JPH11209461A - Polymer having thiophene structure, composition comprising same, preparation of same and electroconductive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the title polymer useful as an electroconductive material by subjecting a specific compound of a structure wherein two thiophene rings are bonded via a trans-vinylene group to liquid phase polymerization in the presence of a transition metal salt of sulfonic acid. SOLUTION: One mole of a compound of a structure wherein two thiophene rings are bonded via a trans-vinylene group of the formula (wherein n is 1-3; R1 -R4 are each H, alkyl, alkenyl, alkoxy, alkanoyl, alkylthio, aryloxy, alkylthioalkyl, alkylsufinylalkyl, alkylsulfonylalkyl, alkylaryl, arylalkyl, cycloalkyl, alkylsulfinyl, alkylsulfonyl, aryl, arylthio, cycloalkenyl, arylsulfinyl, arylsulfonyl, sulfonic group or the like) is polymerized in the presence of 2-10 moles, preferably 2-5 moles, of a transition metal salt of sulfonic acid in a liquid phase containing 0.01-0.5 mole of the compound per liter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer having a thiophene structure, a polymer composition containing the polymer, and a method for producing the polymer, and more particularly to a polymer which can be suitably used as a conductive polymer. , A polymer composition and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION In recent years, with the development of electronics, new electronic materials have been developed. In particular, remarkable technological progress has been made in the field of functional organic materials. A conductive compound to which a conductive compound is added as a dopant has been developed and partially put to practical use.

[0003] By the way, a solid electrolytic capacitor has an anode made of tantalum, aluminum, or the like.
It has an oxide film of tantalum, aluminum, etc. as a dielectric, and has manganese dioxide and tetracyanoquinodimethane (T
One using a CNQ) complex salt as a cathode has been developed. However, in the case of a solid electrolytic capacitor using manganese dioxide as a cathode, the impedance in a high-frequency region increases due to the low dielectric constant of manganese dioxide.
In a solid electrolytic capacitor using an NQ complex salt as a cathode, TCN
There is a problem that the heat resistance is inferior because the Q complex salt is easily thermally decomposed.

On the other hand, when the above-mentioned conductive compounds such as polypyrrole and polyaniline are used as the cathode, these conductive compounds have a higher dielectric constant than manganese dioxide and a higher heat resistance than the TCNQ complex salt. It has the characteristic that it is.

For this reason, many proposals have been made for solid electrolytic capacitors using these conductive compounds as cathodes. For example, Japanese Patent Application Laid-Open No. Sho 60-37114 discloses a solid electrolytic capacitor using a heteropentacyclic polymer compound doped with a dopant as a solid electrolyte. Japanese Patent Application Laid-Open No. 6-29159 discloses a solid electrolytic capacitor using polyaniline as a solid electrolyte.

However, since elements for information electronic equipment including solid electrolytic capacitors are required to have high performance and high density, solid electrolytic capacitors have good characteristics up to a high frequency range, and furthermore, have high heat resistance. It is desired to be excellent.

[0007]

An object of the present invention is to provide a polymer or a copolymer having a thiophene structure, which can be suitably used as a conductive material, and a method for producing the same. The purpose is.

[0008]

SUMMARY OF THE INVENTION The polymer having a thiophene structure according to the present invention is obtained by converting a compound having two thiophene rings bonded through a trans-vinylene group represented by the following general formula [1] to a transition metal of sulfonic acid. It is characterized by being obtained by polymerization in a liquid phase in the presence of a salt.

[0009]

Embedded image

In the formula, n represents an integer of 1 to 3, and R _{1 to} R ₄
May be the same or different from each other, and include a hydrogen atom, an alkyl group, an alkenyl group, an alkoxy group, an alkanoyl group, an alkylthio group, an aryloxy group, an alkylthioalkyl group, an alkylsulfinylalkyl group, an alkylsulfonylalkyl group, and an alkylaryl group. An arylalkyl group, a cycloalkyl group, an alkylsulfinyl group, an alkylsulfonyl group, an aryl group, an arylthio group, a cycloalkenyl group, an arylsulfinyl group,
An arylsulfonyl group, a sulfonic acid group, a nitro group, a cyano group, a carboxyl group, and a halogen atom. Among them, a hydrogen atom or a linear, cyclic or branched alkyl group having 1 to 12 carbon atoms is particularly preferred.

The copolymer having a thiophene structure according to the present invention comprises a compound represented by the following general formula [1] in which two thiophene rings are bonded via a trans-vinylene group; And a thiophene compound represented by the formula (1) in the presence of a transition metal salt of sulfonic acid in a liquid phase.

[0012]

Embedded image

In the formula, n represents an integer of 1 to 3, and R _{1 to} R ₆
May be the same or different from each other, and include a hydrogen atom, an alkyl group, an alkenyl group, an alkoxy group, an alkanoyl group, an alkylthio group, an aryloxy group, an alkylthioalkyl group, an alkylsulfinylalkyl group, an alkylsulfonylalkyl group, and an alkylaryl group. An arylalkyl group, a cycloalkyl group, an alkylsulfinyl group, an alkylsulfonyl group, an aryl group, an arylthio group, a cycloalkenyl group, an arylsulfinyl group,
An arylsulfonyl group, a sulfonic acid group, a nitro group, a cyano group, a carboxyl group, and a halogen atom. R _{1 to} R ₄
As a hydrogen atom or a carbon atom of 1
~ 12 linear, cyclic and branched alkyl groups are preferred.

[0014] The polymer composition according to the present invention comprises the above polymer or copolymer and a dopant. Such a polymer composition is suitable as a conductive material.

[Detailed description of the invention] [0015] Hereinafter, a polymer having a thiophene structure, a copolymer, and a composition containing the polymer according to the present invention will be specifically described. In the present specification, the term “polymerization” means
The term “polymer” may be used to include not only a homopolymer but also a copolymer, in some cases.

[Polymer Having Thiophene Structure] The polymer having a thiophene structure according to the present invention is a polymer having two thiophene rings bonded via a trans-vinylene group represented by the following general formula [1]. , Obtained by polymerization in the liquid phase in the presence of a transition metal salt of sulfonic acid.

[0017]

Embedded image

In the formula, n represents an integer of 1 to 3. Also, R
_{1 to} R ₄ may be the same or different from each other, and represent a hydrogen atom, an alkyl group, an alkenyl group, an alkoxy group, an alkanoyl group, an alkylthio group, an aryloxy group, an alkylthioalkyl group, an alkylsulfinylalkyl group,
Alkylsulfonylalkyl group, alkylaryl group,
Arylalkyl, cycloalkyl, alkylsulfinyl, alkylsulfonyl, aryl, arylthio, cycloalkenyl, arylsulfinyl, arylsulfonyl, sulfonic, nitro, cyano, carboxyl, carboxyl, halogen atom Yes,
Preferably, it is a hydrogen atom or a linear, cyclic or branched alkyl group having 1 to 12 carbon atoms.

The trans- represented by the general formula [1]
Compounds in which two thiophene rings are bonded via a vinylene group include trans-1,2-di (2-thienyl) ethylene, tran
s-1,2-di (2-thienyl) butadiene; trans-1,2-di (2-thienyl) hexatriene;

The polymer according to the present invention has the general formula [1]
Is obtained by polymerizing the compound represented by the general formula [1] in a solution in which the compound represented by the formula and a transition metal salt of sulfonic acid are dissolved in a reaction solvent.

The transition metal salt of a sulfonic acid is not particularly limited, but examples thereof include iron p-toluenesulfonate.
(III), iron (III) benzenesulfonate, iron (III) sulfate, 5-
Iron (III) sulfosalicylate, naphthalenesulfonic acid (II
I), pyridinesulfonic acid (III), adamantanesulfonic acid iron (III), anthraquinonesulfonic acid iron (III), benzophenonesulfonic acid iron (III) and the like. These sulfonic acid transition metal salts are preferably used in an amount of usually 2 to 10 mol, preferably 2 to 5 mol, per 1 mol of the compound represented by the general formula [1].

The reaction solvent used is represented by the above general formula [1]
Is not particularly limited as long as the compound represented by the formula (1) and the transition metal salt of sulfonic acid are dissolved, and examples thereof include tetrahydrofuran, water, ethyl alcohol, and acetone. Of these, tetrahydrofuran is preferably used in the present invention. In such a reaction solvent, the concentration of the compound represented by the above general formula [1] at the time of the reaction is 0.0%
1 to 0.5 mol / l, preferably 0.05 to 0.
It is desirable to use it in an amount of 2 mol / liter.

After completion of the reaction, the obtained polymer is usually obtained as a colored solution in the reaction solution. Such coloring is caused by doping the polymer with an anion (sulfonate ion) of a transition metal salt of sulfonic acid added as a catalyst.

The sulfonic acid ions doped in the polymer can be removed by washing with a reducing agent such as hydrazine. Further, in the present invention, it is not necessary to remove the sulfonic acid ion doped in such a polymer, and if it is not removed, the polymer composition doped with the sulfonic acid ion is constituted in the polymer. You.

The obtained polymer is obtained by removing the reaction solvent.
After being separated from the reaction solution, it is washed with water or the like and dried under reduced pressure. The thus obtained polymer having a thiophene structure according to the present invention has a repeating unit represented by the following general formula [3] derived from the above general formula [1].

[0026]

Embedded image

In the formula, R _{1 to} R ₄ and n are the same as described above. The number average molecular weight of such a polymer is 382 to 40
000, preferably 382 to 20,000.

Such a polymer according to the present invention is soluble in a solvent such as tetrahydrofuran. The reason for the expression of such solubility is that by using a transition metal salt of sulfonic acid as a catalyst, the compound represented by the general formula [1] forms a cyclic or helical polymer, and the degree of polymerization is suppressed. It is estimated that

[Copolymer Having Thiophene Structure] In the copolymer having a thiophene structure according to the present invention, two thiophene rings are bonded via a trans-vinylene group represented by the above general formula [1]. It is obtained by copolymerizing a compound and a thiophene compound represented by the following general formula [2] in a liquid phase in the presence of a transition metal salt of sulfonic acid.

[0030]

Embedded image

In the formula, R ₅ and R ₆ may be the same or different from each other and represent a hydrogen atom, an alkyl group, an alkenyl group, an alkoxy group, an alkanoyl group, an alkylthio group,
Aryloxy, alkylthioalkyl, alkylsulfinylalkyl, alkylsulfonylalkyl, alkylaryl, arylalkyl, cycloalkyl, alkylsulfinyl, alkylsulfonyl, aryl, arylthio, cycloalkenyl, arylsulfinyl Group, arylsulfonyl group, sulfonic acid group, nitro group, cyano group, carboxyl group, and halogen atom.

Among these groups, a hydrogen atom and a group having 1 to 1 carbon atoms
An alkyl group having 12 alkyl groups, an alkenyl group having an alkyl group having 1 to 12 carbon atoms, an alkoxy group having an alkyl group having 1 to 12 carbon atoms, an alkanoyl group having an alkyl group having 1 to 12 carbon atoms, Alkylthio group containing an alkyl group, alkylthioalkyl group containing an alkyl group having 1 to 12 carbon atoms, alkylsulfinylalkyl group containing an alkyl group having 1 to 12 carbon atoms, alkylsulfonylalkyl group containing an alkyl group having 1 to 12 carbon atoms , Having 1 to 1 carbon atoms
An alkylaryl group containing 2 alkyl groups, having 1 to 1 carbon atoms
An alkylsulfinyl group including an alkyl group having 12 alkyl groups, an alkylsulfonyl group including an alkyl group having 1 to 12 carbon atoms,
An aryl group having 6 to 12 carbon atoms, an arylalkyl group including an aryl group having 6 to 12 carbon atoms, an aryloxy group including an aryl group having 6 to 12 carbon atoms, an arylthio group including an aryl group having 6 to 12 carbon atoms, An arylsulfinyl group containing an aryl group having 6 to 12 carbon atoms and an arylsulfonyl group containing an aryl group having 6 to 12 carbon atoms are preferable.

Examples of the compound represented by the general formula [1] in which two thiophene rings are bonded via a trans-vinylene group include those described above. Examples of the thiophene compound represented by the general formula [2] include thiophene, 3-methylthiophene, 3,4-dimethylthiophene, and 3-dodecylthiophene.

In the copolymer according to the present invention, the compound represented by the general formula [1], the compound represented by the general formula [2], and the transition metal salt of the sulfonic acid are dissolved in a reaction solvent. It is obtained by copolymerizing a compound represented by the general formula [1] and a compound represented by the general formula [2] in a solution.

In the above reaction, the proportion of the compound represented by the above general formula [1] is 1 to 99 mol%, preferably 5 to 9 mol%.
5 mol%, more preferably 30 to 70 mol%,
When the ratio of the compound represented by the general formula [2] is 99 to 1
It is desirable that the amount be 95% by mole, preferably 95% by mole, and more preferably 70% by mole. In the copolymer according to the present invention, the ratio of the compound represented by the formulas [1] and [2] is such that the structural unit derived from the compound represented by the formula [1] in the copolymer is used. And the ratio of the structural unit derived from the compound represented by the formula [2].

Examples of the transition metal salt of sulfonic acid include the same as described above. The amount of the sulfonic acid transition metal salt to be used is generally 2 to 10 mol, preferably 2 to 10 mol, per 1 mol of the compound represented by the above general formula [1] and the compound represented by the above general formula [1]. Is desirably in an amount of 2 to 5 mol.

The reaction solvent to be used is one which can dissolve the compound represented by the general formula [1], the compound represented by the general formula [2], and the transition metal salt of sulfonic acid. There is no particular limitation, and the same as described above can be used. Such a reaction solvent has a total concentration of the compound represented by the above general formula [1] and the compound represented by the above [2] at the time of the reaction of 0.01 to 0.5 mol / L, preferably. It is desirable to use in an amount of 0.05 to 0.2 mol / liter.

The obtained copolymer is obtained as a colored solution in the reaction solution in the same manner as the above-mentioned polymer. Such coloring occurs when the anion (sulfonate ion) of the added transition metal salt of sulfonic acid is doped into the copolymer. The sulfonic acid ion doped in this manner may be removed or may not be removed in the same manner as the above-mentioned polymer, and if not removed, a polymer composition doped with a dopant described below may be formed. Can be.

The obtained copolymer is recovered by removing the reaction solvent, washed with water and the like, and dried under reduced pressure. The thus obtained copolymer according to the present invention has a repeating unit represented by the following general formula [4] derived from the above general formulas [1] and [2].

[0040]

Embedded image

The number average molecular weight of such a copolymer is 2
It is desirably 74 to 40000, preferably 274 to 20000. Such a copolymer is also soluble in a solvent such as tetrahydrofuran, like the above-mentioned polymer. The reason for the expression of such solubility is that, similarly to the polymer, the compound represented by the general formula [1] and the compound represented by the general formula [2] form a cyclic or helical polymer. However, it is presumed that the degree of polymerization of the copolymer is suppressed.

[Polymer Composition] The polymer composition according to the present invention comprises the above polymer or copolymer and a dopant.

The dopant is not particularly limited as long as it is usually used as a dopant. For example, fluorine, chlorine, iodine, ICl, IC
_{l 3, IBr, PF 5,} AsF 5, SbF 5, AgClO 4, Ag
BF ₄ , BF ₃ , BCl ₃ , BBr ₃ , FSO ₂ COSO ₂ F,
H ₂ SO ₄ , HClO ₄ , (NO ₂ ) (SbF ₆ ), (NO) (SbCl
₆ ), (NO ₂ ) (BF ₄ ), SO ₃ , HNO ₃ , FSO ₃ H, C
Electron acceptors such as F ₃ SO ₃ H; and electron donors such as alkali metals such as Li, Na, and K.

The transition metal salt of sulfonic acid can be used as a dopant. Of these,
Particularly, iodine is preferable.

The doping of the polymer with the dopant can be carried out by contacting the polymer with the gas or solution of the dopant. In addition, if the above-described method for producing a polymer is adopted, an anion of a transition metal salt of sulfonic acid can be doped during polymerization of the polymer.

[0046]

According to the present invention, a polymer having a thiophene structure and a polymer composition which can be suitably used as a conductive material such as a cathode conductive material and an antistatic material of a solid electrolytic capacitor can be obtained. . A solid electrolytic capacitor containing such a polymer and a cathode conductive material composed of a polymer composition has a small impedance at a resonance frequency, has good high-frequency characteristics, and has little deterioration in characteristics at high temperatures.

As described above, the polymer and the polymer composition according to the present invention are highly soluble. Therefore, when the polymer and the polymer composition are used as a cathode conductive material of a solid electrolytic capacitor, the electrical conductivity can be further increased by applying the solution in a dielectric layer and then re-polymerizing the solution. According to this method, a simple and inexpensive new process can be provided for manufacturing a cathode of a solid electrolytic capacitor.

[0048]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0049]

Example 1 A solution of 3.90 g of p-toluenesulfone iron (III) dissolved in 10 ml of tetrahydrofuran was placed in a 30 ml flask, and 255 mg of trans-1,2-di (2-thienyl) ethylene was dissolved in 4 ml of tetrahydrofuran. After dropping the liquid, the reaction was carried out for 24 hours. The obtained precipitate was filtered, washed with water, and dried under reduced pressure. The color of the obtained product was black and was soluble in tetrahydrofuran.

The polymer powder obtained as described above was doped with gas-phase iodine and formed into pellets having a diameter of 10 mm. As a result of measuring the electric conductivity of this pellet by a direct current four-probe method, the electric conductivity was 1.2 × 10 ⁻² S / cm.

[0051]

EXAMPLE 2 A solution of 1.50 g of p-toluenesulfone iron (III) dissolved in 5 ml of tetrahydrofuran was placed in a 30 ml flask, and 128 mg of trans-1,2-di (2-thienyl) ethylene and 76 mg of 3-methoxythiophene were added. Was added dropwise to 4 ml of tetrahydrofuran, and 24
Allowed to react for hours. The resulting precipitate is filtered, washed with water,
Drying under reduced pressure was performed. The color of the obtained product was black and was soluble in tetrahydrofuran.

Claims (9)

[Claims] 1. A compound having two thiophene rings bonded via a trans-vinylene group represented by the following general formula [1]:
A polymer having a thiophene structure, which is obtained by polymerization in a liquid phase in the presence of a transition metal salt of sulfonic acid. Embedded image (In the formula, n represents an integer of 1 to 3, R _{1 to} R ₄ may be the same or different from each other, and include a hydrogen atom, an alkyl group,
Alkenyl, alkoxy, alkanoyl, alkylthio, aryloxy, alkylthioalkyl, alkylsulfinylalkyl, alkylsulfonylalkyl, alkylaryl, arylalkyl, cycloalkyl, alkylsulfinyl, alkylsulfonyl, Aryl group, arylthio group, cycloalkenyl group, arylsulfinyl group, arylsulfonyl group, sulfonic acid group, nitro group, cyano group, carboxyl group, and halogen atom. ) 2. The thiophene structure according to claim 1, wherein R _{1 to} R ₄ are a hydrogen atom or a linear, cyclic or branched alkyl group having 1 to 12 carbon atoms. Having a polymer. 3. A polymer composition comprising the polymer according to claim 1 and a dopant. 4. A compound in which two thiophene rings are bonded via a trans-vinylene group represented by the following general formula [1] and a thiophene compound represented by the following general formula [2]: A copolymer having a thiophene structure, which is obtained by copolymerization in a liquid phase in the presence of a transition metal salt of the above. Embedded image (In the formula, n represents an integer of 1 to 3, and R _{1 to} R ₆ may be the same or different, and each represents a hydrogen atom, an alkyl group, an alkenyl group, an alkoxy group, an alkanoyl group, an alkylthio group, or an aryloxy group. , An alkylthioalkyl group,
Alkylsulfinylalkyl, alkylsulfonylalkyl, alkylaryl, arylalkyl, cycloalkyl, alkylsulfinyl, alkylsulfonyl, aryl, arylthio, cycloalkenyl, arylsulfinyl, arylsulfonyl, sulfonic acid Group, nitro group, cyano group, carboxyl group and halogen atom. ) 5. The thiophene structure according to claim 4, wherein R _{1 to} R ₄ are a hydrogen atom or a linear, cyclic, or branched alkyl group having 1 to 12 carbon atoms. Having a copolymer. 6. A polymer composition comprising the copolymer according to claim 4 and a dopant. 7. A compound in which two thiophene rings are bonded via a trans-vinylene group represented by the general formula [1],
A method for producing a polymer having a thiophene structure, characterized by polymerizing in a liquid phase in the presence of a transition metal salt of sulfonic acid. 8. A compound having two thiophene rings bonded via a trans-vinylene group represented by the above general formula [1] and a thiophene compound represented by the above general formula [2], A method for producing a copolymer having a thiophene structure, wherein the copolymer is copolymerized in a liquid phase in the presence of a transition metal salt. 9. A conductive material comprising the polymer composition according to claim 3 or 6.