JP2649670B2 - Method for producing conductive organic polymer - Google Patents

Description

The present invention relates to a method for producing a novel conductive organic polymer,
Specifically, the present invention relates to a method for producing a novel conductive organic polymer obtained by chemical oxidative polymerization of aniline.

(Prior Art) Most organic materials are electrically insulating, however,
A group of organic polymers having conductivity, known as organic semiconductors, has recently attracted attention. In general, organic substances that are themselves conductive are classified into three types. The first is graphite. Although graphite is not strictly regarded as an organic substance, it can also be considered to have an organic conjugated ultimate structure. The graphite itself has a considerably high conductivity by itself, but by intercalating various compounds with the graphite, it can be made to have a higher conductivity, and finally becomes a superconductor. However, graphite has a strong two-dimensional property and is difficult to mold, and thus has an obstacle in its application.

The second is a charge transfer complex. For example, a crystalline substance obtained by using tetrathiafulvalene and tetracyanoquinodimethane as an electron donor and an electron acceptor, respectively, has a very large conductivity of 400 to 500 S / cm at room temperature. Has the property,
Since such a charge transfer complex is not a polymer, there is a problem in moldability as in the case of graphite for practical application.

The third is a π-electron conjugated organic polymer which has high conductivity by doping, as represented by polyacetylene. The conductivity of polyacetylene before doping is 10 ⁻⁵ S / cm for the trans type and 10 ⁻⁹ S / cm for the cis type, and has properties similar to those of semiconductors and insulators. However, by doping such polyacetylene with an electron-accepting compound such as arsenic pentafluoride, iodine, sulfur trioxide, or ferric chloride or an electron-donating compound such as an alkali metal, a p-type semiconductor can be obtained. And an n-type semiconductor can be formed, and high conductivity at a conductor level as high as 10 ³ S / cm can be provided. The above-mentioned polyacetylene is a conductive organic polymer which is theoretically interesting. However, on the other hand, polyacetylene is extremely susceptible to oxidation, and is easily oxidized and degraded in the air to greatly change properties. In the doped state, it is more susceptible to oxidation, and even a small amount of moisture in the air causes a sharp decrease in conductivity. This tendency is particularly remarkable for n-type semiconductors.

In addition, poly (p-phenylene) and poly (p-phenylene sulfide) also have conductivity before doping of 10 ⁻⁹ S / cm and 10 ⁻¹⁶ S / cm, respectively. By doping with arsenic, a conductive organic polymer having a conductivity of 500 S / cm and 1 S / cm, respectively, can be obtained. The electrical properties of these doped organic polymers are also more or less unstable.

The fact that the electrical properties of conductive organic polymers doped in this way are generally very unstable with respect to the environment is a phenomenon common to these types of conductive organic polymers and it is important to note that these practical It is an obstacle for various applications.

As described above, various organic conductive substances have been conventionally known, but from the viewpoint of developing practical applications thereof, a polymer form having excellent moldability is preferable.

On the other hand, studies on oxidized polymers of aniline as oxidation dyes have been conducted for a long time in connection with aniline black. In particular, as an intermediate for the production of aniline black, an octameric aniline represented by the formula (I) has been identified as emeraldine (AGGree).
n et al., J. Chem. Soc., 97 , 2388 (1910); 101, 1117 (19
12)), which is soluble in 80% acetic acid, cold pyridine and N, N-dimethylformamide. This emeraldine is also oxidized in an ammoniacal medium to produce nigraniline of formula (II), which is also known to have similar dissolution characteristics to emeraldine.

Furthermore, in recent years, it has been found by R. Buvet et al. That the sulfate of this emeraldine has high conductivity (J. Polymer Sci., C, 16 , 2931; 2943 (1967); Two
2 , 1187 (1969)).

It is also known that an organic substance similar to emeraldine can be obtained by electrolytic oxidation polymerization of aniline (DM Mohilner et al., J. Amer. Chem. Soc., 84 , 36).
18 (1962)). That is, according to this, a sulfuric acid aqueous solution of aniline is used with a platinum electrode to avoid electrolysis of water.
Electrolytic oxidative polymerization at an oxidation potential of +0.8 V relative to a standard calomel electrode yields a substance that is soluble in 80% acetic acid, pyridine and N, N-dimethylformamide.

In addition, Diaz et al. (J. Electroanal. Chem., 111, 111 (1
980) and Koyama et al. (Proceedings of the Society of Polymer Science, 30 , (7), 1524)
(1981); J. Electroanal. Chem., 161, 399 (1984)) have also attempted electrolytic oxidative polymerization of aniline.
The operation is performed at the following potential.

(Object of the Invention) The present inventors have conducted intensive studies on oxidative polymerization of aniline and its derivatives in order to obtain a stable and highly conductive organic polymer. By doing so, it has a much higher molecular weight than the above emeraldine, and is stable and has high conductivity without requiring a new doping operation because it is already doped in the oxidative polymerization step. It has been found that an organic polymer can be obtained (Japanese Patent Application No. 58-212280 and Japanese Patent Application No. 58-212281).

Subsequently, the inventors of the present invention have conducted further studies and found that the conductive organic polymer is a substantially linear high molecular weight polymer having a quinone diimine structure as a main repeating unit (Japanese Patent Application No. 59-198873). ), The inventors have found that it is necessary to use a certain group of oxidizing agents in order to obtain such a highly conductive organic polymer, leading to the present invention.

(Constitution of the Invention) The present invention provides a compound represented by the general formula: A substantially linear polymer having a quinone diimine structure represented by the following formula as a main repeating unit, containing an electron acceptor as a dopant, having a conductivity of 10 ^-6 S / cm or more, and containing 80% acetic acid and In a method for producing a conductive organic polymer which is insoluble in N, N-dimethylformamide, an oxidizing agent having a standard electrode potential of 0.6 to 1.78 V defined as an electromotive force in a reduction half-cell reaction based on a standard hydrogen electrode. (Excluding dichromate), while oxidizing aniline while cooling with ice water.

In the present invention, aniline includes its salt.

According to the method of the present invention, a conductive organic polymer obtained by oxidative polymerization of aniline has a general formula Is a substantially linear polymer having a quinone diimine structure represented by the following formula as a main repeating unit, containing an electron acceptor present in a reaction system as a dopant, and having an electric conductivity of 10 ^-6 S / cm or more. .

Such an oxidized aniline polymer produced by the method of the present invention usually shows green to blackish green in a dry powder state, and generally shows a brighter green color as the conductivity is higher. However, a molded product obtained by pressure molding usually shows a glossy blue color.

The conductive organic polymer according to the method of the present invention is insoluble in water and most organic solvents, but usually contains a portion that is slightly soluble or soluble in concentrated sulfuric acid. The solubility in concentrated sulfuric acid varies depending on the reaction method and reaction conditions for producing the polymer, but as described below, a conductive organic polymer obtained by oxidative polymerization of aniline with a chemical oxidizing agent is Usually 0.2
~ 10% by weight, in most cases 0.25-5% by weight
Range. However, this solubility should be understood as including a portion having a solubility in the above range, especially in the case of a high molecular weight polymer. As described above, emeraldine is 80% acetic acid, cold pyridine and N, N-
This is in marked contrast to being soluble in dimethylformamide.

The polymer according to the present invention has a 0.5 g / dl solution of 97% concentrated sulfuric acid in 3 g.
It has a logarithmic viscosity in the range of 0.1 to 1.0 at 0 ° C, most often 0.2 to 0.6. Also in this case, especially in the case of high molecular weight polymers, it should be understood that the portion soluble in concentrated sulfuric acid has a logarithmic viscosity in the above range.
In contrast, the logarithmic viscosities of emeraldine and aniline black under the same conditions are 0.02 and 0.005, respectively, indicating that the polymer according to the invention is a high molecular weight polymer. Further, the results of the differential thermal analysis indicate that the polymer according to the present invention is a high molecular weight polymer.

FIG. 1 shows an infrared absorption spectrum of a conductive polymer obtained by oxidative polymerization of aniline as a typical example of the polymer according to the present invention. For comparison, emeraldine and aniline black (a commercially available diamond 2 and 3 show the infrared absorption spectrum of (black).

The infrared absorption spectrum of the conductive polymer according to the present invention is similar to that of emeraldine, while in the polymer according to the present invention, the C-H out-of-plane bending vibration of monosubstituted benzene which is clearly observed in emeraldine is shown. , Whereas absorption based on para-substituted benzene is relatively large. That is, the numerical ratio Bt / B of the monosubstituted benzene Bt located at the terminal in the polymer chain and the benzene ring B located at a position other than the terminal in the polymer chain.
Is small. However, the spectrum of the polymer according to the method of the present invention is significantly different from the aniline black. Therefore, the polymer according to the method of the present invention has a structure other than emeraldines containing a large number of para-substituted benzenes.

The polymers according to the process of the invention are doped by electron acceptors present in the system during the oxidative polymerization of aniline and, as a result, have a high conductivity. That is, charge transfer from the polymer to the electron acceptor occurs, forming a charge transfer complex between the polymer and the electron acceptor. When the polymer according to the present invention is formed into a disk shape, for example, and a pair of electrodes are attached thereto, and a temperature difference is applied between the electrodes to generate a thermoelectromotive force specific to the semiconductor, the low-temperature electrode side is positive, and the high-temperature electrode is high. The side gives a negative electromotive force, indicating that the polymer according to the invention is a p-type semiconductor.

Further, the polymer according to the present invention has a significantly reduced conductivity due to chemical compensation with ammonia or the like, and also changes in appearance from black green to purple, which is again converted to an electron acceptor such as sulfuric acid. By doping in the body, the color returns to black-green and restores the original high conductivity. This change is reversible and the same result can be obtained by repeated chemical compensation and doping. FIG. 4 shows the change in the infrared absorption spectrum of the polymer due to the chemical compensation and re-doping. A indicates the original polymer, B indicates the chemically compensated polymer, and C indicates the undoped polymer. It is clear that the spectrum of C almost completely matches A.
Therefore, the chemical compensation and re-doping are not changes in the skeletal structure of the polymer, but transfer of electrons between the polymer and the chemical compensating reagent or electron acceptor. In this way, it is understood that the polymer according to the invention is doped at the electron acceptor during the oxidative polymerization stage, and thus the polymer according to the invention contains a dopant.

As the dopant contained in the conductive polymer according to the present invention, for example, chlorine, bromine, halogen such as iodine, ferric chloride, tin tetrachloride, Lewis acid such as copper dichloride, hydrogen chloride,
Hydrogen bromide, sulfuric acid, inorganic acids such as nitric acid and picric acid, organic acids such as p-toluenesulfonic acid can be mentioned,
It is not limited to these.

The chemical structure of the conductive organic polymer according to the present invention can be confirmed by elemental analysis of the polymer in addition to the infrared absorption spectrum described above. , A compensation polymer.)
Elemental analysis confirmed that the polymer was substantially a linear high-molecular polymer composed of the above-mentioned repeating units, and that the π-electron conjugated system had high conductivity due to the inclusion of the dopant.

However, the polymer according to the method of the present invention comprises, together with the repeating unit having the quinone diimine structure, the following repeating unit (IV) having a reduced structure thereof: May be included. A polymer containing such a reduced structure can be easily obtained, for example, by partially reducing the polymer according to the present invention. In addition, the (II
The conductive organic polymer having a repeating unit represented by the formula (I) according to the method of the present invention is reduced with a reducing agent, and the above-mentioned (IV)
After obtaining a reduced structure polymer having a repeating unit represented by the formula, the conductive organic polymer can be obtained by the method of the present invention by re-oxidizing with a oxidizing agent effective as an electron acceptor.

As described above, the conductive organic polymer obtained by the oxidative polymerization of aniline according to the method of the present invention preferably comprises substantially the above-mentioned repeating unit, and at the polymerization stage, already contains a protonic acid or the like. Since it is doped with a dopant, it has high conductivity without requiring a new doping treatment, and its conductivity does not change even if left in air for a long period of time. However, it has a specifically high stability as compared with a conventionally known doped conductive organic polymer.

The method for producing a conductive organic polymer according to the present invention is characterized in that, when aniline is chemically oxidized and polymerized with a chemical oxidizing agent, the oxidizing agent has a standard electrode potential of 0.6 to 1.78 V determined by a reduction process based on a standard hydrogen electrode. (Excluding bichromate) and, if necessary, an oxidant liquid containing a proton donor. Here, the standard electrode potential is 1.78V
Examples of the oxidizing agent include hydrogen peroxide as described below.

In the present invention, aniline or a salt thereof is used as a starting material. The aniline salt is not particularly limited as long as it is dissolved in the reaction medium. For example, when the reaction medium is water, a water-soluble salt of an inorganic acid is preferably used. Usually, mineral salts such as hydrochloric acid and sulfuric acid are suitable, but not limited thereto.

Generally, as an index indicating the strength of the oxidizing power of the oxidizing agent,
The standard electrode potential is known. This standard electrode potential is
The oxidizing agent obtains electrons from the oxide to be oxidized, and considers the chemical reaction when it is reduced as a half-cell composed of electrodes that accept electrons from an external circuit, and refers to the magnitude of the electromotive force of the half-cell in this case. Therefore, the oxidizing power of the oxidizing agent can be quantified by using the standard electrode potential. As is well known in the field of electrochemistry, as a reference electrode for such a standard electrode potential, a hydrogen pressure is 1 atm and a hydrogen ion activity in a solution is a unit activity. The standard electrode potential is determined by using a standard hydrogen electrode and setting the potential of the standard hydrogen electrode to 0V.

In the present invention, the standard electrode potential is defined as an electromotive force in a reduction half-cell reaction based on a standard hydrogen electrode.

That is, in general, the oxidizing agent Ox obtains the electron e ⁻ and becomes an reducing agent Red, and the electrode reaction E. The electrode potential E in Ox + ne ⁻ → Red is given by the following Nernst equation with the standard electrode potential as E ^0. .

(Where F is the Faraday constant, n is the number of electrons involved in the reaction, a is the activity, R is the gas constant, and T is the absolute temperature.) Here, the standard state where all the activities a are 1 In E, E = E ^{0 because} the logarithmic term in the above equation becomes 0. That is, the electrode potential E is equal to the standard electrode potential E ^0.

Strictly, it is necessary to calculate the potential of the oxidizing agent in the reaction system under the actual oxidative polymerization conditions by considering the logarithmic term including the activity according to the above-mentioned Nernst equation. Therefore, when selecting an oxidizing agent, the order of the oxidizing power of the oxidizing agent substantially corresponds to the order of the standard electrode potential, and thus the potential in the standard state without the activity term, that is,
Even if a standard electrode potential is used, there is substantially no problem.

In the method of the present invention, when a proton is involved in the reduction half-cell reaction, such as hydrogen peroxide, the standard electrode potential is determined by the standard electrode potential in a reaction involving protons, and aniline is oxidized. In the polymerization reaction, a proton donor for supplying a required amount or more of protons, typically a protonic acid such as sulfuric acid or hydrochloric acid, is present in the reaction system. Conversely, cerium (IV) salts do not involve protons in their reduction half-cell reactions. Therefore, when these are used as the oxidizing agent in the method of the present invention, the presence of a proton donor in the reaction system is not required, but the presence of the proton donor in the reaction system may be any effect. In order to impart high conductivity to the organic polymer obtained by the reaction, it may be preferable that a proton donor is present.

Such a standard electrode potential is described, for example, in "CRC Handbook of Chemistry and Physics".
(CRC Press Co.) D-155 to D-160, and the Electrochemical Association, "Electrochemical Handbook" (Maruzen Co., Ltd.), pp. 71-74.

Furthermore, in the method of the present invention, when an oxidizing agent having a high standard electrode potential is used, it is desirable to select and use a protonic acid. For example, when using chlorine and bromine whose standard electrode potentials are 1.36 V and 1.09 V, respectively, as the oxidizing agent, when using hydrochloric acid or hydrobromic acid as the protic acid,
The reaction of 2Cl ⁻ → Cl ₂ + 2e ⁻ 2Br ⁻ → Br ₂ + 2e ⁻ occurs in preference to the oxidation of aniline, and the conductivity and yield of the resulting conductive organic polymer are reduced. Preferably, sulfuric acid is used.

Table 1 shows reduction half-cell reactions of various oxidizing agents at 25 ° C. and their standard electrode potentials, applicability in the method of the present invention, and conductivities of the obtained conductive organic polymers.

From these results, it is understood that a conductive organic polymer having a conductivity of 10 ⁻⁶ S / cm or more can be obtained by using an oxidizing agent having a standard electrode potential of 0.6 to 1.78 V. The results shown in Table 1 are obtained when aniline hydrochloride is oxidatively polymerized in an aqueous solution using an oxidizing agent. The condition of oxidative polymerization is that protonic acid is present in the reaction system. Since a highly conductive polymer is easily obtained, a sufficient amount of sulfuric acid for the oxidizing agent is added to the reaction system.

As is evident from the results shown in Table 1, in the present invention, oxidizing agents that can be suitably used include, for example, potassium ferricyanide (potassium hexacyanoferrate (III)), potassium hexachloroplatinate (IV), and sodium iodate. Manganese dioxide, cerium ammonium nitrate (ammonium hexanitratocerate (IV)), sodium chlorate, lead dioxide, potassium permanganate and hydrogen peroxide.

In the present invention, water is used as a reaction medium.

A particularly preferred method for producing the conductive organic polymer according to the present invention is a method in which aniline is dissolved in a reaction medium, and an oxidizing agent solution is gradually added to the solution to carry out oxidative polymerization. However, the required amount of the oxidizing agent solution may be added at a time to the solution in which aniline is dissolved. Further, a solution in which aniline is dissolved in an oxidant solution may be added. As described above, when the proton donor needs to be present in the reaction system, it may be contained in the aniline solution and / or the oxidant solution.

 The reaction is performed while cooling with ice water.

In the method of the present invention, a polymer precipitates immediately after an induction period of usually about several minutes after the start of the reaction. As described above, the reaction is completed immediately, but usually the mixture may be stirred for several minutes to several hours for aging. Next, the reaction mixture is poured into a large amount of water or an organic solvent, the polymer is separated by filtration, washed with water until the filtrate becomes neutral, and then washed with an organic solvent such as acetone until the color is no longer colored. Drying gives the conductive organic polymer according to the invention.

(Effects of the Invention) As described above, according to the method of the present invention, aniline is oxidatively polymerized using an oxidizing agent having a standard electrode potential of 0.6 to 1.78 V to form a main repeating unit having a quinone diimine structure. Is a substantially linear high molecular weight polymer having a high conductivity without the necessity of a new doping operation because it has already been doped in the oxidative polymerization step. When left in air for a long time, its conductivity does not change at all, and the conductive organic polymer has a specific high stability as compared with conventionally known conductive organic polymers. Coalescence can be obtained.

(Examples) Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. still,
As a reference example, an example using potassium dichromate as an oxidizing agent to show the chemical and physical properties of the conductive organic polymer according to the present invention will be described.

Reference Example (Example of using potassium dichromate having a standard electrode potential of 1.33 V in an aqueous solution in the presence of a protonic acid) (1) Production of polymer 45 g of water was placed in a 300 ml flask, and 4 ml of concentrated hydrochloric acid was added. Further, 5 g (0.0537 mol) of aniline was dissolved to prepare an aniline hydrochloride aqueous solution, and the flask was cooled with ice water.

Separately, 4.61 g (0.047 mol) of concentrated sulfuric acid was added to 28.8 g of water,
Further, an oxidizing agent aqueous solution (protonic acid / potassium dichromate molar ratio 7.5) in which 1.84 g (0.00625 mol) of potassium dichromate was dissolved was prepared, and this was stirred in an aqueous solution of the above aniline hydrochloride cooled with ice water. It took 30 minutes to drop from the dropping funnel. After the start of the dropping, the solution was only colored yellow for the first few minutes, after which a green solid was immediately precipitated, and the reaction solution exhibited black color.

After completion of the dropwise addition, the mixture was further stirred for 30 minutes. Thereafter, the reaction mixture was poured into 400 ml of acetone, stirred for 2 hours, and then the polymer was separated by filtration. The polymer obtained was washed with stirring in distilled water, filtered off and the washing was repeated in this manner until the filtrate became neutral. Next, the polymer separated by filtration was repeatedly washed with acetone until the filtrate no longer colored. The polymer separated by filtration was vacuum-dried over phosphorus pentoxide at room temperature for 10 hours to obtain a conductive organic polymer according to the present invention as a green powder.

(2) Physical properties of polymer The polymer obtained above was added to concentrated sulfuric acid having a concentration of 97% at room temperature, stirred, and the solubility was examined.
It was 2% by weight. The logarithmic viscosity at a temperature of 30 ° C. of a 97% concentrated sulfuric acid solution of this polymer having a concentration of 0.5 g / dl was 0.46. For comparison, viscosities of emeraldine and diamond black under the same conditions were 0.02 and 0.02, respectively.
It was 0.005.

FIG. 5 shows the results of thermogravimetric analysis of the polymer and emeraldine in air. The heating rate is 10 ° C./min.

Next, after about 120 mg of the polymer powder obtained above was pulverized in an agate mortar, a pressure of 6000 kg was applied using a tablet press for an infrared spectrophotometer.
It was pressed into a 13 mm diameter disk at a pressure of / cm ² . Four copper foils having a width of about 1 mm were adhered to the four corners of the disk with silver paste or graphite paste, and the conductivity was 2.0 S / cm as a result of measurement in air according to the Van der Pauw method. The molded polymer showed almost the same conductivity as measured in a vacuum of 10 ^-2 Torr. The disk was left in the air for four months, but the conductivity did not change substantially.

(3) Infrared absorption spectrum of polymer The infrared absorption spectrum of the polymer obtained above is shown in FIG. For comparison, the infrared absorption spectra of emeraldine and commercially available diamond black are shown in FIGS. 2 and 3, respectively. Emeraldine was prepared by the method of AGGreen et al. (AGGreen et al., J. Chem. So
c., 97 , 2388 (1910)).

The infrared absorption spectrum of the above polymer is similar to that of emeraldine, but at the same time there are large differences. That is, emeraldine has C—H based on monosubstituted benzene.
Although a clear absorption of 690 cm ^-1 and 740 cm ^-1 due to out-of-plane deformation vibration is observed, in the polymers according to the present invention, these absorption was not observed most of 800 cm ^-1 indicating the para-substituted benzene in place Absorption is strongly observed. This is because emeraldine is a low-molecular-weight substance, so that absorption based on mono-substituted benzene at the molecular end appears relatively strongly, whereas the above-mentioned polymer is a high-molecular-weight substance, and thus forms a polymer chain. This is because the absorption based on para-substituted benzene appears relatively strongly. In contrast, the infrared absorption spectrum of aniline wanders, the above polymers and also differs markedly from any of Emerarudein, particularly wide absorption around 3200～3400Cm ^-1, and a quinone carbonyl group in 1680 cm ^-1 observed is absorbed, C-N stretching vibration region of 1200~1300cm ^-1, differ in 600 cm ^-1 or less in the region and the like is obvious.

The assignment of the infrared absorption spectrum of the above polymer is as follows.

1610 cm ^-1 (shoulder, C = N stretching vibration) 1570, 1480 cm ^-1 (benzene ring CC stretching vibration) 1300, 1240 cm ^-1 (CN stretching vibration) 1120 cm ^-1 (absorption based on dopant. Type of dopant 800 cm ^-1 (para-substituted benzene C-H out-of-plane angular vibration) 740, 690 cm ^-1 (mono-substituted benzene C-H out-of-plane bending vibration) FIG. 4 (B) shows the infrared absorption spectrum when the polymer was ammonia-compensated, and FIG. 4 (C) shows the infrared absorption spectrum after doping it again with 5N sulfuric acid. The spectrum after this re-doping is the fourth.
It is almost completely the same as the initial one shown in FIG. (A), and the electric conductivity is the same as before the ammonia compensation. The change in conductivity is 0.45 S / cm before compensation (A) and after compensation (B)
Was 1.6 × 10 ⁻⁸ S / cm, and after re-doping (C) was 0.31 S / cm. Thus, it is shown that the polymer before ammonia compensation was already doped with the protonic acid used in the oxidative polymerization stage.

(4) Chemical structure of polymer The elemental analysis value of the conductive polymer is shown. Even if the polymer is purified by washing with water and acetone, it is recognized that a green powder of anhydrous chromium oxide (Cr ₂ O ₃ ) remains as a residue after elemental analysis. The converted values are also shown when the value of is set to 100. It is recognized that the converted value matches the theoretical value. The results are also shown for a polymer chemically compensated with ammonia.

(A) Polymer containing sulfuric acid as dopant C ₁₂ H ₈ N ₂ (H ₂ SO ₄ ) _0.58 theoretical value measured value converted value C 60.79 58.11 60.99 H 3.89 4.05 4.25 N 11.81 10.80 11.34 S 7.84 7.45 7.82 O 15.66 (14.87) (15.61) The amount of sulfuric acid in the theoretical formula was calculated from the actually measured value of sulfur, and the amount of oxygen in the theoretical value was calculated based on the amount of sulfuric acid. The amount of oxygen in the measured value was calculated from the measured amount of sulfur and the amount of sulfuric acid.

(B) Compensating polymer C ₁₂ H ₈ N ₂ theoretical value measured value converted value C 70.98 73.24 79.77 H 4.48 4.34 4.73 N 15.54 14.23 15.50 Example 1 (Cerium (IV) ammonium nitrate having a standard electrode potential of 1.44 V was converted to proton Example of Using in the Presence of an Acid) A 200 ml-capacity glass reaction vessel with a lid was charged with 53 g of distilled water and 3.9 g (0.030 mol) of aniline hydrochloride to prepare an aniline hydrochloride aqueous solution.

Separately, an acidic aqueous solution composed of 38 g of distilled water and 11.8 g of sulfuric acid was prepared, and 16.5 g of cerium (IV) ammonium nitrate was added thereto.
(0.030 mol) was dissolved to prepare an oxidant solution.

While cooling with ice water, this oxidizing agent solution was dropped into the above aniline hydrochloride aqueous solution with stirring. The reaction mixture immediately turned blue and soon turned black-green, producing a black-colored precipitate.

The black-green precipitate was separated by filtration, purified and dried in the same manner as in Reference Example to obtain a conductive organic polymer according to the present invention in a yield of 50.
%. In addition, the conductivity of this conductive organic polymer is 0.
It was 46 S / cm.

Example 2 (Example of using sodium chlorate having a standard electrode potential of 1.45 V in the presence of a protonic acid) A 200 ml capacity, 35 g of distilled water and 3.9 g (0.033 mol) of sulfuric acid were placed in a glass-made reaction vessel with a lid. Aniline hydrochloride 3.3
g (0.030 mol) was added and dissolved.

Separately, an oxidizing solution consisting of 38 g of distilled water and 3.2 g (0.030 mol) of sodium chlorate was prepared, and this oxidizing solution was added to the aniline salt aqueous solution at a time with stirring, and then cooled with ice water to obtain a catalyst. Was added as cupric chloride (1 mol% based on sodium chlorate). A black-green precipitate formed immediately. After standing in a refrigerator overnight, a black-green precipitate was separated by filtration, purified and dried in the same manner as in Reference Example to obtain a conductive organic polymer according to the present invention in a yield of 1%. The conductivity was 0.19 S / cm.

When the reaction was carried out in the same manner as above except that 70 mg of ammonium metavanadate (2 mol% based on sodium chlorate) was used instead of cupric chloride, the yield of the polymer was 56%, The conductivity was 3.6 × 10 ⁻⁴ S / cm.

Example 3 (Example in which manganese dioxide having a standard electrode potential of 1.21 V is used in the presence of a protonic acid) A 100 ml-capacity, glass reaction vessel with a lid is charged with 35 g of distilled water and 2.9 g (0.030 mol) of sulfuric acid. Aniline 3.9
g (0.030 mol) was dissolved to prepare an aniline salt aqueous solution.

While the aqueous solution was cooled with ice, 2.6 g (0.030 mol) of manganese dioxide powder was added little by little with stirring. The reaction mixture turned blue-green immediately and a black-green precipitate formed. 2
After continuing stirring for hours, it was left overnight.

The black-green precipitate was separated by filtration, purified and dried in the same manner as in Reference Example to obtain a bright green conductive organic polymer according to the present invention in a yield of 90%. The conductivity was 2.5 S / cm.

The manganese dioxide used was water-soluble after the reaction was completed.
It was confirmed that Mn ²⁺ was completely removed from the polymer during the purification process of the polymer.

Next, in a method using manganese dioxide, a polymer was obtained in the same manner as described above in the case where sulfuric acid was not used and the case where sulfuric acid was used in an amount 5 times the amount described above in order to investigate the influence of sulfuric acid.

When sulfuric acid was not used, the polymer yield was 64%, the conductivity was 6.3 × 10 ⁻⁵ S / cm, and when sulfuric acid was used in an amount 5 times the above,
The yield of the polymer was 89%, and the conductivity was 3.0 S / cm.

Example 4 (Example in which sodium iodate having a standard electrode potential of 1.085 V is used in the presence of a protonic acid) A 200 ml capacity, 26 g of distilled water, 1.3 ml of hydrochloric acid, and 1.3 g of sulfuric acid are placed in a glass reaction vessel with a lid, and put into this. 1.3 g of aniline (0.0
14 mol) and dissolved.

Separately, 2.3 g of sulfuric acid and 0.9 g of sodium iodate were added to 10 g of distilled water.
2 g (0.00465 mol) was dissolved to prepare an oxidizing solution, and this oxidizing solution was gradually added to the above aniline salt aqueous solution with stirring under ice cooling. The solution immediately turned from purple to blue to turquoise and eventually a green precipitate formed.

This precipitate was separated by filtration, purified and dried in the same manner as in Reference Example to obtain a conductive organic polymer according to the present invention in a yield of 71%. The conductivity was 4.7 S / cm.

Example 5 (Example of using lead dioxide having a standard electrode potential of 1.46 V in the presence of a protonic acid) In Example 4, 25 g of distilled water and sulfuric acid were used as the oxidizing solution.
A black-green conductive organic polymer according to the present invention was obtained in exactly the same manner as in Example 4, except that a dispersion of 3.35 g (0.014 mol) of lead dioxide in a 5.5 g aqueous solution was used. Conductivity
It was 1.5 × 10 ⁻³ S / cm.

Comparative Example (Example using arsenic acid having a standard electrode potential of 0.58 V) In Example 9, a 60% arsenic acid aqueous solution was used as an oxidizing solution.
The same treatment as in Example 11 was carried out except that a mixture of 3 g (0.014 mol as arsenic acid) and 2.75 g of sulfuric acid was used. But,
After one month, no polymer was formed at all, and the solution was slightly yellow-green.

[Brief description of the drawings]

1 is an infrared absorption spectrum of the conductive organic polymer prepared in Reference Example, FIGS. 2 and 3 are infrared absorption spectra of emeraldine and aniline black, respectively, and FIG. B is an infrared absorption spectrum of a conductive organic polymer, B is a polymer obtained by ammonia-compensating the polymer, and C is an infrared absorption spectrum of a polymer obtained by re-doping the polymer of B with sulfuric acid. FIG. 5 is a graph showing the weight residual ratio by heating of the conductive organic polymer and emeraldine.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takeshi Sasaki 1-2-1, Shimohozumi, Ibaraki City Inside Nitto Electric Industry Co., Ltd. (56) References JP-A-61-204266 (JP, A) JP-A-61 JP-A-64729 (JP, A) JP-A-60-197728 (JP, A) JP-A-60-501262 (JP, A) British patent 1216549 (GB, A)

Claims (2)

(57) [Claims] An aniline is chemically oxidized and polymerized in an aqueous solution to obtain a compound represented by the general formula A substantially linear polymer having a quinone diimine structure represented by the following formula as a main repeating unit, containing an electron acceptor as a dopant, having a conductivity of 10 ^-6 S / cm or more, and containing 80% acetic acid and In a method for producing a conductive organic polymer which is insoluble in N, N-dimethylformamide, an oxidizing agent having a standard electrode potential of 0.6 to 1.78 V defined as an electromotive force in a reduction half-cell reaction based on a standard hydrogen electrode. A method for producing a conductive organic polymer, comprising oxidizing aniline while cooling with ice water using (excluding dichromate). 2. The method according to claim 1, wherein the 0.5 g / dl concentrated sulfuric acid solution of the polymer has a logarithmic viscosity at 30 ° C. of 0.10 or more.