Liquid detection sensor

Abstract

The present invention provides a liquid detection sensor which has versatility and can prevent deterioration of a metal-air cell which is a power source even if installed for extended periods of time, and in which the metal-air cell that is a power source can exhibit excellent power generating performance.　The present invention is a liquid detection sensor, comprising a metal-air cell having a positive electrode, a negative electrode, and an electrolyte component located between the positive electrode and the negative electrode, wherein the electrolyte component is sealed inside a resin bag, and the resin of the resin bag has dissolving or dispersing characteristics in a liquid for detection.

Description

Technical Field

[0001] The present invention relates to a liquid detection sensor provided with a metal-air battery, and more particularly to a liquid detection sensor having excellent power generation performance and excellent long-term storage stability.

Background Art

[0002] In buildings, underground facilities, factories, medical sites, etc., liquid detection sensors for detecting liquid leakage and flooding may be used. The liquid detection sensor is arranged at a location where liquid leakage and flooding should be prevented. The liquid detection sensor detects liquid leakage by capturing an electrical change that occurs when a liquid comes into contact from the outside.

[0003] As a liquid detection sensor, for example, there is a liquid detection sensor for a medical site provided with a water battery that generates electricity by the leaked liquid (Patent Document 1). In Patent Document 1, the water battery is fixed on an absorbent member by an adhesive fixed tape, and the liquid such as blood and drip solution absorbed and diffused by the absorbent member is supplied to the entire water battery, so that the water battery generates electricity and detects liquid leakage.

[0004] Further, as a liquid detection sensor, for example, there is a liquid detection sensor for a medical site provided with a liquid leakage sensor unit composed of a magnesium battery (Patent Document 2). In Patent Document 2, the magnesium battery is formed by sequentially laminating a positive electrode sheet, a catalyst sheet, a sheet-like separator, and a negative electrode sheet, and is electrically connected to the liquid leakage sensor unit, and a transmission unit that transmits a detection signal by the power of the magnesium battery, and a reception unit that receives the detection signal transmitted from the transmission unit, and a receiving terminal having an alarm means for alarming a liquid leakage state based on the detection signal from the reception unit. The liquid leakage sensor unit detects a state in which the magnesium battery generates electricity using blood or an injection solution leaked from an injection needle as an electrolyte as a liquid leakage state.

[0005] Although it is necessary to accurately detect liquid leakage, in the liquid detection sensors of Patent Documents 1 and 2 in which the detection target such as blood functions as an electrolyte, there is no particular proposal other than the detection of blood and the like at a medical site as a liquid detection target.

[0006] On the one hand, detecting liquid leakage and waterlogging is required not only in the medical field but also in a wide range of fields such as buildings, underground facilities, factories, etc. The liquid detection sensor may be required to have versatility such as detecting water and detecting oil. However, as described above, the liquid detection sensors of Patent Documents 1 and 2 have poor versatility.

[0007] In addition, when imparting versatility to the liquid detection sensor, when monitoring liquid leakage and waterlogging in buildings, underground facilities, factories, etc. with the liquid detection sensor, the monitor may monitor from a location away from the site of liquid leakage and waterlogging. In order for the liquid detection sensor to reliably transmit an alarm to a location away from the site of liquid leakage and waterlogging, it is necessary to improve the power generation performance of the battery mounted on the liquid detection sensor.

[0008] When a metal-air battery is used as the power source mounted on the liquid detection sensor, the power generation performance of the metal-air battery may be improved by using an alkali metal salt such as sodium chloride or potassium chloride as the electrolyte. For example, when an alkali metal salt is previously included in the separator of the metal-air battery and the separator containing the alkali metal salt comes into contact with water, which is the liquid to be detected, the ionic conductivity between the positive electrode and the negative electrode is improved by the action of the water containing the alkali metal salt, so that the metal-air battery can exhibit excellent power generation performance.

[0009] However, if the liquid detection sensor is installed for a long time with the separator containing the alkali metal salt, the alkali metal salt in the separator may absorb moisture and liquefy, deteriorating the negative electrode of the metal-air battery. If the negative electrode of the metal-air battery deteriorates during long-term installation of the liquid detection sensor, there is a problem that liquid leakage and waterlogging cannot be accurately detected.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] In view of the above circumstances, an object of the present invention is to provide a liquid detection sensor that has versatility, can prevent deterioration of a metal-air battery as a power source even when installed for a long period of time, and can exhibit excellent power generation performance of the metal-air battery as a power source.

MEANS FOR SOLVING THE PROBLEMS

[0012] The gist of the configuration of the present invention is as follows. [1] A metal-air battery having a positive electrode, a negative electrode, and an electrolytic solution component located between the positive electrode and the negative electrode, wherein the electrolytic solution component is enclosed inside a resin-made bag, and the resin of the resin-made bag has solubility or dispersibility in a liquid to be detected, which is a liquid detection sensor. [2] The liquid detection sensor according to [1], wherein the resin of the resin-made bag is a water-soluble resin or an oil-soluble resin. [3] The liquid detection sensor according to [1] or [2], wherein there is one or more resin-made bags in which the electrolytic solution component is enclosed. [4] The liquid detection sensor according to any one of [1] to [3], further comprising a support member having voids and supporting the positive electrode and the negative electrode between the positive electrode and the negative electrode. [5] The liquid detection sensor according to [4], wherein the resin-made bag in which the electrolytic solution component is enclosed is carried on the support member. [6] The liquid detection sensor according to any one of [1] to [5], wherein the resin-made bag in which the electrolytic solution component is enclosed is disposed between the positive electrode and the negative electrode. [7] The liquid detection sensor according to [4], wherein the resin-made bag in which the electrolytic solution component is enclosed is disposed between the support member and the positive electrode and / or between the support member and the negative electrode. [8] The liquid detection sensor according to any one of [1] to [7], wherein the electrolytic solution constituent contains water, an alkali metal salt, or an aqueous solution of an alkali metal salt. [9] The liquid detection sensor according to any one of [1] to [8], wherein the active material of the negative electrode contains at least one metal selected from the group consisting of magnesium (Mg), aluminum (Al), lithium (Li), calcium (Ca), and zinc (Zn).

[10] The liquid detection sensor according to any one of [1] to [9], further comprising a notification unit that receives power from the metal-air battery and notifies liquid detection.

[11] The liquid detection sensor according to any one of [1] to [9], further comprising a notification unit capable of wirelessly transmitting the detection signal of the metal-air battery to a receiving unit.

[12] The liquid detection sensor according to any one of [1] to

[11] , which is a water detection sensor.

[13] The liquid detection sensor according to any one of [1] to

[11] , which is an oil detection sensor.

[0013] In the aspect of [1] above, when the liquid to be detected by the liquid detection sensor comes into contact with the resin bag of the metal-air battery, the resin bag dissolves in the liquid to be detected, and the electrolytic solution constituent enclosed inside the resin bag is released between the positive electrode and the negative electrode of the metal-air battery. When the electrolytic solution constituent is released between the positive electrode and the negative electrode of the metal-air battery, the metal-air battery generates electricity or its power generation performance is improved, and the liquid detection sensor notifies the outside that the liquid to be detected has been detected by the power generation of the metal-air battery.

Advantages of the Invention

[0014] According to an aspect of the liquid detection sensor of the present invention, by enclosing the electrolyte constituent components of a metal-air battery, which is a power source, inside a resin bag having solubility in the liquid to be detected, the versatility such as water detection and oil detection is improved by appropriately selecting the resin type of the resin bag. Further, according to an aspect of the liquid detection sensor of the present invention, since the electrolyte constituent components of the metal-air battery are enclosed inside the resin bag, it is possible to prevent the metal-air battery from deteriorating due to the electrolyte constituent components even when the liquid detection sensor is installed for a long period. Further, according to an aspect of the liquid detection sensor of the present invention, since the electrolyte constituent components of the metal-air battery are enclosed inside the resin bag, it is possible to use an electrolyte constituent component that imparts excellent power generation performance to the metal-air battery while preventing the deterioration of the metal-air battery, so that the metal-air battery can exhibit excellent power generation performance.

[0015] According to an aspect of the liquid detection sensor of the present invention, when the resin of the resin bag is a water-soluble resin, it functions as a water detection sensor, and when the resin of the resin bag is an oil-soluble resin, it functions as an oil detection sensor.

[0016] According to an aspect of the liquid detection sensor of the present invention, since there are a plurality of resin bags enclosing the electrolyte constituent components, the electrolyte constituent components are smoothly supplied to the entire electrode, so that the power generation efficiency of the metal-air battery is improved.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0018] Hereinafter, the liquid detection sensor according to the embodiment of the present invention will be described in detail. First, the liquid detection sensor according to the first embodiment of the present invention will be described. Note that FIG. 1 is a side view for explaining the outline of the liquid detection sensor according to the first embodiment of the present invention, and FIG. 2 is a side view for explaining the state at the time of liquid detection of the liquid detection sensor according to the first embodiment of the present invention.

[0019] As shown in FIG. 1, the liquid detection sensor 1 according to the first embodiment of the present invention includes a metal-air battery 10 and a notification unit 100 connected to the metal-air battery 10 via a wire unit 101. When the notification unit 100 receives the power generated from the metal-air battery 10 via the wire unit 101, it has a function of notifying liquid detection by a notification means.

[0020] The metal-air battery 10 includes a positive electrode 11, a negative electrode 12 facing the positive electrode 11, and a separator 13 having a gap located between the positive electrode 11 and the negative electrode 12. In the metal-air battery 10 of the liquid detection sensor 1, the positive electrode 11, the separator 13, and the negative electrode 12 are all in a sheet shape and have a laminate structure laminated in the order of the positive electrode 11, the separator 13, and the negative electrode 12. Further, the peripheral edge portion 14 of the separator 13 extends outward from the positive electrode 11 and the negative electrode 12 and is exposed from the positive electrode 11 and the negative electrode 12. The separator 13 functions as a support member that supports the positive electrode 11 and the negative electrode 12 at a predetermined interval in order to prevent the positive electrode 11 and the negative electrode 12 from short-circuiting by coming into contact with each other.

[0021] In the metal-air battery 10, an electrolytic solution component 20 is disposed between the positive electrode 11 and the negative electrode 12. That is, the electrolytic solution component 20 is interposed between the positive electrode 11 and the negative electrode 12. The electrolytic solution component 20 is a component constituting the electrolytic solution of the metal-air battery 10 or the electrolytic solution of the metal-air battery 10. The metal-air battery 10 starts self-power generation when the positive electrode 11 and the negative electrode 12 come into contact with the electrolytic solution.

[0022] As shown in FIG. 1, the electrolytic solution component 20 is enclosed inside a resin-made bag body 21. Therefore, the electrolytic solution component 20 is in a state of not contacting either the positive electrode 11 or the negative electrode 12. The form of the resin-made bag body 21 is, for example, a thin-film bag-shaped member, a film-shaped bag-shaped member, a capsule-shaped member such as a microcapsule, etc. The resin-made bag body 21 contains the electrolytic solution component 20 and hermetically packages a certain amount of the electrolytic solution component 20. Therefore, the resin-made bag body 21 functions as a shell.

[0023] In the metal-air battery 10, there are a plurality of resin-made bag bodies 21 in which the electrolytic solution component 20 is enclosed, and the electrolytic solution component 20 is divided into a plurality of portions by a certain amount and enclosed inside each resin-made bag body 21. Further, the resin-made bag body 21 in which the electrolytic solution component 20 is enclosed is supported by a separator 13 having a porous structure. Since the resin-made bag body 21 in which the electrolytic solution component 20 is enclosed is supported by the separator 13, the electrolytic solution component 20 is interposed between the positive electrode 11 and the negative electrode 12. The resin-made bag body 21 in which the electrolytic solution component 20 is enclosed is supported in a dispersed state on the surface portion and inside of the separator 13. In FIG. 1, a plurality of resin-made bag bodies 21 in which the electrolytic solution component 20 is enclosed are supported over the entire separator 13.

[0024] The resin-made bag body 21 is formed of a resin having solubility or dispersibility in the liquid to be detected by the liquid detection sensor 1. When the liquid to be detected by the liquid detection sensor 1 is water or a liquid containing water, the resin-made bag body 21 is formed of, for example, a water-soluble resin. Since the resin-made bag body 21 is formed of a water-soluble resin, the liquid detection sensor 1 functions as a water detection sensor.

[0025] Examples of the water-soluble resin include a resin composition containing 100 parts by mass of a polyvinyl alcohol-based resin (A) containing copolymerized units composed of sulfonic acid groups or carboxyl groups, and 3 to 100 parts by mass of an addition reaction product (B) obtained by subjecting 1 mol of a trivalent to hexavalent polyhydric alcohol to an addition reaction with 1 to 4 mol of an alkylene oxide.

[0026] The polyvinyl alcohol-based resin (A) is a saponified product of a polyvinyl ester containing copolymerized units composed of sulfonic acid groups or carboxyl groups. Examples of the vinyl ester include vinyl acetate, vinyl propionate, and vinyl formate. These compounds may be used alone or in combination of two or more.

[0027] The monomer containing a sulfonic acid group is not particularly limited as long as it is copolymerizable with a vinyl ester and a sulfonic acid group or its salt is present in the polyvinyl alcohol-based resin after saponification. Specifically, for example, 2-(meth)acrylamide-2-methylpropanesulfonic acid, an alkali metal salt of 2-(meth)acrylamide-2-methylpropanesulfonic acid, 2-(meth)acrylamide-1-methylpropanesulfonic acid, an alkali metal salt of 2-(meth)acrylamide-1-methylpropanesulfonic acid, olefin sulfonic acids such as ethylene sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid, and metal salts of the olefin sulfonic acids. These compounds may be used alone or in combination of two or more. In the present specification, “(meth)acryl” means “acryl and / or methacryl”.

[0028] The monomer containing a carboxyl group is not particularly limited as long as it can copolymerize with a vinyl ester and a carboxylic acid or its salt is present in the polyvinyl alcohol-based resin after saponification. Specifically, for example, maleic anhydride, monoalkyl maleate, dialkyl maleate, itaconic acid, alkyl itaconate, (meth)acrylic acid, allyl carboxylic acid, (meth)acrylate derived from a carboxylic acid or its salt after saponification, etc. may be mentioned. These compounds may be used alone or in combination of two or more.

[0029] The content of the above copolymerized unit in the polyvinyl alcohol-based resin is not particularly limited, but for example, from the balance of excellent water solubility and mechanical strength, 0.1 to 20 mol% may be mentioned. The saponification degree of the polyvinyl alcohol-based resin (A) is, for example, 40 mol% or more and 100 mol% or less. Further, the viscosity average polymerization degree of the polyvinyl alcohol-based resin (A) is, for example, 200 or more and 10000 or less.

[0030] Examples of the trivalent to hexavalent polyhydric alcohol which is a raw material of the addition reaction product (B) include glycerin, trimethylolpropane, diglycerin, pentaerythritol, xylose, arabinose, ribulose, sorbitol, etc. Examples of the alkylene oxide which is a raw material of the addition reaction product (B) include ethylene oxide, propylene oxide, etc. These compounds may be used alone or in combination of two or more.

[0031] Examples of the method for forming a film (filming) of the above resin composition include a method of casting an aqueous solution of the above resin composition. The resin bag body 21 of the above resin composition has a high dissolution rate in water, retains water solubility even when the electrolytic solution component 20 is enclosed for a long time, and is also excellent in mechanical strength.

[0032] In addition, examples of the water-soluble resin include a resin complex of at least one resin selected from polyvinyl alcohol-based polymers, polysaccharides, and acrylic resins. Examples of the embodiment of the resin bag 21 using the resin complex include a resin laminate having a first layer containing a polyvinyl alcohol-based polymer and a second layer containing at least one resin selected from polysaccharides and acrylic resins.

[0033] Examples of the polyvinyl alcohol-based polymer include those prepared by polymerizing vinyl ester-based monomers and saponifying the resulting polyvinyl ester-based polymer. Examples of the vinyl ester-based monomers include vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl laurate, vinyl stearate, vinyl benzoate, and the like. These compounds may be used alone or in combination of two or more.

[0034] The polyvinyl alcohol-based polymer may be a copolymer of a vinyl ester-based monomer and another monomer copolymerizable with the vinyl ester-based monomer. Examples of the other monomer include olefins having 2 to 30 carbon atoms such as ethylene, propylene, and butene; (meth)acrylic acid; (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, dodecyl (meth)acrylate, and octadecyl (meth)acrylate; (meth)acrylamides such as (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, diacetone(meth)acrylamide, (meth)acrylamidopropyldimethylamine, and N-methylol(meth)acrylamide; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, dodecyl vinyl ether, and stearyl vinyl ether; vinyl cyanides such as (meth)acrylonitrile; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl fluoride, and vinylidene fluoride; allyl compounds such as allyl acetate and allyl chloride; maleic acid; maleic acid esters; itaconic acid; itaconic acid esters; vinyl silyl compounds such as vinyltrimethoxysilane; isopropenyl acetate; vinyl amides such as N-vinylformamide, N-methyl-N-vinylformamide, N-vinylacetamide, and N-methyl-N-vinylacetamide; N-vinyl-2-pyrrolidones; N-vinyl-2-caprolactam; sulfonic acid group-containing monomers such as 2-(meth)acrylamido-2-methylpropanesulfonic acid, 2-(meth)acrylamido-1-methylpropanesulfonic acid, ethylenesulfonic acid, allylsulfonic acid, and methacrylic sulfonic acid. These compounds may be used alone or in combination of two or more.

[0035] The saponification degree of the polyvinyl alcohol-based polymer is, for example, 75 mol% or more and 99 mol% or less. The viscosity average polymerization degree of the polyvinyl alcohol-based polymer is, for example, 300 or more and 2500 or less. As a method for preparing the first layer, for example, a method using a polyvinyl alcohol-based polymer solution in which a polyvinyl alcohol-based polymer is dissolved in a solvent (for example, a casting film formation method, a solution coating method, a wet film formation method, a gel film formation method, etc.) can be mentioned.

[0036] The second layer contains at least one resin selected from polysaccharides and acrylic resins. Examples of the polysaccharides in the second layer include starches and cellulose-based resins.

[0037] Examples of starches include natural-derived starches such as potato starch, corn starch, wheat starch, and rice starch; starches obtained by heating and gelatinizing natural-derived starches and drying them; processed starches such as acetylated oxidized starch, sodium octenyl succinate starch, acetic acid starch, oxidized starch, hydroxypropyl starch, hydroxypropyl-phosphorus crosslinked starch, monoesterified phosphate crosslinked starch, phosphorylated starch, and nitrate starch. Examples of cellulose-based resins include carboxymethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, and methyl cellulose. These compounds may be used alone or in combination of two or more.

[0038] Examples of acrylic resins include polyacrylamide.

[0039] As a method for preparing the second layer, for example, a method using a resin solution in which at least one resin selected from polysaccharides and acrylic resins is dissolved in a solvent (for example, a casting film formation method, a solution coating method, a wet film formation method) can be mentioned.

[0040] As a method for preparing a resin laminate having a first layer and a second layer, for example, a method of laminating the first layer and the second layer after preparing them in advance; a method of coating a coating liquid containing at least one resin selected from polysaccharides and acrylic resins on the first layer prepared in advance; a method of coating a coating liquid for forming a first layer containing a polyvinyl alcohol-based polymer on the second layer prepared in advance; a method of co-extruding the first layer and the second layer; a method of extruding or coating and laminating the second layer on the first layer before the first layer is completely dried or cooled when manufacturing the first layer, and drying or cooling the first layer and the second layer simultaneously, etc. can be mentioned.

[0041] In addition, examples of water-soluble resins other than the above include water-soluble vinyl resins such as polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, and polyvinyl methylene ether; polyether resins such as polyethylene oxide; cellulose resins such as carboxymethyl cellulose, hydroxypropyl cellulose, and hydroxyethyl cellulose; acrylic resins such as poly(meth)acrylate; and polysaccharide-based polymers such as alginic acid, pullulan, and xanthan.

[0042] The method of enclosing the electrolyte constituent 20 in the resin bag is not particularly limited. For example, after putting the electrolyte constituent 20 into the resin bag from the opening of the resin bag, the opening of the resin bag is adhered or heat-sealed and enclosed. Examples include methods of enclosing using a microcapsule manufacturing method using W / O dispersion or O / W dispersion. In addition, the method of supporting a plurality of resin bags 21 in which the electrolyte constituent 20 is enclosed on the separator 13 is not particularly limited. For example, a method of press-fitting the resin bag 21 into the void portion of the separator 13, a method of dispersing the resin bag 21 in a dispersion medium such as a solvent and then impregnating the separator 13 and drying and removing the dispersion medium, a method of dividing the separator 13 into a plurality, arranging the resin bag 21 between them, and then adhering the separator 13, etc. can be mentioned.

[0043] As the electrolyte constituent 20 enclosed in the resin bag 21 whose resin type is a water-soluble resin, for example, alkali metal salts such as salts of alkali metals and halogens like sodium chloride and potassium chloride, or aqueous solutions of the alkali metal salts can be mentioned. Also, as another electrolyte constituent 20, water can be mentioned. Note that even if water, an alkali metal salt, or an aqueous solution of an alkali metal salt is stored inside the resin bag 21 which is a water-soluble resin, since salting out occurs inside the resin bag 21, the resin bag 21 does not dissolve and functions as a shell.

[0044] As the active material of the negative electrode 12, magnesium (Mg), magnesium alloy, aluminum (Al), aluminum alloy, lithium (Li), lithium alloy, calcium (Ca), calcium alloy, zinc (Zn), zinc alloy, etc. can be mentioned. Among these, from the viewpoints of power generation efficiency and availability, magnesium (Mg) and magnesium alloy are preferable.

[0045] The separator 13 is formed of a material having electrical insulation, ion permeability, and liquid permeability. Examples of the material forming the separator 13 include resins such as polyethylene, polypropylene, polyethylene terephthalate, cellulose, polyamide, and acrylic resin, and glass. Also, the separator 13 is a member having voids, and examples thereof include non-woven fabric, glass fiber, woven fabric having a mesh structure, and membrane members having independent holes or connecting holes. Examples of the member having voids constituting the separator 13 include members having a porous structure.

[0046] The positive electrode 11 has a positive electrode current collector and a catalyst layer. The positive electrode current collector is a member having conductivity to transmit electrons released from the negative electrode 12 to the catalyst layer and air permeability to allow oxygen to permeate. Examples of the positive electrode current collector include wire mesh and foamed metal. The catalyst layer functions as the reaction part of the positive electrode.

[0047] Next, the power generation system of the metal-air battery 10 when water, which is the detection target of the liquid detection sensor 1, comes into contact with the metal-air battery 10 will be described. Here, for the sake of convenience of explanation, the case where the negative electrode 12 is made of magnesium (Mg) will be described. When water comes into contact with the peripheral edge 14 of the separator 13 and penetrates through the entire separator 13, the following oxidation reaction shown in (1) occurs at the negative electrode 12. Also, at the positive electrode 11, the following reduction reaction shown in (2) occurs. From the above, as for the entire metal-air battery 10, the reaction shown in (3) occurs, and the metal-air battery 10 discharges, that is, self-generates electricity. (1) 2Mg → 2Mg2 + + 4e - (2) O2 + 2H2O + 4e - → 4OH - (3) 2Mg + O2 + 2H2O → 2Mg(OH)2

[0048] Next, the detection operation when the liquid detection sensor 1 detects water, which is the detection target, will be described. As shown in FIG. 2, when the water 110, which is the detection target, comes into contact with the metal-air battery 10 of the liquid detection sensor 1, it comes into contact with the peripheral edge 14 of the separator 13 and then penetrates through the entire separator 13. As the water 110, which is the detection target, penetrates through the entire separator 13, the resin bag body 21 formed of a resin having solubility or dispersibility in the water 110 dissolves or disperses. That is, the resin bag body 21 is destroyed by the water 110, which is the detection target. When the resin bag body 21 dissolves or disperses, the electrolyte constituent 20 (for example, sodium chloride, water containing sodium chloride) encapsulated in the resin bag body 21 is released into the water 110. Also, as described above, when the water 110, which is the detection target, penetrates through the separator 13, the water 110 acts as an electrolyte, so the metal-air battery 10 discharges. When the metal-air battery 10 discharges, since the electrolyte constituent 20 released from the resin bag body 21 is contained in the water 110 acting as an electrolyte, the ionic conductivity between the positive electrode 11 and the negative electrode 12 is improved by the action of the electrolyte constituent 20, and the power generation performance of the metal-air battery 10 is improved.

[0049] When the metal-air battery 10 generates electricity, the power from the metal-air battery 10 is supplied to the notification unit 100 through the wire part 101. When the notification unit 100 receives the power generated from the metal-air battery 10, the notification unit 100 notifies liquid detection by the provided notification means.

[0050] In the liquid detection sensor 1, since the electrolyte component 20 of the metal-air battery 10, which is the power source, is enclosed inside the resin-made bag body 21 having solubility or dispersibility with respect to the water 110 which is the detection target, it can be used in any field for water detection, and the versatility is improved. Further, in the liquid detection sensor 1, since the electrolyte component 20 of the metal-air battery 10 is enclosed inside the resin-made bag body 21, it is possible to prevent the metal-air battery 10 from deteriorating due to the electrolyte component 20 even when the liquid detection sensor 1 is installed for a long period, and the detection accuracy is improved. Also, in the liquid detection sensor 1, since the electrolyte component 20 of the metal-air battery 10 is enclosed inside the resin-made bag body 21, it is possible to use the electrolyte component 20 which imparts excellent power generation performance to the metal-air battery 10 while preventing the deterioration of the metal-air battery 10, so that the metal-air battery 10 can exhibit excellent power generation performance. Furthermore, since the metal-air battery 10 exhibits excellent power generation performance, the amount of power received by the notification unit 100 increases, and the notification performance of the notification unit 100 is improved.

[0051] Also, in the liquid detection sensor 1, since there are a plurality of resin-made bag bodies 21 in which the electrolyte component 20 is enclosed, the electrolyte component 20 is smoothly supplied to the entire electrode, so that the power generation efficiency of the metal-air battery 10 is improved.

[0052] Next, the liquid detection sensor according to the second embodiment of the present invention will be described. Since the main part of the liquid detection sensor according to the second embodiment is common to the liquid detection sensor according to the first embodiment, the same components as those of the liquid detection sensor according to the first embodiment will be described using the same reference numerals. Note that FIG. 3 is a side view for explaining the outline of the liquid detection sensor according to the second embodiment of the present invention, and FIG. 4 is a side view for explaining the state at the time of liquid detection of the liquid detection sensor according to the second embodiment of the present invention.

[0053] The liquid detection sensor according to the first embodiment is a water detection sensor, and the resin bag is formed of a resin having solubility or dispersibility in water. Instead of this, in the liquid detection sensor 2 according to the second embodiment, which is an oil detection sensor, the resin bag 31 in which the electrolytic solution component 30 is enclosed is formed of a resin having solubility or dispersibility in oil.

[0054] Thus, in the liquid detection sensor of the present invention, the type of the liquid to be detected can be appropriately changed by appropriately changing the solubility or dispersibility of the resin forming the resin bag. That is, the liquid detection sensor of the present invention is also excellent in versatility in that the type of the liquid to be detected can be appropriately changed.

[0055] As shown in FIG. 3, in the metal-air battery 10, the electrolytic solution component 30 is disposed between the positive electrode 11 and the negative electrode 12. The electrolytic solution component 30 is enclosed inside the resin bag 31. There are a plurality of resin bags 31 in which the electrolytic solution component 30 is enclosed, and the electrolytic solution component 30 is divided into a plurality of portions by a certain amount and enclosed inside each resin bag 31. Further, the resin bag 31 in which the electrolytic solution component 30 is enclosed is supported on the surface portion and inside of the separator 13 over the entire separator 13 having a porous structure.

[0056] The resin bag 31 is formed of an oil-soluble resin, for example, as a resin having solubility or dispersibility in oil. By forming the resin bag 31 of an oil-soluble resin, the liquid detection sensor 2 functions as an oil detection sensor.

[0057] Examples of the oil-soluble resin include terpene resins such as candelilla resin, pentaerythrityl hydrogenated rosinate, and glyceryl hydrogenated abietate; silicone resins such as trimethylsiloxysilicic acid, polymethylsilsesquioxane, and acrylic-silicone graft copolymer; and hydrocarbon resins such as polyvinyl isobutyl ether and polyisobutylene. These compounds may be used alone or in combination of two or more.

[0058] The method of enclosing the electrolytic solution constituent 30 in the resin-made bag is not particularly limited. For example, after putting the electrolytic solution constituent 20 into the resin-made bag through the opening of the resin-made bag, the opening of the resin-made bag is adhered or heat-sealed for enclosing. Examples of the method of enclosing include the method using a microcapsule manufacturing method using W / O dispersion or O / W dispersion. Further, the method of supporting a plurality of resin-made bags 31 in which the electrolytic solution constituent 30 is enclosed on the separator 13 is not particularly limited. For example, the method of press-fitting the resin-made bag 21 into the void portion of the separator 13, the method of dispersing the resin-made bag 21 in a dispersion medium such as a solvent and then impregnating the separator 13 and drying and removing the dispersion medium, and the method of dividing the separator 13 into a plurality, arranging the resin-made bag 21 therebetween, and then adhering the separator 13 are mentioned.

[0059] The oil to be detected by the liquid detection sensor 2 is not an electrolytic solution constituent of the metal-air battery 10. Therefore, the electrolytic solution is enclosed as the electrolytic solution constituent 30 in the resin-made bag 31 whose resin type is an oil-soluble resin. Examples of the electrolytic solution constituent 30 include water (an aqueous solution of an alkali metal salt) containing an alkali metal salt such as sodium chloride and potassium chloride, or water.

[0060] Next, the detection operation when the liquid detection sensor 2 detects oil as the detection target will be described. As shown in FIG. 4, when the oil 120 which is the detection target comes into contact with the metal-air battery 10 of the liquid detection sensor 2, it contacts the peripheral edge portion 14 of the separator 13, and then penetrates over the entire separator 13. As the oil 120 penetrates over the entire separator 13, the resin-made bag body 31 formed of a resin having solubility or dispersibility in the oil 120 dissolves or disperses. That is, the resin-made bag body 31 is destroyed by the oil 120 which is the detection target. When the resin-made bag body 31 dissolves or disperses, the electrolytic solution constituent 30 (for example, an aqueous solution of an alkali metal salt) enclosed in the resin-made bag body 31 is released into the oil 120. Since the electrolytic solution constituent 30 released into the oil 120 acts as an electrolytic solution, the metal-air battery 10 discharges. When the metal-air battery 10 discharges, since an aqueous solution of an alkali metal salt is released from the resin-made bag body 31 as the electrolytic solution, the ionic conductivity between the positive electrode 11 and the negative electrode 12 is improved by the action of the electrolytic solution constituent 30, and the power generation performance of the metal-air battery 10 is improved.

[0061] In the liquid detection sensor 2, the electrolytic solution constituent 30 of the metal-air battery 10 which is a power source is enclosed inside the resin-made bag body 31 having solubility or dispersibility in the oil 120 which is the detection target, so that it can be used for detecting oil. Further, in the liquid detection sensor 2, since the electrolytic solution constituent 30 of the metal-air battery 10 is enclosed inside the resin-made bag body 31, it is possible to prevent the metal-air battery 10 from being deteriorated by the electrolytic solution constituent 30 even when the liquid detection sensor 2 is installed for a long period of time, and the detection accuracy is improved.

[0062] Next, the liquid detection sensor according to the third embodiment of the present invention will be described. Note that since the main part of the liquid detection sensor according to the third embodiment is common to the liquid detection sensors according to the first and second embodiments, the same components as those of the liquid detection sensors according to the first and second embodiments will be described using the same reference numerals. Note that FIG. 5 is a side view for explaining the outline of the liquid detection sensor according to the third embodiment of the present invention.

[0063] In the liquid detection sensors according to the above-described first and second embodiments, a plurality of resin-made bags enclosing electrolyte constituent components were dispersed and carried on the surface portion and inside of the separator over the entire separator. Instead of this, as shown in FIG. 5, in the liquid detection sensor 3 according to the third embodiment, a resin-made bag 41 enclosing the electrolyte constituent component 40 is sandwiched between the positive electrode 11 or the negative electrode 12 and the separator 13. That is, the resin-made bag 41 enclosing the electrolyte constituent component 40 is interposed between the positive electrode 11 or the negative electrode 12 and the separator 13. The resin-made bag 41 enclosing the electrolyte constituent component 40 may be interposed between the positive electrode 11 and the separator 13, or may be interposed between the negative electrode 12 and the separator 13. In FIG. 5, the resin-made bag 41 enclosing the electrolyte constituent component 40 is interposed between the positive electrode 11 and the separator 13.

[0064] In the liquid detection sensor 3, one or more resin-made bags 41 enclosing the electrolyte constituent component 40 are provided between the electrode (the positive electrode 11 in FIG. 5) and the separator 13. The number of resin-made bags 41 installed may be one or plural, but from the viewpoints of ease of installation and fixing stability of the resin-made bag 41, one resin-made bag 41 is preferable. In FIG. 5, one resin-made bag 41 is provided. Therefore, in the liquid detection sensor 3 of FIG. 5, the electrolyte constituent component 40 is enclosed in the resin-made bag 41 in a united state. Further, the resin-made bag 41 enclosing the electrolyte constituent component 40 is provided over substantially the entire surface of the separator 13.

[0065] When the liquid detection sensor 3 is used as a water detection sensor, the resin-made bag 41 is formed of a water-soluble resin. Further, examples of the electrolyte constituent component 40 enclosed in the resin-made bag 41 include alkali metal salts such as salts of alkali metals and halogens such as sodium chloride and potassium chloride, or aqueous solutions of the alkali metal salts.

[0066] When the liquid detection sensor 3 is used as an oil detection sensor, the resin bag 41 is formed of an oil-soluble resin. Further, examples of the electrolytic solution constituent 40 enclosed in the resin bag 41 include water (an aqueous solution of an alkali metal salt) containing an alkali metal salt such as sodium chloride or potassium chloride, or water.

[0067] Even in the case of the liquid detection sensor 3, since the electrolytic solution constituent 40 of the metal-air battery 10 is enclosed inside the resin bag 41, it is possible to prevent the metal-air battery 10 from being deteriorated by the electrolytic solution constituent 40 even when the liquid detection sensor 3 is installed for a long period of time, and the detection accuracy is improved. Also, even in the case of the liquid detection sensor 3, since the electrolytic solution constituent 40 of the metal-air battery 10 is enclosed inside the resin bag 41, it is possible to use an electrolytic solution constituent 40 that imparts excellent power generation performance to the metal-air battery 10 while preventing the deterioration of the metal-air battery 10, so that the metal-air battery 10 can exhibit excellent power generation performance.

[0068] Next, an example of a method of using the liquid detection sensor of the present invention will be described. Here, for the sake of convenience of explanation, an example of a method of using the liquid detection sensor will be described using the liquid detection sensor 1 according to the first embodiment of the present invention. Note that FIG. 6 is an explanatory diagram of an example of a method of using the liquid detection sensor of the present invention.

[0069] As shown in FIG. 6, as the notification unit 100 connected to the metal-air battery 10 via the electric wire unit 101, for example, a transmission unit whose transmission function to the reception unit 200 operates when receiving the power generated from the metal-air battery 10 is used. When the metal-air battery 10 detects a liquid to be detected (water 110 in FIG. 6) and generates power, the notification unit 100 operates its transmission function by receiving power from the metal-air battery 10 and transmits a detection signal to the reception unit 200. Examples of the transmission unit include a wireless transmission unit and a wired transmission unit. In FIG. 6, a wireless transmission unit is used as the notification unit 100, and wireless transmission of a detection signal is possible from the notification unit 100 to the reception unit 200. As the wireless communication, for example, existing wireless systems such as wireless LAN, Bluetooth (registered trademark), and Wi-Fi can be used.

[0070] When the receiving unit 200 receives a detection signal from the notification unit 100 of the liquid detection sensor 1, it detects that leakage of the liquid to be detected (in FIG. 6, water leakage or flooding) has occurred, notifies people that water leakage or flooding has occurred, and automatically stops the device or the like as necessary.

[0071] Next, another embodiment of the liquid detection sensor of the present invention will be described. In the liquid detection sensors according to the first and second embodiments, as a method of causing the separator to carry a plurality of resin-made bags enclosing the electrolytic solution components, a method of press-fitting the resin-made bags into the void portions of the separator, a method of dispersing the resin-made bags in a dispersion medium such as a solvent and then impregnating the separator with the dispersion medium and drying and removing the dispersion medium, and a method of dividing the separator into a plurality of parts, arranging the resin-made bags therebetween, and then bonding the separator were exemplified. Instead of these, after applying a material containing the resin-made bags to the surface of the separator and drying the material, the resin-made bags may be carried and adhered to the separator. In this aspect, the resin-made bags are mainly carried and adhered to the surface portion of the separator. Further, to the material containing the resin-made bags, a dispersion medium such as a binder and an organic solvent may be added as necessary to improve the coatability on the separator surface. Since the material containing the resin-made bags becomes paste-like by including a dispersion medium such as a binder and an organic solvent, excellent coatability can be imparted to the material containing the resin-made bags.

[0072] Examples of the binder include acrylic polymers, polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), ethylene chlorotrifluoroethylene copolymer (ECTFE), perfluoroalkoxy alkane (PFA), perfluoroethylene propene copolymer (FEP), and the like. Examples of the dispersion medium include alcohol-based compounds such as ethylene glycol, propylene glycol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, and diethylene glycol, and organic solvents such as N-methylpyrrolidone.

[0073] Also, in order to dispose a resin bag between the positive electrode and the negative electrode, in the liquid detection sensors according to the first and second embodiments, a resin bag enclosing an electrolytic solution component is carried by a separator, and in the liquid detection sensor according to the third embodiment, the resin bag is sandwiched between the positive electrode or the negative electrode and the separator. Instead of this, a material containing a resin bag may be applied to the surface of the positive electrode facing the negative electrode, and then the material may be dried to carry and adhere the resin bag to the surface of the positive electrode facing the negative electrode. By carrying and adhering the resin bag to the surface of the positive electrode facing the negative electrode, the resin bag is disposed between the positive electrode and the negative electrode. More specifically, when a separator is provided between the positive electrode and the negative electrode, the resin bag is disposed between the positive electrode and the separator.

[0074] Further, in the material containing the resin bag, in order to improve the coatability on the positive electrode surface, etc., a binder, a dispersion medium such as an organic solvent, etc. may be added as necessary. Examples of the binder include acrylic polymers, polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), ethylene chlorotrifluoroethylene copolymer (ECTFE), perfluoroalkoxy alkane (PFA), perfluoroethylene propene copolymer (FEP), etc. Examples of the dispersion medium include alcohol-based compounds such as ethylene glycol, propylene glycol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, diethylene glycol, and organic solvents such as N-methylpyrrolidone.

[0075] Also, in the liquid detection sensor according to the first embodiment, the resin bag was formed of a water-soluble resin, and in the liquid detection sensor according to the second embodiment, the resin bag was formed of an oil-soluble resin. Instead, in one metal-air battery, a resin bag formed of a water-soluble resin and a resin bag formed of an oil-soluble resin may be used in combination. By using the resin bag of the water-soluble resin and the resin bag of the oil-soluble resin in combination, one liquid detection sensor can detect both water and oil. Further, in the liquid detection sensors according to the first to third embodiments, a separator was provided between the positive electrode and the negative electrode. However, if short circuit can be prevented by the contact between the positive electrode and the negative electrode, the separator may not be provided. Also, any support member that supports the positive electrode and the negative electrode with a predetermined interval therebetween may be used instead of the separator.

[0076] Also, in the liquid detection sensor according to the third embodiment, a resin bag was sandwiched between one electrode (positive electrode) and the separator. Instead, resin bags may be respectively sandwiched between the positive electrode and the separator and between the negative electrode and the separator. Also, in the liquid detection sensor according to the third embodiment, one resin bag was sandwiched between one electrode and the separator. Instead, a plurality of resin bags may be sandwiched between one electrode and the separator.

[0077] Also, in the example of the method of using the liquid detection sensor, the notification unit was a transmission unit having a transmission function to the reception unit. Instead, it may be a liquid detection display unit that receives power from the metal-air battery and notifies people of the liquid detection. Examples of the display means of the liquid detection display unit include, for example, lighting of a warning lamp, emission of a warning sound, etc.

Industrial Applicability

[0078] The liquid detection sensor of the present invention has versatility, can prevent the deterioration of a metal-air battery as a power source even when installed for a long period of time, and the metal-air battery as a power source can exhibit excellent power generation performance. Therefore, it can be used in a wide range of liquid detection fields such as detecting building leaks and rain leaks, detecting leaks of various equipment, factories, etc., detecting waterlogging of roads and underground facilities, etc., detecting the arrival of a dangerous water level by detecting the water level of rivers, lakes, etc., detecting blood leakage and drug solution leakage in a medical site, detecting urination in a nursing care site, etc.

Explanation of symbols

[0079] 1, 2, 3 Liquid detection sensor 10 Metal-air battery 11 Positive electrode 12 Negative electrode 13 Separator 20, 30, 40 Electrolyte components 21, 31, 41 Resin bags 100 Notification unit

Claims

1. A metal-air battery having a positive electrode, a negative electrode, and an electrolytic solution component located between the positive electrode and the negative electrode, wherein the electrolytic solution component is enclosed inside a resin-made bag, and the resin of the resin-made bag has solubility or dispersibility in a liquid to be detected, the oil detection sensor.

2. The oil detection sensor according to claim 1, wherein the resin of the resin-made bag is an oil-soluble resin.

3. The oil detection sensor according to claim 1 or 2, wherein there is one or more resin-made bags enclosing the electrolytic solution component.

4. The oil detection sensor according to any one of claims 1 to 3, further comprising a support member having a void between the positive electrode and the negative electrode and supporting the positive electrode and the negative electrode.

5. The oil detection sensor according to claim 4, wherein the resin-made bag enclosing the electrolytic solution component is carried by the support member.

6. The oil detection sensor according to any one of claims 1 to 5, wherein the resin-made bag enclosing the electrolytic solution component is disposed between the positive electrode and the negative electrode.

7. The oil detection sensor according to claim 4, wherein the resin-made bag enclosing the electrolytic solution component is disposed between the support member and the positive electrode and / or between the support member and the negative electrode.

8. The oil detection sensor according to any one of claims 1 to 7, wherein the electrolytic solution component contains water or an aqueous solution of an alkali metal salt.

9. The oil detection sensor according to any one of claims 1 to 8, wherein the active material of the negative electrode contains at least one metal selected from the group consisting of magnesium (Mg), aluminum (Al), lithium (Li), calcium (Ca), and zinc (Zn).

10. The oil detection sensor according to any one of claims 1 to 9, having a notification unit that receives power from the metal-air battery and notifies liquid detection.

11. The oil detection sensor according to any one of claims 1 to 9, having a notification unit capable of wirelessly transmitting the detection signal of the metal-air battery to a receiving unit.

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