JP2014234359A - Compound, and conductive polymer obtained by polymerization of the compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive polymer with high conductivity, and a compound useful for the production of the conductive polymer.SOLUTION: This invention relates to a compound represented by the following general formula (1), where R-Rindependently represent a hydrogen atom, a hydroxy group, a 1-24C alkyl group, a 1-24C alkoxy group, an aldehyde group, an acetyl group, an acidic group or a salt thereof, and at least one of R-Ris a hydrogen atom. This invention also relates to a conductive polymer obtained by polymerization of monomers comprising the compound.

Description

  The present invention relates to a compound and a conductive polymer obtained by polymerizing the compound.

Known conductive polymers include polyaniline conductive polymers, polythiophene conductive polymers, and polypyrrole conductive polymers. These conductive polymers are used in various applications.
In general, the conductivity (σ) of a conductive polymer depends on the charge (q) of the carrier, the number of carriers (n), and the mobility (μ) between and within the molecular chains of the carrier, It is derived from the following formula (I). Therefore, increasing the carrier charge (q), the number of carriers (n), and the mobility (μ) is effective in improving the conductivity of the conductive polymer.
σ = qnμ (I)

In the case of a polyaniline-based conductive polymer, the carrier charge (q) is an eigenvalue determined by the type of carrier. Therefore, in order to improve conductivity, the number of carriers (n) and mobility (μ) must be It is important to increase.
In order to increase the mobility (μ), it is considered effective to increase the molecular weight of the conductive polymer or reduce the proportion of impurities contained in the conductive polymer.
In order to increase the number (n) of carriers, it is considered effective to introduce an acidic group such as a sulfonic acid group or a carboxy group and remove a base that inhibits dope.

  As the polyaniline-based conductive polymer having an acidic group introduced therein, for example, a conductive polymer having an acidic group-substituted aniline as a precursor such as a compound (2-aminoanisole-4-sulfonic acid) represented by the following formula (II) is proposed. (See Patent Documents 1 and 2). In Patent Documents 1 and 2, a conductive polymer is obtained by polymerizing acidic group-substituted aniline with an oxidizing agent in a solution containing a basic compound. The conductive polymer is said to exhibit high conductivity, excellent solubility in water or an organic solvent exhibiting any pH, and excellent coating properties.

JP-A-7-196791 JP 7-324132 A

  However, there is still room for improvement in the conductivity of the conductive polymers described in Patent Documents 1 and 2. In particular, when the conductive polymer is heated, the conductivity tends to be insufficient. For example, one of the uses of conductive polymers is a capacitor. In such applications, for example, a conductive polymer or a solution containing a conductive polymer or a dispersion containing a conductive polymer is applied or impregnated, and then a treatment such as heating is performed to form a conductive polymer layer (electrolyte layer). To do. When the conductive polymer described in Patent Documents 1 and 2 is used as the conductive polymer, it cannot be said that the conductivity of the formed conductive polymer layer is sufficient.

  This invention is made | formed in view of the said situation, Comprising: It aims at providing the conductive polymer which has high electroconductivity, and a conductive polymer precursor useful for the manufacture.

  The first aspect of the present invention is a compound represented by the following general formula (1).

［式中、Ｒ^１〜Ｒ^３はそれぞれ独立して、水素原子、ヒドロキシ基、炭素数１〜２４のアルキル基、炭素数１〜２４のアルコキシ基、アルデヒド基、アセチル基、酸性基またはその塩であり、Ｒ^１〜Ｒ^３のうち少なくとも１つは水素原子である。］

[Wherein, R ^{1 to} R ³ are each independently a hydrogen atom, a hydroxy group, an alkyl group having 1 to 24 carbon atoms, an alkoxy group having 1 to 24 carbon atoms, an aldehyde group, an acetyl group, an acidic group or a salt thereof. And at least one of R ^{1 to} R ³ is a hydrogen atom. ]

  The second aspect of the present invention is a conductive polymer obtained by polymerizing a monomer containing the compound of the first aspect.

  According to the present invention, it is possible to provide a conductive polymer having high conductivity and a compound useful for the production thereof.

≪Compound (conductive polymer precursor) ≫
The compound of the present invention is a compound represented by the following general formula (1) (hereinafter also referred to as “compound (1)”).

［式中、Ｒ^１〜Ｒ^３はそれぞれ独立して、水素原子、ヒドロキシ基、炭素数１〜２４のアルキル基、炭素数１〜２４のアルコキシ基、アルデヒド基、アセチル基、酸性基またはその塩であり、Ｒ^１〜Ｒ^３のうち少なくとも１つは水素原子である。］

[Wherein, R ^{1 to} R ³ are each independently a hydrogen atom, a hydroxy group, an alkyl group having 1 to 24 carbon atoms, an alkoxy group having 1 to 24 carbon atoms, an aldehyde group, an acetyl group, an acidic group or a salt thereof. And at least one of R ^{1 to} R ³ is a hydrogen atom. ]

In R ^{1 to} R ³ in the general formula (1), the alkyl group may be linear or branched. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 3 carbon atoms from the viewpoint of suppressing the influence of steric hindrance.
The alkyl group in the alkoxy group is the same as the alkyl group.

Examples of the acidic group include a sulfonic acid group, a sulfoalkyl group, a phosphoric acid group, and a phosphoalkyl group. In the present invention, the “phosphate group” means —PO ₃ H ₂ .
The acidic group may be included in an acid state (for example, —S (═O) ₂ OH) or may be included in an ionic state (for example, —S (═O) ₂ O ⁻ ).
As the acidic group, in particular, the sulfonic acid group or the sulfoalkyl having 1 to 10 carbon atoms can be used to enhance the affinity for water, and when it becomes a conductive polymer, a higher conductivity can be expressed. Groups are preferred, and sulfonic acid groups are particularly preferred.

The salt of an acidic group is a group formed from an acidic group in an ionic state and its counter ion.
Examples of the counter ion include alkali metal ions, alkaline earth metal ions, ammonium ions, substituted ammonium ions, and the like. That is, examples of the salt of an acidic group include alkali metal salts, alkaline earth metal salts, ammonium salts, and substituted ammonium salts.
Examples of alkali metal ions include lithium ions, sodium ions, potassium ions, and the like.
Examples of the alkaline earth metal ions include magnesium ions and calcium ions.
Examples of the substituted ammonium ion include a chain ammonium ion, a cyclic saturated ammonium ion, and a cyclic unsaturated ammonium ion.
Examples of the chain ammonium ions include ammonium ions represented by the following general formula (III).

In formula (III), R ^{7 to} R ¹⁰ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
Examples of such chain ammoniums include methylammonium, dimethylammonium, trimethylammonium, ethylammonium, diethylammonium, triethylammonium, methylethylammonium, diethylmethylammonium, dimethylethylammonium, propylammonium, dipropylammonium, isopropyl. Ammonium, diisopropylammonium, butylammonium, dibutylammonium, methylpropylammonium, ethylpropylammonium, methylisopropylammonium, ethylisopropylammonium, methylbutylammonium, ethylbutylammonium, tetramethylammonium, tetraethylammonium, tetran-butylammonium, tetrase - butyl ammonium, tetra-t- butyl ammonium.
Among these, from the viewpoint of solubility, one of R ^{7 to} R ¹⁰ is a hydrogen atom, the other three are ammonium ions having 1 to 4 carbon atoms, or two of R ^{7 to} R ¹⁰ are hydrogen. An ammonium ion in which an atom and the other two are alkyl groups having 1 to 4 carbon atoms is preferred, and an ammonium ion in which one of R ^{7 to} R ¹⁰ is a hydrogen atom and the other three are alkyl groups having 1 to 4 carbon atoms. Particularly preferred.

Examples of the cyclic saturated ammoniums include piperidinium, pyrrolidinium, morpholinium, piperazinium, and derivatives having these skeletons.
Examples of the cyclic unsaturated ammonium include pyridinium, α-picolinium, β-picolinium, γ-picolinium, quinolinium, isoquinolinium, pyrrolinium, and derivatives having these skeletons.

In the general formula (1), at least one of R ^{1 to} R ³ is a hydrogen atom, and at least R ³ is preferably a hydrogen atom from the viewpoint of improving conductivity.
In the general formula (1), from the viewpoint of improving conductivity, R ¹ and R ² are each a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an acidic group, or a salt thereof. It is preferable that it is a hydrogen atom, a C1-C3 alkyl group, a C1-C3 alkoxy group, an acidic group, or its salt.
In the general formula (1), in particular, from the viewpoint that the conductivity after heating of the conductive polymer obtained by polymerizing the compound (1) is improved and the production of the compound (1) is easy, R ¹ and It is preferable that at least one of R ² is an acidic group or a salt thereof, R ³ is a hydrogen atom, one of R ¹ and R ² is an acidic group or a salt thereof, and the other is a hydrogen atom, R ³ is more preferably a hydrogen atom, particularly preferably R ¹ is a hydrogen atom, R ² is an acidic group or a salt thereof, and R ³ is a hydrogen atom. As the acidic group or a salt thereof, a sulfonic acid group or a salt thereof is particularly preferable.

<Method for Producing Compound (1)>
Compound (1) can be produced, for example, by a production method through the following steps (a) to (e). However, the production method is a method for producing a compound in which R ² in the general formula (1) is a sulfonic acid group or a salt thereof (hereinafter referred to as “compound (1-1)”).
Step (a): A compound represented by the following general formula (2) (hereinafter referred to as “compound (2)”) is sulfonated using fuming sulfuric acid, and the compound represented by the following general formula (3): (Hereinafter referred to as “compound (3)”).
(B) Step: A step of obtaining a compound represented by the following general formula (4) (hereinafter referred to as “compound (4)”) by nitration of the compound (3) using fuming nitric acid.
(C) Step: A step of dihydroxylating compound (4) to obtain a compound represented by the following general formula (5) (hereinafter referred to as “compound (5)”).
Step (d): A step of cyclizing the compound (5) to obtain a compound represented by the following general formula (6) (hereinafter referred to as “compound (6)”).
(E) Step: A step of obtaining compound (1-1) by reducing compound (6).

Formula (2) to (6), (1-1), ^{R 1} and ^{R 3} are respectively the same as ^{R 1} and ^{R 3} in the general formula (1). In the production method, R ¹ and R ³ are each preferably a hydrogen atom.
A is a sulfonic acid group or a salt thereof.
R ^2A is a substituent that can be converted to A (sulfonic acid group or a salt thereof) by the reaction in the step (a). Examples of the substituent that can be converted to A include a hydrogen atom and a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
R ⁴ and R ⁵ are each independently a substituent that can be converted to a hydroxy group by the reaction in step (c), or a hydroxy group, and at least one of R ⁴ and R ⁵ is the substituent. Examples of the substituent that can be converted to a hydroxy group include an aldehyde group and an acetyl group. In addition, when using the compound whose both R < ⁴ > and R < ⁵ > are hydroxy groups as a compound (2), (d) process can be performed without performing (c) process after (b) process.
Hereinafter, each step will be described in detail by taking as an example the case of producing a compound in which A is a sulfonic acid group as the compound (1-1).

(Step (a))
In the step (a), the compound (2) is sulfonated using fuming sulfuric acid. Thereby, a compound represented by the following general formula (3-1) (hereinafter referred to as “compound (3-1)”) is obtained.

The sulfonation is performed, for example, by adding fuming sulfuric acid to a solution of the compound (2) using concentrated sulfuric acid as a solvent and causing the reaction.
The reaction ratio (mol ratio) between the compound (2) and fuming sulfuric acid is preferably 1: 1 to 1: 2. When there is too little fuming sulfuric acid, it becomes difficult to complete the reaction. When there is too much fuming sulfuric acid, it is necessary to remove excess fuming sulfuric acid, which takes time and manufacturing costs. Fuming sulfuric acid contains sulfur trioxide, but it is treated as sulfuric acid in the calculation of the reaction ratio.
The reaction temperature is preferably 60 ° C. or higher, and the reaction time is preferably 0.5 to 10 hours.
In sulfonation, fuming sulfuric acid is generally used, but concentrated sulfuric acid or hot concentrated sulfuric acid may be used. Even when concentrated sulfuric acid or hot concentrated sulfuric acid is used, the same reaction as described above can proceed.

((B) Process)
In step (b), compound (3-1) is nitrated using fuming nitric acid. Thereby, a compound represented by the following general formula (4-1) (hereinafter referred to as “compound (4-1)”) is obtained.

The sulfonation is performed, for example, by adding fuming nitric acid to a solution of the compound (3-1) using acetic acid as a solvent and reacting the solution.
The reaction ratio (mol ratio) between the compound (3-1) and fuming nitric acid is preferably 1: 1 to 1: 2. When there is too little fuming nitric acid, it becomes difficult to complete the reaction. When there is too much fuming nitric acid, it is necessary to remove excess fuming nitric acid, which requires labor and manufacturing costs. Fuming nitric acid contains nitrogen dioxide, but it is treated as nitric acid in the calculation of the reaction rate.
The reaction temperature is preferably 10 ° C. or higher, and the reaction time is preferably 1.0 to 20 hours.

(Step (c))
In the step (c), the compound (4-1) is dihydroxylated. Thereby, a compound represented by the following general formula (5-1) (hereinafter referred to as “compound (5-1)”) is obtained.

The dihydroxylation is performed, for example, by reacting the compound (4-1) with hydrogen peroxide in a mixed solvent of an aqueous sodium hydroxide solution and methanol.
This reaction is a reaction called Dakin reaction or Dakin oxidation. The reaction conditions in the step (c) may be the same as those in general Dakin reaction or Dakin oxidation, and are not particularly limited.

((D) step)
In the step (d), the compound (5-1) is cyclized. Thereby, a compound represented by the following general formula (6-1) (hereinafter referred to as “compound (6-1)”) is obtained.

The cyclization is performed, for example, by reacting compound (5-1) with dibromoethane using potassium carbonate as a catalyst in a solvent.
The solvent is not particularly limited as long as it does not inhibit the reaction, and examples thereof include dimethylformamide, tetrahydroamine, dimethyl sulfoxide and the like.
The reaction temperature is preferably 70 to 80 ° C., and the reaction time is preferably 10 to 50 hours.

(Step (e))
In the step (e), the compound (6-1) is reduced. Thereby, a compound (1-1) is obtained.

  The reaction conditions in the step (e) are not particularly limited as long as they are general reduction conditions for a nitro group. Specific examples include catalytic hydrogenation using a reducing agent such as palladium carbon and Raney nickel, and reduction using a reducing agent such as zinc powder and tin under acidic conditions.

The production method of the compound (1) has been described above by taking the case of producing the compound (1-1) as an example. However, addition, omission, substitution, and other changes of steps are appropriately performed according to the compound to be produced. Is possible.
For example, when sulfonic acid is obtained as a salt depending on reaction conditions, it can be recovered as sulfonic acid by using a cation exchange resin. If the salt state does not affect the reaction in the subsequent steps, it can be omitted.
Moreover, in the manufacturing method of said compound (1-1), although the process was advanced in order of (a) process-> (b) process, it is also possible to replace in order of (b) process-> (a) process. is there.
Moreover, it is also possible to change the kind and position of the substituents (R ¹ , A, R ³ ) of the compound (1-1) by changing the starting material.
Candidate acid group, a phosphoric acid group (-PO 3 _{H 2)} is also mentioned, by selecting the compound that halogen atoms are provided as a starting material, easily possible to introduce a phosphate group is there.

≪Conductive polymer≫
The conductive polymer of the present invention (hereinafter also referred to as conductive polymer (a)) is obtained by polymerizing a monomer containing the compound (1), and is a structural unit based on the compound (1) ( (Hereinafter also referred to as a structural unit (1-A)).
The structural unit (1-A) was obtained by removing one of the amino group hydrogen atoms and one of the hydrogen atoms bonded to the benzene ring (any one of R ^{1 to} R ³ ) from the compound (1). It has a structure.
As the structural unit (1-A), structural units represented by general formula (1-A-1) shown below are preferred. The structural unit is formed from a compound in which R ³ in the general formula (1) is a hydrogen atom.

［式中、Ｒ^１およびＲ^２はそれぞれ独立して、水素原子、ヒドロキシ基、炭素数１〜２４のアルキル基、炭素数１〜２４のアルコキシ基、アルデヒド基、アセチル基、酸性基またはその塩である。］

[Wherein, R ¹ and R ² are each independently a hydrogen atom, a hydroxy group, an alkyl group having 1 to 24 carbon atoms, an alkoxy group having 1 to 24 carbon atoms, an aldehyde group, an acetyl group, an acidic group or a salt thereof. It is. ]

In the general formula (1-A-1), examples of the alkyl group, alkoxy group, acidic group, and salt thereof in R ¹ and R ² are the same as those described in the description of the compound (1). It is done.
R ¹ and R ² are each preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an acidic group or a salt thereof from the viewpoint of improving conductivity, It is more preferable that they are a C1-C3 alkyl group, a C1-C3 alkoxy group, an acidic group, or its salt.
In the general formula (1-A-1), at least one of R ¹ and R ² is preferably an acidic group or a salt thereof, and ^one of R ¹ and R ² is an acidic group or a salt thereof. It is more preferable that the salt and the other be a hydrogen atom, and it is particularly preferable that R ¹ is a hydrogen atom and R ² is an acidic group or a salt thereof. As the acidic group or a salt thereof, a sulfonic acid group or a salt thereof is particularly preferable.

Among the monomers to be polymerized in the production of the conductive polymer (a), the proportion of the compound (1) is preferably 1 to 100% by mass, preferably 10 to 100%, based on the total mass (100% by mass) of the monomer. The mass% is more preferable. The higher the content of compound (1), the easier it is to obtain a conductive polymer having high conductivity and excellent thermal stability.
A compound (1) may be used individually by 1 type, and may use 2 or more types together. When using 2 or more types of compounds (1) together, those ratios can be set arbitrarily.
The method for producing the conductive polymer (a) will be described in detail later.

The conductive polymer (a) may further have a structural unit (monomer component) other than the structural unit (1-A) as long as the effects of the present invention are not impaired.
The structural unit other than the structural unit (1-A) is not particularly limited as long as it is based on a monomer that can be polymerized with the compound (1) and does not impair the properties such as conductivity. The monomer component used for the conductive polymer can be used. For example, substituted or unsubstituted aniline (excluding compound (1), hereinafter also referred to as other aniline monomer) unit, thiophene unit, pyrrole unit, phenylene unit, vinylene unit, divalent unsaturated group And divalent saturated groups.
As the structural unit other than the structural unit (1-A), a structural unit based on another aniline monomer is preferable.

Examples of other aniline monomers include aniline, methylaniline, dimethylaniline, trimethylaniline, tetramethylaniline, ethylaniline, diethylaniline, triethylaniline, tetraethylaniline, propylaniline, dipropylaniline, tripropylaniline, tetra Propylaniline, Butylaniline, Dibutylaniline, Tributylaniline, Tetrabutylaniline, Methoxyaniline, Dimethoxyaniline, Trimethoxyaniline, Tetramethoxyaniline, Ethoxyaniline, Diethoxyaniline, Triethoxyaniline, Tetraethoxyaniline, Bromoaniline, Chloroaniline , Aniline fluoride, cyanoaniline, hydroxyaniline, nitroaniline, dibromoaniline, dichloroaniline, diph Aniline, dicyanoaniline, dihydroxyaniline, dinitroaniline, diaminobenzene, N-methylaniline, N-ethylaniline, Nn-propylaniline, N-iso-propylaniline, N-butylaniline, aminobenzenesulfonic acid, amino Benzenedisulfonic acid, aminophenolsulfonic acid, aminophenoldisulfonic acid, methoxyanilinesulfonic acid, aminobenzoic acid, aminobenzenedicarboxylic acid, aminobenzenephosphoric acid, aminobenzenediphosphoric acid, aminobenzenesulfonamide, aminobenzenethiol, aminobenzamide, Acetotoluidine, aminoacetophenone, aminobenzenethiol, aminochlorophenol, aminonaphthalene, aminonaphthalenesulfonic acid, aminonaphthalenecarbo Acid, aminonaphthalene phosphoric acid, the amino nitrophenol, aminophenyl, amino phenylphenol, Aminokinrin, aminobenzotrifluoride, aminobenzyl alcohol, aminophenyl boronic acid, amino cresol, aminoindole, such as luminol and the like.
Among these aniline monomers, those having a sulfonic acid group and / or a carboxy group may use salts such as alkali metal salts, alkaline earth metal salts, ammonium salts, and substituted ammonium salts. .

Among the monomers to be polymerized in the production of the conductive polymer (a), the proportion of the monomers other than the compound (1) is 0 to 99% by mass with respect to the total mass (100% by mass) of the monomer. Preferably, 0 to 90% by mass is more preferable.
Monomers other than the compound (1) may be used alone or in combination of two or more.

The conductive polymer (a) preferably has an acidic group bonded to an aromatic ring or a salt thereof from the viewpoint of improving conductivity and improving solubility in water or an organic solvent. By improving the solubility in water and organic solvents, it becomes easy to produce a capacitor or the like using the conductive polymer (a).
The content of the acidic group or salt thereof with respect to the aromatic ring in the conductive polymer (a) (the ratio of the aromatic ring to which the acidic group is bonded out of the total aromatic rings) is preferably 70% or more, more preferably 80% or more, 90% or more is particularly preferable.

The weight average molecular weight of the conductive polymer (a) is preferably from 3,000 to 500,000, more preferably from 5,000 to 200,000, particularly preferably from 7,000 to 100,000, from the viewpoints of conductivity, film formability and film strength. When the mass average molecular weight is 3000 or more, film formability and conductivity are improved. When the mass average molecular weight is 500,000 or less, the solubility in water or an organic solvent is improved. Moreover, the impregnation property of the solution or dispersion into the porous molded body is improved.
In the present invention, the weight average molecular weight of the conductive polymer (a) is a value in terms of sodium polystyrene sulfonate measured by gel permeation chromatography.

The conductive polymer (a) has conductivity.
In the present invention, the polymer “having conductivity” indicates that a coating film having a film thickness of about 0.1 μm formed from the polymer has a surface resistance value of 10 ¹⁴ Ω / □ or less.
The surface resistance of the coating film formed from the conductive polymer (a) is preferably ¹⁰ 10 Ω / □ or less, more preferably 10 ⁸ Ω / □ or less. The lower the surface resistance value, the higher the conductivity of the conductive polymer (a). For example, when used in the production of a solid electrolytic capacitor, a solid electrolytic capacitor with good performance such as frequency characteristics can be obtained.
The surface resistance value is obtained by measuring the surface resistance value of a thin film obtained by applying a polymer solution onto a glass substrate by a spin coating method and heating at 120 ° C. for 10 minutes.

<Method for producing conductive polymer (a)>
The conductive polymer (a) can be obtained by polymerizing a monomer containing the compound (1). After the polymerization, the product may be subjected to treatment such as purification and desalting as necessary. Polymerization, purification, desalting and the like can be performed by known methods. For example, the polymerization method of the monomer is not particularly limited, and a known polymerization method used in the production of an aniline-based conductive polymer such as a chemical oxidative polymerization method using an oxidizing agent or an electrolytic polymerization method can be used.

Hereinafter, the manufacturing method of a conductive polymer (a) is demonstrated more concretely, showing an embodiment example. The manufacturing method of embodiment shown below is a method of manufacturing a conductive polymer (a) by the chemical oxidative polymerization method.
The production method of this embodiment includes a step (polymerization step) in which a monomer containing the compound (1) is polymerized (chemical oxidative polymerization) with an oxidizing agent in a polymerization solvent.

<Oxidizing agent>
Examples of the oxidizing agent include peroxodisulfuric acid such as peroxodisulfuric acid, ammonium peroxodisulfate, sodium peroxodisulfate, and potassium peroxodisulfate, and hydrogen peroxide. These oxidizing agents may be used individually by 1 type, and 2 or more types may be mixed and used for them in arbitrary ratios.
1-5 mol is preferable with respect to 1 mol of monomers, and, as for the usage-amount of an oxidizing agent, 1-3 mol is more preferable. When the amount of the oxidizing agent used is within the above range, the conductive polymer can have a high molecular weight and the main chain can be oxidized sufficiently.
It is also effective to use a transition metal compound such as iron or copper in combination with an oxidizing agent as a catalyst.

<Polymerization solvent>
Examples of the polymerization solvent include water and organic solvents. Examples of the organic solvent include alcohols such as methanol, ethanol, isopropyl alcohol, propyl alcohol and butanol; ketones such as acetone and ethyl isobutyl ketone; ethylene glycols such as ethylene glycol and ethylene glycol methyl ether; propylene glycol and propylene glycol Propylene glycols such as methyl ether, propylene glycol ethyl ether, propylene glycol butyl ether and propylene glycol propyl ether; Amides such as N, N-dimethylformamide and N, N-dimethylacetamide; N-methylpyrrolidone, N-ethylpyrrolidone and the like Pyrrolidones and the like.
As the polymerization solvent, water or a mixed solvent of water and an organic solvent is preferable.

<Polymerization process>
In the polymerization step, the monomer containing compound (1) is polymerized (chemical oxidative polymerization) with an oxidizing agent in a polymerization solvent. Thereby, the conductive polymer is obtained in the state of a polymer solution dissolved or dispersed in the polymerization solvent.
For monomer polymerization, the monomer solution is dropped into the oxidizer solution, the oxidizer solution is dropped into the monomer solution, and the monomer solution and the oxidizer solution are dropped into the reaction vessel at the same time. It can be carried out by various methods such as a method for conducting a polymerization, a method in which a monomer solution and an oxidant solution are continuously supplied to a reaction vessel and the like and polymerized by an extrusion flow.
As the solvent for each of the oxidant solution and the monomer solution, the polymerization solvent described above can be used.
In the polymerization, a protonic acid may be added to the reaction system. Examples of the protic acid include mineral acids such as hydrochloric acid, nitric acid, sulfuric acid, and borofluoric acid, super strong acids such as trifluoromethanesulfonic acid, and organic substances such as methanesulfonic acid, dodecylbenzenesulfonic acid, toluenesulfonic acid, and camphorsulfonic acid. Examples thereof include sulfonic acids and polymer acids such as polystyrene sulfonic acid, polyacrylic acid, polyvinyl sulfonic acid, and poly-2-methylpropane-2-acrylamide sulfonic acid.
The reaction temperature of the polymerization reaction is preferably 50 ° C. or lower, more preferably −15 to 30 ° C., and further preferably −10 to 20 ° C. When the reaction temperature of the polymerization reaction is 50 ° C. or lower, particularly 30 ° C. or lower, it is possible to suppress the decrease in conductivity due to the progress of side reactions and the change in the redox structure of the main chain of the conductive polymer to be generated. If the reaction temperature of the polymerization reaction is −15 ° C. or higher, a sufficient reaction rate can be maintained and the reaction time can be shortened.

<Purification process>
In the polymerization step, the produced conductive polymer is obtained in a state (polymer solution) dissolved or dispersed in a polymerization solvent. The conductive polymer may be used for various purposes as it is after removing the polymerization solvent, but the polymer solution may contain impurities such as unreacted monomers and oligomers. Impurities in the conductive polymer may hinder the conductivity. For example, when the conductive polymer has an acidic group, the conductive polymer produced in the above polymerization step may form a salt with a cation, but the cation becomes a factor that inhibits conductivity.
Therefore, it is preferable to perform the process (purification process) which refine | purifies a conductive polymer after a superposition | polymerization process.
Since the purified conductive polymer has sufficiently removed low molecular weight substances such as monomers and oligomers and impurities such as cations, it exhibits more excellent conductivity.

Examples of the method for purifying the conductive polymer include a washing method using water or an organic solvent, a membrane filtration method, a cation exchange method, and the like, and can be appropriately selected depending on the object to be removed.
For example, when removing low molecular weight substances such as monomers and oligomers, by washing with a cleaning liquid (water, organic solvent, etc.) that is a good solvent for the low molecular weight substances and a poor solvent for the target conductive polymer, Low molecular weight can be removed.
As a method for removing (desalting) a cation, a method in which a conductive polymer dispersed or dissolved in a solvent (a dispersion or dissolved solution of a conductive polymer) is brought into contact with a cation exchange resin is preferable.
Solvents include alcohols such as water, methanol, ethanol, isopropanol, propanol, and butanol; ketones such as acetone, methyl ethyl ketone, ethyl isobutyl ketone, and methyl isobutyl ketone; ethylene glycol, ethylene glycol methyl ether, ethylene glycol mono-n- Ethylene glycols such as propyl ether; propylene glycols such as propylene glycol, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol butyl ether and propylene glycol propyl ether; amides such as dimethylformamide and dimethylacetamide; N-methylpyrrolidone, Pyrrolidones such as N-ethylpyrrolidone; methyl lactate, ethyl lactate, β-methoxyiso Methyl acid, hydroxy esters such as α- hydroxy methyl isobutyrate, and a mixture of these preferred.
As a density | concentration at the time of disperse | distributing or melt | dissolving a conductive polymer in the said solvent, 0.1-20 mass% is preferable from a viewpoint of industrial property or refinement | purification efficiency, and 0.1-10 mass% is more preferable.

Commercially available products can be used as the cation exchange resin, and for example, strong acid type cation exchange resins such as “Amberlite” manufactured by Organo Corporation are preferred.
The form of the cation exchange resin is not particularly limited, and various forms can be used. Examples thereof include spherical fine particles, membranes, and fibers.
The amount of the cation exchange resin relative to the conductive polymer is preferably 1 to 20 parts by mass and more preferably 5 to 15 parts by mass with respect to 1 part by mass of the conductive polymer from the viewpoints of industrial properties and purification efficiency.

As a method for contacting the dispersion or solution of the conductive polymer with the cation exchange resin, the dispersion or solution of the conductive polymer and the cation exchange resin are placed in a container, and the cation exchange is performed by stirring or rotating. The method of making it contact with resin is mentioned.
Further, the column is filled with a cation exchange resin as a filter medium, and the dispersion or solution of the conductive polymer is preferably passed at a flow rate of SV = 0.01 to 20, more preferably SV = 0.2 to 5. Alternatively, a method of performing cation exchange treatment may be used.
Here, space velocity SV (1 / hr) = flow rate (m ³ / hr) / filter medium amount (volume: m ³ ).

From the viewpoint of purification efficiency, the time for which the conductive polymer dispersion or solution is brought into contact with the cation exchange resin is preferably 0.1 hours or more, and more preferably 0.5 hours or more.
The upper limit of the contact time is not particularly limited, and may be appropriately set in accordance with conditions such as the concentration of the dispersion or eluent of the conductive polymer, the amount of the cation exchange resin, and the contact temperature described later.
From the industrial viewpoint, the temperature when the conductive polymer dispersion or solution is brought into contact with the cation exchange resin is preferably 10 to 50 ° C, more preferably 10 to 30 ° C.

<Effect>
The conductive polymer (a) of the present invention has high conductivity. Further, the conductivity is high in thermal stability, and sufficient conductivity is maintained even after heat treatment.
This is due to having the structural unit (1-A) based on the compound (1) of the present invention.
First, compound (1) has a structure in which —O—CH ₂ CH ₂ —O— is introduced into the benzene ring of aniline. —O—CH ₂ CH ₂ —O— is a substituent having a high electron-donating property, and its introduction improves the polymerizability. By improving the polymerizability, the conductive polymer (a) has a high molecular weight, and the conductivity is improved. In particular, when an acidic group or a salt thereof is contained, high conductivity is exhibited.
In addition, since -O-CH ₂ CH ₂ -O- is introduced to form a bicyclic ring skeleton (2,3-dihydro-1,4-benzodioxin skeleton), the compound (1) The flatness upon polymerization is improved. By improving the planarity, the molecules of the conductive polymer (a) can easily overlap each other, and can be doped not only within the molecule but also between the molecules to obtain high conductivity. In addition, the thermal stability is improved. For example, in the case of having an acidic group or a salt thereof, the acidic group or a salt thereof is difficult to be removed even by heat treatment, and the conductivity is reduced due to the elimination of the acidic group or a salt thereof. Hateful.

In addition, as a monomer, the conductive polymer obtained by polymerizing the compound (1) in which R ³ in the general formula (1) is a hydrogen atom has a structure represented by the following general formula (7). I think that.
In general formula (7), the structure in parentheses with x is a phenylenediamine structure (reduced type), and the structure in parentheses with 1-x is a quinodiimine structure (oxidized type).

［式中、ｘは、０〜１の数であり、ｙは重合度であり、Ｒ^１１〜Ｒ^１８はそれぞれ独立して、水素原子、ヒドロキシ基、炭素数１〜２４のアルキル基、炭素数１〜２４のアルコキシ基、アルデヒド基、アセチル基、酸性基またはその塩である。］

[Wherein, x is a number from 0 to 1, y is a polymerization degree, R ^{11 to} R ¹⁸ are each independently a hydrogen atom, a hydroxy group, an alkyl group having 1 to 24 carbon atoms, or a carbon number. 1 to 24 alkoxy groups, aldehyde groups, acetyl groups, acidic groups or salts thereof. ]

In the general formula (7), x represents the ratio of the phenylenediamine structure (reduced type) to the quinodiimine structure (oxidized type). x is preferably in the range of 0.2 <x <0.8, more preferably in the range of 0.3 <x <0.7, from the viewpoint of conductivity and solubility. The value of x can be arbitrarily converted to any value reversibly by oxidation or reduction.
Examples of the alkyl group, alkoxy group, acidic group, and salt thereof in R ^{11 to} R ¹⁸ are the same as those described in the description of R ¹ and R ^{2 in} the general formula (1-A-1). Can be mentioned.
R ¹¹ and R ¹² are preferably, similarly to R ¹ and R ² , at least one of them is an acidic group or a salt thereof, one is an acidic group or a salt thereof, and the other is a hydrogen atom. More preferably, R ¹¹ is particularly preferably a hydrogen atom and R ¹² is an acidic group or a salt thereof. The same applies to R ¹³ and R ¹⁴ , R ¹⁵ and R ¹⁶ , R ¹⁷ and R ¹⁸ .

The conductive polymer (a) of the present invention has good solubility in water and organic solvents, and is simply water, water containing bases and basic salts, water containing acids, organic solvents such as methanol, ethanol, and iso-propanol. Or a mixture thereof.
Therefore, the conductive polymer (a) of the present invention is excellent in processability.
For example, the conductor can be formed by a simple method such as dissolving the conductive polymer (a) of the present invention in a solvent, applying or impregnating the solution onto an arbitrary substrate, and drying.
It can be carried out by a known method such as application or impregnation of a solution, spray coating method, dip coating method, roll coating method, gravure coating method, reverse coating method, roll brush method, air knife coating method, curtain coating method.

Therefore, the conductive polymer (a) of the present invention can be used for various applications.
For example, the conductive polymer (a) of the present invention and a composition containing the same as the main component include various antistatic agents, capacitors, batteries, EMI shields, chemical sensors, display elements, nonlinear materials, anticorrosion, adhesives, fibers, It can be applied to antistatic paints, anticorrosion paints, electrodeposition paints, plating primers, electrostatic coating bases, anticorrosion, and improvement of battery storage capacity.
Among these, since the conductive polymer (a) of the present invention exhibits high conductivity, it is suitable for applications such as capacitors that require high conductivity.
As a method for using the conductive polymer (a) in the capacitor application, for example, a solution or dispersion containing the conductive polymer (a) is applied or impregnated on the metal electrode, and then a predetermined treatment (heating, etc.) is performed. And forming a conductive polymer layer (electrolyte layer).

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples.
In addition, the measurement / evaluation method in an Example and a comparative example is as follows.

(NMR measurement)
^The compound was identified by measuring ¹ H-NMR spectrum. This measurement is performed using a Fourier transform nuclear magnetic resonance apparatus (FT-NMR) (manufactured by JEOL Ltd., “JNM-GX270”) so that the concentration is about 5% by mass in deuterated water or deuterated dimethyl sulfoxide. The sample dissolved in was placed in a test tube having a diameter of 5 mmΦ, and the measurement was performed at a measurement temperature of 25 ° C., a measurement frequency of 270 MHz, and a single pulse mode with 64 integrations.

(Measurement of mass average molecular weight of conductive polymer)
First, sodium carbonate and sodium bicarbonate are mixed in a mixed solvent in which water (ultra pure water) and methanol are mixed so that the volume ratio is water: methanol = 8: 2, and the solid content concentration is 20 mmol / L. , 30 mmol / L was added to prepare an eluent. The resulting eluent had a pH of 10.8 at 25 ° C. In this eluent, the conductive polymer powder was dissolved so that the solid content concentration was 0.1% by mass to prepare a test solution.
About the obtained test solution, molecular weight distribution was measured using the polymeric material evaluation apparatus provided with the gel permeation chromatograph. Subsequently, about the obtained chromatogram, the retention time was converted into the molecular weight (M) of polystyrene sulfonate conversion, and the mass average molecular weight of the conductive polymer was obtained.

(Evaluation of thermal stability and conductivity)
A conductive polymer solution is applied onto a glass substrate using a spin coater, heated on a hot plate at a predetermined temperature for 10 minutes, and a test piece having a coating film (film thickness: about 100 nm) formed on the glass substrate is obtained. Obtained.
The surface resistance value at 20 ° C. of the obtained test piece was measured by attaching a two-probe probe to a resistivity meter (manufactured by Mitsubishi Chemical Analytech Co., Ltd., “Hiresta IP”).

[Example 1: Synthesis of compound]
<Step (a): Synthesis of 3-formyl-4-hydroxybenzenesulfonic acid>
In a 200 mL three-necked flask equipped with a thermometer and a condenser, 10.0 g (0.0819 mol) of salicylaldehyde and 40.0 g of concentrated sulfuric acid were added and stirred, and then 33.0 g of fuming sulfuric acid (containing 25 mass% sulfur trioxide) was added. In addition, the mixture was stirred, heated to 70 ° C., and aged for 2 hours. By treating the reaction solution with a sodium hydroxide / methanol solution, 6.57 g (yield 39.7%) of 3-formyl-4-hydroxybenzenesulfonic acid was recovered.

<(B) Step: Synthesis of 3-formyl-4-hydroxy-5-nitrobenzenesulfonic acid>
50.0 g of acetic acid was added to 5.00 g (0.0247 mol) of 3-formyl-4-hydroxybenzenesulfonic acid obtained in step (a) and stirred. Subsequently, after adding 21.5 g of fuming nitric acid, the temperature was raised to 30 ° C. and aged for 17 hours. The reaction solution was cooled and filtered to recover 2.97 g (yield 48.1%) of 3-formyl-4-hydroxy-5-nitrobenzenesulfonic acid.

<(C) Step: Synthesis of 3,4-dihydroxy-5-nitrobenzenesulfonic acid>
(B) 3-Formyl-4-hydroxy-5-nitrobenzenesulfonic acid 2.38 g (9.63 mmol) obtained in the step was added to a mixed solvent of 24.0 g of pure water and 24.0 g of methanol, and dissolved. 9.63 mL of 1N sodium hydroxide aqueous solution and 10.9 g of 30% hydrogen peroxide aqueous solution were added and stirred, heated to 50 ° C. and aged for 8 hours. The reaction solution was concentrated and filtered to recover 2.20 g of 3,4-dihydroxy-5-nitrobenzenesulfonic acid (yield 88.6%).

<Step (d): Synthesis of 2,3-dihydro-1,4-benzodioxin-5-nitro-7-sulfonic acid>
(C) 1.09 g (4.24 mmol) of 3,4-dihydroxy-5-nitrobenzenesulfonic acid obtained in the step was dissolved in 20.0 mL of dimethylformamide, to which 2.34 g of potassium carbonate and 2.00 g of dibromoethane were added. The mixture was stirred and aged at 80 ° C. for 38 hours. The reaction solution was filtered, and the filtrate was concentrated to recover 1.08 g (yield 89.9%) of 2,3-dihydro-1,4-benzodioxin-5-nitro-7-sulfonic acid.

<Step (e): Synthesis of 5-amino-2,3-dihydro-1,4-benzodioxin-7-sulfonic acid>
(C) 1.00 g (3.83 mmol) of 2,3-dihydro-1,4-benzodioxin-5-nitro-7-sulfonic acid obtained in step (c) was dissolved in 60.0 mL of pure water, and 5 mass% palladium. Carbon 0.595g was added. Thereafter, the internal pressure was increased to 0.70 MPa with hydrogen and aged at 50 ° C. for 6 hours. After completion of the reaction, palladium carbon was filtered off, and the reaction solution was concentrated under reduced pressure to give 0.436 g of 5-amino-2,3-dihydro-1,4-benzodioxin-7-sulfonic acid (yield 49.3%). Was recovered.
¹ H-NMR (270 MHz in D ₂ O): δ 4.30 (m, 4H), δ 7.46 (d, 1H), δ 785 (d, 1H).

[Example 2: Production of conductive polymer]
2.24 g (10 mmol) of ammonium peroxodisulfate (molecular weight 224.20) was stirred and dissolved in 25 g of water to prepare an oxidant solution.
Separately, 2.31 g (10 mmol) of 5-amino-2,3-dihydro-1,4-benzodioxin-7-sulfonic acid (molecular weight 231.23) as an aniline monomer was dissolved in 25 g of 1 mol / l hydrochloric acid. Then, an aniline monomer solution was prepared.
While the oxidant solution was cooled in an ice bath and stirred, the aniline monomer solution was dropped into the oxidant solution over 1 hour. After completion of the dropwise addition, stirring was continued for 12 hours under ice cooling. Subsequently, stirring was continued for 2 hours at room temperature (25 ° C.) to carry out a polymerization reaction. This obtained the reaction liquid containing a black deposit.
The obtained reaction solution was filtered, and the residue (black precipitate) was collected, washed with water, and then dried under reduced pressure. As a result, 0.50 g of poly (5-amino-2,3-dihydro-1,4-benzodioxin-7-sulfonic acid) (hereinafter referred to as conductive polymer (a-1)) was obtained.
This conductive polymer (a-1) had a mass average molecular weight of about 1,000.

0.200 g of the obtained conductive polymer (a-1) was dissolved in ammonia water having an ammonia concentration of 0.2 mol / L to prepare a conductive polymer solution.
Using this conductive polymer solution, thermal stability and electrical conductivity were evaluated (measurement of surface resistance value). The heating conditions for preparing the test piece were 120 ° C. × 10 minutes. The measurement result of the surface resistance was 3.59 × 10 ⁶ Ω / □. From this result, it has confirmed that a conductive polymer (a-1) had sufficient electroconductivity after a heating, and was useful as a conductive polymer.

Claims (4)

A compound represented by the following general formula (1).

[Wherein, R ^{1 to} R ³ are each independently a hydrogen atom, a hydroxy group, an alkyl group having 1 to 24 carbon atoms, an alkoxy group having 1 to 24 carbon atoms, an aldehyde group, an acetyl group, an acidic group or a salt thereof. And at least one of R ^{1 to} R ³ is a hydrogen atom. ] The compound according to claim 1, wherein in the general formula (1), at least one of R ¹ and R ² is an acidic group or a salt thereof, and R ³ is a hydrogen atom. The compound according to claim 2, wherein, in the general formula (1), ^one of R ¹ and R ² is an acidic group or a salt thereof, the other is a hydrogen atom, and R ³ is a hydrogen atom.   The electroconductive polymer obtained by polymerizing the monomer containing the compound as described in any one of Claims 1-3.