JP2008214446A - Electroconductive polymer composition and production method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new electroconductive polymer composition causing little environmental load in production steps, and excellent in film-formability and electroconductivity. <P>SOLUTION: The electroconductive polymer composition is composed of a soluble polypyrrole derivative and an ionic liquid, which polypyrrole derivative has a structural unit represented by the formula [wherein, R<SB>1</SB>is a (substituted) alkyl, a (substituted) alkoxy, a halogen or a (substituted) phenyl; and R<SB>2</SB>is a (substituted) alkyl or a (substituted) phenyl] and 500-1,000,000 weight-average molecular weight. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a conductive polymer composition excellent in processability and a method for producing the same, and more specifically, a conductive material and molding that are soluble in various solvents, excellent in processability, excellent in electrical and mechanical properties, and molding. The present invention relates to a conductive polymer composition applicable to a body manufacturing method and a method for producing the same.

  Conductive polymers are attracting attention as materials having many functions as conjugated organic polymers, utilizing the electrical, chemical, and optical properties of π electrons. However, conductive polymers lack insolubility and infusibilities and lack the moldability unique to polymers, and their application range is limited. Recently, it has been proposed to introduce a substituent into a conjugated main chain to solubilize, and at the same time, an attempt has been made to oxidize and dope a dissolved polymer in a solution state.

In recent years, organic polymer materials having electron conductivity have been studied for a wide range of application to antistatic materials, electromagnetic wave shielding materials, secondary batteries, capacitors, electrochromic display elements, and the like. As the electron conductive polymer, polyacetylene, polyaniline, polyphenylene vinylene, polypyrrole, polythiophene and the like are known. Among them, polyaniline soluble in N-methyl-2-pyrrolidone (M. Abe et al .; J. Chm. Soc., Chem. Commun.,
1989, p. 1736), polypyrrole and polythiophene introduced with substituents such as alkyl groups (M. -A. Sato, S. Tanaka, K. Kaeriyama: Synth. Met.,
1987, 18, p. 229). Further, it is known that a polymer such as polyphenylene vinylene is soluble in its precursor polymer. Since these polymers can be formed by casting, application of various polymer films to antistatic materials and the like has been studied. However, in order to impart conductivity to the conductive polymer, it is necessary to treat (doping) with an electron-accepting or electron-donating compound after molding, and operations such as immersion in an acidic solution and exposure to a dopant vapor are required. Therefore, there was a problem in the processing surface.

  As means for solving the problems of the conductive polymer described above, a conductive polymer having a self-doping property in which a counter ion serving as a dopant is covalently bonded to a polymer has been proposed (for example, see Non-Patent Document 1). . However, this type of conductive polymer has a sulfonic acid group in the polymer chain, so the polymer itself is strongly acidic and applied to applications that come into contact with materials that are subject to corrosion or acid degradation. I couldn't. In addition, a method for producing a conductive polymer film using a homogeneous solution of an organic electron acceptor and a polypyrrole derivative has been proposed. However, a high-concentration polymer solution has a problem that the mixed solution tends to be in a gel state.

Therefore, various attempts have been made to obtain a stable uniform mixed solution even in a high concentration solution by examining a combination of a soluble conductive polymer and a dopant (see, for example, Patent Document 1). ). In preparing a uniform solution of a solution of a polypyrrole derivative and an organic electron acceptor, the substituents on the pyrrole ring are limited, and 2,3,7,8-tetracyano-1,4, It has been proposed to prepare a solution for forming a conductive polymer film excellent in film formability by using 6,9-tetraazanaphthalene (see, for example, Patent Document 2).
JP-A-08-157574 (page 3-4) JP 05-287088 A (second page) A. Oh. AO Patil et al., “Journal of the American Chemical Society”, 1987, 109, p. 1858-1859

  The methods described in Patent Documents 1 and 2 require a large amount of organic solvent to produce the target conductive polymer, and it is desired to cope with environmental problems in recent years. There's a problem. Further, there is a problem that it is essential to use 2,3,7,8-tetracyano-1,4,6,9-tetraazanaphthalene as the organic electron acceptor. For this reason, development of a new conductive polymer composition is desired.

  The present invention has been made in view of the circumstances as described above, and an object thereof is to provide a novel conductive polymer composition having a low environmental load in the production process and excellent in film formability and conductivity. And providing a manufacturing method thereof.

但し、化１に示す式中において、Ｒ_１ は、置換もしくは未置換のアルキル、置換もしくは未置換のアルコキシ、ハロゲンまたは置換もしくは未置換のフェニルを表し、Ｒ_２は、置換もしくは未置換のアルキルまたは置換もしくは未置換のフェニルを表す。 The inventor of the present application has intensively studied to achieve the above object. As a result, it has been found that the above object can be achieved by the coexistence of the polypyrrole derivative and the ionic liquid, and the present invention has been completed.
That is, the conductive polymer composition of the invention according to claim 1 includes a soluble polypyrrole derivative having a structural unit represented by the chemical formula shown in Chemical Formula 1 and having a weight average molecular weight of 500 to 1,000,000, an ion It is composed of a sex liquid.

However, in the formula shown in Chemical Formula ₁ , R ₁ Represents substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, halogen or substituted or unsubstituted phenyl, and R ₂ represents substituted or unsubstituted alkyl or substituted or unsubstituted phenyl.

  The invention according to claim 2 is the conductive polymer composition according to claim 1, wherein the ionic liquid is composed of an imidazolium salt, a pyridinium salt, an aliphatic quaternary ammonium salt, and an alicyclic quaternary ammonium salt. 1 type selected from the group which consists of, or a combination of 2 or more types.

但し、化２に示す式中において、Ｒ_１ は、置換もしくは未置換のアルキル、置換もしくは未置換のアルコキシ、ハロゲンまたは置換もしくは未置換のフェニルを表し、Ｒ_２は、置換もしくは未置換のアルキルまたは置換もしくは未置換のフェニルを表す。
上記した構成によれば、過剰の有機溶剤を用いることなく目的とする導電性高分子組成物を得ることができる。 According to a third aspect of the present invention, in the method for producing the conductive polymer composition according to the first or second aspect, the polymerization of the monomer represented by the chemical formula shown in Chemical Formula 2 is performed in an ionic liquid. It is characterized by.

However, in the formula shown in Chemical Formula 2, R ₁ Represents substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, halogen or substituted or unsubstituted phenyl, and R ₂ represents substituted or unsubstituted alkyl or substituted or unsubstituted phenyl.
According to the configuration described above, the intended conductive polymer composition can be obtained without using an excessive organic solvent.

  As described above, the conductive polymer composition of the present invention includes a soluble polypyrrole derivative and an ionic liquid. Therefore, this conductive polymer composition is a novel composition that does not necessarily require the commonly used organic electron acceptor to coexist for the development of conductivity. Further, since the polymerization reaction is carried out in an ionic liquid that should coexist in the production process, there is an advantage that it is not necessary to use an excessively large amount of organic solvent.

但し、化１に示す式中において、Ｒ_１ は、置換もしくは未置換のアルキル、置換もしくは未置換のアルコキシ、ハロゲンまたは置換もしくは未置換のフェニルを表し、Ｒ_２は、置換もしくは未置換のアルキルまたは置換もしくは未置換のフェニルを表す。 The conductive polymer composition according to the present invention comprises a soluble polypyrrole derivative having a structural unit represented by the chemical formula shown in Chemical Formula 1 and having a weight average molecular weight of 500 to 1,000,000 and an ionic liquid. The

However, in the formula shown in Chemical Formula ₁ , R ₁ Represents substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, halogen or substituted or unsubstituted phenyl, and R ₂ represents substituted or unsubstituted alkyl or substituted or unsubstituted phenyl.

Preferable specific examples of the polypyrrole derivative represented by the chemical formula shown in Chemical Formula 1 include R ₁ Is a linear alkyl group, more preferably a methyl group, and R ₂ is a linear alkyl group, more preferably an alkyl group having 2 to 18 carbon atoms. The polypyrrole derivative referred to in the present invention includes a copolymer of structural units represented by the chemical formula shown in Chemical Formula 1, a monomer that forms the structural unit represented by the chemical formula shown in Chemical Formula 1, and other monomers, for example, Copolymers obtained from monomers such as pyrrole, N-methylpyrrole, 3-methylpyrrole, thiophene, and 3-methylthiophene are also included. A typical molecular weight is 10,000 to 200,000 in terms of a weight average molecular weight, and is preferably 200,000 or less in order to obtain high solubility, and 20 in order to obtain high conductivity and toughness. , 000 or more is preferable.

The conductive polymer composition of the present invention comprises, for example, one or more compounds represented by the chemical formula shown in Chemical Formula 2 (wherein R ₁ and R ₂ have the same meaning as described above), The polypyrrole derivative shown in Chemical formula 1 can be chemically polymerized in the presence of an oxidative transition metal halide using an ionic liquid as a solvent, followed by post-treatment such as neutralization washing. Further, a copolymer containing other monomer units can be produced in the same manner.

  The method for producing a polypyrrole derivative represented by the chemical formula shown in Chemical Formula 1 can be produced by appropriately selecting a known reaction or a similar reaction.

  The ionic liquid used in the present invention is not particularly limited as long as it is a liquid in the temperature range where the polymerization reaction of the polypyrrole derivative is carried out, but preferably an imidazolium salt, a pyridinium salt, an aliphatic quaternary ammonium salt and It is selected from one or a combination of two or more selected from the group consisting of alicyclic quaternary ammonium salts.

The imidazolium salt is represented by, for example, each chemical formula shown in Chemical Formula 3, Chemical Formula 4, and Chemical Formula 5 (wherein R ₁ represents H or alkyl, and R ₂ represents alkyl). A compound is used.

As the pyridium salt, for example, a compound represented by the chemical formula shown in Chemical Formula 6 (wherein R represents alkyl) is used.

As the aliphatic quaternary ammonium salt, for example, a compound represented by the chemical formula shown in Chemical Formula 7 (wherein R represents alkyl) is used.

但し、化３ないし化９に示す各式中において、Ｘ⁻は、Ｂｒ⁻、ＰＦ_６ ⁻、ＢＦ_４ ⁻または（ＣＦ_３ＳＯ_２）_２Ｎ⁻）を表す。 In addition, as the alicyclic quaternary ammonium salt, for example, compounds represented by chemical formulas shown in Chemical Formula 8 and Chemical Formula 9 (wherein R ₁ and R ₂ each represent alkyl) are used. The

However, in each formula shown in Chemical Formula 3 to Chemical Formula 9, X ⁻ represents Br ⁻ , PF ₆ ⁻ , BF ₄ ⁻ or (CF ₃ SO ₂ ) ₂ N ⁻ ).

  The conductive polymer composition obtained by the method according to the present invention can be dissolved in a suitable solvent and an organic electron acceptor can be added.

  The conductive polymer composition of the present invention can be applied to, for example, an antistatic film, a transparent conductive film, and various electronic device electrodes.

  Ethoxymethylpyrrole (0.5 g, 3.2 mmol) was dissolved in 1-ethyl-3-methyl-imidazole boron tetrafluoride (2.0 g) and stirred at room temperature. An anhydrous ferric chloride solution (3.13 g, 9.65 mmol) in 1-ethyl-3-methyl-imidazole boron tetrafluoride (10.35 g) solution was blown into the ethoxymethylpyrrole solution while the solution temperature was 25. The solution was added dropwise so as to keep the temperature ± 2 ° C. The polymerization reaction of ethoxymethylpyrrole was carried out by stirring at room temperature while blowing dry air into the solution for 4 hours after the completion of the dropping. The reaction was terminated by stopping the blowing of dry air into the solution and adding 2.5 g of dry methanol into the solution. Further, 15 g of dry methanol was added to the solution and stirred for 15 minutes, and then the reaction solution was filtered under reduced pressure to obtain a black powder. The black powder was put into 15 g of methanol and stirred, and then filtered to remove excess 1-ethyl-3-methyl-imidazole tetratetrafluoroboron salt and ferric chloride residue by washing.

  The obtained black powder was dispersed in 6 ml of tetrahydrofuran and stirred, and 80% hydrazine hydrate was added dropwise until the pH reached 9, followed by stirring for 1 hour. Next, a 10% sulfuric acid-tetrahydrofuran solution was added dropwise until pH 7 was reached, followed by stirring for 1 hour. Further, 5 ml of toluene and 0.1 ml of distilled water were added, stirred for 1 hour, allowed to stand, and the precipitate was filtered through a funnel covered with celite. The filtrate was washed twice with 10 ml of distilled water and dried over magnesium sulfate to obtain a tetrahydrofuran-toluene mixed solution of ethoxymethyl polypyrrole. The molecular weight of the ethoxymethyl polypyrrole obtained here was 18,000 (weight average molecular weight in terms of styrene). The electrical conductivity of the conductive polymer composition film obtained by forming this conductive polymer composition solution was measured (Mitsubishi Chemical, Hiresta or Loresta), and the pencil hardness was measured. The measurement results are shown in Table 1. Moreover, the infrared absorption spectrum (IR spectrum) of the obtained conductive polymer composition was measured. The measurement results are shown in FIG.

  In the same manner as in Example 1, polypyrrole was synthesized by changing only the ionic liquid to N-methyl-N-propylpiperidinium bis (trifluoromethanesulfonyl) imide. Measurement of electrical conductivity of the conductive polymer composition film obtained by forming the resulting conductive polymer composition solution (Mitsubishi Chemical, Hiresta or Loresta) and pencil hardness were performed. . The measurement results are shown in Table 1.

[Comparative Example 1]
The 1-ethyl-3-methyl-imidazole boron tetrafluoride salt in Example 1 described above was changed to butyl acetate, and a tetrahydrofuran-toluene mixed solution of ethoxymethyl polypyrrole was obtained in the same manner. The molecular weight of ethoxymethyl polypyrrole obtained here was 52,000 (weight average molecular weight in terms of styrene). The electrical conductivity of the conductive polymer composition film obtained by forming this conductive polymer composition solution was measured (manufactured by Mitsubishi Chemical, Hiresta or Loresta), and the pencil hardness was measured. The measurement results are shown in Table 1. Table 1 also shows the electrical conductivity of the PET film. Moreover, the infrared absorption spectrum of the obtained conductive polymer composition was measured. The measurement results are shown in FIG.

  In the conductive polymer composition solution obtained in Example 1, 2,3,7,8-tetracyano-1,4,6,9-tetraazanaphthalene (TCNA) was added to the conductive polymer composition. On the other hand, the electrical conductivity of the film obtained by adding 25 weight percent (Mitsubishi Chemical, Hiresta or Loresta) and pencil hardness were measured. The measurement results are shown in Table 2. Moreover, the infrared absorption spectrum of the obtained conductive polymer composition was measured. The measurement results are shown in FIG.

  In the conductive polymer composition solution obtained in Example 2, 2,3,7,8-tetracyano-1,4,6,9-tetraazanaphthalene (TCNA) was added to the conductive polymer composition. On the other hand, the electrical conductivity of the film obtained by adding 25 weight percent (Mitsubishi Chemical, Hiresta or Loresta) and pencil hardness were measured. The measurement results are shown in Table 2.

[Comparative Example 2]
In the conductive polymer composition solution obtained in Comparative Example 1, 2,3,7,8-tetracyano-1,4,6,9-tetraazanaphthalene (TCNA) was added to the conductive polymer composition. On the other hand, the electrical conductivity of the film obtained by adding 25 weight percent (Mitsubishi Chemical, Hiresta or Loresta) and pencil hardness were measured. The measurement results are shown in Table 2. Moreover, the infrared absorption spectrum of the conductive polymer composition was measured. The measurement results are shown in FIG.

  The conductive polymer compositions obtained in the above examples of the present invention have not been able to specify a clear structure, but comparison of IR spectra with the conductive polymer compositions obtained in Comparative Examples Thus, rather than a simple mixture of polypyrrole and ionic liquid, it exhibits some interaction between polypyrrole and ionic liquid, resulting in the presence of dopants normally required for conductivity development. It is considered that conductivity was confirmed even without it.

  The conductive composition of the present invention is used to produce, for example, an antistatic film, a transparent conductive film, and various electronic device electrodes.

It is a figure which shows the infrared absorption spectrum of the conductive polymer composition obtained in Example 1 of this invention. It is a figure which shows the infrared absorption spectrum of the conductive polymer composition obtained in Example 3 of this invention. 4 is a diagram showing an infrared absorption spectrum of a conductive polymer composition obtained in Comparative Example 1. FIG. It is a figure which shows the infrared absorption spectrum of the conductive polymer composition obtained by the comparative example 2.

Claims (3)

The chemical formula shown in Chemical Formula 1 (wherein R ₁ Represents substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, halogen or substituted or unsubstituted phenyl, and R ₂ represents substituted or unsubstituted alkyl or substituted or unsubstituted phenyl. And a soluble polypyrrole derivative having a weight average molecular weight of 500 to 1,000,000 and an ionic liquid.

The conductive polymer composition according to claim 1,
The ionic liquid is one or a combination of two or more selected from the group consisting of imidazolium salts, pyridinium salts, aliphatic quaternary ammonium salts and alicyclic quaternary ammonium salts. Conductive polymer composition. In the method for producing the conductive polymer composition according to claim 1 or 2,
Chemical formula shown in Chemical Formula 2 (wherein R ₁ Represents substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, halogen or substituted or unsubstituted phenyl, and R ₂ represents substituted or unsubstituted alkyl or substituted or unsubstituted phenyl. ) Is carried out in an ionic liquid. A method for producing a conductive polymer composition.

Images