JP2014199838A - Thermoelectric conversion material, composition for thermoelectric conversion element, thermoelectric conversion film, and thermoelectric conversion element using them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoelectric conversion material and a composition for the thermoelectric conversion element which are excellent in a non-dimensional thermoelectric figure of merit (ZT) and long-term reliability and capable of being coated on a plastic base material to form a film, and also to provide a thermoelectric conversion film, and the thermoelectric conversion element using such a material, a composition, and a film.SOLUTION: A thermoelectric conversion material contains polyanion (A) including a specific structure having sulfonic acid as a structural unit and a conjugated electroconductive polymer (B).

Description

  The present invention relates to a thermoelectric conversion material, and a thermoelectric conversion element composition, a thermoelectric conversion film, and a thermoelectric conversion element for forming a thermoelectric conversion material.

  The thermoelectric conversion assembly element is an element that converts heat and electric power. The Seebeck effect is used, in which an electromotive force is generated when two different metals or semiconductors are joined and a temperature difference is generated between both ends. In order to obtain a large potential difference, a p-type semiconductor and an n-type semiconductor are used in combination.

“Thermoelectric conversion technology handbook (first edition)” As described in NTS P19, the performance of thermoelectric conversion materials is indexed by the dimensionless thermoelectric figure of merit (ZT), and ZT is expressed by the following equation: The
ZT = (S ² · σ · T) / κ
Here, S is the Seebeck coefficient (V / K), σ is the conductivity (S · m), T is the absolute temperature (K), and κ is the thermal conductivity (W / (m · K)). The thermal conductivity κ is expressed by the following formula.
κ = α ・ ρ ・ C
Here, α is the thermal diffusivity (m ² / s), ρ is the density (kg / m ³ ), and C is the specific heat capacity (J / (kg · K)).
That is, in order to improve the performance of thermoelectric conversion, it is important to improve the Seebeck coefficient or electrical conductivity and to reduce thermal conductivity.

  The thermoelectric conversion element is used as a thermoelectric module in which a large number of elements are combined in a plate shape or a cylindrical shape. Thermoelectric conversion element materials include, for example, bismuth and tellurium (Bi-Te) from room temperature to 500K, lead and tellurium (Pb-Te) from room temperature to 800K, and silicon and germanium from room temperature to 1000K ( Si-Ge system) is used. Thermoelectric power generation using thermoelectric conversion elements is used as a power source for ground power generation and artificial satellites.

  Thermoelectric conversion elements using these inorganic materials often contain rare elements or contain harmful substances. In addition, it is difficult to process, and has a problem that a thermoelectric conversion element having excellent flexibility due to its rigidity cannot be formed. For this reason, it is difficult to make it versatile, and researches using organic materials as heat conversion materials are underway. Among them, a conductive polymer is promising, a heat conversion element using polyaniline is disclosed in Patent Document 1, a heat conversion element using poly (3-alkylthiophene) is described in Patent Document 2, and polyphenylene vinylene is described in Patent Document 3. Thermoelectric conversion elements using poly (3,4-ethylenedioxythiophene) (hereinafter sometimes referred to as “PEDOT”) are disclosed in Patent Document 4 as the heat conversion elements used.

  However, a problem of thermoelectric conversion elements using these conductive polymers is that the Seebeck coefficient and the thermoelectric conversion efficiency index are insufficient. In order to improve this problem, the thermoelectric conversion efficiency index is improved by increasing the conductivity by adding a small amount of dopant to these conductive polymers.

  In particular, a thiophene polymer represented by PEDOT is known as a hole transfer semiconductor having excellent conductivity. By adding a polymer electrolyte such as poly (styrene sulfonic acid) (hereinafter sometimes referred to as “PSS”) to PEDOT, conductivity and solubility in water are imparted as a “dopant”. It is known that it exhibits a relatively high thermoelectric conversion efficiency index.

  In addition to adding a polymer electrolyte such as PSS to PEDOT and adding a high boiling point solvent such as ethylene glycol, dimethyl sulfoxide, n-methylpyrrolidone or dimethylformamide, thermoelectric conversion is achieved by improving conductivity. There are reports that the efficiency index is further improved and applied to thermoelectric conversion elements.

  However, since PSSs have a polyethylene skeleton with a flexible main chain structure, there is a problem that long-term reliability in a high-temperature environment or a use environment is insufficient.

JP 2000-323758 A JP 2003-332638 A JP 2003-332639 A JP2012-84821A

  To solve the problem of thermoelectric conversion elements using inorganic materials and conventional conductive polymer materials, and to provide a thermoelectric conversion element having a high thermoelectric conversion efficiency index and excellent long-term reliability.

  The objective of this invention is providing the composition for thermoelectric conversion elements containing the conductive polymer excellent in the thermoelectric conversion performance. Furthermore, it is providing the thermoelectric conversion film and thermoelectric conversion element which are excellent in the thermoelectric conversion performance by using the said composition for thermoelectric conversion elements.

［一般式（１）中、Ｒ₁、Ｒ₂、Ｒ₃およびＲ₄は互いに独立して水素またはＳＯ₃Ｘであり、Ｒ₁、Ｒ₂、Ｒ₃およびＲ₄のいずれか１つ以上はＳＯ₃Ｘであり、Ｘは水素原子、Ｌｉ、Ｎａ、Ｋ、アンモニウムイオン、プロトン化された第１級、プロトン化された第２級、プロトン化された第３級アミンまたは第４級アンモニウムイオンである。］

一般式（２）

［一般式（２）中、Ｒ₅、Ｒ₆、Ｒ₇およびＲ₈は互いに独立して水素またはＳＯ₃Ｘであり、Ｒ₅、Ｒ₆、Ｒ₇およびＲ₈のいずれか１つ以上はＳＯ₃Ｘであり、Ｘは水素原子、Ｌｉ、Ｎａ、Ｋ、アンモニウムイオン、プロトン化された第１級、プロトン化された第２級、プロトン化された第３級アミンまたは第４級アンモニウムイオンである。］ That is, the first invention relates to a thermoelectric conversion material containing a polyanion (A) having a structural unit of the following general formula (1) or general formula (2) and a conjugated conductive polymer (B).
General formula (1)

[In the general formula (1), R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or SO ₃ X, and any one or more of R ₁ , R ₂ , R ₃ and R ₄ are SO ₃ X, where X is a hydrogen atom, Li, Na, K, ammonium ion, protonated primary, protonated secondary, protonated tertiary amine or quaternary ammonium ion It is. ]

General formula (2)

[In General Formula (2), R ₅ , R ₆ , R ₇ and R ₈ are each independently hydrogen or SO ₃ X, and any one or more of R ₅ , R ₆ , R ₇ and R ₈ are SO ₃ X, where X is a hydrogen atom, Li, Na, K, ammonium ion, protonated primary, protonated secondary, protonated tertiary amine or quaternary ammonium ion It is. ]

  The second invention includes a polyanion (A) having a structural unit of the following general formula (1) or general formula (2) and a conjugated conductive polymer (B), and a dimensionless thermoelectric figure of merit. It is related with the composition for thermoelectric conversion elements characterized by (ZT) being 0.02 or more.

The third invention relates to the composition for thermoelectric conversion elements according to claim 2, wherein the conjugated conductive polymer (B) is polythiophene and derivatives thereof.

  Moreover, 4th invention is related with the composition for thermoelectric conversion elements of Claim 2 or 3 whose conjugated system conductive polymer (B) is poly (3,4-ethylenedioxythiophene).

  Moreover, 5th invention is related with the composition for thermoelectric conversion elements in any one of Claims 2-4 characterized by including a conductive support agent (C).

［式中、Ｍは、リチウム原子、ナトリウム原子、または、カリウム原子を表す。
Ａ₁はフッ素原子またはトリフルオロメチル基を表す。］

一般式（４）

［式中、Ａ₂は、直接結合、置換もしくは未置換の２価の脂肪族炭化水素基、置換もしくは未置換の２価の芳香族炭化水素基、置換もしくは未置換の２価の脂肪族複素環基、または、置換もしくは未置換の２価の芳香族複素環基を表し、Ｘは、直接結合、酸素原子、窒素原子、または、硫黄原子を表し、Ｍは、リチウム原子、ナトリウム原子、または、カリウム原子を表す。］ Moreover, 6th invention is related with the composition for thermoelectric conversion elements of Claim 5 characterized by the conductive auxiliary agent (C) containing the compound of the following general formula (3) or general formula (4). .
General formula (3)

[Wherein, M represents a lithium atom, a sodium atom, or a potassium atom.
A ₁ represents a fluorine atom or a trifluoromethyl group. ]

General formula (4)

[In the formula, A ₂ represents a direct bond, a substituted or unsubstituted divalent aliphatic hydrocarbon group, a substituted or unsubstituted divalent aromatic hydrocarbon group, a substituted or unsubstituted divalent aliphatic complex; Represents a cyclic group or a substituted or unsubstituted divalent aromatic heterocyclic group, X represents a direct bond, an oxygen atom, a nitrogen atom, or a sulfur atom, and M represents a lithium atom, a sodium atom, or Represents a potassium atom. ]

  Moreover, 7th invention is related with the thermoelectric conversion film formed from the composition for thermoelectric conversion elements in any one of Claims 2-6.

  Moreover, 8th invention is related with the thermoelectric conversion element obtained using the composition for thermoelectric conversion elements in any one of Claims 2-6, or the thermoelectric conversion film of Claim 7.

  The thermoelectric conversion element material of the present invention exhibits excellent thermoelectric conversion performance due to the addition of a small amount of polyanion or conductive additive. Moreover, the thermoelectric conversion element of this invention is excellent in thermoelectric conversion performance, and can be used suitably for utilization of waste heat, such as a factory and a waste incineration plant.

Hereinafter, the present invention will be described in detail.
<Thermoelectric conversion material, composition for thermoelectric conversion element>
The composition for thermoelectric conversion elements of the present invention contains a polyanion (A) having a structural unit of the following general formula (1) or general formula (2) and a conjugated conductive polymer (B). It has excellent thermoelectric conversion performance.
As described above, the dimensionless thermoelectric figure of merit (ZT) is an index of the thermoelectric conversion performance of the thermoelectric conversion material, and the larger the value of ZT, the better the thermoelectric conversion material having the thermoelectric conversion ability.
In order to improve the performance of thermoelectric conversion, it is important to improve the Seebeck coefficient or conductivity and to reduce the thermal conductivity.

  The thermoelectric conversion material and the composition for a thermoelectric conversion element of the present invention comprise a polyanion (A) having a structural unit of the following general formula (1) or general formula (2), and a conjugated conductive polymer (B). It is characterized by containing.

    Generally, when the polyanion (A) and the conjugated conductive polymer (B) coexist, the anion group of the polyanion is doped into the conjugated conductive polymer (B), and the conjugated conductive polymer (B). And produce salt. In particular, strong ionic bonds are generated in anionic groups such as sulfonic acid groups. As a result, the conjugated conductive polymer (B) is strongly attracted to the main chain of the polyanion (A), and the conjugated conductive polymer (B) arranged regularly is obtained. Thus, a polyanion is present between the conjugated conductive polymer (B), and a thermoelectric conversion material and a composition for thermoelectric conversion elements excellent in compatibility can be obtained.

<Polyanion (A)>
The polyanion (A) included in the present invention has a structural unit represented by the following general formula (1) or general formula (2).

［一般式（１）中、Ｒ₁、Ｒ₂、Ｒ₃およびＲ₄は互いに独立して水素またはＳＯ₃Ｘであり、Ｒ₁、Ｒ₂、Ｒ₃およびＲ₄のいずれか１つ以上はＳＯ₃Ｘであり、Ｘは水素原子、Ｌｉ、Ｎａ、Ｋ、アンモニウムイオン、プロトン化された第１級、プロトン化された第２級、プロトン化された第３級アミンまたは第４級アンモニウムイオンである。］

一般式（２）

［一般式（２）中、Ｒ₅、Ｒ₆、Ｒ₇およびＲ₈は互いに独立して水素またはＳＯ₃Ｘであり、Ｒ₅、Ｒ₆、Ｒ₇およびＲ₈のいずれか１つ以上はＳＯ₃Ｘであり、Ｘは水素原子、Ｌｉ、Ｎａ、Ｋ、アンモニウムイオン、プロトン化された第１級、プロトン化された第２級、プロトン化された第３級アミンまたは第４級アンモニウムイオンである。］ General formula (1)

[In the general formula (1), R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or SO ₃ X, and any one or more of R ₁ , R ₂ , R ₃ and R ₄ are SO ₃ X, where X is a hydrogen atom, Li, Na, K, ammonium ion, protonated primary, protonated secondary, protonated tertiary amine or quaternary ammonium ion It is. ]

General formula (2)

[In General Formula (2), R ₅ , R ₆ , R ₇ and R ₈ are each independently hydrogen or SO ₃ X, and any one or more of R ₅ , R ₆ , R ₇ and R ₈ are SO ₃ X, where X is a hydrogen atom, Li, Na, K, ammonium ion, protonated primary, protonated secondary, protonated tertiary amine or quaternary ammonium ion It is. ]

  A method for synthesizing the polyanion (A) included in the present invention will be described.

The polyanion having the structural unit of the general formula (1) or the general formula (2) can be obtained by polymerizing a compound represented by the following general formula (5) or the general formula (6).

［一般式（５）中、Ｒ₉、Ｒ₁₀、Ｒ₁₁およびＲ₁₂は互いに独立して水素またはＳＯ₃Ｘであり、Ｒ₉、Ｒ₁₀、Ｒ₁₁およびＲ₁₂のいずれか１つ以上はＳＯ₃Ｘであり、Ｘは水素原子、Ｌｉ、Ｎａ、Ｋ、アンモニウムイオン、プロトン化された第１級、プロトン化された第２級、プロトン化された第３級アミンまたは第４級アンモニウムイオンである。］ General formula (5)

[In General Formula (5), R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are each independently hydrogen or SO ₃ X, and any one or more of R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are SO ₃ X, where X is a hydrogen atom, Li, Na, K, ammonium ion, protonated primary, protonated secondary, protonated tertiary amine or quaternary ammonium ion It is. ]

［一般式（６）中、Ｒ₁₃、Ｒ₁₄、Ｒ₁₅およびＲ₁₆は互いに独立して水素またはＳＯ₃Ｘであり、Ｒ₁₃、Ｒ₁₄、Ｒ₁₅およびＲ₁₆のいずれか１つ以上はＳＯ₃Ｘであり、Ｘは水素原子、Ｌｉ、Ｎａ、Ｋ、アンモニウムイオン、プロトン化された第１級、プロトン化された第２級、プロトン化された第３級アミンまたは第４級アンモニウムイオンである。］ General formula (6)

[In General Formula (6), R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ are each independently hydrogen or SO ₃ X, and any one or more of R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ are SO ₃ X, where X is a hydrogen atom, Li, Na, K, ammonium ion, protonated primary, protonated secondary, protonated tertiary amine or quaternary ammonium ion It is. ]

Examples of the general formula (5) include 4-sulfo-1H-indene, 5-sulfo-1H-indene, 6-sulfo-1H-indene, 7-sulfo-1H-indene, 1H-indene-4,5- Disulfonic acid, 1H-indene-4,6-disulfonic acid, 1H-indene-4,7-disulfonic acid, 1H-indene-5,6-disulfonic acid, 1H-indene-5,7-disulfonic acid, 1H-indene -6,7-disulfonic acid, 1H-indene-4,5,6-trisulfonic acid, 1H-indene-4,5,7-trisulfonic acid, 1H-indene-4,6,7-trisulfonic acid, 1H-indene-5,6,7-trisulfonic acid, 1H-indene-4,5,6,7-tetrasulfonic acid, and lithium, sodium, potassium, ammonium, protonated Level 1, Level 2, A tertiary amine or a quaternary ammonium salt may be mentioned.
Examples of the general formula (6) include benzofuran-4-sulfonic acid, benzofuran-5-sulfone, benzofuran-6-sulfonic acid, benzofuran-7-sulfone, benzofuran-4,5-disulfonic acid, and benzofuran-4,6. -Disulfonic acid, benzofuran-4,7-disulfonic acid, benzofuran-5,6-disulfonic acid, benzofuran-5,7-disulfonic acid, benzofuran-6,7-disulfonic acid, benzofuran-4,5,6-trisulfone Acid, benzofuran-4,5,7-trisulfonic acid, benzofuran-4,6,7-trisulfonic acid, benzofuran-5,6,7-trisulfonic acid, benzofuran-4,5,6,7-tetrasulfone Acids, and their lithium, sodium, potassium, ammonium salts, protonated Primary, secondary, tertiary amines or quaternary ammonium salts.
In general formula (5) or general formula (6), 5-sulfo-1H-indene, 6-sulfo-1H-indene, 5-sulfo-benzofuran, 6-sulfo-benzofuran and its sodium salt and potassium salt are It is a preferable monomer from the viewpoint of polymerizability.
These monomers can be used alone or in combination of two or more.

  Polymerization of the compound represented by the general formula (5) or (6) is carried out using an azo compound, a peroxide, an oxidizing agent, an oxidation polymerization catalyst, or the like in a solvent in which the polymer to be formed is dissolved. Examples of the solvent include water, methanol, ethanol, isopropyl alcohol, and the like.

The polyanion (A) may be a copolymer of the compound represented by the general formula (5) or (6) and other monomers.
Examples of the copolymerizable monomer include conjugated diene monomers such as 1,3-butadiene, isoprene, 2-chloro-1,3-butadiene, and 2-methyl-1,3-butadiene;
Aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene;
Ethylenically unsaturated carboxylic acid alkyl ester monomers such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate;
Ethylenically unsaturated carboxylic acid amide monomers such as acrylamide, methacrylamide, N, N-dimethylacrylamide, N-methylolacrylamide;
Ethylenically unsaturated carboxylic acid hydroxyalkyl ester monomers such as hydroxyalkyl (meth) acrylate and glycerin di (meth) acrylate;
Carboxylic acid vinyl ester monomers such as vinyl acetate;
And (meth) acrylonitrile, N-vinylpyrrolidone, (meth) acryloylmorpholine, cyclohexylmaleimide, isopropylmaleimide, glycidyl (meth) acrylate, and the like. These can be used alone or in combination of two or more.

  In addition, the polyanion having the structural unit of the general formula (1) or the general formula (2) is obtained by polymerizing a compound represented by the following general formula (7) or the general formula (8), and the aromatic ring of the obtained polymer. The polyanion (A) can be obtained by sulfonating the cation.

［一般式（７）中、Ｒ₁₇、Ｒ₁₈、Ｒ₁₉およびＲ₂₀は互いに独立して水素または炭素数１〜６のアルキル基であり、Ｒ₁₇、Ｒ₁₈、Ｒ₁₉およびＲ₂₀のいずれか１つ以上は水素である。］ General formula (7)

[In General Formula (7), R ₁₇ , R ₁₈ , R ₁₉ and R ₂₀ are each independently hydrogen or an alkyl group having 1 to 6 carbon atoms, and any of R ₁₇ , R ₁₈ , R ₁₉ and R ₂₀ One or more is hydrogen. ]

［一般式（７）中、Ｒ₂₁、Ｒ₂₂、Ｒ₂₃およびＲ₂₄は互いに独立して水素または炭素数１〜６のアルキル基であり、Ｒ₂₁、Ｒ₂₂、Ｒ₂₃およびＲ₂₄のいずれか１つ以上は水素である。］ General formula (8)

[In General Formula (7), R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ are each independently hydrogen or an alkyl group having 1 to 6 carbon atoms, and any of R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ One or more is hydrogen. ]

Examples of the general formula (7) include 1H-indene, 4-methyl-1H-indene, 5-methyl-1H-indene, 6-methyl-1H-indene, 7-methyl-1H-indene, 4-ethyl- 1H-indene, 5-ethyl-1H-indene, 6-ethyl-1H-indene, 7-ethyl-1H-indene, 4-butyl-1H-indene, 4-hexyl-1H-indene, 4-cyclohexyl- 1H-indene, 4,5-dimethyl-1H-indene, 4,6-dimethyl-1H-indene, 4,7-dimethyl-1H-indene, 5,6-dimethyl-1H-indene, 5,7-dimethyl- 1H-indene, 6,7-dimethyl-1H-indene, 4,5,6-trimethyl-1H-indene, 4,5,7-trimethyl-1H-indene, 4,6,7-trimethyl-1H-indene, 5, 6 7-trimethyl -1H- indene, and these lithium salts, sodium salts, potassium salts, ammonium salts, primary protonated, secondary, etc. tertiary amines or quaternary ammonium salts.
Examples of the general formula (8) include benzofuran, 4-methyl-1H-benzofuran, 5-methyl-1H-benzofuran, 6-methyl-1H-benzofuran, 7-methyl-1H-benzofuran, 4-ethyl-1H- Benzofuran, 5-ethyl-1H-benzofuran, 6-ethyl-1H-benzofuran, 7-ethyl-1H-benzofuran, 4-butyl-1H-benzofuran, 4-hexyl-1H-benzofuran, 4-cyclohexyl-1H- Benzofuran, 4,5-dimethyl-1H-benzofuran, 4,6-dimethyl-1H-benzofuran, 4,7-dimethyl-1H-benzofuran, 5,6-dimethyl-1H-benzofuran, 5,7-dimethyl-1H- Benzofuran, 6,7-dimethyl-1H-benzofuran, 4,5,6-trimethyl-1H-benzofuran, 4,5,7- Limethyl-1H-benzofuran, 4,6,7-trimethyl-1H-benzofuran, 5,6,7-trimethyl-1H-benzofuran, and lithium salts, sodium salts, potassium salts, ammonium salts thereof, protonated compounds Primary, secondary, tertiary amine, quaternary ammonium salt, etc. are mentioned.

  Polymerization of the compound represented by the general formula (7) or (8) is performed in a solvent in which the polymer to be formed is dissolved using an azo compound, a peroxide, an oxidizing agent, an oxidation polymerization catalyst, or the like. Examples of the solvent include methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate, tetrahydrofuran, toluene, xylene, dichloromethane, trichloromethane, chloroform, tetrachloromethane, chlorobenzene, o-chlorobenzene and the like.

In addition, the polyanion (A) may sulfonate the aromatic of a copolymer of the compound represented by the general formula (7) or (8) and another monomer.
Examples of the copolymerizable monomer include conjugated diene monomers such as 1,3-butadiene, isoprene, 2-chloro-1,3-butadiene, and 2-methyl-1,3-butadiene;
Aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene;
Ethylenically unsaturated carboxylic acid alkyl ester monomers such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate;
Ethylenically unsaturated carboxylic acid amide monomers such as acrylamide, methacrylamide, N, N-dimethylacrylamide, N-methylolacrylamide;
Ethylenically unsaturated carboxylic acid hydroxyalkyl ester monomers such as hydroxyalkyl (meth) acrylate and glycerin di (meth) acrylate;
Carboxylic acid vinyl ester monomers such as vinyl acetate;
And (meth) acrylonitrile, N-vinylpyrrolidone, (meth) acryloylmorpholine, cyclohexylmaleimide, isopropylmaleimide, glycidyl (meth) acrylate, and the like. These can be used alone or in combination of two or more.

  The sulfonation of the aromatic ring is preferably carried out in the presence of a sulfonating agent described in US Pat. No. 3,870,841, for example, sulfuric acid, chlorosulfonic acid, acetyl sulfuric acid and the like. 0.01 to 10 mol of a sulfonating agent is added to 1 mol of an aromatic ring to be sulfonated, and the reaction is performed at a temperature in the range of 10 to 100 ° C., preferably 20 to 70 ° C. for 1 to 48 hours.

  The monomer unit derived from the general formula (5), the general formula (6), the sulfonated general formula (7), or the sulfonated general formula (8) in the polyanion (A) is represented by the polyanion (A). It is preferable that it is the range of 50-100 mol% with respect to the molar amount of all the monomer units in it, More preferably, it is 85-97 mol%. If it is less than 50 mol%, doping may be insufficient.

  The weight average molecular weight of the polyanion (A) is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. When the molecular weight is less than 1,000, a dispersion failure may occur due to a short molecular chain. Moreover, when larger than 500,000, the viscosity of the composition for thermoelectric conversion elements may be very high.

  The main chain of the polyanion (A) of the present invention is rigid compared to the main chain of polystyrene sulfonic acid conventionally used as a dopant, and its mobility is suppressed due to its rigidity, and long-term reliability in high temperature environments and use environments is improved. Excellent.

An anionic compound other than the polyanion (A), that is, an acceptor dopant or a donor dopant is necessary for the purpose of further improving the conductivity of the thermoelectric conversion film formed using the composition for thermoelectric conversion elements of the present invention. Can be added.
For example, acceptor dopants such as halogen compounds, Lewis acids, proton acids, organic cyano compounds;
Examples thereof include donor metals such as alkali metals, alkaline earth metals, and quaternary ammonium ions.

Suitable halogen compounds as acceptor dopants include chlorine (Cl ₂ ), bromine (Br ₂ ), iodine (I ₂ ), iodine chloride (ICl), iodine bromide (IBr), and iodine fluoride (IF). Can be mentioned.
Examples of the Lewis acid include PF ₅ , AsF ₅ , SbF ₅ , BF ₅ , BCl ₅ , BBr ₅ , SO _{3 and the} like.

  Examples of the protic acid include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, borohydrofluoric acid, hydrofluoric acid, and perchloric acid, and organic acids such as organic carboxylic acids, phenols, and organic sulfonic acids. . Of the organic acids, organic carboxylic acids and organic sulfonic acids are preferably used in terms of the doping effect.

  As the organic carboxylic acids, those in which one or more carboxylic acid groups are bonded to a group such as aliphatic, aromatic, and cycloaliphatic can be used. For example, formic acid, acetic acid, oxalic acid, benzoic acid, phthalic acid, maleic acid , Fumaric acid, malonic acid, tartaric acid, citric acid, lactic acid, succinic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, nitroacetic acid, triphenylacetic acid and the like.

As the organic sulfonic acids, those in which one or more sulfonic acid groups are bonded to an aliphatic, aromatic, or cycloaliphatic group can be used.
Those containing one sulfonic acid group include methanesulfonic acid, ethanesulfonic acid, 1-propanesulfonic acid, 1-butanesulfonic acid, 1-hexanesulfonic acid, 1-heptanesulfonic acid, 1-octanesulfonic acid, 1 -Nonanesulfonic acid, 1-decanesulfonic acid, 1-dodecanesulfonic acid, 1-tetradecanesulfonic acid, 1-pentadecanesulfonic acid, 2-bromoethanesulfonic acid, 3-chloro-2-hydroxypropanesulfonic acid, trifluoromethanesulfone Acid, colistin methanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, aminomethanesulfonic acid, 1-amino-2-naphthol-4-sulfonic acid, 2-amino-5-naphthol-7- Sulfonic acid, 3-aminopropanesulfonic acid, N-cyclohexyl-3-amino Propanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, ethylbenzenesulfonic acid, propylbenzenesulfonic acid, butylbenzenesulfonic acid, pentylbenzenesulfonic acid, hexylbenzenesulfonic acid, heptylbenzenesulfonic acid, octylbenzenesulfone Acid, nonylbenzenesulfonic acid, decylbenzenesulfonic acid, undecylbenzenesulfonic acid, dodecylbenzenesulfonic acid, pentadecylbenzenesulfonic acid, hexadecylbenzenesulfonic acid, 2,4-dimethylbenzenesulfonic acid, dipropylbenzenesulfonic acid , Butylbenzenesulfonic acid, 4-aminobenzenesulfonic acid, o-aminobenzenesulfonic acid, m-aminobenzenesulfonic acid, 4-amino-2-chlorotoluene- -Sulfonic acid, 4-amino-3-methylbenzene-1-sulfonic acid, 4-amino-5-methoxy-2-methylbenzenesulfonic acid, 2-amino-5-methylbenzene-1-sulfonic acid, 4-amino 2-methylbenzene-1-sulfonic acid, 5-amino-2-methylbenzene-1-sulfonic acid, 4-amino-3-methylbenzene-1-sulfonic acid, 4-acetamido-3-chlorobenzenesulfonic acid, 4 -Chloro-3-nitrobenzenesulfonic acid, p-chlorobenzenesulfonic acid, naphthalenesulfonic acid, methylnaphthalenesulfonic acid, propylnaphthalenesulfonic acid, butylnaphthalenesulfonic acid, pentylnaphthalenesulfonic acid, dimethylnaphthalenesulfonic acid, 4-amino-1- Naphthalenesulfonic acid, 8-chloronaphthalene-1-s Acid, naphthalenesulfonic acid-formalin polycondensates, include melamine sulfonic acid-formalin polycondensates, and the like.

<Conjugated conductive polymer (B)>
Conjugated conductive polymers (B) include polypyrroles, polythiophenes, polyanilines, copolymers of polyphenylene, polyphenylene vinylene, polyphenylene ethynylene, polyacetylene, polyacene, and monomers constituting the polymer. Can be mentioned. Preferred are polythiophenes from the viewpoint of conductivity and chemical stability in an air atmosphere, and more preferred is poly (3,4-ethylenedioxythiophene).

  In the present invention, since the polyanion (A) coexists, the solvent solubility of the conjugated conductive polymer (B) can be reduced without introducing a special functional group into the conjugated conductive polymer (B). Compatibility (dispersibility) with other resins is good. However, by introducing functional groups such as alkyl groups, carboxy groups, sulfonic acid groups, alkoxy groups, and hydroxy groups into the conjugated conductive polymer (B), solvent solubility and compatibility with other resins (dispersibility) ) Can be further improved.

As a specific example of the conjugated conductive polymer (B),
Polypyrrole, poly (3-methylpyrrole), poly (3-ethylpyrrole), poly (3-n-propylpyrrole), poly (3-butylpyrrole), poly (3-hexylpyrrole), poly (3-octylpyrrole) ), Poly (3-decylpyrrole), poly (3-dodecylpyrrole), poly (3,4-dimethylpyrrole), poly (3,4-dibutylpyrrole), poly (3-carboxylpyrrole), poly (3- Methyl-4-carboxylpyrrole), poly (3-methyl-4-carboxyethylpyrrole), poly (3-methyl-4-carboxybutylpyrrole), poly (3-hydroxypyrrole), poly (3-methoxypyrrole), Poly (3-ethoxypyrrole), poly (3-butoxypyrrole), poly (3-hexyloxypyrrole), poly (3- Chill-4-hexyloxy-pyrrole), poly (3,4-ethylenedioxy-pyrrole) polypyrroles such as;
Polythiophene, poly (3-methylthiophene), poly (3-ethylthiophene), poly (3-propylthiophene), poly (3-butylthiophene), poly (3-hexylthiophene), poly (3-heptylthiophene), Poly (3-octylthiophene), poly (3-decylthiophene), poly (3-dodecylthiophene), poly (3-octadecylthiophene), poly (3-bromothiophene), poly (3-chlorothiophene), poly ( 3-iodothiophene), poly (3-cyanothiophene), poly (3-phenylthiophene), poly (3,4-dimethylthiophene), poly (3,4-dibutylthiophene), poly (3,4-dipentylthiophene) ), Poly (3-hydroxythiophene), poly (3-methoxythiophene), poly ( -Ethoxythiophene), poly (3-butoxythiophene), poly (3-hexyloxythiophene), poly (3-heptyloxythiophene), poly (3-octyloxythiophene), poly (3-decyloxythiophene), poly (3-dodecyloxythiophene), poly (3-octadecyloxythiophene), poly (3,4-dihydroxythiophene), poly (3,4-dimethoxythiophene), poly (3,4-diethoxythiophene), poly ( 3,4-dipropoxythiophene), poly (3,4-dibutoxythiophene), poly (3,4-dihexyloxythiophene), poly (3,4-diheptyloxythiophene), poly (3,4-dioctyl) Oxythiophene), poly (3,4-didecyloxythiophene), poly (3, -Didodecyloxythiophene), poly (3-chloro-4-cyclohexylthiophene), poly (3,4-ethylenedioxythiophene), poly (3-methyl-3,4-ethylenedioxythiophene), poly (3 4-dipropyl-3,4-ethylenedioxythiophene), poly (3-methoxy-3,4-ethylenedioxythiophene), poly (3-phenyl-3,4-ethylenedioxythiophene), poly (3 -Cyclohexyl-3,4-ethylenedioxythiophene), poly (3,4-propylenedioxythiophene), poly (3,4-butenedioxythiophene), poly (3-methyl-4-methoxythiophene), poly (3-methyl-4-ethoxythiophene), poly (3-carboxythiophene), poly (3-methyl-4-carboxyl) Polythiophene), poly (3-methyl-4-carboxyethylthiophene), poly (3-methyl-4-carboxybutylthiophene), poly (thieno [3,4-b] [1,4] dioxin), etc. Kind,
Examples thereof include polyanilines such as polyaniline, poly (2-methylaniline), poly (3-isobutylaniline), poly (2-aniline sulfonic acid), and poly (3-aniline sulfonic acid).

Other monomers used for the production of the conjugated conductive polymer (B) include pyrrole, 3-methylpyrrole, 3-ethylpyrrole, 3-n-propylpyrrole, 3-butylpyrrole, 3-hexylpyrrole, 3 -Octylpyrrole, 3-decylpyrrole, 3-dodecylpyrrole, 3,4-dimethylpyrrole, 3,4-dibutylpyrrole, 3-carboxylpyrrole, 3-methyl-4-carboxylpyrrole, 3-methyl-4-carboxyethyl Pyrrole, 3-methyl-4-carboxybutylpyrrole, 3-hydroxypyrrole, 3-methoxypyrrole, 3-ethoxypyrrole, 3-butoxypyrrole, 3-hexyloxypyrrole, 3-methyl-4-hexyloxypyrrole, 3- Pyrroles such as methyl-4-hexyloxypyrrole;
Thiophene, 3-methylthiophene, 3-ethylthiophene, 3-propylthiophene, 3-butylthiophene, 3-hexylthiophene, 3-heptylthiophene, 3-octylthiophene, 3-decylthiophene, 3-dodecylthiophene, 3-octadecyl Thiophene, 3-bromothiophene, 3-chlorothiophene, 3-iodothiophene, 3-cyanothiophene, 3-phenylthiophene, 3,4-dimethylthiophene, 3,4-dibutylthiophene, 3,4-dipentylthiophene, 3- Hydroxythiophene, 3-methoxythiophene, 3-ethoxythiophene, 3-butoxythiophene, 3-hexyloxythiophene, 3-heptyloxythiophene, 3-octyloxythiophene, 3-decyloxythiophene, 3- Decyloxythiophene, 3-octadecyloxythiophene, 3,4-dihydroxythiophene, 3,4-dimethoxythiophene, 3,4-diethoxythiophene, 3,4-dipropoxythiophene, 3,4-dibutoxythiophene, 3, 4-dihexyloxythiophene, 3,4-diheptyloxythiophene, 3,4-dioctyloxythiophene, 3,4-didecyloxythiophene, 3,4-didodecyloxythiophene, 3-chloro-4-cyclohexylthiophene, 3,4-ethylenedioxythiophene, 3-methyl-3,4-ethylenedioxythiophene, 3,4-dipropyl-3,4-ethylenedioxythiophene, 3-methoxy-3,4-ethylenedioxythiophene, 3-Phenyl-3,4-ethylenedioxythio , 3-cyclohexyl-3,4-ethylenedioxythiophene, 3,4-propylenedioxythiophene, 3,4-butenedioxythiophene, 3-methyl-4-methoxythiophene, 3-methyl-4-ethoxy Thiophene, 3-carboxythiophene, 3-methyl-4-carboxythiophene, 3-methyl-4-carboxyethylthiophene, 3-methyl-4-carboxybutylthiophene, thieno [3,4-b] [1,4] dioxin Thiophenes such as
Examples include anilines such as aniline, 2-methylaniline, 3-isobutylaniline, 2-anilinesulfonic acid, and 3-anilinesulfonic acid.
These can use 1 type (s) or 2 or more types.
Polymerization of the monomer used for the production of the conjugated conductive polymer (B) is carried out using a azo compound, a peroxide, an oxidant, an oxidative polymerization catalyst, etc., in a solvent in which the produced polymer is dissolved.

<Conductive aid (C)>
The conductive auxiliary agent (C) is added as necessary for the purpose of further improving the conductivity of the conductive film formed by using the composition for thermoelectric conversion elements of the present invention, and specifically, lactam. , Alcohols, amino alcohols, furan carboxylic acid, halogen-substituted acetic acid, ionic liquid and the like.
Specific examples thereof include, for example,
Lactams such as N-methylpyrrolidone, pyrrolidone, caprolactam, N-methylcaprolactam, N-octylpyrrolidone;
Sucrose, glucose, fructose, lactose, sorbitol, mannitol, xylitol, ethylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol, triethylene glycol, glycerin, polyethylene glycol, polypropylene glycol, trifluoroethanol, alcohols such as m-cresol and thiodiglycol;
Amino alcohols such as diethanolamine and triethanolamine;
Carboxylic acids such as 2-furancarboxylic acid, 3-furancarboxylic acid, dichloroacetic acid, trifluoroacetic acid;
Acetic anhydride, propionic anhydride, acrylic anhydride, methacrylic anhydride, benzoic anhydride, succinic anhydride, maleic anhydride, itaconic anhydride, glutaric anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride (also known as : Cyclohexane-1,2-dicarboxylic anhydride), trimellitic anhydride, hexahydro trimellitic anhydride, pyromellitic anhydride, hymic anhydride, biphenyltetracarboxylic anhydride, 1,2,3,4-butanetetra Carboxylic anhydride, naphthalenetetracarboxylic anhydride, 9,9-fluorenylidenebisphthalic anhydride, styrene-maleic anhydride copolymer, ethylene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, alkyl vinyl ether-maleic anhydride Acid copolymer etc. , And the like acid anhydrides such as copolymers obtained by copolymerizing the maleic acid and other vinyl monomers anhydrous.
Moreover, as an ionic liquid, the compound included by General formula (2), such as conductive support agents (C1)-(C6);
Examples include compounds included in the general formula (3) such as the conductive assistants (C7) to (C26).

Among these, lactams, alcohols, ionic liquids and the like are preferable from the viewpoint of conductivity.
It is preferable that 0.1-50 weight% of conductive adjuvants (C) are contained in the composition for thermoelectric conversion elements. When the amount is less than 0.1% by weight, no improvement in conductivity due to the conductive auxiliary agent (C) can be expected. On the other hand, when the amount is more than 50% by weight, the physical properties of the film are often adversely affected.

The composition for thermoelectric conversion elements of the present invention may contain other components as necessary.
For example, a solvent or other organic resin (F) can be used in combination for the purpose of adjusting film formability and film strength.
Examples of the solvent include water;
Alcohols such as methanol, ethanol, propanol, isopropanol;
Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone;
Carbonates such as propylene carbonate, ethylene carbonate, vinylene carbonate, methylpropyl carbonate;
Esters such as ethyl propionate, γ-butyrolactone, γ-valerolactone, δ-valerolactone, methyl acetate, ethyl acetate;
Ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, glycol ether;
These include compounds in which a substituent such as fluorine is introduced. A solvent can be used individually or in combination of 2 types or more, respectively.
As the organic resin (F), any one of a thermosetting resin and a thermoplastic resin may be used as long as it is compatible or mixed and dispersed in the thermoelectric conversion element composition.
Specific examples include polyester resin, polyimide resin, polyamide resin, fluororesin, vinyl resin, epoxy resin, xylene resin, aramid resin, polyurethane resin, polyurea resin, melamine resin, phenol resin, polyether, acrylic resin, acrylamide resin. And copolymer resins thereof.

In order to improve the thermoelectric conversion performance, fine particles made of an inorganic thermoelectric material may be added to the thermoelectric conversion composition of the present invention. Inorganic thermoelectric materials include Bi— (Te, Se), Si—Ge, Mg—Si, Pb—Te, GeTe—AgSbTe, (Co, Ir, Ru) —Sb, (Ca, Sr). , Bi) Co ₂ O ₅ system, and the like. Specifically, Bi ₂ Te ₃ , PbTe, AgSbTe ₂ , GeTe, Sb ₂ Te ₃ , NaCo ₂ O ₄ , CaCoO ₃ , SrTiO ₃ , ZnO, Examples thereof include SiGe, Mg ₂ Si, FeSi ₂ , Ba ₈ Si ₄₆ , MnSi _1.73 , ZnSb, Zn ₄ Sb ₃ , GeFe ₃ CoSb ₁₂ , and LaFe ₃ CoSb ₁₂ . At this time, impurities may be added to the inorganic thermoelectric material to control the polarity (p-type, n-type) and conductivity.

<The manufacturing method of the composition for thermoelectric conversion elements>
Next, the manufacturing method of the composition for thermoelectric conversion elements of this invention is demonstrated.
Specifically, the composition for a thermoelectric conversion element of the present invention is a conjugated conductive solution dissolved or dispersed in a solvent in the presence of a polyanion (A) having a structural unit of the general formula (1) or (2). A polymer (B) monomer (one or more monomers) using a polymerization initiator or the like, a polymerizing method using an oxidase such as bilirubin oxidase, or ammonium persulfate, It can be produced by a method (chemical oxidative polymerization) of polymerization using an oxidizing agent such as potassium sulfate, potassium permanganate, sodium chlorite, potassium chlorate and the like.
Among these, from the viewpoint of the ease of polymerization and the conductivity of the resulting composition for a thermoelectric conversion element, a step of chemical oxidative polymerization [hereinafter also referred to as “step (1)”). It is preferable to obtain by the manufacturing method containing this.

  Furthermore, in the production method of the present invention, after the step (1), free ion is obtained by ultrafiltration or ion exchange resin with respect to the solution containing the polyanion (A) and the conjugated conductive polymer (B) produced. The step of removing [hereinafter also referred to as “step (2)”. It is preferable to have

  The ultrafiltration method is a type of membrane separation method, for example, a method of separating components using an ultrafiltration membrane having a polymer membrane having pores smaller than that on a porous support substrate. . In the present invention, since a necessary polymer component does not permeate the membrane, it is preferable to adopt a cross flow method. By carrying out the ultrafiltration treatment once or a plurality of times while diluting as necessary, only impurities including small particles and residual ions can be passed through the membrane and removed. In the present invention, for example, it is preferable to use an ultrafiltration membrane having a fractional molecular weight of 1 to 1,000,000.

The production method of the present invention is further expressed as a step of adding a proton-containing solution [hereinafter referred to as “step (3)”. It is preferable to have Step (3) may be performed simultaneously with step (2) or after step (2).
Although there is no restriction | limiting in particular as a proton containing solution used at a process (3), The solution containing a sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, a sulfonic acid compound, etc. is mentioned. By performing step (3) as necessary, a cation complexed with an anion group can be exchanged for a proton. As a result, higher electrical conductivity is obtained and free metal ions are removed, which is preferable.

<Thermoelectric conversion membrane>
Next, a method for forming a thermoelectric conversion film using the prepared composition for thermoelectric conversion elements will be described. A wet film forming method is mainly used for forming the thermoelectric conversion film. Specifically, spin coating method, spray method, roller coating method, gravure coating method, die coating method, comma coating method, roll coating method, curtain coating method, bar coating method, ink jet method, dispenser method, silk screen printing, flexo printing There are methods using various means such as printing. These methods can be appropriately used depending on the thickness, viscosity, and the like to be applied.

In addition, as a substrate for forming the thermoelectric conversion composition of the present invention, a plastic film such as polyethylene, polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polypropylene, polyimide, polycarbonate, or cellulose triacetate Alternatively, glass or the like can be used.
A laminated body can be obtained by forming a thermoelectric conversion film on the base material using the composition for thermoelectric conversion elements of the present invention.

  In general, various treatments can be performed on the surface of the substrate for the purpose of improving the adhesion between the substrate and the thermoelectric conversion film. Specific examples include UV ozone treatment, corona treatment, plasma treatment, and easy adhesion treatment.

<Thermoelectric conversion element>
When manufacturing the thermoelectric conversion element of this invention, the manufacturing method in particular is not restrict | limited. For example, a conventionally well-known thing is mentioned.

A thermoelectric conversion element can be produced by attaching two electrodes to a thermoelectric conversion film obtained using a thermoelectric conversion composition.
As the electrode, a metal, an alloy, and a semiconductor can be preferably used, but a metal and an alloy are preferable because of high conductivity, and gold, silver, copper, aluminum, and an alloy thereof are preferable.
The electrode can be formed by vacuum deposition, thermocompression bonding of a film having an electrode material foil or an electrode material film, application of a paste in which fine particles of the electrode material are dispersed, and the like. Among these, from the viewpoint that the process is simple, it is preferable to form an electrode by thermocompression bonding of a film having an electrode material foil or an electrode material film and application of a paste in which the electrode material is dispersed.

As a representative example of the positional relationship between the thermoelectric conversion film and the two electrodes, when electrodes are formed at both ends of the thermoelectric conversion film of the present invention, when the thermoelectric conversion film of the present invention is sandwiched between two electrodes, There are two.
For example, after forming a thermoelectric conversion film on a substrate, a thermoelectric element in which electrodes are formed on both ends of the thermoelectric conversion film of the present invention can be created by applying a silver paste to both ends thereof. Further, for example, an electrode film is formed by coating a silver paste on a substrate, a thermoelectric conversion film of the present invention is formed thereon, and a silver paste is further coated thereon to form 2 A thermoelectric element in which the thermoelectric conversion film of the present invention is sandwiched between two electrodes can be formed.

  When electrodes are formed on both ends of the thermoelectric conversion film, it is easy to increase the distance between the two electrodes, and as a result, a large temperature difference can be generated between the two electrodes to perform thermoelectric conversion. .

  When the thermoelectric conversion film of the present invention is sandwiched between two electrodes, it is difficult to increase the distance between the two electrodes. This is because it depends on the thickness of the thermoelectric conversion film. For this reason, it is difficult to generate a large temperature difference between the two electrodes. However, since a temperature difference in a direction perpendicular to the base material can be used, it can be used in a form such as being attached to a heating element, which is preferable in terms of easy utilization of a large area of the heat source.

  Further, it is possible to generate a high voltage by connecting thermoelectric elements in series, and it is possible to generate a large current by connecting them in parallel. It is also possible to connect two or more thermoelectric elements.

It is also effective to combine the thermoelectric element of the present invention with a thermoelectric element made of another thermoelectric material. For example, inorganic thermoelectric materials include Bi- (Te, Se), Si-Ge, Mg-Si, Pb-Te, GeTe-AgSbTe, (Co, Ir, Ru) -Sb, (Ca , Sr, Bi) Co ₂ O _{5 and the} like, and specifically, Bi ₂ Te ₃ , PbTe, AgSbTe ₂ , GeTe, Sb ₂ Te ₃ , NaCo ₂ O ₄ , CaCoO ₃ , SrTiO ₃ , _{ZnO, SiGe, Mg 2 Si,} FeSi 2, Ba 8 Si 46, MnSi 1.73, ZnSb, Zn 4 Sb 3, GeFe 3 CoSb 12, such as LaFe ₃ CoSb ₁₂ and the like. At this time, impurities may be added to the inorganic thermoelectric material to control the polarity (p-type, n-type) and conductivity. Examples of the organic thermoelectric material include polythiophene, polyaniline, polyacetylene, fullerene, and derivatives thereof.

  When connecting a plurality of thermoelectric elements, they can be connected and used in a state of being integrated on one base material. At this time, it is preferable to combine a thermoelectric element made of a thermoelectric material exhibiting n-type polarity with the thermoelectric element of the present invention and connect them in series because it is easy to densely integrate the thermoelectric elements.

  Hereinafter, the present invention will be described more specifically by way of examples. In the examples, “parts” means “parts by weight”, and “%” means “% by weight”.

  The weight average molecular weight Mw was determined in terms of polyethylene oxide by GPC measurement using a column in which α-2500, α-3000 and α-4000 of TSK-GEL manufactured by Tosoh Corporation were connected one by one. The column temperature was 40 ° C., the flow rate was 1.0 mL / min, and the eluent was a 0.2 M sodium nitrate aqueous solution.

<Production of polyanion (A)>
[Production Example 1]
In a reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer, 200 parts of ion-exchanged water and 300 parts of 5-sulfo-1H-indene Na salt were added and heated to 60 ° C. Polymerization was started by adding 1.75 parts of 2,2′-azobis (2-methylpropionamidine) dihydrochloride (V-50 manufactured by Wako Pure Chemical Industries, Ltd.). After stirring at 60 ° C. for 8 hours, 0.58 part of V-50 was added. Subsequently, after stirring at 60 degreeC for 8 hours, 0.58 part of V-50 was added and it heated at 70 degreeC. Furthermore, it stirred at 70 degreeC for 8 hours, and cooled. Thereafter, polyanion (A1) having a solid content of 15%, Mw 20000, and a monomer unit of 100 mol% derived from the general formula (1) was obtained by adding ion-exchanged water.

[Production Example 2]
In a reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer, 200 parts of ion-exchanged water and 100 parts of a potassium salt of 6-sulfo-benzofuran were added and heated to 50 ° C. The polymerization was initiated by adding 2.75 g of V-50. After stirring at 50 ° C. for 8 hours, 0.92 part of V-50 was added. Subsequently, after stirring at 50 degreeC for 8 hours, 0.92 part of V-50 was added and it heated at 70 degreeC. Furthermore, it stirred at 70 degreeC for 8 hours, and cooled. Thereafter, polyanion (A2) having a solid content of 15%, Mw of 175000, and a monomer unit of 100 mol% derived from the general formula (2) was obtained by adding ion exchange water.

[Production Example 3]
In a reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer, 250 parts of ion-exchanged water, 40 parts of sodium salt of 5-sulfo-1H-indene, and 10 parts of acrylamide were placed at 50 ° C. Warmed up. Polymerization was initiated by adding 2.25 g of V-50. After stirring at 50 ° C. for 8 hours, 0.75 part of V-50 was added. Subsequently, after stirring at 50 degreeC for 8 hours, 0.75 part of V-50 was added and it heated at 70 degreeC. The mixture was further stirred at 70 ° C. for 16 hours and cooled. Thereafter, ion-exchanged water was added to obtain a polyanion (A3) having a solid content of 15%, Mw of 300,000, and a monomer unit of 57 mol% derived from the general formula (1).

[Production Example 4]
In a reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer, 150 parts of toluene and 150 parts of indene were added and heated to 90 ° C. The polymerization was started by adding 1 part of dimethyl 2,2′-azobis (2-methylpropionate) (V-601 manufactured by Wako Pure Chemical Industries, Ltd.). After stirring at 90 ° C. for 5 hours, 0.026 part of V-601 was added. Subsequently, after stirring at 90 degreeC for 2 hours, 0.026 part of V-601 was added and it heated at 100 degreeC. Furthermore, it stirred at 100 degreeC for 3 hours, and cooled to 50 degreeC. Thereafter, 173.5 parts of acetyl sulfuric acid and 150 parts of dichloromethane were added and stirred at 50 ° C. for 5 hours, and then the volatile components were evaporated by an evaporator. By adding ion-exchanged water to the non-volatile component, a polyanion (A4) having a solid content of 15%, Mw of 80,000, and a monomer unit of 100 mol% derived from the general formula (1) was obtained.

[Production Example 5]
In a reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer, 200 parts of toluene, 80 parts of indene, and 20 parts of benzofuran were placed and heated to 90 ° C. Polymerization was initiated by adding 0.75 part of V-601. After stirring at 90 ° C. for 5 hours, 0.020 part of V-601 was added. Subsequently, after stirring at 90 degreeC for 2 hours, 0.020 part of V-601 was added and it heated at 100 degreeC. Furthermore, it stirred at 100 degreeC for 3 hours, and cooled to 50 degreeC. Thereafter, 115.3 parts of acetylsulfuric acid and 150 parts of dichloromethane were added and stirred at 50 ° C. for 5 hours, and then the volatile components were evaporated with an evaporator. By adding ion-exchanged water to the nonvolatile component, a polyanion (A5) having a solid content of 15%, Mw of 150,000, and a monomer unit of 100 mol% derived from the general formula (1) or (2) was obtained.

[Production Example 6]
In a reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer, 200 parts of toluene, 50 parts of indene, 20 parts of benzofuran, and 30 parts of cyclohexylmaleimide were added and heated to 90 ° C. Polymerization was initiated by adding 0.70 parts of V-601. After stirring at 90 ° C. for 5 hours, 0.018 part of V-601 was added. Subsequently, after stirring at 90 degreeC for 2 hours, 0.018 part of V-601 was added and it heated at 100 degreeC. Furthermore, it stirred at 100 degreeC for 3 hours, and cooled to 60 degreeC. Thereafter, 63.6 parts of acetylsulfuric acid and 120 parts of dichloromethane were added and stirred at 60 ° C. for 5 hours, and then the volatile components were evaporated by an evaporator. By adding ion-exchanged water to the non-volatile component, a polyanion (A6) having a solid content of 15%, Mw of 250,000, and a monomer unit of 65 mol% derived from the general formula (1) or (2) was obtained.

<Manufacture of thermoelectric conversion composition>
[Example 1]
10.8 parts (solid content 1.62 parts) of polyanion (A1) and 1.42 parts of 3,4-ethylenedioxythiophene were mixed in ion-exchanged water 77.7. This mixed liquid was kept at 25 ° C., and a catalyst solution in which 1.1 parts of ammonium persulfate and 0.1 g of ferric sulfate were dissolved in 10 parts of ion-exchanged water was slowly added and stirred at the same temperature for 24 hours (step (step ( 1)).
The operation of adding 2000 ml of ion-exchanged water to the resulting reaction solution and concentrating the solution to 300 ml by ultrafiltration was repeated twice to remove free ions of the polymerization catalyst (step (2)). Further, 100 ml of ion exchange water and 20 g of 10% sulfuric acid aqueous solution were sequentially added to the concentrate, and the operation of concentrating the solution to 300 ml by ultrafiltration was repeated 5 times in total to perform proton exchange (steps (3) and (3)). 2)). Furthermore, the operation of adding 3000 ml of ion-exchanged water and concentrating to 300 ml by ultrafiltration is repeated until the filtrate becomes neutral (step (2)), and thermoelectric conversion of a black-blue liquid having a solid content of 2.0% A device composition 1 was obtained.

[Example 2]
10.8 parts of polyanion (A1) (solid content 1.62 parts) and 1.42 parts of 3,4-ethylenedioxythiophene were mixed with 62.8 parts of ion-exchanged water. This mixed liquid was kept at 25 ° C., and a catalyst solution in which 1.1 parts of ammonium persulfate and 0.1 g of ferric sulfate were dissolved in 10 parts of ion-exchanged water was slowly added and stirred at the same temperature for 24 hours (step (step ( 1)).
The operation of adding 2000 ml of ion-exchanged water to the resulting reaction solution and concentrating the solution to 300 ml by ultrafiltration was repeated twice to remove free ions of the polymerization catalyst (step (2)). Further, 100 ml of ion exchange water and 20 g of 10% sulfuric acid aqueous solution were sequentially added to the concentrate, and the operation of concentrating the solution to 300 ml by ultrafiltration was repeated 5 times in total to perform proton exchange (steps (3) and (3)). 2)). Further, 3000 ml of ion-exchanged water was added, and the operation of concentrating to 300 ml by the ultrafiltration method was repeated until the filtrate became neutral (step (2)) to obtain a black-blue liquid having a solid content of 2.0%. . Thermoelectric conversion element composition 2 was obtained by adding 15% N-methylpyrrolidone to the solid content of the black-blue liquid.

[Example 3]
10.8 parts of polyanion (A2) (solid content 1.62 parts) and 1.42 parts of pyrrole were mixed with 72.8 parts of ion-exchanged water. This mixed liquid was kept at 25 ° C., and a catalyst solution in which 1.1 parts of ammonium persulfate and 0.1 g of ferric sulfate were dissolved in 10 parts of ion-exchanged water was slowly added and stirred at the same temperature for 24 hours (step (step ( 1)).
The operation of adding 2000 ml of ion-exchanged water to the resulting reaction solution and concentrating the solution to 300 ml by ultrafiltration was repeated twice to remove free ions of the polymerization catalyst (step (2)). Further, 100 ml of ion exchange water and 20 g of 10% sulfuric acid aqueous solution were sequentially added to the concentrate, and the operation of concentrating the solution to 300 ml by ultrafiltration was repeated 5 times in total to perform proton exchange (steps (3) and (3)). 2)). Further, 3000 ml of ion-exchanged water was added, and the operation of concentrating to 300 ml by the ultrafiltration method was repeated until the filtrate became neutral (step (2)) to obtain a black-blue liquid having a solid content of 2.0%. . A thermoelectric conversion element composition 3 was obtained by adding 5% ethylene glycol to the solid content of the black-blue liquid.

[Example 4]
10.8 parts of polyanion (A3) (solid content 1.62 parts) and 1.42 parts of 3-hexylthiophene were mixed with 57.8 parts of ion-exchanged water. This mixed liquid was kept at 25 ° C., and a catalyst solution in which 1.1 parts of ammonium persulfate and 0.1 g of ferric sulfate were dissolved in 10 parts of ion-exchanged water was slowly added and stirred at the same temperature for 24 hours (step (step ( 1)).
The operation of adding 2000 ml of ion-exchanged water to the resulting reaction solution and concentrating the solution to 300 ml by ultrafiltration was repeated twice to remove free ions of the polymerization catalyst (step (2)). Further, 100 ml of ion exchange water and 20 g of 10% sulfuric acid aqueous solution were sequentially added to the concentrate, and the operation of concentrating the solution to 300 ml by ultrafiltration was repeated 5 times in total to perform proton exchange (steps (3) and (3)). 2)). Further, 3000 ml of ion-exchanged water was added, and the operation of concentrating to 300 ml by the ultrafiltration method was repeated until the filtrate became neutral (step (2)) to obtain a black-blue liquid having a solid content of 2.0%. . The composition 4 for thermoelectric conversion elements was obtained by adding 20% of conductive auxiliary agent (C1) with respect to solid content of this black blue liquid.

[Example 5]
10.8 parts of polyanion (A4) (solid content 1.62 parts) and 1.42 parts of thiophene were mixed with 57.8 parts of ion-exchanged water. This mixed liquid was kept at 25 ° C., and a catalyst solution in which 1.1 parts of ammonium persulfate and 0.1 g of ferric sulfate were dissolved in 10 parts of ion-exchanged water was slowly added and stirred at the same temperature for 24 hours (step (step ( 1)).
The operation of adding 2000 ml of ion-exchanged water to the resulting reaction solution and concentrating the solution to 300 ml by ultrafiltration was repeated twice to remove free ions of the polymerization catalyst (step (2)). Further, 100 ml of ion exchange water and 20 g of 10% sulfuric acid aqueous solution were sequentially added to the concentrate, and the operation of concentrating the solution to 300 ml by ultrafiltration was repeated 5 times in total to perform proton exchange (steps (3) and (3)). 2)). Further, 3000 ml of ion-exchanged water was added, and the operation of concentrating to 300 ml by the ultrafiltration method was repeated until the filtrate became neutral (step (2)) to obtain a black-blue liquid having a solid content of 2.0%. . The composition 5 for thermoelectric conversion elements was obtained by adding 20% of thioglycol with respect to solid content of this black blue liquid.

[Example 6]
10.8 parts (solid content 1.62 parts) of polyanion (A5) and 1.42 parts of 3,4-ethylenedioxythiophene were mixed with 37.8 parts of ion-exchanged water. This mixed liquid was kept at 25 ° C., and a catalyst solution in which 1.1 parts of ammonium persulfate and 0.1 g of ferric sulfate were dissolved in 10 parts of ion-exchanged water was slowly added and stirred at the same temperature for 24 hours (step (step ( 1)).
The operation of adding 2000 ml of ion-exchanged water to the resulting reaction solution and concentrating the solution to 300 ml by ultrafiltration was repeated twice to remove free ions of the polymerization catalyst (step (2)). Further, 100 ml of ion exchange water and 20 g of 10% sulfuric acid aqueous solution were sequentially added to the concentrate, and the operation of concentrating the solution to 300 ml by ultrafiltration was repeated 5 times in total to perform proton exchange (steps (3) and (3)). 2)). Further, 3000 ml of ion-exchanged water was added, and the operation of concentrating to 300 ml by the ultrafiltration method was repeated until the filtrate became neutral (step (2)) to obtain a black-blue liquid having a solid content of 2.0%. . The composition 6 for thermoelectric conversion elements was obtained by adding 40% of conductive support agent (C3) with respect to solid content of this black blue liquid.

[Example 7]
10.8 parts (solid content 1.62 parts) of polyanion (A4) and 1.42 parts of 3,4-ethylenedioxythiophene were mixed with 52.8 parts of ion-exchanged water. This mixed liquid was kept at 25 ° C., and a catalyst solution in which 1.1 parts of ammonium persulfate and 0.1 g of ferric sulfate were dissolved in 10 parts of ion-exchanged water was slowly added and stirred at the same temperature for 24 hours (step (step ( 1)).
The operation of adding 2000 ml of ion-exchanged water to the resulting reaction solution and concentrating the solution to 300 ml by ultrafiltration was repeated twice to remove free ions of the polymerization catalyst (step (2)). Further, 100 ml of ion exchange water and 20 g of 10% sulfuric acid aqueous solution were sequentially added to the concentrate, and the operation of concentrating the solution to 300 ml by ultrafiltration was repeated 5 times in total to perform proton exchange (steps (3) and (3)). 2)). Further, 3000 ml of ion-exchanged water was added, and the operation of concentrating to 300 ml by the ultrafiltration method was repeated until the filtrate became neutral (step (2)) to obtain a black-blue liquid having a solid content of 2.0%. . The composition 7 for thermoelectric conversion elements was obtained by adding 5% of N-methylpyrrolidone and 20% of a conductive additive (C5) to the solid content of the black-blue liquid.

[Example 8]
10.8 parts (solid content 1.62 parts) of polyanion (A5) and 1.42 parts of 3,4-ethylenedioxythiophene were mixed with 42.8 parts of ion-exchanged water. This mixed liquid was kept at 25 ° C., and a catalyst solution in which 1.1 parts of ammonium persulfate and 0.1 g of ferric sulfate were dissolved in 10 parts of ion-exchanged water was slowly added and stirred at the same temperature for 24 hours (step (step ( 1)).
The operation of adding 2000 ml of ion-exchanged water to the resulting reaction solution and concentrating the solution to 300 ml by ultrafiltration was repeated twice to remove free ions of the polymerization catalyst (step (2)). Further, 100 ml of ion exchange water and 20 g of 10% sulfuric acid aqueous solution were sequentially added to the concentrate, and the operation of concentrating the solution to 300 ml by ultrafiltration was repeated 5 times in total to perform proton exchange (steps (3) and (3)). 2)). Further, 3000 ml of ion-exchanged water was added, and the operation of concentrating to 300 ml by the ultrafiltration method was repeated until the filtrate became neutral (step (2)) to obtain a black-blue liquid having a solid content of 2.0%. . The composition 8 for thermoelectric conversion elements was obtained by adding 5% of N-methylpyrrolidone and 30% of conductive aid (C7) to the solid content of the black-blue liquid.

[Comparative Example 1]
1.62 parts (solid content 1.62 parts) of polystyrene sulfonic acid having a Mw of 75000 and 1.42 parts of 3,4-ethylenedioxythiophene were mixed with 72.0 parts of ion-exchanged water. This mixed liquid was kept at 25 ° C., and a catalyst solution in which 1.1 parts of ammonium persulfate and 0.1 g of ferric sulfate were dissolved in 10 parts of ion-exchanged water was slowly added and stirred at the same temperature for 24 hours (step (step ( 1)).
The operation of adding 2000 ml of ion-exchanged water to the resulting reaction solution and concentrating the solution to 300 ml by ultrafiltration was repeated twice to remove free ions of the polymerization catalyst (step (2)). Further, 100 ml of ion exchange water and 20 g of 10% sulfuric acid aqueous solution were sequentially added to the concentrate, and the operation of concentrating the solution to 300 ml by ultrafiltration was repeated 5 times in total to perform proton exchange (steps (3) and (3)). 2)). Further, 3000 ml of ion-exchanged water was added, and the operation of concentrating to 300 ml by the ultrafiltration method was repeated until the filtrate became neutral (step (2)) to obtain a black-blue liquid having a solid content of 2.0%. . A thermoelectric conversion element composition 9 was obtained by adding 15% of N-methylpyrrolidone to the solid content of the black-blue liquid.

[Comparative Example 2]
6.48 parts of polystyrene sulfonic acid having a Mw of 75,000 (solid content: 6.48 parts) and 1.42 parts of 3,4-ethylenedioxythiophene were mixed with 67.1 parts of ion-exchanged water. This mixed liquid was kept at 25 ° C., and a catalyst solution in which 1.1 parts of ammonium persulfate and 0.1 g of ferric sulfate were dissolved in 10 parts of ion-exchanged water was slowly added and stirred at the same temperature for 24 hours (step (step ( 1)).
The operation of adding 2000 ml of ion-exchanged water to the resulting reaction solution and concentrating the solution to 300 ml by ultrafiltration was repeated twice to remove free ions of the polymerization catalyst (step (2)). Further, 100 ml of ion exchange water and 20 g of 10% sulfuric acid aqueous solution were sequentially added to the concentrate, and the operation of concentrating the solution to 300 ml by ultrafiltration was repeated 5 times in total to perform proton exchange (steps (3) and (3)). 2)). Further, 3000 ml of ion-exchanged water was added, and the operation of concentrating to 300 ml by the ultrafiltration method was repeated until the filtrate became neutral (step (2)) to obtain a black-blue liquid having a solid content of 2.0%. . The composition 10 for thermoelectric conversion elements was obtained by adding 15% of N-methylpyrrolidone to the solid content of the black-blue liquid.

[Comparative Example 3]
3.24 parts of dodecylbenzene sulfonic acid (solid content 3.24 parts) and 1.42 parts of pyrrole were mixed with 65.3 parts of ion-exchanged water. This mixed liquid was kept at 25 ° C., and a catalyst solution in which 1.1 parts of ammonium persulfate and 0.1 g of ferric sulfate were dissolved in 10 parts of ion-exchanged water was slowly added and stirred at the same temperature for 24 hours (step (step ( 1)).
The operation of adding 2000 ml of ion-exchanged water to the resulting reaction solution and concentrating the solution to 300 ml by ultrafiltration was repeated twice to remove free ions of the polymerization catalyst (step (2)). Further, 100 ml of ion exchange water and 20 g of 10% sulfuric acid aqueous solution were sequentially added to the concentrate, and the operation of concentrating the solution to 300 ml by ultrafiltration was repeated 5 times in total to perform proton exchange (steps (3) and (3)). 2)). Further, 3000 ml of ion-exchanged water was added, and the operation of concentrating to 300 ml by the ultrafiltration method was repeated until the filtrate became neutral (step (2)) to obtain a black-blue liquid having a solid content of 2.0%. . A thermoelectric conversion element composition 11 was obtained by adding 20% ethylene glycol to the solid content of the black-blue liquid.

[Comparative Example 4]
Sodium dialkylsulfosuccinate (Latemul PS manufactured by Kao Corporation) (3.24 parts) (solid content 3.24 parts) and 3-hexylthiophene (1.42 parts) were mixed with ion-exchanged water (65.3 parts). This mixed liquid was kept at 25 ° C., and a catalyst solution in which 1.1 parts of ammonium persulfate and 0.1 g of ferric sulfate were dissolved in 10 parts of ion-exchanged water was slowly added and stirred at the same temperature for 24 hours (step (step ( 1)).
The operation of adding 2000 ml of ion-exchanged water to the resulting reaction solution and concentrating the solution to 300 ml by ultrafiltration was repeated twice to remove free ions of the polymerization catalyst (step (2)). Further, 100 ml of ion exchange water and 20 g of 10% sulfuric acid aqueous solution were sequentially added to the concentrate, and the operation of concentrating the solution to 300 ml by ultrafiltration was repeated 5 times in total to perform proton exchange (steps (3) and (3)). 2)). Further, 3000 ml of ion-exchanged water was added, and the operation of concentrating to 300 ml by the ultrafiltration method was repeated until the filtrate became neutral (step (2)) to obtain a black-blue liquid having a solid content of 2.0%. . A thermoelectric conversion element composition 12 was obtained by adding 5% N-methylpyrrolidone and 20% conductive auxiliary (C8) to the solid content of the blue liquid.

[Comparative Example 5]
1.62 parts (solid content 1.62 parts) of sodium alkyldiphenyl ether disulfonate (Perox SS-L manufactured by Kao Corporation) and 1.42 parts of thiophene were mixed in 27.0 parts of ion-exchanged water. This mixed liquid was kept at 25 ° C., and a catalyst solution in which 1.1 parts of ammonium persulfate and 0.1 g of ferric sulfate were dissolved in 10 parts of ion-exchanged water was slowly added and stirred at the same temperature for 24 hours (step (step ( 1)).
The operation of adding 2000 ml of ion-exchanged water to the resulting reaction solution and concentrating the solution to 300 ml by ultrafiltration was repeated twice to remove free ions of the polymerization catalyst (step (2)). Further, 100 ml of ion exchange water and 20 g of 10% sulfuric acid aqueous solution were sequentially added to the concentrate, and the operation of concentrating the solution to 300 ml by ultrafiltration was repeated 5 times in total to perform proton exchange (steps (3) and (3)). 2)). Further, 3000 ml of ion-exchanged water was added, and the operation of concentrating to 300 ml by the ultrafiltration method was repeated until the filtrate became neutral (step (2)) to obtain a black-blue liquid having a solid content of 2.0%. . The composition 13 for thermoelectric conversion elements was obtained by adding 60% of thioglycol with respect to solid content of this blue liquid.

<Evaluation of thermoelectric conversion material (composition for thermoelectric conversion element)>
(Calculation of ZT)
In order to evaluate the performance of the thermoelectric conversion material of the present invention, the composition for thermoelectric conversion elements was applied onto a PET (polyethylene terephthalate) film having a thickness of 50 μm using a bar coater (# 20). Using a thermoelectric conversion film obtained by drying at 100 ° C. for 2 minutes, the Seebeck coefficient and conductivity are ZEM-2 (manufactured by ULVAC-RIKO), and the thermal diffusivity is flash method thermal diffusivity measuring apparatus LFT-447 (Netch The specific heat capacity was measured using a differential scanning calorimeter DSC6200 (manufactured by Seiko Instruments Inc.), and the density was regarded as 1.45 (g / cm ³ ) from the literature value, and ZT was calculated.
(Reliability test)
Moreover, the reliability test in a use environment was done by measuring ZT after the heat test which stored the thermoelectric conversion film in the oven heated at 120 degreeC for 1000 hours. If the ZT after heating was within ± 20% of the ZT before heating, it was evaluated as ◯, when it was larger than ± 20% but less than ± 30%, and when it was ± 30% or more, it was marked as ×.

PSS: polystyrene sulfonate DBSA: dodecylbenzene sulfonate latemul PS: sodium alkane sulfonate (manufactured by Kao Corporation)
Perex SS-L: Sodium alkyldiphenyl ether disulfonate (manufactured by Kao Corporation)
PEDOT: Poly (3,4-ethylenedioxythiophene)
P3HT: Poly (3-hexylthiophene)
NMP: N-methylpyrrolidone EG: ethylene glycol

As is clear from the above evaluation results, the thermoelectric conversion films obtained by applying the compositions for thermoelectric conversion elements of Examples 1 to 8 using the polyanion (A) used in the present invention to the substrate are initially and The dimensionless thermoelectric figure of merit (ZT) after the heating test is good.
On the other hand, in Comparative Examples 1 and 2, if the amount of polyanion (A) added is increased in order to improve ZT, the reliability is lowered. Moreover, in Comparative Examples 3-5, since a dopant is low molecular weight, heat resistance is inadequate and reliability fell.

The thermoelectric conversion material of the present invention was found to be excellent in thermoelectric conversion performance and excellent in long-term reliability. Furthermore, it turned out that the thermoelectric conversion element which is excellent in thermoelectric conversion performance is obtained by using the composition of this invention.

Claims (8)

A thermoelectric conversion material comprising a polyanion (A) having a structural unit represented by the following general formula (1) or general formula (2) and a conjugated conductive polymer (B).
General formula (1)

[In the general formula (1), R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or SO ₃ X, and any one or more of R ₁ , R ₂ , R ₃ and R ₄ are SO ₃ X, where X is a hydrogen atom, Li, Na, K, ammonium ion, protonated primary, protonated secondary, protonated tertiary amine or quaternary ammonium ion It is. ]

General formula (2)

[In General Formula (2), R ₅ , R ₆ , R ₇ and R ₈ are each independently hydrogen or SO ₃ X, and any one or more of R ₅ , R ₆ , R ₇ and R ₈ are SO ₃ X, where X is a hydrogen atom, Li, Na, K, ammonium ion, protonated primary, protonated secondary, protonated tertiary amine or quaternary ammonium ion It is. ]   It contains a polyanion (A) having a structural unit of the following general formula (1) or general formula (2) and a conjugated conductive polymer (B), and has a dimensionless thermoelectric figure of merit (ZT) of 0.02 or more. The composition for thermoelectric conversion elements characterized by these. The composition for thermoelectric conversion elements according to claim 2, wherein the conjugated conductive polymer (B) is polythiophene or a derivative thereof. The composition for thermoelectric conversion elements according to claim 2 or 3, wherein the conjugated conductive polymer (B) is poly (3,4-ethylenedioxythiophene). The composition for thermoelectric conversion elements according to any one of claims 2 to 4, comprising a conductive additive (C). The composition for thermoelectric conversion elements according to claim 5, wherein the conductive auxiliary agent (C) comprises a compound represented by the following general formula (3) or general formula (4).
General formula (3)

[Wherein, M represents a lithium atom, a sodium atom, or a potassium atom.
A ₁ represents a fluorine atom or a trifluoromethyl group. ]

General formula (4)

[In the formula, A ₂ represents a direct bond, a substituted or unsubstituted divalent aliphatic hydrocarbon group, a substituted or unsubstituted divalent aromatic hydrocarbon group, a substituted or unsubstituted divalent aliphatic complex; Represents a cyclic group or a substituted or unsubstituted divalent aromatic heterocyclic group, X represents a direct bond, an oxygen atom, a nitrogen atom, or a sulfur atom, and M represents a lithium atom, a sodium atom, or Represents a potassium atom. ]   The thermoelectric conversion film formed from the composition for thermoelectric conversion elements in any one of Claims 2-6.   The thermoelectric conversion element obtained using the composition for thermoelectric conversion elements in any one of Claims 2-6, or the thermoelectric conversion film of Claim 7.