JP5773723B2 - Moisture sensor - Google Patents

Description

  The present invention relates to a structure of a moisture sensor mounted on an adult diaper or an artificial dialysis sheet.

  Adults with dementia symptoms need care. For example, diapers (for adults) may be used for excretion assistance. Conventional diapers are equipped with a moisture sensor that detects urination and the like so that a caregiver can recognize the presence or absence of excretion by the care recipient.

  In addition, since the treatment of artificial dialysis takes a long time, a patient with dementia symptoms may pull out the needle himself during the treatment and bleed from his arm. For this reason, at the time of artificial dialysis, an artificial dialysis sheet is provided under the patient's arm, and the above-mentioned moisture sensor is provided on this, so that leaked blood is detected.

  FIG. 5 is a perspective view of a conventional diaper worn by an adult who needs care.

  The diaper 1 has a built-in moisture sensor 2 for detecting urination. The moisture sensor 2 is formed in an elongated sheet shape, and a notification device 3 is attached to the moisture sensor 2. The notification device 3 emits a warning sound when the moisture sensor 2 detects urine. With this warning sound, the caregiver or the like can grasp the urination of the care recipient and the replacement time of the diaper 1 (see, for example, Patent Document 1 and Patent Document 2).

  FIG. 6 is a plan view of a conventional diaper.

  As shown in the figure, the moisture sensor 2 is disposed at a substantially central portion of the diaper 1. The moisture sensor 2 includes a pair of electrodes 4 and 5 for detecting urine, and normally, the pair of electrodes 4 and 5 is electrically insulated. However, the pair of electrodes 4 and 5 are electrically connected by urination and become conductive. The notification device 3 includes a connector 6 connected to the electrodes 4 and 5. The connector 6 is attached to the moisture sensor 2 so as to span between the pair of electrodes 4 and 5. When the pair of electrodes 4 and 5 are electrically connected by urination, the notification device 3 detects conduction between the pair of electrodes 4 and 5 via the connector 6 and emits a warning sound.

  FIG. 7 is a diagram schematically showing a specific structure of a conventional moisture sensor. FIG. 8 is a diagram schematically showing a cross-sectional structure of the moisture sensor.

  The moisture sensor 2 has a six-layer structure. The moisture sensor 2 includes a waterproof film 7, Japanese paper 8, electrodes 9, 10 and Japanese paper 11. The electrodes 9 and 10 are made of an aluminum foil cut into a strip shape. The waterproof film 7 is bonded to the lower surface of the Japanese paper 8 via a glue (chemical glue) 12. Electrodes 9 and 10 are bonded to the upper surface of the Japanese paper 8. Paraffin (not shown) is employed as the adhesive. A conductive adhesive 13 is interposed between the Japanese paper 8 and the Japanese paper 11, and electrodes 9 and 10 are embedded in the conductive adhesive 13. This conductive adhesive 13 is disclosed in a patent gazette (Patent No. 3274130) relating to a patent right owned by the applicant of the present application, exhibits insulation in a dry state, and exhibits conductivity when absorbing moisture. It is shown.

  For example, when urination is performed on the Japanese paper 11, urine moisture passes through the Japanese paper 11 and reaches the conductive adhesive 13. Thereby, the said conductive adhesive 13 shows electroconductivity, between the electrode 9 and the electrode 10 is conduct | electrically_connected, and the moisture sensor 2 detects urination.

JP 2002-55074 A JP 2011-75347 A

  The electrodes 9 and 10 are configured by cutting a sheet-like aluminum foil into a strip shape as described above. However, in order to form the electrodes 9 and 10 by such a process, a required rust prevention process is needed for the surrounding surface (front and back surfaces) of aluminum foil on production technology. This is because the sheet-like aluminum foil as a raw material may be corroded if the aluminum foil peripheral surface is in a stripped state.

  However, when such a rust prevention treatment is performed, the portion showing good conductivity is only a cut surface, and it cannot be denied that the conductivity of the electrodes 9 and 10 is hindered. Moreover, the manufacturing process becomes complicated and the manufacturing cost of the moisture sensor 2 increases. Furthermore, as described above, the electrodes 9 and 10 are bonded to the Japanese paper 8 via paraffin. However, since the paraffin exhibits hydrophobicity, the electrodes 9 and 10 have water repellency. And from such a situation, there existed a problem that the moisture sensor 2 was not able to exhibit the design sensitivity.

  In order to solve such a problem, the present applicant invented the moisture sensor according to Patent Document 2 and filed a patent application. In this moisture sensor, a pair of electrodes for detecting the presence of moisture is made of water-soluble conductive ink (aqueous carbon ink), and the electrodes are printed on the sheet using the ink. Thereby, the moisture detection sensitivity is improved.

  However, when the electrode is composed of the water-based carbon ink or the like, the durability of the electrode is lowered. That is, when a large amount of moisture exists around the electrode, the electrode may be melted. If the electrode is melted, not only the detection sensitivity is remarkably lowered but also the detection is impossible.

  The present invention has been made based on such a background, and an object of the present invention is to provide a moisture sensor that is used in an adult diaper or an artificial dialysis sheet that exhibits high sensing accuracy and excellent durability. Is to provide.

(1) The moisture sensor according to the present invention includes a first sheet having water absorption, a pair of strip electrodes arranged in parallel on the upper surface of the first sheet at a predetermined distance, and a non- conductive adhesive. And a second sheet bonded to the upper surface of the first sheet so as to sandwich the pair of band-shaped electrodes, and the pair of band-shaped electrodes are made of conductive glue applied on the first sheet.

  Since the strip electrode is made of conductive glue, the strip electrode is excellent in corrosion resistance. For this reason, a pair of strip electrode can be arrange | positioned on the upper surface of a 1st sheet | seat in the bare state, without performing surface rust prevention process etc. especially. Therefore, the conductivity of each strip electrode is not hindered. In addition, since the strip electrode is made of the conductive paste, the strip electrode is not easily melted even in an environment where a large amount of moisture exists, and the moisture sensing function is not significantly lowered.

  (2) The conductive paste is obtained by kneading hydrophilic carbon black in water-soluble paste containing 1% by mass to 5% by mass of potato and 74% by mass to 84% by mass of water. Is preferred.

  In this structure, since the said strip | belt-shaped electrode is formed with what is called a natural material, it does not harm a user's body. Moreover, the strip electrode is manufactured at a low cost.

  (3) The pair of strip electrodes are preferably formed by gravure printing using the conductive paste as ink.

  In this configuration, the pair of strip electrodes can be formed easily and at a lower cost.

  (4) It is preferable that a water repellent sheet is superimposed on the lower surface of the first sheet. Furthermore, a fluorescent paint may be attached to a position corresponding to the strip electrode of the water repellent sheet.

  In this configuration, since the water repellent sheet is provided, moisture does not pass through the first sheet. For this reason, when the said moisture sensor is employ | adopted for the diaper for adults or the sheet | seat for artificial dialysis, for example, it is prevented that a wearer's clothing and sheets become dirty. In addition, adult diapers and artificial dialysis sheets are regularly replaced. At the time of replacement, the connector is attached to and detached from the strip electrode. This operation may be performed at night, in which case it is difficult for the caregiver to confirm the position of the strip electrode. However, in this configuration, since the fluorescent paint is applied to the position corresponding to the strip electrode, the caregiver can easily confirm the position of the strip electrode, and the exchange operation of the adult diaper and the artificial dialysis sheet is easy. .

  According to the present invention, since the strip electrode is formed of the conductive paste having excellent corrosion resistance and durability (water resistance), the strip electrode need not be subjected to surface rust prevention treatment or the like. Therefore, the conductivity of the strip electrode is not hindered and high sensing accuracy is maintained.

FIG. 1 is a perspective view of an adult diaper equipped with a moisture sensor according to an embodiment of the present invention. FIG. 2 is a plan view of an adult diaper equipped with a moisture sensor according to an embodiment of the present invention. FIG. 3 is a schematic diagram showing the structure of a moisture sensor according to an embodiment of the present invention. FIG. 4 is a schematic diagram showing the structure of a moisture sensor according to a modification of the embodiment of the present invention. FIG. 5 is a perspective view of a conventional diaper worn by an adult who needs care. FIG. 6 is a plan view of a conventional diaper. FIG. 7 is a diagram schematically showing a specific structure of a conventional moisture sensor. FIG. 8 is a diagram schematically showing a cross-sectional structure of a conventional moisture sensor.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

[Schematic configuration]

  As FIG. 1 shows, this adult diaper 20 is used by an adult who has developed dementia symptoms that require nursing care, for example. The adult diaper 20 includes a moisture sensor 22 according to an embodiment of the present invention. The caregiver periodically replaces the adult diaper 20, but the diaper replacement operation should be performed immediately after urination or the like. The time for urination or the like has been conventionally informed to the caregiver by the urine notification device 21. The urination notification device 21 notifies the timing of urination or the like with a buzzer or the like, and the presence or absence of urination or the like is detected by the moisture sensor 22. Further, the urine leaving device 21 includes a connector 23, and the moisture sensor 22 and the urine notification device 21 are connected via the connector 23.

[Diaper body]

  The adult diaper 20 includes a diaper main body 24. The diaper main body 24 has a known structure. The diaper body 24 is made of, for example, a non-woven fabric made of a predetermined polymer, and has a sufficient capacity of moisture absorbing material. As shown in FIG. 2, both side portions 25 of the diaper main body 24 are cut out in an arc shape, and a fixing tape 27 is provided at an end portion. The user places the diaper main body 24 against the shadow and fixes it with the fixing tape 27. Accordingly, the adult diaper 20 has an underwear shape in which a leg hole 26 (see FIG. 1) is formed, and the user can obtain an excellent wearing feeling.

[Moisture sensor]

  The moisture sensor 22 is provided inside the nonwoven fabric constituting the diaper main body 24. The moisture sensor 22 is formed in a strip shape, and is disposed along the longitudinal direction of the diaper main body 24 as shown in FIG. Therefore, as shown in FIG. 1, when the user wears the adult diaper 20, the moisture sensor 22 is arranged so as to cover the crotch.

  As shown in FIG. 3, the moisture sensor 22 has a five-layer structure. That is, the moisture sensor 22 includes a main sheet 31 (an example of the “first sheet” in the present invention) and a sub-sheet 32 (an example of the “second sheet” in the present invention) disposed inside the main sheet 31. And a waterproof sheet 33 (an example of the “water-repellent sheet” in the present invention) disposed outside the main sheet 31. An adhesive 34 is interposed between the main sheet 31 and the sub sheet 32, and an adhesive 35 is also interposed between the main sheet 31 and the waterproof sheet 33. These adhesives 34 and 35 form an adhesive layer. The main sheet 31 includes a pair of electrodes 36 and 37 (an example of a “band electrode” in the present invention). The sub-sheet 32 is disposed directly under the nonwoven fabric constituting the inner wall surface of the adult diaper 20, and if moisture such as urine adheres to the nonwoven fabric, the moisture passes through the nonwoven fabric and is The sub-sheet 32 is reached.

  The main sheet 31 is formed in an elongated strip shape, and is made of Japanese paper in this embodiment. The material constituting the main sheet 31 is not necessarily limited to Japanese paper. In short, as long as it is rich in water absorption but hardly dissolves in water and has electrical insulation properties in a dry state, cloth or the like other than paper can be adopted as the material of the main sheet 31. Further, the thickness of the main sheet 31 is set to about 0.3 mm to 0.8 mm.

  The electrodes 36 and 37 are made of conductive ink. That is, in this embodiment, this ink is obtained by kneading hydrophilic carbon black in water-soluble glue. In the present embodiment, for example, a paste containing 1% by mass to 5% by mass of potato and 74% by mass to 84% by mass of water can be used as the water-soluble paste. This water-soluble paste is produced by mixing water and potato starch and stirring with heating. And if this stirring product exhibits uniform viscosity, a water-soluble paste will be manufactured by cooling this.

  But salt may be knead | mixed with the said water-soluble paste. That is, conductive glue may be used for the ink. Specifically, for example, a paste composed of 1% by mass to 5% by mass of potato, 15% by mass to 21% by mass of sodium chloride, and 74% by mass to 84% by mass of water can be employed. The amount of salt to be kneaded may be an amount in the vicinity of saturation solubility that can be dissolved in water at room temperature. This conductive paste is produced by mixing water, salt and potato starch and stirring with heating. And if this stirring product exhibits uniform viscosity, the paste with electroconductivity will be manufactured by cooling this.

  The electrodes 36 and 37 are printed on the upper surface 38 of the main sheet 31. In this case, the ink obtained by kneading hydrophilic carbon black in the water-soluble paste is used. As described above, the water-soluble paste may have conductivity. Both electrodes 36 and 37 are arranged at a predetermined distance along a direction (in the direction of arrow 39 in FIG. 3) perpendicular to the longitudinal direction of the main sheet 31 (that is, the longitudinal direction of the moisture sensor 22). The gap s between them can be set to about 5 mm to 25 mm. The width w of each electrode 36, 37 is set to about 2 mm to 25 mm. In the present embodiment, each of the electrodes 36 and 37 is configured by gravure printing using the ink. Therefore, the thickness dimension of each electrode 36 and 37 is set to be extremely small, and as a result, the flexibility of the main sheet 31 is not impaired.

  Note that the electrodes 36 and 37 may be configured by silk printing using the ink instead of the gravure printing. Further, in place of the hydrophilic carbon black, a material that improves the electrical conductivity of the electrodes 36 and 37 may be employed in addition to aluminum alloy powder and other metal powders. By adopting hydrophilic carbon black as in the present embodiment, when the diaper 20 for adults is discarded, it is necessary to separate and discard the moisture sensor 22 portion (specifically, the electrodes 36 and 37 portions). There is also an advantage that it can be treated as general garbage.

  The sub-sheet 32 is formed in an elongated strip shape similar to the main sheet 31 and completely covers the upper surface 38 of the main sheet 31. In the present embodiment, the sub sheet 32 is also made of Japanese paper, and the thickness thereof is set to about 0.3 mm to 0.8 mm. The material constituting the sub-sheet 32 is not limited to Japanese paper. In short, any material may be used as long as it has high water absorption, hardly dissolves in water, and has electrical insulation in a dry state.

  In this embodiment, the adhesive 34 is a water-soluble adhesive in which salt is kneaded. That is, the adhesive 34 has conductivity. In addition, before the sub sheet | seat 32 adhere | attaches on the main sheet | seat 31, salt solution may be absorbed into the sub sheet | seat 32 previously and may be dried. As a result, the pair of electrodes 36 and 37 are sandwiched between the main sheet 31 and the sub sheet 32, are electrically insulated during drying, and are conducted while the adhesive 34 or the sub sheet 32 absorbs water.

  Specifically, as the adhesive 34, for example, 1% by mass to 5% by mass of potato, 15% by mass to 21% by mass of sodium chloride, and 74% by mass of water are used in the same manner as the paste used in the conductive ink. % Or more and 84% by mass or less can be used. The amount of the salt may be an amount in the vicinity of the saturation solubility that can be dissolved in water at room temperature. This glue is produced by mixing water, salt and potato starch and stirring with heating. And if this stirring product exhibits uniform viscosity, the paste with electroconductivity will be manufactured by cooling this. However, in the present embodiment, the adhesive 34 has conductivity, but a paste that does not contain the above-described salt and does not have conductivity may be employed as the adhesive 34.

  The waterproof sheet 33 is formed in an elongated strip shape similar to the main sheet 31 and completely covers the lower surface of the main sheet 31. The waterproof sheet 33 is made of, for example, a polyethylene terephthalate film. Since this polyethylene terephthalate film is rich in flexibility, the flexibility of the moisture sensor 20 is not impaired. The material constituting the waterproof sheet 33 is not limited to the polyethylene terephthalate film, and an ethylene vinyl acetate copolymer film, a polytetrafluoroethylene film, or the like may be employed. The waterproof sheet 33 may be omitted.

  The adhesive 35 adheres the waterproof sheet 33 to the main sheet 31. As the adhesive 35, urethane paste or other general-purpose industrial paste can be used.

[Action / Effect]

  For example, when the user urinates while wearing the adult diaper 20, the moisture sensor 22 detects urination, and the urination leaving device 21 notifies the caregiver of the urination. Since the electrodes 36 and 37 of the moisture sensor 22 are made of the above-described adhesive paste, the electrodes 36 and 37 are excellent in corrosion resistance. For this reason, unlike the prior art, the surfaces of the electrodes 36 and 37 need not be subjected to rust prevention treatment or the like, and the electrodes 36 and 37 are arranged on the main sheet 31 in a bare state. That is, the conductivity of the electrodes 36 and 37 is not hindered. Therefore, when there is urination, the moisture adhering to the main sheet 31 reaches the adhesive 34, and the adhesive 34 exhibits conductivity and immediately conducts between the electrodes 36 and 37. As a result, urination is detected quickly and reliably.

  In particular, in the present embodiment, since the electrodes 36 and 37 are made of the above glue, for example, even if a large amount of urine is discharged, the electrodes are not easily melted by moisture. Therefore, the sensing function of the moisture sensor 22 is not impaired, and durability (water resistance) is improved. In the case where a polymer having a predetermined conductivity is adopted as the material constituting the diaper main body 24, the adhesive 34 does not need to have electrical conductivity, and the diaper main body 24 has the electrodes 36, 37 when urinating. Conduct between them.

  In the present embodiment, the pair of electrodes 36 and 37 are formed by gravure printing using the above-described conductive paste as ink as described above. Therefore, there is an advantage that the electrodes 36 and 37 are formed easily and inexpensively. The electrodes 36 and 37 can also be formed by silk printing instead of gravure printing.

  Furthermore, in the present embodiment, since the waterproof sheet 33 is superimposed on the lower surface of the main sheet 31, moisture does not pass through the main sheet 31. For this reason, even when urination or the like occurs, the clothes of the user are not soiled.

[Modification]

  As shown in FIG. 4, the moisture sensor 42 according to this modification is different from the moisture sensor 22 according to the above embodiment in that fluorescent paints 44 and 45 are applied to the lower surface 43 of the waterproof sheet 33. The fluorescent paints 44 and 45 are printed on the lower surface 43 of the waterproof sheet 33. The fluorescent paint 44 is applied in the form of an elongated strip, and is disposed so as to face the electrode 36. Similarly, the fluorescent paint 45 is also applied in the form of an elongated strip, and is disposed so as to face the electrode 37.

  The adult diaper 20 is regularly replaced. At the time of replacement, the connector 23 is attached to and detached from the electrodes 36 and 37. By the way, the replacement work of the adult diaper 20 may be performed at night. In this case, there is a problem that it is difficult for the caregiver to confirm the positions of the electrodes 36 and 37. However, in this modified example, since the fluorescent paint is applied in a band shape at positions corresponding to the electrodes 36 and 37, the caregiver can easily confirm the positions of the electrodes 36 and 37, and the exchange operation is facilitated. There is an advantage.

  In the present embodiment, the moisture sensors 22 and 42 are applied to adult diapers, but the moisture sensors 22 and 42 may be mounted on an artificial dialysis sheet or the like. However, in this case, the adhesive 34 preferably has conductivity.

22 ... Moisture sensor 31 ... Main sheet 32 ... Sub sheet 33 ... Waterproof sheet 34 ... Adhesive 35 ... Adhesive 36 ... Electrode 37 ... Electrode 38 ... Upper surface 42 ... moisture sensor 43 ... lower surface 44 ... fluorescent paint 45 ... fluorescent paint

Claims (4)

A first sheet having water absorption;
A pair of strip electrodes arranged in parallel on the upper surface of the first sheet at a predetermined distance;
A second sheet adhered to the upper surface of the first sheet so as to sandwich the pair of strip electrodes via an adhesive having no conductivity ,
The pair of strip electrodes are moisture sensors made of conductive glue applied on the first sheet.   2. The conductive paste according to claim 1, wherein hydrophilic carbon black is kneaded in a water-soluble paste containing 1% by mass to 5% by mass of potato and 74% by mass to 84% by mass of water. The moisture sensor described.   The moisture sensor according to claim 1 or 2, wherein the pair of strip electrodes are formed by gravure printing using the conductive paste as ink. The moisture sensor according to any one of claims 1 to 3, wherein a water repellent sheet is superimposed on a lower surface of the first sheet, and a fluorescent paint is applied to a position corresponding to the strip electrode of the water repellent sheet. .

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