JP7312542B2 - absorbent article - Google Patents

Description

TECHNICAL FIELD The present invention relates to an absorbent article provided with a sweat-absorbing sheet having a sweat-absorbing function.

2. Description of the Related Art Absorbent articles such as disposable diapers are known which are provided with a top sheet arranged to be in contact with the wearer's skin, a back sheet arranged farther from the wearer's skin than the top sheet, and an absorbent body interposed between the two sheets, wherein the absorbent body comprises an absorbent core containing an absorbent material such as pulp, and a core wrap sheet covering the absorbent core. In the absorbent article having such a structure, a sweat-absorbent sheet containing a hydrophilic material capable of absorbing sweat is conventionally arranged at a portion that can come into contact with the wearer's skin when worn for the purpose of reducing skin troubles such as eczema.

Patent Document 1 describes that, in a pants-type disposable diaper, a hydrophilic web having long fibers, which is a highly absorbent material, is arranged as a sweat-absorbing sheet on the dorsal end flap extending outward from the edge of the absorbent body. The hydrophilic web is arranged so as to be able to come into contact with the wearer's skin, and the dorsal end flap is arranged farther from the wearer's skin than the hydrophilic web. The dorsal end flap is composed of two sheet materials, and elastic members extending in the lateral direction of the diaper are arranged between the two sheet materials in a stretched state at predetermined intervals in the longitudinal direction. According to Patent Document 1, since the sweat emitted from the wearer's waist is quickly absorbed and diffused by the hydrophilic web, the wearer's waist is kept in a low-humidity, dry state, and skin troubles are less likely to occur. The longitudinal direction is the direction corresponding to the front-rear direction of the wearer of the absorbent article, and the lateral direction is the direction orthogonal to the longitudinal direction.

Patent Literature 2 describes attaching a sweat-absorbing sheet to a hydrophobic sheet that covers the inner surface of the front and back waist regions of a disposable diaper. The hydrophobic sheet overlaps the surface sheet in the thickness direction at its inner end in the longitudinal direction, and the hydrophobic sheet is positioned closer to the wearer's skin than the surface sheet in the overlapping portion of the two sheets. The sweat-absorbing sheet entirely overlaps the hydrophobic sheet in the thickness direction and does not have a contact portion with the topsheet. The disposable diaper described in Patent Document 2 is configured so that even if the non-bonded region of the hydrophobic sheet is turned over while being worn, the sweat-absorbing sheet will not be turned over and its function as a sweat-absorbing sheet will not be impaired.

Patent Document 3 describes that a hydrophilic sheet functioning as a sweat-absorbing sheet is arranged on the waist flap, which is positioned outside the absorbent core in the longitudinal direction of the disposable diaper, and a waist elastic member is arranged on the waist flap in a laterally stretched state to form gathers. The hydrophilic sheet comprises an inner hydrophilic sheet, which is a so-called surface sheet, and an outer hydrophilic sheet disposed on the non-skin facing side of the inner hydrophilic sheet. According to the disposable diaper described in Patent Document 3, the waist flap of the diaper, which is likely to cause skin troubles, is formed with gathers by the waist elastic member. Therefore, due to the expansion and contraction of the gathers due to the movement of the wearer, sweat transferred to the inner hydrophilic sheet is easily transferred to the outer hydrophilic sheet. It is also described that by making the outer hydrophilic sheet higher in liquid diffusivity than the inner hydrophilic sheet, the perspiration transferred to the outer hydrophilic sheet can be quickly diffused.

JP 2006-141549 A JP 2007-259874 A JP 2010-246901 A

In an absorbent article provided with a sweat-absorbing sheet, a problem arises when the amount of sweat absorbed by the sweat-absorbing sheet reaches the sweat absorption capacity of the sweat-absorbing sheet. In that case, the sweat absorption sheet cannot absorb sweat and there is a wet sweat absorption sheet that has absorbed a large amount of sweat. As a countermeasure for this problem, it is conceivable to increase the thickness of the sweat-absorbent sheet to increase the absorption capacity. A technology capable of absorbing a large amount of sweat without deteriorating the wearing comfort of the absorbent article has not yet been provided.

Therefore, an object of the present invention is to provide an absorbent article that can quickly absorb a large amount of sweat, reduces the inconvenience of the absorbed body fluid returning to the wearer's skin side, and hardly causes skin troubles caused by the body fluid.

The present invention is an absorbent article having a vertical direction corresponding to the front-rear direction of the wearer and a horizontal direction orthogonal thereto, comprising a liquid-retaining absorbent core and a core wrap sheet in contact with the skin-facing surface of the absorbent core, wherein a top sheet and a sweat absorbent sheet are arranged on the skin facing side of the core wrap sheet in order of proximity to the core wrap sheet. The absorbent article has low liquid diffusibility and low liquid diffusivity compared to the core wrap sheet.

According to the present invention, an absorbent article is provided that can quickly absorb a large amount of sweat, reduces the inconvenience of the absorbed body fluid returning to the wearer's skin side, and hardly causes skin troubles caused by the body fluid.

FIG. 1 is a perspective view schematically showing an underpants-type disposable diaper, which is one embodiment of the absorbent article. FIG. 2 is a developed plan view schematically showing the skin-facing surface side (inner surface side) of the diaper shown in FIG. 1 in an unfolded and stretched state. FIG. 3 is a cross-sectional view schematically showing a section taken along line II in FIG. 2 (a section along the horizontal direction). FIG. 4 is a cross-sectional view schematically showing the II-II line cross section (cross section along the longitudinal direction) of FIG. 2, and is a longitudinal cross-sectional view schematically showing an enlarged one end portion of the diaper shown in FIG. FIG. 5 is a view equivalent to FIG. 4 of another embodiment of the absorbent article of the present invention. FIG. 6 is a view corresponding to FIG. 4 of still another embodiment of the absorbent article of the present invention. FIG. 7 is a view equivalent to FIG. 4 of still another embodiment of the absorbent article of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on its preferred embodiments with reference to the drawings. 1 to 4 show an underpants-type disposable diaper 1 that is one embodiment of the absorbent article of the present invention. As shown in FIGS. 1 to 4, the diaper 1 has a longitudinal direction X corresponding to the longitudinal direction of the wearer, that is, a direction extending from the abdomen to the dorsal side through the crotch, and a lateral direction Y perpendicular to the longitudinal direction. It is An absorbent body 23 is composed of the absorbent core 24 and a core wrap sheet 25 that is in contact with and wraps the outer surface of the absorbent core 24 .

As used herein, the term “skin-facing surface” refers to the surface of the absorbent article or its constituent members (e.g., topsheet) that faces the wearer’s skin when the absorbent article is worn, i.e., the side that is relatively close to the wearer’s skin. It should be noted that the term "when worn" as used herein means a state in which the absorbent article is maintained in a normal and appropriate wearing position, that is, in a correct wearing position of the absorbent article.

As shown in FIGS. 1 and 2, the diaper 1 has a crotch portion M, and an abdominal portion F and a back portion R extending in the longitudinal direction X from the front and rear of the crotch portion M. As shown in FIGS. The crotch part M is a part that is arranged between the crotch parts of the wearer when the diaper 1 is worn, the ventral part F is a part that is arranged on the abdomen side of the wearer, that is, the front side in the longitudinal direction X, rather than the crotch part M when the diaper 1 is worn, and the back part R is a part that is arranged on the back side of the wearer, that is, the back side in the longitudinal direction X, of the crotch part M when the diaper 1 is worn. The abdominal side portion F and the dorsal side portion R are waist-surrounding portions arranged around the wearer's waist when the diaper 1 is worn. In other words, the waist portion of the diaper 1 is divided into an abdominal portion F and a dorsal portion R. As shown in FIG.

The diaper 1 includes an absorbent main body 2 including an absorbent body 23 (absorbent core 24 and core wrap sheet 25) in the central portion in the lateral direction Y, and an exterior body 3 disposed on the non-skin-facing side of the absorbent body 2, i.e., on the side farther from the wearer's body than the absorbent body 2. Both side edges along the longitudinal direction X of the exterior body 3 in each of the ventral portion F and the dorsal portion R are joined to each other by a known joining means such as an adhesive, heat sealing, or ultrasonic sealing. 1, a pair of side seals S, S, a waist opening WH through which the wearer's torso is passed, and a pair of leg openings LH, LH through which the wearer's lower legs are passed are formed.

The absorbent main body 2 has a rectangular shape in plan view when the diaper 1 is in the unfolded and stretched state as shown in FIG. 2, and extends in the longitudinal direction X from the ventral side F to the back side R. The absorbent main body 2 is arranged in the center of the outer body 3 in the lateral direction Y with its longitudinal direction aligned with the longitudinal direction X of the diaper 1 in the unfolded and stretched state, and is joined to the outer body 3 with an adhesive. The "unfolded and stretched state" of the diaper 1 refers to a state in which the diaper 1 is separated at the side seal portions S to be in the unfolded state, and the elastic members of each portion of the diaper 1 in the unfolded state are stretched to reach design dimensions (the same dimensions as when the diaper 1 is flattened while completely eliminating the influence of the elastic members).

As shown in FIG. 3, the absorbent body 2 includes a liquid-permeable top sheet 21 forming a skin-facing surface, a liquid-impermeable or liquid-sparingly permeable or water-repellent back sheet 22 forming a non-skin facing surface, and a liquid-retaining absorbent body 23 interposed between the two sheets 21 and 22. These are integrated by a known bonding means such as an adhesive. The total length of the absorbent body 2 in the longitudinal direction X is the same as that of the absorbent body 23, and the longitudinal ends 23a, 23a are located at the same positions as the longitudinal ends of the absorbent body 2, as shown in FIG. As the top sheet 21 and the back sheet 22, various types of materials conventionally used for this type of absorbent article can be used without particular limitation. For example, various non-woven fabrics, perforated films, etc. can be used as the top sheet 21, and resin films, laminates of resin films and non-woven fabrics, etc. can be used as the back sheet 22. FIG.

The absorbent body 23 includes a liquid-retaining absorbent core 24 mainly made of an absorbent material, and a core wrap sheet 25 covering the outer surface of the absorbent core 24, that is, the skin-facing surface and the non-skin-facing surface. The absorbent core 24 has a rectangular shape elongated in the longitudinal direction X in plan view as shown in FIG. As the absorbent material that forms the main body of the absorbent core 24, any material that is used as a material for the absorbent body in this type of absorbent article can be used without particular limitation. A typical form of the absorbent core 24 is a fiber assembly of hydrophilic fibers such as wood pulp, or a fiber assembly holding particulate water-absorbent polymers.

In the diaper 1, the core wrap sheet 25 is a single continuous liquid-permeable sheet having a width two to three times the length of the absorbent core 24 in the lateral direction Y. As shown in FIG. It covers the entire surface. The absorbent core 24 and the core wrap sheet 25 may be joined by a known joining means such as a hot-melt adhesive. As the core wrap sheet 25, for example, liquid-permeable sheets such as paper, various nonwoven fabrics, and perforated films can be used.

In the present invention, the core wrap sheet does not have to be such a single sheet, and for example, it may include one skin-side core wrap sheet that covers the skin-facing surface of the absorbent core 24 and one non-skin-side core wrap sheet that is separate from the skin-side core wrap sheet and covers the non-skin-facing surface of the absorbent core 24.

As shown in FIGS. 2 and 3, a pair of leak-proof cuffs 26, 26 made of a liquid-resistant or water-repellent and breathable leak-proof cuff-forming sheet 27 is provided on both sides of the skin-facing surface of the absorbent body 2 along the longitudinal direction X. One or more string-like elastic members 28 for forming a leak-preventing cuff are arranged in the longitudinal direction X in a stretched state near the free end of each leak-preventing cuff 26 . The anti-leakage cuff 26 stands up at least at the crotch portion M by contraction of the elastic member 28 arranged in a stretched state when the diaper 1 is put on, thereby preventing excreted fluid such as urine from flowing out in the lateral direction Y. - 特許庁

The outer body 3 forms the outer shape of the diaper 1 in the unfolded and stretched state as shown in FIG. As shown in FIG. 2, the outer body 3 has a rectangular shape in which the ventral part F and the dorsal part R are longer in the lateral direction Y than the longitudinal direction X. In the crotch part M located between the ventral part F and the dorsal part R, both side edges along the longitudinal direction X of the outer body 3, that is, a pair of leg edges LS, LS are curved in a convex arc shape toward the center in the lateral direction Y. In a plan view as shown in FIG. It has an hourglass shape that constricts inward.

As shown in FIGS. 3 and 4, the outer body 3 includes a laminate of an outer layer sheet 31 that forms the outer surface, that is, the non-skin facing surface of the diaper 1 in the worn state, and an inner layer sheet 32 that is arranged to face the skin facing surface of the outer layer sheet 31. When the diaper 1 is worn, the outer layer sheet 31 is positioned farther from the wearer's body and forms the non-skin facing surface (outer surface) of the diaper 1, and the inner layer sheet 32 is positioned closer to the wearer's body and forms the skin facing surface (inner surface) of the diaper 1. The outer layer sheet 31 and the inner layer sheet 32 are joined to each other at a predetermined site through a joining means such as an adhesive.

In the diaper 1, as shown in FIGS. 2 and 4, the outer layer sheet 31 extends from the edge of the inner layer sheet 32 in the longitudinal direction X and is folded back toward the skin facing side of the inner layer sheet 32 at the ventral side F and the dorsal side R. The folded part 31E covers the longitudinal direction X end of the absorbent body 2. Although FIG. 4 shows an enlarged longitudinal end of the dorsal portion R and does not show an enlarged view of the ventral portion F, the ventral portion F is configured in the same manner as the dorsal portion R, and unless otherwise specified, the description of the dorsal portion R applies to the ventral portion F as appropriate.

The sheets 31 and 32 forming the exterior body 3 may be sheets of the same type or different types of sheets, and examples of the latter include forms having different stretchability. Specifically, for example, a stretchable sheet having stretchability in the lateral direction Y can be used as the outer layer sheet 31 , and a non-stretchable sheet having no stretchability can be used as the inner layer sheet 32 . Further, for example, the stretchability of the outer layer sheet 31 may be partially different. Specifically, the portions of the outer layer sheet 31 located on the ventral side F and the dorsal side R may be made of a stretchable sheet having stretchability in the lateral direction Y, and the portion of the outer layer sheet 31 located on the crotch portion M may be made of a non-stretchable sheet that does not have stretchability.

Examples of the stretchable sheet that can be used as the exterior body 3 include a stretchable sheet in which stretchable fiber layers are integrated on both or one side of an elastic fiber layer. Methods for integrating the elastic fiber layer and the stretchable fiber layer include, for example, a method of laminating and hydroentangling them, a method of entangling fibers by air-through or the like, and a method of bonding by heat embossing, an adhesive, ultrasonic waves, or the like. Non-stretchable sheets that can be used as the exterior body 3 include, for example, nonwoven fabrics produced by various methods, and specific examples include spunbond nonwoven fabrics, air-through nonwoven fabrics, and needle-punched nonwoven fabrics.

As shown in FIGS. 1, 2, and 4, a plurality of thread-like or band-like waist elastic members 33 are arranged in a stretched state in the horizontal direction Y in each of the ventral portion F and the dorsal portion R, and the plurality of waist elastic members 33 are intermittently arranged at predetermined intervals in the longitudinal direction X. Since the waist elastic member 33 is arranged in such a manner that its elastic stretchability is exhibited, an annular waist gather that is substantially continuous over the entire circumference is formed at the opening edge of the waist opening WH. In addition, one or a plurality of thread-like or belt-like leg elastic members 34 for forming leg gathers are arranged in a stretched state on the leg edge LS forming the opening edge of each of the pair of leg openings LH and LH, thereby forming an annular leg gather that is substantially continuous over the entire circumference of each of the opening edges of each of the pair of leg openings LH and LH. These elastic members 33 and 34 are sandwiched and fixed between the outer layer sheet 31 and the inner layer sheet 32 that constitute the exterior body 3 by a bonding means such as an adhesive.

As described above, in the diaper 1 , the outer body 3 is arranged farther from the skin of the wearer of the diaper 1 than the absorbent body 23 . In addition, the outer body 3 is elastic in the horizontal direction Y due to the presence of the waist elastic member 33 fixed in a stretched state in the horizontal direction Y, and is a stretchable sheet having elasticity in the same direction.

As used herein, the term "elasticity" means the property of being able to stretch in a given direction and shrinking when the stretch is released. The fact that the sheet does not substantially stretch in a certain direction (non-elasticity) means that the sheet hardly stretches even if a pulling force is applied to the sheet in the certain direction. For example, if a sample with a length of 15 cm and a width of 5 cm is pulled in the longitudinal direction with a material tensile tester such as Tensilon and the elongation at break is 10% or less, the sample has substantially no elasticity in the longitudinal direction. The elongation at break can be calculated by (length of the sample at break−original length of the sample)/(original length of the sample)×100.

The sweat-absorbent sheet 10 is intended to absorb sweat around the wearer's waist, and is arranged at a portion of the diaper 1 that can come into contact with the wearer's skin when the diaper 1 is worn. In the diaper 1, as shown in FIGS. 1, 2, and 4, a sweat-absorbent sheet 10, a top sheet 21, a core wrap sheet 25, and an absorbent core 24 are arranged in the order closest to the wearer's skin, and elastic members 33 are arranged in a stretched state in the lateral direction Y, respectively, on the abdominal side F and the back side R, which are the waist-surrounding parts that are arranged around the wearer's waist when worn. Although the stretchability of the elastic member 33 may be partially hindered in each of the ventral portion F and the dorsal portion R, the overall stretchability in the lateral direction Y is due to the provision of the elastic member 33.

In the diaper 1, the sweat-absorbing sheet 10 has a shape elongated in one direction, specifically a rectangular shape in a plan view as shown in FIG. The sweat-absorbent sheet 10 is arranged across both a core arrangement area where the absorbent core 24 (absorbent main body 2) is arranged and a core non-arranged area where the absorbent core 24 (absorbent main body 2) is not arranged in each of the abdominal part F and the back part R. The non-core regions in the ventral portion F and the dorsal portion R include both side edges along the longitudinal direction X of the absorbent core 24 (absorbent main body 2) and regions (side flap regions) positioned outward in the lateral direction Y from their imaginary extension lines (side flap regions), and longitudinal ends of the absorbent core 24 (absorbent main body 2) (longitudinal ends 23 a of the absorbent body 23) and regions positioned outward in the longitudinal direction X from their imaginary extension lines (end flap regions). In this way, the sweat absorbent sheet 10 is arranged so as to straddle both the core arrangement area and the core non-arrangement area in each of the ventral part F and the back part R, which is different from the surface sheet 21 which is arranged substantially only in the core arrangement area.

The sweat-absorbing sheet 10 is arranged in the vicinity of the opening edge of the waist opening WH along the skin-facing side of each of the abdominal part F and the back part R, and is arranged closest to the skin of the wearer of the diaper 1 in its arrangement position. The sweat-absorbent sheet 10 has a longitudinal outer edge 10a relatively close to the waist opening WH and a longitudinal inner edge 10b relatively distant from the waist opening WH. The outer longitudinal end 10a of the sweat absorbing sheet 10 is located outside the longitudinal end 23a of the absorbent body 23 in the longitudinal direction X, and the inner longitudinal end 10b of the sweat absorbing sheet 10 is located innerward in the longitudinal direction X than the longitudinal end 23a of the absorbent body 23. The longitudinal ends 23a of the absorbent body 23 are also longitudinal ends of the absorbent core 24 and the core wrap sheet 25, respectively.

The sweat absorbing sheet 10 is typically mainly made of nonwoven fabric. As the nonwoven fabric constituting the sweat-absorbent sheet 10, nonwoven fabrics produced by various manufacturing methods that can be used as a constituent member of this type of absorbent article can be used without particular limitation.

In the diaper 1, since the sweat-absorbing sheet 10 having a sweat-absorbing function is arranged at a portion (around the waist opening WH on the skin-facing surface) that can come into contact with the wearer's skin, skin troubles caused by sweat such as eczema, eczema, and rash are reduced. However, the sweat absorbing capacity of the sweat absorbing sheet 10 is finite, and after the amount of sweat absorbed by the sweat absorbing sheet 10 reaches its absorbing capacity, the sweat absorbing sheet 10 hardly absorbs sweat, and since the sweat absorbing sheet 10 in a wet state having absorbed a large amount of sweat comes into contact with the wearer's skin, continuing to wear the diaper 1 in that state may lead to skin troubles. As a solution to this problem, it is conceivable to increase the absorption capacity by increasing the thickness of the sweat absorbing sheet 10, but this method may lead to deterioration in wearing comfort of the diaper 1. FIG.

On the other hand, in the diaper 1, instead of increasing the absorption capacity of the sweat-absorbing sheet 10 itself, the sweat-absorbing sheet 10 and another member having a sweat-absorbing function are connected so that sweat can migrate between these members, thereby increasing the sweat absorption capacity of the diaper 1 as a whole. Specifically, as shown in FIG. 4, the end portion on the side of the inner end 10b in the vertical direction, which is a part of the sweat absorbent sheet 10, is arranged so as to face the top sheet 21 so as to be in contact with the top sheet 21, and the end portion functions as a conduction path for sweat from the sweat absorbent sheet 10 to the top sheet 21. With such a configuration, when the diaper 1 is worn, when the amount of sweat absorbed by the sweat-absorbing sheet 10 reaches the saturation of the sweat-absorbing capacity of the sweat-absorbing sheet 10, part of the sweat moves from the end of the sweat-absorbing sheet 10 on the side of the inner end 10b in the longitudinal direction to the topsheet 21, sequentially permeates the topsheet 21 and the core wrap sheet 25 located on the non-skin facing side in the thickness direction, reaches the absorbent core 24, and can be absorbed and held there. In this way, the diaper 1 utilizes not only the sweat-absorbing sheet 10, which is in direct contact with the wearer's skin, but also other members such as the absorbent core 24, as sweat-absorbing members. Therefore, it is difficult for the sweat-absorbing sheet 10 to saturate its absorption capacity while the diaper 1 is being worn, and sweat can be stably absorbed for a long period of time.

However, when a conductive path for perspiration is formed from the sweat-absorbing sheet 10 to the absorbent core 24, body fluids such as sweat and urine that are once absorbed and held in the absorbent core 24 flow back through the conductive path, migrate to the sweat-absorbent sheet 10 side, and spread, causing so-called liquid return. Therefore, in the diaper 1, a part of the sweat-absorbent sheet 10 (the end on the inner end 10b side in the longitudinal direction) is arranged so as to face the topsheet 21 so as to be in contact with the topsheet 21, and in addition, the liquid diffusibility of the members arranged closer to the wearer's skin than the absorbent core 24, specifically the sweat-absorbent sheet 10, the topsheet 21, and the core wrap sheet 25, has a specific size relationship. Specifically, the liquid diffusibility of the surface sheet 21 is lower than that of the sweat absorbent sheet 10 and lower than that of the core wrap sheet 25 . In this way, regarding the liquid diffusion of components that are closer to the skin of the wearer than the absorbent core 24, by forming a large and small relationship of "sweat -absorbing sheet 10> surface sheet 21" and "core lap sheet 25> surface sheet 21", the sweat from sweat absorption sheet 10 to the absorbent core 24, while shifting sweating from absorbent core 24. Since the spontaneous fluid flow in the surface sheet 21 does not occur, the transition of body fluids to the 10 side of the sweat absorbing sheet is effectively prevented. Liquid diffusibility is judged based on the liquid diffusion area measured by the following method. It is evaluated that the larger the liquid diffusion area is, the higher the liquid diffusibility is and the easier it is for the body fluid to spread.

<Method for measuring liquid diffusion area>
A 100 mm×100 mm square is cut from the object to be measured (the sweat absorbent sheet 10, the top sheet 21, and the core wrap sheet 25) to obtain a sample. A sample is placed on an acrylic plate, and 0.05 mL of colored water is dropped onto the sample from a position 30 mm above the sample. After 10 minutes have passed since the dropping, the area of the colored portion (the portion where the dropped water diffuses) in the sample is measured using an image analyzer.

The ratio of the liquid diffusion area of the sweat absorbent sheet 10 to the liquid diffusion area of the top sheet 21 is preferably 1.5 or more, more preferably 2.0 or more, and preferably 30 or less, more preferably 15 or less, assuming that the liquid diffusion area of the sweat absorbent sheet 10 (former) > the liquid diffusion area of the top sheet 21 (latter). The ratio of the liquid diffusion area of the core wrap sheet 25 to the liquid diffusion area of the top sheet 21 is preferably 2.0 or more, more preferably 2.5 or more, and preferably 40 or less, more preferably 35 or less, assuming that the liquid diffusion area of the core wrap sheet 25 (the former) > the liquid diffusion area of the top sheet 21 (the latter).

The liquid diffusion area of the sweat absorbent sheet 10 is preferably 100 mm ² or more, more preferably 150 mm ² or more, and preferably 1000 mm ² or less, more preferably 800 mm ² or less.
The liquid diffusion area of the core wrap sheet 25 is preferably 120 mm ² or more, more preferably 170 mm ² or more, and preferably 1000 mm ² or less, more preferably 800 mm ² or less.
The liquid diffusion area of the surface sheet 21 is preferably 10 mm ² or more, more preferably 20 mm ² or more, and preferably 100 mm ² or less, more preferably 200 mm ² or less, and even more preferably 300 mm ^{2 or} less.

Regarding the size relationship between the liquid diffusion area of the sweat absorbent sheet 10 and the liquid diffusion area of the core wrap sheet 25, it is preferable that the core wrap sheet 25 has a liquid diffusion area larger than that of the sweat absorbent sheet 10, from the viewpoint that sweat absorbed by the sweat absorbent sheet 10 can efficiently transfer to the core wrap sheet 25 via the top sheet 21.

The transfer of sweat from the sweat-absorbent sheet 10 to the topsheet 21 described above is possible as long as a portion of the sweat-absorbent sheet 10 (the end on the side of the longitudinally inner end 10b) is in contact with the topsheet 21 at least when the diaper 1 is worn, and the two sheets do not have to be in contact when the diaper 1 is not in use. This is because, as long as part of the sweat-absorbing sheet 10 and the surface sheet 21 are arranged opposite to each other without any other member interposed between the sheets, even if the sheets are not in contact with each other when the diaper 1 is not in use, the sheets are generally pressed together against the wearer's skin due to the contraction of the elastic member 33 around the waist when the diaper 1 is worn, thereby causing the sheets to come into contact with each other. However, from the viewpoint of ensuring that a portion of the sweat-absorbent sheet 10 and the topsheet 21 are in contact with each other when the diaper 1 is worn and allowing sweat to flow smoothly between the two sheets, it is preferable that the sweat-absorbent sheet 10 is joined to the topsheet 21 at a portion (the end on the side of the longitudinally inner end 10b) facing the topsheet 21 so as to be in contact with the topsheet 21, i.e., the overlapping portion between the sweat-absorbent sheet 10 and the topsheet 21 (the portion indicated by symbol A3 in FIG. 4). The means for joining the sweat-absorbing sheet 10 and the surface sheet 21 is not particularly limited, and known joining means such as adhesives and fusion bonding can be used.

Moreover, from the viewpoint of preventing the liquid from returning from the absorbent core 24 to the sweat absorbent sheet 10 side, it is preferable that the sweat absorbent sheet 10 and the surface sheet 21 are partially joined. That is, the sweat-absorbent sheet 10 is preferably partially joined to the topsheet 21 at the portion facing the topsheet 21 so as to be in contact therewith, that is, the overlapping portion of the sweat-absorbent sheet 10 and the topsheet 21 (the portion indicated by symbol A3 in FIG. 4). Since both sheets are partially joined, both the smooth transfer of sweat from the sweat-absorbent sheet 10 to the topsheet 21 and the prevention of liquid return are achieved at a high level. The pattern of the joining portion joining the two sheets can be appropriately set in consideration of the balance between the sweat absorption performance and the liquid backflow prevention performance.

From the viewpoint of ensuring the above effects, especially from the viewpoint of preventing liquid return, the ratio of the total area of the joints between the sheets 10 and 21 to the total area of the overlapping portions of the sweat absorbent sheet 10 and the top sheet 21 (joint area occupation ratio) is preferably 20% or less, more preferably 15% or less. The lower limit of the joint area occupation ratio is preferably 0.5% or more, more preferably 2% or more, particularly from the viewpoint of ensuring transfer of sweat from the sweat-absorbent sheet 10 to the topsheet 21 .

From the viewpoint of establishing the above-described liquid diffusion area size relationship in the sweat-absorbent sheet 10, the top sheet 21, and the core wrap sheet 25 and achieving both sweat absorption and liquid backflow prevention, the top sheet 21 preferably has a longer inter-fiber distance (lower fiber density) than the core wrap sheet 25. Thus, establishing a size relationship of "top sheet 21>core wrap sheet 25" with respect to the inter-fiber distance or a size relationship of "top sheet 21<core wrap sheet 25" with respect to fiber density is particularly effective in preventing liquid from returning from the absorbent core 24 to the sweat absorbent sheet 10 side.

From the same point of view, the surface sheet 21 preferably has a longer inter-fiber distance (lower fiber density) than the sweat-absorbing sheet 10 . By adopting such a configuration, the size relationship of "top sheet 21>sweat-absorbing sheet 10" is established with respect to the inter-fiber distance, or the size relationship of "top sheet 21<sweat-absorbing sheet 10" is established with respect to fiber density. The sweat more than the absorption capacity of is transferred to the topsheet 21, and the diaper 1 is endowed with the ability to continue to absorb sweat. The interfiber distance is measured by the following method.

<Method for measuring distance between fibers>
The inter-fiber distance of a fiber assembly such as non-woven fabric and paper is determined by the following formula (1) based on Wrotnowski's assumption. The following formula (1) is generally used when determining the inter-fiber distance of a fiber assembly. Under Wrotnowski's assumption, the fibers are cylindrical, and the individual fibers are regularly arranged without crossing each other.
When the sheets to be measured (the sweat-absorbing sheet 10, the top sheet 21, and the core wrap sheet 25) have a single-layer structure, the inter-fiber distance of the single-layer structure sheet is obtained by the following formula (1).
When the sheet to be measured (the sweat absorbing sheet 10, the top sheet 21, the core wrap sheet 25) has a multilayer structure such as an SMS nonwoven fabric, the inter-fiber distance of the multilayer sheet is obtained according to the following procedure.
First, the inter-fiber distance of each fiber layer constituting the multilayer structure is calculated by the following formula (1). At that time, the thickness t, basis weight W, fiber resin density ρ, and fiber diameter D used in the following formula (1) are those for the layer to be measured. The thickness t, basis weight W, and fiber diameter D are average values of measured values at a plurality of measurement points.
The thickness t (mm) is measured by the following method. First, a sheet to be measured is cut into a size of 50 mm in the longitudinal direction and 50 mm in the width direction to prepare a cut piece of the sheet. However, if a cut piece of this size cannot be produced as a sheet to be measured, such as when a sheet is collected from a small absorbent article, a cut piece as large as possible is produced. Next, this cut piece is placed on a flat plate, a glass plate on the flat plate is placed on it, a weight is evenly placed on the glass plate so that the load including the glass plate is 49 Pa, and the thickness of the cut piece is measured. The measurement environment is a temperature of 20±2° C. and a relative humidity of 65±5%, and a microscope (manufactured by Keyence Corporation, VHX-1000) is used as the measuring instrument. To measure the thickness of the cut piece, first, an enlarged photograph of the cut surface of the cut piece is obtained. In this magnified photograph, an object of known dimensions is photographed at the same time. Next, the scale is adjusted to the enlarged photograph of the cut surface of the cut piece, and the thickness of the cut piece, that is, the thickness of the sheet to be measured is measured. The above operation is performed three times, and the average value of the three times is taken as the thickness t of the sheet to be measured. When the sheet to be measured is a laminated product, the boundary is determined from the difference in fiber diameter and/or fiber density, and the thickness is calculated.
The grammage W (g/m ² ) is obtained by cutting the sheet to be measured into a predetermined size (for example, 12 cm × 6 cm), measuring the mass, and then dividing the measured mass by the area determined from the predetermined size (“grammage W (g/m ² ) = mass ÷ area determined from the predetermined size”). It measures 4 times and let the average value be a basis weight.
The resin density ρ (g/cm ² ) of the fiber is measured using a density gradient tube according to the density gradient tube method described in JIS L1015 Chemical Fiber Staple Test Method (URL is http://kikakurui.com/l/L1015-2010-01.html, JIS Handbook Textile-2000 for books, P.764- of (Japanese Standards Association) 765).
The fiber diameter D (μm) is obtained by measuring 10 fiber cross sections of cut fibers using an S-4000 field emission scanning electron microscope manufactured by Hitachi, Ltd., and taking the average value as the fiber diameter. The method for measuring the fiber diameter D follows <Method for measuring fiber diameter> described later.
Next, the inter-fiber distance of each layer is multiplied by the ratio of the thickness of the layer to the total thickness of the multilayer structure, and the obtained numerical values for each layer are totaled to obtain the inter-fiber distance of the constituent fibers of the desired multilayer structure sheet. For example, in an SMS nonwoven fabric having a three-layer structure consisting of two S layers and one M layer, the two S layers are collectively treated as one layer. is 43.8 μm [=(47.9×0.1+3.2×0.01)/0.11].

<Method for measuring fiber diameter>
The object to be measured (sweat absorbent sheet 10, top sheet 21, core wrap sheet 25) is cut with a razor (for example, a single-edged blade manufactured by Feather Safety Shave Co., Ltd.) to obtain a square (8 mm x 4 mm) measurement piece in plan view. When cutting the object to be measured, care must be taken so that the structure of the cut surface of the piece to be measured formed by the cutting is not destroyed by pressure or the like during cutting. As a preferred method for cutting the object to be measured, prior to cutting the object to be measured, the object to be measured is immersed in liquid nitrogen and sufficiently frozen, and then cut. Using a double-sided paper tape (Nichiban Co., Ltd., Nicetac NW-15), the measurement piece is attached to the sample stage. The measuring piece is then platinum coated. For the coating, an ion sputtering apparatus E-1030 (trade name) manufactured by Hitachi Naka Seiki Co., Ltd. is used, and the sputtering time is 30 seconds. A cut surface of the measurement piece is observed at a magnification of 1000 using a S-4000 field emission scanning electron microscope manufactured by Hitachi, Ltd. For example, when the object to be measured is a laminated nonwoven fabric, the boundary between each layer of the laminated nonwoven fabric is determined from the difference in fiber diameter and / or fiber density from the electron microscope image, and for each fiber in each layer, the width direction of the fiber with respect to the longitudinal direction of the fiber is measured.

As described above, the ratio of the inter-fiber distance of the top sheet 21 to the inter-fiber distance of the core wrap sheet 25 is preferably 1.5 or more, more preferably 2.0 or more, and preferably 10 or less, more preferably 8 or less, assuming that the inter-fiber distance of the top sheet 21 (former) > the inter-fiber distance of the core wrap sheet 25 (latter).
As described above, the ratio of the inter-fiber distance of the surface sheet 21 to the inter-fiber distance of the sweat absorbent sheet 10 is preferably 1.5 or more, more preferably 2.0 or more, and preferably 10 or less, more preferably 8 or less, assuming that the former > the latter.

The surface sheet 21 preferably has higher liquid permeability than the sweat absorbent sheet 10 . More specifically, the surface sheet 21 preferably has a shorter liquid permeation time (strike-through time measured according to the “153.0-02 REPEATED Liquid Strike-Through Time” method) measured by the following method than the sweat-absorbent sheet 10. With such a configuration, it is possible to more reliably achieve both sweat absorption and liquid backflow prevention. The liquid permeability (liquid permeation time) of a fiber sheet (nonwoven fabric) such as the surface sheet 21 and the sweat absorbent sheet 10 is closely related to the inter-fiber distance, and thus can be adjusted by the inter-fiber distance. The distance between fibers is as described above. As described above, in order to establish the size relationship of "top sheet 21>core wrap sheet 25" with respect to liquid permeability, that is, to establish the size relationship of "top sheet 21<core wrap sheet 25" with respect to the liquid permeation time, the inter-fiber distance of the top sheet 21 should be longer than that of the core wrap sheet 25.

<Method for measuring liquid passage time (strike-through time)>
A strike-through time measurement device Lister manufactured by Lenzing Technik is used, and measurement is performed according to the "153.0-02 REPEATED Liquid Strike-Through Time" method of EDANA (European Nonwovens Association). The liquid permeation time (strike-through time) indicates the time (seconds) required for a predetermined amount of the test liquid to pass from one side of the sheet to be measured (for example, the top sheet 21) to the other side, and the shorter the liquid permeation time, the better the liquid permeability can be evaluated. Specifically, one sheet of "Kimtowel White 4-Fold" (manufactured by Nippon Paper Crecia) is placed in a folded state on the pedestal of the tester, and the sheet to be measured is placed thereon. Next, a strike-through plate having electrodes is placed on the sheet to be measured, 5 ml of the test solution (physiological saline) is introduced from the liquid inlet connected to the strike-through plate, and then the power of the tester is turned on. The tester measures the time (seconds) from when the test liquid is in contact with the electrode until the test liquid passes through the sheet to be measured, the water level drops, and the electrode is no longer in contact with the electrode. The measurement is performed three times, and the average value is taken as the liquid permeation time of the sheet to be measured.

The ratio of the liquid permeation time (strike-through time) of the surface sheet 21 to that of the sweat absorbent sheet 10 is preferably 0.2 or more, more preferably 0.5 or more, and preferably 0.9 or less, more preferably 0.8 or less, assuming that the former < the latter.
The liquid permeation time (strike-through time) of the surface sheet 21 is preferably 1.5 seconds or longer, more preferably 2.0 seconds or longer, and preferably 7 seconds or shorter, more preferably 5 seconds or shorter.
The permeation time (strikethrough time) of the sweat absorbent sheet 10 is preferably 2 seconds or longer, more preferably 3 seconds or longer, and preferably 10 seconds or shorter, more preferably 8 seconds or shorter.

The sweat-absorbent sheet 10 preferably has a lower hydrophilicity on the skin-facing side than on the non-skin-facing side. Since the sweat-absorbing sheet 10 has such a hydrophilicity gradient in the thickness direction, it is particularly possible to effectively prevent liquid from returning from the absorbent core 24 to the sweat-absorbing sheet 10 side. In addition, even if the skin-facing surface of the sweat-absorbing sheet 10, which directly contacts the wearer's skin of the diaper 1 and absorbs sweat, has relatively low hydrophilicity, the sweat-absorbing sheet 10 can also be excellent in sweat-absorbing properties by appropriately controlling the absolute hydrophilicity of the skin-facing surface, the layer structure of the sweat-absorbing sheet 10, and the like.

As an indicator of the hydrophilicity of the surface (skin-facing surface, non-skin-facing surface) of the sweat absorbent sheet 10, a contact angle with water measured by the following method can be used. It can be judged that the smaller the contact angle with water measured by the following method, the higher the hydrophilicity (lower hydrophobicity), and the larger the contact angle, the lower the hydrophilicity (higher hydrophobicity).

<Method for measuring contact angle of fiber layer (nonwoven fabric)>
From the fiber layer (non-woven fabric) to be measured, a square shape in plan view of 150 mm in the MD direction and 70 mm in the CD direction is cut out as a measurement sample, and a droplet of ion-exchanged water is attached to the surface of the measurement sample whose contact angle is to be measured. The droplet is recorded, and the contact angle is measured based on the recorded image. More specifically, a microscope VHX-1000 manufactured by KEYENCE CORPORATION is used as a measuring device, and a medium-magnification zoom lens is attached to the microscope in a state tilted at 90°. The measurement sample is set on the measurement stage of the measurement apparatus so that the surface to be measured faces upward and can be observed from the CD direction of the measurement sample. Then, a droplet of 3 μL of ion-exchanged water is attached to the surface to be measured of the measurement sample set on the measurement stage, and the image of the droplet is recorded and taken into the measuring device. Among the plurality of recorded images, select 10 images in which both ends or one end of the droplet in the CD direction is clear, measure the contact angle of the droplet for each of the 10 images, and take the average value of these contact angles as the contact angle of the fiber layer (nonwoven fabric) to be measured. The measurement environment is 20° C./50% RH.

The contact angle of the surface facing the skin of the sweat absorbent sheet 10 is preferably 90 degrees or more, more preferably 100 degrees or more, and preferably 150 degrees or less, more preferably 140 degrees or less.
The contact angle of the non-skin facing surface of the sweat absorbent sheet 10 is preferably 15 degrees or more, more preferably 20 degrees or more, and preferably 88 degrees or less, more preferably 85 degrees or less.

There is no particular limitation on the form of the sweat-absorbing sheet having the magnitude relationship of "skin-facing surface<non-skin-facing surface" with respect to hydrophilicity, and a single-layer structure may be employed. A preferred embodiment of such a sweat-absorbent sheet is "a laminated nonwoven fabric having a laminated structure including a first layer forming a skin-facing surface and a second layer forming a non-skin-facing surface, wherein the first layer has a lower hydrophilicity than the second layer".

In the laminated nonwoven fabric, one or more other layers may be interposed between the first layer and the second layer in the laminated structure. In addition, it is preferable that the plurality of layers forming the laminated structure are joined together to be integrated, and the joint portion is preferably an interlayer fused portion in which the layers forming the laminated structure are fused to each other and the thickness is smaller than that of the peripheral portion. Such an interlayer fused portion can be formed by subjecting the laminated structure to a pressing process accompanied by a melting promoting means such as heat or ultrasonic waves for promoting melting of the constituent fibers (thermoplastic fibers), specifically, for example, heat sealing, ultrasonic sealing, or the like. Further, it is preferable that a plurality of the interlayer fused parts are scattered on the skin-facing surface and/or the non-skin-facing surface of the laminated nonwoven fabric. The interlayer fused part may be recessed from the skin-facing surface side to the non-skin-facing surface side, or conversely, may be recessed from the non-skin-facing surface side to the skin-facing surface side, but the former is preferred.

As the fiber (the fiber content preferably accounts for 70% by mass or more of the total constituent fibers of the first layer) forming the main body of the first layer (the layer forming the skin-facing surface) of the laminated nonwoven fabric, for example, hydrophobic thermoplastic fibers (heat-fusible fibers) can be used. Examples of materials for the hydrophobic thermoplastic fibers include hydrophobic thermoplastic resins such as polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate; polyamides such as nylon 6 and nylon 66;

In addition, hydrophilic thermoplastic fibers (heat-fusible fibers) can be used as the main fibers of the second layer (the layer forming the non-skin facing surface) of the laminated nonwoven fabric (preferably 70% by mass or more of the total fibers constituting the second layer). The seeds can be used singly or in combination of two or more. Examples of the latter "hydrophilized thermoplastic fibers" include thermoplastic fibers kneaded with a hydrophilizing agent, thermoplastic fibers having a hydrophilizing agent attached to the surface, and plasma-treated thermoplastic fibers. The hydrophilizing agent is not particularly limited as long as it is a general hydrophilizing agent used for sanitary products. In addition, naturally hydrophilic fibers such as cellulose fibers and other natural or semi-natural fibers can also be used.

The first layer and the second layer constituting the laminated nonwoven fabric may each be a short-fiber nonwoven fabric mainly composed of short fibers, or a long-fiber nonwoven fabric mainly composed of long fibers. Examples of short-fiber nonwoven fabrics include air-through nonwoven fabrics, spunlaced nonwoven fabrics, needle-punched nonwoven fabrics, and chemical-bonded nonwoven fabrics. Examples of long-fiber nonwoven fabrics include single-layer nonwoven fabrics such as spunbond nonwoven fabrics and meltblown nonwoven fabrics, laminated nonwoven fabrics obtained by laminating a spunbond layer mainly composed of long fibers, meltblown layers, etc., heat-rolled nonwoven fabrics obtained by carding, etc. Examples of the laminated nonwoven fabrics include spunbond-spunbond laminated nonwoven fabrics (SS nonwoven fabrics), spunbond-spunbond-spunbond laminated nonwoven fabrics (SSS nonwoven fabrics), spunbond-meltblown-spunbond laminated nonwoven fabrics (SMS nonwoven fabrics), and spunbond-meltblown-melt fabrics. A lawn-spunbond nonwoven fabric (SMMS nonwoven fabric) and the like can be mentioned.

The basis weight of the first layer (layer forming the skin-facing surface) constituting the laminated nonwoven fabric is preferably 8 g/m ² or more, more preferably 10 g/m ² or more, and preferably 30 g/m ² or less, more preferably 25 g/m ² or less.
The basis weight of the second layer (layer forming the non-skin facing surface) constituting the laminated nonwoven fabric is preferably 10 g/m ² or more, more preferably 13 g/m ² or more, and preferably 40 g/m ² or less, more preferably 35 g/m ² or less.

Moreover, as shown in FIGS. 3 and 4, it is preferable that the surface sheet 21 has an uneven shape on the side facing the skin, and the sweat absorbent sheet 10 can be contacted by the convex portions of the uneven shape. Further, the projections of the surface sheet 21 and the sweat-absorbing sheet 10 should not only be in contact with each other, but should also be joined together. This is because the sweat-absorbing sheet 10 is joined to the convex portions of the top sheet 21 at the portion (end portion on the side of the inner end 10b in the longitudinal direction) that is arranged to face the top sheet 21 so as to be in contact therewith, so that the two sheets are partially joined together, and both the smooth transfer of sweat from the sweat-absorbing sheet 10 to the top sheet 21 and the prevention of liquid returning from the absorbent core 24 to the sweat-absorbing sheet 10 side are achieved at a high level. Another advantage of the skin-facing surface of the topsheet 21 being uneven is that the contact area between the wearer's skin of the diaper 1 and the topsheet 21 is reduced compared to when the skin-facing surface is substantially flat without unevenness, which leads to a reduction in skin troubles.

The uneven shape of the surface facing the skin of the topsheet 21 is not particularly limited, and the uneven shape of the topsheet in this type of absorbent article can be appropriately adopted. As an example of the uneven shape, there is a form in which a plurality of protrusions are arranged in a scattered pattern over the entire skin-facing surface of the topsheet, and recesses are provided around each protrusion. The shape of the convex portion in plan view is not particularly limited, and may be appropriately selected from a circle, an ellipse, a polygon having a quadrangle or more, and the like. Specifically, for example, on the skin-facing surface of the topsheet 21, there are arranged planar line-of-sight first recesses extending in a first direction that intersects both the longitudinal direction X and the lateral direction Y, and planar line-of-sight second recesses extending in a second direction that intersects with the first direction in a grid pattern, and a convex portion is present in each of a plurality of sections surrounded by both recesses. Another example of the uneven shape is a form in which convex portions as ridges extending in the vertical direction X or the horizontal direction Y and concave portions as grooves extending in the same direction are alternately arranged in a direction orthogonal to their extending direction. Moreover, the convex portions (ridge portions) forming the uneven shape may have a solid structure in which fibers forming the surface sheet are filled therein, or may have a hollow structure. An example of a surface sheet having a hollow convex structure is a form in which two sheets are partially joined in a laminated state, and one sheet relatively close to the wearer's skin protrudes away from the other sheet (a sheet relatively far from the wearer's skin) at a portion other than the joined portion, forming a plurality of protrusions protruding toward the wearer's skin side. As shown in FIGS. 3 and 4, the non-skin-facing surface of the topsheet 21 (the surface facing the core wrap sheet 25) is generally a flat surface that does not substantially have irregularities.

As the surface sheet 21, a liquid-permeable sheet material conventionally used in this type of absorbent article can be used. Examples thereof include various nonwoven fabrics such as nonwoven fabrics manufactured by carding, air-through nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlace nonwoven fabrics, and needle-punched nonwoven fabrics; These nonwoven fabrics and films may be subjected to hydrophilization treatment using hydrophilizing agents such as surfactants. The basis weight of the top sheet 21 is preferably 12 g/m ² or more, more preferably 15 g/m ² or more, and preferably 50 g/m ² or less, more preferably 45 g/m ² or less.

A preferred example of the surface sheet 21 is a bulky nonwoven fabric. A bulky nonwoven fabric has a large number of spaces defined by the constituent fibers of the nonwoven fabric (portions in which nonwoven fabric components such as fibers do not exist), and the ratio of the space to the total volume of the nonwoven fabric (space occupation ratio) is large. By using the bulky nonwoven fabric having such characteristics as the surface sheet 21, the return of liquid from the absorbent core 24 to the sweat absorbent sheet 10 side is effectively prevented. As the bulky nonwoven fabric, for example, an air-through nonwoven fabric, an air-laid nonwoven fabric, a resin-bonded nonwoven fabric, or the like can be suitably used.

The bulky nonwoven fabric has an apparent density of preferably 0.01 g/cm ³ or more, more preferably 0.02 g/cm ³ or more, and preferably 0.30 g/cm ³ or less, more preferably 0.20 g/cm ^{3 or} less, from the viewpoint of ensuring the effects described above.
From the same point of view, the basis weight of the bulky nonwoven fabric is preferably 15 g/m ² or more, more preferably 20 g/m ² or more, and preferably 50 g/m ² or less, more preferably 40 g/m ² or less.

In addition, from the viewpoint of more reliably preventing the liquid from returning from the absorbent core 24 to the sweat-absorbent sheet 10 side, the fiber orientation of the constituent fibers of the sweat-absorbent sheet 10 and the fiber orientation of the constituent fibers of the surface sheet 21 preferably intersect each other. Specifically, for example, a configuration in which the constituent fibers of the sweat absorbent sheet 10 are oriented in the horizontal direction Y and the constituent fibers of the surface sheet 21 are oriented in the longitudinal direction X can be mentioned. Alternatively, conversely, the fibers forming the sweat absorbent sheet 10 may be oriented in the vertical direction X, and the fibers forming the surface sheet 21 may be oriented in the horizontal direction Y. The term "oriented in the longitudinal direction (lateral direction)" as used herein means that the angle between the longitudinal direction of the constituent fibers of the sheet and the longitudinal direction (lateral direction) of the absorbent article is 45 degrees or less.

As described above, in the diaper 1, the sweat-absorbing sheet 10, the surface sheet 21, the core wrap sheet 25, and the absorbent core 24 are arranged in the abdomen portion F and the back portion R, which are the waist portions arranged around the wearer's waist when worn, and the waist elastic member 33 is arranged in a state of being stretched in the lateral direction Y, and each of the ventral portion F and the back portion R as a whole has elasticity in the lateral direction Y. Therefore, the stretching stress in the lateral direction Y, which is closely related to this stretchability, is devised. By doing so, it is possible to improve the sweat absorption of the diaper 1 .

Specifically, as shown in FIG. 4, the sweat absorbent sheet 10 has longitudinally outwardly extending portions 10S extending outward in the longitudinal direction X from the longitudinal ends 21a of the top sheet 21 in the waist portion (abdominal portion F, dorsal portion R) as shown in FIG. When a region located at the same position as 10S in the longitudinal direction X (in the illustrated embodiment, coincides with the arrangement region of the longitudinally outwardly extending portion 10S) is defined as region B, in the diaper 1, the region A has a larger tensile stress in the lateral direction than the region B. The stretching stress in the lateral direction Y correlates with the degree of tightness of the diaper 1 to the wearer, and the greater the stretching stress in the lateral direction Y, the stronger the tightness. Therefore, in the diaper 1, in which the interrelationship between the stretching stresses in the transverse direction Y is area A>area B as described above, the area A including the overlapping area A1 (the hatched area in FIG. 2), in which the sweat-absorbing sheet 10 and the topsheet 21 overlap in the thickness direction (overlapping area), is more tightly tightened to the wearer than the area B not including the overlapping area A1. Extension stress is measured by the following method.

<Method for measuring elongation stress>
The diaper 1 is unfolded into a flat shape, and the regions A and B are cut out along straight lines parallel to the lateral direction Y of the diaper 1 to obtain measurement samples. In this cutting, not only the outer body 3 but also the entire diaper 1 including the absorbent main body 2 and the like are cut. Both ends of the measurement sample in the longitudinal direction (lateral direction Y) (immediately inside the side seal portion S) are sandwiched between chucks of a Tensilon universal tester (RTC-1210A) manufactured by ORIENTEC Co., Ltd. The measurement sample is stretched in the longitudinal direction at a speed of 300 mm / min, and the stress of the measurement sample at that time is measured. Specifically, when the inner dimension of the exterior body 3 (the length between the pair of side seal portions S and S when the sheets 31 and 32 of the exterior body 3 are not contracted by the elastic member 33) is 100 (for example, 350 mm), the tensile load (cN) when the measurement sample is elongated to a length equivalent to 80 (for example, 280 mm) and then contracted to a length equivalent to 71 (for example, 250 mm) is taken as the stress of the measurement sample. The stress of the measurement sample, that is, the stress of each of the regions A and B is calculated as an average stress by converting per length in the longitudinal direction (horizontal direction Y) of each region.
The reason why the stress of the measurement sample (regions A and B) is defined as the return force at the length corresponding to 71 when the inner dimension of the outer package is 100 is that the length of the abdominal circumference of a main infant who wears a pants diaper such as the diaper 1 is about 71% of the inner dimension of the diaper. The length of the abdominal circumference referred to here is the average value of the abdominal circumference measured in the standing and sitting positions, taking into account changes in the circumference of the abdomen when the infant's posture changes.

As described above, in the waist portion (abdominal portion F, dorsal portion R) of the diaper 1, the mutual relationship of stretching stress in the lateral direction Y is region A>region B. This increases the adhesion of the layered body (overlapping region A1) of the sweat absorbent sheet 10 and the topsheet 21 in the region A to the wearer's skin of the diaper 1, so that the sweat absorption by the sweat absorbent sheet 10 and the transfer of sweat from the sweat absorbent sheet 10 to the top sheet 21 are performed more smoothly. The sweat absorption of 1 is improved. In this way, by increasing the tensile stress of the entire torso portion without partially varying the elongation stress of the torso portion, the sweat absorption of the diaper 1 can be expected to be improved. In this regard, in the diaper 1, since the extensional stress is selectively increased in the portion (the overlapping region) that particularly affects the improvement of sweat absorption, skin troubles caused by such tightening are less likely to occur. In addition, the area A has a high cushioning property because it includes a laminated structure of a plurality of layers including the sweat absorbing sheet 10 and the surface sheet 21, so that even if the tightening of the area A is somewhat increased, the skin is less likely to be marked.

The ratio of the tensile stress in the lateral direction Y of the region A to the tensile stress in the lateral direction Y of the region B is preferably 1.05 or more, more preferably 1.1 or more, and preferably 2.5 or less, more preferably 2.0 or less, as region A/region B, on the premise that region A>region B.
The tensile stress in the transverse direction Y of the region A is preferably 0.04 N/mm or more, more preferably 0.05 N/mm or more, and preferably 0.12 N/mm or less, more preferably 0.10 N/mm or less.
The tensile stress in the transverse direction Y of the region B is preferably 0.02 N/mm or more, more preferably 0.04 N/mm or more, and preferably 0.10 N/mm or less, more preferably 0.08 N/mm or less.

The tensile stress (elasticity) in the lateral direction Y of the region A (the overlapping region A1 and the regions A2 and A3 described later) and the region B can be adjusted by appropriately adjusting the number of the waist elastic members 33 arranged in the region A and the region B and in the vicinity thereof, the thickness of the elastic members 33, the distance between the elastic members 33, and the types (stretchability) of the sheet-like members to which the elastic members 33 are fixed, that is, the outer layer sheet 31 and the inner layer sheet 32.

In the diaper 1, as shown in FIG. 2, the waist portion is divided into an abdominal portion F and a dorsal portion R, and the surface sheet 21 (absorbent main body 2) is arranged in the lateral direction Y central portion of the region A of each of the abdominal portion F and the dorsal portion R (region where the sweat absorbing sheet 10 and the top sheet 21 are at the same position in the longitudinal direction X). The central portion in the lateral direction Y is an overlapping region A1 where the sweat absorbent sheet 10 and the surface sheet 21 are overlapped in the thickness direction, and this overlapping region A1 has lower stretchability in the lateral direction Y than both sides in the lateral direction Y (both sides in the lateral direction of the region A). Both sides of the region A in the lateral direction Y are regions in which the sweat absorbent sheet 10 extends outward in the lateral direction Y from both side edges along the longitudinal direction X of the surface sheet 21 (absorbent main body 2), and are non-overlapping regions in which the sweat absorbent sheet 10 exists without overlapping the surface sheet 21 in the thickness direction. In this way, the mutual relationship of stretchability in the lateral direction Y in the region A of each of the ventral portion F and the dorsal portion R is "lateral direction center portion (overlapping region A1)<lateral direction side portions (said non-overlapping portions)". In particular, if the mutual relationship between the stretching stresses in the transverse direction Y in the waist portion (abdominal portion F, dorsal portion R) satisfies Region A>Region B as described above, the sweat absorption of the diaper 1 is further improved in combination with the effect of such mutual relation.

The central portion (overlapping area A1) in the horizontal direction Y of the area A is an area where a plurality of members such as the absorbent core 24 having a relatively large thickness overlap in addition to the sweat-absorbent sheet 10 and the topsheet 21, and is stiffer than both side portions (the non-overlapping portions) in the horizontal direction Y. If the stretchability in the horizontal direction Y of such a highly rigid overlapping area A1 is equal to that of the peripheral portion, wrinkles extending in the vertical direction X in the sweat-absorbing sheet 10 forming the skin-facing surface of the overlapping area A1. When the sweat-absorbent sheet 10 with such vertical wrinkles comes into contact with the skin of the wearer of the diaper 1, a gap is generated between the two, and the adhesion of the sweat-absorbent sheet 10 to the skin may be lowered. Therefore, in the diaper 1, as described above, the mutual relationship of stretchability in the lateral direction Y in the regions A of the ventral portion F and the dorsal portion R is such that the lateral center portion (overlapping region A1) < the lateral direction both sides (the non-overlapping portions), thereby suppressing the occurrence of vertical wrinkles on the skin-facing surface of the sweat-absorbing sheet 10 in the overlapping region A1, thereby increasing the adhesion of the sweat-absorbing sheet 10 to the skin and improving the sweat absorption of the diaper 1.

Regarding the stretchability in the horizontal direction Y in the region A, as a method of establishing the size relationship of "horizontal direction central portion (overlapping region A1)<horizontal direction both side portions (said non-overlapping portions)", there is a method of intentionally reducing the stretchability in the horizontal direction Y of the overlapping region A1. The overlapping region A1 subjected to such stretch inhibition treatment may have no stretchability in the lateral direction Y, or may have some stretchability in the lateral direction Y due to the stretchability remaining in the waist elastic member 33 subjected to the stretch inhibition treatment.

In the diaper 1, as shown in FIGS. 2 and 4, the hydrophobic sheet 11 is interposed between the sheets 10 and 21 in the overlap region A1 where the sweat absorbent sheet 10 and the topsheet 21 overlap in the thickness direction. The sweat absorbent sheet 10 has a longitudinally inwardly extending portion 10T (see FIG. 4) extending inwardly in the longitudinal direction X from the longitudinally inner end 11b of the hydrophobic sheet 11. The longitudinally inwardly extending portion 10T, i.e., the end of the sweat absorbent sheet 10 on the side of the longitudinally inner end 10b, is disposed opposite to the surface sheet 21 so as to be in contact therewith. The hydrophobic sheet 11 is a sheet that has at least a hydrophobic surface and does not absorb sweat, and is typically made of a nonwoven fabric containing hydrophobic fibers (heat-fusible fibers). In this way, the hydrophobic sheet 11 impermeable to body fluids such as urine is interposed between the top sheet 21 arranged on the skin facing side of the absorbent core 24 and the sweat absorbent sheet 10 in the overlap region A1, thereby effectively preventing liquid from returning from the absorbent core 24 to the sweat absorbent sheet 10 side. The sweat absorbing sheet 10, the hydrophobic sheet 11 and the surface sheet 21 may be joined together by a known joining means such as an adhesive or fusion.

The hydrophobic sheet 11 in the diaper 1 is part of the outer layer sheet 31 that constitutes the outer body 3 . That is, the outer layer sheet 31 is longer than the inner layer sheet 32 in the longitudinal direction X, and has extending portions extending from both ends of the inner layer sheet 32 in the longitudinal direction X. As shown in FIGS. The hydrophobic sheet 11 (folded portion 31E) has the same planar shape as the sweat-absorbing sheet 10, and is elongated in one direction in planar view, specifically a rectangular shape (strip shape). The hydrophobic sheet 11 is arranged along the longitudinal edge 23 a of the absorbent body 23 , that is, along the longitudinal edge of the absorbent main body 2 so as to overlap therewith.

In the diaper 1, as shown in FIG. 4, in the area A (the area where the sweat absorbent sheet 10 and the surface sheet 21 are at the same position in the vertical direction X), the area A2 where the sweat absorbent sheet 10 and the hydrophobic sheet 11 are at the same position in the vertical direction X has a larger tensile stress in the horizontal direction Y than the area A3 where the longitudinally inwardly extending portion 10T of the sweat absorbent sheet 10 is at the same position in the vertical direction X. That is, in the overlapping region A1 (the region where the sweat-absorbing sheet 10 and the topsheet 21 overlap in the thickness direction), which is a part of the region A (the central portion in the lateral direction Y), the region where the hydrophobic sheet 11 is arranged (region A2) has a larger elongation stress in the lateral direction Y than the region where the hydrophobic sheet 11 is not arranged (region A3). With such a configuration, the hydrophobic sheet 11 fits the skin of the wearer of the diaper 1 with good adhesion, so that body fluids such as urine absorbed by the absorbent core 24 are effectively prevented from leaking outside along the sweat absorbing sheet 10. - 特許庁

The ratio of the tensile stress in the lateral direction Y of the region A2 to the tensile stress in the lateral direction Y of the region A3 is preferably 1.03 or more, more preferably 1.05 or more, and preferably 2.5 or less, more preferably 2.0 or less, as region A2/region A3, on the premise that region A2>region A3.
The tensile stress in the transverse direction Y of the region A2 is preferably 0.04 N/mm or more, more preferably 0.05 N/mm or more, and preferably 0.12 N/mm or less, more preferably 0.10 N/mm or less.
The tensile stress in the transverse direction Y of the region A3 is preferably 0.02 N/mm or more, more preferably 0.03 N/mm or more, and preferably 0.10 N/mm or less, more preferably 0.08 N/mm or less.

Further, from the viewpoint of ensuring that the above-described sweat-absorbing sheet 10 is effective in preventing leakage of body fluids, it is preferable that, of the area A (the area where the sweat-absorbing sheet 10 and the surface sheet 21 are at the same position in the longitudinal direction X), the area A2 where the sweat-absorbing sheet 10 and the hydrophobic sheet 11 are at the same position in the longitudinal direction X has elasticity in the lateral direction Y. Specifically, it is preferable that at least one waist elastic member 33 is arranged in the region A2 so as to be stretchable in the horizontal direction Y. As shown in FIG. On the other hand, in the area A3 at the same position in the vertical direction as the longitudinally inwardly extending portion 10T of the sweat absorbent sheet 10, that is, the area where the hydrophobic sheet 11 is not arranged in the area A, as described above, from the viewpoint of preventing the occurrence of vertical wrinkles on the skin-facing surface of the sweat absorbent sheet 10 in the overlapping area A1, which is the central portion of the area A in the lateral direction Y, the stretchability of the waist elastic member 33 is preferably inhibited.

5-7 show another embodiment of the invention. Regarding other embodiments to be described later, components different from those of the diaper 1 described above will be mainly described, and similar components will be denoted by the same reference numerals, and description thereof will be omitted. The description of the diaper 1 is appropriately applied to components that are not particularly described.

The diaper 1A shown in FIG. 5 differs from the diaper 1 (see FIG. 4) in which the hydrophobic sheet 11 is part of the outer layer sheet 31 (folded portion 31E) in that the hydrophobic sheet 11 is an independent member. The hydrophobic sheet 11 is joined to the sweat-absorbing sheet 10 and the exterior body 3 (inner layer sheet 32) via the adhesive 12. As shown in FIG. The same effects as those of the diaper 1 are exhibited by the diaper 1A.

A diaper 1B shown in FIG. 6 differs from the diaper 1 (see FIG. 4) in that the hydrophobic sheet 11 is not provided. Since the diaper 1B does not have the hydrophobic sheet 11, it is inferior to the diaper 1 having the absorbent core 24 in terms of preventing liquid return from the absorbent core 24 to the sweat-absorbing sheet 10 side.

A diaper 1C shown in FIG. 7 differs from the diaper 1 (see FIG. 4) in that the absorbent body 23 is not arranged in the area (overlapping area) A1 where the sweat absorbent sheet 10 and the topsheet 21 overlap in the thickness direction. More specifically, in the dorsal portion R (abdominal portion F) of the diaper 1C, the sweat-absorbent sheet 10 is located only in a region (end flap region) positioned outward in the longitudinal direction X from the longitudinal end 23a of the absorbent body 23 and its imaginary extension line (end flap region), and does not overlap the absorbent body 23 in plan view. The extending portion from 23a and the sweat absorbent sheet 10 are overlapped to form an overlapping area A1 outside the absorber 23 in the longitudinal direction X. As shown in FIG. In the form shown in FIG. 7, the backsheet 22 also extends outward in the longitudinal direction X from the longitudinal ends 23a of the absorber 23, and contacts the non-skin-facing surface of the topsheet 21 in the overlap region A1. The term "absorptive core 24 and core wrap sheet 25" as used herein includes a form in which all of the constituent members of absorbent body 23 (absorbent core 24 and core wrap sheet 25) are not arranged, and a form in which only part of the constituent members of absorbent body 23 are arranged and the other part is not arranged. The form shown in FIG. The diaper 1C also differs from the diaper 1 in that the hydrophobic sheet 11 is not provided. However, the diaper 1C may include a hydrophobic sheet 11. In this case, the hydrophobic sheet 11 may be interposed between the sweat-absorbing sheet 10 and the topsheet 21 in the overlapping area A1, or may be a part (folded portion 31E) of the outer layer sheet 31 as shown in FIG. 4, or may be an independent constituent member as shown in FIG. Further, in the diaper 1C, the topsheet 21 does not have unevenness on the skin-facing surface side, and the skin-facing surface of the topsheet 21 is flat, but may have unevenness. The uneven shape of the surface sheet 21 is as described above. The diaper 1C also exhibits the same effect as the diaper 1B, but in particular, the absence of the absorber 23 in the overlap region A1 between the sweat-absorbing sheet 10 and the topsheet 21 has the effect of suppressing the return of body fluid from the absorber 23 to the wearer side when the wearer's load is applied to the overlap region A1 in a state where the absorber 23 absorbs and holds body fluid.

Although the present invention has been described based on the embodiments, the present invention is not limited to the above embodiments and can be modified as appropriate. All the parts that only one embodiment has as described above can be used interchangeably as appropriate.
For example, in the diaper 1, as shown in FIG. 2, the outer body 3 has a continuous shape extending over the abdominal part F, the crotch part M, and the back part R, but instead of this, the outer body 3 may be divided into an abdominal side sheet member and a back side sheet member, and the absorbent main body 2 may be fixed across both sheet members.
In the above-described embodiment, the sweat absorbent sheet 10 is arranged over the entire length of the lateral direction Y of the ventral portion F and the dorsal portion R, but the arrangement of the sweat absorbent sheet 10 is not limited to this. Considering the role of the sweat-absorbent sheet 10, the length of the sweat-absorbent sheet 10 in the horizontal direction Y is preferably equal to or greater than that of the absorbent body 23. Regarding the arrangement of the sweat-absorbent sheet 10, it is preferable that the sweat-absorbent sheet 10 is arranged over at least the entire length of the horizontal direction Y length of the absorbent body 23 in each of the abdominal portion F and the back portion R, and more preferably over the entire length of the horizontal direction Y of each of the abdominal portion F and the back portion R as in the above embodiment. Moreover, the sweat-absorbing sheet 10 may not be arranged on both the abdominal part F and the dorsal part R, but may be arranged on either one of them.
In addition, the absorbent article of the present invention is not limited to a pants-type disposable diaper such as the diaper 1 described above, but can be applied to general articles used for absorbing bodily fluids, for example, to a spreadable disposable diaper. Can be applied. The following notes are further disclosed with respect to the above-described embodiments of the present invention.

<1> An absorbent article having a vertical direction corresponding to the front-rear direction of the wearer and a horizontal direction orthogonal thereto, comprising a liquid-retaining absorbent core and a core wrap sheet in contact with the skin-facing surface of the absorbent core, wherein a surface sheet and a sweat-absorbent sheet are arranged on the skin-facing surface side of the core wrap sheet in order of proximity to the core wrap sheet,
A part of the sweat-absorbing sheet is arranged so as to be in contact with the surface sheet,
The absorbent article, wherein the liquid diffusibility of the top sheet is lower than the liquid diffusibility of the sweat absorbent sheet and lower than the liquid diffusivity of the core wrap sheet.
<2> The absorbent article according to <1>, wherein the ratio of the liquid diffusion area of the sweat absorbent sheet to the liquid diffusion area of the top sheet is preferably 1.5 or more, more preferably 2.0 or more, and preferably 30 or less, more preferably 15 or less, on the assumption that the liquid diffusion area of the sweat absorbent sheet (former) > the liquid diffusion area of the top sheet (latter).
<3> The absorbent article according to <1> or <2>, wherein the ratio of the liquid diffusion area of the core wrap sheet to the liquid diffusion area of the top sheet is preferably 2.0 or more, more preferably 2.5 or more, and preferably 40 or less, more preferably 35 or less, on the assumption that the liquid diffusion area of the core wrap sheet (former) > the liquid diffusion area of the top sheet (latter).
<4> The absorbent article according to any one of <1> to <3>, wherein the liquid diffusion area of the sweat absorbent sheet is preferably 100 mm ² or more, more preferably 150 mm ² or more, and preferably 1000 mm ² or less, more preferably 800 mm ^{2 or} less.
<5> The absorbent article according to any one of <1> to <4>, wherein the liquid diffusion area of the core wrap sheet is preferably 120 mm ² or more, more preferably 170 mm ² or more, and preferably 1000 mm ² or less, more preferably 800 mm ^{2 or} less.
<6> The absorbent article according to any one of <1> to <5>, wherein the surface sheet has a liquid diffusion area of preferably 10 mm ² or more, more preferably 20 mm ² or more, and preferably 100 mm ² or less, more preferably 200 mm ² or less, and still more preferably 300 mm ^{2 or} less.
<7> The absorbent article according to any one of <1> to <6>, wherein the core wrap sheet has a larger liquid diffusion area than the sweat absorbent sheet.

<8> The absorbent article includes a waist portion arranged around the wearer's waist when worn, and the sweat-absorbing sheet, the surface sheet, the core wrap sheet and the absorbent core are arranged in the waist portion, and the elastic member is arranged in a laterally stretched state,
The sweat-absorbing sheet has, in the waist portion, a longitudinally outward extending portion extending longitudinally outward from the longitudinal end of the surface sheet,
In the waist portion, the area where the sweat absorbent sheet and the surface sheet are at the same position in the vertical direction is area A, and the area at the same position as the longitudinally outwardly extending portion of the sweat absorbent sheet is area B. The absorbent article according to any one of <1> to <7>, wherein the area A has a larger lateral elongation stress than the area B.
<9> The waist part is divided into an abdominal part arranged on the abdomen side of the wearer and a dorsal part arranged on the dorsal side when worn, the surface sheet is arranged in the lateral center of the area A of each of the ventral part and the dorsal part, and the sweat-absorbing sheet extends laterally over the lateral center of the area A and both sides thereof,
The absorbent article according to <8>, wherein a central portion in the lateral direction of the region A where the sweat-absorbing sheet and the topsheet overlap in the thickness direction has lower lateral stretchability than both lateral portions of the region A.
<10> The absorbent article according to any one of <1> to <9>, wherein the sweat-absorbent sheet is joined to the top sheet at a portion facing the top sheet so as to be in contact with the top sheet.
<11> The absorbent article according to <10>, wherein the bonding between the sweat absorbent sheet and the topsheet is partial bonding.
<12> The absorbent article according to <11> or <12> above, wherein the ratio of the total area of the joints between the sweat-absorbing sheet and the topsheet to the total area of the overlapping portions is preferably 20% or less, more preferably 15% or less.
<13> The absorbent article according to any one of <1> to <12>, wherein the top sheet has a higher liquid permeability than the sweat-absorbing sheet, and more specifically, the top sheet has a short liquid permeation time (a strike-through time measured according to the “153.0-02 REPEATED Liquid Strike-Through Time” method) compared to the sweat-absorbing sheet.

<14> The absorbent article according to any one of <1> to <13>, wherein the sweat-absorbent sheet has a lower hydrophilicity on the skin-facing side than on the non-skin-facing side.
<15> The absorbent article according to any one of <1> to <14>, wherein the contact angle of the surface facing the skin of the sweat-absorbing sheet is preferably 90 degrees or more, more preferably 100 degrees or more, and preferably 150 degrees or less, more preferably 140 degrees or less.
<16> The absorbent article according to any one of <1> to <15>, wherein the contact angle of the non-skin facing surface of the sweat absorbent sheet is preferably 15 degrees or more, more preferably 20 degrees or more, and preferably 88 degrees or less, more preferably 85 degrees or less.
<17> The absorbent article according to any one of <1> to <16>, wherein the sweat-absorbent sheet has a laminated structure including a first layer forming a skin-facing surface and a second layer forming a non-skin-facing surface, and the first layer is a laminated nonwoven fabric having a lower hydrophilicity than the second layer.

<18> The absorbent article according to any one of <1> to <17>, wherein the surface sheet has an uneven shape on the side facing the skin, and the protrusions of the uneven shape can come into contact with the sweat absorbent sheet.
<19> The absorbent article according to <18>, wherein the uneven shape of the topsheet is a shape in which a plurality of convex portions are arranged in a scattered manner over the entire skin-facing surface of the topsheet, and a concave portion is formed around each convex portion.
<20> The absorbent article according to <18> or <19>, wherein the protrusions of the topsheet and the sweat absorbent sheet are joined.
<21> The absorbent article according to any one of <1> to <20>, wherein the surface sheet is a bulky nonwoven fabric, and the bulky nonwoven fabric has an apparent density of preferably 0.01 g/cm ³ or more, more preferably 0.02 g/cm ^{3 or more, and preferably 0.30 g/cm 3 or} less, more preferably 0.20 g/cm ³ or less.

<22> The absorbent article according to any one of <1> to <21>, wherein the ratio of the lateral elongation stress of the region A to the lateral elongation stress of the region B is preferably 1.05 or more, more preferably 1.1 or more, and preferably 2.5 or less, more preferably 2.0 or less, as region A/region B, on the assumption that region A>region B.
<23> The absorbent article according to any one of <1> to <22>, wherein the lateral extension stress of the region A is preferably 0.04 N/mm or more, more preferably 0.05 N/mm or more, and preferably 0.12 N/mm or less, more preferably 0.10 N/mm or less.
<24> The absorbent article according to any one of <1> to <23>, wherein the lateral extensional stress of the region B is preferably 0.02 N/mm or more, more preferably 0.04 N/mm or more, and preferably 0.10 N/mm or less, more preferably 0.08 N/mm or less.

<25> The absorbent article according to any one of <1> to <24>, wherein a hydrophobic sheet is interposed between the two sheets in a region (overlapping region A1) where the sweat-absorbing sheet and the top sheet overlap in the thickness direction, and the sweat-absorbing sheet has a longitudinally inwardly extending portion extending longitudinally inwardly from the longitudinally inner end of the hydrophobic sheet, and the longitudinally inwardly extending portion is disposed opposite to the topsheet so as to be in contact therewith.
<26> The absorbent article according to <25>, wherein a region (region A2) in which the sweat-absorbing sheet and the hydrophobic sheet are located at the same position in the longitudinal direction has a larger lateral elongation stress than a region (region A3) in which the longitudinally inwardly extending portion of the sweat-absorbing sheet is located at the same position in the longitudinal direction.
<27> The absorbent article according to <26> above, wherein the ratio of the lateral elongation stress of the region A2 to the lateral elongation stress of the region A3 is preferably 1.03 or more, more preferably 1.05 or more, and preferably 2.5 or less, more preferably 2.0 or less, as region A2/region A3, on the assumption that region A2>region A3.
<28> The absorbent article according to <26> or <27>, wherein the lateral extension stress of the region A2 is preferably 0.04 N/mm or more, more preferably 0.05 N/mm or more, and preferably 0.12 N/mm or less, more preferably 0.10 N/mm or less.
<29> The absorbent article according to any one of <26> to <28>, wherein the horizontal extension stress of the region A3 is preferably 0.02 N/mm or more, more preferably 0.03 N/mm or more, and preferably 0.10 N/mm or less, more preferably 0.08 N/mm or less.
<30> The absorbent article according to any one of <26> to <29>, wherein the region A2 has elasticity in the lateral direction Y.

<31> The absorbent article according to any one of <1> to <30>, wherein the surface sheet has a longer interfiber distance than the core wrap sheet.
<32> The absorbency according to any one of <1> to <31>, wherein the ratio of the inter-fiber distance of the top sheet to the inter-fiber distance of the core wrap sheet is preferably 1.5 or more, more preferably 2.0 or more, and preferably 10 or less, more preferably 8 or less, on the premise that the inter-fiber distance of the top sheet (former)>the inter-fiber distance of the core wrap sheet (the latter). Goods.
<33> The absorbent article according to any one of <1> to <32>, wherein the topsheet has a lower fiber density than the core wrap sheet.
<34> The absorbent article according to any one of <1> to <33>, wherein the surface sheet has a longer interfiber distance than the sweat absorbent sheet.
<35> The absorbency according to any one of <1> to <34>, wherein the ratio of the inter-fiber distance of the top sheet to the inter-fiber distance of the sweat-absorbing sheet is preferably 1.5 or more, more preferably 2.0 or more, and preferably 10 or less, more preferably 8 or less, on the assumption that the inter-fiber distance of the top sheet (former)>the inter-fiber distance of the sweat-absorbing sheet (latter). Goods.
<36> The absorbent article according to any one of <1> to <35>, wherein the surface sheet has a lower fiber density than the sweat absorbent sheet.
<37> The absorbent article according to any one of <1> to <36>, wherein the fiber orientation of the constituent fibers of the sweat absorbent sheet and the fiber orientation of the constituent fibers of the top sheet intersect each other.
<38> The absorbent article includes a waist portion arranged around the waist of the wearer when worn, and the waist portion is divided into an abdominal portion arranged on the abdomen side of the wearer when worn and a dorsal portion arranged on the back side,
The absorbent article according to any one of <1> to <37>, wherein the sweat-absorbing sheet has a shape (rectangular shape) that is elongated in one direction in a plan view, and is arranged over the entire length of each of the abdominal portion and the dorsal portion in the horizontal direction with the longitudinal direction thereof aligned with the horizontal direction.
<39> The absorbent article according to any one of <1> to <38>, wherein the absorbent core is not disposed in a region where the sweat absorbent sheet and the topsheet overlap in the thickness direction.
<40> The absorbent article according to any one of <1> to <39>, wherein the core wrap sheet is not disposed in a region where the sweat absorbent sheet and the top sheet overlap in the thickness direction.

1, 1A, 1B, 1C Absorbent article (pants-type disposable diaper)
F Abdominal part M Crotch part R Back part 2 Absorbent main body 21 Top sheet 22 Back sheet 23 Absorbent body 24 Absorbent core 25 Core wrap sheet 3 Exterior body 31 Outer layer sheet 31E Folded part of outer layer sheet (hydrophobic sheet)
32 inner layer sheet 33 waist elastic member 10 sweat absorbing sheet 10S longitudinally outwardly extending portion 10T longitudinally inwardly extending portion 11 hydrophobic sheet X longitudinal direction Y transverse direction

Claims (22)

An absorbent article having a vertical direction corresponding to the front-rear direction of the wearer and a horizontal direction orthogonal thereto, comprising a liquid-retaining absorbent core and a core wrap sheet in contact with the skin-facing surface of the absorbent core, wherein a surface sheet and a sweat-absorbing sheet are arranged on the skin-facing surface side of the core wrap sheet in order of proximity to the core wrap sheet,
A part of the sweat-absorbing sheet is arranged so as to be in contact with the surface sheet,
The liquid diffusibility of the top sheet is lower than the liquid diffusibility of the sweat absorbent sheet and lower than the liquid diffusivity of the core wrap sheet,
The absorbent article has a waist portion arranged around the wearer's waist when worn, and the sweat-absorbent sheet, the surface sheet, the core wrap sheet and the absorbent core are arranged in the waist portion, and the elastic member is arranged in a laterally stretched state,
The sweat-absorbing sheet has, in the waist portion, a longitudinally outward extending portion extending longitudinally outward from the longitudinal end of the surface sheet,
In the waist portion, when the region A is the region where the sweat absorbent sheet and the top sheet are at the same position in the vertical direction, and the region B is the region where the sweat absorbent sheet is at the same position in the vertical direction as the outwardly extending portion of the sweat absorbent sheet, the region A has a larger lateral elongation stress than the region B,
In an area A1 where the sweat-absorbent sheet and the topsheet overlap in the thickness direction, a hydrophobic sheet is interposed between the two sheets, the sweat-absorbent sheet has a longitudinally inwardly extending portion extending inwardly in the longitudinal direction from the longitudinally inner end of the hydrophobic sheet, and the longitudinally inwardly extending portion is disposed opposite to the topsheet so as to be in contact therewith. An absorbent article having a vertical direction corresponding to the front-rear direction of the wearer and a horizontal direction orthogonal thereto, comprising a liquid-retaining absorbent core and a core wrap sheet in contact with the skin-facing surface of the absorbent core, wherein a surface sheet and a sweat-absorbing sheet are arranged on the skin-facing surface side of the core wrap sheet in order of proximity to the core wrap sheet,
A part of the sweat-absorbing sheet is arranged so as to be in contact with the surface sheet,
The liquid diffusibility of the top sheet is lower than the liquid diffusibility of the sweat absorbent sheet and lower than the liquid diffusivity of the core wrap sheet,
The absorbent article has a waist portion arranged around the wearer's waist when worn, and the sweat-absorbent sheet, the surface sheet, the core wrap sheet and the absorbent core are arranged in the waist portion, and the elastic member is arranged in a laterally stretched state,
The sweat-absorbing sheet has, in the waist portion, a longitudinally outward extending portion extending longitudinally outward from the longitudinal end of the surface sheet,
In the waist portion, when the region A is the region where the sweat absorbent sheet and the top sheet are at the same position in the vertical direction, and the region B is the region where the sweat absorbent sheet is at the same position in the vertical direction as the outwardly extending portion of the sweat absorbent sheet, the region A has a larger lateral elongation stress than the region B,
The waist part is divided into an abdominal part arranged on the abdomen side of the wearer and a dorsal part arranged on the dorsal side when worn, the surface sheet is arranged in the lateral center part of the area A of each of the ventral part and the dorsal part, and the sweat-absorbing sheet extends laterally over the lateral center part of the area A and both sides thereof,
The central portion in the lateral direction of the region A where the sweat-absorbing sheet and the surface sheet overlap in the thickness direction has lower stretchability in the lateral direction than both sides of the region A in the lateral direction,
A hydrophobic sheet is interposed between the two sheets in the lateral center of the region A where the sweat-absorbing sheet and the top sheet overlap in the thickness direction, the sweat-absorbing sheet has a longitudinally inwardly extending portion extending longitudinally inwardly from the longitudinally inner end of the hydrophobic sheet, and the longitudinally inwardly extending portion is disposed opposite to the topsheet so as to be in contact therewith. 3. The absorbent article according to claim 1, wherein the core wrap sheet has a larger liquid diffusion area than the sweat absorbent sheet. 4. The absorbent article according to any one of claims 1 to 3, wherein the sweat-absorbing sheet is joined to the topsheet at a portion facing the topsheet so as to be in contact with the topsheet. 5. The absorbent article according to claim 4, wherein said bonding between said sweat absorbent sheet and said topsheet is partial bonding. 6. The absorbent article according to claim 5, wherein the ratio of the total area of the joints between the two sheets to the total area of the overlapping parts of the sweat absorbent sheet and the topsheet is 0.5% or more and 20% or less. The absorbent article according to any one of claims 1 to 6, wherein the sweat-absorbent sheet has a lower hydrophilicity on the skin-facing side than on the non-skin-facing side. 8. The absorbent article according to any one of claims 1 to 7, wherein the surface sheet has an uneven shape on the side facing the skin, and the projections of the uneven shape can come into contact with the sweat absorbent sheet. 9. The absorbent article according to claim 8, wherein the uneven shape of the topsheet is a shape in which a plurality of convex portions are arranged in a scattered manner over the entire skin-facing surface of the topsheet, and a concave portion is formed around each convex portion. 10. The absorbent article according to claim 8, wherein the protrusions of the topsheet and the sweat absorbent sheet are joined together. 3. The absorbent article according to claim 1 or 2, wherein the ratio of the lateral elongation stress of said region A to the lateral elongation stress of said region B is 1.05 or more and 2.5 or less as region A/region B, provided that region A > region B. 12. The absorbent article according to any one of claims 1, 2 and 11, wherein said region A has a lateral extensional stress of 0.04 N/mm or more and 0.12 N/mm or less. 13. The absorbent article according to any one of claims 1, 2, 11 and 12, wherein said region B has a lateral extensional stress of 0.02 N/mm or more and 0.10 N/mm or less. The absorbent article according to any one of claims 1 to 13, wherein the area A2 where the sweat-absorbing sheet and the hydrophobic sheet are at the same position in the longitudinal direction has a larger stretching stress in the lateral direction than the area A3 at the same position in the longitudinal direction as the longitudinally inwardly extending portion of the sweat-absorbing sheet. 15. The absorbent article according to claim 14 , wherein the ratio of the lateral elongation stress of the region A2 to the lateral elongation stress of the region A3 is 1.03 or more and 2.5 or less as region A2/region A3 on the assumption that region A2>region A3. 16. The absorbent article according to claim 14 or 15, wherein said region A2 has a lateral extensional stress of 0.04 N/mm or more and 0.12 N/mm or less. 17. The absorbent article according to any one of claims 14 to 16 , wherein said region A3 has a lateral extensional stress of 0.02 N/mm or more and 0.10 N/mm or less. 18. The absorbent article according to any one of claims 14 to 17 , wherein said region A2 has stretchability in the lateral direction. The absorbent article according to any one of claims 1 to 18 , wherein the surface sheet has a longer interfiber distance than the core wrap sheet. The absorbent article according to any one of claims 1 to 19 , wherein the surface sheet has a longer interfiber distance than the sweat absorbent sheet. The absorbent article according to any one of claims 1 to 20 , wherein the ratio of the inter-fiber distance of the top sheet and the inter-fiber distance of the sweat-absorbing sheet is 1.5 or more and 10 or less as the former/latter on the assumption that the former > the latter. The absorbent article according to any one of claims 1 to 21 , wherein the topsheet has a lower fiber density than the sweat absorbent sheet.

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