JPH08848B2 - Polypyrrole-based complex film and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a functional polymer material, and more particularly to a functional polymer material having high mechanical strength.

2. Description of the Related Art In recent years, research on electronic materials has been actively carried out, and among them, functional polymer materials using conjugated polymer materials have attracted attention as having various possibilities.

Examples of electronic materials include various materials such as solar cells, secondary batteries, sensors, electrode materials, antistatic materials, electromagnetic shield materials, switching elements, and semiconductor elements. Performances that are commonly required for many of such electronic materials include conductivity, mechanical strength, and stability, but none that has all the performances and can be used practically has not yet been obtained. .

It is known that when a conjugated polymer is doped with an impurity, a complex is usually formed, and an insulator or a semiconductor has an electric conductivity similar to that of a metal, and its conduction mechanism has not yet been clarified. However, it is expected as a functional material and various materials have been studied.

In the present invention, the conjugated polymer complex obtained by adding the dopant as described above will be hereinafter referred to as “polymerized complex”.

There are various polymer complexes that have been studied so far, such as acetylene-based, paraphenylene-based, thiophene-based, and pyrrole-based, but none of them have yet exhibited sufficient properties.

Particularly, acetylene-based materials have been extensively studied and many reports have been made. However, although the acetylene-based compound has satisfactory conductivity by doping, it has many problems that the mechanical strength and heat resistance are rather lowered, and there is a problem in stability.

On the other hand, various doping methods for producing a polymer complex have been tried, such as a) exposure to gas, b) immersion in a liquid containing a dopant, and c) electrochemical method.

The electropolymerization method applying an electrochemical method is a method in which a complex is formed at the same time as polymerization when a current is passed through a liquid in which a monomer and an electrolyte are dissolved, and the film thickness can be controlled by controlling the amount of electricity supplied. Therefore, in particular, a pyrrole-based and thiophene-based heterocyclic compound, which easily forms a film simultaneously with the reaction, is attracting attention as an advantageous method.

However, thiophene-based compounds tend to lack stability over a long period of time and lack stability. In this respect, the pyrrole type is superior to the thiophene type.

For the pyrrole-based polymer complex, see US Pat. No. 3,574,07.
No. 2 and JP-A-57-133,127 show that a pyrrole polymer complex is formed by an electrolytic polymerization reaction.

In the above-mentioned US patent, a complex is formed with a pyrrole using lithium tetrafluoroborate, lithium perchlorate or the like as an anion electrolyte, but the stability of the obtained complex cannot be said to be sufficient. In addition, the tensile strength when formed into a film is 5,000 psi or less, which is unsatisfactory for use as an electronic material.

Further, in the above publication, a tetrabutylammonium salt of a nitroaromatic compound is used as an electrolyte to form a pyrrole-based polymer complex at a current density of about 10 mA / cm ² ,
When it is made into a film, it becomes porous and sufficient tensile strength cannot be obtained.

The present invention has good homogeneity, excellent stability, and 5000
An object of the present invention is to provide a polypyrrole-based complex film having a tensile strength of psi or more and a method for producing the same.

Configuration The present inventors have conducted various studies for this purpose, and in particular, the type of anion electrolyte constituting the polymer complex and the current density used for the electropolymerization reaction affect the provision of the desired pyrrole polymer complex. The present invention has been found by the finding.

That is, the constitution of the present invention is (1) 5000 psi prepared by electrolytically polymerizing pyrrole or its derivative in the presence of an alkali metal salt of toluenesulfonic acid anion.
Polypyrrole-based complex film having the above tensile strength, and (2) pyrrole or its derivative in the presence of an alkali metal salt of toluenesulfonic acid anion at 0.3 to 1.5 mA / c
5000 psi characterized by electropolymerization at current density of m ²
It is a method for producing a polypyrrole-based complex film having the above tensile strength.

The pyrrole or its derivative which is a constituent of the present invention is not particularly limited, but, for example, in addition to pyrrole, 3,4-alkyl (carbon number: 1 to 4) pyrrole, 3,4-
Arylpyrrole, 3 (or 4) alkyl-4 (or 3)
-Arylpyrrole (carbon number; 1-4) can be mentioned.

The content of pyrrole or its derivative in the electrolytic solution is 0.
02 to 1.00 mol is preferable, and 0.10 to 0.30 mol is particularly effective. If it is less than 0.02 mol, the film-forming efficiency will be poor, while if it is 1.00 mol or more, it tends to be difficult to obtain a uniform film.

Further, the anion which is a constituent component of the present invention is toluenesulfonic acid.

 As the metal cation, Na, K and Li are preferable.

The content of the toluenesulfonic acid anion metal salt in the electrolytic solution is preferably 0.01 to 0.2 mol. If it is less than 0.01 mol, the polymerization efficiency will be poor, and if it is 0.2 mol or more, the undissolved electrolyte will be dispersed in the membrane and the mechanical strength will tend to be lowered, such being undesirable.

Examples of the solvent used in the production method of the present invention include polar solvents such as water, methanol, acetonitrile, benzonitrile, propylene carbonate, ν-butyl lactone, nitrobenzene, dioxane, dimethylformamide, and acetone. From the viewpoint of reactivity, acetonitrile, benzonitrile, and propylene carbonate are preferable, and when water is not used or the solvent does not contain water, a more homogeneous polymer complex is formed, and a film having high tensile strength tends to be obtained. is there.

The pyrrole-based polymer complex of the present invention is produced by placing a liquid obtained by dissolving the above-mentioned pyrrole-based monomer and an anion metal salt in a solvent in a predetermined electrolytic cell, and then performing an electrolytic polymerization reaction by anodic oxidation. If necessary, additives such as a catalyst may be added.

There are no particular restrictions on the configuration or shape of the electrolytic cell and the electrodes arranged therein, and those commonly used in the electrolysis technical field can be applied.For example, a rotating disk electrode or a multi-layered electrode can also be used, and A cathode separated by a porous film made of glass or polymer can also be used.

Examples of the material forming the electrodes include Au, Pt, Ni and other metals, oxides thereof, SnO, InO, composite electrodes or coating electrodes thereof, and particularly when a metal oxide is used for the anode, It is preferable because a film having a strong polymer complex can be obtained.

The adjustment of the electric current supplied during the electrolytic reaction is one of the most important points in the present invention, and affects the reactivity, the homogeneity of the polymer complex, the strength or the film thickness in the case of a film.
For this reason, in the present invention, the current density is set to be in the range of at least 0.3 to 1.5 mA, but it is more preferably 0.6 to 1.5 mA. If it is less than 0.3 mA, it is difficult to polymerize and only weak strength can be obtained.
If it is 1.5 mA or more, the strength is still weak, which is not preferable.

In the present invention, an alkali metal salt such as Na, Li, or K is used as the anion salt, but the electrolyte containing these salts is stable and has excellent long-term storability. The yield of the polymer complex is high, and this tendency is particularly remarkable for Na salt.

Although the bonding state of the pyrrole simple substance and the anion constituting the pyrrole polymer complex thus obtained is not exactly clear, as far as the present inventors have analyzed, the pyrrole simple substance / Anion is about 3/1
It is considered that those bonded at the ratio of are repeatedly bonded side by side.

Effect According to the method for producing a pyrrole-based polymer complex of the present invention, not only the efficiency of the polymerization reaction is excellent and the yield of the polymer complex is increased, but also the polymer complex having various properties that have not been hitherto obtained. With this characteristic, of course, regarding conductivity and stability,
When formed into a film, the homogeneity is good and the tensile strength is about 5,000 psi or more and about 10,000 psi, so that it can be applied to various electronic materials.

Hereinafter, the present invention will be described more specifically with reference to examples.

Example 1 An electrolysis solution having the following composition was placed in an electrolytic cell in which a Nesa glass plate (a composite alloy of ITO, SnO and InO) as a positive electrode and a Ni plate as a negative electrode were arranged to face each other.

Pyrrole (0.1 mol) Na-toluenesulfonate (0.05 mol) Acetonitrile was applied to this solution under the following conditions to form a film of a polymer complex on a Nesa glass plate.

Current density 1.0mA / cm ² ; Applied voltage 3.5V The yield was over 500C / L.

(It means the amount of the polymer complex corresponding to the charge amount of 500 coulomb per liter of the electrolytic solution) The properties of the polymer complex film produced are shown below.

Film thickness 38 μm; Uniformity 5; Stability ○ Tensile strength 10,500 psi; Electric conductivity 90 S / cm Measuring method (same for the following examples and comparative examples) Film thickness: By stylus film thickness meter. Electrical conductivity: By four-terminal method. Tensile strength: Tensilon UTM-III (made by Toyo Baldwin) is chucked at a width of 1 cm and a length of 3 cm.

Uniformity: Visually measure the degree of gloss. (The uniformity of the film obtained in Comparative Example 1 to be described later is set to the standard rank 3 based on the uniformity, and “excellent” is 4 and “much better” is
5, "Inferior" 5, "Inferior" as 2, and "Poor" as 1) Stability: After storage in vacuum at 80 ° C for 1 week, decrease in electrical conductivity is less than 2 digits, ○, 2 digits or more Is ●. Example 2 A solution for electrolysis having the following composition was placed in the same electrolytic cell as that used in Example 1.

Pyrrole (0.2 mol) Na paratoluenesulfonate (0.05 mol) Propylene carbonate This solution was subjected to a low current electric field anodic oxidation reaction at a current density of 0.8 mA / cm ² to form a film of the polymer complex on a Nesa glass plate. The yield was over 300 C / L.

The properties of the generated polymerized complex film are shown below.

Film thickness 20 μm; Uniformity 5; Stability ○ Tensile strength 11,000 psi; Electric conductivity 37 S / cm Example 3 An electrolytic solution having the following composition was put in the same electrolytic cell as that used in Example 1.

Pyrrole (0.2 mol) Na-toluenesulfonate (0.04 mol) Benzonitrile This solution was anodized under the following conditions to form a film of a polymer complex on a Nessa glass plate.

Current density 0.6mA / cm ² ; Applied voltage 4.0V The yield was more than 300C / L.

The properties of the generated polymerized complex film are shown below.

Film thickness 16 μm; Uniformity 5; Stability ○ Tensile strength 9,000 psi; Electric conductivity 20 S / cm Example 4 The same electrolytic bath as used in Example 1 was charged with an electrolytic solution having the following composition.

3,4 Methylpyrrole (0.1 mol) Paratoluenesulfonate Na (0.06 mol) Acetonitrile This solution was anodized under the following conditions to form a film of the polymer complex on the Nesa glass plate.

Current density 0.8mA / cm ² ; Applied voltage 4.0V The yield was more than 300C / L.

The properties of the generated polymerized complex film are shown below.

Film thickness 18 μm; Uniformity 3.5; Stability ○ Tensile strength 12,000 psi; Electric conductivity 15 S / cm Example 5 An electrolytic solution having the following composition was placed in the same electrolytic cell as that used in Example 1.

Pyrrole (0.2 mol) Orthotoluenesulfonic acid Na (0.01 mol) Acetonitrile This solution was subjected to anodic oxidation reaction under the following conditions to form a film of a polymer complex on a Nesa glass plate.

Current density 1.1mA / cm ² ; Applied voltage 3.5V The yield was over 500C / L.

The properties of the generated polymerized complex film are shown below.

Film thickness 25 μm; Uniformity 4.5; Stability ○ Tensile strength 10,000 psi; Electric conductivity 40 S / cm Comparative Example 1 The same electrolytic bath as that used in Example 1 was charged with an electrolytic solution having the following composition.

Pyrrole (0.2 mol) Tetrabutylammonium perchlorate (0.1 mol)
Nitrobenzene This solution was subjected to an anodic oxidation reaction under the following conditions to form a film of the polymer complex on the Nesa glass plate.

Current density 1.4mA / cm ² ; Applied voltage 4.0V The yield was over 50C / L.

The properties of the generated polymerized complex film are shown below.

Film thickness 18 μm; uniformity 3; stability ● Tensile strength 6,000 psi; electric conductivity 18 S / cm Comparative Example 2 The same electrolytic bath as used in Example 1 was charged with an electrolytic solution having the following composition.

Pyrrole (0.2 mol) Lithium perchlorate (0.1 mol) Acetonitrile This solution was anodized under the following conditions to form a film of a polymer complex on a Nessa glass plate.

Current density 2.0mA / cm ² ; Applied voltage 4.0V The yield was less than 50C / L.

The properties of the generated polymerized complex film are shown below.

Film thickness 22 μm; uniformity 2; stability ● Tensile strength 3,000 psi; electric conductivity 28 S / cm Comparative Example 3 The same electrolytic bath as used in Example 1 was charged with an electrolytic solution having the following composition.

Pyrrole (0.2 mol) Nitrobenzenesulfonic acid Na (0.01 mol) Acetonitrile This solution was anodized under the following conditions to form a film of a polymer complex on a Nessa glass plate.

Current density 100.0mA / cm ² ; Applied voltage 40.0V Yield was 50C / L or more.

The properties of the generated polymerized complex film are shown below.

Thickness 40μm; Uniformity 3; Stability ● Tensile strength 4,800psi; Electric conductivity 30S / cm

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Keiichi Kanto 2-1-501 Takeyacho, Suita City, Osaka Prefecture (56) References JP-A-59-23889 (JP, A) JP-A-59-226020 (JP, A)

Claims (2)

[Claims] 1. Pyrrole or its derivative is added in an amount of 0.3 to 1.5 mA in the presence of an alkali metal salt of toluenesulfonic acid anion.
50 produced by electropolymerization at a current density of / cm ²
A polypyrrole-based complex film having a tensile strength of 00 psi or more. 2. Pyrrole or its derivative is added in an amount of 0.3 to 1.5 mA in the presence of an alkali metal salt of toluenesulfonic acid anion.
5000ps characterized by electrolytic polymerization at a current density of / cm ²
A method for producing a polypyrrole-based complex film having a tensile strength of i or more.