JPH0528746B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Field of Application) The present invention relates to a method for producing a P-type electroactive conductive material. (Prior Art) Conventionally, polyacetylene, polypyrrole, polyaniline, etc. are known as organic conductive polymers. However, since these organic conductive polymers are generally insoluble and infusible, they have poor moldability and processability, and it has been difficult to obtain a film-like conductive polymer. Therefore, various special methods have been proposed to obtain film-like conductive polymers. for example,
(1) A method in which a polymerization catalyst is applied to a glass wall, acetylene gas is sprayed onto it to form a polyacetylene film, and then it is peeled off. (2) A method in which thiophene or pyrrole is polymerized by an electrochemical oxidation reaction and an electrode is formed. (3) After forming a film-like material of polythiophene or polypyrrole on the electrode substrate, the film is peeled off from the electrode. (3) After forming a thermoplastic resin film on the electrode substrate, pyrrole is polymerized by an electrochemical oxidation reaction. , a method of forming a composite film of thermoplastic resin and polypyrrole on an electrode substrate has been proposed. However, the film formed by the above method (1) has the disadvantage that it is unstable in air, easily deteriorates due to oxidation, and its mechanical strength becomes weak. Also (2) and (3)
This method has disadvantages in that the size of the film is limited by the size of the electrode, and that special equipment and electrolytes are used, making the manufacturing process complicated and expensive. On the other hand, there are conductive oligomers that are soluble in specific solvents due to their small molecular weights. However, even if a film is formed from this low molecular weight conductive oligomer by a casting method, the film has the disadvantage that it is brittle and has low mechanical strength. In some cases, the molecular weight is too low to form a film. Furthermore, even if this film is used as an electrode, it will be eluted into the electrolyte, and the repeatability of electrochemical oxidation and reduction reactions (doping and dedoping) is poor, making it currently unusable. . (Problems to be Solved by the Invention) The present invention solves the drawbacks of low-molecular conductive oligomers, has strong mechanical strength, and has high electrochemical oxidation resistance.
The present invention provides a method for producing a P-type electroactive conductive material with good repeatability of reduction reactions. (Means for Solving the Problems) As a result of the inventors' intensive research on diphenylamine oligomers as conductive oligomers,
This completes the present invention. That is, the present invention is based on the general formula (Here, R represents hydrogen or a hydrocarbon residue having 1 to 20 carbon atoms, and n is 2≦n≦50) and a general-purpose polymer are dissolved in an organic solvent, and then The present invention relates to a method for producing a P-type electroactive conductive material, which comprises removing the organic solvent. The conductive material obtained by the method of the present invention not only has high mechanical strength, but also has the completely unexpected effect that diphenylamine oligomers do not elute into the electrolyte solution when composited by the method of the present invention. Therefore, the repeatability of electrochemical oxidation and reduction reactions is extremely excellent. The diphenylamine oligomer used in the present invention can be synthesized by a known method. For example, JP-A-61-206170 or JP-A-61-
It can be synthesized by a known method such as the oxidation coupling method or Grignard coupling method used in No. 28524. general formula

In the formula, R represents hydrogen or a hydrocarbon residue having 1 to 20 carbon atoms, preferably 1 to 8 carbon atoms, and examples of the hydrocarbon residue include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, Examples include n-butyl group, i-butyl group, n-hexyl group, or allyl group, various aryl groups such as phenyl group, tolyl group, and ethyl phenyl group, aralkyl group, and derivatives thereof. Further, n is 2≦n≦50, preferably 2≦n≦30, and more preferably 2≦n≦10. As the general-purpose polymer used in the present invention, known polymers that are soluble in organic solvents and have film-forming properties are appropriately selected, and specifically, polyvinyl chloride, polymethyl methacrylic acid, chloromethylated polystyrene, polystyrene, Examples include styrene-butadiene copolymer, ethyl cellulose, cellulose acetate, polyethylene terephthalate, polyethylene oxide, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyethylene, polypropylene, polychloroprene, natural rubber, and phenolic resin. It is essential that the organic solvent used in the present invention is a solvent that can simultaneously dissolve the diphenylamine oligomer and the general-purpose polymer. Preferred organic solvents include ethers such as tetrahydrofuran, diethyl ether, diisopropyl ether, and diisoamyl ether; aromatic nitrates or halides such as benzene, nitrobenzene, orthodichlorobenzene, and trichlorobenzene; organic halides such as chloroform and methylene chloride; Dimethylformamide, N-methyl-2-pyrrolidone and the like can be mentioned. The method for obtaining a homogeneous composite of diphenylamine oligomer and general-purpose polymer is as follows: (1) diphenylamine oligomer and general-purpose polymer are each dissolved in an organic solvent separately, and then both solutions are mixed and cast. A method for vacuum drying organic solvents,
(2) A method is preferably employed in which a mixture of a diphenylamine oligomer and a general-purpose polymer is brought into contact with an organic solvent and dissolved to form a homogeneous solution, which is then cast and the organic solvent is removed under reduced pressure. The mixing ratio of diphenylamine oligomer and general-purpose polymer shows that if the ratio of diphenylamine oligomer is too large, the mechanical strength tends to weaken.
Moreover, if it is too small, the electrochemical activity will be low. Usually, the weight ratio of diphenylamine oligomer to general-purpose polymer is preferably in the range of 1:1000 to 1:0.1, more preferably in the range of 1:10 to 1:1.
When mixing diphenylamine oligomers and general-purpose polymers, electron acceptors that are soluble in organic solvents, such as halogens such as chlorine, bromine, and iodine, and dichloride
Lewis acids such as iron, tin tetrachloride, and copper dichloride; inorganic acids such as hydrogen chloride, hydrogen bromide, sulfuric acid, and sulfuric acid; and organic acids such as picric acid and p-toluenesulfonic acid may also be present. (Effects of the Invention) By the method of the present invention, it is possible to easily obtain a P-type electroactive conductive material with high mechanical strength and good repeatability of electrochemical oxidation and reduction reactions. Furthermore, the materials obtained according to the present invention can be widely used as electronic materials and organic semiconductor materials. (Example) The present invention will be specifically described below with reference to Examples, but the present invention is not limited thereto. Example 1 (a) Synthesis of N-methyldiphenylamine polymer 50.0 g of anhydrous FeCl ₃ was placed in a 300 ml three-necked flask, and 150 ml of ethanol was added to dissolve it.
18.4 g of N-methyldiphenylamine was added, and the mixture was reacted for 24 hours at room temperature with stirring in a nitrogen atmosphere. The blue-green precipitate formed after the reaction was filtered, washed with ethanol and ion-exchanged water, washed again with ethanol, and dried to obtain 12.1 g of blue solid. The obtained solid was further dissolved in 200 ml of dichloromethane and filtered, and the filtrate was collected, dichloromethane was removed, and then dried to obtain dichloromethane-soluble N-methyldiphenylamine polymer 11.6
I got g. The obtained N-methyldiphenylamine polymer was an oligomer of N-methyldiphenylamine with a degree of polymerization of 2 and 3, with main peaks detected at mass numbers 364 and 545 from the results of mass spectrometry.
In addition, infrared absorption spectroscopy was performed and absorption at 820 cm ^-1 derived from para-substituted benzene was observed, indicating that this polymer has a structure linked at the para position with the phenyl group of N-methyldiphenylamine. It turns out that it is. (b) Synthesis of composite film 0.1 g of the N-methyldiphenylamine oligomer obtained in (a) was dissolved in 2 ml of tetrahydrofuran (solution (A)). Separately, 2.0g of polyvinyl chloride
was dissolved in 20 ml of tetrahydrofuran (solution
(B)). 1 ml of solution (A) and 5 ml of solution (B) were mixed to form a homogeneous solution, which was then poured onto a Teflon plate.
After air drying for 5 hours, vacuum drying was performed for 2 hours to obtain a uniform film with a thickness of 30 μm. (c) Cyclic voltammetry measurement Prepare and measure a uniform composite film on ITO glass using the same procedure as in the previous section (b), except that ITO glass was used instead of the Teflon plate in the previous section (b). It was used as an electrode for use. as an electrolyte
Measure the cyclic voltammetry of the above electrode in _a dry nitrogen atmosphere using a solution of 0.07 mol/(n- _C4H9 ) _4NClO4 in acetonitrile, a _platinum plate as a counter electrode, and an Ag/ _AgNO3 electrode as a reference electrode. did. A sweep rate of 50 mV/sec was used.
The results obtained are shown in FIG. There was no change even after dozens of redox cycles, indicating reversible and extremely stable redox behavior. The redox potential is
It was 0.38VVS.Ag/AgNO ₃ . Example 2 A composite film with N-methyldiphenylamine oligomer was prepared on ITO glass in the same manner as in Example 1 except that polymethyl methacrylate was used instead of polyvinyl chloride. Further, when cyclic voltammometry was measured in the same manner as in Example 1, there was no change even after several tens of redox cycles, indicating reversible and extremely stable redox behavior. The redox potential is
It was 0.45V VS Ag/AgNO ₃ . Example 3 A composite film with N-methyldiphenylamine oligomer was prepared on ITO glass in the same manner as in Example 1 except that polyethylene oxide was used instead of polyvinyl chloride. Further, when cyclic voltammometry was measured in the same manner as in Example 1, there was no change even after several tens of redox cycles, indicating reversible and extremely stable redox behavior. Redox potential is 0.50V
It was VS Ag/AgNO ₃ .

[Brief explanation of the drawing]

FIG. 1 shows the measurement results of cyclic voltammetry in Example 1.

Claims (1)

[Claims] 1. General formula (Here, R represents hydrogen or a hydrocarbon residue having 1 to 20 carbon atoms, and n is 2≦n≦50) and a general-purpose polymer are dissolved in an organic solvent, and then A method for producing a P-type electroactive conductive material, which comprises removing the organic solvent.