JPH0770294A - Production of conductive polymer - Google Patents

Abstract

PURPOSE:To provide a production method of a conductive polymer having a high dielectric constant by a simple method capable of corresponding to mass production. CONSTITUTION:The characteristic of this method for producing a highly conductive pyrrole polymer by polymerizing a pyrrole compound in the solution of the pyrrole compound and an oxidizing agent comprising sulfonic acid oxide anions and high-valent transition metal cations all mixed at <=-30 deg.C therein is to perform the polymerization reaction under conditions in which the polymerization solution contains >=2wt.% of water. The concentration of the oxidizing agent is >=20wt.%; and the mixing molar ratio of the monomer is >=3 based on the oxidizing agent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a conductive polymer used as a conductive material in the field of electronics, and particularly to a method for producing a conductive polymer having high conductivity and excellent stability at high temperature. Regarding

[0002]

2. Description of the Related Art As a method for producing a conductive polymer, an electrolytic polymerization method in which an aromatic compound is electrochemically anodically polymerized and a polymerization method using an oxidizing agent are known. this house,
The electrolytic polymerization method is a method of immersing an electrode pair in an electrolyte solution containing a monomer to be polymerized and electrochemically anodizing for polymerization to obtain a film having high conductivity. For example, Synthetic Metal, Vol. 14, 271 by Sato et al.
Page (1986), conductivity of 500 S / c by electrolytic polymerization of pyrrole with p-toluene sulfonate as electrolyte.
m polypyrrole is described.

On the other hand, a conductive polymer using an oxidant is synthesized by oxidatively polymerizing a monomer with an oxidant such as ferric chloride. Journal of by Walker of of
Polymer Science, Part A, Po
Lymer Chemistry, Vol. 26, p. 1285 (1988) describes an example of polymerization of pyrrole using ferric dodecylbenzenesulfonate as an oxidant. Further, JP-A-4-46214 uses a method for synthesizing polypyrrole in which ferric dodecylbenzenesulfonate and a methanol solution of pyrrole are mixed at −30 ° C. or lower and the temperature is raised to −20 ° C. or higher for polymerization. A method of manufacturing a solid electrolytic capacitor is disclosed. However, this publication does not show a specific method for obtaining a conductive polymer having high conductivity.

[0004]

[Problems to be Solved by the Invention] In the above-mentioned method for synthesizing a conductive polymer, the reaction proceeds only on the electrode surface in the synthesis of the conductive polymer by the electrolytic polymerization method. Therefore, a conductive support must be used. It is necessary to perform a complicated operation such that the polymerization product has to be peeled off from the electrode.
Also, it was difficult to obtain a large amount of powdery product by this method. On the other hand, in the polymerization of pyrrole with an oxidizing agent, a large amount of powdery polypyrrole can be synthesized, but there is a problem that the electrical conductivity of the product is significantly smaller than that in the electrolytic polymerization method.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a method for producing a conductive polymer having a high conductivity by a simple method regardless of the presence or absence of a support.

[0006]

Means for Solving the Problems The present inventors have made various studies in order to solve the above problems. As a result, an oxidizer having a sulfonic acid compound as an anion and an expensive transition metal as a cation and pyrrole or a derivative thereof is -3
It was found that the above object can be achieved when the method for producing a polypyrrole or a polypyrrole derivative which is polymerized from a polymerization solution mixed at 0 ° C. or lower is carried out under specific conditions, and the present invention has been completed. That is, the present invention is a method for producing a polypyrrole or a polypyrrole derivative, which comprises polymerizing from a polymerization solution in which a sulfonic acid compound is an anion, and an oxidizing agent having a high number of transition metals as a cation and pyrrole or a derivative thereof are mixed at -30 ° C or less Polymerization solution is 2% polymerization amount
A method for producing a conductive polymer containing the above water, having an oxidant concentration of 20% or more and a monomer mixing molar ratio of 3 or more with respect to the oxidant.

The polymerization temperature of the present invention is not particularly limited,
The temperature is preferably 25 ° C. or lower in view of the conductivity of the conductive polymer to be generated.

In the present invention, the sulfonic acid compound which is an anion constituting the oxidizing agent is not particularly limited as long as it is a compound having a sulfonic acid group, and p-toluenesulfonate ion, ethylbenzenesulfonate ion, octylbenzenesulfonate ion, Alkylbenzenesulfonate ion such as dodecylbenzenesulfonate ion, β-naphthalenesulfonate ion, naphthalenesulfonate ion such as butylnaphthalenesulfonate ion, sulfosuccinate ion, organic sulfonate ion such as N-acylsulfonate ion, C ₈ To C ₁₂ alkyl sulfonate ion and α-olefin sulfonate ion, and the like, and aromatic sulfonate anion having an alkyl substituent such as alkylbenzene sulfonate ion is particularly preferable. In addition, as the expensive transition metal ions that are cations that constitute the oxidizing agent, Ag ⁺ , Cu ^{2 +} , Fe ^{3 +} ,
^{Al 3 +, Ce 4 +,} W 6 +, Mo 6 +, Cr 6 +, M
n ^{7 +} , Sn ^{4 +,} etc., but especially Fe ^{3 +} ,
And Cu ²⁺ are preferred.

In the present invention, the derivative of pyrrole is a compound having a pyrrole skeleton and having a substituent at the 3-position or N-position, or a mixture of these and pyrrole, and the substituent is a hydroxyl group, an acetyl group or a carboxyl group. Base,
An alkyl group is mentioned.

In the present invention, a solution is prepared by mixing the above-mentioned pyrrole or its derivative and an oxidizing agent at -30 ° C or lower. The solvent is particularly limited as long as it can dissolve both the pyrrole or its derivative and the oxidizing agent. Not done. Examples of these are methanol, ethanol, isopropyl alcohol, acetone, methyl ethyl ketone,
Diethyl ether, acetonitrile, tetrahydrofuran and the like can be mentioned.

In the present invention, the solution in which pyrrole or its derivative and the oxidizing agent are mixed contains 2% by weight or more of water, but a completely dehydrated solution does not become a uniform solution due to polymerization even at -30 ° C or lower. According to the study by the present inventors, if the amount of water in the reaction solution is 2% by weight or more, the conductivity of the resulting conductive polymer is not affected. If it is less than that, the polymerization proceeds before the oxidizing agent and the monomer become a uniform solution, and the conductivity decreases.

In the present invention, the polymerization atmosphere is not particularly limited.

The present invention will be described below with reference to the drawings. Fig. 1 shows the relationship between the ferric dodecylbenzene sulfonate concentration and the conductivity of the polypyrrole produced in a methanol solution prepared by mixing 3 mol of pyrrole with dodecyl benzene sulfonate at -70 ° C. is there. It can be seen that the electrical conductivity sharply increases at 20% by weight or more.
FIG. 2 is a plot of conductivity of polypyrrole obtained by dissolving 20% by weight of ferric dodecylbenzenesulfonic acid in methanol and reacting pyrrole with the amount of pyrrole added to dodecylbenzenesulfonic acid. In the figure, (a) is the result of polymerizing ferric dodecylbenzene sulfonate and pyrrole at -70 ° C., stirring and polymerizing,
(B) is the result of mixing at the polymerization temperature. -30 ° C
The conductivity is higher when mixed below, and the amount of pyrrole added is 3 with respect to ferric dodecylbenzene sulfonate.
It can be seen that the value becomes 60 S / cm or more beyond the double molar limit. This conductivity value is in agreement with the conductivity of polypyrrole synthesized by the electrolytic polymerization method using the same electrolyte anion. In general, in the polymerization reaction of pyrrole with a ferric salt, it is considered that 2 mol per mol of pyrrole is used for coupling, and about 0.25 mol is used for doping. Therefore, the pyrrole required per mol of the ferric salt is calculated to be 0.44 mol. The above results show that polypyrrole of high conductivity can be obtained with a much larger amount of pyrrole added. In FIG. 3, 20% by weight of ferric dodecylbenzene sulfonate was dissolved in methanol to give 2 parts of ferric dodecylbenzene sulfonate.
The polypyrrole conductivity obtained by reacting a double mole of pyrrole is plotted against the polymerization temperature. In the figure, (a) shows ferric dodecylbenzene sulfonate and pyrrole at -70 ° C.
(B) is the result of mixing at the polymerization temperature. It can be seen that the conductivity is higher when mixed at −30 ° C. or lower, and becomes 40 S / cm or higher at around 25 ° C. as a boundary with respect to the polymerization temperature.

The conductive polymer produced by the method of the present invention has high conductivity and excellent stability, and therefore can be used as a solid electrolyte of a capacitor, an electrode material, an antistatic material, an electromagnetic wave shielding material and the like.

[0015]

EXAMPLES Next, examples of the present invention will be described.

(Example 1) Concentrations of 26.7% by weight, 40% by weight, and 53.3% by weight in three glass reaction vessels.
75 g of a solution of ferric dodecylbenzene sulfonate in methanol was added to each, and 5 g of distilled water was added dropwise, and the mixture was stirred-
An oxidant solution was prepared by cooling to 70 ° C. Next, 3.84 g, 5.76 G, and 7.67 g of pyrrole were dissolved in 16.16 g, 14.24 g, and 12.33 g of methanol to prepare 20 g of a methanol solution of pyrrole. These solutions were added dropwise to ferric dodecylbenzene sulfonate solutions cooled to -70 ° C, respectively, and the oxidant concentrations were 20% by weight, 30% by weight, and 40% by weight, respectively. A solution containing pyrrole and 5 wt% water was prepared. When these solutions were reacted at 0 ° C. for 2 hours, black polypyrrole was produced. This was separated by filtration, washed with methanol, and further dried at 60 ° C. for 30 minutes to obtain a conductive polypyrrole powder.
As shown in FIG. 1, the electric conductivity was 10 S / cm or more, and had excellent characteristics as a conductive material.

(Comparative Example 1) Concentration of 1 in a glass reaction vessel
75 g of a 3.3 wt% ferric dodecyl benzene sulfonate methanol solution was added, 5 g of distilled water was added dropwise, and the mixture was cooled to -70 ° C with stirring to prepare an oxidant solution. Next, 1.92 g of pyrrole was dissolved in 18.08 g of methanol and added dropwise to the oxidizing solution at -70 ° C to adjust the oxidant concentration to 10
A solution was prepared containing, by weight, 3 times the molar amount of pyrrole to the oxidant and 5% by weight of water. When this solution was reacted at 0 ° C. for 2 hours, black polypyrrole was produced. This was separated by filtration, washed with methanol, and further dried at 60 ° C. for 30 minutes to obtain polypyrrole powder. Conductivity to 10 as shown in FIG. 1 ^- a ² S / cm, was extremely low.

(Example 2) 75 g of a solution of ferric dodecyl benzene sulfone in methanol having a concentration of 40% by weight was placed in 6 glass reaction vessels, 5 g of distilled water was added dropwise, and the mixture was cooled to -70 ° C while stirring. Then, an oxidant solution was prepared. Next, 20 g of a methanol solution containing 7.67 g of pyrrole,
20 g of a methanol solution containing 8.95 g of pyrrole,
20 g of a methanol solution containing 2.56 g of pyrrole, 1
20 g of a methanol solution containing 0.23 g of pyrrole, 1
20 g of a methanol solution containing 2.8 g of pyrrole, 15
3. 20 g of a methanol solution containing 20 g of pyrrole, and 20 g of pyrrole were dropped into an oxidant solution kept at -70 ° C., respectively, and the oxidant concentration was 30% by weight, and 3.0, 3.5, Solutions were prepared containing 4.0, 5.0, 6.0, and 8.0 moles of pyrrole and 5% by weight water. When this solution was reacted at 0 ° C. for 2 hours, black polypyrrole was produced. This was separated by filtration, washed with methanol, and further dried at 60 ° C. for 30 minutes to obtain conductive polypyrrole powder. As shown in FIG. 2 (a), the electric conductivity was 50 S / cm or more, and had excellent characteristics as a conductive material.

(Comparative Example 2) 75 g of a solution of ferric dodecylbenzenesulfone in methanol having a concentration of 40% by weight was placed in 6 glass reaction vessels, 5 g of distilled water was added dropwise, and the mixture was cooled to -70 ° C while stirring. To prepare an oxidant solution. Next, 20 g of a methanol solution containing 1.02 g of pyrrole,
20 g of a methanol solution containing 1.28 g of pyrrole,
20 g of a methanol solution containing 2.56 g of pyrrole,
20 g of a methanol solution containing 3.84 g of pyrrole,
20 g of a methanol solution containing 5.11 g of pyrrole and 20 g of a methanol solution containing 6.39 g of pyrrole were added dropwise to the oxidant solution kept at -70 ° C., and the oxidant concentration was 30 wt% with respect to the oxidant. 0.4, 0.5,
Solutions were prepared containing 1.0, 1.5, 2.0 and 2.5 moles of pyrrole and 5% by weight water. When this solution was reacted at 0 ° C. for 2 hours, black polypyrrole was produced.
This is separated by filtration, washed with methanol, and further washed at 60 ° C for 3 times.
When dried for 0 minutes, a conductive polypyrrole powder was obtained. The conductivity is all 40 S / as shown in FIG.
It was below cm and was low.

(Example 3) 75 g of a solution of ferric dodecylbenzenesulfone in methanol having a concentration of 26.7% was placed in 6 glass reaction vessels, 5 g of distilled water was added dropwise, and the mixture was cooled to -70 ° C while stirring. Then, an oxidant solution was prepared. Next, 20 g of a methanol solution containing 3.84 g of pyrrole was
The oxidant concentration was adjusted to 20 by dropping it into the oxidant solution kept at 70 ° C.
A polymerization solution was prepared containing 3 mol of pyrrole and 5 wt% of water with respect to the oxidizing agent in wt%. This solution at -20 ° C,-
When reacted at 10 ° C, 0 ° C, 10 ° C, 20 ° C, and 25 ° C for 2 hours, black polypyrrole was produced. This was separated by filtration, washed with methanol, and further dried at 60 ° C. for 30 minutes to obtain a conductive polypyrrole powder.
As shown in FIG. 3, the electric conductivity was 30 S / cm or more, and had excellent characteristics as a conductive material.

(Comparative Example 3) When the polymerization solution of Example 3 was reacted at 30 ° C, 40 ° C and 50 ° C for 2 hours, black polypyrrole was produced. This was separated by filtration, washed with methanol, and further dried at 60 ° C. for 30 minutes to obtain a conductive polypyrrole powder. As shown in FIG. 3, the electrical conductivity was 30 S / cm or less, which was low.

(Example 4) Concentration of 2 in a glass reaction vessel
75 g of a 6.6 wt% ferric dodecylbenzenesulfonic acid methanol solution was added, 5 g of distilled water was added dropwise, and the mixture was cooled to −70 ° C. with stirring to prepare an oxidant solution. Next, 20 g of a methanol solution containing 5.53 g of pyrrole
Was added dropwise to the oxidant solution kept at -70 ° C to prepare a polymerization solution having an oxidant concentration of 20% by weight and containing 3 mol of pyrrole and 5% by weight of water with respect to the oxidant. When this solution was reacted at 0 ° C. for 2 hours, black polypyrrole was produced.
This is separated by filtration, washed with methanol, and further washed at 60 ° C for 3 times.
When dried for 0 minutes, a conductive polypyrrole powder was obtained. The conductivity was 30 S / cm or more, and it had excellent properties as a conductive material.

Example 5 A glass reaction vessel with a concentration of 2
75 g of a 6.6 wt% ferric butylnaphthalenesulfonic acid methanol solution was added, 5 g of distilled water was added dropwise, and the mixture was cooled to -70 ° C. with stirring to prepare an oxidant solution. Next, 20 g of a methanol solution containing 4.68 g of pyrrole
Was added dropwise to the oxidant solution kept at -70 ° C to prepare a polymerization solution having an oxidant concentration of 20% by weight and containing 3 mol of pyrrole and 5% by weight of water with respect to the oxidant. When this solution was reacted at 0 ° C. for 2 hours, black polypyrrole was produced.
This is separated by filtration, washed with methanol, and further washed at 60 ° C for 3 times.
When dried for 0 minutes, a conductive polypyrrole powder was obtained. The conductivity was 30 S / cm or more, and it had excellent properties as a conductive material.

(Embodiment 6) Concentration of 2 in a glass reaction vessel
75 g of a 6.7 wt% ferric dodecylbenzenesulfonic acid methanol solution was added, 5 g of distilled water was added dropwise, and the mixture was cooled to -70 ° C with stirring to prepare an oxidant solution. Next, 20 g of a methanol solution containing 4.59 g of N-methylpyrrole was added dropwise to the oxidant solution kept at -70 ° C,
The concentration of the oxidant is 20% by weight and 3 mol of N- with respect to the oxidant
A polymerization solution containing methylpyrrole and 5% by weight of water was prepared. When this solution was reacted at 0 ° C. for 2 hours, black polypyrrole was produced. This was separated by filtration, washed with methanol, and further dried at 60 ° C. for 30 minutes to obtain a conductive polypyrrole powder. The conductivity was 1 S / cm or more, and it had excellent properties as a conductive material.

(Comparative Example 4) Concentration of 2 in a glass reaction vessel
75 g of a 6.6 wt% ferric dodecylbenzenesulfonic acid methanol solution was added, 5 g of distilled water was added dropwise, and the mixture was cooled to −70 ° C. with stirring to prepare an oxidant solution. Next, 25 g of a methanol solution containing 3.84 g of pyrrole
Was added dropwise to the oxidant solution kept at -70 ° C, the solution immediately turned black and a block-like product was obtained. This was washed with methanol and further dried at 60 ° C. for 30 minutes to obtain poropyrrole having an electric conductivity of 1 S / cm or less.

[0026]

As described above, according to the present invention, a conductive polymer having high conductivity can be obtained by a simple method, and the effect is great.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the polypyrrole conductivity and the oxidant concentration obtained in Example 1 and Comparative Example 1.

FIG. 2 is a graph showing the relationship between the electrical conductivity of the polypyrrole obtained in Example 2 and Comparative Example 2 and the molar ratio of the monomer in the polymerization solution to the oxidizing agent.

FIG. 3 is a graph showing the relationship between the electrical conductivity of the polypyrrole obtained in Example 3 and Comparative Example 3 and the polymerization temperature.

Claims (4)

[Claims] 1. A method for producing a polypyrrole or a polypyrrole derivative, which comprises polymerizing from a polymerization solution in which an oxidant having a sulfonic acid compound as an anion and an expensive transition metal as a cation and pyrrole or a derivative thereof are mixed at −30 ° C. or lower, The method for producing a conductive polymer, wherein the polymerization solution contains 2% by weight or more of water, the concentration of the oxidizing agent is 20% by weight or more, and the mixing molar ratio of the monomer is 3 or more with respect to the oxidizing agent. 2. The method for producing a conductive polymer according to claim 1, wherein the polymerization temperature is 25 ° C. or lower. 3. The high-valence transition metal which is a cation of the oxidizing agent is ferric ion or cupric ion.
A method for producing the conductive polymer described. 4. The method for producing a conductive polymer according to claim 1, wherein the sulfonic acid compound which is the anion of the oxidizing agent is an aromatic sulfonic acid having an alkyl substituent.