Absorbent sheet and system toilet for pets

Abstract

To provide an absorbent sheet that can be used for a long period without replacement, and a system toilet for pets equipped with the absorbent sheet.SOLUTION: According to one aspect, an absorbent sheet comprises a water-permeable front sheet, a water-impermeable back sheet, and an absorbent body including an absorbent core disposed between the front sheet and the back sheet, and containing a water-absorbent polymer and pulp. If the absorbent core is divided in a first direction, which is perpendicular to the thickness direction of the absorbent core, into three equal regions, namely, a first region, a second region and a third region in order from one side in the first direction, then the difference between the maximum water retention of the first, second and third regions and the minimum water retention of the first, second and third regions is 20 g or less; and the percentage of the dry weight of the pulp in the first region relative to the dry weight of the first region, the percentage of the dry weight of the pulp in the second region relative to the dry weight of the second region, and the percentage of the dry weight of the pulp in the third region relative to the dry weight of the third region are each 50% or more.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present disclosure relates to an absorbent sheet and a pet toilet system. [Background technology]

[0002] Conventionally, pet toilets having an absorbent sheet for absorbing pet urine have been used to treat the excrement of pets such as cats and dogs kept indoors. For example, Patent Document 1 discloses a pet toilet system that includes an absorbent sheet for absorbing pet urine, a tray for storing the absorbent sheet, and a liquid-permeable panel having a corrugated honeycomb structure provided on the absorbent sheet. This system toilet prevents the pet's legs from directly contacting the absorbent sheet by placing the liquid-permeable panel on the absorbent sheet, and prevents urine from flowing back from the absorbent sheet to the pet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-205541 A Summary of the Invention [Problem to be solved by the invention]

[0004] In order to keep the pet toilet system clean, the absorbent sheet needs to be replaced periodically. Since the task of replacing the absorbent sheet is a burden on the user, it is desirable to reduce the frequency of replacement of the absorbent sheet by making the absorbent sheet usable for a long period of time from the viewpoint of user convenience.

[0005] In order to make the absorbent sheet usable for a long period of time, it is important to increase the amount of absorbent polymer contained in the absorbent sheet and to distribute the absorbent polymer uniformly. In general, pets such as dogs tend to urinate by avoiding the swelling of the absorbent sheet. If the distribution of the absorbent polymer is uneven, the absorbent sheet will swell locally, and the pet will avoid the swelling and urinate in an area with less absorbent polymer, which may make it impossible for the absorbent sheet to absorb the pet's urine. If such a problem occurs, the user will replace the absorbent sheet even if there is still an area of ​​the absorbent sheet that can absorb urine, and as a result, the frequency of replacing the absorbent sheet cannot be reduced.

[0006] On the other hand, since the absorbent sheet is used with a pet on it, even if the absorbent polymer is uniformly distributed during manufacturing, the absorbent polymer may move due to the weight of the pet during use, causing the uniformity of the absorbent polymer distribution to be lost. In this case, it becomes difficult to use the absorbent sheet for a long period of time.

[0007] Therefore, an object of the present disclosure is to provide an absorbent sheet that can be used for a long period of time without replacement, and a system toilet for pets that is equipped with such an absorbent sheet. [Means for solving the problem]

[0008] An absorbent sheet according to one embodiment has a water retention capacity of 350 g or more. The absorbent sheet includes a water-permeable top sheet, a water-impermeable back sheet, and an absorbent core that includes a water-absorbent polymer and pulp and is disposed between the top sheet and the back sheet. When the absorbent core is divided into three equal regions in a first direction perpendicular to the thickness direction of the absorbent core, the regions are designated as a first region, a second region, and a third region in that order from one side in the first direction, the difference between the maximum water retention capacity of the first region, the second region, and the third region and the minimum water retention capacity of the first region, the second region, and the third region is 20 g or less, and the ratio of the dry weight of the pulp in the first region to the dry weight of the first region, the ratio of the dry weight of the pulp in the second region to the dry weight of the second region, and the ratio of the dry weight of the pulp in the third region to the dry weight of the third region are 50% or more.

[0009] In the absorbent sheet according to this embodiment, the difference between the maximum water retention capacity of the first region, the second region, and the third region and the minimum water retention capacity of the first region, the second region, and the third region is 20 g or less, and the absorbent polymer is distributed with high uniformity in the first direction. In addition, the ratio of the dry weight of the pulp in the first region to the dry weight of the first region, the ratio of the dry weight of the pulp in the second region to the dry weight of the second region, and the ratio of the dry weight of the pulp in the third region to the dry weight of the third region are 50% or more. By increasing the ratio of the pulp in the first region, the second region, and the third region, the absorbent polymer is captured by the pulp in the absorbent body, and the movement of the absorbent polymer is suppressed. Therefore, the absorbent polymer is less likely to be distributed unevenly during use, and as a result, the absorbent sheet can be used for a long period of time.

[0010] When the absorbent core is divided into three equal parts in the second direction perpendicular to the thickness direction and the first direction, the regions are designated as the fourth region, the fifth region, and the sixth region in order from one side of the second direction, the ratio of the dry weight of the pulp in the fourth region to the dry weight of the fourth region and the ratio of the dry weight of the pulp in the sixth region to the dry weight of the sixth region may be higher than the ratio of the dry weight of the pulp in the fifth region to the dry weight of the fifth region. When the ratio of the absorbent polymer contained in the absorbent body is high, a gel blocking phenomenon occurs, making it difficult for urine to diffuse. In contrast, by making the ratio of pulp in the fourth region and the sixth region higher than the ratio of pulp in the fifth region, the urine excreted in the fifth region can be diffused to the fourth region and the sixth region by the capillary phenomenon. By diffusing the pet's urine over a wide range, it becomes possible to efficiently absorb the urine.

[0011] The absorbent core may have a shape having a longitudinal direction and a lateral direction, with the first direction being the lateral direction of the absorbent body and the second direction being the longitudinal direction of the absorbent body. In this case, the pet's urine is diffused in the longitudinal direction of the absorbent sheet, so that the urine can be efficiently absorbed. In addition, the pet's urine is diffused and absorbed by the entire absorbent sheet, so that the absorbent sheet can be used for a long period of time without replacement.

[0012] The absorbent body further includes a cover sheet disposed between the top sheet and the absorbent core, and the cover sheet may have a colored area colored in a color different from that of the top sheet. Pets such as dogs tend to avoid urine marks on the absorbent sheet because they dislike defecation in unsanitary places. For this reason, pets may urinate outside the absorbent sheet in an attempt to avoid urine marks. Therefore, even if there is an area remaining on the absorbent sheet that can absorb urine, users may replace the absorbent sheet early to prevent pets from urinating outside the absorbent sheet. In contrast, by coloring the cover sheet, urine marks become less visible, and urination outside the absorbent sheet can be prevented. As a result, the absorbent sheet can be used for a long period of time without replacement.

[0013] The cover sheet may have a plurality of non-colored regions, and the area of ​​the colored regions of the cover sheet may be greater than the total area of ​​the plurality of non-colored regions of the cover sheet. By increasing the area of ​​the colored regions of the cover sheet, urine stains can be made less visible. As a result, the absorbent sheet can be used for a long period of time without replacement.

[0014] The non-colored regions may be regularly arranged over the entire cover sheet. The non-colored regions may be two-dimensionally arranged along the first and second directions. By arranging the non-colored regions two-dimensionally along the first and second directions, the urine marks are not clearly visible, but the outlines of the urine marks are visible. This allows the user to visually identify the location where the pet urinates. As a result, the user can easily know when to replace the absorbent sheet while preventing the pet from urinating outside the absorbent sheet.

[0015] The width of each of the non-colored regions in the first direction may be 2 mm or more and 17 mm or less. When urine is absorbed in three or more non-colored regions, it becomes possible to identify the outline of the urine mark. By making the width of the non-colored region 2 mm or more and 17 mm or less, urine is easily spread to three or more non-colored regions, making it possible to identify the outline of the urine mark. As a result, it is possible to easily know when to replace the absorbent sheet while preventing the pet from urinating outside the absorbent sheet.

[0016] Among the multiple non-colored regions, the width between adjacent non-colored regions may be 40 mm or less. By making the width between adjacent non-colored regions 40 mm or less, a part of the urine is absorbed in the non-colored regions, making it easier to identify the outline of the urine stain. As a result, it is possible to easily know when to replace the absorbent sheet while preventing the pet from urinating outside the absorbent sheet.

[0017] The absorbent body may further include a core wrap covering a portion of the absorbent core, wherein an end face of the absorbent core in a first direction is not covered by the core wrap, and an end face of the absorbent core in a second direction is covered by the core wrap.

[0018] The end face of the absorbent core in the first direction may be bonded to the top sheet or the back sheet by a hot melt adhesive. By bonding the end face of the absorbent core that is not covered by the core wrap to the top sheet or the back sheet, the absorbent polymer is prevented from spilling out from the end face.

[0019] The absorbent sheet may have an absorbent section in which an absorbent body is disposed between a top sheet and a back sheet, and a frame-shaped flap section that is disposed so as to surround the absorbent section and in which the top sheet and the back sheet are bonded without an absorbent body. In this case, the absorbent sheet is held by sandwiching the flap section, and the absorbent sheet can be prevented from slipping. As a result, the absorbent sheet can be used stably for a long period of time.

[0020] A gap may be formed between the end face of the absorbent body in the second direction and the flap portion. By forming a gap between the end face of the absorbent body and the flap portion, peeling of the top sheet and the back sheet of the flap portion can be suppressed when the absorbent body expands due to absorption of urine.

[0021] The top sheet may be made of a resin film having a large number of openings penetrating the top sheet in the thickness direction. By making the top sheet a resin film, urine that has soaked into the top sheet can be prevented from adhering to the pet's legs.

[0022] The absorbent body includes a cover sheet disposed between the top sheet and the absorbent core, and the surface of the cover sheet facing the top sheet may have a non-adhesive region that is not adhered to the top sheet. Since the top sheet and the surface of the cover sheet are at least partially not adhered to each other, urine that has permeated the top sheet passes between the top sheet and the cover sheet and is diffused throughout the absorbent sheet. Therefore, urine can be efficiently absorbed by the absorbent sheet.

[0023] A pet system toilet according to one embodiment comprises an absorbent sheet having water absorption properties, a water-permeable mat placed on the absorbent sheet, and a toilet body that holds the absorbent sheet and the water-permeable mat. The absorbent sheet comprises a water-permeable top sheet, a water-impermeable back sheet, and an absorbent body including an absorbent core that contains water-absorbent polymers and pulp and is placed between the top sheet and the back sheet. When the absorbent core is divided into three equal regions in a first direction perpendicular to the thickness direction of the absorbent core, the regions are designated as a first region, a second region, and a third region from one side of the first direction, the difference between the maximum water retention capacity of the first region, the second region, and the third region and the minimum water retention capacity of the first region, the second region, and the third region is 20g or less, and the proportion of the dry weight of the pulp in the first region to the dry weight of the first region, the proportion of the dry weight of the pulp in the second region to the dry weight of the second region, and the proportion of the dry weight of the pulp in the third region to the dry weight of the third region are 50% or more.

[0024] As described above, in the system pet toilet of this embodiment, the absorbent sheet can be used for a long period of time, which improves the maintainability of the system pet toilet. Effect of the Invention

[0025] According to various aspects of the present invention, the absorbent sheet can be used for a long period of time without replacement. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a perspective view showing a system toilet for pets according to one embodiment. [Diagram 2] FIG. 2 is an exploded perspective view showing main components of the pet toilet system shown in FIG. 1. [Diagram 3] 2 is a cross-sectional view of the pet toilet system taken along line AA in FIG. 1. [Figure 4] FIG. 4 is an enlarged cross-sectional view of a part of FIG. [Diagram 5] FIG. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] FIG. [Figure 11] FIG. 2 is a schematic plan view of an absorbent sheet. [Figure 12] FIG. 12 is a cross-sectional view taken along line BB in FIG. [Figure 13] 12 is a cross-sectional view taken along line CC in FIG. 11. [Figure 14] FIG. [Figure 15] FIG. 2 is an enlarged plan view showing a portion of a water-permeable mat. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicated descriptions are omitted. The drawings may be partially simplified or exaggerated for ease of understanding, and the dimensional ratios are not limited to those shown in the drawings.

[0028] Hereinafter, a system toilet for pets (hereinafter referred to as "system toilet") including an absorbent sheet for pets according to one embodiment will be described. Fig. 1 is a perspective view showing a system toilet 1 according to one embodiment. Fig. 2 is a perspective view showing the main components of the system toilet 1 disassembled. Fig. 3 is a cross-sectional view taken along line AA in Fig. 1. Fig. 4 is a cross-sectional view showing an enlarged fitting portion of the system toilet 1 shown in Fig. 3.

[0029] The system toilet 1 shown in Figs. 1 to 4 is an excretion device for pets. In this specification, pets broadly include vertebrates and invertebrates, and typically include pet animals such as dogs, cats, rabbits, and hamsters. Typically, the system toilet 1 is installed indoors for pets kept indoors and provides an excretion space. Pet excrement is typically urine, but also includes body fluids such as low-viscosity feces, saliva, and blood.

[0030] 1 and 2, the system toilet 1 includes a toilet body 2, an absorbent sheet 3 having water-absorbing properties, and a water-permeable mat 4 placed on the absorbent sheet 3. The toilet body 2 holds the absorbent sheet 3 and the water-permeable mat 4.

[0031] In the following description, the stacking direction of the absorbent sheet 3 and the water-permeable mat 4 is referred to as the "vertical direction Z," and the two directions perpendicular to the vertical direction Z are referred to as the "width direction X" and the "depth direction Y," respectively. In the embodiment shown in Fig. 1, the width direction X is parallel to the longitudinal direction of the toilet body 2, and the depth direction Y is parallel to the lateral direction of the toilet body 2. In addition, the direction from the absorbent sheet 3 toward the water-permeable mat 4 is referred to as the "upward direction," and the direction from the water-permeable mat 4 toward the absorbent sheet 3 is referred to as the "downward direction."

[0032] The toilet body 2 is a device for holding the absorbent sheet 3 and the water-permeable mat 4. As shown in Fig. 2, the toilet body 2 includes a bottom plate portion 11, a middle frame portion 12 arranged on the bottom plate portion 11, and an upper frame portion 13 arranged on the middle frame portion 12. The bottom plate portion 11, the middle frame portion 12, and the upper frame portion 13 are formed by molding, for example, a thermoplastic resin, and are flexible. As will be described later, the bottom plate portion 11, the middle frame portion 12, and the upper frame portion 13 are detachable from each other in the vertical direction Z.

[0033] FIG. 5 is a perspective view of the bottom plate 11 of the toilet body 2. As shown in FIG. 5, the bottom plate 11 has a substantially rectangular bottom surface 21 with the width direction X as the longitudinal direction when viewed from the vertical direction Z, and an outer edge portion 22 surrounding the bottom surface 21. The bottom surface 21 has an upper surface 23 on which the absorbent sheet 3 is placed. The upper surface 23 of the bottom surface 21 has an uneven shape. Specifically, the upper surface 23 has a plurality of recesses 23a recessed downward and a protrusion 23b protruding upward. The plurality of recesses 23a are two-dimensionally arranged along the width direction X and the depth direction Y. Each of the plurality of recesses 23a is formed in a quadrangular shape (square shape) when viewed from the vertical direction Z. The protrusion 23b is formed in a lattice shape that divides the plurality of recesses 23a.

[0034] The outer edge portion 22 is formed in a substantially rectangular frame shape when viewed from the vertical direction Z, and is disposed so as to surround the bottom surface portion 21. Typically, the outer edge portion 22 is formed integrally with the bottom surface portion 21 by a thermoplastic resin. The outer edge portion 22 includes a side wall portion 24 rising upward from the outer edge of the bottom surface portion 21, an inner peripheral portion 25 extending outward from the upper end of the side wall portion 24, and an outer peripheral portion 26 extending outward from the outer edge of the inner peripheral portion 25. The side wall portion 24 has a function of blocking urine excreted on the bottom surface portion 21 through the water permeable mat 4 and the absorbent sheet 3. The side wall portion 24 may have a notch (not shown) formed therein for returning urine that has entered a fitting recess 27 (described later) to the bottom surface portion.

[0035] The inner peripheral portion 25 is provided on the outside of the side wall portion 24, and has an upper surface 25a disposed above the upper surface 23 of the bottom surface portion 21 (see FIG. 4). The inner peripheral portion 25 is formed with a fitting recess (first fitting recess) 27 recessed downward from the upper surface 25a of the inner peripheral portion 25. The fitting recess 27 is a groove having a substantially rectangular shape when viewed from the vertical direction Z, and is formed in the region between the side wall portion 24 and the outer peripheral portion 26. The bottom of the fitting recess 27 is disposed above the upper surface 23 of the bottom surface portion 21, and below the upper surface 25a of the inner peripheral portion 25.

[0036] The outer circumferential portion 26 is provided outside the inner circumferential portion 25, and has an upper surface 26a disposed above an upper surface 25a of the inner circumferential portion 25. At a pair of ends of the outer circumferential portion 26 in the depth direction Y, cutout portions 26b are formed by cutting out a part of the outer circumferential portion 26 toward the depth direction Y. A columnar connecting portion 28 is provided in the cutout portion 26b. The connecting portion 28 extends in the width direction X, and both ends are connected to the outer circumferential portion 26.

[0037] Fig. 6 is a perspective view of the middle frame portion 12, and Fig. 7 is a bottom view of the middle frame portion 12. The middle frame portion 12 has a substantially rectangular frame shape when viewed from the up-down direction Z, and is detachably attached to the outer edge portion 22 of the bottom plate portion 11. The middle frame portion 12 includes an inner peripheral portion 31 and an outer peripheral portion 32 disposed outside the inner peripheral portion 31. When the middle frame portion 12 is attached to the bottom plate portion 11, the inner peripheral portion 31 of the middle frame portion 12 is disposed above the inner peripheral portion 25 of the bottom plate portion 11, and the outer peripheral portion 32 of the middle frame portion 12 is disposed above the outer peripheral portion 26 of the bottom plate portion 11.

[0038] As shown in FIG. 4 and FIG. 6, the inner periphery 31 has a fitting protrusion (first fitting protrusion) 33 and a fitting recess (second fitting recess) 34. The fitting protrusion 33 is formed along the inner edge of the middle frame 12 and has a substantially rectangular shape when viewed from below. The fitting protrusion 33 protrudes downward (toward the bottom plate 11) from the lower surface of the middle frame 12. The fitting protrusion 33 is disposed at a position facing the fitting recess 27 of the bottom surface 21 and can be fitted into the fitting recess 27. When the fitting protrusion 33 is fitted into the fitting recess 27, the bottom plate 11 and the middle frame 12 are connected to each other, and displacement of the bottom plate 11 and the middle frame 12 in the horizontal direction (width direction X and depth direction Y) is suppressed. The fitting recess 27 and the fitting protrusion 33 constitute the lower fitting structure 10 that connects the bottom plate 11 and the middle frame 12.

[0039] The fitting recess 34 is recessed downward from the upper surface of the inner circumferential portion 31. The fitting recess 34 is a groove having a substantially rectangular shape, and is disposed outside the fitting protrusion 33 as viewed from the vertical direction Z. As viewed from the vertical direction Z, the depth of the fitting recess 34 (the distance from the upper surface of the inner circumferential portion 31 to the bottom of the fitting recess 34 in the vertical direction Z) may be deeper than the depth of the fitting recess 27 (the distance from the upper surface 25a of the inner circumferential portion 25 to the bottom of the fitting recess 27 in the vertical direction Z).

[0040] One or more openings 37 may be formed in the bottom of the fitting recess 34 (see FIG. 7). The multiple openings 37 are through holes that penetrate the middle frame portion 12 in the thickness direction (up-down direction Z), and allow urine that has entered the fitting recess 34 to be discharged to the bottom portion 21.

[0041] The outer peripheral portion 32 of the middle frame portion 12 has an outer peripheral protrusion 35. The outer peripheral protrusion 35 is formed along the outer edge of the middle frame portion 12. The outer peripheral protrusion 35 has a substantially rectangular shape when viewed from below, and protrudes downward (toward the bottom plate portion 11) from the outer edge of the middle frame portion 12. As shown in FIG. 4, the tip of the outer peripheral protrusion 35 is disposed above the tip of the fitting protrusion 33 and below the bottom of the fitting recess 34. When the fitting protrusion 33 of the middle frame portion 12 is fitted into the fitting recess 27 of the bottom plate portion 11, the outer peripheral protrusion 35 is supported on the outer peripheral portion 26 of the bottom plate portion 11.

[0042] The inner frame portion 12 has a pair of first inner frame sides 12A extending in the width direction X and a pair of second inner frame sides 12B extending in the depth direction Y. As shown in Fig. 6, the length of the pair of first inner frame sides 12A in the width direction X is longer than the length of the pair of second inner frame sides 12B in the depth direction Y. The width w2 of the pair of second inner frame sides 12B in the width direction X may be smaller than the width w1 of the pair of first inner frame sides 12A in the depth direction Y.

[0043] The pair of first inner frame sides 12A have latches (second locking structures) 38 for locking the inner frame portion 12 to the bottom plate portion 11. The latches 38 include a latch body 38a extending downward from the outer edges of the pair of first inner frame sides 12A, and an extension portion 38b that is disposed inside the latch body 38a in the depth direction Y and faces the latch body 38a across a gap 38s (see FIG. 7).

[0044] The latch body 38a has a first claw portion 38c and a second claw portion 38d. The first claw portion 38c protrudes inward in the depth direction Y from the inner surface of the latch body 38a. The second claw portion 38d protrudes outward in the depth direction Y from the outer surface of the latch body 38a. When the middle frame portion 12 is attached onto the bottom plate portion 11, the connection portion 28 of the bottom plate portion 11 is accommodated in the gap 38s, and the first claw portion 38c is engaged with the connection portion 28 due to elastic deformation of the latch body 38a. This fixes the middle frame portion 12 to the bottom plate portion 11.

[0045] Fig. 8 is a perspective view of the upper frame portion 13, and Fig. 9 is a bottom view of the upper frame portion 13. The upper frame portion 13 has a substantially rectangular frame shape when viewed from the up-down direction Z, and is detachably attached onto the middle frame portion 12. The upper frame portion 13 includes an inner peripheral portion 41 and an outer peripheral portion 42 disposed outside the inner peripheral portion 41. When the upper frame portion 13 is attached onto the middle frame portion 12, the inner peripheral portion 41 of the upper frame portion 13 is disposed above the inner peripheral portion 31 of the middle frame portion 12, and the outer peripheral portion 42 of the upper frame portion 13 is disposed above the outer peripheral portion 32 of the middle frame portion 12.

[0046] The inner peripheral portion 41 of the upper frame portion 13 has an inner peripheral convex portion 43 and a fitting convex portion (second fitting convex portion) 44 (see FIG. 4). The inner peripheral convex portion 43 is formed along the inner edge of the upper frame portion 13 and has a generally rectangular shape when viewed from below. The inner peripheral convex portion 43 protrudes downward from the inner edge of the upper frame portion 13 towards the bottom plate portion 11.

[0047] The fitting protrusion 44 has a substantially rectangular shape when viewed from below, and is disposed outside the inner peripheral protrusion 43. The fitting protrusion 44 is disposed at a position facing the fitting recess 34 of the middle frame portion 12, and protrudes downward from the lower surface of the upper frame portion 13 toward the fitting recess 34. The fitting protrusion 44 can be fitted into the fitting recess 34. When the fitting protrusion 44 is fitted into the fitting recess 34, the middle frame portion 12 and the upper frame portion 13 are connected, and misalignment between the middle frame portion 12 and the upper frame portion 13 in the horizontal direction (width direction X and depth direction Y) is suppressed. The fitting recess 34 and the fitting protrusion 44 constitute the upper fitting structure 20 that connects the middle frame portion 12 and the upper frame portion 13.

[0048] 4, when the fitting recess 34 and the fitting protrusion 44 are fitted together, the lower end of the inner peripheral protrusion 43 is disposed lower than the lower end of the fitting protrusion 44. In addition, the maximum length of the fitting protrusion 44 of the upper frame portion 13 may be longer than the maximum length of the fitting protrusion 33.

[0049] The outer periphery 42 of the upper frame portion 13 has an outer periphery protrusion 45. The outer periphery protrusion 45 is formed along the outer edge of the upper frame portion 13. The outer periphery protrusion 45 has a generally rectangular shape when viewed from below, and protrudes downward from the outer edge of the upper frame portion 13 toward the middle frame portion 12. As shown in FIG. 4, when the upper frame portion 13 is attached to the middle frame portion 12 and the fitting protrusion 44 is fitted into the fitting recess 34, the outer periphery protrusion 45 of the upper frame portion 13 is supported on the outer periphery protrusion 35 of the middle frame portion 12.

[0050] 8, the upper frame portion 13 has a pair of first upper frame sides 13A extending in the width direction X and a pair of second upper frame sides 13B extending in the depth direction Y. The length of the pair of first upper frame sides 13A in the width direction X is longer than the length of the pair of second upper frame sides 13B in the depth direction Y. A width w4 in the width direction X of the pair of second upper frame sides 13B may be smaller than a width w3 in the depth direction Y of the pair of first upper frame sides 13A.

[0051] A pair of first upper frame sides 13A has a latch (first locking structure) 46 for locking the upper frame part 13 to the middle frame part 12. The latch 46 extends downward from the outer edge of the first upper frame side 13A. The latch 46 has an opening 46a penetrating the latch 46 in the thickness direction (depth direction Y). When attaching the upper frame part 13 to the middle frame part 12, the latch 46 slides along the outer surface of the latch 38 while elastically deforming so as to spread outward in the depth direction Y, and the second claw part 38d of the latch 38 fits into the opening 46a of the latch 46. As a result, the upper frame part 13 is fixed to the middle frame part 12. FIG. 10 is a side view showing the toilet body 2 in which the latch 46 of the upper frame part 13 fits into the latch 38 of the middle frame part 12, and the bottom plate part 11, the middle frame part 12, and the upper frame part 13 are connected.

[0052] 8, upper frame portion 13 has upper surface 47 that slopes downward (closer to bottom plate portion 11) from the outer edge to the inner edge of upper frame portion 13. Upper surface 47 is a curved surface whose slope angle increases closer to the inner edge of upper frame portion 13. Because upper surface 47 is sloped as described above, when a pet's urine splashes on upper frame portion 13, the urine can fall along upper surface 47 onto bottom plate portion 21.

[0053] In one embodiment, the upper surface 47 of the upper frame portion 13 may have an uneven shape. For example, a plurality of raised portions (convex portions) 48 extending in the depth direction Y are arranged at equal intervals along the width direction X on a pair of first upper frame sides 13A of the upper frame portion 13. Similarly, a plurality of raised portions 48 are arranged at equal intervals along the depth direction Y on a pair of second upper frame sides 13B of the upper frame portion 13. Between the plurality of raised portions 48, an inclined surface (concave portion) 49 that allows urine to flow toward the absorbent sheet 3 is formed. That is, on the upper surface 47 of the pair of first upper frame sides 13A, the raised portions 48 and the inclined surfaces 49 are alternately arranged in the width direction X, and on the upper surface 47 of the pair of second upper frame sides 13B, the raised portions 48 and the inclined surfaces 49 are alternately arranged in the depth direction Y. The inclined surfaces 49 are curved so as to approach downward as they move away from the adjacent raised portions 48. That is, since the center of inclined surface 49 in the width direction X or depth direction Y is the lowest, urine on upper frame portion 13 is collected at the center of inclined surface 49 and guided to bottom portion 21.

[0054] The toilet body 2 holds an absorbent sheet 3 and a water-permeable mat 4. The absorbent sheet 3 is a thin sheet having water absorbency, and is placed on the bottom surface 21 of the bottom plate 11 to absorb pet urine. FIG. 11 is a schematic plan view of the absorbent sheet 3. FIG. 12 is a cross-sectional view taken along line BB in FIG. 11, and FIG. 13 is a cross-sectional view taken along line CC in FIG. 11. FIGS. 11 to 13 show a vertical direction (second direction) V and a horizontal direction (first direction) W that are perpendicular to each other. When the absorbent sheet 3 is attached to the toilet body 2, the vertical direction V is arranged parallel to the width direction X, and the horizontal direction W is arranged parallel to the depth direction Y.

[0055] The absorbent sheet 3 has a generally rectangular planar shape. The vertical direction V is the longitudinal direction of the absorbent sheet 3, and the horizontal direction W is the transverse direction of the absorbent sheet 3. The absorbent sheet 3 has dimensions that correspond to the dimensions of the toilet body 2. For example, the absorbent sheet 3 has a length of 400 mm to 600 mm in the vertical direction V, and a width of 300 mm to 500 mm in the horizontal direction W. The absorbent sheet 3 is placed and held between the bottom plate 11 and the middle frame 12 of the toilet body 2.

[0056] As shown in FIG. 12 and FIG. 13, the absorbent sheet 3 includes a top sheet 51 arranged on the top side of the absorbent sheet 3, a back sheet 52 arranged on the back side of the absorbent sheet 3, and an absorbent 53 arranged between the top sheet 51 and the back sheet 52. The top sheet 51 is liquid permeable and formed in a substantially rectangular shape. The top sheet 51 is made of a resin film having a large number of openings 51a penetrating the top sheet 51 in the thickness direction. Typically, polyethylene or polypropylene is used as the material of the resin film. The top sheet 51 may be made of a laminate in which a nonwoven fabric is bonded to a resin film, or a water-repellent nonwoven fabric. Pet urine excreted on the absorbent sheet 3 moves to the absorbent 53 side through the openings 51a formed in the top sheet 51.

[0057] The back sheet 52 is water impermeable and formed in a generally rectangular shape with substantially the same dimensions as the top sheet 51. Examples of materials for the back sheet 52 include a resin film such as polyethylene or polypropylene, a laminate in which a nonwoven fabric is bonded to the resin film, or a water-repellent nonwoven fabric. By disposing the liquid impermeable back sheet 52 on the back side of the absorbent sheet 3, urine excreted on the absorbent sheet 3 is prevented from leaking to the back side.

[0058] The absorbent 53 is disposed between the top sheet 51 and the back sheet 52, and absorbs urine that has passed through the top sheet 51. The absorbent 53 has a substantially rectangular planar shape, is slightly smaller than the top sheet 51 and the back sheet 52, and is disposed in the center of the absorbent sheet 3. Therefore, as shown in FIG. 11, the absorbent sheet 3 has an absorbent section 3a in which the absorbent 53 is disposed between the top sheet 51 and the back sheet 52, and a flap section 3b in which the absorbent 53 is not disposed between the top sheet 51 and the back sheet 52. The absorbent section 3a is a substantially rectangular area disposed in the center of the absorbent 53 when viewed from the thickness direction, and is partially bonded to the top sheet 51 by the hot melt adhesive HM. The flap section 3b is a rectangular frame-shaped area in which the top sheet 51 and the back sheet 52 are bonded together without the absorbent 53, and is formed so as to surround the absorbent section 3a. That is, the flap section 3b is formed along the outer edge of the absorbent sheet 3. Typically, as shown in Figs. 12 and 13, in the flap portion 3b, the top sheet 51 and the back sheet 52 are directly bonded together by the hot melt adhesive HM without the absorbent body 53 therebetween.

[0059] The absorbent body 53 includes an absorbent core 54 containing pulp and a superabsorbent polymer (SAP), and a core wrap 55 covering the surface of the absorbent core. For example, chemical pulp, cellulose fiber, rayon, acetate, or other cellulose fiber is used as the pulp of the absorbent core 54. For example, starch-based, acrylic acid-based, or amino acid-based particulate or fibrous polymer is used as the SAP. The core wrap 55 is wrapped around the absorbent core 54 so as to cover at least a portion of the surface of the absorbent core 54. Typically, the core wrap 55 is made of white, plain tissue or nonwoven fabric.

[0060] 12, the end face 54a of the absorbent core 54 in the lateral direction W is not covered by the core wrap 55 and is adhered to the top sheet 51 with a hot melt adhesive HM. Adhering the end face 54a of the absorbent core 54 that is not covered by the core wrap 55 to the top sheet 51 prevents SAP from spilling out from the end face 54a. The end face 54a of the absorbent core 54 may be adhered to the back sheet 52 with a hot melt adhesive HM.

[0061] On the other hand, as shown in Fig. 13, the end surface 54b of the absorbent core 54 in the longitudinal direction V is covered with a core wrap 55. The core wrap 55 is bonded to the top sheet 51 by a hot melt adhesive HM. As shown in Fig. 13, a gap 53s may be formed between the end surface 54b of the absorbent core 54 in the longitudinal direction V and the flap portion 3b when viewed from the thickness direction of the absorbent core 54. When urine is absorbed by the absorbent core 54, the absorbent core 54 expands and enters the gap 53s. The gap 53s allows the absorbent core 54 to expand, thereby suppressing peeling of the top sheet 51 and the back sheet 52 of the flap portion 3b.

[0062] 13, the absorbent core 54 may have a void region 68 extending in the lateral direction W along the end surface 54b of the absorbent core 54. The void region 68 is a region where the density of SAP is locally reduced. That is, the proportion of pulp is increased in the void region 68. The void region 68 may be free of SAP.

[0063] The absorbent sheet 3 has a water retention capacity of 350 g or more. The water retention capacity of the absorbent sheet 3 can be measured, for example, by the following procedure. First, the dry weight of the absorbent sheet 3 is measured using an electronic balance. Next, the absorbent sheet 3 is immersed in 0.9% saline solution for 10 minutes to absorb the saline solution. Next, the absorbent sheet 3 is removed from the saline solution, hung to dry for 10 minutes, and the wet weight of the absorbent sheet 3 is measured. Next, the absorbent sheet 3 is dehydrated for 90 seconds at a rotation speed of 763 rpm using a dehydrator, and the weight of the absorbent sheet 3 after dehydration is measured. The weight of the absorbent sheet 3 after dehydration minus the dry weight of the absorbent sheet 3 can be determined as the water retention capacity. The water retention capacity of the absorbent sheet 3 can also be said to be the water retention capacity of the absorbent core 54.

[0064] 11, when the absorbent core 54 is divided into three equal regions in the horizontal direction W, which are designated as a first region 61, a second region 62, and a third region 63 in that order from one side of the horizontal direction W, the water retention capacities of the first region 61, the second region 62, and the third region 63 are substantially the same. For example, the difference between the maximum water retention capacities of the first region 61, the second region 62, and the third region 63 and the minimum water retention capacities of the first region 61, the second region 62, and the third region 63 is 20 g or less.

[0065] Furthermore, the ratio of the dry weight of the pulp in the first region 61 to the dry weight of the first region 61, the ratio of the dry weight of the pulp in the second region 62 to the dry weight of the second region 62, and the ratio of the dry weight of the pulp in the third region 63 to the dry weight of the third region 63 are substantially the same as one another, for example, 50% or more. The ratio of the dry weight of the SAP in the first region 61 to the dry weight of the first region 61, the ratio of the dry weight of the SAP in the second region 62 to the dry weight of the second region 62, and the ratio of the dry weight of the SAP in the third region 63 to the dry weight of the third region 63 are substantially the same as one another, for example, less than 50%. That is, in the first region 61, the second region 62, and the third region 63, the ratio of pulp is higher than the ratio of SAP.

[0066] On the other hand, as shown in Fig. 11, when the absorbent core 54 is divided into three equal regions in the longitudinal direction V, the regions are designated as a fourth region 64, a fifth region 65, and a sixth region 66 in that order from one side of the longitudinal direction VW, the water retention capacities of the fourth region 64, the fifth region 65, and the sixth region 66 are partially different. As described above, the fourth region 64 and the sixth region 66 have depletion regions 68 with locally low SAP density. As a result, the ratio of the dry weight of SAP in the fourth region 64 to the dry weight of the fourth region 64 and the ratio of the dry weight of SAP in the sixth region 66 to the dry weight of the sixth region 66 are lower than the ratio of the dry weight of SAP in the fifth region 65 to the dry weight of the fifth region 65. Conversely, the ratio of the dry weight of the pulp in the fourth region 64 to the dry weight of the fourth region 64 and the ratio of the dry weight of the pulp in the sixth region 66 to the dry weight of the sixth region 66 are higher than the ratio of the dry weight of the pulp in the fifth region 65 to the dry weight of the fifth region 65. As a result, the water retention capacity of the fifth region 65 is higher than the water retention capacities of the fourth region 64 and the sixth region 66, for example, by 10% or more, 20% or more, or 30% or more.

[0067] As described above, in the absorbent core 54, the distribution of SAP is uniform in the transverse direction W, but the distribution of SAP varies in the longitudinal direction V. By making the pulp ratio in the fourth region 64 and the sixth region 66 higher than the pulp ratio in the fifth region 65, urine excreted in the fifth region 65 can be diffused to the fourth region 64 and the sixth region 66 by capillary action.

[0068] The distribution of SAP in the absorbent core 54 may also vary in the thickness direction. For example, the absorbent core 54 may include an upper layer located on the topsheet 51 side and a lower layer located on the backsheet 52 side, and the proportion of SAP in the upper layer may be higher than the proportion of SAP in the lower layer.

[0069] The absorbent sheet 3 may further include a cover sheet 56. The cover sheet 56 is disposed between the top sheet 51 and the absorbent core 54, and covers the surface of the absorbent core 54. The cover sheet 56 has a generally rectangular planar shape, and has substantially the same dimensions as the absorbent body 53 when viewed in the thickness direction. The cover sheet 56 is made of, for example, tissue or nonwoven fabric, and is liquid permeable.

[0070] Fig. 15 is a plan view of an exemplary cover sheet 56. The cover sheet 56 is at least partially colored. In one embodiment, the cover sheet 56 has a colored area 57a that is colored with a color different from that of the top sheet 51, and a plurality of non-colored areas 57b that are not colored. In Fig. 15, the colored area 57a is shown by shading for convenience.

[0071] The colored region 57a ​​may be colored in a relatively dark hue, and may have a lightness L* of 55 or less in the L*a*b* color system when overlaid on a standard white board and viewed in the thickness direction. For example, the colored region 57a ​​is colored gray. The colored region 57a ​​is formed in a lattice pattern. The area of ​​the colored region 57a ​​in the cover sheet 56 may be larger than the total area of ​​the multiple non-colored regions 57b.

[0072] Each of the non-colored regions 57b is a quadrangular (square) white region (the same color as the top sheet 51). The non-colored regions 57b are two-dimensionally arranged along the vertical direction V and horizontal direction W of the cover sheet 56, and are defined by the lattice-like colored regions 57a. That is, the non-colored regions 57b are regularly arranged over the entire cover sheet 56. The non-colored regions 57b may include a region extending over the entire length and width of the cover sheet 56 along the vertical direction V and horizontal direction W of the cover sheet 56.

[0073] The cover sheet 56 is visible through the top sheet 51. When a pet urinates on the absorbent sheet 3, the pet's urine passes through the holes 4a of the top sheet 51 and the cover sheet 56 to be absorbed into the absorbent core 54. At this time, the cover sheet 56 turns yellow due to the urine, and urine marks are formed. Here, the colored area 57a of the cover sheet 56 is colored in a dark shade, so that the urine marks are difficult for the pet to see. Therefore, it is possible to prevent the pet from urinating outside the absorbent sheet 3 in an attempt to avoid the urine marks.

[0074] On the other hand, the non-colored areas 57b of the cover sheet 56 are not colored, so when urine adheres to them, they turn yellow, making the urine marks visible. By arranging the non-colored areas 57b two-dimensionally along the vertical direction V and the horizontal direction W, the urine marks are not clearly visible, but the outlines of the urine marks are visible. This allows the user to visually identify the location where the pet has urinated.

[0075] As shown in FIG. 14, the width d1 of each of the non-colored regions 57b in the lateral direction W may be 2 mm or more and 17 mm or less. By making the width d1 of the non-colored regions 57b 2 mm or more and 17 mm or less, urine is easily spread to three or more non-colored regions 57b, and the contour of the urine mark can be effectively identified. This allows the user to know when to replace the absorbent sheet 3. In addition, the width d2 between adjacent non-colored regions 57b among the multiple non-colored regions 57b may be 40 mm or less. By making the width d2 between adjacent non-colored regions 57b 40 mm or less, part of the urine is absorbed by the non-colored regions 57b, and the contour of the urine mark can be easily identified.

[0076] The outer edge of the cover sheet 56 is adhered to the top sheet 51 by a hot melt adhesive HM. On the other hand, as shown in FIG. 12 and FIG. 13, the surface of the cover sheet 56 facing the top sheet 51 has a non-adhesive region 70 that is not adhered to the top sheet 51. The non-adhesive region 70 is located in the center of the cover sheet 56. In the non-adhesive region 70, the top sheet 51 and the surface of the cover sheet 56 are not adhered at least partially, so that the deterioration of the water permeability of the top sheet 51 can be suppressed. In addition, due to the presence of the non-adhesive region 70, urine that has permeated the top sheet 51 is diffused throughout the absorbent sheet 3 through between the top sheet 51 and the cover sheet 56. Therefore, the absorbent sheet 3 can efficiently absorb urine.

[0077] In addition, in Figures 11 to 14, an example has been described in which the vertical direction V is the longitudinal direction of the absorbent sheet 3 and the horizontal direction W is the short side direction of the absorbent sheet 3, but the vertical direction V may be the short side direction of the absorbent sheet 3 and the horizontal direction W may be the longitudinal direction of the absorbent sheet 3.

[0078] The water-permeable mat 4 is a thin sheet having a porous structure and water permeability. The water-permeable mat 4 is held between the middle frame part 12 and the upper frame part 13 of the toilet body 2, and is placed on the absorbent sheet 3 when used. The water-permeable mat 4 has a function of preventing urine from flowing back from the absorbent sheet 3 while allowing pet urine to pass through. The water-permeable mat 4 is made of a foamed resin having an open cell structure (open cell structure), such as a urethane resin. Since urethane resin has high water resistance, by making the water-permeable mat 4 from a urethane resin, it becomes possible to repeatedly use the water-permeable mat 4 without replacing it. For example, an ether-based urethane resin having high tensile strength is used as the urethane resin.

[0079] Fig. 15 is a plan view showing an enlarged portion of the water-permeable mat 4 according to one embodiment. As shown in Fig. 15, the water-permeable mat 4 has a large number of pores 4a penetrating the water-permeable mat 4 in the thickness direction. The water-permeable mat 4 may have 8 to 20 pores 4a per square inch as viewed in the thickness direction. By setting the number of pores 4a per square inch to 8 to 20, the water-permeable mat 4 can ensure liquid permeability while maintaining its rigidity. The opening shape of the pores 4a may have any planar shape, such as a circle, an ellipse, or a polygon.

[0080] As shown in FIG. 3, the water-permeable mat 4 is placed on the absorbent sheet 3 and used. When no load is applied to the water-permeable mat 4, the water-permeable mat 4 may be placed away from the absorbent sheet 3. A pet using the system toilet 1 sits on the water-permeable mat 4 to urinate. The pet's urine passes through holes 4a formed in the water-permeable mat 4 and moves to the absorbent sheet 3 side, and is absorbed by the absorber 53 of the absorbent sheet 3. At this time, the water-permeable mat 4 prevents the pet's legs from contacting the absorbent sheet 3, so that the urine absorbed by the absorbent sheet 3 is prevented from flowing back to the pet's legs.

[0081] Next, a procedure for attaching the absorbent sheet 3 and the water-permeable mat 4 to the toilet body 2 will be described. First, the latches 38 of the middle frame portion 12 are pushed outward in the width direction X by hand to disengage the latches 38 from the connection portions 28 of the bottom plate portion 11. Then, the middle frame portion 12 is lifted and removed from the bottom plate portion 11. Next, the absorbent sheet 3 is placed on the bottom plate portion 11 so that the flap portions 3b of the absorbent sheet 3 are positioned on the outer edge portion 22 of the bottom plate portion 11. Next, the fitting protrusions 33 of the middle frame portion 12 are fitted into the fitting recesses 27 of the bottom plate portion 11, and the middle frame portion 12 is attached to the bottom plate portion 11. As a result, the flap portions 3b of the absorbent sheet 3 are sandwiched between the fitting recesses 27 and the fitting protrusions 33. At this time, the absorbent sheet 3 is pressed against the fitting protrusions 33 while deeply inserted into the fitting recesses 27, so that a strong frictional force acts on the absorbent sheet 3, and the absorbent sheet 3 is held firmly in place.

[0082] Next, the latches 46 of the upper frame portion 13 are pushed outward in the width direction X to release the engagement between the latches 46 and the latches 38 of the middle frame portion 12. Then, the upper frame portion 13 is lifted and removed from the middle frame portion 12. Next, the water-permeable mat 4 is placed on the middle frame portion 12, and the fitting convex portion 44 of the upper frame portion 13 is fitted into the fitting recessed portion 34 of the middle frame portion 12 to attach the upper frame portion 13 to the middle frame portion 12. As a result, the outer edge of the water-permeable mat 4 is sandwiched between the fitting recessed portion 34 and the fitting convex portion 44. At this time, the water-permeable mat 4 is pressed by the fitting convex portion 44 in a state where it is deeply inserted into the fitting recessed portion 36, so that a strong frictional force acts on the water-permeable mat 4, and the water-permeable mat 4 is firmly held. In particular, since the maximum length of the fitting protrusion 44 is longer than the maximum length of the fitting protrusion 33, the holding force of the upper fitting structure 20 for the water-permeable mat 4 is greater than the holding force of the lower fitting structure 10 for the absorbent sheet 3.

[0083] In addition, the water-permeable mat 4 is pressed downward by the inner peripheral convex portion 43. As a result, frictional force acts between the water-permeable mat 4 and the inner peripheral convex portion 43, and the holding force of the water-permeable mat 4 is further increased.

[0084] When the absorbent sheet 3 and water-permeable mat 4 are attached to the toilet body 2, the system toilet 1 is ready for use. When using the system toilet 1, a pet straddles the relatively narrow second upper frame side 13B and climbs onto the water-permeable mat 4 to urinate. The pet's urine passes through the water-permeable mat 4 and is absorbed by the absorbent sheet 3. After urinating, the pet climbs down from the system toilet 1 by straddling the second upper frame side 13B.

[0085] The absorbent sheet 3 has a high water retention capacity and can be used multiple times. For example, the absorbent sheet 3 can absorb pet urine for three days. Here, since the water-permeable mat 4 is arranged on the absorbent sheet 3, even if the absorbent sheet 3 is used repeatedly, the urine absorbed by the absorbent sheet 3 is prevented from flowing back up the pet's legs. In addition, since the water-permeable mat 4 is arranged on the absorbent sheet 3, the visibility of urine stains on the absorbent sheet 3 is reduced, and it is prevented that the pet dislikes urine stains and avoids using the toilet. Therefore, the frequency of replacing the absorbent sheet 3 can be reduced.

[0086] Next, the procedure for replacing the absorbent sheet 3 will be described. When the pet urinates multiple times and the absorbent sheet 3 needs to be replaced, the latches 38 of the middle frame portion 12 are pushed outward in the width direction X by hand to release the engagement between the latches 38 and the connection portion 28 of the bottom plate portion 11. Then, the middle frame portion 12 is lifted and removed from the bottom plate portion 11. Next, the used absorbent sheet 3 is replaced with a new absorbent sheet 3, and the middle frame portion 12 is reattached to the bottom plate portion 11. In this way, the user can replace the absorbent sheet 3 without directly touching the water-permeable mat 4. Therefore, the absorbent sheet 3 can be replaced without getting hands dirty.

[0087] When replacing the water-permeable mat 4, the water-permeable mat 4 can be removed and replaced individually from the system toilet 1 by removing the upper frame part 13 from the middle frame part 12 in the reverse order to that for attaching the water-permeable mat 4.

[0088] As described above, in the absorbent sheet 3, the ratio of the dry weight of the pulp in the first region 61 to the dry weight of the first region 61, the ratio of the dry weight of the pulp in the second region 62 to the dry weight of the second region 62, and the ratio of the dry weight of the pulp in the third region 63 to the dry weight of the third region 63 are 50% or more. By increasing the ratio of pulp in the first region 61, the second region 62, and the third region 63, SAP is captured by the pulp in the absorbent body 53, and the movement of SAP is suppressed. Therefore, bias in the distribution of SAP during use is less likely to occur, and as a result, the absorbent sheet 3 can be used for a long period of time.

[0089] In the absorbent sheet 3, the proportion of the dry weight of pulp in the fourth region 64 to the dry weight of the fourth region 64 and the proportion of the dry weight of pulp in the sixth region 66 to the dry weight of the sixth region 66 are higher than the proportion of the dry weight of pulp in the fifth region 65 to the dry weight of the fifth region 65. By making the proportion of pulp in the fourth region 64 and the sixth region 66 higher than the proportion of pulp in the fifth region 65, urine excreted in the fifth region 65 can be diffused to the fourth region 64 and the sixth region 66 by capillary action. By diffusing the pet's urine over a wide area, the urine can be efficiently absorbed.

[0090] Since the absorbent sheet 3 can be used for a long period of time, the frequency with which the absorbent sheet 3 needs to be replaced decreases, and therefore the pet toilet system 1 including the absorbent sheet 3 can be made easier to maintain.

[0091] Although the absorbent sheet 3 and the system toilet 1 according to various embodiments have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention. In other words, it should be noted that the above-described embodiments are intended to be illustrative and do not limit the scope of the present invention.

[0092] For example, in the above-mentioned toilet body 2, the bottom plate portion 11 is formed with the fitting recess 27, and the middle frame portion 12 is formed with the fitting protrusion 33, but the bottom plate portion 11 may be formed with an engagement protrusion, the middle frame portion 12 may be formed with a fitting recess, and these engagement protrusions and fitting recesses may be fitted together to connect the middle frame portion 12 to the bottom plate portion 11. Similarly, in the above-mentioned toilet body 2, the middle frame portion 12 is formed with the fitting recess 34, and the upper frame portion 13 is formed with the fitting protrusion 44, but the middle frame portion 12 is formed with an engagement protrusion, the upper frame portion 13 is formed with a fitting recess, and these engagement protrusions and fitting recesses may be fitted together to connect the upper frame portion 13 to the middle frame portion 12.

[0093] In the above-described toilet body 2, the length in the width direction X of the pair of first middle frame sides 12A is longer than the length in the depth direction Y of the pair of second middle frame sides 12B, but the length in the width direction X of the pair of first middle frame sides 12A may be shorter than the length in the depth direction Y of the pair of second middle frame sides 12B.

[0094] The arrangement of the colored area 57a and the non-colored areas 57b of the cover sheet 56 is not limited to the example shown in Fig. 14. The arrangement of the colored area 57a and the non-colored areas 57b can be appropriately designed in consideration of the design. The cover sheet 56 does not necessarily have to be colored.

[0095] The present disclosure includes the following:

[0096] [1] An absorbent sheet for pets having a water retention capacity of 350 g or more, A water permeable surface sheet; A non-permeable back sheet; an absorbent body including an absorbent core comprising a water-absorbent polymer and pulp and disposed between the top sheet and the back sheet; Equipped with when the absorbent core is divided into three equal regions in a first direction perpendicular to the thickness direction of the absorbent core, the regions are designated as a first region, a second region, and a third region in that order from one side in the first direction, the difference between the maximum water retention capacity of the first region, the second region, and the third region and the minimum water retention capacity of the first region, the second region, and the third region is 20 g or less, An absorbent sheet, wherein the ratio of the dry weight of the pulp in the first region to the dry weight of the first region, the ratio of the dry weight of the pulp in the second region to the dry weight of the second region, and the ratio of the dry weight of the pulp in the third region to the dry weight of the third region are 50% or more.

[0097] [2] The absorbent sheet described in [1], wherein when the absorbent core is divided into three equal regions in a second direction perpendicular to the thickness direction and the first direction, the regions are designated as a fourth region, a fifth region, and a sixth region, respectively, from one side of the second direction, the proportion of the dry weight of the pulp in the fourth region to the dry weight of the fourth region and the proportion of the dry weight of the pulp in the sixth region to the dry weight of the sixth region are higher than the proportion of the dry weight of the pulp in the fifth region to the dry weight of the fifth region.

[0098] [3] The absorbent core has a shape having a longitudinal direction and a transverse direction, the first direction is the short-side direction of the absorber, The absorbent sheet according to [2], wherein the second direction is the longitudinal direction of the absorbent body.

[0099] [4] The absorbent body further includes a cover sheet disposed between the top sheet and the absorbent core, The absorbent sheet according to any one of [1] to [3], wherein the cover sheet has a colored area that is colored in a color different from the color of the top sheet.

[0100] [5] The cover sheet has a plurality of non-colored areas, The absorbent sheet according to [4], wherein the area of ​​the colored region of the cover sheet is greater than the sum of the areas of the multiple non-colored regions of the cover sheet.

[0101] [6] The absorbent sheet according to [5], wherein the plurality of non-colored regions are regularly arranged across the entirety of the cover sheet.

[0102] [7] The absorbent sheet described in [5] or [6], wherein the plurality of non-colored regions are arranged two-dimensionally along the first direction and the second direction.

[0103] [8] The absorbent sheet according to any one of [5] to [7], wherein the width of each of the plurality of non-colored regions in the first direction is 2 mm or more and 17 mm or less.

[0104] [9] The absorbent sheet according to any one of [5] to [8], wherein the width between adjacent non-colored regions among the plurality of non-colored regions is 40 mm or less.

[0105]

[10] The absorbent body further includes a core wrap covering a portion of the absorbent core, An absorbent sheet described in any one of [1] to [9], wherein an end face of the absorbent core in the first direction is not covered by the core wrap, and an end face of the absorbent core in the second direction is covered by the core wrap.

[0106]

[11] An absorbent sheet as described in

[10] , wherein the end face of the absorbent core in the first direction is adhered to the top sheet or the back sheet by a hot melt adhesive.

[0107]

[12] An absorbent section in which the absorbent body is disposed between the top sheet and the back sheet; A frame-shaped flap portion is arranged to surround the absorbent portion, and the top sheet and the back sheet are bonded to each other without the absorbent body being interposed therebetween; The absorbent sheet according to any one of [1] to

[11] ,

[0108]

[13] The absorbent sheet according to

[12] , wherein a gap is formed between the end face of the absorbent body in the second direction and the flap portion.

[0109]

[14] The absorbent sheet described in any one of [1] to

[13] , wherein the top sheet is composed of a resin film having a large number of openings penetrating the top sheet in the thickness direction.

[0110]

[15] The absorbent body includes a cover sheet disposed between the top sheet and the absorbent core, The absorbent sheet according to

[14] , wherein the surface of the cover sheet facing the top sheet has a non-adhesive area that is not adhered to the top sheet.

[0111]

[16] An absorbent sheet having water absorption properties; a water-permeable mat disposed on the absorbent sheet; a toilet body that holds the absorbent sheet and the water-permeable mat; Equipped with The absorbent sheet comprises a water-permeable top sheet, a water-impermeable back sheet, and an absorbent body including an absorbent core that includes a water-absorbent polymer and pulp and is disposed between the top sheet and the back sheet; when the absorbent core is divided into three equal regions in a first direction perpendicular to the thickness direction of the absorbent core, the regions are designated as a first region, a second region, and a third region in that order from one side in the first direction, the difference between the maximum water retention capacity of the first region, the second region, and the third region and the minimum water retention capacity of the first region, the second region, and the third region is 20 g or less, A system toilet for pets, wherein the ratio of the dry weight of the pulp in the first region to the dry weight of the first region, the ratio of the dry weight of the pulp in the second region to the dry weight of the second region, and the ratio of the dry weight of the pulp in the third region to the dry weight of the third region are 50% or more. [Explanation of symbols]

[0112] 1...system toilet, 2...toilet body, 3...absorbent sheet, 3a...absorbent section, 3b...flap section, 4...permeable mat, 53s...gap, 51...surface sheet, 51a...opening, 52...back sheet, 53...absorbent body, 54...absorbent core, 54a, 54b...end surfaces, 55...core wrap, 56...cover sheet, 57a...colored region, 57b...non-colored region, 61...first region, 62...second region, 63...third region, 64...fourth region, 65...fifth region, 66...sixth region, 70...non-adhesive region, HM...hot melt adhesive.

Claims

1. An absorbent sheet for pets having a water retention capacity of 350 g or more, A water permeable surface sheet; A non-permeable back sheet; an absorbent body including an absorbent core comprising a water-absorbent polymer and pulp and disposed between the top sheet and the back sheet; Equipped with when the absorbent core is divided into three equal regions in a first direction perpendicular to the thickness direction of the absorbent core, the regions being designated as a first region, a second region and a third region in that order from one side in the first direction, the difference between the maximum water retention capacity of the first region, the second region and the third region and the minimum water retention capacity of the first region, the second region and the third region is 20 g or less, An absorbent sheet, wherein the ratio of the dry weight of the pulp in the first region to the dry weight of the first region, the ratio of the dry weight of the pulp in the second region to the dry weight of the second region, and the ratio of the dry weight of the pulp in the third region to the dry weight of the third region are 50% or more.

2. 2. The absorbent sheet of claim 1, wherein when the absorbent core is divided into three equal regions in a second direction perpendicular to the thickness direction and the first direction, the regions are designated as a fourth region, a fifth region, and a sixth region, respectively, from one side of the second direction, the proportion of the dry weight of the pulp in the fourth region to the dry weight of the fourth region and the proportion of the dry weight of the pulp in the sixth region to the dry weight of the sixth region are higher than the proportion of the dry weight of the pulp in the fifth region to the dry weight of the fifth region.

3. The absorbent core has a shape having a longitudinal direction and a transverse direction, the first direction is the short-side direction of the absorbent body, The absorbent sheet according to claim 2 , wherein the second direction is the longitudinal direction of the absorbent body.

4. The absorbent body further includes a cover sheet disposed between the top sheet and the absorbent core, 3. The absorbent sheet according to claim 2, wherein the cover sheet has a colored area that is colored a color different from the color of the top sheet.

5. the cover sheet having a plurality of non-colored areas; The absorbent sheet according to claim 4 , wherein an area of ​​the colored region of the cover sheet is greater than a sum of areas of the plurality of non-colored regions of the cover sheet.

6. The absorbent sheet according to claim 5 , wherein the non-colored regions are regularly arranged over the entirety of the cover sheet.

7. The absorbent sheet according to claim 5 , wherein the non-colored regions are two-dimensionally arranged along the first direction and the second direction.

8. The absorbent sheet according to claim 7 , wherein the width of each of the plurality of uncolored regions in the first direction is equal to or greater than 2 mm and equal to or less than 17 mm.

9. The absorbent sheet according to claim 7 , wherein the width between adjacent uncolored regions among the plurality of uncolored regions is 40 mm or less.

10. The absorbent body further includes a core wrap covering a portion of the absorbent core, The absorbent sheet according to claim 2 , wherein an end surface of the absorbent core in the first direction is not covered by the core wrap, and an end surface of the absorbent core in the second direction is covered by the core wrap.

11. The absorbent sheet according to claim 10 , wherein an end face of the absorbent core in the first direction is adhered to the top sheet or the back sheet by a hot melt adhesive.

12. an absorbent section in which the absorbent body is disposed between the top sheet and the back sheet; A frame-shaped flap portion is arranged to surround the absorbent portion, and the top sheet and the back sheet are bonded to each other without the absorbent body being interposed therebetween; The absorbent sheet according to claim 2 ,

13. The absorbent sheet according to claim 12 , wherein a gap is formed between the end face of the absorbent body in the second direction and the flap portion.

14. 2. The absorbent sheet according to claim 1, wherein the top sheet is made of a resin film having a large number of openings penetrating the top sheet in the thickness direction.

15. The absorbent body includes a cover sheet disposed between the top sheet and the absorbent core, 15. The absorbent sheet according to claim 14, wherein the surface of the cover sheet facing the top sheet has a non-adhesive area that is not adhered to the top sheet.

16. An absorbent sheet having water absorbency; a water-permeable mat disposed on the absorbent sheet; a toilet body that holds the absorbent sheet and the water-permeable mat; Equipped with The absorbent sheet comprises a water-permeable top sheet, a water-impermeable back sheet, and an absorbent body including an absorbent core that includes a water-absorbent polymer and pulp and is disposed between the top sheet and the back sheet; when the absorbent core is divided into three equal regions in a first direction perpendicular to the thickness direction of the absorbent core, the regions being designated as a first region, a second region and a third region in that order from one side in the first direction, the difference between the maximum water retention capacity of the first region, the second region and the third region and the minimum water retention capacity of the first region, the second region and the third region is 20 g or less, A system toilet for pets, wherein the ratio of the dry weight of the pulp in the first region to the dry weight of the first region, the ratio of the dry weight of the pulp in the second region to the dry weight of the second region, and the ratio of the dry weight of the pulp in the third region to the dry weight of the third region are 50% or more.

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