JP7204459B2 - generator - Google Patents

Description

TECHNICAL FIELD The present invention relates to a power generating device provided with friction bodies made of polyimide resin having excellent dielectric constant.

Recently, a technique for harvesting energy has been in the spotlight. An energy harvesting element can be said to be a new environment-friendly energy generation element that can extract mechanical energy generated by wind, vibration, or human movement in the surrounding environment by converting it into electrical energy.

A triboelectric generator is an energy harvesting device that utilizes the charge transfer phenomenon exhibited when two charged bodies are rubbed to generate electrical energy. The triboelectric generator has high energy conversion efficiency and can obtain high output even with a small external force. In addition, the triboelectric generator is an energy harvesting element that uses a piezoelectric material that generates electrical energy by deformation of a material without time and space restrictions compared to an energy harvesting element that uses heat or the sun. can generate electrical energy continuously.
For example, Patent Literature 1 describes a triboelectric generator that includes two charged bodies and a second charged body that is negatively charged by contact with the first charged body.
However, the triboelectric generator described in Cited Document 1 has room for improvement in the dielectric properties and durability of the charged body that contribute to power generation.

On the other hand, polyimide resin is a material having excellent mechanical strength, chemical stability, and heat resistance properties, and porous polyimide films having these properties are attracting attention.

Japanese Patent Application Laid-Open No. 2017-205005

SUMMARY OF THE INVENTION It is an object of the present invention to provide a power generating apparatus having a novel configuration including a friction body made of a polyimide resin having an excellent dielectric constant.

The present inventors have unexpectedly found that the dielectric constant can be improved by ring-opening a portion of the imide bonds of the polyimide resin, and that the dielectric properties of the friction body that contributes to power generation can be improved. The present invention has been completed. That is, the present invention is as follows.

A first aspect of the present invention is a power generator that converts the external force into electric energy by electrifying the friction bodies due to friction between the friction bodies caused by the external force,
The power generator includes a first electrode, a second electrode, a first friction body, and a second friction body,
The first friction body has a first friction surface,
The second friction body has a second friction surface,
The first friction body and the second friction body are provided so that the first friction surface and the second friction surface face each other,
The first electrode is provided in contact with a surface opposite to the first friction surface of the first friction body,
The second electrode is provided apart from the second friction body so as to face a surface opposite to the second friction surface of the second friction body,
The first friction surface and the second friction surface are spaced apart when no external force acts on them, and are capable of coming into contact with each other and rubbing against each other under the action of an external force,
In the power generating device, the first friction body or the second friction body is made of a polyimide resin in which a part of the imide bond is ring-opened.

A second aspect of the present invention is a friction element for a frictional power generator containing a polyimide resin in which a portion of the imide bond is ring-opened.
A third aspect of the present invention is a wearable device or Internet of Things (IoT) device including the power generator according to the first aspect.

The power generating device of the present invention has a novel structure including a friction body made of polyimide resin having an excellent dielectric constant.
The power generation device of the present invention is expected to be excellent in power generation and durability due to the above configuration, and is expected to be applied as IoT devices such as wearable devices such as clothes and accessories, and sensors such as home appliances.

1 is a cross-sectional view of one exemplary embodiment of a power plant according to the first aspect; FIG. FIG. 2 is a view for explaining a first cycle operation mechanism of the power generator shown in FIG. 1; FIG. FIG. 2 is a view for explaining a first cycle operation mechanism of the power generator shown in FIG. 1; FIG. FIG. 2 is a view for explaining a first cycle operation mechanism of the power generator shown in FIG. 1; FIG. FIG. 2 is a view for explaining a first cycle operation mechanism of the power generator shown in FIG. 1; FIG. FIG. 2 is a view for explaining a first cycle operation mechanism of the power generator shown in FIG. 1; FIG. FIG. 2 is a view for explaining a first cycle operation mechanism of the power generator shown in FIG. 1; FIG. FIG. 2 is a view for explaining a first cycle operation mechanism of the power generator shown in FIG. 1; FIG. FIG. 2 is a view for explaining a first cycle operation mechanism of the power generator shown in FIG. 1; FIG. FIG. 2 is a view for explaining a second cycle operation mechanism of the power generator shown in FIG. 1; FIG. FIG. 2 is a view for explaining a second cycle operation mechanism of the power generator shown in FIG. 1; FIG. FIG. 2 is a view for explaining a second cycle operation mechanism of the power generator shown in FIG. 1; FIG. FIG. 2 is a view for explaining a second cycle operation mechanism of the power generator shown in FIG. 1; FIG. FIG. 2 is a view for explaining a second cycle operation mechanism of the power generator shown in FIG. 1; FIG. FIG. 2 is a view for explaining a second cycle operation mechanism of the power generator shown in FIG. 1; FIG. FIG. 2 is a view for explaining a second cycle operation mechanism of the power generator shown in FIG. 1; FIG. FIG. 2 is a view for explaining a second cycle operation mechanism of the power generator shown in FIG. 1; FIG. Fig. 3 is a cross-sectional view of another exemplary embodiment of a power plant according to the first aspect; FIG. 4 is a cross-sectional view of yet another exemplary embodiment of a power plant according to the first aspect; FIG. 4 is a cross-sectional view of yet another exemplary embodiment of a power plant according to the first aspect; FIG. 4 is a cross-sectional view of yet another exemplary embodiment of a power plant according to the first aspect; FIG. 4 is a cross-sectional view of yet another exemplary embodiment of a power plant according to the first aspect; It is a figure which shows a dielectric-property measurement result.

Embodiments of the present invention will be described in detail below, but the present invention is by no means limited to the following embodiments, and can be carried out with appropriate modifications within the scope of the object of the present invention. .
In this specification, the description of "P and / or Q" such as "polyimide and / or polyamideimide", also, such as "carboxy group, salt type carboxy group and / or -NH- bond" The description of "P, Q and/or R" means "at least one selected from the group consisting of P and Q" and "at least one selected from the group consisting of P, Q and R", respectively. and other descriptions using "and/or" also apply accordingly. Here P, Q and R are arbitrary terms.
In addition, in this specification, unless otherwise specified, "-" represents from the above to the following.

Hereinafter, with reference to the attached drawings, a specific configuration of the power generator according to the first aspect will be described in detail. In the drawings, the same reference numerals refer to the same components, and the size and thickness of each component are exaggerated for clarity of explanation. Further, when a given material layer exists on a substrate or other layer, the material layer may exist in direct contact with the substrate or other layer, and another third layer may be present in between. may exist. In the following embodiments, the materials forming each layer are exemplary, and other materials may be used.

≪Generating device≫
1 is a cross-sectional view of one exemplary embodiment of a power plant according to the first aspect; FIG.
A power generator according to a first aspect is a power generator 100 that converts the external force into electric energy by electrifying the friction bodies due to friction between the friction bodies generated by the external force. Based on electrostatic induction, the external force can be converted into electrical energy to generate a current between the first electrode 112 and the second electrode 122 .
In the first aspect, the power generator 100 includes a first electrode 112, a second electrode 122, a first friction body 131, and a second friction body 132,
The first friction body 131 has a first friction surface,
The second friction body 132 has a second friction surface,
The first friction body 131 and the second friction body 132 are provided so that the first friction surface and the second friction surface face each other,
The first electrode 112 is provided in contact with the surface of the first friction body 131 opposite to the first friction surface,
The second electrode 122 is provided apart from the second friction body 132 so as to face the surface of the second friction body 132 opposite to the second friction surface,
The first friction surface and the second friction surface are spaced apart when no external force acts on them, and are capable of coming into contact with each other and rubbing against each other under the action of an external force,
The first friction body 131 or the second friction body 132 is made of polyimide resin in which a part of the imide bond is ring-opened.
The polyimide resin, in which a portion of the imide bond is ring-opened, has an unexpectedly high dielectric constant. can improve the current generated between

The first electrode 112 and the second electrode 122 include materials with excellent electrical conductivity. For example, the first electrode 112 and the second electrode 122 may include at least one material selected from the group consisting of graphene, carbon nanotubes (CNT), ITO (indium tin oxide), metals, and conductive polymers. Here, the metal may include at least one selected from the group consisting of Ag, Al, Cu, Au, Ni, Cr and Pt, but is not limited thereto. The first electrode 112 and the second electrode 122 may have a single layer structure or a multi-layer structure.

The power generator according to the first aspect may or may not further include the first substrate 110 and the second substrate 120. When the power generator further includes the first substrate 110 and the second substrate 120, the first Preferably, a first electrode 112 is provided on the bottom surface of the substrate 110 and a second electrode 122 is provided on the top surface of the second substrate 120 .
For example, the first substrate 110 can also be an upper substrate, and the second substrate 120 can also be a lower substrate. The first substrate 110 and the second substrate 120 may have flat structures, but are not limited thereto.

The first substrate 110 and the second substrate 120 may include hard materials such as silicon wafers or glass. However, the materials are not necessarily limited to them, and the first substrate 110 and the second substrate 120 may include various materials. For example, the first substrate 110 and the second substrate 120 may include flexible materials such as polyester (PE), polyester sulfone (PES), polyethylene naphthalate (PEN), or Kapton.

At least one first elastic support portion 141 is typically provided between the first substrate 110 and the second friction body 132 . At least one second elastic support 142 may be provided between the second friction body 132 and the second substrate 120 . Here, the first elastic support part 141 and the second elastic support part 142 may include, for example, a first spring and a second spring, respectively. However, it is not limited thereto, and the first elastic support part 141 and the second elastic support part 142 may include various other elastic members. In FIG. 1, four first springs are provided at the corners between the first substrate 110 and the second friction body 132, and four second springs are provided at the second friction body 132 and the second friction body. A case where it is provided at a corner portion between two substrates 120 is illustrated as an example.

The first elastic support part 141 may have an elastic modulus smaller than that of the second elastic support part 142 . For example, when the first elastic support part 141 and the second elastic support part 142 are respectively composed of a first spring and a second spring, the first spring may have a smaller spring constant than the second spring. Accordingly, when the first substrate 110 is pushed, the distance between the first substrate 110 and the second friction body 132 is first narrowed, and then the distance between the second friction body 132 and the second substrate 120 is narrowed. Next, the first friction body 131 and the second friction body 132 first come into contact, and then the second friction body 132 comes into contact with the conductive member 151 and the second electrode 122 of the grounding unit 150 in sequence.

<Polyimide resin in which a part of the imide bond is ring-opened>
In the power generator 100 according to the first aspect, as described above, the first friction body 131 or the second friction body 132 is made of polyimide resin in which a part of the imide bond is ring-opened.
The present invention also relates to a friction element for a friction power generator containing a polyimide resin in which a part of the imide bond is ring-opened. Contains cyclic polyimide resin.
A polyimide resin in which a portion of the imide bond is ring-opened has an unexpectedly high dielectric constant, and can contribute to power generation when used as a friction body.

Examples of the "polyimide resin in which a part of the imide bond is ring-opened" include, for example, a polyimide resin having a ring-opening degree of 1% or more of the imide bond, and from the viewpoint of dielectric constant, the degree of ring-opening is 3% or more. is preferable, and a polyimide resin having a degree of ring opening of 5% or more is more preferable.
The upper limit of the ring-opening degree is not particularly limited as long as it does not impair the effects of the present invention. more preferred.

In the present specification and claims, the "degree of ring-opening of imide bonds" means the imidization rate (X1) of the following "polyimide resin in which a part of the imide bonds are ring-opened". It is defined as a value (%) obtained by subtracting the value normalized by the imidization rate (X2) of the polyimide resin that is not cyclized from 100 (%).

First, in a polyimide resin, the area of a peak representing an imide bond measured by a Fourier transform infrared spectroscopy (FT-IR) device is divided by the area of a peak representing benzene similarly measured by an FT-IR device. defined as the conversion rate. A relatively large imidization rate indicates a large number of imide bonds, that is, a small number of ring-opened imide bonds.
Specifically, for the "polyimide resin in which a part of the imide bond is ring-opened" (for example, the "polyimide resin porous molded body" described later after performing the "imide bond ring-opening step" described later), The value obtained by dividing the area of the peak representing the imide bond measured by the FT-IR device by the area of the peak representing the benzene similarly measured by the FT-IR device is defined as "a part of the imide bond is ring-opened. It is defined as the imidization rate (X1) of the "polyimide resin".
In addition, a "polyimide resin in which the imide bond is not ring-opened" (for example, the later-described "polyimide resin porous molding obtained using the same polymer (varnish) as the porous molded body for which the above value (X1) was obtained A "polyimide resin porous molded body" that does not undergo the imide bond ring-opening step described later (however, if the varnish for making the porous molded body contains polyamic acid, in the baking step, substantially ), the area of the peak representing the imide bond measured by the FT-IR device was divided by the area of the peak representing the benzene measured by the FT-IR device. The value represented by the value is defined as the imidization ratio (X2) of the "polyimide resin in which the imide bond is not ring-opened".
The imidization rate (X1) of the "polyimide resin in which a portion of the imide bond is ring-opened" is preferably 1.2 or more, more preferably 1.2 to 2, and even more preferably 1.3 to 1.6. , 1.30 to 1.55 are even more preferred, and 1.35 to less than 1.5 are particularly preferred.
In addition, it is preferable to use a "polyimide resin in which the imide bond is not ring-opened" with an imidization rate (X2) of 1.5 or more.

In the power generator according to the first aspect, from the viewpoint of power generation performance, at least one of the first friction surface and the second friction surface is a rough surface, or the first friction body 131 and the second friction body 132 are roughened. At least one of them is preferably porous, and from the viewpoint of durability against friction and power generation performance, at least one of the first friction body 131 and the second friction body 132 is porous, and the porosity is the imide It is more preferable to consist of a "polyimide resin in which a part of the bond is ring-opened".
Examples of the rough surface of at least one of the first friction surface and the second friction surface include a rough surface on which a plurality of protrusions are formed. Here, the protrusions may have, for example, a wire shape or a pyramid shape, but are not limited thereto. Thus, by increasing the contact area by roughening the surface, electric energy can be obtained more efficiently.
The method of roughening at least one of the first friction surface and the second friction surface is not particularly limited, but arbitrary embossing, arbitrary pattern formation (for example, dot shape, trench shape, etc.), etc. mentioned.

In the power generator according to the first aspect, it is preferable that the static friction force between the first friction surface and the second friction surface is 16.0 gf or more.
Moreover, in the power generator according to the first aspect, it is preferable that the dynamic friction force between the first friction surface and the second friction surface is 8.0 gf or more.

The polyimide resin in the first aspect includes resins containing polyimide and/or polyamideimide, and may be a resin substantially composed only of polyimide and/or polyamideimide, specifically, 95% by mass or more. , preferably 98% by mass or more, more preferably 99% by mass or more, of polyimide and/or polyamideimide. As the resin to be contained, a resin containing polyimide is preferable, and only polyimide may be used.

(polyimide)
Known polyimides can be used without being limited by their structure and molecular weight. The polyimide may have a condensable functional group such as a carboxyl group in its side chain or a functional group that promotes a cross-linking reaction or the like during baking.

In order to obtain a polyimide that is soluble in organic solvents, a monomer that introduces a flexible bending structure into the main chain may be used. -aliphatic diamines such as diaminocyclohexane, 4,4'-diaminodicyclohexylmethane; 2-methyl-1,4-phenylenediamine, o-tolidine, m-tolidine, 3,3'-dimethoxybenzidine, 4,4'- aromatic diamines such as diaminobenzanilide; polyoxyalkylenediamines such as polyoxyethylenediamine, polyoxypropylenediamine and polyoxybutylenediamine; polysiloxane diamines; 2,3,3′,4′-oxydiphthalic anhydride, 3, Use of 4,3',4'-oxydiphthalic anhydride, 2,2-bis(4-hydroxyphenyl)propanedibenzoate-3,3',4,4'-tetracarboxylic dianhydride, etc. is effective. be. Monomers having functional groups that improve solubility in organic solvents may also be used, such as 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl, 2-trifluoromethyl It is also effective to use fluorinated diamines such as -1,4-phenylenediamine. Furthermore, in addition to the above-mentioned monomers for improving the solubility of the polyimide, the same monomers as described later in the description of the polyamic acid can be used in combination within a range that does not impede the solubility.

The method for producing polyimide is not particularly limited, and known methods such as chemical imidization or thermal imidization of polyamic acid and dissolution in an organic solvent can be used. Examples of such polyimides include aliphatic polyimides (all-aliphatic polyimides), aromatic polyimides, and the like, with aromatic polyimides being preferred. The aromatic polyimide is obtained by thermally or chemically ring-closing polyamic acid having repeating units represented by formula (1), or polyimide having repeating units represented by formula (2) dissolved in a solvent. good. Ar in the formula represents an aryl group.

(polyamide imide)
Known polyamideimides can be used without being limited by their structure and molecular weight. The polyamideimide may have a functional group capable of condensing such as a carboxyl group or a functional group that promotes a cross-linking reaction or the like during baking in the side chain.

In addition, polyamideimide that can be used includes polyamideimide obtained by reacting any trimellitic anhydride and diisocyanate, and imidizing a precursor polymer obtained by reacting any reactive derivative of trimellitic anhydride and diamine. can be used without particular limitation.

Examples of the arbitrary trimetic anhydride or reactive derivative thereof include trimellitic anhydride, trimellitic anhydride halides such as trimellitic anhydride chloride, and trimellitic anhydride esters.

Examples of the arbitrary diisocyanate include metaphenylene diisocyanate, p-phenylene diisocyanate, o-tolidine diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, 4,4′-oxybis(phenylisocyanate), 4,4′-diisocyanate. Diphenylmethane, bis[4-(4-isocyanatophenoxy)phenyl]sulfone, 2,2'-bis[4-(4-isocyanatophenoxy)phenyl]propane, 2,4-tolylenediisocyanate, 2,6-tolylenediisocyanate , 4,4′-diphenylmethane diisocyanate, 3,3′-dimethyldiphenyl-4,4′-diisocyanate, 3,3′-diethyldiphenyl-4,4′-diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 4,4′ -dicyclohexylmethane diisocyanate, m-xylene diisocyanate, p-xylylene diisocyanate, naphthalene diisocyanate and the like.

Examples of the above optional diamines include those similar to those exemplified in the description of the polyamic acid described below.

(Partial ring opening of imide bond)
In the first aspect, at least one selected from the group consisting of a carboxy group, a salt-type carboxy group and a -NH- bond is selected from the group consisting of a polyimide and/or polyamideimide due to ring-opening of a portion of the imide bond. It preferably has a carboxy group and/or a salt-type carboxy group and a -NH- bond.
It is preferable that the polyimide and/or polyamideimide have a carboxy group, a salt-type carboxy group and/or a --NH-- bond other than the terminal of the main chain of the polyimide and/or polyamideimide.

As used herein, a "salt-type carboxy group" means a group in which a hydrogen atom in the carboxy group is substituted with a cation component. As used herein, the term "cationic component" may be a fully ionized cation itself, or a cationic component that is ionically bound to -COO- ^and is virtually uncharged. or a cationic component with a partial charge that is intermediate between the two. When the “cation component” is an M ion component consisting of an n-valent metal M, the cation itself is represented as M ⁿ⁺ , and the cationic component is represented as “M” in “-COOM _1/n ”. It is an element that is

In the present invention, the "cationic component" includes, for example, cations when the compounds listed as compounds contained in the chemical etching solution described later are ionized, and are typically ionic components or organic alkali ion components. is mentioned. For example, when the alkali metal ion component is a sodium ion component, the cation itself is a sodium ion (Na ⁺ ), and the cation component is the element represented by "Na" in "-COONa". A charged cationic component is Na ^δ+ . In the present invention, the cationic component is not particularly limited, and may be an inorganic component or an organic component such as NH ₄ ⁺ and N(CH ₃ ) ₄ ⁺ . Examples of inorganic components include metal elements such as alkali metals such as Li, Na and K, and alkaline earth metals such as Mg and Ca. Organic components, especially organic alkali ion components, include NH ₄ ⁺ , for example, quaternary ammonium cations represented by NR ₄ ⁺ (each of the four R's may be the same or different and represent an organic group). be done. The organic group represented by R is preferably an alkyl group, more preferably an alkyl group having 1 to 6 carbon atoms. Quaternary ammonium cations include N(CH ₃ ) ₄ ⁺ and the like.

In the present invention, the state of the "salt-type carboxyl group" and "cationic component" is not particularly limited, and is usually in an environment where polyimide and/or polyamideimide exists, such as in an aqueous solution, It may be in an organic solvent, dry, and the like. When the cationic component is a sodium ion component, for example, if it is in an aqueous solution, it may be dissociated into -COO- ^and Na ⁺ , and if it is in an organic solvent or dried, it may be dissociated into - It is highly likely that COONa is not dissociated.

With respect to carboxy groups and/or salt-type carboxy groups, the polyimide and/or polyamideimide may have only carboxy groups, may have only salt-type carboxy groups, or may have both carboxy groups and salt-type carboxy groups. You may have both carboxy groups. The ratio of the carboxy group to the salt-type carboxy group in the polyimide and/or polyamideimide varies depending on the environment in which the polyimide and/or polyamideimide exists, even for the same polyimide and/or polyamideimide. and is also affected by the concentration of the cationic component.

The total number of moles of carboxyl groups and salt-type carboxyl groups possessed by the polyimide and/or polyamideimide is, in the case of polyimide, usually an equimolar amount of -NH- bonds, When forming a group and / or a salt-type carboxy group, -NH- bonds are also formed substantially at the same time, and the total number of moles of the formed carboxy group and the salt-type carboxy group is equal to the formed -NH- bond is equimolar to In the case of polyamideimide, the total number of moles of carboxy groups and salt-type carboxyl groups in polyamideimide is not necessarily equimolar with —NH— bonds, and depends on the conditions of the imide bond ring-opening step such as chemical etching described later. The -NH- bond is preferably part of an amide bond (-NH-C(=O)-).

Specifically, the resin containing polyimide and/or polyamideimide preferably has at least one selected from the group consisting of structural units represented by the following formulas (3) to (6). If it is a polyimide, it is preferable to have structural units represented by the following formulas (3) and / or (4), and if it is a polyamideimide, it is a structure represented by the following formulas (5) and / or (6) It is preferred to have units.

In the above formula, X is the same or different and is a hydrogen atom or a cationic component. Ar is an aryl group, and a repeating unit represented by the formula (1) constituting a polyamic acid described later or a repeating unit represented by the formula (2) constituting an aromatic polyimide, respectively Ar to which a carbonyl group is bonded may be the same as the aryl group represented by Y is a divalent residue excluding the amino group of the diamine compound, a repeating unit represented by the formula (1) constituting a polyamic acid described later or a repeating unit represented by the formula (2) constituting an aromatic polyimide It may be the same as the aryl group represented by Ar to which each N is attached in the unit.

The above polyimide and / or polyamideimide is a general polyimide and / or polyamideimide has imide bond ([-C (= O)] ₂ -N-) is partly ring-opened, in the case of polyimide the above formula (3) and/or (4), and in the case of polyamideimide, those having a structural unit represented by the above formula (5) are preferable.
However, in the case of polyamideimide, the object of the present invention can be achieved only by having an amide bond (-NH-C(=O)-) originally possessed without depending on ring opening of the imide bond possessed by general polyamideimide. achievable. However, also in polyamideimide, it is preferable that some of the imide bonds originally possessed by the polyamideimide are ring-opened to have the constitutional unit represented by the above (5).

The "polyimide resin in which a portion of the imide bond is ring-opened" in the first aspect is a carboxy group, a salt-type carboxy group, and -NH- from the group consisting of a ring-opening of a part of the imide bond. Polyimide and/or polyamideimide having at least one selected may be used.
"Polyimide resin in which a part of the imide bond is ring-opened" is, for example, a molded article such as a film mainly composed of polyimide and/or polyamideimide (hereinafter simply referred to as "polyimide and/or polyamideimide molded article" ), and then opening the imide bond (hereinafter also simply referred to as the “imide bond ring-opening step”).

By ring-opening the imide bond, a carboxy group and/or a salt-type carboxy group can be formed from a portion of the imide bond, and at the same time, theoretically equimolar -NH- bonds are also formed with these groups. be.

However, if the resin containing polyimide and / or polyamideimide is substantially made of polyamideimide, it already has -NH- bonds without performing the imide bond ring-opening step, and the imide bond ring-opening step is not necessarily required. However, in order to more reliably achieve ring-opening of the imide bond, it is preferable to produce by a method including an imide-bond ring-opening step.

The polyimide and/or polyamideimide molded body to be subjected to the imide bond ring-opening step may be porous or non-porous, and its shape is not particularly limited, From the viewpoint of increasing porosity, the polyimide and/or polyamide-imide molded body is preferably porous and preferably in a thin shape such as a film.

When the polyimide and/or polyamideimide molded body is porous, it is preferably a porous body containing pores having curved surfaces on the inner surface, and many (preferably substantially all) of the pores in the porous body have curved surfaces. may be formed of In the present specification, the phrase "having a curved inner surface" with respect to a pore means that at least the inner surface of the pore that provides porosity has a curved surface on at least part of the inner surface. At least substantially all of the inner surfaces of the pores in the porous body are preferably curved surfaces.

When the polyimide and/or polyamide-imide molding is porous, the above-mentioned pores having curved inner surfaces may form communicating pores. Normally, a communicating hole is formed by connecting a plurality of holes having curved inner surfaces to form a communicating hole as a whole. It can also be said that the communicating hole is a hole formed in a portion where fine particles used in the manufacturing method described later are in contact with each other.

(Imide bond ring-opening step)
The imide bond ring-opening step can be performed by a chemical etching method, a physical removal method, or a combination thereof. The chemical etching method is not particularly limited, and conventionally known methods can be used, for example.

The chemical etching method includes treatment with a chemical etchant such as an inorganic alkaline solution or an organic alkaline solution. Inorganic alkaline solutions are preferred. Examples of inorganic alkaline solutions include hydrazine solutions containing hydrazine hydrate and ethylenediamine, solutions of alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, sodium carbonate, sodium silicate and sodium metasilicate, ammonia solutions, and alkali hydroxides. and hydrazine and 1,3-dimethyl-2-imidazolidinone as main components. Examples of organic alkaline solutions include primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; and dimethylethanolamine. alcohol amines such as , triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; alkaline solutions such as cyclic amines such as pyrrole and pyreridine.

Pure water and alcohols can be appropriately selected as the solvent for each of the above solutions. Moreover, what added appropriate amount of surfactant can also be used. Alkali concentration is, for example, 0.01 to 20 mass %.

As a physical method, for example, dry etching using plasma (oxygen, argon, etc.), corona discharge, etc. can be used.

The above-described method may be applicable to either the imide bond ring-opening step before or after the microparticle removal step described below.
In addition, when the chemical etching method is performed after the fine particle removal step, it is easy to form continuous pores inside the polyimide and/or polyamide-imide molded body, and the porosity can be improved.

In addition, when chemical etching is performed as the imide bond ring-opening step, a cleaning step may be performed again to remove excessive etchant components.
As cleaning after chemical etching, water cleaning may be used alone, but it is preferable to combine acid cleaning and/or water cleaning.

As described above, the polyimide and/or polyamideimide molded article may be non-porous when subjected to the imide bond ring-opening step, but in that case, it may be made porous after the imide bond ring-opening step. preferable.
As a method for making a polyimide and/or polyamideimide molded article porous regardless of whether it is before or after the imide bond ring-opening step, a composite of polyimide and/or polyamideimide and fine particles (hereinafter simply referred to as A method including a fine particle removal step of removing the fine particles from the polyimide resin-fine particle composite to make it porous is preferred.

Specifically, (a) before the fine particle removal step, the composite of polyimide and/or polyamideimide and fine particles may be subjected to an imide bond ring-opening step, or (b) after the fine particle removal step The imide bond ring-opening step may be applied to the polyimide and/or polyamideimide molded article made porous by this step, but the method (b) is preferred from the viewpoint of increasing the porosity.

(Method for producing polyimide and/or polyamideimide porous molded body)
A preferred example of the production method for the case where the polyimide and/or polyamideimide molded article is porous (hereinafter also simply referred to as "polyimide resin porous molded article") will be described below. A polyimide resin porous molded article can be suitably produced using a varnish.

((manufacture of varnish))
The varnish production is performed by mixing an organic solvent in which fine particles are dispersed in advance, polyamic acid described later, polyimide or polyamideimide described above in an arbitrary ratio, or by mixing tetracarboxylic dianhydride and tetracarboxylic acid dianhydride in an organic solvent in which fine particles are dispersed in advance It can be produced by polymerizing a diamine to form a polyamic acid, or by further imidizing it to form a polyimide.
The organic solvent used for the varnish is not particularly limited as long as it can dissolve the polyamic acid and/or the polyimide resin and does not dissolve the fine particles.

In the varnish, resin fine particles are added so that the ratio of fine particles/polyimide resin is 1 to 4 (mass ratio) when the fine particles are baked (dried if baking is optional) to form a polyimide resin-fine particle composite. and polyamic acid or polyimide or polyamideimide, and the ratio of fine particles/polyimide resin is preferably 1.1 to 3.5 (mass ratio). If the mass ratio or volume ratio of fine particles/polyimide resin is at least the lower limit, it is possible to obtain pores with an appropriate density as a porous body. Film formation can be stably performed without causing problems. In addition, in this specification, volume % and volume ratio are values at 25°C.

((fine particles))
The material of the fine particles is not particularly limited as long as it is insoluble in the organic solvent used for the varnish and can be selectively removed after film formation. For example, inorganic materials include metal oxides such as silica (silicon dioxide), titanium oxide, alumina (Al ₂ O ₃ ), and calcium carbonate, and organic materials include high-molecular-weight olefins (polypropylene, polyethylene, etc.), polystyrene, acrylic. system resin (methyl methacrylate, isobutyl methacrylate, polymethyl methacrylate (PMMA), etc.), epoxy resin, cellulose, polyvinyl alcohol, polyvinyl butyral, polyester, polyether, organic polymer fine particles (resin fine particles) such as polyethylene. .

Inorganic materials that are preferably used during production include silica such as colloidal silica, PMMA of organic polymer fine particles, and the like. Among them, it is preferable to select these spherical particles in order to form minute holes having curved inner surfaces.

The fine resin particles can be selected from, for example, ordinary linear polymers and known depolymerizable polymers depending on the purpose without particular limitation. A normal linear polymer is a polymer whose molecular chains are randomly cut during thermal decomposition, and a depolymerizable polymer is a polymer whose polymer decomposes into monomers during thermal decomposition. Both can be removed from the polyimide resin film by decomposing into monomers, low molecular weight substances, or _CO2 when heated.

Among these depolymerizable polymers, methyl methacrylate or isobutyl methacrylate alone (polymethyl methacrylate or polyisobutyl methacrylate) having a low thermal decomposition temperature, or a copolymer containing this as a main component is preferable for handling during hole formation. .

The fine particles preferably have a high sphericity because the inner surfaces of the pores in the formed porous body are likely to have curved surfaces. The particle diameter (average diameter) of the microparticles to be used is, for example, 50 to 2000 nm, preferably 200 to 1000 nm. Also, the particle size distribution index (d25/75) should be 1-6. Note that d25 and d75 are the values of the particle diameters when the cumulative frequencies of the particle size distribution are 25% and 75%, respectively, and in this specification, d25 is the larger particle diameter.

Further, in the production method described later, when the unfired composite is formed as a two-layered unfired composite film, the fine particles (B1) used for the first varnish and the fine particles (B2) used for the second varnish are the same. You may use a thing and you may use a mutually different thing. In order to make the pores on the side in contact with the substrate more dense, the fine particles of (B1) preferably have a particle size distribution index smaller than or equal to that of the fine particles of (B2). Alternatively, the fine particles of (B1) preferably have a smaller or the same sphericity than the fine particles of (B2). In addition, the fine particles of (B1) preferably have a particle size (average diameter) smaller than that of the fine particles of (B2). ) is 500 to 2000 nm (more preferably 700 to 2000 nm). By using fine particles (B1) having a particle size smaller than that of (B2), the opening ratio of the pores on the surface of the obtained polyimide resin porous molded product can be made high and uniform, and the polyimide resin porous molded product can be obtained. The strength of the porous body (film) can be increased as compared with the case where the whole body has the particle size of the fine particles of (B1).

For the purpose of uniformly dispersing the fine particles in the varnish, a dispersant may be added together with the fine particles. By adding a dispersant, the polyamic acid described later, the polyimide or polyamideimide described above, and the fine particles can be mixed more uniformly, and furthermore, the fine particles can be uniformly distributed in the precursor film formed or formed into a film. can.

((polyamic acid))
Polyamic acid that can be used is not particularly limited and can be obtained by polymerizing any tetracarboxylic dianhydride and diamine. The amount of tetracarboxylic dianhydride and diamine to be used is not particularly limited, but it is preferable to use 0.50 to 1.50 mol of diamine per 1 mol of tetracarboxylic dianhydride.

The tetracarboxylic dianhydride can be appropriately selected from tetracarboxylic dianhydrides conventionally used as synthetic raw materials for polyamic acid. The tetracarboxylic dianhydride may be either an aromatic tetracarboxylic dianhydride or an aliphatic tetracarboxylic dianhydride. Preference is given to using carboxylic dianhydrides. You may use a tetracarboxylic dianhydride in combination of 2 or more types.

Preferred specific examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxy phenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 2,3,3′,4′- Biphenyltetracarboxylic dianhydride, 2,2,6,6-biphenyltetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2 ,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2 -bis(2,3-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis(2,3-dicarboxyphenyl) ether dianhydride, 2,2′,3,3′-benzophenonetetracarboxylic dianhydride, 4,4 -(p-phenylenedioxy)diphthalic dianhydride, 4,4-(m-phenylenedioxy)diphthalic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4, 5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9, 10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, 9,9-bisphthalic anhydride Fluorene, 3,3',4,4'-diphenylsulfonetetracarboxylic acid dianhydride and the like. Examples of aliphatic tetracarboxylic dianhydrides include ethylenetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, 1, 2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-cyclohexanetetracarboxylic dianhydride and the like. Among these, 3,3',4,4'-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride are preferred in terms of price, availability, and the like. Moreover, these tetracarboxylic dianhydrides can also be used individually or in mixture of 2 or more types.

The diamine can be appropriately selected from diamines conventionally used as raw materials for synthesizing polyamic acid. This diamine may be an aromatic diamine or an aliphatic diamine, but is preferably an aromatic diamine from the viewpoint of the heat resistance of the resulting polyimide resin. These diamines may be used in combination of two or more.

Examples of aromatic diamines include diamino compounds in which one or about 2 to 10 phenyl groups are bonded. Specifically, phenylenediamine and derivatives thereof, diaminobiphenyl compounds and derivatives thereof, diaminodiphenyl compounds and derivatives thereof, diaminotriphenyl compounds and derivatives thereof, diaminonaphthalene and derivatives thereof, aminophenylaminoindane and derivatives thereof, diaminotetraphenyl compounds and their derivatives, diaminohexaphenyl compounds and their derivatives, and cardo-type fluorenediamine derivatives.

Compounds in which the hydrogen atoms of these diamines are substituted with at least one substituent selected from the group of halogen atoms, methyl groups, methoxy groups, cyano groups, phenyl groups and the like may also be used.

The method for producing the polyamic acid is not particularly limited, and known methods such as a method of reacting an acid and a diamine component in an organic solvent can be used.

Further, when the unbaked composite is formed as a two-layered unbaked composite film, the volume ratio of the polyamic acid, polyimide or polyamideimide (A1) and the fine particles (B1) in the first varnish is 19:81 to 45: 65 is preferred. If the volume of fine particles is 65 or more when the total volume of fine particles is 100, the particles are uniformly dispersed. Holes can be formed uniformly. Also, the volume ratio of the polyamic acid, polyimide or polyamideimide (A2) to the fine particles (B2) in the second varnish is preferably 20:80 to 50:50. If the volume of the fine particles is 50 or more when the total volume of the fine particles is 100, the particles are uniformly dispersed. Therefore, it is possible to stably form a polyimide resin porous molded body having good mechanical properties such as stress and elongation at break.

In addition to the above components, antistatic agents, flame retardants, chemical imidizing agents, condensing agents, releasing agents, surface Known components such as modifiers can be contained as necessary.

(Production of green composite)
In the case of forming a film, the unbaked composite containing polyamic acid or polyimide resin and fine particles is molded by applying the above varnish on the substrate and applying the above varnish to the substrate at normal pressure or vacuum at 0 to 120 ° C. (preferably 0 to 100 ° C.), more preferably at 60 to 95° C. (more preferably 65 to 90° C.) under normal pressure. A release layer may be provided on the substrate, if necessary.
As the release agent used here, any known release agent such as an alkylphosphate ammonium salt type, fluorine type or silicone can be used without particular limitation.

It is preferable to wash the unfired composite separated from the substrate with an organic solvent or the like. The cleaning method can be selected from known methods such as a method of immersing the green composite in a cleaning liquid and then taking it out, a method of shower cleaning, and the like.

Further, when forming a two-layered unfired composite, first, the first varnish is applied as it is on a substrate such as a glass substrate, and the ° C.), more preferably at normal pressure 10 to 100° C. (more preferably 10 to 90° C.) to form a first green composite having a film thickness of 1 to 5 μm.

Subsequently, the second varnish is applied on the formed first unfired composite, and the temperature is maintained at 0 to 80° C. (preferably 0 to 50° C.), more preferably at normal pressure 10 to 80° C. ( It is further preferably dried at 10 to 30° C.) to form a second green composite having a film thickness of 5 to 30 μm to obtain a two-layered green composite.

(Polyimide resin-manufacturing of fine particle composite (baking process))
The above dried unbaked composite (or two-layered unbaked composite, hereinafter the same) is post-treated (baked) by heating to form a composite film (polyimide resin-fine particle composite) composed of a polyimide resin and fine particles. can do. When the varnish contains polyamic acid, it is preferable to complete imidization in the baking step. Note that the firing step is an optional step. Especially when polyimide or polyamideimide is used for the varnish, the baking step may not be performed.
The sintering temperature is preferably 120 to 400° C., although it varies depending on the structure of the polyamic acid or polyimide resin contained in the unsintered composite and the presence or absence of a condensing agent.

For firing, it is not always necessary to clearly separate the drying process from the drying process. For example, when firing at 375°C, the temperature is raised from room temperature to 375°C in 3 hours, and then held at 375°C for 20 minutes. A stepwise dry-thermal imidization method such as raising the temperature from room temperature to 375°C in steps of 50°C (holding for 20 minutes at each step) and finally holding at 375°C for 20 minutes. can also At that time, a method of fixing the ends of the unfired composite to a SUS formwork or the like to prevent deformation may be adopted.

(Fine particle removal step (polyimide resin-porous fine particle composite))
By removing the fine particles from the polyimide resin-fine particle composite by selecting an appropriate method, a polyimide resin porous body having micropores can be produced with good reproducibility. For example, when silica is used as the fine particles, the polyimide resin-fine particle composite can be made porous by dissolving and removing the silica with a low-concentration hydrogen fluoride solution (HF) or the like. When the fine particles are resin fine particles, the fine resin particles can be decomposed and removed by heating to a temperature higher than the thermal decomposition temperature of the fine resin particles and lower than the thermal decomposition temperature of the polyimide resin.

<Physical properties of polyimide resin>
The porosity of the porous material made of "a polyimide resin in which a portion of the imide bond is ring-opened" in the first aspect preferably has a porosity of 60% or more from the viewpoint of durability against friction and power generation performance. , the porosity is more preferably 65% or more, and more preferably 70% or more.
Although the upper limit of the porosity is not particularly limited, it is preferably 80% or less, more preferably 85% or less, from the viewpoint of strength.

The porosity indicates, for example, the ratio of pores per unit volume of the porous polyimide film. The porosity can be calculated, for example, by the following formula (A).
Porosity (%)={volume of test piece (cm ³ )−[weight of test piece (g)/specific gravity of polyimide (g/cm ³ )]}/volume of test piece (cm ³ )×100・(A)
As will be described later, a desired porosity can be obtained by appropriately adjusting the particle size and content of the fine particles used when producing the porous polyimide film.

The average opening diameter of the porous made of "a polyimide resin in which a part of the imide bond is ring-opened" in the first aspect is, for example, 50 nm or more and 3500 nm or less from the viewpoint of durability against friction and power generation performance. , preferably 100 nm or more and 3000 nm or less, more preferably 150 nm or more and 2500 nm or less. In the present specification, the average opening diameter is a value obtained by determining the average amount of change in the size of the communicating pores with a porometer after chemical etching treatment, and obtaining the actual average opening diameter from that value. In the case where the above-mentioned chemical etching is not performed, the average particle diameter of the fine particles used in the production of the porous formed body can be used as the average opening diameter.

The mass average molecular weight (Mw) of the polyimide resin in the first aspect is not particularly limited as long as it does not impair the effects of the present invention, but from the viewpoint of durability against friction and power generation performance, it is preferably 5000 or more. , is more preferably 8,000 or more, still more preferably 10,000 or more, and particularly preferably 15,000 or more.
Moreover, Mw of the polyimide resin in the first aspect may be 30,000 or more, and is preferably 50,000 or more.
The upper limit of Mw of the polyimide resin in the first aspect is not particularly limited as long as the effect of the present invention is not impaired, but is preferably 100,000 or less, more preferably 80,000 or less.
In the present specification, the mass average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC) in terms of polystyrene.

<Other Matters Regarding the Friction Body>
In the power generator according to the first aspect, one of the first friction body 131 and the second friction body 132 is made of a polyimide resin in which a part of the imide bond is ring-opened, and the first friction body 131 or the second friction body The other of bodies 132 is preferably a frictional body that becomes positively or negatively charged by contact with each other.
The positively charged friction body preferably contains a substance with relatively low electrical conductivity compared to polyimide resin in which a portion of the imide bond is ring-opened.
Positively charged friction bodies may include, for example, dielectric or insulating materials such as polyformaldehyde, ethylcellulose, polyamide, melamine formal, wool, silk, mica or nylon. However, it is not limited to these, and the positively charged frictional body includes various substances that are positively charged by contact with the frictional body made of polyimide resin in which a part of the imide bond is ring-opened. may contain.
Negatively charged friction bodies may include, for example, Teflon (polytetrafluoroethylene), polydimethylsiloxane, polyvinyl chloride (PVC), polypropylene, polyethylene, or polystyrene (PS). However, the negatively charged friction body includes various substances that are negatively charged by contact with the friction body made of polyimide resin in which a part of the imide bond is ring-opened. may contain.

The second friction body 132 preferably contains a material with relatively high electrical conductivity compared to polyimide resin in which a portion of the imide bond is ring-opened. This is to facilitate charge transfer between the second frictional body 132 and the charge storage portion 171 . The second friction body 132 may include a metal material such as Al, Cu, Ag, Au or steel, for example. However, it is not limited to them.

In the power generator according to the first aspect, at least one of the first friction body and the second friction body is doped with a p-type dopant or an n-type dopant to adjust charging characteristics of the surface thereof. Sources of p _- type dopants include, for example, ionic liquids such as _NO2BF4 , _{NOBF4 , NO2SbF6} ; _acid compounds such as HCl, _H2PO4 , _{CH3COOH , H2SO4} , _HNO3 ; Organic compounds such as dichlorodicyanoquinone, oxone, dimyristoylphosphatidylinositol, trifluoromethanesulfonimide, and the like may also be included. Alternatively, p-type dopant sources include HPtCl4, _AuCl3 , _HAuCl4 , AgOTf (silver trifluoromethanesulfonate), _{AgNO3 , H2PdCl6} , Pd(OAc) ₂ , Cu _{(CN)2 ,} and the like. It's okay.

Sources of n-type dopants include, for example, reduced products of substituted or unsubstituted nicotinamide; reduced products of compounds chemically bound to substituted or unsubstituted nicotinamide; and two or more pyridinium derivatives, including one or more nitrogen-reduced compounds of pyridinium derivatives of For example, the source of n-type dopants may include NMNH, NADH, NADPH, or may include viologen. Alternatively, the source of n-type dopant may comprise a polymer such as polyethyleneimine (PEI). Alternatively, the n-type dopant may include alkali metals such as K and Li. Meanwhile, the p-type dopant and n-type dopant materials mentioned above are only examples, and other various materials can be used as dopants.

The thickness of each of the first friction body 131 and the second friction body 132 is not particularly limited, and is preferably 1 μm or more and 500 μm or less, more preferably 3 μm or more and 200 μm or less, even more preferably 5 μm or more and 100 μm or less, and 7 μm or more and 80 μm or less. Especially preferred.
The length and width of the friction body are not particularly limited and can be set as appropriate.

The power generating device 100 according to the first aspect may or may not further include the grounding unit 150 that intermittently connects the second friction body 132 and the charge storage section 171 . Here, the charge storage unit 171 can also be earth or ground, for example. The grounding unit 150 may intermittently connect the second frictional body 132 and the charge storage part 171 according to the movement of the second frictional body 132 .
The grounding unit 150 may be provided between the second friction body 132 and the second substrate 120 and intermittently connected to the second friction body 132 according to the movement of the second friction body 132 . Therefore, the grounding unit 150 includes a conductive member 151 that intermittently contacts the second frictional body 132 due to the movement of the second frictional body 132, and an elastic member 152 that elastically supports the movement of the conductive member 151. , may include Here, the conductive member 151 is electrically connected to the charge storage unit 171 . The ground unit 150 is also provided on the second substrate 120, which is the lower substrate, but is not necessarily limited thereto.

In such a configuration of the grounding unit 150, when the second frictional body 132 moves toward the second electrode 122 and contacts the conductive member 151 of the grounding unit 150, the second frictional body 132 , is electrically connected to the charge storage unit 171 . As a result, electrons in the second friction body 132 move to the charge storage section 171 via the grounding unit 150, or electrons in the charge storage section 171 move to the second friction body 132 via the grounding unit 150. can move. Also, when the second frictional body 132 is far from the second electrode 122 and the second frictional body 132 is separated from the conductive member 151 of the grounding unit 150 , the second frictional body 132 is insulated from the charge storage portion 171 .

A conductive member forming the charge storage unit 171 may have a plate shape and may be provided under the second substrate 120 . However, it is not limited thereto, and the conductive member may have various shapes and be provided at various positions. Such charge storage unit 171 may include a conductive member such as a metal film.

The grounding unit 150 may include a switching element that intermittently connects the second friction body 132 and the charge storage unit 171 . Such switching elements may include, for example, mechanical switches, CMOS elements, etc., but are not limited thereto. Such a switching element electrically connects the second friction body 132 and the charge storage part 171 to each other or electrically insulates the second friction body 132 and the charge storage part 171 under certain conditions. can be done. For example, when the power generator 100 moves regularly, the switching element can turn on/off the electrical connection between the second frictional body 132 and the charge storage unit 171 at set time intervals. In addition, the switching element receives feedback of voltage information and/or current information of the first electrode 112 and the second electrode 122 to turn on/off the electrical connection between the second friction body 132 and the charge storage unit 171 . can.

The grounding unit 150 may include a conductive member electrically connecting the second friction body 132 and the charge storage part 171 and an insulating member electrically insulating the second friction body 132 and the charge storage part 171 . good. For example, the grounding unit 150 is installed at the edge portion between the first substrate 110 and the second substrate 120 and extends under the conductive member fixed to the first substrate 110 and the conductive member 191 . (Paragraph 0058 to Paragraph 0061 of Patent Document 1). Here, according to the movement of the first substrate 110, the conductive member can electrically connect the second friction body 132 and the charge storage part 171 to each other, and the insulating member can electrically connect the second friction body 132 and the charge storage part 171 to each other. The storage unit 171 can be electrically insulated from each other.

<Operating Mechanism of Generator>
Hereinafter, an operation mechanism of the power generation device 100 shown in FIG. 1 will be described with an example in which the first frictional body 131 and the second frictional body 132 are positively charged bodies and negatively charged bodies, respectively.
A similar operating mechanism can be applied when the first frictional body 131 and the second frictional body 132 are negatively charged and positively charged bodies, respectively.

2A to 2H are diagrams for explaining the first cycle operation mechanism of the power generator 100. FIG.
FIG. 2A illustrates a state in which no external force is acting on the power generator 100 . In the drawings, reference number 161 indicates a first load for detecting electron flow between the first electrode 112 and the second electrode 122, and reference number 162 indicates a load between the grounding unit 150 and the charge storage unit 171. shows a second load for detecting the electron flow of .

FIG. 2B illustrates a state in which the first friction body 131 and the second friction body 132 are in contact with each other. Referring to FIG. 2B, as described above, since the first elastic support part 141 has a smaller elastic modulus than the second elastic support part 142, when a force is applied to the first substrate 110, the first As the distance between the first substrate 110 and the second friction body 132 narrows, the first friction body 131 and the second friction body 132 come into contact with each other. Here, the first frictional body 131 and the second frictional body 132 are the positively charged body and the negatively charged body, respectively, as described above. Therefore, when the first friction body 131 and the second friction body 132 contact each other, the contact surface of the first friction body 131 is positively charged and the contact surface of the second friction body 132 is negatively charged. Next, when a pressing force is continuously applied to the first substrate 110, as shown in FIG. It moves to the second electrode 122 side.

FIG. 2D illustrates a state in which the first friction body 131 and the second friction body 132 are in contact, and the second friction body 132 is in contact with the ground contact unit 150 . Referring to FIG. 2D , if the first substrate 110 is continuously pressed while the first friction body 131 and the second friction body 132 are in contact with each other, the second friction body 132 becomes conductive to the ground unit 150 . contact with the elastic member 151 . Here, the conductive member 151 is electrically connected to the charge storage unit 171 such as ground. On the other hand, in this state, since the first friction body 131 and the second friction body 132 are in charge equilibrium with each other, charge transfer does not occur between the second friction body 132 and the charge storage section 171 .

FIG. 2E illustrates a state in which the first friction body 131 and the second friction body 132 are in contact, and the second friction body 132 is in contact with the second electrode 122 . Referring to FIG. 2E, when the second frictional body 132 is in contact with the conductive member 151 of the grounding unit 150 and the pressing force is continuously applied to the first substrate 110, the second frictional body 132 moves to the second contact with the electrode 122; Here, the second friction body 132 maintains contact with the conductive member 151 of the grounding unit 150 . In this state, the first friction body 131 and the second friction body 132 are in contact, and the second friction body 132 is in contact with the second electrode 122 and the conductive member 151 of the grounding unit 150, but the charge balance , no charge transfer occurs between the second frictional body 132 and the charge storage portion 171 .

FIG. 2F illustrates a state in which the second friction body 132 and the second electrode 122 are separated, and the first friction body 131 and the second friction body 132 are separated. 2F, when the force applied to the first substrate 110 is released, the second friction body 132 is separated from the second electrode 122, and the first friction body 131 is separated from the second friction body 132. isolated from Here, the second friction body 132 is in contact with the conductive member 151 of the grounding unit 150 . In this state, electrons move from the second frictional body 132, which is a negatively charged body, to the charge storage portion 171 in order to establish a charge balance inside the second frictional body 132, thereby causing a current to flow through the second load 162. . In addition, the positive charge on the surface of the first frictional body 131, which is a positively charged body, induces a negative charge to the first electrode 112, which is the upper electrode, thereby causing electrons to flow from the second electrode 122 to the first electrode 112. moves, a current flows through the first load 161 .

As the release of the first substrate 110 continues, the second frictional body 132 separates from the conductive member 151 of the grounding unit 150, as shown in FIG. 2G, and then, as shown in FIG. 2H. The power generator 100 returns to its initial state. In the state illustrated in FIG. 2H, the first electrode 112 and the second electrode 122 maintain a negative charge state and a positive charge state, respectively, and the first frictional body 131 maintains a positive charge state. Then, the positive and negative charges inside the second friction body 132 move to maintain electrical neutrality.

3A to 3H are diagrams for explaining the second cycle operation mechanism of the power generator 100. FIG.

FIG. 3A shows the same state as FIG. 2H, in which the first electrode 112 and the second electrode 122 maintain a negative charge state and a positive charge state, respectively, and the first friction body 131 maintains a positive charge state. And the second friction body 132 maintains neutrality.

FIG. 3B illustrates a state in which the first friction body 131 and the second friction body 132 are in contact with each other. Referring to FIG. 3B, when a pressing force is applied to the first substrate 110, the distance between the first substrate 110 and the second friction body 132 is narrowed, so that the first friction body 131 and the second friction body 132 are separated. comes into contact. Thus, when the positively charged first frictional body 131 contacts the second frictional body 132, which may contain a conductive material, the contact surface (upper surface) of the second charged body 132 is negatively charged. , the surface opposite to the contact surface (lower surface) of the second charged body 132 is positively charged.

FIG. 3C illustrates a state in which electrostatic induction is formed between the second friction body 132 and the second electrode 122. As shown in FIG. Referring to FIG. 3C, when a force is continuously applied to the first substrate 110, the second friction body 132 moves toward the second electrode 122 while the first friction body 131 and the second friction body 132 are in contact with each other. will come closer. In this way, when the second frictional body 132 and the second electrode 122 are close to each other, the positive charges on the bottom surface of the second frictional body 132 induce negative charges to the second electrode 122 due to the electrostatic induction phenomenon. . As a result, electrons move from the first electrode 112 to the second electrode 122 , causing a current to flow through the first load 161 .

FIG. 3D illustrates a state in which the first friction body 131 and the second friction body 132 are in contact, and the second friction body 132 is in contact with the ground unit 150 . Referring to FIG. 3D , if the first substrate 110 is continuously pressed while the first friction body 131 and the second friction body 132 are in contact with each other, the second friction body 132 may become conductive to the ground unit 150 . contact with the elastic member 151 . Here, the conductive member 151 is electrically connected to the charge storage unit 171 . In this state, since the first electrode 112, the first friction body 131, the second friction body 132 and the second electrode 122 are in charge equilibrium with each other, electrons move from the charge storage unit 171 to the second charged body 132 side. As a result, a current flows through the second load 162 .

FIG. 3E illustrates a state in which the first friction body 131 and the second friction body 132 are in contact, and the second friction body 132 is in contact with the second electrode 122 . Referring to FIG. 3E, when the second frictional body 132 is in contact with the conductive member 151 of the grounding unit 150 and the pressing force is continuously applied to the first substrate 110, the second frictional body 132 moves to the second electrode. 122. Here, the second friction body 132 maintains contact with the conductive member 151 of the grounding unit 150 . In this state, the first friction body 131 and the second friction body 132 are in contact, and the second friction body 132 is in contact with the second electrode 122 and the conductive member 151 of the grounding unit 150, but the charge balance is maintained. Therefore, charge transfer does not occur between the second frictional body 132 and the charge storage portion 171 .

FIG. 3F illustrates a state in which the second friction body 132 and the second electrode 122 are separated, and the first friction body 131 and the second friction body 132 are separated. 3F, when the force applied to the first substrate 110 is released, the second friction body 132 is separated from the second electrode 122, and the first friction body 131 is separated from the second friction body 132. be. Here, the second friction body 132 is in contact with the conductive member 151 of the grounding unit 150 . In this state, electrons move from the second frictional body 132, which is a negatively charged body, to the charge storage portion 171 in order to establish a charge balance inside the second frictional body 132, thereby causing a current to flow through the second load 162. . In addition, the positive charge on the surface of the first frictional body 131, which is a positively charged body, induces a negative charge to the first electrode 112, which is the upper electrode, thereby causing electrons to flow from the second electrode 122 to the first electrode 112. moves, a current flows through the first load 161 .

As the release of the first substrate 110 continues, the second frictional body 132 moves away from the conductive member 151 of the grounding unit 150, as shown in FIG. 3G, and then, as shown in FIG. 3H. The power generator 100 returns to its initial state. In the state shown in FIG. 3H, the first electrode 112 and the second electrode 122 maintain the negative charge state and the positive charge state, respectively, and the first friction body 131 maintains the positive charge state, similar to the state shown in FIG. 3A. maintain state. The positive and negative charges inside the second friction body 132 move to maintain neutrality. After that, when the pushing force is repeatedly applied to the first substrate 110, the power generator 100 repeatedly performs the second cycle.

As described above, in the power generator 100 according to the exemplary embodiment, by pressing the first substrate 110 , the pressure between the first electrode 112 and the second electrode 122 and between the second frictional body 132 and the charge storage portion 171 is increased. can generate electrical energy between Therefore, by repeatedly applying an external force to the power generator 100, electrical energy can be obtained more efficiently.

<Other Embodiments of Power Generation Device>
Other embodiments of the power generator according to the first aspect will be exemplified below, but the present invention is not limited to these.
4 is a cross-sectional view of another exemplary embodiment of a power plant according to the first aspect; FIG.
4, the power generator 300 includes a first substrate 310 and a second substrate 320, a first electrode 312 and a second electrode 322, a first friction body 331 provided on one surface of the first electrode 312, The grounding unit 350 includes the second friction body 332 and the second friction body 332 provided between the first friction body 331 and the second electrode 322 and is intermittently connected to the charge storage part 371 . You can In the power generation device 300, the first friction body 331, the second friction body 332 and the second electrode 322 are separated from each other and maintained in a separated state when no external force is applied. Sometimes they have physical structures or mechanisms that come into contact with each other.

The first substrate 310 and the second substrate 320 may include a flexible material that is deformed by an external force. Also, the first substrate 310 and the second substrate 320 may include a material having a restoring force to return to its original state when an external force is removed. For example, the first substrate 310 and the second substrate 320 may include, but are not limited to, polyester (PE), polyester sulfone (PES), polyethylene naphthalate (PEN), or Kapton. . The first substrate 310 and the second substrate 320 are provided facing each other with the second friction body 332 interposed therebetween. For example, the first substrate 310 may have a convex shape above the second friction body 332 and the second substrate 320 may have a convex shape below the second friction body 332 . Here, the first substrate 310 may include a material that is more easily deformed than the second substrate 320 . This is to ensure that the first substrate 310 deforms first when an external force is applied to the power generator 300 .

A first electrode 312 is provided on the lower surface of the first substrate 310 , and a second electrode 322 is provided on the upper surface of the second substrate 320 . The first electrode 312 and the second electrode 322 may have flexibility corresponding to deformation of the first substrate 310 and the second substrate 320 . Materials for the first electrode 312 and the second electrode 322 are the same as those described above for the first electrode 112 and the second electrode 122 .

A first friction body 331 is provided on the lower surface of the first electrode 312 facing the second electrode 322 . A second friction body 332 is provided between the first friction body 331 and the second electrode 322 . The first friction body 331 and the second friction body 332 may have flexibility corresponding to deformation of the first substrate 310 and the second substrate 320 . Here, the first friction body 331 is provided so as to contact the bottom surface of the first electrode 312 . The second frictional body 332 is separated from the first frictional body 331 and the second electrode 322 when no external force is applied to the power generation device 300 . The first frictional body 331 and the second frictional body 332 may include materials charged with electric charges of different polarities upon contact.
Specific examples and preferable examples of the first friction body 331 and the second friction body 332 are the same as those described above for the first friction body 131 and the second friction body 132 .

At least one of the first friction body 331 and the second friction body 332 may be doped with a p-type dopant or an n-type dopant, as described above, in order to adjust charging characteristics of its surface.

The grounding unit 350 is installed to intermittently connect the second friction body 332 and the charge storage part 371 . Here, the charge storage unit 371 can also be a ground or a conductive member, for example. Accordingly, the grounding unit 350 can intermittently connect the second friction body 332 and the charge storage part 371 according to the movement of the second friction body 332 . Specifically, when the second frictional body 332 moves toward the second electrode 322 and contacts the grounding unit 350 , the second frictional body 332 is electrically connected to the charge storage unit 371 . be done. Also, when the second frictional body 332 is far from the second electrode 322 and the second frictional body 332 is separated from the grounding unit 350 , the second frictional body 332 is insulated from the charge storage portion 371 . Since the example of the grounding unit 350 capable of implementing such functions has been described, a detailed description of the grounding unit 350 will be omitted.

Reference can be made to paragraphs 0098 to 0102 of Patent Document 1 and FIGS. Since the mechanism of occurrence has been described in detail in the above embodiment, the description thereof will be omitted.

FIG. 5 is a cross-sectional view of yet another exemplary embodiment of a power plant according to the first aspect;
5, the power generator 400 includes a first substrate 410 and a second substrate 420, a first electrode 412 and a second electrode 422, a first friction body 431 provided on one surface of the first electrode 412, The second friction body 432 is provided between the first friction body 431 and the second electrode 422, and the grounding unit 450 intermittently connects the second friction body 432 and the charge storage part 471. good. A first support portion 441 is provided between the first substrate 410 and the second friction body 432 , and a second support portion 442 is provided between the second friction body 432 and the second substrate 420 . is provided.

The first substrate 410 and the second substrate 420 may include a material that has flexibility to be deformed by an external force and has elasticity to expand and contract. A first electrode 412 is provided on the lower surface of the first substrate 410 and a second electrode 422 is provided on the upper surface of the second substrate 420 . The first electrode 412 and the second electrode 422 may have flexibility and stretchability corresponding to the first substrate 410 and the second substrate 420 . The first electrode 412 and the second electrode 422 may include a material with excellent electrical conductivity.

A first friction body 431 is provided on the lower surface of the first electrode 412 facing the second electrode 422 . A second friction body 432 is provided between the first friction body 431 and the second electrode 422 . The first friction body 431 and the second friction body 432 may have flexibility and stretchability corresponding to the first substrate 410 and the second substrate 420 . Here, the first friction body 431 is provided so as to contact the lower surface of the first electrode 412 . The second friction body 432 is separated from the first friction body 431 and the second electrode 422 when no external force is applied to the triboelectric generator 400 . Here, the first frictional body 431 and the second frictional body 432 may include materials charged with different polarities upon contact.

The first frictional body 431 and the second frictional body 432 are also positively charged and negatively charged bodies, respectively. In that case, the first frictional body 431 is positively charged by contact with the second frictional body 432, and may contain a substance with low electrical conductivity. The second frictional body 432 is negatively charged by contact with the first frictional body 431, and may contain a conductive material with high electrical conductivity. Alternatively, the first frictional body 431 and the second frictional body 432 are also the negative and positive charging bodies, respectively. In that case, the first frictional body 431 is negatively charged by contact with the second frictional body 432 and may contain a material with low electrical conductivity. The second frictional body 432 is positively charged by contact with the first frictional body 431, and may contain a conductive material with high electrical conductivity.
Specific examples and preferred examples of the first friction body 431 and the second friction body 432 are the same as those described above for the first friction body 131 and the second friction body 132 .

The ground unit 450 is installed to intermittently connect the second friction body 432 and the charge storage part 471 . Here, the charge storage part 471 can also be a ground or a conductive member, for example. Accordingly, the grounding unit 450 can intermittently connect the second frictional body 432 and the charge storage part 471 according to the movement of the second frictional body 432 . Specifically, when the second frictional body 432 moves toward the second electrode 422 and contacts the grounding unit 450 , the second frictional body 432 is electrically connected to the charge storage unit 471 . be done. Also, when the second frictional body 432 is far from the second electrode 422 and the second frictional body 432 is separated from the grounding unit 450 , the second frictional body 432 is insulated from the charge storage part 471 . Since the example of the grounding unit 450 capable of implementing such functions has been described, a detailed description of the grounding unit 450 will be omitted.

The first supports 441 are provided on both sides of the edge between the first substrate 410 and the second friction body 432 . The second supports 442 are provided on both sides of the edge between the second substrate 420 and the second friction body 432 . The first support part 441 and the second support part 442 may include a hard material that is not easily deformed by an external force.

Reference can be made to paragraphs 0110 to 0113 of Patent Document 1 and FIGS. Since the mechanism of occurrence has been described in detail in the above embodiment, the description thereof will be omitted.

FIG. 6 is a cross-sectional view of yet another exemplary embodiment of a power plant according to the first aspect;
6, the power generator 500 includes a first substrate 510 and a second substrate 520, a first electrode 512 and a second electrode 522, a first friction body 531 provided on one surface of the first electrode 512, The second friction body 532 is provided between the first friction body 531 and the second electrode 522, and the grounding unit 550 intermittently connects the second friction body 532 and the charge storage part 571. good. A first support portion 541 is provided between the first substrate 510 and the second friction body 532, and a second support portion 542 is provided between the second friction body 532 and the second substrate 520. is provided.

The first substrate 510 and the second substrate 520 may include a material that has flexibility to be deformed by an external force and has elasticity to expand and contract. A first electrode 512 is provided on the lower surface of the first substrate 510 and a second electrode 522 is provided on the upper surface of the second substrate 520 . The first electrode 512 and the second electrode 522 may have flexibility and stretchability corresponding to the first substrate 510 and the second substrate 520 . The first electrode 512 and the second electrode 522 may contain a material with excellent electrical conductivity.

A first friction body 531 is provided on the lower surface of the first electrode 512 facing the second electrode 522 . A second friction body 532 is provided between the first friction body 531 and the second electrode 522 . The first friction body 531 and the second friction body 532 may have flexibility and stretchability corresponding to the first substrate 510 and the second substrate 520 . Here, the first friction body 531 is provided so as to contact the lower surface of the first electrode 512 . The second frictional body 532 is separated from the first frictional body 531 and the second electrode 522 when no external force is applied to the power generating device 500 . Here, the first frictional body 531 and the second frictional body 532 may include materials charged with electric charges of different polarities upon contact.

The first frictional body 531 and the second frictional body 532 are also positively charged and negatively charged, respectively. In that case, the first frictional body 531 is positively charged by contact with the second frictional body 532, and may contain a substance with low electrical conductivity. The second frictional body 532 is negatively charged by contact with the first frictional body 531, and may contain a conductive material with high electrical conductivity. Alternatively, the first frictional body 531 and the second frictional body 532 are also negative and positive charge bodies, respectively. In that case, the first frictional body 531 is negatively charged by contact with the second frictional body 532, and may contain a material with low electrical conductivity. The second frictional body 532 is positively charged by contact with the first frictional body 531, and may contain a conductive material with high electrical conductivity.
Specific examples and preferable examples of the first friction body 531 and the second friction body 532 are the same as those described above for the first friction body 131 and the second friction body 132 .

The grounding unit 550 is installed to intermittently connect the second friction body 532 and the charge storage part 571 . Here, the charge storage unit 571 can also be, for example, a ground or a conductive member. Accordingly, the grounding unit 550 can intermittently connect the second frictional body 532 and the charge storage part 571 according to the movement of the second frictional body 532 . Specifically, when the second frictional body 532 moves toward the second electrode 522 and contacts the grounding unit 550 , the second frictional body 532 is electrically connected to the charge storage unit 571 . be done. Also, when the second frictional body 532 is far from the second electrode 522 and the second frictional body 532 is separated from the grounding unit 550 , the second frictional body 532 is insulated from the charge storage portion 571 . Since the example of the grounding unit 550 capable of implementing such functions has been described, a detailed description of the grounding unit 550 will be omitted.

The first support part 541 is provided on one side of the edge between the first substrate 510 and the second friction body 532 , and the second support part 542 is provided between the second substrate 520 and the second friction body 532 . Provided on one side of the edge. Here, the first support part 541 may be positioned above the second support part 542 . The first support part 541 and the second support part 542 may include a hard material that is not easily deformed by an external force.

Paragraphs 0121 to 0124 of Patent Document 1 and FIGS. 18A to 18D of Patent Document 1 can be referred to for the mechanism of operation of the power generation device 500 shown in FIG. Since the mechanism of occurrence has been described in detail in the above embodiment, the description thereof will be omitted.

FIG. 7 is a cross-sectional view of yet another exemplary embodiment of a power plant according to the first aspect;
7, the power generator 600 includes a first substrate 610 and a second substrate 620, a first electrode 612 and a second electrode 622, a first friction body 631 provided on one surface of the first electrode 612, The second friction body 632 is provided between the first friction body 631 and the second electrode 622, and the grounding unit 650 intermittently connects the second friction body 632 and the charge storage unit 671. good.

The first substrate 610 may have a spherical shape, and the second substrate 620 may have a spherical shape surrounding the first substrate 610 . A first electrode 612 is provided on the outer surface of the first substrate 610 , and a second electrode 622 is provided on the inner surface of the second substrate 620 . The first electrode 612 and the second electrode 622 may include materials with excellent electrical conductivity.

A first friction body 631 is provided on the outer surface of the first electrode 612 , and a second friction body 632 is provided between the first friction body 631 and the second electrode 622 . Here, the first friction body 631 is provided so as to be in contact with the outer surface of the first electrode 612, and in a state where no external force is applied to the power generator 600, the second friction body 632 is in contact with the first electrode 612. It is provided so as to be separated from the friction body 631 and the second electrode 622 . The first frictional body 631 and the second frictional body 632 may include materials charged with electric charges of different polarities upon contact.

The first frictional body 631 and the second frictional body 632 are also positively charged and negatively charged, respectively. In that case, the first friction body 631 is positively charged by contact with the second friction body 632, and may contain a substance with low electrical conductivity. The second friction body 632 is negatively charged by contact with the first friction body 631, and may contain a conductive material with high electrical conductivity. Alternatively, the first frictional body 631 and the second frictional body 632 are also negative and positive charge bodies, respectively. In that case, the first frictional body 631 is negatively charged by contact with the second frictional body 632, and may contain a substance with low electrical conductivity. The second frictional body 632 is positively charged by contact with the first frictional body 631, and may contain a conductive material with high electrical conductivity.
Specific examples and preferable examples of the first friction body 631 and the second friction body 632 are the same as those described above for the first friction body 131 and the second friction body 132 .

An elastic support portion 640 is provided between the first friction body 631 and the second friction body 632 . For example, the elastic support part 640 can also be a spring provided between the first friction body 631 and the second friction body 632, but is not limited thereto. FIG. 7 exemplarily illustrates a case where an elastic support is provided on the upper portion of the first friction body 631 . A string 660 is connected to the first friction body 631, and the string 660 is provided to be exposed to the outside through the second friction body 632, the second electrode 622, and the second substrate 620. ing. FIG. 7 exemplarily illustrates a case where a string 660 is provided under the first friction body 631 .

The ground unit 650 is installed to intermittently connect the second friction body 632 and the charge storage part 671 . Here, the charge storage unit 671 can also be, for example, a ground or a conductive member. Accordingly, the grounding unit 650 can intermittently connect the second friction body 632 and the charge storage part 671 according to the movement of the second friction body 632 . Specifically, when the second friction body 632 moves toward the second electrode 622 and contacts the ground unit 650 , the second friction body 632 is electrically connected to the charge storage unit 671 . be done. Also, when the second frictional body 632 is far from the second electrode 622 and the second frictional body 632 is separated from the grounding unit 650 , the second frictional body 632 is insulated from the charge storage portion 671 . Since the example of the grounding unit 650 capable of implementing such functions has been described, a detailed description of the grounding unit 650 will be omitted.

Reference can be made to paragraphs 0132 to 0135 of Patent Document 1 and FIGS. Since the mechanism of occurrence has been described in detail in the above embodiment, the description thereof will be omitted.

FIG. 8 is a cross-sectional view of yet another exemplary embodiment of a power plant according to the first aspect;
Referring to FIG. 8, the power generator 700 includes a first substrate 710 and a second substrate 720, a first electrode 712 and a second electrode 722, a first friction body 731 provided on one surface of the first electrode 712, It includes a second friction body 732 provided between the first friction body 731 and the second electrode 722, and further includes a grounding unit 750 intermittently connecting the second friction body 732 and the charge storage part 771. good too. The first substrate 710 and the second substrate 720 have a flat structure and may include rigid or flexible materials. A first electrode 712 is provided on the lower surface of the first substrate 710 , and a second electrode 722 is provided on the upper surface of the second substrate 720 . The first electrode 712 and the second electrode 722 may include a material with excellent electrical conductivity.

A first friction body 731 is provided on the lower surface of the first electrode 712 , and a second friction body 732 is provided between the first friction body 731 and the second electrode 722 . Here, the first friction body 731 is provided so as to contact the lower surface of the first electrode 712 . The second frictional body 732 is separated from the first frictional body 731 and the second electrode 722 when no external force is applied to the power generating device 700 . Here, the first frictional body 731 and the second frictional body 732 may include materials charged with electric charges of different polarities upon contact.

The first frictional body 731 and the second frictional body 732 are also positively charged and negatively charged bodies, respectively. In this case, the first frictional body 731 may contain a material that is positively charged by contact with the second frictional body 732 and has low electrical conductivity. The second frictional body 732 is negatively charged by contact with the first frictional body 731, and may contain a conductive material with high electrical conductivity. Alternatively, the first frictional body 731 and the second frictional body 732 are also the negative and positive charging bodies, respectively. In that case, the first frictional body 731 is negatively charged by contact with the second frictional body 732, and may contain a material with low electrical conductivity. The second frictional body 732 is positively charged by contact with the first frictional body 731, and may contain a conductive material with high electrical conductivity.
Specific examples and preferred examples of the first friction body 731 and the second friction body 732 are the same as those described above for the first friction body 131 and the second friction body 132 .

The grounding unit 750 is installed to intermittently connect the second friction body 732 and the charge storage part 771 . Here, the charge storage portion 771 can also be, for example, a ground or a conductive member. Accordingly, the grounding unit 750 can intermittently connect the second frictional body 732 and the charge storage part 771 according to the movement of the second frictional body 732 . Specifically, when the second frictional body 732 moves toward the second electrode 722 and contacts the ground unit 750 , the second frictional body 732 is electrically connected to the charge storage unit 771 . be done. Also, when the second frictional body 732 is far from the second electrode 722 and the second frictional body 732 is separated from the grounding unit 750 , the second frictional body 732 is insulated from the electric charge storage portion 771 . Since the example of the grounding unit 750 capable of implementing such functions has been described, a detailed description of the grounding unit 750 will be omitted.

A guide member 790 is provided on the upper surface of the second friction body 732 to guide the vertical movement of the first substrate 710 , the first electrode 712 and the first friction body 731 . Such guide members 790 are installed on both sides of the edge of the second friction body 732 . An elastic support portion 740 is provided between the second friction body 732 and the second substrate 720 . Such elastic supports 740 are provided on both sides of the edge between the second friction body 732 and the second substrate 720 .

Reference can be made to paragraphs 0142 to 0146 of Patent Document 1 and FIGS. Since the mechanism of occurrence has been described in detail in the above embodiment, the description thereof will be omitted.

<Application of power generator>
The power generation device according to the first aspect is expected to be excellent in power generation and durability due to the above configuration, and is expected to be applied as IoT devices such as wearable devices such as clothes and accessories, and sensors such as home appliances.
A wearable device or IoT device according to a second aspect includes the power generator according to the first aspect.

Hereinafter, the present invention will be described in more detail with reference to preparation examples and comparative preparation examples, but the scope of the present invention is not limited to these examples.

In the following preparation examples and comparative preparation examples, the following tetracarboxylic dianhydride, diamine, polyamic acid, organic solvent, dispersant and fine particles were used.
Tetracarboxylic dianhydride: pyromellitic dianhydride Diamine: 4,4'-diaminodiphenyl ether Polyamic acid solution: reaction product of pyromellitic dianhydride and 4,4'-diaminodiphenyl ether (solid content 21.9% by mass (organic solvent: N,N-dimethylacetamide))
- Organic solvent (1): N,N-dimethylacetamide (DMAc)
・Organic solvent (2): gamma butyrolactone ・Dispersant: polyoxyethylene secondary alkyl ether-based dispersant ・Fine particles: silica with an average particle size of 300 nm (particle size distribution index (d25/75): about 1.5)
・Etching solution:
Tetramethylammonium hydroxide 4.5% by mass solution of methanol:water (mass ratio 4:6)

<Polyimide porous friction bodies of Preparation Examples 1 and 2 and polyimide porous friction bodies of Comparative Preparation Examples>
(Preparation of silica dispersion)
23.1 parts by mass of the fine particles (silica) were added to a mixture of 23.1 parts by mass of the organic solvent (1) and 0.1 part by mass of the dispersant, and the mixture was stirred to prepare a silica dispersion.

(Preparation of varnish)
To 41.1 parts by mass of the polyamic acid solution, 42.0 parts by mass of the silica dispersion obtained in Preparation of Silica Dispersion-1 was added, and organic solvents (1) and (2) were added so that the solvent composition of the entire varnish was organic. Solvent (1) and organic solvent (2) were added at a ratio of 90:10 and stirred to prepare a varnish. The volume ratio of polyamic acid and silica in the obtained varnish was 40:60 (the mass ratio was 30:70).

(Film formation of unfired composite)
The above varnish was formed into a film using an applicator on a polyethylene terephthalate (PET) film as a substrate. It was pre-baked at 90° C. for 5 minutes to produce an unfired composite (unfired composite film) with a film thickness of 40 μm. After soaking in water for 3 minutes, the green composite membrane was passed between two rolls and pressed. At that time, the roll pressing pressure was 3.0 kg/cm ² , the roll temperature was 80° C., and the moving speed of the unsintered composite film was 0.5 m/min. An unfired composite was obtained by peeling the unfired composite from the substrate.

(Imidation of green composite)
The unbaked composite film was subjected to heat treatment (baking) at 340° C. for 15 minutes each for imidization to obtain a polyimide-fine particle composite.

(Formation of polyimide porous molded body)
The polyimide-fine particle composite obtained above was immersed in a 10% HF solution for 10 minutes to remove fine particles contained in the film, followed by washing with water and drying to obtain a polyimide porous molded body (thickness thickness: 49 nm).
The polyimide porous molded body before being subjected to the following chemical etching is referred to as "a polyimide porous friction body of comparative preparation example".

(chemical etching)
As the imide bond ring-opening step, the polyimide porous molded body is immersed in an etching solution under the chemical etching conditions of Condition 1 or 2 below to perform the "imide bond ring-opening step", thereby partially ring-opening the imide bond. After that, they were re-baked at 340° C. for 15 minutes to obtain polyimide porous friction bodies of Preparation Examples 1 and 2 (thickness: 49 nm).
Condition 1: Immersed in the etching solution for 2 minutes Condition 2: Immersed in the etching solution for 5 minutes

(Calculation of ring-opening degree of imide bond)
For each of the polyimide porous friction bodies of Preparation Examples 1 and 2 obtained above, the area of the peak representing the imide bond measured with the FT-IR device was divided by the area of the peak representing benzene measured with the FT-IR device. A value (imidization ratio (X1)) was calculated.
In addition, the value obtained by dividing the area of the peak representing the imide bond measured by the FT-IR device for the polyimide porous friction body of the comparative preparation example by the area of the peak representing the benzene similarly measured by the FT-IR device (imidization rate (X2)) was calculated.
The value obtained by normalizing the imidization ratio (X1) of each of the polyimide porous friction bodies of Preparation Examples 1 and 2 obtained above by the imidization ratio (X2) of the polyimide porous friction body of Comparative Preparation Example is 100 (%). ) was calculated as the “degree of ring-opening of imide bond”. The results are shown in the table below.

<Dielectric property evaluation>
A 20 mm square test piece of each of the polyimide porous friction bodies of Preparation Examples 1 and 2 and the polyimide porous friction body of Comparative Preparation Example was prepared, sandwiched between two copper electrode flat plates, and one of the copper electrode flat plates had a diameter of 1 mm. One drop of 15% by mass ethanol aqueous solution was dropped into each hole, and the dielectric properties of the polyimide porous friction bodies of Preparation Examples 1 and 2 and the polyimide porous friction bodies of Comparative Preparation Example were evaluated by an impedance analyzer.

First, the capacitance C (relative dielectric constant ε _r ') and dielectric loss tangent tan δ (relative dielectric loss factor ε _r '') were measured in the frequency range of 4 Hz to 5 MHz. got a yen In addition, when a sufficient Debye-type semicircle was not obtained, a capacitive semicircle was formed by interpolating the fitting by the least-squares method. The results are shown in FIGS. 9(a) and (b).
From the measurement results of the relative dielectric constant and the relative dielectric loss factor, changes (dielectric dispersion) due to frequency were observed for both the polyimide porous friction bodies of Preparation Examples 1 and 2 and the polyimide porous friction bodies of Comparative Preparation Examples. It was confirmed that both the polyimide porous friction bodies of Preparation Examples 1 and 2 and the polyimide porous friction bodies of Comparative Preparation Example were dielectrics.

図９及び表２に示した結果から明らかなように、比較調製例のポリイミド多孔質摩擦体と比べ、調製例１及び２のポリイミド多孔質摩擦体は、誘電率ε_０（特に低周波数側の円）が大きいことが分かる。
一方、本発明者らは、ポリイミド多孔質の空孔率が大きくなればなるほど、誘電率が１に近づくように低下する結果を得ており、開環度が向上するほど誘電率ε_０が向上するという相反する図９及び表２に示された結果は予想外であった。 Further, from the obtained Debye type semicircle or capacitive semicircle (see FIGS. 9A and 9B), the dielectric constant ε _∞ at the measurement frequency of 0 Hz, and the maximum or infinite measurement frequency ( The dielectric constant ε ₀ in vacuum), the relaxation time (polarization response speed) τ, and the constant β representing the distribution of the relaxation time (0≦β≦1. If there is only one relaxation time, β=1) were calculated.

As is clear from the results shown in FIG. 9 and Table 2, compared with the polyimide porous friction bodies of Comparative Preparation Examples, the polyimide porous friction bodies of Preparation Examples 1 and 2 had a dielectric constant ε ₀ (especially circle) is large.
On the other hand, the present inventors have obtained the result that the higher the porosity of the polyimide porous, the lower the dielectric constant approaches 1, and the higher the degree of ring opening, the higher the dielectric constant ε ₀ . The results shown in FIG. 9 and Table 2, which are contradictory, were unexpected.

In addition, it can be seen that the circle on the low frequency side is based on structural changes brought about by ring opening, and has a higher τ compared to the unopened polyimide porous friction body of the comparative preparation example. . In addition, it can be seen that the relaxation time is distributed in the circle on the low frequency side from β, and it can be said that this β is within the range of 0.3 to 0.6 for general polymer solids.
As described above, since the polyimide porous friction bodies of Preparation Examples 1 and 2 both have large dielectric constants, the first friction body or the second friction body (preferably the second friction body) is used in the first mode. It can be incorporated into such a power generator, and can contribute to the power generation performance of the built-in power generator.

100,300,400,500,600,700 Power generator 110,310,410,510,610,710 First substrate 120,320,420,520,620,720 Second substrate 112,312,412,512,612 , 712 First electrode 122, 322, 422, 522, 622, 722 Second electrode 131, 331, 431, 531, 631, 731 First friction body 132, 332, 432, 532, 632, 732 Second friction body

Claims (13)

A power generating device that converts the external force into electric energy by electrifying the friction bodies by friction between the friction bodies caused by the external force,
The power generator includes a first electrode, a second electrode, a first friction body, and a second friction body,
The first friction body has a first friction surface,
the second friction body has a second friction surface,
The first friction body and the second friction body are provided so that the first friction surface and the second friction surface face each other,
The first electrode is provided in contact with a surface opposite to the first friction surface of the first friction body,
The second electrode is provided apart from the second friction body so as to face a surface opposite to the second friction surface of the second friction body,
The first friction surface and the second friction surface are spaced apart when no external force acts, and are capable of coming into contact with each other and rubbing against each other due to the action of an external force;
The power generating device , wherein the first friction body or the second friction body is made of a polyimide resin in which the imide bond is partially opened, wherein the "polyimide resin in which the imide bond is partially opened" A power generating device, wherein the "resin" is a polyimide resin having a dielectric constant higher than that of a polyimide resin in which the imide bond is not ring-opened . The power generator according to claim 1, wherein the polyimide resin has a degree of ring opening of 1% or more. A power generating device that converts the external force into electric energy by electrifying the friction bodies by friction between the friction bodies caused by the external force,
The power generator includes a first electrode, a second electrode, a first friction body, and a second friction body,
The first friction body has a first friction surface,
the second friction body has a second friction surface,
The first friction body and the second friction body are provided so that the first friction surface and the second friction surface face each other,
The first electrode is provided in contact with a surface opposite to the first friction surface of the first friction body,
The second electrode is provided apart from the second friction body so as to face a surface opposite to the second friction surface of the second friction body,
The first friction surface and the second friction surface are spaced apart when no external force acts, and are capable of coming into contact with each other and rubbing against each other due to the action of an external force;
The power generating device, wherein the first friction body or the second friction body is made of a polyimide resin in which the imide bond is partially opened, wherein the "polyimide resin in which the imide bond is partially opened" A power generating device, wherein the "resin" is a polyimide resin having a ring-opening degree of 1% or more, which has a dielectric constant higher than that of a polyimide resin in which imide bonds are not ring-opened . The dielectric constant ε when the dielectric constant is a vacuum ₀ The power generator according to claim 1 or 3, wherein 4. The method according to claim 1 , wherein at least one of said first friction surface and said second friction surface is a rough surface, or at least one of said first friction body and said second friction body is porous. generator. One of the first friction body and the second friction body is the porous body, and the porous body is made of the polyimide resin in which a part of the imide bond is ring-opened. 2. The power generator according to item 1. The power generator according to claim 6 , wherein the porosity of the porous material made of the polyimide resin is 60% or more and 80% or less. The power generator according to any one of claims 1 to 7 , wherein the porous polyimide resin has an average opening diameter of 50 nm or more and 3500 nm or less on the first friction surface or the second friction surface. Claims 1 to 8 , in the power generator according to the first aspect, wherein the static friction force between the first friction surface and the second friction surface is 16.0 gf or more, and the dynamic friction force is 8.0 gf or more. The power generator according to any one of . A wearable device or an Internet of Things (IoT) device comprising the power generator according to any one of claims 1 to 9 . A friction element for a friction power generator containing a polyimide resin in which a portion of the imide bond is ring- opened, wherein the "polyimide resin in which the imide bond is partially ring-opened" causes ring-opening of the imide bond. The friction body, which is a polyimide resin having a dielectric constant higher than that of a polyimide resin that does not have a dielectric constant . The dielectric constant ε when the dielectric constant is a vacuum ₀ 12. The friction body according to claim 11, wherein: 12. The friction body according to claim 11, wherein the "polyimide resin in which a portion of the imide bond is ring-opened" is a polyimide resin having a ring-opening degree of 1% or more.

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