JP7265235B2 - absorbent material - Google Patents

Description

The present disclosure relates to absorbent members.

Patent Literature 1 discloses that an electromotive force is generated by contacting an electrode with urine excreted on an absorbent body.

JP 2015-229003 A

The inventors of the present invention have found that detecting the size of the liquid non-contact range of the electrodes is effective for grasping the liquid absorption state of the absorbing member.

The magnitude of the parasitic resistance of the electrode changes depending on the magnitude of the non-contact area of the electrode with the liquid. Therefore, the size of the non-contact range can be grasped by detecting the size of the parasitic resistance. Further details are described as embodiments below.

FIG. 1 is an exploded side view of an absorbent member. FIG. 2 is a front view of an absorbent member. 3 is a cross-sectional view taken along the line AA of FIG. 2. FIG. FIG. 4 is a rear view of the absorbent member. FIG. 5 is a circuit diagram of the detection device. FIG. 6 is a configuration diagram of the urination detection system. FIG. 7 is a photograph showing the diffusion range of urine. FIG. 8 is a graph showing the relationship between the total amount of urine injected and the length of the diffusion range. FIG. 9 is a schematic diagram showing a diffusion range. FIG. 10 is a diagram showing the relationship between charging time and capacitor potential. FIG. 11 is a diagram showing an RC circuit configured by a power generation section and a capacitor C. As shown in FIG. FIG. 12 is a diagram showing the relationship between the total amount of urine injected and the charging time. FIG. 13 is a schematic diagram showing the diffusion range. FIG. 14 is a diagram showing charging time and capacitor potential. FIG. 15 is a schematic diagram showing a diffusion range. FIG. 16 is a diagram showing storage time and capacitor potential. FIG. 17 is a diagram showing time intervals of radio signals. FIG. 18 is a diagram showing changes in time intervals.

<1. Overview of Absorbing Material>

(1) The absorbent member according to the embodiment is worn, for example, on the human body. The absorbent member worn on the human body is, for example, a diaper. The diaper is preferably a disposable diaper. Diapers may be for adults or infants.

The absorbent member can comprise an absorbent body. The absorber absorbs liquid. The absorbent body preferably contains a superabsorbent polymer so that it can absorb more liquid, but it need not contain a superabsorbent polymer. The absorber may be configured as a single member, or may be a structure configured by combining a plurality of members.

The absorbent member can comprise an electrode. The electrodes generate electric current by coming into contact with the liquid absorbed by the absorber. In other words, the electrodes constitute a battery (power generation unit) that is activated by the liquid. The electrodes include a positive electrode and a negative electrode. The electrodes are preferably placed in contact with the absorber. In this case, when the absorber absorbs liquid, an electric current is generated between the electrodes. The electrodes may be arranged so as to be in contact with the outer surface of the absorber, or may be arranged inside the absorber so as to be in contact with the absorber.

The absorbent member comprises a detection device. The detection device outputs a signal corresponding to the magnitude of the parasitic resistance that changes according to the magnitude of the liquid non-contact area of the electrode. A signal corresponding to the magnitude of the parasitic resistance makes it possible to grasp the magnitude of the non-contact range. Here, the parasitic resistance is the resistance of the electrode in the non-contact range with the liquid. Parasitic resistance results in the internal resistance of the battery being liquid activated.

The non-contact range is a range other than the contact range with the liquid in the electrode. The larger the non-contact range, the smaller the contact range. On the other hand, if the non-contact range is small, the contact range is large. Since the size of the non-contact area of the electrode with the liquid can correspond to the remaining capacity of the liquid to spread in the absorber, it is advantageous in grasping the remaining capacity of the absorption capacity of the absorber.

The parasitic resistance changes according to the distance from the current output end of the electrode to the liquid contact area of the electrode. The larger the non-contact area, the larger the parasitic resistance, and the smaller the non-contact area, the smaller the parasitic resistance. It should be noted that the electrode preferably has a large resistance value to the extent that the resistance changes sufficiently according to the size of the non-contact range. Therefore, the electrodes are preferably made of a material with a high resistance rather than a conductor with a low resistance. An electrode with a large resistance value is, for example, a carbon electrode.

(2) The sensing device may comprise a capacitor charged by current from the electrodes. The signal is preferably a signal corresponding to a time constant of an RC circuit composed of the parasitic resistance and the capacitor. The RC circuit is a delay circuit. The time constant is represented by R×C, where R is the value of the parasitic resistance and C is the capacitance of the capacitor. The time constant varies with R if C is constant. Therefore, the time constant changes according to the magnitude of the parasitic resistance. That is, the larger the parasitic resistance, the larger the time constant. The larger the time constant, the larger the delay.

(3) The signal may indicate the time it takes for the capacitor to reach a predetermined potential after being charged by the current from the electrode. The larger the time constant, the longer the delay, and the longer it takes to reach a predetermined potential. In other words, the time required to reach the predetermined potential varies depending on the magnitude of the parasitic resistance.

(4) It is preferable that the electrodes have a longitudinal direction along the spreading direction of the liquid in the absorber. In this case, the size of the non-contact range can easily indicate how the liquid spreads. In addition, when the spread of the liquid is, for example, a planar spread, the longitudinal direction of the electrodes may be any direction within the plane.

(5) The absorber is preferably an absorber for disposable diapers. The absorbent body for diapers has a front end positioned on the front side of the human body and a rear end positioned on the back side of the human body when the absorbent member is worn on the human body. The electrodes may have a longitudinal direction along the front-rear direction of the absorber. In the case of diapers, since liquid such as urine spreads mainly along the front-back direction of the absorbent body, it is preferable that the electrodes also have their longitudinal direction along the front-back direction of the absorbent body.

(6) One longitudinal end of the electrode may be positioned near the rear end of the absorber. One longitudinal end of the electrode is preferably a current output end. In diapers, liquid such as urine spreads mainly toward the rear end of the absorbent. Therefore, by setting the current output end of the electrode near the rear end of the absorber, it is possible to ascertain how the liquid spreads up to the rear end of the absorber.

(7) The absorbing member of the embodiment may further include wiring for guiding the current output from the output end to a front area located on the front side of the human body when the absorbing member is worn on the human body. . In this case, the degree of freedom in arranging the detection device is increased.

(8) The detection device is arranged in the front range and connected to the electrode via the wiring. In this case, the detection device can be positioned on the front side of the human body.

(9) The absorber may have a structure that promotes diffusion of excreted fluid in the front-rear direction of the absorber. The structure that promotes the diffusion of excreted liquid in the front-rear direction is, for example, grooves formed in the absorbent body. By providing such a structure, diffusion of the excreted liquid in the front-rear direction is promoted.

<2. Examples of Absorbing Materials>

1 to 4 show a disposable diaper worn by a wearer as an example of the absorbent member 10. FIG. The absorbent member 10 shown in FIGS. 1 to 4 includes an absorbent member main body 20 and a detection device 90 .

<2.1 Absorbing member main body>

The absorbent member main body 20 of the embodiment has a basic configuration as a diaper. The absorbent member main body 20 includes a topsheet 30 , a backsheet 40 and an absorbent body 50 . Furthermore, the absorbent member main body 20 of the embodiment includes electrodes 61 and 62 for detecting excrement such as urine.

As shown in FIGS. 2 and 4, the absorbent member main body 20 has a substantially rectangular shape in plan view in the unfolded state. When worn by the wearer, the absorbent member main body 20 has a crotch position 21 positioned generally at the crotch of the wearer, a front range 22 positioned on the front side of the wearer, and a back range 23 positioned on the back side of the wearer. and have In the illustrated absorbent member main body 20, the back area 23 is longer in the front-rear direction than the front area 22 in correspondence with the swelling of the buttocks.

1 to 4, the left-right direction (width direction) of the diaper is indicated as the X direction, the front-back direction (longitudinal direction) of the diaper is indicated as the Y direction, and the thickness direction of the diaper is indicated as the Z direction. there is The front side of the diaper 22 is the front side, and the rear side of the diaper is the rear side.

The absorbent body 50 is arranged between the topsheet 30 and the backsheet 40 . Here, the surface is the surface facing the wearer when the absorbent member 10 is worn by the wearer. The back side is the opposite side of the front side.

The surface sheet 30 is a substantially rectangular liquid-permeable sheet. The surface sheet 30 contacts the wearer's skin when worn by the wearer. The surface sheet 30 is also called a top sheet. The surface sheet 30 is made of nonwoven fabric or woven fabric, for example.

The backsheet 40 is a substantially rectangular liquid-impermeable sheet. The back sheet 40 prevents the excreted liquid absorbed by the absorbent body 50 from leaking out to the back side. The back sheet 40 is configured with a waterproof film or the like. The backsheet 40 has a first surface 40a on the absorber 50 side and a second surface 40b opposite to the first surface 40a.

The absorber 50 absorbs liquid that has passed through the topsheet 30 . The absorbent body 50 of the embodiment is an absorbent structure composed of a plurality of absorbent members. The absorber 50 has a front end 50a located on the wearer's front side when worn by the wearer, and a rear end 50b located on the wearer's back side. That is, the absorber 50 is arranged across the front area 22 and the back area 23 of the absorbent member main body 10 . The absorbent body 50 is capable of absorbing excreted liquid over a wide range from the front range 22 to the back range 23 . The absorbent body 50 is wider at the back area 23 than at the front area 22 . The absorbent body 50 located in the back area 23 allows a large area to absorb liquid.

The absorbent structure of the embodiment comprises a first absorbent member 51 , a second absorbent member 52 and a third absorbent member 53 . The first absorbent member 51, the second absorbent member 52, and the third absorbent member 53 are laminated in this order from the topsheet 30 side.

The first absorbent member 51 is composed of absorbent fibers such as pulp and superabsorbent polymer. The second absorbent member 52 is also composed of absorbent fibers such as pulp and superabsorbent polymer. Both the first absorbent member 51 and the second absorbent member 52 are substantially rectangular mat bodies, and have the same shape and size in plan view. As shown in FIG. 3, the second absorbent member 52 is formed with grooves 52a serving as liquid passages.

As shown in FIG. 2, the groove 52a is formed in a range from the vicinity of the crotch position 21 to the vicinity of the rear end 50b of the absorbent body 50. As shown in FIG. The groove 52a is formed such that its longitudinal direction faces the front-rear direction. There may be one groove 52a or a plurality of grooves 52a, but the illustrated second absorbing member 52 has two grooves 52a. The plurality of grooves 52a are formed at intervals in the left-right direction.

The longitudinal direction of the grooves 52 a coincides with the front-rear direction of the absorbent body 50 so that the diffusion of excreted liquid in the absorbent body 50 is promoted in the front-rear direction of the absorbent body 50 . The grooves 52a allow the excreted liquid that has flowed in from the first absorbent member 51 to move along the longitudinal direction of the grooves 52a and diffuse into the second absorbent member 52 and the like, thereby displacing the excreted liquid in the entire absorbent body 50 in the front-rear direction. It is a liquid-permeable part that promotes diffusion. Note that the liquid passage part is disclosed in, for example, Japanese Patent Application Laid-Open No. 2016-7495. The structure that promotes the diffusion of the excreted fluid in the front-rear direction is not limited to the groove, and is not particularly limited as long as it can promote the diffusion of the fluid in a desired direction.

In the embodiment, the grooves 52 a are mainly formed in the back area 23 , so urine excreted in the vicinity of the front area 22 can be diffused into the back area 23 . By diffusing the urine into the back area 23, the absorption capacity of the absorbent body 50 in the back area 23 can be utilized. Note that the groove 52a may also be formed in the front area 22 . In this case, from the viewpoint of prioritizing diffusion to the back area 23 , it is preferable that the length of the groove 52 a located in the back area 23 is longer than the length of the groove 52 a located in the front area 22 .

The third absorbent member 53 is made of nonwoven fabric having water absorption properties. The third absorbent member 53 has substantially the same shape and size as the second absorbent member 52 in plan view. The third absorbent member 53 is attached to the back sheet 40 side of the second absorbent member 52 . The third absorbent member 53 is in a wet state in a range corresponding to the wet state in which the second absorbent member 52 absorbs the liquid.

On the surface of the third absorbent member 53 on the back sheet 40 side, a power generating section 60 for detecting excreted fluid is arranged. The power generation section 60 has a pair of electrodes 61 and 62 . A pair of electrodes 61 and 62 has a positive electrode 61 and a negative electrode 62 . The electrodes 61 and 62 are attached to the third absorbing member 53 . The electrodes 61 , 62 can contact the liquid absorbed by the absorbent 50 .

The positive electrode 61 is configured by, for example, a long sheet-like carbon electrode. Carbon electrodes are, for example, activated carbon electrodes containing activated carbon. The negative electrode 62 is composed of, for example, a long sheet-shaped aluminum electrode. The electrodes 61 and 62 are formed with a length of 580 mm, for example. The positive electrode 61 has a width of about 10 mm, and the negative electrode 62 has a width of about 1.8 mm.

A carbon electrode such as an activated carbon electrode has a relatively large resistance compared to an aluminum electrode which has excellent conductivity. Conductors that are also used as wiring, such as aluminum, have sufficiently low resistance. In contrast, the carbon electrode itself is a material that functions as a resistor. The sheet resistance of the activated carbon electrode is, for example, about 100 to 200 Ω square. In the experiments described below, activated carbon electrodes with a sheet resistance of 180Ω square with a width of 10 mm are used.

The carbon applied to the positive electrode 61 can include synthetic resin such as phenol, activated carbon made of raw materials derived from fossil fuels such as coal, coke, pitch, or mesoporous carbon. The carbon of the positive electrode 61 is porous and can absorb and retain liquid. For example, the carbon of the positive electrode 61 has many nano-order holes.

The thickness of the positive electrode 61 can be 50-500 μm, more preferably 100-400 μm. The carbon density of the positive electrode 61 can be 0.3 to 1.0 g/cc, more preferably 0.4 to 0.7 g/cc. The carbon specific surface area of the positive electrode 61 can be 500 to 4000 m2/g, more preferably 1000 to 2000 m2/g. The average particle size of the carbon of the positive electrode 61 can be 0.1 to 10 μm, more preferably 1 to 5 μm.

The positive electrode 61 is made by, for example, mixing and kneading a predetermined amount of steam-activated activated carbon with a tetrafluoroethylene resin dispersion as a binder and ketjen black as a conductive auxiliary material, and then applying the kneaded material to a biaxial roller. It can be produced by stretching into a sheet while applying pressure with.

The electrodes 61 and 62 are spaced apart in the lateral direction of the absorber 50 . The electrodes 61 and 62 have a longitudinal direction along the front-rear direction of the absorber 50 . The length of the electrodes 61 and 62 in the longitudinal direction is approximately the same as the length of the absorber 50 in the front-rear direction. Electrodes 61 and 62 respectively have first ends 61a and 62a located near front end 50a of absorber 50 . The electrodes 61 and 62 also have second ends 61b and 62b located near the rear end 50b of the absorbent body 50, respectively. In addition, the electrodes 61 and 62 may have a longitudinal direction along the lateral direction of the absorber 50 .

The backsheet 40 has wiring 70 connected to the electrodes 61 and 62 . The wiring 70 serves as a path for current generated between the electrodes 61 and 62 . The wiring 70 is connected to second ends (longitudinal ends) 61b and 62b of the electrodes 61 and 62, respectively. That is, the second ends 61b and 62b of the electrodes 61 and 62 are connection ends to the wirings 70 and 70, respectively. The second ends 61b and 62b are output ends for currents from the electrodes 61 and 62, respectively.

The wiring 70 is formed of a sheet-like conductor and attached to the back sheet 40 . The wiring 70 electrically connects the electrodes 61 and 62 and the detection device 90 . As shown in FIG. 4, the detection device 90 is arranged in the front area 22 on the second surface 40b of the backsheet 40. As shown in FIG. Such placement of the detection device 90 is placed in the vicinity of the wearer's abdomen, which facilitates the wearer's supine posture. The detection device 90 is detachably attached to the backsheet 40 by, for example, hook-and-loop fasteners.

The wiring 70 connects the electrodes 61 and 62 arranged on the first surface 40 a side of the back sheet 40 and the detection device 90 arranged on the second surface 40 b side of the back sheet 40 . Also, the wiring 70 connects the connection ends 61 b and 62 b in the back area 23 and the detection device 90 in the front area 22 . The connection ends 61b, 62b and the detection device 90 can be separated from each other by the wiring 70, and the degree of freedom for appropriately arranging the connection ends 61b, 62b and the detection device 90 can be increased.

The electrodes 61 and 62 are formed in the front-rear direction of the backsheet 40 on the second surface 40b, and extend around the first surface 40a at the rear end of the backsheet 40. As shown in FIG. A wiring 70 positioned on the first surface 40a is connected to the second ends 61b and 62b of the electrodes 61 and 62 .

<2.2 Detection Device>

FIG. 5 shows the detection device 90 . The detection device 90 includes a capacitor C connected to a power generation section 60 having electrodes 61 and 62 . The capacitance of the capacitor C is, for example, 10 mF. Capacitor C stores the power generated by power generation unit 60 .

The detection device 90 includes an intermittent power supply circuit 94 . When the potential of the capacitor C reaches a predetermined potential, the intermittent power supply circuit 94 receives power stored in the capacitor C and outputs power supply voltage to be supplied to the radio transmitter 95 . After discharging the power, the capacitor C can store the power supplied from the power generation unit 60 again. Therefore, while the power generation unit 60 is generating power, the capacitor C repeatedly stores and discharges power. The intermittent power supply circuit 94 intermittently supplies power to the radio transmitter 95 each time the capacitor C discharges power.

The intermittent power supply circuit 94 operates each time the potential of the capacitor C reaches a predetermined voltage. The intermittent operation period of the intermittent power supply circuit 94 is the time required for the potential of the capacitor C to reach a predetermined voltage. The time it takes for the potential of the capacitor C to reach a predetermined voltage varies depending on how the excreted liquid is absorbed into the absorber 50 . How the time required for the potential of the capacitor C to reach a predetermined voltage will be described later.

The wireless transmitter 95 transmits a wireless signal each time power is supplied from the intermittent power supply circuit 94 . That is, the radio transmitter 95 intermittently transmits radio signals. The period in which the radio signal is intermittently transmitted is the time required for the potential of the capacitor C to reach a predetermined voltage. Note that the transmitter 95 may be one that transmits a signal by wire.

<3. Management device>

A signal transmitted from the transmitter 95 is received by the management device 100 shown in FIG. The management device 100 is used, for example, in a nursing care facility to manage whether or not the disposable diapers 10 worn by a plurality of care recipients need to be replaced.

Management device 100 includes receiver 101 that receives a radio signal transmitted from transmitter 95 . Receiver 101 provides the received signal to processor 102 . The processor 102 executes a program stored in the memory 103 to determine the necessity of changing diapers. When it is determined that the diaper needs to be changed, the output device 104 of the management device 100 outputs that the diaper needs to be changed.

<4. Experiment on urination>

All of the following experiments were performed with electrodes attached to commercially available adult disposable diapers.

FIG. 7 shows experimental results of confirming the diffusion state of urine (artificial urine) in the absorbent body 50 of the disposable diaper. In the experiment, 200 cm ³ , 400 cm ³ and 600 cm ³ of urine were poured into the diaper 10 from the urination position shown as "Pouring Point" (pouring position) in FIG. The urine injection position in the experiment was within the front area 22 of the diaper 10, and generally corresponds to the actual urination position when wearing the diaper. In the diaper shown in FIG. 7, the dark gray area is the diffusion range of urine.

Regardless of the amount of urine injected, the diffusion of urine backward from the injection position (lower in FIG. 7) was greater than the diffusion of urine forward from the injection position (upper in FIG. 7). It is considered that this is due to the effect of promoting diffusion by the grooves 52a.

In FIG. 7, L1, L2, and L3 indicate the length L of the diffusion range of urine from the injection position to the rear (lower side in FIG. 1). L1 is the backward diffusion length when 200 cm ³ of urine is injected. L2 is the backward spread length when 400 cm ³ of urine is injected. L3 is the backward spread length when 600 cm ³ of urine is injected. As shown in FIG. 7, the backward diffusion length L increases as the implant dose increases.

FIG. 8 shows the measurement results of the diffusion length L when 100 cm ³ , 200 cm ³ , 300 cm ³ and 400 cm ³ of urine were repeatedly injected. Note that the number of injections of 400 cm ³ is one time. As shown in FIG. 8, it can be seen that the diffusion length L increases as the total amount of urine increases.

FIG. 9 shows a schematic diagram of three diffusion ranges S1, S2, S3. The diffusion range S1 is the diffusion range when 200 cm ³ of urine is injected. The diffusion range S2 is the diffusion range when 400 cm ³ of urine is injected. The diffusion range S3 is the diffusion range when 600 cm ³ of urine is injected. FIG. 10 shows temporal changes in the potential V _out of the capacitor C when 200 cm ³ , 400 cm ³ , and 600 cm ³ of urine are injected into diapers, as shown in FIG. In FIG. 10, 0(s) is the injection time point.

As shown in FIG. 10, after a sufficient amount of time (for example, 180 s from the time of injection) has passed, the potential V _out of the capacitor C increases as the amount of urine increases, but the difference between these potentials is small, and the amount of urine increases. It becomes about 0.8V regardless of the amount. However, as the amount of injected urine increases, the potential rises steeper. Therefore, the time required to reach a predetermined potential (0.6 V, for example) increases as the amount of urine injected decreases.

That is, the smaller the injected amount of urine, the longer the potential change delay. This is because the parasitic resistance R of the electrode 61 and the capacitor C constitute an RC circuit (RC delay circuit), as shown in FIG. An equivalent circuit of the power generation section 60 consisting of the electrodes 61 and 62 is represented by a current source and a parasitic resistance R (internal resistance of the power generation section). When the entire electrode 61 absorbs urine, the parasitic resistance R of the electrode 61 is so low that it does not pose a problem. However, as shown in FIG. 9, the resistance of the electrode 61 becomes a parasitic resistance R in non-contact ranges (ranges where the electrode 61 is dry) N1, N2, and N3 that are not in contact with urine.

The magnitude of the parasitic resistance R is determined by the non-contact ranges N1, N2, N3 from the urine diffusion range (urine-electrode contact range) S1, S2, S3 to the electrode rear end 61b, which is the connection end with the wiring 70. It changes according to the length (longitudinal length). When the amount of urine is 200 cm ³ , for example, the length of the non-contact range N1 is 190 mm. In this case, since the electrode 61 has a sheet resistance of 180Ω square and an electrode width of 10 mm, the parasitic resistance R of the non-contact area N1 is approximately 3.4 kΩ. Also, when the amount of urine is 600 cm ³ , for example, the length of the non-contact range N3 is 40 mm. In this case, the parasitic resistance R of the non-contact area N3 is approximately 0.7 kΩ.

Thus, when the amount of urine is small, the non-contact range becomes large and the parasitic resistance R increases. An increase in the parasitic resistance R increases the time constant (R×C) of the RC circuit, increasing the delay. As a result, the time required for the potential V _out of the capacitor C to reach a predetermined potential (for example, 0.6 V) changes according to the magnitude of the parasitic resistance R. FIG.

FIG. 12 shows the charging time until the potential Vout of the urine capacitor C reaches 0.6 V when 100 cm ³ , 200 cm ³ , 300 cm ³ and 400 cm ³ of urine were repeatedly injected. ing. Note that the number of injections of 400 cm ³ is one time. The horizontal axis of FIG. 12 indicates the total amount of urine injected. As shown in FIG. 12, it can be seen that the parasitic resistance R decreases and the charging time shortens as the total amount of urine injected increases.

Similar to FIG. 9, FIG. 13 shows diffusion ranges S1, S2 and S3 when 200 cm ³ , 400 cm ³ and 600 cm ³ of urine are injected. FIG. 14 shows temporal changes in the potential Vout of the capacitor C when 200 cm ³ , 400 cm ³ , and 600 cm ³ of urine are poured into diapers as shown in FIG. However, the results in FIG. 14 are obtained when the connection ends between the electrodes 61 and 62 and the wiring 70 are the first ends 61a and 62a of the electrodes 61 and 62 as shown in FIG.

In FIG. 13, the lengths of non-contact ranges N1, N2, and N3 from urine diffusion ranges (urine-electrode contact ranges) S1, S2, and S3 to the electrode front end 61a, which is the connection end with the wiring 70, are , the change is smaller than the change in the non-contact ranges N1, N2, N3 in FIG. This is because the way urine spreads over the front area 22 of the absorber 50 varies little with the amount of urine. If the change in the length of the non-contact areas N1, N2, N3 is small, the change in the parasitic resistance R is also small.

Therefore, as shown in FIG. 14, it becomes difficult for the time until the potential V _out of the capacitor C reaches a predetermined potential (for example, 0.6 V) to differ according to the non-contact ranges N1, N2, and N3. . Therefore, in order to obtain a temporal change in the potential Vout of the capacitor C according to the size of the non-contact range, it is preferable to use the rear end 61b of the electrode 61 as the connection end (electrode terminal) as shown in FIG. .

FIG. 15 shows diffusion ranges S1 and S2 when the same amount (200 cm ³ ) of urine is injected into diapers at different injection points. Diffusion range S1 is the diffusion range when injecting from injection point P1 in front area 22 of the diaper. The diffusion range S2 is the diffusion range S3 when injected from the injection point P2 in the back area 23 of the diaper. In FIG. 15, the connection ends between the electrode 61 and the wiring 70 are electrode rear ends 61b and 62b. FIG. 16 shows temporal changes in the potential Vout of the capacitor C when 200 cm ³ of urine is injected as shown in FIG.

In FIG. 15, the lengths of non-contact ranges N1 and N2 from the urine diffusion range (urine-electrode contact range) S1 to the electrode rear end 61b, which is the connection end with the wiring 70, are the urine injection points P1, It changes according to the front-back direction position of P2. That is, the closer the injection point is to the electrode rear end 61b, the shorter the length of the non-contact range.

As a result, in the case of the injection point P1 far from the electrode rear end 61b, the non-contact range N1 becomes longer, the parasitic resistance R increases, and the delay becomes longer. On the other hand, in the case of the injection point P2 near the electrode rear end 61b, the parasitic resistance R becomes small and the delay becomes small.

That is, as shown in FIG. 16, even if the same amount of urine (200 cm ³ ) is injected from the injection point P2 in the back area 23, the potential of the capacitor C rises sharply. Thus, it can be seen that the time required for the potential _Vout of the capacitor C to reach a predetermined potential varies depending on the magnitude of the parasitic resistance R even if the amount of urine is the same.

Since the excess absorption capacity of the absorbent body 50 depends on the size of the non-contact area, it is desired to change the diaper when the non-contact area becomes smaller. Therefore, the value of the parasitic resistance R, which changes according to the size of the non-contact range, is an index suitable for changing diapers.

FIG. 17 shows time intervals Δt during which the radio signal (detection signal) transmitted from the transmitter 95 of the detection device 90 is received by the receiver 101 . The time interval Δt shown in FIG. 17 is for a diaper filled with 300 cm ³ of urine. In FIG. 17, Δt is about 20s.

FIG. 18 shows changes in Δt due to urine injection. The horizontal axis of FIG. 18 indicates the elapsed time from the first urine injection (0 s), and the vertical axis indicates the time interval Δt. In FIG. 18, an additional 300 cm ³ of urine is injected 1200 seconds after the first urine injection.

From the first urine injection to the second urine injection (0 s to 1200 s), Δt is approximately 20 s. With a second urine injection, Δt drops to around 10 s. Therefore, the management device 100 can grasp the size of the non-contact range (absorption capacity) from Δt. In addition, the management device 100 can detect the number of times of urination based on the number of times Δt changes significantly. Based on Δt, the management device can determine whether the diaper needs to be changed.

<5. Note>
The present invention is not limited to the above embodiments, and various modifications are possible.

REFERENCE SIGNS LIST 10 absorbent member 20 absorbent member body 21 crotch position 22 front area 23 back area 30 topsheet 40 backsheet 40a first surface 40b second surface 50 absorber 50a front end 50b rear end 51 first absorbent member 52 second absorbent member 52a groove 53 third absorption member 60 power generation unit 61 positive electrode 61a first end 61b second end 62 negative electrode 62a first end 62b second end 70 wiring 90 detection device 94 intermittent power supply circuit 95 radio transmitter 100 management device 101 receiver 102 processor 103 memory 104 output device C capacitor C1 contact range C2 contact range C3 contact range N1 non-contact range N2 non-contact range N3 non-contact range P1 injection point P2 injection point

Claims (4)

an absorbent body for disposable diapers;
an electrode that generates an electric current by coming into contact with the liquid absorbed by the absorber;
a detection device that outputs a signal corresponding to the magnitude of parasitic resistance that changes according to the magnitude of the liquid non-contact range of the electrode;
An absorbent member comprising
The absorbent body has a front end located on the front side of the human body and a rear end located on the back side of the human body when the absorbent body is worn on the human body,
The absorbent body has a structure that promotes diffusion of excreted fluid in the front-rear direction of the absorbent body,
the electrode has a longitudinal direction along the front-rear direction of the absorber, and one end in the longitudinal direction is positioned near the rear end of the absorber and serves as a current output end;
The detection device is arranged in a front range positioned on the front side of the human body when the absorbing member is worn on the human body,
In order to electrically connect the electrodes to the detection device, wiring is provided for guiding the current output from the output end to a front area located on the front side of the human body when the absorbing member is worn on the human body. further prepared,
The absorbent body has a surface facing the wearer when the absorbent member is worn by the wearer and a surface opposite thereto,
The wiring is an absorbent member arranged on a surface opposite to the absorber-side surface of a non-liquid-permeable sheet provided on the opposite surface side of the absorber. The wiring is formed of a sheet-shaped conductor
The absorbent member of Claim 1. said sensing device comprising a capacitor charged by current from said electrode;
2. The electrode according to claim 1, wherein the signal is a signal corresponding to a time constant of an RC circuit composed of the parasitic resistance and the capacitor, and the electrode has a longitudinal direction along the spreading direction of the liquid in the absorber. absorption member. 4. The absorbing member according to claim 3 , wherein the signal indicates the time required for the capacitor to reach a predetermined potential after being charged by the current from the electrode.

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