JP7724707B2 - absorbent articles - Google Patents

Description

The present invention relates to an absorbent article.

BACKGROUND ART There are known techniques for absorbing and dispersing forces acting on an absorbent article due to the wearer's movements when the absorbent article is worn.
For example, Patent Document 1 describes a technology in which a constricted portion is provided laterally outside the side edge of the absorbent body in an absorbent article, and a constricted portion is also provided in the absorbent body itself, thereby absorbing the torsional force generated in the absorbent article due to the wearer's movements and allowing the absorbent article to follow the movements of the wearer's body.

Patent Document 2 describes a technology in which fiber masses containing synthetic fibers are placed in the region of the absorbent core facing the excretory area, imparting high deformation-recovery properties to the absorbent core, thereby improving the recovery of the absorbent core when compressed by the wearer's body pressure.

International Publication No. 2019/26176 Japanese Patent Application Laid-Open No. 2020-96779

Although the technology described in Patent Document 1 suppresses deformation of the absorbent article due to twisting forces generated in the absorbent article as a result of the wearer's movements, when the wearer is standing and walking, it is difficult to make the absorbent article fit closely to the wearer's body, and the wearing state is likely to be uncomfortable, for example, making it difficult to move. Furthermore, the technology described in this document cannot suppress compressive deformation of the absorbent article due to the wearer's body pressure.
The technology described in Patent Document 2 improves the recovery of the absorbent core compressed by the wearer's body pressure, and also makes it easier for the absorbent article to return to its original state even if it is twisted. However, further improvements are desired in terms of the fit of the absorbent article to the body when the wearer is standing and walking for long periods of time, for example, and in terms of ease of movement while wearing the absorbent article.
Therefore, an object of the present invention is to provide an absorbent article that has excellent adhesion to the body of the wearer and can follow the movements of the wearer without causing discomfort.

The present invention is an absorbent article that includes an absorbent body capable of absorbing and retaining bodily fluids, and has a longitudinal direction corresponding to the front-to-back direction of a wearer and a lateral direction perpendicular to the longitudinal direction.
In one embodiment of the absorbent article of the present invention, the absorbent article comprises a flap portion extending outward from the outer edge of the absorbent body and forming the contour of the absorbent article, and the flap portion comprises a pair of side flap portions located laterally outward of a pair of imaginary straight lines extending in the vertical direction through the outermost lateral end of the absorbent body.
In one embodiment of the absorbent article of the present invention, the outer edges of the side flap portions have a front constricted portion located in the front in the longitudinal direction and a rear constricted portion located in the rear in the longitudinal direction.
In one embodiment of the absorbent article of the present invention, the absorbent article comprises a front region located forward in the longitudinal direction from the rear end of the front constriction, a rear region located rearward in the longitudinal direction from the front end of the rear constriction, and an intermediate region defined by the front constriction and the rear constriction.
In one embodiment of the absorbent article of the present invention, the intermediate region includes an excretory region facing region that faces the excretory region of the wearer when worn.
In one embodiment of the absorbent article of the present invention, the intermediate region has a compression recovery region containing a compression recovery material.
In one embodiment of the absorbent article of the present invention, the absorbent article has a rear convex portion located between the rear constricted portion and the longitudinal rear end of the absorbent article and projecting outward in the lateral direction beyond the rear constricted portion.
In one embodiment of the absorbent article of the present invention, the portion of the flap portion located rearward in the longitudinal direction from the rear convex portion has a tapered shape in which the length in the lateral direction gradually decreases toward the rear end of the flap portion in the longitudinal direction.
Other features, advantages and embodiments of the present invention are described below.

The present invention provides an absorbent article that adheres well to the wearer's body and can follow the wearer's movements without causing discomfort.

FIG. 1 is a schematic plan view of the skin-facing side of a sanitary napkin, which is one embodiment of the absorbent article of the present invention. FIG. 2 is a schematic cross-sectional view taken along line II in FIG. 1 (a cross-section taken along the thickness and lateral directions of the sanitary napkin). FIG. 3 is a schematic plan view of the non-skin-facing side of the sanitary napkin shown in FIG. FIG. 4 is an enlarged view of a main part of the sanitary napkin shown in FIG. FIG. 5 is an enlarged view of a main part of the sanitary napkin shown in FIG. 6(a), 6(b), and 6(c) are explanatory diagrams of a method for measuring the torsional torque value. FIG. 7 is a schematic plan view of the skin-facing side of a sanitary napkin showing another embodiment of the present invention.

The present invention will now be described based on preferred embodiments with reference to the drawings. Note that in the following description of the drawings, identical or similar parts are designated by identical or similar reference numerals. The drawings are essentially schematic, and the proportions of each dimension may differ from those of the actual product.

1 to 3 show a sanitary napkin 1, which is one embodiment of the absorbent article of the present invention. The napkin 1 has a longitudinal direction X, which corresponds to the front-to-back direction of the wearer and extends from the front side (belly side) of the wearer through the crotch region to the rear side (dorsal side), and a transverse direction Y, which is perpendicular to the longitudinal direction X.
In the present invention, "vertically forward" refers to a position that is longitudinally forward of the reference position (toward the wearer's ventral side), and "vertically rear" refers to a position that is longitudinally rearward of the reference position (toward the wearer's back side).

In this embodiment, the napkin 1 is elongated in the vertical direction X, as shown in FIGS. 1 and 3, and its longitudinal direction coincides with the vertical direction X.
In this embodiment, the napkin 1 is formed symmetrically on one side and the other side with respect to the horizontal center line CLy. The horizontal center line CLy is an imaginary line extending in the vertical direction X, dividing the napkin 1 in the unfolded state as shown in Figures 1 and 3 into two equal parts in the horizontal direction Y.

The napkin 1 comprises an absorbent body 4 capable of absorbing and retaining bodily fluids (menstrual blood, urine, feces, sweat, etc.). In addition, the napkin 1 preferably further comprises a liquid-permeable top sheet 2 that can come into contact with the wearer's skin, and a leak-proof back sheet 3. In this case, the absorbent body 4 is disposed between the top sheet 2 and the back sheet 3, as shown in FIG. 2. In the napkin 1, the top sheet 2 covers the entire skin-facing side of the absorbent body 4, and the back sheet 3 covers the entire non-skin-facing side of the absorbent body 4. Both sheets 2 and 3 can be made of any material commonly used in this type of absorbent article, without any particular restrictions. The top sheet 2 can be made of any liquid-permeable sheet, including, for example, nonwoven fabric, woven fabric, and paper. The backsheet 3 can be a leak-proof sheet, specifically a liquid-impermeable sheet (one that does not allow liquid to pass through at all) or a sheet that is poorly liquid-permeable (one that does not quite allow liquid to pass through, but does so with difficulty), such as a moisture-permeable resin film or a laminate of such a resin film and nonwoven fabric.

In this embodiment, as shown in FIG. 1, a pair of side sheets 5, 5 are arranged on both sides of the skin-facing surface of the napkin 1 (the skin-facing surface of the topsheet 2) along the longitudinal direction X. The pair of side sheets 5, 5 are arranged over substantially the entire length of the longitudinal direction X so as to overlap both sides of the absorbent body 4 along the longitudinal direction X in a plan view. As shown in FIG. 2, of both sides of the side sheet 5 along the longitudinal direction X, the outer portions including the outer edges located on the outer sides in the lateral direction Y are fixed to another member (the backsheet 3 in the illustrated embodiment) to form fixed edges, while the inner portions including the inner edges located on the inner sides in the lateral direction Y are free edges that are not fixed to other members. When the napkin 1 is worn, the free edges of the side sheets 5 rise toward the wearer's skin, thereby preventing the outflow of exudates such as menstrual blood outward in the lateral direction Y. The side sheets 5 can be made of a sheet with the same leak-proof properties as the backsheet 3.

In the present invention, the "skin-facing side" refers to the side of the absorbent article or its constituent member (e.g., absorbent core 4) that faces the wearer's skin when the absorbent article is worn, i.e., the side that is relatively closer to the wearer's skin. The "non-skin-facing side" refers to the side of the absorbent article or its constituent member that faces the opposite side from the skin when the absorbent article is worn, i.e., the side that is relatively farther from the wearer's skin. Note that "when worn" here refers to the normal, appropriate wearing position, i.e., a state in which the correct wearing position of the absorbent article is maintained.

In the napkin 1, the outer edge of a side flap portion 6S (see FIG. 1 ), which will be described later, has a front constricted portion 61 and a rear constricted portion 62. The front constricted portion 61 is located in the front of the napkin 1 in the longitudinal direction X. The rear constricted portion 62 is located in the rear of the napkin 1 in the longitudinal direction X.
The napkin 1 also has a front region F, a rear region R, and a middle region C. The front region F is located forward of the rear end of the front constricted portion 61 in the longitudinal direction X. The rear region R is located rearward of the front end of the rear constricted portion 62 in the longitudinal direction X. The middle region C is a region defined by the rear end of the front constricted portion 61 and the front end of the rear constricted portion 62. The middle region C is a region that includes the excretory part facing region M, which will be described later. In this specification, the "rear end of the front constricted portion" refers to the inflection point between the convex curve directed outward from the napkin 1, which is formed by the outer edge of the side flap portion 6S located in the middle region C, and the convex curve directed inward from the napkin 1, at the front constricted portion 61. The "front end of the rear constricted portion" is the inflection point between the convex curve directed outward from the napkin 1, formed by the outer edge of the side flap portion 6S located in the middle region C, and the convex curve directed inward from the napkin 1 at the rear constricted portion 62.
The excretory part facing region M includes a central region in the longitudinal direction X and a central region in the lateral direction Y of the intermediate region C. The excretory part facing region M may be the same region as the intermediate region C or may be a part of the intermediate region C.
In this specification, the area defined by the longitudinal rear end of the front constricted portion 61 and the longitudinal front end of the rear constricted portion 62 is also referred to as "defined by the rear end of the front constricted portion 61 and the front end of the rear constricted portion 62." The front constricted portion 61 and the rear constricted portion 62 will be described later.

In the present invention, the "excretory part-facing region" refers to a region of the absorbent article's absorber-disposed region (region overlapping the absorber in a planar view) that includes an excretory part-facing region that is disposed opposite the excretory part. The "excretory part" refers to the site where bodily fluids (menstrual blood, urine, feces, sweat, etc.) of the wearer of the absorbent article are excreted, and is typically the vaginal opening, penis, or anus, but varies depending on the intended use of the absorbent article. The "excretory part-facing region" refers to a region of the absorbent article that overlaps with the excretory part in a planar view when worn. The excretory part-facing region can be, for example, the entire region of the absorber-disposed region of the absorbent article that is in the same vertical position as the excretory part-facing region (the region that overlaps with the projected image of the excretory part-facing region when projected horizontally). When the absorbent article is a feminine absorbent article such as a napkin 1, its excretory part-facing region is typically positioned opposite only the vaginal opening when worn, and not opposite the anus, but it may also be positioned opposite the anus in addition to the vaginal opening. In this embodiment, the excretory part-facing region M is the region where the absorbent body 4 is located, and is positioned opposite the vaginal opening (excretory part) of the female wearer when the napkin 1 is worn, but not opposite the anus.

The absorbent body 4 includes at least an absorbent core 40. In this embodiment, the absorbent core 40 has a shape that is elongated in the longitudinal direction X in a plan view, and its longitudinal direction coincides with the longitudinal direction X of the napkin 1.
The absorbent core 40 constitutes the main body of the absorbent body 4 and contains a water-absorbent material that enables it to absorb and retain body fluids. Examples of the water-absorbent material include water-absorbent fibers and water-absorbent polymers, and these may be used alone or in combination. Examples of the water-absorbent fibers include natural fibers such as wood pulp and hydrophilic fibers such as hydrophilic synthetic fibers. Examples of the water-absorbent polymers that may be used include those conventionally used in this type of absorbent body, without particular limitation, and examples thereof include polymers or copolymers of acrylic acid or alkali metal acrylates.
The absorbent core 40 may be of either a stacked fiber type or a sheet type. The stacked fiber type absorbent core typically comprises an aggregate of fibrous materials such as absorbent fibers, with absorbent polymer particles optionally supported on the aggregate. The stacked fiber type absorbent core can be manufactured by a conventional method using a known stacking device equipped with a rotating drum. On the other hand, the sheet type absorbent core typically comprises a fiber sheet having absorbent polymer particles fixed to the interior or surface thereof, and is also referred to as an absorbent sheet. Examples of the fiber sheet include paper and nonwoven fabric. The sheet type absorbent core is thinner and more flexible than the stacked fiber type absorbent core. The sheet type absorbent core may, for example, comprise two opposing fiber sheets with absorbent polymer particles interposed between them.

In this embodiment, as shown in FIG. 2, the absorbent body 4 includes, in addition to the absorbent core 40, a liquid-permeable core wrap sheet 41 that covers the outer surfaces (skin-facing surface and non-skin-facing surface) of the absorbent core 40. The core wrap sheet 41 is used for purposes such as improving the shape retention of the absorbent core 40 and preventing the materials that make up the absorbent core 40, such as water-absorbent polymer particles, from falling off, and is typically made of paper, water-permeable nonwoven fabric, or the like. The core wrap sheet 41 may consist of only one sheet, or may be made up of multiple sheets. The absorbent core 40 and the core wrap sheet 41 may be bonded together with an adhesive, such as a hot-melt adhesive.

In this embodiment, as shown in FIG. 2, the absorbent body 4 has a compression recovery region L containing a compression recovery material in the middle region C. Preferably, at least the excretory-facing region M of the middle region C has a compression recovery region L containing a compression recovery material. The compression recovery region L includes a fiber agglomerate layer 42 mainly composed of a compression recovery material, which is a fiber agglomerate 11 containing non-absorbent fibers. Here, "mainly composed of fiber agglomerates" means that the fiber agglomerates 11 account for 90% by mass or more of the total fibers constituting the fiber agglomerate layer 42, preferably 95% by mass or more, and more preferably 100% by mass. The fiber agglomerate layer 42, together with the absorbent core 40, is covered by a core wrap sheet 41. In this embodiment, the fiber agglomerate layer 42 is disposed over the entire excretory-facing region M. Therefore, in this embodiment, the compression recovery region L is the same region as the excretory-facing region M. The fiber agglomerate layer 42 extends over the entire excretory-facing region M, from one side edge to the other. However, it is also possible to arrange the fiber mass layer 42 only in a portion of the excretory part-facing region M. In this case, the compression recovery region L forms part of the excretory part-facing region M.

The fiber clump layer 42-free region of the absorbent body 4 includes an absorbent core 40 but no fiber clump layer 42. Therefore, the fiber clump layer 42-free region, i.e., the excretory part-facing region M, is thicker and bulkier than the fiber clump layer 42-free region. Due to the difference in thickness of the absorbent body 4 resulting from the presence or absence of the fiber clump layer 42, the excretory part-facing region M, where the fiber clump layer 42 is located, is raised on the skin-facing side compared to the front region F and rear region R, where the fiber clump layer 42 is not located, forming a so-called "middle peak." In other words, the absorbent body thickness 4 is thinner in the front region F and rear region R than in the central region in the lateral direction Y of the excretory part-facing region M. This improves the wearing comfort of the napkin 1, allows the napkin 1 to fit more closely to the wearer's body, and effectively prevents liquid leakage.

The fiber agglomerates 11 are fiber aggregates formed by accumulating and integrating a plurality of non-absorbent fibers into agglomerates, and are present in the absorbent body 4 (fiber agglomerate layer 42) while retaining their shape. The fiber agglomerates 11 primarily contribute to improving the flexibility, cushioning properties, compression recovery, and shape retention of the absorbent body 4 due to the shape of the fiber aggregates.
The non-absorbent fibers constituting the fiber agglomerates 11 are preferably fibers (hydrophobic fibers) with lower hydrophilicity than the absorbent fibers such as cellulosic fibers used as the absorbent material in the absorbent core 40, and specific examples include synthetic fibers mainly made of thermoplastic resin. By including non-absorbent fibers in the fiber agglomerates 11, the fiber agglomerates 11 can fully exhibit their properties such as flexibility even when they come into contact with body fluids.
The shape of the fiber agglomerates 11 is not particularly limited and may be irregular, but regular shapes such as sheet pieces obtained by cutting a synthetic fiber sheet to a certain size can also be used. Examples of such regular fiber agglomerates that can be suitably used include the fiber agglomerates described in JP 2019-063469 A, JP 2019-098157 A, and JP 2020-188918 A, specifically, fiber agglomerates having two opposing base surfaces and a skeletal surface connecting the two base surfaces.

The fiber agglomerate layer 42 is preferably a region in which the fiber agglomerates 11 are present across the entire length of the absorbent body 4 in the lateral direction Y. The fiber agglomerate layer 42 may be composed of only the fiber agglomerates 11, but may also contain an absorbent material in addition to the fiber agglomerates 11. A fiber agglomerate layer 42 containing an absorbent material is capable of absorbing and retaining body fluids, thereby improving the absorption performance of the absorbent body 4. Any absorbent material that can be used in the absorbent core 40 can be used for the fiber agglomerate layer 42 without any particular restrictions.

In this embodiment, the fiber agglomerate layer 42 contains fiber agglomerates 11, as shown in FIG. 2 . In the fiber agglomerate layer 42, the fiber agglomerates 11 are entangled with each other. The fiber agglomerates 11, each having the aforementioned "two basic surfaces and a skeletal surface," are entangled with each other at their basic surfaces and skeletal surfaces, forming a three-dimensional entanglement. This configuration of the fiber agglomerate layer 42 improves the shape retention of the fiber agglomerate layer 42, enabling the absorbent body 4 including the fiber agglomerate layer 42 to deform appropriately and with good compliance to external forces applied from various directions during wear, and to exhibit excellent flexibility, cushioning, and compression recovery. To further enhance the above-described effects, it is preferable that the fiber agglomerates 11 and the absorbent fibers 12 are entangled at the interface between the fiber agglomerate layer 42 and the absorbent core 40. Furthermore, a napkin 1 including such an absorbent body 4 easily deforms and recovers from external forces, resists wrinkling, and provides an excellent fit to the wearer's body. The term "entanglement" as used herein includes both: (i) a form in which the entangled objects (either fiber agglomerates or fiber agglomerates and absorbent fibers) are not fused to each other, but rather maintain their bonded state through the entanglement of the constituent fibers of the fiber agglomerates; and (ii) a form in which, in the natural state of the absorbent article (absorbent body) (when no external force is applied), the fiber agglomerates or the fiber agglomerates and absorbent fibers are not bonded to each other, but when an external force is applied to the absorbent article (absorbent body), the fiber agglomerates or the fiber agglomerates and absorbent fibers can be bonded to each other through the entanglement of the constituent fibers.

In this embodiment, as shown in FIG. 2 , the skin-facing side of the absorbent body 4 in the compression recovery region L comprises an absorbent core 40 mainly composed of absorbent fibers 12 and absorbent polymer particles 13, and does not substantially contain fiber agglomerates 11, whereas the non-skin-facing side of the absorbent body 4 comprises a fiber agglomerate layer 42 mainly composed of fiber agglomerates 11.
More specifically, in this embodiment, the ratio of the mass content of fiber agglomerates to the total mass content of fiber agglomerates and absorbent fibers (hereinafter also referred to as the "fiber agglomerate content ratio") is lower on the skin-facing side than on the non-skin-facing side in the compression recovery region L of the absorbent body 4. That is, in this embodiment, in the compression recovery region L, the skin-facing side of the absorbent body 4 may have an uneven distribution of absorbent fibers 12 and the content of fiber agglomerates 11 may be zero, whereas the non-skin-facing side of the absorbent body 4 may have an uneven distribution of fiber agglomerates 11 and the content of absorbent fibers 12 may be zero. In this way, in the compression recovery region L of the absorbent body 4, the above-mentioned relationship of "skin-facing side of the absorbent body 4 < non-skin-facing side of the absorbent body 4" is established for the fiber agglomerate content ratio, and the action of the absorbent fibers 12 unevenly distributed on the skin-facing side of the absorbent body 4 improves the body fluid attraction force (capillary force) of the absorbent body 4, thereby improving the liquid absorption properties, and the action of the fiber agglomerates 11 unevenly distributed on the non-skin-facing side of the absorbent body 4 can improve the cushioning properties, etc. of the absorbent body 4.

The fiber agglomerate content on the skin-facing side of the compression recovery region L of the absorbent body 4 is preferably 10% by mass or less, more preferably 5% by mass or less, provided that it is lower than that on the non-skin-facing side of the absorbent body 4, and may contain no fiber agglomerates 11. The fiber agglomerate content on the non-skin-facing side of the compression recovery region L of the absorbent body 4 is preferably 50% by mass or more, more preferably 80% by mass or more, and may be 100% by mass, provided that it is higher than that on the skin-facing side of the absorbent body 4. Note that the "skin-facing side of the absorbent body" referred to here refers to the side that includes the skin-facing surface (the side relatively closer to the wearer's skin) when the absorbent body 4 is divided into two equal parts in the thickness direction, and the "non-skin-facing side of the absorbent body" refers to the opposite side (the side relatively farther from the wearer's skin).

1 and 3, the napkin 1 includes flap portions 6 that extend outward from the outer edge (periphery) of the absorbent body 4 and form the outline of the napkin 1. The flap portions 6 are areas where the absorbent body 4 is not placed.
In this embodiment, the flap portion 6 is composed of members arranged so as to straddle the outer edge of the absorbent body 4 from the inside to the outside, and in the illustrated embodiment, is composed of one or more of the topsheet 2, the backsheet 3, and the sidesheet 5. The multiple members constituting the flap portion 6 are joined to each other by a joining means such as adhesive, thermal or ultrasonic fusion. In this embodiment, an end seal portion 60 is formed by fusion-bonding the outer edge of the flap portion 6 (the outer edge of the flap portion 6 and its vicinity) all around.

The flap portion 6 is composed of a pair of side flaps 6S, 6S located outward in the horizontal direction Y from a pair of imaginary straight lines VL, VL that pass through the outermost ends of the absorbent body 4 in the horizontal direction Y and extend in the vertical direction X, a front flap portion 6F located inward in the horizontal direction Y from the reference line and in a front region F, and a rear flap portion 6R located inward in the horizontal direction Y from the reference line and in a rear region R. The "outermost ends of the absorbent body in the horizontal direction" are the portions located furthest outward in the horizontal direction Y on each side of the absorbent body 4 in the horizontal direction Y, and in this embodiment, are a pair of side edges 4S, 4S along the vertical direction of the absorbent body 4.

As shown in Figures 1 and 3, in the napkin 1, part of the outer edge of the side flap portion 6S (curved portion 63 described later) has a curved portion that convexly extends outward in the horizontal direction Y and extends further outward in the horizontal direction Y than the peripheral portion. However, unlike the wing portions, the side flap portions 6S are not folded back toward the non-skin-facing side of the clothing by manual manipulation using fingers when fastening the napkin 1 to the clothing, and are therefore clearly distinguishable from the wing portions.
In the napkin 1, the distance G1 (see FIG. 1 ) in the horizontal direction Y between the outer edge (side edge along the vertical direction X) of the side flap portion 6S and the absorbent body 4 is not constant in the vertical direction X and is typically about 35 mm at most. In contrast, in absorbent articles equipped with wing portions, from the viewpoint of facilitating the manual folding operation of the wing portions with the fingers, the horizontal length of the wing portions, i.e., the distance between the tip (outermost end in the horizontal direction) of the wing portions and the absorbent body, usually significantly exceeds the typical maximum value of 35 mm for the distance G1.

One of the main features of the napkin 1 is its outer shape, and in particular the outer shape of the side flap portions 6S that form the outline of the napkin 1 along the longitudinal direction X. That is, as shown in Figures 1 and 3, the outer edges of the side flap portions 6S, more specifically, the side edges of the side flap portions 6S along the longitudinal direction X, have a front constricted portion 61 located in the front region F and a rear constricted portion 62 located in the rear region R, and the portion sandwiched between the constricted portions 61, 62 has a curved portion 63 that is convex outward in the transverse direction Y.
In detail, as shown in FIGS. 1 and 3 , the outer edge of the flap portion 6, which is composed of the side flap portion 6S, the front flap portion 6F, and the rear flap portion 6R, has a front convex portion 64 that is located forward of the front constricted portion 61 in the longitudinal direction X, connected to the front constricted portion 61, and protrudes in a direction away from the absorbent body 4, and a rear convex portion 65 that is located rearward of the rear constricted portion 62 in the longitudinal direction X, connected to the rear constricted portion 62, and protrudes in a direction away from the absorbent body 4.

As described above, the napkin 1 is divided into an intermediate region C defined by the front constricted portion 61 and the rear constricted portion 62, a front region F located closer to the front region F than the intermediate region C, and a rear region R located closer to the rear region R than the intermediate region C. The excretory area facing region M is included in the intermediate region C. As described above, the excretory area facing region M is an area that includes the central region in the longitudinal direction X and the central region in the lateral direction Y of the intermediate region C. In the curved portion 63 described above, the outermost location in the lateral direction Y of the intermediate region C (i.e., the location where the distance between the curved portions 63, 63 in the lateral direction Y is longest) is located forward in the longitudinal direction X of the curved portion 63 that bisects the length of the curved portion 63 in the longitudinal direction X.

When the napkin 1 is viewed in plan, the innermost position in the lateral direction Y of the front constricted portion 61 is either the same as the innermost position in the lateral direction Y of the rear constricted portion 62, or is located further inward in the lateral direction Y than the innermost position in the lateral direction Y of the rear constricted portion 62. This positional relationship in the lateral direction Y between the front constricted portion 61 and the rear constricted portion 62 is advantageous in that it allows the side flap portion 6S to easily deform in response to body movements such as walking, eliminating any discomfort when worn.

In this embodiment, the constricted portions 61, 62 and the curved portion 63 are arranged in pairs on both sides of the horizontal centerline CLy in the horizontal direction Y. The curved portion 63 extends over the entire length of the excretory-facing region M in the vertical direction X, and forms a curve that convexly extends outward in the horizontal direction Y. There is no inflection point in the portion of the outer edge of the side flap portion 6S sandwiched between the constricted portions 61, 62. Both constricted portions 61, 62 form a curve that convexly extends inward in the horizontal direction Y. In the present invention, either or both of the constricted portions 61, 62 may be bent inward in the horizontal direction Y and configured as a straight line.

In contrast to the curved portion 63 located in the excretory area-facing region M, which forms a curve that convexly extends outward in the horizontal direction Y, as shown in Figures 1 and 3, the absorbent 4 located in the excretory area M has its side edges along the vertical direction X that are straight lines parallel to the vertical direction X and extend with a constant width along the vertical direction X. This is advantageous in that it can prevent sagging of the side flap portions 6S caused by movement while wearing the garment, preventing side leakage, allowing the properties of the compression recovery material to be effectively utilized, and allowing the absorbent 4 to be molded.

The area of the napkin 1 between the two constricted portions 61, 62 includes the excretory part-facing region M, an area where the fit and comfort of the napkin 1 are particularly important. Therefore, by disposing the fiber clump layer 42, which has excellent flexibility, in this area, these important characteristics can be further improved. From the perspective of fully achieving the effects of a leak-free, secure fit and ease of movement when worn, the fiber clump layer 42 may be present throughout the middle region C, including the excretory part-facing region M. Alternatively, the fiber clump layer 42 may be present throughout the middle region C, as well as in at least one of the front region F and the rear region R. However, from the perspective of providing a good fit, it is preferable for the fiber clump layer 42 to be present only in the middle region C. From the perspective of further improving fit, it is particularly preferable for the fiber clump layer 42 to be present only in the excretory part-facing region M.

1 and 3, the napkin 1 has a tapered shape in the front region F, in which the width of the napkin 1 gradually decreases toward the front end 1F in the longitudinal direction. In the front region F, the width of the napkin 1 at the front end 1F is at its smallest.
The napkin 1 has a tapered shape in the rear region R, in which the width of the napkin 1 gradually decreases toward the rear end 1R in the longitudinal direction. In the rear region R, the width of the napkin 1 at the rear end 1R is at its smallest.

Similar to the rear region R of the napkin 1, the absorbent 4 has a rear tapered portion 45, as shown in FIG. 3, located rearward of the rear constriction 62 in the longitudinal direction X, in which the length (width) of the absorbent 4 in the transverse direction Y gradually decreases toward the longitudinal rear end 4R of the absorbent 4.
Furthermore, similar to the front region F of the napkin 1, the absorbent 4 has, as shown in Figure 3, a front tapered portion 46 located forward of the front constricted portion 61 in the longitudinal direction X, in which the length (width) of the absorbent 4 in the transverse direction Y gradually decreases toward the front end 4F of the absorbent 4 in the longitudinal direction.

As shown in Figure 3, the non-skin-facing side of the napkin 1 is provided with a fastening part 7 for fastening the napkin 1 to the wearer's clothing. The fastening part 7 can be any material conventionally used to fasten this type of absorbent article to clothing such as shorts, and can be, for example, a pressure-sensitive adhesive, a pressure-sensitive adhesive, etc.

In the napkin 1 of this embodiment, the side flap portions 6S have a distinctive outer shape (i.e., a front constricted portion 61 and a rear constricted portion 62), which effectively prevents deformation that can cause discomfort, such as sagging, while the napkin 1 is being worn. Furthermore, the napkin 1 is more compliant with the wearer's movements. Shorts, which are typically fastened to the napkin 1, are generally designed so that their horizontal length (width) increases from the crotch area toward the front and back. In particular, the leg holes are designed so that the curvature increases from near the boundary between the crotch area and the front body toward the back body. By fastening the napkin 1 in the appropriate position in the crotch area, the two constricted portions 61, 62 on the outer edges of the side flap portions 6S are positioned along the leg holes of the shorts, which can cushion sagging of the side flap portions 6S caused by the wearer's movements at the front and back bodies of the shorts.

In particular, as shown in Figures 1 and 3, if the distance in the lateral direction Y between the outer edge of the side flap portion 6S and the absorbent body 4 is shortest at the front constricted portion 61 in the front region F and at the rear constricted portion 62 in the rear region R, when an external force is applied to the napkin 1 due to movements such as walking while wearing the napkin 1, the positions of the two constricted portions 61, 62 allow the napkin 1 to flexibly deform and follow the wearer's movements, which is advantageous in that it provides a comfortable fit with less discomfort and easier movement.

Furthermore, because the napkin 1 of this embodiment has a tapered rear region R, the napkin 1 easily fits closer to the wearer's buttocks. This allows for better conformance to the wearer's movements, particularly when standing and walking. This advantage is made even more pronounced by the fact that not only the rear region R of the napkin 1 but also the absorbent body 4 has a rear tapered portion 45. As shown in FIG. 4 , the angle α formed by two imaginary straight lines L1, L1 connecting the rear end 4R of the absorbent body 4 in the longitudinal direction X and the longitudinal front ends of the pair of contour lines of the rear tapered portion 45 extending outward from the rear end 4R in the transverse direction Y is preferably set to less than 120°, more preferably 100° or less, and even more preferably 70° to 90°, allowing the rear tapered portion 45 to conform even more easily to the wearer's movements.

Furthermore, in the rear region R, the outer edge of the flap portion 6 located between the rear convex portion 65 and the longitudinal rear end 1R has a center of curvature on the outside of the outer edge and is curved in a convex shape toward the inside of the napkin 1. This is preferable because it makes it less likely that external forces caused by the bulging shape of the wearer's buttocks will be applied to the rear region R when the wearer is walking or sitting, making it easier to achieve the above-mentioned effects.

Furthermore, the napkin 1 of this embodiment also has a tapered portion in its front region F, where the length in the horizontal direction Y gradually decreases from the middle region toward the outside in the vertical direction X. This allows the napkin 1 to fit more easily toward the wearer's abdomen. This also improves the napkin's ability to follow the wearer's movements, particularly when standing and walking. This advantage is further enhanced by the fact that not only the front region F of the napkin 1 but also the absorbent body 4 has a front tapered portion 46. As shown in FIG. 5 , the angle β formed by two imaginary straight lines L2, L2 connecting the front end 4F in the vertical direction X of the absorbent body 4 and the rear vertical ends of the pair of contour lines of the front tapered portion 46 extending outward in the horizontal direction Y from the front end 4F of the absorbent body 4 is preferably set to less than 120°, more preferably 100° or less, and even more preferably 70° to 90°. This allows the napkin 1 to follow the wearer's movements, particularly when standing and walking, even more easily.

In particular, it is preferable that the tapered portion in the front region F has a center of curvature on the inside of the outer edge of the flap portion 6 and has a curved shape that is convex outward toward the outside of the napkin 1, as this allows the front region F to fit along the relatively flat shape of the wearer's abdominal side, making it less likely to feel uncomfortable when worn.

As described above, the napkin 1 of this embodiment prevents the napkin 1 from shifting from its correct position while being worn, and the excretory-facing region M of the napkin 1 conforms closely to the wearer's body, preventing leakage of body waste.

In particular, in this embodiment, as shown in FIG. 2, as described above, the absorbent body 4 is provided in the compression recovery region L with a fiber agglomerate layer 42 primarily made of fiber agglomerates 11, which have excellent flexibility, cushioning, etc. Therefore, even if the side flap portions 6S become twisted while the napkin 1 is being worn, the twisting of the side flap portions 6S is unlikely to spread to the area where the fiber agglomerate layer 42 is located. Therefore, according to this embodiment, the twisting prevention effect of the side flap portions 6S by the two constrictions 61, 62 and the twisting prevention effect of the absorbent body 4 by the fiber agglomerate layer 42 work together to more reliably prevent deformation that causes discomfort when the napkin 1 is worn, thereby further improving leak prevention.

In particular, in the compression recovery region L, the ratio of the mass content of the fiber agglomerates 11 to the total mass content of the fiber agglomerates 11 and the absorbent fibers 12 is lower on the skin-facing side of the absorbent body 4 than on the non-skin-facing side of the absorbent body 4. This more reliably prevents deformation that causes discomfort when wearing the napkin 1, and ultimately further improves leak prevention.

In order to ensure that the napkin 1 conforms to the wearer more reliably through the front constricted portion 61 and the rear constricted portion 62, it is preferable to set the dimensions of the front constricted portion 61 and the rear constricted portion 62 as follows.
The front constriction 61 is preferably positioned at a position vertically forward of the vertical front end of the excretory region M of the napkin 1, preferably at least 5 mm, more preferably at least 7 mm, and preferably within 30 mm, more preferably within 20 mm.
The rear constriction 62 is preferably positioned at a position at least 5 mm, more preferably at least 7 mm, and preferably within 50 mm, more preferably within 40 mm, longitudinally rearward of the longitudinal rear end of the excretory region M of the napkin 1.

1 and 3, it is preferable to make the radius of curvature of the portion of the outer edge of the side flap portion 6S extending from the rear convex portion 65 to the rear constricted portion 62 smaller than that of the portion of the outer edge of the side flap portion 6S extending from the front convex portion 64 to the front constricted portion 61. That is, the portion of the outer edge of the side flap portion 6S extending from the front convex portion 64 to the front constricted portion 61 has a relatively gentle curve toward the inside of the napkin 1, while the portion of the outer edge of the side flap portion 6S extending from the rear convex portion 65 to the rear constricted portion 62 has a relatively sharp curve. This configuration of the outer edge of the side flap portion 6S more reliably prevents the napkin 1 from sagging or slipping during wear. In particular, because the radius of curvature of the portion extending from the rear convex portion 65 to the rear constricted portion 62 is relatively small, even if sagging occurs in the rear region R, for example, as a result of the wearer of the napkin 1 sitting for an extended period of time, this sagging is less likely to propagate to the front region F. Furthermore, because the radius of curvature of the section from the front convex portion 64 to the front constricted portion 61 is relatively large, the front region F fits more easily to the wearer's abdominal area than the excretory area, such as the vaginal opening, making it less likely to crease or wrinkle.

The radius of curvature R1 of the portion of the outer edge of the flap portion 6 extending from the forward convex portion 64 to the forward narrowed portion 61 and the radius of curvature R2 of the portion of the outer edge of the flap portion 6 extending from the rearward convex portion 65 to the rearward narrowed portion 62 satisfy the relationship R1 < R2.

As shown in Figures 1 and 3, it is preferable that the outer edges of the side flaps 6S at the position of the widest part in the middle region C (excretory part facing region M) are located further outward in the lateral direction Y than the outer edges of the side flaps 6S at the position of the widest part in the rear region R. This prevents side leakage of menstrual blood in the excretory part facing region M and prevents the shorts from becoming soiled, and at the same time has the advantageous effect of eliminating the discomfort of the rear part of the napkin 1 touching the skin while being worn and the discomfort of the napkin rubbing against the skin due to body movements.

1, when attention is focused on the outer edge of the flap portion 6 in the rear region R of the napkin 1, it is preferable that the outer edge, between the rear convex portion 65 and the rear longitudinal end 1R, has, in this order, a first portion 66 that forms a convex curve convexly inward in the horizontal direction Y, and a second portion 67 that is connected to the first portion 66 and forms a convex curve convexly outward in the horizontal direction Y. This provides an advantageous effect of providing a snug fit around the buttocks, eliminating the discomfort of the rear portion of the napkin 1 touching the skin while being worn and the discomfort of the napkin rubbing against the skin due to body movements.

After extensive research into factors that enable the napkin 1 to easily follow the wearer's movements, the inventors have discovered that reducing the "torsion torque value," measured by the method described below, is effective. Furthermore, it has been found that the above-described configuration of the napkin 1 of this embodiment, namely the front constricted portion 61, the rear constricted portion 62, and the tapered shape of the rear region R of the napkin 1, is extremely effective in reducing the torsion torque value.

To further reduce the torsional torque value, it is effective for the absorbent body 4 to have a rear tapered portion 45 in addition to the rear region R of the napkin 1. Furthermore, it is also effective for the front region F of the napkin 1 to have a tapered shape, and for the absorbent body 4 to have a front tapered portion 46 in addition to that, to further reduce the torsional torque value.

<Method for measuring torsional torque value>
The absorbent article to be measured is used as the measurement sample. Figures 6(a) to 6(c) show a measurement method when a sanitary napkin 1 is used as the measurement sample. The basic configuration of the napkin 1 is the same as that of the napkin 1 described above. As shown in Figure 6(a), both ends of the longitudinal direction X (lengthwise direction) of the napkin 1 are clamped between upper and lower clamps 101 and 102 provided on a tension-controlled torque tester (manufactured by Imada Co., Ltd.), and the napkin 1 is fixed between the upper and lower clamps 101 and 102. Next, as shown in Figures 6(b) and 6(c), the upper clamp 101 is rotated back and forth by 60° in the forward and reverse directions (forward and reverse rotations) around the longitudinal direction X of the napkin 1 as the rotation axis, and the torsional moment value (60° torsional torque value) applied to the napkin 1 is measured. Specifically, the back and forth rotation is performed 10 times, and 10 maximum points of the torsional moment value in each of the forward and reverse directions are obtained. The average of the maximum values of the 10 points is then calculated for each of the forward and reverse directions, and the sum of the absolute values of both average values is taken as the torsional torque value (unit: Ncm) of the object being measured. This measurement is carried out for five measurement samples, and the average of the five measurements is calculated. The measurement is carried out with the tension applied to the measurement sample during rotation in the range of 3 to 6 N. During measurement, the length between the clamps is 175 mm under no tension. The torque testing machine used is in accordance with the one shown in Figure 2 of JIS K 7244-2.

In this embodiment, the compression recovery of each region is differentiated. Specifically, the compression recovery rate of the excretory area-facing region M is set higher than that of the front region F and rear region R. The excretory area-facing region M, which has high compression recovery, has excellent cushioning properties, deforms responsively to external forces, and quickly returns to its original state when the external force is released. This configuration improves the fit of the excretory area-facing region M to the wearer's body, and, combined with the aforementioned external features of the napkin 1, improves the overall fit and conformability of the napkin 1 to the body, further improving leak prevention and comfort. In this case, it is sufficient that the compression recovery rate of the excretory area-facing region M is higher than that of either the front region F or the rear region R; it is not necessary for the compression recovery rates of the front region F and the rear region R to be the same.

From the above perspective, the compression recovery rate of the excretory area-facing region M, provided that it is higher than the compression recovery rates of the front region F and rear region R, is preferably 40% or more, more preferably 50% or more, and preferably 100% or less, more preferably 90% or less. When this relationship is achieved, the excretory area-facing region M of the napkin 1, which fits closely to the wearer's excretory area and its surroundings, has excellent shape retention and cushioning properties against external forces, and because the fiber agglomerations 11 are concentrated close to the wearer's skin, the overall fit and conformability of the napkin 1 to the body are improved, resulting in outstanding leak prevention and comfort.

The "compression recovery property" can be evaluated using the compression work (hereinafter also referred to as "WC") and the recovery work (hereinafter also referred to as "WC'") as indicators.
The WC is an index of the cushioning properties of the object to be measured, and the larger the WC value, the better the cushioning properties of the object to be measured, and therefore the better the compression recovery properties of the object to be measured. In other words, further improvements can be expected in the overall fit and conformance to the body of the napkin 1, as well as in leak prevention and comfort.
WC' is an index of the recovery (compression recovery) of a test object when an external force is applied to the test object, compressing it, and then the external force is removed, and the larger the WC' value, the more excellent the compression recovery of the test object is evaluated. WC and WC' are measured by the following methods.

<Method for measuring compression work (WC) and recovery work (WC')>
It is generally known that the WC and WC' to be measured can be expressed as the measured values using the KES (Kawabata Evaluation System) manufactured by Kato Tech Co., Ltd. (Reference: Standardization and Analysis of Texture Evaluation (2nd Edition), author Kawabata Toshio, published July 10, 1980). Specifically, WC and WC' can be measured using a compression testing device KES-G5 manufactured by Kato Tech Co., Ltd. The measurement procedure is as follows.
First, a sample is attached to the test table of the compression tester. The sample is, for example, an absorbent article such as a napkin 1 or a component thereof (e.g., an absorbent core 4). The sample is dry, and the napkin 1 is either left as is or adjusted to a rectangular shape in plan view with dimensions of 120 mm length and 70 mm width. If the dry sample is an absorbent core or an absorbent article containing the same, the absorbent core is unused, has not absorbed any liquid, and is in a dry state. Next, the sample is compressed between steel plates with a circular flat surface having an area of 2 ^cm2 . The portion to be compressed is the non-recessed portion of the sample, i.e., the portion that has not been subjected to compression processing and retains its original shape. The compression speed is 0.2 cm/sec, and the maximum compression load is 2450 mN/ ^cm2 . The recovery process is also measured at the same speed. WC is expressed by the following formula (1), and WC' is expressed by the following formula (2), each in units of "mN·cm/ ^cm2 ." In the following formula, _Tm represents the thickness under a load of 2450 mN/ ^cm2 (4.9 kPa), and _T0 represents the thickness under a load of 4.902 mN/ ^cm2 (49 Pa). Furthermore, Pa in the following formula (1) and Pb in the following formula (2) represent the measured load (mN/ ^cm2 ) during the compression process and the measured load (mN/ ^cm2 ) during the thickness recovery process, respectively.

Note that WC' is not displayed on the measurement results screen of the KES-G5; instead, what is displayed on the measurement results screen is WC and the compression recovery rate or compression resilience (hereinafter also referred to as "RC") calculated from WC'. In such cases, WC' is calculated using the following formula using the parameters (WC, RC) displayed on the measuring device.

To ensure the aforementioned effects of the side flap portions 6S are achieved more reliably, it is preferable that the excretory-compartment-facing region M include a portion where the distance G1 (see FIG. 1) in the transverse direction Y between the outer edge (side edge along the longitudinal direction X) of the side flap portion 6S and the absorbent body 4 is maximum. Furthermore, this maximum distance G1max is preferably 10 mm or more, more preferably 40 mm or more, and preferably 100 mm or less, more preferably 50 mm or less. The portion with the maximum distance G1max is typically a portion of the side flap portion 6S that includes the curved portion 63 sandwiched between the two constricted portions 61, 62. By positioning this portion in the excretory-compartment-facing region M and having the maximum distance G1max between the absorbent body 4 within the above-mentioned range, the curved portion 63 and its vicinity extending from the side edge of the crotch portion of the shorts will be more likely to deform to conform to the wearer's thighs when the napkin 1 is worn, thereby more effectively preventing unintended deformation of the napkin 1, such as wrinkling or creases, during wear.

In order to ensure the above-described effects of the side flap portions 6S, it is preferable to set the dimensions of each portion of the napkin 1 as follows.
The front constricted portion 61 is preferably positioned at a position rearward in the longitudinal direction X from the longitudinal front end 1F of the napkin 1, preferably at least 20 mm, more preferably at least 40 mm, and preferably within 90 mm, more preferably within 70 mm.
The rear constricted portion 62 is preferably positioned at a position forward in the longitudinal direction X from the longitudinal rear end 1R of the napkin 1, preferably at least 40 mm, more preferably at least 60 mm, and preferably within 120 mm, more preferably within 90 mm.
The distance G2 (see FIG. 1) between the front constricted portion 61 and the rear constricted portion 62 in the longitudinal direction X is preferably 90 mm or more, more preferably 100 mm or more, and is preferably 150 mm or less, more preferably 130 mm or less.
The maximum length (maximum width) of the napkin 1 in the lateral direction Y is preferably 90 mm or more, more preferably 100 mm or more, and preferably 170 mm or less, more preferably 120 mm or less. The portion of the napkin 1 having the maximum width is typically located in the excretory region M, which in the illustrated embodiment is the portion where the apex of the convex curved portion 63 of the side flap portion 6S is located.
The total length of the napkin 1 in the longitudinal direction X is preferably 140 mm or more, more preferably 200 mm or more, and is preferably 450 mm or less, more preferably 350 mm or less.

It is preferable that the length (width) in the transverse direction Y of the absorbent body 4 is shorter at a portion of the absorbent body 4 that is at the same position in the longitudinal direction X as the front constricted portion 61 than at a portion of the absorbent body 4 that is at the same position in the longitudinal direction X as the rear constricted portion 62. In Fig. 1, symbol W1 indicates the width of the former, and symbol W2 indicates the width of the latter, and it is preferable that the relationship of width W1 < width W2 holds.
In addition to the establishment of the above-mentioned magnitude relationship, it is also preferable that the distance G1 in the lateral direction Y between the outer edge of the side flap portion 6S and the absorbent body 4 is the same in the portion where the front constricted portion 61 is located and the portion where the rear constricted portion 62 is located. Here, "the distance G1 is the same" means that the absolute value of the difference between the distance G1 in the portion where the front constricted portion 61 is located and the distance G1 in the portion where the rear constricted portion 62 is located is within 3 mm.
In shorts, which are a typical fastening target for the napkin 1, the curvature of the leg holes from the crotch region to the front body is generally greater than that from the crotch region to the back body. Therefore, for example, when the wearer is sitting, the pressure from the wearer's thighs is likely to be greater on the front body side of the shorts than on the back body side. Therefore, in the napkin 1 fastened to shorts, external forces due to the wearer's body movements are particularly likely to be applied to the front region F, and unintended deformation such as creases and wrinkles tends to occur in the rear region R. In contrast, as described above, the magnitude relationship W1 < W2 holds for the width of the absorbent body 4, and the gap G1 is the same between the portions where both the constricted portions 61 and 62 are located, so that unintended deformation such as creases and wrinkles is even less likely to occur in both the side flap portions 6S and the absorbent body 4, mainly in the region from the front constricted portion 61 to the rear constricted portion 62 (the region M facing the excretory area).

The ratio of the width W1 to the width W2 of the absorbent body 4 is W1<W2.
The width W1 (see FIG. 1) of the portion of the absorbent body 4 that is at the same position in the longitudinal direction X as the front constricted portion 61 is, on the premise that it is shorter than the width W2, preferably 30 mm or more, more preferably 40 mm or more, and preferably 80 mm or less, more preferably 65 mm or less.
The width W2 (see FIG. 1) of the portion of the absorbent body 4 that is at the same position in the longitudinal direction X as the rear constricted portion 62 is, provided that it is longer than the width W1, preferably 50 mm or more, more preferably 60 mm or more, and preferably 90 mm or less, more preferably 70 mm or less.
The distance G1 in the lateral direction Y between the front constricted portion 61 or the rear constricted portion 62 and the absorbent body 4 is preferably 10 mm or more, more preferably 40 mm or more, and preferably 50 mm or less, more preferably 30 mm or less.

As shown in FIG. 3 , the fastening portions 7 are arranged in multiple rows extending in the horizontal direction Y and spaced apart in the vertical direction X in the region overlapping with the absorbent body 4 in a plan view (the absorbent body arrangement region). From the viewpoint of ensuring the fastening force of the napkin 1 to clothing such as shorts while ensuring good conformability of the napkin 1 to the wearer's body and providing a comfortable fit, it is preferable that the length (width) in the horizontal direction Y of the fastening portions 7 in at least a portion of the front region F is shorter than the length (width) in the horizontal direction Y of the fastening portions 7 in the excretory portion-facing region M. From the same viewpoint, it is preferable that the length (width) in the horizontal direction Y of the fastening portions 7 in at least a portion of the rear region R is shorter than the length (width) in the horizontal direction Y of the fastening portions 7 in the excretory portion-facing region M. In this embodiment, the widths W3 and W5 of the fastening portions 7 in both a portion of the front region F (the front tapered portion 46 described below) and a portion of the rear region R (the rear tapered portion 45 described below) are shorter than the width W4 of the fastening portions 7 in the excretory portion-facing region M.

As shown in FIG. 3 , the fastening portion 7 arranged in the region overlapping with the rear tapered portion 45 in a plan view has a shorter length (width) in the horizontal direction Y than the fastening portion 7 arranged in the region sandwiched between the front constricted portion 61 and the rear constricted portion 62. In the figure, symbol W3 indicates the width of the former, and symbol W4 indicates the width of the latter, with the dimensional relationship of width W3 < width W4 being established in this embodiment. In particular, when a wearer of the napkin 1 remains in a seated position for a long period of time, body pressure is likely to be applied to the rear region R of the napkin 1, making it prone to unintended deformation such as crease in the rear region R. However, by establishing the dimensional relationship of width W3 < width W4 for the width of the fastening portion 7 in relation to the rear region R, crease and shifting of the rear region R during wear can be more reliably prevented.

In this embodiment, the fastening portions 7 are spaced apart in the vertical direction X in the region overlapping with the rear tapered portion 45 in a plan view, and the widths W3 of the fastening portions are the same. Furthermore, the fastening portions 7 are spaced apart in the vertical direction X in the region sandwiched between the front constricted portion 61 and the rear constricted portion, and the widths W4 of the fastening portions are the same. Furthermore, the fastening portions 7 are spaced apart in the vertical direction X in the region overlapping with the front tapered portion 46 in a plan view, and the widths W5 of the fastening portions are the same.
If the widths W3 of the fastening portions 7 arranged in the region overlapping with the rear tapered portion 45 in a plan view are different from one another, the maximum value of the widths W3 is defined as the width W3 of the fastening portions 7 arranged in that region. If the widths W4 of the fastening portions 7 arranged in the region sandwiched between the front constricted portion 61 and the rear constricted portion 62 are different from one another, the maximum value of the widths W4 is defined as the width W4 of the fastening portions 7 arranged in that region. If the widths W5 of the fastening portions 7 arranged in the region overlapping with the front tapered portion 46 in a plan view are different from one another, the maximum value of the widths W5 is defined as the width W5 of the fastening portions 7 arranged in that region.

The ratio of the width W3 to the width W4 of the fastening part 7, W3/W4, is preferably 0.1 or more, more preferably 0.4 or more, and preferably 0.9 or less, more preferably 0.5 or less, assuming that W3<W4.
The ratio of the width W5 to the width W4 of the fastening part 7, W5/W4, is preferably 0.1 or more, more preferably 0.5 or more, and is preferably 0.9 or less, more preferably 0.7 or less, assuming that W5<W4.
The width W4 (see Figure 3) of the fastening part 7 arranged in the region sandwiched between the front constriction 61 and the rear constriction 62 is preferably 50 mm or more, more preferably 55 mm or more, and preferably 90 mm or less, more preferably 70 mm or less, provided that it is less than the width (length in the horizontal direction Y) of the absorbent body 4.

While the present invention has been described above based on its preferred embodiments, the present invention is not limited to the above embodiments and can be modified as appropriate without departing from the spirit of the present invention. For example, as shown in Figure 7, the absorbent article of the present invention may be a sanitary napkin having a pair of wing portions.
The absorbent article of the present invention includes articles used to absorb body fluids discharged from the human body (menstrual blood, urine, loose stool, sweat, etc.), and is not limited to the sanitary napkins mentioned above.

The following supplementary notes are further disclosed regarding the above-described embodiment of the present invention.
<1>
An absorbent article having an absorbent body capable of absorbing and retaining bodily fluids, and having a longitudinal direction corresponding to the front-to-back direction of a wearer and a lateral direction perpendicular to the longitudinal direction,
a flap portion extending outward from the outer edge of the absorbent body and forming an outline of the absorbent article, the flap portion comprising a pair of side flap portions positioned outward in the horizontal direction from a pair of imaginary straight lines extending in the vertical direction through the outermost end of the absorbent body in the horizontal direction;
an outer edge of the side flap portion has a front constricted portion located forward in the longitudinal direction and a rear constricted portion located rearward in the longitudinal direction;
the absorbent article comprises a front region located forward of a rear end of the front constricted portion in the longitudinal direction, a rear region located rearward of a front end of the rear constricted portion in the longitudinal direction, and an intermediate region defined by the front constricted portion and the rear constricted portion,
the intermediate region includes an excretory region facing region that faces the excretory region of the wearer when worn,
the intermediate region has a compression recovery region including a compression recovery material;
a rear convex portion located between the rear constricted portion and the longitudinal rear end of the absorbent article and protruding outward in the lateral direction beyond the rear constricted portion,
An absorbent article, wherein a portion of the flap portion located rearward in the longitudinal direction from the rear convex portion has a tapered shape in which the length in the lateral direction gradually decreases toward the rear end of the flap portion in the longitudinal direction.

<2>
The absorbent article according to <1>, wherein the lateral distance between the outer edge of the side flap portion and the absorbent body is shortest at the front constricted portion in the front region and shortest at the rear constricted portion in the rear region.
<3>
the absorbent body has a rear tapered portion in the rear region where the length of the absorbent body in the lateral direction gradually decreases toward the rear end of the absorbent body in the longitudinal direction,
The absorbent article according to <1> or <2>, wherein the angle formed by two imaginary straight lines connecting the rear end of the absorbent body in the longitudinal direction and the front end of each of a pair of contour lines of the rear tapered portion extending from the rear end of the absorbent body in the longitudinal direction to both sides outward in the horizontal direction is less than 120°.
＜4＞
the front constricted portion is located 5 mm or more forward in the longitudinal direction from the front end of the excretory portion-facing region in the longitudinal direction,
The absorbent article according to any one of <1> to <3>, wherein the rear constricted portion is located at least 5 mm rearward in the longitudinal direction from the rear end of the excretory-part-facing region in the longitudinal direction.
<5>
The absorbent article according to any one of <1> to <4>, wherein the excretion-part-facing region has a compression recovery rate higher than the compression recovery rates of the front region and the rear region.
<6>
The absorbent article according to any one of <1> to <5>, wherein the thickness of the absorber is thinner in the front region and the rear region than in a central region in the lateral direction of the excretory part-facing region.

＜７＞
the absorbent body includes a fiber mass containing non-absorbent fibers, absorbent fibers, and an absorbent polymer, the fiber mass being the compression recovery material;
The absorbent article according to any one of <1> to <6>, wherein the ratio of the mass of the fiber agglomerates to the total mass of the fiber agglomerates and the absorbent fibers is higher in the excretory region than in the front region and the rear region.
＜8＞
The absorbent article according to <7>, wherein in the compression recovery region, the ratio of the mass content of the fiber agglomerates to the total mass content of the fiber agglomerates and the absorbent fibers is lower on the skin-facing side of the absorbent body than on the non-skin-facing side of the absorbent body.
＜９＞
The absorbent article according to any one of <1> to <8>, wherein the excretory region has a compression recovery rate of 40% or more.
<10>
The absorbent article according to any one of <1> to <9>, wherein a side edge along the longitudinal direction of the absorber located in the excretory part-facing region is a straight line parallel to the longitudinal direction.
<11>
a fastening portion for fastening the absorbent article to a wearer's clothing is arranged in a region of the non-skin-facing surface of the absorbent article that overlaps with the absorbent body in a plan view,
The fastening portion is arranged in a plurality of rows extending in the horizontal direction and spaced apart in the vertical direction,
The absorbent article according to any one of <1> to <10>, wherein the lateral length of the fastening portion in at least a part of both the front region and the rear region is shorter than the lateral length of the fastening portion in the excretory region facing region.

<12>
The absorbent article according to any one of <1> to <11>, wherein there is no inflection point in the portion sandwiched between the front constricted portion and the rear constricted portion at the outer edge of the side flap portion.
<13>
The absorbent article according to any one of <1> to <12>, wherein the radius of curvature of a portion of the outer edge of the side flap portion extending from the rear convex portion to the rear constricted portion is smaller than the radius of curvature of a portion of the outer edge of the side flap portion extending from the front convex portion to the front constricted portion.
<14>
The absorbent article according to any one of <1> to <13>, wherein the fiber mass layer is present only in the intermediate region.
＜15＞
The absorbent article according to any one of <1> to <14>, wherein an outer edge of the flap portion located between the rear convex portion and the longitudinal rear end has a center of curvature on the outer side of the outer edge and has a curved shape that is convex toward the inside of the absorbent article.
<16>
The absorbent article according to any one of <1> to <15>, wherein the front region has a front tapered portion having a tapered shape in which the length in the lateral direction gradually decreases from the middle region side toward the outside in the longitudinal direction of the absorbent article.

＜17＞
The absorbent article according to <16>, wherein the tapered portion in the front region has a center of curvature inside the outer edge of the flap portion and has a curved shape that is convex outward from the absorbent article.
＜18＞
The absorbent article according to <16> or <17>, wherein the angle formed by two imaginary straight lines connecting the front end of the absorbent body in the longitudinal direction and the rear ends of the pair of contour lines of the front tapered portion extending from the front end of the absorbent body in the longitudinal direction outward in both directions in the horizontal direction is less than 120°, preferably 100° or less, and more preferably 70° or more and 90° or less.
＜19＞
The absorbent article according to any one of <1> to <18>, wherein the outer edge of the side flap portion at the position where the widest part is located in the intermediate region is located further outward in the lateral direction than the outer edge of the side flap portion at the position where the widest part is located in the rear region.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples.

Example 1
A sanitary napkin was produced having the same basic structure as the napkin 1 shown in Figure 1. Details of the main components of the sanitary napkin of Example 1 are as follows.
Top sheet: An air-through nonwoven fabric (basis weight 28 g/m ² ) was used.
Back sheet: A polyethylene resin film (basis weight 37 g/m ² ) was used.
Side sheet: A spunbond nonwoven fabric (basis weight 20 g/m ² ) was used.
Absorbent core: A stacked fiber type was used, in which absorbent polymer particles (50 g/m ² ) were carried on a fiber aggregate made of absorbent fibers (softwood bleached kraft pulp, basis weight 240 g/m ² in the excretory region M, basis weight 160 g/m ² in the front region F and rear region R). The angle α shown in Figure 4 was 89°, and the angle β shown in Figure 5 was 83°.
Core wrap sheet: Absorbent paper (basis weight 16 g/m ² ) was used.
Fiber agglomerate layer: 180 g/m ² of fiber agglomerates were used. The fiber agglomerates were produced by the following method.

(Method for producing fiber mass)
The fiber agglomerates were produced according to the method described in JP 2019-063469 A. Specifically, a raw fiber sheet was cut into a dice pattern to produce rectangular parallelepiped fiber agglomerates (fiber agglomerates having two opposing base surfaces and a skeletal surface connecting the two base surfaces). The raw fiber sheet used was an air-through nonwoven fabric (a fiber sheet having heat-fused portions between the constituent fibers) with a basis weight of 25 g/ ^m² , whose constituent fibers were hydrophobic thermoplastic fibers (non-absorbent fibers, fiber diameter 18 μm) made of polyethylene resin and polyethylene terephthalate resin. The fiber agglomerates had a short side of the base surface of 3.9 mm, a long side of 5.0 mm, and a thickness of 1.1 mm.

Example 2
The sanitary napkin 1 shown in Figure 7 was produced. The napkin 1 of this example is basically constructed in the same manner as the napkin 1 described above (the sanitary napkin of Example 1), except for the components described below. In Figure 7, components similar to those in the napkin 1 of this example are assigned the same reference numerals as those in the napkin 1 described above. For components of the napkin 1 of this example that are not specifically described, the explanation of the napkin 1 described above applies as appropriate.
The napkin 1 shown in Fig. 7 differs from the napkins described above in that it has wing portions. The "wing portions" are areas that are manually folded over with the fingers toward the non-skin-facing side of the crotch portion when fastening the absorbent article to the skin-facing side of the crotch portion of clothing such as shorts. Typically, in the case of napkin 1, the wing portions are portions of the side flaps 6S located in the excretory region M that extend farther outward in the lateral direction Y than the peripheral portions.

Comparative Example 1
A sanitary napkin was produced having the same shape as a sanitary napkin manufactured by Kao Corporation (product name: "Laurier (registered trademark) Slim Guard, especially heavy flow, daytime use, 25 cm"). The sanitary napkin of this comparative example does not have a front constricted portion or a rear constricted portion. Details of each component are as follows.
Top sheet: An air-through nonwoven fabric (basis weight 28 g/m ² ) was used.
Back sheet: A polyethylene resin film (basis weight 37 g/m ² ) was used.
Side sheet: A spunbond nonwoven fabric (basis weight 20 g/m ² ) was used.
- Absorbent core: A stacked fiber type was used, in which a fiber aggregate made of absorbent fibers (softwood bleached kraft pulp, basis weight 210 g/ ^m2 in the excretory area facing region M, basis weight 200 g/ ^m2 in the front area F and rear area R) is supported with absorbent polymer particles (basis weight 50 g/ ^{m2 in the excretory area facing region M,} basis weight 35 g/ ^m2 in the front area F and rear area R).
Core wrap sheet: Absorbent paper (basis weight 16 g/m ² ) was used.
Fiber agglomerate layer: 200 g/m ² of fiber agglomerates were used.

Comparative Example 2
This comparative example corresponds to Patent Document 1. A sanitary napkin was produced in the same manner as in Example 1, except that the side flap portion had the following structure and no compression recovery region was provided. The side flap portion of the sanitary napkin in this comparative example had one constricted portion at the front end and another constricted portion on the outer side of the excretory region. No constricted portion was provided in the rear region.

For the sanitary napkins of each example and comparative example, the wearing pressure amplitude and dynamic maximum absorption capacity were measured using the following methods. Using the same methods, the torsional torque value, compression recovery rate, and compression work load were also measured. The results are shown in Table 1 below.

<Method for measuring the amplitude of the wearing pressure>
The napkin to be measured was fixed to sanitary shorts and attached to the dynamic human model used in the "Dynamic Maximum Absorption Capacity" section above. A small three-axis force sensor (manufactured by Tech Gihan Co., Ltd., model number USL06-H5) was placed between the excretory-facing portion of the dynamic model and the napkin to measure the wearing pressure during walking. The wearing pressure periodically fluctuated as the dynamic model walked, resulting in a periodic waveform graph synchronized with the walking motion. In this measurement, the wearing pressure was continuously measured from the start of walking until one minute had elapsed. The walking speed of the dynamic model was measured at 50 steps per minute. Based on the obtained wearing pressure waveform graph, the average difference in wearing pressure fluctuations due to walking motion (also referred to as the wearing pressure amplitude) was calculated from the difference in fluctuations between the maximum and minimum wearing pressures per cycle. The smaller the wearing pressure amplitude, the better the napkin fit to the body and the higher the evaluation.

<Method for measuring dynamic maximum absorption>
The sanitary napkin to be measured was fixed to sanitary shorts and attached to a dynamic human model. A movable female waist model capable of walking both legs was used as the dynamic human model. The dynamic model began walking, and 1 minute after the start of walking, 2 g of simulated blood was injected through the liquid excretion point (first injection). Another 3 g of simulated blood was injected 3 minutes after the end of the first injection (second injection). Another 2 g of simulated blood was injected 3 minutes after the end of the second injection (third injection). From the third injection onwards, the procedure of injecting 2 g of simulated blood 3 minutes after the first injection was repeated, and the injection procedure was terminated when the simulated blood began to seep out from the side flaps or wings of the sanitary napkin. The total weight of the simulated blood injected up to that point was recorded as the dynamic maximum absorption amount (g).
The artificial blood used was defibrinated horse blood (manufactured by Japan Biotest Laboratory Co., Ltd.) with an adjusted blood cell/plasma ratio so that the viscosity measured using a B-type viscometer (manufactured by Toki Sangyo Co., Ltd., model number TVB-10M, measurement conditions: rotor No. 19, 30 rpm, 25°C, 60 seconds) was 8 mPa s. The larger the dynamic maximum absorption value, the more quickly body fluids move into the absorbent and the less likely it is to leak, resulting in a higher evaluation.

As shown in Table 1, the sanitary napkins of each Example had smaller torsional torque values and wearing pressure amplitudes than the sanitary napkins of each Comparative Example. This demonstrates that the sanitary napkins of each Example have excellent adhesion to the wearer's body and can follow the wearer's movements.

1. Sanitary napkins (absorbent articles)
2 Topsheet 3 Backsheet 4 Absorbent body 40 Absorbent core 41 Core wrap sheet 42 Fiber agglomerate layer 5 Sidesheet 6 Flap portion 6S Side flap portion 6F Front flap portion 6R Rear flap portion 61 Front constricted portion 62 Rear constricted portion 63 Curved portion 64 Front convex portion 65 Rear convex portion 7 Fastening portion 11 Fiber agglomerates 12 Absorbent fiber M Excretory portion facing region F Front region C Middle region R Rear region X Longitudinal direction Y Lateral direction

Claims (11)

An absorbent article having an absorbent body capable of absorbing and retaining bodily fluids, and having a longitudinal direction corresponding to the front-to-back direction of a wearer and a lateral direction perpendicular to the longitudinal direction,
a flap portion extending outward from the outer edge of the absorbent body and forming an outline of the absorbent article, the flap portion comprising a pair of side flap portions positioned outward in the horizontal direction from a pair of imaginary straight lines extending in the vertical direction through the outermost end of the absorbent body in the horizontal direction;
an outer edge of the side flap portion has a front constricted portion located forward in the longitudinal direction and a rear constricted portion located rearward in the longitudinal direction;
the absorbent article comprises a front region located forward of a rear end of the front constricted portion in the longitudinal direction, a rear region located rearward of a front end of the rear constricted portion in the longitudinal direction, and an intermediate region defined by the front constricted portion and the rear constricted portion,
the intermediate region includes an excretory region facing region that faces the excretory region of the wearer when worn,
the intermediate region has a compression recovery region including a compression recovery material;
a rear convex portion located between the rear constricted portion and the longitudinal rear end of the absorbent article and protruding outward in the lateral direction beyond the rear constricted portion,
a portion of the flap portion located rearward in the longitudinal direction from the rear convex portion has a tapered shape in which the length in the lateral direction gradually decreases toward a rear end of the flap portion in the longitudinal direction ,
The absorbent article has both outer edges of the flap portion located between the rear convex portion and the longitudinal rear end, each of which has a convex curved shape with a center of curvature on the outer side of the both outer edges . The absorbent article of claim 1, wherein the lateral distance between the outer edges of the side flap portions and the absorbent body is shortest at the front constricted portion in the front region and shortest at the rear constricted portion in the rear region. the absorbent body has a rear tapered portion in the rear region, in which the length of the absorbent body in the lateral direction gradually decreases toward the rear end of the absorbent body in the longitudinal direction,
3. The absorbent article according to claim 1, wherein an angle formed by two imaginary straight lines connecting the longitudinal rear end of the absorbent body and the longitudinal front ends of a pair of contour lines of the rear tapered portion extending from the longitudinal rear end of the absorbent body outward in both lateral directions is less than 120°. the front constricted portion is located 5 mm or more in front of the front end of the excretory portion-facing region in the longitudinal direction,
The absorbent article according to claim 1 , wherein the rear constricted portion is located at least 5 mm rearward in the longitudinal direction from the rear end of the excretory portion-facing region in the longitudinal direction. The absorbent article according to any one of claims 1 to 4, wherein the compression recovery rate of the excretory region is higher than the compression recovery rates of the front region and the rear region. The absorbent article according to any one of claims 1 to 5, wherein the thickness of the absorber is thinner in the front and rear regions than in the central region in the lateral direction of the excretory part-facing region. the absorbent body includes a fiber mass containing non-absorbent fibers, absorbent fibers, and an absorbent polymer, the fiber mass being the compression recovery material;
7. The absorbent article according to claim 1, wherein the ratio of the mass of the fiber agglomerates to the total mass of the fiber agglomerates and the absorbent fibers is higher in the excretory region than in the front region and the rear region. The absorbent article of claim 7, wherein in the compression recovery region, the ratio of the mass content of the fiber agglomerates to the total mass content of the fiber agglomerates and the absorbent fibers is lower on the skin-facing side of the absorbent body than on the non-skin-facing side of the absorbent body. The absorbent article according to any one of claims 1 to 8, wherein the compression recovery rate of the excretory region is 40% or more. The absorbent article according to any one of claims 1 to 9, wherein the side edges of the absorbent body located in the excretory region along the longitudinal direction are straight lines parallel to the longitudinal direction. a fastening portion for fastening the absorbent article to a wearer's clothing is arranged in a region of the non-skin-facing surface of the absorbent article that overlaps with the absorbent body in a plan view,
The fastening portion is arranged in a plurality of rows extending in the horizontal direction and spaced apart in the vertical direction,
11. The absorbent article according to claim 1, wherein the lateral length of the fastening portion in at least a portion of both the front region and the rear region is shorter than the lateral length of the fastening portion in the excretory region-facing region.