CN111374831B

CN111374831B - Disposable diaper having a disposable diaper

Info

Publication number: CN111374831B
Application number: CN201911216046.6A
Authority: CN
Inventors: 川上祐介; 高居义; 沈莲莲
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2018-12-29
Filing date: 2019-12-02
Publication date: 2022-10-28
Anticipated expiration: 2039-12-02
Also published as: JP6818119B2; CN212166012U; JP2020108742A; CN111374831A; WO2020137433A1

Abstract

Provided is a disposable diaper capable of suppressing leakage of liquid in the width direction. A disposable diaper includes a stomach-side portion, a back-side portion, and an absorbent body including an absorbent body. The absorbent body contains a super absorbent polymer and includes a crotch region, a back region overlapping with the back side in the thickness direction, and a stomach region overlapping with the stomach side in the thickness direction. At least one of the back-side region and the stomach-side region includes a low basis weight region in which the weight per unit area of the super absorbent polymer is lower than that in the crotch region. The absorbent main body includes a pair of side panels. The pair of side sheets each have: a fixing region fixed to a surface of the absorbent main body; and a leakage preventing wall, the outer edge of which in the width direction is fixed to the surface of the absorbent main body, and the inner edge of which in the width direction is not fixed. The edge of the fixing region on the center side in the longitudinal direction overlaps the low basis weight region in the thickness direction.

Description

Disposable diaper having a disposable diaper core

Technical Field

The present invention relates to a disposable diaper.

Background

Absorbent articles using an Absorbent material containing relatively large amounts of Super Absorbent Polymers (SAP) as the Absorbent material are known. An absorbent material containing a relatively large amount of superabsorbent polymer (so-called SAP sheet) is thin, and therefore can improve wearability, fit, and the like, and is therefore preferable. As such an absorbent body, for example, patent document 1 discloses an absorbent core including an absorbent material. The absorbent core is used in an absorbent article, and the absorbent material contains substantially no cellulose fibers and forms a pattern of discrete absorbent material regions. The pattern includes a dot formation region and at least one of a region extending in a width direction and a region extending in a length direction.

Documents of the prior art

Patent literature

Patent document 1: japanese patent application laid-open No. 2017-516542

Disclosure of Invention

Problems to be solved by the invention

When an absorbent body containing a relatively large amount of superabsorbent polymer is applied to a disposable diaper, it is considered to use an absorbent body in which the superabsorbent polymer is substantially uniformly arranged in a planar shape. In such a disposable diaper, when the superabsorbent polymer absorbs liquid (exemplified by urine) and gradually swells after wearing, the rigidity of the absorbent body increases, and the absorbent body has a relatively straight shape along the longitudinal direction. Thus, the pair of leakage preventing walls extending in the longitudinal direction along the absorbent body on both sides in the width direction of the absorbent body are pulled and extended in the longitudinal direction from both sides, and are less likely to rise toward the skin surface of the wearer. As a result, there is a possibility that the height of the leakage preventing walls is lowered to cause liquid to leak across the pair of leakage preventing walls in the width direction.

Here, in order to improve wearing comfort and the like, the absorbent body (absorbent core) of patent document 1 is divided into a plurality of regions in a plan view. However, the following cases are not considered: after the disposable diaper is worn, the absorbent body may absorb liquid and have a shape protruding outward.

An object of the present invention is to provide a disposable diaper containing a super absorbent polymer, wherein the disposable diaper can suppress leakage of a liquid in a width direction.

Means for solving the problems

The disposable diaper of the present invention is as follows. (1) A disposable diaper having a longitudinal direction, a width direction and a thickness direction which are orthogonal to each other, comprising a front side portion, a back side portion and an absorbent main body which is positioned between the front side portion and the back side portion and which includes an absorbent, wherein the absorbent contains a highly water-absorbent polymer, and the absorbent comprises: a crotch region; a back-side region adjacent to the crotch region on a back side of the crotch region in the longitudinal direction, overlapping with the back-side portion in the thickness direction; and a stomach-side region adjacent to the crotch region on a front side in the longitudinal direction of the crotch region, and overlapping with the stomach-side portion in the thickness direction, at least one of the back-side region and the stomach-side region including a low unit area weight region in which a unit area weight of the super absorbent polymer is lower than that of the crotch region, the absorbent main body including, on a skin-side surface, a pair of side sheets located on both sides in the width direction and extending in the longitudinal direction, the pair of side sheets each having: fixing regions which are located at end portions of the front and rear sides in the longitudinal direction of the side sheet and are fixed to a surface of the absorbent main body; and a leakage preventing wall including an elastic member extending in the longitudinal direction, the leakage preventing wall being located between the fixing regions on the front side and the rear side in the longitudinal direction of the side sheet, an outer end edge in the width direction being fixed to a surface of the absorbent main body, an inner end edge in the width direction being unfixed, and an end edge on a central side in the longitudinal direction of the fixing region overlapping with the low unit area weight region in the thickness direction.

In the disposable diaper of the present invention, since the abdomen-side region and/or the back-side region in the longitudinal direction of the absorbent member are provided with the low basis weight region in which the weight per unit area of the super absorbent polymer is low, the starting point of the change in the weight per unit area can be formed at a position between the low basis weight region and the crotch region in which the weight per unit area of the super absorbent polymer is high. That is, in the absorbent body, the starting point of the change in stiffness can be formed at a position between the low basis weight region having low stiffness and the crotch region having high stiffness in the longitudinal direction. Such a starting point becomes a bending starting point at which the end portion of the absorbent body is bent when a contraction force in the longitudinal direction of the leakage preventing wall is applied to the end portion of the absorbent body as a force toward the center in the longitudinal direction. In the disposable diaper, the bending start point, i.e., the crotch region-side end edge of the low basis weight region, is located closer to the center side than the center-side end edge in the longitudinal direction of the fixing region in plan view.

Here, when the superabsorbent polymer absorbs liquid and gradually swells after wearing, the absorbent body becomes higher in rigidity and has a relatively straight shape along the longitudinal direction, and therefore, the leakage preventing wall is pulled and extended from both sides in the longitudinal direction, and the contraction force in the longitudinal direction of the leakage preventing wall increases.

In this case, in the disposable diaper of the present invention, when the edge on the center side in the longitudinal direction of the fixing region is strongly pulled toward the center side by the contraction force in the longitudinal direction of the leakage preventing wall, the bending start point is set as described above, and therefore the absorbent body can be bent at the bending start point and the end portion in the longitudinal direction of the absorbent body can be raised toward the skin surface of the wearer. This reduces the extent to which the leakage preventing wall is pulled toward both sides in the longitudinal direction by the end portions in the longitudinal direction of the standing absorbent body, and the leakage preventing wall can be made to stand toward the skin surface of the wearer. That is, the height of the leakage preventing wall can be prevented from decreasing, and the liquid can be prevented from flowing over the leakage preventing wall and leaking in the width direction.

A disposable diaper according to the present invention may be (2) the disposable diaper according to the above (1), wherein an end edge of an effective portion of the elastic member on the side of the fixing region and the low basis weight region, which can exert an elastic force, overlap in the thickness direction.

In the disposable diaper, an end edge of the effective portion of the elastic member on the side of the fixing region overlaps the low basis weight region in the thickness direction. That is, the distance between the fixed region and the effective portion can be made close in a plan view. This makes it possible to easily pull the fixing region with the effective portion, and therefore, the absorbent body can be more easily folded at the fold starting point to raise the end portion in the longitudinal direction of the absorbent body toward the skin surface of the wearer. This can further reduce the extent to which the leakage preventing wall is pulled toward both sides in the longitudinal direction by the end portions in the longitudinal direction of the standing absorbent body, and can further raise the leakage preventing wall toward the skin surface of the wearer. That is, the height of the leakage preventing wall can be further suppressed from decreasing, and the liquid can be further suppressed from leaking in the width direction beyond the leakage preventing wall.

A disposable diaper according to the present invention may be (3) the disposable diaper according to (1) or (2), wherein a distance from a position of an end edge on a center side in the longitudinal direction of the anchor region to an end edge on the crotch region side of the low basis weight region is larger than a distance from a position of an end edge on a center side in the longitudinal direction of the anchor region to an end edge on an opposite side to the crotch region side of the low basis weight region.

In the disposable diaper, the distance from the position of the end edge on the center side in the longitudinal direction of the fixed region to the end edge on the crotch region side of the low unit area weight region is larger than the distance from the position of the end edge on the center side in the longitudinal direction of the fixed region to the end edge on the opposite side (back region or stomach region side) of the crotch region side of the low unit area weight region. Wherein the position of the end edge at the central side in the longitudinal direction of the fixing region is a position on which the contraction force of the leakage preventing wall acts. The end edge of the low basis weight region on the crotch region side is a position to be a bending start point. Therefore, in the disposable diaper, the position on which the contraction force acts is further away from the position of the folding start point. That is, in the disposable diaper, the distance between the fixing region on which the contraction force acts and the folding start point is made larger.

Here, in the case where the object fixed to the rotation shaft by the arm member is rotated around the rotation shaft by applying the force F in the direction perpendicular to the arm member to the object, the longer the length r of the arm member is, the larger the torque N for rotating the object is when the force F is constant.

In the disposable diaper, the bending start point corresponds to the rotation axis, and the member between the fixing region and the bending start point corresponds to the arm member, so that the distance between the fixing region and the bending start point corresponds to the length r of the arm member, the end portion including the fixing member of the absorbent body corresponds to the object, and the contraction force of the leakage preventing wall corresponds to the force F. Therefore, in the disposable diaper of the present invention, when the end portion of the absorbent body is rotated, that is, bent, with the bending start point as an axis and the contraction force of the leakage preventing wall, the force for bending the end portion of the absorbent body can be further increased by further increasing the distance between the fixing region and the bending start point without changing the contraction force of the leakage preventing wall. This enables the leakage preventing wall to further rise toward the skin surface of the wearer. That is, the height of the leakage preventing wall can be further suppressed from decreasing, and the liquid can be further suppressed from leaking in the width direction beyond the leakage preventing wall.

The disposable diaper of the present invention may be (4) the disposable diaper according to any one of (1) to (3), wherein at least one of the back-side region and the stomach-side region, which is a region including the low basis weight region, further includes a non-disposed region not including the high water absorbent polymer, the non-disposed region is adjacent to the low basis weight region on a side of the low basis weight region opposite to the crotch region side in the longitudinal direction, and at least a part of the anchor region overlaps the non-disposed region in the thickness direction in the longitudinal direction.

In the disposable diaper, the fixing region extends to the non-disposition region in the longitudinal direction, and at least a part of the fixing region overlaps with the non-disposition region in the thickness direction. Therefore, when the leakage preventing wall is pulled and fixed by the contraction, the portion located outside in the longitudinal direction of the low area weight region can be pulled together with the pull and fixed region. Therefore, the absorbent body can be prevented from being folded at a portion other than (the folding start point of) the low basis weight region. This makes it easier to bend the absorbent body at the bending start point of the low basis weight region, and makes it easier to raise the leakage preventing wall toward the skin surface of the wearer. As a result, the height of the leakage preventing wall can be further suppressed from decreasing, and the liquid can be further suppressed from leaking in the width direction beyond the leakage preventing wall.

The disposable diaper of the present invention may be (5) the disposable diaper according to the above (4), wherein an end edge of the fixing region on a side opposite to the leakage preventing wall side is located outside an end edge of the non-placement region on a side opposite to the low basis weight region side in the longitudinal direction.

In the disposable diaper, the fixing region extends beyond the non-placement region to the outside of the absorbent body in the longitudinal direction. Therefore, when the leakage preventing wall is pulled and fixed by contraction, the portion on the outer side in the longitudinal direction of the low basis weight region and the region including the outer portion of the absorbent body can be pulled together with the pulled and fixed region. Therefore, the absorbent body can be prevented from being folded at a portion other than (the folding start point of) the low basis weight region. This makes it easier to bend the absorbent body at the bending start point of the low basis weight region, and makes it easier to raise the leakage preventing wall toward the skin surface of the wearer. As a result, the height of the leakage preventing wall can be further suppressed from decreasing, and the liquid can be further suppressed from leaking in the width direction beyond the leakage preventing wall.

The disposable diaper of the present invention may be (6) the disposable diaper according to any one of (1) to (5) above, wherein the leakage preventing wall includes, in the width direction: a 1 st wall portion having an outer edge fixed to a surface of the absorbent main body; and a 2 nd wall portion having an inner end edge connected to an inner end edge of the 1 st wall portion, and an outer end edge that is not fixed.

In the disposable diaper, the leakage preventing wall has a shape of a laterally inverted letter V (convex inward) when viewed in the longitudinal direction. Therefore, the leakage preventing wall can be easily raised higher toward the skin surface of the wearer. As a result, the height of the leakage preventing wall can be further suppressed from decreasing, and the liquid can be further suppressed from leaking in the width direction beyond the leakage preventing wall.

A disposable diaper according to the present invention may be (7) the disposable diaper according to the above (1) to (6), wherein the back-side region has a back-side low unit area weight region as the low unit area weight region, the stomach-side region has a stomach-side high unit area weight region adjacent to the crotch region in the longitudinal direction, the unit area weight of the superabsorbent polymer is equal to the unit area weight of the superabsorbent polymer in the crotch region, a center-side end edge in the longitudinal direction of the fixing region on the rear side in the longitudinal direction overlaps the back-side low unit area weight region in the thickness direction, and a center-side end edge in the longitudinal direction of the fixing region on the front side in the longitudinal direction overlaps the stomach-side high unit area weight region in the thickness direction.

In the disposable diaper according to claim 7, since the back-side low basis weight region is provided in the back-side region of the absorber, the starting point of the change in stiffness, which is the starting point of the change in basis weight, can be formed at a position between the back-side low basis weight region and the crotch region. Such a starting point becomes a bending starting point at which the end portion of the absorbent body bends when a contraction force in the longitudinal direction of the leakage preventing wall, that is, a force toward the center in the longitudinal direction is applied to the end portion of the absorbent body. In the disposable diaper of the present invention, the bending start point, i.e., the crotch region side end edge of the back-side low basis weight region, is located closer to the center side than the center side end edge of the back-side fastening region in plan view. As a result, in the disposable diaper of the present invention, when the end edge on the center side of the back-side fastening region is strongly pulled toward the center side by the contraction force in the longitudinal direction of the leakage preventing wall, the absorbent body can be bent at the bend starting point and the end portion in the longitudinal direction of the absorbent body can be raised toward the skin surface of the wearer. This reduces the extent to which the leakage preventing wall is pulled toward both sides in the longitudinal direction by the end portions in the longitudinal direction of the standing absorbent body, and the leakage preventing wall can be made to stand toward the skin surface of the wearer.

In the disposable diaper of the present invention, the abdomen-side region of the absorber has the abdomen-side high basis weight region and does not have the low basis weight region, and therefore the position between the abdomen-side high basis weight region and the crotch region does not have a starting point of a change in stiffness, which is a starting point of a change in basis weight. Therefore, the end portion of the absorbent body is not bent near the end edge on the center side in the longitudinal direction of the abdomen-side fixing region, so that the adhesiveness of the abdomen-side portion is improved, and conduction leakage through the abdomen-side region can be suppressed.

Thus, the situation in which the height of the leakage preventing wall is lowered, the situation in which the liquid flows over the leakage preventing wall and leaks in the width direction, and the conduction leakage via the abdomen side can be suppressed, and the adhesion can be improved.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a disposable diaper can be provided which contains a super absorbent polymer, wherein the disposable diaper can suppress leakage of liquid in the width direction.

Drawings

Fig. 1 is a plan view showing a configuration example of a disposable diaper according to an embodiment.

Fig. 2 is a sectional view taken along line II-II of fig. 1.

Fig. 3 is a plan view and a sectional view showing a structural example of the absorber of the embodiment.

Fig. 4 is a partially enlarged plan view of the back side portion of the disposable diaper according to the embodiment.

Fig. 5 is a partially enlarged plan view of the abdomen-side portion of the disposable diaper according to the embodiment.

Fig. 6 is a schematic diagram illustrating the effect of the disposable diaper of the embodiment.

Fig. 7 is a sectional view taken along line II-II of fig. 1 of another embodiment.

Fig. 8 is a partially enlarged plan view of a back side portion of a disposable diaper according to another embodiment.

Description of the reference numerals

1. A disposable diaper; 2. the ventral portion (ventral waistband); 3. a dorsal side portion (dorsal waistband); 10. an absorbent main body; 14. an absorbent body; 15. a fixed area; 15E, end edges; 16. a leakage preventing wall; 17. a side panel; BA. A back side region; FA. A ventral region; MA, crotch region.

Detailed Description

Hereinafter, a disposable diaper according to an embodiment will be described by taking a pants-type disposable diaper as an example. The type of the disposable diaper is not limited to this example, and other types of disposable diapers may be used without departing from the scope of the present invention. Examples of such a disposable diaper include tape-type disposable diapers.

Fig. 1 and 2 are views showing a configuration example of a disposable diaper 1 according to an embodiment. Fig. 1 is a plan view showing a state in which a disposable diaper 1 is unfolded, and fig. 2 is a sectional view taken along a line II-II of fig. 1. The disposable diaper 1 has a longitudinal direction L, a width direction W, and a thickness direction T which are orthogonal to each other in the state shown in fig. 1, and has a longitudinal direction center line CL which passes through the center in the width direction W and extends in the longitudinal direction L, and a width direction center line CW which passes through the center in the length direction L and extends in the width direction W. The direction and the side close to the longitudinal center line CL are set as the inward direction and the inward side in the width direction W, respectively, and the direction and the side away from the longitudinal center line CL are set as the outward direction and the outward side in the width direction W, respectively. The direction and the side closer to the width direction center line CW are set as the inward direction and the inward side in the longitudinal direction L, respectively, and the direction and the side farther from the width direction center line CW are set as the outward direction and the outward side in the longitudinal direction L, respectively. In addition, a side in the longitudinal direction L that faces an end edge (an end edge on the abdomen side) of the disposable diaper 1 corresponding to the abdomen of the wearer is also referred to as a front side in the longitudinal direction L, and a side in the longitudinal direction L that faces an end edge (an end edge on the back side) of the disposable diaper 1 corresponding to the back of the wearer is also referred to as a rear side in the longitudinal direction L. The "plan view" refers to the disposable diaper 1 in a state where a plane including the longitudinal direction L and the width direction W is developed as viewed from the upper side in the thickness direction T, and the "plan view" refers to a shape grasped in the plan view. The "planar direction" is an arbitrary direction parallel to a plane including the width direction W and the length direction L. The "skin side" and the "non-skin side" are respectively a side relatively close to the skin surface of the wearer and a side relatively distant from the skin surface of the wearer in the thickness direction T when the disposable diaper 1 is worn on the wearer. These definitions apply not only to the disposable diaper 1 but also to the absorbent member of the disposable diaper 1 and the respective materials disposed thereon.

The case where the member, the structure, the shape, or the like extends in the longitudinal direction L includes not only the case where the member or the like is parallel to the longitudinal direction L but also the case where the component Dx in the longitudinal direction L of the member or the like is larger than the component Dy in the width direction W of the member or the like (Dx > Dy). Similarly, the case where the member or the like extends in the width direction W includes not only the case where the member or the like is parallel to the width direction W but also the case where the component Dy in the width direction W of the member or the like is larger than the component Dx in the longitudinal direction L of the member or the like (Dy > Dx). For a curved or curved member, the member is evaluated as described above with respect to the tangent line at each point on the curve or the like.

As shown in fig. 1, the disposable diaper 1 includes, in the longitudinal direction L, an abdominal portion (abdominal-side waistband) 2, a back portion (back-side waistband) 3, and an absorbent main body 10 positioned between the abdominal portion 2 and the back portion 3. In the present embodiment, the disposable diaper 1 further includes a crotch portion 4 located between the abdomen-side portion 2 and the back-side portion 3. The abdomen portion 2 is a portion that abuts against the abdomen of the wearer. The back portion 3 is a portion that abuts against the hip or the back of the wearer. The absorbent main body 10 is a portion that comes into contact with the crotch of the wearer, and has one end portion in the longitudinal direction L laminated to the stomach-side portion 2 and the other end portion in the longitudinal direction L laminated to the back-side portion 3. The crotch portion 4 is a portion that supports the absorbent main body 10 from the non-skin side. The disposable diaper 1 is formed by overlapping both

end portions

2a, 2a in the width direction W of the abdomen-side portion 2 and both

end portions

3a, 3a in the width direction W of the back-side portion 3 in the thickness direction T, respectively, and joining them along the longitudinal direction L. In this case, in the disposable diaper 1, the waist opening through which the waist of the wearer passes is defined by the outer end 2e of the stomach-side portion 2 in the longitudinal direction L and the outer end 3e of the back-side portion 3 in the longitudinal direction L. In the disposable diaper 1, a pair of leg openings through which the legs of the wearer pass are defined by the

side portions

5e, 5e on both sides in the width direction W of the crotch portion 4. The abdomen-side portion (abdomen-side waistband) 2 and the back-side portion (back-side waistband) 3 can be said to be defined by the range in the longitudinal direction L where both end

portions

2a, 2a are joined to both

end portions

3a, 3 a.

In the present embodiment, in the state shown in fig. 1, each of the ventral portion 2 and the dorsal portion 3 has a rectangular shape that expands substantially along the width direction W, and is separated from each other in the longitudinal direction L. The crotch portion 4 is located between the stomach portion 2 and the back portion 3, and both side edges in the width direction W are recessed inward in the width direction W. The stomach-side portion 2, the crotch portion 4, and the back-side portion 3 are formed integrally with each other. In another embodiment, the stomach-side section 2, the crotch section 4, and the back-side section 3 are formed independently of each other. In another embodiment (not shown), the disposable diaper 1 includes the abdomen-side portion 2 and the back-side portion 3, and does not include the crotch portion 4.

In the present embodiment, the stomach portion 2, the back portion 3, and the crotch portion 4 are provided with liquid-impermeable cover sheets (sheet members) 5. The cover sheet 5 includes a cover sheet 5a on the skin side and a cover sheet 5b on the non-skin side. The cover sheet 5a and the cover sheet 5b are stacked in the thickness direction T and bonded to each other with an adhesive or the like. Both ends in the longitudinal direction L of the covering sheet 5b are folded back toward the skin side so as to cover both ends in the longitudinal direction L of the covering sheet 5 a. In this case, the portion of the covering sheet 5b at the folded-back position of the abdomen portion 2 constitutes the end 2e of the abdomen portion 2, and the portion of the covering sheet 5b at the folded-back position of the back portion 3 constitutes the end 3e of the back portion 3.

Examples of the cover sheet 5 include liquid-impermeable nonwoven fabric, synthetic resin film, composite sheet thereof, SB nonwoven fabric,An optional liquid-impermeable sheet such as SMS nonwoven fabric. Examples of the material of the cover sheet 5 include polyolefin materials such as polypropylene and polyethylene. The weight per unit area of the cover sheet 5 is, for example, 5g/m ² ～100g/m ² Preferably 10g/m ² ～50g/m ² . The dimension (thickness) of the cover sheet 5 in the thickness direction T is, for example, 0.1mm to 5mm, preferably 0.1mm to 2mm. In another embodiment, the number of the cover sheets 5 is one or three or more (not shown). In yet another embodiment, the cover sheet 5b is not folded back (not shown).

In the present embodiment, the abdomen-side portion 2 is provided with a plurality of elastic members 6a, 6b for waist gather between the covering sheet 5a and the covering sheet 5b, and the back-side portion 3 is provided with a plurality of

elastic members

7a, 7b for waist gather between the covering sheet 5a and the covering sheet 5b. The plurality of elastic members 6a and 6b are disposed inside and outside the abdominal portion 2 in the longitudinal direction L. The plurality of elastic members 6a extend in the width direction W in predetermined regions located on both sides with respect to the longitudinal center line CL and are arranged at intervals in the longitudinal direction L. The predetermined region is a region from the end portion 2a to a portion inside an end edge of the absorbent main body 10 in the width direction W opposed to the end portion 2 a. The plurality of elastic members 6b extend from the one end portion 2a to the other end portion 2a in the width direction W, and are arranged at intervals in the longitudinal direction L. Similarly, the plurality of

elastic members

7a and 7b are disposed inside and outside the back portion 3 in the longitudinal direction L. The plurality of elastic members 7a extend in the width direction W in predetermined regions located on both sides with respect to the longitudinal center line CL and are arranged at intervals in the longitudinal direction L. The predetermined region is a region from the end portion 3a to a portion inside an end edge of the absorbent main body 10 in the width direction W opposed to the end portion 3 a. The plurality of elastic members 7b extend from the one end portion 3a to the other end portion 3a in the width direction W and are arranged at intervals in the longitudinal direction L. The plurality of

elastic members

6a, 6b, 7a, and 7b are for extending and contracting the waist opening, and are exemplified by rubber bands. The abdomen-side portion (abdomen-side waistband) 2 and the back-side portion (back-side waistband) 3 may be defined by a range in the longitudinal direction L in which the plurality of

elastic members

6a, 6b, 7a, 7b are arranged.

In the present embodiment, the disposable diaper 1 includes a plurality of elastic members 8 for leg gathers from the crotch portion 4 to the back portion 3 and the stomach portion 2. The plurality of elastic members 8 extend in the longitudinal direction L mainly at both ends in the width direction W of the crotch portion 4. The plurality of elastic members 8 are for expanding and contracting the pair of leg openings, respectively, and are exemplified by rubber bands.

In the present embodiment, the absorbent body 10 has a substantially rectangular shape, and includes a liquid-permeable front sheet 12, a liquid-impermeable back sheet 13, and an absorbent body 14 that is positioned between the front sheet 12 and the back sheet 13 and absorbs and retains liquid. Examples of the top sheet 12 include a liquid-permeable nonwoven fabric, a woven fabric, a synthetic resin film having liquid-permeable holes formed therein, and a composite sheet thereof. Examples of the back sheet 13 include liquid impermeable nonwoven fabric, synthetic resin film, composite sheet thereof, and SMS nonwoven fabric. The absorbent body 14 includes an absorbent core for absorbing and retaining liquid and a core cladding for enclosing the absorbent core in the present embodiment. The absorbent body 14 will be described in detail later. The absorbent body 14, the front sheet 12, and the back sheet 13 are bonded together with an adhesive, and the front sheet 12 and the back sheet 13 are bonded together with an adhesive at their peripheral edge portions. The adhesive is a material known in disposable diapers, and examples thereof include a hot melt adhesive. The shape of the absorbent main body 10 is not limited to the above example as long as it is long in the longitudinal direction L, and examples thereof include a rectangular shape with rounded corners, a rectangular shape with a short side being a curve protruding outward, and an hourglass shape. In another embodiment, the back sheet 13 is omitted, and the non-skin side surface of the absorbent body 14 and the non-skin side surface of the peripheral edge portion of the top sheet 12 are joined to the cover sheet 5.

In the present embodiment, the surface of the absorbent main body 10 on the skin side includes a pair of

side sheets

17 and 17 located on both sides in the width direction W and extending along the longitudinal direction L. Each side sheet 17 has a leakage preventing wall 16 and

fastening regions

15, 15. The

fastening regions

15, 15 are positioned at the front and rear ends of the side sheet 17 in the longitudinal direction L and are fastened to the skin-side surface of the absorbent main body 10. The leakage preventing wall 16 is positioned between and adjacent to the front and

rear fixing regions

15, 15 in the longitudinal direction L of the side sheet 17, and has an outer end edge in the width direction W fixed to the skin-side surface of the absorbent main body 10 and an inner end edge in the width direction W unfixed. In this case, the leakage preventing walls 16 and the

fastening regions

15, 15 are formed by, for example, inner portions of the side sheets 17 in the width direction W, and outer portions of the side sheets 17 in the width direction W are fastened to the absorbent main body 10. In this manner, the absorbent main body 10 includes the pair of

leakage preventing walls

16, 16. The pair of

leakage preventing walls

16, 16 are disposed so as to face each other at both end portions in the width direction W on the skin side of the absorbent main body 10, and extend continuously along the longitudinal direction L. Each of the leakage preventing walls 16 includes two elastic members 61 extending in the longitudinal direction L at inner ends in the width direction W. The elastic member 61 is exemplified as a rubber band. In another embodiment, the inner ends of the pair of

leakage preventing walls

16 and 16 in the width direction W are further folded back to the outer sides in the width direction W (described later). In another embodiment, the number of the elastic members 61 is one or more than three. The pair of

leakage preventing walls

16, 16 are each formed of a hydrophobic sheet, such as a hydrophobic nonwoven fabric. In another embodiment, the pair of

leakage preventing walls

16, 16 are each formed of a hydrophilic sheet, such as a hydrophilic nonwoven fabric.

Next, the absorbent body 14 will be described with reference to fig. 1 to 3. Fig. 3 is a diagram showing a configuration example of the absorbent body 14 of the embodiment, fig. 3 (a) is a plan view, and fig. 3 (b) is a cross-sectional view taken along line IIIb-IIIb in fig. 3 (a). The absorbent body 14 is a layer having liquid absorbing performance and liquid retaining performance, and in the present embodiment includes a 1 st absorbent layer 41 on the skin side, a 2 nd absorbent layer 42 on the non-skin side, and an intermediate layer 43 between the 1 st absorbent layer 41 and the 2 nd absorbent layer 42. The absorbent body 14 has a two-layer structure in which a 1 st absorbent layer 41, an intermediate layer 43, and a 2 nd absorbent layer 42 are sequentially stacked in the thickness direction T. In another embodiment, the absorber 14 has a single-layer structure in which the 1 st absorption layer 41 and the 2 nd absorption layer 42 are integrated in the thickness direction, and the intermediate layer 43 is not present. In another embodiment, the absorbent body 14 has a multilayer structure of three or more layers in which another intermediate layer and another absorbent layer are further stacked between the 1 st absorbent layer 41 and the 2 nd absorbent layer 42. In another embodiment, the 1 st absorbent layer 41 is on the skin side and the 2 nd absorbent layer 42 is on the non-skin side.

In the present embodiment, the absorber 14 has a substantially rectangular planar shape extending along the longitudinal direction L. The absorbent body 14 can be considered to have the 1 st and 2 nd water

absorbent materials

45 and 47 as absorbent cores and the 1 st and 2

nd base materials

44 and 46 as core claddings. However, the shape is not particularly limited, and examples thereof include a rectangle having a short side projecting in an arc shape, a rounded rectangle, an ellipse, and an hourglass shape. The thickness of the absorbent member 14 is, for example, 0.5mm to 20mm, preferably 1mm to 10mm. The basis weight of the absorbent body 14 can be appropriately adjusted according to the absorption performance required of the pants-type diaper 1, but for example, 60g/m is mentioned ² ～1600g/m ² 。

In the present embodiment, the 1 st absorbent layer 41 includes a 1 st base 44 formed of a liquid-permeable sheet and a 1 st absorbent material 45 having a water-absorbent material containing a water-absorbent polymer and disposed on the intermediate layer 43 side of the 1 st base 44. The 1 st absorbent layer 41 can be viewed as having the 1 st absorbent material 45 as the absorbent core and the 1 st substrate 44 (and intermediate layer 43) as the core cladding. In addition, in another embodiment, a core wrap sheet such as a cotton paper in which the 1 st water absorbent material 45 is wrapped is provided as a core wrap layer at the inner side thereof in addition to the 1 st base material 44 (and the intermediate layer 43). The 1 st water absorbent material 45 is fixed to at least one of the 1 st base material 44 and the intermediate layer 43 with an adhesive applied to at least one of the surface of the 1 st base material 44 on the intermediate layer 43 side and the surface of the intermediate layer 43 on the 1 st base material 44 side. The water absorbing material of the 1 st water absorbing material 45 is disposed in the 1 st absorbing layer 41 with a substantially uniform basis weight. However, the weight per unit area of the end portions in the longitudinal direction L and/or the width direction W may gradually decrease toward the end edges. In this case, the end portion is, for example, a region at both ends in the longitudinal direction L and/or the width direction W, in which the dimension in the longitudinal direction L and/or the width direction W is within 10% of the maximum dimension in the longitudinal direction L and/or the width direction W. In another embodiment, the water absorbing materials of the 1 st water absorbing material 45 are arranged in a predetermined distribution having sites with a large weight per unit area and sites with a small weight per unit area in the 1 st absorbing layer 41. The 1 st water absorbing material 45 has a substantially rectangular planar shape. The 1 st base material 44 has a substantially rectangular planar shape, and covers the 1 st absorbent material 45 from the skin side in plan view, and the peripheral edge portion of the 1 st base material 44 extends slightly outward from the periphery of the 1 st absorbent material 45. The outer dimension (outer edge) of the 1 st absorbent layer 41 in the planar direction is set to, for example, the outer dimension (outer edge) of the 1 st absorbent material 45 in the planar direction. The outer dimension (outer edge) is measured, for example, at an intermediate position in the thickness direction T of the 1 st water absorbent material 45.

In the present embodiment, the 2 nd absorbent layer 42 includes a 2 nd base 46 formed of a sheet having water retentivity and liquid diffusibility, and a 2 nd absorbent 47 having a water absorbent material containing a water absorbent polymer and disposed at a position closer to the intermediate layer 43 than the 2 nd base 46. The 2 nd absorbent layer 42 can be considered to have the 2 nd absorbent material 47 as the absorbent core and the 2 nd substrate 46 (and intermediate layer 43) as the core cladding. In addition, in another embodiment, in addition to the 2 nd base material 46 (and the intermediate layer 43), there is a core clad sheet such as a cotton paper sheet as a core clad layer on the inner side thereof in which the 2 nd water absorbent material 47 is wrapped. The 2 nd water absorbing material 47 is fixed to at least one of the 2 nd base material 46 and the intermediate layer 43 with an adhesive applied to at least one of the surface of the 2 nd base material 46 on the intermediate layer 43 side and the surface of the intermediate layer 43 on the 2 nd base material 46 side. The absorbent material of the 2 nd absorbent material 47 is disposed in the 2 nd absorbent layer 42 with a substantially uniform basis weight except for the pair of channels 48, 48 (described later). However, the weight per unit area of the end portions in the longitudinal direction L and/or the width direction W may gradually decrease toward the end edges. In this case, the end portions are as described above. In another embodiment, the water absorbent material of the 2 nd water absorbent material 47 is disposed in a predetermined distribution having sites with a large weight per unit area and sites with a small weight per unit area within the 2 nd absorbent layer 42. The 2 nd water absorbing material 47 has a substantially rectangular planar shape one turn larger than the 1 st water absorbing material 45 in the width direction W and the length direction L. The 2 nd base 46 has a substantially rectangular planar shape, and covers the 2 nd water absorbent member 47 from the non-skin side in plan view, and the peripheral edge portion of the 2 nd base 46 extends slightly outward from the periphery of the 2 nd water absorbent member 47. At this time, both end portions in the width direction W of the 2 nd base material 46 cover both side surfaces of the 2 nd water absorbent material 47, and cover skin-side surfaces of both end portions in the width direction W of the 1 st base material 44. That is, on the skin-side surface of the end portion in the width direction W of the 1 st absorbent layer 41, the end portion in the width direction W of the 2 nd base material 46 and the end portion in the width direction W of the 1 st base material 44 are overlapped and joined. The outer dimension (outer edge) of the 2 nd absorbent layer 42 in the plane direction is set to, for example, the outer dimension (outer edge) of the 2 nd absorbent material 47 in the plane direction. The outer dimension (outer edge) is measured, for example, at an intermediate position in the thickness direction T of the 2 nd water absorbing material 47.

As described above, the both end portions in the width direction W of the 2 nd base 46 cover the side surfaces in the width direction W of the 2 nd water absorbent 47 and the side surfaces in the width direction W of the 1 st base 44, whereby the 2 nd water absorbent 47 is enclosed in the 2 nd absorbent layer 42 in the width direction W and the 1 st water absorbent 45 is enclosed in the 1 st absorbent layer 41 in the width direction W. In another embodiment, both ends of the 1 st base 44 in the width direction W cover both ends of the 2 nd base 46 in the width direction W. In another embodiment, the 1 st base material 44, the intermediate layer 43, and the 2 nd base material 46 are laminated and joined in the thickness direction T at both ends in the width direction W.

In the present embodiment, the 1 st base material 44, the intermediate layer 43, and the 2 nd base material 46 are laminated and joined in the thickness direction T at both ends in the longitudinal direction L of the absorbent body 14. Thus, the 1 st water absorbent material 45 is enclosed in the 1 st absorbent layer 41 by the 1 st base material 44 and the intermediate layer 43 in the longitudinal direction L, and the 2 nd water absorbent material 47 is enclosed in the 2 nd absorbent layer 42 by the 2 nd base material 46 and the intermediate layer 43 in the longitudinal direction L. In another embodiment, both ends of the absorbent body 14 in the longitudinal direction L are not covered with the 1 st base material 44 and the 2 nd base material 46.

In the present embodiment, the intermediate layer 43 is a liquid-permeable sheet and has a substantially rectangular planar shape. The intermediate layer 43 includes an upper layer 43a and a pair of

lower layers

43b, 43b adjacent to the upper layer 43a on both sides of the non-skin side surface of the upper layer 43a in the width direction W. The intermediate layer 43 is formed by folding back and overlapping a pair of side portions located on both sides of a central portion in the width direction W toward the non-skin side of the central portion in a sheet member having a substantially rectangular planar shape. At this time, the central portion of the sheet member becomes the upper layer 43a, and the pair of side portions of the sheet member becomes the pair of

lower layers

43b, 43b. Therefore, both sides of the intermediate layer 43 in the width direction W have a two-layer structure in which the upper layer 43a and the lower layer 43b are laminated, and have a substantially rectangular shape extending along the longitudinal direction L. The intermediate layer 43 has a single-layer structure in which only the upper layer 43a is present in a portion 43d near the center in the width direction W, and has a substantially rectangular shape extending along the longitudinal direction L. The upper layer 43a and the lower layer 43b of the two-layer structure are joined by a pair of heat-

seal portions

43c, 43c extending in the longitudinal direction L on both sides in the width direction W of the portion 43 d. The heat-seal lands 43c are formed by heating and compression. In another embodiment, the upper layer 43a and the lower layer 43b of the two-layer construction are joined with embossed portions extending along the length direction L on both sides in the width direction W of the portion 43 d. The embossed portion is formed by compression. In another embodiment, the heat-seal land and the embossed land have a shape of a plurality of dots, a plurality of curves, or a pattern. Both end edges in the width direction W of the intermediate layer 43 are sandwiched and bonded to both end portions in the width direction W of the 1 st base material 44 and the 2 nd base material 46, and both end edges in the length direction L of the intermediate layer 43 are sandwiched and bonded to both end portions in the length direction L of the 1 st base material 44 and the 2 nd base material 46. In another embodiment, the two edges in the longitudinal direction L are not sandwiched between and joined to the two ends in the longitudinal direction L of the 1 st substrate 44 and the 2 nd substrate 46. By adopting the double-layer structure, the liquid can be temporarily stored, and the time required for the super absorbent polymer to absorb can be easily ensured.

In the present embodiment, the absorber 14 has a pair of

channels

48, 48 extending along the longitudinal direction L. The pair of

passages

48, 48 are strip-shaped regions that are located in the 2 nd absorption layer 42, extend in the longitudinal direction L, and are arranged at predetermined intervals on both sides in the width direction W with a longitudinal center line CL therebetween. The channel 48 is formed at least in the center portion in the longitudinal direction L across the width direction center line CW. In another embodiment, the channel 48 is formed to reach at least one of both end edges in the longitudinal direction L. The pattern of the pair of

passages

48, 48 in plan view is, for example, a pattern formed so that the interval between the two is constant along the longitudinal direction L. In another embodiment, the pattern of the pair of

passages

48, 48 is formed such that the interval between the passages is narrower near the center in the longitudinal direction L and expands toward both outer sides in the longitudinal direction L, for example. Here, the channels 48 are regions where the weight per unit area of the water-absorbing material is smaller than the regions around the channels of the absorbent body 14, for example, regions where the weight per unit area of the water-absorbing material is smaller than the regions around the channels 48 of the 2 nd absorbent layer 42, including the case where the weight per unit area is zero. The channels 48 are formed in such a manner that the 2 nd base material 46 is recessed toward the intermediate layer 43 side, that is, the 2 nd water absorbing material 47 is recessed toward the intermediate layer 43 side. In another embodiment, the 2 nd water absorbent 47 is formed so as to be recessed toward the 2 nd base 46 side. The pair of

passages

48, 48 overlaps the pair of heat-

seal lands

43c, 43c in the thickness direction T. In another embodiment, at least a part of the passage 48 does not overlap with the heat-seal land 43c in the thickness direction T. In addition, in another embodiment, the channel 48 does not extend along the length direction L but extends along the width direction W, or extends along not only the length direction L but also the width direction W. In yet another embodiment, the channel 48 is one or more than three. In yet another embodiment, the channel 48 is not formed in the 2 nd absorption layer 42 but formed in the 1 st absorption layer 41, or is formed in the 1 st absorption layer 41 in addition to the 2 nd absorption layer 42. In yet another embodiment, the channel 48 is not formed.

As described above, the 1 st and 2 nd

water Absorbent materials

45 and 47 contain Super Absorbent Polymers (SAP). The super absorbent polymer is not particularly limited as long as it can absorb and retain water, and examples thereof include granular or fibrous super absorbent polymers. The basis weights of the super absorbent polymers of the 1 st water absorbent material 45 and the 2 nd water absorbent material 47 can be appropriately adjusted according to the absorption performance required for the disposable diaper 1, but for example, the basis weights are respectively 10g/m ² ～500g/m ² Preferably 100g/m ² ～400g/m ² . The basis weights of the 1 st water-absorbing material 45 and the 2 nd water-absorbing material 47 may be larger in one than in the other, or may be the same. Wherein, the same means that one is in the range of 100% + -30% of the other. The 1 st water absorbing material 45 and the 2 nd water absorbing material 47 may further contain hydrophilic fibers such as pulp fibers and water absorbing fibers. The proportion of the super absorbent polymer to the 1 st water absorbent material 45 and the 2 nd water absorbent material 47 is, for example, 80 to 100% by mass, preferably 90 to 100% by mass, and more preferably 95 to 100% by mass. Therefore, the 1 st water absorbent material 45 and the 2 nd water absorbent material 47 can be said to contain a super absorbent polymer as a main component, and the absorbent body 14 can be said to be a so-called SAP sheet. The proportion of the super absorbent polymer to the absorbent body 14 (including not only the 1 st and 2 nd water

absorbent materials

45 and 47 but also the adhesive, the 1 st base material 44, the intermediate layer 43, and the 2 nd base material 46) is, for example, 40 to 80% by mass, preferably 50 to 80% by mass, and more preferably 60 to 80% by mass. In the present embodiment, the 1 st water absorbing material 45 and the 2 nd water absorbing material 47 are formed only of a super absorbent polymer and do not contain hydrophilic fibers. In another embodiment, the 1 st water absorbent material 45 and the 2 nd water absorbent material 47 contain pulp fibers and/or water absorbent fibers in addition to the super absorbent polymer.

Examples of the super absorbent polymer include starch-based, cellulose-based, and synthetic polymer-based polymeric absorbents. Examples of the starch-based or cellulose-based super absorbent polymer include a starch-acrylic acid (salt) graft copolymer, a saponified product of a starch-acrylonitrile copolymer, and a crosslinked product of sodium carboxymethylcellulose. Examples of the synthetic polymer-based super absorbent polymer include polyacrylate-based, polysulfonate-based, maleic anhydride-based, polyacrylamide-based, polyvinyl alcohol-based, polyethylene oxide-based, polyaspartate-based, polyglutamate-based, polyalphamate-based, starch-based, and cellulose-based polymers. In the present embodiment, a polyacrylate-based (particularly, sodium polyacrylate-based) super absorbent polymer is preferable. In addition, in the present embodiment, it is preferable that 90% by mass to 100% by mass of the super absorbent polymer in the absorbent body 14 is formed of super absorbent polymer particles having a particle diameter of 150 μm to 500 μm. The superabsorbent polymer particles having such a particle size distribution have a small and uniform particle size and are therefore easily retained in the adhesive. The particle diameter of the super absorbent polymer particles is measured in accordance with JIS R6002: the screening test method described in 1998 was standard.

The adhesive is not particularly limited as long as it can fix the super absorbent polymer, and examples thereof include a hot melt adhesive. The pattern of the adhesive to be applied is not particularly limited, but examples thereof include a continuous or intermittent Ω pattern, a spiral pattern, and a line pattern. The basis weight of the adhesive can be adjusted appropriately so as not to significantly reduce the liquid absorbency of the absorbent body 14, and for example, each layer is 3g/m ² ～50g/m ² . Each layer is a layer of the adhesive between the 1 st water absorbent material 45 and the 1 st base 44, a layer of the adhesive between the 1 st water absorbent material 45 and the intermediate layer 43, a layer of the adhesive between the 2 nd water absorbent material 47 and the 2 nd base 46, and a layer of the adhesive between the 2 nd water absorbent material 47 and the intermediate layer 43.

The 1 st base material 44 is not particularly limited as long as it is a liquid-permeable sheet. Examples of the 1 st substrate 44 include a liquid-permeable nonwoven fabric, a hydrophilic nonwoven fabric, and a laminated nonwoven fabric thereof, and among them, a nonwoven fabric having high water permeability is preferable. Examples of the nonwoven fabric include a spunbond nonwoven fabric and a through-air nonwoven fabric formed of polyolefin fibers such as Polyethylene (PE) and polypropylene (PP), polyester fibers such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT) and polyethylene naphthalate (PEN), and a combination thereof. These fibers are preferably subjected to hydrophilization treatment by a known method. Alternatively, for example, an air-laid nonwoven fabric in which hydrophilic fibers such as pulp fibers and rayon fibers are coated with a hydrophilic binder, and a spunlace nonwoven fabric in which the hydrophilic fibers and the synthetic fibers are combined may be mentioned. In this embodiment, use is made ofAn air-laid nonwoven fabric having liquid permeability and liquid retention properties, which is obtained by coating pulp fibers with a hydrophilic binder. Further, as the 1 st base material 44, one kind or plural kinds of the above nonwoven fabrics may be laminated in plural. The weight per unit area of the 1 st substrate 44 is, for example, 10g/m ² ～100g/m ² Preferably 20g/m ² ～80g/m ² . The thickness of the 1 st substrate 44 is, for example, 0.1mm to 5mm, preferably 0.15mm to 3mm.

The 2 nd substrate 46 is not particularly limited as long as it is a sheet having water retentivity and liquid diffusibility. Examples of the 2 nd base 46 include nonwoven fabrics formed of synthetic fibers such as polyamide fibers, regenerated fibers such as rayon fibers and acetate fibers, natural fibers such as cotton, silk, hemp and pulp (cellulose) fibers, or a combination thereof. Specifically, for example, a spunbonded nonwoven fabric containing nylon and a spunlace nonwoven fabric containing rayon fibers and/or pulp fibers can be cited. The spun lace nonwoven fabric containing rayon fibers and/or pulp fibers may also contain polyolefin fibers and/or polyester fibers. In the present embodiment, a spunlace nonwoven fabric containing rayon fibers and pulp fibers, which has liquid retention and liquid diffusion properties, is used. Further, as the 2 nd base material 46, one kind or plural kinds of the above nonwoven fabrics may be laminated in plural. The weight per unit area of the 2 nd substrate 46 is, for example, 10g/m ² ～200g/m ² Preferably 35g/m ² ～150g/m ² . The thickness of the 2 nd substrate 46 is, for example, 0.1mm to 5mm, preferably 0.15mm to 3mm.

The intermediate layer 43 is not particularly limited as long as it is a liquid-permeable sheet. As the intermediate layer 43, for example, the same sheet as the 1 st substrate 44 can be used. The weight per unit area of the intermediate layer 43 is, for example, 10g/m ² ～100g/m ² Preferably 15g/m ² ～80g/m ² . The thickness of the intermediate layer 43 is, for example, 0.1mm to 5mm, preferably 0.15mm to 3mm.

In the present embodiment, as shown in fig. 3, the absorber 14 includes a back-side region BA, a stomach-side region FA, and a crotch region MA which are arranged along the longitudinal direction L. Here, the back-side area BA is an area of the absorbent body 14 that overlaps with the back-side portion 3 in the thickness direction T. The stomach-side region FA is a region of the absorbent body 14 that overlaps the stomach-side portion 2 in the thickness direction T. The crotch region MA is a region located between the back-side region BA and the stomach-side region FA of the absorber 14, i.e., a region overlapping the crotch portion 4 in the thickness direction T. Thus, the absorber 14 is divided into a back-side region BA overlapping the back-side portion 3, a stomach-side region FA overlapping the stomach-side portion 2, and a crotch region MA overlapping the crotch portion 4 along the longitudinal direction L.

In the present embodiment, the absorber 14 includes a high basis weight region 14a, a low basis weight region 14b, and a non-arrangement region 14c. The high basis weight region 14a is a region in which the basis weight of the super absorbent polymer is high, and is a region in which the 1 st absorbent layer 41 and the 2 nd absorbent layer 42 overlap in the thickness direction T. The boundary between the high basis weight region 14a and the low basis weight region 14b is, for example, the outer edge of the 1 st absorbent layer 41. The low basis weight region 14b is a region in which the basis weight of the super absorbent polymer is low, and is a region in which the 1 st absorbent layer 41 is not present but only the 2 nd absorbent layer 42 is present in the thickness direction T. The boundary between the low area weight region 14b and the non-arrangement region 14c is, for example, the outer edge of the 2 nd absorbent layer. The non-arrangement region 14c is a region not containing the super absorbent polymer, and is a region where the 1 st absorption layer 41 and the 2 nd absorption layer 42 are not present in the thickness direction T. The case where the super absorbent polymer is not contained includes the case where the weight per unit area is very small although the super absorbent polymer is present. "very small" means that the weight per unit area of the super absorbent polymer is 5% or less of the weight per unit area of the super absorbent polymer in the high weight-per-unit-area region 14a. The high area weight region 14a, the low area weight region 14b, and the non-arrangement region 14c have substantially rectangular shapes. However, the shape is not particularly limited, and examples thereof include a rectangle having a short side projecting in an arc shape, a rounded rectangle, an ellipse, and an hourglass shape. In addition, the low basis weight region 14b is a region that surrounds the high basis weight region 14a in a substantially frame shape (surrounds from at least three sides) in the longitudinal direction L and the width direction W in a plan view, and the outer dimension of the low basis weight region 14b is, for example, 5% to 25% larger than the outer dimension of the high basis weight region 14a. The non-arrangement region 14c is a region surrounding the low basis weight region 14b in a substantially frame shape, and the outer dimension of the non-arrangement region 14c is, for example, 3% to 15% larger than the outer dimension of the low basis weight region 14 b. The weight per unit area of the low area weight region 14b is, for example, 40% to 60% of the weight per unit area of the high area weight region 14a, and the weight per unit area of the non-arrangement region 14c is, for example, 0% to 5% of the weight per unit area of the high area weight region 14a. In the case where the absorbent body 14 has a single-layer structure without the 1 st absorbent layer 41 and the 2 nd absorbent layer 42, and is difficult to be divided into two regions, the high basis weight region is a region in which the thickness of the water-absorbent material (including the adhesive) is in a range from the maximum value to 50% of the maximum value. The low basis weight portion is a region in which the thickness of the water-absorbent material (including the adhesive) is in a range from 50% to 5% of the maximum value, and the non-arrangement region is a region in which the thickness of the water-absorbent material (including the adhesive) is in a range from 5% to 0% of the maximum value. The thickness is an arithmetic average height (Ra: JIS B0601-2001).

Thus, in the absorber 14, the back-side area BA includes back-side high area-weight areas BAa as the high area-weight areas 14a, back-side low area-weight areas BAb as the low area-weight areas 14b, and back-side non-arrangement areas barc as the non-arrangement areas 14c. In the absorbent body 14, the ventral region FA includes ventral high basis weight regions FAa as the high basis weight regions 14a and ventral non-disposition regions FAc as the non-disposition regions 14c. In addition, the crotch region MA has only the high area weight region 14a. Therefore, the basis weight of the superabsorbent polymer in the back-side high basis weight region BAa and the stomach-side high basis weight region FAa is equivalent to the basis weight of the superabsorbent polymer in the crotch region MA. "equivalent" means that one is in the range of 0.7 to 1.3 times (100% ± 30%) the other. In another embodiment, the ventral region FA includes a ventral low basis weight region FAb as the low basis weight region 14b in addition to the ventral high basis weight region FAa and the ventral non-disposition region FAc.

Here, the end portion of the 2 nd absorbent layer 42 on the rear side in the longitudinal direction L in plan view includes a protruding portion that protrudes to the outside of the end edge of the 1 st absorbent layer 41. The protruding portion includes a back-side low area weight region BAb, and in the present embodiment, the protruding portion is the same as the back-side low area weight region BAb. The 2 nd absorption layer 42 is covered with the intermediate layer 43, and thus the skin side of the protruding portion, i.e., the back side low basis weight area BAb, is covered with the intermediate layer 43 and the 1 st base material 44. In the present embodiment, the 2 nd absorbent layer 42 includes, in a plan view, widthwise protruding portions that protrude to the outside of the end edges of the 1 st absorbent layer 41 at both ends in the widthwise direction W. The skin side of the widthwise protruding portion is covered with the intermediate layer 43 and the 1 st base material 44. In another embodiment, the front end of the 2 nd absorbent layer 42 in the longitudinal direction L in plan view includes another protruding portion that protrudes to the outside of the end edge of the 1 st absorbent layer 41. The other protrusion includes a ventral low basis weight region. In still another embodiment, the skin side of the protruding portion, i.e., the back-side low basis weight region BAb, is covered with either one of the intermediate layer 43 and the 1 st base material 44, but not the other. In still another embodiment, the 2 nd absorbent layer 42 does not include a widthwise protruding portion that protrudes outward beyond the end edge of the 1 st absorbent layer 41 at both widthwise end portions in a plan view.

In the absorbent body 14 of the disposable diaper 1 of the present embodiment, the abdomen-side region FA and/or the back-side region BA in the longitudinal direction L include a low basis weight region (exemplified as the back-side low basis weight region BAb) in which the basis weight of the super absorbent polymer is low. Therefore, the starting point of the change in basis weight can be formed at a position between the low basis weight region and the crotch region MA where the basis weight of the super absorbent polymer is high. That is, in the absorbent body 14, the starting point of the change in stiffness can be formed at a position between the low basis weight region having low stiffness and the crotch region having high stiffness in the longitudinal direction L. In the present embodiment, the starting point of the change in the basis weight can be formed at the boundary between the back-side low basis weight region BAb and the back-side high basis weight region BAa. The starting point can be a bending starting point at which the end portion of the absorber 14 is bent toward the central portion of the absorber 14 (crotch region MA; portion including the back high unit area weight region BAa) when a force directed substantially inward in the substantially longitudinal direction L is applied to the end portion of the absorber 14 (low unit area weight region; portion including the back low unit area weight region BAb).

In the absorbent member 14 of the disposable diaper 1 of the present embodiment, the weight per unit area of the superabsorbent polymer in the crotch region MA is relatively high, and the weight per unit area of the superabsorbent polymer in the low-weight-per-unit-area region (exemplified as the back-side low-weight-per-unit-area region BAb) in at least one of the back-side region BA and the stomach-side region FA is relatively low. Therefore, since a relatively large amount of the super absorbent polymer is disposed in the crotch region MA where liquid absorption is required, the absorbent body 14 can reliably absorb liquid (exemplified by urine) without leakage while ensuring absorption performance. On the other hand, since the low basis weight region of at least one of the back-side region BA and the stomach-side region FA, which is not required to absorb liquid, is made thin by arranging a small amount of the super absorbent polymer, the absorbent body can be made less likely to stick to the skin surface when the part of the stomach-side portion 2 or the back-side portion 3 corresponding to the region is in close contact with the skin surface of the wearer. This makes it difficult for the wearer to feel a sense of discomfort, and improves the fit of the disposable diaper 1. Thus, with the disposable diaper 1 including the super absorbent polymer, it is possible to secure the absorption performance and improve the fit.

Fig. 4 is a partially enlarged plan view of the disposable diaper according to the embodiment including the back side portion 3. In the present embodiment, the back portion 3 has a back-side low stretchable region 31 having low stretchability in the width direction W and a pair of back-side high

stretchable regions

32, 32 having high stretchability in the width direction W. The back-side low stretch region 31 is located at the center of the back-side portion 3 in the width direction W and extends rearward from the front end edge in the longitudinal direction L. The pair of back-side

high stretch regions

32 and 32 are adjacent to the back-side low stretch region 31 on both sides in the width direction W. The back-side low stretchable region 31 is a region in which the elongation rate ((length after stretching-original length)/(original length)) against a predetermined tensile force in the width direction W is 1/3 or less, preferably 1/5 or less, and more preferably 1/10 or less of the elongation rate in the width direction W of the back-side high stretchable region 32. For example, the back-side low stretch region 31 is a region where there is no elastic member that stretches and contracts in the width direction W, or a region where, although there is an elastic member, the elastic member does not function as an elastic member much (does not stretch and contract much). On the other hand, the back-side high stretch region 32 is a region where the elastic member 7a that stretches and contracts in the width direction W is present. Therefore, the back-side high stretchable region 32 and the back-side low stretchable region 31 are defined by the region where the elastic member 7a capable of functioning as an elastic member is present and the region where the elastic member capable of functioning as an elastic member is absent. In addition, "low" stretchability includes the case of no stretchability. The stretchability of each stretchable region is determined by the stretchability of the elastic member. The back side portion 3 also has another back side high stretchability region 34 exhibiting high stretchability in the width direction W. The other back-side high stretchable region 34 is adjacent to the pair of back-side high

stretchable regions

32, 32 and the back-side low stretchable region 31 on the rear side in the longitudinal direction L in a plan view. The other back-side high stretch region 34 is a region having substantially the same elongation in the width direction W as the back-side high stretch region 32. The other backside high stretch region 34 is defined as a region where the elastic member 7b exists. Therefore, the rear end portion of the back portion 3 in the longitudinal direction L is easily pressed against the back of the wearer by the other rear highly stretchable region 34.

In the present embodiment, the rear portion of the passage 48 in the longitudinal direction L overlaps with the rear low expansion and contraction region 31 in the thickness direction T. In addition, in a plan view, the inner end edge K1 in the width direction W of each of the pair of back-side highly

stretchable regions

32, 32 is located between the end edge 14EW facing the back-side highly stretchable region 32 in the width direction W of the absorbent body 14 and (the end edge 48E in the width direction W of) the channel 48. The end edge K1 is substantially an inner end edge of the elastic member 7a in the width direction W. Therefore, the central portion in the width direction W in the absorbent body 14 including the portion on the rear side in the longitudinal direction L of the channel 48 is hardly elongated in the width direction W by the back-side low stretch region 31, and both end portions in the width direction W are elongated in the width direction W by the pair of back-side

high stretch regions

32, 32.

Fig. 5 is a partially enlarged plan view of the disposable diaper according to the embodiment including the abdomen-side portion 2. In the present embodiment, the ventral portion 2 is substantially the same as the dorsal portion 3. That is, the ventral portion 2 has a ventral low-stretchability region 36 having a low stretchability in the width direction W and a pair of ventral high-stretchability regions 37 and 37 having a high stretchability in the width direction W. The ventral low expansion region 36 is located at the center of the ventral portion 2 in the width direction W, and extends from the rear end edge in the longitudinal direction L to the front side. The pair of ventral-side high stretch regions 37 and 37 are adjacent to the ventral-side low stretch region 36 on both sides in the width direction W. The ventral-side low-stretchability region 36 is a region in which the elongation (the length after elongation-the original length)/(the original length)) to a predetermined tensile force in the width direction W is 1/3 or less, preferably 1/5 or less, and more preferably 1/10 or less of the elongation in the width direction W of the ventral-side high-stretchability region 37. For example, the abdominal-side low stretch region 36 is a region where there is no elastic member that stretches and contracts in the width direction W, or a region where, although there is an elastic member, the elastic member does not function as an elastic member much (does not stretch much). On the other hand, the abdominal-side high stretch region 37 is a region where the elastic member 6a which stretches and contracts in the width direction W is present. Therefore, the abdominal side high stretch region 37 and the abdominal side low stretch region 36 are defined by the region where the elastic member 6a capable of functioning as an elastic member is present and the region where the elastic member capable of functioning as an elastic member is absent. The stretchability of each stretchable region is determined by the stretchability of the elastic member. The ventral portion 2 also has another ventral high-stretchability region 39 exhibiting high stretchability in the width direction W. The other ventral-side high stretch region 39 is adjacent to the pair of ventral-side high stretch regions 37, 37 and the ventral-side low stretch region 36 on the front side in the longitudinal direction L. The other abdominal side high stretch region 39 has an elongation in the width direction W substantially equal to that of the abdominal side high stretch region 37. The other ventral high stretch region 39 is defined as a region where the elastic member 6b is present. Therefore, the front end portion in the longitudinal direction L of the abdominal portion 2 is easily pressed against the abdomen of the wearer by the other abdominal side highly stretchable region 39.

In the present embodiment, the edge 61e of the elastic member 61 on the side closer to the fixing region 15 overlaps the low basis weight region (exemplified as the back-side low basis weight region BAb) in the thickness direction T. Here, the end edge 61e of the elastic member 61 refers to an end edge of an effective portion of the elastic member 61 that can exert an elastic force. Therefore, in the elastic member 61, when a portion that does not exert an elastic force, for example, a portion that does not substantially expand or contract (an elongation percentage against a predetermined tensile force ((a length after elongation-an original length)/(an original length)) is 1/5 or less, preferably 1/10 or less of an original elongation percentage) is present at an end portion of the elastic member 61, the effective portion does not include the portion. Therefore, the distance between the fixing region 15 and (the effective portion of) the elastic member 61 can be made close in a plan view.

In the present embodiment, the front portion of the channel 48 in the longitudinal direction L overlaps the ventral low expansion region 36 in the thickness direction T. In addition, in a plan view, the inner end edge K2 in the width direction W of each of the pair of abdominal side high stretching regions 37, 37 is positioned between the end edge 14EW opposing the abdominal side high stretching region 37 in the width direction W of the absorbent body 14 and (the end edge 48E in the width direction W of) the channel 48. The end edge K2 is substantially an inner end edge of the elastic member 6a in the width direction W. Therefore, the center portion in the width direction W of the absorbent body 14 including the front portion in the longitudinal direction L of the channel 48 hardly expands and contracts in the width direction W due to the abdomen-side low stretch region 36, and both end portions in the width direction W are expanded in the width direction W due to the pair of abdomen-side high stretch regions 37, 37.

In the disposable diaper 1 of the present embodiment, the channel 48 of the absorber 14 reaches at least one of the back-side portion 3 (back-side waistband) and the abdominal-side portion 2 (abdominal-side waistband) in the longitudinal direction L. Therefore, the liquid (exemplified by urine) can be transported and distributed to the end portion on the back side (the back side in the longitudinal direction L) and/or the abdomen side (the front side in the longitudinal direction L) of the absorbent body 14. This enables the superabsorbent polymer at the rear and front ends of the absorbent body 14 in the longitudinal direction L, which is less likely to be absorbed, to absorb liquid, and the superabsorbent polymer can be effectively used. Further, the inner end in the width direction W of the high stretch region (back-side high stretch region 32, stomach-side high stretch region 37) of at least one of the back-side portion 3 and the stomach-side portion 2 of the disposable diaper 1 is positioned between the end edge 14EW of the absorbent body 14 in the width direction W, which is opposed to the high stretch region, and the channel 48. That is, the center portion in the width direction W of the absorbent body 14 overlaps the low stretch region (the back-side low stretch region 31, the abdomen-side low stretch region 36) in the thickness direction T. Therefore, since the contraction force for contracting the absorbent body 14 in the width direction W is not excessively strong, it is possible to suppress a phenomenon in which the end portion on the back side in the longitudinal direction L of the absorbent body 14 before wearing contracts in the width direction W to have a convex shape. Further, portions on both sides in the width direction W of the absorbent body 14 overlap with the high stretch region in the thickness direction T. Therefore, the absorbent body 14 can be pulled in the width direction W from both sides of the channel 48 by the contraction force of the high stretch region. This can suppress the phenomenon that the end portion in the longitudinal direction L of the absorbent body 14 is formed in a convex shape and the end portion in the longitudinal direction L of the absorbent main body 10 protrudes from the body of the wearer. That is, the flatness of at least one of the back portion 3 and the stomach portion 2 can be maintained before and after wearing. This can suppress leakage of liquid from the gap between the skin surface and at least one of the back portion 3 and the stomach portion 2. This can suppress the decrease in the fit of the disposable diaper 1 and suppress the leakage of liquid.

Next, a method for producing the absorbent body 14 will be described.

First, the sheet for the 2 nd substrate 46 is moved in the longitudinal direction L, and the hot melt adhesive is applied onto the sheet for the 2 nd substrate 46. Next, the super absorbent polymer was spread along the longitudinal direction L over both end portions and the central portion in the width direction W of the sheet for the 2 nd substrate 46 coated with the hot melt adhesive by the super absorbent polymer supply device, respectively. At this time, a small amount of the super absorbent polymer is transferred to the region (corresponding to the channel) between the both end portions and the central portion. Next, a sheet for the intermediate layer 43 coated with hot melt adhesive on both sides was laminated on the super absorbent polymer on the sheet for the 2 nd substrate 46. Next, the laminate was moved in the longitudinal direction L, and a superabsorbent polymer was spread in the longitudinal direction L over the central portion in the width direction W of the sheet for the intermediate layer 43 coated with the hot melt adhesive by another superabsorbent polymer supplying apparatus. Next, the sheet for the 1 st substrate 44 coated with the hot melt adhesive was laminated on the super absorbent polymer on the sheet for the intermediate layer 43 so that the hot melt adhesive faced the super absorbent polymer side. Then, both side portions in the width direction W of the 2 nd base material 46 sheet are folded back onto both side portions in the width direction W of the 1 st base material 44 sheet to obtain a laminate. Thereafter, the thickness of the laminate is adjusted by passing the laminate through a pair of press rolls, i.e., pressing, to obtain the absorbent body 14.

Next, a method for manufacturing a disposable diaper using the absorbent body 14 will be described.

The liquid-permeable front sheet 12 is attached to the upper surface (the surface of the 1 st base 44) of the absorbent body 14 produced as described above, and the liquid-impermeable back sheet 13 is attached to the lower surface (the surface of the 2 nd base 46) of the absorbent body 14, thereby obtaining a laminate. Next, the side sheets 17 with the leakage preventing walls 16 are attached to both sides in the width direction W of the laminate to obtain the absorbent main body 10. Then, the absorbent body 10 is attached to the cover sheet 5 (including the elastic members 6, 7, 8), and both

ends

2a, 2a in the width direction W of the abdominal section 2 and both

ends

3a, 3a in the width direction W of the back section 3 are joined. Thereby, the disposable diaper 1 is manufactured.

Fig. 6 is a schematic diagram illustrating the effect of the disposable diaper 1 of the embodiment. Fig. 6 (a) and (b) show a conventional pants-type diaper, and fig. 6 (c) and (d) show a pants-type diaper according to the present embodiment (illustration of the cover sheet is omitted). First, in a typical disposable diaper, a topsheet 112, an absorber 114, and a backsheet 113 are sequentially laminated in the thickness direction. A pair of

leakage preventing walls

116, 116 extending along the width direction of the absorbent body 114 and along the longitudinal direction are disposed on both sides of the absorbent body 114, and both end portions of each leakage preventing wall 116 are fixed to the top sheet 112 by fixing regions 115. When an absorbent body containing a relatively large amount of superabsorbent polymer is applied to such a disposable diaper, an absorbent body 114 in which the superabsorbent polymer is substantially uniformly arranged in a flat shape is generally used. Immediately after the disposable diaper is worn, that is, before the super absorbent polymer absorbs liquid (exemplified by urine), the rigidity of the absorber 114 is low. Therefore, as shown in fig. 6 (a), the absorber 114 is curved relatively gently, and the leakage preventing wall 116 can rise relatively easily toward the skin surface of the wearer. However, when the super absorbent polymer absorbs liquid and gradually swells after wearing, the rigidity of the absorbent body 114 increases. Therefore, as shown in fig. 6 (b), the absorbent body has a relatively straight shape along the longitudinal direction, and the leakage preventing walls 116 are pulled and stretched along the longitudinal direction from both sides, and are less likely to rise toward the skin surface of the wearer. As a result, the height of the leakage preventing wall 116 is lowered, and there is a possibility that liquid leaks in the width direction across the pair of

leakage preventing walls

116, 116.

On the other hand, in the disposable diaper 1 of the present embodiment, similarly to the conventional pants-type diaper, the rigidity of the absorbent body 14 is low until the super absorbent polymer absorbs liquid (exemplified by urine). Therefore, as shown in fig. 6 (c), the absorbent body 14 is curved relatively gently, and the leakage preventing walls 16 can rise relatively easily toward the skin surface of the wearer.

On the other hand, when the super absorbent polymer absorbs liquid and gradually swells after wearing, the rigidity of the absorbent body 14 increases, and the super absorbent polymer has a relatively straight shape along the longitudinal direction L. Therefore, the leakage preventing wall 16 is pulled and extended from both sides in the longitudinal direction L, and the contraction force of the leakage preventing wall 16 in the longitudinal direction L is increased. At this time, in the disposable diaper 1, the end edge on the center side in the longitudinal direction L of the fixed region 15 is strongly pulled toward the center side by the contraction force in the longitudinal direction L of the leakage preventing wall 16. Therefore, even in the case of the disposable diaper 1, as in the case of the conventional disposable diaper, the leakage preventing wall 16 is unlikely to rise toward the skin surface of the wearer, as in fig. 6 (b).

However, as described above, in the absorbent body 14 of the disposable diaper 1, the bending starting point FL is formed at which the end portion of the absorbent body 14 is bent toward the central side portion of the absorbent body 14. Specifically, the starting point of the change in the weight per unit area at the boundary between the back-side low-area-weight region BAb and the back-side high-area-weight region BAa is the bending starting point FL. Therefore, as shown in fig. 6 (d), the absorbent body 14 can be bent at the bending start point FL, and the end portion (low basis weight region; portion including the back-side low basis weight region BAb) in the longitudinal direction L of the absorbent body 14 can be raised toward the skin surface of the wearer. This can reduce the extent to which the leakage preventing walls 16 are pulled toward both sides in the longitudinal direction L by the end portions in the longitudinal direction L of the absorbent body 14 that stand up, and can raise the leakage preventing walls 16 toward the skin surface of the wearer. That is, a situation in which the height of the leakage preventing wall 16 is lowered can be suppressed, and a situation in which the liquid flows over the leakage preventing wall 16 and leaks in the width direction W can be suppressed.

In the present embodiment, as a preferred mode, in the disposable diaper 1, the end edge 61e of the effective portion of the elastic member 61 on the side of the fixed region 15 overlaps the low basis weight region (exemplified by the back-side low basis weight region BAb) in the thickness direction T. That is, the distance between the fixed region 15 and the effective portion can be made close in a plan view. This makes it possible to easily pull the fixing region 15 with the effective portion, and therefore, the absorbent body 14 can be more easily folded at the folding start point to raise the end portion of the absorbent body 14 in the longitudinal direction L toward the skin surface of the wearer. This can further reduce the extent to which the leakage preventing wall 16 is pulled toward both sides in the longitudinal direction L by the end portions in the longitudinal direction L of the absorbent body 14 that stand up, and can further raise the leakage preventing wall 16 toward the skin surface of the wearer.

In the present embodiment, as a preferable mode, the distance from the position of the center-side end edge 15E in the longitudinal direction L of the fixed region 15 to the crotch region MA-side end edge of the low basis weight region (exemplified by the back-side low basis weight region BAb) is greater than the distance from the position of the center-side end edge 15E in the longitudinal direction L of the fixed region 15 to the end edge of the low basis weight region opposite to the crotch region MA-side (exemplified by the back-side region BA-side) end edge. Here, the position of the end edge 15E on the center side in the longitudinal direction L of the fixing region 15 is a position on which the contraction force of the leakage preventing wall 16 acts. The crotch region-side end edge of the low basis weight region is a position that serves as a bending start point FL. Therefore, in the disposable diaper 1, the position where the contraction force acts is further away from the position of the folding start point FL. That is, in the disposable diaper 1, the distance between the fixing region 15 on which the contraction force acts and the folding start point FL is made larger.

Here, in general, when a force F in a direction perpendicular to the arm member is applied to an object fixed to the rotation shaft by the arm member to rotate the object about the rotation shaft, the longer the length r of the arm member is, the larger the torque N for rotating the object is when the force F is constant.

In the disposable diaper 1, the folding start point FL corresponds to the rotation axis, and the member between the fixing region 15 and the folding start point FL corresponds to the arm member, so that the distance between the fixing region 15 and the folding start point FL corresponds to the length r of the arm member, the end portion of the absorbent body 14 including the fixing region 15 corresponds to the object, and the contraction force of the leakage preventing wall 16 corresponds to the force F. Therefore, in the disposable diaper 1, when the end portion of the absorbent body 14 is rotated, i.e., folded, using the contraction force of the leakage preventing wall 16 with the folding start point FL as the axis, the force for folding the end portion of the absorbent body 14 can be further increased by further increasing the distance between the fixed region 15 and the folding start point FL without changing the contraction force of the leakage preventing wall 16. This allows the leakage preventing wall 16 to further rise toward the skin surface of the wearer.

In the present embodiment, as a preferable mode, the fixed region 15 extends to a non-disposed region (exemplified as a back side non-disposed region barc) in the longitudinal direction L, and at least a part of the fixed region 15 overlaps with the non-disposed region in the thickness direction T. Therefore, when the leakage preventing wall 16 is pulled and fixed by contraction of the fixing region 15, the portion located outside in the longitudinal direction L of the low area weight region (for example, the back-side low area weight region BAb) can be pulled together with the pulling and fixing region 15. Therefore, the absorbent body 14 can be prevented from being folded at a portion other than (the folding start point FL of) the low basis weight region. This makes it easier to bend the absorbent body 14 at the bending starting point FL in the low basis weight region, and makes it easier to raise the leakage preventing wall 16 toward the skin surface of the wearer.

In the present embodiment, as a preferable mode, the fixing region 15 extends beyond the non-arrangement region (exemplified by the back side non-arrangement region barc) to the outside of the absorber 14 in the longitudinal direction L. Therefore, when the leakage preventing wall 16 is pulled and fixed by contraction, the region including the portion outside the absorbent body 14 and the portion outside the low basis weight region (in the illustrated example, the back-side low basis weight region BAb) in the longitudinal direction L can be pulled together with the pull and fixed region 15. Therefore, the absorbent body 14 can be prevented from being folded at a portion other than (the folding start point FL of) the low basis weight region. This makes it easier to bend the absorbent body 14 at the bending starting point FL in the low basis weight region, and makes it easier to raise the leakage preventing wall 16 toward the skin surface of the wearer.

Another embodiment is explained. Fig. 7 is a sectional view taken along line II-II of fig. 1 of another embodiment. As shown in the figure, the leakage preventing wall 16 has a shape of a horizontal letter V (protruding inward) when viewed from the longitudinal direction L. Specifically, the leakage preventing wall 16 includes a 1 st wall portion 16a and a 2 nd wall portion 16b between the fixing

regions

15, 15 on the front and rear sides in the longitudinal direction L of the side sheet 17. The outer edge of the 1 st wall portion 16a in the width direction W is fixed to the surface of the absorbent main body 10. The inner end edge of the 2 nd wall portion 16b in the width direction W is connected to the inner end edge of the 1 st wall portion 16a in the width direction W, and the outer end edge of the 2 nd wall portion 16b in the width direction W is not fixed. Of the 1 st wall portion 16a and the 2 nd wall portion 16b, at least the 2 nd wall portion 16b includes an elastic member 61 extending in the longitudinal direction. The leakage preventing wall 16 can be said to have a shape of a horizontal V-letter (convex inward) when viewed from the longitudinal direction L, because of the 1 st wall portion 16a and the 2 nd wall portion 16b described above. In this case, the leakage preventing walls 16 can be raised in the thickness direction T. Therefore, the leakage preventing wall 16 can be easily raised higher toward the skin surface of the wearer. As a result, the height of the leakage preventing wall 16 can be further suppressed from decreasing.

Another embodiment is explained. Fig. 8 is a partially enlarged plan view of a back side portion of a disposable diaper according to another embodiment. As shown in the figure, an end edge 15E (see fig. 1) on the center side (inner side) in the longitudinal direction L of the fixing region 15 on the rear side (the back side portion 3 side) in the longitudinal direction L overlaps with the rear side low basis weight region BAb in the thickness direction T. Similarly, as shown in fig. 1, the end edge 15E on the center side (inner side) in the longitudinal direction L of the fixing region 15 on the front side (ventral portion 2 side) in the longitudinal direction L overlaps with the ventral high basis weight region FAa in the thickness direction T.

In this disposable diaper 1, when the central end edge 15E of the back-side fastening region 15 is strongly pulled toward the central side by the contraction force in the longitudinal direction L of the leakage preventing wall 16, the absorbent body 14 can be bent at the bending start point FL and the end portion in the longitudinal direction L of the absorbent body 14 can be raised toward the skin surface of the wearer. This can reduce the extent to which the leakage preventing walls 16 are pulled toward both sides in the longitudinal direction L by the end portions in the longitudinal direction L of the absorbent body 14 that stand up, and can raise the leakage preventing walls 16 toward the skin surface of the wearer.

In the disposable diaper 1, the abdomen-side high basis weight region FAa and the low basis weight region are included in the abdomen-side region of the absorber 14, and therefore the position between the abdomen-side high basis weight region FAa and the crotch region MA does not include a start point of a change in stiffness, which is a start point of a change in basis weight. Therefore, the end portions of the absorbent body 14 are not bent near the end edge 15E on the center side in the longitudinal direction L of the abdominal-side fastening region 15, so that the adhesiveness of the abdominal-side portion 2 is improved, and conduction leakage through the abdominal-side region FA can be suppressed.

As another embodiment, the disposable diaper 1 is a tape-type diaper, although not shown. The belt-type diaper includes a pair of locking members located on both outer sides in the width direction W of a portion on the back side of the absorbent main body 10. In this belt-type diaper, it is preferable that an extensible member that crosses the longitudinal center line CL is further provided at the center in the width direction W of the portion on the back side of the absorbent main body 10, and it is more preferable that an extensible member is further provided between the pair of locking members. The structure of the absorbent main body 10 is as described above. In this case, the above-described respective effects can be obtained.

The disposable diaper and the absorbent body thereof according to the present invention are not limited to the above-described embodiments, and the embodiments may be combined with each other and known techniques may be applied thereto without departing from the object and spirit of the present invention.

Claims

1. A disposable diaper having a longitudinal direction, a width direction and a thickness direction which are orthogonal to each other, comprising a stomach-side portion, a back-side portion and an absorbent body including an absorbent body positioned between the stomach-side portion and the back-side portion,

the absorbent body comprises a superabsorbent polymer,

the absorbent body includes:

a crotch region;

a back-side region adjacent to the crotch region on a back side of the crotch region in the longitudinal direction, overlapping with the back-side portion in the thickness direction; and

a stomach-side region adjacent to the crotch region on a front side in the longitudinal direction of the crotch region, and overlapping with the stomach-side portion in the thickness direction,

at least one of the back-side region and the stomach-side region includes a low-basis-area-weight region in which the weight per unit area of the super absorbent polymer is lower than that in the crotch region,

the surface of the absorbent main body on the skin side includes a pair of side sheets located on both sides in the width direction and extending in the length direction,

the pair of side sheets each have:

fixing regions which are located at end portions of the front and rear sides in the longitudinal direction of the side sheet and are fixed to a surface of the absorbent main body; and

a leakage preventing wall including an elastic member extending in the longitudinal direction, the leakage preventing wall being located between the fixing regions on the front side and the rear side in the longitudinal direction of the side sheet, an outer end edge in the width direction being fixed to a surface of the absorbent main body, and an inner end edge in the width direction being non-fixed,

an end edge of the fixing region on the center side in the longitudinal direction overlaps with the low area-per-weight region in the thickness direction,

at least one of the back-side region and the stomach-side region and being a region including the low area-weight region further includes a non-disposed region not including the super absorbent polymer,

the non-disposition region being adjacent to the low unit area weight region on a side of the low unit area weight region opposite to the crotch region side in the longitudinal direction,

at least a part of the fixing region overlaps with the non-disposition region in the thickness direction in the longitudinal direction,

an end edge of the fixing region on a side opposite to the leakage preventing wall side is located at a position outside an end edge of the non-disposition region on a side opposite to the low basis weight region side in the longitudinal direction.

2. A disposable diaper having a longitudinal direction, a width direction and a thickness direction which are orthogonal to each other, comprising a front side portion, a back side portion and an absorbent main body including an absorber and located between the front side portion and the back side portion,

the absorbent body comprises a superabsorbent polymer,

the absorbent body includes:

a crotch region;

the surface of the absorbent main body on the skin side includes a pair of side sheets located on both sides in the width direction and extending along the length direction,

the pair of side sheets each have:

a leakage preventing wall including an elastic member extending in the longitudinal direction, the leakage preventing wall being positioned between the fixing regions on the front side and the rear side in the longitudinal direction of the side sheet, an outer end edge in the width direction being fixed to a surface of the absorbent main body, and an inner end edge in the width direction being non-fixed,

the back side region has a back side low area weight region as the low area weight region,

the stomach-side region has a stomach-side high basis weight region adjacent to the crotch region in the longitudinal direction, and the weight per unit area of the superabsorbent polymer is equal to the weight per unit area of the superabsorbent polymer in the crotch region,

an end edge of the rear side in the longitudinal direction on the center side in the longitudinal direction of the fixing region overlaps with the rear side low basis weight region in the thickness direction,

an end edge of the front side in the longitudinal direction of the fixing region on the longitudinal direction on the center side overlaps with the abdomen side high basis weight region in the thickness direction.

3. The disposable diaper according to claim 1 or 2,

an end edge of an effective portion of the elastic member, the effective portion being capable of exerting an elastic force, on the side of the fixing region overlaps the low basis weight region in the thickness direction.

4. The disposable diaper according to claim 1 or 2,

the distance from the position of the end edge on the center side in the longitudinal direction of the fixing region to the end edge on the crotch region side of the low basis weight region is larger than the distance from the position of the end edge on the center side in the longitudinal direction of the fixing region to the end edge on the opposite side of the crotch region side of the low basis weight region.

5. The disposable diaper according to claim 1 or 2,

the leakage preventing wall includes, in the width direction:

a 1 st wall portion having an outer edge fixed to a surface of the absorbent main body; and

and a 2 nd wall part, wherein the inner end edge of the 2 nd wall part is connected with the inner end edge of the 1 st wall part, and the outer end edge of the 2 nd wall part is unfixed.