GB2581054A

GB2581054A - Absorbent article

Info

Publication number: GB2581054A
Application number: GB2005212.2A
Authority: GB
Inventors: Ueda Akiyuki; Fukuda Yuko; Okuda Yasuyuki
Original assignee: Kao Corp
Current assignee: Kao Corp
Priority date: 2017-12-27
Filing date: 2018-12-14
Publication date: 2020-08-05
Anticipated expiration: 2038-12-14
Also published as: GB2581054B; DE112018006684T5; GB202005212D0; JP2019118799A; JP7312542B2

Abstract

The absorbent article (1) according to the present invention is provided with a liquid-retaining absorbent core (24) and a core wrap sheet (25) which is in contact with the skin-facing surface of the absorbent core (24), wherein the skin-facing surface side of the core wrap sheet (25) is provided with a topsheet (21) and a sweat-absorbent sheet (10) sequentially from the core wrap sheet (25) in this order. The sweat-absorbent sheet (10) has a portion (10T) thereof disposed opposite to the topsheet (21) so as to be able to come into contact therewith. The topsheet (21) has a fluid diffusive property lower than that of the sweat-absorbent sheet (10) and also lower than that of the core wrap sheet (25).

Description

Title of Invention: ABSORBENT ARTICLE

Technical Field

[0001] The present invention relates to an absorbent article provided with a sweat-absorbent sheet having a sweat-absorbent function.

Background Art

[0002] There is a conventionally known absorbent article such as a disposable diaper, which is configured to include a topsheet disposed to be contactable with a skin of a wearer, a backsheet disposed on a side farther from the skin of the wearer than the topsheet, and an absorbent member interposed between both sheets, in which the absorbent member includes an absorbent core including an absorbent material such as pulp and a core-wrap sheet that covers the absorbent core. In the absorbent article having such a configuration, for the purpose of reducing skin troubles such as heat rash, a sweat-absorbent sheet including a hydrophilic material capable of absorbing sweat is conventionally disposed at a portion where it may come into contact with the skin of the wearer when worn.

[0003] Patent Literature 1 discloses a pull-on disposable diaper, in which a hydrophilic web having long fibers being highly water-absorbing material is disposed, as a sweat-absorbent sheet, on a rear end flap extending outward from an end edge of an absorbent member. The hydrophilic web is disposed so as to come into a skin of a wearer, and the rear end flap is disposed on a side farther from the skin of the wearer than the hydrophilic web. The rear end flap is constituted by two sheet materials, and, between both sheet materials, elastic members extending in a lateral direction of the diaper are disposed in stretched state at a predetermined interval in the longitudinal direction. With such a configuration, the rear end flap has elasticity in the lateral direction. According to Patent Literature 1, since sweat generated around the waist of the wearer is quickly absorbed and diffused by the hydrophilic web, the waist of the wearer can be maintained in a dry state with low humidity and skin troubles are unlikely to occur. In this case, the longitudinal direction is a direction corresponding to the front-back direction of the wearer of an absorbent article, and the lateral direction is a direction orthogonal to the longitudinal direction.

[0004] Patent Literature 2 discloses that a sweat-absorbent sheet is attached to a hydrophobic sheet that covers an inner surface side of a front-rear waist region of the disposable diaper. The hydrophobic sheet has a longitudinal inner end that is overlapped with a topsheet in the thickness direction. In an overlapping region of both sheets, the hydrophobic sheet is disposed at a position closer to a skin of a wearer than the topsheet. The sweat-absorbent sheet is entirely overlapped with the hydrophobic sheet in the thickness direction, and has no portion in contact with the topsheet. The disposable diaper disclosed in Patent Literature 2 is configured to prevent the sweat-absorbent sheet from being turned over even when a non-joint region of the hydrophobic sheet is turned over during wearing, thereby preventing the function of the sweat-absorbent sheet from being impaired.

[0005] Patent Literature 3 discloses that a hydrophilic sheet that functions as a sweat-absorbent sheet is disposed at a waist flap that is a longitudinal outer position of an absorbent core of a disposable diaper, and further, a waist elastic member is disposed on the waist flap in a laterally stretched state to form a gather. The hydrophilic sheet includes an inner hydrophilic sheet that is a so-called topsheet and an outer hydrophilic sheet that is disposed on a non-skin-facing surface side of the inner hydrophilic sheet. According to the disposable diaper disclosed in Patent Literature 3, since the gather formed by the waist elastic member is present at the waist flap of the diaper where skin troubles are likely to occur, the expansion and contraction of the gather resulting from the movement of the wearer facilitates transfer of sweat to the outer hydrophilic sheet from the inner hydrophilic sheet. For this reason, skin troubles are unlikely to occur. Further, it is also disclosed that setting the liquid diffusibility of the outer hydrophilic sheet to be higher than that of the inner hydrophilic sheet can quickly diffuse the sweat once transferred to the outer hydrophilic sheet.

Citation List Patent Literature [0006] Patent Literature 1 JP 2006-141549 A Patent Literature 2: JP 2007-259874 A Patent Literature 3: JP 2010-246901 A

Summary of Invention

[0007] The present invention relates to an absorbent article having a longitudinal direction corresponding to a front-back direction of a wearer and a lateral direction orthogonal to the longitudinal direction, comprising a liquid-retentive absorbent core and a core-wrap sheet in contact with a skin-facing surface of the absorbent core, and including a topsheet and a sweat-absorbent sheet, the topsheet and the sweat-absorbent sheet being disposed on a skin-facing surface side of the core-wrap sheet in the order closer to the core-wrap sheet. The sweat-absorbent sheet has a part that is opposed and disposed to be contactable with the topsheet. The liquid diffusibility of the topsheet is lower than the liquid diffusibility of the sweat-absorbent sheet and is lower than the liquid diffusibility of the core-wrap sheet.

Brief Description of Drawings

[0008] [Fig. I] Fig. I is a perspective view schematically illustrating a pull-on disposable diaper that is an embodiment of an absorbent article.

[Fig. 2] Fig. 2 is a developed plan view schematically illustrating a skin-facing surface side (inner surface side) of the diaper illustrated in Fig. t in its flat-out, uncontracted state. [Fig. 3] Fig. 3 a cross-sectional view schematically illustrating a cross section taken along a line I-I (a cross section along the lateral direction) in Fig. 2.

[Fig. 4] Fig. 4 is cross-sectional view schematically illustrating a cross section taken along a line II-II (a cross section along the longitudinal direction) in Fig. 2, and is a longitudinal cross-sectional view schematically illustrating an enlarged longitudinal one end (a longitudinal end on the rear side) of the diaper illustrated in Fig. 1.

[Fig. 5] Fig. 5 is a view illustrating another embodiment of the absorbent article according to the present invention, which corresponds to Fig. 4.

[Fig. 6] Fig. 6 is a view illustrating another embodiment of the absorbent article according to the present invention, which corresponds to Fig. 4.

[Fig. 7] Fig. 7 is a view illustrating another embodiment of the absorbent article according to the present invention, which corresponds to Fig. 4.

Detailed Description of Invention [0009]

In an absorbent article including a sweat-absorbent sheet, there is a problem that occurs when the amount of sweat absorbed by the sweat-absorbent sheet reaches the sweat absorption capacity of the sweat-absorbent sheet. In that case, the absorption of sweat by the sweat-absorbent sheet is no longer possible and the sweat-absorbent sheet is present in a wet state where a great amount of sweat has been absorbed. Therefore, there is a risk of causing skin troubles such as heat rash if the absorbent article is kept worn as it is. As a countermeasure for such a problem, a method for increasing the absorption capacity by increasing the thickness of the sweat-absorbent sheet can be conceived. However, this method may induce a risk of causing deterioration in the feeling of wearing due to the thickness increase of the sweat-absorbent sheet. There has not yet been provided a technique capable of absorbing a great amount of sweat without deteriorating the feeling of wearing the absorbent article.

[0010] Accordingly, the present invention relates to an absorbent article that can quickly absorb a great amount of sweat, reduce the inconvenience that absorbed body fluid returns to the skin side of a wearer, and hardly cause skin troubles resulting from the body fluid.

[0011] Hereinafter, the present invention will be described based on preferred embodiments with reference to attached drawings. Figs. 1 to 4 illustrate a pull-on disposable diaper 1 that is an embodiment of the absorbent article according to the present invention. The diaper 1, as illustrated in Figs. 1 to 4, has a longitudinal direction X corresponding to the front-back direction of a wearer, that is, a direction extending from the front side to the rear side via a crotch part, and a lateral direction Y orthogonal thereto. The diaper 1 includes a liquid-retentive absorbent core 24, a core-wrap sheet 25 in contact with a skin-facing surface of the absorbent core 24. A topsheet 21 and a sweat-absorbent sheet 10 are disposed, in the order closer to the core-wrap sheet 25, on a skin-facing surface side of the core-wrap sheet 25. The absorbent core 24 and the core-wrap sheet 25, which contacts and wraps an outer surface of the absorbent core 24, cooperatively constitute an absorbent member 23.

[0012] In the present description, the "skin-facing surface" is a surface of the absorbent article or a constituent member thereof (e.g., the topsheet) that is directed to the skin side of the wearer at the time of wearing the absorbent article, that is, a side that is relatively close to the skin of the wearer, and the "non-skin-facing surface" is a surface of the absorbent article or a constituent member thereof that is directed to a side opposite to the skin side at the time of wearing the absorbent article, that is, a side relatively far from the skin of the wearer. In addition, "the time of wearing" means a state where normal appropriate wearing position, that is, correct wearing position of the absorbent article is maintained.

[0013] The diaper 1, as illustrated in Figs. 1 and 2, has a crotch portion M and a front portion F and a rear portion R that extend in the longitudinal direction X from front and rear sides of the crotch portion M. The crotch portion M is a part disposed in the crotch part of the wearer in the worn state of the diaper 1. The front portion F is a part disposed on the front side of the wearer, that is, the front side in the longitudinal direction X, rather than the crotch portion M, in the worn state of the diaper 1. The rear portion R is a part disposed on the rear side of the wearer, that is, the rear side in the longitudinal direction X, rather than the crotch portion M, in the worn state of the diaper 1. The front portion F and the rear portion R constitute a waist part disposed at the waist of the wearer when the diaper I is worn. In other words, the waist part of the diaper I is constituted by the front portion F and the rear portion R segmented.

[0014] The diaper 1 includes an absorbent assembly 2, which includes the absorbent member 23 (the absorbent core 24 and the core-wrap sheet 25), in the center in the lateral direction Y, and an outer cover 3 disposed on a side farther from the body of the wearer than the non-skin-facing surface side of the absorbent assembly 2, that is, the absorbent assembly 2. Both side edges of the front portion F and the rear portion R along the longitudinal direction X of the outer cover 3 are joined together by a known joining means such as adhesive agent, heat seal, ultrasonic seal. Thus, as illustrated in Fig. 1, a pair of side seals S and S, a waist opening portion WH through which the torso of the wearer is inserted, and a pair of leg openings LH and LH through which lower limbs of the wearer are inserted are formed.

[0015] The absorbent assembly 2, in its flat-out, uncontracted state of the diaper 1 as illustrated in Fig. 2, has a rectangular shape in plan view, and extends in the longitudinal direction X from the front portion F to the rear portion R. The absorbent assembly 2, while the longitudinal direction thereof is aligned with the longitudinal direction X of the diaper 1 in its flat-out, uncontracted state, is disposed at the center of the outer cover 3 in the lateral direction Y, and joined to the outer cover 3 with an adhesive agent. The "flat-out, uncontracted state" of the diaper 1 is a state in which the diaper 1 is brought into an expanded state by separating the side seals S and the diaper 1 in the expanded state is expanded until the elastic member of each part is caused to extend to design dimensions (that are identical to the dimensions when flattened in a state where the influence of the elastic member is completely eliminated).

[0016] The absorbent assembly 2, as illustrated in Fig. 3, includes the liquid-permeable topsheet 21 that forms a skin-facing surface, a liquid-impermeable, or sparingly liquid permeable, or water-repellent backsheet 22 that forms a non-skin-facing surface, and the liquid-retentive absorbent member 23 interposed between both the sheets 21 and 22. These members are integrated by a known joining means such as an adhesive agent. The entire length of the absorbent assembly 2 in the longitudinal direction X is the same as that of the absorbent member 23, and both longitudinal ends 23a and 23a are at the same position as the longitudinal end of the absorbent assembly 2, as illustrated in Fig. 2. As each of the topsheet 21 and the backsheet 22, various types conventionally used for this kind of absorbent article can be used without any particular limitations. For example, various nonwoven fabrics or apertured films can be used as the topsheet 21, and a resin film or a laminate of a resin film and a nonwoven fabric, or the like can be used as the backsheet 22.

[0017] The absorbent member 23 is configured to include the liquid-retentive absorbent core 24 mainly constituted by an absorbent material and the core-wrap sheet 25 that covers outer surfaces, that is, skin-facing surface and non-skin-facing surface, of the absorbent core 24. The absorbent core 24 has a rectangular shape that is long in the longitudinal direction X, in plan view as illustrated in Fig. 1, and extends in the longitudinal direction X from the front portion F to the rear portion R. As an absorbent material that forms a main part of the absorbent core 24, what is used as the material of the absorbent member in this kind of absorbent article can be used without any particular limitations. Examples thereof include wood pulp, synthetic fibers subjected to a hydrophilic treatment, and absorbent polymer. As a typical form of the absorbent core 24, there can be exemplified a fiber aggregate of hydrophilic fibers such as wood pulp, or the fiber aggregate holding particulate absorbent polymer.

[0018] In the diaper 1, the core-wrap sheet 25 is a single continuous liquid-permeable sheet that has a width not less than 2 times and not greater than 3 times the length of the absorbent core 24 in the lateral direction Y, and as illustrated in Fig. 3, covers the whole area of the skin-facing surface of the absorbent core 24, and extends outward in the lateral direction Y from both side edges along the longitudinal direction X of the absorbent core 24. The extension portion is wound downward below the absorbent core 24 so as to cover the whole area of the non-skin-facing surface of the absorbent core 24. The absorbent core 24 and the core-wrap sheet 25 may be joined together by a known joining means such as a hot-melt adhesive agent. For example, liquid-permeable sheets such as papers, various nonwoven fabrics, and apertured films can be used as the core-wrap sheet 25.

[0019] In the present invention, the core-wrap sheet may not be such a single sheet, and for example, may be configured to include a single skin-side core-wrap sheet that covers the skin-facing surface of the absorbent core 24, and a single 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.

[0020] As illustrated in Figs. 2 and 3, a pair of leak-proof cuffs 26 and 26 constituted by a liquid-resistive, or water-repellent, and air-permeable leak-proof cuff forming sheet 27 is provided on both sides along the longitudinal direction X of the skin-facing surface of the absorbent assembly 2. In the vicinity of the free-end portion of each leak-proof cuff 26, one or more filamentous leak-proof cuff forming elastic members 28 are disposed in stretched state in the longitudinal direction X. The leak-proof cuffs 26 stand up at least at the crotch portion 1\4 when the elastic member 28 disposed in stretched state contracts when the diaper 1 is worn, so as to prevent liquid excreta such as urine from flowing out in the lateral direction Y. [0021] The outer cover 3 forms the outer shape of the diaper 1 in its flat-out, uncontracted state illustrated in Fig. 2, and the periphery of the outer cover 3 forms contour lines of the diaper 1 in this state, that is, contour lines of the front portion F, the crotch portion Ni, and the rear portion R. The outer cover 3, as illustrated in Fig. 2, has a rectangular shape in which the length in the lateral direction Y is longer than the length in the longitudinal direction X, in the front portion F and the rear portion R. In the crotch portion M positioned between the front portion F and the rear portion R, both side edges, that is, a pair of leg edges LS and LS, along the longitudinal direction X of the outer cover 3 are curved in a convex arc shape toward the center in the lateral direction Y, and in plan view as illustrated in Fig. 2, the central region in the longitudinal direction X has a sandglass shape that is bound inward in the lateral direction Y. [0022] The outer cover 3, as illustrated in Figs. 3 and 4, is configured to include a laminated body constituted by an outer sheet 31 that forms an outer surface, that is, non-skin-facing surface, of the diaper 1 in a worn state, and an inner sheet 32 disposed to be opposed to the skin-facing surface of the outer sheet 31. In the worn state of the diaper 1, the outer sheet 31 is positioned on the side farther from the body of the wearer so as to form the non-skinfacing surface (outer surface) of the diaper 1. The inner sheet 32 is positioned on the side closer to the body of the wearer so as to form the skin-facing surface (inner surface) of the diaper 1. The outer sheet 31 and the inner sheet 32 are joined together through a joining means such as an adhesive agent at a predetermined portion.

[0023] In the diaper 1, as illustrated in Figs. 2 and 4, the outer sheet 31 has a folded part 31E extending from the end edge of the inner sheet 32 in the longitudinal direction X and folded on the skin-facing surface side of the inner sheet 32, at the front portion F and the rear portion R. The folded part 31E covers the end of the absorbent assembly 2 in the longitudinal direction X. In addition, in Fig. 4, the longitudinal end of the rear portion R is enlargedly illustrated. Although an enlarged view of the front portion F is not illustrated, the front portion F is also configured in the same manner as the rear portion R Unless otherwise mentioned, the description of the rear portion R is appropriately applied to the front portion F. [0024] The sheets 31 and 32 constituting the outer cover 3 may be the same type of sheets or different types of sheets, and examples of the latter include forms differing mutually in elasticity. Specifically, for example, a stretchable sheet having elasticity in the lateral direction Y can be used as the outer sheet 31, and a non-stretchable sheet having no elasticity can be used as the inner sheet 32. Further, for example, the elasticity of the outer sheet 31 may be partly differentiated. Specifically, examples thereof include the outer sheet 31 constituted by a stretchable sheet having elasticity in the lateral direction Y at portions located at the front portion F and the rear portion R thereof and a non-stretchable sheet having no elasticity at a portion located at the crotch portion M thereof [0025] Examples of the stretchable sheet usable as the outer cover 3 include a stretchable sheet in which stretchable fiber layers are integrated on both surfaces or one surface of an elastic fiber layer. Examples of the method for integrating the elastic fiber layer and the stretchable fiber layer include a method for laminating and hydro-entangling the both, a method for entangling fibers by air-through or the like, and a method for joining them by heat embossing, an adhesive agent, ultrasonic waves, etc. Further, examples of the non-stretchable sheet usable as the outer cover 3 include nonwoven fabrics produced by various manufacturing methods, and specifically, spunbond nonwoven fabrics, air-through nonwoven fabrics, and needle-punched nonwoven fabrics can be exemplified.

[0026] As illustrated in Figs. 1, 2, and 4, a plurality of filamentous or continuous waist elastic members 33 being in stretched state is disposed in the lateral direction Y, in each of the front portion F and the rear portion R. These waist elastic members 33 are intermittently disposed at a predetermined interval in the longitudinal direction X. As described above, the waist elastic members 33 are disposed in a state where the elastic stretchability can be expressed so that at the opening edge of the waist opening portion WH is formed an annular waist gather that is substantially continuous over the entire circumference. Further, on a leg edge LS that forms the opening edge of each of the pair of leg openings LH and LH, a leg elastic member 34 for forming one or a plurality of filamentous or continuous leg gathers is disposed in stretched state. As a result, an annular leg gather substantially continuous over the entire circumference is formed at the opening edge of each of the pair of leg openings LH and LH. These elastic members 33 and 34 each are sandwiched and fixed between the outer sheet 31 and the inner sheet 32 that cooperatively constitute the outer cover 3 by a joining means such as an adhesive agent.

[0027] In the diaper 1, as described above, the outer cover 3 is disposed on the side farther from the skin of the wearer of the diaper 1 than the absorbent member 23. Further, since the waist elastic members 33 are fixed in stretched state in the lateral direction Y, the outer cover 3 is provided with elasticity and thus a stretchable sheet that has elasticity in the lateral direction Y. [0028] In the present specification, the "elasticity" means such a property that it is extendable in a predetermined direction and contracts when the extension is released. When the sheet has substantially no elasticity in a certain direction (being non-elastic), it means that the sheet hardly stretches even when a pulling force is applied to the sheet in the certain direction. For example, when a sample being 15 cm in length and 5 cm in width is pulled in the longitudinal direction with a material tensile tester such as Tensilon and the breaking elongation when the sample breaks is not greater than 10%, the sample has substantially no elasticity in the longitudinal direction. The breaking elongation can be calculated by (sample length at breakage -original sample length)/ (original sample length) x 100.

[0029] The sweat-absorbent sheet 10 is intended to absorb sweat around the waist of the wearer, and is disposed in a portion where it can contact the skin of the wearer when the diaper 1 is worn. In the diaper 1, as illustrated in Figs. 1, 2, and 4, in each of the front portion F and the rear portion R that are the waist part to be disposed at the waist of the wearer when worn, the sweat-absorbent sheet 10, the topsheet 21, the core-wrap sheet 25, and the absorbent core 24 are disposed in the order closer to skin of the wearer, and the elastic members 33 are disposed in stretched state in the lateral direction Y. Each of the front portion F and the rear portion R has elasticity in the lateral direction Y due to the provision of the elastic members 33, as a whole, although the elasticity of the elastic members 33 may be partly impeded.

[0030] In the diaper 1, the sweat-absorbent sheet 10 has a shape that is long in one direction in plan view as illustrated in Fig. 2, specifically a rectangular shape, and is disposed over the entire length in the lateral direction Y of each of the front portion F and the rear portion R, while the longitudinal direction thereof is aligned with the lateral direction Y. In each of the front portion F and the rear portion R, the sweat-absorbent sheet 10 is disposed in such a way as to straddle both a core arranging region in which the absorbent core 24 (the absorbent assembly 2) is disposed and a core-less region in which the absorbent core 24 (the absorbent assembly 2) is not disposed. The core-less region in each of the front portion F and the rear portion R includes a region (side flap region) positioned on the outside in the lateral direction Y from both side edges along the longitudinal direction X of the absorbent core 24 (the absorbent assembly 2) and the imaginary extended line thereof, and a region (end flap region) positioned on the outside in the longitudinal direction X from the longitudinal end of the absorbent core 24 (the absorbent assembly 2) (the longitudinal end 23a of the absorbent member 23) and the imaginary extended line thereof As described above, the sweat-absorbent sheet 10 is disposed in such a way as to straddle both of the core arranging region and the core-less region in each of the front portion F and the rear portion R, and is different in this respect from the topsheet 21 that is substantially disposed only in the core arranging region.

[0031] On the skin-facing surface side of each of the front portion F and the rear portion R, the sweat-absorbent sheet 10 is disposed in the vicinity of the opening edge of the waist opening portion WH, along the opening edge, and is disposed closest to the skin of the wearer of the diaper 1 at this arranging position. The sweat-absorbent sheet 10 has a longitudinal outer end 10a that is relatively close to the waist opening portion WH and a longitudinal inner end 10b relatively far from the waist opening portion WH. Both the longitudinal end 10a and 10b extend in parallel with the lateral direction Y. The longitudinal outer end 10a of the sweat-absorbent sheet 10 is positioned outwardly in the longitudinal direction X than the longitudinal end 23a of the absorbent member 23. The longitudinal inner end 10b of the sweat-absorbent sheet 10 is positioned inwardly in the longitudinal direction X than the longitudinal end 23a of the absorbent member 23. The longitudinal end 23a of the absorbent member 23 is also the longitudinal end of each of the absorbent core 24 and the core-wrap sheet 25.

[0032] The sweat-absorbent sheet 10 is mainly constituted by a nonwoven fabric, typically. As the nonwoven fabric constituting the sweat-absorbent sheet 10, nonwoven fabrics manufactured by various methods and usable as a constituent member of this kind of absorbent article can be used without any particular limitations. Examples thereof include nonwoven fabrics manufactured by the card method, spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlaced nonwoven fabrics, needle-punched nonwoven fabrics.

[0033] In the diaper 1, the sweat-absorbent sheet 10 having a sweat-absorbent function is disposed in a portion where it can be brought into contact with the skin of the wearer (around the waist opening portion WH on the skin-facing surface). Therefore, skin troubles resulting from sweat such as heat rash, eczema, and any other rash can be reduced. However, the sweat absorption capacity of the sweat-absorbent sheet 10 is limited, and after the amount of sweat absorbed by the sweat-absorbent sheet 10 once reaches the absorption capacity, the sweat-absorbent sheet 10 hardly absorbs sweat. Moreover, since the wet sweat-absorbent sheet 10 that has absorbed a great amount of sweat comes into contact with the skin of the wearer, it will be concerned that skin troubles may be caused if the diaper 1 is kept worn in this state. To solve this problem, a method for increasing the absorption capacity by increasing the thickness of the sweat-absorbent sheet 10 can be conceived. However, this method may deteriorate the wearing feeling of the diaper 1.

[0034] On the other hand, in the diaper 1, instead of increasing the absorption capacity of the sweat-absorbent sheet 10 itself, the sweat-absorbent sheet 10 and another member having a sweat-absorbent function are connected so that sweat can transfer between these members, thereby intending to increase the sweat absorption capacity of the diaper 1 as a whole. Specifically, as illustrated in Fig. 4, the end of the longitudinal inner end 10b side being a part of the sweat-absorbent sheet 10 is opposed and disposed to be contactable with the topsheet 21, so that the end functions as a conduit for sweat from the sweat-absorbent sheet 10 to the topsheet 21. With such a configuration, when the diaper 1 is worn, if the amount of sweat absorbed by the sweat-absorbent sheet 10 reaches saturation of the sweat-absorbent capacity of the sweat-absorbent sheet 10, a part of the sweat can transfer from the end of the longitudinal inner end 10b of the sweat-absorbent sheet 10 side to the topsheet 21, and sequentially penetrate the topsheet 21 and the core-wrap sheet 25 located on the non-skin-facing surface side thereof in the thickness direction, so as to reach the absorbent core 24 and to be absorbed and held there. In this manner, in the diaper 1, not only the sweat-absorbent sheet 10 to be directly brought into contact with the skin of the wearer but also other members such as the absorbent core 24 can be utilized as sweat absorption members. Therefore, the situation that the absorption capacity of the sweat-absorbent sheet 10 saturates during wearing of the diaper 1 seldom occurs, and sweat can be absorbed stably for a long time.

[0035] However, when such a sweat conduit extending from the sweat-absorbent sheet 10 to the absorbent core 24 is formed, there is a concern about occurrence of so-called fluid return in which body fluid such as sweat and urine having been once absorbed and held by the absorbent core 24 flows back through the conduit and transfers and spreads to the sweat-absorbent sheet 10 side. Therefore, in the diaper 1, in addition to arranging a part of the sweat-absorbent sheet 10 (the end on the side of the longitudinal inner end 10b) so as to be opposed and disposed to be contactable with the topsheet 21, a specific magnitude correlation with respect to liquid diffusibility is further given to the members disposed on the side closer to the skin of the wearer than the absorbent core 24, specifically the sweat-absorbent sheet 10, the topsheet 21, and the core-wrap sheet 25. Specifically, the liquid diffusibility of the topsheet 21 is set to be lower compared with that of the sweat-absorbent sheet 10, and set to be lower compared with that of the core-wrap sheet 25. Thus, regarding the liquid diffusibility of the member positioned closer to the skin of the wearer than the absorbent core 24, when the magnitude correlation of "sweat-absorbent sheet 10 > topsheet 21" and "core-wrap sheet 25 > topsheet 21" is satisfied, sweat is caused to transfer from the sweat-absorbent sheet 10 to the absorbent core 24, and no spontaneous fluid flow occur from the absorbent core 24 to the topsheet 21. Therefore, the transfer of body fluid to the sweat-absorbent sheet 10 side, so-called fluid return, can be effectively prevented. The liquid diffusibility can be determined based on liquid diffusion area measurable by the following method. The larger the liquid diffusion area, the higher the liquid diffusibility, and it can be evaluated that the body fluid is easily spread.

[0036] <Liquid diffusion area measuring method> The method includes obtaining samples of measurement objects (sweat-absorbent sheet 10, topsheet 21, and core-wrap sheet 25) by cutting a square of 100 mm x 100 mm from respective objects. The method further includes placing each sample on an acrylic board, dropping 0.05 mL of colored water onto the sample from an upper position 30 mm above the sample, and measuring the area of a colored part of the sample (diffusion part of the dropped water) with an image analysis device after elapse of 10 minutes from the dropping.

[0037] The ratio of the liquid diffusion area of the sweat-absorbent sheet 10 and the liquid diffusion area of the topsheet 21 is preferably not less than 1.5, more preferably not less than 2.0, and is preferably not greater than 30, more preferably not greater than 15, as a value obtainable by dividing the liquid diffusion area of the sweat-absorbent sheet 10 (the former) by the liquid diffusion area of the topsheet 21 (the latter), on the premise that the liquid diffusion area of the sweat-absorbent sheet 10 (the former) is greater than the liquid diffusion area of the topsheet 21 (the latter). The ratio of the liquid diffusion area of the core-wrap sheet 25 and the liquid diffusion area of the topsheet 21 is preferably not less than 2.0, more preferably not less than 2.5, and is preferably not greater than 40, more preferably not greater than 35, as a value obtainable by dividing the liquid diffusion area of the core-wrap sheet 25 (the former) by the liquid diffusion area of the topsheet 21 (the latter), on the premise that the liquid diffusion area of the core-wrap sheet 25 (the former) is greater than the liquid diffusion area of the topsheet 21 (the latter).

[0038] The liquid diffusion area of the sweat-absorbent sheet 10 is preferably not less than 100 mm2, more preferably not less than 150 mm2, and is preferably not greater than 1000 mm2, more preferably not greater than 800 mm2. The liquid diffusion area of the core-wrap sheet 25 is preferably not less than 120 mm2, more preferably not less than 170 mm2, and is preferably not greater than 1000 mm2, more preferably not greater than 800 mm2. The liquid diffusion area of the topsheet 21 is preferably not less than 10 mm2, more preferably not less than 20 mm2, and is preferably not greater than 300 mm2, more preferably not greater than 200 mm2, even more preferably not greater than 100 mm2.

[0039] In addition, regarding the magnitude correlation 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 is larger in liquid diffusion area than the sweat-absorbent sheet 10 from the viewpoint of enabling the sweat absorbed by the sweat-absorbent sheet 10 to efficiently transfer the core-wrap sheet 25 via the topsheet 21.

[0040] The above-mentioned transfer of sweat from sweat-absorbent sheet 10 to the topsheet 21 is feasible when a part of the sweat-absorbent sheet 10 (the end on the longitudinal inner end 10b side) is in contact with the topsheet 21, at least at the time of wearing the diaper 1. When the diaper 1 is not used, both the sheets may not be in contact with each other. This is because, as long as a part of the sweat-absorbent sheet 10 and the topsheet 21 are disposed to be opposed to each other without interposing other members between both sheets, even if these sheets are not in contact with each other when the diaper 1 is not used, it is usual that these sheets are integrally pressed against the skin of the wearer due to the contraction of the waist elastic members 33 at the time of wearing the diaper 1 and the sheets are brought into contact with each other. However, from the viewpoint of surely bringing a part of the sweat-absorbent sheet 10 into contact with the topsheet 21 at the time of wearing the diaper 1 and smoothening the transfer of sweat between both sheets, it is preferable that the sweat-absorbent sheet 10 is joined with the topsheet 21 at a portion opposed and disposed to be contactable with the topsheet 21 (the end of the longitudinal inner end 10b side), that is, an overlapping part of the sweat-absorbent sheet 10 and the topsheet 21 (part indicated by Reference A3 in Fig. 4). Such a means for joining the sweat-absorbent sheet 10 and the topsheet 21 is not particularly limited, and a known joining means such as an adhesive agent or fusion can be used.

[0041] Further, from the viewpoint of preventing the fluid return from the absorbent core 24 to the sweat-absorbent sheet 10 side, it is preferable that the joining between the sweat-absorbent sheet 10 and the topsheet 21 are partially joined. That is, it is preferable that the sweat-absorbent sheet 10 is partly joined with the topsheet 21 at the portion opposed and disposed to be contactable with the topsheet 21, that is, the overlapping part of the sweat-absorbent sheet 10 and the topsheet 21 (the part indicated by Reference A3 in Fig. 4). Partly joining both sheets can realize, at a higher level, smooth transfer of sweat from the sweat-absorbent sheet 10 to the topsheet 21 and prevention of fluid return. The pattern of the joint region for joining both sheets can be appropriately set in consideration of the balance between the sweat-absorbent performance and the fluid return prevention performance or the like.

[0042] From the viewpoint of surely exerting the above-mentioned effects, particularly from the viewpoint of the fluid return prevention, "the ratio of the total area of the joint region between both sheets 10 and 21 to the total area of the overlapping part of the sweat-absorbent sheet 10 and the topsheet 21" (joint region area occupancy) is preferably not greater than 20%, more preferably not greater than 15%. Particularly from the viewpoint of securing the transfer of sweat from the sweat-absorbent sheet 10 to the topsheet 21, the lower limit of the joint region area occupancy is preferably not less than 0.5%, more preferably not less than 2%.

[0043] From the viewpoint of satisfying the above-mentioned magnitude correlation between liquid diffusion areas in the sweat-absorbent sheet 10, the topsheet 21, and the core-wrap sheet 25 and achieving both of the sweat-absorbent performance and the fluid return prevention performance, it is preferable that the topsheet 21 is longer in inter-fiber distance (lower in fiber density), compared with the core-wrap sheet 25. In this manner, satisfying the magnitude correlation of "topsheet 21 > core-wrap sheet 25" with respect to the inter-fiber distance, or satisfying the magnitude correlation of "topsheet 21 < core-wrap sheet 25" with respect to the fiber density, is particularly effective to prevent the fluid return from the absorbent core 24 to the sweat-absorbent sheet 10 side.

[0044] Further from a similar point of view, it is preferable that the topsheet 21 is longer in inter-fiber distance (lower in fiber density) compared with the sweat-absorbent sheet 10. In adopting such a configuration, satisfying the magnitude correlation of "topsheet 21 > sweat-absorbent sheet 10" with respect to the inter-fiber distance, or satisfying the magnitude correlation of "topsheet 21 < sweat-absorbent sheet 10" with respect to the fiber density, can satisfy the magnitude correlation of "topsheet 21 < sweat-absorbent sheet 10" with respect to the liquid diffusibility. As a result, when sweating, sweat diffuses and evaporates in the sweat-absorbent sheet 10 having higher diffusibility, whereas in the case of a great amount of sweating, sweat exceeding the absorption capacity of the sweat-absorbent sheet 10 becomes transferring to the topsheet 21, and accordingly the diaper 1 is given the ability of continuously absorbing sweat. The inter-fiber distance can be measured by the following method.

[0045] <Inter-fiber distance measuring method> The inter-fiber distance of a fiber aggregate such as a nonwoven fabric or a paper can be obtained by the following formula (1) based on the assumption of Wrotnowski. The following formula (1) is generally used when determining the inter-fiber distance of the fiber aggregate. Under the assumption of Wrotnowski, fibers are columnar and respective fibers are regularly arranged without crossing. When sheet to be measured (the sweat-absorbent sheet 10, the topsheet 21, or the core-wrap sheet 25) has a single-layer structure, the inter-fiber distance of the single-layer structured sheet can be obtained by the following formula (1). When the sheet to be measured (the sweat-absorbent sheet 10, the topsheet 21, or the core-wrap sheet 25) has a multilayer structure such as an SKIS nonwoven fabric, the inter-fiber distance of the multilayer structured sheet can be obtained by 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, thickness t, basis weight W, fiber resin density p, and fiber diameter D used in the following formula (1) are respectively those of the layer to be measured. The thickness t, the basis weight W, and the fiber diameter D are average values obtained from measurement values at a plurality of measuring points, respectively. The following method is used to measure the thickness t (mm). First, a measurement object sheet is cut into the size of 50 mm in the longitudinal direction and 50 mm in the width direction to produce a cut piece of the sheet. However, when it is difficult to produce a cut piece of this size as the measurement object sheet, for example, when a sheet is collected from a small absorbent article, a largest possible cut piece is produced. Next, this cut piece is placed on a flat plate, and subsequently a flat glass plate is placed thereon. Further, a weight is placed evenly on the glass plate so that the load including the glass plate becomes 49 Pa, and the thickness of the cut piece is measured. As the measurement environment, the temperature is set to 20±2°C and the relative humidity is set to 65±5%. As a measuring equipment, a microscope (manufactured by Keyence Corporation, VHX-1000) is used. In measuring the thickness of the cut piece, first, an enlarged photo of a cut surface of the cut piece is obtained, so that this enlarged photo includes an image of an object having a known size at the same time. Next, the scale is matched with the enlarged photo of the cut surface of the cut piece, and the thickness of the cut piece, that is, the thickness of the measurement object sheet is measured. The above operations are performed three times, and an average value of the three is defined as the thickness t of the measurement object sheet. When the measurement object sheet is a laminated product, the boundary is determined from the difference in fiber diameter and/or fiber density, and the thickness is calculated. The basis weight W (g/m2) can be obtained by cutting the measurement object sheet into a predetermined size (e.g., 12 cm x 6 cm), and after mass measurement, dividing the mass measurement value by an area obtained from the predetermined size ("basis weight W (g/m2) = mass = area obtained from predetermined size"). The above measurement is performed four times, and an obtained average value is defined as the basis weight. The fiber resin density p (g/cm2) is measured using a density gradient tube in accordance with the measuring method of the density gradient tube method described in JIS L1015 Testing method for chemical staple fibers (refer to http://kikakurui.com/l/L1015-2010-01.html or JIS Handbook for fibers-2000 (Japanese Standards Association), P.764 to 765). To obtain the fiber diameter D (pm), ten cross sections of cut fibers are measured using S-4000 field emission-type scanning electron microscope manufactured by Hitachi, Ltd., and an obtained average value is defined as the fiber diameter. The method for measuring the fiber diameter D follows <Fiber diameter measuring method> described below. 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 further by totaling numerical values of the layers thus obtained, the inter-fiber di stance of a target constituent fiber of the multilayer structured sheet can be obtained. For example, in an SMS nonwoven fabric having a three-layered structure constituted by a two-layered S layer and a single-layered M layer, in which the two-layered S layer is regarded as one layer, when the entire thickness t of the three-layered structure is 0.11 mm, the thickness t of the S layer is 0.1 mm, the inter-fiber distance LS of the S layer is 47.8 him, the thickness t of the NI layer is 0.01 mm, the interfiber distance LS of the M layer is 3.2 him, the inter-fiber distance of the constituent fiber of such an SMS nonwoven fabric is 43.8 µm [=(47.9 x 0.1 + 3.2 x 0.01)/ 0.11].

[0046] [Numerical Expression 1] D leer diameter (pm) p fiber resin density (gictn3) t thickness (mm) w basis weight (g/ne) Average inter-fiber distance(m) = 106' P"In2 D (1) \ 4 * W * 109 [0047] <Fiber diameter measuring method> The measurement object (the sweat-absorbent sheet 10, the topsheet 21, or the core-wrap sheet 25) is cut with a razor (e.g., a single blade manufactured by Feather Safety Razor Co., Ltd.), to obtain a measurement piece having a rectangle shape (8 mm x 4 mm) in plan view. When cutting this measurement object, care is taken so that the structure of the cut surface of the measurement piece formed by the cutting is not broken by the pressure at the time of cutting or the like. As a preferable measurement object cutting method, there is a method for placing a measurement object in liquid nitrogen and freezing it sufficiently and subsequently cutting the measurement object. Using a double-sided paper tape (Nicetack NW-15 manufactured by Nichiban Co. Ltd.), the measurement piece is affixed to a sample stage. Next, the measurement piece is coated with platinum. For coating, an ion sputtering device E-1030 (trade name) manufactured by Hitachi Naka Seiki Co., Ltd is used, and the sputtering time is set to 30 seconds. The cut surface of the measurement piece is observed at a magnification of 1000 times using the S-4000 field emission-type scanning electron microscope manufactured by Hitachi, Ltd. For example, when the measurement object is a laminated nonwoven fabric, the boundary of each layer of the laminated nonwoven fabric is determined from the difference in fiber diameter and/or fiber density from an electron microscope image. Then, for each fiber existing in each layer, ten lengths in the width direction with respect to the longitudinal direction of the fiber are measured, and an obtained average value is defined as the fiber diameter.

[0048] The ratio of the inter-fiber distance of the topsheet 21 and the inter-fiber distance of the core-wrap sheet 25 is preferably not less than 1.5, more preferably not less than 2.0, and is preferably not greater than 10, more preferably not greater than 8, as a value obtainable by dividing the inter-fiber distance of the topsheet 21 (the former) by the inter-fiber distance of the core-wrap sheet 25 (the latter), on the premise that the inter-fiber distance of the topsheet 21 (the former) is greater than the inter-fiber distance of the core-wrap sheet 25 (the latter), as mentioned above. The ratio of the inter-fiber distance of the topsheet 21 and the inter-fiber distance of the sweat-absorbent sheet 10 is preferably not less than 1.5, more preferably not less than 2.0, and is preferably not greater than 10, more preferably not greater than 8, as a value obtainable by dividing the former by the latter, on the premise that the former is greater than the latter, as mentioned above.

[0049] It is preferable that the topsheet 21 is higher in liquid permeability compared with the sweat-absorbent sheet 10. More specifically, it is preferable that the topsheet 21 is shorter in liquid passing time measured by the following method (strike-through time measured according to the "153.0-02 REPEATED Liquid Strike-Through Time" method), compared with the sweat-absorbent sheet 10. With such a configuration, both the sweat-absorbent performance and the fluid return prevention performance can be more surely achieved. Since the liquid permeability (liquid passing time) of a fiber sheet (nonwoven fabric) such as the topsheet 21 and the sweat-absorbent sheet 10 is closely related to the inter-fiber distance, it can be adjusted by the inter-fiber distance. Regarding the interfiber distance, it is as described above. As described above, in order to satisfy the magnitude correlation of "topsheet 21 > core-wrap sheet 25" with respect to the liquid permeability, that is, the magnitude correlation of "topsheet 21 < core-wrap sheet 25" with respect to the liquid passing time, the inter-fiber distance of the topsheet 21 may be made longer than that of the core-wrap sheet 25.

[0050] <Liquid passing time (strike-through time) measuring method> A strike-through time measuring device Lister manufactured by Lenzing Technik GmbH is used for measurement according to the "153.0-02 REPEATED Liquid Strike-Through Time" method of EDANA (European Disposables and Nonwovens Association). The liquid passing time (strike-through time) indicates the time (seconds) required for a predetermined amount of test liquid to pass from one surface to the other surface of the measurement object sheet (e.g., the topsheet 21). It can be evaluated that what is shorter in liquid passing time is better in liquid permeability. Specifically, a sheet of "Kim Towel White folded in four" (manufactured by Nippon Paper Crecia Co., Ltd.) is placed in a folded state on a pedestal of a testing machine and the measurement object sheet is placed thereon. Next, an electrode equipped strike-through plate is placed on the measurement object sheet, and 5 ml of test liquid (physiologic saline) is added from a liquid inlet connected to the strike-through plate, and then the power of the testing machine is turned on. The testing machine measures the time (seconds) from when the test liquid is brought into contact with the electrode until the test liquid is released from the contact with the electrode as a result of water level drop after passing through the measurement object sheet. The measurement is performed three times, and an obtained average value is defined as liquid permeation time of the measurement object sheet.

[0051] The ratio of the liquid passing time (strike-through time) of the topsheet 21 and that of the sweat-absorbent sheet 10 is preferably not less than 0.2, more preferably not less than 0.5, and is preferably not greater than 0.9, more preferably not greater than 0.8, as a value obtainable by dividing the former by the latter, on the premise that the former is shorter than the latter. The liquid passing time (strike-through time) of the topsheet 21 is preferably not shorter than 1.5 seconds, more preferably not shorter than 2.0 seconds, and is preferably not longer than 7 seconds, more preferably not longer than 5 seconds. The liquid passing time (strike-through time) of the sweat-absorbent sheet 10 is preferably not shorter than 2 seconds, more preferably not shorter than 3 seconds, and is preferably not longer than 10 seconds, more preferably not longer than 8 seconds.

[0052] It is preferable that the skin-facing surface side of the sweat-absorbent sheet 10 is lower in hydrophilicity compared with the non-skin-facing surface side thereof When the sweat-absorbent sheet 10 has such a hydrophilicity gradient in the thickness direction, in particular, the fluid return from the absorbent core 24 to the sweat-absorbent sheet 10 side can be effectively prevented. Even when the skin-facing surface of the sweat-absorbent sheet 10, which directly contacts the skin of the wearer of the diaper 1 and absorbs sweat, is relatively low in hydrophilicity, appropriately controlling the absolute hydrophilicity of the skin-facing surface, the layer configuration of the sweat-absorbent sheet 10, or the like can make the sweat-absorbent sheet 10 excellent in sweat-absorbent performance.

[0053] As an index representing the hydrophilicity of the surface (skin-facing surface or non-skin-facing surface) of the sweat-absorbent sheet 10, the contact angle with water measured by the following method can be used. It can be determined that when the contact angle with water measured by the following method is smaller the hydrophilicity is higher (hydrophobicity is lower), and when the contact angle is larger the hydrophilicity is lower (hydrophobicity is higher).

[0054] <Fiber layer (nonwoven fabric) contact angle measuring method> From a measurement object fiber layer (nonwoven fabric), a rectangle shape in plan view of 150 mm in hiD direction and 70 mm in CD direction is cut out as a measurement sample. A droplet of ion-exchanged water is attached to the surface to be measured of the contact angle in the measurement sample, the droplet is recorded, and the contact angle is measured based on the recorded image. More specifically, the microscope VHX-1000 manufactured by Keyence Corporation is used as a measuring device, and a medium-magnification zoom lens is attached to this while it is tilted to 90°. The measurement sample is set on a measurement stage of the measuring device, so that the surface to be measured is directed upward and can be observed from CD direction of the measurement sample. Then, 3 lit droplet of ion-exchanged water is attached to the surface to be measured of the measurement sample set on the measurement stage, and an image of the droplet is recorded and taken into the measuring device. Of the recorded plurality of images, ten images that clearly show both ends or one end of the droplet in the CD direction are selected. The contact angle of the droplet is measured for each of the ten images, and an average value of the measured contact angles is defined as the contact angle of the measurement object fiber layer (nonwoven fabric). The measurement environment is set to 20°C/50%RH.

[0055] The contact angle of the skin-facing surface of the sweat-absorbent sheet 10 is preferably not less than 90 degrees, more preferably not less than 100 degrees, and is preferably not greater than 150 degrees, more preferably not greater than 140 degrees. The contact angle of the non-skin-facing surface of the sweat-absorbent sheet 10 is preferably not less than 15 degrees, more preferably not less than 20 degrees, and is preferably not greater than 88 degrees, more preferably not greater than 85 degrees.

[0056] The form of the sweat-absorbent sheet having the magnitude correlation of "skin-facing surface < non-skin-facing surface" with respect to the hydrophilicity is not particularly limited, and may have a single-layer structure. A preferable embodiment of such a sweat-absorbent sheet is "a laminated nonwoven fabric having a laminate structure including a first layer that forms a skin-facing surface and a second layer that forms a nonskin-facing surface, in which the first layer is lower in hydrophilicity compared with the second layer".

[0057] In the laminated nonwoven fabric, one or more other layers may be interposed between the first layer and the second layer, as a laminate structure. Further, it is preferable that the plurality of layers constituting the laminate structure are joined together and integrated. The joint region is preferably an interlaminar fusion part in which the thickness is smaller compared with the peripheral portion and respective layers constituting the laminate structure are mutually fused. Such an interlaminar fusion part can be formed by applying squeezing processing with a fusion promoting means for promoting melting of constituent fibers (thermoplastic fibers), such as heat and ultrasonic waves, specifically, for example, heat sealing processing or ultrasonic sealing, on the laminate structure. Moreover, it is preferable that a plurality of interlaminar fusion parts is present in a scattered manner on the skin-facing surface and/or non-skin-facing surface of the laminated nonwoven fabric. The interlaminar fusion part may be recessed in a concave shape from the skin-facing surface side to the non-skin-facing surface side, and conversely, it may be recessed in a concave shape from the non-skin-facing surface side to the skin-facing surface side, although the former is preferable.

[0058] As the fibers constituting the main part (the fibers occupying preferably 70 mass or more of all constituent fibers of the first layer) of the first layer of the laminated nonwoven fabric (the layer forming the skin-facing surface), for example, hydrophobic thermoplastic fibers (fusion bond fibers) can be used. Examples of the material for the hydrophobic thermoplastic fibers include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate; polyamides such as nylon 6 and nylon 66; polyacrylic acid, polymethacrylic acid alkyl ester, polyvinyl chloride, and polyvinylidene chloride, as hydrophobic thermoplastic resins. One of these can be used alone, or two or more can be used in combination.

[0059] Further, as the fibers constituting the main part (the fibers occupying preferably 70 mass °,/l, or more of all constituent fibers of the second layer) of the second layer of the laminated nonwoven fabric (the layer forming the non-skin-facing surface), hydrophilic thermoplastic fibers (fusion bond fibers) can be used. Specifically, for example, inherently hydrophilic thermoplastic fibers such as polyacrylonitrile fibers may be used. Alternatively, hydrophobic thermoplastic fibers usable in the first layer may be subjected to a hydrophilic treatment. One of these can be used alone, or two or more can be used in combination. Examples of the latter "thermoplastic fibers subjected to the hydrophilic treatment" include thermoplastic fibers kneaded with a hydrophilizing agent, thermoplastic fibers with a hydrophilizing agent attached to the surface thereof, and thermoplastic fibers treated with plasma. The hydrophilizing agent is not particularly limited as long as it is a general hydrophilizing agent usable for hygiene products. Further, fibers that are inherently hydrophilic, for example, natural or semi-natural fibers such as cellulose fibers can be used.

[0060] Each of the first layer and the second layer constituting the laminated nonwoven fabric may be short-fiber nonwoven fabrics mainly constituted by short fibers, or may be long-fiber nonwoven fabrics mainly constituted by long fibers. Examples of the short-fiber nonwoven fabrics include air-through nonwoven fabrics, spunlaced nonwoven fabrics, needle-punched nonwoven fabrics, and chemically bonded nonwoven fabrics. Examples of the long-fiber nonwoven fabrics include single-layer nonwoven fabrics such as spunbond nonwoven fabrics and meltblown nonwoven fabrics, or laminated nonwoven fabrics in which spunbond layers and meltblown layers mainly constituted by long fibers are laminated, or heat roller nonwoven fabrics according to the card method. Examples of the laminated nonwoven fabrics include spunbond-spunbond lamination nonwoven fabrics (SS nonwoven fabrics), spunbond-spunbond-spunbond lamination nonwoven fabrics (SSS nonwoven fabrics), spunbond-meltblown-spunbond lamination nonwoven fabrics (SMS nonwoven fabrics), and spunbond-meltblown-meltblown-spunbond nonwoven fabrics (SMMS nonwoven fabrics).

[0061] The basis weight of the first layer constituting the laminated nonwoven fabric (the layer forming the skin-facing surface) is preferably not less than 8 g/m2, more preferably not less than 10g/m2, and is preferably not greater than 30g/m2, more preferably not greater than 25g/m2. The basis weight of the second layer constituting the laminated nonwoven fabric (the layer forming the non-skin-facing surface) is preferably not less than 10g/m2, more preferably not less than]3g/m2, and is preferably not greater than 40g/m2, more preferably not greater than 35g/m2.

[0062] Further, as illustrated in Figs. 3 and 4, it is preferable that the topsheet 21 has an uneven shape on the skin-facing surface side and is contactable with the sweat-absorbent sheet 10 at projections of the uneven shape. Further, it is further preferable that the projections of the topsheet 21 and the sweat-absorbent sheet 10 are not only contactable with each other but also joined together. This is because when the sweat-absorbent sheet 10 is joined with the projections of the topsheet 21 at a portion opposed and disposed to be contactable with the topsheet 21 (the end of the longitudinal inner end 10b side), these sheets are partly joined and therefore both the smooth transfer of sweat from the sweat-absorbent sheet 10 to the topsheet 21 and the prevention of fluid return from the absorbent core 24 to the sweat-absorbent sheet 10 side can be achieved at a higher level. In addition, as another advantage of the uneven shape on the skin-facing surface of the topsheet 21, the contact area between the skin of the wearer of the diaper 1 and the topsheet 21 is reduced and therefore skin troubles can be reduced, compared with a case where the skin-facing surface has no uneven shape and is substantially flat.

[0063] The uneven shape of the skin-facing surface of the topsheet 21 is not particularly limited, and the uneven shape of the topsheet in this kind of absorbent article can be appropriately adopted. Examples of the uneven shape include a form in which a plurality of projections is disposed in a scattered manner in the whole area of the skin-facing surface of the topsheet and the periphery of each projection is depressed. The shape of the projection in plan view is not particularly limited, and may be appropriately selected from a circle, an ellipse, and a quadrilateral or more polygon. Specifically, for example, it may be desirable to provide, on the skin-facing surface of the topsheet 21, first depressions linearly arrayed in plan view and extending in a first direction that intersects both the longitudinal direction X and the lateral direction Y and second depressions linearly arrayed in plan view and extending in a second direction that intersects the first direction, so that the first and second depressions are disposed in a grid pattern, and a projection is present in each of a plurality of sections surrounded by both of the depressions. Further, as another example of the uneven shape, it may be desirable to provide projections serving as ridges extending in the longitudinal direction X or in the lateral direction Y and depressions serving as grooves extending in the same direction, so that they are alternately disposed in a direction orthogonal to the extending directions thereof. Moreover, the projections (ridges) constituting the uneven shape may have a solid structure whose inside is filled with constituent fibers of the topsheet or a hollow structure. Examples of the top sheet having hollow-structured projections include a form in which two sheets are partly joined in a laminated state, and a sheet that is relatively close to the skin of the wearer protrudes away from the other sheet (the sheet that is relatively far from the skin of the wearer), at a portion other than the joint region thereof, to form a plurality of projections protruding toward the skin side of the wearer. In addition, as illustrated in Figs. 3 and 4, it is usual that the nonskin-facing surface of the topsheet 21 (the surface facing the core-wrap sheet 25) is a flat surface that has substantially no uneven shape.

[0064] As the topsheet 21, a liquid-permeable sheet material conventionally used in this kind of absorbent article can be used. Examples thereof include various nonwoven fabrics such as nonwoven fabrics manufactured by the card method, air-through nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlaced nonwoven fabrics, and needle-punched nonwoven fabrics, and also include films made liquid permeable by an opening means. These nonwoven fabrics and films may be subjected to a hydrophilic treatment using a hydrophilizing agent such as a surfactant. The basis weight of the topsheet 21 is preferably not less than 12g/m2, more preferably not less than 15g/m2, and is preferably not greater than 50g/m2, more preferably not greater than 45g/m2.

[0065] Preferable examples of the topsheet 21 include bulky nonwoven fabrics. The bulky nonwoven fabric has numerous inner spaces (portions in which nonwoven fabric constituent components such as fibers are not present) defined by constituent fibers of the nonwoven fabric, and the ratio of the spaces to the total volume of the nonwoven fabric (space occupancy) is large. Using the bulky nonwoven fabric having the above characteristics as the topsheet 21 can effectively prevent the fluid return from the absorbent core 24 to the sweat-absorbent sheet 10 side, in particular. As the bulky nonwoven fabric, for example, an air-through nonwoven fabric, an airlaid nonwoven fabric, a resin-pond nonwoven fabric, or the like can be suitably used.

[0066] From the viewpoint of ensuring that the above-mentioned effects are exerted, an apparent density of the bulky nonwoven fabric has is preferably not less than 0.01 g/cm2, more preferably not less than 0.02 g/cm3, and is preferably not greater than 0.30 g/cm2, more preferably not greater than 020 g/cm3. From a similar point of view, the basis weight of the bulky nonwoven fabric is preferably not less than 15 g/m2, more preferably not less than 20 g/m2, and is preferably not greater than 50 g/m2, more preferably not greater than 40 g/m2.

[0067] Further, from the viewpoint of surely preventing the fluid return from the absorbent core 24 to the sweat-absorbent sheet 10 side, it is preferable that the fiber orientation of constituent fibers of the sweat-absorbent sheet 10 and the fiber orientation of constituent fibers of the topsheet 21 intersect each other. Specifically, for example, the constituent fibers of the sweat-absorbent sheet 10 may be oriented in the lateral direction Y, and the constituent fibers of the topsheet 21 may be oriented in the longitudinal direction X. Alternatively, on the contrary, the constituent fibers of the sweat-absorbent sheet 10 may be oriented in the longitudinal direction X, and the constituent fibers of the topsheet 21 may be oriented in the lateral direction Y. In the above-mentioned configuration, the expression "oriented in the longitudinal direction (lateral direction)" means that the angle formed between the longitudinal direction of the constituent fibers of the sheet and the longitudinal direction (lateral direction) of the absorbent article is not greater than 45 degrees.

[0068] In the diaper 1, as mentioned above, the sweat-absorbent sheet 10, the topsheet 21, the core-wrap sheet 25, and the absorbent core 24 are disposed at the front portion F and the rear portion R that are the waist part disposed at the waist of the wearer when worn, and a waist elastic member 33 is disposed in stretched state in the lateral direction Y. Each of the front portion F and the rear portion R has elasticity, as a whole, in the lateral direction Y. By devising the extension stress in the lateral direction Y, which is closely related to the elasticity, it is feasible to improve the sweat-absorbent performance of the diaper 1.

[0069] Specifically, as illustrated in Fig 4, the sweat-absorbent sheet 10 has a longitudinally outwardly extending portion I OS that extends outward in the longitudinal direction X from a longitudinal end 21a of the topsheet 21 at the waist part (the front portion F and the rear portion R). In the waist part, as illustrated in Figs. 2 and 4, when a region A is a region where the sweat-absorbent sheet 10 and the topsheet 21 are located at the same position in the longitudinal direction X, and a region B is a region located at the same position in the longitudinal direction X as the longitudinally outwardly extending portion 105 of the sweat-absorbent sheet 10 (the region that coincides with the arrangement region of the longitudinally outwardly extending portion 10S, in the illustrated form), the region A is larger in extension stress in the lateral direction compared with the region B, in the diaper 1. The extension stress in the lateral direction Y correlates with the tightening degree of the diaper 1 with respect to the wearer, and tightening becomes stronger as the extension stress in the lateral direction Y increases. Therefore, in the diaper 1, when the extension stress in the lateral direction Y satisfies the mutual relationship of region A greater than region B as described above, the wearer is strongly tightened in the region A that includes an overlapping region Al in which the sweat-absorbent sheet 10 and the topsheet 21 are overlapped in the thickness direction (the shaded region in Fig. 2), rather than the region B that does not include the overlapping region Al The extension stress can be measured by the following method.

[0070] <Extension stress measuring method> The diaper 1 is developed and expanded in flattened state, the regions A and B are cut out along a straight line parallel to the lateral direction Y of the diaper 1 to obtain measurement samples. This cutting is performed in such a way as to cut not only the outer cover 3 but also the entire the diaper 1 including the absorbent assembly 2 and the like. Both ends (immediately inside the side seals S) of the measurement sample in the longitudinal direction (the lateral direction Y) are sandwiched between chucks of Tensilon Universal Testing Machine (RTC-1210A) manufactured by OATEN (LC Co. Ltd, and the stress of the measurement sample is measured when the measurement sample is extended in the longitudinal direction at the speed of 300 mm/min. Specifically, when the inner dimension of the outer cover 3 (the length between the pair of side seals S and S in a state where the sheets 31 and 32 of the outer cover 3 are not contracted by the elastic member 33) is 100 (e.g., 350 mm), the tensile load (cN) measured when the measurement sample is contracted to a length corresponding to 71 (e.g., 250 mm) after once extending to a length corresponding to 80 (e.g., 280 mm) is defined 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, can be calculated as an average stress by conversion into a value per length in the longitudinal direction (the lateral direction Y) of each region. The reason why the stress of the measurement sample (the regions A and B) is defined as the return force at the length corresponding to 71 when the inner dimension of the outer cover is 100, as described above, is because the length around the abdomen of a representative infant wearing a pull-on diaper such as the diaper 1 is about 7l% when compared with the inner dimension of the diaper. The length around the abdomen, in this case, is an average value around the abdomen measured in the standing and sitting positions in consideration of changes in the circumference around the abdomen when the infant's posture changes.

[0071] As described above, in the waist part of the diaper 1 (the front portion Fand the rear portion R), the extension stress in the lateral direction Y satisfies the mutual relationship of region A > region B. Thus, the adhesion of the laminated body of the sweat-absorbent sheet 10 and the topsheet 21 existing in the region A (the overlapping region Al) to the skin of the wearer of the diaper 1 is enhanced, and therefore absorption of sweat by the sweat-absorbent sheet 10 and transfer of sweat from the sweat-absorbent sheet 10 to the topsheet 21 can be performed more smoothly. As a result, the sweat-absorbent performance of the diaper 1 can be improved. It may be expected that the sweat-absorbent performance of the diaper 1 can be improved by increasing the extension stress of the entire waist part without partly differentiating the extension stress of the waist part in this manner. However, in that case, since the skin of the wearer is strongly tightened by the entire waist part, there is a risk of causing skin troubles such as traces due to tightening remaining on the skin. In this regard, the diaper 1 is relatively free from such skin troubles caused by the tightening, since the extension stress of the portion that particularly affects the improvement of the sweat-absorbent performance (the overlapping region) is selectively set to be larger. In addition, the region A has a higher cushioning property because it includes the laminate structure of a plurality of layers including the sweat-absorbent sheet 10 and the topsheet 21. Therefore, even if the tightening of the region A is slightly increased, a trace is seldom left on the skin.

[0072] The ratio of the extension stress in the lateral direction Yin the region A and the extension stress in the lateral direction Y in the region B is preferably not less than 1.05, more preferably not less than 1.1, and is preferably not greater than 2.5, more preferably not greater than 2.0, as a value obtainable by dividing the region A by the region B, on the premise that the region A is greater than the region B. The extension stress in the lateral direction Y in the region A is preferably not less than 0.04 N/mm, more preferably not less than 0.05 N/mm, and is preferably not greater than 0.12 N/mm, more preferably not greater than 0.10 N/mm. The extension stress in the lateral direction Y in the region B is preferably not less than 0.02 N/mm, more preferably not less than 0.04 N/mm, and is preferably not greater than 0.10 N/mm, more preferably not greater than 0.08 N/mm.

[0073] The extension stress (elasticity) of each of the region A (the overlapping region At and the regions A2 and A3 described below) and the region B in the lateral direction Y is adjustable by appropriately setting the number of the waist elastic members 33 disposed in the regions A and B and in the vicinity thereof, the thickness of the elastic member 33, and the clearance between respective elastic members 33, and also by selecting the type (elasticity) of the sheet-like member, that is, each of the outer sheet 31 and the inner sheet 32, to which the elastic members 33 are fixed.

[0074] Further, in the diaper 1, as illustrated in Fig. 2, the waist part is segmented into the front portion F and the rear portion R, and the topsheet 21 (the absorbent assembly 2) is disposed at the center in the lateral direction Y of the region A (the region in which the sweat-absorbent sheet 10 and the topsheet 21 are in the same position in the longitudinal direction X) of each of the front portion F and the rear portion R. The sweat-absorbent sheet 10 extends in the lateral direction Y over the center of the region A in the lateral direction Y and both sides thereof, and the center of the region A in the lateral direction Y is the overlapping region Al where the sweat-absorbent sheet 10 and the topsheet 21 are overlapped in the thickness direction. The overlapping region Al is lower in elasticity in the lateral direction Y compared with both outer sides in the lateral direction Y (both laterally sides of the region A). The both sides in the lateral direction Y of the region A are the 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 topsheet 21 (the absorbent assembly 2), and are non-overlapping regions in which the sweat-absorbent sheet 10 does not overlap the topsheet 21 in the thickness direction. In this manner, when the mutual relationship "laterally center part (overlapping region Al)< both laterally sides (the non-overlapping portion)" is satisfied with respect to the elasticity in the lateral direction Y of the region A in each of the front portion F and the rear portion R, the adhesion of the sweat-absorbent sheet 10 to the skin of the wearer of the diaper 1 can be enhanced and therefore the sweat-absorbent performance of the diaper 1 can be improved. In particular, satisfying the above-mentioned mutual relationship of region A > region B with respect to the extension stress in the lateral direction Y in the waist part (the front portion F, the rear portion R) exerts the effect of further improving the sweat-absorbent performance of the diaper 1 together with the effects brought by the above mutual relationship.

[0075] The center of the region A in the lateral direction Y (the overlapping region Al) is the region where plural members such as the absorbent core 24 having a relatively large thickness in addition to the sweat-absorbent sheet 10 and the topsheet 21 are overlapped, and is rigid compared with both sides in the lateral direction Y (the non-overlapping portion). If the elasticity in the lateral direction Y of such a high-rigid overlapping region Al is not so different from that of the peripheral portion, a crease extending in the longitudinal direction X will be likely to occur on the sweat-absorbent sheet 10 that forms a skin-facing surface in the overlapping region Al. When the sweat-absorbent sheet 10 with such vertical creases are brought into contact with the skin of the wearer of the diaper 1, there is a risk of deteriorating the adhesion of the sweat-absorbent sheet 10 to the skin because of gaps formed between them. Hence, in the diaper 1, as described above, the elasticity in the lateral direction Y in the region A of each of the front portion F and the rear portion R is set to satisfy the mutual relationship of laterally center part (overlapping region Al) < both laterally sides (the non-overlapping portion), so that the occurrence of vertical creases on the skin-facing surface of the sweat-absorbent sheet 10 in the overlapping region Al can be suppressed, thereby enhancing the adhesion of the sweat-absorbent sheet 10 to the skin and improving the sweat-absorbent performance of the diaper 1.

[0076] Examples of the method for establishing the magnitude correlation of "laterally center part (overlapping region Al) < both laterally sides (the non-overlapping portion)" with respect to the elasticity in the lateral direction Y in the region A include a method for intentionally lowering the elasticity in the lateral direction Y in the overlapping region Al, more specifically, a method for applying extension inhibition processing such as cutting or heating on the waist elastic members 33 existing in the overlapping region Al. The overlapping region Al subjected to such extension inhibition processing may have no elasticity in the lateral direction Y or may have some elasticity in the lateral direction Y due to the elasticity remaining in the waist elastic members 33 subjected to the extension inhibition processing.

[0077] In the diaper 1, as illustrated in Figs. 2 and 4, in the overlapping region Al where the sweat-absorbent sheet 10 and the topsheet 21 are overlapped in the thickness direction, the hydrophobic sheet 11 is interposed between both sheets 10 and 21. The sweat-absorbent sheet 10 has a longitudinally inwardly extending portion 10T (see Fig. 4) that extends inward in the longitudinal direction X from a longitudinal inner end 1 lb of the hydrophobic sheet 11. The longitudinally inwardly extending portion 10T, that is, the end on the longitudinal inner end 10b side of the sweat-absorbent sheet 10, is opposed and disposed to be contactable with the topsheet 21. The hydrophobic sheet 11 is a sheet that has at least a hydrophobic surface and does not absorb any sweat, and is typical made of a nonwoven fabric that is configured to include hydrophobic fibers (fusion bond fibers). As this king of nonwoven fabric, those usable as the sweat-absorbent sheet 10 can be used. As described above, the hydrophobic sheet 11 through which body fluid such as urine is impermeable is interposed between the topsheet 21 and the sweat-absorbent sheet 10 disposed on the skin-facing surface side of the absorbent core 24 in the overlapping region Al. Thus, the fluid return from the absorbent core 24 to the sweat-absorbent sheet 10 side can be effectively prevented. The sweat-absorbent sheet 10, the hydrophobic sheet 11, and the topsheet 21 may be joined together by a known joining means such as an adhesive agent or fusion.

[0078] The hydrophobic sheet 11 in the diaper 1 is a part of the outer sheet 31 that constitutes the outer cover 3. That is, the outer sheet 31 is longer in the longitudinal direction X than the inner sheet 32, and has extension portions extending from both ends of the inner sheet 32 in the longitudinal direction X. As illustrated in Figs. 2 and 4, each of the extension portions is folded back to the skin-facing surface side of the inner sheet 32 to form the folded part 31E. The folded part 31E is the hydrophobic sheet 11. The hydrophobic sheet 11 (the folded part 31E) has the same shape in plan view as the sweat-absorbent sheet 10, and the shape thereof is long in one direction in plan view, specifically, a rectangular(continuous) shape, and is disposed over the entire length in the lateral direction Y of each of the front portion F and the rear portion R while the longitudinal direction thereof is aligned with the lateral direction Y. The hydrophobic sheet 11 is disposed along the longitudinal end 23a of the absorbent member 23, that is, the longitudinal end of the absorbent assembly 2 in an overlapped manner.

[0079] Further, in the diaper 1, as illustrated in Fig. 4, in the region A (the region in which the sweat-absorbent sheet 10 and the topsheet 21 are in the same position in the longitudinal direction X), the extension stress in the lateral direction Y is larger in the region A2 in which the sweat-absorbent sheet 10 and the hydrophobic sheet 11 are in the same position in the longitudinal direction X, compared with the region A3 located at the same position in the longitudinal direction X as the longitudinally inwardly extending portion 10T of the sweat-absorbent sheet 10. That is, in the overlapping region Al (the region in which the sweat-absorbent sheet 10 and the topsheet 21 are overlapped in the thickness direction) that is a part of the region A (the center in the lateral direction Y), the extension stress in the lateral direction Y is larger in the arrangement region of the hydrophobic sheet 11 (the region A2) rather than the non-arrangement region of the hydrophobic sheet 11 (the region A3). With such a configuration, since the hydrophobic sheet 11 fits well to the skin of the wearer of the diaper 1, the inconvenience can be effectively prevented, for example, body fluid such as urine absorbed by the absorbent core 24 can be prevented from leaking out through the sweat-absorbent sheet 10.

[0080] The ratio of the extension stress in the lateral direction Y in the region A2 and the extension stress in the lateral direction Y in the region A3 is preferably not less than 1.03, more preferably not less than 1.05, and is preferably not greater than 2.5, more preferably not greater than 2.0, as a value obtainable by dividing the region A2 by the region A3, on the premise that the region A2 is greater than the region A3. The extension stress in the lateral direction Y in the region A2 is preferably not less than 0.04 N/mm, more preferably not less than 0.05 N/mm, and is preferably not greater than 0.12 N/mm, more preferably not greater than 0.10 N/mm. The extension stress in the lateral direction Y in the region A3 is preferably not less than 0.02 N/mm, more preferably not less than 0.03 N/mm, and is preferably not greater than 0.10 N/mm, more preferably not greater than 0.08 N/mm.

[0081] Further, from the viewpoint of surely exerting the above-mentioned body fluid leakage prevention effect by the sweat-absorbent sheet 10, it is preferable that the region A2 in which the sweat-absorbent sheet 10 and the hydrophobic sheet 11 are in the same position in the longitudinal direction X, of the region A (the region in which the sweat-absorbent sheet 10 and the topsheet 21 are in the same position in the longitudinal direction X), has elasticity in the lateral direction Y. Specifically, it is preferable that the region A2 is provided with at least one waist elastic member 33 disposed in a state where it has elasticity in the lateral direction Y. On the other hand, as mentioned above, from the viewpoint of preventing the occurrence of vertical creases on the skin-facing surface of the sweat-absorbent sheet 10 in the overlapping region Al that is the center of the region A in the lateral direction Y, it is preferable that the elasticity of the waist elastic member 33 is inhibited, in the region A3 located at the same position in the longitudinal direction as the longitudinally inwardly extending portion 10T of the sweat-absorbent sheet 10, that is, the non-arrangement region of the hydrophobic sheet 11 in the region A. [0082] Figs. 5 to 7 illustrate another embodiments of the present invention. In another embodiments described below, configurations different from those of the above-mentioned diaper 1 are mainly described, and similar components are denoted by the same reference numerals and redundant description thereof is avoided. The above description about the diaper 1 is appropriately applied to configurations not specifically described below.

[0083] A diaper 1 A illustrated in Fig. 5 is different in that the hydrophobic sheet 11 is as an independent single constituent member, compared with the diaper 1 (see Fig. 4) in which the hydrophobic sheet 11 is a part (the folded part 31E) of the outer sheet 31. The hydrophobic sheet 11 is joined via an adhesive agent 12 to the sweat-absorbent sheet 10 and the outer cover 3 (the inner sheet 32). Effects similar to those of the diaper 1 can be exerted by the diaper IA.

[0084] A diaper lB illustrated in Fig. 6 is different from the diaper 1 (see Fig. 4) in that the hydrophobic sheet 11 is not provided. Because of no provision of the hydrophobic sheet 11, the diaper 1B is inferior to the diaper 1 including this with respect to the performance of preventing fluid return from the absorbent core 24 to the sweat-absorbent sheet 10 side. However, the rest of the configuration is substantially the same as that of the diaper 1, and therefore both the smooth transfer of sweat from the sweat-absorbent sheet 10 to the topsheet 21 and the prevention of fluid return can be achieved at a higher level.

[0085] A diaper IC illustrated in Fig. 7 is different from the diaper 1 (see Fig. 4) in that the absorbent member 23 is not disposed in the region (overlapping region)A1 in which the sweat-absorbent sheet 10 and the topsheet 21 are overlapped in the thickness direction. More specifically, in the rear portion R (the front portion F) of the diaper 1C, the sweat-absorbent sheet 10 is positioned only in the region (end flap region) located outside the longitudinal end 23a of the absorbent member 23 and the imaginary extended line thereof in the longitudinal direction X, and is not overlapped with the absorbent member 23 in plan view. Further, the topsheet 21 extends outward in the longitudinal direction X from the longitudinal end 23a of the absorbent member 23. An extension portion from the longitudinal end 23a of the topsheet 21 is overlapped with the sweat-absorbent sheet 10, and the overlapping region Al is formed at an outer position in the longitudinal direction X than the absorbent member 23. In the form illustrated in Fig. 7, the backsheet 22 also extends outward in the longitudinal direction X from the longitudinal end 23a of the absorbent member 23, and is in contact with the non-skin-facing surface of the topsheet 21 in the overlapping region Al. In this embodiment, the configuration that "the absorbent member 23 is not disposed" includes a form in which none of all constituent members (the absorbent core 24 and core-wrap sheet 25) of the absorbent member 23 is disposed and a form in which only a part of the constituent members of the absorbent member 23 is disposed and the rest is not disposed. The form illustrated in Fig. 7 is the former, in which both the absorbent core 24 and core-wrap sheet 25 are not disposed in the overlapping region Al. Further, the diaper 1C is different from the diaper 1 in that the hydrophobic sheet 11 is not provided. However, the diaper 1C may include the hydrophobic sheet 11, and in that case, the hydrophobic sheet 11 may be interposed between the sweat-absorbent sheet 10 and the topsheet 21 in the overlapping region Al. Further, as illustrated in Fig. 4, it may be a part (the folded part 31E) of the outer sheet 31, or as illustrated in Fig. 5, it may be an independent single constituent member. Moreover, in the diaper 1C, the topsheet 21 does not have an uneven shape on the skin-facing surface side, and the skin-facing surface of the topsheet 21 is a flat surface. However, topsheet 21 may have an uneven shape. Such an uneven shape of the topsheet 21 is as mentioned above. Effects similar to those of the diaper 1B can be exerted by the diaper IC. In particular, the configuration that the absorbent member 23 is not disposed in the region At in which the sweat-absorbent sheet 10 and the topsheet 21 are overlapped with each other exerts the effect of suppressing body fluid from returning from the absorbent member 23 to the wearer side, when the load of the wearer is imparted on the overlapping region Al, in a state where the absorbent member 23 absorbs and retains body fluid.

[0086] Although the present invention has been demonstrated based on some embodiments thereof, the present invention is not limited to these embodiments and can be appropriately modified. The parts only described in one or some of the above-mentioned embodiments can be appropriately and mutually used in another embodiments. For example, in the diaper 1, as illustrated in Fig. 2, the outer cover 3 has a continuous shape extending over the front portion F, the crotch portion NT, and the rear portion R. Alternatively, the outer cover 3 may be configured to include a front sheet member and a rear sheet member as separate members and the absorbent assembly 2 may be fixed over both of these members. Further, in the above embodiment, although the sweat-absorbent sheet 10 is disposed over the entire length in the lateral direction Y of each of the front portion F and the rear portion R, the arrangement of the sweat-absorbent sheet 10 is not limited to the described example. When the role of the sweat-absorbent sheet 10 is taken into consideration, the length of the sweat-absorbent sheet 10 in the lateral direction Y is preferably equal to or greater than that of the absorbent member 23. Regarding the arrangement of the sweat-absorbent sheet 10, it is preferable that the sweat-absorbent sheet 10 is disposed over the entire length of at least the absorbent member 23 in the lateral direction Yin each of the front portion F and the rear portion R. It is more preferable that the sweat-absorbent sheet 10 is disposed over the entire length of each of the front portion F and the rear portion R in the lateral direction Y, as in the above-described embodiment. Moreover, the sweat-absorbent sheet 10 may not be disposed in both of the front portion F and the rear portion R, or in either one of them, and in that case, it is preferable that the sweat-absorbent sheet 10 is disposed in the rear portion R. In addition, the absorbent article according to the present invention is not limited to the pull-on disposable diaper such as the above-mentioned diaper 1, and can be applied to all articles used for absorption of body fluid. For example, it can be applied to open-type disposable diapers. Further, the following additional notes are disclosed with respect to the above-mentioned embodiments of the present invention.

[0087] <1> An absorbent article having a longitudinal direction corresponding to a front-back direction of a wearer and a lateral direction orthogonal to the longitudinal direction, comprising a liquid-retentive absorbent core and a core-wrap sheet in contact with a skin-facing surface of the absorbent core, and including a topsheet and a sweat-absorbent sheet, the topsheet and the sweat-absorbent sheet being disposed on a skin-facing surface side of the core-wrap sheet in the order closer to the core-wrap sheet, wherein the sweat-absorbent sheet has a part that is opposed and disposed to be contactable with the topsheet, and the liquid diffusibility of the topsheet is lower than the liquid diffusibility of the sweat-absorbent sheet and is lower than the liquid diffusibility of the core-wrap sheet.

<2> The absorbent article as set forth in clause <1>, wherein the ratio of the liquid diffusion area of the sweat-absorbent sheet and the liquid diffusion area of the topsheet is preferably not less than 1.5, more preferably not less than 2.0, and is preferably not greater than 30, more preferably not greater than 15, as a value obtainable by dividing the former by the latter, on the premise that the former is greater than the latter.

<3> The absorbent article as set forth in clause <1> or <2>, wherein the ratio of the liquid diffusion area of the core-wrap sheet and the liquid diffusion area of the topsheet is preferably not less than 2.0, more preferably not less than 2.5, and is preferably not greater than 40, more preferably not greater than 35, as a value obtainable by dividing the former by the latter, on the premise that the former is greater than the latter.

<4> The absorbent article as set forth in any one of clauses <1> to <3>, wherein the liquid diffusion area of the sweat-absorbent sheet is preferably not less than 100 mm2, more preferably not less than 150 mm2, and is preferably not greater than 1000 mm2, more preferably not greater than 800 mm2 <5> The absorbent article as set forth in any one of clauses <1> to <4>, wherein the liquid diffusion area of the core-wrap sheet is preferably not less than 120 mm2, more preferably not less than 170 mm2, and is preferably not greater than 1000 mm2, more preferably not greater than 800 mm2 <6> The absorbent article as set forth in any one of clauses <1> to <5>, wherein the liquid diffusion area of the topsheet is preferably not less than 10 mm2, more preferably not less than 20 mm2, and is preferably not greater than 300 mm2, more preferably not greater than 200 mm2, even more preferably not greater than 100 mm2.

<7> The absorbent article as set forth in any one of clauses <1> to <6>, wherein the core-wrap sheet is larger in liquid diffusion area compared with the sweat-absorbent sheet.

[0088] <8> The absorbent article as set forth in any one of clauses <1> to <7>, wherein the absorbent article includes a waist part disposed at the waist of the wearer when worn, the sweat-absorbent sheet, the topsheet, the core-wrap sheet, and the absorbent core are disposed at the waist part, an elastic member is disposed in stretched state in the lateral direction, the sweat-absorbent sheet has a longitudinally outwardly extending portion that extends outward in the longitudinal direction from a longitudinal end of the topsheet, at the waist part, and further in the waist part, when a region A is a region where the sweat-absorbent sheet and the topsheet are in the same position in the longitudinal direction, and a region B is a region located at the same position in the longitudinal direction as the longitudinally outwardly extending portion of the sweat-absorbent sheet, the region A is larger in extension stress in the lateral direction compared with the region B. <9> The absorbent article as set forth in clause <8>, wherein the waist part is segmented into a front portion disposed on the front side and a rear portion disposed on the rear side of the wearer when worn, the topsheet is disposed at a laterally center part of the region A of each of the front portion and the rear portion, the sweat-absorbent sheet extends in the lateral direction over the laterally center part of the region A and both sides thereof, the laterally center part of the region A where the sweat-absorbent sheet and the topsheet are overlapped in the thickness direction is lower in elasticity in the lateral direction compared with both laterally sides of the region A. <10> The absorbent article as set forth in any one of clauses <1> to <9>, wherein the sweat-absorbent sheet is joined with the topsheet at a portion opposed and disposed to be contactable with the topsheet.

<11> The absorbent article as set forth in clause <10>, wherein the joining between the sweat-absorbent sheet and the topsheet is partial joining.

<12> The absorbent article as set forth in clause <11>, wherein the ratio of the total area of a joint region of both sheets to the total area of an overlapping part of the sweat-absorbent sheet and the topsheet is preferably not greater than 20%, more preferably not greater than 15%.

<13> The absorbent article as set forth in any one of clauses <1> to <12>, wherein the topsheet is higher in liquid-permeability compared with the sweat-absorbent sheet, more specifically, the topsheet is shorter in liquid passing time (strike-through time measured according to the "153.0-02 REPEALED Liquid Strike-Through Time" method), compared with the sweat-absorbent sheet.

[0089] <14> The absorbent article as set forth in any one of clauses <1> to <13>, wherein the sweat-absorbent sheet has a skin-facing surface side that is lower in hydrophilicity compared with a non-skin-facing surface side thereof <15> The absorbent article as set forth in any one of clauses <1> to <14>, wherein the contact angle of the skin-facing surface of the sweat-absorbent sheet is preferably not less than 90 degrees, more preferably not less than 100 degrees, and is preferably not greater than 150 degrees, more preferably not greater than 140 degrees.

<16> The absorbent article as set forth in any one of clauses <1> to <15>, wherein the contact angle of the non-skin-facing surface of the sweat-absorbent sheet is preferably not less than 15 degrees, more preferably not less than 20 degrees, and is preferably not greater than 88 degrees, more preferably not greater than 85 degrees.

<17> The absorbent article as set forth in any one of clauses <1> to <16>, wherein the sweat-absorbent sheet is a laminated nonwoven fabric having a laminate structure including a first layer that forms a skin-facing surface and a second layer that forms a non-skin-facing surface, in which the first layer is lower in hydrophilicity compared with the second layer.

[0090] <18> The absorbent article as set forth in any one of clauses <1> to <17>, wherein the topsheet has an uneven shape on the skin-facing surface side, and projections of the uneven shape are contactable with the sweat-absorbent sheet.

<19> The absorbent article as set forth in clause <18>, wherein the uneven shape of the topsheet is a shape in which a plurality of projections is disposed in a scattered manner in the whole area of the skin-facing surface of the topsheet, and the periphery of each projection is depressed.

<20> The absorbent article as set forth in clause <18> or <19>, wherein the projections of the topsheet and the sweat-absorbent sheet are joined.

<21> The absorbent article as set forth in any one of clauses <1> to <20>, wherein the topsheet is a bulky nonwoven fabric, and an apparent density of the bulky nonwoven fabric is preferably not less than 0.01 g/cm3, more preferably not less than 0.02 g/cm3, and is preferably not greater than 0.30 g/cm3, more preferably not greater than 0.20 g/cm3.

[0091] <22> The absorbent article as set forth in any one of clauses <1> to <21>, wherein the ratio of the extension stress in the lateral direction in the region A and the extension stress in the lateral direction in the region B is preferably not less than 1.05, more preferably not less than 1.1, and is preferably not greater than 2.5, more preferably not greater than 2.0, as a value obtainable by dividing the region A by the region B, on the premise that the region A is greater than the region B. <23> The absorbent article as set forth in any one of clauses <1> to <22>, wherein the extension stress in the lateral direction in the region A is preferably not less than 0.04 N/mm, more preferably not less than 0.05 N/mm, and is preferably not greater than 0.12 N/mm, more preferably not greater than 0.10 N/mm.

<24> The absorbent article as set forth in any one of clauses <1> to <23>, wherein the extension stress in the lateral direction in the region B is preferably not less than 0.02 N/mm, more preferably not less than 0.04 N/mm, and is preferably not greater than 0.10 N/mm, more preferably not greater than 0.08 N/mm.

[0092] <25> The absorbent article as set forth in any one of clauses <1> to <24>, wherein a hydrophobic sheet is interposed between the sweat-absorbent sheet and the topsheet in a region Al where the sweat-absorbent sheet and the topsheet are overlapped in the thickness direction, and the sweat-absorbent sheet has a longitudinally inwardly extending portion that extends inward in the longitudinal direction from a longitudinal inner end of the hydrophobic sheet, and the longitudinally inwardly extending portion is opposed and disposed to be contactable with the topsheet.

<26> The absorbent article as set forth in clause <25>, wherein a region (Region A2) where the sweat-absorbent sheet and the hydrophobic sheet are in the same position in the longitudinal direction is larger in extension stress in the lateral direction compared with a region (Region A3) located at the same position in the longitudinal direction as the longitudinally inwardly extending portion of the sweat-absorbent sheet.

<27> The absorbent article as set forth in clause <26>, wherein the ratio of the extension stress in the lateral direction in the region A2 and the extension stress in the lateral direction in the region A3 is preferably not less than 1.03, more preferably not less than 1.05, and is preferably not greater than 2.5, more preferably not greater than 2.0, as a value obtainable by dividing the region A2 by the region A3, on the premise that the region A2 is greater than the region A3.

<28> The absorbent article as set forth in clause <26> or <27>, wherein the extension stress in the lateral direction in the region A2 is preferably not less than 0.04 N/mm, more preferably not less than 0.05 N/mm, and is preferably not greater than 0.12 N/mm, more preferably not greater than 0.10 N/mm.

<29> The absorbent article as set forth in any one of clauses <26> to <28>, wherein the extension stress in the lateral direction in the region A3 is preferably not less than 0.02 N/mm, more preferably not less than 0.03 N/mm, and is preferably not greater than 0.10 N/mm, more preferably not greater than 0.08 N/mm.

<30> The absorbent article as set forth in any one of clauses <26> to <29>, wherein the region A2 has elasticity in lateral direction.

[0093] <31> The absorbent article as set forth in any one of clauses <1> to <30>, wherein the topsheet is longer in inter-fiber distance compared with the core-wrap sheet.

<32> The absorbent article as set forth in any one of clauses <1> to <31>, wherein the ratio of the inter-fiber distance of the topsheet and the inter-fiber distance of the core-wrap sheet is preferably not less than 1.5, more preferably not less than 2.0, and is preferably not greater than 10, more preferably not greater than 8, as a value obtainable by dividing the former by the latter, on the premise that the former is greater than the latter.

<33> The absorbent article as set forth in any one of clauses <1> to <32>, wherein the topsheet is lower in fiber density compared with the core-wrap sheet.

<34> The absorbent article as set forth in any one of clauses <1> to <33>, wherein the topsheet is longer in inter-fiber distance compared with the sweat-absorbent sheet.

<35> The absorbent article as set forth in any one of clauses <1> to <34>, wherein the ratio of the inter-fiber distance of the topsheet and the inter-fiber distance of the sweat-absorbent sheet is preferably not less than 1.5, more preferably not less than 2.0, and is preferably not greater than 10, more preferably not greater than 8, as a value obtainable by dividing the former by the latter, on the premise that the former is greater than the latter. <36> The absorbent article as set forth in any one of clauses <1> to <35>, wherein the topsheet is lower in fiber density compared with the sweat-absorbent sheet.

<37> The absorbent article as set forth in any one of clauses <1> to <36>, wherein the fiber orientation of constituent fibers of the sweat-absorbent sheet and the fiber orientation of constituent fibers of the topsheet intersect each other.

<38> The absorbent article as set forth in any one of clauses <1> to <37>, wherein the absorbent article includes a waist part disposed at the waist of the wearer when worn, and the waist part is segmented into a front portion disposed on the front side and a rear portion disposed on the rear side of the wearer when worn, the sweat-absorbent sheet has a shape that is long in one direction (rectangular shape) in plan view, and is disposed over the entire length in the lateral direction of each of the front portion and the rear portion while the longitudinal direction thereof is aligned with the lateral direction of the absorbent article. <39> The absorbent article as set forth in any one of clauses <1> to <38>, wherein the absorbent core is not disposed in the region Al where the sweat-absorbent sheet and the topsheet are overlapped in the thickness direction.

<40> The absorbent article as set forth in any one of clauses 1 to 39, wherein the core-wrap sheet is not disposed in the region Al where the sweat-absorbent sheet and the topsheet are overlapped in the thickness direction.

Industrial Applicability

[0094] The present invention can provide an absorbent article that can quickly absorb a great amount of sweat and can reduce the inconvenience that absorbed body fluid returns to the skin side of a wearer, thereby hardly causing skin troubles resulting from the body fluid.

Claims

CLAIMS1. An absorbent article having a longitudinal direction corresponding to a front-back direction of a wearer and a lateral direction orthogonal to the longitudinal direction, comprising a liquid-retentive absorbent core and a core-wrap sheet in contact with a skin-facing surface of the absorbent core, and including a topsheet and a sweat-absorbent sheet, the topsheet and the sweat-absorbent sheet being disposed on a skin-facing surface side of the core-wrap sheet in the order closer to the core-wrap sheet, wherein the sweat-absorbent sheet has a part that is opposed and disposed to be contactable with the topsheet, and the liquid diffusibility of the topsheet is lower than the liquid diffusibility of the sweat-absorbent sheet and is lower than the liquid diffusibility of the core-wrap sheet.
2. The absorbent article according to claim 1, wherein the ratio of the liquid diffusion area of the sweat-absorbent sheet and the liquid diffusion area of the topsheet is not less than 1.5 and not greater than 30, as a value obtainable by dividing the former by the latter, on the premise that the former is greater than the latter.
3. The absorbent article according to claim 1 or 2, wherein the ratio of the liquid diffusion area of the core-wrap sheet and the liquid diffusion area of the topsheet is not less than 2.0 and not greater than 40, as a value obtainable by dividing the former by the latter, on the premise that the former is greater than the latter.
4. The absorbent article according to any one of claims I to 3, wherein the liquid diffusion area of the sweat-absorbent sheet is not less than 100 mm2 and not greater than 1000 mm2.
The absorbent article according to any one of claims 1 to 4, wherein the liquid diffusion area of the core-wrap sheet is not less than 120 mm2 and not greater than 1000 ITIM.
6. The absorbent article according to any one of claims 1 to 5, wherein the liquid diffusion area of the topsheet is not less than 10 mm2 and not greater than 300 mm2.
7. The absorbent article according to any one of claims 1 to 6, wherein the core-wrap sheet is larger in liquid diffusion area compared with the sweat-absorbent sheet.
8. The absorbent article according to any one of claims 1 to 7, wherein the absorbent article includes a waist part disposed at the waist of the wearer when worn, the sweat-absorbent sheet, the topsheet, the core-wrap sheet, and the absorbent core are disposed at the waist part, an elastic member is disposed in stretched state in the lateral direction, the sweat-absorbent sheet has a longitudinally outwardly extending portion that extends outward in the longitudinal direction from a longitudinal end of the topsheet, at the waist part, and further in the waist part, when a region A is a region where the sweat-absorbent sheet and the topsheet are in the same position in the longitudinal direction, and a region B is a region located at the same position in the longitudinal direction as the longitudinally outwardly extending portion of the sweat-absorbent sheet, the region A is larger in extension stress in the lateral direction compared with the region B.
9. The absorbent article according to claim 8, wherein the waist part is segmented into a front portion disposed on the front side and a rear portion disposed on the rear side of the wearer when worn, the topsheet is disposed at a laterally center part of the region A of each of the front portion and the rear portion, the sweat-absorbent sheet extends in the lateral direction over the laterally center part of the region A and both sides thereof, the laterally center part of the region A where the sweat-absorbent sheet and the topsheet are overlapped in the thickness direction is lower in elasticity in the lateral direction compared with both laterally sides of the region A. 10. The absorbent article according to any one of claims 1 to 9, wherein the sweat-absorbent sheet is joined with the topsheet at a portion opposed and disposed to be contactable with the topsheet.11. The absorbent article according to claim 10, wherein the joining between the sweat-absorbent sheet and the topsheet is partial joining.12. The absorbent article according to claim ll, wherein the ratio of the total area of a joint region of both sheets to the total area of an overlapping part of the sweat-absorbent sheet and the topsheet is not greater than 20%.13. The absorbent article according to any one of claims 1 to 12, wherein the topsheet is higher in liquid-permeability compared with the sweat-absorbent sheet.14. The absorbent article according to any one of claims 1 to 13, wherein the sweat-absorbent sheet has a skin-facing surface side that is lower in hydrophili city compared with a non-skin-facing surface side thereof 15. The absorbent article according to any one of claims 1 to 14, wherein the contact angle of the skin-facing surface of the sweat-absorbent sheet is not less than 90 degrees and not greater than 150 degrees.16. The absorbent article according to any one of claims 1 to 15, wherein the contact angle of the non-skin-facing surface of the sweat-absorbent sheet is not less than 15 degrees and not greater than 88 degrees 17. The absorbent article according to any one of claims 1 to 16, wherein the sweat-absorbent sheet is a laminated nonwoven fabric having a laminate structure including a first layer that forms a skin-facing surface and a second layer that forms a non-skin-facing surface, in which the first layer is lower in hydrophilicity compared with the second layer.18. The absorbent article according to any one of claims 1 to 17, wherein the topsheet has an uneven shape on the skin-facing surface side, and projections of the uneven shape are contactable with the sweat-absorbent sheet.19. The absorbent article according to claim 18, wherein the uneven shape of the topsheet is a shape in which a plurality of projections is disposed in a scattered manner in the whole area of the skin-facing surface of the topsheet, and the periphery of each projection is depressed.20. The absorbent article according to claim 18 or 19, wherein the projections of the topsheet and the sweat-absorbent sheet are joined.21. The absorbent article according to any one of claims I to 20, wherein the topsheet is a bulky nonwoven fabric, and an apparent density of the bulky nonwoven fabric is not less than 0.01 g/cm3 and not greater than 0.30 g/cm3.22. The absorbent article according to claim 8 or 9, wherein the ratio of the extension stress in the lateral direction in the region A and the extension stress in the lateral direction in the region B is not less than 1.05 and not greater than 2.5, as a value obtainable by dividing the region A by the region B, on the premise that the region A is greater than the region B. 23. The absorbent article according to any one of claims 8, 9, and 22, wherein the extension stress in the lateral direction in the region A is not less than 0.04 N/mm and not greater than 0.12 N/mm.24. The absorbent article according to any one of claims 8, 9, 22, and 23, wherein the extension stress in the lateral direction in the region B is not less than 0.02 N/mm and not greater than 0.10 N/mm.25. The absorbent article according to any one of claims 1 to 24, wherein a hydrophobic sheet is interposed between the sweat-absorbent sheet and the topsheet in a region Al where the sweat-absorbent sheet and the topsheet are overlapped in the thickness direction, and the sweat-absorbent sheet has a longitudinally inwardly extending portion that extends inward in the longitudinal direction from a longitudinal inner end of the hydrophobic sheet, and the longitudinally inwardly extending portion is opposed and disposed to be contactable with the topsheet.26. The absorbent article according to claim 25, wherein a region A2 where the sweat-absorbent sheet and the hydrophobic sheet are in the same position in the longitudinal direction is larger in extension stress in the lateral direction compared with a region A3 located at the same position in the longitudinal direction as the longitudinally inwardly extending portion of the sweat-absorbent sheet.27. The absorbent article according to claim 26, wherein the ratio of the extension stress in the lateral direction in the region A2 and the extension stress in the lateral direction in the region A3 is not less than 1.03 and not greater than 2.5, as a value obtainable by dividing the region A2 by the region A3, on the premise that the region A2 is greater than the region A3 28. The absorbent article according to claim 26 or 27, wherein the extension stress in the lateral direction in the region A2 is not less than 0.04 N/mm and not greater than 0.12 N/mm.29. The absorbent article according to any one of claim 26 to 28, wherein the extension stress in the lateral direction in the region A3 is not less than 0.02 N/mm and not greater than 0.
10 N/mm.30. The absorbent article according to any one of claim 26 to 29, wherein the region A2 has elasticity in lateral direction.31. The absorbent article according to any one of claims 1 to 30, wherein the topsheet is longer in inter-fiber distance compared with the core-wrap sheet.32. The absorbent article according to any one of claims 1 to 31, wherein the ratio of the inter-fiber distance of the topsheet and the inter-fiber distance of the core-wrap sheet is not less than 1.5 and not greater than 10, as a value obtainable by dividing the former by the latter, on the premise that the former is greater than the latter.33. The absorbent article according to any one of claims 1 to 32, wherein the topsheet is lower in fiber density compared with the core-wrap sheet.34. The absorbent article according to any one of claims 1 to 33, wherein the topsheet is longer in inter-fiber distance compared with the sweat-absorbent sheet.35. The absorbent article according to any one of claims 1 to 34, wherein the ratio of the inter-fiber distance of the topsheet and the inter-fiber distance of the sweat-absorbent sheet is not less than 1.5 and not greater than 10, as a value obtainable by dividing the former by the latter, on the premise that the former is greater than the latter.36. The absorbent article according to any one of claims 1 to 35, wherein the topsheet is lower in fiber density compared with the sweat-absorbent sheet.37. The absorbent article according to any one of claims 1 to 36, wherein the fiber orientation of constituent fibers of the sweat-absorbent sheet and the fiber orientation of constituent fibers of the topsheet intersect each other.38. The absorbent article according to any one of claims 1 to 37, wherein the absorbent article includes a waist part disposed at the waist of the wearer when worn, and the waist part is segmented into a front portion disposed on the front side and a rear portion disposed on the rear side of the wearer when worn, the sweat-absorbent sheet has a shape that is long in one direction in plan view, and is disposed over the entire length in the lateral direction of each of the front portion and the rear portion while the longitudinal direction thereof is aligned with the lateral direction of the absorbent article.39. The absorbent article according to any one of claims 1 to 38, wherein the absorbent core is not disposed in the region Al where the sweat-absorbent sheet and the topsheet are overlapped in the thickness direction.40. The absorbent article according to any one of claims 1 to 39, wherein the core-wrap sheet is not disposed in the region Al where the sweat-absorbent sheet and the topsheet are overlapped in the thickness direction.