CN112566595B

CN112566595B - Disposable diaper having a disposable diaper

Info

Publication number: CN112566595B
Application number: CN201980053019.3A
Authority: CN
Inventors: 市原拓巳; 高桥真衣香; 坂口智; 山中康弘
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2018-08-14
Filing date: 2019-08-13
Publication date: 2022-04-29
Anticipated expiration: 2039-08-13
Also published as: CN114099152A; CN112566595A; WO2020036165A1; CN114099152B

Abstract

A disposable diaper is provided which can appropriately cover the body of a wearer by deforming an absorbent core so as to fit along the crotch of the body. A disposable diaper (10) comprises a crotch stretch unit (41) which stretches and contracts in the front-rear direction (L) in a region of a crotch region (S3) which overlaps an absorbent core (31), and a central high-rigidity unit (71) which has a higher rigidity in the crotch region than in the surrounding region and which extends forward than the crotch stretch unit. The crotch stretch unit extends rearward beyond the central high-rigidity unit at positions on both sides of the center in the width direction. The absorbent core has a 1 st region (R41), a 2 nd region (R42), and a 3 rd region (R43), wherein the 1 st region (R41) has a crotch stretch unit disposed at a position rearward of the central high rigidity unit, the 2 nd region (R42) has a high rigidity unit and a crotch stretch unit overlapped with each other in the thickness direction or the width direction, and the 3 rd region (R43) has a high rigidity unit disposed at a position forward of the crotch stretch unit.

Description

Disposable diaper having a disposable diaper

Technical Field

The present invention relates to a disposable diaper.

Background

Patent document 1 discloses a belt-type absorbent article. When wearing an absorbent article configured as described above, the hip of the wearer is first placed on the rear torso-surrounding region of the absorbent article in a state where the absorbent article is unfolded. Then, the absorbent article is passed between the legs of the wearer, and pulled up so as to cover the abdomen of the wearer.

Patent document 2 discloses an underpants-type absorbent article. When wearing an absorbent article having such a configuration, first, both legs of the wearer are passed through the leg hole openings of the absorbent article, and the wearer holds at least one of the front body hole region and the rear body hole region to pull up the absorbent article.

Further, patent document 3 discloses a disposable diaper having a pair of groove-like portions as low basis weight portions extending in the front-rear direction in a crotch region, and a high rigidity portion provided between the pair of low basis weight portions. The groove-like portion serves as a deformation base point of the absorbent core. The absorbent core of the disposable diaper thus configured deforms in the thickness direction with the groove-like portions extending in the front-rear direction as starting points when worn. In this case, the high rigidity portion provided between the groove portions is intended to maintain the deformation of the absorbent core from the groove portions as the origin.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-63848

Patent document 2: japanese laid-open patent publication No. 2018-68818

Patent document 3: japanese patent laid-open publication No. 2018-472

Disclosure of Invention

Problems to be solved by the invention

When the absorbent core is not deformed along the buttocks when wearing a tape-type disposable diaper like the absorbent article of patent document 1, the absorbent core is not properly accommodated between the thighs of the wearer, and the absorbent core may not fit between the thighs. Further, when a pants-type diaper is put on like the absorbent article of patent document 2, if the absorbent core is not deformed along the buttocks, the absorbent core may not be properly accommodated between the wearer's thighs and the absorbent core may not fit between the thighs. When the absorbent core is not fitted to the crotch part, the diaper is worn in a state where a gap is created between the crotch part and the disposable diaper. When the absorbent core is not properly accommodated between the thighs, the outer side portion of the disposable diaper is put around the leg band when worn, and the length in the front-back direction of the front leg band region covering the abdomen cannot be sufficiently secured, and the abdomen cannot be properly covered with the front leg band region in some cases.

Thus, a disposable diaper is desired which can deform the absorbent core so as to fit along the crotch of the body and can appropriately cover the body of the wearer.

A disposable diaper according to one aspect comprises: a front-back direction and a width direction orthogonal to each other; a front torso-surrounding region, a rear torso-surrounding region, and a crotch region disposed between the front torso-surrounding region and the rear torso-surrounding region; an absorbent core disposed in at least the crotch region; a fastening band disposed in the rear torso region; a crotch stretch unit that stretches and contracts in the front-back direction in a region of the crotch region that overlaps with the absorbent core; and a high rigidity portion having higher rigidity in the crotch region than in a peripheral region and extending forward from the crotch stretch unit, wherein the crotch stretch unit extends rearward from the high rigidity portion at positions on both sides of the center in the width direction of the high rigidity portion, the absorbent core includes a 1 st region, a 2 nd region, and a 3 rd region, the 1 st region has the crotch stretch unit disposed at a position rearward from the high rigidity portion, the 2 nd region has the high rigidity portion and the crotch stretch unit overlapped with each other in the thickness direction or the width direction, and the 3 rd region has the high rigidity portion disposed at a position forward from the crotch stretch unit.

A disposable diaper according to another aspect is an underpants type diaper comprising: a front-back direction and a width direction orthogonal to each other; a front torso-surrounding region, a rear torso-surrounding region, and a crotch region disposed between the front torso-surrounding region and the rear torso-surrounding region; an absorbent core disposed in at least the crotch region; a crotch stretch unit that stretches and contracts in the front-back direction in a region of the crotch region that overlaps with the absorbent core; and a high rigidity portion having higher rigidity in the crotch region than in a peripheral region and extending forward from the crotch stretch unit, wherein the crotch stretch unit extends rearward from the high rigidity portion at positions on both sides of the center in the width direction of the high rigidity portion, the absorbent core includes a 1 st region, a 2 nd region, and a 3 rd region, the 1 st region has the crotch stretch unit disposed at a position rearward from the high rigidity portion, the 2 nd region has the high rigidity portion and the crotch stretch unit overlapped with each other in the thickness direction or the width direction, and the 3 rd region has the high rigidity portion disposed at a position forward from the crotch stretch unit.

A disposable diaper according to still another aspect includes: a front-back direction and a width direction orthogonal to each other; a front torso-surrounding region, a rear torso-surrounding region, and a crotch region disposed between the front torso-surrounding region and the rear torso-surrounding region; and an absorbent core disposed at least in the crotch region, wherein the absorbent core in the crotch region is provided with a pair of low basis weight portions and a pair of high stiffness portions, the low basis weight portions extending in the front-back direction and being disposed with a space in the width direction, and the high stiffness portion is higher in stiffness than a surrounding region between the pair of low basis weight portions, and wherein, assuming that a is the length of the high stiffness portion in the width direction and B is the distance between the high stiffness portion and the low basis weight portion, a + B × 2> a is satisfied, and B × 2< a is satisfied.

Drawings

Fig. 1 is a plan view of a disposable diaper according to embodiment 1 as viewed from the skin surface side.

Figure 2 is a top view of the absorbent core of embodiment 1.

Fig. 3 is a schematic sectional view taken along the a-a section of the disposable diaper shown in fig. 1.

Fig. 4 is a schematic sectional view taken along the B-B section of the disposable diaper shown in fig. 1.

Fig. 5 is a view schematically showing a worn state of the disposable diaper at a-a section.

Fig. 6 is a diagram for explaining a deformation mode of the high rigidity portion.

Fig. 7 is a view schematically showing a worn state of the disposable diaper according to the embodiment.

Fig. 8 is a view showing an absorbent core according to a modification.

Figure 9 is a top view of the absorbent core of embodiment 2.

Detailed Description

(1) Brief description of the embodiments

At least the following matters will be clear from the description of the present specification and the drawings.

A disposable diaper of one embodiment comprises: a front-back direction and a width direction orthogonal to each other; a front body surrounding region, a rear body surrounding region, and a crotch region arranged between the front body surrounding region and the rear body surrounding region; an absorbent core disposed at least in the crotch region; a fastening band disposed in the rear body surrounding region; a crotch stretch unit that stretches and contracts in the front-rear direction in a region of the crotch region that overlaps with the absorbent core; and a high rigidity portion having higher rigidity in the crotch region than in a peripheral region and extending forward from the crotch stretch unit, wherein the crotch stretch unit extends rearward from the high rigidity portion at positions on both sides of the center of the high rigidity portion in the width direction, the absorbent core includes a 1 st region, a 2 nd region, and a 3 rd region, the 1 st region has the crotch stretch unit disposed at a position rearward from the high rigidity portion, the high rigidity portion and the crotch stretch unit overlap in the thickness direction or the width direction in the 2 nd region, and the 3 rd region has the high rigidity portion disposed at a position forward from the crotch stretch unit.

When wearing a belt-type disposable diaper, the rear body region is placed on the buttocks, and the diaper is pulled toward the crotch region to cover the body with the crotch region. At this time, the disposable diaper is pulled in the front-rear direction, and the crotch stretch unit is extended in the front-rear direction. When the crotch region is to be brought into contact with the crotch under the extended state of the crotch stretch unit, the region in which the crotch stretch unit is disposed is pulled up toward the body by the contraction of the crotch stretch unit. At this time, the 1 st region is pulled up to the position closest to the body side, and the 2 nd region is also pulled up toward the body side in accordance with the pulling up of the 1 st region. Further, since the crotch stretch unit is disposed on both sides of the center in the width direction of the high-rigidity unit, the high-rigidity unit is pulled up toward the body side in the region sandwiched by the crotch stretch unit. In this case, in the 3 rd region, the high rigidity portion is not contracted by the crotch stretch portion, and is easily arranged in a planar shape along the crotch. In the crotch region, the absorbent core in the crotch region is arranged along the body by deforming the high-rigidity portion in a predetermined region into a convex shape protruding toward the body. The absorbent core can be appropriately accommodated between the wearer's crotch when worn. The disposable diaper can be placed at an appropriate position between the wearer's thighs, and the front waistline region can be pulled to a position covering the abdomen of the wearer. This enables the body of the wearer to be covered appropriately in the case of a tape-type disposable diaper.

A disposable diaper according to another embodiment is an underpants type diaper comprising: a front-back direction and a width direction orthogonal to each other; a front body surrounding region, a rear body surrounding region, and a crotch region arranged between the front body surrounding region and the rear body surrounding region; an absorbent core disposed at least in the crotch region; a crotch stretch unit that stretches and contracts in the front-rear direction in a region of the crotch region that overlaps with the absorbent core; and a high rigidity portion having higher rigidity in the crotch region than in a peripheral region and extending forward from the crotch stretch unit, wherein the crotch stretch unit extends rearward from the high rigidity portion at positions on both sides of the center of the high rigidity portion in the width direction, the absorbent core includes a 1 st region, a 2 nd region, and a 3 rd region, the 1 st region has the crotch stretch unit disposed at a position rearward from the high rigidity portion, the high rigidity portion and the crotch stretch unit overlap in the thickness direction or the width direction in the 2 nd region, and the 3 rd region has the high rigidity portion disposed at a position forward from the crotch stretch unit.

When putting on the underpants type disposable diaper, the legs of the wearer are passed through the leg hole openings, and at least one of the body surrounding region and the rear body surrounding region is pulled up. At this time, in a posture in which the wearer lies, the front torso surrounding region is pulled up with the rear torso surrounding region in close contact with the body, and the crotch region is pulled in the front-rear direction. When the crotch region is pulled in the front-rear direction, the crotch stretch unit is extended in the front-rear direction, and the region where the crotch stretch unit is disposed is pulled up with respect to the body. At this time, the 1 st region is also pulled up to the position closest to the body side, and the 2 nd region is also pulled up toward the body side as the 1 st region is pulled up. Further, since the crotch stretch unit is disposed on both sides of the center in the width direction of the high-rigidity unit, the high-rigidity unit is pulled up toward the body side in the region sandwiched by the crotch stretch unit. In this case, in the 3 rd region, the high rigidity portion is not contracted by the crotch stretch portion, and is easily arranged in a planar shape along the crotch. In the crotch region, the absorbent core in the crotch region is arranged along the body by deforming the high-rigidity portion in a predetermined region into a convex shape protruding toward the body. The absorbent core can be appropriately accommodated between the wearer's crotch when worn. The disposable diaper can be placed at an appropriate position between the wearer's thighs, and the front waistline region can be pulled to a position covering the abdomen of the wearer. This enables the body of the wearer to be covered appropriately in the case of a pants-type disposable diaper.

According to a preferred aspect, the length of the 1 st region in the front-rear direction may be longer than the length of the 2 nd region in the front-rear direction. In this mode, the absorbent core is pulled up toward the body side by the contractile force of the crotch stretch unit more easily in the 1 st region than in the 2 nd region. By securing the length of the 1 st region in the front-rear direction, the 1 st region can be pulled up toward the body side, and the 2 nd region is also pulled up along with the 1 st region.

According to a preferred aspect, the length of the 3 rd region in the front-rear direction may be longer than the length of the 2 nd region in the front-rear direction. In this mode, by securing the length of the 3 rd region in the front-rear direction, a region which is arranged in a planar shape with respect to the body can be secured, and the fit between the crotch and the thigh can be improved. Further, by securing the length of the 3 rd region in the front-rear direction, the region pulled up toward the body is formed to the abdomen side, and the convex shape is maintained to the abdomen side with respect to the body, and the fit can be further improved.

According to a preferred aspect, the disposable diaper may be folded such that the skin surface sides of the disposable diaper face each other with a fold line (japanese patent: folded り mesh) extending in the width direction as a base point, and the high-rigidity portion may straddle the fold line. In this form, the vicinity of the fold of the disposable diaper is easily deformed into a convex shape toward the non-skin surface side by the fold (Japanese: fold り fold). The high-rigidity portion straddles the fold line, thereby suppressing deformation due to the fold line and facilitating maintenance of convex deformation with respect to the body side. The fold is disposed in the 2 nd region or the 3 rd region. Since no fold is provided in the 1 st region, the region located forward of the fold can be prevented from being pulled toward the fold (away from the body) by contraction of the crotch stretch unit. This allows the crotch region to be positioned along the body, and allows the absorbent core to be appropriately accommodated between the wearer's thighs when worn.

According to a preferred aspect, the fold may be provided in the 3 rd region. In this aspect, since the crotch stretch unit is not disposed across the fold line, it is possible to prevent the region on the front side of the fold line from being pulled toward the fold line (the side away from the body) by contraction of the crotch stretch unit. This allows the crotch region to be positioned along the body, and allows the absorbent core to be appropriately accommodated between the wearer's thighs when worn.

According to a preferred aspect, the fold line may be provided in the 2 nd region at a position rearward of the center in the front-rear direction of the 2 nd region. In this mode, the fold line is located more rearward than the center in the front-rear direction of the 2 nd region, and is provided at a position away from the front end edge of the 3 rd region serving as a fulcrum of deformation of the absorbent core and closer to the point of action. This allows deformation due to the crease to be pulled up by contraction of the crotch stretch unit.

According to a preferred aspect, the fastening tape may have a joint portion joined to the front waistline region, and the rear end edge of the crotch stretch unit may be disposed on the front side of a center in the front-rear direction of the disposable diaper and a center line in the front-rear direction of a front end edge of the joint portion. The position on the rear side of the center of the disposable diaper in the front-rear direction and the middle line of the front end edge of the joint is a region for bearing the buttocks when worn. The rear end edge of the crotch stretch unit is positioned on the front side of the center line and is disposed in a region not supporting the buttocks of the wearer. When the wearer wears the garment, the region not supporting the buttocks is pulled forward in a state where the region rearward of the center line is pressed by the buttocks, and the entire crotch stretch unit is easily extended. Thus, the region in which the crotch stretch unit is disposed is pulled up with respect to the body, and the absorbent core can be further appropriately accommodated in the crotch of the wearer.

According to a preferred aspect, the fastening tape may have a joint portion joined to the front waistline region, and the rear end edge of the crotch stretch unit may be disposed on the rear side of a center in the front-rear direction of the disposable diaper and a center line in the front-rear direction of a front end edge of the joint portion. The rear end edge of the crotch stretch unit is located on the rear side of the center line and is disposed in a region not supporting the buttocks of the wearer. When the wearer wears the garment, the crotch stretch unit is easily extended because the front end edge of the crotch stretch unit is pulled toward the front side in a state where the rear end edge of the crotch stretch unit is pressed by the buttocks. Thus, the region in which the crotch stretch unit is disposed is pulled up with respect to the body, and the absorbent core can be further appropriately accommodated in the crotch of the wearer.

According to a preferred aspect, the absorbent core in the crotch region may be provided with a pair of low basis weight portions extending in the front-back direction and arranged at an interval in the width direction, and at least a part of the high rigidity portion may be arranged in a region sandwiched between the pair of low basis weight portions. In this configuration, the absorbent core in the crotch region deforms from the low basis weight portion extending in the front-rear direction as a base point when worn, and the low basis weight portion is likely to deform in a convex shape toward the body side. In this case, the rigidity of the region between the pair of low basis weight portions is increased by the high rigidity portion, and the state along the body is easily maintained. This makes it easier to appropriately store the absorbent core between the wearer's thighs.

According to a preferred aspect, the rear end edge of the low basis weight portion may be disposed at the same position as the rear end edge of the crotch stretch unit in the front-rear direction, or may be disposed at a position further to the rear side than the rear end edge of the crotch stretch unit in the front-rear direction. In this form, the region deformed from the low basis weight portion can be pulled up by the crotch stretch unit. In addition, the region provided with the low basis weight portion has lower rigidity than the region not provided with the low basis weight portion, and the contractive force of the crotch stretch unit is more easily exhibited. This makes it easier to pull up the absorbent core toward the body side by the crotch stretch unit.

According to a preferred aspect, the crotch stretch unit may be disposed in a region overlapping the low basis weight portion in the thickness direction or the width direction. In this form, the region deformed from the low basis weight portion can be pulled up by the crotch stretch unit. In addition, the region provided with the low basis weight portion has lower rigidity than the region not provided with the low basis weight portion, and the contractive force of the crotch stretch unit is more easily exhibited. This makes it easier to pull up the absorbent core toward the body side by the crotch stretch unit.

According to a preferred aspect, the length of the high rigidity portion in the width direction may be shorter than the distance between the pair of low basis weight portions in the width direction. In this aspect, the high rigidity portion and the low basis weight portion are separated from each other, and the separated region is more easily deformed than the high rigidity portion. When the region between the low basis weight portions is not accommodated between the thighs, the divided region is deformed. The deformation state with the low basis weight portion as the base point and the state with the high rigidity portion along the body are easily maintained, and the fit with the body can be improved. Since the low basis weight portion is not connected to the high rigidity portion, a difference in rigidity occurs between the inner edge of the low basis weight portion and the outer edge of the high rigidity portion with respect to the regions adjacent in the width direction. The inner edge of the low basis weight portion and the outer edge of the high rigidity portion also serve as deformation origin points, and deformation is performed at a plurality of origin points, so that the absorbent core is more easily attached to the body.

According to a preferred aspect, the high rigidity portion may be a compressed portion obtained by compressing at least the absorbent core. The high rigidity portion is not contracted by the crotch stretch portion, and is easily arranged in a planar shape along the crotch. Therefore, it is easy to dispose the absorbent core 31 along the crotch portion in at least the region where the compressed portions are provided. The absorbent core can be compactly stored in a space sandwiched between both legs by absorbing body fluid with the squeezing portions arranged along the crotch, and leakage of body fluid can be suppressed.

A disposable diaper according to another aspect includes: a front-back direction and a width direction orthogonal to each other; a front body surrounding region, a rear body surrounding region, and a crotch region arranged between the front body surrounding region and the rear body surrounding region; and an absorbent core disposed at least in the crotch region, wherein the absorbent core in the crotch region is provided with a pair of low basis weight portions and a high stiffness portion, the pair of low basis weight portions extending in the front-back direction and being disposed with a space therebetween in the width direction, and the high stiffness portion is higher in stiffness than a surrounding region between the pair of low basis weight portions, wherein when a length of the high stiffness portion in the width direction is denoted by a, and a distance between the high stiffness portion and the low basis weight portion is denoted by B, a + B × 2> a is satisfied, and B × 2< a is satisfied.

In a state of being worn like the disposable diaper of patent document 3, the groove-like portion is deformed into a convex shape toward the body side, and the fit between the crotch of the wearer is improved. However, the high-rigidity portion is provided so as to straddle the pair of groove portions, and the rigidity of the entire region sandwiched between the groove portions is increased. Therefore, when the region sandwiched by the groove-like portions is longer than the width-directional length of the crotch, the high-rigidity portion is not accommodated in the crotch, and there is a concern that the high-rigidity portion may hit the leg and cause discomfort. Alternatively, the convex deformation from the groove-like portion as a base point cannot be maintained, and a gap with respect to the body is generated, which may cause leakage. Thus, a disposable diaper is desired which can reduce leakage by deforming the absorbent core so as to fit along the crotch of the body. The disposable diaper of another embodiment is configured to reduce leakage by deforming the absorbent core so as to fit along the crotch of the body.

In the disposable diaper according to the present aspect, the absorbent core in the crotch region deforms from the low basis weight portion extending in the front-rear direction as a base point when worn, and the low basis weight portion is likely to deform convexly toward the body side. In this case, the rigidity of the region between the pair of low basis weight portions is increased by the high rigidity portion, and the state along the body is easily maintained. In order to satisfy A + B × 2> A, a distance B is provided between the high rigidity portion and the low basis weight portion. The region of distance B is more easily deformed than the high-rigidity portion. When the region between the low basis weight portions is not accommodated between the thighs, the region of the distance B is deformed. The deformation state with the low unit area weight portion as the base point and the state of the high rigidity portion along the body are easily maintained, and the gap with respect to the body is reduced. Since the low basis weight portion is not connected to the high rigidity portion, a difference in rigidity occurs between the inner edge of the low basis weight portion and the outer edge of the high rigidity portion with respect to the regions adjacent in the width direction. The inner edge of the low basis weight portion and the outer edge of the high rigidity portion also serve as deformation origin points, and deformation is performed at a plurality of origin points, so that the absorbent core is more easily attached to the body. Further, in order to satisfy Bx 2< A, the proportion of the high rigidity portion is higher than the proportion of the distance B in the region between the low basis weight portions. This makes it possible to arrange the absorbent core along the body between the low basis weight portions, thereby reducing the gap between the absorbent core and the body. Leakage can be reduced by deforming the absorbent core in a manner that follows the crotch of the body.

According to a preferred aspect, the disposable diaper may be folded so that the skin surface sides of the disposable diaper face each other with a fold line extending in the width direction as a base point, and the high-rigidity portion may straddle the fold line. In this mode, the disposable diaper is likely to be deformed into a convex shape toward the non-skin surface side due to the fold in the vicinity of the fold. The high-rigidity portion straddles the fold line, thereby suppressing deformation due to the fold line and facilitating maintenance of convex deformation with respect to the body side.

According to a preferred aspect, the disposable diaper may include a pair of crotch stretch units that stretch in the front-rear direction in the crotch region, and the crotch stretch units may be disposed on both outer sides in the width direction with respect to the high-rigidity unit. In this configuration, the region outside the high rigidity portion in the width direction can be pulled up toward the body side by the contraction energy of the crotch stretch portion. This makes it easy for the vicinity of the low basis weight portion to deform convexly toward the body. In addition, the high-rigidity portion is less likely to be contracted by the crotch stretch portion. This can maintain the convex shape along the crotch, while ensuring the absorption area, and can reduce leakage.

According to a preferred aspect, at least a part of the crotch stretch unit may be disposed in a region overlapping with the low basis weight portion. In this configuration, the crotch stretch unit overlaps the low basis weight unit, so that the crotch stretch unit is easily contracted and the convex deformation is more easily maintained.

According to a preferred aspect, an overlapping region in which the high rigidity portion is arranged may be provided in a region extending in the width direction from the crotch stretch unit, and the length of the overlapping region in the front-rear direction may be 1/2 or less of the length of the high rigidity portion in the front-rear direction. With this configuration, the entire high-rigidity portion is less likely to contract due to contraction of the crotch stretch portion. This makes it possible to ensure the absorption area, and the high-rigidity portion can easily maintain the convex shape along the crotch, thereby reducing leakage.

According to a preferred aspect, D > E/4 may be satisfied where D is a distance between the low basis weight portion and the outer edge of the absorbent core and E is a length between the outer edges of the absorbent core. In this form, when the deformation is convex toward the body side with the low basis weight portion as a base point, the region on the outer side in the width direction than the low basis weight portion (region of the distance D) becomes a region for supporting the convex deformation. Since the region outside the low basis weight portion in the width direction (region of the distance D) is longer than 1/4 in the entire region of the absorbent core in the width direction, the convex deformation is stably supported, and the convex shape is easily maintained.

According to a preferred aspect, when a distance between a 1 st low unit area weight portion, which is one of the pair of low unit area weight portions, and the high rigidity portion is B1, and a distance between a 2 nd low unit area weight portion, which is the other of the pair of low unit area weight portions, and the high rigidity portion is B2, the B1 ≠ B2 may be satisfied. In this embodiment, since the distance B1 between the 1 st low basis weight portion and the high rigidity portion and the distance B2 between the 2 nd low basis weight portion and the high rigidity portion are different, when a force is applied from both the left and right sides, one of the region of the distance B1 and the region of the distance B2 deforms first. Therefore, the force is uniformly applied to the high-rigidity portion from both the left and right sides, and the failure of bending the high-rigidity portion itself can be suppressed. This can maintain a convex shape along the crotch, ensure an absorption area, and reduce leakage.

According to a preferred aspect, the high rigidity portion may be disposed only in a region sandwiched by the low basis weight portions. In this aspect, the high rigidity portion is provided only in the region sandwiched by the low basis weight portions, and therefore the high rigidity portion is disposed only in the region deformed in a convex shape toward the body side. The high rigidity portion can be arranged in a flat shape along the crotch, and the fit between the high rigidity portion and the crotch can be further improved.

(2) Overall schematic structure of disposable diaper

The disposable diaper according to embodiment 1 is explained below with reference to the drawings. In the description of the drawings below, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic drawings, and the ratio of the dimensions and the like are different from those in the actual case. Therefore, specific dimensions and the like should be determined with reference to the following description. In addition, the drawings may include portions having different dimensional relationships and ratios from each other.

The disposable diaper is a tape-type disposable diaper. Fig. 1 is a plan view of a disposable diaper 10 according to the present embodiment as viewed from the skin surface side, and fig. 2 is a plan view of an absorbent core according to the embodiment as viewed from the skin surface side. The plan views shown in fig. 1 and 2 show the disposable diaper in an extended state. Fig. 3 is a schematic sectional view of the disposable diaper shown in fig. 1 taken along the section a-a. Fig. 4 is a schematic sectional view of the disposable diaper shown in fig. 1 taken along the section B-B. The extended state in the present invention is a state in which the disposable diaper 10 is extended to a state in which no wrinkles are formed. In the present invention, the natural state is a state in which, in the case of the disposable diaper 10 contained in a package, the disposable diaper 10 is taken out of the package and left to stand in an environment of 20 ℃ ± 2 ℃ and a relative humidity of 60% ± 5% RH for 24 hours.

The disposable diaper 10 has a front-back direction L and a width direction W orthogonal to each other. The front-back direction L is defined by a direction extending to the front side and the back side of the body. In other words, the front-back direction L is a direction extending in the front-back direction on the disposable diaper 10 after being unfolded. The disposable diaper 10 has a thickness direction T orthogonal to both the front-back direction L and the width direction W. The thickness direction T extends toward the skin surface side T1 on the wearer side and toward the non-skin surface side T2 on the side opposite to the skin surface side. The disposable diaper 10 has a front body surrounding region S1, a rear body surrounding region S2, and a crotch region S3. The front waistline region S1 is a region opposed to the front waistline (abdomen) of the wearer. The rear torso-surrounding region S2 is a region opposed to the rear torso (back) of the wearer, and includes a region for supporting the body (buttocks) when worn. The crotch region S3 is a region located in the crotch of the wearer and disposed between the front body surrounding region S1 and the rear body surrounding region S2. The crotch region S3 is a region provided with leg hole openings arranged around the legs of the wearer. The leg hole openings are portions recessed inward in the width direction from the outer edge of the disposable diaper.

The disposable diaper 10 comprises an absorbent core 31, the absorbent core 31 comprising an absorbent material. The absorbent core 31 contains absorbent material such as comminuted pulp or superabsorbent polymers (SAP) or mixtures of these. The absorbent core 31 may be covered by a core wrap sheet 32. The absorbent body 30 can be constituted by the absorbent core 31 and the core wrap 32. The core wrap 32 may be made of a paper towel, and is disposed on the skin surface side T1 of the absorbent core 31 and the non-skin surface side of the absorbent core.

As shown in fig. 1 and 3, the topsheet 21 and the side sheet 22 may be provided on the skin surface side T1 of the absorbent body 30 including the absorbent core 31. The topsheet 21 may be arranged across the center of the absorber 30 in the width direction W. The side sheet 22 may be arranged to cover the outer side of the front sheet 21. The front sheet 21 and the side sheets 22 may be made of a liquid-permeable sheet such as a nonwoven fabric or an apertured plastic film. The inner side portions of the side sheets 22 may be folded back to be overlapped. A leakage preventing stretchable portion 43 stretchable in the front-rear direction L may be provided between the overlapped side sheets 22. The leakage preventing stretchable portion 43 may be formed of a rubber thread stretchable in the front-rear direction L. The side sheet 22 and the leakage preventing stretchable parts 43 constitute leakage preventing gathers 60 which rise toward the skin surface side T1 when worn. The back sheet 23 and the outer sheet 24 may be provided on the non-skin surface side T2 of the absorbent body 30. The exterior sheet 24 may be provided on the non-skin surface side T2 of the back sheet 23. The length of the back sheet 23 in the width direction W may be shorter than the length of the exterior sheet 24 in the width direction W, and the length of the back sheet 23 in the front-rear direction L may be shorter than the length of the exterior sheet 24 in the front-rear direction L. The back sheet 23 may be formed of a liquid-impermeable film. The outer sheet 24 may be made of a liquid-permeable nonwoven fabric.

A fastening tape 91 is provided on the outer side of the rear body surrounding region. The fastening tape 91 has a base portion 92 and a joining portion 93. The base portion 92 is disposed between the exterior sheet 24 and the side sheet 22 in the thickness direction T, and extends outward from the exterior sheet 24 and the side sheet 22 in the width direction W. The coupling portion 93 is disposed on the base portion 92 and coupled to a target portion 95 (see fig. 5). The target portions 95 are arranged in the width direction at intervals in the front body surrounding region S1, and are configured to be fixed by the fastening tapes 91, respectively.

The presentation section 51 may be disposed between the back sheet 23 and the absorber 30. The presentation portions 51 may extend in the front-rear direction L and be arranged with a space in the width direction W. The presentation unit 51 is disposed between the low basis weight units 33 described later. The presentation unit 51 is configured to change color by absorbing body fluid in the absorber, and can grasp the absorption state of body fluid from the non-skin surface side T2 of the disposable diaper 10.

The disposable diaper 10 may have a leg hole stretch unit 42 that stretches and contracts in the front-rear direction at a position outside the absorbent core 31 in the width direction. The leg hole stretch units 42 may be provided between the side sheet 22 and the back sheet 23 and between the side sheet 22 and the exterior sheet 24. The leg hole stretch units 42 are formed of band-shaped stretch pieces that stretch in the front-rear direction L. By contraction of the leg hole stretch units 42, the leg hole openings of the disposable diaper 10 are brought into contact with the leg holes when the disposable diaper 10 is worn. The disposable diaper 10 may have a waist stretchable unit 45 extending in the width direction W along the rear end edge of the disposable diaper. The waist stretch units 45 may be provided between the back sheet 23 and the exterior sheet 24, between the front sheet 21 and the exterior sheet 24, and between the side sheets 22 and the exterior sheet 24. The rear end edge of the waist stretchable panel 45 may be positioned on the front side of the rear end edge of the disposable diaper, and the front end edge of the waist stretchable panel 45 may be positioned on the front side of the rear end edge of the absorbent core 31. The waist elastics 45 may extend outward in the width direction W from the absorbent core 31. The waist stretchable unit 45 is formed of a band-shaped stretchable sheet stretchable in the width direction W.

The disposable diaper 10 can be folded so that the skin surface sides of the disposable diaper face each other with the fold line extending in the width direction as a base point in a state before use. The fold FL of the disposable diaper of the present embodiment is located at the center 10LC in the front-rear direction of the disposable diaper. The fold line FL of the disposable diaper may be a fold line for folding the disposable diaper in two or more. In the case of folding the disposable diaper into a fold line of three or more folds, the fold line may be a fold line for folding the disposable diaper so that the non-skin surface side of the disposable diaper becomes the outer side.

The disposable diaper 10 may have a pair of crotch stretch units 41 provided in a region overlapping the absorbent core 31 in the crotch region. The crotch stretch unit 41 may be disposed on the non-skin surface side of the absorbent core 31. The crotch stretch unit 41 may be provided between the back sheet 23 and the exterior sheet 24. The crotch stretch unit 41 extends in the front-rear direction L and is disposed at intervals in the width direction W. The crotch stretch unit 41 is not disposed at the center of the absorbent core 31 in the width direction W, and two crotch stretch units 41 are disposed on each side of the absorbent core 31 with respect to the center in the width direction W. Thereby, the absorbent core in the region overlapping the crotch stretch unit 41 is pulled up to a position closer to the body side than the center in the width direction of the absorbent core by the contraction of the crotch stretch unit 41. The pair of crotch stretch units 41 may be positioned inward in the width direction from the outer edge of the absorbent core 31. The region located between the pair of crotch stretch units 41 is pulled up toward the body side with respect to the region located outside the pair of crotch stretch units 41 in the width direction. Thus, the center of the absorbent core in the width direction can be deformed into a convex shape with the side portions as base points, and fit between the crotch of the body can be secured. The crotch stretch unit 41 is formed of a rubber thread arranged in the front-rear direction L. In another embodiment, the crotch stretch unit 41 may be formed of a belt-like stretch sheet which stretches in the front-rear direction, may be formed of 1 rubber thread, or may be formed of 3 or more rubber threads. In the present invention, the overlapped state refers to a state in which one member is overlapped with another member in a plan view, and is a state in which another member is disposed on a skin surface side or a non-skin surface side of one member. The overlapped state includes not only a state in which one member and the other member are in contact with each other but also a structure in which the other member is interposed between the one member and the other member.

The crotch stretch unit 41 may extend across the center 10LC of the disposable diaper in the front-back direction. The center 10LC in the front-back direction of the disposable diaper can be pulled up toward the body by contraction of the crotch stretch unit 41. In particular, in a state where the skin surface sides of the disposable diaper before use are folded in two so as to face each other, the fold due to the folding can be pulled up. In other embodiments, the crotch stretch unit 41 may be disposed only on the front side of the center 10LC, not across the center 10LC in the front-rear direction of the disposable diaper, or may be disposed only on the rear side of the center 10 LC. The crotch stretch unit 41 may extend across the center 10LC in the width direction of the disposable diaper, or may be disposed on both sides of the disposable diaper with respect to the center 10LC in the width direction. The crotch stretch unit 41 is disposed on both sides of the center in the width direction of the central high stiffness unit 71, which will be described later. The crotch stretch unit 41 may be disposed at least on both sides of the center in the width direction of the central high rigidity portion 71, or may be disposed in a region overlapping the central high rigidity portion 71. As in the crotch stretch unit 41C of modification example 3 described later, the center high rigidity portion 71 may be continuous in the width direction W so as to extend across both sides with respect to the center in the width direction.

The crotch stretch unit 41 may be positioned inward in the width direction W from the outer edge of the absorbent core 31. A region in which the contraction force of the crotch stretch unit 41 is less likely to act is provided on the absorbent core 31 at a position outside the crotch stretch unit 41 in the width direction W. In fig. 3, a central region R32 between the side regions R31 and R31 where the absorbent core 31 is located outward of the crotch stretch unit 41 is shown. The side region R31 is a region located outward in the width direction W from the crotch stretch unit 41 located outermost in the width direction W. The central region R32 is a region obtained by combining a region overlapping the crotch stretch unit 41 and a region located inward in the width direction W from the crotch stretch unit 41. The central region R32 is pulled up toward the body side with respect to the side regions R31 by contraction of the crotch stretch unit 41.

The stretchable unit including the leakage-preventing stretchable unit 43, the leg-surrounding stretchable unit 42, the waist-surrounding stretchable unit 45, and the crotch stretchable unit 41 in the present invention is a portion in which an elastic member such as a rubber thread or a stretchable sheet is arranged in a stretchable state, and does not include a portion in which an elastic member is arranged in a non-stretchable state. That is, the stretchable portion is an effective length portion of the elastic member constituting the stretchable portion.

(3) Absorbent core structure

Next, the structure of the absorbent core 31 will be described in detail with reference to fig. 2. The absorbent core 31 has: a narrow portion 35 having a length in the width direction shorter than the maximum width 31M of the absorbent core 31; and a wide portion disposed on the outer side of the narrow portion 35 in the front-rear direction. The narrow portion 35 is disposed between the wide portions disposed in the front-rear direction. The width-directional length of the narrowed portion 35 increases toward the outer side in the front-rear direction L. The top view shape of the absorbent core 31 is an hourglass timer shape. In addition, not only the absorbent core 31 but also the absorbent body including the core-covering sheet may have an hourglass timer shape. The absorbent core 31 may have a low basis weight portion 33 in which the weight per unit area of the absorbent material is lower than that of the surrounding area. The low area weight portion 33 is provided along the front-rear direction L. The low basis weight portion 33 may extend in the front-rear direction L, may be parallel to the front-rear direction L, or may be inclined at an angle of less than 90 degrees with respect to the front-rear direction L.

The low basis weight portion 33 is a portion of the absorbent material having a lower basis weight than the surrounding absorbent core 31, is thinner than the surrounding absorbent core 31, and has lower rigidity than the surrounding absorbent core 31. Thus, the low basis weight portion 33 is likely to be a deformation base point in the worn state. The absorbent core 31 is easily formed with deformation base points extending in the front-rear direction L in a worn state. The low basis weight portion 33 may be a portion where the basis weight of the absorbent material is substantially zero (a portion where the basis weight is 0 in design but the surrounding absorbent material is included), or a portion where the absorbent material having a smaller basis weight than the surrounding is disposed. The low basis weight portion 33 may be a slit having a constant length in the width direction W, or may be a notch having a substantially zero length in the width direction W. The length of each low basis weight portion 33 in the width direction W may be 2mm or more and 10mm or less, and more preferably, may be 8mm or more and the thickness of the absorbent core 31. By setting the length of the low basis weight portion 33 in the width direction to be equal to or greater than the thickness of the absorbent core 31, the absorbent core 31 is easily deformed in the thickness direction with the low basis weight portion 33 as a base point. Further, by setting the length of the low basis weight portion 33 in the width direction to 8mm or less, it is possible to suppress the feeling of discomfort in the absorption performance due to the long length of the low basis weight portion in the width direction. The length of the low basis weight portion 33 in the front-rear direction L may be 30mm to 180 mm.

The low basis weight portions 33 are arranged in pairs with a space therebetween in the width direction W. The low basis weight parts 33 may be disposed on both sides of the center 10WC of the disposable diaper in the width direction W with a space therebetween. The center in the front-rear direction of the low basis weight section 33 may be disposed on the rear side of the center 10LC in the front-rear direction L of the disposable diaper. The front end edge 33F of the low basis weight portion 33 may be positioned on the front side of the front end edge 41F of the crotch stretch unit 41, and the rear end edge 33R of the low basis weight portion 33 may be positioned on the rear side of the rear end edge 41R or aligned with the rear end edge 41R of the crotch stretch unit 41. The outer edge of the low basis weight portion 33 may be aligned in the width direction with a rubber thread located on the outer side in the width direction of the rubber threads constituting the crotch stretch unit 41, and the inner edge of the low basis weight portion 33 may be aligned in the width direction with a rubber thread located on the inner side in the width direction of the rubber threads constituting the crotch stretch unit 41.

The absorbent core 31 may have a high rigidity portion 70 having higher rigidity than the surrounding area. The high rigidity portion 70 may include a central high rigidity portion 71 disposed between the pair of crotch stretch units 41, a rear high rigidity portion 72 disposed on the rear side of the crotch stretch units 41, and a front high rigidity portion 73 disposed on the front side of the crotch stretch units 41. The central high rigidity portion 71, the rear high rigidity portion 72, and the front high rigidity portion 73 are separated in the front-rear direction L, respectively. The high rigidity portion 70 is a region having higher bending rigidity than the surrounding region. The high rigidity portion 70 may be a portion having a higher mass per unit area than the surrounding region, or may be a portion obtained by compressing the absorbent core 31 in the thickness direction. The high rigidity portion 70 of the present embodiment is a portion provided with a compressed portion that compresses the absorbent core 31. The compressed portion may be formed by compressing at least the absorbent core 31 in the thickness direction T, or may be formed by compressing the absorbent core 31 and other members such as the core covering sheet 32.

The central high rigidity portion 71 is provided in a region between the pair of low basis weight portions 33. The front end edge 71F of the central high rigidity portion 71 may be positioned in alignment with the front end edge 33F of the low basis weight portion 33 or on the rear side of the front end edge 33F of the low basis weight portion 33. The rear end edge 71R of the central high rigidity portion 71 may be located on the front side of the rear end edge 33R of the low basis weight portion 33. The center of the central high rigidity portion 71 in the front-rear direction may be located forward of the center of the low basis weight portion 33 in the front-rear direction. The central high rigidity portion 71 may be disposed at a distance from the low unit area weight portion 33 in the width direction W. The central high rigidity portion 71 may straddle the center 10LC of the disposable diaper and the center 10WC of the disposable diaper in the width direction W. The central high rigidity portion 71 extends further toward the front side than the crotch stretch unit 41, and constitutes a "high rigidity portion" of the present invention.

The crotch stretch unit 41 may be located on both sides of the center in the width direction of the central high rigidity portion 71 and extend rearward of the central high rigidity portion 71. The absorbent core 31 may have a 1 st region R41, a 2 nd region R42, and a 3 rd region R43, the 1 st region R41 may have the crotch stretch unit 41 disposed rearward of the central high rigidity unit 71, the 2 nd region R42 may have the central high rigidity unit 71 and the crotch stretch unit 41 overlapped with each other in the thickness direction or the width direction, and the 3 rd region R43 may have the central high rigidity unit 71 disposed forward of the crotch stretch unit 41. The 1 st region R41 and the 2 nd region R42 are adjacent in the front-rear direction L, and the 2 nd region R42 and the 3 rd region R43 are adjacent in the front-rear direction L. The rear end edge of the 1 st region R41 is aligned with the rear end edge 41R of the crotch stretch unit 41, and the front end edge of the 1 st region R41 is aligned with the rear end edge 71R of the central high rigidity portion 71. The rear end edge of the 2 nd region R42 is aligned with the front end edge of the 1 st region R41, and the front end edge of the 2 nd region R42 is aligned with the front end edge 41F of the crotch stretch unit 41. The rear end edge of the 3 rd region R43 is aligned with the front end edge of the 2 nd region R42, and the front end edge of the 3 rd region R43 is aligned with the front end edge 71F of the central high rigidity portion 71.

The central high rigidity portion 71 may not be disposed across the fold. The front end edge 71F of the central high rigidity portion 71 may extend further toward the front than the front end edge 33F of the low basis weight portion 33. The central high-rigidity portion 71 may be an aggregate of a plurality of high-rigidity portions separated in the front-rear direction. An aggregate of the plurality of high rigidity portions may be integrated to function as the central high rigidity portion 71. The high-rigidity portion constituting the aggregate of the central high-rigidity portions 71 formed of the aggregate of the plurality of high-rigidity portions may be arranged so as not to cross the fold line. The rear high rigidity portion 72 may be disposed on the rear side of the low basis weight portion 33. The outer side edge of the rear high rigidity portion 72 may extend outward in the width direction W toward the rear side. The length of the front end edge of the rear high rigidity portion 72 in the width direction W may be longer than the length of the center high rigidity portion 71 in the width direction W. The central high rigidity portion 71 may straddle the center 10WC of the disposable diaper in the width direction W. The front high rigidity portion 73 may be disposed on the front side of the low basis weight portion 33. The front high rigidity portions 73 may be disposed on both sides of the center 10WC of the disposable diaper in the width direction W with a space therebetween.

The high rigidity portion 70 may be a compressed portion obtained by compressing at least the absorbent core 31. The high rigidity portion 70 is not contracted by the crotch stretch portion 41, and is easily arranged in a planar shape along the crotch. Therefore, it is easy to dispose the absorbent core 31 along the crotch portion in at least the region where the compressed portions are provided. The liquid can be absorbed by the squeezing portions arranged along the crotch, the absorbent core 31 can be compactly stored in the space sandwiched between the legs, and leakage of the liquid can be suppressed.

Here, the outer portion in the present invention means a portion that occupies a certain range in the width direction W including an outer edge in the width direction W, and the outer edge means an outer edge in the width direction W. The inner side portion is a portion that occupies a certain range in the width direction W including an inner edge in the width direction W, and the inner side edge is an inner edge in the width direction W.

(4) Wearing state of disposable diaper

Next, a wearing state of the disposable diaper 10 will be described with reference to fig. 5 and 6. Fig. 5 is a view schematically showing a wearing state of a disposable diaper at a section a-a. Fig. 6 is a view for explaining a deformation form of the central high rigidity portion when worn. Fig. 6 is a diagram for explaining a deformation mode of the absorbent core 31 due to contraction of the crotch stretch unit 41, and fig. 6 does not show the configuration of the absorbent core 31 except for the central high rigidity portion 71 and the crotch stretch unit 41. Fig. 7 is a view schematically showing a wearing state of the disposable diaper according to the embodiment, and is a view for viewing a wearer in a lying state from the front side. The line BL shown in fig. 5 and 6 indicates a line of the body of the wearer.

When the tape-type disposable diaper 10 is put on, the rear body region S2 is placed over the buttocks, and the diaper is pulled toward the crotch region S3 side to cover the body with the crotch region S3. At this time, the disposable diaper 10 is pulled in the front-rear direction L, and the crotch stretch unit 41 is extended in the front-rear direction as shown in fig. 6 (a). When the crotch region S3 is to be brought into contact with the crotch of the wearer in a state where the crotch stretch unit 41 is extended, the region where the crotch stretch unit 41 is disposed is pulled up toward the body by the contraction of the crotch stretch unit 41, as shown in fig. 6 (b). The deformation in the 1 st to 3 rd regions R41 and R43 is such that the 1 st region R41 is pulled up to the closest position to the body side, and the 2 nd and 3 rd regions R42 and R43 are also pulled up toward the body side with the 1 st region R41. At this time, when the deformation of the central high rigidity portion 71 is replaced by the "principle of leverage", the leading edge of the 3 rd region R43 becomes a fulcrum. Since the contraction of the crotch stretch unit 41 acts on the entire 2 nd region, the point of action is the center in the front-rear direction of the central high stiffness portion 71 (the center in the front-rear direction of the region obtained by combining the 2 nd region R42 and the 3 rd region R43). The force point is a region where the crotch stretch unit 41 is disposed, and therefore, is the center in the front-rear direction of the 2 nd region R42. The absorbent core is pulled up toward the body side with the front end edge of the 3 rd region R43 as a base point by the contraction of the crotch stretch unit 41 as a lever action of the 2 nd type.

Further, since the crotch stretch unit 41 is disposed on both sides of the center of the central high rigidity portion 71 in the width direction, the central high rigidity portion 71 is pulled up toward the body side in a constant region in the width direction. Specifically, the central high-rigidity portion 71 disposed in the region sandwiched in the width direction by the crotch stretch unit 41 (the 2 nd region R42 in the present embodiment) is pulled up toward the body side by the contraction of the crotch stretch unit 41 as it is. In the 3 rd region R43, the central high rigidity portion 71 is not directly affected by the contraction force of the crotch stretch unit 41, and is easily arranged in a planar shape along the crotch. In the crotch region, the absorbent core 31 in the crotch region is arranged along the body by deforming a certain region of the central high stiffness portion 71 into a convex shape protruding toward the body. The absorbent core 31 can be appropriately accommodated between the wearer's crotch when worn. By disposing the disposable diaper at an appropriate position between the wearer's thighs, the front waistline region can be pulled up to a position covering the abdomen of the wearer. This enables the belt-type disposable diaper to appropriately cover the body of the wearer.

The length of the 1 st region R41 in the front-rear direction may be longer than the length of the 2 nd region R42 in the front-rear direction. The 1 st region R41 makes it easier to pull up the absorbent core 31 toward the body side by the contractive force of the crotch stretch unit 41 than the 2 nd region R42. By securing the length of the 1 st region R41 in the front-rear direction, the 1 st region R41 can be pulled up toward the body side, and the 2 nd region R42 can also be pulled up along with this 1 st region R41. Further, by making the length of the 1 st region R41 in the front-rear direction longer, the distance between the point of action and the point of force becomes longer, and the central high rigidity portion 71 is easily pulled up even with a small contraction force of the crotch stretch unit 41. Further, by making the length of the 1 st region R41 in the front-rear direction longer and the length of the 2 nd region R42 shorter, the distance between the force point and the fulcrum becomes longer, and the central high rigidity portion 71 is easily pulled up even with a small contraction force of the crotch stretch unit 41.

The length of the 3 rd region R43 in the front-rear direction L may be longer than the length of the 2 nd region R42 in the front-rear direction L. The 3 rd region R43 can be secured in the longitudinal direction, and the fit between the crotch and the thigh can be improved by securing a region arranged in a planar shape with respect to the body. Further, by securing the length of the 3 rd region in the front-rear direction, the region pulled up toward the body is formed to the abdomen side, and the convex shape is maintained to the abdomen side with respect to the body, and the fit can be further improved.

The central high rigidity portion 71 may cross the fold FL. In the vicinity of the fold FL of the disposable diaper, the fold tends to deform convexly toward the non-skin surface side. The central high-rigidity portion 71 straddles the fold FL, thereby suppressing deformation due to the fold and facilitating maintenance of convex deformation with respect to the body side. The fold FL is disposed in the 2 nd region R42 or the 3 rd region R43. Since the fold FL is not provided in the 1 st region R41, the region forward of the fold FL can be prevented from being pulled toward the fold FL (the side away from the body) by contraction of the crotch stretch unit 41. This allows the crotch region to be positioned along the body, and allows the absorbent core 31 to be appropriately accommodated between the wearer's thighs when worn. In the modification, the central high rigidity portion 71 may not extend across the fold line FL. By making the central high-rigidity portion 71 not to straddle the fold line FL, the central high-rigidity portion 71 having relatively high rigidity can suppress the occurrence of a crease due to the fold line. This can suppress deformation due to the creases, and maintain convex deformation with respect to the body side.

The fold FL of the present embodiment is provided in the 2 nd region R42. The fold FL may be provided in the 2 nd region R42 at a position rearward of the center in the front-rear direction of the 2 nd region R42. The fold FL is located more rearward than the center of the 2 nd region R42 in the front-rear direction, and is located farther from the front end edge of the 3 rd region R43 serving as a deformation fulcrum of the absorbent core 31 and closer to the point of action. This makes it easier to pull up the deformation caused by the crease due to the contraction of the crotch stretch unit 41. In addition, in the modification, the fold FL may be provided to the 3 rd region R43. Since the crotch stretch unit 41 is not disposed across the fold line FL, it is possible to suppress the region in front of the fold line FL from being pulled to the side close to the fold line FL (the side away from the body) by the contraction of the crotch stretch unit 41. This allows the crotch region to be positioned along the body, and allows the absorbent core 31 to be appropriately accommodated between the wearer's thighs when worn.

The rear end edge of the crotch stretch unit 41 may be disposed on the front side of the intermediate line ML1, and the intermediate line ML1 may be located between the center 10LC of the disposable diaper in the front-rear direction L and the front end edge of the joint unit 93 in the front-rear direction L. As shown in fig. 1, the intermediate line ML1 is a line that passes through the center 10LC in the front-rear direction L of the disposable diaper and the center in the front-rear direction L of the front end edge of the joint 93 and extends in the width direction W. The position more posterior than the middle line ML1 is generally the area that bears the buttocks when worn. The rear end edge of the crotch stretch unit 41 is located on the front side of the intermediate line ML1 and is disposed in a region not supporting the buttocks of the wearer. When the wearer wears the garment, the crotch stretch unit 41 is more likely to stretch by pulling the region not bearing the buttocks forward in a state where the region on the rear side of the center line ML1 is pressed by the buttocks. This makes it easier to pull up the region where the crotch stretch unit 41 is disposed with respect to the body, and the absorbent core 31 can be further appropriately accommodated between the wearer's thighs. In the modification, the rear end edge 41R of the crotch stretch unit 41 may be located rearward of the intermediate line ML 1. When the wearer wears the garment, the front end edge 41F side of the crotch stretch unit 41 is pulled forward in a state where the rear end edge 41R of the crotch stretch unit 41 is pressed against the buttocks, and the crotch stretch unit 41 is more easily extended. This allows the region in which the crotch stretch unit 41 is disposed to be pulled up with respect to the body, and the absorbent core can be further appropriately accommodated in the crotch of the wearer.

At least a part of the central high rigidity portion 71 may be disposed in a region sandwiched by the pair of low basis weight portions 33. In the present embodiment, the entire region of the central high rigidity portion 71 is disposed in a region sandwiched between the pair of low basis weight portions 33. The absorbent core 31 in the crotch region deforms when worn from the low basis weight portions 33 extending in the front-back direction, and the low basis weight portions 33 tend to deform convexly toward the body side. In this case, the region between the pair of low basis weight portions 33 is increased in rigidity by the central high rigidity portion 71, and the state along the body is easily maintained. This makes it easier to appropriately store the absorbent core 31 in the crotch of the wearer.

The rear end edge 33R of the low basis weight portion 33 may be located at the same position as the rear end edge 41R of the crotch stretch unit 41 in the front-rear direction L, or may be located at a position rearward of the rear end edge 41R of the crotch stretch unit 41 in the front-rear direction L. The region deformed from the low basis weight portion 33 can be pulled up by the crotch stretch unit 41. In addition, the region provided with the low basis weight portion 33 has lower rigidity than the region not provided with the low basis weight portion 33, and the contractive force of the crotch stretch unit 41 is more easily exhibited. This makes it easier to pull up the absorbent core 31 toward the body side by the crotch stretch unit 41.

The crotch stretch unit 41 is disposed in a region overlapping the low basis weight unit 33 in the thickness direction or a region overlapping the low basis weight unit 33 in the width direction. The region deformed from the low basis weight portion 33 can be pulled up by the crotch stretch unit 41. In addition, the region provided with the low basis weight portion 33 has lower rigidity than the region not provided with the low basis weight portion 33, and the contractive force of the crotch stretch unit 41 is more easily exhibited. This makes it easier to pull up the absorbent core 31 toward the body side by the crotch stretch unit 41.

The length of the central high rigidity portion 71 in the width direction W may be shorter than the distance between the pair of low basis weight portions 33 in the width direction. That is, the central high rigidity portion 71 and the low unit area weight portion 33 may be separated in the width direction. The central high rigidity portion 71 and the low unit area weight portion 33 are separated from each other, and the separated region is more easily deformed than the central high rigidity portion 71. When the region between the low basis weight parts 33 is not accommodated between the thighs, the divided region is deformed. The deformed state with the low basis weight portion 33 as the base point and the state in which the central high rigidity portion 71 is along the body can be easily maintained, and the fit with the body can be improved. Since the low basis weight portion 33 is not connected to the central high rigidity portion 71, a rigidity difference occurs between the inner edge of the low basis weight portion 33 and the outer edge of the central high rigidity portion 71 with respect to the regions adjacent in the width direction. The inner edge of the low basis weight portion 33 and the outer edge of the central high stiffness portion 71 also serve as deformation base points, and the absorbent core 31 is deformed at a plurality of base points, thereby being more easily fitted to the body.

(5) Modification example

Next, an absorbent core according to a modification will be described. Fig. 8 is a plan view schematically showing an absorbent core according to a modification. In the following modifications and the description of embodiment 2 to be described later, only the configurations different from those of the above-described embodiments will be described, and the same reference numerals are used for the same configurations as those of the embodiments, and the description thereof will be omitted. Fig. 8 (a) shows an absorbent core 31A of modification 1. The crotch stretch unit 41A and the central high rigidity portion 71A of the absorbent core 31A of modification 1 overlap in the thickness direction. The central high rigidity portion 71A of the absorbent core 31A of modification 1 extends outward in the width direction from the outer edge of the crotch stretch unit 41A. The absorbent core 31A of modification 1 is pulled up toward the body side by contraction of the crotch stretch units 41A in the region overlapping with the crotch stretch units 41A and in the region sandwiched between the crotch stretch units 41A in the width direction. The absorbent core 31A of modification 1 does not have the low basis weight portion 33. The absorbent core 31 is pulled up against the crotch of the wearer by contraction of the crotch stretch unit 41, and fits between the crotch.

Fig. 8 (B) shows an absorbent core 31B of modification 2. The crotch stretch unit 41B of the absorbent core 31B of modification 2 is formed of an elastic sheet and extends across the outer edge of the central high stiffness portion 71A in the width direction. The crotch stretch unit 41B is provided in a region overlapping the central high rigidity portion 71B and a region located outside the central high rigidity portion 71A in the width direction. The absorbent core 31B of modification 2 is pulled up toward the body side by contraction of the crotch stretch unit 41B in the region overlapping with the crotch stretch unit 41B and in the region sandwiched between the crotch stretch unit 41B in the width direction.

Fig. 8 (C) shows an absorbent core 31C of modification 3. The crotch stretch unit 41C of the absorbent core 31C of modification 3 is formed of an elastic sheet and overlaps the center in the width direction of the central high stiffness unit 71C. The central high rigidity portion 71C extends outward in the width direction than the crotch stretch unit 41C. The absorbent core 31C of modification 3 is pulled up toward the body side by contraction of the crotch stretch unit 41C in the region overlapping with the crotch stretch unit 41B.

Fig. 8 (D) shows an absorbent core 31D of modification 4. The absorbent core 31D of modification 4 has a variable length in the width direction of the low basis weight portion 33A. More specifically, the outer edge of the low-basis-weight portion 33A is linear along the front-rear direction, and the inner edge of the low-basis-weight portion 33A includes a linear portion 33X along the front-rear direction and a protruding portion 33Y protruding inward in the width direction. With such a low basis weight portion 33A, the rigidity changes at the boundary between the linear portion 33X and the protruding portion 33Y and at the center in the front-rear direction of the protruding portion 33Y (the apex of the protruding portion), and a deformation base point of the absorbent core is formed. This facilitates the roundness of the absorbent core 31D in the front-back direction of the body.

The measurement of "weight per unit area of absorbent core" in the present specification was performed by the following measurement method. When the disposable diaper 10 is sealed in a package or the like, a sample is taken out from the package and left in this state for 12 hours in an environment of 20 ℃. + -. 2 ℃ and a relative humidity of 60%. + -. 5% RH. In the case of a disposable diaper packaged with a packaging sheet or the like, the packaging sheet is opened and the folded disposable diaper is unfolded. Next, a portion for measuring the basis weight is cut out from the disposable diaper, and a portion other than the absorbent core such as a topsheet is removed from the cut-out portion. Then, the area and weight of the portion for measuring the weight per unit area of the absorbent core were measured. The weight per unit area was calculated based on the weight and the area.

The "flexural rigidity" in the present specification may be a value measured from gurley stiffness. The measurement of the Gurley stiffness can be carried out in accordance with JIS-L1096 using a Gurley softness tester No311 manufactured by Antian Seiki machine (manufactured by Kabushiki Kaisha). The length of the sample in the width direction W for the measurement of gurley stiffness can be set to 30mm, and the length in the front-rear direction can be set to 25 mm.

(6) Embodiment 2

Next, the disposable diaper of embodiment 2 is explained. The disposable diaper according to embodiment 2 may be a tape-type disposable diaper or a pants-type disposable diaper. Fig. 9 is a plan view of the absorbent core 31X of embodiment 2 as viewed from the skin surface side. The central high rigidity portion 71 is provided in a region between the pair of low basis weight portions 33. The front end edge 71F of the central high rigidity portion 71 may be positioned to be aligned with the front end edge 33F of the low basis weight portion 33 or positioned on the rear side of the front end edge 33F of the low basis weight portion 33. The rear end edge 71R of the central high rigidity portion 71 may be located on the front side of the rear end edge 33R of the low basis weight portion 33. The center of the central high rigidity portion 71 in the front-rear direction L may be disposed forward of the center of the low basis weight portion 33 in the front-rear direction L. The central high rigidity portion 71 may be disposed at a distance from the low unit area weight portion 33 in the width direction W. The central high rigidity portion 71 may straddle the center 10LC of the disposable diaper and the center 10WC of the disposable diaper in the width direction W. The central high rigidity portion 71 constitutes a "high rigidity portion" of the present invention. As shown in fig. 9, assuming that the length of the central high stiffness portion 71 in the width direction W is a and the distance between the central high stiffness portion 71 and the low unit area weight portion 33 is B, a + B × 2> a and B × 2< a are satisfied.

The front high rigidity portion 73 may be disposed on the front side of the low basis weight portion 33. The front high rigidity portions 73 may be disposed on both sides of the center 10WC of the disposable diaper in the width direction W with a space therebetween. The front end edge of the front high rigidity portion 73 may extend toward the outer side in the width direction W toward the front side.

Next, a wearing state of the disposable diaper 10 will be described with reference to fig. 5 and 6 of embodiment 1. When the disposable diaper is worn, a force toward the skin surface side T1 and the inside in the width direction W is applied to the absorbent core 31X in the crotch region S3 by being pulled up and sandwiched between the legs of the wearer when the disposable diaper is worn, and the absorbent core 31X in the crotch region S3 deforms with the low basis weight portions 33 extending in the front-rear direction L as base points when the disposable diaper is worn, and the low basis weight portions 33 easily deform to be convex toward the body side. In this case, the rigidity of the region between the pair of low basis weight parts 33 is increased by the central high rigidity part 71, and the state along the body is easily maintained.

At this time, the length a + (the distance B × 2 between the central high stiffness portion 71 and the low unit area weight portion 33) in the width direction W of the central high stiffness portion 71 > the length a in the width direction W of the central high stiffness portion 71 is satisfied, and the distance B is provided between the central high stiffness portion 71 and the low unit area weight portion 33. The region of distance B is more easily deformed than the central high rigidity portion 71. When the region between the low basis weight portions is not accommodated between the thighs, the region of the distance B is deformed. The convex deformation state from the low basis weight part 33 and the state in which the central high rigidity part 71 is along the body can be easily maintained, and the gap with respect to the body can be reduced.

The low basis weight portion 33 and the central high rigidity portion 71 are not connected to each other with a space therebetween in the width direction W. Therefore, a difference in rigidity occurs between the inner edge of the low basis weight portion 33 and the outer edge 71E of the central high rigidity portion 71 with respect to the regions adjacent in the width direction. The inner edge of the low basis weight portion 33 and the outer edge of the central high stiffness portion 71 also serve as deformation base points, and the absorbent core is deformed at a plurality of base points, thereby being more easily fitted to the body. More specifically, as shown in fig. 6, the absorbent core 31X deforms from the low basis weight portions 33, and the central region R32 is convex toward the body with respect to the side regions R31. In the central region R32, since the rigidity also changes with the outer edge 71E of the central high rigidity portion 71 as a boundary, the region where the central high rigidity portion 71 is disposed is deformed with the outer edge 71E of the central high rigidity portion 71 as a base point, and the region where the central high rigidity portion 71 is disposed is convex toward the body side with respect to the region of the distance B. Further, in order to satisfy B × 2< a, the ratio of the central high rigidity portion 71 is higher than the ratio of the distance B in the region between the low basis weight portions 33. Thus, the absorbent core 31X is disposed along the body between the low basis weight portions 33, and the gap with the body can be reduced. Leakage can be reduced by deforming the absorbent core 31X in a manner to follow the crotch of the body.

The central high-rigidity portion 71 can straddle the fold lines FL folded so that the skin surface sides of the disposable diaper 10 face each other. In the vicinity of the fold FL of the disposable diaper 10, the fold tends to deform convexly toward the non-skin surface side. The central high-rigidity portion 71 straddles the fold FL, thereby suppressing deformation due to the fold and facilitating maintenance of convex deformation with respect to the body side.

The crotch stretch unit 41 may be disposed on both outer sides in the width direction W with respect to the central high rigidity unit 71. The region on the outer side in the width direction W than the central high rigidity portion 71 can be pulled up toward the body by the contraction of the crotch stretch unit 41. This makes it easy for the vicinity of the low basis weight portion 33 to deform convexly toward the body. In addition, the central high rigidity portion 71 is less likely to contract due to the crotch stretch unit 41. This can ensure the absorption area, maintain the convex shape along the crotch, and reduce leakage. At least a part of the crotch stretch unit 41 may be disposed in a region overlapping the low basis weight portion 33. Since the low basis weight portion 33 has lower rigidity than the surroundings, the crotch stretch unit and the low basis weight portion overlap each other, and the crotch stretch unit is easily contracted and more easily maintains convex deformation.

In the 1 st region R1 extending in the width direction W from the crotch stretch unit 41, an overlap region R2 in which the central high rigidity portion 71 is arranged is provided, and the length in the front-rear direction L of the overlap region R2 may be 1/2 or less of the length L71 in the front-rear direction of the central high rigidity portion 71. The entire central high-rigidity portion 71 is less likely to contract due to contraction of the crotch stretch unit 41. This makes it easy to maintain the convex shape of the high rigidity central portion 71 along the crotch, while ensuring the absorption area, and thus reduces leakage.

D > E/4 may be satisfied where D is the distance between the low basis weight portion 33 and the outer edge 31E of the absorbent core 31X and E is the length between the outer edges 31E of the absorbent core 31X. The outer edge 31E of the absorbent core 31X herein refers to an outer edge in a region extending in the width direction W from the low basis weight portion 33. That is, D > E/4 may be satisfied on a straight line passing through the low unit area weight portion 33 and extending in the width direction W. When the deformation toward the body side is convex from the low basis weight portion 33 as a base point, a region on the outer side in the width direction W than the low basis weight portion 33 (region of the distance D) becomes a region for supporting the convex deformation. The region outside the low basis weight portion 33 in the width direction W (region of the distance D) is longer than 1/4 in the entire region of the absorbent core 31X in the width direction W, and therefore the convex deformation is stably supported, and the convex shape is easily maintained.

B1 ≠ B2 may be satisfied where B1 denotes a distance between the 1 st low unit area weight portion 331 serving as one of the pair of low unit area weight portions 33 and the central high rigidity portion 71, and B2 denotes a distance between the 2 nd low unit area weight portion 332 serving as the other of the pair of low unit area weight portions 33 and the central high rigidity portion 71. Since the distance B1 between the 1 st low basis weight portion 331 and the central high rigidity portion 71 is different from the distance B2 between the 2 nd low basis weight portion 332 and the central high rigidity portion 71, when a force is applied from both the left and right sides, one of the region of the distance B1 and the region of the distance B2 deforms first. Therefore, the force is uniformly applied to the central high-rigidity portion from both the left and right sides, and the defect that the central high-rigidity portion is bent can be suppressed. This can maintain a convex shape along the crotch, ensure an absorption area, and reduce leakage.

The central high rigidity portion 71 may be disposed only in a region sandwiched by the low basis weight portions 33. That is, the front end edge 71F of the central high rigidity portion 71 may be positioned in alignment with the front end edge 33F of the low unit area weight portion 33 or in a position closer to the rear side than the front end edge 33F of the low unit area weight portion 33, and the rear end edge 71R of the central high rigidity portion 71 may be positioned in alignment with the rear end edge 33R of the low unit area weight portion 33 or in a position closer to the front side than the rear end edge 33R of the low unit area weight portion 33. Since the central high rigidity portion 71 is provided only in the region sandwiched by the low basis weight portions 33, the central high rigidity portion 71 is disposed only in the region deformed into a convex shape toward the body side. The central high-rigidity portion 71 can be arranged in a flat shape along the crotch, and the fit between the crotch and the crotch can be further improved.

The center of the low basis weight portion 33 in the front-rear direction L may be disposed on the rear side of the center 10LC of the disposable diaper 10 in the front-rear direction L. Since the low basis weight portion 33 is shifted toward the rear side, deformation from the low basis weight portion 33 can be provided on the hip side.

The leg hole stretch units 42 may be disposed on an extension line extending outward in the width direction W from the crotch stretch unit 41. The absorbent core 31X is deformed in a state where the leg hole stretch units are fitted to the body, and the central region R32 is more likely to stand up with respect to the side regions R31. The absorbent core 31X is more easily pulled up toward the wearer by the contraction of the crotch stretch unit 41.

The leg hole stretch units 42 may extend rearward and outward in the width direction W. The leg hole stretch units extending toward the rear side and toward the outer side in the width direction W are in close contact with the body, and the hips of the wearer can be covered with the disposable diaper. The absorbent core 31X can be deformed so that the length in the width direction W of the absorbent core 31X becomes shorter toward the crotch region in a state where the absorbent core covers the buttocks in a wide range toward the rear side. The absorbent core 31X can be appropriately accommodated in the crotch of the wearer, and the entire body can be covered with the disposable diaper, and leakage can be suppressed.

The present invention has been described in detail with reference to the above embodiments, but it is clear to those skilled in the art that the present invention is not limited to the embodiments described in the present specification. The present invention can be implemented as modifications and variations without departing from the spirit and scope of the present invention defined by the claims. Therefore, the description in the present specification is for the purpose of illustration and description, and does not have any restrictive meaning to the present invention.

The above-described embodiment is a tape-type disposable diaper, but may be a pants-type disposable diaper in a modification. When putting on the underpants type disposable diaper, the legs of the wearer are passed through the leg hole openings, and at least one of the body surrounding region and the rear body surrounding region is pulled up. At this time, in a posture in which the wearer lies, the front torso surrounding region is pulled up with the rear torso surrounding region in close contact with the body, and the crotch region is pulled in the front-rear direction. When the crotch region is pulled in the front-rear direction, the crotch stretch unit is stretched in the front-rear direction, and the region where the crotch stretch unit is disposed is pulled up relative to the body. At this time, the 1 st region is also pulled up to the position closest to the body side, and the 2 nd region is also pulled up toward the body side as the 1 st region is pulled up. Further, since the crotch stretch unit is disposed on both sides of the center in the width direction of the high-rigidity unit, the high-rigidity unit is pulled up toward the body side in the region sandwiched by the crotch stretch unit. In this case, in the 3 rd region, the high rigidity portion is not contracted by the crotch stretch portion, and is easily arranged in a planar shape along the crotch. In the crotch region, the absorbent core in the crotch region is arranged along the body by deforming the high-rigidity portion in a predetermined region into a convex shape protruding toward the body. The absorbent core can be appropriately accommodated between the wearer's crotch when worn. The disposable diaper can be placed at an appropriate position between the wearer's thighs, and the front waistline region can be pulled to a position covering the abdomen of the wearer. This enables the body of the wearer to be covered appropriately in the case of a pants-type disposable diaper.

In addition, the entire contents of japanese patent application No. 2018-152784 and japanese patent application No. 2018-152780, which were filed on 14.8.8.2018, are incorporated by reference in the present specification.

Industrial applicability

The present invention can provide a disposable diaper which can deform an absorbent core so as to fit along the crotch of the body and can appropriately cover the body of a wearer.

Description of the reference numerals

10. A disposable diaper; 10LC, center in the front-rear direction of the diaper; 31. 31X, absorbent core; 33. a low unit area weight portion; 41. a crotch stretch unit; 42. a leg-surrounding expansion part; 71. a central high-rigidity portion (high-rigidity portion); 72. a rear high-rigidity portion (high-rigidity portion); 73. a front high-rigidity portion (high-rigidity portion); 91. a fastening tape; 93. a bonding section; r41, region 1; r42, region 2; r43, region 3; s1, a front surrounding area; s2, a posterior body surrounding area; s3, a crotch region; t, the thickness direction; t1, skin surface side; t2, non-skin face side; l, the front-back direction; w, width direction.

Claims

1. A disposable diaper having:

a front-back direction and a width direction orthogonal to each other;

a front torso-surrounding region, a rear torso-surrounding region, and a crotch region disposed between the front torso-surrounding region and the rear torso-surrounding region;

an absorbent core disposed in at least the crotch region;

a fastening band disposed in the rear torso region;

a crotch stretch unit that stretches and contracts in the front-back direction in a region of the crotch region that overlaps the absorbent core in the thickness direction; and

a central high rigidity portion having higher rigidity in the crotch region than in the peripheral region and extending forward from the crotch stretch unit,

wherein,

the crotch stretch unit extends rearward from the central high rigidity unit at positions on both sides of the center of the central high rigidity unit in the width direction,

the absorbent core has a 1 st region, a 2 nd region and a 3 rd region,

in the 1 st region, the crotch stretch unit is disposed rearward of the central high rigidity unit,

in the 2 nd region, the central high rigidity portion and the crotch stretch portion overlap in the width direction,

the 3 rd region is provided with the central high rigidity portion on the front side of the crotch stretch unit,

the central high rigidity portion is disposed apart from the crotch stretch portion at a position inward in the width direction of the crotch stretch portion.

2. The disposable diaper according to claim 1,

the length of the 1 st region in the front-rear direction is longer than the length of the 2 nd region in the front-rear direction.

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

the 3 rd region has a length in the front-rear direction longer than that of the 2 nd region.

4. The disposable diaper according to claim 1,

the disposable diaper is folded so that the skin surface sides of the disposable diaper face each other with a fold line extending in the width direction as a base point,

the central high stiffness portion spans the fold.

5. The disposable diaper according to claim 4,

the crease is arranged in the No. 3 area.

6. The disposable diaper according to claim 4,

the fold is provided on the 2 nd region at a position rearward of the center in the front-rear direction of the 2 nd region.

7. The disposable diaper according to claim 1,

the fastening tape has a combining part combined with the front surrounding area,

the rear end edge of the crotch stretch unit is disposed on the front side of an intermediate line between the center of the disposable diaper in the front-rear direction and the front end edge of the bonded unit in the front-rear direction.

8. The disposable diaper according to claim 1,

the rear end edge of the crotch stretch unit is disposed on the rear side of an intermediate line between the center of the disposable diaper in the front-rear direction and the front end edge of the bonded unit in the front-rear direction.

9. The disposable diaper according to claim 1,

the absorbent core in the crotch region is provided with a pair of low basis weight portions extending in the front-back direction and arranged at an interval in the width direction,

at least a part of the central high rigidity portion is disposed in a region sandwiched by the pair of low basis weight portions.

10. The disposable diaper according to claim 9,

the rear end edge of the low basis weight portion is disposed at the same position as the rear end edge of the crotch stretch portion in the front-rear direction, or at a position rearward of the rear end edge of the crotch stretch portion in the front-rear direction.

11. The disposable diaper according to claim 9 or 10,

the crotch stretch unit is disposed in a region overlapping the low basis weight unit in the thickness direction or the width direction.

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

the crotch stretch unit is formed by two rubber threads arranged along the front-rear direction on both sides of the center of the absorbent core with respect to the width direction.