JPH0580509B2 - - Google Patents

Abstract

PURPOSE:To provide an electrically conductive polymer solution composed of an oxidized polymer of a specific aniline derivative, a dopant and an organic solvent, having high electrical conductivity, high stability in air and excellent safety, and useful as an electrolyte of battery, electrolyte of capacitor, etc. CONSTITUTION:An aniline derivative of formula I (R1-R4 are H, 1-5C alkyl or alkoxy; at least one of R1-R4 is not H), preferably an alkoxyaniline having >=2 substituent alkoxy groups is subjected to the electrolytic oxidation polymerization in the presence of a dopant comprising a salt containing Cl<->, I<->, BF4<->, etc., and the resultant polymer containing >=50mol% recurring unit of formula II is dissolved in an organic solvent (e.g. ketone, ether, ester, amide, etc.). As an alternative method, the aniline derivative is subjected to the chemical oxidation polymerization with an oxidizing strong acid (and peroxide), the polymer is doped with a dopant and the obtained dopant-containing oxidized polymer is dissolved in an organic solvent.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a conductive polymer solution, and more specifically, a conductive polymer solution useful as a battery electrolyte, a capacitor electrolyte, etc., which is composed of an oxidized polymer of a specific aniline derivative, a dopant, and an organic solvent. This invention relates to a conductive polymer solution. [Prior Art] It is known to obtain a conductive polymer by doping a polymer substance with a dopant, and polyacetylene or polyparaphenylene has been particularly studied in detail. By doping polyacetylene with AsF ₅ etc. as an acceptor and sodium etc. as a donor, p-type and n-type
It is known that conductive polymers of the shape can be obtained. Furthermore, it is known that by selecting and using various dopants from polyphenylene sulfide, polythiophene, polypyrrole, and polyaniline, conductive polymers exhibiting conductivity ranging from electrical insulators or semiconductors to metallic regions can be obtained. It has been revealed that the conductivity can be arbitrarily controlled by adjusting the type of dopant and the amount used. Therefore, these conductive polymers are expected to be used in applications such as solar cells, electrodes, and electrochromic devices. In addition, these known conductive polymers are expected to have a wide range of uses, such as for shielding electromagnetic waves, as computer control has begun to be used in automobiles, and they are also expected to be applied to various bonding elements and other electronic devices. ing. [Problems to be Solved by the Invention] However, among the conventionally known conductive polymers mentioned above, for example, polyacetylene, polyparaphenylene, polythiophene, polypyrrole, and polyaniline, these polymers themselves and their doped products There is no solvent that can dissolve both at once, and it is known that for polyparaphenylene sulfide and its doped products, AsF ₃ can be used as a solvent that dissolves both (Japanese Patent Application Laid-Open No. 59-1999).
-11324), AsF ₃ is known to be highly toxic, and furthermore, the electrical conductivity of the polymer solution decreases rapidly in the air, and the product cannot be used as an electrically conductive material. There is a drawback that it cannot be used as a As mentioned above, conventionally known conductive polymers, except for certain conductive polymers, are generally insoluble and infusible, which limits the possibility of melting or melting them to produce liquid conductive materials. , and also has the disadvantage that its uses are naturally limited. This has been an obstacle in researching various applications of conductive polymers, and solutions to these obstacles have been desired from various quarters. [Means for Solving the Problems] The present inventors have solved the above-mentioned conventional drawbacks, and have developed a method that has high electrical conductivity and good stability in air.
Moreover, as a result of intensive studies to obtain a conductive polymer solution with excellent safety in use, we found that an oxidized polymer of a specific aniline derivative has excellent solubility in organic solvents, and the resulting polymer solution meets the above objectives. We have found that this can be achieved very effectively and have arrived at the present invention. That is, the present invention provides general formula (1)

[Formula] (In the formula, R ₁ to _{R 4} may be different or the same and are a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group. However, all of R ₁ to _{R 4} may be at the same time Oxidized polymers of aniline derivatives represented by (never hydrogen atoms), 10 to 90 mol% Cl ^- per aniline derivative monomer unit,
I ^- , Br ^- , F ^- , BF ₄ ^- , ClO ₄ ^- , IO ₄ ^- , SbF ₆ ^- ,
PF ₆ ^- , SiF ₄ ^- , AsF ₆ ^- , HSO ₄ ^- , FSO ₄ ^- , SO ₄ ^2- ,
The present invention relates to a conductive polymer solution comprising at least one electron-accepting dopant selected from the group consisting of CF ₃ SO ₃ ^- , CF ₃ COO ^- and NO ₃ ^- and an organic solvent that dissolves an oxidized polymer of an aniline derivative. The oxidized polymer of aniline derivative used in the present invention is obtained by polymerizing the aniline derivative represented by the general formula (2).

[Formula] [However, R ₁ to _{R 4} are the same as in the above general formula (1). ] It is an organic solvent-soluble polymer containing at least 50 mol% of the repeating unit represented by the formula. If the repeating unit represented by the general formula (2) is less than 50 mol%, the electrical conductivity is insufficient. Specific examples of the aniline derivative having no substituent at the p-position represented by general formula (1) include 2-methoxy-aniline, 3-methoxy-aniline, 2,3-
Dimethoxy-aniline, 2,5-dimethoxy-aniline, 3,5-dimethoxy-aniline, 2,6
-dimethoxy-aniline, 2-ethoxy-aniline, 2-ethoxy-3-methoxy-aniline, 3
-ethoxy-aniline, 2,3-diethoxy-aniline, 2,5-diethoxy-aniline, 2,6
-diethoxy-aniline, 3,5-diethoxy-
Aniline, 2,6-diethoxy-aniline, 2-
Methoxy-3-ethoxy-aniline, 2-methoxy-5-ethoxy-aniline, 2,3,6-trimethoxy-aniline, 2,3,5-trimethoxy-aniline, 2,3,5,6-tetramethoxy-
Aniline, 2,3,5,6-tetraethoxy-aniline, 2,3-dimethyl-aniline, 2-methyl-3-methoxy-aniline, 2,3,5,6-
Examples include, but are not limited to, tetramethyl-aniline, 2-methyl-5-methoxy-aniline, 3,5-dimethyl-aniline, and the like. Among the above-mentioned aniline derivatives, those having two or more substituents are preferable, and in particular, oxidized polymers of alkoxyaniline having two or more alkoxy group substitutions have good solubility in organic solvents and have good electrical conductivity. It can be preferably used from a high place. The oxidized polymer of aniline derivative may be produced by any method. Examples of oxidized polymers of aniline derivatives include oxidized polymers of aniline derivatives, dopant-containing oxidized polymers doped with a dopant after the production of oxidized polymers of aniline derivatives, and dopants obtained by oxidative polymerization of aniline derivatives in the presence of a dopant. Containing oxidized polymers, etc. Among the above-mentioned oxidized polymers of aniline derivatives, oxidized polymers containing a dopant in advance are preferable because there is no need to further blend a dopant when preparing the conductive polymer solution of the present invention. Depending on the amount of dopant contained in the coalescence, a dopant may be further added during preparation of the conductive polymer solution. The oxidized polymer of the aniline derivative doped with a dopant can be produced by electrochemically or chemically oxidatively polymerizing the aniline derivative. In the case of electrochemical polymerization, the polymerization of aniline derivatives is carried out by anodic oxidation, with a current of about 0.01-50 mA/
cm ² , the electrolytic voltage is usually in the range of 1 to 300 V, and a constant current method, a constant voltage method, and any other method can be used. Polymerization is carried out in an aqueous solution, an alcoholic solvent, or a mixed solvent thereof,
Preferably, it is carried out in an aqueous solution. The alcohol may or may not dissolve the produced oxidized polymer. The alcohol used varies depending on the type of aniline derivative, but methyl alcohol, ethyl alcohol, ethylene glycol, propyl alcohol, butyl alcohol, etc. are usually used. There is no particular restriction on the pH of the suitable electrolytic solution, but the pH is preferably 3 or less, particularly preferably 2 or less. Specific examples of acids used for pH adjustment include
Examples include, but are not limited to, HCl, HBF ₄ , CF ₃ COOH, H ₂ SO ₄ and HNO ₃ . Dopants used when polymerizing the above aniline derivative by electrochemical method include Cl ^- , I ^- ,
Br ^- , F ^- , BF ^- ₄ , ClO ^- ₄ , IO ^- ₄ , AsF ^- ₆ , SbF ^- ₆ ,
PF ^- ₆ , SiF ^- _{4 ,} AsF ^- ₆ , FSO ^- ₄ , HSO ^- ₄ , ^SO2-4 , _CF3
Salts containing groups such as SO ^- ₃ , CF ₃ COO ^- and NO ^- ₃ are used, and the resulting oxidized polymer contains these anions as p-type dopants. These salts contain cations such as alkali metal ions such as lithium, sodium, and potassium, and quaternary ammonium ions. The oxidized polymer thus obtained usually contains 10 to
90 mol % (per monomer unit) of anions are included as dopants. According to the electrochemical method, the oxidized polymer is usually deposited as a black polymer on the anode, and after washing, peeling, and drying, the oxidized polymer is dissolved in an organic solvent and used for various purposes. In the case of chemical polymerization, for example, aniline derivatives can be oxidatively polymerized in aqueous solution with oxidizing strong acids or with a combination of strong acids and peroxides such as potassium persulfate. Since the oxidized polymer obtained by this method can be obtained in powder form, it can be separated and dried before use. In this case too, the oxidized polymer is obtained doped with the corresponding anion. The resulting oxidized polymer usually contains 10 to 90 mol % (per monomer unit) of an anion as a dopant. The oxidized polymer of the aniline derivative obtained by separation and drying is dissolved in an organic solvent in which the polymer is dissolved to obtain a polymer solution, which can be used for various purposes. As the dopant used in the present invention, the same dopants as those used in the oxidative polymerization of aniline derivatives are used. The amount of the dopant to be blended depends on whether the oxidized polymer of the aniline derivative used contains the dopant in advance,
Although it cannot be determined unconditionally because it differs depending on whether the aniline derivative is contained or not, it is usually blended so that the proportion of the dopant in the oxidized polymer of the aniline derivative is 10 to 90 mol% (per monomer unit). The organic solvent used to dissolve the oxidized polymer of the aniline derivative varies depending on the type of the oxidized polymer of the aniline derivative used, so it cannot be specified specifically, but it must be one that can dissolve the oxidized polymer of the aniline derivative. Aliphatic and aromatic ketones, ethers, esters, amides, nitriles, carbonates, carboxylic acids, halogen compounds, sulfolane compounds, nitro compounds, sulfoxides, lactams, lactones, Examples include saturated and unsaturated heterocyclic compounds. Aliphatic and aromatic ketones include acetone, diethyl ketone, methylpropyl ketone, hydroxyacetone, methoxyacetone, phenylacetone, 4-phenylbutanone-2, etc.; ethers include tetrahydrofuran, dioxane, dimethyl ether, diethyl ether , methyl-ethyl ether, dimethoxyethane, diethoxymethane, methyl glycol, anisole,
1,2-dimethoxybenzene, 1,4-dimethoxybenzene, 1,3-dioxolane, etc.; As esters, methyl acetate, ethyl acetate, trimethyl orthoformate, ethyl oxalate, trimethyl phosphate, etc.; as amides Examples of nitriles include formamide, N-methylformamide, dimethylformamide, N-methylacetamide, dimethylacetamide, N-methylpropioamide, hexamethylphosphoramide, etc.
Acetonitrile, valeronitrile, benzonitrile, etc.; Carbonates include propylene carbonate, ethylene carbonate, dimethyl carbonate, etc.; Carboxylic acids include formic acid, acetic acid, benzoic acid, oxalic acid, etc.; Halogen compounds include chloroform, carbon tetrachloride, etc. , chlorobenzene, dichlorobenzene, benzoyl chloride, benzoyl bromide, benzenesulfonyl chloride, benzenesulfonyl dichloride, benzenethiophosphonyl dichloride, methanesulfonyl chloride, acetyl chloride, dimethylsulfamyl chloride, ethyloxalyl chloride, chlorosulfonylacetyl chloride, etc.; Examples of sulfolane compounds include sulfolane and 3-methyl-sulfolane; examples of nitro compounds include nitromethane and nitrobenzene; examples of sulfoxides include dimethylsulfoxide; and examples of lactams include N-
Methylpyrrolidone, etc.; Lactones include γ-
Butyrolactone, etc.; examples of saturated and unsaturated heterocyclic compounds include tetrahydrothiophene, 3-methyl-2-oxazolidone, pyrrole, 1-methylpyrrole, 2,4-dimethylthiazole, furan, and the like. Methods for preparing the conductive polymer solution of the present invention include () a method of dissolving an anion-doped oxidized polymer obtained by electrochemical oxidative polymerization in the above-mentioned organic solvent; A method of dissolving the obtained anion-doped oxidized polymer in the above-mentioned organic solvent; (2) A method in which a chemically synthesized oxidized polymer that is not doped with an anion is dissolved in the above organic solvent, and a dopant is added to this solution. It is not limited to this method. The concentration of the oxidized polymer of the aniline derivative in the polymer solution is not particularly limited, but is usually used in the range of 0.01 to 90% by weight. The electrical conductivity of the conductive polymer solution obtained in this way varies depending on the type of oxidized polymer used and the concentration of the oxidized polymer of the aniline derivative in the solution, but is usually 10 ^-5 to ^{10 -1} s/ It is in the cm range. [Effects of the Invention] The conductive polymer solution of the present invention is non-toxic, has excellent stability in air, and has high electrical conductivity, so it is extremely useful as a battery electrolyte, a capacitor electrolyte, etc. It is. [Example] Hereinafter, the present invention will be explained in more detail by referring to Examples and Comparative Examples. Example 1 A 1.5 mol HBF ₄ aqueous solution was placed in a glass reaction vessel.
20 ml and 0.35 mol of 2,5-dimethoxy-aniline to prepare an aqueous solution with pH<1.0. Two platinum electrodes each having an electrode area of 10 cm ² were inserted into this aqueous solution at a distance of 2 cm, and then 20 clones of electricity was applied under stirring to carry out electrolytic oxidation polymerization. On this occasion,
A black oxidized polymer was deposited on the platinum electrode of the anode. After the electrolytic polymerization was completed, the coated anode was washed with distilled water and vacuum dried at 70°C. The polymer was then peeled off from the platinum electrode. From elemental analysis, this polymer was found to have a
It was found that 0.45 mol of BF ^- ₄ was doped. Infrared spectroscopy and NMR revealed that this polymer contained 80 mol% or more of repeating units having the structure of general formula (2). Next, the obtained polymer was dissolved in acetonitrile to prepare a polymer solution having a polymer concentration of 30% by weight. The electrical conductivity of the obtained polymer solution at room temperature was 5.2×10 ⁻³ s/cm. Further, after the obtained polymer solution was left in the air for one month, the electrical conductivity was measured again and it was found to be 5.0×10 ^-3 s/cm, with almost no change in electrical conductivity. Examples 2-4 2,5 used as aniline derivative in Example 1
Electropolymerization was carried out in exactly the same manner as in Example 1, except that the aniline derivatives shown in the table were used instead of -dimethoxy-aniline, to prepare a polymer solution. The physical property values of the obtained polymer solution are shown in the table. In addition, according to infrared spectra and NMR, each polymer contains 80 mol% of repeating units with the structure of general formula (2).
It included the above.

[Table] Comparative Example An oxidized polymer of aniline was obtained by electropolymerization in exactly the same manner as in Example 1, except that aniline was used instead of 2,5-dimethoxy-aniline used in Example 1. , this polymer was insoluble in organic solvents. Example 5 Chemical synthesis of poly-2,5-dimethoxy-aniline 1 Purification of monomer: Under Ar, Zn powder was added and recrystallization was performed with ethanol. 2 Polymerization: Attach a thermometer, stirrer, and condenser to the four-necked flask from 1, and add
500 ml of HBF ₄ aqueous solution was added and cooled to 22°C on ice. To this was dissolved 33.62 g of 2,5-dimethoxy-aniline (0.2195 mol). To this, while stirring, ammonium persulfate 11.5g
(0.05 mol) was added as a solid, and within 2 minutes after addition, a blue color began to form and a dark blue precipitate formed. Since this was an exothermic reaction, the reaction solution was kept at 22°C by cooling with ice during this time. After reacting for 1 hour, the reaction solution was filtered, and the residue was washed with 250 ml of 42% _HBF4 aqueous solution for 10 minutes under normal pressure.
Passed under reduced pressure. Furthermore, add 500ml of distilled water to this residue.
ml under strong vacuum for 10 minutes. Elemental analysis and IR measurements of this product revealed that it had the same composition and structure as the poly-2,5-dimethoxy-aniline obtained by electropolymerization in Example 1. In addition, from the results of elemental analysis, this oxidized polymer has a
It was found that 0.49 mol of BF ^- ₄ was doped. A polymer solution was prepared in exactly the same manner as in Example 1 except that the oxidized polymer obtained by the above method was used. The electrical conductivity of this polymer solution at room temperature is
It was 4.7×10× ^-3 s/cm. Further, after the obtained polymer solution was left in the air for one month, the electrical conductivity was measured again and found to be 4.6×10 ^-3 s/cm.

Claims (1)

[Claims] 1 General formula (1) [Formula] (In the formula, R ₁ to _{R 4} may be different or the same and are a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group (However, R ₁ to _{R 4} are not all hydrogen atoms at the same time.) Oxidized polymer of aniline derivative represented by 10 to 90 mol% Cl ^- per aniline derivative monomer unit,
I ^- , Br ^- , F ^- , BF ₄ ^- , ClO ₄ ^- , IO ₄ ^- , SbF ₆ ^- ,
PF ₆ ^- , SiF ₄ ^- , AsF ₆ ^- , HSO ₄ ^- , FSO ₄ ^- , SO ₄ ^2- ,
A conductive polymer solution comprising at least one electron-accepting dopant selected from the group consisting of CF ₃ SO ₃ ^- , CF ₃ COO ^- , and NO ₃ ^- and an organic solvent that dissolves an oxidized polymer of an aniline derivative. 2 An oxidized polymer of an aniline derivative has the general formula (2) [Formula] (wherein R ₁ to _{R 4} may be different or the same, and are a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group) (However, R ₁ to _{R 4} are not all hydrogen atoms at the same time.) Claim 1 is an organic solvent-soluble polymer containing at least 50 mol% of the repeating unit represented by The conductive polymer solution described in . 3. The conductive polymer solution according to claim 1, wherein the oxidized polymer of the aniline derivative is an organic solvent-soluble dopant-containing oxidized polymer produced by an electrolytic oxidative polymerization method. 4 The oxidized polymer of aniline derivative is an oxidizing strong acid,
Alternatively, the conductive polymer solution according to claim 1, which is an organic solvent-soluble dopant-containing oxidized polymer produced by a chemical oxidative polymerization method using a combination of a strong oxidizing acid and a peroxide. 5 Ketones whose organic solvent is aliphatic and aromatic,
Ethers, esters, amides, nitriles, carbonates, carboxylic acids, halides, sulfolane compounds, nitro compounds, sulfoxides, lactams, lactones, saturated and unsaturated heterocyclic compounds, or these The conductive polymer solution according to claim 1, which is a mixture of two or more of the following.