Absorbent sheet and package

Abstract

An absorbent sheet according to one embodiment of the present invention comprises: a water-permeable front surface sheet, a water-impermeable back surface sheet; and an absorbent body disposed between the front surface sheet and the back surface sheet. When regions obtained by dividing the absorbent body into three equal portions in the vertical direction are denoted as a first end portion, a middle portion, and a second end portion sequentially from one side in the vertical direction, each of the first end portion, the middle portion, and the second end portion has recesses recessed in the thickness direction of the absorbent body. The average value of depths of the recesses formed in the first end portion and the second end portion is greater than the average value of depths of the recesses formed in the middle portion.

Description

Absorbent sheet and packaging

[0001] The present disclosure relates to absorbent sheets and packages.

[0002] Absorbent sheets for absorbing urine are known. Widely used examples of this type of absorbent sheet include pet sheets for absorbing pet urine and bed sheets placed on beds to absorb urine during incontinence. Patent Document 1 listed below describes a treatment sheet comprising a liquid-absorbent core material disposed between a liquid-permeable sheet and a liquid-impermeable sheet, the liquid-permeable sheet and the liquid-absorbent core material being joined by a plurality of compressed grooves extending and intersecting each other. Patent Document 2 listed below describes an absorbent sheet for pets, which comprises a top sheet disposed on the top side, a back sheet disposed on the back side, and an absorbent body disposed between the top sheet and the back sheet, the absorbent body having linear recesses with non-branched curved portions.

[0003] JP 2010-51261 A JP 2019-91 A

[0004] When the absorbent body has depressions such as compressed grooves formed therein as described above, urine excreted on the absorbent sheet spreads along the depressions and is absorbed by the absorbent sheet over a wide area. As a result, it is possible to improve the urine absorption of the absorbent sheet. On the other hand, excessive urine diffusion causes the absorbent sheet to become soiled over a wide area, which is problematic from a hygienic standpoint. In particular, pets such as dogs have a tendency to dislike re-excreting in places where urination marks are visible. Therefore, if urine is diffused excessively, users may replace the pet absorbent sheet even though there is still an area available for absorbing urine.

[0005] Therefore, an object of the present disclosure is to provide an absorbent sheet that can prevent excessive diffusion of urine while ensuring absorbency, and a package that houses the absorbent sheet.

[0006] In one aspect, an absorbent sheet having a shape with a longitudinal direction and a transverse direction is provided. The absorbent sheet includes a water-permeable topsheet, a water-impermeable backsheet, and an absorbent body disposed between the topsheet and the backsheet. When the absorbent body is divided into three equal regions longitudinally, namely a first end region, a central region, and a second end region, each of the first end region, the central region, and the second end region has a recess that is recessed in the thickness direction of the absorbent body, and the average depth of the recesses formed in the first end region and the second end region is greater than the average depth of the recesses formed in the central region.

[0007] In the absorbent sheet according to the above aspect, relatively deep recesses are formed at the first end and the second end, so that the diffusibility of urine at the first end and the second end is relatively high. Therefore, at the first end and the second end, urine excreted in the absorbent sheet can be effectively diffused within those regions. On the other hand, a relatively shallow recess is formed in the central portion, so that the diffusibility of urine at the central portion is relatively low. Therefore, the diffusion of urine between the first end and the second end through the central portion is suppressed. Therefore, this absorbent sheet can suppress excessive diffusion of urine while maintaining absorbency.

[0008] In one embodiment, the absorbent body includes an absorbent core having water-absorbing properties, and the basis weight of the absorbent core may be 100 gsm or more. By increasing the basis weight of the absorbent core, the absorbency of the absorbent sheet can be increased.

[0009] In one embodiment, the basis weight of the absorbent core at the first end and the second end may be greater than the basis weight of the absorbent core at the central portion. By relatively increasing the basis weight of the absorbent core at the first end and the second end, water absorption at the first end and the second end can be improved. By varying the basis weight of the absorbent sheet at the boundary between the first end and the central portion and the boundary between the second end and the central portion, it becomes easier to fold the absorbent sheet along the boundary between the first end and the central portion and the boundary between the second end and the central portion.

[0010] In one embodiment, the absorbent sheet may be for use with pets. Pets such as dogs tend to avoid leaving excretion marks (urine marks) when urinating. As a result, pets may urinate in an awkward position to avoid the urine marks, resulting in urinating outside the absorbent sheet and soiling the pet's living space. In contrast, the absorbent sheet according to this embodiment can prevent excessive diffusion of urine, thereby preventing pets from avoiding the urine marks and urinating outside the absorbent sheet.

[0011] In one aspect, the recesses may be formed in a lattice pattern in the absorbent body when viewed in the thickness direction of the absorbent body. By forming the recesses in a lattice pattern, urine can be diffused in the planar direction in each region.

[0012] In one aspect, the recess includes a plurality of first compressed grooves extending in a first direction inclined with respect to the longitudinal and lateral directions, and a plurality of second compressed grooves extending in a second direction intersecting the first direction, and the distance between adjacent first compressed grooves among the plurality of first compressed grooves and the distance between adjacent second compressed grooves among the plurality of second compressed grooves may be 10 mm or less. In this aspect, urine can be effectively diffused in the planar direction in each region.

[0013] In one embodiment, the absorbent core includes a first layer containing pulp and a superabsorbent polymer, and a second layer disposed on the first layer and containing a superabsorbent polymer, and the proportion of the superabsorbent polymer in the second layer may be higher than the proportion of the superabsorbent polymer in the first layer. In the absorbent sheet according to this embodiment, recesses are formed in the absorbent body, which restricts the movement of the superabsorbent polymer in the second layer in the in-plane direction. As a result, the uniformity of the absorbency of the absorbent sheet in the in-plane direction can be improved.

[0014] In one embodiment, the absorbent core may contain deodorizing particles, which can suppress odors when urine is urinated onto the absorbent sheet.

[0015] In one embodiment, the absorbent body may include a core wrap covering the absorbent core, and the superabsorbent polymer in the absorbent core may be in close contact with the core wrap. In this case, the movement of the superabsorbent polymer within the absorbent core is restricted, thereby improving the uniformity of the absorbency of the absorbent sheet.

[0016] In one embodiment, an antibacterial agent may be provided on the surface of the absorbent core. By providing the antibacterial agent on the surface of the absorbent core, urine comes into contact with the antibacterial agent when it is absorbed into the absorbent core, making it less likely for urine to spoil. This makes it possible to suppress urine odor.

[0017] In the absorbent sheet according to one embodiment, the absorbent core may contain a fragrance, in which case the fragrance can suppress the odor of urine.

[0018] In one embodiment, the absorbent body is bonded to the top sheet and back sheet using an adhesive, and the amount of adhesive applied between the absorbent body and the back sheet may be greater than the amount of adhesive applied between the absorbent body and the top sheet. In this embodiment, the amount of adhesive applied between the absorbent body and the top sheet is relatively small, which prevents the adhesive from reducing the water permeability between the top sheet and the absorbent body, thereby promoting urine absorption by the absorbent body.

[0019] In one embodiment, an adhesive may be applied to the entire surface of the absorbent body facing the backsheet. By applying an adhesive to the entire surface of the backsheet, the bond between the absorbent body and the backsheet is strengthened, preventing the absorbent body from slipping relative to the backsheet.

[0020] In one embodiment, the width of the back sheet in the longitudinal direction may be greater than the width of the top sheet in the longitudinal direction, in which case, when the absorbent sheet is placed on a floor with the back sheet facing down, the top sheet is prevented from contacting the floor, thereby keeping the floor clean.

[0021] In one embodiment, the absorbent body includes a core wrap that covers the absorbent core, and the core wrap may cover at least one of the horizontal and vertical ends of the absorbent core. Covering the ends of the core wrap can prevent the superabsorbent polymer from spilling out from the ends of the absorbent core.

[0022] In one embodiment, the longitudinal ends of the absorbent core may be covered with a core wrap, and the transverse ends of the absorbent core may be exposed from the core wrap, which can prevent the superabsorbent polymer from spilling out from the longitudinal ends of the absorbent core.

[0023] In one embodiment, the fiber direction of the top sheet may be oriented in the cross direction, which allows the absorbent sheet to be easily folded in the longitudinal direction.

[0024] In one aspect, a package is provided that contains a plurality of absorbent sheets, each having a shape with a longitudinal direction and a transverse direction. Each of the plurality of absorbent sheets includes a water-permeable top sheet, a water-impermeable back sheet, and an absorbent body disposed between the top sheet and the back sheet. When the absorbent body is divided into three equal regions longitudinally, the regions are designated, in order from one side in the longitudinal direction, as a first end, a central region, and a second end, and each of the first end, the central region, and the second end has a recess that is recessed in the thickness direction of the absorbent body, and the average depth of the recesses formed in the first end and the second end is greater than the average depth of the recess formed in the central region. Each of the plurality of absorbent sheets is stored in a state folded longitudinally in thirds.

[0025] According to the present disclosure, it is possible to suppress excessive diffusion of urine while ensuring absorbency.

[0026] FIG. 1 is a perspective view showing an absorbent sheet according to one embodiment. FIG. 2 is a plan view of the absorbent sheet shown in FIG. 1, viewed from the front side. FIG. 3 is a cross-sectional view of the absorbent sheet taken along line A-A in FIG. 2. FIG. 4 is a cross-sectional view of the absorbent sheet taken along line B-B in FIG. 2. FIG. 5 is a plan view of an absorbent body, viewed from the front side. FIG. 6 is a schematic cross-sectional view showing a package that contains a plurality of absorbent sheets. FIG. 7 is a diagram showing an example of a tray on which absorbent sheets are placed. FIG. 8 is a perspective view showing an example of a system toilet. FIG. 9 is a cross-sectional view of an absorbent sheet according to another embodiment.

[0027] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate explanations will be 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] Fig. 1 is a perspective view showing an absorbent sheet 1 according to one embodiment. Fig. 2 is a plan view of the absorbent sheet 1 as viewed from the front side Z1. Fig. 3 is a cross-sectional view of the absorbent sheet taken along line A-A in Fig. 2. Fig. 4 is a cross-sectional view of the absorbent sheet taken along line B-B in Fig. 2.

[0029] The absorbent sheet 1 is a thin, water-absorbent sheet that absorbs urine. For example, the absorbent sheet 1 is a pet sheet that absorbs urine from pets. In this specification, pets broadly encompass vertebrates and invertebrates, and typically include pet animals such as dogs, cats, rabbits, and hamsters.

[0030] The absorbent sheet 1 has a substantially rectangular planar shape. Figures 1 to 4 show a horizontal direction X, a vertical direction Y, and a thickness direction Z, which are perpendicular to one another. The horizontal direction X is the short side direction of the absorbent sheet 1, and the vertical direction Y is the longitudinal direction of the absorbent sheet 1. The thickness direction Z is a direction perpendicular to the horizontal direction X and the vertical direction Y, and includes a top side Z1 and a back side Z2. The top side Z1 is the direction from a back sheet 20 (described later) toward the top sheet 10, and the back side Z2 is the direction from the top sheet 10 (described later) toward the back sheet 20.

[0031] The absorbent sheet 1 comprises a topsheet 10 disposed on the top side Z1, a backsheet 20 disposed on the back side Z2, and an absorber 30 disposed between the topsheet 10 and the backsheet 20. The topsheet 10 is water-permeable and formed in a substantially rectangular shape. The topsheet 10 provides a surface that faces the pet (upward) during use. Typically, the topsheet 10 is made of a water-permeable nonwoven fabric, and transfers urine excreted by the pet toward the absorber 30. Examples of nonwoven fabrics that constitute the topsheet 10 include air-through nonwoven fabrics, spunbond nonwoven fabrics, and point-bond nonwoven fabrics. The topsheet 10 may be hydrophilized with a surfactant. In one embodiment, the fiber direction of the topsheet 10 may be oriented in the transverse direction X.

[0032] The backsheet 20 is disposed on the opposite side of the topsheet 10 in the thickness direction Z and is water-impermeable. The backsheet 20 is disposed so as to at least partially overlap the topsheet 10 in the thickness direction Z. The backsheet 20 provides a back surface that faces downward during use. Typically, the backsheet 20 is made of a water-impermeable resin film. Examples of the resin film that constitutes the backsheet 20 include a polyethylene film and a polypropylene film. The backsheet 20 may be made of a water-repellent or hydrophobic nonwoven fabric, or may be a laminate formed by bonding a resin film and a nonwoven fabric. In one embodiment, the fiber direction of the backsheet 20 may be oriented in the transverse direction X.

[0033] The absorbent body 30 is disposed between the top sheet 10 and the back sheet 20, and absorbs pet urine that passes through the top sheet 10. The absorbent body 30 has a substantially rectangular planar shape. The absorbent body 30 is slightly smaller than the top sheet 10 and the back sheet 20, and is disposed in the center of the absorbent sheet 1. As a result, the absorbent sheet 1 is formed with an absorbent section 1a in which the absorbent body 30 is disposed between the top sheet 10 and the back sheet 20, and a flap section 1b in which the absorbent body 30 is not disposed between the top sheet 10 and the back sheet 20.

[0034] As shown in Fig. 2, the absorbent section 1a is a substantially rectangular region located in the center of the absorbent sheet 1 when viewed from the thickness direction Z. The absorbent section 1a is partially bonded to the topsheet 10 with a hot melt adhesive HM. Typically, the flap section 1b is a rectangular frame-shaped region formed by bonding the topsheet 10 and the backsheet 20 together without an absorbent body 30 therebetween, and is formed so as to surround the absorbent section 1a. In other words, the flap section 1b is formed along the outer edge of the absorbent sheet 1. Typically, as shown in Figs. 3 and 4, in the flap section 1b, the topsheet 10 and the backsheet 20 are directly bonded together with a hot melt adhesive HM without an absorbent body 30 therebetween.

[0035] In one embodiment, as shown in Fig. 4, the width of the backsheet 20 in the longitudinal direction Y may be larger than the width of the topsheet 10 in the longitudinal direction Y. That is, the outer edge of the backsheet 20 in the longitudinal direction Y extends further outward than the outer edge of the topsheet 10 in the longitudinal direction Y. On the other hand, as shown in Fig. 3, the width of the backsheet 20 in the transverse direction X may be substantially the same as the width of the topsheet 10 in the transverse direction X. Note that the width of the backsheet 20 in the longitudinal direction Y may be substantially the same as the width of the topsheet 10 in the longitudinal direction Y, or the width of the backsheet 20 in the transverse direction X may be larger than the width of the topsheet 10 in the transverse direction X.

[0036] The absorbent body 30 has a first surface 30a disposed on the front side Z1 and a second surface 30b disposed on the back side Z2. The first surface 30a is disposed opposite the topsheet 10, and at least a portion of the first surface 30a is bonded to the topsheet 10 with a hot melt adhesive HM. The second surface 30b is disposed opposite the backsheet 20, and at least a portion of the second surface 30b is bonded to the backsheet 20 with a hot melt adhesive HM. The amount of hot melt adhesive HM applied between the backsheet 20 and the absorbent body 30 may be greater than the amount of hot melt adhesive HM applied between the topsheet 10 and the absorbent body 30. For example, in the embodiment shown in Figures 3 and 4, the hot melt adhesive HM is applied only to the outer edge of the first surface 30a, and the first surface 30a is bonded to the topsheet 10 via the hot melt adhesive HM. On the other hand, the second surface 30b is entirely coated with a hot melt adhesive HM, and the second surface 30b is joined to the backsheet 20 via the hot melt adhesive HM. In other words, the hot melt adhesive HM is coated on the entire surface of the backsheet 20 facing the absorbent body 30. By relatively reducing the amount of hot melt adhesive HM coated between the topsheet 10 and the absorbent body 30, it is possible to suppress a decrease in the permeability of urine from the topsheet 10 to the absorbent body 30. Note that "coating the hot melt adhesive HM on the entire surface of the second surface 30b" includes coating the hot melt adhesive HM in a spiral pattern on almost the entire surface of the second surface 30b. For example, coating the hot melt adhesive HM on the entire surface of the second surface 30b means coating the hot melt adhesive HM on an area of ​​9 cm2 or less of continuous uncoated areas. ２ Less than 4 cm, more preferably ２ Less than 1 cm, more preferably ２ This includes the following:

[0037] As shown in Figures 3 and 4, the absorbent body 30 includes an absorbent core 31 containing pulp and a superabsorbent polymer (SAP), and a core wrap 32 covering the surface of the absorbent core 31. Pulp for the absorbent core 31 may be, for example, chemical pulp, cellulose fiber, rayon, acetate, or other cellulose fibers. SAP may be, for example, a starch-based, acrylic acid-based, or amino acid-based particulate or fibrous polymer. In one embodiment, the absorbent core 31 has a basis weight of 100 gsm or more. The core wrap 32 is wrapped around the absorbent core 31 so as to cover at least a portion of the surface of the absorbent core 31. The core wrap 32 covers at least the upper surface of the absorbent core 31 facing the topsheet 10 and the lower surface of the absorbent core 31 facing the backsheet 20.

[0038] As shown in Fig. 3, the end face 31x of the absorbent core 31 in the transverse direction X is not covered by the core wrap 32 and may be exposed from the core wrap 32. The end face 31x exposed from the core wrap 32 is adhered to the topsheet 10 with a hot melt adhesive HM. By adhering the end face 31x of the absorbent core 31 that is not covered by the core wrap 32 to the topsheet 10, SAP in the absorbent core 31 is prevented from spilling out from the end face 31x. The end face 31x of the absorbent core 31 may also be adhered to the backsheet 20 with a hot melt adhesive HM.

[0039] 4 , the end face 31y of the absorbent core 31 in the longitudinal direction Y is covered with a core wrap 32. The core wrap 32 is adhered to the topsheet 10 and the backsheet 20 with a hot melt adhesive HM. Covering the end face 31y of the absorbent core 31 with the core wrap 32 prevents the SAP in the absorbent core 31 from spilling out from the end face 31y. In one embodiment, the end face 31x of the absorbent core 31 may be covered with the core wrap 32, and the end face 31y of the absorbent core 31 may not be covered with the core wrap 32. Alternatively, both the end faces 31x and 31y of the absorbent core 31 may be covered with the core wrap 32.

[0040] As shown in Figures 3 and 4, the absorbent body 30 has a laminated structure including a first layer 31a and a second layer 31b. The first layer 31a is a water-absorbent layer containing pulp 51 and SAP 52 and is disposed between the backsheet 20 and the second layer 31b. The second layer 31b is disposed on the first layer 31a. The second layer 31b is a water-absorbent layer containing SAP 52 and is disposed between the topsheet 10 and the first layer 31a. The proportion of SAP 52 in the second layer 31b may be higher than the proportion of SAP 52 in the first layer 31a. For example, the second layer 31b may contain only SAP 52 without containing pulp. Note that the proportion of SAP 52 is a mass ratio in a dry state. The SAP 52 in the second layer 31b may be in close contact with the core wrap 32.

[0041] In one embodiment, the absorbent core 31 may contain deodorizing particles 53. The deodorizing particles 53 may be, for example, cyclodextrin. The deodorizing particles 53 are arranged, for example, on the first layer 31a of the absorbent core 31. The deodorizing particles 53 arranged on the first layer 31a suppress the odor of urine excreted in the absorbent sheet 1.

[0042] An antibacterial agent 54 may be provided on the surface of the absorbent core 31. The antibacterial agent 54 is, for example, polyhexamethylene biguanide (PHMB), a quaternary ammonium salt, or citric acid. For example, the antibacterial agent 54 is applied to the surface of the front side Z1 of the absorbent core 31. The antibacterial agent applied to the surface of the absorbent core 31 eliminates urine odor, keeping the absorbent sheet 1 clean. The absorbent core 31 may also contain a fragrance 55. A natural fragrance or a synthetic fragrance is used as the fragrance 55.

[0043] FIG. 5 is a plan view of the absorber 30 as viewed from the front surface side. As shown in FIG. 5, the absorber 30 has a rectangular planar shape when viewed from the front surface side Z1. That is, the width of the absorber 30 in the horizontal direction X is substantially constant in the vertical direction Y. As shown in FIG. 5, the absorber 30 has recesses 35 recessed in the thickness direction Z (back surface side Z2) from the first surface 30a to the second surface 30b of the absorber 30. The recesses 35 are groove-shaped regions compressed from the front surface side Z1 to the back surface side Z2 by embossing. At the positions where the recesses 35 are formed, the absorbent core 31 and the core wrap 32 are pressed together. The recesses 35 function to diffuse urine excreted in the absorbent sheet 1 in the in-plane direction of the absorber 30.

[0044] In the embodiment shown in FIG. 5 , the recesses 35 are formed in a grid pattern when viewed from the front side Z1. More specifically, the recesses 35 include a plurality of first compressed grooves 36 extending along a first direction inclined relative to the horizontal direction X and the vertical direction Y, and a plurality of second compressed grooves 37 extending along a second direction intersecting the first direction. The first compressed grooves 36 are, for example, arranged at approximately equal intervals in the second direction and extend linearly in the first direction. The second compressed grooves 37 are, for example, arranged at approximately equal intervals in the first direction and extend linearly in the second direction. The first compressed grooves 36 and the second compressed grooves 37 intersect with each other. The distance D1 between adjacent first compressed grooves 36 among the plurality of first compressed grooves 36 and the distance D2 between adjacent second compressed grooves 37 among the plurality of second compressed grooves 37 are, for example, 10 mm or less.

[0045] As described above, by forming the lattice-shaped recesses 35, a plurality of absorbent regions 40 are formed in the absorbent body 30. The plurality of absorbent regions 40 are regions defined by the lattice-shaped recesses 35, and are arranged two-dimensionally across substantially the entire area of ​​the absorbent body 30 when viewed from the front side Z1. In other words, each absorbent region 40 is an area surrounded by recesses 35. The plurality of absorbent regions 40 are arranged at intervals in a diagonal direction intersecting the horizontal direction X and the vertical direction Y. For example, each of the plurality of absorbent regions 40 has a diamond shape. Note that the absorbent region 40 may have a shape other than a diamond shape, such as a circle, an ellipse, or a polygon.

[0046] As described above, the recesses 35 are formed over substantially the entire area of ​​the absorbent body 30. Therefore, as shown in FIG. 5 , when the absorbent body 30 is divided into three equal regions in the longitudinal direction Y, the regions are designated, in order from one side of the longitudinal direction Y, as a first end portion 41, a central portion 42, and a second end portion 43, each of the first end portion 41, the central portion 42, and the second end portion 43 includes a portion of the recesses 35. Here, as shown in FIG. 4 , the average value of the depth d1 of the recesses 35 formed in the first end portion 41 and the second end portion 43 is greater than the average value of the depth d2 of the recesses 35 formed in the central portion 42. The depths d1 and d2 of the recesses 35 refer to the distance in the thickness direction Z between the first surface 30a of the absorbent body 30 (i.e., the surface on the front side Z1 of the absorbent region 40) and the bottoms 35a of the recesses 35. The depth of the recesses 35 may be constant in each region.

[0047] 4 , the depth d1 of the recesses 35 formed in the first end portion 41 and the second end portion 43 may be greater than the thickness Ta of the second layer 31b in the absorbent region 40. On the other hand, the depth d2 of the recesses 35 formed in the central portion 42 may be less than the thickness Ta of the second layer 31b in the absorbent region 40. Note that both of the depths d1 and d2 of the recesses 35 may be greater than the thickness Ta of the second layer 31b, or both of the depths d1 and d2 of the recesses 35 may be less than the thickness Ta of the second layer 31b.

[0048] 4, the absorbent regions 40 are partitioned by the recesses 35, so that the SAP in the first layer 31a in the absorbent regions 40 is restricted from migrating in the in-plane direction. In particular, when the depth d1 of the recesses 35 is greater than the thickness Ta of the first layer 31a, the first layers 31a of adjacent absorbent regions 40 are separated by the recesses 35, so that migration of SAP between the first layers 31a of adjacent absorbent regions 40 is prevented. Therefore, the uniformity of the water absorption of the absorbent sheet 1 in the in-plane direction is improved.

[0049] In one embodiment, the basis weight of the absorbent core 31 may vary depending on the position in the in-plane direction of the absorbent core 31. For example, the basis weight of the absorbent core 31 in the first end portion 41 and the second end portion 43 may be greater than the basis weight of the absorbent core 31 in the central portion 42. In other words, the amount of SAP 52 per unit area in the first end portion 41 and the second end portion 43 is greater than the amount of SAP 52 per unit area in the central portion 42. In this case, the water absorbency at the first end portion 41 and the second end portion 43 can be increased.

[0050] The absorbent sheet 1 described above is folded and contained in a package 80. Figure 6 is a schematic cross-sectional view showing the package 80 containing a plurality of absorbent sheets 1. The package 80 is, for example, a bag having a substantially rectangular parallelepiped shape, and is made of, for example, synthetic resin, paper, or a combination of these. A tear line (not shown) is formed in the package 80, and by opening the package 80 along the tear line, an opening is formed for removing the absorbent sheets 1 contained in the package 80.

[0051] As shown in FIG. 6 , the absorbent sheet 1 is folded in thirds in the longitudinal direction Y and placed inside the package 80 in a stacked state. When using the absorbent sheet 1, the absorbent sheet 1 is removed from the package 80 by inserting a finger into the package 80 through the opening of the package 80, grasping and pulling the absorbent sheet 1. As described above, since the absorbent sheet 1 is folded in thirds in the longitudinal direction Y, when the absorbent sheet 1 is removed from the package 80, fold lines L1 and L2 extending in the transverse direction X are formed in the absorbent sheet 1 (see FIG. 2 ). The fold lines L1 and L2 are linear wrinkles formed along the transverse direction X when the absorbent sheet 1 is compressed in a folded state. As shown in FIG. 2 , the fold lines L1 and L2 extend in the transverse direction X so as to cross the absorbent sheet 1. In other words, the fold lines L1 and L2 can be said to be tri-fold lines for folding the absorbent sheet 1 into thirds. Here, since the fiber direction of the topsheet 10 is oriented in the transverse direction X, the bending rigidity of the topsheet 10 in the longitudinal direction Y is lower than the bending rigidity of the topsheet 10 in the transverse direction X. Therefore, the absorbent sheet 1 can be easily folded in the longitudinal direction Y and stored in the package 80.

[0052] As described above, the absorbent body 30 of the absorbent sheet 1 has embossed recesses 35 formed therein. Forming the recesses 35 in the absorbent body 30 increases the rigidity of the absorbent body 30. As a result, the absorbent sheet 1 can be prevented from rolling up during use. Furthermore, since the absorbent sheet 1 has relatively deep recesses 35 formed at the first end 41 and the second end 43, the urine diffusibility at the first end 41 and the second end 43 is relatively high. Therefore, urine excreted in the absorbent sheet 1 can be effectively diffused within the first end 41 and the second end 43. Meanwhile, since the central portion 42 has a relatively shallow recess 35 formed therein, the urine diffusibility at the central portion 42 is relatively low. Therefore, urine diffusion between the first end 41 and the second end 43 through the central portion 42 is suppressed. Therefore, the absorbent sheet 1 can suppress excessive urine diffusion.

[0053] Typically, as shown in Fig. 7, the absorbent sheet 1 removed from the package 80 is placed on a tray 100 of a pet toilet. The tray 100 shown in Fig. 7 has a placement surface 101 and side walls 102 erected from the edges of the placement surface 101. The absorbent sheet 1 is placed on the placement surface 101 of the tray 100. A pet using the toilet urinates by standing on the absorbent sheet 1 placed on the tray 100.

[0054] Dogs tend to avoid excretion marks (urine marks) when urinating. As a result, dogs may urinate in an awkward position to avoid urine marks, resulting in urinating outside the tray 100 and soiling the enclosure. In contrast, the absorbent sheet 1 can prevent urine from spreading excessively, thereby preventing dogs from avoiding urine marks and urinating outside the tray 100. The dog litter box may have a tray and a mesh member placed on the tray, and the absorbent sheet 1 may be placed between the tray and the mesh member. When a dog urinates on the mesh member, the urine passes through openings formed in the mesh member and is absorbed by the absorbent sheet 1 placed below the mesh member.

[0055] The absorbent sheet 1 may also be used in a system toilet. Fig. 8 is a perspective view showing an example of a system toilet. The system toilet 200 shown in Fig. 8 is a cat toilet and includes a base 210, a litter tray 220, and a cover 230. The base 210 is a container with an open top, and includes a tray 211 for receiving pet waste. The tray 211 is housed within the base 210 so as to be slidable in the front-to-rear direction. The absorbent sheet 1 is placed on the tray 211 by the user.

[0056] The toilet tray 220 is supported on the base 210 so as to cover the upper opening of the base 210. The toilet tray 220 provides an excretion surface 221 for the pet to stand on during excretion. Litter may be placed on the excretion surface 221 of the toilet tray 220. Litter is a granular material that can absorb or pass through excrement such as urine. Examples of litter include bentonite, which can cover feces and absorb liquids, wood or paper with a water-repellent coating, or zeolite, silica gel, minerals, etc., which have deodorizing properties and are molded into approximately spherical shapes of several centimeters. The toilet tray 220 has a roughly rectangular planar shape and multiple bars arranged in a slatted pattern. Multiple openings 222 are regularly formed between the bars. The multiple openings 222 are located above the tray 211 and are capable of passing through pet excrement. When a pet stands on the excretion surface 221 to excrete, the excrement passes through the multiple openings 222 and falls toward the tray 211 , where it is absorbed by the absorbent sheet 1 arranged on the tray 211 .

[0057] The cover 230 is disposed above the excretion table 220. The cover 230 is, for example, a half-cover type container, and surrounds the space above the excretion surface 221 from the sides.

[0058] Generally, cats tend to prefer to excrete on one side of the litter placed on the excretion surface 221. In this case, the cat's excrement (urine) passes through the litter and the multiple openings 222 and is absorbed primarily by the first end 41 or the second end 43 of the absorbent sheet 1. Here, the absorbent sheet 1 is designed to prevent urine from spreading between the first end 41 and the second end 43. Therefore, for example, after the cat urinates at the first end 41, the tray 211 can be opened, the absorbent sheet 1 can be rotated 180 degrees, and then the tray 211 can be returned to its original position. This allows the absorbent sheet 1 to absorb urine in the same position. This allows a wide area to be used for urine absorption.

[0059] Furthermore, in the absorbent sheet 1, the basis weight of the absorbent core 31 in the first end portion 41 and the second end portion 43 is greater than the basis weight of the absorbent core 31 in the central portion 42. Varying the basis weight of the absorbent core 31 in the longitudinal direction Y makes it easier to fold the absorbent sheet 1 along the boundary between the first end portion 41 and the central portion 42 and the boundary between the second end portion 43 and the central portion 42. When the absorbent sheet 1 is folded, the first end portion 41 and the second end portion 43, which have a relatively large basis weight, cover the inner surface of the absorbent sheet 1, thereby trapping the odor of bodily waste within the folded absorbent sheet 1.

[0060] In the embodiment shown in Fig. 4, the thickness of the absorbent body 30 is constant at the first end 41, the central portion 42, and the second end 43, but in one embodiment, the thickness of the absorbent body 30 may be different at the first end 41, the central portion 42, and the second end 43. For example, as shown in Fig. 9, the thickness of the absorbent body 30 at the first end 41 and the second end 43 may be thicker than the thickness of the absorbent body 30 at the central portion 42. In the embodiment shown in Fig. 9 as well, the average value of the depth d1 of the recesses 35 formed at the first end 41 and the second end 43 is greater than the average value of the depth d2 of the recesses 35 formed in the central portion 42.

[0061] The depth of the recesses 35 in the lateral direction X may be substantially uniform. That is, as shown in FIG. 5 , when the absorbent body 30 is divided into three equal regions in the lateral direction X, namely, a first end portion 61, a central portion 62, and a second end portion 63, starting from one side of the lateral direction X, the average depth of the recesses 35 formed in the first end portion 61 and the second end portion 63 is substantially uniform. The basis weight of the absorbent core 31 in the first end portion 61 and the second end portion 63 may be substantially uniform as the basis weight of the absorbent core 31 in the central portion 62. Some of the recesses 35 may be formed on the outer edges of the absorbent body 30 (the four sides of the absorbent body 30). For example, some of the recesses 35 may be formed on the edges of the absorbent body 30 in the lateral direction X. In this case, the average depth of the recesses 35 formed in the portions of the edge of the absorbent body 30 in the lateral direction X that are located within the first end 41 and the second end 43 (both ends of the edge of the absorbent body 30 in the lateral direction X) may be greater than the average depth of the recesses 35 formed in the portions of the edge of the absorbent body 30 in the lateral direction X that are located within the central portion 42 (the central portion of the edge of the absorbent body 30 in the lateral direction X). Furthermore, the basis weight of the portions of the edge of the absorbent core 31 in the lateral direction X that are located within the first end 41 and the second end 43 may be greater than the basis weight of the portion of the edge of the absorbent core 31 in the lateral direction X that is located within the central portion 42.

[0062] The absorbent sheet 1 according to various embodiments has been described above, but it 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 for illustrative purposes only and do not limit the scope of the present invention. The various embodiments described above can be combined within a consistent range.

[0063] For example, in the above embodiment, an example was described in which the absorbent sheet 1 is used as a pet sheet for absorbing pet excrement, but the absorbent sheet 1 is not limited to this. For example, the absorbent sheet may be placed on a bed and used as a bed sheet for absorbing urine during incontinence. The various embodiments described above can be combined within a consistent range.

[0064] The present disclosure includes the following contents.

[0065] [1] An absorbent sheet having a shape having a longitudinal direction and a transverse direction, comprising: a water-permeable top sheet; a water-impermeable back sheet; and an absorbent body arranged between the top sheet and the back sheet, wherein when the absorbent body is divided into three equal regions in the longitudinal direction, which are designated as a first end portion, a central portion, and a second end portion in that order from one side in the longitudinal direction, each of the first end portion, the central portion, and the second end portion has a recess that is recessed in the thickness direction of the absorbent body, and the average depth of the recesses formed in the first end portion and the second end portion is greater than the average depth of the recesses formed in the central portion.

[0066] [2] The absorbent sheet according to [1], wherein the absorbent body includes an absorbent core having water absorption properties, and the absorbent core has a basis weight of 100 gsm or more.

[0067] [3] The absorbent sheet according to [2], wherein the basis weight of the absorbent core at the first end and the second end is greater than the basis weight of the absorbent core at the center.

[0068] [4] The absorbent sheet according to any one of [1] to [3], wherein the absorbent sheet is for pets.

[0069] [5] The absorbent sheet according to any one of [1] to [4], wherein the recesses are formed in a lattice pattern in the absorbent body when viewed in the thickness direction of the absorbent body.

[0070] [6] The absorbent sheet described in [5], wherein the recess includes a plurality of first compressed grooves extending along a first direction inclined with respect to the longitudinal direction and the lateral direction, and a plurality of second compressed grooves extending along a second direction intersecting the first direction, and the distance between adjacent first compressed grooves among the plurality of first compressed grooves and the distance between adjacent second compressed grooves among the plurality of second compressed grooves is 10 mm or less.

[0071] [7] The absorbent sheet according to [2] or [3], wherein the absorbent core comprises a first layer containing pulp and a superabsorbent polymer, and a second layer disposed on the first layer and containing a superabsorbent polymer, and the proportion of the superabsorbent polymer in the second layer as a whole is higher than the proportion of the superabsorbent polymer in the first layer as a whole.

[0072] [8] The absorbent sheet according to [2], [3] or [7], wherein the absorbent core contains deodorizing particles.

[0073] [9] The absorbent sheet according to [7], wherein the absorbent body includes a core wrap that covers the absorbent core, and the superabsorbent polymer in the absorbent core is in close contact with the core wrap.

[0074]

[10] The absorbent sheet according to any one of [2], [3], and [7] to [9], wherein an antibacterial agent is provided on the surface of the absorbent core.

[0075]

[11] The absorbent sheet according to any one of [2], [3], and [7] to

[10] , wherein the absorbent core contains a fragrance.

[0076]

[12] The absorbent sheet according to any one of [1] to

[11] , wherein the absorbent body is bonded to the top sheet and the back sheet using an adhesive, and the amount of adhesive applied between the absorbent body and the back sheet is greater than the amount of adhesive applied between the absorbent body and the top sheet.

[0077]

[13] The absorbent sheet according to

[12] , wherein the adhesive is applied to the entire surface of the absorbent body facing the backsheet.

[0078]

[14] The absorbent sheet according to any one of [1] to

[13] , wherein the width of the backsheet in the longitudinal direction is greater than the width of the topsheet in the longitudinal direction.

[0079]

[15] The absorbent sheet according to any one of [2], [3], and [7] to

[11] , wherein the absorbent body includes a core wrap that covers the absorbent core, and the core wrap covers at least one of the ends of the absorbent core in the horizontal direction and the ends of the absorbent core in the vertical direction.

[0080]

[16] The absorbent sheet according to

[15] , wherein the end portions of the absorbent core in the longitudinal direction are covered with the core wrap, and the end portions of the absorbent core in the lateral direction are exposed from the core wrap.

[0081]

[17] The absorbent sheet according to any one of [1] to

[16] , wherein the fiber direction of the topsheet is oriented in the lateral direction.

[0082]

[18] A package containing a plurality of absorbent sheets, each having a shape with a vertical direction and a horizontal direction, wherein each of the plurality of absorbent sheets comprises: a water-permeable top sheet; a water-impermeable back sheet; and an absorbent body arranged between the top sheet and the back sheet; when the absorbent body is divided into three equal regions in the vertical direction and each region is defined as a first end portion, a central portion, and a second end portion, starting from one side in the vertical direction, each of the first end portion, the central portion, and the second end portion has a recess that is recessed in the thickness direction of the absorbent body; the average depth of the recesses formed in the first end portion and the second end portion is greater than the average depth of the recesses formed in the central portion; and each of the plurality of absorbent sheets is contained in a state folded in three in the vertical direction.

[0083] 1...absorbent sheet, 10...top sheet, 20...back sheet, 30...absorbent body, 31...absorbent core, 31a...first layer, 31b...second layer, 32...core wrap, 35...recess, 36...first compressed groove, 37...second compressed groove, 41...first end, 42...central portion, 43...second end, 51...pulp, 53...deodorizing particles, 54...antibacterial agent, 55...fragrance, X...horizontal direction, Y...vertical direction, Z...thickness direction.

Claims

1. An absorbent sheet having a shape with longitudinal and lateral directions, comprising: a water-permeable top sheet; a water-impermeable back sheet; and an absorbent body arranged between the top sheet and the back sheet, wherein when the absorbent body is divided into three equal regions in the longitudinal direction, which are designated, from one side in the longitudinal direction, as a first end, a central portion, and a second end, each of the first end, the central portion, and the second end has a recess that is recessed in the thickness direction of the absorbent body, and the average depth of the recesses formed in the first end and the second end is greater than the average depth of the recesses formed in the central portion.

2. The absorbent sheet according to claim 1, wherein the absorbent body comprises an absorbent core having water absorbency, and the basis weight of the absorbent core is 100 gsm or more.

3. The absorbent sheet according to claim 2, wherein the basis weight of the absorbent core at the first end and the second end is greater than the basis weight of the absorbent core at the center portion.

4. The absorbent sheet of claim 1, wherein the absorbent sheet is for pets.

5. The absorbent sheet according to claim 1, wherein the recesses are formed in a lattice pattern in the absorbent body when viewed in the thickness direction of the absorbent body.

6. An absorbent sheet as described in claim 5, wherein the recess includes a plurality of first compressed grooves extending along a first direction inclined with respect to the longitudinal direction and the lateral direction, and a plurality of second compressed grooves extending along a second direction intersecting the first direction, and the distance between adjacent first compressed grooves among the plurality of first compressed grooves and the distance between adjacent second compressed grooves among the plurality of second compressed grooves is 10 mm or less.

7. The absorbent sheet according to claim 2, wherein the absorbent core comprises a first layer containing pulp and a superabsorbent polymer, and a second layer disposed on the first layer and containing a superabsorbent polymer, and the proportion of the superabsorbent polymer in the second layer as a whole is higher than the proportion of the superabsorbent polymer in the first layer as a whole.

8. The absorbent sheet of claim 2, wherein the absorbent core contains deodorizing particles.

9. The absorbent sheet according to claim 7, wherein the absorbent body includes a core wrap surrounding the absorbent core, and the highly absorbent polymer in the absorbent core is in intimate contact with the core wrap.

10. The absorbent sheet according to claim 2, wherein an antibacterial agent is provided on the surface of the absorbent core.

11. The absorbent sheet of claim 2, wherein the absorbent core includes a fragrance.

12. The absorbent sheet according to claim 1, wherein the absorbent body is bonded to the top sheet and the back sheet using an adhesive, and the amount of adhesive applied between the absorbent body and the back sheet is greater than the amount of adhesive applied between the absorbent body and the top sheet.

13. The absorbent sheet according to claim 12, wherein the adhesive is applied to the entire surface of the absorbent body facing the backsheet.

14. The absorbent sheet of claim 1, wherein the width of the backsheet in the machine direction is greater than the width of the topsheet in the machine direction.

15. The absorbent sheet according to claim 2, wherein the absorbent body includes a core wrap that covers the absorbent core, and the core wrap covers at least one of the ends of the absorbent core in the horizontal direction and the ends of the absorbent core in the vertical direction.

16. The absorbent sheet according to claim 15, wherein the end portions of the absorbent core in the longitudinal direction are covered by the core wrap, and the end portions of the absorbent core in the transverse direction are exposed from the core wrap.

17. The absorbent sheet according to claim 1, wherein the fiber direction of the top sheet is oriented in the cross direction.

18. A package containing a plurality of absorbent sheets, each having a shape with vertical and horizontal directions, wherein each of the plurality of absorbent sheets comprises a water-permeable top sheet, a water-impermeable back sheet, and an absorbent body arranged between the top sheet and the back sheet, wherein when the absorbent body is divided into three equal regions in the vertical direction and the regions are designated, in order from one side in the vertical direction, as a first end, a central portion, and a second end, each of the first end, the central portion, and the second end has a recess that is recessed in the thickness direction of the absorbent body, the average depth of the recesses formed in the first end and the second end is greater than the average depth of the recesses formed in the central portion, and each of the plurality of absorbent sheets is contained in a state where it is folded in thirds in the vertical direction.

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