JP2023046931A - Thermoelectric conversion module - Google Patents

Abstract

To provide a thermoelectric conversion module in which overlapping of upper and lower heat sinks is suppressed and high thermoelectric performance is maintained.SOLUTION: In a thermoelectric conversion module 1A in which P-type thermoelectric element layers 4 and N-type thermoelectric element layers 5 are arrayed alternately and so as to be in contact with each other, a first heat sink 9A and a second heat sink 9B are installed so as to be covered by each other in a boundary 6 of a thermoelectric conversion element layer 7 at a first surface side 8A in an array direction 10 and a boundary 6 of the thermoelectric conversion element layer 7 at a second surface side 8B with respect to the boundaries 6 existing at intervals in the array direction 10. When an interval between the first heat sink 9A and the second heat sink 9B being adjacent to each other in the P-type thermoelectric element layer 4 is defined as DP, an interval between the second heat sink 9B and the first heat sink 9A being adjacent to each other in the N-type thermoelectric element layer 5 is defined as DN, a length of the P-type thermoelectric element layer 4 is defined as LP and a length of the N-type thermoelectric element layer 5 is defined as LN, a ratio DP/(LP+LN) and a ratio DN/(LP+LN) respectively range from 0.005 to 0.300.SELECTED DRAWING: Figure 1

Description

The present invention relates to thermoelectric conversion modules.

2. Description of the Related Art Conventionally, as one means of effective utilization of energy, there is a device that directly and mutually converts heat energy and electric energy by means of a thermoelectric conversion module having a thermoelectric effect such as the Seebeck effect or the Peltier effect.
As the thermoelectric conversion module, use of a so-called in-plane type thermoelectric conversion element is known. In the in-plane type, P-type thermoelectric elements and N-type thermoelectric elements are alternately provided in the in-plane direction of the substrate. It is configured by interposing and electrically connecting in series. Normally, in order to provide a temperature difference between the adjacent boundaries alternately and efficiently, heat sinks are provided on the upper and lower surfaces in the arrangement direction of the thermoelectric conversion elements composed of the P-type thermoelectric elements and the N-type thermoelectric elements at each boundary. It is performed by appropriately arranging so as to straddle alternately.

Under such circumstances, Patent Literature 1 describes the arrangement of a heat dissipation layer with respect to a thermoelectric element layer used in an in-plane type thermoelectric conversion module.

WO2018/179544

However, in Patent Document 1, the ratio of the heat dissipation layer to the entire width in the arrangement direction of the pair of P-type thermoelectric element layers and the N-type thermoelectric element layers, and the ratio of the position of the heat dissipation layer to the arrangement direction of the pair of P-type thermoelectric elements It is disclosed that the heat dissipation layer is symmetrically arranged at the junction (boundary) between the thermoelectric layer and the N-type thermoelectric element layer, but the heat dissipation layer is misaligned with respect to the junction (boundary) of each thermoelectric element layer. As a result, there is no description or suggestion about suppressing the deterioration of thermoelectric performance when the heat dissipation layers alternately arranged facing the upper and lower surfaces overlap each other along the thickness direction of each thermoelectric element layer.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a thermoelectric conversion module in which overlapping of upper and lower heat sinks is suppressed and high thermoelectric performance is maintained.

The present inventors have made intensive studies to solve the above problems, and as a result, the P-type thermoelectric element layer with respect to the sum of the length in the arrangement direction of the P-type thermoelectric element layer and the length in the arrangement direction of the N-type thermoelectric element layer The ratio of the spacing in the arrangement direction between the adjacent first heat sink and the second heat sink in the arrangement direction, and the length in the arrangement direction of the P-type thermoelectric element layer and the arrangement direction of the N-type thermoelectric element layer By setting the ratio of the spacing in the arrangement direction between the second heat sink and the first heat sink adjacent in the arrangement direction of the N-type thermoelectric element layer to the sum of the lengths to specific values, the above We have found that the problem can be solved, and have completed the present invention.
That is, the present invention provides the following [1] to [9].
[1] P-type thermoelectric element layers and N-type thermoelectric element layers are arranged alternately and in contact with each other. The thermoelectric element layer and the N-type thermoelectric element layer are arranged at intervals in the arrangement direction of the thermoelectric element layer and the first surface side of the thermoelectric conversion element layer so as to straddle the boundary. , an electrode connecting the P-type thermoelectric element layer and the N-type thermoelectric element layer in series; and a second heat sink disposed on the second surface side of the thermoelectric conversion element layer so as to cover the boundary, wherein
The first heat dissipation plate and the second heat dissipation plate have the boundary on the first surface side in the arrangement direction and the second surface with respect to the boundary spaced apart in the arrangement direction. It is installed so as to alternately cover the border on the side,
D _P is the interval in the arrangement direction between the first heat dissipation plate and the second heat dissipation plate that are adjacent to each other in the arrangement direction of the P-type thermoelectric element layers, and D _N is the interval in the arrangement direction between the adjacent second heat dissipation plate and the first heat dissipation plate, L _P is the length of the P-type thermoelectric element layer in the arrangement direction, and the N-type thermoelectric element When the length of the layer in the arrangement direction is L _N , the ratio D _P /(L _P +L _N ) is 0.005 to 0.300, and the ratio D _N /(L _P +L _N ) is 0.005 to Thermoelectric conversion module, which is 0.300.
[2] The first heat sink and the second heat sink are each independently at least selected from the group consisting of a metal material, a ceramic material, a mixture of a metal material and a resin, and a mixture of a ceramic material and a resin. The thermoelectric conversion module according to the above [1], which is one type.
[3] The thermoelectric conversion according to [1] or [2] above, wherein the thermal conductivity of the first heat sink and the second heat sink are each independently 5 to 500 W / (m K). module.
[4] The thermoelectric conversion module according to any one of [1] to [3] above, wherein the thicknesses of the first heat sink and the second heat sink are independently 40 to 550 μm.
[5] The thermoelectric conversion module according to any one of [1] to [4] above, further including a first substrate between the first surface side of the thermoelectric conversion element layer and the first heat sink. .
[6] The thermoelectric conversion module according to [5] above, further including a first coating layer between the first substrate and the first radiator plate.
[7] The above [1] to [6], further comprising a second substrate and/or a second coating layer between the second surface side of the thermoelectric conversion element layer and the second heat sink. The thermoelectric conversion module according to any one of the above.
[8] The ratio D _P /(L _P +L _N ) is 0.010 to 0.270, and the ratio D _N /(L _P +L _N ) is 0.010 to 0.270. ] The thermoelectric conversion module according to any one of [7].

Advantageous Effects of Invention According to the present invention, it is possible to provide a thermoelectric conversion module in which overlapping of upper and lower heat sinks is suppressed and high thermoelectric performance is maintained.

1 is a cross-sectional view showing an embodiment of a thermoelectric conversion module of the present invention; FIG. 1 is a cross-sectional view of a thermoelectric conversion module used in an example of the present invention; FIG. FIG. 2 is a plan view showing an example of the positional relationship between a thermoelectric conversion element layer composed of a P-type thermoelectric element layer and an N-type thermoelectric element layer and electrodes used in the examples of the present invention.

[Thermoelectric conversion module]
In the thermoelectric conversion module of the present invention, the P-type thermoelectric element layers and the N-type thermoelectric element layers are arranged alternately and in contact with each other. is provided on the first surface side of the thermoelectric conversion element layer and the thermoelectric conversion element layer that are spaced apart in the arrangement direction of the P-type thermoelectric element layer and the N-type thermoelectric element layer so as to straddle the boundary and an electrode connecting the P-type thermoelectric element layer and the N-type thermoelectric element layer in series, and the boundary and the electrode on the first surface side of the thermoelectric conversion element layer A thermoelectric conversion module comprising: a first heat sink installed to cover the thermoelectric conversion element layer; and a second heat sink installed to cover the boundary on the second surface side of the thermoelectric conversion element layer. hand,
The first heat dissipation plate and the second heat dissipation plate have the boundary on the first surface side in the arrangement direction and the second surface with respect to the boundary spaced apart in the arrangement direction. It is installed so as to alternately cover the border on the side,
More specifically, the first heat sink and the second heat sink are arranged so as to alternately cover the boundaries spaced apart in the arrangement direction in order of the arrangement direction,
Therefore, the first heat radiation plate is installed so as to cover the one end side of the one end and the other end in the arrangement direction of each P-type thermoelectric element layer, and the second heat radiation plate is installed on the one end side. is not installed, the second heat sink is installed so as to cover the other end side, and the first heat sink is not installed on the other end side,
The second radiator plate is installed so as to cover the one end side of one end and the other end in the arrangement direction of each N-type thermoelectric element layer, and the first radiator plate is installed on the one end side. the first heat sink is installed so as to cover the other end side, and the second heat sink is not installed on the other end side;
D _P is the interval in the arrangement direction between the first heat dissipation plate and the second heat dissipation plate that are adjacent to each other in the arrangement direction of the P-type thermoelectric element layers, and D _N is the interval in the arrangement direction between the adjacent second heat dissipation plate and the first heat dissipation plate, L _P is the length of the P-type thermoelectric element layer in the arrangement direction, and the N-type thermoelectric element When the length of the layer in the arrangement direction is L _N , the ratio D _P /(L _P +L _N ) is 0.005 to 0.300, and the ratio D _N /(L _P +L _N ) is 0.005 to It is characterized by being 0.300.
In the thermoelectric conversion module of the present invention, the first heat sinks adjacent in the arrangement direction of the P-type thermoelectric element layers with respect to the sum of the length in the arrangement direction of the P-type thermoelectric element layers and the length in the arrangement direction of the N-type thermoelectric element layers and the second heat sink in the arrangement direction, and the sum of the length in the arrangement direction of the P-type thermoelectric element layer and the length in the arrangement direction of the N-type thermoelectric element layer The first heat sink and the second It is possible to suppress the decrease in the temperature difference generated in the in-plane direction due to the overlapping of the heat sinks, and to maintain high thermoelectric performance.

In this specification, the term "thermoelectric conversion element layer" means an array of thermoelectric element layers composed of a P-type thermoelectric element layer and an N-type thermoelectric element layer. Further, each of the P-type thermoelectric element layer and the N-type thermoelectric element layer may be simply referred to as "thermoelectric element layer".
In addition, the first heat sink, the second heat sink, the first substrate, the second substrate, and the first coating layer and the second coating layer are simply referred to in this order as “heat sink”, “substrate”, It is sometimes called a "coating layer".

A thermoelectric conversion module of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing an embodiment (basic configuration) of the thermoelectric conversion module of the present invention. In the thermoelectric conversion module 1A, P-type thermoelectric element layers 4 and N-type thermoelectric element layers 5 are arranged alternately in the in-plane direction and in contact with each other. and a thermoelectric conversion element layer ₇ in which a boundary ₆ between the The electrode 3 which is installed so as to straddle the boundary 6 on the first surface side 8 _A of the A and electrically connects the P-type thermoelectric element layer 4 and the N-type thermoelectric element layer 5 in series, and the thermoelectric On the first surface side _8A of the conversion element layer 7, a first heat sink _9A installed so as to cover the boundary 6 and the electrodes 3, and on the second surface side _8B of the thermoelectric conversion element layer 7, and a second heat sink 9 _B installed to cover the boundary 6 .
The first heat sink 9 _A and the second heat sink 9 _B are located on the first surface side 8 _A in the arrangement direction 10 with respect to the boundary 6 that exists with an interval L _P or an interval L _N in the arrangement direction 10 . 6, and the second surface side _8B so as to alternately cover the boundary 6.
Here, D _P denotes the spacing in the arrangement direction 10 between the first heat sink 9 _A and the second heat sink 9 _B adjacent to each other in the arrangement direction 10 of each P-type thermoelectric element layer 4, and D _N indicates the spacing in the arrangement direction 10 between the second heat sink _9B and the first heat sink _9A adjacent to each other in the arrangement direction 10 of each N-type thermoelectric element layer 5, and _LP is the P-type thermoelectric The length in the arrangement direction 10 of the element layer 4 is indicated, and _LN indicates the length in the arrangement direction 10 of the N-type thermoelectric element layer 5 . Also, L _A is the length of the first heat sink _9A , L _AL is the length in the direction opposite to the arrangement direction 10 starting from the boundary 6 of the first heat sink, and _LAR is the first heat sink. The length of the arrangement direction 10 starting from the boundary 9 of the plate _9A , _LB is the length of the second heat sink _9B , and _LBL is the arrangement direction 10 starting from the boundary of the second heat sink _9B . , and _LBR indicates the length in the arrangement direction 10 starting from the boundary of the second heat sink _9B .

FIG. 2 is a cross-sectional view of a thermoelectric conversion module used in Examples of the present invention. In addition to the configuration of the thermoelectric conversion module in FIG. 1, the thermoelectric conversion module 1B includes a coating layer _11B between the thermoelectric conversion element layer 7 (second surface side _8B ) and the second heat sink _9B , Further, a substrate 2 (polyimide substrate 2a) and _a covering layer _11A are provided between the thermoelectric conversion element layer 7 (first surface side _8A ) and the first heat sink 9A.

In the thermoelectric conversion module of the present invention, the distance in the arrangement direction between the first heat sink and the second heat sink adjacent to each other in the arrangement direction of the P-type thermoelectric element layers is D _P , and the arrangement direction of the N-type thermoelectric element layers is D _N is the interval in the arrangement direction between the adjacent second heat sink and the first heat sink in the arrangement direction, L _P is the length in the arrangement direction of the P-type thermoelectric element layer, and L P is the arrangement direction of the N-type thermoelectric element layer When the length is L _N , the ratio D _P /(L _P +L _N ) is 0.005 to 0.300, and the ratio D _N /(L _P +L _N ) is 0.005 to 0.300. be.
When the ratio D _P /(L _P +L _N ) is less than 0.005, the spacing in the arrangement direction between the first heat sink and the second heat sink adjacent to each other in the arrangement direction of the P-type thermoelectric element layers is or overlap along the thickness direction of the P-type thermoelectric element layer between the first heat sink and the second heat sink. On the other hand, a temperature difference is less likely to be applied between boundaries adjacent to each other in the arrangement direction.
When the ratio D _P /(L _P +L _N ) is more than 0.300, the spacing in the arrangement direction between the first heat sink and the second heat sink adjacent to each other in the arrangement direction of the P-type thermoelectric element layers is Since it becomes too large, it becomes easy to suppress the application of a temperature difference between the boundaries adjacent to each other in the arrangement direction.
The ratio D _P /(L _P +L _N ) is preferably 0.010 to 0.270, more preferably 0.030 to 0.260, still more preferably 0.040 to 0.250.
Similarly, when the ratio D _N /(L _P +L _N ) is less than 0.005, the arrangement direction between the adjacent second heat sink and first heat sink in the arrangement direction of the N-type thermoelectric element layers , or the overlap along the thickness direction of the N-type thermoelectric element layer between the second heat sink and the first heat sink occurs, so the temperature difference is given in the thickness direction On the other hand, a temperature difference is less likely to be applied between boundaries adjacent to each other in the arrangement direction.
When the ratio D _N /(L _P +L _N ) is more than 0.300, the spacing in the arrangement direction between the second heat sink and the first heat sink adjacent to each other in the arrangement direction of the N-type thermoelectric element layers is Since it becomes too large, it becomes easy to suppress the application of a temperature difference between the boundaries adjacent to each other in the arrangement direction.
The ratio D _N /(L _P +L _N ) is preferably 0.010 to 0.270, more preferably 0.030 to 0.260, still more preferably 0.040 to 0.250.
When the ratio D _P /(L _P +L _N ) and the ratio D _N /(L _P +L _N ) are within the above ranges, even if the heat sink is misaligned with respect to the boundary of the thermoelectric conversion element layer, the first There is no overlap along the thickness direction of the thermoelectric conversion element layer between the heat sink and the second heat sink, and the deterioration of the thermoelectric performance can be effectively suppressed or maintained.

<Heat sink>
A thermoelectric conversion module of the present invention includes a first heat sink and a second heat sink. The first heat sink and the second heat sink used in the present invention alternately and efficiently generate a temperature difference between adjacent boundaries in the arrangement direction of the thermoelectric conversion element layers composed of the P-type thermoelectric element layers and the N-type thermoelectric element layers. can be given.

The radiator plate used in the present invention is preferably formed using a high thermal conductivity material from the viewpoint of thermoelectric performance. The method of forming the heat sink is not particularly limited, but a sheet-like high thermal conductivity material is subjected to known physical or chemical treatments in advance mainly by photolithography, or by using them in combination. A method of processing into a predetermined pattern shape can be mentioned.

Materials for the first heat sink and the second heat sink include metal materials, ceramic materials, carbon-based materials such as carbon fibers, and mixtures of these materials and resins. Among these, the first heat sink and the second heat sink are each independently selected from at least the group consisting of a metal material, a ceramic material, a mixture of a metal material and a resin, and a mixture of a ceramic material and a resin. One kind is preferable, and at least one kind selected from the group consisting of metal materials and ceramic materials is more preferable.
Metal materials include single metals such as gold, silver, copper, nickel, tin, iron, chromium, platinum, palladium, rhodium, iridium, ruthenium, osmium, indium, zinc, molybdenum, manganese, titanium, aluminum, stainless steel, and brass. alloys containing two or more metals such as (brass).
Ceramic materials include barium titanate, aluminum nitride, boron nitride, aluminum oxide, silicon carbide, silicon nitride, and the like.
Among these, metal materials are preferable from the viewpoint of high thermal conductivity, workability, and flexibility. Among metal materials, copper (including oxygen-free copper) and stainless steel are preferred, and copper is more preferred because of its high thermal conductivity and easy workability.
Examples of the resin include, but are not limited to, resin films.
Resins used for resin films include polyimide, polyamide, polyamideimide, polyphenylene ether, polyetherketone, polyetheretherketone, polyolefin, polyester, polycarbonate, polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, nylon, Examples include acrylic resins, cycloolefin polymers, and aromatic polymers.
Among these, polyesters include polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate (PEN), polyarylates, and the like. Cycloolefin polymers include norbornene polymers, monocyclic cyclic olefin polymers, cyclic conjugated diene polymers, vinyl alicyclic hydrocarbon polymers, and hydrides thereof.
Among resins used for resin films, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and nylon are preferable from the viewpoint of cost and heat resistance.
Moreover, the resin may contain a filler from the viewpoint of controlling the modulus of elasticity and controlling the thermal conductivity.
Fillers added to the resin film include magnesium oxide, anhydrous magnesium carbonate, magnesium hydroxide, aluminum oxide, boron nitride, aluminum nitride, silicon oxide and the like. Among these, aluminum oxide, boron nitride, aluminum nitride, and silicon oxide are preferable from the viewpoint of elastic modulus control, thermal conductivity, and the like.

Here, representative metal materials having high thermal conductivity used in the present invention are shown below.
Oxygen-free copper Oxygen-free copper (OFC) generally refers to high-purity copper of 99.95% (3N) or higher that does not contain oxides. The Japanese Industrial Standards define oxygen-free copper (JIS H 3100, C1020) and oxygen-free copper for electron tubes (JIS H 3510, C1011).
・Stainless steel (JIS)
SUS304: 18Cr-8Ni (containing 18% Cr and 8% Ni)
SUS316: 18Cr-12Ni (stainless steel containing 18% Cr, 12% Ni and molybdenum (Mo))

The thermal conductivity of the heat sink is preferably 5 to 500 W/(m·K), more preferably 12 to 450 W/(m·K), still more preferably 15 to 420 W/(m·K). is. When the thermal conductivity of the radiator plate is within the above range, it is possible to efficiently impart a temperature difference.

The thickness of the radiator plate is preferably 40 to 550 μm, more preferably 60 to 530 μm, even more preferably 80 to 510 μm. If the thickness of the radiator plate is within this range, heat can be selectively radiated in a specific direction.

The thermoelectric conversion module of the present invention preferably includes a first substrate between the first surface side of the thermoelectric conversion element layer and the first radiator plate.
Moreover, it is preferable to include a first coating layer between the first substrate and the first heat sink.
Furthermore, it is preferable to include a second substrate and/or a second coating layer between the second surface side of the thermoelectric conversion element layer and the second heat sink.

<Substrate>
The first substrate and the second substrate used in the present invention are not particularly limited, and may be made of the same material or different materials. It has excellent flexibility and can maintain the performance of the thermoelectric conversion element layer without thermal deformation even when a coating film (thin film) made of the thermoelectric semiconductor composition described later is baked (annealed). Polyimide films, polyamide films, polyetherimide films, polyaramid films, and polyamideimide films are preferred from the viewpoint of high dimensional stability, and polyimide films are particularly preferred from the viewpoint of high versatility.

The thicknesses of the first substrate and the second substrate are each independently preferably 1 to 1000 μm, more preferably 5 to 500 μm, particularly preferably 10 to 100 μm, from the viewpoint of flexibility, heat resistance and dimensional stability. is.
The 5% mass loss temperature measured by thermogravimetric analysis (TG) of the first substrate and the second substrate is preferably 300° C. or higher, more preferably 400° C. or higher. The heat dimensional change rate measured at 200° C. in accordance with JIS K7133 (1999) is preferably 0.5% or less, more preferably 0.3% or less. The coefficient of linear expansion in the plane direction measured according to JIS K7197 (2012) is preferably 0.1 to 50 ppm·°C ^-1 , more preferably 0.1 to 30 ppm·°C ^-1 .

<Coating layer>
The first coating layer and the second coating layer used in the present invention are not particularly limited, and may be layers with the same specifications or layers with different specifications. For example, a sealing layer, a gas barrier layer, etc. mentioned.

<Sealing layer>
The thermoelectric conversion module of the present invention may contain a sealing layer as a coating layer. The sealing layer has a function of effectively suppressing permeation of water vapor in the atmosphere. Moreover, when the sealant to be used has tackiness, it also functions as an adhesive.
The sealing layer may be laminated directly on the thermoelectric conversion element layer or via a substrate, or may be laminated via a gas barrier layer which will be described later.

The main component constituting the sealing layer used in the present invention is preferably polyolefin resin, epoxy resin, or acrylic resin.
Moreover, it is preferable that the sealing layer is made of a sealing agent having tackiness (hereinafter sometimes referred to as a "sealing agent composition"). In the present specification, having tackiness means that the sealant has tackiness, adhesiveness, and tackiness in the normal state of attachment, and then adheres and cures upon application of energy. By using the sealing layer, it can be easily laminated on the thermoelectric conversion element layer. In addition, it becomes easy to attach to the radiator plate, the substrate, the gas barrier layer described later, and the like.

Although the polyolefin resin is not particularly limited, it may be a diene rubber having a carboxylic acid functional group (hereinafter sometimes referred to as "diene rubber"), or a diene rubber and carboxylic acid functional group having a carboxylic acid functional group. Examples thereof include rubber-based polymers having no acid-based functional group (hereinafter sometimes referred to as "rubber-based polymer").

A diene rubber is a diene rubber composed of a polymer having a carboxylic acid functional group at the main chain terminal and/or side chain. Here, the term "carboxylic acid-based functional group" means "a carboxyl group or a carboxylic acid anhydride group". The term "diene rubber" means "a rubber-like polymer having a double bond in the main chain of the polymer".
The diene rubber is not particularly limited as long as it has a carboxylic acid functional group.
Examples of diene rubber include polybutadiene rubber containing carboxylic acid functional groups, polyisoprene rubber containing carboxylic acid functional groups, copolymer rubber of butadiene and isoprene containing carboxylic acid functional groups, and carboxylic acid functional groups. Copolymer rubber of contained butadiene and n-butene and the like can be mentioned. Among these, polyisoprene-based rubbers containing carboxylic acid functional groups are preferable as the diene-based rubber from the viewpoint of being able to efficiently form a sealing layer having sufficiently high cohesion after cross-linking.
The diene rubber can be used alone or in combination of two or more.
A method of performing a copolymerization reaction using a diene rubber, for example, a monomer having a carboxyl group, or a method of adding maleic anhydride to a polymer such as polybutadiene, which is described in JP-A-2009-29976. ,Obtainable.

The content of the diene rubber in the sealant composition is preferably 0.5 to 95.5% by mass, more preferably 1.0 to 50% by mass, still more preferably 2.0 to 20% by mass. be. When the content of the diene rubber is 0.5% by mass or more in the sealant composition, a sealing layer having sufficient cohesion can be efficiently formed. Also, by not increasing the content of the diene rubber too much, a sealing layer having sufficient adhesive strength can be efficiently formed.

The cross-linking agent used in the present invention is a compound capable of forming a cross-linked structure by reacting with the carboxylic acid functional group of the diene rubber.
Examples of cross-linking agents include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, aziridine-based cross-linking agents, and metal chelate-based cross-linking agents.

A rubber-based polymer refers to a "resin exhibiting rubber elasticity at 25°C". The rubber-based polymer is preferably a polymethylene type rubber having a saturated main chain or a rubber having an unsaturated carbon bond in the main chain.
Specific examples of such rubber-based polymers include homopolymers of isobutylene (polyisobutylene, IM), copolymers of isobutylene and n-butene, natural rubber (NR), homopolymers of butadiene (butadiene rubber, BR), homopolymer of chloroprene (chloroprene rubber, CR), homopolymer of isoprene (isoprene rubber, IR), copolymer of isobutylene and butadiene, copolymer of isobutylene and isoprene (butyl rubber, IIR), Halogenated butyl rubber, copolymer of styrene and 1,3-butadiene (styrene-butadiene rubber, SBR), copolymer of acrylonitrile and 1,3-butadiene (nitrile rubber), styrene-1,3-butadiene-styrene block copolymer polymer (SBS), styrene-isoprene-styrene block copolymer (SIS), ethylene-propylene-nonconjugated diene terpolymer and the like. Among these, isobutylene homopolymer, isobutylene and n-butene are preferred from the viewpoint that they themselves have excellent moisture blocking properties, are easily mixed with the diene rubber (A), and easily form a uniform sealing layer. Isobutylene-based polymers such as copolymers, isobutylene/butadiene copolymers, and isobutylene/isoprene copolymers are preferred, and isobutylene/isoprene copolymers are more preferred.
When a rubber polymer is blended, its content in the sealant composition is preferably 0.1% by mass to 99.5% by mass, more preferably 10% to 99.5% by mass, and still more preferably 50% by mass. ~99.0% by mass, particularly preferably 80 to 98.0% by mass.

Although the epoxy resin is not particularly limited, polyfunctional epoxy compounds having at least two epoxy groups in the molecule are preferred.
Examples of epoxy compounds having two or more epoxy groups include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, and brominated bisphenol S. Diglycidyl ether, novolac type epoxy resin (e.g., phenol/novolac type epoxy resin, cresol/novolac type epoxy resin, brominated phenol/novolak type epoxy resin), hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether , hydrogenated bisphenol S diglycidyl ether, pentaerythritol polyglycidyl ether, 1,6-hexanediol diglycidyl ether, hexahydrophthalic acid diglycidyl ester, neopentyl glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, 2,2 -bis(3-glycidyl-4-glycidyloxyphenyl)propane, dimethyloltricyclodecane diglycidyl ether and the like.
These polyfunctional epoxy compounds can be used singly or in combination of two or more.
The lower limit of the molecular weight of the polyfunctional epoxy compound is preferably 700 or more, more preferably 1,200 or more. The upper limit of the molecular weight of the polyfunctional epoxy compound is preferably 5,000 or less, more preferably 4,500 or less.
The epoxy equivalent of the polyfunctional epoxy compound is preferably 100 g/eq or more and 500 g/eq or less, more preferably 150 g/eq or more and 300 g/eq or less.

The content of the epoxy resin in the sealant composition is preferably 10 to 50% by mass, more preferably 10 to 40% by mass.

The acrylic resin is not particularly limited, but a (meth)acrylic acid ester copolymer is preferable.
The (meth)acrylic acid ester-based copolymer includes a (meth)acrylic acid alkyl ester having 1 to 18 carbon atoms in the alkyl group of the ester portion, and a crosslinkable functional group-containing ethylenic unit that is used as necessary. Polymers and copolymers with other monomers are preferred. (Meth)acrylic acid alkyl esters in which the alkyl group in the ester portion has 1 to 18 carbon atoms include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n-butyl Acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, n-hexyl acrylate n-hexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, stearyl methacrylate and the like. These may be used individually by 1 type, and may be used in combination of 2 or more type.
The crosslinkable functional group-containing ethylenic monomer used as necessary is an ethylenic monomer having a functional group such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, an epoxy group, etc. in the molecule. A hydroxyl group-containing ethylenically unsaturated compound and a carboxyl group-containing ethylenically unsaturated compound are preferably used. Specific examples of such crosslinkable functional group-containing ethylenic monomers include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, and 2-hydroxybutyl acrylate. , hydroxy group-containing (meth)acrylates such as 2-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, carboxyl group-containing such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, citraconic acid Examples include ethylenically unsaturated compounds. The crosslinkable functional group-containing ethylenic monomers may be used singly or in combination of two or more.
Other monomers used as necessary include (meth)acrylic acid esters having an alicyclic structure such as cyclohexyl acrylate and isobornyl acrylate; vinyl esters such as vinyl acetate and vinyl propionate; Olefins such as propylene and isobutylene; Halogenated olefins such as vinyl chloride and vinylidene chloride; Styrenic monomers such as styrene and α-methylstyrene; Diene monomers such as butadiene, isoprene and chloroprene; Nitrile-based monomers such as ronitrile; N,N-dialkyl-substituted acrylamides such as N,N-dimethylacrylamide and N,N-dimethylmethacrylamide; These may be used individually by 1 type, and may be used in combination of 2 or more type.
The above (meth) acrylic acid ester, and the crosslinkable functional group-containing ethylenic monomer and other monomers used as necessary are used in predetermined proportions, respectively, and are copolymerized using a conventionally known method. to produce a (meth)acrylate polymer having a weight average molecular weight of preferably about 300,000 to 1,500,000, more preferably about 350,000 to 1,300,000.
In addition, the said weight average molecular weight is a value of standard polystyrene conversion measured by the gel permeation chromatography (GPC) method.
As the cross-linking agent used as necessary, any one can be appropriately selected and used from those conventionally used as cross-linking agents in acrylic resins. Examples of such cross-linking agents include polyisocyanate compounds, epoxy compounds, melamine resins, urea resins, dialdehydes, methylol polymers, aziridine compounds, metal chelate compounds, metal alkoxides, and metal salts. When the meth)acrylic acid ester copolymer has a hydroxyl group as a crosslinkable functional group, a polyisocyanate compound is preferable, and when it has a carboxyl group, a metal chelate compound or an epoxy compound is preferable.

The content of the acrylic resin in the sealant composition is preferably 30 to 95% by mass, more preferably 40 to 90% by mass.

The encapsulant constituting the encapsulating layer may contain other components as long as the effects of the present invention are not impaired. Other components that can be contained in the sealant include, for example, high thermal conductivity materials, flame retardants, tackifiers, ultraviolet absorbers, antioxidants, preservatives, antifungal agents, plasticizers, antifoaming agents, and wettability modifiers and the like.

The sealing layer may be a single layer or a laminate of two or more layers. Moreover, when two or more layers are laminated, they may be the same or different.
The thickness of the sealing layer is preferably 0.5 to 100 μm, more preferably 3 to 50 μm, still more preferably 5 to 30 μm. Within this range, when laminated on the first surface side and/or the second surface side of the thermoelectric conversion element layer of the thermoelectric conversion module, the water vapor transmission rate can be suppressed, and the durability of the thermoelectric conversion module can be improved. improves.
Furthermore, as described above, it is preferable that the thermoelectric conversion element layer and the sealing layer are in direct contact. Since the thermoelectric conversion element layer and the sealing layer are in direct contact with each other, water vapor in the air does not directly exist between the thermoelectric conversion element layer and the sealing layer. is suppressed, and the sealing property of the sealing layer is improved.

<Gas barrier layer>
The thermoelectric conversion module of the present invention may further contain a gas barrier layer as a coating layer. The gas barrier layer can effectively suppress permeation of atmospheric water vapor.

The gas barrier layer may be directly laminated on the thermoelectric conversion element layer, or may be composed of a layer containing the main component described later on the base material, and any surface thereof may be directly laminated on the thermoelectric conversion element layer. Alternatively, they may be laminated via a sealing layer, a substrate, or the like.
The gas barrier layer used in the present invention is mainly composed of one or more selected from the group consisting of metals, inorganic compounds and polymer compounds. The gas barrier layer can improve the durability of the thermoelectric conversion module.

As the base material, a material having flexibility is used, and for example, the resin used for the material of the heat sink described above can be used. The same applies to preferable resins.

Examples of metals include aluminum, magnesium, nickel, zinc, gold, silver, copper, tin, and the like, and these are preferably used as vapor deposition films. Among these, aluminum and nickel are preferable from the viewpoint of productivity, cost, and gas barrier properties. Moreover, these can be used individually by 1 type or in combination of 2 or more types including an alloy. The vapor deposition film may be formed by a vapor deposition method such as a vacuum vapor deposition method or an ion plating method. A film may be formed by a dry method. In addition, since the metal deposition film or the like usually has conductivity, it is laminated on the thermoelectric conversion element layer via the substrate or the like.

Examples of inorganic compounds include inorganic oxides (MO _x ), inorganic nitrides (MN _y ), inorganic carbides (MC _z ), inorganic oxide carbides (MO _x C _z ), inorganic nitride carbides (MN _y C _z ), inorganic oxides Nitrides (MO _x N _y ), inorganic oxynitride carbides (MO _x N _y C _z ), and the like. Here, x, y, and z represent the composition ratio of each compound. Examples of M include metal elements such as silicon, zinc, aluminum, magnesium, indium, calcium, zirconium, titanium, boron, hafnium, and barium. M may be a single element or two or more elements. Each inorganic compound is an oxide such as silicon oxide, zinc oxide, aluminum oxide, magnesium oxide, indium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, barium oxide; silicon nitride, aluminum nitride, boron nitride , nitrides such as magnesium nitride; carbides such as silicon carbide; sulfides; Moreover, it may be a composite of two or more kinds (oxynitrides, oxycarbides, oxynitrides, oxynitride carbides) selected from these inorganic compounds. Also, a composite containing two or more metal elements such as SiOZn (including oxynitrides, oxycarbides, nitride carbides, and oxynitride carbides) may be used. These are preferably used as vapor deposition films, but if they cannot be formed as vapor deposition films, they may be formed by methods such as DC sputtering, magnetron sputtering, and plasma CVD.
M is preferably a metal element such as silicon, aluminum, or titanium. In particular, an inorganic layer made of silicon oxide in which M is silicon has high gas barrier properties, and an inorganic layer made of silicon nitride has even higher gas barrier properties. In particular, a composite of silicon oxide and silicon nitride (inorganic oxynitride (MO _x N _y )) is preferred, and gas barrier properties improve when the content of silicon nitride is large.
Incidentally, vapor-deposited films of inorganic compounds usually have insulating properties in many cases, but include those having conductivity such as zinc oxide and indium oxide. In this case, when these inorganic compounds are laminated on the thermoelectric conversion element layer, they are laminated via the base material described above, or are used within a range that does not affect the performance of the thermoelectric conversion module.

Examples of polymer compounds include silicon-containing polymer compounds such as polyorganosiloxanes and polysilazane compounds, polyimides, polyamides, polyamideimides, polyphenylene ethers, polyetherketones, polyetheretherketones, polyolefins, and polyesters. These polymer compounds can be used singly or in combination of two or more.
Among these, silicon-containing polymer compounds are preferable as the polymer compound having gas barrier properties. Polysilazane-based compounds, polycarbosilane-based compounds, polysilane-based compounds, polyorganosiloxane-based compounds, and the like are preferable as the silicon-containing polymer compound. Among these, polysilazane-based compounds are more preferable from the viewpoint of forming a barrier layer having excellent gas barrier properties.

In addition, a silicon oxynitride layer composed of a layer having oxygen, nitrogen, and silicon as main constituent atoms formed by modifying a layer containing an inorganic compound or a layer containing a polysilazane compound has excellent interlayer adhesion and gas barrier properties. It is preferably used from the viewpoint of having flexibility and flexibility.
The gas barrier layer can be formed, for example, by subjecting the polysilazane compound-containing layer to plasma ion implantation treatment, plasma treatment, ultraviolet irradiation treatment, heat treatment, or the like. Ions implanted by the plasma ion implantation process include hydrogen, nitrogen, oxygen, argon, helium, neon, xenon, krypton, and the like.
As a specific processing method of the plasma ion implantation treatment, there is a method of implanting ions present in plasma generated using an external electric field into a polysilazane compound-containing layer, or a method of implanting a gas barrier without using an external electric field. A method of injecting ions present in a plasma generated only by an electric field by a negative high voltage pulse applied to a layer made of a layer-forming material into a layer containing a polysilazane compound can be used.
Plasma treatment is a method of exposing the polysilazane compound-containing layer to plasma to modify the layer containing the silicon-containing polymer. For example, plasma treatment can be performed according to the method described in JP-A-2012-106421. The ultraviolet irradiation treatment is a method of modifying the layer containing the silicon-containing polymer by irradiating the polysilazane compound-containing layer with ultraviolet rays. For example, ultraviolet modification treatment can be performed according to the method described in JP-A-2013-226757.
Among these, the ion implantation process is preferable because the inside of the polysilazane compound-containing layer can be efficiently modified without roughening the surface of the polysilazane compound-containing layer, and a gas barrier layer having more excellent gas barrier properties can be formed.

The thickness of the layer containing a metal, an inorganic compound and a polymer compound varies depending on the compound used, etc., but is usually 0.01 to 50 μm, preferably 0.03 to 10 μm, more preferably 0.05 to 0.80 μm, More preferably, it is 0.10 to 0.60 μm. If the thickness including the metal, the inorganic compound and the resin is within this range, the water vapor transmission rate can be effectively suppressed.

The thickness of the gas barrier layer having a substrate of the metal, inorganic compound, or polymer compound is preferably 10 to 80 μm, more preferably 15 to 50 μm, and still more preferably 20 to 40 μm. When the thickness of the gas barrier layer is within this range, excellent gas barrier properties can be obtained, and both flexibility and film strength can be achieved.
The gas barrier layer may be a single layer or a laminate of two or more layers. Moreover, when two or more layers are laminated, they may be the same or different.

<electrode>
The electrodes used in the present invention are provided for electrical connection between the P-type thermoelectric element layer and the N-type thermoelectric element layer that constitute the thermoelectric conversion element layer. Examples of electrode materials include gold, silver, nickel, copper, and alloys thereof.
The thickness of the electrodes is preferably 10 nm to 200 μm, more preferably 30 nm to 150 μm, even more preferably 50 nm to 120 μm. If the thickness of the electrode is within the above range, the electrical conductivity is high and the resistance is low, and the total electrical resistance of the thermoelectric conversion element layer can be kept low. Moreover, sufficient strength as an electrode can be obtained.

<Thermoelectric conversion element layer>
As described above, the thermoelectric conversion element layer of the thermoelectric conversion module used in the present invention includes a P-type thermoelectric element layer and an N-type thermoelectric element layer, and the P-type thermoelectric element layer and the N-type thermoelectric element layer face each other. They are alternately arranged adjacent to each other in the inward direction and configured to be electrically connected in series. Furthermore, the connection between the P-type thermoelectric element layer and the N-type thermoelectric element layer is formed from a highly conductive metal material or the like from the viewpoint of connection stability and thermoelectric performance, and it is preferable to use the electrode material described above.

The thermoelectric conversion element layer used in the present invention is preferably made of a thermoelectric semiconductor composition containing thermoelectric semiconductor particles, a binder resin and an ionic liquid.

(thermoelectric semiconductor particles)
The thermoelectric semiconductor particles constituting the thermoelectric conversion element layer composed of the P-type thermoelectric element layer and the N-type thermoelectric element layer used in the present invention are made of a material capable of generating a thermoelectromotive force by applying a temperature difference. Bismuth-tellurium-based thermoelectric semiconductor materials such as P-type bismuth telluride and N-type bismuth telluride; Telluride-based thermoelectric semiconductor materials such as GeTe and PbTe; Antimony-Tellurium-based thermoelectric semiconductor materials; ZnSb , Zn ₃ Sb _2, Zn ₄ Sb ₃ and the like; silicon-germanium based thermoelectric semiconductor materials such as SiGe; bismuth selenide based thermoelectric semiconductor materials such as Bi ₂ Se _{3 ;} Silicide-based thermoelectric semiconductor materials such as CrSi ₂ , MnSi _1.73 , and Mg ₂ Si; oxide-based thermoelectric semiconductor materials; Heusler materials such as FeVAl, FeVAlSi, and FeVTiAl; and sulfide-based thermoelectric semiconductor materials such as TiS ₂ . .

Among these, the thermoelectric semiconductor material used in the present invention is preferably a bismuth-tellurium thermoelectric semiconductor material such as P-type bismuth telluride or N-type bismuth telluride.
The p-type bismuth telluride has holes as carriers and a positive Seebeck coefficient, and is preferably represented by, for example, Bi _X Te ₃ Sb _2-X . In this case, X preferably satisfies 0<X≦0.8, more preferably 0.4≦X≦0.6. When X is greater than 0 and 0.8 or less, the Seebeck coefficient and electric conductivity are increased, and the properties of the P-type thermoelectric conversion material are maintained, which is preferable.
The N-type bismuth telluride has electrons as carriers and a negative Seebeck coefficient, and is represented by, for example, Bi ₂ Te _3-Y Se _Y , which is preferably used. In this case, Y preferably satisfies 0≦Y≦3 (when Y=0: Bi ₂ Te ₃ ), more preferably 0<Y≦2.7. When Y is 0 or more and 3 or less, the Seebeck coefficient and electrical conductivity are increased, and the properties as an N-type thermoelectric conversion material are maintained, which is preferable.

The thermoelectric semiconductor particles used for the thermoelectric conversion element layer composed of the P-type thermoelectric element layer and the N-type thermoelectric element layer are preferably obtained by pulverizing the thermoelectric semiconductor material to a predetermined size using a pulverizer or the like.
The method of pulverizing the thermoelectric semiconductor material to obtain thermoelectric semiconductor particles is not particularly limited, and includes jet mill, ball mill, bead mill, colloid mill, conical mill, disc mill, edge mill, milling mill, hammer mill, pellet mill, Willie mill, and roller. It may be pulverized to a predetermined size by a known pulverizing device such as a mill.

The average particle size of the thermoelectric semiconductor particles is preferably 10 nm to 200 μm, more preferably 10 nm to 30 μm, even more preferably 50 nm to 10 μm, particularly preferably 1 to 6 μm. Within the above range, uniform dispersion is facilitated, and electrical conductivity can be increased.
The average particle diameter of the thermoelectric semiconductor particles was obtained by measuring with a laser diffraction particle size analyzer (manufactured by CILAS, Model 1064) and taken as the median value of the particle size distribution.

Further, the thermoelectric semiconductor particles are preferably annealed (hereinafter sometimes referred to as "annealing treatment A"). By performing the annealing treatment A, the crystallinity of the thermoelectric semiconductor particles is improved, and the surface oxide film of the thermoelectric semiconductor particles is removed, so that the Seebeck coefficient (absolute value of the Peltier coefficient) of the thermoelectric conversion element layer is increased. and the thermoelectric figure of merit can be further improved. The annealing treatment A is not particularly limited, but before preparing the thermoelectric semiconductor composition, the gas flow rate is controlled so as not to adversely affect the thermoelectric semiconductor particles, under an inert gas atmosphere such as nitrogen and argon. , It is preferably carried out under a reducing gas atmosphere such as hydrogen or under vacuum conditions, more preferably under a mixed gas atmosphere of an inert gas and a reducing gas. Although the specific temperature conditions depend on the thermoelectric semiconductor particles used, it is generally preferred that the temperature be below the melting point of the particles and be 100 to 1500° C. for several minutes to several tens of hours.

(binder resin)
The binder resin used in the present invention acts as a binder between thermoelectric semiconductor particles, can increase the flexibility of the thermoelectric conversion module described later, and facilitates the formation of a thin film by coating or the like.

The binder resin is preferably a resin that decomposes at a firing (annealing) temperature of 90% by mass or more, more preferably a resin that decomposes at 95% by mass or more, and a resin that decomposes at 99% by mass or more. It is particularly preferred to have
In addition, a resin that maintains various physical properties such as mechanical strength and thermal conductivity without impairing when crystal growth of thermoelectric semiconductor particles is performed by baking (annealing) a coating film (thin film) made of a thermoelectric semiconductor composition. more preferred.
As the binder resin, if a resin that decomposes at a firing (annealing) temperature of 90% by mass or more, that is, a resin that decomposes at a lower temperature than conventionally used heat-resistant resins, the binder resin will decompose upon firing. The content of the binder resin, which is an insulating component contained in the fired body, is reduced, and the crystal growth of the thermoelectric semiconductor particles in the thermoelectric semiconductor composition is promoted. rate can be improved.
As one aspect, it is preferable that 90% by mass or more of the binder resin decompose at a firing (annealing) temperature of 400°C.
Whether or not the resin decomposes at a predetermined value (e.g., 90% by mass) or more at the firing (annealing) temperature is determined by thermogravimetry (TG) at the mass reduction rate (mass before decomposition) at the firing (annealing) temperature. The value obtained by dividing the mass after decomposition by ).

A thermoplastic resin or a curable resin can be used as such a binder resin. Examples of thermoplastic resins include polyolefin resins such as polyethylene, polypropylene, polyisobutylene, and polymethylpentene; polycarbonates; thermoplastic polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polystyrene, acrylonitrile-styrene copolymers, and polyacetic acid. Polyvinyl polymers such as vinyl, ethylene-vinyl acetate copolymer, vinyl chloride, polyvinylpyridine, polyvinyl alcohol and polyvinylpyrrolidone; polyurethanes; cellulose derivatives such as ethyl cellulose; Examples of curable resins include thermosetting resins and photocurable resins. Examples of thermosetting resins include epoxy resins and phenol resins. Examples of photocurable resins include photocurable acrylic resins, photocurable urethane resins, and photocurable epoxy resins. These may be used individually by 1 type, and may use 2 or more types together.
Among these, from the viewpoint of the electrical resistivity of the thermoelectric conversion element layer, thermoplastic resins are preferred, cellulose derivatives such as polycarbonate and ethyl cellulose are more preferred, and polycarbonate is particularly preferred.

The binder resin is appropriately selected according to the temperature of annealing treatment B, which will be described later, on the thermoelectric semiconductor particles. From the viewpoint of the electrical resistivity of the thermoelectric conversion element layer, it is preferable to perform the baking (annealing) treatment at a temperature higher than the final decomposition temperature of the binder resin.
As used herein, the term “final decomposition temperature” refers to the temperature at which the mass reduction rate at the firing (annealing) temperature by thermogravimetry (TG) is 100% (the mass after decomposition is 0% of the mass before decomposition). say.

The final decomposition temperature of the binder resin is generally 150-600°C, preferably 200-560°C, more preferably 220-460°C, and particularly preferably 240-360°C. If a binder resin having a final decomposition temperature within this range is used, it functions as a binder for the thermoelectric semiconductor material and facilitates the formation of a thin film during printing.

The content of the binder resin in the thermoelectric semiconductor composition is 0.1 to 40% by mass, preferably 0.5 to 20% by mass, more preferably 0.5 to 10% by mass, and particularly preferably 0.5 to 5% by mass. % by mass. When the content of the binder resin is within the above range, the electrical resistivity of the thermoelectric conversion element layer can be reduced.

(ionic liquid)
The ionic liquid used in the present invention is a molten salt formed by combining a cation and an anion, and refers to a salt that can exist as a liquid in any temperature range from -50°C to less than 400°C. In other words, an ionic liquid is an ionic compound having a melting point in the range of -50°C or higher and lower than 400°C. The melting point of the ionic liquid is preferably −25° C. or higher and 200° C. or lower, more preferably 0° C. or higher and 150° C. or lower. Ionic liquids have characteristics such as extremely low vapor pressure and non-volatility, excellent thermal and electrochemical stability, low viscosity, and high ionic conductivity. Therefore, it can effectively suppress the decrease in the electrical conductivity between the thermoelectric semiconductor particles as a conductive auxiliary agent. In addition, the ionic liquid exhibits high polarity based on the aprotic ionic structure and is excellent in compatibility with the binder resin, so that the thermoelectric conversion element layer can have uniform electrical conductivity.

Known or commercially available ionic liquids can be used. For example, nitrogen-containing cyclic cation compounds such as pyridinium, pyrimidinium, pyrazolium, pyrrolidinium, piperidinium, imidazolium and their derivatives; tetraalkylammonium-based amine-based cations and their derivatives; Phosphine-based cations and derivatives thereof; cation components such as lithium cations and derivatives thereof, Cl ⁻ , Br ⁻ , I ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , NO ₃ ⁻ , CH ₃ COO ⁻ , CF ₃ COO ⁻ , CH ₃ SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , NbF ₆ ⁻ , TaF ₆ ⁻ , F(HF) _n ⁻ , (CN) ₂ N ⁻ , C ₄ F ₉ SO ₃ ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , C ₃ F ₇ COO ⁻ , (CF ₃ SO ₂ )(CF ₃ CO)N ⁻ and other anion components. These may be used individually by 1 type, and may use 2 or more types together.

Among the above ionic liquids, the cation component of the ionic liquid is pyridinium cation and its It preferably contains at least one selected from derivatives, imidazolium cations and derivatives thereof. The anion component of the ionic liquid preferably contains a halide anion, more preferably at least one selected from Cl ⁻ , Br ⁻ and I ⁻ .

Specific examples of ionic liquids in which the cationic component contains pyridinium cations and derivatives thereof include 4-methyl-butylpyridinium chloride, 3-methyl-butylpyridinium chloride, 4-methyl-hexylpyridinium chloride, and 3-methyl-hexylpyridinium chloride. chloride, 4-methyl-octylpyridinium chloride, 3-methyl-octylpyridinium chloride, 3,4-dimethyl-butylpyridinium chloride, 3,5-dimethyl-butylpyridinium chloride, 4-methyl-butylpyridinium tetrafluoroborate, 4- methyl-butylpyridinium hexafluorophosphate, 1-butylpyridinium bromide, 1-butyl-4-methylpyridinium bromide, 1-butyl-4-methylpyridinium hexafluorophosphate, 1-butyl-4-methylpyridinium iodide and the like. be done. These may be used individually by 1 type, and may use 2 or more types together.
Among these, 1-butylpyridinium bromide, 1-butyl-4-methylpyridinium bromide, 1-butyl-4-methylpyridinium hexafluorophosphate, and 1-butyl-4-methylpyridinium iodide are preferred.

Specific examples of ionic liquids containing imidazolium cations and derivatives thereof as cationic components include [1-butyl-3-(2-hydroxyethyl)imidazolium bromide], [1-butyl-3-(2 -hydroxyethyl)imidazolium tetrafluoroborate], 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium chloride, 1-hexyl-3 -methylimidazolium chloride, 1-octyl-3-methylimidazolium chloride, 1-decyl-3-methylimidazolium chloride, 1-decyl-3-methylimidazolium bromide, 1-dodecyl-3-methylimidazolium chloride, 1-tetradecyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium tetrafluorooroborate, 1-butyl-3-methylimidazolium tetrafluorooroborate, 1-hexyl-3-methylimidazolium tetrafluoro Oroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-methyl-3-butylimidazolium methylsulfate, 1,3-dibutylimidazolium methyl Sulfate and the like can be mentioned. These may be used individually by 1 type, and may use 2 or more types together.
Among these, [1-butyl-3-(2-hydroxyethyl)imidazolium bromide] and [1-butyl-3-(2-hydroxyethyl)imidazolium tetrafluoroborate] are preferred.

The electrical conductivity of the ionic liquid is preferably 10 ⁻⁷ S/cm or higher, more preferably 10 ⁻⁶ S/cm or higher. If the electrical conductivity is within the above range, it can effectively suppress the decrease in the electrical conductivity between the thermoelectric semiconductor particles as a conductive auxiliary agent.

Further, the above ionic liquid preferably has a decomposition temperature of 300° C. or higher. If the decomposition temperature is within the above range, the effect as a conductive auxiliary agent can be maintained even when a coating film (thin film) made of the thermoelectric semiconductor composition is subjected to baking (annealing) treatment, as described later.
As used herein, the term "decomposition temperature" refers to the temperature at which the mass reduction rate at the firing (annealing) temperature by thermogravimetry (TG) is 10%.

In the above ionic liquid, the mass reduction rate at 300° C. by thermogravimetry (TG) is preferably 10% or less, more preferably 5% or less, and particularly preferably 1% or less. If the mass reduction rate is within the above range, as described later, even when a coating film (thin film) made of the thermoelectric semiconductor composition is subjected to baking (annealing) treatment, the effect as a conductive auxiliary agent can be maintained.

The content of the ionic liquid in the thermoelectric semiconductor composition is preferably 0.01-50% by mass, more preferably 0.5-30% by mass, and particularly preferably 1.0-20% by mass. If the content of the ionic liquid is within the above range, the decrease in electrical conductivity is effectively suppressed, and a film having high thermoelectric performance can be obtained.

<Inorganic ionic compound>
The thermoelectric semiconductor composition may further contain an inorganic ionic compound.
An inorganic ionic compound is a compound composed of at least a cation and an anion. Inorganic ionic compounds are solid at room temperature, have a melting point in a temperature range of 400 to 900° C., and have high ionic conductivity. Reduction in electrical conductivity between thermoelectric semiconductor particles can be suppressed.

The content of the inorganic ionic compound in the thermoelectric semiconductor composition is preferably 0.01 to 50% by mass, more preferably 0.5 to 30% by mass, particularly preferably when the thermoelectric semiconductor composition contains the inorganic ionic compound. is 1.0 to 10% by mass. If the content of the inorganic ionic compound is within the above range, the decrease in electrical conductivity can be effectively suppressed, and as a result, a film with improved thermoelectric performance can be obtained.
When the inorganic ionic compound and the ionic liquid are used together, the total content of the inorganic ionic compound and the ionic liquid in the thermoelectric semiconductor composition is preferably 0.01 to 50% by mass, more preferably is 0.5 to 30% by weight, particularly preferably 1.0 to 10% by weight.

<Other additives>
In addition to the above, if necessary, the thermoelectric semiconductor composition may further contain a dispersant, a film forming aid, a light stabilizer, an antioxidant, a tackifier, a plasticizer, a colorant, a resin stabilizer, a filler, Other additives such as pigments, conductive fillers, conductive polymers, and curing agents may be included. These may be used individually by 1 type, and may use 2 or more types together.

The thickness of the thermoelectric conversion element layer is preferably 1000 μm or less, more preferably 600 μm or less, and even more preferably 400 μm or less, from the viewpoint of thermoelectric performance, flexibility and film strength.

[Method for manufacturing thermoelectric conversion module]
A method for manufacturing a thermoelectric conversion module of the present invention includes a step of forming electrodes, a step of forming a thermoelectric conversion element layer, and a step of forming a heat sink.
The steps included in the present invention will be sequentially described below.

<Electrode formation process>
The manufacturing process of the thermoelectric conversion module includes an electrode forming process of forming electrodes on a substrate using the above-described electrode material or the like. As a method for forming the electrodes on the substrate, after providing an electrode having no pattern formed on the substrate, a known physical treatment or chemical treatment mainly based on a photolithography method, or a combination thereof is used. or the like, or a method of directly forming an electrode pattern by a screen printing method, an inkjet method, or the like.
Methods for forming electrodes without a pattern include PVD (physical vapor deposition) such as vacuum deposition, sputtering, and ion plating, or CVD (chemical vapor deposition) such as thermal CVD and atomic layer deposition (ALD). vapor phase growth method), or various coatings such as dip coating method, spin coating method, spray coating method, gravure coating method, die coating method, doctor blade method, wet process such as electrodeposition method, silver salt method , electroplating method, electroless plating method, lamination of metal foil, etc., and are appropriately selected according to the material of the electrode.

<Thermoelectric element layer forming process>
The manufacturing process of the thermoelectric conversion module includes a thermoelectric conversion element layer forming process of forming a P-type thermoelectric element layer and an N-type thermoelectric element layer. The P-type thermoelectric element layer and the N-type thermoelectric element layer used in the present invention are preferably formed from the thermoelectric semiconductor composition on one surface of the substrate. Examples of the method for applying the thermoelectric semiconductor composition onto the substrate include known methods such as screen printing, flexographic printing, gravure printing, spin coating, dip coating, die coating, spray coating, bar coating, and doctor blade. , is not particularly limited. When the coating film is formed in a pattern, screen printing, slot die coating, or the like, which allows easy pattern formation using a screen plate having a desired pattern, is preferably used.
Then, the obtained coating film is dried to form a thin film. As a drying method, a conventionally known drying method such as hot air drying, hot roll drying, infrared irradiation, or the like can be employed. The heating temperature is usually 80 to 150° C., and the heating time varies depending on the heating method, but is usually several seconds to several tens of minutes.
Moreover, when a solvent is used in the preparation of the thermoelectric semiconductor composition, the heating temperature is not particularly limited as long as it is within a temperature range where the solvent used can be dried.
After forming the thin film, it is preferable to further perform an annealing treatment (hereinafter sometimes referred to as annealing treatment B). By performing the annealing treatment B, the thermoelectric performance can be stabilized, and the thermoelectric semiconductor fine particles in the thin film can be crystal-grown, thereby further improving the thermoelectric performance. Annealing treatment B is not particularly limited, but is usually performed in an inert gas atmosphere such as nitrogen or argon with a controlled gas flow rate, in a reducing gas atmosphere, or under vacuum conditions. Although it depends on the heat resistance temperature, etc., it is performed at 100 to 500° C. for several minutes to several tens of hours.

<Heat sink forming process>
The manufacturing process of the thermoelectric conversion module includes a heat sink forming process. The heat sink forming step is a step of forming a heat sink on the thermoelectric conversion element layer.
The heat sink can be formed by a known method. For example, the heat sink may be formed directly on the surface of the thermoelectric conversion element layer or may be formed via a coating layer. Alternatively, it may be formed directly on the substrate, or via the substrate and the coating layer.
As described above, the material processed into a predetermined pattern shape by a known physical treatment or chemical treatment mainly based on the photolithography method, or by using them in combination, is applied directly to the thermoelectric conversion element layer, or You may bond together through a coating layer. Alternatively, it may be bonded directly onto the substrate, or through the substrate and the coating layer.

<Coating layer forming step>
The manufacturing process of the thermoelectric conversion module preferably includes a coating layer forming process. The coating layer forming step is a step of forming a coating layer between the thermoelectric conversion element layer and the radiator plate.

The covering layer forming step preferably includes a sealing layer forming step. The formation of the sealing layer can be performed by a known method, and for example, it may be formed directly on the surface of the thermoelectric conversion element layer or via the substrate. Alternatively, a sealing layer formed on a release sheet in advance may be attached to the thermoelectric conversion element layer, and the sealing layer may be transferred to the thermoelectric conversion element layer. Furthermore, two or more kinds of sealing layers may be laminated, or another coating layer may be interposed therebetween.

The coating layer forming step preferably includes a gas barrier layer forming step. The gas barrier layer can be formed by a known method, and for example, it may be formed directly on the surface of the thermoelectric conversion element layer or via the substrate. Alternatively, a gas barrier layer previously formed on a release sheet may be attached to the thermoelectric conversion element layer, and the gas barrier layer may be transferred to the thermoelectric conversion element layer. It may be laminated so as to face the conversion element layer. Moreover, two or more kinds of gas barrier layers may be laminated, and other coating layers may be interposed therebetween.

INDUSTRIAL APPLICABILITY According to the manufacturing method of the present invention, it is possible to manufacture a thermoelectric conversion module in which overlapping of upper and lower heat sinks is suppressed and high thermoelectric performance is maintained by a simple method.

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited by these examples.

The output evaluation, heat transfer efficiency evaluation, and upper and lower heat sink spacing evaluation of the thermoelectric conversion modules produced in Examples were performed by the following methods.
(a) Output evaluation One surface of the thermoelectric conversion module prepared in the example was held while being heated to 40 ° C. with a hot plate (manufactured by AS ONE, model name: HP-2SA), and the other surface was a water-cooled chiller. By cooling to 30 ° C. with [cooling water circulation device (manufactured by AS ONE, model name: LTCi-150HP) and thin water cooling plate (manufactured by Takagi Seisakusho)], a temperature difference of 10 ° C. is given, and the digital high tester (manufactured by Takagi Seisakusho) The output [electromotive force] (mV/° C.) from lead-out electrode portions at both ends of the thermoelectric conversion element layer of the thermoelectric conversion module was measured using a model name: 3801-50 manufactured by Hioki Electric Co., Ltd.).
(b) Heat transfer efficiency evaluation For the thermoelectric conversion module produced in the example, a hot plate and a water-cooled chiller were used in the same manner as in the output evaluation, and a P-type thermoelectric element layer and an N-type thermoelectric element layer and an N-type thermoelectric element layer At the boundary between the P-type thermoelectric element layer and the N-type thermoelectric element layer in the arrangement direction with the element layer, between the boundaries of both ends of the P-type thermoelectric element layer and between the boundaries of both ends of the N-type thermoelectric element layer A temperature difference ΔT _TE was obtained, and heat transfer efficiency [(ΔT _TE /ΔT _Module )×100(%)] was calculated and evaluated according to the following criteria.
A: Heat transfer efficiency of 40% or more B: Heat transfer efficiency of less than 40% Here, ΔT _TE is the electromotive force per pair of elements of the thermoelectric conversion module, and the Seebeck coefficient [P Type thermoelectric element (Seebeck coefficient): 205 μV/K, N-type thermoelectric element (Seebeck coefficient): −118 μV/K].
In addition, the ΔT _Module has a thermocouple (manufactured by MiSUMi-VONA, model name: TH- 8196) was installed.
(c) Evaluation of the distance between the first heat sink and the second heat sink company, model name: VHX-5000), and the first heat sink and the second heat sink straddling the boundary between the adjacent N-type thermoelectric element layers at both ends of the P-type thermoelectric element layer distance was measured. Similarly, the distance between the first heat sink and the second heat sink across the boundary between the adjacent P-type thermoelectric element layers at both ends of the N-type thermoelectric element layer was measured. Then, the ratio of the distance between the first heat sink and the second heat sink to the sum of the length in the arrangement direction of the P-type thermoelectric element layers and the length in the arrangement direction of the N-type thermoelectric element layers was obtained.
Note that when the first heat sink and the second heat sink overlap along the thickness direction of the thermoelectric conversion element layer, the distance at which the overlap occurs is the distance between the first heat sink and the second heat sink. Defined as the distance from the heat sink, the distance between the first heat sink and the second heat sink with respect to the sum of the length in the arrangement direction of the P-type thermoelectric element layer and the length in the arrangement direction of the N-type thermoelectric element layer A ratio was determined and the resulting value was given a negative sign.

(Example 1)
(Method for producing thermoelectric semiconductor particles)
P-type bismuth telluride Bi _0.4 Te ₃ Sb _1.6 (manufactured by Kojundo Chemical Laboratory, maximum particle size: 90 μm or less), which is a bismuth-tellurium thermoelectric semiconductor material, is milled in a planetary ball mill (manufactured by Fritsch Japan, Premium Line P-7) was used to produce thermoelectric semiconductor particles T1 having an average particle size of 1.2 μm. The average particle size of T1 was obtained by measuring the particle size distribution of the pulverized thermoelectric semiconductor particles using a laser diffraction particle size analyzer (Mastersizer 3000 manufactured by Malvern).
In addition, N-type bismuth telluride Bi ₂ Te ₃ (manufactured by Kojundo Chemical Laboratory Co., Ltd., maximum particle size: 90 μm or less), which is a bismuth-tellurium thermoelectric semiconductor material, was pulverized in the same manner as above to obtain a thermoelectric material having an average particle size of 1.4 μm. A semiconductor fine particle T2 was produced. The average particle size of T2 is obtained by measuring the particle size distribution of the thermoelectric semiconductor particles obtained by pulverization in the same manner as the average particle size of T1, using a laser diffraction particle size analyzer (Malvern, Mastersizer 3000). rice field.
(Preparation of thermoelectric semiconductor composition)
・Coating liquid (P)
Particles T1 of the obtained P-type bismuth-tellurium thermoelectric semiconductor material were added to 75.7% by mass, and a polyamideimide solution (manufactured by Arakawa Chemical Industries, Ltd., product name: Comporacene AI301, solvent: N-methylpyrrolidone, solid content concentration: 19 % by mass) 12.7% by mass, and ionic liquid (manufactured by Koei Chemical Industry Co., Ltd., product name: IL-P18B) 8.8% by mass, diluent (N-methylpyrrolidone: butyl cellosolve = 8% by mass: 2% by mass) 2 A coating liquid (P) comprising a thermoelectric semiconductor composition in which 8% by mass was mixed and dispersed was prepared.
・Coating liquid (N)
82.3% by mass of fine particles T2 of the obtained N-type bismuth-tellurium thermoelectric semiconductor material, a polyamideimide solution (manufactured by Arakawa Chemical Industries, Ltd., product name: Comporacene AI301, solvent: N-methylpyrrolidone, solid content concentration: 19 13.2% by mass) and 4.5% by mass of an ionic liquid (manufactured by Koei Chemical Industry Co., Ltd., product name: IL-P18B) were mixed and dispersed to prepare a coating liquid (N) consisting of a thermoelectric semiconductor composition. .

(Formation and arrangement of electrodes)
FIG. 3 is a plan view showing an example of the positional relationship between a thermoelectric conversion element layer composed of a P-type thermoelectric element layer and an N-type thermoelectric element layer and electrodes used in an embodiment of the present invention, and FIG. 2 shows a conceptual diagram related to the arrangement of the electrodes formed in FIG. 2, and (b) shows a conceptual diagram related to the arrangement of the thermoelectric conversion element layer composed of the P-type thermoelectric element layer and the N-type thermoelectric element layer formed on the electrodes.
For the electrode 3, a polyimide substrate 2a (manufactured by Ube Exsimo Co., Ltd., product name: Upicel N, polyimide substrate thickness: 50 μm, copper foil: 9 μm) to which copper foil is attached is prepared. Wet etching using a diiron solution, forming an electrode pattern so as to correspond to the arrangement of the P-type thermoelectric element layer 4 and the N-type thermoelectric element layer 5 described later, and then electroless plating on the patterned copper foil A pattern layer of the electrode 3 was formed by laminating a nickel layer (thickness: 3 μm) by laminating a nickel layer (thickness: 3 μm) and further laminating a gold layer (thickness: 40 nm) on the nickel layer by electroless plating. Each size of the electrodes 3 is 550 μm×800 μm, 3a is a connection electrode (size: 550 μm×2.4 mm) for each row of the thermoelectric conversion element layer 7, and 3b is an electromotive force extraction electrode (size: 3 mm×5 mm), and 6 indicates the boundary between the P-type thermoelectric element layer 4 and the N-type thermoelectric element layer.

(Formation and Arrangement of Thermoelectric Element Layer)
A P-type thermoelectric element layer 4 with a length of 1 mm (L _P )×0.8 mm and an N-type thermoelectric element layer 5 with a length of 1 mm (L _N )×0.8 mm are formed on the electrodes 3 on the polyimide substrate 2a. First, the coating liquid (N) prepared above is applied to the polyimide substrate 2a by screen printing using a printing plate having a plate thickness of 80 μm and an opening of 1 mm × 0.8 mm so that are alternately arranged. and dried in the atmosphere at a temperature of 125 ° C. for 10 minutes. was applied onto the polyimide substrate 2a using a , and dried in the atmosphere at a temperature of 125° C. for 10 minutes. Furthermore, each of the obtained thin films was heated at a heating rate of 5 K/min in a mixed gas atmosphere of hydrogen and argon (hydrogen: argon = 3% by volume: 97% by volume) to 310°C for 30 minutes. By holding and annealing, the thermoelectric semiconductor particles were crystal-grown, and the P-type thermoelectric element layer 4 and the N-type thermoelectric element layer 5 were produced.
The P-type thermoelectric element layer 4 and the N-type thermoelectric element layer 5 thus obtained form a pair adjacent to each other so as to be in contact with each other at a side having a length of 0.8 mm. A total of 408 pairs of P-type thermoelectric element layers 4 and N-type thermoelectric element layers 5 are formed and arranged in series electrically in the plane of the polyimide substrate 2 to form a thermoelectric conversion element layer 7. , the thermoelectric conversion element layer 7 has a folded structure. Specifically, 17 pairs of the P-type thermoelectric element layers 4 and the N-type thermoelectric element layers 5 were connected to form one line, and 24 lines were provided. Each column of the thermoelectric conversion element layer 7 is electrically connected in series by the connecting electrode 3a. The arrangement of the thermoelectric conversion element layer 7 and the electrodes 3 is conceptually shown, and the size ratio and the number of the thermoelectric conversion element layers 7 and the electrodes 3 are different from those of the thermoelectric conversion element layer 7 and the electrodes 3 actually produced.

(Arrangement of coating layer and heat sink)
A cross-sectional configuration of the fabricated thermoelectric conversion module will be described with reference to FIG.
Using a PET film (manufactured by Mitsubishi Shindoh Co., Ltd., PET film thickness: 12 μm, aluminum film thickness: 4 nm) on which an aluminum film is vapor-deposited, an adhesive layer (manufactured by Somar Co., product name: EP-0002EF-01MB, thickness: 25 μm) was laminated to form a coating layer _11B . Lamination was performed at 70°C.
On the second surface side _8B of the thermoelectric conversion element layer 7 consisting of the P-type thermoelectric element layer 4 and the N-type thermoelectric element layer 5 on the polyimide substrate 2a, the thermoelectric conversion elements are attached via the coating layer _11B . On the first surface side _8A of the layer 7, a coating consisting of a single layer of a polyimide substrate 2a and an adhesive layer having adhesiveness (manufactured by Somar, trade name: EP-0002EF-01MB, thickness: 25 μm) Through the layer _11A in this order, a first heat sink _9A and a second heat sink _9B made of a high thermal conductivity material (copper foil) are placed across the boundary 6 as shown in FIG. placed in
・First radiator plate _9A
(C1020, thermal conductivity: 398 (W/m·K), thickness: 200 μm, _LA : 0.500 mm, L _AL : 0.250 mm, _LAR : 0.250 mm, depth: 100 mm)
・Second heat sink _9B
(C1020, thermal conductivity: 398 (W/m·K), thickness: 200 μm, _LB : 0.500 mm, L _BL : 0.250 mm, L _BR : 0.250 mm, depth: 100 mm)
[ _DP : 0.500 mm, _DN : 0.500 mm, _LP : 1.000 mm, _LN : 1.000 mm, _DN : 0.500 mm, ratio DP _/ ( _LP + _LN ): 0.250 , the ratio D _N /(L _P +L _N ): 0.250]

The lamination of the covering layer _11B to the thermoelectric conversion element layer 7 and the lamination of the covering layer _11A consisting of a single adhesive layer to the substrate were carried out under vacuum at 90° C. and 0.2 MPa for 10 seconds. In addition, the lamination of the second heat sink _9B to the coating layer _11B and the lamination of the first heat sink _9A to the coating layer _11A consisting of a single adhesive layer were carried out at 90°C for 10 seconds under vacuum. gone. After that, the thermoelectric conversion module was allowed to stand at 150° C. under normal pressure for 30 minutes to cure the adhesive layer having tackiness, thereby obtaining a thermoelectric conversion module.

(Example 2)
In Example 1, the first heat sink _9A and A thermoelectric conversion module was produced in the same manner as in Example 1, except that the second heat sink _9B was changed as follows.
・First radiator plate _9A
(C1020, thermal conductivity: 398 (W/m·K), thickness: 200 µm, _LA : 0.750 mm, L _AL : 0.375 mm, _LAR : 0.375 mm, depth: 100 mm)
・Second heat sink _9B
(C1020, thermal conductivity: 398 (W/m·K), thickness: 200 μm, _LB : 0.750 mm, L _BL : 0.375 mm, L _BR : 0.375 mm, depth: 100 mm)
[ _DP : 0.250 mm, _DN : 0.250 mm, _LP : 1.000 mm, _LN : 1.000 mm, ratio DP _/ ( _LP + _LN ): 0.125, ratio DN _/ (L _P + _LN ): 0.125]

(Example 3)
In Example 1, the first heat sink _9A and A thermoelectric conversion module was produced in the same manner as in Example 1, except that the second heat sink _9B was changed as follows.
・First radiator plate _9A
(C1020, thermal conductivity: 398 (W/m·K), thickness: 200 µm, _LA : 0.750 mm, L _AL : 0.300 mm, _LAR : 0.450 mm, depth: 100 mm)
・Second heat sink _9B
(C1020, thermal conductivity: 398 (W/m·K), thickness: 200 μm, _LB : 0.750 mm, L _BL : 0.450 mm, L _BR : 0.300 mm, depth: 100 mm)
[ _DP : 0.100 mm, _DN : 0.400 mm, _LP : 1.000 mm, _LN : 1.000 mm, ratio _DP /( _LP + _LN ): 0.050, ratio DN _/ (L _P + _LN ): 0.200]

(Comparative example 1)
In Example 1, the first heat sink _9A and A thermoelectric conversion module was produced in the same manner as in Example 1, except that the second heat sink _9B was changed as follows.
・First radiator plate _9A
(C1020, thermal conductivity: 398 (W/m·K), thickness: 200 μm, _LA : 1.000 mm, L _AL : 0.420 mm, _LAR : 0.580 mm, depth: 100 mm)
・Second heat sink _9B
(C1020, thermal conductivity: 398 (W/m·K), thickness: 200 μm, _LB : 1.000 mm, L _BL : 0.580 mm, L _BR : 0.420 mm, depth: 100 mm)
[D _P : -0.080 mm, D _N : 0.080 mm, L _P : 1.000 mm, L _N : 1.000 mm, ratio D _P / (L _P + L _N ): -0.040, ratio D _N / (L _P + L _N ): 0.040]

(Comparative example 2)
In Example 1, the first heat sink _9A and A thermoelectric conversion module was produced in the same manner as in Example 1, except that the second heat sink _9B was changed as follows.
・First radiator plate _9A
(C1020, thermal conductivity: 398 (W/m·K), thickness: 200 µm, _LA : 1.100 mm, L _AL : 0.450 mm, _LAR : 0.650 mm, depth: 100 mm)
・Second heat sink _9B
(C1020, thermal conductivity: 398 (W/m·K), thickness: 200 μm, _LB : 1.100 mm, L _BL : 0.650 mm, L _BR : 0.450 mm, depth: 100 mm)
[D _P : −0.300 mm, D _N : 0.100 mm, L _P : 1.000 mm, L _N : 1.000 mm, ratio D _P /(L _P +L _N ): −0.150, ratio D _N / (L _P + L _N ): 0.050]

Table 1 shows the evaluation results of the output [electromotive force], heat transfer efficiency, and the distance between the upper and lower heat sinks of the thermoelectric conversion modules produced in Examples 1-3 and Comparative Examples 1-2.

The distance D _P between the first heat sink 9 _A and the second heat sink 9 _B , the distance D _N between the second heat sink 9 _B and the first heat sink 9 _A , the length of the P-type thermoelectric element layer The ratio D P /(L _P +L _N ), the ratio D _N / ₍ L _P +L _N ) defined using the (arrangement direction) L P and the length (arrangement direction) L _N of the N _- type thermoelectric element layer However, Examples 1 to 3, which satisfy the specific values stipulated in the present invention, are superior in electromotive force and heat transfer efficiency compared to Comparative Examples 1 and 2, which do not satisfy them, and the deterioration of thermoelectric performance is suppressed. I understand.

The configuration of the thermoelectric conversion module of the present invention is applied to an in-plane type thermoelectric conversion module because it suppresses a decrease in the temperature difference generated in the in-plane direction due to the overlapping of the upper and lower heat sinks, and can maintain high thermoelectric performance.

1A, 1B: thermoelectric conversion module 2: substrate 2a: polyimide substrate 3: electrode 3a: connection electrode 3b for each row of thermoelectric conversion element layer: electromotive force extraction electrode 4: P-type thermoelectric element layer 5: N-type thermoelectric element Layer 6: Boundary 7: Thermoelectric conversion element layer (P-type thermoelectric element layer/N-type thermoelectric element layer)
8 _A : First surface side 8 _B : Second surface side 9 _A : First heat sink 9 _B : Second heat sink 10: Arrangement direction 11 _A : First coating layer 11 _B : Second coating layer D _P : Distance between the first heat sink _9A and the second heat sink _9B (within the boundaries of both ends of the P-type thermoelectric element layer)
D _N : Distance between the second heat sink 9 _B and the first heat sink 9 _A (within the boundaries of both ends of the N-type thermoelectric element layer)
L _P : Length of P-type thermoelectric element layer (arrangement direction)
L _N : Length of N-type thermoelectric element layer (arrangement direction)
L _A : Length _of the first heat sink _9A L _AL : Length in the direction opposite to the arrangement direction 10 starting from the boundary 6 of the first heat sink 9A L _AR : First heat sink _9A Length L _B of the arrangement direction 10 starting from the boundary 6 of the second heat sink _9B : Length L _BL of the second heat sink _9B : A direction opposite to the arrangement direction 10 starting from the boundary 6 of the second heat sink 9B Length L _BR : length in the arrangement direction 10 starting from the boundary 6 of the second heat sink _9B

Claims (8)

P-type thermoelectric element layers and N-type thermoelectric element layers are arranged alternately and in contact with each other. and a thermoelectric conversion element layer present at intervals in the arrangement direction of the N-type thermoelectric element layer,
an electrode disposed on the first surface side of the thermoelectric conversion element layer so as to straddle the boundary and connecting the P-type thermoelectric element layer and the N-type thermoelectric element layer in series;
a first radiator plate installed on the first surface side of the thermoelectric conversion element layer so as to cover the boundary and the electrode;
a second radiator plate installed on the second surface side of the thermoelectric conversion element layer so as to cover the boundary;
A thermoelectric conversion module having
The first heat dissipation plate and the second heat dissipation plate have the boundary on the first surface side in the arrangement direction and the second surface with respect to the boundary spaced apart in the arrangement direction. It is installed so as to alternately cover the border on the side,
D _P is the interval in the arrangement direction between the first heat dissipation plate and the second heat dissipation plate that are adjacent to each other in the arrangement direction of the P-type thermoelectric element layers, and D _N is the interval in the arrangement direction between the adjacent second heat dissipation plate and the first heat dissipation plate, L _P is the length of the P-type thermoelectric element layer in the arrangement direction, and the N-type thermoelectric element When the length of the layer in the arrangement direction is L _N , the ratio D _P /(L _P +L _N ) is 0.005 to 0.300, and the ratio D _N /(L _P +L _N ) is 0.005 to Thermoelectric conversion module, which is 0.300. The first heat sink and the second heat sink are each independently made of at least one selected from the group consisting of a metal material, a ceramic material, a mixture of a metal material and a resin, and a mixture of a ceramic material and a resin. The thermoelectric conversion module according to claim 1, wherein 3. The thermoelectric conversion module according to claim 1, wherein the thermal conductivity of said first heat sink and said second heat sink are each independently 5 to 500 W/(m·K). The thermoelectric conversion module according to any one of claims 1 to 3, wherein thicknesses of said first heat sink and second heat sink are independently 40 to 550 µm. 5. The thermoelectric conversion module according to claim 1, further comprising a first substrate between the first surface side of said thermoelectric conversion element layer and said first heat sink. 6. The thermoelectric conversion module according to claim 5, further comprising a first coating layer between said first substrate and said first radiator plate. 7. The thermoelectric conversion element layer according to any one of claims 1 to 6, further comprising a second substrate and/or a second coating layer between the second surface side of the thermoelectric conversion element layer and the second heat sink. thermoelectric conversion module. The method of claims 1 to 7, wherein the ratio D _P /(L _P +L _N ) is 0.010 to 0.270, and the ratio D _N /(L _P +L _N ) is 0.010 to 0.270. The thermoelectric conversion module according to any one of items 1 and 2.

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