Power generation body

Abstract

To raise a power generation amount in friction power generation technology.SOLUTION: In a power generation body of the present invention, a first member in which an insulation film and an electrode layer are laminated, and a second member in which the insulation film and the electrode layer are laminated are installed by separating the insulation films of each by facing each other, and at least either of the first member or the second member comprises a conductive adhesive layer containing conductive filler between the insulation film and the electrode layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power generator, and more particularly to a power generator that generates electricity by frictional charging. [Background technology]

[0002] In recent years, energy harvesting, which involves collecting small amounts of energy present in the surrounding environment to obtain electrical power, has been attracting attention. Various methods have been studied for converting environmental energy, such as sunlight, lighting, mechanical vibrations, and heat, into electricity, and one such method is a power generator that utilizes contact electrification. One such power generator is known as the technology described in Patent Document 1. The technology that utilizes frictional electrification, such as that described in Patent Document 1, is also called frictional power generation, and generates power by arranging members with insulating films facing each other and changing the contact area due to external pressure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-191454 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology of Patent Document 1 has a problem in that the amount of power generated depends on the contact area, and the only way to improve the amount of power generated is to increase that area. Therefore, an object of the present invention is to further improve the amount of power generated in friction power generation technology. [Means for solving the problem]

[0005] In view of the above problems, the inventors of the present invention came up with the idea that the amount of power generation can be improved by improving the configuration of the components in various ways.

[0006] That is, the power generating body of the present invention is a power generating body in which a first member on which an insulating film and an electrode layer are laminated, and a second member on which an insulating film and an electrode layer are laminated are installed with the insulating films facing each other and spaced apart, and is characterized in that at least one of the first member and the second member has a conductive adhesive layer containing a conductive filler between the insulating film and the electrode layer. [Effects of the Invention]

[0007] The power generator of the present invention having the above configuration further improves the amount of power generated in a friction power generation technology in which a first member having an insulating film and an electrode layer stacked thereon and a second member having an insulating film and an electrode layer stacked thereon are installed with the insulating films facing each other and spaced apart. More specifically, the opposing insulating films come into contact with each other and become charged, and electrons and holes in the insulating film move to the electrode via a conductive adhesive layer containing a conductive filler. The conductive adhesive layer containing a conductive filler has excellent conductivity, so electrons and holes move efficiently from the insulating film to the electrode layer. Therefore, a high amount of power can be obtained. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a schematic cross-sectional view showing an example of a power generating body according to an embodiment. [Figure 2] FIG. 10 is a schematic partial cross-sectional view showing another example of a power generating body according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiment is merely exemplary in nature and is not intended to limit the present invention, its applications, or its uses. For the sake of simplicity, components having substantially the same functions will be designated by the same reference numerals.

[0010] As shown in FIG. 1, the power generating body 1 of the present invention is a power generating body in which a first member 10 having an insulating film 12 and an electrode layer 18 laminated thereon, and a second member 20 having an insulating film 22 and an electrode layer 28 laminated thereon are placed with the insulating films 12, 22 facing each other and spaced apart, and is characterized in that at least one of the first member 10 and the second member 20 has conductive adhesive layers 16, 26 containing conductive fillers 14, 24 between the insulating films 12, 22 and the electrode layers 18, 28.

[0011] The conductive filler is preferably one or more conductive fillers selected from the group consisting of silver powder, copper powder, carbon powder, silver-coated copper powder, silver-coated aluminum powder, silver-coated silica powder, and silver-coated alumina powder.

[0012] The conductive adhesive layer is preferably composed of the conductive filler and one or more adhesives selected from the group consisting of polyester resin-based, epoxy resin-based, acrylic resin-based, silicone rubber-based, phenolic resin-based, vinyl acetate-based, nitrile rubber-based, chloroprene rubber-based, styrene butadiene rubber-based, cyanoacrylate-based, and starch-based adhesives.

[0013] The conductive adhesive layer preferably contains 10 to 97% by weight of the conductive filler, with the remainder being adhesive.

[0014] The conductive adhesive layer is preferably provided between the insulating film and the electrode layer of the first member and between the insulating film and the electrode layer of the second member.

[0015] (Embodiment 1) Each component will be described in detail below with reference to the drawings as appropriate.

[0016] (power generating body) The power generating unit 1 includes a first member 10 and a second member 20. The first member 10 includes an insulating film 12, and the second member 20 includes an insulating film 22. The insulating films 12 and 22 are disposed facing each other with a space between them. That is, the insulating film 12 is exposed on one surface of the first member 10, and the insulating film 22 is exposed on one surface of the second member 20. When pressure is applied to the power generating unit 1 from the outside, the insulating films 12 and 22 approach and contact each other, causing friction and charging the insulating films 12 and 22. The first member 10 includes an electrode layer 18, and the second member 20 includes an electrode layer 28. When the insulating films 12 and 22 approach and contact each other, friction occurs, and charged energy flows to the electrode layers 18 and 28. At this time, the electrode layers 18 and 28 function as an anode and a cathode, respectively, and electrical energy can be extracted by connecting conductors.

[0017] The power generating body 1 only needs to include a first member 10 and a second member 20, and may also include a protective layer that protects the first member 10 and the second member 20, and wiring that electrically connects the first member 10 and the second member 20 via a load (electronic device, battery, etc.).

[0018] (electrode layer) The electrode layer is a layer laminated on the insulating film. The electrode layer acts as a conductor and transmits generated power. For example, metal foil, metal plate, metal wire, conductive material, conductive paste, metal-plated material, etc. can be suitably used as the electrode layer. In the case of metal foil, silver, copper, aluminum, gold, etc. can be suitably used. The electrode layer is not particularly limited, but it is preferable to use a metal from the viewpoint of conductivity. Furthermore, the thickness of the electrode layer is not particularly limited, but it is preferably 1 to 100 μm because flexibility is necessary from the viewpoint of performance.

[0019] (Conductive adhesive layer) The conductive adhesive layer is a layer having adhesiveness and conductivity. More specifically, the conductive adhesive layer contains a conductive filler in the adhesive. Therefore, the conductive adhesive layer can bond the electrode layer and the insulating film and obtain electrical conduction.

[0020] The type of conductive filler is not particularly limited, but it is preferable to use one or more conductive fillers selected from the group consisting of silver powder, copper powder, carbon powder, silver-coated copper powder, silver-coated aluminum powder, silver-coated silica powder, and silver-coated alumina powder. Among these, silver or silver-coated copper powder is particularly preferred because it exhibits good conductivity. The shape and size of the conductive filler are also not particularly limited, and any shape, such as spherical or scaly, can be used. However, spherical shapes are preferred because they allow for the formation of a uniform conductive adhesive layer. Furthermore, conductive fillers with a D50 of 0.1 μm to 10 μm are suitable. The method for measuring the size of the conductive filler is not particularly limited, but it can be measured using laser diffraction. Specifically, the volume-based average diameter D50 can be measured using a Microtrack MT3300-Ex2. Furthermore, a volume-based average diameter D50 in the range of 0.1 μm to 10 μm allows for efficient transfer of electrons and holes, particularly from the insulating film to the electrode. This allows for high power generation. The content of the conductive filler in the conductive adhesive layer is not limited either, but it is preferable that the conductive adhesive layer contains 10% by weight or more and 97% by weight or less of the conductive filler, with the remainder being adhesive. If the conductive filler content is 10% by weight or less, it may be difficult to achieve high conductivity, and the difference from conventional power generators may be small. If the conductive filler content exceeds 97% by weight, the adhesive component is too small, reducing the adhesive performance between the electrode layer and the insulating film, and there is a risk that the electrode layer and the insulating film may peel off when the power generator of the present invention is used for a long period of time. A range of 40% by weight or more and 97% by weight or less is more preferable.

[0021] As described above, the conductive adhesive layer contains an adhesive in addition to the conductive filler. The type of adhesive is not limited, and adhesives such as polyester resin-based, epoxy resin-based, acrylic resin-based, silicone rubber-based, phenol resin-based, vinyl acetate-based, nitrile rubber-based, chloroprene rubber-based, styrene butadiene rubber-based, cyanoacrylate-based, and starch-based adhesives can be used. Polyester-based adhesives are particularly preferred from the viewpoint of adhesion between the electrode layer and the insulating film.

[0022] The thickness of the conductive adhesive layer is not particularly limited, and is preferably in the range of 0.1 μm to 30 μm because it provides good conductivity. In addition to the conductive filler and adhesive, the conductive adhesive layer may contain optional additives such as dispersants, colorants, antifoaming agents, adhesion (curing) accelerators, plasticizers, etc., in an amount of 10% or less.

[0023] (insulating film) The first member 10 has an insulating film 12 laminated on an electrode layer 18, and the second member 20 has an insulating film 22 laminated on an electrode layer 28. The insulating film 12 is configured to be charged with the opposite polarity to the insulating film 22 when it comes into contact with the insulating film 22. Therefore, the insulating films 12 and 22 are preferably made of materials that are easily charged with opposite polarities. For example, when the insulating film 12 is positively charged when it comes into contact with the insulating film 22, the insulating film 22 is negatively charged when it comes into contact with the insulating film 12. The material constituting the insulating film 12 and the insulating film 22 is selected from the group consisting of, for example, polymethyl methacrylate, nylon, polyvinyl alcohol, polyester, polyisobutylene, polyurethane, polyethylene terephthalate, polyvinyl butyral, polychloroprene, natural rubber, polyacrylonitrile, polydiphenol carbonate, chlorinated polyether, polyvinylidene chloride, polystyrene, polyethylene, polypropylene, polyimide, polyvinyl chloride, polydimethylsiloxane, polytetrafluoroethylene, vinylidene fluoride, trifluorochloroethylene, tetrafluoroethylene and ethylene copolymer, tetrafluoroethylene and hexafluoropropylene copolymer, tetrafluoroethylene and perfluoroalkoxyethylene copolymer, and trifluorochloroethylene and ethylene copolymer.

[0024] It is preferable that the materials constituting the insulating film 12 and the insulating film 22 are different from each other, and it is particularly preferable that they are located at positions apart from each other in the triboelectric series.It is also preferable that one or both of the insulating films 12 and 22 have a thickness of 1 μm or more and 20 μm or less.

[0025] At least one of the insulating films 12 and 22 may have projections and recesses on the opposing surfaces. The ten-point mean roughness of such projections and recesses is preferably 100 μm or more and 2 mm or less. The ten-point mean roughness of the projections and recesses is measured in accordance with JIS B 0601:2001.

[0026] As a method for providing the insulating film 12 and the insulating film 22 with unevenness, for example, a method of forming the first member 10 or the second member 20 so that the entire member is uneven can be mentioned. For example, as shown in FIG. 2, a method of forming the first member 10 or the second member 20 so that the cross section thereof has a structure in which peaks and valleys are continuous can be mentioned. This results in the insulating film 12 and the insulating film 22 having an uneven structure. As a method for providing such unevenness, for example, a method of using a metal foil with an uneven shape having a ten-point average roughness of 100 μm or more and 2 mm or less as an electrode layer, coating this with a conductive adhesive layer, and further forming an insulating film on the surface of the conductive adhesive layer can be mentioned.

[0027] Another method for providing the insulating film 12 and the insulating film 22 with irregularities is to prepare a flat first member 10 or a flat second member 20 and emboss the flat first member 10 or the flat second member 20 to form an irregular shape. This results in the insulating film 12 and the insulating film 22 having an irregular shape. A specific embossing process involves, for example, preparing an embossing roll with an irregular shape having a ten-point mean roughness of 100 μm or more and 2 mm or less, and passing the first member 10 or the second member 20 through the embossing roll, thereby forming the insulating film 12 of the first member 10 and the insulating film 22 of the second member 20 into an irregular shape having a ten-point mean roughness of 100 μm or more and 2 mm or less. By providing irregularities in the insulating film 12 and the insulating film 22 in this manner, the specific surface area is increased, and higher electrical energy can be obtained.

[0028] (Flexible layer) As shown in FIG. 2, the first member 10 and the second member 20 may have flexible layers (32, 34) on the surfaces opposite to the surfaces on which the insulating films (12, 22) are provided. The flexible layers (32, 34) are arranged so as to contact the adjacent electrode layers (18, 28). More specifically, the flexible layers (32, 34) provided on the outer sides of the first member 10 and the second member 20 are arranged so as to contact the outer surfaces of the insulating films (18, 28). The flexible layers (32, 34) are flexible, i.e., have a lower modulus of elasticity than the insulating films (12, 22). The material constituting the flexible layers (32, 34) is preferably an elastomer. In other words, the material constituting the flexible layers preferably has rubber elasticity. Furthermore, the flexible layers (32, 34) are preferably conductive. It is particularly preferable that the flexible layers (32, 34) are made of, for example, a conductive elastomer. The flexible layers (32, 34) may be made of an insulating elastomer whose surface is coated with a conductive film. Examples of insulating elastomers include nitrile rubber and silicone rubber. Examples of materials that make up the conductive film that coats the surface of the insulating elastomer include silver and copper. [Example]

[0029] Example 1 Two 18 μm-thick copper foils (electrolytic copper foils manufactured by Fukuda Metal Foil & Powder Co., Ltd.) were prepared as the electrode layers for the first and second members. Nylon (25 μm-thick, manufactured by Kohjin Film & Chemicals Co., Ltd.) was prepared as the insulating film for the first member, and polyimide (40 μm-thick, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was prepared as the insulating film for the second member. Furthermore, for the conductive adhesive layers of each of the first and second members, silver-coated copper powder (volume-based mean diameter D50 = 3.6 μm, manufactured by Toyo Aluminum Co., Ltd.) was prepared as a conductive filler by mixing it with adhesive TM-K55 (a polyester-based adhesive manufactured by Toyo Morton Co., Ltd.) and CAT-10L (a polyisocyanate-based curing agent manufactured by Toyo Morton Co., Ltd.) to a thickness of 40 μm. This was then laminated to a thickness of 20 μm on each copper foil using a bar coater. The silver-coated copper powder was copper powder with a volume-based mean diameter D50 = 3.6 μm coated with silver by plating. Next, before the conductive adhesive layer hardened, the above-mentioned nylon was attached to the conductive adhesive layer laminated surface of one copper foil, and the above-mentioned polyimide was attached to the conductive adhesive layer laminated surface of the other copper foil, to obtain power generation samples with the configurations of "copper electrode / silver-coated copper powder-containing conductive adhesive layer / nylon" and "polyimide / silver-coated copper powder-containing conductive adhesive layer / copper electrode."

[0030] Example 2 The electrode layers of the first and second members were 30 μm-thick sheets (DIC Corporation, conductive tape, 8520FDW-30) (abbreviated as "silver electrodes") with a silver-coated nonwoven fabric layer. The conductive filler was a mixture of commercially available silver powder (average particle size 5.0 μm) with adhesive TM-K55 (a polyester-based adhesive manufactured by Toyo-Morton) and CAT-10L (a polyisocyanate-based curing agent manufactured by Toyo-Morton) at a content of 60 wt%. The same procedures as in Example 1 were repeated, except that the electrode layers were laminated to a thickness of 20 μm using a bar coater. As a result, generator samples with the configurations "silver electrode / silver powder-containing conductive adhesive layer / nylon" and "polyimide / silver powder-containing conductive adhesive layer / silver electrode" were obtained.

[0031] Example 3 Except for changing the insulating film of the second member from polyimide to a 40 μm-thick fluororesin film, generator samples were prepared in the same manner as in Example 2. As a result, generator samples with the configurations of "silver electrode / silver powder-containing conductive adhesive layer / nylon" and "fluororesin / silver powder-containing conductive adhesive layer / silver electrode" were obtained.

[0032] Example 4 A sample of a power generating body was obtained in the same manner as in Example 1, except that the content of the conductive filler was set to 97 wt %. Example 5 A sample of a power generating body was obtained in the same manner as in Example 1, except that the content of the conductive filler was set to 10 wt %. Example 6 A power generating unit sample was obtained in the same manner as in Example 1, except that the conductive filler used was silver-coated copper powder (manufactured by Toyo Aluminum KK) made by silver-plating copper powder having a volume-based average diameter D50 of 10 μm. Example 7 A sample of a power generating body was obtained in the same manner as in Example 1, except that the conductive filler used was silver-coated copper powder (manufactured by Toyo Aluminum KK) made by silver-plating copper powder having a volume-based average diameter D50 of 0.1 μm. Example 8 A power generating unit sample was obtained in the same manner as in Example 1, except that the conductive filler used was silver-coated copper powder (manufactured by Toyo Aluminum KK) made by silver-plating copper powder having a volume-based average diameter D50 of 12 μm. Example 9 A power generating unit sample was obtained in the same manner as in Example 1, except that the conductive filler used was silver-coated copper powder (manufactured by Toyo Aluminum KK) made by silver-plating copper powder having a volume-based average diameter D50 of 0.05 μm. (Comparative Example 1)

[0033] Except for the absence of conductive filler in the adhesive layer, power generator samples were prepared in the same manner as in Example 1. As a result, power generator samples with the configurations of "copper electrode / adhesive layer / nylon" and "polyimide / adhesive layer / copper electrode" were obtained. (Comparative Example 2)

[0034] Except for the absence of conductive filler in the adhesive layer, power generator samples were prepared in the same manner as in Example 2. As a result, power generator samples with the configurations of "silver electrode / adhesive layer / nylon" and "polyimide / adhesive layer / silver electrode" were obtained.

[0035] (Test example) Each generator sample was cut to a size of 70mm x 70mm, and a clipped conductive wire was clamped to each electrode (copper foil, silver foil). This was then connected to an oscilloscope (Tektronix TBS1102C) to measure the voltage. The power generation method involved a person weighing 60kg walking on a generator sample placed on the floor, applying pressure to the generator, and the peak voltage at this time was recorded. The results are shown in Table 1.

[0036] [Table 1]

[0037] As shown by the above results, the samples of the power generator having a conductive adhesive layer containing a conductive filler between the electrode layer and the insulating layer all produced higher voltages than the samples of the power generator having an adhesive layer not containing a conductive filler between the electrode layer and the insulating layer. Therefore, it can be said that the power generator of the present invention can produce higher amounts of power than the prior art. (Other embodiments)

[0038] The above-described embodiments are merely examples of the present invention, and the present invention is not limited to these examples. These examples may be combined with or partially replaced by well-known, commonly used, or publicly known techniques. Modified inventions that would be easily conceived by a person skilled in the art are also included in the present invention. [Explanation of symbols]

[0039] 1, 2 Power generating body 10 First member 20 Second member 12, 22 insulating film 18, 28 electrode layer 14, 24 Conductive filler 16, 26 Conductive adhesive layer 32, 34 Flexible layers

Claims

1. A power generating body including a first member on which an insulating film and an electrode layer are laminated, and a second member on which an insulating film and an electrode layer are laminated, the first member and the second member being disposed apart from each other with their insulating films facing each other, A power generating body, characterized in that at least one of the first member and the second member has a conductive adhesive layer containing a conductive filler between the insulating film and the electrode layer.

2. 2. The power generating body according to claim 1, wherein the conductive filler is one or more conductive fillers selected from the group consisting of silver powder, copper powder, carbon powder, silver-coated copper powder, silver-coated aluminum powder, silver-coated silica powder, and silver-coated alumina powder.

3. 2. The power generator according to claim 1, wherein the conductive adhesive layer is composed of the conductive filler and one or more adhesives selected from the group consisting of polyester resin-based, epoxy resin-based, acrylic resin-based, silicone rubber-based, phenolic resin-based, vinyl acetate-based, nitrile rubber-based, chloroprene rubber-based, styrene butadiene rubber-based, cyanoacrylate-based, and starch-based adhesives.

4. 2. The power generating unit according to claim 1, wherein the conductive adhesive layer contains 10% by weight or more and 97% by weight or less of the conductive filler, the remainder being an adhesive.

5. The power generating unit according to claim 1 , wherein the conductive adhesive layer is provided both between the insulating film and the electrode layer of the first member and between the insulating film and the electrode layer of the second member.

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