is particularly subject to high thermal history. In addition to the above-mentioned ionic element, it can be used for all applications in which a normal electrolytic solution can be used.

[0042]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited thereto.

[0043]

Example 1 1.0 mol of ethylene glycol monomethyl ether and 3.5 mol of chloromethyloxirane,
0.01 mol of tetrabutylammonium bromide was placed in a 2 liter flask. Next, while cooling to 5 ° C. and stirring, 220 g of a 20% aqueous sodium hydroxide solution was added dropwise over 1 hour. After completion of dropping, the mixture was reacted at 40 ° C. for 5 hours, extracted with methylene chloride, and distilled under reduced pressure to obtain ethylene glycol glycidyl methyl ether. The boiling point was 77 ° C./10 mmHg, and the yield was 70%.

0.7 mol of the obtained ethylene glycol glycidyl methyl ether was dissolved in 200 ml of N, N'-dimethylformamide and placed in a 300 ml four-necked flask. 2 mol% sodium iodide as a catalyst,
Triphenylphosphine was added, and carbon dioxide was vigorously stirred and reacted while bubbling at 100 ° C. 12
After reacting for a period of time, N, N′-dimethylformamide was removed, and 4- (2,5-dioxahexyl) -1,3-dioxolan-2-one was obtained by distillation under reduced pressure. This boiling point is 115 ° C./0.15 mmHg,
The yield was 84%. The result of the NMR spectrum analysis is shown in FIG. 1, and the result of the thermogravimetric analysis by a thermobalance is shown in FIG.

Tetraethylammonium tetrafluoroborate was dissolved in the obtained 4- (2,5-dioxahexyl) -1,3-dioxolan-2-one,
A 5M electrolyte was prepared. Next, the ionic conductivity of the electrolytic solution was measured by the complex impedance method and found to be 30 ° C.
Was 1.6 mS / cm.

[0046]

Example 2 3.0 mol of diethylene glycol monomethyl ether and 1.0 mol of chloromethyloxirane were placed in a 2-liter 4-neck flask, 0.01 mol of tin tetrachloride was added as a catalyst, and the mixture was stirred at 100 ° C. with vigorous stirring. The temperature was raised to 1, and the reaction was performed for 1 hour. Then, the reaction was stopped by adding a small amount of potassium carbonate, the unreacted material was removed, and the residue was distilled under reduced pressure to obtain chlorohydrin ether. The boiling point of the obtained chlorohydrin ether was 98 ° C./0.05 mmHg, and the yield was 85%.

Next, a 25% aqueous sodium hydroxide solution was added dropwise to the obtained chlorohydrin ether, and a ring-closing reaction was performed to obtain ethylene glycol glycidyl methyl ether. Boiling point is 77 ° C / 10mmHg, yield is 80
%Met.

The obtained ethylene glycol glycidyl methyl ether was subjected to an acid cleavage reaction with a 5% aqueous solution of sulfuric acid at 40 ° C. for 1 hour to give diethylene glycol (2,2).
3-Dihydroxypropyl) methyl ether was obtained. This boiling point is 112 ° C./0.15 mmHg, and the yield is 8
It was 6%.

Then, the obtained diethylene glycol (2,3-dihydroxypropyl) methyl ether,
1.2 molar amount of diethyl carbonate was added to a 500 ml flask, a small amount of metallic sodium was added, and
The mixture was heated and stirred at ℃. After reacting for 5 hours while removing the produced ethanol, vacuum distillation was performed to give 4-
(2,5,8-Trioxanonyl) -1,3-dioxolan-2-one was obtained. This boiling point is 128 ℃ / 0.1m
It was mHg, and the yield was 80%. The result of NMR spectrum analysis is shown in FIG. 2, and the result of thermogravimetric analysis by a thermobalance is shown in FIG.

Tetraethylammonium tetrafluoroborate was dissolved in the obtained 4- (2,5,8-trioxanonyl) -1,3-dioxolan-2-one,
A 0.5 M electrolytic solution was prepared. When the ionic conductivity of the electrolytic solution was measured in the same manner as in Example 1, it was 1.3 m at 30 ° C.
It was S / cm.

[0051]

Example 3 The reaction was carried out according to Example 2, except that diethylene glycol diglycidyl ether was used instead of diethylene glycol monomethyl ether.
4 '-(1,5- (3-oxa-pentanediyl) bis (oxymethylene)) bis-1,3-dioxolane-2
-I got on. Then, the obtained compound was purified by a known column method. This compound is 150 ℃ /
It decomposed at 0.1 mmHg or more, and the yield was 75%.
The result of NMR spectrum analysis is shown in FIG. 3, and the result of thermogravimetric analysis by a thermobalance is shown in FIG.

The obtained 4,4 '-(1,5- (3-
Tetraethylammonium tetrafluoroborate was dissolved in oxa-pentanediyl) bis (oxymethylene)) bis-1,3-dioxolan-2-one to give 0.4M.
The electrolytic solution of was prepared. When the ionic conductivity of the electrolytic solution was measured in the same manner as in Example 1, it was 0.5 mS / cm at 30 ° C.
Met.

[0053]

Comparative Example 1 Thermogravimetric analysis was carried out in accordance with Example 1 on propylene carbonate used as a solvent for an ordinary electrolytic solution. The results are shown in Fig. 4.

Tetraethylammonium tetrafluoroborate was dissolved in the propylene carbonate to prepare a 0.7M electrolytic solution. The ionic conductivity of the electrolyte was measured and found to be 8.2 mS / cm at 30 ° C.

[Brief description of drawings]

FIG. 1 is a chart showing an NMR spectrum analysis of 4- (2,5-dioxahexyl) -1,3-dioxolan-2-one synthesized in Example 1.

FIG. 2 is a graph of 4- (2,5,8) synthesized in Example 2.
2 is a chart showing NMR spectrum analysis of -trioxanonyl) -1,3-dioxolan-2-one.

FIG. 3 is a graph of 4,4- (1,5) synthesized in Example 3.
NMR of-(3-oxa-pentanediyl) bis (oxymethylene)) bis-1,3-dioxolan-2-one
It is a chart which shows a spectrum analysis.

FIG. 4 is a chart showing the results of thermogravimetric analysis of each substance obtained in Examples 1 to 3 and Comparative Example 1.

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[Submission date] April 16, 1993

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0.7 mol of the obtained ethylene glycol glycidyl methyl ether was dissolved in 200 ml of N, N'-dimethylformamide and placed in a 300 ml four-necked flask. 2 mol% sodium iodide as a catalyst,
Add triphenylphosphine, 100 ℃, carbon dioxide
The substance was vigorously stirred and reacted while bubbling. 12
After reacting for a period of time, N, N′-dimethylformamide was removed, and 4- (2,5-dioxahexyl) -1,3-dioxolan-2-one was obtained by distillation under reduced pressure. This boiling point is 115 ° C./0.15 mmHg,
The yield was 84%. The result of the NMR spectrum analysis is shown in FIG. 1, and the result of the thermogravimetric analysis by a thermobalance is shown in FIG.

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Claims (2)

[Claims] 1. An organic solvent containing a compound represented by the following general formula 1 as a main component. [Chemical 1] 2. An electrolytic solution containing the organic solvent according to claim 1 and a supporting electrolyte.