Disposable diaper

Abstract

To provide a disposable diaper in which a mark of a leg gather part is hardly left on a groin part, which is not affected by the movement of a wearer, and which can cover the hip with a hip cover part.SOLUTION: A disposable diaper 1 includes an abdominal side part 3 and a back side part 2 in which both side edges in a width direction W are joined by a pair of side joining parts SC, and an absorbent body 4 having a leg gather part 5. The back side part 2 includes a back side body part 21 located on the outer side in the longitudinal direction L and a back side extension part 20 located on the inner side. The back side extension part 20 includes an extension central part 31 and a pair of hip cover parts 30 located on both sides in the width direction W of the extension central part 31. The hip cover part 30 has a hip elastic member 40 whose effective part is within a range of the hip cover part 30. When 15% from the inner end edge in the longitudinal direction L of a side joining part SC is defined as a lower range S4, the tensile stress in the width direction W is larger in the abdominal side lower region BA4 between a back side lower region AA4 and the abdominal side lower region BA4 corresponding to the lower range S4 in the back side part 2 and the abdominal side part 3.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a disposable diaper, and more particularly to a disposable diaper having a buttocks cover portion. [Background technology]

[0002] Disposable diapers having buttocks covering portions for covering the buttocks are known. For example, Patent Document 1 discloses a wearable article (such as a diaper). The wearable article includes a front belt, a rear belt, and a main body having both longitudinal ends connected to the centers of the front and rear belts, and is formed by joining the lateral edges of the front and rear belts together with seams. The front and rear belts are formed by a plurality of elastic members extending laterally and sandwiched between an inner sheet and an outer sheet.

[0003] In Patent Document 1, the entire side edge of the front belt and a certain portion of the side edge of the rear belt are joined together to define a seam length LS. In this case, the portion of the rear belt that is not joined to the front belt forms a buttocks cover. The joined portions of the front and rear belts are then divided into four zones extending laterally. The four zones are defined by the position from the distal edge to the proximal edge as a percentage of the seam length LS. That is, 0 to 25% of the seam length LS is the waist zone, 25 to 50% is the distal abdominal zone, 50 to 85% is the proximal abdominal zone, and 85 to 100% is the leg zone. The tensile stress of the front leg zone is 50% or less of the tensile stress of the front proximal abdominal zone. The tensile stress of the rear leg zone is 100% or less of the tensile stress of the rear proximal abdominal zone. The tensile stress in the anterior proximal abdominal zone is greater than the tensile stress in any other zone, and the tensile stress in the anterior distal abdominal zone is less than the tensile stress in the posterior distal abdominal zone.

[0004] Furthermore, for example, Patent Document 2 discloses a pants-type absorbent wearing article (such as a diaper). The wearing article has a front panel, a back panel, and a crotch panel whose front and rear ends are connected to the centers of the front and back panels, respectively. The back panel is formed with a rear waist-covering portion and a buttocks-covering portion connected to the lower part of the rear waist-covering portion. The crotch panel has an absorbent portion and gasket cuffs on both lateral sides of the absorbent portion, each having gasket elastics extending in the front-to-rear direction. The buttocks-covering portion has buttocks-covering elastics extending in the lateral direction. The buttocks-covering portion and the crotch panel are joined in the lateral direction between the gasket cuffs on both sides of the absorbent portion, but are not joined at the gasket cuffs. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2017-525485 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-11056 Summary of the Invention [Problem to be solved by the invention]

[0006] In the wearable article of Patent Document 1, the buttocks cover is a portion of the rear belt that is not joined to the front belt and extends longitudinally forward from the longitudinal front edge of the rear leg zone. Therefore, the buttocks cover is affected by and deforms in response to deformation of the rear leg zone. The arrangement of multiple elastic members in the front and rear belts creates an S-shaped side seam when viewed from the side while the article is being worn by a wearer. Therefore, the seam in the leg zone is inclined from the front to the rear. Therefore, the tensile stress in the rear leg zone is stronger than the tensile stress in the front leg zone. In this case, the rear leg zone is more likely to contract laterally, which could lead to a corresponding contraction of the buttocks. This could result in the buttocks cover becoming smaller, making it difficult to cover the buttocks. Furthermore, because the tensile stress in the rear leg zone is stronger than that in the front leg zone, the front leg zone is pulled backward (backward) by the rear leg zone, which may also pull the elastic in the leg gathers near the groin, causing the elastic in the leg gathers to dig into the wearer's groin and leaving marks.

[0007] In Patent Document 2, the buttocks-covering portion and the crotch panel are joined in the horizontal direction of the buttocks-covering portion between the gasket cuffs (leg gathers) on both sides of the absorbent portion (absorbent body), but are not joined at the gasket cuffs. In this case, when the absorbent portion deforms laterally inward (away from the buttocks) due to the wearer's leg-closing action, the elastic body of the buttocks-covering portion may be pulled by the absorbent portion, causing the buttocks cover to shrink laterally. This may result in the buttocks cover becoming smaller, making it difficult to cover the buttocks.

[0008] Therefore, the object of the present invention is to provide a disposable diaper that is capable of covering and hiding the buttocks with a buttocks cover part while suppressing the influence of the wearer's movements and making it difficult for the leg gather part to leave a mark on the wearer's groin. [Means for solving the problem]

[0009] The disposable diaper of the present invention has, in an unfolded state, longitudinal, width and thickness directions which are orthogonal to one another, and comprises an abdominal section which covers the abdominal side of a wearer, a back section which covers the back side, and an absorbent main body which covers the crotch of the wearer and includes an absorbent body, wherein the absorbent main body has front and rear ends in the longitudinal direction connected to central portions in the width direction of the abdominal section and the back section, respectively, and is formed by joining both side edges in the width direction of the abdominal section and both side edges in the width direction of the back section at a pair of side joining sections, wherein the absorbent main body includes a main body central section which is located at the central portion in the width direction and which includes an absorbent body, and a pair of leg gather sections which are located at both end portions in the width direction and which have a plurality of leg elastic members extending along the longitudinal direction, and the back section has a back main body section which occupies substantially the same area in the longitudinal direction as each of the pair of side joining sections. and a back-side extending portion extending forward from the front longitudinal edge of the back-side main body portion, the back-side extending portion including an extending central portion overlapping the main body central portion in the thickness direction, and a pair of buttocks-covering portions extending outward from both widthwise edges of the extending central portion, each of the pair of buttocks-covering portions having a buttocks elastic member extending along the width direction, the effective portion of the buttocks elastic member as an elastic member being within the range of each of the pair of buttocks-covering portions, and in each of the pair of side joints, when the longitudinal length is 100% and a length range of 15% from the inner longitudinal edge is defined as a lower range, in the back-side lower region and the ventral-side lower region, which are regions located between the lower ranges of the pair of side joints in each of the back-side portion and the ventral-side region, the tensile stress in the width direction is greater in the ventral-side lower region than in the back-side lower region. [Effects of the Invention]

[0010] According to the present invention, a disposable diaper can be provided that is capable of covering and concealing the buttocks with a buttocks cover portion while making it difficult for the leg gather portion to leave marks on the wearer's groin and suppressing the effects of the wearer's movements. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view illustrating an example of the configuration of a disposable diaper according to an embodiment. [Figure 2] 1 is a plan view of a configuration example of a disposable diaper according to an embodiment in an unfolded state. [Figure 3] FIG. 3 is a cross-sectional view taken along a longitudinal center line CL in FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view taken along the widthwise center line CW in FIG. 2. [Figure 5] 1 is a partial plan view of an example of a configuration of a disposable diaper according to an embodiment in an unfolded state. [Figure 6] 1 is a plan view of a configuration example of a disposable diaper according to an embodiment in an unfolded state. [Figure 7] 1 is a partial side view of a configuration example of a disposable diaper according to an embodiment. [Figure 8] 1 is a partial plan view of an example of a configuration of a disposable diaper according to an embodiment in an unfolded state. [Figure 9] 1 is a perspective view showing a state in which a disposable diaper according to an embodiment is worn. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present embodiment relates to the following aspects.

[0013] [Aspect 1] a disposable diaper having, in an unfolded state, longitudinal, width, and thickness directions which are orthogonal to one another, a abdominal portion which covers the abdominal side of a wearer, a back portion which covers the back side, and an absorbent main body which covers the crotch of the wearer and includes an absorbent body, wherein the absorbent main body has front and rear ends in the longitudinal direction connected to central portions in the width direction of the abdominal portion and the back portion, respectively, and is formed by joining both side edges in the width direction of the abdominal portion and both side edges in the width direction of the back portion at a pair of side joining portions, wherein the absorbent main body includes a main body central portion which is located at the central portion in the width direction and which includes an absorbent body, and a pair of leg gather portions which are located at both ends in the width direction and which have a plurality of leg elastic members extending along the longitudinal direction, and the back portion has a back main body portion which occupies substantially the same area in the longitudinal direction as each of the pair of side joining portions, and a back-side extending portion extending forward from the front longitudinal edge of the main body portion, the back-side extending portion including an extending central portion overlapping the main body central portion in the thickness direction, and a pair of buttocks-covering portions extending outward from both widthwise edges of the extending central portion, each of the pair of buttocks-covering portions having a buttocks elastic member extending along the width direction, the effective portion of the buttocks elastic member as an elastic member being within the range of each of the pair of buttocks-covering portions, and in each of the pair of side joints, when the longitudinal length is defined as 100% and a length range of 15% from the inner longitudinal edge is defined as a lower range, in the back-side lower region and the ventral-side lower region, which are regions located between the lower ranges of the pair of side joints in each of the back-side and ventral-side portions, the tensile stress in the width direction is greater in the ventral-side lower region than in the back-side lower region.

[0014] In this disposable diaper, the tensile stress in the width direction is greater in the back lower region located between the lower regions of a pair of side joints in the back portion and in the abdominal lower region located between the lower regions of a pair of side joints in the abdominal portion than in the back lower region. Therefore, the abdominal lower region can be contracted in the width direction and pulled toward the abdominal portion in the width direction. Here, the back lower region is a portion of the back main body portion adjacent to the buttocks-covering portion (back extension portion). Therefore, by pulling the back lower region toward the abdominal portion in the width direction, the buttocks-covering portion can be pulled toward the abdominal portion in the width direction. This allows the buttocks-covering portion to be used more widely in the width direction, and allows the buttocks-covering portion to adequately cover and conceal the buttocks. Furthermore, in this disposable diaper, the abdominal lower region is not pulled toward the abdominal region in the width direction by the abdominal lower region, which prevents the leg elastic members in the leg gathers near the groin from being pulled toward the abdominal region. This prevents the leg gathers from leaving marks on the wearer's groin. Furthermore, in this disposable diaper, the effective elastic portions of the buttocks elastic members (portions that function as elastic members) in the buttocks cover portion are within the buttocks cover portion. Therefore, even if the absorber deforms inward in the width direction (away from the buttocks) due to the wearer's leg squeezing, the buttocks elastic members are prevented from being pulled by the deformation of the absorber. This prevents the buttocks cover portion from shrinking in the width direction, which, combined with the effect of pulling the buttocks cover portion toward the abdominal region in the width direction, prevents the buttocks cover portion from becoming smaller, allowing the buttocks to be properly covered. (The buttocks covers in Patent Documents 1 and 2 correspond to the back extension portion of this disposable diaper.) In this way, this disposable diaper is able to adequately cover and conceal the buttocks while preventing the leg gathers from leaving marks on the wearer's groin and suppressing the effects of the wearer's movements.

[0015] [Aspect 2] A disposable diaper as described in aspect 1, wherein the back portion includes a plurality of back portion elastic members extending along the width direction, the ventral portion includes a plurality of ventral portion elastic members extending along the width direction, and the number of ventral portion elastic members included in the ventral lower region is greater than the number of back portion elastic members included in the back lower region.

[0016] In this disposable diaper, the number of abdominal-side elastic members in the abdominal lower region is greater than the number of back-side elastic members in the back lower region. This more reliably contracts the abdominal lower region in the width direction and pulls the back lower region toward the abdominal side in the width direction. Pulling the back lower region toward the abdominal side in the width direction with the multiple abdominal-side elastic members more reliably pulls the buttocks-covering portion toward the abdominal side in the width direction. This more reliably allows the buttocks-covering portion to be used more widely in the width direction and properly cover the buttocks. This also more reliably prevents the leg elastic members near the wearer's groin from digging into and leaving marks.

[0017] [Aspect 3] A disposable diaper according to aspect 1 or 2, wherein the buttocks cover portion has an inner region joined to the leg gather portion in the width direction, and the buttocks elastic member does not overlap in the thickness direction with the innermost leg elastic member that is located furthest in the width direction among the plurality of leg elastic members.

[0018] In this disposable diaper, the buttocks elastic members do not overlap with the innermost leg elastic members in the thickness direction. Therefore, even if the absorber deforms inward in the width direction as the wearer closes their legs, pulling the leg gathers inward in the width direction, the buttocks elastic members are less likely to be pulled inward in the width direction. This more reliably pulls the buttocks-covering portion toward the abdominal side in the width direction, allowing the buttocks-covering portion to properly cover the buttocks while suppressing the effects of the wearer's movements.

[0019] [Aspect 4] A disposable diaper as described in any one of aspects 1 to 3, wherein the inner region of the buttocks cover portion in the width direction is joined to the leg gather portion, and the buttocks elastic member overlaps in the thickness direction with the outermost leg elastic member that is located furthest outward in the width direction among the plurality of leg elastic members.

[0020] In this disposable diaper, the outermost leg elastic members of the multiple leg elastic members overlap the buttocks elastic members in the thickness direction. As a result, the buttocks elastic members pull the outermost leg elastic members outward in the width direction, and only the outer widthwise portions of the leg gathers near the buttocks-covering portions are pulled outward appropriately, allowing them to conform to the surfaces of the legs near the buttocks. This allows the buttocks to be appropriately covered by the buttocks-covering portions, while the leg gathers can be appropriately brought into surface contact with the legs near the buttocks, allowing them to properly perform their functions.

[0021] [Aspect 5] A disposable diaper according to any one of aspects 1 to 4, wherein the outermost leg elastic member located furthest outward in the width direction among the plurality of leg elastic members has the weakest elastic force among the plurality of leg elastic members.

[0022] In this disposable diaper, the outermost leg elastic members among the multiple leg elastic members have the weakest elastic stress. Therefore, even if the absorber deforms inward in the width direction as the wearer's legs close in, pulling the leg gathers inward in the width direction, the outer portions of the leg gathers are less likely to be pulled inward in the width direction. This makes it less likely that the buttocks-covering portions adjacent to the leg gathers are pulled inward in the width direction (and outward in the longitudinal direction). This more reliably pulls the buttocks-covering portions toward the abdominal portion in the width direction, allowing the buttocks-covering portions to properly cover and conceal the buttocks while suppressing the effects of the wearer's movements.

[0023] [Aspect 6] A disposable diaper according to any one of aspects 1 to 5, wherein when a first distance is defined as a distance between an outermost leg elastic member among the plurality of leg elastic members that is located furthest outward in the width direction and a second leg elastic member adjacent to the outermost leg elastic member on the inside in the width direction, and a second distance is defined as a distance between the second leg elastic member and a third leg elastic member adjacent to the second leg elastic member on the inside in the width direction, the second distance is shorter than the first distance.

[0024] In this disposable diaper, the second distance between the second leg elastic member and the third leg elastic member in the leg gathers is shorter than the first distance between the outermost leg elastic member and the second leg elastic member. Thus, in the leg gathers, the pitch between the leg elastic members in the inner portion closer to the absorbent core is narrower than the pitch between the leg elastic members in the outer portion farther from the absorbent core. Therefore, the longitudinal tensile stress in the inner portion closer to the absorbent core is higher than the longitudinal tensile stress in the outer portion farther from the absorbent core. This allows the leg gathers to firmly lift the absorbent core and fit the wearer's body. Furthermore, the leg elastic members tend to move inward in the width direction of the leg gathers due to the wearer's movements. Therefore, in this disposable diaper, the pitch between the leg elastic members in the inner portion closer to the absorbent core is narrowed. This tightening force makes it difficult for the leg elastic members to move inward in the width direction, preventing the inner part of the leg gathered portion from rolling up due to the movement of the leg elastic members. This makes it difficult for the buttocks-covering portion adjacent to the leg gathered portion to be pulled inward in the width direction. This makes it possible to more reliably pull the buttocks-covering portion toward the abdominal side in the width direction, thereby enabling the buttocks-covering portion to properly cover and conceal the buttocks while suppressing the effects of the wearer's movements.

[0025] [Aspect 7] A disposable diaper according to any one of aspects 1 to 6, wherein, among the plurality of leg elastic members, an outermost leg elastic member located at the outermost side in the width direction is spaced inward from the outermost edge in the width direction of each of the pair of leg gather portions.

[0026] In this disposable diaper, the outermost leg elastic members are spaced inward from the outermost widthwise edge of the leg gathers. That is, no leg elastic members are located at the outermost widthwise edge of the leg gathers. Therefore, even if the absorber deforms inward in the widthwise direction as the wearer clenches their legs, pulling the leg gathers inward in the widthwise direction, the outer portions of the leg gathers are less likely to be pulled inward in the widthwise direction. This makes it less likely that the buttocks-covering portion adjacent to the leg gathers will be pulled inward in the widthwise direction. This more reliably pulls the buttocks-covering portion toward the abdominal side in the widthwise direction, allowing the buttocks-covering portion to adequately cover and conceal the buttocks while suppressing the effects of the wearer's movements.

[0027] [Aspect 8] A disposable diaper as described in any one of aspects 1 to 7, wherein the buttocks-covering portion has an inner widthwise region joined to the leg gathered portion, the leg gathered portion includes an elasticated region in which the plurality of leg elastic members are arranged, and the buttocks-covering portion includes, in the inner widthwise region, an overlapping region located on the front side in the longitudinal direction and overlapping in the thickness direction with the rear end region in the longitudinal direction of the elasticated region.

[0028] In this disposable diaper, the longitudinal rear (back) end region of the stretchable region of the leg gathers and the longitudinal front (ventral) region of the widthwise inner region of the buttocks-covering portion overlap in the thickness direction. This allows the longitudinal front (ventral) overlap region of the buttocks-covering portion to be pulled toward the longitudinal front (ventral) side by the leg elastic members. This prevents the buttocks-covering portion from contracting excessively in the longitudinal direction. This allows the buttocks-covering portion to adequately cover and conceal the buttocks. Furthermore, by adequately covering and concealing the buttocks, the wearer feels more secure in preventing bodily excrement leakage.

[0029] [Aspect 9] Aspect 9. The disposable diaper according to aspect 8, wherein the overlap region occupies less than 50% of the length of the buttocks-covering portion in the longitudinal direction.

[0030] In this disposable diaper, the overlapping region, i.e., the region where the longitudinal front portion of the widthwise inner region of the buttocks-covering portion overlaps the elastic region of the leg gathers in the thickness direction, is an area less than 50% of the length of the buttocks-covering portion in the longitudinal direction. By limiting the overlapping range between the buttocks-covering portion and the leg gathers, the buttocks-covering portion is less likely to be pulled inward in the width direction even when the leg gathers are pulled inward in the width direction by the wearer's leg-closing movement. This more reliably pulls the buttocks-covering portion toward the abdominal region in the width direction, enabling the buttocks-covering portion to adequately cover and conceal the buttocks while suppressing the effects of the wearer's movements.

[0031] [Aspect 10] Aspect 10. The disposable diaper of any one of aspects 1 to 9, wherein the absorbent body includes pulp fibers.

[0032] In this disposable diaper, the absorbent body contains pulp fibers. Therefore, the rigidity of the absorbent body can be increased compared to when the absorbent body is formed solely from a superabsorbent polymer. The relatively high rigidity of the absorbent body makes it difficult for the absorbent main body to shrink in the longitudinal and width directions due to elastic members in the leg gathers, ventral side portion, and back side portion. Since the absorbent main body is less likely to shrink in the longitudinal and width directions, the buttocks cover portion in the back side portion is less likely to shrink in the longitudinal and width directions. This allows the buttocks to be more reliably and appropriately covered by the buttocks cover portion.

[0033] [Aspect 11] The disposable diaper according to any one of aspects 1 to 10, wherein the absorber has an hourglass shape, and the widest part of the hourglass shape is located on an extension line of the buttocks elastic member in the width direction.

[0034] In this disposable diaper, the widest part of the hourglass-shaped absorbent body in the width direction is located on the extension of the buttocks elastic members in the width direction. Therefore, the buttocks-covering portion is located in a high-rigidity portion of the absorbent body in the longitudinal direction. By positioning the buttocks-covering portion in this high-rigidity portion of the absorbent body, the buttocks-covering portion is less likely to contract in the longitudinal direction. This ensures that the buttocks-covering portion properly covers the buttocks.

[0035] [Aspect 12] The disposable diaper according to any one of aspects 1 to 11, wherein the absorber has an hourglass shape, and when the disposable paper diaper is folded in half so that the front edge of the longitudinal direction of the ventral portion and the rear edge of the longitudinal direction L of the dorsal portion 2 are aligned, the starting position of the constriction in the hourglass shape is located at least 10 mm from the fold line of the fold.

[0036] In this disposable diaper, the start of the constriction in the hourglass-shaped absorbent body is located at least 10 mm from the fold line of the disposable diaper when folded in half, toward the edges of the ventral and dorsal sections. In other words, the crotch portion of the absorbent body, which is susceptible to the wearer's leg-closing action, is narrowed. This prevents the absorbent body from deforming inward in the width direction (and away from the buttocks) due to the wearer's leg-closing action. This prevents the absorbent body from deforming inward in the width direction, pulling the buttocks-covering portion toward the absorbent body and, as a result, pulling the lower ventral region toward the dorsal section. This prevents the leg gathers from leaving marks on the wearer's groin. Furthermore, because the absorbent body is prevented from deforming inward in the width direction (and away from the buttocks), it also prevents the leg gathers from being pulled inward in the width direction due to the deformation of the absorbent body. This prevents the buttocks-covering portion from being pulled inward in the width direction and being pulled up, allowing the buttocks-covering portion to properly cover and conceal the buttocks. In this way, the disposable diaper can properly cover and conceal the buttocks while preventing the leg gathers from leaving marks on the wearer's groin and reducing the effects of the wearer's movements.

[0037] Hereinafter, a disposable diaper according to an embodiment of the present invention will be described using a so-called three-piece type disposable diaper as an example. However, the present invention is not limited to this embodiment and example, and can be applied to various disposable diapers for children and adults without departing from the subject matter of the present invention, including, for example, so-called two-piece type disposable diapers.

[0038] 1 to 4 are views showing a disposable diaper 1 according to this embodiment. FIG. 1 is a perspective view showing an example of the configuration of the disposable diaper 1. FIG. 2 is a plan view showing the example of the configuration of the disposable diaper 1 in an unfolded state, and therefore shows the state in which the elastic members and stretchable members are stretched. FIG. 3 is a cross-sectional view taken along the longitudinal center line CL in FIG. 2. FIG. 4 is a cross-sectional view taken along the widthwise center line CW in FIG. 2.

[0039] In the unfolded state shown in Figures 2 to 4, the disposable diaper 1 has a longitudinal direction L, a width direction W, and a thickness direction T that are perpendicular to each other. The disposable diaper 1 has a longitudinal centerline CL that passes through the center of the width direction W and extends along the longitudinal direction L, and a widthwise centerline CW that passes through the center of the longitudinal direction L and extends along the width direction W. Here, the directions and sides approaching the longitudinal centerline CL are referred to as the inward and inner sides of the width direction W, respectively, and the directions and sides moving away from the longitudinal centerline CL are referred to as the outward and outer sides of the width direction W, respectively. Meanwhile, the directions and sides approaching the widthwise centerline CW are referred to as the inward and inner sides of the longitudinal direction L, respectively, and the directions and sides moving away from the widthwise centerline CW are referred to as the outward and outer sides of the longitudinal direction L, respectively. In addition, the term "planar view" refers to the state in which the disposable diaper 1 is placed on a plane and viewed in the thickness direction T from a position perpendicular to the plane above the plane, and the shape as seen in the planar view is referred to as the "planar shape," and any direction within a plane including the longitudinal direction L and the width direction W is referred to as the "planar direction." The terms "skin side" and "non-skin side" refer to the side relatively closer to and farther from the wearer's skin surface in the thickness direction T of the disposable diaper 1 when the disposable diaper 1 is worn. In the longitudinal direction L, the side relatively closer to the ventral portion (described below) or the side relatively farther from the dorsal portion (described below) is also referred to as the ventral side or front side, and the side relatively closer to the dorsal portion or the side relatively farther from the ventral portion is also referred to as the dorsal side or rear side. The above definitions are also used for each material of the disposable diaper 1 and for the disposable diaper 1 in the state shown in Figure 1.

[0040] Note that a component, structure, shape, etc. aligned with the longitudinal direction L includes not only the case where the component is parallel to the longitudinal direction L, but also the case where it is within a range of ±30° from the longitudinal direction L. Similarly, a component, etc. aligned with the width direction W includes not only the case where the component is parallel to the width direction W, but also the case where it is within a range of ±30° from the width direction W. For curved or curved components, the component, etc. is evaluated as described above for the tangents to each point on the curve, etc.

[0041] The disposable diaper 1 comprises a ventral section 3, a back section 2, and an absorbent main body 4 located between the ventral section 3 and the back section 2. The ventral section 3 is the section of the disposable diaper 1 that covers the ventral side of the wearer. The absorbent main body 4 is the section of the disposable diaper 1 that covers the crotch area of ​​the wearer and includes an absorber 8. The back section 2 is the section of the disposable diaper 1 that covers the back side of the wearer. The front and back ends of the absorbent main body 4 in the longitudinal direction L are connected to the central portions of the ventral section 3 and the back section 2 in the width direction W, respectively, by, for example, an adhesive (e.g., a hot melt adhesive; the same applies hereinafter). The disposable diaper 1 is formed by joining a pair of ventral joining sections 3a located at both end edges of the ventral section 3 in the width direction W and a pair of back joining sections 2a located at both end edges of the back section 2 in the width direction W to each other. The pair of ventral-side joining portions 3a and the pair of dorsal-side joining portions 2a joined together are also referred to as a pair of side joining portions SC. In this case, in the disposable diaper 1, the ventral-side portion 3 and the dorsal-side portion 2 joined together at the pair of side joining portions SC form a waist portion WP that covers the wearer's waist. Furthermore, the outer ends of the ventral-side portion 3 and the dorsal-side portion 2 in the longitudinal direction L define a waist opening WH through which the wearer's waist passes. Furthermore, in the disposable diaper 1, the opposite ends of the absorbent main body 4 in the width direction W and the inner ends of the ventral-side portion 3 and the dorsal-side portion 2 in the longitudinal direction L define a pair of leg openings LH through which the wearer's legs pass.

[0042] In the unfolded state, the abdominal portion 3 and the back portion 2 each have a generally rectangular shape that is elongated in the width direction W and are spaced apart from each other in the longitudinal direction L. The absorbent main body 4 has a generally rectangular shape that is elongated in the longitudinal direction L, and one end in the longitudinal direction L is connected to the abdominal portion 3 and the other end to the back portion 2. The abdominal portion 3, the absorbent main body 4, and the back portion 2 are formed separately from each other. At least two of the abdominal portion 3, the absorbent main body 4, and the back portion 2 may be formed integrally or may be connected integrally by a separate outer sheet or the like. A three-piece disposable diaper is a disposable diaper that, in the unfolded state, has the abdominal portion 3, the back portion 2, and a crotch portion between the abdominal portion 3 and the back portion 2, and the crotch portion joins the abdominal portion 3 and the back portion 2 and separates the abdominal portion 3 and the back portion 2 from each other. A two-piece disposable diaper is a type of disposable diaper that, when unfolded, has a ventral section 3, a dorsal section 2, and a crotch section between the ventral section 3 and the dorsal section 2, and the crotch section is joined to the ventral section and the dorsal section by a single outer body.

[0043] The ventral side portion 3 and the back side portion 2 are each formed from a liquid-impermeable sheet material. Each of the ventral side portion 3 and the back side portion 2 is formed by laminating at least a sheet material located on the skin side and a sheet material located on the non-skin side in the thickness direction T and joining them with an adhesive, heat sealing, or the like (adhesive, etc., the same applies below). The outer edge of the sheet material on the non-skin side in the longitudinal direction L is folded back toward the skin side. In this case, the sheet material on the non-skin side at the folded position in each of the ventral side portion 3 and the back side portion 2 constitutes the edge of the ventral side portion 3 and the back side portion 2 in the longitudinal direction L, respectively.

[0044] The abdominal portion 3 includes a plurality of waist-gathering elastic members 13 between the sheet member located on the skin side and the sheet member located on the non-skin side. The plurality of waist-gathering elastic members 13 extend from one end to the other end of the abdominal portion 3 in the width direction W, except for a region overlapping with the center of the absorbent body 8 in the thickness direction T, along the width direction W, and are arranged at intervals in the longitudinal direction L. The skin- and non-skin-side sheet members and the plurality of waist-gathering elastic members 13 are joined with an adhesive or the like. The back portion 2 includes a plurality of waist-gathering elastic members 12a, 12b between the sheet member located on the skin side and the sheet member located on the non-skin side. The plurality of waist-gathering elastic members 12a extend from one end to the other end of the back portion 2 in the width direction W, except for a region overlapping with the center of the absorbent body 8 in the thickness direction T, and are arranged at intervals in the longitudinal direction L. The multiple waist elastic members 12b extend along the width direction W in the back portion 2 from one end to the other in the width direction W, and are spaced apart in the longitudinal direction L. The skin-side and non-skin-side sheet members and the multiple waist elastic members 12a, 12b are joined with an adhesive or the like. The multiple waist elastic members 12a, 12b, 13 stretch the waist portion WP. The material of each elastic member is not particularly limited, but examples include thread-like or sheet-like rubber. The type of each elastic member is not particularly limited, but examples include styrene butadiene rubber and urethane rubber. The properties of each elastic member, such as the cross-sectional size (wire diameter, etc.) and elongation ratio, are appropriately selected depending on the magnitude of the tightening force corresponding to the position within the waist portion WP.

[0045] Examples of each sheet member include any liquid-impermeable sheet such as a liquid-impermeable nonwoven fabric or synthetic resin film, a composite sheet of these, an SB nonwoven fabric, or an SMS nonwoven fabric. The type of nonwoven fabric is not particularly limited, and examples include meltblown nonwoven fabric, spunbond nonwoven fabric, airlaid nonwoven fabric, and air-through nonwoven fabric. The material of the nonwoven fabric or synthetic resin film of the sheet member is not particularly limited as long as it can be used for sanitary products, and examples include polyolefin resins such as polypropylene and polyethylene, polyamide resins such as 6-nylon and 6,6-nylon, and polyester resins such as polyethylene terephthalate and polybutylene terephthalate. The basis weight of the nonwoven fabric of the sheet member is, for example, 5 to 100 g / m 2 and preferably 10 to 50 g / m 2 The length (thickness) of the sheet member in the thickness direction T is, for example, 0.1 to 5 mm, and preferably 0.1 to 2 mm. The sheet member constituting each of the ventral side portion 3 and the dorsal side portion 2 may be one sheet member or three or more sheets (not shown). The sheet member does not have to be folded (not shown).

[0046] In this embodiment, the disposable diaper 1 further includes an exterior sheet member 14 that bridges the gap between the ventral portion 3 and the back portion 2. The exterior sheet member 14 is a liquid-impermeable sheet member, such as a nonwoven fabric, and both ends in the longitudinal direction L are laminated to the ventral portion 3 and the back portion 2, respectively, and joined with an adhesive or the like. The type and material of the nonwoven fabric are as described above. The exterior sheet member 14 is also joined with an adhesive or the like to the non-skin side of the absorbent main body 4, which is located roughly between the ventral portion 3 and the back portion 2, to supplement and protect the absorbent main body 4 from the non-skin side. The exterior sheet member 14 may be composed of two or more sheet members (not shown). A sheet member other than the exterior sheet member 14 may be provided on the non-skin side (not shown).

[0047] The disposable diaper 1 may further include a sheet-like elastic member bonded with an adhesive to the skin side or non-skin side of at least one of the ventral side portion 3 and the back side portion 2 and extending along the width direction W. The sheet-like elastic member is a sheet-like member that is elastic in the width direction W and functions, for example, as a waist gather and / or a sweat-absorbing sheet. Examples of types of sheet-like elastic members include elastic nonwoven fabrics that combine styrene rubber, olefin rubber, urethane rubber, etc. with nonwoven fabric, paper, etc.

[0048] The absorbent main body 4 has a main body central portion 10 located in the center in the width direction W and extending in the longitudinal direction L, and a pair of leg gather portions 5 located at both ends in the width direction W and having multiple leg elastic members 5a extending along the longitudinal direction L.

[0049] The main body central portion 10 has a substantially rectangular shape and includes a liquid-permeable topsheet 7, a liquid-impermeable backsheet 9, and an absorbent body 8 that is positioned between the topsheet 7 and the backsheet 9 and absorbs and retains liquid. The absorbent body 8 is bonded to the topsheet 7 and the backsheet 9 with an adhesive, and the topsheet 7 and the backsheet 9 are bonded to each other at their peripheral edges with an adhesive. The shape of the main body central portion 10 is not limited to the above example as long as it is long in the longitudinal direction L, and examples include a rectangle with rounded corners, a rectangle with outwardly convex curved short sides, and an hourglass shape.

[0050] Examples of the top sheet 7 include liquid-permeable nonwoven fabrics or woven fabrics, synthetic resin films with liquid-permeable holes, and composite sheets of these. Examples of the back sheet 9 include liquid-impermeable nonwoven fabrics or synthetic resin films, composite sheets of these, and SMS nonwoven fabrics. The type of nonwoven fabric is not particularly limited, and examples include meltblown nonwoven fabrics, spunbond nonwoven fabrics, airlaid nonwoven fabrics, and air-through nonwoven fabrics. The type of synthetic resin film is not particularly limited, and known film materials can be used. Materials for the nonwoven fabric and synthetic resin film are not particularly limited as long as they are usable for sanitary products, and examples include olefin-based resins such as polyethylene and polypropylene, polyamide-based resins such as 6-nylon and 6,6-nylon, and polyester-based resins such as polyethylene terephthalate and polybutylene terephthalate. Cellulose-based fibers may also be used as the nonwoven fabric material. To provide breathability, the synthetic resin film may contain inorganic particles such as calcium carbonate.

[0051] The absorbent body 8 includes an absorbent core 8b that absorbs and retains liquid, a core wrap 8a that encases the absorbent core 8b, and grooves 8c that can diffuse liquid in the longitudinal direction L and the width direction W. The absorbent core 8b is made of an absorbent material, such as at least one of cellulose-based fibers and superabsorbent polymers. Examples of cellulose-based fibers include natural cellulose fibers, such as pulp fibers (e.g., wood pulp fibers, crosslinked pulp fibers, and non-wood pulp fibers), regenerated cellulose fibers, and semi-synthetic cellulose fibers. Pulp fibers have an average fiber length of, for example, several tens of micrometers, preferably 20 to 40 micrometers, and an average fiber length of, for example, several millimeters, preferably 2 to 5 mm. Examples of superabsorbent polymers (SAPs) include polyacrylate-based, polysulfonate-based, and maleic anhydride-based superabsorbent polymers. The size (when dry) of the superabsorbent polymer is, for example, an average particle size of several hundred micrometers, preferably 200 to 500 micrometers. The basis weight of the cellulosic fiber and the highly absorbent polymer is, for example, 100 to 400 g / m 2Examples of materials for the core wrap 8a include liquid-permeable sheets such as nonwoven fabrics and tissues.

[0052] The main body central portion 10 includes a pair of leak-proof walls 6 arranged on both sides in the width direction W facing each other and extending along the longitudinal direction L. Each leak-proof wall 6 extends along the longitudinal direction L and is formed of a sheet member 6b containing multiple leak-proof elastic members 6a arranged at intervals in the width direction W. Each leak-proof wall 6 has an outer end in the width direction W bonded to at least one of the topsheet 7, absorbent body 8, and backsheet 9 with an adhesive or the like to form a fixed end, and an inner end in the width direction W to form a free end separated from the other sheets, including the topsheet 7. The multiple leak-proof elastic members 6a are bonded to the sheet member 6b near the free end with an adhesive. Examples of the sheet member 6b include hydrophobic nonwoven fabrics and hydrophilic nonwoven fabrics. The type and material of the nonwoven fabric are as described above. The multiple leak-proof elastic members 6a are exemplified by rubber threads, and the type and material of the elastic members are as described above. The properties of the elastic member, such as the cross-sectional size (wire diameter, etc.) and the elongation ratio, are appropriately selected depending on the function of the leak preventing walls 6. Note that the inner end of each leak preventing wall 6 in the width direction W may be further folded back outward in the width direction W.

[0053] A pair of leg gathers 5 are joined to both ends of the main body central portion 10 in the width direction W. Each leg gather 5 extends along the longitudinal direction L and includes multiple leg elastic members 5a spaced apart in the width direction W, and skin-side and non-skin-side sheet members 5b sandwiching the multiple leg elastic members 5a. Each leg gather 5 has its inner end in the width direction W joined to the non-skin-side surface of the width direction W end of the main body central portion 10 with an adhesive or the like to form a fixed end, and its outer end in the width direction W to form a free end spaced apart from the main body central portion 10. The multiple leg elastic members 5a are joined with an adhesive near the free ends of the skin-side and non-skin-side sheet members 5b. The multiple leg elastic members 5a stretch each leg gather 5. Examples of sheet members 5b include hydrophobic nonwoven fabrics and hydrophilic nonwoven fabrics. The type and material of the nonwoven fabric are as described above. The leg elastic members 5a are exemplified by rubber threads, and the types and materials of the elastic members are as described above. The properties of the elastic members, such as the cross-sectional size (linear, etc.) and elongation ratio of the elastic members, are appropriately selected depending on the magnitude of the tightening force corresponding to the position in the leg gathered portion 5.

[0054] In the disposable diaper 1, the pair of leg gathers 5 are bridged by an exterior sheet member 14. Both ends of the exterior sheet member 14 in the width direction W are laminated onto the inner ends of each of the pair of leg gathers 5 in the width direction W and joined with an adhesive or the like, thereby supporting and protecting the pair of leg gathers 5 from the non-skin side.

[0055] The back portion 2 includes a back main body portion 21 that occupies substantially the same area as the back joint portion 2a in the longitudinal direction L, and a back extension portion 20 that extends forward from the front edge of the back main body portion 21 in the longitudinal direction L. In other words, the back main body portion 21 is the rear region of the back portion 2 in the longitudinal direction L, and its length in the longitudinal direction L is substantially the same as that of the back joint portion 2a and its length in the width direction W is the same as that of the back portion 2. The waist elastic members 12a, 12b of the back portion 2 are arranged in the back main body portion 21. Therefore, the back main body portion 21 is the region where at least the waist elastic members 12a, 12b are arranged. The meaning of "substantially the same area as the back joint portion 2a" will be explained later. On the other hand, the back-side extension portion 20 is the front region of the back-side portion 2 in the longitudinal direction L, and its length in the longitudinal direction L is the length of the back-side portion 2 minus the length of the back-side main body portion 21, and its length in the width direction W is the same as that of the back-side portion 2. The back-side extension portion 20 is the remaining region of the back-side portion 2 minus the back-side main body portion 21.

[0056] The back-side extending portion 20 includes an extending central portion 31 that overlaps the main body central portion 10 in the thickness direction T, and a pair of buttocks-covering portions 30 that extend outward from both side edges of the extending central portion 31 in the width direction W. In other words, the extending central portion 31 is a central (inner) region of the back-side extending portion 20 in the width direction W, and its length in the width direction W is the same as the length of the main body central portion 10, and its length in the longitudinal direction L is the same as the length of the back-side extending portion 20. On the other hand, the buttocks-covering portions 30 are regions of the back-side extending portion 20 that are outer in the width direction W, and their length in the width direction W is half the length of the back-side extending portion 20 minus the length of the main body central portion 10, and their length in the longitudinal direction L is the same as the length of the back-side extending portion 20. The buttocks-covering portions 30 can also be said to be regions of the back-side extending portion 20 that do not overlap with the main body central portion 10 in the thickness direction T.

[0057] FIG. 5 is a partial plan view showing an example of the configuration of a disposable diaper 1 according to this embodiment in an unfolded state. This view is an enlarged view of the area near the buttocks-covering portion 30, and can also be considered a view showing the diaper in an extended state. As described above, the length of the buttocks-covering portion 30 in the width direction W, i.e., the extended widthwise length dWa, is equal to the length of the back-side extending portion 20 minus the length of the main body central portion 10 (or the extended central portion 31), and then halved. Meanwhile, the length in the longitudinal direction L, i.e., the extended longitudinal length dLa, is equal to the length of the back-side extending portion 20. The buttocks-covering portion 30 includes a buttocks elastic member 40 extending along the width direction W in an inner region of the longitudinal direction L. The effective portion of the buttocks elastic member 40 as an elastic member is within the widthwise W range of the buttocks-covering portion 30. The type, material, and properties of the elastic member constituting the buttocks elastic member 40 are as described above.

[0058] Here, when it is stated that "the dorsal main body portion 21 occupies substantially the same area as the dorsal joint portion 2a in the longitudinal direction L," the meaning of "substantially the same area as the dorsal joint portion 2a" is as follows. As shown in FIG. 5, the end P on the inner side (front side) of the dorsal joint portion 2a in the longitudinal direction L is included in the dorsal extension portion 20, not in the dorsal main body portion 21. However, the length of the end P in the longitudinal direction L is smaller than the entire length of the dorsal joint portion 2a. Therefore, the area that the dorsal main body portion 21 occupies in the dorsal portion 2 in the longitudinal direction L is the range of the dorsal joint portion 2a excluding the length of the end P, but is still "substantially" the same area as the dorsal joint portion 2a. The ratio of the length of the end P to the length of the dorsal joint portion 2a in the longitudinal direction L is, for example, 2 to 4%, and the actual length is, for example, 2 to 5 mm.

[0059] The buttocks-covering portion 30 has a plurality of rigid portions 2h arranged continuously or intermittently along the longitudinal direction L at the outer end in the width direction W. The plurality of rigid portions 2h are arranged side by side in the longitudinal direction L on the inside (front side) of the end P of the back-side joining portion 2a. The plurality of rigid portions 2h join the sheet member located on the skin side of the back-side portion 2 and the sheet member located on the non-skin side in the thickness direction T. The plurality of rigid portions 2h are exemplified by, for example, heat sealing.

[0060] 6 is a plan view of an example of the configuration of a disposable diaper 1 according to the embodiment in an unfolded state. Here, consider the case where each of the pair of side joints SC (dorsal joints 2a) in the back portion 2 is virtually divided into four parts in the longitudinal direction L. That is, the length of the side joints SC (dorsal joints 2a) in the longitudinal direction L is defined as 100%, and the range from the inner edge to the outer edge in the longitudinal direction L is virtually divided into a 15% length range, a 35% length range, a 25% length range, and a 25% length range, respectively. The 15% length range, the 35% length range, the 25% length range, and the 25% length range are defined as a lower region S4 (2a4), a lower central region S3 (2a3), an upper central region S2 (2a2), and an upper region S1 (2a1), respectively. In this case, in the pair of lateral joints SC (dorsal joints 2a), the area located between the pair of lower ranges S4 (2a4), the area located between the pair of lower central ranges S3 (2a3), the area located between the pair of upper central ranges S2 (2a2), and the area located between the pair of upper ranges S1 (2a1) are respectively referred to as the lower dorsal area AA4, the lower dorsal central area AA3, the upper dorsal central area AA2, and the upper dorsal area AA1.

[0061] Similarly, in the ventral portion 3, consider virtually dividing each of the pair of side joints SC (ventral joints 3a) into four in the longitudinal direction L. That is, the length of the side joints SC (ventral joints 3a) in the longitudinal direction L is taken as 100%, and the range from the inner edge to the outer edge in the longitudinal direction L is virtually divided into a 15% length range, a 35% length range, a 25% length range, and a 25% length range, respectively. The 15% length range, the 35% length range, the 25% length range, and the 25% length range are then defined as a lower range S4 (3a4), a lower central range S3 (3a3), an upper central range S2 (3a2), and an upper range S1 (3a1), respectively. In this case, in the pair of lateral joints SC (ventral joints 3a), the area located between the pair of lower ranges S4 (3a4), the area located between the pair of lower central ranges S3 (3a3), the area located between the pair of upper central ranges S2 (3a2), and the area located between the pair of upper ranges S1 (3a1) are respectively referred to as the ventral lower area BA4, the ventral lower central area BA3, the ventral upper central area BA2, and the ventral upper area BA1.

[0062] Fig. 7 is a partial side view of an example of the configuration of a disposable diaper according to an embodiment. This figure shows the vicinity of one of a pair of side joints SC where a pair of ventral joints 3a and a pair of dorsal joints 2a of the disposable diaper 1 are joined together. Here, the dorsal lower region AA4 and the ventral lower region BA4 are adjacent to each other via the side joint SC. Similarly, the dorsal central lower region AA3 and the ventral central lower region BA3 are adjacent to each other via the side joint SC. The dorsal central upper region AA2 and the ventral central upper region BA2 are adjacent to each other via the side joint SC. The dorsal upper region AA1 and the ventral upper region BA1 are adjacent to each other via the side joint SC.

[0063] In the disposable diaper 1 having the above-described configuration, the tensile stress in the width direction W of the adjacent dorsal lower region AA4 and ventral lower region BA4 is greater in the ventral lower region BA4 than in the dorsal lower region AA4. The tensile stress in the ventral lower region BA4 is preferably 2 to 15 times, more preferably 3 to 10 times, and even more preferably 4 to 7 times, the tensile stress in the dorsal lower region AA4. While specific values ​​vary depending on the size of the product and the intended wearer, the tensile stress in the ventral lower region BA4 is, for example, 6 to 25 N / m, preferably 8 to 20 N / m, and more preferably 10 to 15 N / m. The tensile stress in the dorsal lower region AA4 is, for example, 1 to 6 N / m, preferably 1.5 to 5 N / m, and more preferably 2 to 4 N / m.

[0064] However, the tensile stress can be measured by the following method. (1) Prepare a tensile testing machine (Instron Corporation, Universal Material Testing Machine, Model No. 5565). (2) Prepare a test specimen. For example, when measuring the tensile stress in the ventral lower region BA4, remove the ventral portion 3 from the disposable diaper 1, and cut out the ventral lower region BA4 from the ventral portion 3 to use as a test specimen. Similarly, when measuring the tensile stress in the dorsal lower region AA4, remove the dorsal portion 2 from the disposable diaper 1, and cut out the dorsal lower region AA4 from the dorsal portion 2 to use as a test specimen. (3) Clamp one end of the test piece in the upper chuck. (4) Raise the upper chuck until the specimen hangs above the lower chuck and no longer touches the lower bar. (5) The force is corrected to zero and the weight of the test piece is eliminated. (6) Lower the upper chuck to the initial chuck distance (20 mm). (7) The other end of the test piece is clamped in the lower chuck. The area between the upper and lower chucks is the measurement area. (8) The test is started, and the upper chuck is moved upward at 100 mm / min until it reaches 80% of the template dimension (maximum extension state = expanded state). (9) Then, the upper chuck is immediately returned at the same speed until it reaches the initial chuck distance. (10) Record the force at 80% of the template size (maximum extension). (11) Calculate the average tension (N) of the five measurements in (10) above. If the test specimen is the ventral lower region BA4, the tensile stress of the ventral lower region BA4 is determined by dividing this average tension by the length of the ventral lower region BA4 in the longitudinal direction L. Similarly, if the test specimen is the dorsal lower region AA4, the tensile stress of the dorsal lower region AA4 is determined by dividing this average tension by the length of the dorsal lower region AA4 in the longitudinal direction L.

[0065] The tensile stress may be measured by the method described in paragraphs 0048 to 0060 of Patent Document 1. This method was adopted in the present embodiment. However, the front waist zone 102, the front distal abdominal zone 104, the front proximal abdominal zone 106, and the front leg zone 108 in Patent Document 1 correspond to the abdominal upper region BA1, the abdominal central upper region BA2, the abdominal central lower region BA3, and the abdominal lower region BA4, respectively. Meanwhile, the rear waist zone 102, the rear distal abdominal zone 104, the rear proximal abdominal zone 106, and the rear leg zone 108 in Patent Document 1 correspond to the dorsal upper region AA1, the dorsal central upper region AA2, the dorsal central lower region AA3, and the dorsal lower region AA4, respectively.

[0066] As described above, in the disposable diaper 1 of this embodiment, in the back-side lower region AA4 located between the lower regions S4 (2a4) of the pair of side joints SC in the back-side portion 2 and the ventral-side lower region BA4 located between the lower regions S4 (3a4) of the pair of side joints SC in the ventral-side portion 3, the tensile stress in the width direction W is greater in the ventral-side lower region BA4 than in the back-side lower region AA4. Therefore, the ventral-side lower region BA4 can be contracted in the width direction W, and the back-side lower region AA4 can be pulled toward the ventral-side portion 3 in the width direction W. Here, the back-side lower region AA4 is a portion of the back-side main body portion 21 adjacent to the buttocks-covering portion 30 (back-side extension portion 20). Therefore, by pulling the back-side lower region AA4 toward the ventral-side portion 3 in the width direction W, the buttocks-covering portion 30 can be pulled toward the ventral-side portion 3 in the width direction W. This allows the buttocks covering portion 30 to be used widely in the width direction W, and the buttocks covering portion 30 can adequately cover and conceal the buttocks.

[0067] Furthermore, in the disposable diaper 1, the tensile stress in the width direction W of the ventral lower region BA4 is greater than the tensile stress in the width direction W of the dorsal lower region AA4, which prevents the ventral lower region BA4 from being pulled in the width direction W toward the dorsal portion 2 by the dorsal lower region AA4. This makes it difficult for the leg elastic members 5a of the leg gathers 5 near the groin to be pulled toward the dorsal portion 2. This prevents the leg elastic members 5a of the leg gathers 5 from digging into the wearer's groin and leaving marks.

[0068] Furthermore, in this disposable diaper, the effective portion of the buttocks elastic members 40 as elastic members (portions that function as elastic members) is within the buttocks covering portion 30. Therefore, even if the absorber 8 deforms inward in the width direction W (away from the buttocks) due to the wearer's leg squeezing, the buttocks elastic members 40 can be prevented from being pulled by the deformation of the absorber 8. This prevents the buttocks covering portion 30 from shrinking in the width direction W, which, combined with the action of pulling the buttocks covering portion 30 toward the ventral side in the width direction W, prevents the buttocks covering portion from becoming smaller and allows the buttocks to be properly covered. (Note that the buttocks covers in Patent Documents 1 and 2 correspond to the entire back-side extension portion 20 of the disposable diaper 1.)

[0069] FIG. 9 is a perspective view showing the disposable diaper 1 according to this embodiment in a worn state, and is a traced photograph of the disposable diaper 1 in a worn state. As described above, the tensile stress in the width direction W is greater in the ventral lower region BA4 than in the dorsal lower region AA4, which allows the dorsal lower region AA4 to be pulled toward the ventral portion 3 in the width direction W, as indicated by the white arrow in the figure. This causes the buttocks-covering portion 30 to be pulled in the direction of the white arrow in the figure and expand in the width direction W, thereby enabling the buttocks to be properly covered. In addition, because the ventral lower region BA4 is less likely to be pulled in the direction opposite the white arrow in the figure, the leg elastic members 5aX near the groin of the leg gathers 5 are less likely to be pulled toward the dorsal portion 2, thereby preventing the leg elastic members 5aX from digging into the wearer's groin and leaving marks. Furthermore, because the effective portion of the buttocks elastic members 40 is within the range of the buttocks covering part 30, contraction of the buttocks covering part 30 in the width direction W can be suppressed even when the wearer closes their legs, and this, combined with the action of pulling the buttocks covering part 30 toward the ventral side in the width direction W, enables the buttocks to be properly covered and concealed by the buttocks covering part 30. In this case, the pair of side joints SC form a gentle curve (for example, a C-shape or a J-shape) that is convex diagonally downward when viewed from the side.

[0070] As described above, the disposable diaper 1 can appropriately cover and conceal the buttocks while preventing the leg gathers 5 from leaving marks on the wearer's groin and suppressing the effects of the wearer's movements.

[0071] The relationship between the tensile stress in the width direction W in the dorsal-side lower-central region AA3 and the ventral-side lower-central region BA3 is not particularly limited, but for example, the tensile stress in the width direction W in the ventral-side lower-central region BA3 is the same as or greater than that in the dorsal-side lower-central region AA3. Preferably, the tensile stress in the ventral-side lower-central region BA3 is 1 to 2 times the tensile stress in the dorsal-side lower-central region AA3. Specific values ​​vary depending on the size of the product and the intended wearer, but the tensile stress in the ventral-side lower-central region BA3 is, for example, 9 to 36 N / m, with 12 to 27 N / m being preferred. The tensile stress in the dorsal-side lower-central region AA3 is, for example, 6 to 26 N / m, with 9 to 19 N / m being preferred.

[0072] The relationship between the tensile stress in the width direction W in the dorsal upper-central region AA2 and the ventral upper-central region BA2 is not particularly limited. For example, the tensile stress in the width direction W in the ventral upper-central region BA2 is the same as or greater than that in the dorsal upper-central region AA2. Preferably, the tensile stress in the ventral upper-central region BA2 is 1 to 2 times the tensile stress in the dorsal upper-central region AA2. Specific values ​​vary depending on the size of the product and the intended wearer, but examples of the tensile stress in the ventral upper-central region BA2 include 12 to 48 N / m, with 18 to 36 N / m being preferred. Examples of the tensile stress in the dorsal upper-central region AA2 include 9 to 36 N / m, with 13 to 27 N / m being preferred. Depending on the size (e.g., maximum size), the tensile stress in the width direction W in the ventral upper-central region BA2 may be smaller than that in the dorsal upper-central region AA2.

[0073] The relationship between the tensile stress in the width direction W in the upper back region AA1 and the upper ventral region BA1 is not particularly limited. For example, the tensile stress in the width direction W in the upper ventral region BA1 is the same as or greater than that in the upper back region AA1. Preferably, the tensile stress in the upper ventral region BA1 is 1 to 2 times the tensile stress in the upper back region AA1. Specific values ​​vary depending on the size of the product and the intended wearer, but the tensile stress in the upper ventral region BA1 is, for example, 6 to 25 N / m, preferably 8 to 20 N / m. The tensile stress in the upper back region AA1 is, for example, 4 to 20 N / m, preferably 6 to 15 N / m. Depending on the size (e.g., maximum size), the tensile stress in the width direction W in the upper ventral region BA1 may be smaller than that in the upper back region AA1.

[0074] There are no particular restrictions on the relationship between the tensile stress in the width direction W in the ventral lower region BA4, the ventral lower central region BA3, the ventral upper central region BA2, and the ventral upper region BA1, but for example, the tensile stress in the width direction W is such that the ventral upper central region BA2 ≧ the ventral lower central region BA3 ≧ the ventral upper region BA1, the ventral lower region BA4.

[0075] In a preferred aspect of this embodiment, the number of waist elastic members 13 (belly elastic members) included in the lower belly region BA4 of the belly portion 3 is greater than the number of waist elastic members 12a (dorsal elastic members) included in the lower dorsal region AA4 of the dorsal portion 2. In the example shown in Figures 6 and 7, the lower belly region BA4 includes two waist elastic members 13, and the lower dorsal region AA4 includes one waist elastic member 12a.

[0076] With this configuration, in the disposable diaper 1, the abdominal lower region BA4 can be more reliably contracted in the width direction W and the back lower region AA4 can be pulled toward the abdominal side in the width direction W. In this way, by pulling the waist elastic members 12a (back elastic members) toward the abdominal side in the width direction W with a large number of waist elastic members 13 (abdominal elastic members), the buttocks-covering portion 30 can be more reliably pulled toward the abdominal side in the width direction W. This more reliably allows the buttocks-covering portion 30 to be used widely in the width direction W, and allows the buttocks-covering portion 30 to adequately cover and conceal the buttocks. Furthermore, it is more reliably possible to prevent the leg elastic members 5aX in the vicinity of the wearer's groin from digging into and leaving marks on the groin.

[0077] In a preferred aspect of this embodiment, the buttocks-covering portion 30 has its inner region in the width direction W joined to the leg gathered portion 5. As shown in Fig. 5, the buttocks elastic member 40 does not overlap in the thickness direction T with the innermost leg elastic member 5ai, which is located innermost in the width direction W among the multiple leg elastic members 5a.

[0078] With this configuration, even if the absorber 8 is deformed inward in the width direction W due to the wearer's movement to close in on their legs, and the leg gathered portions 5 are consequently pulled inward in the width direction W, the buttocks elastic members 40 are less likely to be pulled inward in the width direction W. This makes it possible to more reliably pull the buttocks covering portion 30 toward the abdominal side in the width direction W, and makes it possible to appropriately cover and conceal the buttocks with the buttocks covering portion 30 while suppressing the effects of the wearer's movement.

[0079] In a preferred aspect of this embodiment, the buttocks-covering portion 30 has its inner region in the width direction W joined to the leg gathered portion 5. As shown in Fig. 5, the buttocks elastic member 40 overlaps in the thickness direction T with the outermost leg elastic member 5ao that is located outermost in the width direction W among the multiple leg elastic members 5a.

[0080] With this configuration, the buttocks elastic members 40 pull the outermost leg elastic members 5ao outward in the width direction W, so that only the outer portions of the leg gathered parts 5 near the buttocks-covering part 30 in the width direction W are pulled outward appropriately, allowing them to fit along the surfaces of the legs near the buttocks. This allows the buttocks to be appropriately covered and concealed by the buttocks-covering part 30, while the leg gathered parts 5 can be appropriately brought into surface contact with the legs near the buttocks, allowing them to properly perform their function.

[0081] In a preferred embodiment of the present invention, the outermost leg elastic members 5ao, which are located on the outermost sides of the leg elastic members 5a in the width direction W, have the weakest elastic force among the leg elastic members 5a. The weakening of the elastic force can be achieved, for example, by reducing the wire diameter or the elongation ratio.

[0082] With this configuration, even if the absorber 8 is deformed inward in the width direction W due to the wearer's action of closing in on their legs and the leg gathered portions 5 are consequently pulled inward in the width direction W, it is possible to make it difficult for the outer portions of the leg gathered portions 5 to be tucked up (rolled up) inward in the width direction W. This makes it possible to make it difficult for the buttocks-covering portions 30 adjacent to the leg gathered portions 5 to be pulled inward in the width direction W (and outward in the longitudinal direction L). This makes it possible to more reliably pull the buttocks-covering portions 30 toward the abdominal side in the width direction W, and it becomes possible for the buttocks-covering portions 30 to appropriately cover and conceal the buttocks while suppressing the effects of the wearer's action.

[0083] In a preferred aspect of this embodiment, the first distance dg1 is the distance between the outermost leg elastic member 5ao, which is located outermost in the width direction W, and the second leg elastic member 5as, which is adjacent to the outermost leg elastic member 5ao on the inside in the width direction W, and the second distance dg2 is the distance between the second leg elastic member 5as and the third leg elastic member 5at, which is adjacent to the second leg elastic member 5as on the inside in the width direction W. In other words, the first distance dg1 is greater than the second distance dg2.

[0084] Thus, in the leg gathered portions 5, the pitch (dg2) between the leg elastic members 5a in the inner portion close to the absorbent body 8 is narrower than the pitch (dg1) between the leg elastic members 5a in the outer portion far from the absorbent body 8. Therefore, the tensile stress in the longitudinal direction L in the inner portion close to the absorbent body 8 is higher than the tensile stress in the longitudinal direction L in the outer portion far from the absorbent body 8. This allows the leg gathered portions 5 to firmly lift the absorbent body 8 and fit it to the wearer's body. Note that the tensile stress can be measured by using the test piece as the measurement target area of ​​the leg gathered portions 5 in the measurement method described above.

[0085] Furthermore, the leg elastic members 5a tend to move inward in the width direction W of the leg gathered portion 5 due to deformation of the absorber 8 inward in the width direction W (and away from the buttocks) caused by the wearer's movement (movement of the wearer closing their legs). Therefore, in the disposable diaper 1, the pitch between the leg elastic members at the inner widthwise portions of the leg gathered portion 5 is narrowed. This tightening force makes it difficult for the leg elastic members 5a to move inward in the width direction W, thereby preventing the inner portions of the leg gathered portion 5 from rolling up (being rolled up) due to the movement of the leg elastic members 5a. This makes it difficult for the buttocks-covering portion 30 adjacent to the leg gathered portion 5 to be pulled inward in the width direction W. This more reliably pulls the buttocks-covering portion 30 toward the abdominal side in the width direction W, thereby enabling the buttocks-covering portion 30 to properly cover and conceal the buttocks while suppressing the influence of the wearer's movement.

[0086] From the viewpoint of the above-mentioned effects, the first distance dg1 is, for example, 5 to 30% of the length in the width direction W of the leg gathered portion 5 (the portion that does not overlap with the main body central portion 10 in the thickness direction T), preferably 7 to 20%, and more preferably 9 to 15%. Furthermore, the first distance dg1 is, for example, more than 1 to 3 times the second distance dg2, preferably 1.2 to 2 times. The actual value of the first distance dg1 is, for example, 3 to 10 mm, and preferably 4 to 8 mm.

[0087] In a preferred aspect of this embodiment, among the multiple leg elastic members 5a, the outermost leg elastic member 5ao located on the outermost side in the width direction W is spaced inward from the outermost edge 5e in the width direction W of each of the pair of leg gathered portions 5.

[0088] That is, as shown in Fig. 5, the leg elastic members 5a are not arranged on the outermost edges 5e of the leg gathered portions 5 in the width direction W. Therefore, even if the absorber 8 is deformed inward in the width direction W due to the wearer's movement to close in on their legs and the leg gathered portions 5 are pulled inward in the width direction W, the outer portions of the leg gathered portions 5 are less likely to be tucked up inward in the width direction W. This makes it possible to make the buttocks-covering portions 30 adjacent to the leg gathered portions 5 less likely to be pulled inward in the width direction W. This makes it possible to more reliably pull the buttocks-covering portions 30 toward the abdominal side in the width direction W, thereby enabling the buttocks-covering portions 30 to appropriately cover and conceal the buttocks while suppressing the effects of the wearer's movement.

[0089] From the viewpoint of the above-mentioned effects, the distance between the outermost leg elastic member 5ao and the edge 5e is, for example, 0.5 to 3 times the size of dg1, and preferably 1 to 2. The actual value of the distance between the outermost leg elastic member 5ao and the edge 5e is, for example, 2 to 15 mm, and preferably 4 to 10 mm.

[0090] FIG. 8 is a partial plan view of an example of a disposable diaper according to an embodiment in an unfolded state. This view is an enlarged view of the area near the buttocks-covering portion 30, and can also be considered a view showing the stretched state. The leg gathers 5 include a stretchable region EA in which multiple leg elastic members 5a are arranged. The buttocks-covering portion 30 includes an overlapping region OA located on the front side in the longitudinal direction L in its inner region in the width direction W, which overlaps in the thickness direction T with the rear end region EAe of the stretchable region EA in the longitudinal direction L. In this case, the buttocks-covering portion 30 may further include a non-overlapping region UA ​​located on the rear side in the longitudinal direction L in its inner region in the width direction W, which does not overlap with the stretchable region EA in the thickness direction T.

[0091] The overlapping region OA allows the front region of the buttocks-covering portion 30 in the longitudinal direction L (overlapping region OA) to be pulled forward in the longitudinal direction L by the leg elastic members 5a. This prevents the buttocks-covering portion 30 from shrinking too much in the longitudinal direction L. Furthermore, the non-overlapping region UA ​​makes the rear region of the buttocks-covering portion 30 in the longitudinal direction L (non-overlapping region UA) less likely to be pulled and shrink by the leg elastic members 5a. This prevents the overlapping region OA of the buttocks-covering portion 30, and therefore the front region of the buttocks-covering portion 30 in the longitudinal direction L, from shrinking too much in the longitudinal direction L. At the same time, the non-overlapping region UA ​​of the buttocks-covering portion 30, and therefore the rear region of the buttocks-covering portion 30 in the longitudinal direction L, from deforming to a certain extent. This prevents the buttocks-covering portion 30 from shrinking too much in the longitudinal direction L, and also makes it easier for the buttocks-covering portion 30 to bulge outward gently. This allows the buttocks-covering portion 30 to more reliably encase and adequately cover the buttocks. This increases the sense of security that the buttocks-covering portion 30 will prevent leakage of excrement.

[0092] In a preferred aspect of this embodiment, the overlapping region OA is in a range of less than 50% of the length of the buttocks-covering part 30 in the longitudinal direction L. Therefore, the length of the overlapping region OA in the longitudinal direction L is less than 50% of the extended longitudinal length dLa of the buttocks-covering part 30. Correspondingly, the length of the non-overlapping region UA ​​in the longitudinal direction L is 50% or more of the extended longitudinal length dLa of the buttocks-covering part 30. Note that the overlapping region OA may be in a range of less than 40% of the length of the buttocks-covering part 30 (extended longitudinal length dLa) in the longitudinal direction L, but may also be in a range of at least 5% or more, and may be in a range of 10% or more.

[0093] In this way, in the disposable diaper 1, by limiting the overlapping area between the buttocks-covering portion 30 and the leg gathered portions 5, even if the leg gathered portions 5 are pulled inward in the width direction W by the wearer's leg-closing action, the buttocks-covering portion 30 can be made less likely to be pulled inward in the width direction W. This makes it possible to more reliably pull the buttocks-covering portion 30 toward the abdominal portion 3 in the width direction W, thereby making it possible to appropriately cover the buttocks with the buttocks-covering portion 30 while suppressing the effects of the wearer's action. Furthermore, because the overlapping area is 5% or more, it is possible to more reliably prevent the buttocks-covering portion 30 from contracting too much in the longitudinal direction L.

[0094] In a preferred aspect of this embodiment, the absorbent body 8 contains pulp fibers. The basis weight of the pulp fibers is, for example, 100 to 400 g / m 2 Therefore, the rigidity of the absorbent body 8 can be increased compared to when the absorbent body 8 is formed only from a highly water-absorbent polymer. The relatively high rigidity of the absorbent body 8 makes it difficult for the absorbent main body 4 to shrink in the longitudinal direction L and the width direction W due to the elastic members of the leg gathered portions 5, the abdominal portion 3, the back portion 2, etc. The fact that the absorbent main body 4 is difficult to shrink in the longitudinal direction L and the width direction W makes it possible to make the buttocks-covering portion 30 of the back portion 2 difficult to shrink in the longitudinal direction L and the width direction W. This allows the buttocks to be more reliably and appropriately covered by the buttocks-covering portion 30.

[0095] In a preferred aspect of this embodiment, the absorber 8 has an hourglass shape. The widest part 8E of the hourglass shape is located on an extension of the buttocks elastic member 40 in the width direction W. Here, the widest part 8E of the absorber 8 can be said to be the most rigid part of the absorber 8. Therefore, the buttocks-covering part 30 is located in the highly rigid part of the absorber 8 in the longitudinal direction L. In this way, the buttocks-covering part 30 is located in the highly rigid part of the absorber 8, making it difficult for the buttocks-covering part 30 to contract in the longitudinal direction L. This allows the buttocks to be more reliably and appropriately covered.

[0096] In a preferred aspect of this embodiment, the absorbent body 8 has an hourglass shape. The constriction start positions 8Wa (on the back section 2 side) and 8Wb (on the abdominal section 3 side) in the hourglass shape are located at least 10 mm inward in the longitudinal direction L from the fold line when the disposable disposable diaper 1 is folded in half. The fold line is the widthwise centerline CW. In other words, the fold line is a fold line formed when the disposable diaper 1 is folded in half so that the outer edge of the abdominal section 3 in the longitudinal direction L and the outer edge of the back section 2 in the longitudinal direction L are aligned. Therefore, the distance EWa between the fold line and the constriction start position 8Wa (on the back section 2 side) is 10 mm or more, and the distance EWb between the fold line and the constriction start position 8Wb (on the abdominal section 3 side) is also 10 mm or more. The upper limit of each distance can be naturally understood because, due to the nature of the product, when the absorbent body 8 has an hourglass shape, the upper limit of the size of the absorbent body 8 is determined.

[0097] As described above, in the disposable diaper 1, the constriction start positions 8Wa, 8Wb of the hourglass-shaped absorbent body 8 are located at least 10 mm from the fold line of the disposable diaper 1 when folded in half, toward the edges of the abdominal section 3 and the back section 2. In other words, the crotch portion of the absorbent body 8, which is easily affected by the wearer's leg-closing action, is narrowed. This prevents the absorbent body 8 from deforming inward in the width direction W (and away from the buttocks) due to the wearer's leg-closing action. This prevents the absorbent body 8 from deforming inward in the width direction W, pulling the buttocks-covering portion 30 toward the absorbent body 8 and, as a result, pulling the abdominal lower region BA4 toward the back section 2. This prevents the leg gathers 5 from leaving marks on the wearer's groin. Furthermore, since the absorber 8 can be prevented from deforming inward in the width direction W (and away from the buttocks), the leg gathered portions 5 can also be prevented from being pulled inward in the width direction W in response to the deformation of the absorber 8. This prevents the buttocks-covering portions from being pulled inward in the width direction and pulled up, allowing the buttocks-covering portions to properly cover and conceal the buttocks. In this way, the disposable diaper 1 can properly cover and conceal the buttocks while preventing the leg gathered portions 5 from leaving marks on the wearer's groin and suppressing the effects of the wearer's movements.

[0098] From the viewpoint of effectiveness, the constriction start positions 8Wa and 8Wb are more preferably 15 mm or more from the folding line, and even more preferably 20 mm or more.

[0099] In a preferred aspect of this embodiment, the buttocks-covering portion 30 may include an upper rear region, a central region, and a lower front region, which are regions obtained by virtually dividing the buttocks-covering portion 30 into three equal parts along the longitudinal direction L. In this case, the buttocks-covering portion 30 has buttocks elastic members 40 extending along the width direction W only in the lower region (see FIG. 5, etc.). Therefore, the buttocks-covering portion 30 lightly holds the buttocks in place in the lower region, preventing it from separating from the buttocks, while the upper and central regions fit around the buttocks, making it easier for the buttocks-covering portion 30 to assume a shape that bulges outward to cover the outside of the buttocks as a whole. This allows the buttocks-covering portion 30 to wrap around and appropriately conceal the buttocks. Furthermore, by wrapping around and concealing the buttocks, the buttocks-covering portion can enhance the sense of security that body waste leakage is prevented. The buttocks elastic member 40 may be one or two or more.

[0100] The disposable diaper of the present invention is not limited to the above-described embodiment, and can be appropriately combined with or modified in accordance with known techniques, etc., within the scope of the object and spirit of the present invention. [Explanation of symbols]

[0101] 1. Disposable diapers 2 Dorsal part 3 Ventral part 4. Absorbent body 5. Gathered leg part 5a Leg elastic member 10 Center of the main body 20 Dorsal extension 21 Dorsal body part 30 Buttocks cover 31 Central extension 40 Buttocks elastic member OA overlap area UA non-overlapping area SC side joint S4 Lower Range AA4 lower dorsal region BA4 ventral lower region

Claims

1. A disposable diaper having, in an unfolded state, longitudinal, width and thickness directions which are orthogonal to one another, a ventral section which covers the ventral side of a wearer, a dorsal section which covers the dorsal side, and an absorbent main body which covers the crotch of the wearer and includes an absorbent body, wherein the absorbent main body has front and rear ends in the longitudinal direction connected to central portions in the width direction of the ventral section and the dorsal section, respectively, and is formed by joining both side edges in the width direction of the ventral section and both side edges in the width direction of the dorsal section at a pair of side joining sections, The absorbent body is a main body central portion located at the center in the width direction and having an absorbent body; a pair of leg gathers located at both ends in the width direction and having a plurality of leg elastic members extending along the longitudinal direction; Including, The dorsal portion is a back body portion that is substantially coextensive with each of the pair of side joints in the longitudinal direction; a back-side extension portion extending forward from a front end edge of the back-side main body portion in the longitudinal direction; Including, The dorsal extension portion is an extending central portion overlapping the main body central portion in the thickness direction; a pair of buttocks cover portions extending outward from both widthwise edges of the extending central portion; Including, Each of the pair of buttocks covering portions has a buttocks elastic member extending along the width direction, an effective portion of the buttocks elastic member as an elastic member is within the range of each of the pair of buttocks covering portions; In each of the pair of side joints, when the length in the longitudinal direction is 100% and a length range of 15% from the inner end edge in the longitudinal direction is defined as a lower range, in the dorsal lower region and the ventral lower region, which are regions located between the lower ranges of the pair of side joints in each of the dorsal and ventral portions, the tensile stress in the width direction is greater in the ventral lower region than in the dorsal lower region. Disposable diapers.

2. the back side portion includes a plurality of back side portion elastic members extending along the width direction, the abdominal portion includes a plurality of abdominal portion elastic members extending along the width direction, the number of abdominal elastic members included in the abdominal lower region is greater than the number of dorsal elastic members included in the dorsal lower region; The disposable diaper according to claim 1.

3. The buttocks-covering portion has an inner region in the width direction joined to the leg gathered portion, the buttocks elastic members do not overlap in the thickness direction with the innermost leg elastic members that are located innermost in the width direction among the plurality of leg elastic members; The disposable diaper according to claim 1 or 2.

4. The buttocks-covering portion has an inner region in the width direction joined to the leg gathered portion, The buttocks elastic members overlap in the thickness direction with the outermost leg elastic members that are positioned outermost in the width direction among the plurality of leg elastic members. The disposable diaper according to claim 1 or 2.

5. the outermost leg elastic members located on the outermost sides in the width direction among the plurality of leg elastic members have the weakest elastic force among the plurality of leg elastic members; The disposable diaper according to claim 1 or 2.

6. When the distance between the outermost leg elastic member located outermost in the width direction among the plurality of leg elastic members and the second leg elastic member adjacent to the outermost leg elastic member on the inside in the width direction is defined as a first distance, and the distance between the second leg elastic member and the third leg elastic member adjacent to the second leg elastic member on the inside in the width direction is defined as a second distance, The second distance is shorter than the first distance. The disposable diaper according to claim 1 or 2.

7. Among the plurality of leg elastic members, an outermost leg elastic member located outermost in the width direction is spaced inward from the outermost end edge of each of the pair of leg gathered portions in the width direction. The disposable diaper according to claim 1 or 2.

8. The buttocks-covering portion has an inner region in the width direction joined to the leg gathered portion, the leg gather portion includes a stretchable region in which the plurality of leg elastic members are arranged, The buttocks-covering portion includes an overlapping region located on the inner side in the width direction, the overlapping region being located on the front side in the longitudinal direction and overlapping with the rear end region in the longitudinal direction of the stretchable region in the thickness direction. The disposable diaper according to claim 1 or 2.

9. The overlapping region is in a range of less than 50% of the length of the buttocks-covering portion in the longitudinal direction. The disposable diaper according to claim 8.

10. The absorbent body includes pulp fibers. The disposable diaper according to claim 1 or 2.

11. the absorbent body has an hourglass shape; The widest part of the hourglass shape is located on an extension line of the buttocks elastic member in the width direction. The disposable diaper according to claim 1 or 2.

12. the absorbent body has an hourglass shape; When the disposable paper diaper is folded in half so that a front edge of the ventral portion in the longitudinal direction L and a rear edge of the dorsal portion in the longitudinal direction L are aligned, the start position of the constriction in the hourglass shape is located 10 mm or more away from the fold line of the folded portion. The disposable diaper according to claim 1 or 2.

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