Pants-type diapers

Abstract

To provide an underpants-type diaper capable of suppressing leakage of liquid while suppressing lowering of fitting property in the underpants-type diaper.SOLUTION: An underpants-type diaper comprises a ventral side waist belt 2, a back side waist belt 3, and an absorbent body 10 including an absorber 14. The absorber contains a super absorbent polymer and has at least one channel 48 extending along the longitudinal direction. The back side waist belt or the ventral waist belt has a low-elasticity region 31 positioned in a central part in the width direction, and having low elasticity in the width direction, and a pair of high-elasticity regions 32, 32 adjacent to both sides in the width direction of the low-elasticity region and having high elasticity in the width direction. At least one part of the rear side and the front side in the longitudinal direction of the channel is overlapped on the low-elasticity region in the thickness direction. In a plane view, an inner edge K in the width direction in the high-elasticity region is positioned between an edge 14EW facing the high-elasticity region in the width direction and the channel in the absorber.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pants-type diaper. [Background technology]

[0002] Pants-type diapers using an absorbent body containing a relatively large amount of super absorbent polymer (SAP) as an 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 the rear distal end of the channel is positioned above the lower edge of the elastic belt structure.

[0003] 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. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2018-505718 Summary of the Invention [Problem to be solved by the invention]

[0005] In the pants-type diaper described in Patent Document 1, the absorbent main body (absorbent structure) may be tightened by both thighs from both sides in the width direction when worn. In this case, the absorbent body (absorbent layer) deforms into a shape extending in the longitudinal direction and 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 end to the other in the longitudinal direction. 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 cause liquid to leak from gaps formed between the waist belt and the skin surface.

[0006] According to Patent Document 1, the ends of the channels are held by a 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 the absorbent main body is tightened from both widthwise sides by the wearer's thighs when worn, which can easily cause the absorber to deform into a longitudinally extending convex shape even before absorbing liquid. Therefore, the pants-type diaper of Patent Document 1 leaves room for improvement.

[0007] 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 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 also cause the waist belt to wrinkle significantly due to the contraction of the absorber, which may lead to the diaper being mistaken for a defective product.

[0008] Furthermore, Patent Document 1 discloses a waist belt structure in which high-stretch regions are formed outside both widthwise ends of a 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.

[0009] The present invention provides a pants-type diaper that includes an absorbent body containing a highly water-absorbent polymer and having channels, and that can prevent liquid leakage while preventing a decrease in fit. [Means for solving the problem]

[0010] The pants-type diaper of the present invention is as follows. (1) A pants-type diaper having longitudinal, width, and thickness directions 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 highly absorbent 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 rear and front portion of the channel in the longitudinal direction 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.

[0011] 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 do not contribute much 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.

[0012] The pants-type diaper of the present invention may be the pants-type diaper described in (1) above, (2) wherein the back waist belt has a back low-elasticity area as the low-elasticity area and a pair of back high-elasticity areas as the pair of high-elasticity areas, and in a plan view, the inner edge in the width direction of each of the pair of back high-elasticity areas is closer to the edge in the width direction of the channel than the edge of the absorber facing the back high-elasticity area in the width direction. 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.

[0013] The pants-type diaper of the present invention may be the pants-type diaper described in (2) above, (3) wherein the ventral waist belt has a ventral low-stretch area as the low-stretch area and a pair of ventral high-stretch areas as the pair of high-stretch areas, and the distance between the inner edges in the width direction of the pair of ventral high-stretch areas is shorter in plan view than the distance between the inner edges in the width direction of the pair of dorsal high-stretch areas. 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.

[0014] The pants-type diaper of the present invention may be (4) the pants-type diaper as 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.

[0015] The pants-type diaper of the present invention may be (5) the pants-type diaper according to 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 longitudinal rear side thereof 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.

[0016] The pants-type diaper of the present invention may be a pants-type diaper as described in any one of (2) to (5) above, wherein (6) the rear longitudinal end of the rear low-elasticity region of the back waist belt is located rearward in the longitudinal direction relative to 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.

[0017] The pants-type diaper of the present invention may be the pants-type diaper according to any one of (1) to (6) above, wherein (7) 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 length directions via the fixed region. This prevents the longitudinal end of the absorber from becoming convex and makes it easier for the leakage barrier walls to stand up, thereby suppressing fluid leakage in the width direction.

[0018] The pants-type diaper of the present invention may be a pants-type diaper as described in any one of (1) to (7) above, wherein (8) the channel includes two channels extending along the longitudinal direction and 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.

[0019] The pants-type diaper of the present invention may be (9) the pants-type diaper according to any one of the above (1) to (8), wherein the absorber 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. [Effects of the Invention]

[0020] According to the present invention, a pants-type diaper having an absorbent body containing a highly absorbent polymer and having channels can be provided, which can suppress leakage of liquid while suppressing deterioration of fit. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a plan view showing an example of the configuration of a pants-type diaper according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] 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. [Figure 4] 1 is an enlarged plan view of a portion of a rear portion of a pants-type diaper according to an embodiment. FIG. [Figure 5] 1 is an enlarged plan view of a portion of a ventral portion of a pants-type diaper according to an embodiment. [Figure 6] 1A to 1C are schematic diagrams illustrating the effects of the pants-type diaper according to the embodiment. [Figure 7] 1A to 1C are schematic diagrams illustrating the effects of the pants-type diaper according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] A pants-type disposable diaper (hereinafter simply referred to as "pants-type diaper") according to an embodiment will be described below. However, the type of pants-type diaper is not limited to this example, and other types of pants-type diapers may be used without departing from the scope of the present invention. An example of such pants-type diapers is a three-piece diaper.

[0023] 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. The pants-type diaper 1 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 defined as the inward and inner sides in the width direction W, respectively, and the directions and sides moving away from the longitudinal centerline CW are defined as the outward and outer sides in the width direction W, respectively. The directions and sides approaching the widthwise centerline CW are defined as the inward and inner sides in the longitudinal direction L, respectively, and the directions and sides moving away from the widthwise centerline CW are defined as the outward and outer sides in the longitudinal direction L, respectively. In addition, the side of the pant-type diaper 1 in the longitudinal direction L, which faces the edge (the abdominal edge) of the pant-type diaper 1 corresponding to the wearer's abdomen, is also referred to as the front side of the longitudinal direction L, and the side of the pant-type diaper 1 in the longitudinal direction L, which faces the edge (the dorsal edge) of the pant-type diaper 1 corresponding to the wearer's back, is also referred to as the rear side of 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.

[0024] Note that "a component, structure, shape, etc. aligned with the longitudinal direction L" includes not only the case where the component is parallel to the longitudinal direction L, but also the case where the component Dx of the component in the longitudinal direction L is greater than the component Dy of the component in the width direction W (Dx>Dy). Similarly, "a component is aligned with the width direction W" includes not only the case where the component is parallel to the width direction W, but also the case where the component Dy of the component in the width direction W is greater than the component Dx of the component in the longitudinal direction L (Dy>Dx). For curved or curved components, the component is evaluated as described above for the tangent to each point on the curve.

[0025] As shown in FIG. 1 , the pants-type diaper 1 comprises, in the longitudinal direction L, a ventral section (ventral waist belt) 2, a dorsal section (dorsal waist belt) 3, and an absorbent main body 10 located between the ventral section 2 and the dorsal section 3. In this embodiment, the pants-type diaper 1 further comprises a crotch section 4 located between the ventral section 2 and the dorsal section 3. The ventral section 2 is a section that comes into contact with the wearer's abdomen. The dorsal section 3 is a section that comes into contact with the wearer's buttocks or back. The absorbent main body 10 comes into contact with the wearer's crotch, and one end in the longitudinal direction L is layered on the ventral section 2, while the other end is layered on the dorsal section 3. The crotch section 4 is a section 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 of the crotch portion 4 in the width direction W 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.

[0026] 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, the crotch portion 4, and the back portion 3 are formed integrally with each other. In another embodiment, the abdominal portion 2, the crotch portion 4, and the back portion 3 are formed separately from each other. Furthermore, in 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.

[0027] 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-back 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.

[0028] 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 may be, for example, 5 to 100 g / m². 2 and preferably 10 to 50 g / m 2 The dimension (thickness) of the cover sheet 5 in the thickness direction T is, for example, 0.1 to 5 mm, and preferably 0.1 to 2 mm. In another embodiment, the cover sheet 5 is one sheet or three or more sheets (not shown). In yet another embodiment, the cover sheet 5b is not folded (not shown).

[0029] In this embodiment, the abdominal portion 2 and the back portion 3 are respectively provided with a plurality of elastic members 6a, 6b and a plurality of elastic members 7a, 7b for waist gathering between the cover sheets 5a and 5b. The plurality of elastic members 6a, 6b are respectively 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 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 respectively arranged on the outer and inner sides of the back portion 3 in the longitudinal direction L. 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 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, 7b stretch the waist opening and are exemplified by elastic threads. The ventral side portion (ventral waist belt) 2 and the dorsal side portion (dorsal waist belt) 3 can also be said to be portions defined by the range in the longitudinal direction L in which the multiple elastic members 6a, 6b, 7a, 7b are arranged.

[0030] In this embodiment, the pants-type diaper 1 includes a plurality of elastic members 8 for leg gathering from the crotch region 4 to the back region 3 and the ventral region 2. The plurality of elastic members 8 extend mainly from both ends in the width direction W of the crotch region 4 along the longitudinal direction L. The plurality of elastic members 8 stretch each of the pair of leg openings, and are exemplified by rubber threads.

[0031] In this embodiment, the absorbent body 10 has a substantially rectangular shape and includes a liquid-permeable topsheet 12, a liquid-impermeable backsheet 13, and an absorber 14 located between the topsheet 12 and the backsheet 13 and absorbing and retaining liquid. Examples of the topsheet 12 include liquid-permeable nonwoven fabrics or woven fabrics, synthetic resin films with liquid-permeable holes, and composite sheets thereof. Examples of the backsheet 13 include liquid-impermeable nonwoven fabrics or synthetic resin films, composite sheets thereof, and SMS nonwoven fabric. In this embodiment, the absorber 14 includes an absorber core that absorbs and retains liquid and a core wrap that encloses the absorber core. Details of the absorber 14 will be described later. The absorber 14, the topsheet 12, and the backsheet 13 are each bonded with an adhesive, and the topsheet 12 and the backsheet 13 are bonded with an adhesive at their peripheral portions. Examples of the adhesive 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 short sides that curve convexly outward, 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.

[0032] In this embodiment, the absorbent main body 10 includes a pair of side sheets 17, 17 located on both sides in the width direction W on the skin-facing surface and extending in the longitudinal direction L. Each side sheet 17 has a leakage barrier 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 barrier 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 is fixed at its outer edge in the width direction W to the skin-facing surface of the absorbent main body 10 and its inner edge in the width direction W is unfixed. In this case, the leakage barrier wall 16 and the fixed regions 15, 15 are formed, for example, at 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. In this way, 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 of a hydrophobic sheet, for example, a hydrophobic nonwoven fabric. In another embodiment, it is formed of a hydrophilic sheet, for example, a hydrophilic nonwoven fabric.

[0033] Next, the absorbent body 14 will be described with reference to FIGS. 1 to 3. FIG. 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, includes a first absorbent layer 41 located on the skin side, a second absorbent layer 42 located away from the 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. In another embodiment, the absorbent body 14 does not include 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 in which other intermediate layers and other absorbent layers are further laminated between the first absorbent layer 41 and the second absorbent layer 42. In another embodiment, the first absorbent layer 41 is located on the skin side, and the second absorbent layer 42 is located on the non-skin side.

[0034] In this embodiment, the absorbent body 14 has a substantially rectangular planar shape extending in the longitudinal direction L. The absorbent body 14 can be seen as having a first water-absorbing material 45 and a second water-absorbing 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 thereof include a rectangle with short sides protruding in an arc shape, a rectangle with rounded corners, 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 as appropriate depending on the absorption performance required for the pants-type diaper 1, and is, for example, 60 to 1600 g / m 2 Examples include:

[0035] In this embodiment, the first absorbent layer 41 includes a first substrate 44 formed of a liquid-permeable sheet and a first water-absorbing material 45, which is disposed closer to the intermediate layer 43 than the first substrate 44 and contains a water-absorbing material containing a water-absorbent polymer. The first absorbent layer 41 can be considered to have the first water-absorbing 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 enveloping the first water-absorbing material 45 therein. The first water-absorbing 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 water-absorbing material 45 is disposed in the first absorbent layer 41 with a generally uniform basis weight. 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 having areas with high and low basis weights. 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. The outer dimension (outer edge) is measured, for example, at a position halfway in the thickness direction T of the first water-absorbing material 45.

[0036] In this embodiment, the second absorbent layer 42 includes a second substrate 46 formed of a sheet having 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 containing 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 the 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 the intermediate layer 43) and enclosing the second water-absorbing material 47 therein. 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 disposed 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-absorbent material 47 is arranged in the second absorbent layer 42 in a predetermined distribution having areas with high and low basis weights. The second water-absorbent material 47 has a substantially rectangular planar shape that is slightly larger than the first water-absorbent 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-absorbent 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-absorbent 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 on the skin-facing surface at 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.

[0037] In this way, both end portions in the width direction W of the second substrate 46 cover the side surfaces of the second water absorbent 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 absorbent material 47 is enclosed in the second absorbent layer 42 in the width direction W, and the first water absorbent material 45 is enclosed in the first absorbent layer 41 in the width direction W. In another embodiment, both end portions in the width direction W of the first substrate 44 cover both end portions in the width direction W of the second substrate 46. In yet another embodiment, the first substrate 44, the intermediate layer 43 and the second substrate 46 are stacked and joined in the thickness direction T at both end portions in the width direction W.

[0038] In this embodiment, the first substrate 44, the intermediate layer 43, and the 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-absorbent material 47 is enclosed in the second absorbent layer 42 by the first substrate 44 and the intermediate layer 43 in the longitudinal direction L, and the first water-absorbent material 45 is enclosed in the second absorbent layer 42 by the second substrate 46 and the intermediate layer 43 in the longitudinal direction L. In another embodiment, both ends of the absorbent body 14 in the longitudinal direction L are not covered with the first substrate 44 and the second substrate 46.

[0039] 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 a 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 and overlapping them. 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. A 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 makes it possible to temporarily store liquid, making it easier to ensure the time required for absorption by the superabsorbent polymer.

[0040] 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 strip-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 plan 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 as to be 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 in the longitudinal direction L, or not only in the longitudinal direction L. In yet another embodiment, the channel 48 is one or a plurality of three or more channels 48.

[0041] As described above, the first water-absorbing material 45 and the second water-absorbing material 47 contain a super absorbent polymer (SAP). There are no particular limitations on the super absorbent polymer as long as it is a polymer that can absorb and retain moisture, and examples thereof include particulate or fibrous super absorbent polymers. The basis weight of the super absorbent 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 for the pants-type diaper 1, and is, for example, 10 to 500 g / m2 and preferably 100 to 400 g / m 2 The basis weight of the first water absorbent material 45 and the second water absorbent material 47 may be greater than that of the other, or may be equal. "Equal" here means that one is within ±30% of the other. The first water absorbent material 45 and the second water absorbent material 47 may further contain hydrophilic fibers such as pulp fibers or absorbent fibers. The ratio of superabsorbent polymer to the first water absorbent material 45 and the second water absorbent material 47 is, for example, 80 to 100% by mass, preferably 90 to 100% by mass, and more preferably 95 to 100% by mass. Therefore, the first water absorbent material 45 and the second water absorbent 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-absorbent material 45 and the second water-absorbent material 47 but also the adhesive, the first base material 44, the intermediate layer 43 and the second base material 46) is, for example, 40 to 80 mass %, preferably 50 to 80 mass %, and more preferably 60 to 80 mass %. In this embodiment, the first water-absorbent material 45 and the second water-absorbent material 47 are composed only of superabsorbent polymer and do not contain hydrophilic fibers. In another embodiment, the first water-absorbent material 45 and the second water-absorbent material 47 contain pulp fibers and / or water-absorbent fibers in addition to the superabsorbent polymer.

[0042] 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 carboxymethylcellulose. Examples of synthetic polymer-based superabsorbent polymers include polyacrylate-based, polysulfonate-based, maleic anhydride-based, polyacrylamide-based, polyvinyl alcohol-based, polyethylene oxide-based, polyaspartate-based, polyglutamate-based, polyalginate-based, starch-based, and cellulose-based. In this embodiment, polyacrylate-based (especially 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 absorber 14 be composed of superabsorbent polymer particles having a particle size of 150 to 500 μm. Superabsorbent polymer particles with such a particle size distribution have a small and uniform particle size, making them easily retained by adhesives. The particle size of the highly water-absorbent polymer particles is measured in accordance with the sieving test method described in JIS R 6002:1998.

[0043] The adhesive is not particularly limited as long as it can fix the superabsorbent polymer, and examples thereof include hot melt adhesives. The pattern of application of the adhesive is not particularly limited, and examples thereof include a continuous or intermittent omega pattern, a spiral pattern, and a line pattern. The basis weight of the adhesive can be appropriately adjusted so as not to significantly reduce the liquid absorbency of the absorbent body 14, and is, for example, 3 to 50 g / m for each layer. 2 Here, the respective layers refer to a layer of adhesive between the first water-absorbing material 45 and the first substrate 44, a layer of adhesive between the first water-absorbing material 45 and the intermediate layer 43, a layer of adhesive between the second water-absorbing material 47 and the second substrate 46, and a layer of adhesive between the second water-absorbing material 47 and the intermediate layer 43.

[0044] 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 by a known method. Other examples include airlaid nonwoven fabrics in which hydrophilic fibers such as pulp fibers and 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 base material 44 is, for example, 0.1 to 5 mm, and preferably 0.15 to 3 mm.

[0045] The second substrate 46 is not particularly limited as long as it is a sheet having 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. The second substrate 46 may be formed by laminating multiple layers of one or more types of nonwoven fabrics from the above-mentioned nonwoven fabrics. The basis weight of the second substrate 46 is, for example, 10 to 200 g / m. 2 and preferably 35 to 150 g / m 2 The thickness of the second base material 46 is, for example, 0.1 to 5 mm, and preferably 0.15 to 3 mm.

[0046] 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 / m 2 and preferably 15 to 80 g / m 2 The thickness of the intermediate layer 43 is, for example, 0.1 to 5 mm, and preferably 0.15 to 3 mm.

[0047] In this embodiment, as shown in Fig. 3, the absorber 14 includes 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 overlaps with the dorsal portion 3 of the absorber 14 in the thickness direction T. The ventral region FA overlaps with the ventral portion 2 of the absorber 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 absorber 14, i.e., overlaps with the crotch portion 4 in the thickness direction T. Therefore, the absorber 14 is partitioned along the longitudinal direction L into the dorsal region BA overlapping with the dorsal portion 3, the ventral region FA overlapping with the ventral portion 2, and the crotch region MA overlapping with the crotch portion 4.

[0048] 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 a 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 a 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 each 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 ellipse, and an hourglass shape. In addition, 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 the 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 regions 14a, the low basis weight regions 14b, and the non-placement regions 14c.

[0049] 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 has only the high basis weight region 14a. Therefore, the basis weights of the superabsorbent polymer in the back-side high basis weight region BAa and the ventral high basis weight region FAa are equivalent to the basis weight of the superabsorbent polymer in the crotch region MA. "Equivalent" means that one is within a range of 0.7 to 1.3 times (±30%) that of the other. In another embodiment, the ventral region FA includes a ventral low basis weight region FAb as the low basis weight region 14b in addition to the ventral high basis weight region FAa and the ventral non-placement region FAc.

[0050] 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 edges of the first absorbent layer 41. The protruding portion includes a 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 base material 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 edges of the first absorbent layer 41. The skin side of the widthwise protruding portions is covered by the intermediate layer 43 and the first base material 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 edges of the first absorbent layer 41. The other protruding portion includes a ventral-side 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 is not covered 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.

[0051] In the present embodiment, in the absorbent body 14, 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, so that 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 part in the longitudinal direction L. This can make it easier to prevent leakage of liquid that flows to the back side, even though the amount is small.

[0052] In the present embodiment, in the absorbent body 14, when the length of the ventral-side high basis weight region FAa in the longitudinal direction L is da1 and the length of the ventral-side non-application region FAc is dc1, da1>dc1. That is, in the ventral region FA, the length of the ventral-side high basis weight region FAa is relatively long, the basis weight of the superabsorbent polymer is increased 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 the amount of excretion is large.

[0053] In the present embodiment, in the absorber 14, dc2>dc1 in the longitudinal direction L. By relatively increasing the length of the back-side non-application area BAc, the amount of superabsorbent polymer used in the back-side area BA where the amount of excretion is small can be kept low, while by relatively decreasing the length of the ventral-side non-application area FAc, it is possible to facilitate accurate absorption of liquid in the ventral area FA where the amount of excretion is large.

[0054] In another embodiment, in the absorbent body 14, da2+db2>da1 in the longitudinal direction L. In this case, by disposing the highly absorbent polymer in the back region BA in the longitudinal direction L up to a more rearward portion, it is possible to more easily prevent leakage of liquid that flows toward the back, even though the amount is small.

[0055] 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 the amount of superabsorbent polymer used in the dorsal region BA, where excretion is low, to be kept low while allowing liquid to be absorbed accurately in the ventral region FA, where excretion is high.

[0056] In this embodiment, a print film (not shown) is disposed between the back portion 3 and the back region BA of the absorbent body 14. The print film displays a design or pattern to the outside through the cover sheet 5 of the back portion 3.

[0057] 4 is an enlarged plan view of a portion of the pants-type diaper according to the embodiment, including the back section 3. In this embodiment, the back section 3 has a low-elasticity back section 31, which has low elasticity in the width direction W, and a pair of high-elasticity back sections 32, 32, which have high elasticity in the width direction W. The low-elasticity back section 31 is located in the center of the back section 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 sections 32, 32 are adjacent to both sides of the low-elasticity back section 31 in the width direction W. The low-elasticity back section 31 has an elongation rate ((length after stretching - original length) / (original length)) in the width direction W of the high-elasticity back section 32 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 section 32. For example, the low-elasticity 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-elasticity back region 32 is a region where there is an elastic member 7a that stretches in the width direction W. Therefore, the high-elasticity back region 32 and the low-elasticity 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" elasticity includes the case where there is no elasticity. Note that the elasticity of each elasticity region is determined by the elasticity of the elastic member.

[0058] In this embodiment, a rear portion of the channel 48 in the longitudinal direction L overlaps with the back-side low-elasticity region 31 in the thickness direction T. In plan view, an inner edge K1 in the width direction W of each of the pair of back-side high-elasticity regions 32 is located between an edge 14EW of the absorbent 14 that faces the back-side high-elasticity region 32 in the width direction W and the channel 48 (an edge 48E in the width direction W). The edge K1 is generally the inner edge of the elastic member 7a in the width direction W. Therefore, of the absorbent 14 including the rear portion of the channel 48 in the longitudinal direction L, a central portion in the width direction W is hardly stretched in the width direction W by the back-side 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-side high-elasticity regions 32.

[0059] 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 to the edge 14EW in the width direction W of the absorbent 14 that faces the back-side high-elasticity region 32. Therefore, of the absorbent 14 including the rear portion of the channel 48 in the longitudinal direction L, both end portions in the width direction W are stretched in the width direction W by the pair of back-side high-elasticity regions 32, 32.

[0060] In this embodiment, the back portion 3 further has another back high-stretch region 34 that exhibits high stretchability in the width direction W. In a plan view, the other back high-stretch region 34 is adjacent to the pair of back high-stretch regions 32, 32 and the back low-stretch region 31 on the rear side in the longitudinal direction L. The other back high-stretch region 34 is a region where the extensibility in the width direction W is approximately the same as the extensibility in the width direction W of the back high-stretch region 32. The other back high-stretch region 34 is defined as a region 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 back high-stretch region 34.

[0061] In this embodiment, in the back portion 3, the rear end 31E in the longitudinal direction L of the back-side 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 absorber 14 in the longitudinal direction L is less likely to be pressed against the wearer's back by the back-side low-elasticity region 31.

[0062] In this embodiment, the fixed region 15 and the inner end of the back-side highly elastic region 32 in the width direction W overlap in the thickness direction T. Therefore, the fixed region 15 is easily stretched at least outward in the width direction W by the back-side highly elastic region 32.

[0063] In this embodiment, the back-side low-elasticity region 31 of the back-side portion 3 overlaps with the back-side low basis weight region BAb and the back-side high basis weight region BAa in a plan view. The ventral-side low-elasticity region 36 of the ventral portion 2 overlaps with the ventral-side high basis weight region FAa in a plan view. Therefore, shrinkage of each high basis weight region and low basis weight region in the width direction W can be suppressed, and a decrease in absorption performance due to shrinkage of the absorbent core 14 can be suppressed.

[0064] In this embodiment, the other back-side high-elasticity region 34 of the back-side portion 3 overlaps with a region in 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 a region in 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 more in the width direction the portions of the absorbent body 14 in each of the back-side portion 3 and the ventral-side portion 2 that are further outward in the longitudinal direction L than the high / low basis weight regions, and presses these portions more against the skin.

[0065] FIG. 5 is an enlarged plan view of a portion including the ventral portion 2 of a pants-type diaper according to an embodiment. In this embodiment, the ventral portion 2 is generally the same as the back portion 3. That is, the ventral portion 2 has a ventral low-elasticity region 36, which has low elasticity in the width direction W, and a pair of ventral high-elasticity regions 37, 37, which have high elasticity in the width direction W. The ventral low-elasticity region 36 is located in the center of the ventral 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 ventral high-elasticity regions 37, 37 are adjacent to both sides of the ventral low-elasticity region 36 in the width direction W. The ventral low-elasticity region 36 has an elongation rate ((length after stretching - original length) / (original length)) in response to a predetermined 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 ventral high-elasticity region 37. For example, the abdominal-side low-elasticity region 36 is a region where there are no elastic members that stretch in the width direction W, or a region where there are elastic members but the elastic members do not function very well as elastic members (do not stretch very much). On the other hand, the abdominal-side high-elasticity region 37 is a region where there are elastic members 6a that stretch in the width direction W. Therefore, the abdominal-side high-elasticity region 37 and the abdominal-side low-elasticity region 36 are defined by the region where there are elastic members 6a that can function as elastic members and the region where there are no elastic members that can function as elastic members. The stretchability of each stretchable region is determined by the stretchability of the elastic members.

[0066] In this embodiment, a front portion of the channel 48 in the longitudinal direction L overlaps with the abdominal-side low-elasticity region 36 in the thickness direction T. In plan view, an inner edge K2 in the width direction W of each of the pair of abdominal-side high-elasticity regions 37, 37 is located between an edge 14EW of the absorbent 14 that faces the abdominal-side high-elasticity region 37 in the width direction W and (an edge 48E in the width direction W) of the channel 48. The edge K2 is generally the inner edge of the elastic member 6a in the width direction W. 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 hardly stretched in the width direction W by the abdominal-side low-elasticity region 36, and both end portions in the width direction W are stretched in the width direction W by the pair of abdominal-side high-elasticity regions 37, 37.

[0067] 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 stretch regions 37, 37 is equal to the distance between the inner edges K1, K1 in the width direction W of the pair of back high stretch 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 stretch regions 37, 37 is closer than the distance between the inner edges K1, K1 in the width direction W of the pair of back high stretch regions 32, 32. In this case, both end portions in the width direction W of the front portion of the longitudinal direction L of the absorbent 14 are stretched in the width direction W by the pair of ventral high stretch regions 37, 37.

[0068] In this embodiment, the abdominal portion 2 further has another abdominal high stretch region 39 that exhibits high stretchability in the width direction W. The other abdominal high stretch region 39 is adjacent to the front side in the longitudinal direction L of the pair of abdominal high stretch regions 37, 37 and the abdominal low stretch region 36. The other abdominal high stretch region 39 is a region where the elastic modulus in the width direction W is approximately the same as the elastic modulus in the width direction W of the abdominal high stretch region 37. The other abdominal high stretch region 39 is defined as a region 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 abdomen of the wearer by the other abdominal high stretch region 39.

[0069] Next, a method for manufacturing the absorbent body 14 will be described. First, while the sheet for the second substrate 46 is being moved in the longitudinal direction L, a hot melt adhesive is applied onto the sheet for the second substrate 46. Next, a superabsorbent polymer is sprayed from a superabsorbent polymer supply device along the longitudinal direction L onto both end portions and the center portion in the width direction W of the sheet for the second substrate 46 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 center portion. Next, a sheet for the intermediate layer 43, both sides of which are coated with hot melt adhesive, is laminated on top of the superabsorbent polymer on the sheet for the second substrate 46. Next, while the laminate is being moved in the longitudinal direction L, a superabsorbent polymer is sprayed from another superabsorbent polymer supply device along the longitudinal direction L onto the center portion in the width direction W of the sheet for the intermediate layer 43 to which the hot melt adhesive has been applied. Next, the sheet for the first substrate 44, to which a hot melt adhesive has been applied, is laminated on top of the superabsorbent polymer on the sheet for the intermediate layer 43, with the hot melt adhesive facing the superabsorbent polymer side. Then, both side edges of the sheet for the second substrate 46 in the width direction W are folded back onto both side edges of the sheet for the first substrate 44 in the width direction W to obtain a laminate. Thereafter, the thickness of the laminate is adjusted by passing the laminate through a pair of press rolls, i.e., pressing, to obtain the absorbent body 14.

[0070] 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 back side portion 3 are joined together. In this way, the pants-type diaper 1 is manufactured.

[0071] 6 and 7 are schematic diagrams illustrating the effects of a pants-type diaper according to an embodiment. FIGS. 6(a), 6(b), and 7(a) show a pants-type diaper according to a prior art, while FIGS. 6(c), 7(b), and 7(c) show a pants-type diaper according to the present embodiment. In the pants-type diaper 1, as described above, the channels 48 of the absorber 14 reach at least one of the back section 3 (back waist belt) and the ventral section 2 (ventral waist belt). This allows liquid (e.g., urine) to be transported and distributed to the back (rear side in the longitudinal direction L) and ventral (front side in the longitudinal direction L) ends of the absorber 14. This allows the superabsorbent polymer at the back and front ends of the absorber 14 in the longitudinal direction L, which are less likely to contribute to absorption, to absorb the liquid, thereby effectively utilizing the superabsorbent polymer.

[0072] Referring to FIG. 6(a), consider a case where the back portion 103 (waist belt) is provided with an elastic member over 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 wrinkles 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.

[0073] Also, referring to FIG. 6(b), consider a case where, as in another example of Patent Document 1, the back portion 103 (waist belt) has high-elasticity regions 132, 132 outside both ends of the absorber 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 absorber 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 absorber 114 in the width direction W are separated from the absorber 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 absorber 114 in the width direction W. Therefore, it is difficult to prevent the absorber 114 from becoming convex, as shown in FIG. 7(a). That is, it is difficult to prevent both ends of the absorber 114 in the longitudinal direction L from protruding from the wearer's body (see the arrows in FIG. 7(a)) by the dorsal portion 103 (or the ventral portion 102).

[0074] 6(c), the case of the pants-type diaper 1 of this embodiment will be considered. 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 portion 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 edge 14EW of the absorber 14 that faces the high-elasticity region in the width direction W and the channel 48. That is, the center portion 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 causes the absorbent body 14 to contract in the width direction W is not too strong, which prevents the back end of the absorbent body 14 in the longitudinal direction L from contracting in the width direction W and becoming convex before wearing.

[0075] 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 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 with an absorber 14 containing a superabsorbent polymer and having channels 48 to suppress liquid leakage while preventing a decrease in fit.

[0076] In a preferred aspect of the present embodiment, in plan view, the inner edge K1 in the width direction W of the back-side 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 body 14 that faces the back-side high-elasticity region 32 in the width direction W. Therefore, the contractile force of the back-side high-elasticity region 32 can more strongly pull the absorbent body 14 in the width direction W from both sides of the channel 48. This more reliably prevents the end of the absorbent body 14 in the longitudinal direction L from becoming convex, thereby preventing the end of the absorbent main body 10 (absorbent body 14) in the longitudinal direction L from protruding from the wearer's body.

[0077] In a preferred aspect of the present 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. Therefore, on the ventral side, the absorber 14 can be pulled more strongly from both sides of the channel 48 in the width direction W. That is, the absorber 14 can be pulled more strongly from both sides in the ventral portion 2 (ventral waist belt) that 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 that is relatively close to the position where it forms the most convex shape. In addition, on the back side, by relatively weakening the force pulling the absorbent body 14 from both sides across the channel 48 in the width direction W, a slight convex portion is formed in the absorbent body 14, which can function as a space for storing feces.

[0078] 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 39 pulls 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 this portion can 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 be fitted to the abdomen in a substantially flat shape.

[0079] 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 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 more rearward in the longitudinal direction L than the absorbent body 14 more in the width direction W, and this portion can 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 substantially flat shape.

[0080] In a preferred aspect of the present embodiment, the rear end of the back-side low-elasticity region 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. That is, the back-side low-elasticity region 31 is also present in a portion further rearward than the rear end of the channel 48 in the longitudinal direction L. Therefore, the portion of the back portion 3 (back-side waist belt) on the outer side rearward in the longitudinal direction L than 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, and a convex portion capable of accommodating a small amount of feces can be formed in the absorbent body 14. Therefore, it is possible to ensure a space for accommodating feces while preventing the end of the absorbent body 14 in the longitudinal direction L from becoming convex.

[0081] In a preferred aspect of the present embodiment, the absorbent main body 10 includes a pair of side sheets 17, 17, each of which has fixed regions 15, 15 and a leakage barrier wall 16, and the fixed 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 barrier wall 16 can be pulled outward in the width direction W and the longitudinal direction L via the fixed region 15. This prevents the end of the absorbent main body 14 in the longitudinal direction L from becoming convex, and also makes it easier for the leakage barrier wall 16 to stand up, thereby suppressing liquid leakage in the width direction W.

[0082] In a preferred embodiment of the present invention, the channels 48 include two channels 48 extending along the longitudinal direction L and spaced apart in the width direction W. This allows liquid to be transported and distributed more efficiently along the superabsorbent polymer arranged in 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 likely to deform due to the uneven shape extending in the longitudinal direction L with the channels 48 as folding 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 cause liquid to leak through gaps formed 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 the back-side portion 3 and the ventral-side portion 2 from becoming flat, prevents the fit of the pants-type diaper 1 from becoming poor, and prevents liquid leakage from gaps formed between the back-side portion 3 and the ventral-side portion 2 and the skin surface.

[0083] In a preferred aspect of the present embodiment, the absorber 14 has a rectangular shape in plan view, which allows for efficient distribution 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 folding line. This may impair the planarity of the back-side portion 3 and the ventral-side portion 2 (waist belt), potentially impairing the fit of the pants-type diaper 1 and potentially causing fluid 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 configuration, in plan view, 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. Therefore, it is possible to prevent the flatness of the back side portion 3 and the ventral side portion 2 from decreasing, the fit of the pants-type diaper 1 from decreasing, and liquid leakage from gaps that occur between the back side portion 3 and the ventral side portion 2 and the skin surface.

[0084] The pants-type diaper and its absorbent core 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. [Explanation of symbols]

[0085] 1. Pants-type diapers 2 Ventral part (ventral waist belt) 3 Back part (back waist belt) 10 Absorbent body 14 Absorbent 31 Dorsal low stretch area 32 Dorsal high stretch area 48 channels K, 14EW edge

Claims

1. 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 of 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.

2. In a plan view, the inner edge in the width direction of each of the pair of back-side high-elasticity regions is closer to the edge in the width direction of the channel than the edge of the absorbent body facing the corresponding back-side high-elasticity region in the width direction. The pants-type diaper according to claim 1.

3. 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.

4. 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.

5. 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.

6. 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.

7. 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.

8. 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.

9. The absorber is rectangular in plan view. The pants-type diaper according to any one of claims 1 to 8.

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