JP2843935B2 - Method for producing conductive organic polymer composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a conductive organic polymer composition, and more particularly, to a conductive organic polymer composition obtained by oxidative polymerization of aniline or a derivative thereof. And a method for producing a conductive organic polymer composition having only a selected polyvalent polymer sulfonic acid as a dopant. 2. Description of the Related Art Aniline, a derivative thereof or a salt thereof is chemically oxidized and polymerized in an oxidizing solution containing an oxidizing agent, contains an electron acceptor as a dopant, and has a conductivity of 10 ⁻⁶ S / cm or more. A method for producing an organic polymer is already known, and furthermore, in the production of a conductive organic polymer by such chemical oxidation polymerization, a standard electrode potential defined as an electromotive force in a reduction half-cell reaction based on a standard hydrogen electrode. The oxidizing agent having a value of 0.6 V or more is particularly preferably used.
No. 58831. On the other hand, in general, for example, plastic batteries and electrochromic displays have been proposed as applications of the conductive organic polymer composition. These use doping and undoping in which electrolyte ions, which are dopants in the conductive organic polymer composition, are taken in or released from the polymer. In such a case, the conductive organic polymer composition may be used in an aqueous system, but is often used in an organic solvent system. Therefore, when the conductive organic polymer composition obtained by oxidative polymerization of the aniline or a derivative thereof is used in an organic solvent, for example, in the above-described application to a plastic battery or an electrochromic display, a heavy polymerization may occur. It is necessary that the electrolyte ions contained as a dopant in the coalescence be soluble in the organic solvent, and as such electrolyte ions, for example, perchlorate ions and borofluoride ions are preferably used. Further, a polymer electrolyte ion is also preferably used as a dopant. Problems to be Solved by the Invention However, for example, when ammonium peroxodisulfate is used as the oxidizing agent, even if perchloric acid is used as the protic acid, the conductive organic polymer composition obtained after the oxidative polymerization has a problem in that the peroxooxodisulfonate is used. Sulfate ions generated by the decomposition of ammonium disulfate are incorporated into the polymer as a dopant. Moreover, it is well known that an aqueous solution of ammonium peroxooxodisulfate becomes strongly acidic when left standing. The present inventors have conducted further detailed and extensive research on the chemical oxidative polymerization of aniline and its derivatives, and have found that by appropriately controlling the oxidative polymerization conditions, it is possible to obtain a conductive material having only the selected polyvalent polymer sulfonic acid as a dopant. The present inventors have found that an organic polymer composition can be obtained by chemical oxidative polymerization of aniline or a derivative thereof, and have reached the present invention. Means for solving the problems The method for producing a conductive organic polymer composition according to the present invention comprises:
An aniline or alkyl aniline or a salt thereof is chemically oxidized and polymerized using an oxidizing agent, and contains a dopant.In a method for producing a conductive organic polymer composition having an electric conductivity of 10 ^-6 S / cm or more, a standard is used. The standard electrode potential determined as the electromotive force in the reduction half-cell reaction based on the hydrogen electrode is 0.
When it is 6 V or more and is soluble in water, the aqueous solution is neutral, and an oxidizing agent that does not generate anionic species after itself is reduced, and an acid dissociation constant pKa of 3.0 or less. It is characterized by using only a polyvalent polymer sulfonic acid as a dopant by using a combination with a polyvalent polymer sulfonic acid. According to the method of the present invention, the standard electrode potential determined as the electromotive force in the reduction half-cell reaction based on the standard hydrogen electrode is 0.6 V or more, the aqueous solution is neutral, and furthermore, it is reduced itself. Aniline or an alkyl aniline or a salt thereof (hereinafter referred to as aniline or an alkyl aniline) using an oxidizing agent obtained by combining an oxidizing agent that does not generate an anionic species with a polyvalent polymer sulfonic acid having an acid dissociation constant pKa of 3.0 or less. Is simply referred to as a monomer.) By conducting chemical oxidative polymerization, a conductive organic polymer composition in which only the polyvalent polymer sulfonic acid is directly incorporated as a dopant can be obtained. The oxidizing agent used in the method of the present invention is itself reduced in the oxidative polymerization reaction of the monomer as described above,
In doing so, it must not produce anionic species. The conductive organic polymer composition obtained by the above-described oxidative polymerization contains a π-electron conjugated system, which is partially oxidized to form a site having a positive charge, but when the oxidizing agent generates an anionic species, The anionic species is incorporated into the site, and the anionic species also constitutes a dopant together with the polyvalent polymer sulfonic acid, and thus, a conductive organic polymer composition having only the intended polyvalent polymer sulfonic acid as a dopant For they cannot get things. Further, the oxidizing agent used in the present invention needs to have an oxidizing power capable of oxidatively polymerizing the monomer.As such an oxidizing agent, as described in JP-A-61-258831, It is necessary that the standard electrode potential determined as the electromotive force in the reduction half-cell reaction based on the standard hydrogen electrode is 0.6 V or more. Here, in the method of the present invention, when the proton is involved in the reduction half-cell reaction, such as Cr ₂ O ₇ ²⁻ , the standard electrode potential is based on the standard electrode potential in the reaction involving the proton. I do. Such a standard electrode potential is described in, for example, "CRC Handbook
Of Chemistry and Physics "(CRC Press), D-155 to D-160, and" Electrochemical Handbook "edited by The Electrochemical Society (Maruzen Co., Ltd.), pp. 71-74. Oxidizing agents that satisfy the above two conditions include hydrogen peroxide, permanganate, lead dioxide, dichromate,
Manganese dioxide and the like can be mentioned and used as an aqueous solution or a solid. These oxidants do not generate anionic species after themselves are reduced, as shown below. ^{_{H 2 O 2 + 2H + +}} 2e - → 2H 2 O MnO 4 - + 8H + + 5e - → Mn 2+ + 4H 2 O PbO 2 + 4H + + 2e - → Pb 2+ + 2H 2 O Cr 2 O 7 2+ 14H + + 6e - → 2Cr ³⁺ + 7H ₂ O MnO ₂ + 4H ⁺ + 2e ⁻ → Mn ²⁺ + 2H ₂ O Next, according to the method of the present invention, the oxidizing agent as described above and a protonic acid having an acid dissociation constant pKa of 3.0 or less are used. An oxidizing agent system is formed by combining with a certain polyvalent polymer sulfonic acid. The polyvalent polymer sulfonic acid as a protic acid is capable of doping a monomeric oxidized polymer,
The acid dissociation constant pKa needs to be 3.0 or less. When using a polyvalent polymer sulfonic acid having an acid dissociation constant pKa greater than 3.0, the resulting oxidized polymer cannot be doped, and therefore, a conductive organic polymer having a conductivity of 10 ^-6 S / cm or more. No composition can be obtained. Examples of polyvalent polymer sulfonic acids having an acid dissociation constant pKa of 3.0 or less include, for example, polyvinyl sulfonic acid, polystyrene sulfonic acid, polyallyl sulfonic acid, polymethallyl sulfonic acid, poly-2-acrylamide-2-methylpropane sulfonic acid. Acids, "Nafion" (registered trademark) and the like. These polyvalent polymer sulfonic acids may be used as they are, or may be easily obtained by subjecting a commercially available monomer to radical polymerization by an ordinary method. An alkali metal salt of a polyvalent polymer sulfonic acid can be subjected to ordinary acid treatment or ion exchange resin treatment to obtain a polyvalent polymer sulfonic acid as a free acid. In the method of the present invention, the oxidizing agent is
It is preferred to use equivalents. When the oxidizing agent is used in excess of the equivalent amount, the oxidizing agent remains in the reaction system in an excessive amount and the oxidizing agent that does not generate an anionic species after itself is reduced. This is because it may have The polyvalent polymer sulfonic acid requires, for example, at least an equimolar amount with respect to the monomer in order to dissolve the monomer in water. In the present invention, regardless of the type of the reaction medium, In general, it is preferable to use a molar amount of several times to several tens times with respect to the monomer, and usually about 2 to 10 times.
A molar range is optimal. In the method of the present invention, aniline is particularly preferably used as a monomer, but o-methylaniline, m-
Alkyl anilines such as methyl aniline, o-ethyl aniline and m-ethyl aniline can also be used. When these monomers are used as salts, it will be apparent that they need to be used as salts of the same polymer sulfonic acid as the polyvalent polymer sulfonic acid for doping the resulting oxidized polymer. In the method of the present invention, as the reaction medium, one or a mixture of water, a water-miscible organic solvent and a water-immiscible organic solvent can be used. When used, the reaction medium is usually water that dissolves these water-soluble salts, a water-miscible organic solvent or a mixture thereof, and when aniline or alkylaniline itself is used, the reaction medium is A water-miscible organic solvent or a water-immiscible organic solvent that dissolves these is used. It is necessary that none of the above organic solvents be oxidized by the oxidizing agent used. For example, water-miscible organic solvents include acetone, tetrahydrofuran, ketones such as acetic acid, ethers or organic acids, and water-immiscible organic solvents include chloroform, carbon tetrachloride, and hydrocarbons. Used. A preferred method for producing the conductive organic polymer composition according to the present invention is to dissolve aniline or an alkylaniline or a salt thereof in a reaction medium containing a polyvalent polymer sulfonic acid, add an oxidizing agent to the solution, and oxidize the solution. This is a method of polymerizing. The reaction temperature is not particularly limited as long as it is equal to or lower than the boiling point of the solvent, but as the reaction temperature increases, the conductivity of the obtained conductive organic polymer composition tends to decrease. From the viewpoint of obtaining, room temperature or lower is preferable. In the method of the present invention, the polymer may be precipitated immediately after the addition of the oxidizing agent, but usually, after an induction period of about several minutes, the reaction is started and the polymer is precipitated. In any case, the reaction is completed in a short time, 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 reaction product is separated by filtration, washed with water until the filtrate becomes neutral, washed with an organic solvent such as acetone until the color is no longer colored, and dried under vacuum to obtain a conductive organic polymer composition according to the present invention. obtain. According to the method of the present invention, a conductive organic polymer composition obtained by oxidative polymerization of aniline, alkylaniline or a salt thereof is represented by a general formula: (Where R represents hydrogen or an alkyl group.) A substantially linear polymer having a quinone diimine structure represented by the following formula as a main repeating unit comprises only the polyvalent polymer sulfonic acid as a dopant, The conductivity is 10 ^-6 S / cm or more. The conductive organic polymer composition thus obtained is
In a dry powder state, it usually exhibits green to blackish green, and generally, the higher the conductivity, the brighter the green. However, a molded product obtained by pressure molding usually shows a glossy blue color. The conductive organic polymer composition 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 conductive organic polymer composition, but is usually 0.2 to 10%.
%, Most often in the range of 0.25 to 5% by weight. However, this solubility should be understood as including, in the case of a conductive organic polymer composition having a high molecular weight, a portion having a solubility in the above range. Further, the conductive organic polymer composition according to the present invention has 97%
A 0.5 g / dl solution of concentrated sulfuric acid has a logarithmic viscosity in the range of 0.1 to 1.0 at 30 ° C., most often 0.2 to 0.6. Also in this case, especially when the composition is a high molecular weight polymer composition, it should be understood that the portion soluble in concentrated sulfuric acid has a logarithmic viscosity in the above range. As described above, according to the method of the present invention, the standard electrode potential is 0.6 V or more, and when soluble in water,
The aqueous solution is neutral, and further, an oxidizing agent that does not generate an anionic species after itself is reduced, and an acid dissociation constant pKa of 3.0
By using in combination with the following polyvalent polymer sulfonic acid, by oxidative polymerization of aniline, alkyl aniline or a salt thereof, the substantially linear high molecular weight polymer having a quinone diimine structure as a main repeating unit is described above. A conductive organic polymer composition having only a polyvalent polymer sulfonic acid as a dopant can be obtained. Such a conductive organic polymer composition can be suitably used, for example, as a conductive organic polymer composition for a plastic battery or an electrochromic display element which performs doping and undoping in an organic solvent. EXAMPLES Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. Example 1 (Synthesis of polyvinyl sulfonic acid) Water was distilled off from 160 g of a 25% aqueous solution of sodium vinyl sulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.) using a rotary evaporator, and concentrated to 87 g (concentration: 46%). The whole amount of the concentrated aqueous solution of sodium vinyl sulfonate is put into a separable flask equipped with a stirrer, a nitrogen introducing device and a condenser, and nitrogen is introduced into the solution from the nitrogen introducing device into the solution.
I blew for a minute. A redox-based initiator aqueous solution in which 0.213 g of potassium peroxodisulfate and 0.108 g of sodium sulfite were dissolved in 12.3 g of distilled water was prepared, added to the flask, and stirred at room temperature. After about one hour, it was noted that the viscosity of the solution had increased. After reacting for 3 hours, the resulting reaction mixture was poured into 700 mL of methanol with stirring to produce a white precipitate.
The precipitate was separated by filtration with a glass filter, sufficiently washed with methanol, and dried in a desiccator under vacuum for 8 hours to obtain 33.6 g of sodium polyvinyl sulfonate (yield: 84).
%) As a white powder. The logarithmic viscosity of this polymer (0.5 g / dl, 30 ° C, in water) is 0.2
It was 0. Using an Ubbelohde viscometer to measure the viscosity while diluting the concentration, as the concentration becomes lower,
The phenomenon of so-called low concentration anomaly in which both the logarithmic viscosity and the reduced viscosity increased was shown. This indicates that the obtained polymer is a polymer electrolyte. Next, 13 g of this sodium vinyl sulfonate was added to distilled water 7
It was dissolved in 4 g to prepare a 15% aqueous solution. A glass column filled with H-type cation exchange resin (DOWEX 50WX2, H-type manufactured by Dow Chemical Company) was sufficiently washed with distilled water, and after confirming that the distillate became neutral, the column was added to the above column. An aqueous solution of sodium polyvinylsulfonate was supplied to the column by a metering pump, and the distillate was collected from the time when the distillate turned acidic, and then collected until neutral. However,
After the addition of the aqueous solution of sodium polyvinylsulfonate to the column was completed, distilled water was continuously supplied to the column by a metering pump. About 200 mL of this distillate was treated with a rotary evaporator to distill off water, and the resulting starch syrup was vacuum-dried at 80 ° C. for 5 hours to completely evaporate residual water, and to obtain brown syrup. As a result, 10 g of polyvinyl sulfonic acid was obtained. (Synthesis of aniphosphorylated polymer composition doped with polyvinyl sulfonic acid) 81 g of distilled water was placed in a 200-mL glass reaction vessel, and 8.65 g of the above-mentioned polyvinyl sulfonic acid was added and dissolved therein. The resulting solution was strongly acidic. 3.73 g of aniline is added to this aqueous solution of polyvinyl sulfonic acid.
(0.04 mol) and dissolved under stirring. Cool with ice water, and at a temperature of 5 ° C, 3.48 g (0.04 g) of manganese dioxide powder.
Mol) was added in small portions to the reaction vessel. Immediately after the addition of manganese dioxide, the reaction solution was colored green, and immediately thereafter, a black-green solid was formed. Manganese dioxide was added over about 30 minutes, after which stirring was continued for a further 1.5 hours. After completion of the reaction, the reaction mixture was added to 500 mL of distilled water, and the powder of the aniphosphorylated polymer composition was added to a glass filter G4.
, And ultrasonically washed in distilled water. Similarly, ultrasonic cleaning was repeated twice using fresh distilled water.
This confirmed that the water became neutral. Then, the powder of the aniphosphorylated polymer composition was repeatedly washed with acetone until the washing liquid became colorless, and then dried in a desiccator at room temperature for 5 hours under vacuum to give 3.99 g of the aniphosphorylated polymer composition vividly. Green powder. The aniphosphorylated polymer composition contained 6.1% sulfur as a result of elemental analysis. The conductivity according to the van der Pauw method was 0.64 S / cm.

Continuation of the front page (56) References JP-A-63-215722 (JP, A) JP-A-61-266435 (JP, A) JP-A-61-258831 (JP, A) JP-A-61-256764 (JP) , A) JP-A-60-197728 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08G 73/00 C08L 79/00

Claims (1)

(57) [Claims] An aniline or alkyl aniline or a salt thereof is chemically oxidized and polymerized using an oxidizing agent, containing a dopant, and a method for producing a conductive organic polymer composition having an electric conductivity of 10 ^-6 S / cm or more. When the standard electrode potential determined as the electromotive force in the reduction half-cell reaction based on the hydrogen electrode is 0.6 V or more and is soluble in water,
The aqueous solution is neutral, and further, an oxidizing agent that does not generate an anionic species after itself is reduced, and an acid dissociation constant pKa of 3.0
A method for producing a conductive organic polymer composition, comprising using the following polyvalent polymer sulfonic acid in combination with the polyvalent polymer sulfonic acid alone as a dopant.