JP6276726B2 - Thermoelectric conversion element - Google Patents

Description

  The present invention relates to a thermoelectric conversion element.

Thermoelectric conversion materials that can mutually convert thermal energy and electrical energy are used in thermoelectric conversion elements such as thermoelectric power generation elements and Peltier elements. Thermoelectric power generation using such thermoelectric conversion elements can directly convert thermal energy into electric power, does not require moving parts, and is used for wristwatches, remote power supplies, space power supplies, etc. that operate at body temperature. Yes.
In recent years, carbon nanotubes (hereinafter also referred to as “CNT”) have attracted attention as thermoelectric conversion materials, and several techniques relating to thermoelectric conversion materials containing CNTs have been proposed (for example, Patent Document 1).

International Publication No. 2012/121133

On the other hand, in recent years, further improvement in the thermoelectric conversion performance of thermoelectric conversion elements has been demanded in order to improve the performance of equipment in which thermoelectric conversion elements are used.
When the present inventors produced the thermoelectric conversion layer on the resin substrate using the thermoelectric conversion material containing CNT as described in patent document 1, and evaluated the characteristic (power generation amount), it is requested | required these days. It was discovered that further improvement is necessary.

  In recent years, there has been an increasing demand for attaching a thermoelectric conversion element to the surface of a device having a curved surface or unevenness, and even when the thermoelectric conversion element is bent, its characteristics are not easily changed, and bending resistance is also required.

  In view of the above circumstances, an object of the present invention is to provide a thermoelectric conversion element that is excellent in thermoelectric conversion performance and also excellent in bending resistance.

As a result of intensive studies on the above problems, the present inventors have found that a desired effect can be obtained by using a resin substrate surface-treated with a predetermined surface treatment agent.
More specifically, the present inventors have found that the above object can be achieved by the following configuration.

(1) any one of the following substrate A and substrate B surface-treated substrate;
A thermoelectric conversion element comprising: a thermoelectric conversion layer including carbon nanotubes, disposed on a surface-treated surface of a surface treatment substrate.
Substrate A: A surface-treated substrate obtained by surface-treating a resin substrate with a first surface treatment agent represented by (R ₁ ) _n M (X) _m .
M represents Si, Ti, or Zr. X represents a hydrolyzable group or a hydroxyl group. R ₁ represents a monovalent organic group, and at least one of R ₁ represents a monovalent organic group containing an aromatic ring. n represents an integer of 1 to 3, m represents an integer of 1 to 3, and n + m = 4. However, the monovalent organic group does not include a hydrolyzable group or a hydroxyl group.
Substrate B: A resin substrate that has a reactive group and is surface-treated with a second surface treatment agent represented by (R ₂ ) _n M (X) _m , and then a functional group that reacts with the reactive group A surface-treated substrate obtained by surface treatment with a third surface treatment agent having a group and an aromatic ring.
M represents Si, Ti, or Zr. X represents a hydrolyzable group or a hydroxyl group. R ₂ represents a monovalent organic group, and at least one of R ₂ represents a monovalent organic group containing a reactive group. n represents an integer of 1 to 3, m represents an integer of 1 to 3, and n + m = 4. However, the monovalent organic group does not include a hydrolyzable group or a hydroxyl group.
(2) The thermoelectric conversion element according to (1), wherein the surface-treated substrate is a substrate B.
(3) The thermoelectric conversion element according to (1) or (2), wherein the aromatic ring is a polycyclic aromatic ring.
(4) The thermoelectric conversion element according to any one of (1) to (3), wherein the resin substrate is a resin substrate subjected to energy ray irradiation.
(5) The thermoelectric conversion element according to any one of (1) to (4), wherein the resin substrate is a polyimide substrate.

  ADVANTAGE OF THE INVENTION According to this invention, while being excellent in thermoelectric conversion performance, the thermoelectric conversion element which is excellent also in bending resistance can be provided.

It is sectional drawing of the 1st embodiment of the thermoelectric conversion element of this invention. The arrow in FIG. 1 shows the direction of the temperature difference provided when using the thermoelectric conversion element. (A) is a top view conceptually showing the second embodiment of the thermoelectric conversion element of the present invention, (B) is a front view conceptually showing the second embodiment of the thermoelectric conversion element of the present invention, (C) ) Is a bottom view conceptually showing a second embodiment of the thermoelectric conversion element of the present invention. (A)-(C) are the conceptual diagrams for demonstrating another example of the 2nd embodiment of the thermoelectric conversion element of this invention. (A)-(D) are the conceptual diagrams for demonstrating an example of the thermoelectric conversion module of this invention. (A) is a conceptual diagram which shows another example of the board | substrate used for the thermoelectric conversion element of this invention, (B) is a conceptual diagram which shows another example of the board | substrate used for the thermoelectric conversion module of this invention. .

Below, the suitable aspect of the thermoelectric conversion element of this invention is demonstrated. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
One of the features of the thermoelectric conversion element of the present invention is that a resin substrate surface-treated with a surface treatment agent having an aromatic ring is used. In the prior art, since the thermoelectric conversion layer using CNT has poor adhesion to the resin substrate in the prior art, voids are likely to be generated between the thermoelectric conversion layer and the resin substrate. As a result, the thermoelectric conversion layer is formed from the resin substrate to the thermoelectric conversion layer. It was found that the heat transfer efficiency to was not sufficient. Therefore, the present inventor uses a resin substrate (surface treatment substrate) surface-treated with a surface treatment agent having an aromatic ring, whereby the CNT contained in the thermoelectric conversion layer disposed on the surface treatment substrate, and the surface It has been found that the adhesion between the surface treatment substrate and the thermoelectric conversion layer is further improved by interaction with the aromatic ring derived from the surface treatment agent on the surface of the treatment substrate. In addition, as the adhesion between the surface treatment substrate and the thermoelectric conversion layer is improved, the thermoelectric conversion layer becomes difficult to peel off from the surface treatment substrate even when the thermoelectric conversion element is bent. It is also known that the deterioration of) is suppressed.

<First Embodiment>
FIG. 1 conceptually shows a first embodiment of the thermoelectric conversion element of the present invention.
As shown in FIG. 1, the thermoelectric conversion element 1 includes a surface treatment substrate 2, a first electrode 3 and a second electrode 4 disposed on the surface treatment substrate 2, and a surface treatment substrate 2. The thermoelectric conversion layer 5 is disposed so as to be in contact with the first electrode 3 and the second electrode 4, and the protective substrate 6 is disposed on the thermoelectric conversion layer 5. When the thermoelectric conversion element 1 is used, a temperature difference is given in the direction of the arrow as shown in FIG.
The surface 2a of the surface treatment substrate 2 is a surface that has been surface-treated with a predetermined surface treatment agent to be described later, and the thermoelectric conversion layer 5 is disposed on the surface 2a.
In addition, in the said aspect, although the 1st electrode and the 2nd electrode are arrange | positioned on a board | substrate, the position will not be restrict | limited especially if it is contacting with the thermoelectric conversion layer.
Hereinafter, each member which comprises a thermoelectric conversion element is explained in full detail.

[Surface treatment substrate]
The following substrate A or substrate B is used as the surface treatment substrate.
Substrate A: A surface-treated substrate obtained by surface-treating a resin substrate with a first surface treatment agent represented by (R ₁ ) _n M (X) _m .
Substrate B: A resin substrate that has a reactive group and is surface-treated with a second surface treatment agent represented by (R ₂ ) _n M (X) _m , and then a functional group that reacts with the reactive group A surface-treated substrate obtained by surface treatment with a third surface treatment agent having a group and an aromatic ring.
As described above, in the substrate A and the substrate B, an aromatic ring is introduced onto the surface of the resin substrate by treating the resin substrate with a predetermined surface treatment agent. The presence of this aromatic ring improves the interaction with CNT, and as a result, the adhesion between the surface-treated substrate and the thermoelectric conversion layer is further improved, and the thermoelectric conversion characteristics (particularly, the amount of power generation) are improved.
Below, the surface treating agent (1st surface treating agent-3rd surface treating agent) used for the said surface treatment and a resin substrate are explained in full detail first.

(First surface treatment agent)
The first surface treatment agent is a compound represented by (R ₁ ) _n M (X) _m . In the first surface treatment agent, the hydrolyzable group represented by X reacts with the resin substrate (condensation reaction) via the hydroxyl group formed by hydrolysis reaction or the hydroxyl group represented by X, An aromatic ring derived from one surface treatment agent is immobilized on a resin substrate.
In the above formula, M represents Si (silicon atom), Ti (titanium atom) or Zr (zirconium atom). Among them, Si is more excellent in thermoelectric conversion characteristics of the thermoelectric conversion element and / or more excellent in bending resistance of the thermoelectric conversion element (hereinafter, also simply referred to as “the point where the effect of the present invention is more excellent”). preferable.

X represents a hydrolyzable group or a hydroxyl group. The hydrolyzable group is a group that is directly bonded to M and can proceed with a hydrolysis reaction and / or a condensation reaction, and examples thereof include an alkoxy group, a halogen atom, an acyloxy group, and an alkenyloxy group. Among these, an alkoxy group is preferable in terms of better handleability. The number of carbon atoms in the alkoxy group is not particularly limited, but 1 to 5 is preferable and 1 to 3 is more preferable in terms of excellent reactivity.
When there are a plurality of Xs, the plurality of Xs may be the same or different.

R ₁ represents a monovalent organic group (excluding a hydrolyzable group and a hydroxyl group), and at least one of R ₁ represents a monovalent organic group containing an aromatic ring.
The monovalent organic group may be any organic group other than a hydrolyzable group and a hydroxyl group. For example, an alkyl group, a cycloalkyl group, an aryl group, an alkylcarbonyl group, a cycloalkylcarbonyl group, an arylcarbonyl group, an alkyloxy group Examples thereof include a carbonyl group, a cycloalkyloxycarbonyl group, an aryloxycarbonyl group, an alkylaminocarbonyl group, a cycloalkylaminocarbonyl group, an arylaminocarbonyl group, or a combination thereof. Especially, a C1-C6 alkyl group and an aryl group are mentioned preferably.

At least one of R _{1 represents} a monovalent organic group containing an aromatic ring (hereinafter also referred to as organic group A). In other words, the organic group A is a monovalent group containing an aromatic ring structure. Among them, in terms of the effect of the present invention is more excellent, it is preferable that all of R ₁ is a monovalent organic group containing an aromatic ring.
The aromatic ring contained in the organic group A may be a hydrocarbon aromatic ring or a heteroaromatic ring.
Examples of the hydrocarbon aromatic ring include a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, pyrene ring, azulene ring, chrysene ring, perylene ring, triphenylene ring, pentalene ring, indacene ring, fluoranthene ring, and acephenanthrylene ring. , An asanthrylene ring, a naphthacene ring, a pentaphen ring, a pentacene ring, a hexaphen ring, and the like.
Examples of the heteroaromatic ring include furan ring, thiophene ring, pyrrole ring, pyrroline ring, pyrrolidine ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, imidazoline ring, imidazolidine ring, pyrazole ring, Pyrazoline ring, pyrazolidine ring, triazole ring, furazane ring, tetrazole ring, pyran ring, thiyne ring, pyridine ring, piperidine ring, oxazine ring, morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring, triazine ring , Benzofuran ring, isobenzofuran ring, benzothiophene ring, indole ring, indoline ring, isoindole ring, benzoxazole ring, benzothiazole ring, indazole ring, benzimidazole ring, quinoline ring, isoquinoline ring, cinno Ring, phthalazine ring, quinazoline ring, quinoxaline ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring, xanthene ring, acridine ring, phenanthridine ring, phenanthroline ring, phenazine ring, phenoxazine ring, thianthrene ring, indolizine ring, A quinolidine ring, a quinuclidine ring, a naphthyridine ring, a purine ring, a pteridine ring, etc. are mentioned.

Further, the aromatic ring contained in the organic group A may be a monocyclic aromatic ring or a polycyclic aromatic ring (condensed polycyclic aromatic ring). Among these, a polycyclic aromatic ring is preferable and a polycyclic aromatic ring having 3 or more rings is more preferable in that the effect of the present invention is more excellent. The upper limit of the number of polycyclic aromatic rings is not particularly limited, but is often 10 or less, and more often 5 or less.
A polycyclic aromatic ring is a ring structure formed by condensation of two or more aromatic rings.

A preferred embodiment of the monovalent organic group containing an aromatic ring includes a group represented by the formula (1). * Represents a bonding position with M.
Formula (1) Ar-L _1- *
Ar represents an aromatic ring. The definition of the aromatic ring is as described above.
L ₁ represents a single bond or a divalent linking group. Examples of the divalent linking group include a divalent hydrocarbon group (a divalent saturated hydrocarbon group or a divalent aromatic hydrocarbon group. A divalent saturated hydrocarbon group may be used. May be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, and examples thereof include an alkylene group, and a divalent aromatic hydrocarbon group includes carbon. The number is preferably 5 to 20, for example, a phenylene group, or an alkenylene group or an alkynylene group.) A divalent heterocyclic group, -O-, -S- , —SO ₂ —, —NR _L —, —CO—, —COO—, —CONR _L —, —SO ₃ —, —SO ₂ NR _L —, or a combination of two or more thereof (for example, alkylene Oxy group, alkyleneoxycarbonyl group, alkylene Etc. Ruboniruokishi group). Among these, an alkylene group, —O—, —COO—, —SO ₃ —, or a combination thereof is preferable. Here, _RL represents a hydrogen atom or an alkyl group (preferably having 1 to 10 carbon atoms).
Ar may be substituted with a substituent. Examples of the substituent include the groups exemplified as the monovalent organic group.

n represents an integer of 1 to 3, and 1 or 2 is preferable and 1 is more preferable in that the effect of the present invention is more excellent.
m represents an integer of 1 to 3, and 2 to 3 is preferable and 3 is more preferable in that the effect of the present invention is more excellent.
Note that n + m = 4. That is, the sum of n and m satisfies the relationship of 4.

(Second surface treatment agent)
The second surface treatment agent is a compound having a reactive group and represented by (R ₂ ) _n M (X) _m . In the second surface treatment agent, the hydrolyzable group represented by X reacts with the resin substrate through the hydrolysis reaction or the hydroxyl group represented by X (condensation reaction), and the second surface treatment agent 2 Reactive groups derived from the surface treatment agent are immobilized on the resin substrate.
In the above formula, the definitions of M, X, n and m are the same as those of the first surface treatment agent.

R ₂ represents a monovalent organic group (excluding a hydrolyzable group and a hydroxyl group), and at least one of R ₂ represents a monovalent organic group containing a reactive group.
The definition of the monovalent organic group is the same as the definition of the monovalent organic group described in R ₁ above.
The reactive group contained in the monovalent organic group containing a reactive group may be any group capable of reacting with the third surface treatment agent described later. For example, methacryloyl group, acryloyl group, epoxy group, primary amino Group, secondary amino group, styryl group, vinyl group, phenol group, isocyanate group, mercapto group, carboxyl group and the like, and methacryloyl group or acryloyl group is preferable from the viewpoint of more excellent reactivity.

A preferred embodiment of the monovalent organic group containing a reactive group is a group represented by the formula (2). * Represents a bonding position with M.
Formula (2) YL _2- *
Y represents a reactive group. The definition of the reactive group is as described above.
L ₂ represents a single bond or a divalent linking group. The definition of a bivalent coupling group is as the above-mentioned.

(Third surface treatment agent)
The third surface treatment agent is a compound having a functional group that reacts with the reactive group and an aromatic ring. When the third surface treatment agent is used with respect to the resin substrate in which the surface treatment is performed by the second surface treatment agent and the reactive group is introduced, the reactive group and the third surface treatment agent react, An aromatic ring can be introduced on the resin substrate.
The functional group that reacts with the reactive group contained in the third surface treatment agent is not particularly limited as long as it is a functional group that can react with the reactive group in the second surface treatment agent to form a chemical bond. For example, a methacryloyl group, an acryloyl group, an epoxy group, a hydroxyl group, a primary amino group, a secondary amino group, a styryl group, a vinyl group, a phenol group, an isocyanate group, a mercapto group, or a carboxyl group can be given.
Suitable combinations of the reactive group and the functional group (reactive group: functional group) include, for example, (methacryloyl group: mercapto group), (acryloyl group: mercapto group), (mercapto group: methacryloyl group), (Mercapto group: acryloyl group), (epoxy group: carboxylic acid group), (isocyanate group: hydroxyl group) and the like.

  The third surface treatment agent includes an aromatic ring. The definition of the aromatic ring is as described above.

As a suitable aspect of a 3rd surface treating agent, the compound represented by Formula (3) is mentioned.
Equation (3) _Ar-L 3 -Z
Ar represents an aromatic ring. The definition of the aromatic ring is as described above.
L ₃ represents a single bond or a divalent linking group. The definition of a bivalent coupling group is as the above-mentioned.
Z represents a functional group that reacts with a reactive group. The definition of this functional group is as described above.

(Resin substrate)
The resin substrate subjected to the surface treatment with the surface treatment agent is not particularly limited as long as it is made of resin. The resin substrate preferably has flexibility. Specifically, the resin substrate preferably has flexibility such that the number of bending resistances MIT according to the measurement method prescribed in ASTM D2176 is 10,000 cycles or more. .
More specifically, examples of the resin substrate include polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, polybutylene terephthalate, poly (1,4-cyclohexylenedimethylene terephthalate), polyethylene-2,6-phthalenedicarboxyl. Polyester substrates such as rate, ZEONOR film (trade name, manufactured by Nippon Zeon), Arton film (trade name, manufactured by JSR), Sumilite FS1700 (trade name, manufactured by Sumitomo Bakelite), Kapton (product) Name, Toray DuPont), Apical (trade name, manufactured by Kaneka), Iupilex (trade name, manufactured by Ube Industries), Pomilan (trade name, manufactured by Arakawa Chemical Co., Ltd.) and other polyimide substrates, Pure Ace (trade name) , Manufactured by Teijin Chemicals Ltd.), Elmec (product) Polycarbonate substrates such as Kaneka), polyether ether ketone substrates such as Sumilite FS1100 (trade name, manufactured by Sumitomo Bakelite), polyphenyl sulfide substrates such as Torelina (trade name, manufactured by Toray Industries, Inc.), polyacetal substrates, polyamide substrates , A polyphenylene ether substrate, a polyolefin substrate (for example, a polyethylene substrate), a polystyrene substrate, a polyarylate substrate, a polysulfone substrate, a polyethersulfone substrate, a fluororesin substrate, a liquid crystal polymer substrate, and the like. A polyimide substrate is preferable from the viewpoint of easy availability, heat resistance (preferably 100 ° C. or higher), and more excellent effects of the present invention.

  The thickness of the resin substrate is preferably 1 to 3000 μm, more preferably 5 to 1000 μm, still more preferably 5 to 1000 μm, and particularly preferably 5 to 800 μm, from the viewpoints of handleability and durability.

In addition, as the resin substrate, a resin substrate whose surface is irradiated with energy rays is preferable because the effect of the present invention is more excellent. If it is a resin substrate subjected to such treatment, it is excellent in reactivity with the above-described surface treatment agent and more excellent in adhesion with the thermoelectric conversion layer. In addition, the surface treatment mentioned above is given to the surface side to which the energy ray irradiation was given.
The method of energy beam irradiation is not particularly limited. For example, corona treatment using corona discharge, plasma treatment exposed to a plasma atmosphere, ultraviolet irradiation treatment that performs ultraviolet irradiation (preferably UV (ultraviolet light that performs ultraviolet irradiation in an ozone atmosphere) ) Ozone treatment), and EB (Electoron Beam) irradiation treatment that irradiates an electron beam can be used, and preferred examples include plasma treatment, corona treatment, and UV ozone treatment. By these treatments, polar hydroxyl groups, carboxyl groups, basic groups or the like can be generated on the resin substrate surface, and the reactivity with the surface treatment agent is further improved.

(Manufacturing method of substrate A)
The substrate A is a surface-treated substrate obtained by surface-treating a resin substrate with a first surface treatment agent represented by (R ₁ ) _n M (X) _m .
The surface treatment method is not particularly limited as long as the first surface treatment agent and the resin substrate can be brought into contact with each other. For example, a method of immersing the resin substrate in a solution containing the first surface treatment agent, And a method of applying a solution containing the first surface treatment agent.
Various solvents may be contained in the solution. The kind in particular of solvent used is not restrict | limited, Water and an organic solvent are mentioned. The concentration of the first surface treatment agent in the solution is not particularly limited, but is preferably 0.01 to 10% by mass and more preferably 0.1 to 2.0% by mass in terms of productivity and reactivity. preferable.
In addition, the solution may contain a catalyst such as an acid catalyst or a base catalyst as necessary. By including the catalyst, the hydrolysis reaction and the condensation reaction proceed more efficiently.
The contact time between the resin substrate and the first surface treatment agent (or the solution containing the first surface treatment agent) is not particularly limited, and is preferably 1 to 72 hours, more preferably 10 to 48 in terms of more excellent effects of the present invention. Time is more preferred.
After bringing the resin substrate into contact with the first surface treatment agent (or a solution containing the first surface treatment agent), the resin substrate surface may be washed with a solvent as necessary.

(Manufacturing method of substrate B)
The substrate B has a reactive group and is surface-treated with a second surface treatment agent represented by (R ₂ ) _n M (X) _m and then reacts with the reactive group. It is a surface treatment substrate obtained by surface-treating with the 3rd surface treating agent which has a functional group and an aromatic ring.
The surface treatment method using the second surface treatment agent is the same method as the surface treatment method using the first surface treatment agent described above, and a method of using the second surface treatment agent instead of the first surface treatment agent. Is mentioned.
Next, the surface treatment method using the third surface treatment agent is not particularly limited as long as the resin substrate surface-treated with the second surface treatment agent can be brought into contact with the third surface treatment agent. A method of immersing a resin substrate surface-treated with the second surface treatment agent in a solution containing the third surface treatment agent, or a solution containing the third surface treatment agent on the resin substrate surface-treated with the second surface treatment agent The method of apply | coating is mentioned.
Various solvents may be contained in the solution. The kind in particular of solvent used is not restrict | limited, Water and an organic solvent are mentioned.
The contact time between the resin substrate and the second surface treatment agent (or the solution containing the second surface treatment agent) is not particularly limited, and optimal conditions are appropriately selected depending on the types of reactive groups and functional groups. Especially, from the point of productivity, 1-48 hours are preferable and 2-36 hours are more preferable normally.
Moreover, in the case of the said contact, you may heat-process as needed.
After bringing the resin substrate into contact with the third surface treatment agent (or a solution containing the third surface treatment agent), the resin substrate surface may be washed with a solvent as necessary.

[First electrode and second electrode]
A 1st electrode and a 2nd electrode are members arrange | positioned in contact with the thermoelectric conversion layer mentioned later.
As an electrode material for forming the first electrode 3 and the second electrode 4, various materials can be used as long as they have necessary electrical conductivity.
Specifically, various materials such as copper, silver, gold, platinum, nickel, aluminum, constantan, chromium, indium, iron, copper alloy, and other devices such as indium tin oxide (ITO) and zinc oxide (ZnO) Examples include materials used as transparent electrodes. Among these, copper, gold, silver, platinum, nickel, copper alloy, aluminum, constantan and the like are preferably exemplified, and copper, gold, silver, platinum and nickel are more preferably exemplified.

  The first electrode and the second electrode are formed by vapor deposition, printing (for example, screen printing, metal mask printing, ink jet printing, etc.), adhesive / adhesive, etc., depending on the material for forming the first electrode and the second electrode. It may be carried out by a known method such as attachment to a substrate via The electrode pattern may be formed using a mask during vapor deposition or printing, and may be formed by patterning by a known method such as etching, sandblasting, laser engraving, or electron beam method after the electrode is formed on the surface.

[Thermoelectric conversion layer]
The thermoelectric conversion layer is a layer disposed on the surface-treated substrate (on the surface-treated surface of the surface-treated substrate), and exhibits excellent adhesion with the surface-treated substrate.
The thermoelectric conversion layer includes CNT. The CNT includes a single-layer CNT in which one carbon film (graphene sheet) is wound in a cylindrical shape, a two-layer CNT in which two graphene sheets are wound in a concentric shape, and a plurality of graphene sheets. There are multi-walled CNTs wound concentrically. In the present invention, single-walled CNTs, double-walled CNTs, and multilayered CNTs may be used alone or in combination of two or more. In particular, it is preferable to use single-walled CNT and double-walled CNT having excellent properties in terms of conductivity and semiconductor properties, and more preferably single-walled CNT.
Single-walled CNTs may be semiconducting or metallic, and both may be used in combination. When both semiconducting CNT and metallic CNT are used, the content ratio of both in the composition can be appropriately adjusted according to the use of the composition. The CNT may contain a metal or the like, or may contain a molecule such as fullerene.

  The average length of CNT is not particularly limited, and can be appropriately selected according to the use of the composition. Specifically, although it depends on the distance between the electrodes, the average length of the CNT is preferably 0.01 to 2000 μm, more preferably 0.1 to 1000 μm from the viewpoints of manufacturability, film formability, conductivity, and the like. 1 to 1000 μm is particularly preferable.

The diameter of the CNT is not particularly limited, but is preferably 100 nm or less, more preferably 50 nm or less, and preferably 15 nm or less from the viewpoints of durability, transparency, film formability, conductivity, and the like. The lower limit is not particularly limited, but is often 0.4 nm or more.
In particular, when single-walled CNT is used, 0.5 to 2.2 nm is preferable, 1.0 to 2.2 nm is more preferable, and 1.5 to 2.0 nm is particularly preferable.

In the present invention, CNTs modified or treated with CNTs can also be used. The modification or treatment method includes a method of including a ferrocene derivative or nitrogen-substituted fullerene (azafullerene), a method of doping an alkali metal (such as potassium) or a metal element (such as indium) into the CNT by an ion doping method, or CNT in a vacuum. The method etc. which heat this are illustrated.
When CNT is used, in addition to single-walled CNT and multi-walled CNT, nanocarbon such as carbon nanohorn, carbon nanocoil, carbon nanobead, graphite, graphene, and amorphous carbon may be included.

  The content of CNT in the thermoelectric conversion layer is not particularly limited, but is preferably 5 to 80% by mass with respect to the total mass of the thermoelectric conversion layer in terms of more excellent performance of the thermoelectric conversion layer, and 5 to 70. It is more preferable that it is mass%, and it is especially preferable that it is 5-50 mass%.

The thermoelectric conversion layer may contain components other than CNT.
For example, the thermoelectric conversion layer may contain a resin material as a binder as necessary.
Various known non-conductive resin materials (polymers) can be used as the resin material.
Specifically, various known resin materials such as vinyl compounds, (meth) acrylate compounds, carbonate compounds, ester compounds, epoxy compounds, siloxane compounds, and gelatin can be used.
The content of the resin material is not particularly limited, but in terms of the mechanical strength of the thermoelectric conversion layer, the resin material / CNT mass ratio is preferably 0.5 to 10, more preferably 0.5 to 5, and preferably 1 to 4. Is more preferable.

The thermoelectric conversion layer may contain a dispersant (CNT dispersant) as necessary. A surfactant is preferably used as the dispersant.
As the surfactant, a known surfactant can be used as long as it has a function of dispersing CNTs. More specifically, various surfactants can be used as long as they have a group that dissolves in water, a polar solvent, or a mixture of water and a polar solvent and adsorbs CNTs.
Accordingly, the surfactant may be ionic or nonionic. The ionic surfactant may be any of cationic, anionic and amphoteric.
Examples of the anionic surfactant include alkylbenzene sulfonates such as dodecylbenzene sulfonic acid, aromatic sulfonic acid surfactants such as dodecyl phenyl ether sulfonate, monosoap anionic surfactants, ether sulfates Surfactants, phosphate surfactants and carboxylic acid surfactants such as sodium deoxycholate and sodium cholate, carboxymethylcellulose and salts thereof (sodium salt, ammonium salt, etc.), ammonium polystyrene sulfonate, Examples thereof include water-soluble polymers such as polystyrene sulfonate sodium salt.
Examples of the cationic surfactant include alkylamine salts and quaternary ammonium salts. Examples of amphoteric surfactants include alkylbetaine surfactants and amine oxide surfactants.
Furthermore, nonionic surfactants include sugar ester surfactants such as sorbitan fatty acid esters, fatty acid ester surfactants such as polyoxyethylene resin acid esters, ether surfactants such as polyoxyethylene alkyl ethers, etc. Is exemplified.
Among these, ionic surfactants are preferably used, and among them, cholate and deoxycholate are preferably used.

  When the thermoelectric conversion layer contains a surfactant, the content is preferably low. Specifically, the surfactant / CNT mass ratio is preferably 5 or less, and more preferably 2 or less.

  In addition to the above, the thermoelectric conversion layer may contain dopants, antifoaming agents, drying inhibitors, fungicides, and the like.

The average thickness of the thermoelectric conversion layer is preferably 0.1 to 1000 μm and more preferably 1 to 100 μm from the viewpoint of imparting a temperature difference.
In addition, the average thickness of a thermoelectric conversion layer measures the thickness of the thermoelectric conversion layer in arbitrary 10 points | pieces, and calculates | requires them by arithmetic average.

The method for forming the thermoelectric conversion layer is not particularly limited, but as an example, CNT and a component such as a resin material or a surfactant added as necessary are dissolved or dispersed in a solvent such as water or an organic solvent. And a method using a CNT dispersion liquid.
A thermoelectric conversion layer can be formed by applying the CNT dispersion on the surface-treated substrate and forming a film.
The film forming method is not particularly limited. For example, spin coating method, extrusion die coating method, blade coating method, bar coating method, screen printing method, stencil printing method, roll coating method, curtain coating method, spray coating method, dip coating. A known coating method such as a method or an ink jet method can be used.
In addition, when producing a thermoelectric conversion layer in a predetermined position, the method of apply | coating a CNT dispersion liquid in a pattern form can be used.
As an example, a method of pattern printing a CNT dispersion liquid on a surface-treated substrate by a printing method is exemplified. As the printing method, various known printing methods such as screen printing, metal mask printing, gravure printing, flexographic printing, and offset printing can be used.
Further, it is also possible to use a method in which a mold or mask is provided at a predetermined position on the surface treatment substrate, and a CNT dispersion liquid or paste is applied in a pattern using the mold or mask.
Moreover, after application | coating, a drying process is performed as needed. For example, the solvent can be volatilized and dried by blowing hot air.

Furthermore, instead of applying a CNT dispersion or the like in a pattern, the CNT dispersion is applied to the entire surface of the surface-treated substrate, dried, and then unnecessary by etching such as laser engraving, sandblasting, electron beam method, or plasma etching. A method of patterning the thermoelectric conversion layer by removing the portion can also be used.
Note that etching may be performed using a mask formed using photolithography, a metal mask, or the like, if necessary.

[Protection board]
The protective substrate is a substrate disposed on the thermoelectric conversion layer, and protects the thermoelectric conversion layer from the outside. The protective substrate may be disposed as necessary.
The kind in particular of a protective substrate is not restrict | limited, From the point of the bending resistance of a thermoelectric conversion element, a resin substrate is preferable. Specific examples of the resin substrate include the specific examples described for the resin substrate used in the surface treatment substrate described above.

<Second Embodiment>
FIG. 2A to FIG. 2C conceptually show a second embodiment of the thermoelectric conversion element of the present invention. 2A is a top view (a view of FIG. 2B viewed from above), FIG. 2B is a front view (a view of a substrate or the like to be described later), and FIG. C) is a bottom view (a view of FIG. 2B viewed from the lower side of the drawing).

As shown in FIGS. 2A to 2C, the thermoelectric conversion element 10 basically includes a first substrate 12, a thermoelectric conversion layer 16, an adhesive layer 18, a second substrate 20, The first electrode 26 and the second electrode 28 are included.
Specifically, the thermoelectric conversion layer 16 is formed on the surface of the first substrate 12. Further, the thermoelectric conversion layer 16 is also referred to as a substrate surface direction of the first substrate 12 (hereinafter simply referred to as “surface direction”. In other words, the first substrate 12 and the second substrate 20 are stacked. The first electrode 26 and the second electrode 28 (electrode pair) are formed by being connected to the thermoelectric conversion layer 16 so as to be sandwiched in a direction perpendicular to the direction. Furthermore, an adhesive layer 18 is provided so as to cover the first substrate 12, the thermoelectric conversion layer 16, the first electrode 26, and the second electrode 28, and the second substrate 20 is attached to the adhesive layer 18.

As shown in FIG. 2, the first substrate 12 includes a low thermal conductivity portion 12 a and a high thermal conductivity portion 12 b having a higher thermal conductivity than the low thermal conductivity portion 12 a. Similarly, the 2nd board | substrate 20 also has the high heat conductive part 20b whose heat conductivity is higher than the low heat conductive part 20a and the low heat conductive part 20a. In the thermoelectric conversion element 10, the high heat conduction part 12b of the first substrate 12 is the first high heat conduction part in the present invention, the low heat conduction part 20a of the second substrate 20 is the low heat conduction layer in the present invention, and the second substrate 20 The high heat conduction portion 20b corresponds to the second high heat conduction portion in the present invention.
As will be described in detail later, the low thermal conductivity portion 12a in the first substrate 12 corresponds to the surface-treated substrate described above.

In the thermoelectric conversion element 10, the two substrates are arranged such that their high heat conduction portions are located at different positions in the separation direction (that is, the energization direction) between the first electrode 26 and the second electrode 28.
The thermoelectric conversion element 10 has the 2nd board | substrate 20 stuck by the adhesion layer 18 as a preferable aspect, and also the 1st board | substrate 12 and the 2nd board | substrate 20 have both a low heat conduction part and a high heat conduction part. . The thermoelectric conversion element 10 has a configuration in which two substrates having a high heat conduction portion and a low heat conduction portion are used, and the high heat conduction portions of the two substrates are located at different positions in the plane direction, and the thermoelectric conversion layer is sandwiched between the two substrates. Have

  That is, the thermoelectric conversion element 10 is a thermoelectric conversion element (hereinafter also referred to as an in-plane type thermoelectric conversion element) that generates a temperature difference in the surface direction of the thermoelectric conversion layer and converts heat energy into electric energy. In the example shown, by using a substrate having a low thermal conductivity portion and a high thermal conductivity portion having a higher thermal conductivity than the low thermal conductivity portion, a temperature difference is caused in the surface direction of the thermoelectric conversion layer 16 to convert the thermal energy into electrical energy. Can be converted to

  In addition, the high heat conduction part or the low heat conduction part in the present invention indicates that the thermal conductivity is high or low with respect to the adjacent layer (adjacent high heat conduction part or low heat conduction part). The ratio of the thermal conductivity between the high heat conduction part and the low heat conduction part is preferably 100: 1 or less, more preferably 500: 1 or less, and even more preferably 100: 1 or less.

  In the illustrated thermoelectric conversion element 10, the first substrate 12 and the second substrate 20 have different arrangement positions, front and back surfaces, and directions in the surface direction (substrate surface direction), and further, the low heat conduction portion in the first substrate 12. The configuration is the same except that 12a corresponds to the above-described surface-treated substrate. Therefore, in the following description, the first substrate 12 will be described as a representative example, unless the first substrate 12 and the second substrate 20 need to be distinguished.

In the illustrated thermoelectric conversion element 10, the first substrate 12 (second substrate 20) covers a region on one half of one surface of the plate-like material that becomes the low thermal conduction portion 12 a (low thermal conduction portion 20 a). It has a configuration in which the high heat conduction part 12b (high heat conduction part 20b) is laminated. In other words, in the first substrate 12, the high thermal conductivity portion 12 b is provided so as to cover the low thermal conductivity portion 12 a, that is, the half surface of the first substrate 12.
Accordingly, on one surface of the first substrate 12, a half region in the surface direction is the low heat conduction portion 12a, and the other half region is the high heat conduction portion 12b. Further, the entire surface of the other surface (12c) of the first substrate 12 becomes the low thermal conductive portion 12a. In the thermoelectric conversion element 10, the surface (12 c) of the first substrate 12 on which the high heat conductive portion 12 b of the low heat conductive portion 12 a is not formed becomes the formation surface of the thermoelectric conversion layer 16.

  In addition, in the thermoelectric conversion element of this invention, the 1st board | substrate 12 can utilize various structures other than the structure formed by laminating | stacking a high heat conduction part on the surface of a low heat conduction part. For example, as conceptually shown in FIG. 5 (A), the first substrate is formed with a recess in a half region of one surface of the plate-like material that becomes the low heat conduction portion 12a, The structure which incorporates the high heat conductive part 12b so that may become uniform may be sufficient.

The low heat conduction part 12a corresponds to the surface treatment substrate described above. More specifically, the surface 12c on the thermoelectric conversion layer 16 side of the low thermal conductive portion 12a corresponds to the surface 2a on which the surface treatment of the surface treatment substrate 2 described above is performed. In the thermoelectric conversion element 10, the thermoelectric conversion layer 16 is arrange | positioned on the surface 12c of the low heat conductive part 12a, and it is excellent in the adhesiveness of the low heat conductive part 12a and the thermoelectric conversion layer 16. FIG.
A known resin substrate can be used as the low thermal conductive portion 20a. Examples of the resin substrate include the examples described in the first embodiment.

As long as the high heat conductive part 12b has a heat conductivity higher than the low heat conductive part 12a, the film and metal foil which consist of various materials are illustrated.
Specifically, various metals such as gold, silver, copper, and aluminum are exemplified in terms of thermal conductivity and the like. Among these, copper and aluminum are preferably used in terms of thermal conductivity, economy, and the like.

In the present invention, the thickness of the first substrate 12, the thickness of the low thermal conductive portion 12a, the thickness of the high thermal conductive portion 12b, etc. are the same as the forming material of the high thermal conductive portion 12b and the low thermal conductive portion 12a. What is necessary is just to set suitably according to a magnitude | size. In addition, the thickness of the 1st board | substrate 12 is the thickness of the low heat conductive part 12a of the area | region which does not have the high heat conductive part 12b. According to the study by the present inventors, the thickness of the first substrate 12 is preferably 2 to 100 μm, and more preferably 2 to 50 μm.
In addition, the size in the surface direction of the first substrate 12 (when viewed from the direction orthogonal to the substrate surface), the area ratio in the surface direction of the high heat conduction portion 12b in the first substrate 12, and the like are also included. What is necessary is just to set suitably according to the formation material of the part 12b, the magnitude | size of the thermoelectric conversion element 10, etc. FIG.

Furthermore, the position of the first substrate 12 in the surface direction of the high thermal conductive portion 12b is not limited to the illustrated example, and various positions can be used.
For example, in the 1st board | substrate 12, the high heat conductive part 12b may be included in the low heat conductive part 12a in the surface direction. Alternatively, a part of the high heat conduction unit 12b may be located at the end of the first substrate 12 in the plane direction, and the other region may be included in the low heat conduction unit 12a.
Further, the first substrate 12 may have a plurality of high heat conducting portions 12b in the surface direction.

2 is a preferable mode in which a temperature difference between the first substrate 12 and the second substrate 20 is likely to occur, both the first substrate 12 and the second substrate 20 have high thermal conductivity. The part 12b and the high heat conduction part 20b are located outside in the stacking direction.
However, the present invention may have a configuration in which the first substrate 12 and the second substrate 20 both have the high heat conduction portion 12b and the high heat conduction portion 20b located inside in the stacking direction. Alternatively, the first substrate 12 may be configured such that the high heat conductive portion 12b is positioned outside in the stacking direction, and the second substrate 20 is positioned such that the high heat conductive portion 20b is positioned inside in the stacking direction.
In the configuration in which the high heat conduction part is formed of a conductive material such as metal and the high heat conduction part is disposed inside the stacking direction, the high heat conduction part, the first electrode 26, the second electrode 28, and In a case where at least one of the thermoelectric conversion layers 16 is electrically connected, in order to ensure insulation between the high heat conduction portion and at least one of the first electrode 26, the second electrode 28, and the thermoelectric conversion layer 16. In addition, an insulating layer may be provided therebetween.

In the thermoelectric conversion element 10, the thermoelectric conversion layer 16 is formed on the surface (12 c) where the entire surface of the first substrate 12 is the low thermal conductive portion 12 a. As described above, the surface 12c corresponds to the surface of the surface treatment substrate that has been subjected to the surface treatment.
The aspect of the thermoelectric conversion layer 16 is the same as the aspect of the thermoelectric conversion layer 5 of the first embodiment described above, and includes at least CNT.
In addition, the second substrate 20 is provided on the thermoelectric conversion layer 16 via the adhesive layer 18. The second substrate 20 is provided with the surface of the low heat conductive portion 20 a on which the high heat conductive portion 20 b is not formed facing the thermoelectric conversion layer 16.
The high thermal conductive portions 12b and 20b of both the substrates are arranged so as to efficiently generate a temperature difference in the surface direction of the thermoelectric conversion layer 16. That is, it is preferable that the high heat conductive portions 12b and 20b of both the substrates are arranged at different positions in the plane direction with respect to the thermoelectric conversion layer 16, and the boundary between the low heat conductive portion and the high heat conductive portion of both the substrates is More preferably, the conversion layer 16 is provided so as to coincide with the center of the surface direction, and it is further preferable that the boundary is spaced apart in the electrode separation direction.
The thermoelectric conversion layer 16 is connected to an electrode pair including the first electrode 26 and the second electrode 28 so as to be sandwiched in the surface direction.

For example, a thermoelectric conversion element generates a temperature difference due to heating due to contact with a heat source or the like, and accordingly, in the thermoelectric conversion layer, a difference occurs in the carrier density in the direction of the temperature difference in accordance with the temperature difference. Occurs.
For example, a heat source is provided on the first substrate 12 side, and a temperature difference is generated between the high heat conductive portion 12b of the first substrate 12 and the high heat conductive portion 20b of the second substrate 20, thereby causing the inside of the thermoelectric conversion layer 16 to be inside. Therefore, a difference occurs in the carrier density in the direction of the temperature difference, and power is generated. Further, by connecting wiring to the first electrode 26 and the second electrode 28, electric power (electric energy) generated by heating is taken out.

  In the thermoelectric conversion element 10 of the present invention, the thickness of the thermoelectric conversion layer 16, the size in the surface direction, the area ratio in the surface direction with respect to the substrate, and the like depend on the forming material of the thermoelectric conversion layer 16, the size of the thermoelectric conversion element 10, etc. Accordingly, it may be set appropriately.

In the example shown in FIGS. 2A to 2C, the thermoelectric conversion layer 16 has a rectangular parallelepiped shape, but in the thermoelectric conversion element of the present invention, various shapes can be used for the thermoelectric conversion layer 16. is there.
For example, the thermoelectric conversion layer may have a quadrangular pyramid shape or the like. Alternatively, it may be a columnar shape, a prism shape other than a square shape, a truncated cone, a truncated pyramid, an indefinite shape, or the like.

A first electrode 26 and a second electrode 28 are provided on the surface of the first substrate 12 so as to sandwich the thermoelectric conversion layer 16 in the surface direction.
In the thermoelectric conversion element 10, the first electrode 26 and the second electrode 28 rise from the first substrate 12 at the end of the thermoelectric conversion layer 16, as shown in FIGS. The thermoelectric conversion layer 16 has a shape extending from the side surface to the vicinity of the end of the upper surface.

In the thermoelectric conversion element of the present invention, the shapes of the first electrode 26 and the second electrode 28 are not limited to the shapes shown in FIGS. 2A to 2C, and are sufficiently conductive and thermoelectric. Various shapes can be used as long as they are connected to the conversion layer 16.
For example, as conceptually shown in FIG. 3A, the end portions of the plate-like first electrode 30 and the second electrode 32 formed on the surface of the first substrate 12 are connected to the thermoelectric conversion layer 16. The structure which covers may be sufficient. The structure shown in FIG. 2B and the like can be manufactured by forming the first electrode 26 and the second electrode 28 after forming the thermoelectric conversion layer on the surface of the first substrate 12. On the other hand, the configuration shown in FIG. 3A can be manufactured by forming the thermoelectric conversion layer 16 after first forming the first electrode 30 and the second electrode 32 on the surface of the first substrate 12. .
Further, as conceptually shown in FIG. 3 (B), the structure shown in FIG. 3 (A) is further connected to the first electrode 30 and the second electrode 32, and from the side surface of the thermoelectric conversion layer 16 to the upper surface. The structure which has the auxiliary electrodes 30a and 32a which contact | connects to the edge part vicinity may be sufficient.
Further, as conceptually shown in FIG. 3C, the first electrode 34 and the second electrode 36 may be in contact with the side surface of the thermoelectric conversion layer 16.

  The aspect of the 1st electrode 26 and the 2nd electrode 28 is synonymous with the 1st electrode 3 and the 2nd electrode 4 which were described in the 1st embodiment mentioned above.

  In addition, the thickness, size, shape, and the like of the first electrode 26 and the second electrode 28 may be appropriately set according to the thickness, size, shape, the size of the thermoelectric conversion element 10, etc. of the thermoelectric conversion layer 16. Good.

  The thermoelectric conversion element 10 of the illustrated example has an adhesive layer 18 on the first substrate 12 so as to cover the thermoelectric conversion layer 16 and the first electrode 26 and the second electrode 28, and the adhesive substrate 18 includes the second substrate 20. Is pasted.

The forming material of the adhesive layer 18 is affixed according to the forming material of the first substrate 12 (low heat conduction part 12a), the second substrate 20 (low heat conduction part 20a), the first electrode 26 and the second electrode 28, and the like. A variety of wearable items are available.
Specific examples include acrylic resin, urethane resin, silicone resin, epoxy resin, rubber, EVA (Ethylene-Vinyl Acetate), α-olefin polyvinyl alcohol, polyvinyl butyral, polyvinyl pyrrolidone, gelatin, starch and the like. Moreover, you may form the adhesion layer 18 using a commercially available double-sided tape and an adhesive film.

  The thickness of the adhesive layer 18 is such that sufficient adhesion can be obtained according to the forming material of the adhesive layer 18, the forming material and size of the first substrate 12 and the second substrate 20, and the thermoelectric conversion layer 16. What is necessary is just to set suitably the thickness which can fill the level | step difference resulting from.

  In addition, the thermoelectric conversion element of this invention makes the thermoelectric conversion layer, the 1st electrode, and the 2nd electrode the same height, and does not use an adhesion layer, but on the thermoelectric conversion layer, the 1st electrode, and the 2nd electrode. The second substrate may be laminated, and the first substrate, the thermoelectric conversion layer, the first electrode, the second electrode, and the second substrate may be fixed to each other by a known method (including self-adhesion).

In the illustrated thermoelectric conversion element 10, the high thermal conductive portion 12 b of the first substrate 12 and the high thermal conductive portion 20 b of the second substrate 20 face each other in the inter-electrode direction and abut the end portions thereof. Arranged at different positions.
In addition to this, various configurations can be used for the thermoelectric conversion element of the present invention.
For example, in the example shown in FIGS. 2A to 2C, the high thermal conductivity portion 12b of the first substrate 12 is moved to the right side in the drawing, and the high thermal conduction portion 20b of the second substrate 20 is moved to the left side in the drawing. Then, in the surface direction, both high heat conducting portions may be separated in the inter-electrode direction. Specifically, the high heat conductive portion 12b of the first substrate 12 and the high heat conductive portion 20b of the second substrate 20 are in the plane direction of the thermoelectric conversion layer 16 in the direction in which the first electrode 26 and the second electrode 28 are separated from each other. The size is preferably 10% to 90% apart, more preferably 10% to 50% apart in the direction between the electrodes.
On the other hand, in the example shown in FIG. 2, the high heat conduction portion 12b of the first substrate 12 is moved to the left side in the drawing, and the high heat conduction portion 20b of the second substrate 20 is moved to the right side in the drawing, A part of the conductive portion may overlap in the surface direction.

Alternatively, a circular high heat conduction part is formed on the first substrate, and a square high heat conduction part of the same size (diameter and length of one side coincides) is formed on the second substrate, and the center of both high heat conduction parts is faced. You may arrange | position both board | substrates so that it may correspond in a direction. Even in this configuration, although the distance is short, since the end (periphery) positions of the two high heat conducting portions are different in the surface direction, a temperature difference in the surface direction is generated in the thermoelectric conversion layer, and a temperature difference is generated in the thickness direction. Efficient power generation is possible compared to thermoelectric conversion elements.
That is, in the present invention, various configurations can be used for the first substrate and the second substrate as long as the high thermal conductivity portions do not completely overlap in the plane direction between the first substrate and the second substrate. In other words, when the first substrate and the second substrate are viewed from the direction perpendicular to the substrate surface, various configurations can be used as long as the high thermal conductivity portions of the first substrate and the second substrate do not completely overlap. is there.

  In the thermoelectric conversion element of the present invention, the low heat conduction layer and the second high heat conduction part are not limited to the low heat conduction part 20a and the high heat conduction part 20b constituting the second substrate 20, and the low heat conduction layer and the low heat conduction layer A second high heat conductive portion having a higher thermal conductivity than the low thermal conductive layer provided (in contact with) (a second thermal conductive portion provided with the second high thermal conductive portion; a low thermal conductive layer having a lower thermal conductivity than the high thermal conductive portion; If the first high heat conduction portion and the second high heat conduction portion do not completely overlap in the surface direction, various configurations can be used.

For example, an insulating layer (insulating layer) may be formed on the adhesive layer 18 as a low thermal conductive layer, and a second high thermal conductive portion similar to the high thermal conductive portion 20b described above may be provided thereon.
At this time, the insulating layer may be formed by a known method. As an example, a method of forming an insulating layer made of an insulating material such as a resin by a coating method or sticking a film (sheet), a method of forming an insulating layer by vapor deposition of a metal oxide, or the like is exemplified.

Further, in the configuration shown in FIG. 3C, the first electrode 34 and the second electrode 36 having a thickness that does not cause a step with respect to the thermoelectric conversion layer 16 are formed, and the thermoelectric conversion layer 16 is not provided with an adhesive layer. An insulating layer may be formed on the first electrode 34 and the second electrode 36 in the same manner as described above, and a second high heat conductive portion similar to the high heat conductive portion 20b may be provided on the insulating layer. .
Alternatively, in the configuration shown in FIG. 2A to FIG. 2C and the like, the adhesive layer 18 is not provided, and the thermoelectric conversion layer 16 and the first electrode 26 and the second electrode 28 are covered to form a step. An insulating layer may be formed in the same manner as described above so as to be buried, and a second high heat conductive portion similar to the high heat conductive portion 20b may be provided on the insulating layer.

Furthermore, in the example shown in FIGS. 2 (A) to 2 (C), when the adhesive layer 18 has an insulating property, the adhesive layer 18 is used as the low thermal conductive layer without providing the low thermal conductive portion 20a. A second high heat conduction part similar to the high heat conduction part 20 b may be provided on the layer 18. In this case, if necessary, a layer that covers the whole may be provided so that the adhesiveness of the adhesive layer 18 does not become a problem, or a layer that covers a region where the adhesive layer 18 is exposed may be provided. .
Or when the adhesion layer 18 has insulation, the adhesion layer 18 is made into a low heat conductive layer, the layer which covers the adhesion layer 18 is provided, and the 2nd high heat conduction part similar to the high heat conduction part 20b is provided on this layer. May be provided.

  In the present invention, having insulation means that the insulation resistance per element when the layer is formed is 0.1 MΩ or more.

<Thermoelectric conversion module>
4 (A) to 4 (D) conceptually show an example of the thermoelectric conversion module of the present invention in which a plurality of such thermoelectric conversion elements 10 of the present invention are connected in series. 4A to 4C are top views and FIG. 4D is a front view. As described in detail later, in the embodiment of the thermoelectric conversion module in FIG. 4, the low thermal conductive portion 12 a of the first substrate 12 </ b> A corresponds to the above-described surface treatment substrate (substrate A or substrate B).

In this example, each of the first substrate 12A and the second substrate 20A has a rectangular plate-like high heat conductive portion that extends in one direction on the surface of a rectangular plate-like low heat conductive material, and a side that contacts the low heat conductive portion of the square pillar. Are arranged in the direction orthogonal to the extending direction of the quadrangular prism at equal intervals.
That is, in the first substrate 12A and the second substrate 20A, the entire surface of one surface is a low heat conductive portion, and the other surface is a low heat conductive portion and a high heat conductive portion extending in one direction. It has a configuration in which they are alternately formed at equal intervals in the orthogonal direction (see FIGS. 4A, 4C, and 4D).
Also in this example, the first substrate (second substrate) can use various configurations other than the configuration in which the high thermal conductivity portion is placed on the surface of the low thermal conductivity portion. For example, as conceptually shown in FIG. 5B, the first substrate is a rectangular plate-like low heat conductive material, and is in one direction (a direction perpendicular to the paper surface of FIG. 5B). The extending groove may be formed in the direction orthogonal to the extending direction at equal intervals with the width of the groove, and a high heat conductive material may be incorporated in the groove.

As shown in FIG. 4B, the thermoelectric conversion layer 16 has a rectangular surface shape, and the entire surface of the first substrate 12A is the surface (12c) on the side that is the low thermal conductive portion 12a (see FIG. 4D). In this state, the boundary and the center of the low heat conduction portion 12a and the high heat conduction portion 12b are aligned in the plane direction. The horizontal direction of the thermoelectric conversion layer 16 in FIG. 3B (hereinafter, also simply referred to as “lateral direction”) is between 0.5 times and less than 2.0 times the width of the high thermal conductive portion 12b. Set to That is, the horizontal direction is an alternate arrangement direction of the low heat conduction portions 12a and the high heat conduction portions 12b.
The thermoelectric conversion layer 16 is formed at equal intervals every other boundary with respect to the boundary between the low thermal conductivity portion 12a and the high thermal conductivity portion 12b in the lateral direction. That is, the thermoelectric conversion layer 16 is formed at equal intervals with the same center as the distance of twice the width of the high thermal conductive portion 12b.
Further, the thermoelectric conversion layers 16 are arranged such that the rows of the thermoelectric conversion layers 16 arranged at equal intervals in the horizontal direction are arranged at equal intervals in the vertical direction in FIG. 4B (hereinafter also simply referred to as “vertical direction”). Thus, it is formed two-dimensionally. That is, the up and down direction is the extending direction of the low heat conduction portion 12a and the high heat conduction portion 12b.
Furthermore, as shown in FIG. 4B, the horizontal arrangement of the thermoelectric conversion layers 16 is shifted in the horizontal direction by the width of the high thermal conduction portion 12b in the columns adjacent in the vertical direction. In other words, in the rows adjacent in the vertical direction, the thermoelectric conversion layers 16 are alternately formed with the horizontal centers corresponding to the widths of the high heat conduction portions 12b.

The thermoelectric conversion layers 16 are connected in series by the first electrode 26 (second electrode 28). Specifically, as shown in FIG. 4B, in the arrangement of the thermoelectric conversion layers 16 in the horizontal direction in the drawing, the first electrodes 26 (shown by shading for the sake of clarity) are connected to the thermoelectric conversion layers 16. The conversion layer 16 is provided so as to sandwich the horizontal direction. Thereby, the thermoelectric conversion layers 16 arranged in the lateral direction are connected in series by the first electrode 26.
At the ends of the rows in the horizontal direction of the thermoelectric conversion layers 16, the thermoelectric conversion layers 16 in rows adjacent in the vertical direction are connected by the first electrode 26. The connection of the thermoelectric conversion layer 16 in the vertical direction by the first electrode 26 at the end of the horizontal row is such that the thermoelectric conversion layer 16 at one end is connected to the thermoelectric conversion layer 16 at the same end of the upper row. The thermoelectric conversion layer 16 at the other end is connected to the thermoelectric conversion layer 16 at the same end in the lower row.
Thereby, all the thermoelectric conversion layers 16 are connected in series like the one line | wire folded in multiple times in the horizontal direction.

As conceptually shown in FIG. 4 (A), on the thermoelectric conversion layer 16 and the first electrode 26, the entire surface of the second substrate 20A is the surface (20c) on which the low thermal conductive portion 20a is located, And the 2nd board | substrate 20A is laminated | stacked by making the boundary of the low heat conductive part 12a and the high heat conductive part 12b correspond with the 1st board | substrate 12A. This stacking is performed so that the high thermal conductive portion 12b of the first substrate 12A and the high thermal conductive portion 20b of the second substrate 20A are alternated.
Although not shown, the adhesive layer 18 is formed on the thermoelectric conversion layer 16 and the first electrode 26 so as to cover the entire surface of the first substrate 12A prior to the lamination of the second substrate 20A.

Therefore, the low heat conduction part 12a of the first substrate 12A and the region of the second substrate 20A only with the high heat conduction part 20b are aligned in the plane direction and face each other, and the high heat conduction part 12b of the first substrate 12A and the second substrate 20A The region of only the low heat conducting portion 20a faces the surface direction in alignment.
Thereby, the thermoelectric conversion module of this invention formed by connecting two or more thermoelectric conversion elements 10 of this invention in series is comprised.

In the above aspect, the low thermal conductive portion 12a of the first substrate 12A corresponds to the surface treatment substrate (substrate A or substrate B) described above, and the entire surface of the first substrate 12A is the low thermal conductive portion 12a. (12c) corresponds to the surface of the surface-treated substrate that has been subjected to the surface treatment described above.
That is, the thermoelectric conversion layer 16 in the thermoelectric conversion module is disposed on the surface (12c) on which the surface treatment of the surface treatment substrate constituting the low thermal conductive portion 12a of the first substrate 12A is performed.

Here, as described above, in the horizontal arrangement of the thermoelectric conversion layers 16, in the columns adjacent in the vertical direction, the horizontal center line of the thermoelectric conversion layers 16 is the high heat conduction portion 12b (that is, the high heat conduction portion 20b). This is formed by shifting in the horizontal direction by the width of. In other words, in the rows adjacent in the vertical direction, the thermoelectric conversion layers 16 are formed so that the horizontal center lines of the thermoelectric conversion layers 16 are staggered by the width of the high thermal conductivity portion 12b.
For this reason, the thermoelectric conversion layers 16 connected in series as a single folded line have all the thermoelectric conversion layers 16 in the flow in one direction of the connection direction, and one half of the thermoelectric conversion layers 16 is the high thermal conductivity of the first substrate 12A. The portion 12b faces the region of the second substrate 20A only of the low heat conduction portion 20a, and the other half faces the region of only the low heat conduction portion 12a of the first substrate 12A and the high heat conduction portion 20b of the second substrate 20A. .
For example, when viewed in the serial connection direction from the top to the bottom of FIG. 4B, as shown in FIGS. 4A to 4C, all the thermoelectric conversion layers 16 are upstream. Half of the first substrate 12A faces the region of only the high thermal conductivity portion 12b and the second substrate 20A of the low thermal conductivity portion 20a, and the half of the downstream side of the first substrate 12A of the region of only the low thermal conductivity portion 12a and the second substrate 20A. It faces the high heat conduction part 20b.
Therefore, when the heat source is arranged on the first substrate 12A side or the second substrate 20A side, the heat flow direction relative to the connection direction, that is, the flow direction of the generated electricity is the same in all the thermoelectric conversion layers 16 connected in series. And the thermoelectric conversion module can generate electricity properly.

(Method for manufacturing thermoelectric conversion module)
Below, an example of the manufacturing method of the thermoelectric conversion module shown to FIG. 4 (A)-FIG.4 (D) is demonstrated. In addition, a thermoelectric conversion element can be manufactured according to the manufacturing method of this thermoelectric conversion module.

First, a first substrate 12A (first substrate 12) having a low thermal conductivity portion 12a and a high thermal conductivity portion 12b, and a second substrate 20A (second substrate 20) having a low thermal conductivity portion 20a and a high thermal conductivity portion 20b are prepared. .
As described above, the low thermal conductive portion 12a corresponds to the surface treatment substrate described above.

The first substrate 12A and the second substrate 20A may be manufactured by a known method using photolithography, etching, film formation technology, or the like.
For example, it is produced by etching one side of a copper polyimide film in which copper is laminated on both sides of a substrate (for example, the above-mentioned surface-treated substrate) and etching the other side so as to form a high thermal conductive pattern. Can do. In addition, a sheet-like material of a substrate (for example, the above-described surface treatment substrate) to be a low heat conduction portion is prepared, and the width of the belt is set in a direction perpendicular to the extending direction of the belt-like high heat conduction portion. The first substrate 12A and the second substrate 20A may be manufactured by pasting at equal intervals.
Commercially available products can also be used for the first substrate 12A and the second substrate 20A.

Next, the thermoelectric conversion layer 16 is formed. Examples of the method for forming the thermoelectric conversion layer 16 include the method for forming the thermoelectric conversion layer 5 described in the first embodiment.
Next, the first electrode 26 and the second electrode 28 are formed so as to sandwich the thermoelectric conversion layer 16 in the plane direction. Examples of the method of forming the first electrode 26 and the second electrode 28 include the method of forming the first electrode 3 and the second electrode 4 described in the first embodiment.

Next, the adhesive layer 18 is formed so as to cover the entire surface of the first substrate 12A and cover the thermoelectric conversion layer 16, the first electrode 26, and the second electrode 28.
The adhesive layer 18 may be formed by a known method such as a coating method depending on the material for forming the adhesive layer 18. Moreover, as described above, the adhesive layer 18 may be formed using a double-sided tape or an adhesive film.

Furthermore, the prepared second substrate 20A is attached to the thermoelectric conversion layer 16 with the surface (20c) on which the high heat conducting portion 20b is not formed, and a thermoelectric conversion module (thermoelectric conversion element 10) is manufactured. To do.
Alternatively, instead of forming the adhesive layer 18 on the first substrate 12A, the adhesive layer 18 is formed on the surface of the second substrate 20A where the high thermal conductive portion 20b is not formed, and is adhered to the first substrate 12A. Thus, a thermoelectric conversion module (thermoelectric conversion element 10) may be manufactured.

  In addition, although the said aspect is an aspect in which the low heat conductive part 12a of 12 A of 1st board | substrates corresponds to a surface treatment board | substrate (the board | substrate A or the board | substrate B), it is not limited to this aspect, The low heat conductive part of the 1st board | substrate 12A Both 12a and the low heat conductive part 20a of the 2nd board | substrate 20A may be an aspect applicable to the surface treatment board | substrate mentioned above.

Such a thermoelectric conversion element and thermoelectric conversion module of the present invention can be used for various applications.
Examples include various power generation applications such as hot spring thermal generators, solar thermal generators, waste heat generators, and other devices (devices) such as wristwatch power supplies, semiconductor drive power supplies, and small sensor power supplies. The Moreover, as a use of the thermoelectric conversion element of this invention, sensor element uses, such as a thermal sensor and a thermocouple, are illustrated besides a power generation use.

  As described above, the thermoelectric conversion element and the thermoelectric conversion module of the present invention have been described in detail. However, the present invention is not limited to the above-described examples, and various improvements and modifications may be made without departing from the gist of the present invention. Of course it is good.

  Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention. However, the present invention is not limited to the following examples.

<Preparation of CNT dispersion>
To 20 mL of water, 500 mg of CNT (manufactured by Meijo Nanocarbon Co., Ltd.) and 1500 mg of sodium deoxycholate were added.
This solution was dispersed for 7 minutes using a bladed homogenizer. The obtained dispersion was further subjected to a stirring process for 5 minutes at a peripheral speed of 30 m / s using a high-speed rotating thin film dispersion method (Filmix, manufactured by Primex) to obtain a CNT dispersion.

<Manufacture of surface-treated substrates>
As shown in Table 1 to be described later, the surface treatment of the resin substrate used in each example was performed.
Specifically, when a resin substrate (polyimide substrate, polycarbonate substrate, or polyamide substrate) used in each example shown in Table 1 is prepared and pretreatment is performed, the pretreatment described in Table 1 is performed. After that, the surface of the resin substrate (the surface of the resin substrate on which the pretreatment was performed when the pretreatment was performed) was subjected to a surface treatment using various surface treatment agents described in Table 1. In addition, when the “preprocessing” column in Table 1 is “−”, it is intended that the preprocessing is not performed.
More specifically, for example, the surface-treated substrate used in Example 1 corresponds to a substrate obtained by surface-treating a polyimide substrate with phenyltriethoxysilane.
Regarding Examples 8, 11, 12 and 13 in Table 1, the surface treatment was performed with the third surface treatment agent after the surface treatment with the second surface treatment agent.
Details of each process will be described below.

[UV-O ₃ treatment method]
Surface treatment was performed by using a UV ozone cleaning device OC2506 manufactured by Yamato Scientific Co., Ltd. and irradiating the resin substrate with UV for 1 minute.
[N ₂ -plasma treatment method]
Surface treatment was performed by using a plasma cleaner PDC210 manufactured by Yamato Scientific Co., Ltd., and subjecting the resin substrate to plasma treatment at 200 W for 60 seconds in a nitrogen atmosphere.
[O ₂ -plasma treatment method]
Using a plasma cleaner PDC210 manufactured by Yamato Scientific Co., Ltd., the resin substrate was subjected to a plasma treatment at 200 W for 60 seconds in an oxygen atmosphere to perform a surface treatment.

[Treatment method using first surface treatment agent or second surface treatment agent]
An aqueous solution of 2% by mass of the first surface treatment agent (or second surface treatment agent) and 2% by mass of acetic acid is prepared, and stirred at room temperature for 30 minutes to obtain the first surface treatment agent (or second surface treatment agent). Was hydrolyzed. Thereafter, the resin substrate was immersed in the solution and left overnight. Thereafter, the resin substrate was taken out of the solution, washed with ethanol, and then dried at 100 ° C. for 1 hour.

[Treatment Method Using Third Surface Treatment Agent of Example 8]
In Example 8, after the resin substrate was surfaced with the second surface treatment agent according to the above [treatment method using the first surface treatment agent or the second surface treatment agent], the following treatment was further performed.
The resin substrate surface-treated with the second surface treatment agent was immersed in an ethanol solution of 2% by mass of the third surface treatment agent (benzenethiol) and 0.5% by mass of triethylamine for 24 hours. Thereafter, the resin substrate was taken out from the ethanol solution, dried at 130 ° C. for 2 hours, and then washed with ethanol to carry out a thiol addition reaction to the methacrylate site. By this reaction, a benzene ring derived from benzenethiol was imparted on the surface of the resin substrate.
[Treatment Method Using Third Surface Treatment Agent of Example 11]
In Example 11, after the resin substrate was surfaced with the second surface treatment agent by the above-mentioned [treatment method using the first surface treatment agent or the second surface treatment agent], the following treatment was further performed.
The resin substrate surface-treated with the second surface treatment agent was immersed in an ethanol solution of 2% by mass of the third surface treatment agent (2-naphthalenethiol) and 0.5% by mass of triethylamine for 24 hours. Thereafter, the resin substrate was taken out from the ethanol solution, dried at 130 ° C. for 2 hours, and then washed with ethanol to perform an addition reaction of thiol to the acrylate moiety. By this reaction, a naphthalene ring derived from 2-naphthalenethiol was imparted on the surface of the resin substrate.
[Treatment Method Using Third Surface Treatment Agent of Examples 12 and 13]
In Examples 12 and 13, after the resin substrate was surfaced with the second surface treatment agent according to the above [treatment method using the first surface treatment agent or the second surface treatment agent], the following treatment was further performed.
A resin substrate that has been surface-treated with the second surface treatment agent, 2% by mass of the third surface treatment agent (2-naphthalenecarboxylic acid or 2-anthracenecarboxylic acid), and 0.5 mass of p-toluenesulfonic acid It was immersed in an ethanol solution of 24% for 24 hours. Thereafter, the resin substrate was taken out from the ethanol solution, dried at 130 ° C. for 2 hours, and then washed with ethanol to perform an addition reaction of carboxylic acid to the epoxy site. By this reaction, a naphthalene ring derived from 2-naphthalenecarboxylic acid or an anthracene ring derived from 2-anthracenecarboxylic acid was imparted on the resin substrate surface.

<Manufacture of thermoelectric conversion elements>
A surface treatment substrate (thickness 25 μm, 15 × 12 cm) prepared in each example and comparative example shown in Table 1 has a width of 0.5 mm and a thickness of 70 μm on one surface (surface not subjected to surface treatment). A first substrate 12A in which copper stripes were formed at intervals of 0.5 mm was prepared (see FIGS. 3A to 3D).
As the second substrate 20A, a substrate was prepared by forming copper stripes having a width of 0.5 mm and a thickness of 70 μm at intervals of 0.5 mm on one surface of a resin substrate having a thickness of 25 μm and 15 × 12 cm. In addition, as a resin substrate, the resin substrate used in order to produce the surface treatment board | substrate used by each Example and the comparative example was prepared, respectively. For example, in Example 1, a polyimide substrate was used as the resin substrate.
The entire surface of the first substrate 12A is applied to the 6 × 6 cm region of the surface (surface treated surface) which is the low thermal conductive portion 12a by applying a CNT dispersion by screen printing to form a 0.5 × 1 mm pattern. 1785 pieces were formed. The pattern was formed so that the boundary between the high heat conduction part and the low heat conduction part (the boundary of the copper stripe) coincided with the center of the pattern of 0.5 × 1 mm.
The first substrate 12A on which the pattern was formed was heated on a hot plate at 50 ° C. for 30 minutes, and further heated at 130 ° C. for 2.5 hours to dry the pattern.
Next, the first substrate 12A was immersed in ethanol for 14 hours. The 1st board | substrate 12A immersed in ethanol was heated for 30 minutes at 50 degreeC on the hotplate, and also the thermoelectric conversion layer 16 was produced by heating for 150 minutes at 130 degreeC.
Next, 1785 thermoelectric conversion layers 16 were connected in series with a gold first electrode 26 having a thickness of 200 nm (see FIG. 3B). The first electrode 26 was formed by vacuum vapor deposition using a mask.
On the other hand, a double-sided tape (adhesive transfer tape 8146-1, 3M) having a thickness of 25 μm was stuck as the adhesive layer 18 on the surface of the second substrate 20A, which is the low thermal conductive portion 20a.
This double-sided tape was affixed so as to cover the thermoelectric conversion layer 16 and the first electrode 26 to produce a thermoelectric conversion module as shown in FIGS. 3 (A) to 3 (D). In the second substrate 20A, the center of the thermoelectric conversion layer 16 and the boundary of the copper stripe coincide with each other, the extending direction of the copper stripe coincides with the first substrate 12A, and the first substrate in the plane direction It stuck so that 12A and a copper stripe might not overlap.
The produced thermoelectric conversion module was placed on the hot plate with the first substrate 12 side down, and a Peltier element for temperature control was installed on the second substrate 20.
A temperature difference of 10 ° C. was made between the first substrate 12 and the second substrate 20 of the thermoelectric conversion module by keeping the temperature of the hot plate constant at 100 ° C. and decreasing the temperature of the Peltier element.

<Evaluation>
(Evaluation of power generation (thermoelectric conversion characteristics))
The power generation amount of the produced thermoelectric conversion module was measured and evaluated according to the following evaluation criteria. The results are summarized in Table 1.
A: Power generation amount 30 μW or more A: Power generation amount 25 μW or more and less than 30 μW B: Power generation amount 20 μW or more and less than 25 μW C: Power generation amount 15 μW or more and less than 20 μW D: Power generation amount 15 μW or less

(Bend resistance evaluation)
The produced thermoelectric conversion module was set in a mandrel bending tester having a diameter of 32 mm, bent five times, and then the resistance of the thermoelectric conversion module was measured to evaluate bending resistance, and evaluated according to the following evaluation criteria. The results are summarized in Table 1. In addition, the following resistance value variation rate (%) is {(resistance value of thermoelectric conversion module after bending test) − (resistance value of thermoelectric conversion module before bending test) / (resistance of thermoelectric conversion module after bending test). Value)} × 100.
A: Resistance value fluctuation rate of less than 10% A: Resistance value fluctuation rate of 10% or more and less than 15% B: Resistance value fluctuation rate of 15% or more and less than 20% C: Resistance value fluctuation rate of 20% or more and less than 25 D: Resistance value fluctuation rate 25% or more

  The structural formulas of the respective surface treatment agents used in Table 1 below are shown below.

As shown in Table 1 above, it was confirmed that a thermoelectric conversion element using a predetermined surface-treated substrate was excellent in thermoelectric conversion performance (power generation amount) and in bending resistance.
Especially, when the polyimide board | substrate was used as a resin substrate from the comparison of Examples 1-3, it was confirmed that the electric power generation amount is more excellent.
Moreover, it was confirmed from the comparison with Example 1 and Examples 4-6 that bending resistance is more excellent when pre-processing (energy-beam irradiation processing) is implemented.
Moreover, from the comparison of Example 4 and 7-8, when M was Si, it was confirmed that bending resistance is more excellent.
Moreover, when the board | substrate B mentioned above was used from the comparison with Example 5 and Examples 11-13 (or when a polycyclic aromatic ring is included), it was confirmed that power generation amount and bending resistance are more excellent. .

  On the other hand, in Comparative Examples 1 to 7 in which the treatment with the predetermined surface treatment agent was not performed, the desired effect was not obtained.

DESCRIPTION OF SYMBOLS 1,10 Thermoelectric conversion element 2 Surface treatment board | substrate 6 Protection board | substrate 12,12A 1st board | substrate 12a, 20a Low heat conduction part 12b, 20b High heat conduction part 5,16 Thermoelectric conversion layer 18 Adhesive layer 20, 20A 2nd board | substrate 3,26, 30, 34 First electrode 4, 28, 32, 36 Second electrode

Claims (6)

Any one of the following substrate A and substrate B surface-treated substrate;
A thermoelectric conversion element comprising: a thermoelectric conversion layer containing carbon nanotubes, disposed on a surface of the surface treatment substrate that has been subjected to surface treatment.
Substrate A: A surface-treated substrate obtained by surface-treating a resin substrate with a first surface treatment agent represented by (R ₁ ) _n M (X) _m and having an aromatic ring introduced on the surface.
M represents Si, Ti, or Zr. X represents a hydrolyzable group or a hydroxyl group. R ₁ represents a monovalent organic group, and at least one of R ₁ represents a monovalent organic group containing an aromatic ring. n represents an integer of 1 to 3, m represents an integer of 1 to 3, and n + m = 4. However, the monovalent organic group does not include the hydrolyzable group and the hydroxyl group.
Substrate B: A resin substrate is surface-treated with a second surface treatment agent having a reactive group and represented by (R ₂ ) _n M (X) _m , and then reacts with the reactive group A surface-treated substrate obtained by surface-treating with a third surface treatment agent having a functional group and an aromatic ring and having an aromatic ring introduced on the surface.
M represents Si, Ti, or Zr. X represents a hydrolyzable group or a hydroxyl group. R ₂ represents a monovalent organic group, and at least one of R ₂ represents a monovalent organic group containing a reactive group. n represents an integer of 1 to 3, m represents an integer of 1 to 3, and n + m = 4. However, the monovalent organic group does not include the hydrolyzable group and the hydroxyl group.   The thermoelectric conversion element according to claim 1, wherein the surface treatment substrate is the substrate B.   The thermoelectric conversion element according to claim 1, wherein the aromatic ring is a polycyclic aromatic ring.   The thermoelectric conversion element according to claim 1 or 2, wherein the aromatic ring is a benzene ring, a naphthalene ring, or an anthracene ring. The thermoelectric conversion element according to any one of claims 1 to 4 , wherein the resin substrate is a resin substrate that has been irradiated with energy rays. Said resin substrate, a polyimide substrate, a thermoelectric conversion device according to any one of claims 1-5.