JPH0625263B2 - Method for treating conductive polymer film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> Aromatic compounds such as benzene, six-membered heterocyclic compounds, five-membered heterocyclic compounds, aromatic amine compounds such as aniline, etc. are easily conductive by electrolytic oxidation polymerization. Recently, it has attracted a great deal of attention as a material for providing a functional polymer film. Doping occurs at the same time during electrolytic polymerization, and a polymer film having a high conductivity is directly obtained, and its stability is also good. It is possible to electrochemically adjust the amount of dopant in these polymers, and the conductivity can be controlled in a wide range. Therefore, by utilizing these properties, various applications such as various sensors, batteries, electrochromic materials, and electronic devices can be obtained.

The conductive polymers obtained by these electrolytic oxidative polymerizations are excellent in high conductivity and mechanical strength. However, it cannot be said that the electric conductivity is sufficient. As a means for improving this conductivity, we have previously found a method for stretching and orienting a pyrrole polymer.

However, as a result of earnest research on a method for further improving the electrical conductivity, it was found that the electrical conductivity is further improved by ultrasonically treating the conductive polymer film obtained by electrolytic oxidation polymerization, and the present invention was completed. It was

<Structure of the Invention> The present invention is a method for treating a conductive polymer film, characterized by improving the conductivity by subjecting a conductive polymer film obtained by electrolytic oxidation polymerization to ultrasonic treatment.

Hereinafter, specific contents of the present invention will be described in detail.

The electroconductive polymer film of the present invention can be obtained by electrolytically oxidatively polymerizing an aromatic compound, a heterocyclic compound or an aromatic amine compound in the presence of an electrolyte to deposit a polymer on the anode plate. Moreover, according to this method, anions coexisting in the reaction system are incorporated as dopants,
High conductivity is exhibited even without doping with an electron-accepting compound.

Examples of the above aromatic compounds include benzene and azulene, and examples of the hetero six-membered ring compounds include pyridazine. The five-membered heterocyclic compound has the following general formula I
And the oligomers thereof.

[Here, X represents S, O, NR (R represents hydrogen, a lower alkyl group or a phenyl group), and R ¹ and R ²
Each independently represents a hydrogen atom, an alkyl group or an alkoxy group. ] Specifically, thiophene, 2,2′-bithiophene, 3−
3-alkylthiophenes such as methylthiophene and 3-ethylthiophene, 3,4-dimethylthiophene, 3,4-
3,4-Dialkylthiophenes such as diethylthiophene, 3-alkoxythiophenes such as 3-methoxythiophene, 3,4-dialkoxythiophenes such as 3,4-dimethoxythiophene; and furan, 3-methylfuran, etc. 3,4-Dialkylfuran such as 3-alkylfuran, 3,4-dimethylfuran, etc .; N-alkylpyrrole such as pyrrole, N-methylpyrrole, N-methylpyrrole, N-phenylpyrrole, 3-methylpyrrole, etc. Examples thereof include 3,4-dialkylpyrrole such as 3-alkylpyrrole and 3,4-dimethylpyrrole. However, it is not limited to this.

The following electrolytes are used in electrolytic oxidation polymerization. That is, inorganic and organic acids and their tetraalkylammonium salts, inorganic and organic acid alkali metal salts and the like can be mentioned. Specifically, inorganic acids such as hydrochloric acid, perchloric acid, hydrofluoric acid, hydrofluoric acid, hydrobromic acid, phosphoric acid, acetic acid, oxalic acid, trifluoromethanesulfonic acid, nonafluorobutanesulfonic acid, octane Organic acids such as sulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, tetraethylammonium perchlorate, tetraethylammonium borofluoride, tetramethylammonium hexafluorophosphate, tetramethylammonium hexafluoroarsenate, tetrabutylammonium sulfonate, tetraethylammonium Examples thereof include trifluoromethyl sulfonate, tetraethylammonium p-toluene sulfonate, lithium trifluromethyl sulfonate, lithium perchlorate and sodium p-toluene sulfonate.

Water or an organic solvent is used as the polymerization solvent. The organic solvent is preferably one that easily dissolves the electrolyte, such as acetonitrile, benzonitrile, nitrobenzene, tetrahydrofuran, nitromethane, propylene carbonate, ethylene carbonate, sulfolane, and dimethoxyethane, but is not necessarily limited thereto.

The amount of the monomer is 0.0001 mol / liter to 1 mol / liter, preferably 0.001 mol / liter to the solvent.
Polymerization is carried out at 0.5 mol / l.

The electrolyte is 0.0001 mol / liter to 1 mol / liter, preferably 0.001 mol / liter to 0.5, relative to the solvent.
Mol / liter is used.

A polymerization temperature of -50 ° C to 100 is adopted. Suitably -50 ℃
From 50 ℃ is adopted. The polymerization time is appropriately selected from the relationship between the amount of electricity supplied and the time of electricity application so that a film having a desired film thickness is produced.

It is more preferable to perform ultrasonic treatment during this polymerization reaction.

The conductive polymer film produced under the above conditions has a high conductivity by itself, but the ultrasonic treatment further improves the conductivity. As the ultrasonic treatment, an unstretched product obtained by polymerization may be directly carried out, or ultrasonic irradiation may be carried out at the time of stretching and orientation treatment. Further, ultrasonic wave irradiation may be performed after the stretching and orientation treatment. Furthermore, these processes can be used in combination.

As the ultrasonic generator used in the ultrasonic treatment of the present invention, an ultrasonic cleaning device, a cell crusher mainly used for biochemistry, and the like are easily used. The frequency of ultrasonic waves is not particularly limited, but those of 20 kHz or higher are mainly used. The power of the ultrasonic wave generation source is appropriately selected from the relationship with the device used and the relationship with the conductive polymer used.

Ultrasonic irradiation preferably uses water or an organic solvent as a medium. Examples of the organic solvent include alcohols, amide-based solvents such as N, N-dimethylformamide and N, N-dimethylacetamide, halogen-based solvents such as dimethylsulfoxide, chloroform carbon tetrachloride, dichloromethane and trichloroethane, in addition to the above reaction solvents. Examples thereof include solvents, aromatic solvents such as ether, benzene, and toluene, and hydrocarbon solvents such as hexane and heptane, but those that transmit ultrasonic vibrations to the conductive polymer and do not deteriorate the conductive polymer. The material is not particularly limited.

The temperature of the medium in the ultrasonic treatment is preferably -50 ° C to 100 ° C.

The ultrasonic wave irradiation time is 1 minute to 2 hours, preferably 2 minutes to 1 hour, depending on the power of the ultrasonic wave generation source.

Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to this. The electric conductivity was measured by a four-terminal method using a silver paste.

Polymerization Example 1 Using a platinum plate as an anode and a platinum foil as a cathode in a 500 ml separable flask, a mixed solution of 400 ml of freshly distilled propylene carbonate and 4 ml of water, 5.26 g of tetramethylammonium hexafluorophosphate (0.0
24 mol) was introduced, and nitrogen gas was introduced to perform deoxidation. Then, 1.61 g (0.024 mol) of pyrrole was added. -20 ° C
After cooling, the mixture was subjected to electrolytic oxidative polymerization under a nitrogen stream at a current density of 0.125 mA / cm ² for 24 hours. 30μm generated after polymerization
The film was peeled from the anode plate, washed with acetonitrile and dried. The electric conductivity of this product was 380 S / cm.

Polymerization Example 2 Using a glassy carbon plate as an anode and a platinum foil as a cathode in a 500 ml separable flask, a mixed solution of 400 ml of freshly distilled propylene carbonate and 4 ml of water, 9.18 g (0.024 mol) of tetraethylene ammonium perchlorate Was charged, and nitrogen gas was introduced to perform deoxidation. Then, 1.61 g (0.024 mol) of pyrrole was added. After cooling to -40 ° C, electrolytic oxidative polymerization was performed under a nitrogen stream at a current density of 0.125 mA for 24 hours. The 30 μm film produced after completion of the polymerization was peeled off from the anode plate, washed with acetonitrile and dried. The electric conductivity of this product was 320 S / cm.

Polymerization Example 3 Using a platinum plate as an anode and a platinum foil as a cathode, 400 ml of freshly distilled propylene carbonate and 8.68 g (0.024 mol) of tetraethylammonium borofluoride were placed in a 500 ml separable flask, and nitrogen gas was introduced to deoxygenate. I went. Then 3,4-dimethoxythiophene 3.4
6 g (0.024 mol) was added. Electrolytic oxidative polymerization was carried out at a current density of 0.25 mA for 8 hours under a nitrogen stream at 15 ° C. The 17 μm film produced after the completion of polymerization was peeled off from the anode plate,
It was washed with acetonitrile and dried. The electrical conductivity of this product was 50 S / cm.

Polymerization Example 3 Example 1-5 The pyrrole polymer film obtained in Polymerization Example 1 was dipped in various media and subjected to ultrasonic wave irradiation for a predetermined time using a Branson B220H type (45 KHz, 180 W) ultrasonic wave transmitter, and then. The stretching treatment was performed for 5 minutes while irradiating with ultrasonic waves.
After stretching, the film is washed with acetonitrile and heated to 150 ° C.
The sample was heat-fixed for 5 minutes under tension, cooled, and then the electrical conductivity was measured. In the following examples and comparative examples, the same treatment was performed after the stretching process.

Comparative Example 1 The pyrrole polymer film obtained in Polymerization Example 1 was immersed in propylene carbonate and stretched without ultrasonic irradiation. At this time, the draw ratio is 2.0 times and the electric conductivity is 1,125 S.
It was / cm.

The effect of stretching while irradiating ultrasonic waves was recognized.

Example 6-8 The film obtained in Polymerization Example 2 was irradiated with ultrasonic waves for 10 minutes by using the ultrasonic oscillator, and then while being further irradiated with ultrasonic waves, 5
Stretching was performed over a period of minutes.

Comparative Example 2 The pyrrole polymer film obtained in Polymerization Example 2 was immersed in propylene carbonate and stretched without ultrasonic irradiation. At this time, the draw ratio is 2.0 times and the electric conductivity is 856S.
It was / cm.

Example 9 The film obtained in Polymerization Example 3 was irradiated with ultrasonic waves for 10 minutes using the ultrasonic oscillator of Example 1, and then stretched for 5 minutes while being further irradiated with ultrasonic waves.

Comparative Example 3 The 3,4-dimethoxythiophene polymer film obtained in Polymerization Example 3 was immersed in propylene carbonate and stretched without ultrasonic irradiation. At this time, the draw ratio was 1.4 times and the electric conductivity was 109 S / cm.

Examples 10-15 The pyrrole polymer film obtained in Polymerization Example 1 was immersed in various media as it was, and ultrasonic irradiation was performed using the ultrasonic oscillator of Example 1.

As described above, it was clearly confirmed that the ultrasonic treatment improved the conductivity.

Examples 16-18 The film obtained in Polymerization Example 2 was sonicated as it was using the ultrasonic oscillator of Example 1.

As described above, the improvement of the electric conductivity was clearly recognized.

Examples 19-20 The film obtained in Polymerization Example 2 was sonicated as it was using the ultrasonic oscillator of Example 1.

As described above, the improvement of the electric conductivity was clearly recognized.

Examples 21-26 The film obtained in Polymerization Example 1 was stretch-oriented, and had a draw ratio of 2.0 and an electric conductivity of 1,125 S / cm. This was subjected to ultrasonic treatment using the ultrasonic oscillator of Example 1. The results are shown below.

As described above, the electric conductivity was clearly improved even by the ultrasonic treatment after the stretch orientation treatment.

Example 27 In a 500 ml separable flask, a glassy carbon plate (GC-20 manufactured by Tokai Carbon Co., Ltd.) whose surface was polished as an anode, platinum foil was used as a cathode, and 400 ml of freshly distilled propylene carbonate and a mixed solution of 4 ml of water, tetra 5.26 g (0.024 mol) of methylammonium hexafluphosphate was added, and nitrogen gas was introduced to perform deoxidation. Then, 1.61 g (0.024 mol) of pyrrole was added. Branson B 220H type (45KHz, cooled to -20 ℃ under nitrogen stream)
180 W) Electrolytic oxidative polymerization was carried out at a current density of 0.125 mA / cm ² for 8 hours while irradiating ultrasonic waves using an ultrasonic oscillator. The 8 μm film produced after the completion of the polymerization was peeled from the anode plate, washed with acetonitrile and dried. The electric conductivity of this product was 610 S / cm. This product can be stretched 2.7 times, and the conductivity after stretching under ultrasonic waves is 2,340.
Reached S / cm.

Claims (7)

[Claims] 1. A method for treating a conductive polymer film, which comprises subjecting a conductive polymer film obtained by electrolytic oxidation polymerization to ultrasonic treatment. 2. The conductive polymer film according to claim 1, wherein the ultrasonic treatment is performed before the stretching / orienting treatment and / or during the stretching / orienting treatment and / or after the stretching / orienting treatment. Processing method. 3. A high-conductivity polymer according to claim 1 or 2, wherein a conductive polymer film obtained by electrolytic oxidation polymerization using a hetero five-membered ring compound as a monomer is used. Processing method of molecular film. 4. The method for treating a conductive polymer film according to claim 3, wherein the five-membered heterocyclic compound is pyrrole, a pyrrole derivative and / or a thiophene or a thiophene derivative. 5. The method for treating a conductive polymer film according to any one of claims 1 to 4, wherein the hetero five-membered ring compound is pyrrole or a pyrrole derivative. 6. The method for treating a conductive polymer film according to any one of claims 1 to 5, wherein the treatment is carried out in an organic solvent and / or water. 7. The method for treating a conductive polymer film according to any one of claims 1 to 6, wherein the treatment is carried out at -50 ° C-100 ° C.