Absorbent article

Abstract

To provide an absorbent article excellent in fitness to a wearer's body.SOLUTION: A sanitary towel 1 has swelling parts 60 in which flap parts 6 expand in an intermediate area M outward in a lateral direction Y, and rear constricted parts 62. A rear area R has a rear width expansion part 63 whose full width gradually increases toward a rear end in a lengthwise direction, and a rear tapered part 64 whose full width gradually decreases toward the rear end in the lengthwise direction. An absorber 4 includes first rear recess parts 71 located in the rear area R and second rear recessed parts 72 located behind the first rear recess parts 71. The first rear recess part 71 and the second rear recess part 72 are present in pairs on both sides with a lengthwise center line of the sanitary towel 1 extending in a lengthwise direction X in between, and a gap in the lateral direction Y between first rear recess parts 71 and a gap in the lateral direction Y between the second rear recess parts 72 become gradually shorter as they go from a front end to a rear end in the lengthwise direction X.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] As a female absorbent article, as typified by sanitary napkins, there is known an absorbent article that includes an absorbent body that absorbs and retains excrement such as menstrual blood, and a flap portion that extends outward from the outer edge of the absorbent body and forms the contour of the absorbent article, and has a recessed portion in which the top sheet and the absorbent body that form the skin-facing surface are integrally recessed toward the non-skin-facing surface. Such a recessed portion is typically formed by subjecting the skin-facing surface of the absorbent article to a compression process, and is also called a compression portion, etc., and is provided for the purpose of controlling the movement of excrement and the like on the skin-facing surface of the absorbent article to prevent leakage, inducing appropriate deformation of the absorbent body when the absorbent article is worn to improve fit, etc., and various shapes according to the purpose have been proposed. For example, Patent Document 1 describes an absorbent article that can reduce irritation to the skin near the sacrum of a wearer, which has a pair of hip flaps that extend largely outward in the horizontal direction from both side edges along the vertical direction of the absorbent body in the rear region in the vertical direction, and a pair of rear compression portions that are spaced apart in the horizontal direction on the skin-facing surface of the rear region. The pair of rear compressed portions are located vertically rearward of the widest position of the hip flaps, and the horizontal distance between one rear compressed portion and the other rear compressed portion gradually increases vertically rearward.

[0003] Patent Document 2 describes an absorbent article in which a high-rise part of an absorbent body that is thickened on the skin side is provided in the center of the width direction of the absorbent article, at least in the range from the body fluid discharge part to the intergluteal cleft, and a pair of left and right compressed grooves extending approximately in the longitudinal direction are formed on both sides of the high-rise part. The absorbent article described in Patent Document 2 is said to improve the fit to the intergluteal cleft, prevent rear leakage of body fluids, prevent twisting when worn, and improve the wearing comfort. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-328 A [Patent Document 2] JP 2018-283 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide an absorbent article that follows the movements of a wearer and has excellent fit to the body, particularly the buttocks. [Means for solving the problem]

[0006] The present invention provides an absorbent article having a vertical direction corresponding to the front-to-back direction of a wearer and a horizontal direction perpendicular to the vertical direction, and having an intermediate region including an excretory part facing region that is positioned opposite the wearer's excretory part when worn, a front region that is positioned forward of the intermediate region in the vertical direction, and a rear region that is positioned rearward of the intermediate region in the vertical direction. The absorbent article preferably comprises an absorbent body capable of absorbing and retaining bodily fluids, and has flap portions extending outward from the outer edge of the absorbent body to form the contour of the absorbent article. It is preferable that the absorbent article has a bulge portion on each side of the vertical direction in the intermediate region, in which the flap portion protrudes convexly outward in the horizontal direction, and the portion where the tip of the bulge portion is located in the vertical direction is an intermediate maximum width portion whose length in the horizontal direction is the maximum in the intermediate region. It is preferable that the absorbent article has a rear constriction portion rearward of the intermediate maximum width portion, the rear constriction portion having a shorter lateral length than the portions located in front and behind, and that the minimum width portion in the rear constriction portion, which has the smallest lateral length, forms the boundary between the intermediate region and the rear region. It is preferable that the rear region has a rear width expanding portion whose width in the horizontal direction gradually increases toward the rear end in the vertical direction, and a rear tapered portion located vertically rearward of the rear width expanding portion and whose width in the horizontal direction gradually decreases toward the rear end in the vertical direction. It is preferable that the absorbent body has a recess that recesses from the skin-facing surface toward the non-skin-facing surface, the recess including a first rear recess located in the rear width expansion portion and a second rear recess located rearward of the first rear recess, and that the first rear recess and the second rear recess each exist in pairs on either side of a vertical centerline of the absorbent article extending in the vertical direction. It is preferable that the lateral distance between the pair of first rear recesses and the lateral distance between the pair of second rear recesses each gradually become shorter from the front end to the rear end in the vertical direction. Effect of the Invention

[0007] According to the present invention, there is provided an absorbent article which follows the movements of the wearer and has excellent fit to the body, particularly the buttocks. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic plan view showing the skin-facing side of a sanitary napkin, which is one embodiment of the absorbent article of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view taken along line II in FIG. 1 (a cross-section taken along the thickness direction and lateral direction of the sanitary napkin). [Diagram 3] FIG. 3 is a schematic cross-sectional view taken along the line II-II in FIG. 1 (a cross-section taken along the thickness direction and lateral direction of the sanitary napkin). [Figure 4] FIG. 4 is a schematic plan view showing the skin-facing side of the rear region of the sanitary napkin shown in FIG. [Diagram 5] FIG. 5 is a schematic plan view showing the skin-facing side of the front region of the sanitary napkin shown in FIG. [Figure 6]FIG. 6 is a schematic plan view showing the non-skin-facing side of the sanitary napkin shown in FIG. [Figure 7] 7(a), 7(b) and 7(c) are explanatory diagrams of a method for measuring the torsional torque value. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The absorbent article of the present invention will be described below based on its preferred embodiments with reference to the drawings. Figures 1 to 6 show a sanitary napkin 1 (hereinafter, also referred to as "napkin 1"), which is one embodiment of the absorbent article of the present invention. The napkin 1 has a longitudinal direction X that corresponds to the front-rear direction of the wearer and extends from the front side (abdominal side) of the wearer through the crotch area to the rear side (dorsal side), and a lateral direction Y that is perpendicular to the longitudinal direction X. In the present invention, "forward in the longitudinal direction" refers to a position forward (toward the wearer's abdomen) of a reference position in the longitudinal direction, and "backward in the longitudinal direction" refers to a position rearward (toward the wearer's back) of a reference position in the longitudinal direction. Hereinafter, the forwardmost (abdominal) position of the napkin 1 in the longitudinal direction X is also referred to as the "foremost end F1 in the longitudinal direction X," and the rearmost (dorsal) position of the napkin 1 in the longitudinal direction X is also referred to as the "rearmost end R1 in the longitudinal direction X."

[0010] 1, the napkin 1 of this embodiment has a shape that is long in the vertical direction X. The vertical direction X coincides with the longitudinal direction of the napkin 1. The napkin 1 of this embodiment is formed symmetrically with respect to a vertical centerline CL that bisects the napkin 1 in the horizontal direction Y and extends in the vertical direction X. This vertical centerline CL is an imaginary straight line.

[0011] The napkin 1 has a middle region M which faces the excretory parts of the wearer when worn, a front region F which is disposed forward of the middle region M in the longitudinal direction X, and a rear region R which is disposed rearward of the middle region M in the longitudinal direction X (see FIG. 1). The middle region M includes an excretory part facing region C which faces the excretory parts such as the vulva of the wearer when worn. In the napkin 1, the rear region R faces the buttocks of the wearer. In order to widely cover the buttocks, the total length of the napkin 1 is preferably 27 cm or more, and particularly preferably 30 cm or more. The contours of the regions F, M, and R are formed by the flap portions 6 which will be described later.

[0012] In this embodiment, the napkin 1 has a rear constricted portion 62 located on the rear side in the longitudinal direction X (see FIG. 1). The rear constricted portion 62 is a portion rearward of an intermediate maximum width portion 67 described later, whose width (length in the lateral direction Y) is shorter than the portions located in front and behind, and is a portion in which both side edges of the napkin 1 are constricted inward in the lateral direction Y. The rear constricted portion 62 has a rear minimum width portion where the width (length in the lateral direction Y) of the napkin 1 is minimum, and this rear minimum width portion forms the boundary between the intermediate region M and the rear region R. Specifically, the rear minimum width portion of the rear constricted portion 62 forms the boundary between the intermediate region M and the rear region R. The width (length in the lateral direction Y) of an absorbent article such as the napkin 1 is measured when the absorbent article is in a flat state as shown in FIG. 1.

[0013] In this specification, the "skin-facing side" refers to the side of the absorbent article or its constituent member (e.g., absorbent body 4) that faces the skin of the wearer when the absorbent article is worn, and the "non-skin-facing side" refers to the side of the absorbent article or its constituent member that faces the opposite side to the skin when the absorbent article is worn. In other words, the skin-facing side is the side that is relatively close to the wearer's skin, and the non-skin-facing side is the side that is relatively far from the wearer's skin. "When worn" and "worn state" refer to the normal proper wearing position, i.e., the state in which the absorbent article is worn while maintaining the proper wearing position.

[0014] The napkin 1 of this embodiment comprises an absorbent body 10 that is elongated in the longitudinal direction X. The absorbent body 10 is the main part of the napkin 1. As shown in Figs. 2 and 3, the absorbent body 10 comprises a topsheet 2 that forms the skin-facing surface, a backsheet 3 that forms the non-skin-facing surface, and an absorbent core 4 located between these sheets 2, 3. The absorbent body 4 is a member capable of absorbing and retaining bodily fluids such as menstrual blood, urine, and sweat, and the entire skin-facing surface of the absorbent body 4 is covered by a top sheet 2, and the entire non-skin-facing surface of the absorbent body 4 is covered by a back sheet 3. The front and rear edges of the top sheet 2 and the back sheet 3 in the longitudinal direction X are aligned with each other, and these sheets 2, 3 are overlapped at the front and rear ends and joined by end seal portions 65 described below. The back sheet 3 extends outward in the lateral direction Y beyond the top sheet 2. As the top sheet 2, various types of sheets conventionally used in absorbent articles such as sanitary napkins can be used without any particular limitation, for example, liquid-permeable sheets such as single-layer or multi-layer nonwoven fabrics and perforated films. As the back sheet 3, a liquid-impermeable sheet such as a moisture-permeable resin film can be used.

[0015] The absorbent body 4 of this embodiment includes a liquid-absorbent core 40 and a liquid-permeable core wrap sheet 41 that covers the outer surface of the absorbent core 40, as shown in Figs. The absorbent body 4 of this embodiment has a portion 4C whose overall width is constant in the longitudinal direction X (hereinafter also referred to as "constant width portion 4C"), and end portions 4E, 4E located on both sides in the longitudinal direction X of the constant width portion and whose overall width gradually decreases outward in the longitudinal direction X (see FIG. 1). The absorbent core 40 constitutes the main body of the absorbent body 4, and has a shape that is long in the longitudinal direction X in plan view as shown in Fig. 1. The plan view shape of the absorbent core 40 approximately coincides with the plan view shape of the absorbent body 4. The absorbent core 40 is disposed in the napkin 1 with its longitudinal direction coinciding with the longitudinal direction X of the napkin 1. The absorbent core 40 and the core wrap sheet 41 may be joined together with an adhesive such as a hot melt adhesive. The core wrap sheet 41 may be a sheet made of the same material as the top sheet 2.

[0016] The absorbent core 40 is the main component of the absorbent body 4, and contains a water-absorbent material, so that it is capable of absorbing and retaining bodily fluids. Examples of the water-absorbent material include water-absorbent fibers and water-absorbent polymers, and these can be used alone or in combination of two or more. 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 include those that have been conventionally used in this type of absorbent body, and are not particularly limited, and examples of such polymers include polymers or copolymers of acrylic acid or alkali metal acrylates. The absorbent core 40 may be of a stacking type or a sheet type. The stacking type absorbent core is typically composed of an aggregate of fibrous materials such as absorbent fibers, and the aggregate is supported with absorbent polymer particles as necessary. The stacking 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 is typically composed of absorbent polymer particles fixed inside or on the surface of a fiber sheet, and is also called an absorbent sheet. For example, paper, nonwoven fabric, etc. can be used as the fiber sheet. The sheet type absorbent core is thinner and more flexible than the stacking type absorbent core. The sheet type absorbent core can be composed of absorbent polymer particles interposed between two opposing fiber sheets.

[0017] As shown in FIG. 1, the napkin 1 of this embodiment has a pair of side sheets 5, 5 on both sides along the longitudinal direction X of the skin-facing surface of the napkin 1 (skin-facing surface of the top sheet 2). 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 along the longitudinal direction X of the absorbent body 4 in a plan view. As shown in FIG. 2 and FIG. 3, the side sheets 5 have, of both sides along the longitudinal direction X, an outer portion including an outer edge located on the outer side of the lateral direction Y, which is fixed to another member (the back sheet 3 in the illustrated embodiment) as a fixed edge portion, and an inner portion including an inner edge located on the inner side of the lateral direction Y, which is a free edge portion not fixed to another member. When the napkin 1 is worn, the free edge portion of the side sheet 5 stands up toward the wearer's skin, thereby preventing excrement such as menstrual blood from flowing outward in the lateral direction Y. The side sheets 5 can be made of the same material as the back sheet 3.

[0018] In the napkin 1 of this embodiment, an end seal portion 65 is formed at the outer end portion in the horizontal direction Y of the side sheet 5, joining the side sheet 5 and the back sheet 3. The end seal portion 65 joins the outer peripheral edges of the top sheet 2 and the back sheet 3 at the front end and rear end portion in the vertical direction X, and also joins the outer peripheral edges of the side sheet 5 and the back sheet 3 at both side edges in the horizontal direction Y, and the outer peripheral edges of the end seal portion 65 form the outline (contour) of the napkin 1.

[0019] The napkin 1 has a flap portion 6 (see FIG. 1) which extends outward from the outer edge of the absorbent body 4 and forms the outline of the napkin 1. The flap portion 6 in this embodiment is a portion which extends outward from the peripheral edge of the absorbent body 4 and is an area where the absorbent body 4 is not placed. The flap portion 6 in this embodiment is composed of members arranged to straddle the outer edge (periphery) of the absorbent body 4 from the inside to the outside. More specifically, the flap portion 6 is composed of two or more sheet members selected from the top sheet 2, the back sheet 3, and the side sheet 5. The multiple sheet members constituting the flap portion 6 are joined to each other by a joining means such as adhesive, heat or ultrasonic fusion. The flap portion 6 in this embodiment has an end seal portion 65 formed by fusion continuously around the entire periphery of the flap portion 6.

[0020] The flap portion 6 in this embodiment has a pair of side flap portions 6S, 6S located on both sides in the lateral direction Y of the napkin 1, and a pair of end flap portions 6E, 6E located on both sides in the longitudinal direction X (see FIG. 1). The side flap portions 6S in this embodiment are formed by side sheets 5 and a back sheet 3 extending outward in the lateral direction Y from both side edges of the absorbent body 4. The end flap portions 6E, 6E in this embodiment are formed by a top sheet 2 and a back sheet 3 extending respectively from the front and rear ends of the absorbent body 4 in the longitudinal direction X. The sheets forming the side flap portions 6S and the end flap portions 6E are joined together by end seal portions 65.

[0021] The rear constricted portion 62 described above is formed by the contour of the side flap portion 6S being curved inwardly in the horizontal direction Y in a convex shape. On the other hand, both side edges of the absorbent body 4 are aligned along the vertical direction X. That is, when the napkin 1 is viewed along the vertical direction X, the length in the horizontal direction Y between the side edges of the side flap portions 6S decreases at the rear constricted portion 62, but the length in the horizontal direction Y of the absorbent body 4 is constant. Hereinafter, the "length in the horizontal direction Y" of the absorbent body is also referred to as the "width", and the "length in the horizontal direction Y" of the absorbent article is also referred to as the "total width".

[0022] The napkin 1 has a bulging portion 60 in which the side flap portion 6S protrudes outward in the horizontal direction Y on both sides of the intermediate region M in the vertical direction X. The bulging portion 60 has a rear narrowing portion 69 in which the overall width (length in the horizontal direction Y) of the napkin 1 gradually decreases from the intermediate maximum width portion 67 toward the rear constricted portion 62, and a front narrowing portion 70 in which the overall width (length in the horizontal direction Y) of the napkin 1 gradually decreases from the intermediate maximum width portion 67 toward the front constricted portion 61. The rear narrowing portion 69 is adjacent to the rear region R in the vertical direction X, and is a portion whose width gradually increases from the minimum width portion of the rear constricted portion 62 toward the front in the vertical direction X. The front narrowing portion 70 is adjacent to the rear narrowing portion 69 in the vertical direction X. That is, the napkin 1 has the front narrowing portion 70 between the rear narrowing portion 69 and the front region F in the vertical direction X (see FIG. 1). In the napkin 1, in the longitudinal direction X, the tip of the bulging portion 60 is located in the intermediate region M, which is an intermediate maximum width portion 67 having a maximum overall width (length in the lateral direction Y) (see FIG. 1).

[0023] The rear region R has a rear width expanding portion 63 where the overall width of the napkin 1 gradually increases toward the rear end R1 in the longitudinal direction X, and a rear tapered portion 64 located rearward of the rear width expanding portion 63 in the longitudinal direction X and where the overall width of the napkin 1 gradually decreases toward the rear end R1 in the longitudinal direction X. The rear width expanding portion 63 is adjacent to the middle region M in the longitudinal direction X, and is a portion where the width gradually increases from the minimum width portion of the rear constriction portion 62 toward the rear in the longitudinal direction X. The rear tapered portion 64 is adjacent to the rear width expanding portion 63 in the longitudinal direction X. That is, the napkin 1 has the rear width expanding portion 63 between the rear tapered portion 64 and the middle region M in the longitudinal direction X (see FIG. 1). In the rear width expanding portion 63, the overall width of the absorbent body 4 in the longitudinal direction X is constant, while the overall width of the side flap portion 6S gradually increases toward the rear end R1 in the longitudinal direction X. The overall width of this side flap portion 6S is not the sum of the overall widths of the side flap portions 6S on both sides, but the overall width of each side flap portion 6S on one side. The napkin 1 has a rear maximum width portion 68 at the boundary between the rear width expanding portion 63 and the rear tapered portion 64, where the overall width is maximum in the rear region R (see Figs. 1 and 4).

[0024] In the rear tapered portion 64, the overall width of the napkin 1 gradually decreases from the rear maximum width portion 68 toward the rear longitudinal end R1. In addition, the outer edge of the napkin 1 in the rear tapered portion 64 may be curved convexly outward, but it is preferable from the viewpoint of fitting to the gluteal sulcus that it is generally straight or has a portion that is gently curved convexly inward (hereinafter, also referred to as an inwardly convex curved portion 76) as shown in Fig. 1. The length La of the rear tapered portion 64 in the longitudinal direction X is preferably 45 mm or more, more preferably 50 mm or more, and is preferably 100 mm or less, more preferably 95 mm or less, from the viewpoint of obtaining a sufficient fit to the gluteal fold of the wearer. In addition, from the viewpoint of adequately covering the buttocks and adequately fitting to the gluteal sulcus, the length Lb (see FIG. 1) in the horizontal direction Y between the rear widest part 68 and the vertical centerline CL is, as a ratio to La (Lb / La), preferably 0.65 or more, more preferably 0.70 or more, and is preferably 1.20 or less, more preferably 1.10 or less.

[0025] The inwardly convex curved portion 76 is a portion of the outer edge of the flap portion 6, which is located between the longitudinal rear end R1 and the rear maximum width portion 68 of the flap portion 6 and has a center of curvature outside the outer edge of the side flap portion 6S. In this embodiment, the inwardly convex curved portion 76 is a portion having a single curved shape, which is formed by curved lines extending from the longitudinal rear end R1 and the rear maximum width portion 68 of the flap portion 6 to a single convex apex (maximum point) 76P located between the two starting points. Therefore, the inwardly convex curved portion 76 is a portion of the outer edge of the flap portion 6 located between the two starting points, excluding the curved portion that is outwardly convex in the horizontal direction Y and is formed including the rear maximum width portion 68, and the curved portion that is outwardly convex in the vertical direction X and includes the longitudinal rear end R1 of the flap portion 6.

[0026] The napkin 1 has a rear maximum width portion 68, and the outer edge of the side flap portion 6S, which is likely to be the starting point of deformation of the rear region R, has a single inwardly convex curved portion 76 between the rear maximum width portion 68 and the longitudinal rear end R1, so that when an external force that causes twisting in the rear region R is generated, for example when the wearer of the napkin 1 walks, the rear maximum width portion 68 becomes the starting point of twisting, and the inwardly convex curved portion 76 follows the external force and easily twists and deforms. Such ease of deformation can be evaluated using as an index the "torsion torque value" measured by the method described below, and the napkin 1 having the rear maximum width portion 68 and the single inwardly convex curved portion 76 connected thereto has a sufficiently small torsion torque value, making it unlikely for the wearer to feel discomfort when twisted and deformed due to the wearer's bodily movements.

[0027] 4, when a triangle is assumed with a base defined by a virtual straight line H1 connecting the longitudinal front end 76A and longitudinal rear end 76B of the inwardly convex curved portion 76 and two sides defined by two virtual straight lines H2 and H3 connecting the apex 76P of the inwardly convex curved portion 76 to the front end 76A and rear end 76B, respectively, the apex angle θ5 of the triangle is preferably 150° to 175°, more preferably 160° to 170°. By having the angle θ5 within the above range, the fit to the bulging area between the gluteal cleft and gluteal fold of the wearer is further improved, and improved liquid absorbency can be expected. Moreover, the angle θ6 between the imaginary line V4 connecting the apexes 76P of the pair of inwardly convex curved portions 76 and the imaginary line H2 is preferably 40° or more, more preferably 42° or more, and is preferably 70° or less, more preferably 60° or less. By having the angle θ6 within the above range, the inwardly convex curved portion 76 can easily deform along the bulging shape between the gluteal crease and the gluteal cleft in response to the wearer's movements.

[0028] In the rear tapered portion 64, the rear end of the constant width portion 4C of the absorbent body 4 and a tapered end portion 4E are disposed on the rear side of the constant width portion 4C (see FIG. 1). In the rear tapered portion 64, the overall width of the napkin 1 and the width of the absorbent body 4 each gradually decrease toward the rear in the longitudinal direction X. In the rear tapered portion 64 of this embodiment, the absorbent body tapered portion 4E and the end flap portion 6E of the absorbent body 4 are curved so as to be similar to each other.

[0029] The absorbent body 4 of this embodiment has a pair of central recesses 74, 74 extending in the longitudinal direction X from the front region F through the middle region M to the rear region R, a front recess 75 located forward of the central recess 74, and a rear recess 73 located rear of the central recess 74 (see FIG. 1). These recesses 73, 74, and 75 are independent of a first rear recess 71 and a second rear recess 72 described below, and are spaced apart from the first rear recess 71 and the second rear recess 72 in the longitudinal direction X. In other words, these recesses 73, 74, and 75 are not continuous with the first rear recess 71 and the second rear recess 72. The rear recess 73, the central recess 74 and the front recess 75, like the first rear recess 71 and the second rear recess 72, are formed by a known embossing process (compression process) in which the top sheet 2 and the absorbent body 4 are recessed integrally toward the non-skin-facing surface.

[0030] The absorbent body 4 has a pair of first rear recesses 71, 71 and second rear recesses 72, 72 in the rear region R, spaced apart from each other in the lateral direction Y and on both sides of the center line CL (see FIG. 1). The first rear recesses 71, 71 and the second rear recesses 72, 72 are recesses formed by compressing from the skin-facing surface of the absorbent body 4 toward the non-skin-facing surface, and can also be called "compressed parts" based on their formation method. The first rear recess 71 is formed in the rear region R, and the second rear recess 72 is formed rearward of the first rear recess 71 and has a higher density than its surroundings. The first rear recess 71 and the second rear recess 72 of this embodiment can be formed by known embossing (compression) such as embossing with or without heat application, ultrasonic embossing, etc. For example, by subjecting the skin-facing surface (topsheet 2) of the absorbent body 10 to a compression process accompanied by heat, the first rear recess 71 and the second rear recess 72 can be formed by the topsheet 2 and the absorbent body 4 being integrally recessed toward the non-skin-facing surface. In this case, at the bottoms of the first rear recess 71 and the second rear recess 72, the topsheet 2, the core wrap sheet 41, and the absorbent core 40 can be heat-sealed and integrated.

[0031] The pair of first rear recesses 71 and second rear recesses 72 are linear compressed grooves having a front end and a rear end, respectively, extending in the vertical direction X. In a plan view, the distance between the first rear recesses 71 and the distance between the second rear recesses 72 gradually decrease from the front end to the rear end in the vertical direction X. In the first rear recesses 71 and the second rear recesses 72 of this embodiment, the rear ends 71r, 71r of the first rear recesses 71 and the rear ends 72r, 72r of the second rear recesses 72 are spaced apart in the horizontal direction Y (see FIG. 4). In this embodiment, the front end of the first rear recess 71 is disposed in the rear region R. That is, the entire first rear recess 71 is disposed in the rear region R.

[0032] As described above, the napkin 1 of this embodiment has a rear tapered portion 64 in the rear region R, and has a pair of first rear recesses 71 and a pair of second rear recesses 72 in the rear region R. When the napkin 1 is worn, the rear tapered portion 64 abuts against the buttocks of the wearer. The rear tapered portion 64 has a smaller area that protrudes outward in the lateral direction Y from the absorbent body than a napkin that does not have the rear tapered portion 64, and the overall width gradually decreases. As a result, the rear region R does not reach the hyperactive parts of the buttocks that are involved in movements such as walking, so that friction and stuffiness between the rear region R and the skin can be suppressed, and discomfort during wearing can be reduced, and the rear tapered portion 64 easily follows along the intergluteal cleft and intergluteal sulcus, providing a good fit. Moreover, in the rear region R, the pair of first rear recesses 71, 71 and second rear recesses 72, 72 are spaced apart from each other in the lateral direction Y, so that the rigidity of the first rear recesses 71 and the second rear recesses 72 can be reduced and excessive rigidity can be prevented. This allows the rear region R to exhibit high conformability to the buttocks, reducing discomfort when worn.

[0033] From the viewpoint of making it easier for the napkin 1 to bend into a convex shape toward the wearer's body along the wearer's intergluteal cleft and the bulge between the intergluteal cleft and the intergluteal sulcus when worn, and to make it easier to maintain the bent shape, it is preferable that the front end 72f of the second rear recess 72 is disposed rearward of the rear maximum width portion 68. In other words, it is preferable that the second rear recess 72 is located rearward of the rear maximum width portion 68 in the longitudinal direction X. In this way, the napkin 1 fits into the intergluteal cleft, and the inconvenience of excrement excreted from an excretory part such as the vaginal opening leaking out from the front and rear of the napkin 1 in the longitudinal direction X along the intergluteal cleft (so-called leakage along the intergluteal cleft) is suppressed, thereby further improving leakage prevention.

[0034] In order to ensure the above-mentioned effects, it is preferable that the rear ends 71r, 71r of the pair of first rear recesses 71 are located more inward in the lateral direction Y than the front ends 72f, 72f of the second rear recesses 72. That is, it is preferable that the distance W1 (see FIG. 4) between the rear ends 71r, 71r of the pair of first rear recesses 71 is shorter than the distance W2 (see FIG. 4) between the front ends 72f, 72f of the pair of second rear recesses 72. The distances W1, W2 are the shortest distance between the rear ends 71r, 71r of the first rear recesses 71 and the shortest distance between the front ends 72f, 72f of the second rear recesses 72, and are lengths along the lateral direction Y in this embodiment. The distance W1 between the rear ends 71r, 71r of the first rear recess 71 is preferably 5% or more, more preferably 10% or more, and even more preferably 15% or more, relative to the distance W2 between the front ends 72f, 72f of the second rear recess 72, and is preferably 80% or less, more preferably 70% or less, and even more preferably 60% or less. Furthermore, the distance W1 between the rear ends 71r, 71r of the first rear recess 71 is preferably 2 mm or more, more preferably 3 mm or more, even more preferably 5 mm or more, and is preferably 50 mm or less, more preferably 40 mm or less, even more preferably 35 mm or less. The distance W2 between the front ends 72f, 72f of the second rear recess 72 is preferably 10 mm or more, more preferably 15 mm or more, even more preferably 20 mm or more, and is preferably 70 mm or less, more preferably 65 mm or less, even more preferably 63 mm or less.

[0035] In this embodiment, as shown in Fig. 4, the absorbent body 4 has an end portion 4E in the rear region R, in which the length (width) in the horizontal direction Y of the absorbent body 4 gradually decreases toward the vertical rear end 4R of the absorbent body 4. As shown in Fig. 4, when the angle formed by two imaginary straight lines V1, V1 connecting the vertical rear end 4R of the absorbent body 4 and the vertical rear ends 48 of a pair of contour lines of the absorbent body end portion 4E extending outward in both sides in the horizontal direction Y from the vertical rear end 4R of the absorbent body 4 is θ1, and the angle formed by a pair of second rear recesses 72, 72 is θ2, the difference between the angle θ1 and the angle θ2 is preferably 60° or less, more preferably 45° or less, and even more preferably 40° or less. The difference between the angles θ1 and θ2 may be 0°, i.e., angle θ1=θ2. However, when the wearer sits for a long time, when a force is generated that deforms the absorbent 4 along the pair of second rear recesses 72, 72 so as to bite into the gluteal cleft, the absorbent 4 located on the outer side in the lateral direction Y from the second rear recesses 72 deforms along the portion from the rear of the wearer's groin to the gluteal cleft, so that the above-mentioned deformation can be suppressed from occurring excessively. Therefore, it is preferable that the angle θ1 is larger than the angle θ2, and the angle θ1 is preferably 1° or more larger than the angle θ2, and more preferably 3° or more larger. With such a configuration, the fit of the napkin 1 to the gluteal cleft can be further improved. The angles θ1 and θ2 are preferably 30° or more, more preferably 40° or more, and preferably 120° or less, more preferably 100° or less, respectively.

[0036] Furthermore, when the angle between the pair of first rear recesses 71, 71 is θ3, the difference between the angle θ1 and the angle θ3 is preferably 60° or less, more preferably 50° or less, and even more preferably 40° or less. The difference between the angle θ1 and the angle θ3 may be 0°, that is, the angle θ1=θ3. However, when the wearer sits for a long time, when a force is generated that causes the absorbent body 4 to deform along the pair of first rear recesses 71, 71 and the pair of second rear recesses 72, 72 so as to bite into the gluteal cleft, the absorbent body 4 located on the outer side of the second rear recesses 72 in the lateral direction Y is deformed along the portion extending from the rear of the wearer's groin to the gluteal cleft, so that the above-mentioned deformation can be suppressed from occurring excessively. Therefore, the angle θ1 is preferably larger than the angle θ3, and the angle θ1 is preferably 1° or more larger than the angle θ3, and more preferably 3° or more larger. Such a configuration makes it possible to more reliably achieve the above-mentioned effects. In addition, θ3 is preferably 5° or more, more preferably 10° or more, and is preferably 35° or less, more preferably 25° or less.

[0037] In this embodiment, the napkin 1 has a front constricted portion 61 located on the front side in the vertical direction X (see FIG. 1). The front constricted portion 61 is a portion forward of the intermediate maximum width portion 67, whose width (length in the horizontal direction Y) is shorter than the portions located in front and behind, and is a portion in which both side edges of the napkin 1 are constricted inward in the horizontal direction Y. The front constricted portion 61 has a front minimum width portion 66 where the width (length in the horizontal direction Y) of the napkin 1 is minimum, and the front minimum width portion 66 forms the boundary between the front region F and the middle region M. Specifically, the front minimum width portion 66 of the front constricted portion 61 forms the boundary between the front region F and the middle region M.

[0038] The front region F has a front width expanding portion 58 in which the overall width of the napkin 1 gradually increases toward the front end F1 in the longitudinal direction X, and a front width narrowing portion 59 located forward of the front width expanding portion 58 in the longitudinal direction X and in which the overall width of the napkin 1 gradually decreases toward the front end F1 in the longitudinal direction X. The front width expanding portion 58 is adjacent to the middle region M in the longitudinal direction X, and is a portion whose width gradually increases from a front minimum width portion 66 of the front constricted portion 61 toward the front in the longitudinal direction X. The front width narrowing portion 59 is adjacent to the front width expanding portion 58 in the longitudinal direction X. That is, the napkin 1 has the front width expanding portion 58 between the front width narrowing portion 59 and the middle region M in the longitudinal direction X (see Figs. 1 and 4). The napkin 1 has a front maximum width portion 57, where the overall width is maximum in the front region F, at the boundary between the front width enlarged portion 58 and the front width reduced portion 59 (see Figs. 1 and 4).

[0039] In this embodiment, as shown in Fig. 1 and Fig. 5, the front constricted portion 61 has a front minimum width portion 66. As shown in Fig. 5, when a virtual line connecting each of both ends 66a, 66a in the lateral direction Y of the front minimum width portion 66 and the front end F1 in the longitudinal direction X is defined as a first line V2, and a virtual line connecting both ends in the lateral direction Y of the front maximum width portion 57 is defined as a second line V3, it is preferable that in the region located outward in the lateral direction Y from the first line V2, V2, the area of ​​the first region A1 in front of the second line V3 is larger than the area of ​​the second region A2 behind the second line V3. In this way, leakage from the front in the longitudinal direction X of the napkin 1 is further suppressed.

[0040] To further enhance the above-mentioned effects, the ratio of the area of ​​the first region A1 to the area of ​​the second region A2 is preferably 1.5 or more, more preferably 2.0 or more, and is preferably 6.0 or less, more preferably 5.0 or less. The area of ​​the first region A1 is preferably 1000 mm 2 More preferably, 2000 mm 2 More than 5000 mm, preferably 2 Less than or equal to 4000 mm, more preferably 2 The following is the result. The area of ​​the second region A2 is preferably 300 mm 2 More preferably, 400 mm 2 More than 1000 mm, preferably 2 Less than or equal to 900mm, more preferably 2 The following is the result.

[0041] 6, the non-skin facing surface of the napkin 1 is provided with a fastening part 7 and a flap fastening part 7S for fastening the napkin 1 to the wearer's clothing. As the fastening part 7 and the flap fastening part 7S, any material that has conventionally been used as a means for fastening this type of absorbent article to clothing such as shorts can be used without any particular limitation, and for example, a pressure sensitive adhesive, a pressure sensitive adhesive, etc. can be used.

[0042] 6, the fastening parts 7 are arranged in a region overlapping with the absorbent 4 in a plan view (absorbent arrangement region) so as to extend in the horizontal direction Y and in a plurality of strips at a distance in the vertical direction X. From the viewpoint of obtaining a good wearing comfort by providing good conformability of the napkin 1 to the wearer's body, particularly the buttocks, while ensuring the fastening force of the napkin 1 to clothing such as shorts, and from the viewpoint of preventing leakage along the napkin, it is preferable that the length in the horizontal direction Y of the rear end fastening part 7r located in the absorbent tapered part 4E and closest to the rear end among the fastening parts 7 in the rear region R is shorter than the lengths of the other fastening parts 7 in the rear region R, and that the rear end fastening part 7r and the second rear recess 72 do not overlap in a plan view. From the viewpoint of wearing comfort, it is preferable that none of the fastening parts 7 extend outward from the side edges along the longitudinal direction X of the absorbent body 4 in a plan view, but some of the fastening parts 7 may extend outward from the side edges of the absorbent body 4 within a range that remains inside in the lateral direction Y of an imaginary line drawn parallel to the longitudinal direction X from the point where the width of the absorbent body 4 is at its widest. For example, in the napkin 1 shown in Fig. 6, the frontmost fastening part 7a and the frontmost fastening part 7b within the range of the tapered part 4E of the absorbent body extend outward from both side edges of the absorbent body 4, but are located inside in the lateral direction Y of the extensions L1, L1 in the longitudinal direction X of the side edges of the constant width part 4C.

[0043] As shown in Fig. 6, the rear end fastening part 7r located in the absorbent tapered region 4E and closest to the rear end does not overlap with the second rear recess 72 in a plan view, and has a shorter length (width) in the lateral direction Y than the other fastening parts 7 in the rear region R. In the figure, the reference character W3 indicates the width of the former, and the reference character W4 indicates the width of the latter. In this embodiment, the relationship of width W3 < width W4 is established, and the rear end fastening part 7r does not overlap with the second rear recess 72 in a plan view. In particular, when the wearer of the napkin 1 sits for a long time, body pressure is likely to be applied to the rear region R of the napkin 1, and unintended deformation such as twisting is likely to occur in the rear region R. However, by having the above-mentioned configuration, twisting and shifting of the rear region R during wear can be more reliably prevented.

[0044] In this embodiment, the fastening parts 7 are arranged at intervals in the vertical direction X in the rear region R, and the widths W4 of the fastening parts are the same. In the napkin 1, the rear end fastening part 7r located closest to the rear end and the fastening part 7j adjacent to the rear end fastening part 7r have the same widths W3, but even if the width of the fastening part 7j is longer than the rear end fastening part 7r, it is preferable that the width is shorter than the distance W2 between the front ends 72f, 72f of the second rear recess 72, because the deformation of the second rear recess 72 can be gradual. In the napkin 1, the fastening portion 7j is also arranged so as not to overlap with the second rear recessed portion 72 in a plan view. In addition, when the widths W4 of the fastening parts 7 in the rear region R are different from each other, the maximum value among the widths W4 is set as the width W4 of the fastening part 7 arranged in the rear region R.

[0045] The ratio of the width W3 to the width W4 of the fastening part 7, expressed as W3 / W4, is preferably 0.1 or more and 0.8 or less, and more preferably 0.3 or more and 0.6 or less. The width W3 (see FIG. 6) of the rear end fastening portion 7r located closest to the rear end is preferably 10 mm or more, more preferably 20 mm or more, and preferably 50 mm or less, more preferably 30 mm or less, provided that it is less than the width of the napkin 1 (the length in the lateral direction Y). The width W4 of the other fastening portion 7 in the rear region R (see FIG. 3) 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 of the napkin 1 (the length in the lateral direction Y).

[0046] It is preferable that the width W3 of the rear end fastening portion 7r is shorter than the distance W2 between the front ends 72f, 72f of the second rear recess 72, from the viewpoint of facilitating deformation of the second rear recess 72 along the buttocks (particularly the gluteal sulcus). Since the napkin 1 has the shape of the rear tapered portion 64, the shape of the absorbent body tapered portion 4E, and the rear end fastening portion 7r having W3, it is considered that the napkin 1 is likely to deform in a widening manner from the rear end of the napkin 1 toward the front side, and the absorbent body 4 is likely to deform along the shape of the second rear recess 72. Furthermore, it is preferable that the width W3 is longer than the distance W5 between the rear ends 72r, 72r of the second rear recess 72, from the viewpoint of easily realizing a soft fit to the buttocks. In this way, the deformation along the shape of the buttocks starting from both ends of the rear end fastening part 7r in the lateral direction Y is formed on the widthwise inner side of the rear end fastening part 7r by the second rear recess 72, so that the deformation of the second rear recess 72 is unlikely to be steep, and a gradual deformation is easily realized.

[0047] In the napkin 1, a fastening portion 7b (also called tapered portion wide fastening portion 7b) that is wider than the rear end fastening portion 7r is provided within the absorbent tapered region 4E so as to overlap the second rear recess 72 in a plan view. With this configuration, even if the first rear recess 71 and the second rear recess 72 are deformed to fit the buttocks, the napkin 1 is unlikely to peel off from the shorts. Also, in the napkin 1, the tapered portion wide fastening portion 7b extends outward beyond both side edges of the absorbent 4. This configuration is preferable because it makes it possible to prevent the side flap portions 6S, 6S located on the outer side of the absorbent tapered portion 4E in the width direction from being twisted or twisted when an unexpected external force is applied between the seat surface and the buttocks of the wearer while sitting for a long time.

[0048] In this embodiment, as shown in FIG. 1 and FIG. 2, the absorbent body 4 preferably includes a fiber agglomeration region L in the middle region M, in which the fiber agglomerations 11 containing synthetic fibers and the absorbent fibers 12 are entangled with each other or with the absorbent fibers 12. The fiber agglomeration region L is preferably disposed forward of the first rear recess 71. As shown in FIG. 2, the fiber agglomeration region L includes a fiber agglomeration layer 42 mainly made of fiber agglomerations 11 containing synthetic fibers. Here, "mainly made of fiber agglomerations 11" means that the fiber agglomerations 11 account for 90% by mass or more of all the fibers constituting the fiber agglomeration layer 42, preferably 95% by mass or more, and more preferably 100% by mass. The fiber agglomeration layer 42 is covered with the core wrap sheet 41 together with the absorbent core 40. In this embodiment, the fiber agglomeration layer 42 is disposed over the entire excretory part facing region C. Therefore, in this embodiment, the fiber agglomeration region L is the same region as the excretory part facing region C. The fiber agglomerate layer 42 extends over the entire area from one side edge to the other side edge of the excretory part-facing region C. However, it is also possible to dispose the fiber agglomerate layer 42 only in a part of the excretory part-facing region C. In this case, the fiber agglomerate-containing region L forms a part of the excretory part-facing region C.

[0049] As shown in FIG. 3, the non-arranged region of the fiber agglomerate layer 42 in the absorbent body 4 includes the absorbent core 40 but does not include the fiber agglomerate layer 42. Therefore, the arranged region of the fiber agglomerate layer 42, i.e., the excretory part facing region C, is thicker and bulkier than the non-arranged region of the fiber agglomerate layer 42. Due to the difference in thickness of the absorbent body 4 caused by the presence or absence of the fiber agglomerate layer 42, the excretory part facing region C, which is the arranged region of the fiber agglomerate layer 42, is raised on the skin facing side compared to the front region F and rear region R, which are the non-arranged regions of the fiber agglomerate layer 42, forming a so-called central high part. In other words, the thickness 4 of the absorbent body 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 C. This improves the wearing comfort of the napkin 1, and the napkin 1 easily adheres to the wearer's body, effectively preventing liquid leakage. It is not excluded that the absorbent core 40 in the non-fiber aggregate layer 42 area may contain a small amount of fiber aggregates during the manufacturing process, and may contain fiber aggregates of 5% by mass or less relative to the total mass of the absorbent core 40 in that area.

[0050] The fiber agglomerates 11 are fiber aggregates in which a plurality of non-absorbent fibers are accumulated and integrated into agglomerates, and are present in the absorbent body 4 (fiber agglomerate layer 42) while retaining their shape. The fiber agglomerates 11 mainly 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 synthetic fibers constituting the fiber agglomerates 11 are preferably fibers (hydrophobic fibers) having a lower hydrophilicity than absorbent fibers such as cellulosic fibers used as the absorbent material in the absorbent core 40, and a specific example is a synthetic fiber mainly made of a thermoplastic resin. By comprising non-absorbent fibers in the fiber agglomerates 11, the properties of the fiber agglomerates 11, such as flexibility, can be fully exhibited even when the fiber agglomerates 11 come into contact with body fluids. The shape of the fiber agglomerate 11 is not particularly limited and may be irregular, but may be a fixed shape, such as a sheet piece obtained by cutting a synthetic fiber sheet to a certain dimension. As such a fixed shape fiber agglomerate, for example, the fiber agglomerates described in JP 2019-063469 A, JP 2019-098157 A, and JP 2020-188918 A, specifically, a fiber agglomerate having two opposing basic surfaces and a skeletal surface connecting the two basic surfaces, can be suitably used.

[0051] The fiber agglomerate layer 42 is preferably a region in which the fiber agglomerates 11 are present over the entire length of the absorbent 4 in the lateral direction Y. The fiber agglomerate layer 42 may be configured to contain only the fiber agglomerates 11, but may also contain a water-absorbent material in addition to the fiber agglomerates 11. The fiber agglomerate layer 42 containing a water-absorbent material is capable of absorbing and retaining bodily fluids, and the absorption performance of the absorbent 4 can be improved. As the water-absorbent material used for the fiber agglomerate layer 42, any material that can be used for the absorbent core 40 can be used without any particular limitation.

[0052] In this embodiment, the fiber agglomeration layer 42 preferably includes fiber agglomerations 11 as shown in FIG. 2. In the fiber agglomeration layer 42, the fiber agglomerations 11 are intertwined with each other, and the fiber agglomerations 11 having the above-mentioned "two basic faces and a skeletal face" are intertwined with each other at the basic faces and skeletal faces to form a three-dimensional intertwined state. By configuring the fiber agglomeration layer 42 in this way, the shape retention of the fiber agglomeration layer 42 is improved, and the absorbent body 4 including the fiber agglomeration layer 42 can be appropriately deformed with good followability to external forces received from various directions when worn, and further has excellent flexibility, cushioning properties, and compression recovery properties. In terms of further enhancing the above-mentioned effects, it is preferable that the fiber agglomerations 11 and the water-absorbent fibers 12 are intertwined at the interface between the fiber agglomeration layer 42 and the absorbent core 40. And, the napkin 1 including such an absorbent body 4 is easily deformed and recovered from external forces, is less likely to twist, and has excellent fit to the wearer's body. The term "entanglement" as used herein includes both of the following: (i) a form in which the entangled objects (fiber clumps or fiber clumps and absorbent fibers) are not fused to each other, but the bonded state is maintained by the entanglement of the constituent fibers of the fiber clumps; and (ii) a form in which the fiber clumps or the fiber clumps and absorbent fibers are not bonded to each other in the natural state of the absorbent article (absorbent body) (a state in which no external force is applied), but the fiber clumps or the fiber clumps and absorbent fibers can be bonded to each other or to each other by the entanglement of the constituent fibers when an external force is applied to the absorbent article (absorbent body).

[0053] In this embodiment, as shown in FIG. 2, the skin-facing side of the absorbent 4 in the fiber agglomerate-containing region L comprises an absorbent core 40 mainly composed of absorbent fibers 12 and water-absorbent polymer particles 13, and does not substantially contain fiber agglomerates 11, whereas the non-skin-facing side of the absorbent 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 clumps to the total mass content of fiber clumps and absorbent fibers (hereinafter also referred to as "fiber clump content ratio") is lower on the skin-facing side than on the non-skin-facing side in fiber clump-containing region L of the absorbent 4. That is, in this embodiment, in fiber clump-containing region L, the skin-facing side of the absorbent 4 has absorbent fibers 12 distributed unevenly and the content of fiber clumps 11 can be zero, whereas the non-skin-facing side of the absorbent 4 has fiber clumps 11 distributed unevenly and the content of absorbent fibers 12 can be zero. In this way, in the fiber clump-containing regions 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 clump content ratio, and the action of the absorbent fibers 12 biased to the skin-facing side of the absorbent body 4 improves the absorbency of the absorbent body 4 by improving its ability to draw in bodily fluids (capillary force), thereby improving its liquid absorption, and the action of the fiber clumps 11 biased to the non-skin-facing side of the absorbent body 4 can improve the cushioning properties, etc. of the absorbent body 4.

[0054] The fiber agglomerate content ratio of the skin-facing side of the fiber agglomerate-containing 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 of the non-skin-facing side of the absorbent body 4, and may not contain any fiber agglomerates 11. The fiber agglomerate content ratio of the non-skin-facing side of the fiber agglomerate-containing 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 of 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 including the skin-facing side when the absorbent body 4 is divided into two equal parts in the thickness direction (the side relatively closer to the wearer's skin), and the "non-skin-facing side of the absorbent body" refers to the opposite side (the side relatively farther from the wearer's skin).

[0055] As a result of extensive research by the present inventors into factors that allow the napkin 1 to easily follow the wearer's movements, it was discovered that reducing the "torsion torque value" measured by the following method is effective. And it was found that the above-mentioned configuration of the napkin 1 of this embodiment, i.e., the front constricted portion 61 and the rear constricted portion 62, and the tapered shape of the rear region R of the napkin 1, are extremely effective in reducing the torsion torque value.

[0056] In order to further reduce the torsional torque value, it is effective that not only the rear region R of the napkin 1 but also the absorbent body 4 has a tapered end portion 4E.

[0057] <Method of measuring torsional torque value> The absorbent article to be measured is used as it is as the measurement sample. Figures 7(a)-7(c) show a measurement method when a napkin 1 is used as the measurement sample. The basic structure of the napkin 1 is the same as that of the napkin 1 described above. As shown in Figure 7(a), both ends of the vertical direction X (longitudinal direction) of the napkin 1 are clamped between the upper and lower clamps 20a, 20c of a tension control type torque tester (manufactured by Imada Co., Ltd.), and the napkin 1 is fixed between the upper and lower clamps 20a, 20c. Next, as shown in Figures 7(b) and 7(c), the upper clamp 20a is rotated back and forth by 60° in the forward and reverse directions (forward and reverse rotations) with the vertical direction X of the napkin 1 as the rotation axis, and the torsion moment value (60° torsion 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 torsion moment value in each of the forward and reverse directions are obtained. Then, the average value of the maximum values ​​of the 10 points is calculated for each of the forward and reverse directions, and the sum of the absolute values ​​of both average values ​​is defined as the torsional torque value (unit: Ncm) of the measurement object. This measurement is performed for five measurement samples, and the average of the five measurements is calculated. The measurement is performed 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 when no tension is applied. The torque tester used is in accordance with the one shown in Figure 2 of JIS K 7244-2.

[0058] From the viewpoints of preventing leakage of bodily fluids from the longitudinal X end and of providing good fit to shorts, it is preferable to set the dimensions of each portion of the napkin 1 as follows. The front constriction 61 is preferably located at a position rearward in the longitudinal direction X from the longitudinal front end 1F of the napkin 1, preferably at least 50 mm, more preferably at least 60 mm, and preferably within 100 mm, more preferably within 90 mm. The rear constricted portion 62 is preferably located at a position 80 mm or more, more preferably 90 mm or more, and preferably 140 mm or less, more preferably 130 mm or less forward in the longitudinal direction X from the longitudinal rear end 1R of the napkin 1. The intermediate maximum width portion 67 of the napkin 1 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 total length of the napkin 1 in the longitudinal direction X is preferably 140 mm or more, more preferably 200 mm or more, and preferably 450 mm or less, more preferably 350 mm or less.

[0059] Although the present invention has been described above based on the preferred embodiment, the present invention is not limited to the above embodiment and can be modified as appropriate without departing from the spirit of the present invention. For example, the first rear recess 71 and the second rear recess 72 in this embodiment are circular, but are not limited to such a shape and may be elliptical, or may be polygonal or regular polygonal such as a triangle or a rectangle, or may be linear. 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. EXAMPLES

[0060] The present invention will be described in more detail below using examples, but the scope of the present invention is not limited to these examples.

[0061] Example 1 A sanitary napkin was produced having a similar basic structure to the napkin 1 shown in Figure 1. Details of the main components of the sanitary napkin of Example 1 are as follows. Surface sheet: Air-through nonwoven fabric (grammage 28g / m 2 ) was used. Back sheet: Polyethylene resin film (grammage 37g / m 2 ) was used. Side sheet: Spunbond nonwoven fabric (grammage 20g / m 2) was used. Absorbent core: Water-absorbent fiber (softwood bleached kraft pulp, basis weight of excretory area C: 240 g / m 2 , the basis weight of the front area F and the rear area R is 160 g / m 2 ) was applied to a fiber assembly made of water-absorbent polymer particles (50 g / m 2 A stacked fiber type carrying the cellulose acylate was used. Core wrap sheet: Absorbent paper (grammage 16g / m 2 ) was used. Fiber clump layer: Fiber clump 180g / m 2 The fiber mass used was produced by the following method.

[0062] (Method of manufacturing fiber mass) The fiber agglomerates were produced according to the method described in JP 2019-063469 A. Specifically, the raw fiber sheet was cut into a dice shape to produce rectangular parallelepiped fiber agglomerates (fiber agglomerates having two opposing basic faces and a skeletal face connecting the two basic faces). The raw fiber sheet was a 25 g / m2 fiber sheet with hydrophobic thermoplastic fibers (non-absorbent fibers, fiber diameter 18 μm) made of polyethylene resin and polyethylene terephthalate resin as constituent fibers. 2 The air-through nonwoven fabric (a fiber sheet having heat-sealed portions between constituent fibers) was used. The fiber mass had a short side of the basic surface of 3.9 mm, a long side of 5 mm, and a thickness of 0.6 mm.

[0063] Comparative Example 1 A nighttime sanitary napkin (total length 37 cm) as shown in FIG. 1 of JP 2017-328 A was produced. The sanitary napkin of this comparative example has a pair of groove-shaped recesses in the rear region, the distance between which increases from the front side to the rear side. In addition, there is no groove-shaped recess corresponding to the second recess of the present invention. The sanitary napkin of this comparative example was produced in the same manner as in Example 1, except that the absorbent body does not contain fiber agglomerates.

[0064] Comparative Example 2 A nighttime sanitary napkin (total length 36 cm) was produced in the shape shown in FIG. 1 of JP 2018-283 A. The sanitary napkin of this comparative example has a pair of front groove-shaped recesses arranged on the front side of the rear region, the distance between which narrows from the front side to the rear side, and a continuous groove-shaped recess having a substantially U shape arranged on the rear side of the front groove-shaped recesses. The sanitary napkin of this comparative example was produced in the same manner as in Example 1, except that the absorbent body did not contain fiber agglomerates.

[0065] For the sanitary napkins of each Example and Comparative Example, the wearing pressure amplitude, dynamic twist rate, DAC, forward shift DAC, and rear shift DAC were measured by the following method. The twist torque value was also measured by the above method. The results are shown in Table 1 below.

[0066] <Method for measuring the amplitude of wearing pressure> The napkin to be measured was fixed to sanitary shorts and attached to the dynamic model of the human body used in the above [Maximum Dynamic Absorption]. At this time, a small three-axis force sensor (manufactured by Tech Gihan Co., Ltd., model number USL06-H5) was placed between the excretory part of the dynamic model and the napkin to measure the wearing pressure during walking. The wearing pressure fluctuates periodically as the dynamic model walks, so a periodic waveform graph synchronized with the walking motion is obtained. In this measurement, the wearing pressure was continuously measured from the start of the walking motion until one minute had elapsed. The walking speed of the dynamic model was measured at 50 steps / min. Then, based on the obtained waveform graph of the wearing pressure, the average variation difference of the wearing pressure due to the walking motion (also called the amplitude of the wearing pressure) was calculated from the variation difference obtained from the maximum wearing pressure and the minimum wearing pressure for each cycle. The smaller the amplitude of the wearing pressure, the better the fit of the napkin to the body and the higher the evaluation.

[0067] <Method of measuring dynamic twist rate> Measurements are carried out using a driven lower body human model for women. First, measure the central width of the sanitary napkin to be measured, more specifically, the horizontal length at the vertical center of the napkin (hereinafter also referred to as the "central width before walking"). After that, wear the napkin on the panties according to the conventional method, and then wear the panties on the human model according to the conventional method. Next, let the human model walk at a speed of 100 steps per minute for 30 minutes. During the walking of the human model, the operation of injecting 1.5 g of defibrinated horse blood into the worn napkin in 15 seconds is repeated 6 times after 3 minutes of walking, and a total of 9 g of defibrinated horse blood is injected into the napkin. Then, remove the napkin from the panties and measure its central width (hereinafter also referred to as the "central width after walking"). From the "central width before walking" and the "central width after walking", calculate the dynamic sway rate (%) by the following formula. Dynamic sway rate (%) = [{(Central width before walking) - (Central width after walking)} / (Central width before walking)] × 100 The smaller the numerical value of the dynamic sway rate, the less likely the napkin to be measured is to sway, and it will receive a high evaluation. The defibrinated horse blood injected into the object to be measured is defibrinated horse blood manufactured by Nippon Bio-Test Laboratories and adjusted to a viscosity of 8 cp at a liquid temperature of 25°C. Such viscosity is the viscosity measured with a TVB-10M viscometer manufactured by Toki Sangyo Co., Ltd. using a rotor with the rotor name L / AdP (rotor code 19) at a rotational speed of 30 rpm.

[0068] <Measurement method of DAC> ​Measurements are performed using a powered female lower body human model. Specifically, the sanitary napkin is attached to the shorts of the human model. The human model is made to walk at a speed of 100 steps / min. While the model is walking, 3g of defibrinated horse blood is injected in 23 seconds after 1 minute of walking, and then 2g is injected at 15g after 3 minutes of walking. After that, the operation of injecting 2g at 15g after 3 minutes of walking is repeated until the sanitary napkin leaks, and the weight of the sanitary napkin after walking is measured by subtracting the weight of the sanitary napkin before walking from the weight of the sanitary napkin after walking. The defibrinated horse blood injected into the measurement subject is defiberized horse blood manufactured by Japan Bio Test Laboratory and adjusted to a viscosity of 8 CPS at a liquid temperature of 25°C. The viscosity is measured using a TVB-10M viscometer manufactured by Toki Sangyo Co., Ltd. with a coater with a rotor name L-AdP (rotor code 19) at a rotation speed of 30 rpm.

[0069] <Measurement method for front-shift DAC and rear-shift DAC> Measurements are performed using a powered female lower-body human model. The walking conditions, injection conditions, and target liquid are the same as those for DAC measurements. Specifically, measurements are performed by shifting the excretion position when the napkin is fitted to the shorts of the human model. The reference position for a normal napkin is the center of the napkin's wings, which is the central position of the excretion point, and the normal reference is 0 mm (excretion part set 125 mm from the front of the product). The absorption amount is measured at an excretion position shifted 40 mm forward from the reference 0 mm, and at an excretion position shifted 40 mm backward from the reference 0 mm.

[0070] [Table 1]

[0071] As shown in Table 1, the sanitary napkins of the Examples had smaller torsional torque values, wearing pressure amplitudes, and dynamic twist rates than the sanitary napkins of the Comparative Examples. This shows that the sanitary napkins of the Examples have excellent adhesion to the wearer's body and can follow the wearer's movements. [Explanation of symbols]

[0072] 1. Sanitary napkins (absorbent articles) 2 Surface sheet 3 Back sheet 4. Absorber 5 Side seat 6 Flap section 6E End flap section 6S Side flap section 7 Fastening part 10 Absorbent body 40 Absorbent Core 57 Front widest part 58 Front width expansion section 59 Front width reduction part 60 Bulge 61 Front constriction 62 Rear constriction 63 Rear width expansion section 64 Rear tapered section 66 Front minimum width part 67 Middle maximum width 68 Rear maximum width part 69 Posterior width reduction part 70 Front width reduction part 71 1st rear recess 72 Second rear recess CL center line F Anterior area M middle area R Rear area X vertical direction Y Horizontal

Claims

1. An absorbent article having a longitudinal direction corresponding to the wearer's front-to-back direction and a transverse direction perpendicular to the longitudinal direction, and including an excretion-facing region that is positioned opposite the wearer's excretion-facing region when worn, a forward region positioned in front of the intermediate region in the longitudinal direction, and a rear region positioned behind the intermediate region in the longitudinal direction, It comprises an absorbent body capable of absorbing and retaining bodily fluids, and has a flap portion that extends outward from the outer edge of the absorbent body and forms the outline of the absorbent article. On each of the vertical sides of the intermediate region, there is a bulging portion in which the flap portion protrudes convexly outward in the horizontal direction, and the portion where the tip of the bulging portion is located in the vertical direction is the intermediate maximum width portion, which is the length of the intermediate region in the horizontal direction. Rearward from the aforementioned intermediate maximum width portion, there is a rear constriction portion whose lateral length is shorter than the portions located front to back, and the minimum width portion in the rear constriction portion, where the lateral length is the minimum, forms the boundary between the intermediate region and the rear region. The rear region has a rear width expanding portion in which the length in the lateral direction gradually increases toward the rear end in the longitudinal direction, and a rear tapering portion located further rear in the longitudinal direction than the rear width expanding portion in which the length in the lateral direction gradually decreases toward the rear end in the longitudinal direction. The absorbent material has a recessed portion that is concave from the skin-facing surface toward the non-skin-facing surface, and the recessed portion includes a first rear recessed portion located in the rear width-enlarged portion and a second rear recessed portion located behind the first rear recessed portion, and the first rear recessed portion and the second rear recessed portion each exist in pairs on both sides of the longitudinal center line of the absorbent article that extends in the longitudinal direction. An absorbent article in which the lateral distance between a pair of first rear recesses and the lateral distance between a pair of second rear recesses gradually decreases from the front end to the rear end in the longitudinal direction.

2. The absorbent article has a rear wide portion at the boundary between the rear wide portion and the rear tapering portion, where the rear wide portion has the maximum lateral length in the rear region. The absorbent article according to claim 1, wherein the second rear recess is located rearward in the longitudinal direction than the maximum rear width portion.

3. The absorbent article according to claim 1 or 2, wherein the lateral distance between the rear ends of a pair of first rear recesses is shorter than the lateral distance between the front ends of a pair of second rear recesses.

4. The absorbent body has a tapered portion in its rear region, where the overall width of the absorbent body gradually decreases toward the longitudinal rear end of the absorbent body. The absorbent article according to claim 1 or 2, wherein when θ1 is the angle between two imaginary straight lines connecting the longitudinal rear end of the absorbent and the longitudinal front ends of each of the pair of contour lines of the tapered portion of the absorbent that extend outward in both directions from the longitudinal rear end of the absorbent, and θ2 is the angle between the pair of second rear recesses, the difference between angle θ1 and angle θ2 is 60° or less.

5. In the region of the non-skin-facing surface of the absorbent article that overlaps with the absorbent material in a plan view, a fastening portion is provided for fastening the absorbent article to the wearer's clothing. The fastening portions are arranged in multiple strips that extend in the lateral direction and are spaced apart in the vertical direction. The absorbent body has a tapered portion in its rear region, where the overall width of the absorbent body gradually decreases toward the longitudinal rear end of the absorbent body. The lateral length of the rear end fastening portion located near the rear end of the tapered portion of the absorbent body is shorter than the length of the other fastening portions located forward of the tapered portion of the absorbent body. The absorbent article according to claim 1 or 2, wherein the rear end fastening portion does not overlap with the second rear recess in a plan view.

6. Ahead of the aforementioned intermediate maximum width portion, there is a front constriction whose lateral length is shorter than the portion located front to back, and the front minimum width portion, where the lateral length is the minimum in the front constriction portion, forms the boundary between the intermediate region and the front region. The aforementioned front region has a front width expansion section in which the length in the lateral direction gradually increases toward the front end in the longitudinal direction, and a front width reduction section located longitudinally forward of the front width expansion section in which the length in the lateral direction gradually decreases toward the front end in the longitudinal direction, and at the boundary between the front width expansion section and the front width reduction section, there is a front maximum width section in which the length in the lateral direction is the maximum in the front region. The absorbent article according to claim 1 or 2, wherein when each of the imaginary lines connecting the lateral ends of the front minimum width portion to the longitudinal front end is defined as the first line, and the imaginary line connecting the lateral ends of the front maximum width portion is defined as the second line, the area of ​​the region located laterally outward from the first line is such that the area of ​​the region in front of the second line is greater than the area of ​​the region behind the second line.

7. The absorbent body includes, in the intermediate region, fiber masses containing synthetic fibers and water-absorbing fibers, and comprises fiber mass-containing regions in which a plurality of such fiber masses or the fiber masses and the water-absorbing fibers are intertwined. The absorbent article according to claim 1 or 2, wherein the fiber mass-containing region is located forward of the first rear recess.

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