JP7618382B2 - Absorbent body for absorbent article, and absorbent article - Google Patents

Description

This disclosure relates to an absorbent body for an absorbent article, and to an absorbent article.

2. Description of the Related Art Absorbent bodies for absorbent articles are known, which include a first absorbent layer containing a superabsorbent polymer, a second absorbent layer containing a superabsorbent polymer, and a fabric layer disposed therebetween.
For example, Patent Document 1 describes a water-absorbent sheet having a structure in which an absorbent layer containing a water-absorbent resin and an adhesive is sandwiched between hydrophilic nonwoven fabrics, the water-absorbent sheet having a structure in which the absorbent layer is divided into a primary absorbent layer and a secondary absorbent layer by a base material layer formed by laminating two or more layers of breathable base materials bonded together with an adhesive, which satisfies the following requirements (1) and (2): (1) the base material layer has a basis weight of 25 g/ ^m2 or more, and (2) the breathable base materials are bonded together with 0.1 to 50 g/ ^m2 of adhesive.

In the absorbent sheet (absorbent) described in Patent Document 1, the base layer is a component that suppresses blocking caused by the absorbent resin (super absorbent polymer) in an absorbent with a high ratio of the absorbent resin (super absorbent polymer), and compensates for the slow absorption of the absorbent resin (super absorbent polymer) by temporarily storing liquid.

International Publication No. 2010/143635

In the absorbent sheet (absorbent body) described in Patent Document 1, liquid that reaches the primary absorbent layer remains around the highly absorbent polymer contained in the primary absorbent layer and is unlikely to migrate in the thickness direction, i.e., to the base material layer present on the clothing side and then to the secondary absorbent layer, and the base material layer is unlikely to temporarily store liquid.
Therefore, an object of the present disclosure is to provide an absorbent body for absorbent articles that is excellent in temporary liquid storage properties and liquid transfer properties in the thickness direction.

The present inventors have discovered an absorbent body for absorbent articles that has a thickness direction and a planar direction and includes a first absorbent layer containing a superabsorbent polymer, a second absorbent layer containing a superabsorbent polymer, and an intermediate layer containing fibers disposed therebetween, the absorbent body being characterized in that the intermediate layer includes a low fiber density portion having a relatively low fiber density and a high fiber density portion having a relatively high fiber density.

The absorbent for absorbent articles disclosed herein has excellent temporary liquid storage properties and liquid transfer properties in the thickness direction.

FIG. 1 is a front view of a pants-type diaper 1 according to a first embodiment in an unfolded state. FIG. 2 is a rear view of the pants-type diaper 1 in an unfolded state. FIG. 3 is a cross-sectional view of the pants-type diaper 1 taken along line III-III in FIG. FIG. 4 is a cross-sectional view of the absorbent body 14 taken along line III-III in FIG. FIG. 5 is a diagram for explaining the absorbent body 14. As shown in FIG.

Specifically, the present disclosure relates to the following aspects:
[Aspect 1]
An absorbent body for an absorbent article, comprising a first absorbent layer containing a superabsorbent polymer, a second absorbent layer containing a superabsorbent polymer, and an intermediate layer containing fibers disposed therebetween, the absorbent body having a thickness direction and a planar direction,
The intermediate layer has a low fiber density portion having a relatively low fiber density and a high fiber density portion having a relatively high fiber density.
The above absorbent body.

The absorbent body has an intermediate layer with a predetermined high fiber density portion, so that the high fiber density portion of the intermediate layer can reach the first absorbent layer, draw in the liquid that has accumulated around the first absorbent material, and temporarily store it. In addition, as the amount of liquid temporarily stored increases, the high fiber density portion of the intermediate layer moves the temporarily stored liquid to the low fiber density portion of the intermediate layer, and then the low fiber density portion containing the liquid can transfer the liquid to the second absorbent layer according to the demands of the second absorbent layer. Therefore, the intermediate layer of the absorbent body has excellent temporary liquid storage properties and excellent liquid migration properties in the thickness direction.

[Aspect 2]
The absorbent body according to aspect 1, wherein the high fiber density portion extends in a predetermined direction within the planar direction.

In the above absorbent, the high fiber density portion of the intermediate layer extends in a specific direction in the planar direction, so the high fiber density portion of the intermediate layer can draw in and diffuse the temporarily stored liquid in a specific direction in the planar direction of the intermediate layer, and the liquid diffused in the planar direction then tends to migrate in the thickness direction, i.e., to the second absorbent layer. Therefore, the above absorbent has excellent liquid migration properties in the thickness direction and planar direction.

[Aspect 3]
The absorbent body according to claim 1 or 2, wherein the intermediate layer has a high basis weight region having a relatively high basis weight and a low basis weight region having a relatively low basis weight, and the high fiber density portion is disposed in the high basis weight region.

In the above absorbent, the high fiber density portion is arranged in the high basis weight region, so the amount of fibers constituting the high fiber density portion is relatively large, and the liquid that reaches the first absorbent layer and accumulates around the first water-absorbing material can be drawn in by the high fiber density portion, and then the liquid can be drawn into the intermediate layer and temporarily stored. As a result, the above absorbent has excellent temporary storage properties.

[Aspect 4]
The absorbent body of claim 3, wherein the intermediate layer is composed of an intermediate sheet folded in the thickness direction at a predetermined folding axis, the intermediate layer is partitioned into an overlapping portion where the intermediate sheet overlaps in the thickness direction and a non-overlapping portion where the intermediate sheet does not overlap in the thickness direction, and the high basis weight region is composed of the overlapping portion.

In the absorbent, the intermediate layer is composed of a folded intermediate sheet, and the high basis weight region of the intermediate layer is composed of overlapping portions. Therefore, when the high fiber density portion of the intermediate layer absorbs liquid, the overlapping portions constituting the high basis weight region can expand in the thickness direction with the folding axis as the base point, so that the high basis weight region (overlapping portion) of the intermediate layer can temporarily store more liquid, and the absorbent has excellent temporary storage properties.

[Aspect 5]
5. The absorbent body according to claim 4, wherein the high fiber density portion is an embossed portion that embosses the overlapping portion.

In the absorbent body, the high fiber density portion is a specific embossed portion, and the overlapping portion is connected by the embossed portion. Therefore, even if the high fiber density portion of the intermediate layer draws in liquid, and the overlapping portion where the high fiber density portion is arranged expands in the thickness direction from the folding axis, the high fiber density portion (embossed portion) can suppress twisting of the absorbent body.

[Aspect 6]
Aspect 6. The absorbent body of any one of aspects 1 to 5, wherein the intermediate layer has a skin side, and the fiber density inside the intermediate layer is higher than the fiber density on the skin side.

In the above absorbent body, the fiber density inside the intermediate layer is higher than the fiber density on the skin side of the intermediate layer, so that liquid absorbed by the intermediate layer can be easily transferred from the skin side to the inside of the intermediate layer and then to the clothing surface by capillary action, and thus liquid transferred to the clothing surface of the intermediate layer can be easily transferred to the second absorbent layer. Therefore, the above absorbent body has excellent liquid transferability in the thickness direction.
In addition, the skin side of the intermediate layer, which has a relatively low fiber density, can retain the superabsorbent polymer contained in the first absorbent layer in the gaps between the fibers, and is excellent in retaining the superabsorbent polymer.

[Aspect 7]
The absorbent body according to claim 6, wherein the intermediate layer is an intermediate sheet having a first surface with a relatively low fiber density and a second surface with a relatively high fiber density, and is folded on a predetermined folding axis with the second surface as the inner surface.

In the above absorbent article, the intermediate layer is composed of an intermediate sheet that is folded so that the first surface, which has a relatively low fiber density, is the outer surface and the second surface, which has a relatively high fiber density, is the inner surface. In addition to the effect of aspect 6, the intermediate sheet can retain the superabsorbent polymer of the first absorbent layer and the superabsorbent polymer of the second absorbent layer in the gaps between the fibers, resulting in excellent retention of the superabsorbent polymer.

[Aspect 8]
The absorbent body has a longitudinal direction and a width direction,
a second absorbent layer extending in the longitudinal direction and including a pair of channels spaced apart in the width direction across a longitudinal centerline of the absorbent body;
The high fiber density portion overlaps each of the pair of channels in the thickness direction.
The absorbent body according to any one of the preceding aspects.

In the absorbent, the high fiber density portion of the intermediate layer overlaps with the pair of channels of the second absorbent layer in the thickness direction. The pair of channels arranged in the second absorbent layer contribute to deformation induction in which the absorbent and the absorbent article including the absorbent form a three-dimensional shape starting from the pair of channels. In the absorbent, the high fiber density portion of the intermediate layer overlaps with the pair of channels in the thickness direction, so that the liquid drawn in by the high fiber density portion of the intermediate layer can be transferred to the pair of channels of the second absorbent layer, and the liquid can be diffused through the pair of channels into the second absorbent layer. As a result, the absorbent has excellent deformation induction properties and excellent liquid migration properties in the thickness direction and planar direction.

In addition, in the above absorbent body, the high fiber density portion of the middle layer overlaps with a pair of channels in the thickness direction, so that the wearer of the absorbent article is unlikely to feel a difference in stiffness at the pair of channels in the second absorbent layer.

[Aspect 9]
An absorbent article comprising a liquid-permeable sheet, a liquid-impermeable sheet, and an absorbent disposed therebetween,
The absorbent body is the absorbent body according to any one of aspects 1 to 8.
The absorbent article described above.
The absorbent article has the same effects as those of the first aspect.

The absorbent body for absorbent articles of the present disclosure (hereinafter, may be referred to as the "absorbent body of the present disclosure") and the absorbent article will be described in detail below. For the sake of simplicity, the absorbent body will be described together with the embodiment of the absorbent article.

Figures 1 to 5 are diagrams for explaining an absorbent article according to one embodiment of the present disclosure (hereinafter, the first embodiment), specifically, a pants-type diaper 1. Specifically, Figures 1 and 2 are a front view and a back view, respectively, of the pants-type diaper 1 in an unfolded state. Figure 3 is a cross-sectional view of the pants-type diaper 1 taken along line III-III in Figure 1. Figure 4 is a cross-sectional view of the absorbent body 14 taken along line III-III in Figure 1. Figure 5 is a diagram for explaining the absorbent body 14, where Figure 5(a) is a plan view and Figure 5(b) is a cross-sectional view taken along line Vb-Vb in Figure 5(a). Note that the drawings are schematic views, and in particular, Figures 3 to 5 are depicted with a thickness in the thickness direction T that is thicker than it actually is for the sake of understanding.

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, a longitudinal centerline CL that passes through the center of the width direction W and extends in the longitudinal direction L, and a widthwise centerline CW that passes through the center of the longitudinal direction L and extends in the width direction W. The directions and sides approaching the longitudinal centerline CL are respectively defined as the inward and inner sides of the width direction W, and the directions and sides moving away from the longitudinal centerline CW are respectively defined as the outward and outer sides of the width direction W. The directions and sides approaching the widthwise centerline CW are respectively defined as the inward and inner sides of the longitudinal direction L, and the directions and sides moving away from the longitudinal centerline CW are respectively defined as the outward and outer sides of the longitudinal direction L.

In addition, the side in the longitudinal direction L toward the edge (ventral edge) of the pants-type diaper 1 corresponding to the wearer's abdomen is also referred to as the front side in the longitudinal direction L, and the side toward the edge (dorsal edge) of the pants-type diaper 1 corresponding to the wearer's back is also referred to as the rear side in the longitudinal direction L.
"Planar view" refers to viewing the pants-type diaper 1 unfolded on a plane including the longitudinal direction L and the width direction W from above in the thickness direction T, and "planar shape" refers to the shape as perceived in a planar view.

The "planar direction" is any direction parallel to a plane including the width direction W and the longitudinal direction L.
The terms "skin side" and "non-skin side" refer to the sides that are relatively closer to and farther from the wearer's skin surface in the thickness direction T, respectively, when the pants-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 each of the materials disposed thereon.

Note that when a member, structure, shape, etc. (hereinafter referred to as "member, etc.") is aligned with the longitudinal direction L, it includes not only when the member, etc. is parallel to the longitudinal direction L, but also when the component Dx of the longitudinal direction L of the member, etc. is greater than the component Dy of the width direction W of the member, etc. (Dx>Dy). Similarly, when a member, etc. is aligned with the width direction W, it includes not only when the member, etc. is parallel to the width direction W, but also when the component Dy of the width direction W of the member, etc. is greater than the component Dx of the longitudinal direction L of the member, etc. (Dy>Dx). For members, etc. having a shape of a curve, curved surface, etc. (hereinafter referred to as "curve, etc."), the member, etc. is evaluated as described above for the tangent to each point on the curve, etc.

As shown in FIGS. 1 and 2, the pants-type diaper 1 has a planar direction P and a thickness direction T which are perpendicular to each other. The planar direction P includes a longitudinal direction L and a width direction W of the pants-type diaper 1.
The pants-type diaper 1 comprises, in the longitudinal direction L, a ventral portion (ventral waist belt) 2, a dorsal portion (dorsal waist belt) 3, and an absorbent body 10 located between the ventral portion 2 and the dorsal portion 3. In the first embodiment, the pants-type diaper 1 further comprises a crotch portion 4 located between the ventral portion 2 and the dorsal portion 3. The ventral portion 2 is a portion that abuts against the wearer's abdomen. The dorsal portion 3 is a portion that abuts against the wearer's buttocks or back. The absorbent body 10 is a portion that abuts against the wearer's crotch, and one end in the longitudinal direction L is layered on the ventral portion 2, and the other end is layered on the dorsal portion 3. The crotch portion 4 is a portion that supports the absorbent body 10 from the non-skin side.

The pants-type diaper 1 is formed by joining both ends 2a, 2a in the width direction W of the abdominal portion 2 and both ends 3a, 3a in the width direction W of the back portion 3 along the longitudinal direction L. In the pants-type diaper 1, the outer end 2e in the longitudinal direction L of the abdominal portion 2 and the outer end 3e in the longitudinal direction L of the back portion 3 define a waist opening through which the wearer's waist passes. In addition, in the pants-type diaper 1, the side portions 5e, 5e on both sides in the width direction W of the crotch portion 4 define a pair of leg openings through which the wearer's legs pass. The abdominal portion (abdominal waist belt) 2 and the back portion (dorsal waist belt) 3 can be said to be parts defined within the range of the longitudinal direction L where the both ends 2a, 2a and the both ends 3a, 3a are joined.

In the first embodiment, in the state shown in Figs. 1 and 2, 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 (not shown), the abdominal portion 2, the crotch portion 4, and the back portion 3 are formed separately from each other. Furthermore, in another embodiment (not shown), the pants-type diaper 1 includes the abdominal portion 2 and the back portion 3, but does not include the crotch portion 4.

In the first 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 located on the skin side and a cover sheet 5b located 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 to the skin side so as to cover both ends of the cover sheet 5a in the longitudinal direction L. 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.

In the first embodiment, the abdominal portion 2 and the back portion 3 are provided with a plurality of elastic members 6a, 6b and a plurality of elastic members 7a, 7b for waist gathers between the cover sheet 5a and the cover sheet 5b. The plurality of elastic members 6a, 6b are arranged on the outer side and inner side of the longitudinal direction L of the abdominal portion 2, respectively. The plurality of elastic members 6a are arranged at intervals from each other in the longitudinal direction L along the width direction W in each predetermined region on both sides of the longitudinal center line CL. The predetermined region is the region from the end 2a to the inner part of the opposing end edge in the width direction W of the absorbent body 10. The plurality of elastic members 6b extend from one end 2a to the other end 2a along the width direction W, and are arranged at intervals from each other in the longitudinal direction L. Similarly, the plurality of elastic members 7a, 7b are arranged on the outer side and inner side of the longitudinal direction L of the back portion 3, respectively.

The multiple elastic members 7a are arranged at intervals in the longitudinal direction L along the width direction W in a predetermined region on each side of the longitudinal center line CL. The predetermined region is the region from the end 3a to the inner part of the opposing end edge in the width direction W of the absorbent body 10. The multiple elastic members 7b extend from one end 3a to the other end 3a along the width direction W 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 rubber thread. The ventral side portion (ventral waist belt) 2 and the dorsal side portion (dorsal waist belt) 3 can be said to be the portion defined by the range in the longitudinal direction L in which the multiple elastic members 6a, 6b, 7a, 7b are arranged.

In the first embodiment, the pants-type diaper 1 has multiple elastic members 8 for leg gathers from the crotch region 4 to the back region 3 and the ventral region 2. The multiple elastic members 8 are mainly provided extending along the longitudinal direction L from both ends in the width direction W of the crotch region 4. The multiple elastic members 8 are for expanding and contracting each of the pair of leg openings, and are exemplified by rubber threads.

In the first embodiment, the absorbent body 10 has a substantially rectangular shape and includes a liquid-permeable sheet 12, a liquid-impermeable sheet 13, and an absorbent 14 that is disposed between the liquid-permeable sheet 12 and the liquid-impermeable sheet 13 and absorbs and retains liquids such as urine. Examples of the liquid-permeable sheet 12 include liquid-permeable nonwoven fabrics, woven fabrics, synthetic resin films with liquid-permeable holes formed therein, and composite sheets thereof. Examples of the liquid-impermeable sheet 13 include liquid-impermeable nonwoven fabrics, synthetic resin films, and composite sheets thereof, such as SMS nonwoven fabrics.

In the first embodiment, the absorbent body 14 includes an absorbent core that absorbs and retains liquid, and a core wrap that contains the absorbent core. Details of the absorbent body 14 will be described later. The absorbent body 14, the liquid-permeable sheet 12, and the liquid-impermeable sheet 13 are each bonded with an adhesive, and the liquid-permeable sheet 12 and the liquid-impermeable sheet 13 are bonded with an adhesive at their peripheral portions. The adhesive may be a material known in pants-type diapers, such as a hot melt adhesive. 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 may be, for example, a rectangular shape with rounded corners, a rectangular shape with short sides that are curved outward, an hourglass shape, etc. In another embodiment, the liquid-impermeable sheet 13 is omitted, and the non-skin side surface of the absorbent body 14 and the non-skin side surface of the peripheral portion of the liquid-permeable sheet 12 are bonded to the cover sheet 5.

In the first embodiment, the absorbent body 10 includes a pair of side sheets 17, 17 located on both sides of the width direction W on the skin-side surface and extending in the longitudinal direction L. Each side sheet 17 has a leak-proof wall 16 and a fixing region 15, 15. The fixing region 15, 15 is located at the front and rear ends of the side sheet 17 in the longitudinal direction L and is fixed to the skin-side surface of the absorbent body 10. The leak-proof wall 16 is located between the fixing regions 15, 15 on the front and rear sides of the longitudinal direction L of the side sheet 17 and is adjacent to them, and has its outer edge in the width direction W fixed to the skin-side surface of the absorbent body 10 and its inner edge in the width direction W not fixed. The leak-proof wall 16 and the fixing region 15, 15 are formed, for example, in the inner part of the side sheet 17 in the width direction W, and the outer part of the side sheet 17 in the width direction W is fixed to the absorbent body 10.

The pair of leak-proof walls 16, 16 are arranged facing each other at both ends of the absorbent body 10 on the skin side in the width direction W, and extend continuously along the longitudinal direction L. Each leak-proof wall 16 includes two elastic members 61 extending along the longitudinal direction L at the inner end in the width direction W. The elastic members 61 are exemplified by rubber threads. Each of the pair of leak-proof walls 16, 16 is formed of a hydrophobic sheet, for example, a hydrophobic nonwoven fabric. In another embodiment, each of the pair of leak-proof walls 16, 16 is formed of a hydrophilic sheet, for example, a hydrophilic nonwoven fabric.

Next, the absorbent body 14 will be described with reference to Figs. 1 to 5. The absorbent body 14 comprises a first absorbent layer 41 arranged on the skin side, a second absorbent layer 42 arranged on the non-skin side, and an intermediate layer 43 arranged between the first absorbent layer 41 and the second absorbent layer 42. The absorbent body 14 has a substantially rectangular planar shape extending in the longitudinal direction L.

In the first embodiment, the first absorbent layer 41 includes a first substrate 44 formed of a liquid-permeable sheet, and a first absorbent material 45 arranged closer to the intermediate layer 43 than the first substrate 44 and having an absorbent material containing a water-absorbing polymer. The first absorbent layer 41 can be considered to have the first absorbent material 45 as an absorbent core portion, and the first substrate 44 (and the intermediate layer 43) as a core wrap. The first absorbent material 45 is fixed to at least one of the first substrate 44 and the intermediate layer 43 by an 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 absorbent material of the first absorbent material 45 is arranged in the first absorbent layer 41 with a generally uniform basis weight. The first absorbent material 45 has a generally rectangular planar shape. The first base material 44 has a generally rectangular planar shape and covers the first absorbent material 45 from the skin side in a planar view, with the peripheral portion of the first base material 44 extending slightly outward from the periphery of the first absorbent material 45.

In the first 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 absorbent material 47 arranged closer to the intermediate layer 43 than the second substrate 46 and having an absorbent material containing a water-absorbing polymer. The second absorbent layer 42 can be considered to have the second absorbent material 47 as an absorbent core portion and the second substrate 46 (and the intermediate layer 43) as a core wrap. The second absorbent material 47 is fixed to at least one of the second substrate 46 and the intermediate layer 43 by an adhesive applied to at least one of the surface of the second substrate 46 on the intermediate layer 43 side and the surface of the intermediate layer 43 on the second substrate 46 side. The absorbent material of the second absorbent material 47 is arranged in the second absorbent layer 42 with a generally uniform basis weight, except for a pair of channels 48, 48 (described later).

The second absorbent material 47 has a generally rectangular planar shape that is slightly larger in the width direction W and the longitudinal direction L than the first absorbent material 45. The second base material 46 has a generally rectangular planar shape, and covers the second absorbent material 47 from the non-skin side in a planar view, with the peripheral portion of the second base material 46 extending slightly outward from the periphery of the second absorbent material 47. Both ends of the second base material 46 in the width direction W cover both side surfaces of the second absorbent material 47, while covering the skin-side surface at both ends of the width direction W of the first base material 44. That is, the ends of the second base material 46 in the width direction W and the ends of the first base material 44 in the width direction W are overlapped and joined on the skin-side surface at the ends of the width direction W of the first absorbent layer 41.

The ends of the second substrate 46 in the width direction W cover the sides of the second absorbent material 47 in the width direction W and further cover the sides of the first substrate 44 in the width direction W, so that the second absorbent material 47 is enclosed in the second absorbent layer 42 in the width direction W, and the first absorbent material 45 is enclosed in the first absorbent layer 41 in the width direction W.

In the first embodiment, at both ends of the absorbent 14 in the longitudinal direction L, the first substrate 44, the intermediate layer 43, and the second substrate 46 are stacked and joined in the thickness direction T. As a result, the first water-absorbing material 45 is enclosed in the first absorbent layer 41 by the first substrate 44 and the intermediate layer 43 in the longitudinal direction L, and the second water-absorbing material 47 is enclosed in the second absorbent layer 42 by the second substrate 46 and the intermediate layer 43 in the longitudinal direction L.

In the first embodiment, the intermediate layer 43 has a generally rectangular planar shape in plan view and includes a low basis weight region LB with a relatively low basis weight and a pair of high basis weight regions HB with a relatively high basis weight. Specifically, the intermediate layer 43 includes a pair of high basis weight regions HB arranged at both ends in the width direction W, and a low basis weight region LB arranged in the center of the width direction W.

The intermediate layer 43 is composed of a single intermediate sheet 43S (specifically, an air-through nonwoven fabric containing core-sheath type composite fibers) having liquid permeability. The intermediate sheet 43S has two folding axes 103 and 104, and in the unfolded state, is divided into a first sheet portion 43a arranged inside the two folding axes 103 and 104, and a pair of second sheet portions 43b, 43b arranged outside the two folding axes 103 and 104. The intermediate layer 43 is formed by folding the single intermediate sheet 43S in the thickness direction T, specifically, toward the second absorbent layer 42 side, by the two folding axes 103 and 104 extending in the longitudinal direction L.

In the intermediate layer 43, a single intermediate sheet 43S is folded by two folding axes 103 and 104, and in the planar direction P, a pair of second sheet portions 43b, 43b are arranged on both sides of the first sheet portion 43a in the width direction W, and in the thickness direction T, a pair of second sheet portions 43b, 43b are arranged on the second absorbent layer 42 side. The portions where the first sheet portion 43a and each of the pair of second sheet portions 43b, 43b overlap in the thickness direction T constitute a pair of overlapping portions OP of the intermediate layer 43, and the portions of the first sheet portion 43a that do not overlap in the thickness direction T with the pair of second sheet portions 43b, 43b constitute a non-overlapping portion NP. Each of the pair of overlapping portions OP coincides with each of the pair of high basis weight regions HB, and the non-overlapping portion NP coincides with the low basis weight region LB.

In the intermediate layer 43, in a pair of high basis weight regions HB (a pair of overlapping portions OP), the first sheet portion 43a and the second sheet portion 43b are joined by a pair of embossed portions 43c extending along the longitudinal direction L.

In the intermediate layer 43, the fiber density of the composite fiber in the pair of embossed portions 43c is higher than the fiber density of the composite fiber in the portion other than the pair of embossed portions 43c.
In other words, the intermediate layer 43 is partitioned into a pair of high fiber density portions HD constituted by the pair of embossed portions 43c, and three low fiber density portions LD constituted by portions other than the pair of embossed portions 43c.

The pair of high fiber density portions HD extend in the longitudinal direction L and are arranged at a predetermined interval on both sides in the width direction W of the longitudinal center line CL.
The pair of high fiber density sections HD allows liquid that reaches the first absorbent layer 41 to tend to accumulate around the first absorbent material 45 of the first absorbent layer 41, but the liquid accumulating around the first absorbent material 45 can be drawn into the pair of high fiber density sections HD (the pair of embossed sections 43c) and ultimately into the intermediate layer 43 by capillary action.

In addition, since each of the pair of high fiber density portions HD extends in the longitudinal direction L, the liquid drawn into the pair of high fiber density portions HD is easily diffused in the longitudinal direction L within the intermediate layer 43. Next, the liquid diffused in the longitudinal direction L within the intermediate layer 43 is easily transferred to the second absorbent layer 42.

The pair of high fiber density sections HD are arranged in the pair of high basis weight regions HB (the pair of overlapping sections OP) described above. Therefore, the amount of composite fibers constituting the high fiber density section HD is relatively large, and the liquid remaining around the first water absorbent material 45 can be drawn into the pair of high fiber density sections HD (the pair of embossed sections 43c) by capillary action, and then the liquid can be drawn into the intermediate layer 43 and temporarily stored.

In the intermediate layer 43, the intermediate sheet 43S has a net surface (not shown) that was in contact with the net (placement surface) when the air-through nonwoven fabric was formed, and a non-net surface (not shown) on the opposite side to the net. The net surface has a relatively higher fiber density than the non-net surface. The intermediate sheet 43S is folded with the net surface on the inside, so that the intermediate layer 43 is configured so that the fiber density inside the intermediate layer 43 is higher than the fiber density on the skin side.

Therefore, the liquid absorbed by the intermediate layer 43 is easily transferred from its skin side to its interior and then to the clothing surface (not shown) by capillary action, and thus the liquid transferred to the clothing surface of the intermediate layer 43 is easily transferred to the second absorbent layer 42. In addition, the skin side (non-net surface) of the intermediate layer 43, which has a relatively low fiber density, can retain the first absorbent material 45 contained in the first absorbent layer 41, and has excellent retention of the superabsorbent polymer.

The pair of high basis weight regions HB are composed of a pair of overlapping portions OP, in which the first sheet portion 43a and the second sheet portion 43b are laminated in the thickness direction T. The first sheet portion 43a and the second sheet portion 43b are not connected except by the pair of embossed portions 43c and the two folding axes 103 and 104. Therefore, when the pair of high fiber density portions HD of the intermediate layer 43 draw in liquid, the pair of overlapping portions OP constituting the pair of high basis weight regions HB can expand in the thickness direction T from the two folding axes 103 and 104 and the pair of embossed portions 43c as base points. Therefore, the pair of high basis weight regions HB (pair of overlapping portions OP) of the intermediate layer 43 can temporarily store liquid.

A pair of high fiber density portions HD are composed of an embossed portion 43c that embosses the first sheet portion 43a and the second sheet portion 43b, and the first sheet portion 43a and the second sheet portion 43b are connected in the embossed portion 43c.
Therefore, even when a pair of high fiber density portions HD of the intermediate layer 43 absorb liquid and a pair of overlapping portions OP in which the pair of high fiber density portions HD are arranged extend in the thickness direction T from the two folding axes 103 and 104 as base points, the pair of high fiber density portions HD (embossed portions 43c) can suppress twisting of the absorbent body 14.

The intermediate layer 43 has both ends in the width direction W sandwiched between and joined to both ends of the first substrate 44 and the second substrate 46 in the width direction W, and both ends in the longitudinal direction L sandwiched between and joined to both ends of the first substrate 44 and the second substrate 46 in the longitudinal direction L.

The absorbent body 14 has a pair of channels 48, 48 extending along the longitudinal direction L. The pair of channels 48, 48 are arranged in the second absorbent layer 42, extend in the longitudinal direction L, and are strip-shaped regions arranged at a predetermined interval on both sides of the longitudinal centerline CL in the width direction W. The channel 48 is arranged at least in the center of the second absorbent layer 42 in the longitudinal direction L so as to straddle the width direction centerline CW.

Each of the pair of channels 48, 48 is an area in which the basis weight of the second water absorbent material 47 is smaller than the area surrounding each of the pair of channels 48, 48. Each of the pair of channels 48, 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.

Each of the pair of channels 48 , 48 is arranged so as to overlap in the thickness direction T with a pair of high basis weight regions HB (a pair of overlapping portions OP) of the intermediate layer 43 .
In addition, the pair of channels 48, 48 are arranged so as to overlap the pair of embossed portions 43c in the thickness direction T, in other words, each of the pair of high fiber density portions HD overlaps with each of the pair of channels 48, 48 in the thickness direction T. This allows the liquid drawn in by the pair of high fiber density portions HD of the intermediate layer 43 to move to the pair of channels 48, 48 of the second absorbent layer 42, and the liquid can be diffused into the second absorbent layer 42 through the pair of channels 48, 48.

The first water-absorbing material 45 and the second water-absorbing material 47 each contain a super absorbent polymer (SAP). The basis weight of the super absorbent polymer of each of the first water-absorbing material 45 and the second water-absorbing material 47 can be appropriately adjusted 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/ ^m2 .

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. However, "equal" means that one is within a range of ±30% of the other. The first water absorbent material 45 and the second water absorbent material 47 may further have hydrophilic fibers such as absorbent fibers (e.g., pulp fibers). The proportion of the highly absorbent polymer in 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, it can be said that the first water absorbent material 45 and the second water absorbent material 47 contain a highly absorbent polymer as a main component, and the absorbent body 14 can be said to be a so-called SAP sheet.

However, the proportion of superabsorbent polymer in the absorbent body 14 (including not only the first absorbent material 45 and the second absorbent material 47 but also the adhesive, the first substrate 44, the intermediate layer 43 and the second substrate 46) is, for example, 40 to 80% by mass, preferably 50 to 80% by mass, and more preferably 60 to 80% by mass.

In the first embodiment, each of the first absorbent material 45 and the second absorbent material 47 is made of only a highly absorbent polymer and does not contain hydrophilic fibers.

The superabsorbent polymer is preferably composed of 90-100% by mass of superabsorbent polymer particles having a particle size of 150-500 μm. The superabsorbent polymer particles having the above particle size are small and uniform, and therefore easily retained in the adhesive. The particle size of the superabsorbent polymer particles is measured in accordance with the sieving test method described in JIS R 6002:1998.

The adhesive is not particularly limited as long as it can fix the superabsorbent polymer, and examples thereof include hot melt adhesives. The 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 that the liquid absorbency of the absorbent body 14 is not significantly reduced, and examples thereof include 3 to 50 g/m ² for each layer. However, each layer means a layer of adhesive between the first water absorbent material 45 and the first substrate 44, a layer of adhesive between the first water absorbent material 45 and the intermediate layer 43, a layer of adhesive between the second water absorbent material 47 and the second substrate 46, and a layer of adhesive between the second water absorbent material 47 and the intermediate layer 43.

The first substrate 44 is not particularly limited as long as it is a liquid-permeable sheet. Examples of the first substrate 44 include liquid-permeable nonwoven fabrics containing synthetic fibers, hydrophilic nonwoven fabrics, and laminated nonwoven fabrics thereof, among which nonwoven fabrics with high water permeability are preferred. Examples of the first substrate 44 include spunbond 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.
The synthetic fibers are preferably subjected to a hydrophilization treatment by a known method.

The liquid-permeable sheet can be, for example, an airlaid nonwoven fabric in which hydrophilic fibers such as pulp fibers or rayon fibers are coated with a hydrophilic binder, or a nonwoven fabric in which the hydrophilic fibers are combined with the synthetic fibers, such as a spunlace nonwoven fabric. In the first embodiment, an airlaid nonwoven fabric in which pulp fibers having liquid permeability and liquid retention are coated with a hydrophilic binder is used.

The first base material 44 may be formed by laminating multiple layers of one or more types of nonwoven fabric selected from the above nonwoven fabrics.
The basis weight of the first base material 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.

There are no particular limitations on the second substrate 46, so long as it is a sheet having water retention and liquid diffusion properties. Examples of the second substrate 46 include 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, and nonwoven fabrics formed from combinations thereof. Specifically, examples of the second substrate 46 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 contain polyolefin fibers and/or polyester fibers. In the first embodiment, a spunlace nonwoven fabric containing rayon fibers and pulp fibers, which has liquid retention and liquid diffusion properties, is used.

The second base material 46 may be made of one of the above nonwoven fabrics, and may be made by laminating a plurality of layers of the above nonwoven fabrics.
The basis weight of the second base material 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.

The intermediate layer 43 (intermediate sheet 43S) may be, for example, a sheet similar to the first substrate 44. The basis weight of the intermediate layer 43 may be, for example, 10 to 100 g/m ² , and preferably 15 to 80 g/m ^2. The thickness of the intermediate layer 43 may be, for example, 0.1 to 5 mm, and preferably 0.15 to 3 mm.

In the first embodiment, as shown in FIG. 5, the absorbent body 14 has a back region BA, a ventral region FA, and a crotch region MA aligned along the longitudinal direction L. However, the back region BA is a region that overlaps with the back portion 3 of the absorbent body 14 in the thickness direction T. The ventral region FA is a region that overlaps with the ventral portion 2 of the absorbent body 14 in the thickness direction T. The crotch region MA is a region located between the back region BA and the ventral region FA of the absorbent body 14, i.e., a region that overlaps with the crotch portion 4 in the thickness direction T. Therefore, the absorbent body 14 is partitioned along the longitudinal direction L into the back region BA that overlaps with the back portion 3, the ventral region FA that overlaps with the ventral portion 2, and the crotch region MA that overlaps with the crotch portion 4.

In the first embodiment, the absorbent 14 includes a SAP high basis weight region 14a, a SAP low basis weight region 14b, and a SAP non-placement region 14c. The SAP high basis weight region 14a is a region where the basis weight of the superabsorbent polymer is relatively high, and is a region where the first absorbent layer 41 and the second absorbent layer 42 overlap in the thickness direction T. The SAP low basis weight region 14b is a region where the basis weight of the superabsorbent polymer is relatively low, and is a region where the first absorbent layer 41 does not exist in the thickness direction T, and only the second absorbent layer 42 exists. The SAP non-placement 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 do not exist in the thickness direction T. However, not containing a superabsorbent polymer includes a case where a superabsorbent polymer is present but its basis weight is very small. "Very small" refers to a case where the basis weight of the superabsorbent polymer is 5% or less of the basis weight of the superabsorbent polymer in the SAP high basis weight region 14a.

Therefore, in the absorbent body 14, the rear region BA has a rear SAP high basis weight region BAa as the SAP high basis weight region 14a, a rear SAP low basis weight region BAb as the SAP low basis weight region 14b, and a rear SAP non-disposition region BAc as the SAP non-disposition region 14c. Also, in the absorbent body 14, the ventral region FA has a ventral SAP high basis weight region FAa as the SAP high basis weight region 14a, and a ventral SAP non-disposition region FAc as the SAP non-disposition region 14c, but does not have a ventral SAP low basis weight region FAb. The crotch region MA has only the SAP high basis weight region 14a.
Therefore, the basis weight of the superabsorbent polymer in the dorsal SAP high basis weight region BAa and the ventral SAP high basis weight region FAa is equivalent to the basis weight of the superabsorbent polymer in the crotch region MA. Note that "equivalent" means that one is within the range of 0.7 to 1.3 times (±30%) the other.

The second absorbent layer 42 includes a protruding portion at the rear end in the longitudinal direction L that protrudes outward from the edge of the first absorbent layer 41 in a plan view. The protruding portion includes the rear SAP low basis weight region BAb, and the protruding portion is identical to the rear SAP low basis weight region BAb. The second absorbent layer 42 is covered by the intermediate layer 43, and therefore the protruding portion, i.e., the rear SAP low basis weight region BAb, is covered on the skin side by the intermediate layer 43 and the first substrate 44.

In the absorbent 14, in the longitudinal direction L, if the length of the rear SAP high basis weight region BAa is da2, the length of the rear SAP low basis weight region BAb is db2, and the length of the rear SAP non-placement region BAc is dc2, then db2 > dc2 > da2. That is, in the rear region BA, the length of the rear SAP low basis weight region BAb is relatively long, keeping the basis weight of the superabsorbent polymer low overall, while placing the superabsorbent polymer up to the rear part in the longitudinal direction L. Although the amount is small, this makes it easier to prevent leakage of liquid that flows to the rear side.

In the absorbent 14, in the longitudinal direction L, if the length of the ventral SAP high basis weight region FAa is da1 and the length of the ventral SAP non-placement region FAc is dc1, then da1>dc1. That is, in the ventral region FA, the length of the ventral SAP high basis weight region FAa is relatively long, the basis weight of the superabsorbent polymer is increased overall, and the superabsorbent polymer is placed 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.

In the absorbent 14, dc2>dc1 in the longitudinal direction L. By making the length of the back SAP-free region BAc relatively long, the amount of superabsorbent polymer used in the back region BA, where the amount of excretion is small, can be kept low, while the length of the ventral SAP-free region FAc can be relatively short to facilitate accurate absorption of liquid in the ventral region FA, where the amount of excretion is large.

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 longitudinal direction L in the back region BA up to the rear portion, it is possible to more easily prevent the leakage of liquid that flows to the back side, even though the amount is small.

Next, a method for manufacturing the absorbent body 14 will be described.
First, the hot melt adhesive is applied onto the second substrate 46 sheet while moving the second substrate 46 sheet in the longitudinal direction L. Next, the 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 second substrate 46 sheet to which the hot melt adhesive has been applied. At that time, a small amount of the superabsorbent polymer migrates to the region (corresponding to the channel) between the end portions and the center portion. Next, the intermediate layer 43 sheet, both sides of which are coated with the hot melt adhesive, is laminated on top of the superabsorbent polymer on the second substrate 46 sheet.

Next, while moving the laminate in the longitudinal direction L, a superabsorbent polymer is sprayed from another superabsorbent polymer supplying device along the longitudinal direction L onto the central portion in the width direction W of the intermediate layer 43 sheet to which the hot melt adhesive has been applied. Next, the first substrate 44 sheet to which the hot melt adhesive has been applied is laminated on top of the superabsorbent polymer on the intermediate layer 43 sheet, with the hot melt adhesive on the superabsorbent polymer side. Then, both sides of the second substrate 46 sheet in the width direction W are folded back onto both sides of the first substrate 44 sheet in the width direction W to obtain a laminate. After that, the laminate is passed through a pair of press rolls, i.e., pressed, to adjust the thickness of the laminate to obtain the absorbent body 14.

Next, a method for producing a pants-type diaper using the absorbent body 14 will be described.
A liquid-permeable sheet 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 sheet 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 prevention walls 16 are attached to both sides in the width direction W of the laminate to obtain an absorbent main body 10. Thereafter, the absorbent main body 10 is attached onto a cover sheet 5 (including elastic members 6, 7, 8), and both ends 2a, 2a in the width direction W of the abdominal side portion 2 and both ends 3a, 3a in the width direction W of the dorsal side portion 3 are joined. In this manner, the pants-type diaper 1 is manufactured.

Absorbent articles containing the absorbent of the present disclosure are not particularly limited, and examples include disposable diapers, incontinence pads, disposable shorts, sanitary napkins, shorts-type sanitary napkins, panty liners, postpartum pads, breast milk pads, hemorrhoid pads, sweat pads, bedsore sheets (dressing sheets), pet diapers, pet sheets, etc.

In the absorbent body of the present disclosure, the intermediate layer contains fibers and has a low fiber density portion with a relatively low fiber density and a high fiber density portion with a relatively high fiber density. This allows the high fiber density portion of the intermediate layer to reach the first absorbent layer and draw in liquid that is accumulating around the first absorbent material.

The high fiber density portion has a fiber density that is preferably 1.2 times or more, more preferably 1.5 times or more, even more preferably 2.0 times or more, and even more preferably 3.0 times or more higher than that of the low fiber density portion. This is from the viewpoint of the above-mentioned effects. Also, the high fiber density portion has a fiber density that is preferably 50 times or less, more preferably 40 times or less, and even more preferably 30 times or less higher than that of the low fiber density portion. This is to prevent the wearer from feeling stiffness in the high fiber density portion.

When the high fiber density portion and the low fiber density portion have the same basis weight, the high fiber density portion has a height that is preferably 1/1.2 times (about 0.83 times) or less than the low fiber density portion, more preferably 1/1.5 times (about 0.67 times) or less, even more preferably 1/2.0 times (0.5 times) or less, and even more preferably 1/3.0 times or less than the low fiber density portion. This is from the viewpoint of the above-mentioned effect. Furthermore, the high fiber density portion has a thickness that is preferably 1/50 times (0.020 times) or more, more preferably 1/40 times (0.025 times) or more, and even more preferably 1/30 times (about 0.033 times) or more than the low fiber density portion. This is to prevent the wearer from feeling the high fiber density portion as stiff.

The thickness of the high fiber density portion and the low fiber density portion are measured using a three-dimensional measuring X-ray CT device (TDM-1000-IS/SP, manufactured by Yamato Scientific Co., Ltd.). Specifically, the thickness of the desired density portion (high fiber density portion or low fiber density portion) is measured at any 20 points from an image scanned using the three-dimensional measuring X-ray CT device, and then the thickness is determined by averaging.

The high fiber density portion preferably extends in a predetermined direction within the planar direction, and preferably extends in the longitudinal direction of the absorbent. This is because the liquid drawn in by the high fiber density portion of the intermediate layer can be diffused in a predetermined direction within the planar direction of the intermediate layer, particularly in the longitudinal direction, and the liquid diffused in the planar direction can then easily migrate in the thickness direction, i.e., to the second absorbent layer.

In the absorbent body of the present disclosure, the intermediate layer may have, in the planar direction, a low basis weight region with a relatively low basis weight and a high basis weight region with a relatively high basis weight. In that case, it is more preferable that the high fiber density portion is disposed in the high basis weight region. This is because the amount of fibers constituting the high fiber density portion is relatively large, and liquid that reaches the first absorbent layer and remains around the first water absorbent material can be drawn in by the high fiber density portion, and the liquid can then be drawn into the intermediate layer and temporarily stored.

In the absorbent body of the present disclosure, the intermediate layer is composed of an intermediate sheet folded in the thickness direction of the absorbent body at a predetermined folding axis, and the intermediate layer can be divided into an overlapping portion where the intermediate sheet overlaps in the thickness direction of the absorbent body and a non-overlapping portion where the intermediate sheet does not overlap in the thickness direction of the absorbent body. In that case, the high basis weight region can be composed of an overlapping portion or a non-overlapping portion, and is preferably composed of an overlapping portion. By the high basis weight region being composed of an overlapping portion, when the high fiber density portion of the intermediate layer draws in liquid, the overlapping portion constituting the high basis weight region can expand in the thickness direction with the folding axis as a base point, so that the high basis weight region (overlapping portion) of the intermediate layer can temporarily store more liquid.
From the viewpoint of allowing the overlapping portion to expand in the thickness direction, it is preferable that the portions of the intermediate sheet constituting the overlapping portion are not fixed to each other except in the high basis weight region.

In the absorbent body of the present disclosure, the intermediate layer (intermediate sheet) having a high fiber density portion and a low fiber density portion is not particularly limited, and any known material in the art can be used. For example, a nonwoven fabric having a high fiber density portion and a low fiber density portion can be manufactured according to the descriptions in JP-A-2008-138340, JP-A-2008-144322, JP-A-2008-264084, JP-A-2008-266813, etc.

The intermediate layer (intermediate sheet) having a high fiber density portion and a low fiber density portion may be a nonwoven fabric having convex portions (e.g., ridge portions) and concave portions (e.g., groove portions) with different basis weights, specifically, a nonwoven fabric having convex portions (e.g., ridge portions) constituting the high fiber density portion and concave portions (e.g., groove portions) constituting the low fiber density portion. Such a nonwoven fabric may be manufactured according to the description in JP-A-2008-002034, JP-A-2008-023311, etc.

Furthermore, an intermediate layer (intermediate sheet) having a high fiber density portion and a low fiber density portion can also be formed by gear drawing of a nonwoven fabric.
Furthermore, an intermediate layer (intermediate sheet) having a high fiber density portion and a low fiber density portion can also be formed by compressing a folded or unfolded intermediate sheet in the thickness direction, for example, by embossing (embossed portion).

In the absorbent body of the present disclosure, the fiber density in the thickness direction of the intermediate layer can be any, for example, the skin side can have a low fiber density and the clothing side can have a high fiber density, or the skin side and clothing side can have low fiber density and the interior can have a high fiber density.
In the absorbent body of the present disclosure, the intermediate layer has a skin side, and the fiber density inside the intermediate layer can be higher than the fiber density on the skin side, which makes it easier for liquid drawn in by the intermediate layer to migrate from the skin side to the interior of the intermediate layer and then to the clothing surface by capillary action, and ultimately makes it easier for liquid migrated to the clothing surface of the intermediate layer to migrate to the second absorbent layer.

In the absorbent body of the present disclosure, the intermediate layer may be composed of an intermediate sheet having a first side with a relatively low fiber density and a second side with a relatively high fiber density, and the intermediate sheet may be arranged so that the first side with a low fiber density faces the skin and the second side with a high fiber density faces the clothing. This makes it easier for liquid that reaches the intermediate layer to transfer to the second absorbent layer by capillary action.

In addition, in the absorbent body of the present disclosure, the intermediate layer can be configured as an intermediate sheet having a first surface with a relatively low fiber density and a second surface with a relatively high fiber density, folded at a predetermined folding axis with the second surface as the inner surface. This makes it easier for liquid that reaches the intermediate layer to transfer to the second absorbent layer by capillary action, and allows the intermediate sheet to retain the superabsorbent polymer of the first absorbent layer and the superabsorbent polymer of the second absorbent layer.

An example of an intermediate sheet having a first surface with a relatively low fiber density and a second surface with a relatively high fiber density is a nonwoven fabric manufactured on a net. For example, an air-through nonwoven fabric is made by placing a web on a net and fusing the constituent fibers to form a nonwoven fabric. At that time, the net surface that was in contact with the net has a relatively high fiber density and constitutes the second surface, and the non-net surface that was not in contact with the net has a relatively low fiber density and constitutes the first surface.

In the absorbent body of the present disclosure, the intermediate sheet constituting the intermediate layer can be folded toward the liquid-impermeable sheet side. This makes it difficult for a gap to form between the intermediate layer and the sheet member adjacent to the liquid-permeable sheet side of the intermediate layer, and makes it easier for the intermediate sheet to receive liquid that reaches the liquid-permeable sheet from the sheet member.

In the absorbent body of the present disclosure, each of the first and second absorbent layers includes a superabsorbent polymer. The superabsorbent polymer is not particularly limited and includes those known in the art, such as starch-based, cellulose-based, and synthetic polymer-based superabsorbent polymers. Examples of starch- or cellulose-based superabsorbent polymers include starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, and crosslinked products of sodium carboxymethyl cellulose. 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, cellulose-based, and other superabsorbent polymers (SAP, Super absorbent Polymers), with polyacrylate-based (particularly sodium polyacrylate-based) superabsorbent polymers being preferred.

In the absorbent body of the present disclosure, the first and second absorbent layers are not particularly limited as long as they are mainly made of a highly absorbent polymer, and may further contain hydrophilic fibers, for example, pulp fibers. The shape of the absorbent body in a plan view is not particularly limited, and examples include a rectangle with short sides protruding in an arc shape, a rectangle with rounded corners, an ellipse, and an hourglass. The thickness of the absorbent body is, for example, 0.5 to 20 mm, and preferably 1 to 10 mm.

The absorbent body of the present disclosure may include a channel. The channel may be disposed in the first absorbent layer and/or the second absorbent layer. This makes it easier to guide the absorbent body, and in turn the absorbent article, to deform when the absorbent article is worn. From this viewpoint, the channel preferably extends along the longitudinal direction, and more preferably, a pair of channels extend along the longitudinal direction with a longitudinal centerline therebetween.
Moreover, the above-mentioned channel (pair of channels) is preferably disposed in the second absorbent layer, from the viewpoint of ease of inducing deformation of the absorbent article.

The pair of channels may be arranged such that, in a plan view, the spacing between the pair of channels is constant along the longitudinal direction of the absorbent body, and the spacing between the pair of channels is narrow near the longitudinal center of the absorbent article and widens toward both outer sides in the longitudinal direction.

The channel (pair of channels) is disposed in the second absorbent layer, and the channel (pair of channels) can be disposed so as to overlap the high fiber density portion of the intermediate layer in the thickness direction of the absorbent. This allows the liquid drawn in by the high fiber density portion of the intermediate layer to be transferred to the channel of the second absorbent layer, and the liquid can be diffused through the channel into the second absorbent layer.

In the absorbent body of the present disclosure, the channel (pair of channels) refers to a region of the absorbent core having a smaller basis weight than the surrounding region of the absorbent layer in which the channel is disposed, i.e., the first absorbent layer and/or the second absorbent layer. The channel (pair of channels) has a basis weight of preferably 70% by mass or less, more preferably 50% by mass or less, and even more preferably 30% by mass or less, compared to the surrounding region of the absorbent layer in which the channel is disposed, i.e., the first absorbent layer and/or the second absorbent layer, and may have a basis weight of 0% by mass. This is from the viewpoint of using the channel as the starting point for change induction.

1. Pants-type diaper 2. Abdominal part (abdominal waist belt)
3 Back part (back waist belt)
4 crotch region 5, 5a, 5b cover sheet 10 absorbent body 12 liquid-permeable sheet 13 liquid-impermeable sheet 14 absorbent body 41 first absorbent layer 42 second absorbent layer 43 intermediate layer 43S intermediate sheet 43a first sheet portion 43b second sheet portion 43c embossed portion 44 first substrate 45 first water-absorbing material 46 second substrate 47 second water-absorbing material 48 channel 103, 104 folding axis L longitudinal direction W width direction T thickness direction CL longitudinal center line CW width direction center line LB low basis weight region HB high basis weight region OP overlapping portion NP non-overlapping portion HD high fiber density portion LD low fiber density portion

Claims (8)

An absorbent body for an absorbent article, comprising a first absorbent layer containing a superabsorbent polymer, a second absorbent layer containing a superabsorbent polymer, and an intermediate layer containing fibers disposed therebetween, the absorbent body having a thickness direction and a planar direction,
The intermediate layer has a low fiber density portion having a relatively low fiber density and a high fiber density portion having a relatively high fiber density,
The intermediate layer has a high basis weight region having a relatively high basis weight and a low basis weight region having a relatively low basis weight, and the high fiber density portion is disposed in the high basis weight region.
The absorbent body, The absorbent body according to claim 1, wherein the high fiber density portion extends in a predetermined direction within the planar direction. 2. The absorbent body of claim 1, wherein the intermediate layer is composed of an intermediate sheet folded in the thickness direction at a predetermined folding axis, the intermediate layer is partitioned into an overlapping portion where the intermediate sheet overlaps in the thickness direction and a non-overlapping portion where the intermediate sheet does not overlap in the thickness direction , and the high basis weight region is composed of the overlapping portion. The absorbent body according to claim 3 , wherein the high fiber density portion is an embossed portion that embosses the overlapping portion. The absorbent body according to any one of claims 1 to 4 , wherein the intermediate layer has a skin side, and the fiber density inside the intermediate layer is higher than the fiber density on the skin side. 6. The absorbent body according to claim 5, wherein the intermediate layer is an intermediate sheet having a first surface having a relatively low fiber density and a second surface having a relatively high fiber density, and is folded at a predetermined folding axis with the second surface as the inner surface. The absorbent body has a longitudinal direction and a width direction,
a second absorbent layer extending in the longitudinal direction and including a pair of channels spaced apart in the width direction across a longitudinal centerline of the absorbent body;
The high fiber density portion overlaps each of the pair of channels in the thickness direction.
The absorbent body according to any one of claims 1 to 6 . An absorbent article comprising a liquid-permeable sheet, a liquid-impermeable sheet, and an absorbent disposed therebetween,
The absorbent body is an absorbent body according to any one of claims 1 to 7 .
The absorbent article.

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