JP7733972B2 - Pants-type diapers - Google Patents

Description

The present invention relates to a pants-type diaper.

Pants-type diapers that use an absorbent body containing a relatively large amount of super absorbent polymer (SAP) as the absorbent material are known. For example, Patent Document 1 discloses disposable absorbent pants comprising an absorbent structure and an elastic belt structure. The absorbent structure comprises an absorbent layer having at least one longitudinally oriented elongated channel. At least one of the front distal end and rear distal end of the channel is positioned above the lower edge of the elastic belt structure.

According to Patent Document 1, longitudinally extending channels help transport and distribute liquid (e.g., urine) along the superabsorbent polymers arranged on both sides of the channels. This helps increase the rate at which the superabsorbent polymers acquire and absorb liquid. However, the presence of longitudinally extending channels can cause the absorbent layer to assume a relatively straight shape in the longitudinal direction when the superabsorbent polymers absorb liquid and swell, potentially resulting in both longitudinal ends of the absorbent structure protruding from the wearer's body. However, according to Patent Document 1, by holding at least one of the front and rear distal ends of the channels with the lower edge of the elastic belt structure, it is possible to prevent both longitudinal ends of the absorbent structure from protruding from the wearer's body.

Special table 2018-505718 publication

In the pants-type diaper described in Patent Document 1, the absorbent main body (absorbent structure) may be tightened from both widthwise sides by the thighs when worn. In this case, the absorbent body (absorbent layer) deforms into a shape that extends in the longitudinal direction and is convex toward the non-skin side, with the longitudinal channels acting as fold lines. In this state, when the superabsorbent polymer absorbs liquid and swells, the longitudinally extending convex shape is further strengthened, increasing the rigidity of the convex-shaped superabsorbent polymer. As a result, the absorbent body has a relatively straight convex shape along the channels from one longitudinal end to the other. In this case, both longitudinal ends of the absorbent body also deform the waist belt (elastic belt structure), disrupting the flatness of the waist belt. This may impair the fit of the pants-type diaper and may also cause liquid to leak from gaps that form between the waist belt and the skin.

According to Patent Document 1, the ends of the channels are held by the waist belt, which prevents both longitudinal ends of the absorbent main body from protruding from the wearer's body. However, Patent Document 1 does not take into consideration the fact that when worn, the absorbent main body is tightened from both widthwise sides by the thighs, which can easily cause the absorbent body to deform into a convex shape extending longitudinally even before absorbing liquid. Therefore, there is room for improvement in the pants-type diaper in Patent Document 1.

For example, Patent Document 1 discloses a structure in which a waist belt is provided with an elastic member across its entire width. In this case, the contractile force of the elastic member is too strong. If the channel overlaps with the waist belt, the waist belt may contract in the width direction before the diaper is put on, causing the longitudinal ends of the absorber to contract in the width direction and deform into a convex shape. This may not only reduce the fit of the diaper when put on, but may also cause the waist belt to wrinkle significantly due to the contraction of the absorber, leading to the diaper being mistaken for a defective product.

Patent Document 1 also discloses a waist belt structure in which high-stretch regions are formed outside both widthwise ends of the laminated absorbent body, and a low-stretch region is formed between the two high-stretch regions. In this case, it is possible to prevent the ends of the absorbent body from shrinking and becoming convex before the diaper is put on. However, because the high-stretch regions on both widthwise sides of the absorbent body are separated from the absorbent body, it is difficult for the contractile force of the high-stretch regions to pull the absorbent body in the width direction when the diaper absorbs liquid after being put on. Therefore, it is difficult to prevent the absorbent body from becoming convex. In other words, it is difficult for the waist belt to prevent both longitudinal ends of the absorbent body from protruding from the wearer's body.

The objective of this study is to provide a pants-type diaper that contains a highly absorbent polymer and has an absorbent body with channels, which can prevent liquid leakage while preventing a decrease in fit.

The pants-type diaper of the present invention is as follows. (1) A pants-type diaper having longitudinal, width, and thickness directions that are perpendicular to one another, comprising a ventral waist belt, a dorsal waist belt, and an absorbent main body including an absorber located between the ventral waist belt and the dorsal waist belt, wherein the absorber contains a superabsorbent polymer and has at least one channel extending along the longitudinal direction, and at least one of the dorsal waist belt and the ventral waist belt has a low-elasticity region located in the center of the width direction, extending outward from the inner edge in the longitudinal direction, and having low elasticity in the width direction, and a pair of high-elasticity regions adjacent to both sides of the low-elasticity region in the width direction, and having high elasticity in the width direction, at least one of the rear and front longitudinal sides of the channel overlaps with the low-elasticity region in the thickness direction, and in a plan view, the inner edge in the width direction of each of the pair of high-elasticity regions is located between the channel and the edge of the absorber facing the high-elasticity region in the width direction.

In this pants-type diaper, the channels in the absorbent body reach at least one of the dorsal and ventral waist belts. This allows liquid (e.g., urine) to be transported and distributed to the dorsal (longitudinal rear) and ventral (longitudinal front) ends of the absorbent body. This allows the superabsorbent polymer in the longitudinal rear and front ends of the absorbent body, which are less likely to contribute to absorption, to absorb the liquid, thereby making effective use of the superabsorbent polymer.
In this pants-type diaper, the inner widthwise edge of the high-elasticity region of at least one of the back waist belt and the ventral waist belt is located between the channel and the widthwise edge of the absorber opposite the high-elasticity region. That is, the widthwise central portion of the absorber overlaps the low-elasticity region in the thickness direction. Therefore, the contractile force that contracts the absorber in the width direction is not too strong, which prevents the back-side longitudinal end of the absorber from contracting in the width direction and becoming convex before wearing.
Furthermore, the absorbent body has widthwise ends that overlap the highly stretchable regions in the thickness direction. This allows the contractile force of the highly stretchable regions to pull the absorbent body in the width direction from both sides of the channel. This prevents the longitudinal ends of the absorbent body from becoming convex and protruding from the wearer's body.
That is, the flatness of at least one of the dorsal and ventral waist belts can be maintained before and after wearing, thereby preventing fluid from leaking through gaps between the skin and at least one of the dorsal and ventral waist belts.
As a result, in a pants-type diaper that contains a highly water-absorbent polymer and has an absorbent body with channels, it is possible to suppress leakage of liquid while suppressing deterioration in fit.

The pants-type diaper of the present invention may be the pants-type diaper described in (1) above, wherein (2) the back waist belt has a back low-elasticity region as the low-elasticity region and a pair of back high-elasticity regions as the pair of high-elasticity regions, and in a plan view, the inner edge in the width direction of each of the pair of back high-elasticity regions is closer to the edge in the width direction of the channel than the edge of the absorber in the width direction that faces the back high-elasticity region.
In this pants-type diaper, the inner widthwise edge of the back highly elastic region is closer to the widthwise edge of the channel than to the widthwise edge of the absorbent body. This allows the contractile force of the back highly elastic region to more strongly pull the absorbent body from both sides of the channel in the width direction. This more reliably prevents the longitudinal edges of the absorbent body from becoming convex and protruding from the wearer's body.

The pants-type diaper of the present invention may be the pants-type diaper described in (3) above (2), wherein the ventral waist belt has a ventral low-elasticity region as the low-elasticity region and a pair of ventral high-elasticity regions as the pair of high-elasticity regions, and the distance between the inner edges in the width direction of the pair of ventral high-elasticity regions is shorter in plan view than the distance between the inner edges in the width direction of the pair of dorsal high-elasticity regions.
In this pants-type diaper, the distance between the pair of ventral high-elasticity regions is closer than the distance between the pair of dorsal high-elasticity regions. Therefore, on the ventral side, the absorber can be pulled more strongly from both sides of the channel in the width direction. That is, the absorber can be pulled more strongly from both sides in the ventral waist belt, which is relatively close to the position where it is tightened by both thighs from both sides in the width direction and becomes most convex when worn. This more reliably prevents the longitudinal ends of the absorber main body from protruding from the wearer's body in the ventral waist belt, which is relatively close to the position where it becomes most convex. Furthermore, on the dorsal side, by relatively weakening the force pulling the absorber from both sides across the channel in the width direction, a slight convexity is formed in the absorber, which can function as a space for containing feces.

The pants-type diaper of the present invention may be (4) the pants-type diaper described in (3) above, wherein the abdominal waist belt further has another abdominal high-elasticity area adjacent to the pair of abdominal high-elasticity areas and the abdominal low-elasticity area on the front side in the longitudinal direction and exhibiting high elasticity in the width direction.
In this pants-type diaper, the pair of abdominal high-elasticity regions and abdominal low-elasticity regions each have another abdominal high-elasticity region on the longitudinal front side thereof. Therefore, contraction of the other abdominal high-elasticity region pulls the portion of the abdominal waist belt that is longitudinally forward of the absorbent body more in the width direction, allowing the portion to be pressed closer to the skin. This makes it less likely that the absorbent body will become convex. In other words, the absorbent body can fit to the abdomen in a generally flat shape.

The pants-type diaper of the present invention may be (5) the pants-type diaper described in any one of (2) to (4) above, wherein the back waist belt further has another back high-elasticity area adjacent to the pair of back high-elasticity areas and the back low-elasticity area on the rear side in the longitudinal direction and exhibiting high elasticity in the width direction.
In this pants-type diaper, the pair of back high-elasticity regions and back low-elasticity regions each have another back high-elasticity region on the longitudinal rear side thereof. Therefore, contraction of the other back high-elasticity region can pull the portion of the back waist belt that is longitudinally rearward of the absorbent body more in the width direction, thereby pressing the portion closer to the skin. This makes it more difficult for the absorbent body to have a convex shape. In other words, the absorbent body can fit in the buttocks crevice in a generally flat shape.

The pants-type diaper of the present invention may be (6) the pants-type diaper described in any one of (2) to (5) above, wherein the rear longitudinal end of the rear low-elasticity region of the back waist belt is located further rearward in the longitudinal direction than the rear longitudinal end of the channel.
In this pants-type diaper, the rear longitudinal end of the back low-elasticity region is located further rearward than the rear longitudinal end of the channel. That is, the back low-elasticity region is also present in a portion further rearward than the rear longitudinal end of the channel. Therefore, the outer portion of the back waist belt that is rearward of the channel in the longitudinal direction is not stretched too much in the width direction, allowing the absorbent body to retain a slightly convex shape, forming a convex portion that can accommodate a small amount of feces in the absorbent body. Therefore, it is possible to ensure a space for accommodating feces while preventing the longitudinal end of the absorbent body from becoming convex.

The pants-type diaper of the present invention may be (7) the pants-type diaper according to any one of (1) to (6) above, wherein the absorbent main body includes a pair of side sheets located on both sides in the width direction on the skin-facing surface and extending in the longitudinal direction, each of the pair of side sheets being located at the front and rear ends of the side sheet in the longitudinal direction and including a fixed region fixed to the skin-facing surface of the absorbent main body and an elastic member extending along the longitudinal direction, and a leak-proof wall located between the fixed regions on the front and rear sides of the side sheet in the longitudinal direction and having an outer edge in the width direction fixed to the skin-facing surface of the absorbent main body and an inner edge in the width direction not fixed, and the fixed region and the inner edge in the width direction of the high-elasticity region overlap in the thickness direction.
In this pants-type diaper, the fixed region and the inner end of the high-elasticity region in the front width direction overlap in the thickness direction. Therefore, when the high-elasticity region contracts in the width direction, it pulls the longitudinal end of the absorber (absorbent main body) in the width direction and also pulls the leakage barrier walls outward in the width and longitudinal directions via the fixed region. This prevents the longitudinal end of the absorber from becoming convex and makes it easier for the leakage barrier to stand up, thereby suppressing fluid leakage in the width direction.

The pants-type diaper of the present invention may be (8) the pants-type diaper described in any one of (1) to (7) above, wherein the channel extends along the longitudinal direction and has two channels spaced apart in the width direction.
In this pants-type diaper, the two longitudinally extending channels allow for more efficient transport and distribution of liquid along the superabsorbent polymer longitudinally arranged within the absorbent core, thereby further increasing the acquisition and absorption rate. However, the two channels make the absorbent core more susceptible to deformation due to the uneven shape extending longitudinally along the channels. This increases the rigidity of the uneven shape, impairing the flatness of the waist belt, potentially impairing the fit of the pants-type diaper and potentially causing liquid leakage through gaps between the waist belt and the skin surface. Therefore, in this pants-type diaper, the inner widthwise edge of each of the pair of high-elasticity regions is positioned between the widthwise edge of the absorbent core and the channels in a plan view. This configuration prevents deterioration of the flatness of the waist belt, prevents deterioration of the fit of the pants-type diaper, and prevents liquid leakage through gaps between the waist belt and the skin surface.

The pants-type diaper of the present invention may be (9) the pants-type diaper according to any one of (1) to (8) above, wherein the absorbent body has a rectangular shape in a plan view.
In this pants-type diaper, the absorbent core has a rectangular shape in a plan view, allowing for efficient placement of the superabsorbent polymer within the absorbent core. However, because the absorbent core is rectangular, it is easily squeezed from both sides in the width direction by the thighs when worn, and is prone to deformation due to its convex shape extending longitudinally along the channels. This can impair the flatness of the waist belt, potentially impairing the fit of the pants-type diaper and potentially causing fluid leakage through gaps between the waist belt and the wearer's skin. Therefore, in this pants-type diaper, the inner widthwise edges of each of the pair of high-elasticity regions are positioned between the widthwise edges of the absorbent core and the channels in a plan view, thereby preventing deterioration in the flatness of the waist belt, preventing deterioration in the fit of the pants-type diaper, and preventing fluid leakage through gaps between the waist belt and the wearer's skin.

The present invention provides a pants-type diaper that contains a highly absorbent polymer and has an absorbent body with channels, which can prevent liquid leakage while suppressing deterioration of fit.

1 is a plan view showing an example of the configuration of a pants-type diaper according to an embodiment. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1A and 1B are a plan view and a cross-sectional view showing an example of the configuration of an absorbent body according to an embodiment. 1 is an enlarged plan view of a portion of a rear portion of a pants-type diaper according to an embodiment. FIG. 1 is an enlarged plan view of a portion of a ventral portion of a pants-type diaper according to an embodiment. 1A to 1C are schematic diagrams illustrating the effects of the pants-type diaper according to the embodiment. 1A to 1C are schematic diagrams illustrating the effects of the pants-type diaper according to the embodiment.

The following describes a pants-type disposable diaper (hereinafter simply referred to as a "pants-type diaper") according to an embodiment. However, the type of pants-type diaper is not limited to this example, and other types of pants-type diapers may be used as long as they do not deviate from the spirit and scope of the present invention. An example of such a pants-type diaper is a three-piece diaper.

1 and 2 are diagrams showing an example of the configuration of a pants-type diaper 1 according to an embodiment. FIG. 1 is a plan view showing the pants-type diaper 1 in an unfolded state, and FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. In the state shown in FIG. 1, the pants-type diaper 1 has a longitudinal direction L, a width direction W, and a thickness direction T that are perpendicular to one another, and has a longitudinal centerline CL that passes through the center of the width direction W and extends in the longitudinal direction L, and a widthwise centerline CW that passes through the center of the longitudinal direction L and extends in the width direction W. The directions and sides approaching the longitudinal centerline CL are respectively defined as the inward and inner sides in the width direction W, and the directions and sides moving away from the longitudinal centerline CW are respectively defined as the outward and outer sides in the width direction W. The directions and sides approaching the widthwise centerline CW are respectively defined as the inward and inner sides in the longitudinal direction L, and the directions and sides moving away from the widthwise centerline CW are respectively defined as the outward and outer sides in the longitudinal direction L. Additionally, the side in the longitudinal direction L toward the edge of the pant-type diaper 1 corresponding to the wearer's abdomen (the abdominal edge) is also referred to as the front side in the longitudinal direction L, and the side toward the edge of the pant-type diaper 1 corresponding to the wearer's back (the dorsal edge) is also referred to as the rear side in the longitudinal direction L. "Plane view" refers to the pant-type diaper 1 unfolded on a plane including the longitudinal direction L and the width direction W, as viewed from above in the thickness direction T, and "planar shape" refers to the shape as seen in a planar view. "Plane direction" refers to any direction parallel to a plane including the width direction W and the longitudinal direction L. "Skin side" and "non-skin side" refer to the side that is relatively closer to and farther from the wearer's skin in the thickness direction T, respectively, when the pant-type diaper 1 is worn by a wearer. These definitions are used not only for the pant-type diaper 1 but also for the absorbent body of the pant-type diaper 1 and the various materials disposed therein.

Note that when a component, structure, shape, etc. is said to be aligned with the longitudinal direction L, it does not only mean that the component is parallel to the longitudinal direction L, but also means that the component Dx in the longitudinal direction L of the component is greater than the component Dy in the width direction W of the component (Dx > Dy). Similarly, when a component is aligned with the width direction W, it does not only mean that the component is parallel to the width direction W, but also means that the component Dy in the width direction W of the component is greater than the component Dx in the longitudinal direction L of the component (Dy > Dx). For curved or curved components, the component is evaluated as described above for the tangent to each point on the curve.

As shown in FIG. 1, the pants-type diaper 1 comprises, in the longitudinal direction L, a ventral portion (ventral waist belt) 2, a dorsal portion (dorsal waist belt) 3, and an absorbent main body 10 located between the ventral portion 2 and the dorsal portion 3. In this embodiment, the pants-type diaper 1 further comprises a crotch portion 4 located between the ventral portion 2 and the dorsal portion 3. The ventral portion 2 is a portion that abuts against the wearer's abdomen. The dorsal portion 3 is a portion that abuts against the wearer's buttocks or back. The absorbent main body 10 is a portion that abuts against the wearer's crotch, and one end in the longitudinal direction L is layered on the ventral portion 2, and the other end is layered on the dorsal portion 3. The crotch portion 4 is a portion that supports the absorbent main body 10 from the non-skin side. The opposite ends 2a, 2a in the width direction W of the ventral portion 2 and the opposite ends 3a, 3a in the width direction W of the back portion 3 overlap in the thickness direction T and are joined along the longitudinal direction L to form the pants-type diaper 1. In this case, in the pants-type diaper 1, the outer end 2e of the ventral portion 2 in the longitudinal direction L and the outer end 3e of the back portion 3 in the longitudinal direction L define a waist opening through which the wearer's waist passes. In addition, in the pants-type diaper 1, the side ends 5e, 5e on both sides in the width direction W of the crotch portion 4 define a pair of leg openings through which the wearer's legs pass. The ventral portion (ventral waist belt) 2 and the back portion (dorsal waist belt) 3 can be said to be parts defined within the range in the longitudinal direction L where the opposite ends 2a, 2a and the opposite ends 3a, 3a are joined.

In this embodiment, in the state shown in FIG. 1, the abdominal portion 2 and the back portion 3 each have a generally rectangular shape extending in the width direction W and are spaced apart from each other in the longitudinal direction L. The crotch portion 4 is located between the abdominal portion 2 and the back portion 3, and both side edges in the width direction W are recessed inward in the width direction W. The abdominal portion 2, crotch portion 4, and back portion 3 are formed integrally with each other. In another embodiment, the abdominal portion 2, crotch portion 4, and back portion 3 are formed separately from each other. In yet another embodiment, the pants-type diaper 1 includes the abdominal portion 2 and the back portion 3, but does not include the crotch portion 4.

In this embodiment, the abdominal portion 2, the back portion 3, and the crotch portion 4 are provided with a liquid-impermeable cover sheet (sheet member) 5. The cover sheet 5 includes a cover sheet 5a positioned on the skin side and a cover sheet 5b positioned on the non-skin side. The cover sheets 5a and 5b are laminated in the thickness direction T and joined to each other with an adhesive or the like. Both ends of the cover sheet 5b in the longitudinal direction L are folded back toward the skin side so as to cover both ends of the cover sheet 5a in the longitudinal direction L. In this case, the cover sheet 5b at the folded positions in the abdominal portion 2 and the back portion 3 constitute the end 2e of the abdominal portion 2 and the end 3e of the back portion 3, respectively.

The cover sheet 5 may be any liquid-impermeable sheet, such as a liquid-impermeable nonwoven fabric, a synthetic resin film, a composite sheet of these, an SB nonwoven fabric, or an SMS nonwoven fabric. The cover sheet 5 may be made of a polyolefin-based material, such as polypropylene or polyethylene. The basis weight of the cover sheet 5 is, for example, 5 to 100 g/ ^m² , preferably 10 to 50 g/ ^m² . The dimension (thickness) of the cover sheet 5 in the thickness direction T is, for example, 0.1 to 5 mm, preferably 0.1 to 2 mm. In another embodiment, the cover sheet 5 may be one or three or more sheets (not shown). In yet another embodiment, the cover sheet 5b is not folded (not shown).

In this embodiment, the abdominal portion 2 and the back portion 3 are provided with a plurality of elastic members 6a, 6b and a plurality of elastic members 7a, 7b for waist gathering, respectively, between the cover sheets 5a and 5b. The plurality of elastic members 6a, 6b are arranged on the outer and inner sides of the abdominal portion 2 in the longitudinal direction L. The plurality of elastic members 6a are arranged along the width direction W in predetermined regions on both sides of the longitudinal centerline CL, spaced apart from each other in the longitudinal direction L. The predetermined regions are the regions from the end 2a to the inner portion of the edge of the absorbent main body 10 in the width direction W that faces the end 2a. The plurality of elastic members 6b extend along the width direction W from one end 2a to the other end 2a, and are arranged spaced apart from each other in the longitudinal direction L. Similarly, the plurality of elastic members 7a, 7b are arranged on the outer and inner sides of the longitudinal direction L of the back portion 3, respectively. The multiple elastic members 7a are arranged at intervals in the longitudinal direction L along the width direction W in predetermined regions on both sides of the longitudinal centerline CL. The predetermined regions are the regions from the end 3a to the inner portion of the edge of the absorbent main body 10 in the width direction W that faces the end 3a. The multiple elastic members 7b extend along the width direction W from one end 3a to the other end 3a and are arranged at intervals in the longitudinal direction L. The multiple elastic members 6a, 6b, 7a, and 7b stretch the waist opening and are exemplified by elastic thread. The ventral portion (ventral waist belt) 2 and the dorsal portion (dorsal waist belt) 3 can also be considered to be the portions defined by the range in the longitudinal direction L in which the multiple elastic members 6a, 6b, 7a, and 7b are arranged.

In this embodiment, the pants-type diaper 1 includes multiple elastic members 8 for leg gathering from the crotch region 4 to the back region 3 and the ventral region 2. The multiple elastic members 8 extend mainly along the longitudinal direction L from both ends of the crotch region 4 in the width direction W. The multiple elastic members 8 stretch each of the pair of leg openings, and are exemplified by rubber threads.

In this embodiment, the absorbent body 10 has a generally rectangular shape and includes a liquid-permeable top sheet 12, a liquid-impermeable back sheet 13, and an absorber 14 positioned between the top sheet 12 and the back sheet 13 and absorbing and retaining liquid. Examples of the top sheet 12 include liquid-permeable nonwoven fabrics or woven fabrics, synthetic resin films with liquid-permeable holes, and composite sheets of these. Examples of the back sheet 13 include liquid-impermeable nonwoven fabrics or synthetic resin films, composite sheets of these, and SMS nonwoven fabric. In this embodiment, the absorber 14 includes an absorber core that absorbs and retains liquid and a core wrap that encases the absorber core. Details of the absorber 14 will be described later. The absorber 14 is bonded to the top sheet 12 and the back sheet 13, respectively, with an adhesive, and the top sheet 12 and the back sheet 13 are bonded to their peripheral edges with an adhesive. Examples of adhesives that can be used include materials commonly used in pants-type diapers, such as hot-melt adhesives. The shape of the absorbent body 10 is not limited to the above example, as long as it is long in the longitudinal direction L, and examples include a rectangle with rounded corners, a rectangle with outwardly convex short sides, and an hourglass shape. In another embodiment, the backsheet 13 is omitted, and the non-skin-facing surface of the absorbent body 14 and the non-skin-facing surface of the peripheral portion of the topsheet 12 are joined to the cover sheet 5.

In this embodiment, the absorbent main body 10 includes a pair of side sheets 17, 17 located on both sides of the width direction W on the skin-facing surface and extending in the longitudinal direction L. Each side sheet 17 has a leakage preventing wall 16 and fixed regions 15, 15. The fixed regions 15, 15 are located at the front and rear ends of the side sheet 17 in the longitudinal direction L and are fixed to the skin-facing surface of the absorbent main body 10. The leakage preventing wall 16 is located between and adjacent to the fixed regions 15, 15 on the front and rear sides of the side sheet 17 in the longitudinal direction L, and has its outer edge in the width direction W fixed to the skin-facing surface of the absorbent main body 10 and its inner edge in the width direction W unfixed. In this case, the leakage preventing wall 16 and fixed regions 15, 15 are formed, for example, on the inner portion of the side sheet 17 in the width direction W, and the outer portion of the side sheet 17 in the width direction W is fixed to the absorbent main body 10. As described above, the absorbent main body 10 includes a pair of leakage barrier walls 16, 16. The pair of leakage barrier walls 16, 16 are arranged facing each other at both ends of the absorbent main body 10 on the skin side in the width direction W and extend continuously along the longitudinal direction L. Each leakage barrier wall 16 includes two elastic members 61 extending along the longitudinal direction L at its inner end in the width direction W. The elastic members 61 are exemplified by rubber threads. In another embodiment, the inner end of each of the pair of leakage barrier walls 16, 16 in the width direction W is further folded back outward in the width direction W. In another embodiment, the number of elastic members 61 is one, or three or more. Each of the pair of leakage barrier walls 16, 16 is formed from a hydrophobic sheet, such as a hydrophobic nonwoven fabric. In another embodiment, it is formed from a hydrophilic sheet, such as a hydrophilic nonwoven fabric.

Next, the absorbent body 14 will be described with reference to Figures 1 to 3. Note that Figure 3 shows an example of the configuration of the absorbent body 14 according to the embodiment, with (a) being a plan view and (b) being a cross-sectional view taken along line IIIb-IIIb in (a). The absorbent body 14 is a layer having liquid absorption and liquid retention properties, and in this embodiment, comprises a first absorbent layer 41 located on the skin side, a second absorbent layer 42 located on the non-skin side, and an intermediate layer 43 located between the first absorbent layer 41 and the second absorbent layer 42. The absorbent body 14 has a two-layer structure in which the first absorbent layer 41, the intermediate layer 43, and the second absorbent layer 42 are laminated in this order in the thickness direction T. Note that in another embodiment, the absorbent body 14 does not have the intermediate layer 43, and has a single-layer structure in which the first absorbent layer 41 and the second absorbent layer 42 are integrated in the thickness direction. In yet another embodiment, the absorbent body 14 has a multi-layer structure of three or more layers, with other intermediate layers and other absorbent layers further laminated between the first absorbent layer 41 and the second absorbent layer 42. In another embodiment, the first absorbent layer 41 is positioned on the skin side, and the second absorbent layer 42 is positioned on the non-skin side.

In this embodiment, the absorbent body 14 has a generally rectangular planar shape extending in the longitudinal direction L. The absorbent body 14 can be seen as having a first absorbent material 45 and a second absorbent material 47 as an absorbent core, and a first substrate 44 and a second substrate 46 as a core wrap. However, the shape is not particularly limited, and examples include a rectangle with arc-shaped short sides, a rounded rectangle, an oval, and an hourglass shape. The thickness of the absorbent body 14 is, for example, 0.5 to 20 mm, and preferably 1 to 10 mm. The basis weight of the absorbent body 14 can be adjusted appropriately depending on the absorption performance required of the pants-type diaper 1, and is, for example, 60 to 1600 g/ ^m2 .

In this embodiment, the first absorbent layer 41 includes a first substrate 44 formed from a liquid-permeable sheet and a first absorbent material 45, which is disposed closer to the intermediate layer 43 than the first substrate 44 and contains a water-absorbing polymer. The first absorbent layer 41 can be considered to have the first absorbent material 45 as an absorbent core and the first substrate 44 (and intermediate layer 43) as a core wrap. In another embodiment, the core wrap may include a core wrap sheet, such as a tissue sheet, separate from the first substrate 44 (and intermediate layer 43) and enclosing the first absorbent material 45 inside them. The first absorbent material 45 is fixed to at least one of the first substrate 44 and the intermediate layer 43 by adhesive applied to at least one of the surface of the first substrate 44 facing the intermediate layer 43 and the surface of the intermediate layer 43 facing the first substrate 44. The water-absorbing material of the first absorbent material 45 is disposed with a generally uniform basis weight within the first absorbent layer 41. However, the basis weight of the end portions in the longitudinal direction L and/or width direction W may gradually decrease toward the end edges. In this case, the end portions are, for example, regions at both ends in the longitudinal direction L and/or width direction W that are within 10% of the maximum dimension in the longitudinal direction L and/or width direction W. In another embodiment, the water-absorbing material of the first water-absorbing material 45 is arranged in the first absorbent layer 41 in a predetermined distribution, with areas of high and low basis weight. The first water-absorbing material 45 has a substantially rectangular planar shape. The first substrate 44 has a substantially rectangular planar shape and covers the first water-absorbing material 45 from the skin side in a planar view, with the peripheral portion of the first substrate 44 extending slightly outward from the periphery of the first water-absorbing material 45. The outer dimension (outer edge) of the first absorbent layer 41 in the planar direction is, for example, the outer dimension (outer edge) of the first water-absorbing material 45 in the planar direction. This outer dimension (outer edge) is measured, for example, at a position halfway along the thickness direction T of the first water-absorbing material 45.

In this embodiment, the second absorbent layer 42 includes a second substrate 46 formed from a sheet with water retention and liquid diffusion properties, and a second water-absorbing material 47 disposed closer to the intermediate layer 43 than the second substrate 46 and including a water-absorbing polymer. The second absorbent layer 42 can be considered to have the second water-absorbing material 47 as an absorbent core and the second substrate 46 (and intermediate layer 43) as a core wrap. In another embodiment, the core wrap may include a core wrap sheet, such as a tissue sheet, separate from the second substrate 46 (and intermediate layer 43) and enclosing the second water-absorbing material 47 inside them. The second water-absorbing material 47 is fixed to at least one of the second substrate 46 and the intermediate layer 43 by adhesive applied to at least one of the surface of the second substrate 46 facing the intermediate layer 43 and the surface of the intermediate layer 43 facing the second substrate 46. The water-absorbing material of the second water-absorbing material 47 is arranged in the second absorbent layer 42 with a generally uniform basis weight, except for a pair of channels 48, 48 (described below). However, the basis weight of the end portions in the longitudinal direction L and/or width direction W may gradually decrease toward the end edges. In this case, the end portions are as described above. In another embodiment, the water-absorbing material of the second water-absorbing material 47 is arranged in the second absorbent layer 42 with a predetermined distribution having areas with high and low basis weights. The second water-absorbing material 47 has a substantially rectangular planar shape that is slightly larger than the first water-absorbing material 45 in the width direction W and longitudinal direction L. The second substrate 46 has a substantially rectangular planar shape and covers the second water-absorbing material 47 from the non-skin side in a planar view, with the peripheral portion of the second substrate 46 extending slightly outward from the periphery of the second water-absorbing material 47. At this time, both ends of the second substrate 46 in the width direction W cover both side surfaces of the second water-absorbent material 47 and also cover the skin-side surface of both ends of the first substrate 44 in the width direction W. That is, the end of the second substrate 46 in the width direction W and the end of the first substrate 44 in the width direction W are overlapped and joined at the skin-side surface of the end of the first absorbent layer 41 in the width direction W. The outer dimension (outer edge) in the planar direction of the second absorbent layer 42 is, for example, the outer dimension (outer edge) in the planar direction of the second water-absorbent material 47. The outer dimension (outer edge) is measured, for example, at a position halfway in the thickness direction T of the second water-absorbent material 47.

In this way, both ends in the width direction W of the second substrate 46 cover the side surfaces of the second water-absorbing material 47 in the width direction W and further cover the side surfaces of the first substrate 44 in the width direction W, so that the second water-absorbing material 47 is encapsulated in the second absorbent layer 42 in the width direction W, and the first water-absorbing material 45 is encapsulated in the first absorbent layer 41 in the width direction W. In another embodiment, both ends in the width direction W of the first substrate 44 cover both ends in the width direction W of the second substrate 46. In yet another embodiment, the first substrate 44, intermediate layer 43, and second substrate 46 are stacked and joined in the thickness direction T at both ends in the width direction W.

In this embodiment, the first substrate 44, intermediate layer 43, and second substrate 46 are stacked and joined in the thickness direction T at both ends of the absorbent body 14 in the longitudinal direction L. As a result, the second water-absorbing material 47 is encapsulated in the second absorbent layer 42 by the first substrate 44 and intermediate layer 43 in the longitudinal direction L, and the first water-absorbing material 45 is encapsulated in the second absorbent layer 42 by the second substrate 46 and intermediate layer 43 in the longitudinal direction L. In another embodiment, both ends of the absorbent body 14 in the longitudinal direction L are not covered by the first substrate 44 and second substrate 46.

In this embodiment, the intermediate layer 43 is a liquid-permeable sheet having a substantially rectangular planar shape. The intermediate layer 43 includes an upper layer 43a and a pair of lower layers 43b, 43b adjacent to both sides of the non-skin-facing surface of the upper layer 43a in the width direction W. The intermediate layer 43 is formed by folding a pair of side portions located on both sides of the central portion in the width direction W of a sheet member having a substantially rectangular planar shape toward the non-skin-facing side of the central portion. In this case, the central portion of the sheet member becomes the upper layer 43a, and the pair of side portions of the sheet member become the pair of lower layers 43b, 43b. Therefore, both sides of the intermediate layer 43 in the width direction W have a two-layer structure in which the upper layer 43a and the lower layer 43b are laminated, and have a substantially rectangular shape extending in the longitudinal direction L. The portion 43d of the intermediate layer 43 near the center in the width direction W has a single-layer structure consisting of only the upper layer 43a, and has a substantially rectangular shape extending along the longitudinal direction L. The upper layer 43a and the lower layer 43b of the two-layer structure are joined by a pair of heat-sealed portions 43c, 43c extending along the longitudinal direction L on both sides of the width direction W of the portion 43d. The heat-sealed portions 43c are formed by heating and compressing. In another embodiment, the upper layer 43a and the lower layer 43b of the two-layer structure are joined by embossed portions extending along the longitudinal direction L on both sides of the width direction W of the portion 43d. The embossed portions are formed by compressing. In still another embodiment, the heat-sealed portions or embossed portions have the shape of multiple dots, multiple curves, or patterns. The intermediate layer 43 is joined by sandwiching both ends of the width direction W of the first substrate 44 and the second substrate 46 between the ends of the width direction W and sandwiching both ends of the longitudinal direction L of the first substrate 44 and the second substrate 46 between the ends of the longitudinal direction L. In another embodiment, both end edges in the longitudinal direction L are not sandwiched or joined to both end portions in the longitudinal direction L of the first substrate 44 and the second substrate 46. The two-layer structure allows for temporary storage of liquid, making it easier to ensure the time required for absorption by the superabsorbent polymer.

In this embodiment, the absorbent body 14 has a pair of channels 48, 48 extending along the longitudinal direction L. The pair of channels 48, 48 are located in the second absorbent layer 42, extend in the longitudinal direction L, and are band-shaped regions aligned at a predetermined interval on both sides of the longitudinal centerline CL in the width direction W. The channel 48 is formed at least in the center of the longitudinal direction L so as to straddle the width centerline CW. In another embodiment, the channel 48 is formed so as to reach at least one of both end edges in the longitudinal direction L. The pattern of the pair of channels 48, 48 in a planar view is, for example, a pattern formed so that the distance between them is constant along the longitudinal direction L. In another embodiment, the pattern of the pair of channels 48, 48 is, for example, a pattern formed so that it is narrow near the center of the longitudinal direction L and widens toward both outer sides in the longitudinal direction L. Here, the channel 48 is a region where the basis weight of the water-absorbent material is smaller than that of the region surrounding the channel in the absorbent body 14. For example, the channel 48 is a region where the basis weight of the water-absorbent material is smaller than that of the region surrounding the channel 48 in the second absorbent layer 42, including a case where the basis weight is zero. The channel 48 is formed so that the second substrate 46 is recessed toward the intermediate layer 43, i.e., so that the second water-absorbent material 47 is recessed toward the intermediate layer 43. In another embodiment, the second water-absorbent material 47 is formed so that it is recessed toward the second substrate 46. Furthermore, the pair of channels 48 overlaps with the pair of heat-sealed portions 43c in the thickness direction T. In another embodiment, at least a portion of the channel 48 does not overlap with the heat-sealed portion 43c in the thickness direction T. Note that in another embodiment, the channel 48 extends along the width direction W, not along the longitudinal direction L, or not only along the longitudinal direction L. In yet another embodiment, there is one channel 48 or a plurality of three or more channels 48.

As described above, the first water-absorbing material 45 and the second water-absorbing material 47 contain a superabsorbent polymer (SAP). The superabsorbent polymer is not particularly limited as long as it is a polymer capable of absorbing and retaining moisture, and examples thereof include particulate or fibrous superabsorbent polymers. The basis weight of the superabsorbent polymers of the first water-absorbing material 45 and the second water-absorbing material 47 can be adjusted appropriately depending on the absorption performance required of the pants-type diaper 1, and may be, for example, 10 to 500 g/ ^m² , and preferably 100 to 400 g/ ^m² . The basis weight of the first water-absorbing material 45 and the second water-absorbing material 47 may be greater than that of the other, or may be equal. Note that equality means that one is within ±30% of the other. The first water-absorbing material 45 and the second water-absorbing material 47 may further contain hydrophilic fibers such as pulp fibers or absorbent fibers. The ratio of the superabsorbent polymer to the first water-absorbing material 45 and the second water-absorbing material 47 is, for example, 80 to 100% by mass, preferably 90 to 100% by mass, and more preferably 95 to 100% by mass. Therefore, the first water-absorbing material 45 and the second water-absorbing material 47 can be said to contain superabsorbent polymer as a main component, and the absorbent body 14 can be said to be a so-called SAP sheet. However, the ratio of the superabsorbent polymer to the absorbent body 14 (including not only the first water-absorbing material 45 and the second water-absorbing material 47 but also the adhesive, first substrate 44, intermediate layer 43, and second substrate 46) can be, for example, 40 to 80% by mass, preferably 50 to 80% by mass, and more preferably 60 to 80% by mass. In this embodiment, the first water-absorbing material 45 and the second water-absorbing material 47 are composed only of superabsorbent polymer and do not contain hydrophilic fibers. In another embodiment, the first absorbent material 45 and the second absorbent material 47 include pulp fibers and/or absorbent fibers in addition to the superabsorbent polymer.

Examples of superabsorbent polymers include starch-based, cellulose-based, and synthetic polymer-based polymer absorbents. Examples of starch-based or cellulose-based superabsorbent polymers include starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, and crosslinked sodium carboxymethyl cellulose. Examples of synthetic polymer-based superabsorbent polymers include polyacrylates, polysulfonates, maleic anhydrides, polyacrylamides, polyvinyl alcohols, polyethylene oxides, polyaspartates, polyglutamates, polyalginates, starch, and cellulose. In this embodiment, polyacrylate-based (particularly sodium polyacrylate-based) superabsorbent polymers are preferred. In this embodiment, it is preferable that 90 to 100% by mass of the superabsorbent polymer in the absorbent body 14 be composed of superabsorbent polymer particles with a particle size of 150 to 500 μm. Superabsorbent polymer particles with such a particle size distribution have a small and uniform particle size and are therefore easily retained by adhesives. The particle size of the superabsorbent polymer particles is measured in accordance with the sieving test method described in JIS R 6002:1998.

The adhesive is not particularly limited as long as it can fix the superabsorbent polymer, and examples thereof include hot melt adhesives. The adhesive application pattern is not particularly limited, and examples include a continuous or intermittent omega pattern, a spiral pattern, and a line pattern. The basis weight of the adhesive can be adjusted appropriately so as not to significantly reduce the liquid absorbency of the absorbent body 14, and examples include 3 to 50 g/ ^m2 for each layer. The respective layers refer to the adhesive layer between the first water-absorbing material 45 and the first substrate 44, the adhesive layer between the first water-absorbing material 45 and the intermediate layer 43, the adhesive layer between the second water-absorbing material 47 and the second substrate 46, and the adhesive layer between the second water-absorbing material 47 and the intermediate layer 43.

The first substrate 44 is not particularly limited as long as it is a liquid-permeable sheet. Examples of the first substrate 44 include liquid-permeable nonwoven fabrics, hydrophilic nonwoven fabrics, and laminated nonwoven fabrics thereof. Among these, highly water-permeable nonwoven fabrics are preferred. Examples include spunbonded nonwoven fabrics and air-through nonwoven fabrics formed from polyolefin fibers such as polyethylene (PE) and polypropylene (PP), polyester fibers such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), and polyethylene naphthalate (PEN), or combinations thereof. These fibers are preferably hydrophilized using a known method. Other examples include airlaid nonwoven fabrics in which hydrophilic fibers such as pulp fibers or rayon fibers are coated with a hydrophilic binder, and spunlace nonwoven fabrics in which the above hydrophilic fibers and the above synthetic fibers are combined. In this embodiment, an airlaid nonwoven fabric in which pulp fibers are coated with a hydrophilic binder is used, which has liquid permeability and liquid retention properties. The first substrate 44 may be formed by laminating multiple layers of one or more of the above nonwoven fabrics. The basis weight of the first substrate 44 is, for example, 10 to 100 g/m ² , and preferably 20 to 80 g/m ^2. The thickness of the first substrate 44 is, for example, 0.1 to 5 mm, and preferably 0.15 to 3 mm.

The second substrate 46 is not particularly limited as long as it is a sheet with water retention and liquid diffusion properties. Examples of the second substrate 46 include nonwoven fabrics made of synthetic fibers such as polyamide fibers, regenerated fibers such as rayon fibers and acetate fibers, natural fibers such as cotton, silk, hemp, and pulp (cellulose) fibers, or combinations thereof. Specific examples include spunbond nonwoven fabrics containing nylon and spunlace nonwoven fabrics containing rayon fibers and/or pulp fibers. Spunlace nonwoven fabrics containing rayon fibers and/or pulp fibers may also contain polyolefin fibers and/or polyester fibers. In this embodiment, a spunlace nonwoven fabric containing rayon fibers and pulp fibers, which has liquid retention and liquid diffusion properties, is used. Note that the second substrate 46 may be formed by laminating multiple layers of one or more of the above nonwoven fabrics. The basis weight of the second substrate 46 is, for example, 10 to 200 g/ ^m² , preferably 35 to 150 g/ ^m² . The thickness of the second base material 46 is, for example, 0.1 to 5 mm, and preferably 0.15 to 3 mm.

There are no particular limitations on the intermediate layer 43, as long as it is a liquid-permeable sheet. For example, the same sheet as the first substrate 44 can be used as the intermediate layer 43. The basis weight of the intermediate layer 43 is, for example, 10 to 100 g/ ^m2 , and preferably 15 to 80 g/ ^m2 . The thickness of the intermediate layer 43 is, for example, 0.1 to 5 mm, and preferably 0.15 to 3 mm.

In this embodiment, as shown in FIG. 3 , the absorbent body 14 comprises a dorsal region BA, a ventral region FA, and a crotch region MA, which are aligned along the longitudinal direction L. The dorsal region BA is a region that overlaps with the dorsal portion 3 of the absorbent body 14 in the thickness direction T. The ventral region FA is a region that overlaps with the ventral portion 2 of the absorbent body 14 in the thickness direction T. The crotch region MA is a region located between the dorsal region BA and the ventral region FA of the absorbent body 14, i.e., a region that overlaps with the crotch portion 4 in the thickness direction T. Therefore, the absorbent body 14 is partitioned along the longitudinal direction L into the dorsal region BA that overlaps with the dorsal portion 3, the ventral region FA that overlaps with the ventral portion 2, and the crotch region MA that overlaps with the crotch portion 4.

In this embodiment, the absorbent body 14 also includes a high basis weight region 14a, a low basis weight region 14b, and a non-application region 14c. The high basis weight region 14a is a region where the basis weight of the superabsorbent polymer is high, and is a region where the first absorbent layer 41 and the second absorbent layer 42 overlap in the thickness direction T. The boundary between the high basis weight region 14a and the low basis weight region 14b is, for example, the outer edge of the first absorbent layer 41. The low basis weight region 14b is a region where the basis weight of the superabsorbent polymer is low, and is a region where the first absorbent layer 41 is not present in the thickness direction T, and only the second absorbent layer 42 is present. The boundary between the low basis weight region 14b and the non-application region 14c is, for example, the outer edge of the second absorbent layer. The non-application region 14c is a region that does not contain superabsorbent polymer, and is a region where the first absorbent layer 41 and the second absorbent layer 42 are not present in the thickness direction T. However, "not containing superabsorbent polymer" includes cases where superabsorbent polymer is present but its basis weight is very small. "Very small" refers to cases where the basis weight of the superabsorbent polymer is 5% or less of the basis weight of the superabsorbent polymer in the high basis weight region 14a. The high basis weight region 14a, the low basis weight region 14b, and the non-application region 14c have a substantially rectangular shape. However, the shape is not particularly limited, and examples include a rectangle with arc-shaped short sides, a rounded rectangle, an oval, and an hourglass shape. Furthermore, in a plan view, the low basis weight region 14b is a region that surrounds the periphery of the high basis weight region 14a in a substantially frame-like shape (enclosing at least three sides) in the longitudinal direction L and width direction W, and the outer dimensions of the low basis weight region 14b are 5 to 25% larger than the outer dimensions of the high basis weight region 14a. The non-application area 14c is a region that surrounds the low-basis-weight area 14b in a roughly frame-like shape, and the outer dimensions of the non-application area 14c are 3 to 15% larger than the outer dimensions of the low-basis-weight area 14b. The basis weight of the low-basis-weight area 14b is, for example, 40 to 60% of the basis weight of the high-basis-weight area 14a, and the basis weight of the non-application area 14c is, for example, 0 to 5% of the basis weight of the high-basis-weight area 14a. When it is difficult to distinguish between two regions, such as when the absorbent body 14 is a single layer without a first absorbent layer 41 and a second absorbent layer 42, the high-basis-weight area is defined as the area where the thickness of the water-absorbent material (including adhesive) ranges from the maximum to 50% of the maximum. The low-basis-weight portion is defined as the area where the thickness of the water-absorbent material (including adhesive) ranges from 50% to 5% of the maximum, and the non-application area is defined as the area where the thickness of the water-absorbent material (including adhesive) ranges from 5% to 0% of the maximum. The thickness is the arithmetic mean height (Ra: JIS B 0601-2001). In another embodiment, the absorbent body 14 does not include at least one of the high basis weight region 14a, the low basis weight region 14b, and the non-placement region 14c.

Therefore, in the absorbent body 14, the back region BA includes a back-side high basis weight region BAa as the high basis weight region 14a, a back-side low basis weight region BAb as the low basis weight region 14b, and a back-side non-application region BAc as the non-application region 14c. Furthermore, in the absorbent body 14, the ventral region FA includes a ventral high basis weight region FAa as the high basis weight region 14a, and a ventral non-application region FAc as the non-application region 14c. The crotch region MA only has the high basis weight region 14a. Therefore, the basis weight of the superabsorbent polymer in the back-side high basis weight region BAa and the ventral high basis weight region FAa is equivalent to the basis weight of the superabsorbent polymer in the crotch region MA. Note that "equivalent" means that one is within the range of 0.7 to 1.3 times (±30%) the other. In another embodiment, the ventral region FA includes a ventral high basis weight region FAa and a ventral non-placement region FAc, as well as a ventral low basis weight region FAb as the low basis weight region 14b.

Here, the second absorbent layer 42 includes, in plan view, a protruding portion at its rear end in the longitudinal direction L that protrudes outward from the edge of the first absorbent layer 41. The protruding portion includes the back-side low basis weight region BAb, and in this embodiment, the protruding portion is the same as the back-side low basis weight region BAb. The second absorbent layer 42 is covered by the intermediate layer 43, and therefore the skin side of the protruding portion, i.e., the back-side low basis weight region BAb, is covered by the intermediate layer 43 and the first substrate 44. Furthermore, in this embodiment, the second absorbent layer 42 includes, in plan view, widthwise protruding portions at both ends in the width direction L that protrude outward from the edge of the first absorbent layer 41. The skin side of the widthwise protruding portions is covered by the intermediate layer 43 and the first substrate 44. In another embodiment, the second absorbent layer 42 includes, in plan view, another protruding portion at its front end in the longitudinal direction L that protrudes outward from the edge of the first absorbent layer 41. The other protruding portions include a ventral low basis weight region. In yet another embodiment, the protruding portion, i.e., the back-side low basis weight region BAb, is covered on the skin side by either the intermediate layer 43 or the first base material 44, but not by the other. In yet another embodiment, the second absorbent layer 42 does not include widthwise protruding portions that protrude outward beyond the edge of the first absorbent layer 41 at either end in the width direction W in plan view.

In this embodiment, in the absorbent body 14, if the length of the back-side high basis weight region BAa in the longitudinal direction L is da2, the length of the back-side low basis weight region BAb is db2, and the length of the back-side non-application region BAc is dc2, then db2 > dc2 > da2. That is, in the back region BA, the length of the back-side low basis weight region BAb is relatively long, keeping the basis weight of the superabsorbent polymer low overall, while distributing the superabsorbent polymer up to the rear portion in the longitudinal direction L. This makes it easier to prevent leakage of liquid, even if it is a small amount, that flows to the back side.

In this embodiment, in the absorbent body 14, if the length of the ventral high basis weight region FAa in the longitudinal direction L is da1 and the length of the ventral non-disposition region FAc is dc1, then da1 > dc1. That is, in the ventral region FA, the length of the ventral high basis weight region FAa is relatively long, increasing the basis weight of the superabsorbent polymer overall, and the superabsorbent polymer is distributed up to the front end in the longitudinal direction L. This makes it easier to accurately absorb liquid on the ventral side, where excretion is greatest.

In this embodiment, the absorbent body 14 satisfies dc2 > dc1 in the longitudinal direction L. By making the length of the back non-application area BAc relatively long, the amount of superabsorbent polymer used in the back area BA, where excretion is low, can be kept low, while the length of the ventral non-application area FAc can be made relatively short to facilitate accurate absorption of liquid in the ventral area FA, where excretion is high.

In another embodiment, in the absorbent body 14, da2 + db2 > da1 in the longitudinal direction L. In this case, by disposing the superabsorbent polymer in the back region BA in the longitudinal direction L up to the rear portion, it is possible to more easily prevent leakage of liquid that flows to the back, even if in small amounts.

In this embodiment, the basis weight of the superabsorbent polymer in the high basis weight ventral region FAa is greater than the sum of the basis weights of the superabsorbent polymer in the high basis weight dorsal region BAa and the low basis weight dorsal region BAb. This allows for the amount of superabsorbent polymer used to be kept low in the dorsal region BA, where excretion is low, while still facilitating accurate absorption of fluid in the ventral region FA, where excretion is high.

In this embodiment, a printed film (not shown) is placed between the back portion 3 and the back area BA of the absorbent body 14. The printed film displays a design or pattern to the outside through the cover sheet 5 of the back portion 3.

Figure 4 is an enlarged plan view of a portion of a pants-type diaper according to an embodiment, including the back portion 3. In this embodiment, the back portion 3 has a low-elasticity back region 31 with low elasticity in the width direction W and a pair of high-elasticity back regions 32, 32 with high elasticity in the width direction W. The low-elasticity back region 31 is located in the center of the back portion 3 in the width direction W and extends from the front (inner) edge in the longitudinal direction L to the rear (outer) side. The pair of high-elasticity back regions 32, 32 are adjacent to both sides of the low-elasticity back region 31 in the width direction W. The low-elasticity back region 31 has an elongation rate ((length after stretching - original length) / (original length)) in response to a given tensile force in the width direction W of not more than 1/3, preferably not more than 1/5, and more preferably not more than 1/10 of the elongation rate in the width direction W of the high-elasticity back region 32. For example, the low-stretch back region 31 is a region where there is no elastic member that stretches in the width direction W, or a region where there is an elastic member but the elastic member does not function as an elastic member (does not stretch much). On the other hand, the high-stretch back region 32 is a region where there is an elastic member 7a that stretches in the width direction W. Therefore, the high-stretch back region 32 and the low-stretch back region 31 are defined by the region where there is an elastic member 7a that can function as an elastic member and the region where there is no elastic member that can function as an elastic member. Note that "low" stretchability includes no stretch. The stretchability of each stretchable region is determined by the stretchability of the elastic member.

In this embodiment, the rear portion of the channel 48 in the longitudinal direction L overlaps the back low-elasticity region 31 in the thickness direction T. In plan view, the inner edge K1 in the width direction W of each of the pair of back high-elasticity regions 32, 32 is located between the edge 14EW of the absorbent 14 facing the corresponding back high-elasticity region 32 in the width direction W and the channel 48 (edge 48E in the width direction W). Edge K1 is generally the inner edge in the width direction W of the elastic member 7a. Therefore, of the absorbent 14 including the rear portion of the channel 48 in the longitudinal direction L, the central portion in the width direction W is hardly stretched in the width direction W by the back low-elasticity region 31, while both end portions in the width direction W are stretched in the width direction W by the pair of back high-elasticity regions 32, 32.

In this embodiment, in a plan view, the inner edge K1 in the width direction W of each of the pair of back-side high-elasticity regions 32, 32 is closer to the edge 48E in the width direction W of the channel 48 than the edge 14EW of the absorbent 14 that faces the corresponding back-side high-elasticity region 32 in the width direction W. Therefore, both end portions in the width direction W of the absorbent 14, including the rear portion of the channel 48 in the longitudinal direction L, are stretched in the width direction W by the pair of back-side high-elasticity regions 32, 32.

In this embodiment, the back portion 3 further has another high-stretch back region 34 that exhibits high stretchability in the width direction W. In a plan view, the other high-stretch back region 34 is adjacent to the rear side in the longitudinal direction L of the pair of high-stretch back regions 32, 32 and the low-stretch back region 31. The other high-stretch back region 34 is an area where the stretch rate in the width direction W is roughly the same as the stretch rate in the width direction W of the high-stretch back region 32. The other high-stretch back region 34 is defined as an area where the elastic member 7b is present. Therefore, the rear end of the back portion 3 in the longitudinal direction L is more likely to be pressed against the wearer's back by the other high-stretch back region 34.

In this embodiment, in the back portion 3, the rear end 31E in the longitudinal direction L of the back low-elasticity region 31 is located further rearward in the longitudinal direction L than the rear end of the channel 48 in the longitudinal direction L. Therefore, the rear end of the absorbent body 14 in the longitudinal direction L is less likely to be pressed against the wearer's back by the back low-elasticity region 31.

In this embodiment, the fixed region 15 and the inner end of the back highly elastic region 32 in the width direction W overlap in the thickness direction T. Therefore, the back highly elastic region 32 makes it easier for the fixed region 15 to stretch at least outward in the width direction W.

In this embodiment, the back-side low-elasticity region 31 of the back-side portion 3 overlaps the back-side low basis weight region BAb and the back-side high basis weight region BAa in a planar view. The ventral-side low-elasticity region 36 of the ventral portion 2 overlaps the ventral-side high basis weight region FAa in a planar view. This prevents the high and low basis weight regions from shrinking in the width direction W, thereby preventing a decrease in absorption performance due to shrinkage of the absorbent core 14.

In this embodiment, the other back-side high-elasticity region 34 of the back portion 3 overlaps with an area of the absorbent body 14 that is further outward in the longitudinal direction L than the back-side low-basis weight region BAb. The other ventral-side high-elasticity region 39 of the ventral portion 2 overlaps with an area of the absorbent body 14 that is further outward in the longitudinal direction L than the ventral-side high-basis weight region FAa. Therefore, contraction of the other high-elasticity regions 34, 39 pulls the portions of the absorbent body 14 in the longitudinal direction L that are further outward in the width direction than the high/low basis weight regions in each of the back portion 3 and ventral portion 2, allowing these portions to be pressed more closely against the skin.

Figure 5 is an enlarged plan view of a portion of a pants-type diaper according to an embodiment, including the abdominal portion 2. In this embodiment, the abdominal portion 2 is generally the same as the back portion 3. That is, the abdominal portion 2 has a abdominal low-elasticity region 36 with low elasticity in the width direction W and a pair of abdominal high-elasticity regions 37, 37 with high elasticity in the width direction W. The abdominal low-elasticity region 36 is located in the center of the abdominal portion 2 in the width direction W, and extends from the rear (inner) edge in the longitudinal direction L to the front (outer) side. The pair of abdominal high-elasticity regions 37, 37 are adjacent to both sides of the abdominal low-elasticity region 36 in the width direction W. The abdominal low-elasticity region 36 has an elongation rate ((length after stretching - original length) / (original length)) in response to a given tensile force in the width direction W of not more than 1/3, preferably not more than 1/5, and more preferably not more than 1/10 of the elongation rate in the width direction W of the abdominal high-elasticity region 37. For example, the abdominal low-elasticity region 36 is a region where there is no elastic member that stretches in the width direction W, or a region where there is an elastic member but the elastic member does not function as an elastic member (does not stretch much). On the other hand, the abdominal high-elasticity region 37 is a region where there is an elastic member 6a that stretches in the width direction W. Therefore, the abdominal high-elasticity region 37 and the abdominal low-elasticity region 36 are defined by the region where there is an elastic member 6a that can function as an elastic member and the region where there is no elastic member that can function as an elastic member. The stretchability of each stretchable region is determined by the stretchability of the elastic member.

In this embodiment, the front portion of the channel 48 in the longitudinal direction L overlaps the abdominal low-elasticity region 36 in the thickness direction T. In plan view, the inner edge K2 in the width direction W of each of the pair of abdominal high-elasticity regions 37, 37 is located between the edge 14EW of the absorbent 14 that faces the abdominal high-elasticity region 37 in the width direction W and the channel 48 (edge 48E in the width direction W). The edge K2 is generally the inner edge in the width direction W of the elastic member 6a. Therefore, of the absorbent 14 including the front portion of the channel 48 in the longitudinal direction L, the central portion in the width direction W is barely stretched in the width direction W by the abdominal low-elasticity region 36, while both end portions in the width direction W are stretched in the width direction W by the pair of abdominal high-elasticity regions 37, 37.

In this embodiment, in a plan view, the distance between the inner edges K2, K2 in the width direction W of the pair of ventral high-elasticity regions 37, 37 is equal to the distance between the inner edges K1, K1 in the width direction W of the pair of dorsal high-elasticity regions 32, 32. In another embodiment, in a plan view, the distance between the inner edges K2, K2 in the width direction W of the pair of ventral high-elasticity regions 37, 37 is closer than the distance between the inner edges K1, K1 in the width direction W of the pair of dorsal high-elasticity regions 32, 32. In this case, both end portions in the width direction W of the front portion of the absorbent 14 in the longitudinal direction L are stretched in the width direction W by the pair of ventral high-elasticity regions 37, 37.

In this embodiment, the abdominal portion 2 further has another abdominal high stretch area 39 that exhibits high stretchability in the width direction W. The other abdominal high stretch area 39 is adjacent to the front side in the longitudinal direction L of the pair of abdominal high stretch areas 37, 37 and the abdominal low stretch area 36. The other abdominal high stretch area 39 is an area where the elastic modulus in the width direction W is roughly the same as the elastic modulus in the width direction W of the abdominal high stretch area 37. The other abdominal high stretch area 39 is defined as an area where the elastic member 6b is present. Therefore, the front end of the abdominal portion 2 in the longitudinal direction L is more likely to be pressed against the wearer's abdomen by the other abdominal high stretch area 39.

Next, a method for manufacturing the absorbent body 14 will be described.
First, hot melt adhesive is applied to the second substrate 46 sheet while the second substrate 46 sheet is moved in the longitudinal direction L. Next, superabsorbent polymer is sprayed from a superabsorbent polymer supply device along the longitudinal direction L onto both end portions and the central portion in the width direction W of the second substrate 46 sheet to which the hot melt adhesive has been applied. At this time, a small amount of superabsorbent polymer migrates to the region (corresponding to the channel) between the end portions and the central portion. Next, an intermediate layer 43 sheet, both sides of which are coated with hot melt adhesive, is laminated on top of the superabsorbent polymer on the second substrate 46 sheet. Next, while the laminate is moved in the longitudinal direction L, superabsorbent polymer is sprayed from another superabsorbent polymer supply device along the longitudinal direction L onto the central portion in the width direction W of the intermediate layer 43 sheet to which the hot melt adhesive has been applied. Next, the first substrate 44 sheet coated with a hot melt adhesive is laminated on top of the superabsorbent polymer on the intermediate layer 43 sheet, with the hot melt adhesive facing the superabsorbent polymer side. Then, both side edges of the second substrate 46 sheet in the width direction W are folded back onto both side edges of the first substrate 44 sheet in the width direction W to obtain a laminate. The laminate is then passed through a pair of press rolls, i.e., pressed, to adjust the thickness of the laminate, and the absorbent body 14 is obtained.

Next, a method for manufacturing a pants-type diaper using the absorbent body 14 will be described.
A liquid-permeable topsheet 12 is attached to the upper surface (surface of the first substrate 44) of the absorbent body 14 prepared as described above, and a liquid-impermeable backsheet 13 is attached to the lower surface (surface of the second substrate 46) of the absorbent body 14 to obtain a laminate. Next, side sheets 17 with leakage barriers 16 are attached to both sides of the laminate in the width direction W to obtain the absorbent main body 10. Thereafter, the absorbent main body 10 is attached to the cover sheet 5 (including elastic members 6, 7, 8), and both end portions 2a, 2a in the width direction W of the ventral side portion 2 and both end portions 3a, 3a in the width direction W of the dorsal side portion 3 are joined. In this manner, the pants-type diaper 1 is manufactured.

Figures 6 and 7 are schematic diagrams illustrating the effects of a pants-type diaper according to an embodiment. Figures 6(a), (b), and 7(a) show pants-type diapers of the prior art, while Figures 6(c), 7(b), and (c) show the pants-type diaper of this embodiment. First, in the pants-type diaper 1, as described above, the channels 48 of the absorbent body 14 reach at least one of the dorsal portion 3 (dorsal waist belt) and the ventral portion 2 (ventral waist belt). This allows liquid (e.g., urine) to be transported and distributed to the dorsal (rear in the longitudinal direction L) and ventral (front in the longitudinal direction L) ends of the absorbent body 14. This allows the superabsorbent polymer at the rear and front ends of the absorbent body 14 in the longitudinal direction L, which do not contribute much to absorption, to absorb the liquid, thereby making effective use of the superabsorbent polymer.

Now, referring to Figure 6(a), consider a case where the back portion 103 (waist belt) is provided with an elastic member across its entire width direction W, as in the example of Patent Document 1. In this case, the contractile force of the elastic member in the width direction W is too strong. Therefore, if the channel overlaps the back portion 103, before the diaper is put on, the back portion 103 may contract in the width direction W, causing the end of the absorber 114 in the longitudinal direction L to contract in the width direction W and deform into a convex shape. This may not only reduce the fit of the diaper when put on, but may also cause significant wrinkling in the back portion 103 due to the contraction of the absorber 114, which may lead to the diaper being mistaken for a defective product.

Also, referring to Figure 6(b), consider a case similar to another example in Patent Document 1, where the back portion 103 (waist belt) has high-elasticity regions 132, 132 outside both ends of the absorbent body 114 in the width direction W, and a low-elasticity region 131 between the high-elasticity regions 132, 132. In this case, it is possible to prevent the ends of the absorbent body 114 from contracting in the width direction W and becoming convex before the diaper is put on. However, the high-elasticity regions 132, 132 on both sides of the absorbent body 114 in the width direction W are separated from the absorbent body 114. Therefore, when the diaper absorbs liquid after being put on, it is difficult for the contractile force of the high-elasticity regions 132, 132 to pull the absorbent body 114 in the width direction W. Therefore, it is difficult to prevent the absorbent body 114 from becoming convex, as shown in Figure 7(a). In other words, it is difficult to prevent the back side portion 103 (or the ventral side portion 102) from causing both ends of the absorber 114 in the longitudinal direction L to protrude from the wearer's body (see the arrows in Figure 7(a)).

6(c), consider the case of the pants-type diaper 1 of this embodiment. In this case, in the pants-type diaper 1, the inner edge K1 in the width direction W of the back-side high-elasticity region 32 of the back-side portion 3 (back-side waist belt) is located between the channel 48 and the edge 14EW of the absorber 14 that faces the high-elasticity region in the width direction W. That is, the center of the absorber 14 in the width direction W overlaps the back-side low-elasticity region 31 in the thickness direction T. Alternatively, the inner edge K2 in the width direction W of the abdominal-side high-elasticity region 37 of the abdominal portion 2 (abdominal-side waist belt) is located between the channel 48 and the edge 14EW of the absorber 14 that faces the high-elasticity region in the width direction W. That is, the center of the absorber 14 in the width direction W overlaps the abdominal-side low-elasticity region 36 in the thickness direction T. Therefore, the contraction force that contracts the absorbent body 14 in the width direction W is not too strong, which prevents the end of the absorbent body 14 on the back side in the longitudinal direction L from contracting in the width direction W and becoming convex before wearing.

Furthermore, both sides of the absorber 14 in the width direction W overlap with the back-side high-elasticity region 32 or the ventral-side high-elasticity region 37 in the thickness direction T. Therefore, the contractile force of these high-elasticity regions can pull the absorber 14 in the width direction W from both sides of the channel 48. This allows the absorber 14, as shown in FIG. 7(b), to assume the state shown in FIG. 7(c) when the diaper absorbs liquid after being worn. This prevents the end of the absorber 14 in the longitudinal direction L from becoming convex and protruding from the wearer's body. In other words, the flatness of at least one of the back-side portion 3 and the ventral-side portion 2 can be maintained before and after wearing. This prevents liquid leakage from gaps that form between at least one of the back-side portion 3 and the ventral-side portion 2 and the skin surface. These features enable a pants-type diaper 1 equipped with an absorber 14 containing a superabsorbent polymer and having channels 48 to suppress liquid leakage while preventing a decrease in fit.

In a preferred aspect of this embodiment, in plan view, the inner edge K1 in the width direction W of the back high-elasticity region 32 is closer to the edge 48E in the width direction W of the channel 48 than the edge 14EW of the absorbent 14 that faces the back high-elasticity region 32 in the width direction W. Therefore, the contractile force of the back high-elasticity region 32 can more strongly pull the absorbent 14 in the width direction W from both sides of the channel 48. This more reliably prevents the end of the absorbent 14 in the longitudinal direction L from becoming convex, thereby preventing the end of the absorbent main body 10 (absorbent 14) in the longitudinal direction L from protruding from the wearer's body.

In a preferred aspect of this embodiment, in a plan view, the distance between the inner edges K2, K2 in the width direction W of the pair of ventral high-elasticity regions 37, 37 is closer than the distance between the inner edges K1, K1 in the width direction W of the pair of dorsal high-elasticity regions 32, 32. This allows the absorbent body 14 to be pulled more strongly in the width direction W from both sides of the channel 48 on the ventral side. That is, the absorbent body 14 can be pulled more strongly from both sides in the ventral portion 2 (ventral waist belt), which is relatively close to the position where it is tightened by both thighs from both sides in the width direction W to form the most convex shape when worn. This more reliably prevents the end of the absorbent main body 10 (absorbent body 14) in the longitudinal direction L from protruding from the wearer's body in the ventral portion 2, which is relatively close to the position where it forms the most convex shape. Additionally, by relatively weakening the force pulling the absorbent body 14 from both sides across the channel 48 in the width direction W on the back side, a slight convex portion is formed in the absorbent body 14, allowing it to function as a space for storing feces.

In a preferred aspect of this embodiment, the abdominal portion 2 (abdominal waist belt) further has another abdominal high stretch region 39 on the front side in the longitudinal direction L of all of the pair of abdominal high stretch regions 37, 37 and the abdominal low stretch region 36. Therefore, contraction of the other abdominal high stretch region 89 can pull the portion of the abdominal portion 2 that is further forward in the longitudinal direction L than the absorbent body 14 more in the width direction W, and press that portion more closely against the skin. This makes it less likely that the absorbent body 14 will become convex. In other words, the absorbent body 14 can fit around the abdomen in a generally flat shape.

In a preferred aspect of this embodiment, the back portion 3 (back waist belt) further has another back high-elasticity region 34 on the rear side in the longitudinal direction L of all of the pair of back high-elasticity regions 32, 32 and the back low-elasticity region 31. Therefore, contraction of the other back high-elasticity region 34 pulls the portion of the back portion 3 that is further rearward in the longitudinal direction L than the absorbent body 14 more in the width direction W, allowing this portion to be pressed more closely against the skin. This makes it more difficult for the absorbent body 14 to take on a convex shape. In other words, the absorbent body 14 can fit in the crevice of the buttocks in a generally flat shape.

In a preferred aspect of this embodiment, the rear end of the back low-elasticity area 31 in the longitudinal direction L is located further rearward in the longitudinal direction L than the rear end of the channel 48 in the longitudinal direction L. In other words, the back low-elasticity area 31 is also present in a portion further rearward in the longitudinal direction L than the rear end of the channel 48. As a result, the portion of the back portion 3 (back waist belt) that is rearward in the longitudinal direction L beyond the channel 48 is not pulled too much in the width direction W, allowing the convex shape of the absorbent body 14 to be slightly retained, forming a convex portion in the absorbent body 14 that can accommodate a small amount of feces. Therefore, it is possible to ensure space for accommodating feces while preventing the end of the absorbent body 14 in the longitudinal direction L from becoming convex.

In a preferred aspect of this embodiment, the absorbent main body 10 includes a pair of side sheets 17, 17, each of which has a fixing region 15, 15 and a leakage preventing wall 16. The fixing region 15 and the inner end of the back-side high-elasticity region 32 or the ventral-side high-elasticity region 37 in the width direction W overlap in the thickness direction T. Therefore, when the back-side high-elasticity region 32 or the ventral-side high-elasticity region 37 contracts in the width direction W, the end of the absorbent main body 14 (absorbent main body 10) in the longitudinal direction L is pulled in the width direction W, and the leakage preventing wall 16 is pulled outward in the width direction W and the longitudinal direction L via the fixing region 15. This prevents the end of the absorbent main body 14 in the longitudinal direction L from becoming convex and makes it easier for the leakage preventing wall 16 to stand up, thereby suppressing liquid leakage in the width direction W.

In a preferred aspect of this embodiment, the channels 48 include two channels 48 extending along the longitudinal direction L and spaced apart in the width direction W. This allows for more efficient transport and distribution of liquid along the superabsorbent polymer arranged along the longitudinal direction L within the absorbent body 14, thereby further increasing the acquisition and absorption rate. However, since there are two channels 48, the absorbent body 14 is more susceptible to deformation due to the uneven shape extending in the longitudinal direction L with the channels 48 as fold lines. This increases the rigidity of the uneven shape, disrupting the flatness of the back side portion 3 and the ventral side portion 2 (waist belt), which may impair the fit of the pants-type diaper 1 and may also result in liquid leakage through gaps between the back side portion 3 and the ventral side portion 2 and the skin surface. Therefore, the pants-type diaper 1 has the above-mentioned configurations, such that, in a plan view, the inner edges K1 and K2 in the width direction W of the back-side high-elasticity region 32 and the ventral-side high-elasticity region 37 are located between the edge 14EW in the width direction W of the absorbent body 14 and the channel 48. This prevents a decrease in the planarity of the back-side portion 3 and the ventral-side portion 2, prevents a decrease in the fit of the pants-type diaper 1, and prevents liquid leakage from gaps that occur between the back-side portion 3 and the ventral-side portion 2 and the skin surface.

In a preferred aspect of the present embodiment, the absorber 14 has a rectangular shape in plan view, allowing for efficient placement of the superabsorbent polymer within the absorber 14. However, because the absorber 14 is rectangular, it is more likely to be squeezed from both sides in the width direction W by the thighs when worn, and is more likely to deform due to its convex shape extending in the longitudinal direction L with the channel 48 as a fold line. This disrupts the planarity of the back portion 3 and the ventral portion 2 (waist belt), potentially impairing the fit of the pants-type diaper 1 and potentially causing fluid leakage through gaps between the back portion 3 and the ventral portion 2 and the skin surface. Therefore, the pants-type diaper 1 has the above-described configuration, such that the inner edges K1 and K2 in the width direction W of the back-side high-elasticity region 32 and the ventral-side high-elasticity region 37 are located between the edge 14EW in the width direction W of the absorber 14 and the channel 48 in plan view. This prevents the flatness of the back portion 3 and the ventral portion 2 from decreasing, prevents the fit of the pants-type diaper 1 from decreasing, and prevents liquid from leaking through gaps that form between the back portion 3 and the ventral portion 2 and the skin surface.

The pants-type diaper and absorbent body thereof of the present invention are not limited to the above-described embodiments, and it is possible to combine the embodiments or apply publicly known technologies within the scope of the purpose and intent of the present invention.

1. Pants-type diaper 2. Abdominal part (abdominal waist belt)
3 Back part (back waist belt)
10 Absorbent body 14 Absorbent body 31 Back low stretch area 32 Back high stretch area 48 Channel K, 14EW Edge

Claims (9)

A pants-type diaper having a longitudinal direction, a width direction, and a thickness direction which are perpendicular to one another, the pants-type diaper comprising a ventral waist belt, a dorsal waist belt, and an absorbent main body including an absorber, positioned between the ventral waist belt and the dorsal waist belt,
The absorbent body is
Contains a highly absorbent polymer,
a plurality of channels extending along the longitudinal direction, arranged at intervals in the width direction, and not connected to each other in the width direction;
The waist belt has a back region that overlaps the back waist belt in the thickness direction, a ventral region that overlaps the ventral waist belt in the thickness direction, and a crotch region that is located between the back region and the ventral region, which are aligned along the longitudinal direction,
At least the dorsal region of the dorsal region and the ventral region
a high-basis weight region adjacent to the back side of the crotch region in the longitudinal direction , the high-absorbent polymer having the same basis weight as the crotch region ;
a low basis weight region adjacent to the high basis weight region on the opposite side of the crotch region in the longitudinal direction , the low basis weight region having a basis weight of the superabsorbent polymer lower than that of the crotch region and a length in the longitudinal direction longer than that of the high basis weight region;
Including,
At least the dorsal waist belt of the dorsal waist belt and the abdominal waist belt is
A back low-stretch area located in the center in the width direction, extending outward from the inner edge in the longitudinal direction, and having low stretchability in the width direction;
A pair of high stretchable back regions adjacent to both sides of the low stretchable back region in the width direction and having high stretchability in the width direction;
and
At least a rear portion of the channel on the rear side and the front side in the longitudinal direction and a central portion of the low basis weight region in the width direction overlap with the back-side low-elasticity region in the thickness direction,
Each of the widthwise side portions of the low basis weight region overlaps each of the pair of back-side highly elastic regions in the thickness direction,
In a plan view, an inner edge in the width direction of each of the pair of back-side high-elasticity regions is located between an edge of the absorbent body facing the back-side high-elasticity region in the width direction and the channel.
Pants-type diapers. In a plan view, an inner edge in the width direction of each of the pair of back-side high-elasticity regions is closer to an edge in the width direction of the channel than an edge of the absorbent body facing the back-side high-elasticity region in the width direction.
The pants-type diaper according to claim 1. The ventral waist belt is
A ventral low-elasticity region located in the center in the width direction, extending outward from the inner edge in the longitudinal direction, and having low elasticity in the width direction ;
A pair of abdominal high elasticity regions adjacent to both sides of the abdominal low elasticity region in the width direction and having high elasticity in the width direction ;
and
In a plan view, the distance between the inner edges in the width direction of the pair of ventral high elasticity regions is shorter than the distance between the inner edges in the width direction of the pair of dorsal high elasticity regions;
3. The pants-type diaper according to claim 2. The ventral waist belt is
Further, another abdominal high stretch area is adjacent to the front side of the pair of abdominal high stretch areas and the abdominal low stretch area in the longitudinal direction and exhibits high stretchability in the width direction,
4. The pants-type diaper according to claim 3. The dorsal waist belt is
Further, another back high stretch area is adjacent to the rear side of the pair of back high stretch areas and the back low stretch area in the longitudinal direction and exhibits high stretchability in the width direction,
The pants-type diaper according to any one of claims 2 to 4. The dorsal waist belt is
The rear end of the back-side low-elasticity region in the longitudinal direction is located further rearward in the longitudinal direction than the rear end of the channel in the longitudinal direction.
The pants-type diaper according to any one of claims 2 to 5. The absorbent main body includes a pair of side sheets located on both sides in the width direction on the skin side surface and extending in the longitudinal direction,
Each of the pair of side sheets is
a fixing region located at the front and rear end portions of the side sheet in the longitudinal direction and fixed to the skin-side surface of the absorbent main body;
a leak-proof wall including an elastic member extending along the longitudinal direction, the leak-proof wall being located between the fixed regions on the front and rear sides of the side sheet in the longitudinal direction, the leak-proof wall having an outer edge in the width direction fixed to the skin-side surface of the absorbent main body and an inner edge in the width direction not fixed;
and
The fixing region and the inner end portion of the back-side highly elastic region in the width direction overlap in the thickness direction.
The pants-type diaper according to any one of claims 1 to 6. The plurality of channels includes two channels extending along the longitudinal direction and spaced apart in the width direction.
The pants-type diaper according to any one of claims 1 to 7. The absorber is rectangular in plan view.
The pants-type diaper according to any one of claims 1 to 8.