JP2003040856A - Meta-fluorobenzenesulfonic acid derivative and dopant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compound useful as a dopant giving a π-conjugated high-molecular compound with high electrical conductivity and also having the high electrical conductivity to even at high temperatures and humidities. SOLUTION: This compound is a m-fluorobenzenesulfonic acid derivative of general formula [1] (where, X is sulfonic acid bearing a countercation; one of R<1> to R<4> is a carboxamido group, the other three being each H, F or an alkyl) to be used as the dopant.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel m-fluorobenzenesulfonic acid derivative and a dopant agent for a conductive polymer substance comprising the same.

[0002]

BACKGROUND OF THE INVENTION In recent years, with the development of electronics, new electronic materials have been developed. Particularly in the field of functional organic materials, remarkable technological innovation has progressed, and even in the case of conductive materials, electron-conjugated polymer substances such as polyacetylene, polyparaphenylene, polypyrrole, and polyaniline are doped with electron-accepting compounds as dopants. In some cases, the conductive polymer material has been developed and has already been put into practical use as a capacitor electrode material, a battery electrode material, an antistatic material, and the like.

However, in order to expand the practicality of these conductive polymer substances, further improvement of electric conductivity and environmental stability such as heat resistance and humidity resistance are major problems.

The inventors of the present invention have described in Japanese Patent Application Laid-Open No. 2000-2 with respect to the problems toward their practical use, especially regarding environmental stability.
JP-A-04074 discloses that a π-conjugated polymer compound using m-sulfobenzamides as a dopant agent is a material having both high conductivity and high heat resistance.

That is, with polypyrrole doped with m-sulfobenzamide, the decrease in electrical conductivity is extremely gentle even when kept in air at 150 ° C.
It has been found that the high conductivity of S / cm or more is continuously maintained. Unfortunately, polypyrrole doped with m-sulfobenzamide has a problem that its conductivity decreases when water is present in addition to high temperature. Therefore, in order to expand the practicality of the conductive polymer material, it can be said that it is essential to improve the stability under the condition where water coexists at high temperature, that is, under high humidity.

[0006]

DISCLOSURE OF THE INVENTION The present invention aims to provide a dopant material capable of maintaining high conductivity in a π-conjugated polymer compound as well as high conductivity in a high temperature and high humidity environment. For the purpose of providing a novel compound of

[0007]

The present invention provides an m-fluorobenzenesulfonic acid derivative represented by the following general formula [1].

[Chemical 3] [1] In the formula, X is a sulfonic acid group having a counter cation, and one of R ^{1 to} R ⁴ is a carboxamide group represented by the following general formula [2],

[Chemical 4] The other three may be the same or different from each other and represent a hydrogen atom, a fluorine atom or an alkyl group having 20 or less carbon atoms, and in the formula [2], R ⁵ and R ⁶ may be the same or different from each other. Represents a hydrogen atom, an alkyl group having 20 or less carbon atoms, or a phenyl group.

In the above general formula [1], the counter cation of the sulfonic acid group is an ion selected from the group consisting of hydrogen ion, alkali metal ion, alkaline earth metal ion and transition metal ion of Group VIII of the periodic table. There is a preferred aspect of the present invention.

Further, in the general formula [1], the counter cation of the sulfonic acid group is an ion selected from the group consisting of hydrogen ion, sodium ion, potassium ion and iron (III) ion. Is a preferred embodiment of.

In the general formula [1], R ¹ to
It is a preferred embodiment of the present invention that all of R ⁴ other than the carboxamide group represented by the general formula [2] are hydrogen atoms.

Further, in the general formula [2], it is a preferred embodiment of the present invention that at least one of R ⁵ and R ⁶ is a hydrogen atom.

Further, the present invention provides a dopant agent for a conductive polymer substance, characterized by comprising the above-mentioned m-fluorobenzenesulfonic acid derivative.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The m-fluorobenzenesulfonic acid derivative according to the present invention is represented by the following general formula [1].

[Chemical 5] [1] In the formula, X is a sulfonic acid group having a counter cation, ^one of R ^{1 to} R ⁴ is a carboxamide group represented by the following general formula [2],

[Chemical 6] The other three may be the same or different from each other and represent a hydrogen atom, a fluorine atom or an alkyl group having 20 or less carbon atoms, and in the formula [2], R ⁵ and R ⁶ may be the same or different from each other. Represents a hydrogen atom, an alkyl group having 20 or less carbon atoms, or a phenyl group.

Specific examples of the m-fluorobenzenesulfonic acid derivative represented by the above general formula [1] include 4-fluoro-2-sulfobenzamide and 5-fluoro-3-.
Sulfobenzamide, 4-fluoro-2-sulfo-N-
Hexylbenzamide, 4-fluoro-2-sulfobenzamide sodium salt, tris- (4-fluoro-2)
-Sulfobenzamide) iron (III) complex salt, 4,5-difluoro-2-sulfobenzamide 4,5,6-trifluoro-2-sulfobenzamide, 4-fluoro-2-sulfo-N-dodecylbenzamide, 4-fluoro -2-
Examples thereof include sulfobenzanilide.

Here, the counter cation of the sulfonic acid group is preferably an ion selected from the group consisting of hydrogen ion, alkali metal ion, alkaline earth metal ion and transition metal ion of Group VIII of the periodic table. . Particularly, the counter cation of the sulfonic acid group is preferably an ion selected from the group consisting of hydrogen ion, sodium ion, potassium ion and iron (III) ion. This is for obtaining a suitable polymerization rate by keeping pH in the neutral region in the electrolytic oxidation polymerization method described later, and sodium ion and potassium ion are particularly preferable. Further, in the chemical oxidative polymerization method described later, oxidation / reduction of transition metal is used, and therefore iron (III) ion is particularly preferable as a metal ion species capable of easily oxidizing pyrrole and the like.

In the general formula [1],
It is preferable in terms of conductivity and heat resistance that all of R ^{1 to} R ⁴ except the carboxamide group represented by the general formula [2] are hydrogen atoms. Furthermore, in the general formula [2],
It is preferable that at least one of R ⁵ and R ⁶ is a hydrogen atom in terms of conductivity and heat resistance.

The method for producing the m-fluorobenzenesulfonic acid derivative represented by the general formula [1] is not particularly limited, but, for example, using a precursor compound having no sulfonic acid group as a raw material, sulfuric acid, fuming sulfuric acid, trioxidation. Sulfur, sulfur trioxide-
It can be produced according to a synthetic route such as a method of sulfonation by contacting with a suitable sulfonating agent such as a pyridine complex or amido sulfuric acid.

In the synthetic reaction using the above-mentioned sulfonation reaction, the reaction conditions are not particularly limited. For example, the reaction ratio of the m-fluorobenzenesulfonic acid derivative precursor constituting the raw material and the sulfonating agent is usually 1: 1 to 1: 2.
It is carried out in the range of 00 (molar ratio). Further, the reaction solvent is not always necessary, but when used, it may be one that dissolves the raw material m-fluorobenzenesulfonic acid derivative precursor and the sulfonating agent, and the solvent itself is not sulfonated, Examples thereof include dichloroethane, carbon tetrachloride, dioxane and the like.

The reaction temperature is an appropriate reaction rate, a side reaction due to a rapid heat generation can be avoided, and the m-fluorobenzenesulfonic acid derivative precursor as a raw material and the sulfonated product as a product are not decomposed. If there is no particular limitation, it is usually performed at 0 to 150 ° C. By adopting such reaction conditions, m
-A fluorobenzenesulfonic acid derivative can be synthesized. The structure of the obtained m-fluorobenzenesulfonic acid derivative can be identified by a nuclear magnetic resonance spectrum and a mass spectrometry spectrum.

The m-fluorobenzenesulfonic acid derivative according to the present invention is useful as a dopant agent for doping an electron conjugated polymer substance, and provides a conductive polymer material which exhibits conductivity for a long period of time. As the electron-conjugated polymer substance, any polymer compound having an electron-conjugated molecular structure can be used. Specifically, for example, a pyrrole-based compound represented by the following general formula [3] is used. Examples of the conjugated polymer include a thiophene-based compound represented by the general formula [4] and an aniline-based compound represented by the general formula [5] as a repeating unit.

[0021]

[Chemical 7] In the above formula, R ⁷ and R ⁸ may be the same or different and each is a hydrogen atom or a linear, cyclic or branched alkyl group or alkoxy group having 1 to 20 carbon atoms. In addition, * indicates the bonding position of the repeating unit (the formula [4],
The same applies to the expression [5].

[0022]

[Chemical 8] In the above formula, R ⁹ and R ¹⁰ may be the same or different and each is a hydrogen atom or a linear, cyclic or branched alkyl group or alkoxy group having 1 to 20 carbon atoms.

[0023]

[Chemical 9] In the above formula, R ¹¹ , R ¹² , R ¹³ and R ¹⁴ may be the same or different and each is a hydrogen atom or a linear, cyclic or branched alkyl group or alkoxy group having 1 to 20 carbon atoms. .

As the electron-conjugated polymer substance, it is preferable to use a conjugated polymer compound constituted by any one of the above-mentioned general formulas [3], [4] and [5] as a repeating unit. It is preferable to use a polypyrrole-based conjugated polymer composed of 3] as a repeating unit.

The method for doping the electron-conjugated polymer substance with the m-fluorobenzenesulfonic acid derivative is as follows:
A generally used method such as a method of immersing the derivative in a solution, a method of electrolytically oxidatively polymerizing the derivative as a supporting electrolyte, or a method of chemically oxidatively polymerizing using a transition metal salt of the derivative can be used.

As the solvent for dissolving the m-fluorobenzenesulfonic acid derivative in the doping by the dipping method, any solvent can be used as long as it has a dissolving power, for example, water, acetonitrile, nitrobenzene, Propylene carbonate, ethylene glycol and the like can be used.

In the electrolytic oxidative polymerization method, a predetermined current or potential is applied to a solution composed of an m-fluorobenzenesulfonic acid derivative as a supporting electrolyte and a monomer which can form a repeating unit of the polymer substance. To dope. Examples of the monomer that can form the repeating unit include pyrrole, thiophene, aniline, and tran.
s-1,2-di (2-thienyl) ethylene, trans-1,2-di (2-
Examples thereof include thienyl) butadiene and 3,4-ethylenedioxythiophene.

As a solvent used in the electrolytic oxidative polymerization reaction, a m-fluorobenzenesulfonic acid derivative is dissolved,
In addition, any monomer capable of dissolving the repeating unit can be used, and examples thereof include water, dimethylformamide, acetonitrile, propylene carbonate, ethylene glycol, and nitrobenzene. The electrolytic oxidative polymerization can be carried out usually in a temperature range of −100 to 150 ° C., preferably in a temperature range of 0 to 50 ° C., and may be a constant current electrolysis method or a constant potential electrolysis method. Further, it is desirable that the electrolytic oxidative polymerization is performed in an atmosphere of an inert gas such as nitrogen or argon.

In the case of doping by the chemical oxidative polymerization method, m
-By bringing a transition metal complex having a conjugated base of a fluorobenzenesulfonic acid derivative as a ligand into contact with a monomer serving as a repeating unit forming a polymer compound having an electron-conjugated molecular structure in a solvent , Doping is performed together with polymerization. Examples of the central metal forming the transition metal complex include iron, cobalt, ruthenium, etc., and among these, iron is particularly preferable. The transition metal complex is usually used in an amount of 1 to 100 mol based on 1 mol of the monomer.

As the monomer which can form the repeating unit, pyrrole, thiophene, aniline, tr
ans-1,2-di (2-thienyl) ethylene, trans-1,2-di (2-
Thienyl) butadiene, 3,4-ethylenedioxythiophene and the like can be used. The solvent used in the reaction may be any solvent capable of dissolving the above transition metal complex and the monomer, and examples thereof include water, dimethylformamide, acetonitrile, tetrahydrofuran, propylene carbonate, ethylene glycol and the like.
The polymerization temperature is preferably 0 to 50 ° C., and the reaction time is 1 to 48.
Time is preferred. Further, it is desirable that the polymerization is carried out in an atmosphere of an inert gas such as nitrogen or argon.

The thus obtained electron-conjugated polymer substance doped with the m-fluorobenzenesulfonic acid derivative of the present invention can maintain high conductivity as well as high conductivity in a high temperature and high humidity environment. , Solid electrolytic capacitor, antistatic film, electromagnetic wave shield material, conductive adhesive, conductive paint, wiring material, secondary battery electrode material, display material, overcurrent protection element, semiconductor element, etc. .

[0032]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited to these examples.

Example 1 65 ml of fuming sulfuric acid (sulfur trioxide 30 wt% excess) was added to a 200 ml three-necked flask, and 25 g of 4-fluorobenzamide was slowly added at room temperature while stirring the fuming sulfuric acid. Stirring was continued at 70 ° C. for 13 hours, and then the reaction solution was left overnight. Next, the reaction solution was put into 50 g of ice to hydrolyze unreacted fuming sulfuric acid. The reaction solution was allowed to stand, and the white powder deposited was filtered off with a glass filter. The obtained white solid was put into 200 ml of acetone and washed with stirring. The solid content obtained by filtering this off was vacuum dried at room temperature for 24 hours to give 4-fluoro-2-sulfobenzamide 2
2.9 g was obtained.

The compound obtained was identified by FD-mass spectrum (m / z = 219) and ¹ H-NMR. The analysis results were as follows. ¹ H-NMR (DMSO-d ₆ ) analysis result δ (ppm) 7.20 (1H, d) 7.86 (1H, d) 8.21 (1H, s)

(Example 2) 4 synthesized in the same manner as in Example 1
-Fluoro-2-sulfobenzamide 21.9 g in 50
It was dissolved in 200 ml of pure water in a 0 ml beaker. Sodium carbonate was added thereto to adjust the pH of the aqueous solution to 7. After water was removed under reduced pressure with an evaporator, it was vacuum dried for 2 days to obtain 23.4 g of 2-carbamoyl-5-fluorobenzenesulfonic acid sodium salt.

Example 3 61 g of iron (III) nitrate nonahydrate was placed in a 200 ml beaker and dissolved in 100 ml of pure water. To this, add 15% aqueous ammonia to adjust the pH of the aqueous solution.
Was set to 12. At this time, iron (III) hydroxide was produced and a brown solid was obtained. This brown solid is designated as Kiriyama funnel (No. 5)
After filtering with B) and washing with water three times, the resultant was dried under vacuum overnight.

4-fluoro-synthesized as in Example 1
An aqueous solution in which 21.9 g of 2-sulfobenzamide was dissolved in 500 ml of pure water was prepared, and the total amount of iron hydroxide obtained was added thereto, followed by stirring for 6 hours. After the insoluble matter in the aqueous solution was filtered off, the filtrate was evaporated and the solvent was distilled off. Further dried under vacuum overnight, tris- (2-carbamoyl-5
-Fluorobenzenesulfonyl) iron (III) salt 13.3
g was obtained.

Example 4 4.38 g of 4-fluoro-2-sulfobenzamide obtained in Example 1 and 1.34 g of pyrrole were dissolved in 200 ml of pure water to prepare a reaction solution for electrolytic oxidation polymerization. After bubbling nitrogen gas into this solution for about 15 minutes to replace it with nitrogen, a 4 cm square stainless steel (s)
Two sheets of (us304) plate were immersed at 1 cm intervals to form a working electrode and a counter electrode.

Using two immersed stainless steel electrodes, a constant current (1.25 mA / cm ² ) was applied for 40 minutes to carry out electrolytic oxidation polymerization. The polypyrrole film produced on the electrode is pure water,
After washing with acetone, peel off from the electrode and
Dried for hours. The electric conductivity of the obtained film was measured by the four-point probe method, and it was 162 S / cm.

The resulting polypyrrole film was placed in air,
After holding at a high temperature of 150 ° C. for 6 hours, the electric conductivity was 117 S / cm as a result of measurement by a four-point probe method.

On the other hand, the polypyrrole film obtained by polymerization was immersed in pure water, the temperature of pure water was set to 90 ° C., and the temperature was maintained for 12 hours. Next, the polypyrrole film was taken out from pure water, dried in vacuum, and then the electrical conductivity was measured by the four-point probe method. As a result, it was 96 S / cm.

(Example 5) 4-carbamoyl-5-fluorobenzenesulfonic acid sodium salt (4.82 g) obtained in Example 2 and pyrrole (1.34 g) were dissolved in pure water (200 ml) to prepare a reaction solution for electrolytic oxidation polymerization. did. Nitrogen gas was bubbled into this solution for about 15 minutes to replace with nitrogen, and then 4
Two cm3 square stainless steel (sus304) plates were immersed at 1 cm intervals to form a working electrode and a counter electrode.

Using two immersed stainless steel electrodes, a constant current (1.25 mA / cm ² ) was applied for 40 minutes to carry out electrolytic oxidation polymerization. The polypyrrole film produced on the electrode is pure water,
After washing with acetone, peel off from the electrode and
Dried for hours. The electric conductivity of the obtained film was measured by the four-point probe method, and it was 103 S / cm.

The resulting polypyrrole film was placed in air,
After keeping at a high temperature of 150 ° C. for 7.5 hours, the electric conductivity was measured by the four-point probe method, and it was 100 S / cm.

On the other hand, the polypyrrole film obtained by polymerization was immersed in pure water to bring the temperature of pure water to 90 ° C.
Held for hours. Then, the polypyrrole film was taken out from pure water, dried in vacuum, and then the electrical conductivity was measured by the four-point probe method. As a result, it was 102 S / cm.

Example 6 Tris-obtained in Example 3
1.3 g of (2-carbamoyl-5-fluorobenzenesulfonyl) iron (III) salt was dissolved in 50 ml of pure water in a 50 ml glass container. Pyrrole 0.13 in this aqueous solution
g was added and stirring was started. Black solids began to precipitate a few seconds after the addition of pyrrole. After stirring was continued for another night, the black solid was filtered off with a Kiriyama funnel (No. 5A). The obtained solid was washed with 10 ml of acetone and then dried under vacuum overnight to obtain 30 mg of a polymer.

10 mg of the obtained polypyrrole polymer was added,
Charged in a tablet molding machine for infrared spectrum sample molding,
When treated for 5 minutes with an excess weight of 200 kg / cm, a disc-shaped plate having a diameter of 1 cm and a thickness of 200 μm could be obtained. The electric conductivity of the obtained disk-shaped plate was measured by the four-point probe method, and it was 36 S / cm.

A disk-shaped polypyrrole plate was placed in air for 150
After keeping at a high temperature of ℃ for 7.5 hours, the electrical conductivity was measured by the four-point probe method, and it was 12 S / cm.

On the other hand, a disk-shaped polypyrrole plate was immersed in pure water, the temperature of pure water was set to 90 ° C., and the temperature was maintained for 7.5 hours. Then, the polycoddle-shaped polypyrrole plate was taken out from pure water, dried in vacuum, and then the electrical conductivity was measured by the four-point probe method. As a result, it was 30 S / cm.

[0050]

The novel m-fluorobenzenesulfonic acid derivative according to the present invention can be used as a doping agent for conductive polymer substances. The conductive polymer material obtained by doping this compound is a material having both high conductivity, high heat resistance, and high hot water resistance. for that reason,
The obtained conductive polymer material can be used as a capacitor electrode material, a battery electrode material, and the like.

Claims (6)

[Claims] 1. An m-fluorobenzenesulfonic acid derivative represented by the following general formula [1]. [Chemical 1] In the formula [1], X is a sulfonic acid group having a counter cation, and one of R ^{1 to} R ⁴ is a carboxamide group represented by the following general formula [2]: The other three may be the same or different from each other and represent a hydrogen atom, a fluorine atom or an alkyl group having 20 or less carbon atoms, and in the formula [2], R ⁵ and R ⁶ may be the same or different from each other. Represents a hydrogen atom, an alkyl group having 20 or less carbon atoms, or a phenyl group. 2. The counter cation of the sulfonic acid group in the general formula [1] is selected from the group consisting of hydrogen ion, alkali metal ion, alkaline earth metal ion and transition metal ion of Group VIII of the periodic table. The m-fluorobenzenesulfonic acid derivative according to claim 1, which is an ion. 3. In the general formula [1], the counter cation of the sulfonic acid group is an ion selected from the group consisting of hydrogen ion, sodium ion, potassium ion and iron (III) ion. M- according to claim 2
Fluorobenzenesulfonic acid derivative. 4. In the general formula [1], all of R ^{1 to} R ⁴ other than the carboxamide group represented by the general formula [2] are hydrogen atoms. The m-fluorobenzenesulfonic acid derivative according to the above. 5. The m-fluorobenzenesulfonic acid derivative according to claim 1, wherein in the general formula [2], at least one of R ⁵ and R ⁶ is a hydrogen atom. . 6. A dopant agent for a conductive polymer substance, which comprises the m-fluorobenzenesulfonic acid derivative according to any one of claims 1 to 5.