JPH0674345B2 - Conductive polymer composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a π-electron conjugated conductive polymer composition.

2. Description of the Related Art It is known that by doping a π-conjugated polymer with an electron-accepting compound or an electron-donating compound, the electric conductivity is increased by eight digits or more, and the electric conductivity is close to that of a metal region from a semiconductor region. As a typical one, polyacetylene doped with halogen is known (CK
Chang et al, Phys. Rev. Lett., 39 (1977) 1098.).

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, since the conventional conductive polymer composition is not uniformly doped with a dopant, there are variations in conductivity, and once the dopant is doped, it is difficult to de-dope. is there.

Means for Solving the Problems The conductive polymer composition of the first invention comprises a polymer having a long π-electron conjugated main chain and a dissolving material containing a dopant imparting electronic conductivity and a dopant-soluble plasticizer. It is characterized by having a mobile dopant dispersed therein.

The conductive polymer composition of the second invention is a polymer having a long π-electron conjugated main chain in which a dopant for imparting electron conductivity and fine particles having a particle size of 10 to 1000 nm are dispersed. It is characterized by having a dopant.

Action According to the first aspect of the invention, the plasticity of the polymer can be enhanced by dispersing the dissolving material containing the dopant-soluble plasticizer in the polymer having a long π-electron conjugated main chain.
As a result, the dopant is likely to be uniformly dispersed in the polymer through the plastic material layer formed between the polymer chains. Further, since the dopant is dissolved in the plastic material layer, it becomes easy to remove the dopant.

According to the second invention, it is possible to form the gap between the polymer chains by the fine particles. As a result, the dopant is easily dispersed uniformly in the polymer through the gap. Also, it becomes easy to dope.

Example As shown in FIG. 1, the conductive polymer composition of the first invention comprises a polymer having a π-electron conjugated main chain, a dissolving material 2 containing a dopant-soluble plasticizer, and a dopant for imparting electronic conductivity. 3 and 3 are dispersed. Polymer is polymer 1,
The strong bond between the polymers 1 and 1 becomes a bond between the polymer 1 and the plasticizer molecule, so that the strong bond is loosened, and the plasticizer looks like a lubricating oil between the polymers 1 and 1. Works well. Since the dopant 3 is dissolved in the plastic material layer formed between the polymers 1 and 1, the dopant 3 can be uniformly dispersed in the polymer. Further, since the periphery of the polymer 1 is covered with the plastic material layer, when the dopant is removed by electrochemical, chemical or physical action, the dopant is more likely to come off than the conventional conductive polymer composition.

The polymer 1 is synthesized by chemical polymerization or electrolytic polymerization (anodic oxidation polymerization, cathodic oxidation polymerization), and specifically, polyacetylene, polythiophene, polypyrrole,
Polyphenylene sulfide, polyaniline, and their respective derivatives are used.

As the dissolving material 2, ordinary polymer plastic materials and high-boiling point solvents are effective, and among them, phthalic acid ester, phosphoric acid ester, and polyester type plastic materials are particularly effective.

The dopant 3 preferably has a small ionic radius in consideration of mobility, and is preferably at least smaller than SbF ₆ ⁻ ions. Specifically, the halogen as an electron acceptor ^{(Cl -, Br -, I} 3 -), BF 4 -, ClO 4 -, SO 4 -, PF 6 -, AsF 6 -, Sb
F ₆ ^- is mentioned. Also, as the electron donor, sodium,
Examples thereof include potassium and cesium.

As shown in FIG. 2, the conductive polymer composition of the second invention is prepared by dispersing fine particles 5 having a particle size of 10 to 1000 nm in a polymer having a π-electron conjugated main chain to obtain a polymer having a polymer content of 4 or 4. A gap is formed between them. As a result, it becomes easy to uniformly disperse in the polymer through the gap of the dopant 6. Therefore, dedoping becomes easy.

Since the fine particles 5 serve as a spacer between the polymers 4 and 4, the particle size thereof is preferably about 10 to 1000 nm. If it is 10 nm or less, it is too small to function as a spacer, and if it is 1000 nm or more, it is too large and it is difficult to form a gap between the polymers 4 and 4.

Examples of the fine particles 5 include metal oxides such as SiO ₂ , TiO ₂ , WO ₃ , ZnO and Fe ₃ O ₄ .

Hereinafter, specific examples 1 to 6 of the present invention and comparative examples 1 to 1 thereof will be described.
5 will be described.

(Example 1) Thiophene 0.2M, tetra-n-butylammonium perchlorate 0.02M, and a dissolving agent di-2-ethylhexyl phthalate
300 ml of nitrobenzene solution containing 0.2M was put in a glass container and kept at 5 ° C., using ITO glass electrode (50 × 70 mm), electrolytically oxidatively polymerized at ² mA / cm ² for 20 minutes, and ClO ₄ ⁻ ion on the anode. A polymer film doped with was obtained.

Then, it was washed with methanol and vacuum dried to obtain a polythiophene film having a thickness of about 10 μm. Ten pieces of this film were cut out for measuring conductivity, and one piece of 20 × 20 mm size was cut out for dedoping.

Example 2 A catalyst solution prepared by mixing 1.8 ml of cumene, 4.5 ml of tri-n-octylaluminum (0.01 mol) and 1.7 ml of tetra-n-butyl titanate (0.005 mol) under an argon atmosphere at 120 ° C. After heating for 2 hours, add 4 ml to a polymerization container,
Argon and cumene in the container were removed with a vacuum pump, and the catalyst solution was applied to the inner wall of the glass while rotating the polymerization container. After the pressure in the polymerization vessel dropped to 10 ^-2 Torr or less, the entire polymerization vessel was cooled to -78 ° C with a mixed refrigerant of dry ice-ethanol, and acetylene gas was introduced into the polymerization vessel while maintaining this temperature. The gas pressure at that time is about 600T
The amount of gas was adjusted to be orr. Simultaneously with the introduction of acetylene gas, polymerization occurred on the surface of the solution and on the inner wall of the container, and formation of a polyacetylene film was observed. The reaction was continued for 4 hours, the acetylene gas was removed, and the inside of the polymerization vessel was returned to an argon atmosphere. The polyacetylene film was washed with toluene under an argon atmosphere. The washing was repeated until the color of the catalyst (blackish brown) did not adhere to the solvent.

As a result, a polyacetylene film having a thickness of about 8 μm was obtained.

The obtained polyacetylene was cut into 50 × 50 mm pieces and immersed in di-2-ethylhexyl phthalate for 1 hour. After di-2-ethylhexyl phthalate adhering to the film surface was washed with toluene, it was dried under an argon atmosphere while spraying argon. This film was iodine doped in the gas phase.

From this film, 10 sheets were cut as a conductivity measuring film having a size of 2 × 20 mm, and one dedoping film having a size of 20 × 20 mm was cut.

(Example 3) Poly (3-hexyl) using 3-hexylthiophene by an organic synthesis method [Synthetic Metals, 26 (1988) 267].
Thiophene was synthesized. Obtained poly (3-hexyl)
Thiophene 1 g and solubilizer propylene adipate 0.5 g were dissolved in chloroform 100 ml. 5 ml of this solution was placed in a chalet having a diameter of 8 cm, and chloroform was spontaneously evaporated to obtain a poly (3-hexyl) thiophene film having a thickness of about 10 μm.

The film for conductivity measurement and the film for dedoping were cut out from the film obtained by doping this film with iodine in the gas phase in the same manner as in Example 1.

Example 4 Pyrrole 0.2M, hexafluoroantimony tetra-n
-Add 300 ml of propylene carbonate solution containing 0.02M butylammonium salt and 0.2M tricresyl phosphate as a solubilizer to a glass container and keep at 5 ° C.
(0 mm) was used for electrolytic oxidation polymerization at ² mA / cm ² for 20 minutes to obtain a polymer film doped with BF ₄ ⁻ ions on the anode.

Then, it was washed with methanol and vacuum dried to obtain a polypyrrole film having a thickness of about 10 μm. A film for measuring conductivity and a film for dedoping were cut out from this film in the same manner as in Example 1.

Example 5 0.02M Na ₂ SO ₄ was added to a 0.2M pyrrole aqueous solution, and 200
Suspend the mg / 1 TiO ₂ powder and then leave it at 20 mA at 20 mA / cm ² .
It was electrolytically oxidatively polymerized for a minute. TiO ₂ (average particle size 100 nm) used was manufactured by Aerosil. A polypyrrole film incorporating TiO ₂ having a thickness of about 12 μm was obtained on the anode.

A film for measuring conductivity and a film for dedoping were cut out from this film in the same manner as in Example 1.

(Example 6) 1 g of poly (3-hexyl) thiophene obtained in Example 3
SiO ₂ powder (average particle size 100 nm) was suspended in 100 ml of a chloroform solution in which was dissolved. 5 ml of this solution was placed in a chalet with a diameter of 8 cm, and chloroform was spontaneously evaporated to obtain a poly (3-hexyl) thiophene film having a thickness of about 12 μm.

This film was doped with iodine in the gas phase, and the film for conductivity measurement and the film for dedoping were cut out in the same manner as in Example 1.

(Comparative Example 1) A thiophene was electrolytically oxidatively polymerized in a solution containing no solubilizer, di-2-ethylhexyl phthalate, in Example 1 to obtain a polythiophene film.

A film for measuring conductivity and a film for dedoping were cut out from this film in the same manner as in Example 1.

(Comparative Example 2) The polyacetylene polymerized in Example 2 was treated with di-2 phthalate.
-Iodine-doped without immersion in ethylhexyl.

From the obtained film, the film for conductivity measurement and the film for dedoping were cut out in the same manner as in Example 1.

(Comparative Example 3) A film was prepared from a chloroform solution without adding the dissolving agent propylene adipate to the poly (3-hexyl) thiophene synthesized in Example 3.

From the obtained film, the film for conductivity measurement and the film for dedoping were cut out in the same manner as in Example 1.

(Comparative Example 4) In Example 4, polypyrrole was electrolytically oxidatively polymerized from a solution containing no solubilizer tricresyl phosphate.

From the obtained film, the film for conductivity measurement and the film for dedoping were cut out in the same manner as in Example 1.

Comparative Example 5 In Example 5, polypyrrole was electrolytically oxidatively polymerized from a solution containing no TiO ₂ powder.

From the obtained film, the film for conductivity measurement and the film for dedoping were cut out in the same manner as in Example 1.

Table 1 shows the results of measuring the electrical conductivity of the materials of Examples 1 to 6 and Comparative Examples 1 to 5 obtained as described above by the four-terminal method.

As is clear from Table 1, the conductivity of Comparatives 1 to 5 had a variation of 50%, but the conductivity of Examples 1 to 6 had a variation of 10% or less and the dopant was uniformly dispersed. I understand.

Next, the dedoping films of Examples 1 to 6 and Comparative Examples 1 to 5 were treated with tetra-n-butylammonium perchlorate 0.02.
It was dedoped by electrolytic reduction at ² mA / cm ² in a propylene carbonate solution containing M. The dedoped film was washed with methanol, dried in vacuum, and the dopant concentration was examined by elemental analysis. Table 2 shows the results.

As is clear from Table 2, Comparative Examples 1 to 5 contained approximately 0.01 dopant per unit of monomer even after dedoping, but in Examples 1 to 6, 0.001 or less was likely to cause dedoping. I understand.

EFFECTS OF THE INVENTION According to the present invention, it is possible to obtain a conductive polymer composition in which a dopant is more likely to be uniformly doped and more easily dedoped as compared with the conventional example.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an embodiment of the first invention, and FIG. 2 is a second diagram.
It is the schematic which shows the Example of invention. 1, 4 ... Polymer 2 ... Dissolving material 3, 6 ... Dopant 5 ... Fine particles

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Claims (5)

[Claims] 1. A mobile dopant comprising a polymer having a long π-electron conjugated main chain and a dopant imparting electron conductivity and a dissolving material containing a dopant-soluble plasticizer dispersed therein. Conductive polymer composition. 2. The conductive polymer composition according to claim 1, wherein the plastic material contains at least one of phthalic acid ester, phosphoric acid ester and polyester. 3. The conductive polymer composition according to claim 1, wherein the dopant is an ion having a radius smaller than that of SbF ₆ ⁻ ion. 4. A mobile dopant comprising a polymer having a long π-electron conjugated main chain and a dopant imparting electronic conductivity and fine particles having a particle size of 10 to 1000 nm dispersed therein. And a conductive polymer composition. 5. The conductive polymer composition according to claim 4, wherein the fine particles are metal oxides.