Absorbent pad

Abstract

To provide an absorbent pad capable of taking in excreta quickly even when excreta that is highly viscose or contains much solid components is discharged.SOLUTION: An absorbent pad 1 includes: a surface layer 2 having projections 21 projecting to a skin side and recesses 22 having open holes 23 on the bottom; a gap forming layer 4 composed of a liquid permeable member, having projections projecting to the skin side and having an internal space S3 and recesses, and forming an excreta diffusion space V diffusing excreta supplied via the open holes in the direction crossing a thickness direction of the absorbent pad between itself and the surface layer 2; and a drawing layer 5 formed by a fiber assembly 5A, having a part 50 entering into the internal space S3, and drawing a low viscose component from excreta in the excreta diffusion space V.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an absorbent pad. [Background technology]

[0002] Regarding components of absorbent articles such as diapers, studies have been conducted taking into consideration the processing and retention of liquid feces. For example, Patent Document 1 proposes an absorbent article comprising a top sheet that is permeable to liquid feces and faces the skin, an absorbent body that retains liquid feces, a second sheet that is interposed between the top sheet and the absorbent body and is permeable to liquid feces and covers the outer surface of the absorbent body, a sheet that is impermeable to liquid feces, etc., on the non-skin-contacting side of the absorbent body and covers the outer surface of the absorbent body, and a back sheet that covers the outside of the impermeable sheet to liquid feces, etc., and forms the non-skin-contacting surface of the absorbent article. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-045393 Summary of the Invention [Problem to be solved by the invention]

[0004] Absorbent articles such as diapers and absorbent pads generally include an absorbent core as the main absorbent for excrement. Absorbent cores generally contain absorbent materials such as fluff pulp and absorbent polymers. However, such cores tend to retain high-viscosity or solid components contained in liquid feces without being absorbed by the core, remaining in sheets or other materials located closer to the skin than the core, causing clogging between the fibers of the sheet and reducing the absorbent article's liquid absorption performance. Absorbent articles equipped with such cores may be unable to quickly absorb feces containing high viscosity or a large amount of solid components. The absorbent article described in Patent Document 1 does not address the case where high-viscosity or a large amount of solid components is excreted, leaving room for improvement.

[0005] Therefore, an object of the present invention is to provide an absorbent pad that can quickly absorb feces even when the feces are highly viscous or contain a large amount of solid components. [Means for solving the problem]

[0006] The present invention relates to an absorbent pad having a surface layer with a convex portion protruding toward the skin side and a concave portion having an opening at the bottom. In one embodiment, it is preferable that the absorbent pad is made of a liquid-permeable material, has convex and concave portions that protrude toward the skin and have internal spaces, and has a gap-forming layer between the surface layer that forms a feces diffusion space that diffuses feces supplied through the openings in a direction perpendicular to the thickness direction of the absorbent pad. In one embodiment, it is preferable that the anti-septic tank further comprises an attraction layer formed from a fiber aggregate, having a portion that penetrates into the internal space, and that attracts low-viscosity components from the feces in the feces diffusion space.

[0007] The present invention also relates to an absorbent article comprising the absorbent pad and a diaper in which the absorbent pad is used with its skin-facing side overlaid. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an absorbent pad that can quickly absorb feces even when the excreted feces are highly viscous or contain a large amount of solid components. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic plan view of an embodiment of the absorbent pad of the present invention, viewed from the skin-facing side. [Figure 2] FIG. 2 is a schematic enlarged cross-sectional view taken along line II in FIG. [Figure 3] FIG. 3 is a schematic enlarged perspective view of a main part of the concave-convex sheet that constitutes the surface layer of the absorbent pad shown in FIG. [Figure 4] FIG. 4 is a schematic enlarged cross-sectional view of a main part of the concavo-convex sheet shown in FIG. [Figure 5] FIG. 5 is a schematic enlarged perspective view of a main part of the embossed sheet that constitutes the gap-forming layer of the absorbent pad shown in FIG. [Figure 6] FIG. 6 is a schematic enlarged cross-sectional view of a main part of the concave-convex sheet shown in FIG. [Figure 7] 7(a) and (b) are explanatory diagrams of the mechanism of intake of the absorbent pad of the present invention. [Figure 8] 8(a) and (b) are explanatory diagrams of the mechanism of intake of the absorbent pad of the present invention. [Figure 9] 9(a) and (b) are explanatory diagrams of the mechanism of intake of the absorbent pad of the present invention. [Figure 10] FIG. 10 is an enlarged perspective view of a main part showing a surface layer and a gap-forming layer of another embodiment of the absorbent pad of the present invention. [Figure 11] FIG. 11 is a schematic cross-sectional view along the thickness direction of another embodiment of the absorbent pad of the present invention. [Figure 12] FIG. 12 is a schematic cross-sectional view along the thickness direction of another embodiment of the absorbent pad of the present invention. [Figure 13] FIG. 13 is a schematic plan view of another embodiment of the absorbent pad of the present invention, as viewed from the skin-facing surface side. [Figure 14] FIG. 14 is a view corresponding to FIG. 2 showing another embodiment of the absorbent pad of the present invention. [Figure 15] FIG. 15 is an explanatory diagram of the mechanism for taking in the absorbent pad shown in FIG. [Figure 16] FIG. 16 is an explanatory diagram of the mechanism for taking in the absorbent pad shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will now be described based on preferred embodiments with reference to the drawings. Fig. 1 shows an absorbent pad 1 according to one embodiment of the present invention. The absorbent pad 1 of this embodiment has a transverse direction Y and a longitudinal direction X perpendicular to the transverse direction Y. It is preferable that the absorbent pad 1 be used by being placed on the skin-facing surface (inner surface) of an absorbent article such as a diaper, with the longitudinal direction X aligned with the direction extending from the wearer's abdomen through the crotch area to the back. That is, the absorbent pad is preferably used together with the absorbent article such as a diaper as an inner layer for absorbing and retaining feces.

[0011] In this specification, the "skin-facing side" of the absorbent pad refers to the side of the absorbent pad or its constituent member that faces the wearer's skin when the absorbent pad is worn, i.e., the side relatively closer to the wearer's skin. The "non-skin-facing side" of the absorbent pad refers to the side of the absorbent pad or its constituent member that faces the opposite side from the skin side (clothing side) when the absorbent pad is worn, i.e., the side relatively farther from the wearer's skin. Note that "when worn" here refers to the normal, proper wearing position, i.e., a state in which the absorbent pad is maintained in the correct wearing position.

[0012] As shown in Fig. 2, the absorbent pad 1 comprises a retaining layer 3 and a surface layer 2 covering one surface of the retaining layer 3. In this embodiment, the surface layer 2 covers one surface of the retaining layer 3 and forms the skin-facing surface. The surface layer 2 has convex portions 21 protruding toward the skin-facing surface side and concave portions 22 having openings 23 at their bottoms 22T. In detail, as shown in Figs. 3 and 4, the surface layer 2 is composed of an uneven sheet 2A having an uneven structure including a plurality of convex portions 21 protruding toward the skin-facing surface side and having internal spaces S1, and a plurality of concave portions 22 protruding toward the non-skin-facing surface side and having internal spaces S2 and openings at their bottoms.

[0013] When the surface layer 2 is viewed in a plane, the convex portions 21 and concave portions 22 are preferably arranged alternately and continuously along two different directions that intersect with each other. Here, the two different directions are preferably an arbitrary first direction in the plane and a second direction intersecting therewith, which intersect at an angle of 30 degrees or more and 90 degrees or less. For example, in the surface layer 2 of this embodiment, the first and second directions intersect at 90 degrees. That is, for example, in the absorbent pad 1, one of the two directions is the horizontal direction Y1, and the other is the vertical direction X1. Therefore, when the concave-convex sheet 2A is viewed in a plane, the convex portions 21 and concave portions 22 are arranged alternately and continuously along the vertical direction X1 and the horizontal direction Y1. Note that in the embodiment shown in FIG. 3, the convex portions viewed from the skin-facing side are convex portions 21, and the concave portions are concave portions 22. Conversely, the convex portions viewed from the non-skin-facing side are concave portions 22, and the concave portions are convex portions 21.

[0014] As shown in FIGS. 3 and 4, in the surface layer 2 of the absorbent pad 1, the protrusions 21 of the uneven sheet 2A have wall portions 21W between their tops 21T and openings 21H of the internal space S1. Furthermore, the recesses 22 have wall portions 22W between their bottoms 22T and openings 22H of the internal space S2. The bottoms 22T of the multiple recesses 22 have a lower fiber density than the surrounding area and have openings 23. In this embodiment, all of the multiple recesses 22 have openings 23, but only some of the multiple recesses 22 may have openings 23. When some of the multiple recesses 22 have openings 23, the uneven sheet 2A has recesses 22 that include both bottoms 22T with through-holes 23 and bottoms 22T without openings 23 and with a lower fiber density than the surrounding area. When some of the recesses 22 have openings 23, the recesses 22 having openings 23 are preferably uniformly dispersed in a plan view of the uneven sheet 2A. Note that the protrusions 21 of the surface layer 2 may be solid and not have an internal space S1.

[0015] The protrusions 21 and recesses 22 of the concave-convex sheet 2A have a hemispherical shape for the protrusions 21, while the recesses 22 have a conical or truncated conical shape with a rounded bottom. The protrusion shapes of the protrusions 21 and recesses 22 are not limited to the above shapes and may be any protrusion shape. For example, they may be cone-shaped, such as a cone, a truncated cone, a pyramid, a truncated pyramid, or an oblique cone.

[0016] The concave-convex sheet 2A having the convex portions 21 and the concave portions 22 preferably has no bent portions and is composed entirely of a continuous curved surface. Here, "continuous" means that there are no discontinuous portions or small holes other than the openings 23 formed in the bottoms 22T of the concave portions 22. However, fine holes such as gaps between fibers are not included in the small holes.

[0017] The concave-convex sheet 2A can be any liquid-permeable sheet conventionally used in the art, without any particular limitations. Examples of the concave-convex sheet 2A include paper such as tissue paper, fiber sheets such as hydrophilic nonwoven fabrics (spunbond nonwoven fabrics, spunlace nonwoven fabrics, etc.), and films. As described above, the concave-convex sheet 2A is preferably liquid-permeable and hydrophilic. The method for producing the perforated concave-convex sheet 2A is not particularly limited. For example, when producing a nonwoven fabric by the hydroentanglement method, a fiber fabric is placed on a net having concaves and convexes, and a water flow is applied to the net to the extent that perforations are formed at the apexes of the convexes, thereby obtaining a perforated nonwoven fabric. The obtained nonwoven fabric is turned upside down so that the perforated portions are located at the bottoms of the concaves 22, and used as the concave-convex sheet 2A having perforations 23.

[0018] The absorbent pad 1 comprises a surface layer 2, a gap-forming layer 4, and a pull-in layer 5, in this order from the skin-facing side to the non-skin-facing side. Note that in some drawings, the surface layer 2 and the gap-forming layer 4 are shown separated from each other for ease of explanation, but in reality, the surface layer 2 and the gap-forming layer 4 are in partial contact with each other. In the absorbent pad 1, the surface layer 2 forms the skin-facing surface, and the retention layer 3 is the portion that captures and retains excrement. As shown in Figure 2, the retention layer 3 has a laminated structure in which, from the skin-facing side to the non-skin-facing side, a gap-forming layer 4, a draw-in layer 5, a diffusion layer 6, and an absorbent layer 7 are laminated. The names "gap-forming layer," "draw-in layer," "diffusion layer," and "absorbent layer" are intended to indicate their functional characteristics. The absorbent pad 1 preferably has a leak-proof layer 8 on the non-skin-facing side. The leak-proof layer 8 can be formed from a liquid-impermeable sheet. Liquid-impermeable includes poorly liquid-permeable, and poorly liquid-permeable sheets also include sheets formed using moisture-permeable films, etc.

[0019] The gap-forming layer 4 is adjacent to the surface layer 2 in the thickness direction of the absorbent pad 1. The gap-forming layer 4 is responsible for forming a feces diffusion space V (described later) between the surface layer 2 and the gap-forming layer 4. The gap-forming layer 4 has an uneven structure to form a gap between the surface layer 2 and the gap-forming layer 4, which becomes the feces diffusion space V. Specifically, in this embodiment, the gap-forming layer 4, like the surface layer 2, is composed of an uneven sheet 4A having an uneven structure with protruding portions 41 protruding toward the skin-facing surface side and having an internal space S3, and recessed portions 42 protruding toward the non-skin-facing surface side and having an internal space S4. When the gap-forming layer 4 is viewed in plan, the uneven sheet 4A has the protruding portions 41 and the recessed portions 42 alternately and continuously arranged along two different directions that intersect with each other (see FIGS. 5 and 6). The uneven sheet 4A is also referred to as a second sheet or a sublayer sheet in this technical field.

[0020] A liquid-permeable material can be used as the concave-convex sheet 4A. Examples of such sheets include nonwoven fabrics (spunbond nonwoven fabrics, spunlace nonwoven fabrics, etc.), urethane sheets, etc. These can be used alone or in combination of two or more.

[0021] In the absorbent pad 1 of the present invention, a feces-diffusing space V is formed between the surface layer 2 and the gap-forming layer 4 (see FIG. 2). The feces-diffusing space V is a region that serves to diffuse feces supplied through the perforations 23 in a direction intersecting the thickness direction Z. From the viewpoint of forming a feces-diffusing space V with excellent feces-diffusing properties, as described above, the gap-forming layer 4 is preferably adjacent to the surface layer 2 in the thickness direction of the absorbent pad 1, and preferably at least a portion of the gap-forming layer 4 is in contact with the surface layer 2. In particular, from the viewpoint of more reliably securing the feces-diffusing space V, it is preferable that the surface layer 2 and the gap-forming layer 4 overlap with each other in a state in which the recesses 22 of the surface layer 2 and the protrusions 41 of the gap-forming layer 4 are in contact with each other. The feces diffusion space V is a space in which the internal space S1 of the protrusions 21 in the textured sheet 2A and the internal space S4 of the recesses 42 in the textured sheet 4A are connected to each other. More specifically, the feces diffusion space V is a space in which the internal space S1 of the protrusions 21 and the internal space S4 of the recesses 42 are continuous in the planar direction. When focusing on one recess 22 in the textured sheet 2A, the feces diffusion space V is preferably formed continuously around the entire periphery surrounding the recess 22, and it is preferable that the spaces surrounding each recess 22 are connected to the spaces surrounding the other recesses 22. Furthermore, when focusing on one protrusion 41 in the textured sheet 4A, the feces diffusion space V is preferably formed continuously around the entire periphery surrounding the protrusion 41, and it is preferable that the spaces surrounding each protrusion 41 are connected to the spaces surrounding the other protrusions 41. The feces diffusion space V contains almost no or no constituent materials of the embossed sheets 2A and 4A. Here, "almost no" means that ideally, each constituent material is completely absent, but does not exclude the presence of some of each constituent material due to fluffing, damage, etc.

[0022] The pull-in layer 5 is located closer to the non-skin-facing surface side than the gap-forming layer 4 in the thickness direction Z, and is adjacent to the gap-forming layer 4. The attraction layer 5 has the role of separating low-viscosity components contained in the feces from the feces in the feces diffusion space V. The low-viscosity components are the portion of the feces, particularly liquid feces, remaining after removing the high-viscosity and solid components contained in the feces, and are a highly fluid portion that contains a lot of water. From the viewpoint of making it easier for low-viscosity components of feces to be drawn into the drawing layer 5 without remaining in the gap-forming layer 4, it is preferable that the inter-fiber distance of the fiber aggregate 5A constituting the drawing layer 5 is smaller than that of the uneven sheet 4A constituting the gap-forming layer 4. It is also preferable that the hydrophilicity of the fiber aggregate 5A constituting the drawing layer 5 is higher than that of the uneven sheet 4A constituting the gap-forming layer 4. From the viewpoint of improving the ability to draw in low-viscosity components of feces, the fiber assembly 5A preferably contains hydrophilic fibers. It is preferable that the constituent fibers of the fiber assembly 5A do not have any junctions between them. Using such a fiber assembly 5A increases the degree of freedom of movement of the constituent fibers, allowing it to deform to fit the shape of the internal space S3 of the embossed sheet 4A. The fiber aggregate 5A constituting the drawing layer 5 is preferably, for example, a stack of short fibers made of flap pulp (cotton-like pulp), synthetic fibers, or a tow (fiber bundle) made of synthetic or semi-synthetic long fibers such as cellulose acetate. These preferably do not have bonds between constituent fibers bonded by fusion, binders, or the like. The fiber aggregate 5A may also be a nonwoven fabric that does not have such bonds or a nonwoven fabric in which the fibers are weakly bound to each other, such as a spunlace nonwoven fabric. As the fiber aggregate 5A, it is preferable to use flap pulp from the viewpoint of improving the ability to draw in low-viscosity components of feces.

[0023] Examples of fibers contained in the fiber assembly 5A include natural fibers such as wood pulp (e.g., softwood pulp, hardwood pulp) and non-wood pulp (e.g., cotton pulp, hemp pulp), modified pulp (e.g., cationic pulp, mercerized pulp), regenerated cellulose fibers (e.g., rayon, cupra) (all of these are cellulose fibers), hydrophilic synthetic fibers (e.g., polyvinyl alcohol fiber, polyacrylonitrile fiber), and synthetic fibers (e.g., polyethylene fiber, polypropylene fiber, polyester fiber) hydrophilized with a hydrophilizing agent (e.g., surfactant). These fibers can be used alone or in combination of two or more. The content of hydrophilic fibers in the fiber assembly 5A is not particularly limited, but is preferably 80% by mass or more, and more preferably 100% by mass, i.e., the fiber assembly 5A is composed solely of hydrophilic fibers. It is preferable that the fiber assembly 5A does not contain an absorbent polymer in order to more smoothly transfer low-viscosity components contained in feces to the diffusion layer 6. Here, "not containing an absorbent polymer" means that the absorbent polymer is substantially not contained, and the mass proportion of the absorbent polymer is less than 10% of the weight of the attraction layer 5.

[0024] 2, the fiber aggregate 5A in this embodiment has a portion 50 that extends into the internal space S3 of the concave-convex sheet 4A. By having the extended portion 50, the contact area between the concave-convex sheet 4A and the fiber aggregate 5A increases compared to when the concave-convex sheet 4A and the fiber aggregate 5A contact each other on their flat surfaces, so that low-viscosity components contained in feces can be drawn into the drawing layer 5 more quickly. From this perspective, the height h1 of the portion 50 of the fiber aggregate 5A that penetrates into the internal space S3 of the uneven sheet 4A (hereinafter also referred to as the portion 50 inside the convex portion) is preferably 50% or more, more preferably 80% or more, and even more preferably 100% of the internal height T of the convex portion 41, i.e., the internal height T of the convex portion 41 and the height h1 of the portion 50 inside the convex portion are approximately the same. As shown in FIG. 2, the height h1 of the convex inner portion 50 is the distance from the recess 42 to the top of the convex inner portion 50, and the height T of the interior of the convex portion 41 is the distance from the non-skin-facing side of the recess 42 to the non-skin-facing side of the top 41T of the convex portion 41.

[0025] The internal height T of the protrusion 41 is preferably 0.5 mm or more and 10 mm or less, and more preferably 0.7 mm or more and 8 mm or less. The height h1 of the inner protrusion portion 50 is preferably 0.4 mm or more and 8 mm or less, and more preferably 0.6 mm or more and 6 mm or less.

[0026] The diffusion layer 6 is a portion that serves to diffuse the low-viscosity components of the stool supplied through the attraction layer 5 in a direction intersecting the layer thickness direction Z. The diffusion layer 6 is adjacent to the attraction layer 5. The diffusion layer 6 is composed of a diffusion sheet 6A. In this embodiment, the non-skin-facing side of the diffusion sheet 6A constituting the diffusion layer 6 has an extension that extends outward in the lateral direction Y from the non-skin-facing side of the absorbent layer 7, and the extension is rolled up toward the skin-facing side to cover the skin-facing side of the absorbent layer 7 (not shown). The diffusion sheet 6A may be made up of two sheets, in which case one diffusion sheet 6A covers the entire non-skin-facing side of the absorbent layer 7, and the other diffusion sheet 6A covers the entire skin-facing side of the absorbent layer 7, and extends outward from both side edges of the absorbent layer 7 in the lateral direction Y, with the extended portions being wrapped down onto the non-skin-facing side of the absorbent layer 7 and overlapping with the other diffusion sheet 6A.

[0027] The diffusion sheet 6A is preferably arranged so as to cover at least the entire skin-facing surface of the absorbent layer 7 in the lateral direction Y, and more preferably so as to cover the entire skin-facing and non-skin-facing surfaces of the absorbent layer 7. With this configuration, low-viscosity components of feces can be quickly transferred to the absorbent layer 7.

[0028] As the diffusion sheet 6A, a fiber sheet, a urethane sheet, or the like is preferably used from the viewpoint of reliably achieving the above-mentioned functions. As the fiber sheet, for example, thin paper such as tissue paper, or nonwoven fabric such as spunbond-meltblown-spunbond (SMS) nonwoven fabric is preferably used. As the urethane sheet, a porous material is used, and for example, it is preferable to use urethane foam having open cells so that low-viscosity components of feces can diffuse inside.

[0029] The absorption layer 7 is adjacent to the diffusion layer 6. The absorption layer 7 is a portion that plays a role in absorbing the low-viscosity component diffused by the diffusion layer 6. A material containing a superabsorbent polymer can be used as the absorbent layer 7. The absorbent layer 7 may be made of, for example, a superabsorbent polymer, or may be made of a mixed stack of a stack of hydrophilic fibers such as pulp fibers and a superabsorbent polymer.

[0030] The superabsorbent polymer contained in the absorbent layer 7 can generally be a hydrogel material capable of absorbing and retaining water, such as a polymer or copolymer of acrylic acid or an alkali metal salt of acrylic acid. Examples include polyacrylic acid and its salts, and polymethacrylic acid and its salts, specifically a partial sodium salt of an acrylic acid polymer. The shape of the superabsorbent polymer is not particularly limited, and can be, for example, spherical, tufted, blocky, bale-shaped, fibrous, irregularly shaped, or particles of a combination thereof. When the absorbent layer 7 contains hydrophilic fibers, examples of the hydrophilic fibers include pulp fibers, rayon fibers, cotton fibers, and cellulosic fibers such as cellulose acetate. In addition to the hydrophilic cellulosic fibers, fibers made of synthetic resins such as polyolefin, polyester, and polyamide that have been hydrophilized with a surfactant or the like can also be used.

[0031] As described above, the absorbent pad 1 of this embodiment is preferably used by being placed over an absorbent article such as a diaper. That is, the wearer's excrement is excreted into the absorbent pad 1. When stool (stool P) that is highly viscous or contains a large amount of solid components is excreted into the absorbent pad 1, the stool P is smoothly taken up by the absorbent pad 1. The mechanism of intake in the present invention will be explained in more detail. An inclined surface is formed between the tops 21T of the projections 21 and the bottoms 22T of the recesses 22, and even if high-viscosity or solid components of feces P supplied from the skin-facing surface side are supplied near the tops 21T of the projections 21, they are guided along the inclined surface to the recesses 22 (see FIG. 7(a)), and migrate through the openings 23 in the recesses 22 toward the gap-forming layer 4. After passing through the surface layer 2, the high-viscosity or solid components of feces P reach the feces-diffusing space V (see FIG. 7(b)), where they are diffused in the lateral direction Y within the feces-diffusing space V (see FIG. 8(a)) and accommodated (see FIG. 8(b)).

[0032] On the other hand, the low-viscosity components contained in the feces P rapidly migrate from the openings 23 in the recesses 22 to the feces diffusion space V, where they diffuse in the lateral direction Y (see FIG. 8(a)). The low-viscosity components of the feces P are then drawn into the drawing layer 5 via the gap-forming layer 4 (see FIG. 8(b)). In the drawing layer 5, the low-viscosity components of the feces P diffuse into the fiber aggregate 5A and migrate to the diffusion layer 6, where they diffuse in a direction intersecting the thickness direction Z of the diffusion layer 6 (see FIG. 9(a)), and rapidly migrate to the absorbent layer 7 (see FIG. 9(b)). The low-viscosity components are then taken up and absorbed by the absorbent layer 7, which contains an absorbent polymer. In this way, the highly viscous or solid components of the stool P are accommodated mainly through a path centered around the openings 23, and even when stool containing a large amount of highly viscous or solid components is excreted, the stool can be smoothly absorbed. As a result, even when a large amount of stool is excreted multiple times, the highly viscous or solid components are absorbed and accommodated within the stool diffusion space V, thereby effectively preventing stool leakage.

[0033] As described above, in the absorbent pad 1 of this embodiment, when the surface layer 2 is viewed in plan, the convex portions 21 and concave portions 22 are arranged alternately and continuously along two different directions that intersect with each other. This allows highly viscous or solid components contained in feces to be more quickly guided to the concave portions 22, allowing the feces to be absorbed more smoothly.

[0034] When the diffusion sheet 6A is made of a fiber sheet, it is preferable to use a nonwoven fabric in which the constituent fibers are entangled or bonded together, from the viewpoint of diffusing the low-viscosity components of stool more quickly in a direction intersecting the thickness direction Z of the layer. Specifically, it is preferable to use a backing such as tissue paper. Here, "entanglement" means that the constituent fibers are sufficiently entangled with each other, and does not include a state in which the fiber layers are simply overlapped.

[0035] In the present invention, the pitch of the projections and recesses of the projection-recessed sheet 2A constituting the surface layer 2 may be the same as or different from the pitch of the projections and recesses of the projection-recessed sheet 4A constituting the gap-forming layer 4. In this embodiment, as shown in FIG. 2, the pitch P2 of the projections and recesses of the projection-recessed sheet 4A constituting the gap-forming layer 4 is finer than the pitch P1 of the projections and recesses of the projection-recessed sheet 2A constituting the surface layer 2. More specifically, the pitch P2 of the projection-recessed sheet 4A is smaller than the pitch P1 of the projection-recessed sheet 2A. The pitch is the distance between the apexes of adjacent projections or recesses, and when there are multiple projections or recesses around a projection or recess that are at different distances from the projection or recess, the pitch is the distance between the closest projections and recesses. In the embodiment shown in FIG. 2, the positions of the recesses 22 of the embossed sheet 2A and the positions of the recesses 42 of the embossed sheet 4A do not overlap in the thickness direction Z, and the positions of the protrusions 21 of the embossed sheet 2A and the positions of the protrusions 41 of the embossed sheet 4A do not coincide. This configuration increases the surface area of ​​the embossed sheet 4A and widens the feces diffusion space V, allowing for smooth absorption of high-viscosity or solid components and low-viscosity components of feces. The difference in the pitch of the recesses and protrusions can be achieved by, for example, adjusting the stretch ratio of the embossed sheet 2A and the embossed sheet 4A during production. The difference in the pitch of the recesses and protrusions can also be achieved by widening the embossed sheet in one direction during production.

[0036] From the viewpoint of increasing the surface area of ​​the gap-forming layer 4 and increasing the efficiency of drawing in low-viscosity components of feces, the ratio of pitch P1 to pitch P2 (P1 / P2) is preferably 1 or more, and more preferably 1.2 or more. If the pitch P2 is too large, the number of recesses 42 will decrease, resulting in fewer areas for absorbing high viscosity or solid components. Therefore, from the viewpoint of ensuring an appropriate number of recesses 42, the ratio of the pitch P1 to the pitch P2 (P1 / P2) is preferably 5 or less, and more preferably 4.5 or less. Taking the above into consideration, the ratio of the pitch P1 to the pitch P2 (P1 / P2) is preferably 1 or more and 5 or less, and more preferably 1.2 or more and 4.5 or less.

[0037] From the viewpoint of enabling the low-viscosity components contained in stool to be drawn in more quickly, it is preferable that the diffusion sheet 6A constituting the diffusion layer 6 has a higher hydrophilicity than the fiber aggregate 5A constituting the drawing-in layer 5. In the present invention, "hydrophilicity" refers to the contact angle of the constituent fibers of the sheet, measured by the method described below, and is determined based on this contact angle. Specifically, high hydrophilicity is synonymous with a small contact angle, and low hydrophilicity is synonymous with a large contact angle. Therefore, in the absorbent pad 1 of this embodiment, the relationship "contact angle of the diffusion sheet 6A≦contact angle of the fiber assembly 5A" holds. Unless otherwise specified, "contact angle" in this specification refers to the contact angle measured by the method described below. In this specification, if the contact angle is 90 degrees or less, the sheet is hydrophilic, and if the contact angle is more than 90 degrees, the sheet is hydrophobic. The difference between the contact angle of the fiber aggregate 5A and the contact angle of the diffusion sheet 6A is preferably 5 degrees or more, more preferably 10 degrees or more, and preferably 70 degrees or less, more preferably 65 degrees or less, and also preferably 5 degrees or more and 70 degrees or less, more preferably 10 degrees or more and 65 degrees or less. The contact angle of the fiber aggregate 5A is preferably 30 degrees or more, more preferably 40 degrees or more, and is preferably 100 degrees or less, more preferably 90 degrees or less; specifically, it is preferably 30 degrees or more and 100 degrees or less, and more preferably 40 degrees or more and 90 degrees or less. The contact angle of the diffusion sheet 6A is preferably 30 degrees or more, more preferably 40 degrees or more, preferably 95 degrees or less, more preferably 85 degrees or less, preferably 30 degrees or more and 95 degrees or less, more preferably 40 degrees or more and 85 degrees or less.

[0038] <Contact angle measurement method> The fiber assembly 5A and the diffusion sheet 6A were used as the measurement objects. A 10 mm x 10 mm square in plan view was cut out from the measurement object to serve as a measurement sample, and the contact angle of water on this measurement sample was measured. The measurement device used was an automatic contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. Deionized water was used to measure the contact angle. The amount of liquid ejected from the inkjet water droplet ejection unit (CTC-25 pulse injector with a 25 μm nozzle diameter manufactured by Cluster Technology Co., Ltd.) was set to 20 picoliters, and the water droplets were dropped directly onto the fibers. The droplets were recorded on a high-speed video recorder connected to a horizontally mounted camera. For later image analysis, a personal computer equipped with a high-speed capture device is recommended. In this measurement, images were recorded every 17 msec. In the recorded video, the first image of the water droplet landing on the fiber is analyzed using the included software FAMAS (software version 2.6.2, analysis method: sessile drop method, analysis method: θ / 2 method, image processing algorithm: non-reflective, image processing image mode: frame, threshold level: 200, no curvature correction), and the angle between the surface of the water droplet in contact with the air and the fiber is calculated, which is taken as the contact angle. A measurement sample cut from the object to be measured is placed on the sample stage of the contact angle meter and maintained horizontally. Contact angles are measured at two different locations for each measurement sample. The contact angles of N=5 samples are measured to one decimal place, and the average value (rounded to two decimal places) of the measured values ​​at a total of 10 locations is defined as the contact angle of the measurement sample with water. The measurement environment is a room temperature of 22±2°C and a humidity of 65±2%RH. If the sheet to be measured is bonded to another member of the absorbent pad by adhesive or fusion, remove the adhesive by spraying cold air onto the bonded portion, etc. This method of removal from the absorbent pad can also be used for other measurements.

[0039] When the diffusion layer 6 is made of a fiber sheet, it is preferable that the fiber sheet constituting the diffusion layer 6 has a smaller inter-fiber distance than the fiber aggregate 5A, in order to enable the low-viscosity components contained in the feces to be drawn in more quickly and to further improve the absorbency of the low-viscosity components of the ingested feces. From the same viewpoint as above, the inter-fiber distance of the fiber aggregate 5A is preferably 10 μm or more, more preferably 20 μm or more, and preferably 100 μm or less, more preferably 80 μm or less, preferably 10 μm or more and 100 μm or less, more preferably 20 μm or more and 80 μm or less. From the same viewpoint as above, the inter-fiber distance of the fiber sheet constituting the diffusion layer 6 is preferably greater than 0 μm, more preferably 2 μm or more, preferably 80 μm or less, more preferably 60 μm or less, preferably greater than 0 μm and 80 μm or less, more preferably 2 μm or more and 60 μm or less. The inter-fiber distance of the fiber aggregate 5A is preferably 1.2 times or more, more preferably 1.4 times or more, and preferably 15 times or less, more preferably 13 times or less, and also preferably 1.2 times or more and 15 times or less, more preferably 1.4 times or more and 13 times or less, relative to the inter-fiber distance of the fiber sheet constituting the diffusion layer 6. The inter-fiber distance is measured by the following method.

[0040] <Method for measuring interfiber distance> The interfiber distance in a fiber sheet, fiber assembly, etc. can be calculated using the following formula (1) based on Wrotnowski's assumption. The following formula (1) is generally used to calculate the interfiber distance in a fiber sheet, fiber assembly, etc. Under Wrotnowski's assumption, the fibers are cylindrical and are arranged regularly without crossing each other. First, the inter-fiber distances in the fiber assembly 5A and the fiber sheets constituting the diffusion layer 6 are calculated using the following formula (1). In this case, the thickness t, basis weight W, fiber resin density ρ, and fiber diameter D used in the following formula (1) are those for the fiber aggregate 5A to be measured and the fiber sheet constituting the diffusion layer 6. The thickness t, basis weight W, and fiber diameter D are each the average values ​​measured at multiple measurement points. The thickness t (mm) is measured using the following method. The fiber sheet constituting the fiber assembly 5A and the diffusion layer 6 is used as the measurement target sheet. First, the measurement target sheet is cut into a piece measuring 50 mm in the longitudinal direction and 50 mm in the transverse direction. However, if it is not possible to prepare a piece of the measurement target sheet of this size, a piece as large as possible is prepared. Next, the cut piece is placed on a flat plate, and a flat glass plate is placed on top of it. Weights are evenly placed on the glass plate so that the load including the glass plate is 49 Pa, and the thickness of the cut piece is measured. The measurement environment is a temperature of 20±2°C and a relative humidity of 65±5%, and a microscope (Keyence Corporation, VHX-1000) is used as the measuring device. To measure the thickness of the cut piece, first, an enlarged photograph of the cut surface of the cut piece is taken. An object with known dimensions is also photographed on this enlarged photograph. Next, a scale is aligned with the enlarged photograph of the cut surface of the cut piece, and the thickness of each piece of the measurement target sheet is measured. The above operation is carried out three times, and the average value of the three measurements is taken as the thickness t of the sheet to be measured.

[0041] Basis weight W(g / m 2 The basis weight W (g / m) can be calculated by cutting the sheet to be measured to a predetermined size (for example, 12 cm x 6 cm), measuring the mass, and then dividing the measured mass by the area calculated from the predetermined size ("basis weight W (g / m)"). 2 ) = mass ÷ area calculated from the specified size). Repeat this measurement four times and use the average value as the basis weight. Fiber resin density ρ (g / cm 2 ) is measured using a density gradient tube in accordance with the density gradient tube method described in JIS L1015 Test Methods for Chemical Fiber Staples (URL: http: / / kikakurui.com / l / L1015-2010-01.html, or in the book JIS Handbook Fibers-2000 (Japanese Standards Association), pages 764-765). The fiber diameter D is measured in accordance with the <Method for measuring fiber diameter> described below.

[0042]

number

[0043] <Method for measuring fiber diameter> The sheet to be measured is cut with a razor (e.g., a single-edged razor manufactured by Feather Safety Razor Co., Ltd.) to obtain a test piece having a rectangular shape (8 mm x 4 mm) in plan view. When cutting the test piece, care must be taken to prevent the structure of the cut surface of the test piece formed by cutting from being destroyed by pressure during cutting. A preferred method for cutting the test piece is to place the test piece in liquid nitrogen to thoroughly freeze it before cutting. The test piece is then attached to the sample stage using double-sided tape (Nichiban Co., Ltd., Nicetack NW-15). The test piece is then platinum-coated. For the coating, an ion sputtering device E-1030 (product name) manufactured by Hitachi Naka Seiki Co., Ltd. is used, and the sputtering time is 30 seconds. The cut surface of the test piece is observed at 1000x magnification using a Hitachi, Ltd., S-4000 field emission scanning electron microscope. The length of 10 fibers constituting the sheet to be measured in the width direction relative to the longitudinal direction of the fiber is measured, and the average value is taken as the fiber diameter.

[0044] When the sheet to be measured is a porous body, for example, a urethane sheet, the interfiber distance is taken as the pore size of the porous body. The pore size of the porous body is measured by the following method. The sheet to be measured is cut with a razor (e.g., a single-edged razor manufactured by Feather Safety Razor Co., Ltd.) to obtain a test piece having a rectangular shape (8 mm x 4 mm) in plan view. When cutting the test piece, care must be taken to ensure that the structure of the cut surface of the test piece formed by the cutting is not destroyed by pressure during cutting. A preferred method for cutting the test piece is to place the test piece in liquid nitrogen to thoroughly freeze it before cutting. The test piece is attached to the sample stage using double-sided tape (Nichiban Co., Ltd., Nicetack NW-15). The test piece is then platinum-coated. For the coating, an ion sputtering device E-1030 (product name) manufactured by Hitachi Naka Seiki Co., Ltd. is used, and the sputtering time is 30 seconds. The cut surface of the test piece was observed at 1000x magnification using a Hitachi S-4000 field emission scanning electron microscope, and 10 porous pores were randomly selected from the two-dimensional image. Their maximum diameters were directly read, and the arithmetic mean value of these was taken as the pore diameter of the porous body.

[0045] The uneven sheet 2A allows the projections 21 to return to their original shape even when crushed by body pressure and inward pressing forces from the wearer's thighs during wear, allowing excreted body fluid to be quickly absorbed into the absorbent core, suppressing diffusion of excreted body fluid on the surface of the uneven sheet 2A, and suppressing return of body fluid absorbed into the absorbent layer 7. From these viewpoints, the compressibility of the uneven sheet 2A in the surface layer 2 is preferably 5% or more, more preferably 10% or more, and preferably 98% or less, more preferably 95% or less, preferably 10% to 95%, and more preferably 30% to 90%. The compressibility of the uneven sheet 2A can be measured using a KES compression tester. The higher the value measured using the KES compression tester, the better the cushioning properties can be evaluated. The compression rate of the textured sheet 2A measured with a KES compression tester is specified in "Standardization and Analysis of Texture Evaluation (2nd Edition)" (by Kawabata Toshio, published by the Texture Measurement and Standardization Research Committee of the Textile Machinery Society of Japan (July 10, 1980)), and is a physical property related to the compression characteristics of fabric. The method for measuring the compression rate of the textured sheet 2A using a KES compression tester is as follows.

[0046] <Method for measuring compression ratio> The measurement device used was a KES-FB3 compression tester manufactured by Kato Tech Co., Ltd. This tester was used to measure the compression area of ​​2 cm. 2 0.5gf / cm of the sample (concave-convex sheet 2A of surface layer 2) 2 The thickness T0 under load is measured. Next, the sample is compressed at a pressure rate of 20 μm / sec. The load increases as the sample is compressed. The compression load is 35 gf / cm 2 Continue until it reaches 35gf / cm 2 The thickness Tm under load is measured. The thickness Tm is subtracted from the thickness T0, divided by the thickness T0, and multiplied by 100 to calculate the compression rate (%) of the textured sheet 2A of the surface layer 2 using a compression tester. In other words, the compression rate (%) is calculated from (T0-Tm) / T0×100.

[0047] The compression energy of the uneven sheet 2A is preferably 0.98 mN·m / cm from the viewpoint of the comfort of the texture when the convex portions 21 contact the skin due to the body pressure when worn and the inward pressing force from the wearer's thighs, and the convex portions 21 following the movement of the body. 2 More preferably, 3.43 mN·m / cm 2 or more, preferably 9.8 mN m / cm 2 Less than or equal to 6.86 mN m / cm, preferably 6.86 mN m / cm 2 less than or equal to 0.98 mN m / cm 2 More than 9.8mN m / cm 2 Less than or equal to 3.43 mN·m / cm 2 More than 6.86mN m / cm 2 It is more preferable that the compression energy of the uneven sheet 2A of the surface layer 2 is less than 100%. The compression energy of the uneven sheet 2A of the surface layer 2 can be measured using a KES compression tester. The larger the WC value measured using the KES compression tester, the more easily the uneven sheet 2A is evaluated to be crushed. The method for measuring the compression energy of the uneven sheet 2A using the KES compression tester is as follows.

[0048] <Method for measuring compression energy> The measurement device used was a Kato Tech KES-G5 handy compression tester. Using this tester, a 5 cm x 10 cm sample (concave-convex sheet 2A) was prepared and attached to the test table. Next, the sample was compressed to an area of ​​2 cm. 2 The sheet is compressed between steel plates with circular flat surfaces. The compression speed is 20 μm / sec and the maximum compression load is 4.9 kPa. The recovery process is also measured at the same speed. The compression energy (WC) of the textured sheet 2A is expressed by the following formula: Tm, T0 and P are 3.43 kPa (35 gf / cm), respectively. 2 ) Thickness under load, 49 Pa (0.5 gf / cm 2 ) indicates the thickness under load and the load at the time of measurement.

[0049]

number

[0050] Next, preferred configurations and the like of each of the above-described embodiments will be described in detail. From the viewpoint of further improving the uptake of highly viscous or solid components contained in stool and making it easier for highly viscous or solid components contained in stool to pass through, the size of the openings 23, i.e., the opening width, is preferably 0.2 mm or more, more preferably 0.5 mm or more, and also preferably 5.0 mm or less, more preferably 4.8 mm or less, and also preferably 0.2 mm or more and 5.0 mm or less, more preferably 0.5 mm or more and 4.8 mm or less. The openings 23 are parts having a lower fiber density than the surrounding areas of the recesses 22.

[0051] The fiber density of the peripheral portion of the bottom portion 22T is preferably 120 fibers / mm 3 in order to make it difficult to be crushed under a high load and to reduce the amount of liquid returning. 2 More preferably, 150 lines / mm 2 or more, and preferably 500 lines / mm 2 Less than or equal to 450 lines / mm, preferably 2 Less than 120 lines / mm, preferably 2 Over 500 lines / mm 2 Less than or equal to 120 lines / mm, preferably 2 Over 450 lines / mm 2More preferably, 150 lines / mm or less 2 Over 330 lines / mm 2 The following is the result. From the viewpoint of further improving the uptake of high-viscosity or solid components contained in feces and facilitating the passage of high-viscosity or solid components contained in feces, the fiber density of the openings 23 is preferably 0 fibers / mm 2 More preferably, 20 lines / mm 2 or more, and preferably 180 lines / mm 2 Less than or equal to 150 lines / mm, preferably 150 lines / mm 2 Less than or equal to 0 fibers / mm 2 Over 180 lines / mm 2 Less than or equal to 0 fibers / mm 2 Over 150 lines / mm 2 More preferably, 20 fibers / mm or less 2 Over 150 lines / mm 2 The following is the result. Fiber density is 1mm 2 The fiber density was evaluated by counting the number of fibers per unit area. The fiber density was measured as follows.

[0052] <Measurement of fiber density> The concave-convex sheet 2A was cut, and the cut surface was magnified and observed using a scanning electron microscope, and the cross-sectional area of ​​the cut fibers in the cut surface per unit area was counted. The magnification for the magnified observation was adjusted to a magnification (150x to 500x) that allowed measurement of approximately 30 to 60 fiber cross sections. Next, 2 This is converted into the number of fiber cross sections per unit area, and the fiber density (fibers / mm 2 The measurement was carried out at three locations for each sample, and the average was taken as the fiber density of the sample. The scanning electron microscope used was JCM-5100 (trade name) manufactured by JEOL Ltd.

[0053] From the viewpoint of further improving the ability to draw in low-viscosity components contained in feces, the basis weights of the concave-convex sheet 4A, the fiber assembly 5A and the diffusion sheet 6A are preferably within the following ranges. The basis weight of the embossed sheet 4A is preferably 15 g / m 2 More preferably, 20 g / m 2or more, and preferably 70 g / m 2 Less than 65g / m 2 and preferably 15 g / m 2 More than 70g / m 2 Less than 20 g / m, more preferably 2 More than 65g / m 2 The following is the result. The basis weight of the fiber assembly 5A is preferably 100 g / m 2 More preferably, 120 g / m 2 or more, and preferably 400 g / m 2 or less, more preferably 350 g / m 2 and preferably 100 g / m 2 More than 400g / m 2 or less, more preferably 120 g / m 2 More than 350g / m 2 The following is the result. The basis weight of the diffusion sheet 6A is preferably 8 g / m 2 More preferably, 10 g / m 2 and preferably 20 g / m 2 Less than 18g / m, more preferably 2 and preferably 8 g / m 2 More than 20g / m 2 Less than 10 g / m, more preferably 2 More than 18g / m 2 The following is the result.

[0054] In the absorbent pad 1, the spaces between the textured sheet 2A and the textured sheet 4A, between the textured sheet 4A and the fiber assembly 5A, between the fiber assembly 5A and the diffusion sheet 6A, and between the diffusion sheet 6A and the absorbent layer 7 are fixed by applying, for example, an adhesive. The adhesive can be applied using known means, for example, a slot coat gun, a spiral spray gun, a spray gun, or a dot gun, and in the absorbent pad 1, it is preferable to apply the adhesive in a spiral pattern using a spiral spray gun. For example, a hot melt adhesive is preferably used as the adhesive to be applied. The amount of hot melt adhesive applied is 0.5 g / m 2 More than 50g / m 2It is preferable that:

[0055] The absorbent pad of the present invention is not limited to the embodiment shown in Figures 1 to 9 described above. Another embodiment of the absorbent pad according to the present invention will be described below. In the following, the components of this another embodiment that differ from the embodiment shown in Figures 1 to 9 will be mainly described, and similar components will be given the same reference numerals and will not be described again. For components that are not specifically described, the description of the embodiment shown in Figures 1 to 9 will be applied as appropriate.

[0056] 14 is a cross-sectional view showing another embodiment of an absorbent pad. The absorbent pad 1a of this embodiment, like the absorbent pad 1 of the above-described embodiment, comprises a surface layer 2, a gap-forming layer 4, and a pull-in layer 5, in this order from the skin-facing side to the non-skin-facing side. In the absorbent pad 1 of the above-described embodiment, the convex portions 41 of the concave-convex sheet 4A constituting the gap-forming layer 4 do not have openings at the apexes 41T. However, in the absorbent pad 1a, the convex portions 41 of the concave-convex sheet 4B constituting the gap-forming layer 4 have openings 44 at the apexes 41T. The method for producing the perforated concave-convex sheet 4B is not particularly limited. For example, when producing a nonwoven fabric by the hydroentanglement method, a fiber fabric is placed on a net having convexities and convexities, and a water stream is applied to the convexities to the extent that openings are formed at the apexes of the convexities, thereby obtaining a nonwoven fabric having openings. The obtained nonwoven fabric is used as a concave-convex sheet 4B having apertures 44, with the portions where apertures are formed being positioned at the tops 41T of the convex portions 41. In the absorbent pad 1a of this embodiment, all of the multiple protrusions 41 have openings 44, but only some of the multiple protrusions 41 may have openings 44. From the viewpoint of further suppressing fecal leakage, the ratio of the number of protrusions having openings 44 to the total number of protrusions 41 is preferably 10% or more and 100% or less, and more preferably 15% or more and 95% or less. When some of the multiple protrusions 41 have openings 44, the protrusions 41 having openings 44 are preferably uniformly dispersed and arranged in a plan view of the uneven sheet 4B.

[0057] The absorbent pad 1a of this embodiment is preferably used over an absorbent article such as a diaper. In other words, the wearer's excrement is excreted into the absorbent pad 1a. The absorbent pad 1a has the same layer structure as the above-described embodiment. Therefore, when feces P are excreted into the absorbent pad 1a, the feces P are smoothly absorbed into the absorbent pad 1a by a mechanism substantially similar to that of the absorbent pad 1. Specifically, when feces P are excreted into the absorbent pad 1a, the high-viscosity or solid components of the feces P migrate from the openings 23 in the recesses 22 of the embossed sheet 2A toward the gap-forming layer 4, where they are diffused in the lateral direction Y in the feces-diffusing space V and are accommodated within the feces-diffusing space V. Meanwhile, the low-viscosity components of the feces P also migrate from the openings 23 in the recesses 22 toward the gap-forming layer 4. The low-viscosity components of the feces P then migrate from the openings 44 in the convex portions 41 toward the drawing layer 5 (the state indicated by symbol A in FIG. 15), or, similar to the absorbent pad 1 of the above-described embodiment, diffuse in the lateral direction Y in the feces diffusion space V and are drawn into the drawing layer 5 via the gap-forming layer 4. After passing through the drawing layer 5, the low-viscosity components of the feces P are taken up by the absorbent layer 7 via the diffusion layer 6 and are absorbed.

[0058] In the absorbent pad 1a of this embodiment, the advantages of providing the openings 44 at the apexes 41T of the convex portions 41 of the concave-convex sheet 4B constituting the gap-forming layer 4 are as follows. The absorbent pad 1a of this embodiment has openings 44 at the tops 41T of the convex portions 41, so that even if there is a localized large amount of defecation, the stool P can be absorbed without leaking out. In particular, when there is a localized large amount of defecation, the low-viscosity components of the stool P cannot be completely absorbed into the intake layer 5 through the gap-forming layer 4, and the stool may leak out. However, since openings 44 are provided at the tops 41T of the convex portions 41, the low-viscosity components of the stool P that cannot be completely absorbed through the gap-forming layer 4 can migrate from the openings 44 to the intake layer 5 (the state shown by symbol B in Figure 15). This allows the absorbent pad 1a to absorb the stool without leaking out.

[0059] Furthermore, since the absorbent pad 1a has openings 44 at the tops 41T of the convex portions 41, there is no risk of the feces P taken in by the absorbent pad 1a leaking out, even if pressure is applied to the absorbent pad 1a. More specifically, when pressure is applied to the absorbent pad 1a, low-viscosity components of the feces P taken in by the absorbent pad 1a may overflow from the openings 44. However, since the openings 44 are provided at the tops 41T of the convex portions 41, even if the low-viscosity components of the feces P overflow from the openings 44, the low-viscosity components can be guided to the concave portions 42 along the inclined surface between the tops 41T of the convex portions 41 and the bottoms 42T of the concave portions 42 (see FIG. 16). This allows the low-viscosity components to migrate again toward the intake layer 5, eliminating the risk of the feces P leaking out. In this way, the absorbent pad 1a has openings 44 at the apexes 41T of the convex portions 41 of the concave-convex sheet 4B, so that the absorbent pad 1a can smoothly take in feces while further suppressing fecal leakage.

[0060] From the viewpoint of further diffusing the feces contained in the feces diffusion space V in a direction intersecting the thickness direction Z, in the region where the surface layer 2 and the gap-forming layer 4 overlap, the total area of ​​the openings 23 in the surface layer 2 is preferably equal to or larger than the total area of ​​the openings 44 in the gap-forming layer 4. Specifically, when the area and number of openings in the same area where the surface layer 2 and the gap-forming layer 4 overlap are measured and compared, it is preferable that the total area A1 obtained by adding up the areas of the openings 23 in the embossed sheet 2A is equal to or larger than the total area A2 obtained by adding up the areas of the openings 44 in the embossed sheet 4B, and it is more preferable that the total area A1 of the openings 23 in the surface layer 2 is larger than the total area A2 of the openings 44 in the gap-forming layer 4. From the viewpoint of promoting the diffusion of feces in a direction intersecting the thickness direction Z, the ratio (A1 / A2) of the total area A1 of the openings 23 in the uneven sheet 2A to the total area A2 of the openings 44 in the uneven sheet 4B is preferably 1 or more, more preferably 1.1 or more. To ensure rapid intake of feces, the ratio (A1 / A2) of the total area A1 of the apertures 23 in the concave-convex sheet 2A to the total area A2 of the apertures 44 in the concave-convex sheet 4B is preferably 2 or less, more preferably 1.8 or less.

[0061] The uneven sheet 2A and the uneven sheet 4B each have an area of ​​100 cm 2 The total area of ​​the openings per unit area is preferably: The total area A1 of the openings 23 in the concave-convex sheet 2A is preferably 70 mm 2 Over 9000mm 2 Less than 300mm, preferably 2 More than 6000mm 2 The following is the result. The total area A2 of the openings 44 in the concave-convex sheet 4B is preferably 30 mm 2 Over 9000mm 2 Less than or equal to 150 mm, preferably 2 More than 6000mm 2 The following is the result. The total area A1 of the openings 23 and the total area A2 of the openings 44 can be adjusted by appropriately adjusting the pitch of the irregularities, the number of openings, the area of ​​the openings, and the like. The total area of ​​the open pores is measured by the following method.

[0062] <Method for measuring the total area of ​​pores> In a plan view of the absorbent pad, a 100mm x 100mm square area was cut out from the area where the textured sheet 2A and the textured sheet 4B overlapped, and the textured sheet 2A and the textured sheet 2B present within this area were used as the measurement piece. If a 100mm x 100mm measurement piece cannot be cut out, cut out a measurement piece with as large an area as possible. Next, the measurement piece was placed on black paper or a jig and photographed at 20x magnification using a KEYENCE VHX-6000 microscope to obtain an image of the observation field. The size of the observation field was 12mm x 16mm. The area of ​​the aperture was calculated using the photographed image in the "Measurement and Scale Mode" for image processing in the VHX-6000. Specifically, "Maximum Area Measurement" was selected under "Special Measurement" in the Measurement and Scale Mode. The dark area was used as the extraction target. When the area corresponding to the recesses 22 is circled with the mouse, the black areas corresponding to the apertures 23 are automatically colored, and the software displays the vertical and horizontal lengths of the maximum area as a rectangle. The vertical and horizontal lengths are recorded, and the apertures 23 within the rectangle are approximated as an ellipse, and the area of ​​each aperture 23 is calculated as the area of ​​the ellipse. This operation is performed for all recesses 22 in one image, and the total area of ​​the apertures 23 in the observation field is calculated by summing them. Five images are taken, and the total area of ​​the apertures 23 is calculated for each of the five images using the method described above. Of these five images, the average of the total areas of the apertures 23 is obtained from the three images excluding the largest and smallest. The total area of ​​the apertures 23 in a 100 mm x 100 mm square region in a plan view of the absorbent pad 1 is calculated from the ratio of the total area of ​​the apertures 23 (the average of the three images) to the area of ​​the observation field, and this is the total area of ​​the apertures 23 in the concave-convex sheet 2A. For example, if the ratio of the total area of ​​the apertures 23 to the area of ​​the observation field is 5.0%, the total area of ​​the apertures 23 is 10,000 mm 2 5.0% of 500mm 2 This becomes: The total area of ​​the textured sheet 4B is measured in the same manner as the total area A1 of the apertures 23 of the textured sheet 2A, except that the measurement piece is the textured sheet 2B that exists within the 100 mm x 100 mm square area cut out in the method for measuring the total area of ​​the textured sheet 2A. When capturing an image of the observation field, the image is captured with the convex side of the textured sheet 4B having the apertures 44 facing the black paper or jig. When a part of the absorbent pad is removed for measurement, if the part to be removed is joined to another part with an adhesive, the adhesive force is removed by, for example, spraying cold air from a cold spray on the joined part before removing it.

[0063] The relationship that the total area A2 of the openings 44 in the embossed sheet 4B is larger than the total area A1 of the openings 23 in the embossed sheet 2A, and more preferably the ratio (A1 / A2) is 1.1 or greater, is preferably satisfied at least in the pad central region or the anus-facing region. Whether or not the above relationship is satisfied in the pad central region or the anus-facing region is determined by cutting out an area where the embossed sheets 2A and 4B overlap, preferably a 100 mm x 100 mm square area in plan view, from the pad central region or the anus-facing region, and comparing the total areas of only the openings present in that area for both the openings 23 in the embossed sheet 2A and the openings 44 in the embossed sheet 4B. For the pad central region, the center point of the square area in plan view is taken as the center point of the pad in the vertical and horizontal directions. The center point of the anus-facing area is a square area in plan view, and the point in the vertical direction of the pad is a point that is 1 / 3 of the total length of the pad in the vertical direction from one end of the pad and that divides the horizontal length of the pad into two equal parts.

[0064] From the viewpoint of taking in feces more smoothly, it is preferable that the area of ​​each opening 23 in the surface layer 2 is approximately the same as the area of ​​each opening 44 in the gap-forming layer 4. Specifically, it is preferable that the area A3 of each opening 23 in the embossed sheet 2A is approximately the same as the area A4 of each opening 44 in the embossed sheet 4B. Here, approximately the same means that the ratio (A3 / A4) of the area A3 of each opening 23 in the embossed sheet 2A to the area A4 of each opening 44 in the embossed sheet 4B is preferably 0.8 or more and 1.2 or less, more preferably 0.9 or more and 1.1 or less, and even more preferably 1.0. The area A3 of each opening 23 in the concave-convex sheet 2A is preferably 2 mm 2 Over 200mm 2 Less than 5mm, preferably 2 More than 180mm 2 The following is the result. The area A4 of each opening 44 in the concave-convex sheet 4B is preferably 2 mm 2 Over 200mm 2 Less than 5mm, preferably 2 More than 180mm 2 The following is the result. The area of ​​each opening is measured by the following method.

[0065] <Method for measuring the area of ​​each opening> In the same manner as in the method for measuring the total area of ​​the openings described above, five images of a 12 mm x 16 mm observation field are obtained, and the total area of ​​the openings is calculated for each image. Of the five images, the average value of the total area of ​​the openings is calculated from three images excluding those with the largest and smallest total areas. From the three images, the average number of openings contained in each image is calculated, and this is used as the average number of openings. The average total area of ​​the apertures divided by the average number of apertures is defined as the "area of ​​each aperture." The area A3 of each aperture 23 is measured using a measuring piece taken from the textured sheet 2A, and the area A4 of each aperture 44 is measured using a measuring piece taken from the textured sheet 4B.

[0066] Although the pitch P4 of the uneven sheet 4B is smaller than the pitch P3 of the uneven sheet 2A in the previous example, the pitch P4 of the uneven sheet 4B may be smaller (see FIG. 14), or the pitch P3 of the uneven sheet 2A and the pitch P4 of the uneven sheet 4B may be the same. From the viewpoint of further diffusing the feces contained in the feces diffusion space V in a direction intersecting the thickness direction Z, in the absorbent pad 1a, it is preferable that the pitch of the unevenness of the uneven sheet 2A constituting the surface layer 2 is finer than the pitch of the unevenness of the uneven sheet 4B constituting the gap-forming layer 4. From this viewpoint, it is preferable that the ratio (P4 / P3) of the pitch P4 of the uneven sheet 4B to the pitch P3 of the uneven sheet 2A, the pitch P3 of the uneven sheet 2A, and the pitch P4 of the uneven sheet 4B are each within the following ranges. The ratio of the pitch P3 to the pitch P4 (P4 / P3) is preferably 1 or more and 5 or less, and more preferably 1.2 or more and 4.5 or less, provided that the pitch P4 is larger than the pitch P3. The pitch P3 is preferably 2 mm or more and 20 mm or less, and more preferably 5 mm or more and 15 mm or less. The pitch P4 is preferably 2 mm or more and 20 mm or less, and more preferably 5 mm or more and 15 mm or less, provided that the pitch P4 is larger than the pitch P3.

[0067] The present invention has been described above based on its preferred embodiments, but the absorbent pads of the present invention are not limited to the absorbent pads 1 and 1a of the above embodiments and can be modified as appropriate. For example, the uneven sheet 2A and the uneven sheet 4A described above have a plurality of convex portions each having an internal space and a plurality of concave portions each having an internal space, and in plan view, the convex portions and concave portions are arranged alternately and continuously along two different directions that intersect with each other. However, as shown in Fig. 10, the uneven sheet 2A and the uneven sheet 4A may be sheets having an uneven structure in which convex portions each having a streak-like internal space extending in one direction and concave portions each having a streak-like internal space extending in one direction are arranged alternately. In this case, as shown in Fig. 10, the streak-like convex portions 21 extending in one direction and the streak-like concave portions 22 extending in one direction of the uneven sheet 2A may be arranged to intersect with the streak-like convex portions 41 extending in one direction and the streak-like concave portions 42 extending in one direction of the uneven sheet 4A.

[0068] Furthermore, although the height T1 of the protrusions 21 of the embossed sheet 2A and the height T2 of the protrusions 41 of the embossed sheet 4A are substantially the same in the above-described embodiment, they may be different. For example, as shown in Fig. 11, the height T1 of the protrusions 21 of the embossed sheet 2A may be higher than the protrusions 41 of the embossed sheet 4A. This makes it possible to ensure a wide feces diffusion space V and to make it difficult for feces contained in the feces diffusion space V to return to the skin. To further enhance the above-mentioned effects, the ratio (T2 / T1) of the height T2 of the protrusions 41 to the height T1 of the protrusions 21 is preferably 0.5 or more, and more preferably 0.6 or more. From the viewpoint of improving the drawing efficiency of the drawing layer 5, the ratio (T2 / T1) of the height T2 of the protrusions 41 to the height T1 of the protrusions 21 is preferably 3 or less, and more preferably 2.8 or less. From the above, the ratio (T2 / T1) of the height T2 of the protrusions 41 to the height T1 of the protrusions 21 is preferably 0.5 or more and 3 or less, and more preferably 0.6 or more and 2.8 or less. The height T1 of the protrusions 21 and the height T2 of the protrusions 41 are both the distance from the non-skin-facing surface side of the recess to the skin-facing surface side of the protrusions.

[0069] The height T1 of the protrusion 21 is preferably 0.5 mm or more and 10 mm or less, and more preferably 0.7 mm or more and 8 mm or less. The height T1 of the protrusion 41 is preferably 0.5 mm or more and 10 mm or less, and more preferably 0.7 mm or more and 8 mm or less.

[0070] Furthermore, in the absorbent pad 1 of the above-described embodiment, the pitch P2 of the embodied uneven sheet 4A is smaller than the pitch P1 of the embodied uneven sheet 2A, but the pitch P1 of the embodied uneven sheet 2A may be smaller (see Figure 12), or the pitch P1 of the embossed uneven sheet 2A and the pitch P2 of the embossed uneven sheet 4A may be the same. Furthermore, in the absorbent pad 1 of the above-described embodiment, the recesses 42 of the uneven sheet 4A constituting the gap-forming layer did not have any openings, but the recesses 42 may have openings 43 (see FIG. 12). Note that when the recesses 42 have openings 43, it is not necessary for all the recesses 42 to have openings 43. Furthermore, in the absorbent pad 1 of the above-described embodiment, the positions of the recesses 22 of the embossed sheet 2A and the positions of the recesses 42 of the embossed sheet 4A do not overlap in the thickness direction Z, and the positions of the protrusions 21 of the embossed sheet 2A and the positions of the protrusions 41 of the embossed sheet 4A do not coincide, but the positions of the recesses 22 of the embossed sheet 2A and the positions of the recesses 42 of the embossed sheet 4A, and the positions of the protrusions 21 of the embossed sheet 2A and the positions of the protrusions 41 of the embossed sheet 4A may overlap. 13, the absorbent pads 1 and 1a may have slits (through holes) 26 penetrating the gap forming layer 4, the drawing layer 5, the diffusion layer 6 and the absorbent layer 7 in the thickness direction Z.

[0071] In the absorbent pad 1a of the above-described embodiment, the openings 44 are provided only in the top portions 41T of the embossed sheet 4B, but openings may also be provided in portions other than the top portions 41T. For example, openings 43 may be provided in the recessed portions 42 of the embossed sheet 4B. In this case, it is preferable that the number of recessed portions 42 having openings 43 is smaller than the number of protruding portions 41 having openings 44, and the ratio of the number of recessed portions 42 having openings 43 to the number of protruding portions 41 having openings 44 is preferably 0 or more and 0.15 or less, more preferably 0 or more and 0.1 or less. [Explanation of symbols]

[0072] 1,1a Absorbent pad 2 Surface layer 2A, 4A, 4B Textured sheet 3 Retention layer 4 Interstitial layer 5. Attraction layer 5A Fiber assembly 6 Diffusion layer 6A Diffusion Sheet 7 Absorbing layer 8 Leak proof layer 21 Convex part 21H opening 21T top 21W wall 22 recess 22H opening 22T bottom 22W wall 23 Open hole 26 Slit (through hole) 41 Convex part 42 recess 50 parts, convex inner part

Claims

1. a surface layer having a protrusion protruding toward the skin side and a recess having an opening at the bottom; a gap-forming layer made of a liquid-permeable material, having convex portions and concave portions protruding toward the skin side and having internal spaces, and forming a feces diffusion space between the surface layer and the gap-forming layer, which diffuses feces supplied through the openings in a direction intersecting the thickness direction of the absorbent pad; An absorbent pad comprising an absorption layer formed from a fiber aggregate, having a portion that penetrates into the internal space, and that absorbs low-viscosity components from the feces in the feces diffusion space.

2. The absorbent pad according to claim 1 , wherein the convex portions of the gap-forming layer have openings at their tops.

3. 3. The absorbent pad according to claim 2, wherein in the region where the surface layer and the gap-forming layer overlap, the total area of ​​the openings in the surface layer is equal to or greater than the total area of ​​the openings in the gap-forming layer.

4. 4. The absorbent pad of claim 3, wherein the area of ​​each of the openings in the surface layer is approximately the same as the area of ​​each of the openings in the gap-forming layer.

5. a diffusion layer that diffuses the low-viscosity component captured in the attraction layer in a direction intersecting the thickness direction of the absorbent pad; The absorbent pad according to claim 1 or 2, further comprising an absorbent layer that absorbs the low-viscosity component diffused by the diffusion layer.

6. The absorbent pad according to claim 5 , wherein, when the surface layer is viewed from above, the convex portions and the concave portions of the surface layer are arranged alternately and continuously along two different directions that intersect with each other.

7. 6. The absorbent pad according to claim 5, wherein the member constituting said diffusion layer has a higher hydrophilicity than the fiber aggregate constituting said attraction layer.

8. 6. The absorbent pad according to claim 5, wherein the diffusion layer is made of a fiber sheet, and the fiber sheet has a smaller inter-fiber distance than the fiber aggregate constituting the attraction layer.

9. The absorbent pad of claim 5 , wherein the absorbent layer comprises a superabsorbent polymer.

10. 6. The absorbent pad according to claim 5, wherein the diffusion layer is made of a fibrous sheet, and the constituent fibers of the fibrous sheet are entangled or bonded to each other.

11. An absorbent article comprising the absorbent pad according to claim 5 and a diaper in which the absorbent pad is placed on the skin-facing side.

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