JPH03134019A - Modified conductive polypyrrole molding - Google Patents

Abstract

PURPOSE:To obtain the title molding decreased in toxicity and improved in oxidizability, hygroscopicity, etc., without detriment to its electrical properties by oxidatively polymerizing pyrrole in the presence of a free PF6<-> and exchanging the counter ion PF6<-> for another ion. CONSTITUTION:A pyrrole (derivative) is subjected to constant potential electrolytic oxidative polymerization at 0 deg.C or below in the presence of an electrolyte which forms a free PF6<-> (e.g. tetramethylammonium hexafluorophosphate) in an organic solvent (e.g. propylene carbonate) optionally containing water and used in an amount to give a pyrrole concentration of 0.0001-1 mol/l by using electrodes wherein the area of the cathode is at least 1.1 times as large as that of the anode at an electrolysis potential (reference electrode: silver/silver chloride) >=0.7 V and an electrolysis current (a current density on the anode) of 0.01-10 mA/cm<2> to deposit a polypyrrole molding (A) on the cathode plate. Component A is immersed in an electrolyte solution (B) formed by dissolving an electrolyte comprising the anion to be introduced in an organic solvent to exchange the counter ion PF6<-> of component A for another anion.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a modified poly roll molded body for use in conductive organic materials.

<Conventional technology> Organic conductive materials have made remarkable progress in recent years, and by taking advantage of their advantages such as mass production, moldability, and lightness, they can be used simply as wiring materials and electromagnetic shields.

It is becoming important to apply it not only as a material for electronic devices such as sensors, but also to molecular electronics, such as molecular devices that are expected to surpass current silicone-based devices.

Oxidative polymerization of teloaromatic compounds (
There are conductive polymers derived from chemical or anodic electrolysis. During this polymerization, counter ions that are introduced into the polymer and exhibit conductivity come from ions constituting the electrolyte in the polymerization solution. The mechanical, electrical, and chemical properties of conductive polymers are greatly influenced by the type of counterions introduced (J, poly
er 3 ciencc.

Polymer Physics [:ditio
n, 33 (1984).

5ynthetic Metals, 26. 2
09 (1988)).

For example, mechanical properties include stretchability and tensile strength and elongation of the formed film, electrical properties include electrical conductivity, and chemical properties include thermal stability and long-term stability.

In practical use, it is sufficient that the conductive polymer satisfies all of these properties S1 at the same time so as to be suitable for the intended use, but this is not necessarily the case.

For example, when verchlorate is used as a counter ion for a conductive polymer, the mechanical properties of the polymer are almost satisfied, but the thermal properties are unstable, and hexafluorophosphate, hexafluoroarsenate, In the case of hexafluoroantimonate, although its mechanical and electrical properties are generally good, it is not necessarily suitable for applications due to its oxidizing properties, toxicity, hygroscopicity, etc.

Therefore, there has been a desire for a technique for obtaining a polypyrrole molded body having desirable properties such as electrical properties, and imparting new desirable properties while retaining those properties.

OBJECTS OF THE INVENTION The present invention was made in view of the current situation, and an object of the present invention is to obtain a modified polypyrrole molded product that exhibits excellent properties as a conductive material.

<Structure of the Invention> The present invention is a polyroll molded product produced by oxidative polymerization in the presence of free PF5-, and furthermore, the counter ion PFe- in the polyroll molded product is mixed with other anions. This is a modified conductive polypyrrole molded article characterized by being replaced.

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

First, the polypyrrole molded article of the present invention, which provides high mechanical properties and electrical properties, is subjected to potentiostatic electrolytic oxidation polymerization of virol and/or its derivatives in the presence of an electrolyte using an organic solvent containing water as necessary. (J, C, S, C
hem, Comm, 1979.

635). According to this method, anions coexisting in the reaction system are taken in as a dopant, so high conductivity can be achieved without newly doping with an electron-accepting compound.

Furthermore, the polymerization of virole in the present invention is not limited to this electrolytic oxidation polymerization method. For example, the polypyrrole of the present invention can be obtained by chemical oxidative polymerization of virol and/or its derivative in the presence of an electrolyte and an oxidizing agent, optionally using an organic solvent containing water as a solvent (ACS
polymer print.

28(2), 256 (1987)).

The virol and its derivatives used in the present invention preferably have high purity, and are preferably distilled before use. Examples of the m1 form of virol include substituents at the N position of the virol ring, monosubstituted substances at the β position of the virol ring, and β
, γ-position disubstituted products, etc. are used, and specific examples include virol, N-alkylvirol such as N-methylvirol, and N-ethylvirol, and 3-alkylvirol such as N-phenylvirol and 3-methylvirol. , 3,4-dialkylvirol such as 3,4-dimethylvirol, and the like.

Virol or its derivatives are 0.0001 to the solvent
Mol/liter (M) to 1M, preferably 0,001
Polymerization is carried out using M to 0.5M.

Examples of electrolytes include (RM-free tetraalkylammonium salts of tohexafluorophosphate, alkali metal salts, etc.).Specifically, examples include tetraalkyl ammonium salts of hexafluorophosphate, tetraethylammonium salts of hexafluorophosphate, propylammonium salt,
Examples include tetrabutylammonium salts, lithium salts, sodium salts, potassium salts, etc. Among these, particularly preferred is detramethylammonium hexafluorophosphiny 1-. Tetrabutylammonium hexafluorophosphate. Moreover, it is not limited to these.

Electric! The quality used is 0.0001 M to IM, preferably 0.001 M to 0.5 M relative to the solvent.

The organic solvent used as the polymerization solvent is preferably one that easily dissolves the electrolyte, such as acetonitrile, benzonitrile, nitrobenzene, tetra-hydrofuran, nitromethane, propylene carbonate, ethylene carbonate, sulfolane, dimethoxyethane, but it is not necessarily limited to these. Not done.

The role of water υ1, which is optionally used, is to enhance the effect of the electrolyte and to improve the form in which polypyrrole is precipitated. The amount used varies depending on the type of electrolyte used, and the concentration of water in the electrolyte solution is 0.1M to 5M, preferably 0.3M to 3M.

Next, the electrolytic polymerization conditions will be described as follows.

The anode material used in the reaction is deficient in the electrode reaction,
Any general-purpose material may be used as long as it does not undergo deterioration, and platinum is not particularly limited.

Metals such as gold, copper, nickel, or similar conductive materials, carbon electrodes, etc. are used. Further, when the electrode area of the negative electrode is larger than that of the anode, the state of precipitation of polypyrrole that is generally produced is better. The ratio of the wire type to the anode surface area is preferably 1.1 times or more, preferably 1.5 times or more, more preferably 2 times or more, particularly preferably 3 times or more.

The electrolytic potential used is 0.7 volt or more with respect to a silver/silver chloride (Δ(]/A[]C,Q) reference electrode.

Preferably 0.8 to 1.2 volts, particularly preferably 0.8 to 1.2 volts.
9 to 1.1 volts are used. In order to suppress the electrolytic potential at a low temperature of 0° C. or lower, KC pattern/agar salt bridge or the like is used. Any method may be used as long as the electrolytic potential can be controlled. The electrolytic current has a current density of 0.01m at the anode.
A/cd ~10 mA/ci, preferably 0.05+1Δ/cd ~5 mA/cd.

The polymerization temperature used is 0°C or lower, preferably -20°C or lower. The lower the temperature the better, but the temperature must be higher than the melting point of the electrolytic solution (Japanese Patent Laid-Open No. 59-14
No. 0027).

Next, the counter ions of the polypyrrole thus obtained are exchanged by immersing the polymer in an electrolytic solution containing an electrolyte containing the anion to be exchanged dissolved in an organic solvent.

Examples of the electrolyte include tetraalkylammonium salts of inorganic and organic acids, and alkali metal salts of inorganic and organic acids.

The preferred electrolyte for this inland water invention is electric W? The ion size of the anions constituting the quality is 10 Å or less. Specifically, tetramethylammonium nitrate (NO
3-Size: 4.5 people), Tetrabutylammonium hydrogen sulfate (HS O<-Size: 5,
1 person), tetraethylammonium tetrafluoroborate (BF4-size: 5.3 people), tetramethylammonium haegi (nofluorophosphate (PFa-size: 5.9 people), tetraethylammonium trifluoromethanesulfonate (CF3SO3) -Size=6.
0 people), tetraethylammonium barchlorate (C
lO2-size: 6.2 people), tetraethylammonium nonylfluorobutane sulfonate (04F9803
-Size = 7.9 people), Tetraethylammonium doshile 1~ (1-43C-(:)←S 03-Size: 10.0
person) can be given. Moreover, it is not limited to these.

Here, the counterion size is the length of the molecule in the long sleeve direction, including the ionized atom, and is the length of the molecule in the long-sleeve direction.
This is a value calculated by referring to the following publications:

It is sufficient that the electrolyte in the dipping solvent has at least a larger number of counter ions than the counter ion contained in the soaked polyurethane roll. Preferably it is 5 times or more -F1, more preferably 10 times or more.

The organic solvent used as the dipping solvent is one that easily dissolves the electrolyte and swells the polypyrrole, such as aretonitrile, benzonitrile, nitrobenzene, terahydrofuran, nitromethane, propylene carbonate, ethylene carbonate, sulfolane, dimethoxyethane, and water. is preferred.

Particularly preferred are propylene carbonate and water. It is not limited to what is listed here.

The soaking temperature is preferably higher than lower for counterion exchange. Moreover, if the temperature is too high, undesirable reactions such as side reactions may occur, so the temperature is preferably 50°C or lower.

The immersion solution during immersion may be stirred using a shaker, an ultrasonic oscillator, or the like, or may be stirred using a non-contact 1i.

The immersion time for 100% counterion exchange is determined by the immersion conditions described in (e) above. For example, when the electrolyte is immersed at a high temperature and the electrolyte is immersed under stirring, counterions can be sufficiently exchanged in a shorter immersion time than vice versa.

The present invention will be explained in detail below with reference to Examples. However, the present invention is not limited to this.

Examples 1 and 2, Comparative Examples (1 to 6) A glassy carbon plate (GC-20 manufactured by Tokai Carbon Co., Ltd.) whose surface was polished as a gi electrode in a 500-inch separable flask
, Using platinum foil as a cathode, a mixed solution of 400 ae of distilled propylene carbonate and 4 d of water, tetramethylammonium hexafluorophosphate
24 g (0,024 mol) of S was added, and nitrogen gas was introduced to remove oxygen. After that, Birol 1.619 (
0,024 mol) was added.

Under nitrogen flow, against AIJ/AgC electrode 1.0■
Electrolytic oxidation was carried out for 24 hours (electrification m425 clone). After polymerization, the eroded 30 μm film was peeled off from the anode plate.

Next, this release film (2.5 ca x 2 cm x
30 μm.

PF5 - content (approximately 0.019) was mixed with an electrolyte containing various ions (Example 1: nonylfluorobutane sulftnate, Example 2: tosylate) in an amount 30 times the molar amount of the counter ion contained therein. 60d propylene carbonate at 20° C. for 48 hours.

The results obtained are shown in Table 1.

From Table 1, all counterions with a size of 10 Å or less were exchanged from 100% PF6-, and their conductivity maintained the high conductivity of the exchanged surface (Example 1゜2, Comparative Examples 4-6
). Moreover, it exhibited higher conductivity than that directly polymerized (Comparative Example 2.3). There was no decrease in conductivity under reduced pressure, which is one measure of stability, and good electrical properties were exhibited (Examples 1 and 2, Comparative Example 1).

Claims (1)

[Claims] 1. A modified polypyrrole molded product produced by oxidative polymerization in the presence of free PF_6^-, in which the counterion PF_6^- in the polypyrrole molded product is exchanged with another anion. conductive polypyrrole molded body.