Disposable diapers

Abstract

In the disposable diaper (1) of the present invention, the outer body (11) is divided into a first region (D3) to a third region (D5). The first region (D3) contains a first laminated structure (5) in which an outer layer sheet (12), an inner layer sheet (13) and a hydrophilic sheet (4) are sequentially laminated in the longitudinal direction (X). The second region (D4) contains a second laminated structure (6) in which a hydrophilic sheet (4) is arranged on the non-skin-opposite surface of the inner layer sheet (13) constituting a folded portion (16) of the outer body (11). The third region (D5) contains a third laminated structure (7) in which an outer layer sheet (12) and an inner layer sheet (13) are laminated. In each of the laminated structures (5) and (6), a plurality of sheets are joined to each other at welded portions (17) dispersed on the surface of the laminated structure. Compared with the second stacked structure (6), the first stacked structure (5) has a greater number of welded portions (17) per unit area, that is, a higher density of welded portions.

Description

Technical Field

[0001] The present invention relates to a disposable diaper comprising a sheet having a sweat absorbing function (sweat absorbing sheet). Background Art

[0002] In the prior art, in order to prevent the occurrence of skin problems such as eczema, prickly heat rash, and macules caused by the wearer's sweat, a sweat-absorbent sheet is used to form the inner surface (skin-opposite surface) of the diaper that contacts the wearer's skin. For example, Patent Document 1 describes a diaper in which the portion (waist end) arranged around the waist of the wearer contains a folded portion formed by folding back the hydrophobic sheet forming the outer surface (non-skin-opposite surface) of the diaper toward the inner surface of the diaper, and the sweat-absorbent sheet is bonded to the skin-opposite surface of the folded portion via an adhesive. Patent Document 2 describes a diaper in which, as a sweat-absorbent sheet forming the inner surface of the waist end of the diaper, the sweat-absorbent sheet contains a hydrophobic layer formed of hydrophobic fibers forming the skin-opposite surface of the sweat-absorbent sheet and a hydrophilic layer formed of hydrophilic fibers stacked on the non-skin-opposite surface of the hydrophobic layer, and the two layers are integrated at multiple welded joints.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: U.S. Patent Application Publication No. 2007 / 203468

[0006] Patent document 2: European patent application publication No. 03466386 Summary of the invention

[0007] The present invention relates to a disposable diaper, which has a longitudinal direction extending from the wearer's ventral side to the back side through the crotch part and a lateral direction orthogonal to the longitudinal direction, and is divided into a crotch part arranged at the crotch part, a ventral part arranged at the wearer's ventral side relative to the crotch part, and a dorsal part arranged at the wearer's dorsal side relative to the crotch part. The disposable diaper includes an absorbent body for absorbing and retaining body fluids and an outer body arranged on the non-skin-opposite side of the absorbent body, and has a waist part arranged at the waist of the wearer at the ventral part and the dorsal part.

[0008] In one embodiment of the disposable diaper of the present invention, the outer body preferably includes: an outer layer sheet disposed relatively far from the absorbent body; and an inner layer sheet disposed relatively near the absorbent body.

[0009] In one embodiment of the disposable diaper of the present invention, preferably, the outer body of the waist portion of at least the back portion has a folded portion, and the folded portion is formed by folding back a portion of the outer body located on the outside of the longitudinal direction than the longitudinal end of the absorbent body toward the inner layer side.

[0010] In one embodiment of the disposable diaper of the present invention, it is preferred that at least the outer body of the waist portion of the back portion is divided into: a first region, which includes a bending position of the outer body for forming the folded portion, and is located at a position closer to the outside of the longitudinal direction than the longitudinal end of the absorbent body; a second region, which is located on the inner side of the longitudinal direction than the first region and closer to the wearer's skin than the bending position; and a third region, which is located on the inner side of the longitudinal direction than the first region and farther from the wearer's skin than the bending position.

[0011] In one embodiment of the disposable diaper of the present invention, the first region preferably includes a first stacked structure comprising a portion in which the outer layer sheet, the inner layer sheet and the hydrophilic sheet are stacked in sequence from the outer side to the inner side in the longitudinal direction, and the multiple sheets constituting the first stacked structure are joined to each other at welded portions dispersed on the surface of the first stacked structure.

[0012] In one embodiment of the disposable diaper of the present invention, the second area preferably includes a second stacked structure in which the hydrophilic sheet is arranged on the non-skin opposite side of the inner layer sheet constituting the folded portion, and the multiple sheets constituting the second stacked structure are joined to each other at welded portions dispersed on the surface of the second stacked structure.

[0013] In one embodiment of the disposable diaper of the present invention, it is preferred that the first layered structure has a larger number of the welded portions per unit area than the second layered structure.

[0014] Other features, effects and embodiments of the present invention are described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic perspective view of an example of a pants-type disposable diaper which is one embodiment of the disposable diaper of the present invention.

[0016] Figure 2 Yes Figure 1 The illustrated developed plan view schematically shows a portion of the skin-facing surface side (the surface on which the absorbent body is disposed) of the diaper in the developed and stretched state, with the surface cut away.

[0017] Figure 3 yes Figure 2 The cross-sectional view along the thickness direction at the I-I line is Figure 1 A schematic cross-sectional view of the crotch portion of a diaper is shown.

[0018] Figure 4 yes Figure 2 The cross-sectional view along the thickness direction at the II-II line is Figure 1The schematic longitudinal cross-sectional view of the waist portion of the back side of the diaper is shown.

[0019] Figure 5 yes Figure 1 The schematic cross-sectional view along the longitudinal direction is shown in the first laminate structure of the waist portion of the back portion of the diaper.

[0020] Figure 6 yes Figure 1 The schematic cross-sectional view along the thickness direction of the second laminate structure of the waist portion of the back side portion of the diaper shown.

[0021] Figure 7 yes Figure 1 FIG. 1 is an explanatory diagram of a method for manufacturing an outer body in a diaper shown in FIG. Figure 7 (a) is an explanatory diagram of the first step of the manufacturing method, Figure 7 (b) is an explanatory diagram of the second step of the manufacturing method. DETAILED DESCRIPTION

[0022] Although the existing disposable diapers with sweat-absorbent sheets have sweat-absorbency, there is still room for improvement in terms of the sweat-absorbency of the waist end portion, which is arranged on the waist of the wearer and where sweat is easy to accumulate. In addition, in addition to sweat-absorbency, the hand feeling and leakage resistance are also important in disposable diapers, and excellent hand feeling, good skin touch, and excellent leakage resistance are required, and excreta such as urine and feces are not easy to leak to the outside. Therefore, even if the sweat-absorbency of the waist end portion of the disposable diaper can be improved, it is meaningless if the hand feeling of the waist end portion and its vicinity decreases and the leakage resistance decreases. A disposable diaper with a good hand feeling, not easy to leak excreta, and excellent sweat-absorbency at the waist end portion has not yet been provided.

[0023] The present invention relates to a disposable diaper which has a good hand feel, is less likely to cause leakage of excrement, and has excellent sweat absorption properties at the waist end portion.

[0024] Hereinafter, the preferred embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in the following description of the accompanying drawings, the same or similar parts are marked with the same or similar symbols. The accompanying drawings are basically schematic diagrams, and there are cases where the ratios of various dimensions, etc. are different from the actual ones.

[0025] Figure 1 to Figure 4Diaper 1 is shown as one embodiment of the disposable diaper of the present invention. Diaper 1 has a longitudinal direction X corresponding to the front-back direction of the wearer, i.e., a direction extending from the ventral side to the dorsal side via the crotch portion, and a lateral direction Y orthogonal to the longitudinal direction X. Diaper 1 is divided into three parts: a crotch portion B disposed in the crotch portion of the wearer and containing an excretion portion opposite to the excretion portion such as the penis of the wearer (not shown), a ventral portion A disposed on the ventral side (front side) of the wearer than the crotch portion B, and a dorsal portion C disposed on the dorsal side (back side) of the wearer than the crotch portion B. Diaper 1 includes an absorbent body 23 for absorbing and retaining body fluids and an outer body 11 disposed on the non-skin-opposing side of the absorbent body 23, and has a waist portion D disposed on the waist of the wearer in the ventral portion A and the dorsal portion C.

[0026] In this embodiment, the diaper 1 is a pants-type disposable diaper, and the outer body 11 of the ventral part A and the back part C are joined to each other at both side edges in the longitudinal direction X. Figure 1 As shown, a pair of side seals S, a waist opening WH and a pair of leg openings LH, LH are formed. In addition, the diaper 1 includes an absorbent body 2 including an absorbent body 23 and disposed on the skin-facing side of the outer body 11. The absorbent body 2 and the outer body 11 are bonded by an adhesive.

[0027] In this specification, the "skin-opposing surface" refers to the surface of the shorts-type disposable diaper or its components (such as absorbent body) that faces the skin side of the wearer when the diaper is worn, that is, the side relatively close to the skin of the wearer, and the "non-skin-opposing surface" refers to the surface of the shorts-type disposable diaper or its components that faces the opposite side of the skin side when the diaper is worn, that is, the side relatively far from the skin of the wearer. In addition, "when worn" here refers to the state of maintaining the normal appropriate wearing position, that is, the correct wearing position of the absorbent article.

[0028] like Figure 2 As shown, the diaper 1 is formed symmetrically on one side and the other side with respect to the transverse center line CLy.

[0029] The ventral part A is a part of the front body F of the diaper 1, and the dorsal part C is a part of the back body R of the diaper 1. The crotch part B spans the longitudinal center line CLx in the longitudinal direction X and exists in the range from the front body F to the back body R. The crotch part B typically includes the region where the leg edges LS and LS are formed as the concave parts for forming the leg openings LH and LH. The leg edges LS are parts of the side edges of the outer body 11 along the longitudinal direction X.

[0030] In the present invention, the abdominal portion A, the crotch portion B, and the back portion C may be regions obtained by dividing the diaper 1 in the unfolded and stretched state into three equal parts in the longitudinal direction X.

[0031] The waist portion D is a portion disposed on the waist including the waistline of the wearer, and is typically a portion of each of the ventral portion A and the dorsal portion C located at the same position as the side seal portion S in the longitudinal direction X. In the present embodiment, it is a rectangular region in a plan view extending from the opening edge of the waist opening WH to the lower end Sb of the side seal portion S. The waist opening WH is defined by the waist wing portions D1 of each of the ventral portion A and the dorsal portion C.

[0032] In this embodiment, Figure 2 As shown, the waist portion D includes a waist wing portion D1 located on the waist opening WH side and a crotch-side waist portion D2 located on the crotch portion B side, with the longitudinal end 23E of the absorber 23 and its virtual extension line as the boundary.

[0033] The waist wing D1 is located outside the longitudinal end 23E of the absorber 23 in the longitudinal direction X and extends in the transverse direction Y, and is a so-called waist end portion of the diaper 1 .

[0034] In such Figure 2 In the unfolded and stretched state of the diaper 1 shown, the length of the waist wing D1 in the longitudinal direction X is preferably 15% or more, more preferably 20% or more, and preferably 55% or less, more preferably 60% or less of the length of the waistline D in the longitudinal direction X.

[0035] The horizontal center line CLy is Figure 2 The diaper 1 in the unfolded and stretched state shown is a virtual straight line that bisects the diaper 1 in the transverse direction Y and extends in the longitudinal direction X. The longitudinal center line CLx is a virtual straight line that bisects the diaper 1 in the unfolded and stretched state in the longitudinal direction X and extends in the transverse direction Y.

[0036] The "expanded and stretched state" mentioned here means that the diaper 1 is separated at the side seal portion S to be in an expanded state, and the expanded diaper 1 is expanded so that the elastic components of each part are stretched to the designed size (the same size as when it is opened into a plane in a state where the influence of the elastic components is completely eliminated).

[0037] In this embodiment, if Figure 2 As shown, the absorbent body 2 has a rectangular shape when viewed from above, with its longitudinal direction being consistent with the longitudinal direction X of the diaper 1, and is arranged in the central part of the transverse direction Y of the outer body 11, extending from the ventral part A through the crotch part B to the dorsal part C in the longitudinal direction X. The outline of the absorbent body 2 when viewed from above is consistent with the outline of the absorbent body 23.

[0038] like Figure 3As shown, the absorbent body 2 includes a liquid-permeable front sheet 21 disposed at a position relatively close to the wearer's skin, a liquid-impermeable or liquid-impermeable or water-repellent back sheet 22 disposed at a position relatively far from the wearer's skin, and an absorbent body 23 disposed between the two sheets 21 and 22. The absorbent body 23 includes an absorbent core 24 capable of absorbing and retaining body fluids and a core wrapping sheet 25 covering the outer surface including the skin-opposing surface and the non-skin-opposing surface of the absorbent core 24. These components constituting the absorbent body 2 are integrated with each other by a known bonding method such as an adhesive.

[0039] As the components constituting the absorbent body 2, materials commonly used in such absorbent articles can be used without particular limitation. For example, various nonwoven fabrics, perforated films, etc. can be used as the front sheet 21, and resin films, or laminated sheets of resin films and nonwoven fabrics, etc. can be used as the back sheet 22. The absorbent core 24 is typically composed of a water-absorbent material as the main body, and the water-absorbent material contains one or more selected from fiber materials such as wood pulp and water-absorbent polymers. The core wrapper 25 is liquid permeable and is typically composed of paper, nonwoven fabrics, etc. The core wrapper 25 can also be omitted.

[0040] like Figure 3 As shown, a pair of leak-proof cuffs 3, 3 are provided on both sides of the absorbent body 2 along the longitudinal direction X, which stand up toward the skin side of the wearer when the diaper 1 is worn. Each leak-proof cuff 3 contains a liquid-resistant or water-repellent and breathable leak-proof sheet 30, one end side of the leak-proof sheet 30 in the transverse direction Y is fixed to other components (in the illustrated embodiment, the absorbent body 2 and the outer body 11) to become a fixed end, and the other side of the transverse direction Y becomes a free end that is not fixed to other components. At the free end of the leak-proof sheet 30, the leak-proof cuff forming elastic member 31 is fixed in an extended state in the longitudinal direction X, so that it is configured to be able to stretch in this direction. When the diaper 1 is worn, the free end side of the leak-proof sheet 30 stands up toward the wearer side with the fixed end as the standing base end at least in the crotch B by using the contraction force of the elastic member 31, so that a pair of leak-proof cuffs 3, 3 stand up, thereby preventing the outflow of excrement such as urine to the outside of the transverse direction Y.

[0041] like Figure 3 and Figure 4As shown, the outer body 11 includes an outer sheet 12 arranged at a relatively far position from the absorbent body 23 (absorbent body 2) and an inner sheet 13 arranged at a relatively close position to the absorbent body 23. The two sheets 12 and 13 are joined to each other by a joining method such as an adhesive and welding to form an integral body. Except for the folded portion 16 of the outer body 11 described later, the outer sheet 12 is the outermost layer of the outer body 11, forming the non-skin facing surface of the outer body 11 and forming the outer surface of the diaper 1, and the inner sheet 13 is the innermost layer of the outer body 11, forming the skin facing surface of the outer body 11. The absorbent body 2 is joined to the skin facing surface of the inner sheet 13.

[0042] As the outer sheet 12 and the inner sheet 13, nonwoven fabrics obtained by various manufacturing methods, resin films, etc. can be used respectively, provided that they comply with the following description. As the nonwoven fabric, for example, spunbonded nonwoven fabrics, hot air nonwoven fabrics, needle punched nonwoven fabrics, etc. can be listed. The two sheets 12 and 13 can be a single-layer structure, or a laminated structure formed by stacking more than two sheets. In addition, the two sheets 12 and 13 can be a stretch sheet with stretchability in the transverse direction Y, or a non-stretch sheet without stretchability. As an example of a stretch sheet, the "stretch sheet formed by joining a plurality of elastic threads arranged in a manner that does not cross each other and extends in one direction in a substantially non-stretched state to a stretchable nonwoven fabric containing non-elastic fibers" described in Japanese Patent Publication No. 2009-61743 can be exemplified. For example, the stretch sheet can be used for the outer sheet 12, and the non-stretch sheet can be used for the inner sheet 13.

[0043] like Figure 2 As shown, the outer body 11 is larger in area than the absorbent body 23 (absorbent body 2), and has an extension extending outward from the periphery of the absorbent body 23. The portion of the extension extending from the periphery of the absorbent body 23 of the outer body 11, which is located outside the longitudinal end 23E of the absorbent body 23 and its virtual extension line in the longitudinal direction X, is the waist wing D1, which is a part arranged around the waist of the wearer when the diaper 1 is worn. That is, the waist wing D1 is a region in the waist portion D where the absorbent body 23 is not arranged in the entire length in the transverse direction Y.

[0044] The waist portion D (waist wing portion D1, crotch waist portion D2) is stretchable in the transverse direction Y. Specifically, between the outer layer sheet 12 and the inner layer sheet 13 constituting the outer body 11 of the waist portion D, a plurality of elastic components (waist elastic components) 14 configured to be stretchable in the transverse direction Y are included, and the waist portion D is stretchable in the transverse direction Y by utilizing the elastic stretchability of the elastic components 14. The plurality of elastic components 14 extend in the transverse direction Y in the waist portion D and are arranged at intervals in the longitudinal direction X. The waist portion D is made by fixing the elastic components 14 between the two sheets 12 and 13 in a state of being stretched in the transverse direction Y, and then releasing the elastic components 14 from the stretched state. When the diaper 1 is worn, a plurality of folds (pleats) extending in a direction (longitudinal direction X) intersecting the elastic components 14 can be formed on the surface of the waist portion D by contraction of the elastic components 14. The portion of the waistline D that overlaps the absorber 23 (absorbent body 2) in a plan view is processed so that the elastic stretchability of the elastic member 14 is not exhibited by cutting the elastic member 14, and thus the portion has no stretchability in the transverse direction Y.

[0045] In this embodiment, leg gathers are formed at the leg edges LS forming the opening edges of the pair of leg openings LH, LH. The leg gathers include an outer body 11 and an elastic member 15 for forming leg gathers fixed to the outer body 11 and having a portion extending along the leg edges LS. The leg gathers are formed by fixing the elastic member 15 in an extended state between the outer sheet 12 and the inner sheet 13 constituting the outer body 11, and then releasing the elastic member 15 from the extended state. When the diaper 1 is worn, the elastic member 15 contracts, and the leg gathers are formed in a substantially continuous ring shape around the entire circumference of the opening edge of the leg opening LH.

[0046] In the present invention, if Figure 4 As shown, at least the outer body 11 of the waist portion D of the back portion C has a folded portion 16, which is formed by folding back a portion of the outer body 11 located on the outside of the longitudinal end 23E of the absorbent body 23 in the longitudinal direction X toward the inner layer sheet 13 side (the skin-facing side of the outer body 11) at a folded position indicated by a symbol 11F. The folded position 11F of the outer body 11 is located at the outermost side of the waist portion D of the back portion C in the longitudinal direction X.

[0047] In this embodiment, if Figure 4 As shown, the folded portion 16 covers the skin-facing surface of the end portion of the absorbent body 2 in the longitudinal direction X, and the front end portion of the folded portion 16 is joined to the member forming the skin-facing surface, specifically the front sheet 21, by a joining method such as an adhesive or welding.

[0048] In the present embodiment, at least the front end portion in the longitudinal direction X of the folded portion 16 does not include the outer layer sheet 12 but includes the inner layer sheet 13 , and a hydrophilic sheet 4 described later is arranged on the non-skin facing surface of the inner layer sheet 13 .

[0049] In this embodiment, if Figure 2 As shown, not only the back part C but also the waist part D of the ventral part A has a folded back part 16 formed by folding the outer body 11 toward the inner layer sheet 13. The waist part D of the ventral part A is constructed in the same manner as the waist part D of the back part C. Unless otherwise specified, the description of the waist part D of the back part C can be applied to the waist part D of the ventral part A.

[0050] like Figure 4 As shown, the outer body 11 of the waist portion D of the back portion C has a first region D3, a second region D4, and a third region D5 described below.

[0051] · First region D3: A region including the folded position 11F of the outer body 11 for forming the folded portion 16, located at the outermost side in the longitudinal direction X of the waist portion D and located further outward in the longitudinal direction X than the longitudinal end 23E of the absorber 23, namely, at the waist wing portion D1.

[0052] · Second region D4: A region located on the inner side (closer to the crotch portion B) in the longitudinal direction X than the first region D3 and on the side closer to the skin of the wearer than the folded position 11F of the outer body 11 .

[0053] · Third region D5: A region located on the inner side (closer to the crotch portion B) in the longitudinal direction X than the first region D3 and on the side farther from the wearer's skin than the folded position 11F of the outer body 11 .

[0054] The first region D3 includes a first stacked structure 5 comprising an outer layer sheet 12, an inner layer sheet 13 and a hydrophilic sheet 4 which are stacked in this order from the outside to the inside of the longitudinal direction X (from the bending position 11F to the crotch portion B) (hereinafter also referred to as the "longitudinal stacked portion"), and the multiple sheets 12, 13, 4 constituting the first stacked structure 5 are joined to each other at welding portions 17 dispersed on the surface of the first stacked structure 5.

[0055] The second region D4 includes a second laminated structure 6 having a hydrophilic sheet 4 arranged on the non-skin facing surface of the inner layer sheet 13 constituting the folded portion 16, and the plurality of sheets 13, 4 constituting the second laminated structure 6 are joined to each other at welded portions 17 dispersed on the surface of the second laminated structure 6.

[0056] Compared with the second stacked structure 6 , the first stacked structure 5 has a larger number of welded portions 17 per unit area (ie, the density of welded portions is high).

[0057] In addition, Figure 4 , a portion of the surface of each of the first stacked structure 5 to the third stacked structure 7 is shown in an enlarged manner.

[0058] In this embodiment, if Figure 4 As shown, the first region D3 (first laminated structure 5 ) includes both the outer layer sheet 12 and the inner layer sheet 13 , whereas the second region D4 (second laminated structure 6 ) includes the inner layer sheet 13 but does not include the outer layer sheet 12 .

[0059] In the present embodiment, the third region D5 includes a third laminated structure 7 formed by laminating an outer layer sheet 12 and an inner layer sheet 13 , and the plurality of sheets 12 , 13 constituting the third laminated structure 7 are joined to each other at welded portions 17 dispersed on the surface of the third laminated structure 7 .

[0060] The first region D3 and the second region D4 both include the hydrophilic sheet 4 , but the third region D5 does not include the hydrophilic sheet 4 .

[0061] The regions D1 to D3 will be further described. In the present embodiment, the first region D3 exists only in the waist wing portion D1, and the second region D4 and the third region D5 exist across the waist wing portion D1 and the crotch waist portion D2, respectively.

[0062] However, in the present invention, the second region D4 and the third region D5 may each be present only in the crotch-side waistline portion D2.

[0063] In addition, in the present embodiment, the outer end of the longitudinal direction X of the second region D4 (the longitudinal end on the boundary side with the first region D3) and the outer end of the longitudinal direction X of the third region D5 (the longitudinal end on the boundary side with the first region D3) are consistent in the longitudinal direction X, and the entire area of ​​the second region D4 overlaps with the third region D5 when viewed from above.

[0064] However, in the present invention, the two regions do not need to be located at the same position in the longitudinal direction X, and only a portion of the second region D4 may overlap with the third region D5 in a plan view, or the two regions D4 and D5 may not overlap with each other in a plan view.

[0065] Figure 5 FIG. 4 shows a cross section of the first stacked structure 5 in the first region D3 along the longitudinal direction X. As described above, the first stacked structure 5 includes a plurality of sheets arranged in the longitudinal direction X ( Figure 4 The longitudinal laminated portion is stacked in the vertical direction (in the vertical direction), and the thickness direction of the longitudinal laminated portion is consistent with the longitudinal direction X. In addition, in this embodiment, Figure 4 As shown, the first stacked structure 5 includes not only the longitudinal stacked portion, but also a plurality of sheets in a direction intersecting the longitudinal direction X, specifically, in a thickness direction Z orthogonal to the longitudinal direction X ( Figure 4The "thickness direction Z" mentioned here is the same direction as the thickness direction of the absorbent body 23 (diaper 1). The thickness direction laminated portion is located on both sides of the thickness direction Z sandwiching the longitudinal laminated portion, that is, on the skin facing side and the non-skin facing side of the absorbent body 23, respectively.

[0066] However, in the present invention, the first stacked structure 5 (first region D3 ) only needs to have at least the longitudinal stacked portion, and may not have the thickness-direction stacked portion.

[0067] In this embodiment, if Figure 5 As shown, the first laminated structure 5 is composed of a three-layer structure of an outer layer sheet 12, an inner layer sheet 13, and a hydrophilic sheet 4, and has a first surface 5a composed of the outer layer sheet 12, and a second surface 5b located on the opposite side of the first surface 5a and composed of the hydrophilic sheet 4. The first surface 5a of the first laminated structure 5 forms the outer surface of the first region D3, and the second surface 5b of the first laminated structure 5 forms the inner surface of the first region D3, that is, forms the inner wall surface of the internal space defined by the folded portion 16 and the portion of the outer body 11 opposite to the folded portion 16.

[0068] A plurality of welded portions 17 are respectively distributed on both surfaces (the first surface 5a and the second surface 5b) of the first laminated structure 5. The welded portions 17 are formed by performing compression processing from the first surface 5a or the second surface 5b side of the first laminated structure 5, and can be referred to as "compressed portions" from the perspective of their formation method. In the illustrated embodiment, compression processing is performed from the first surface 5a side (the outer layer sheet 12 side). In the welded portions 17, there is a situation where the sheets constituting the welded portions 17 lose their original fiber form and become film-like.

[0069] The density of the welded portion 17 is higher than that of its peripheral portion (the portion not subjected to the compression process). That is, the first laminated structure 5 has a high-density portion formed by the welded portion 17 and a low-density portion formed by the peripheral portion (non-welded portion) of the welded portion 17, and density differences are generated on the first surface 5a and the second surface 5b, respectively.

[0070] The compression process for forming the weld 17 can be performed by a method accompanied by melting of the constituent fibers (e.g., thermoplastic fibers) of the first stacked structure 5, namely, the outer layer sheet 12, the inner layer sheet 13, and the hydrophilic sheet 4. As such a method, for example, well-known embossing processes such as embossing with heat and ultrasonic embossing can be listed.

[0071] The first surface 5a of the first laminated structure 5 (the surface subjected to the compression process) is provided with a concavo-convex structure consisting of a plurality of concave portions 50 located at the weld 17 (with the weld 17 as the bottom) and convex portions 51 located at the periphery of each of the concave portions 50 (weld 17).

[0072] Figure 6 The cross section of the second laminated structure 6 in the second region D4 along the thickness direction Z is shown. In the present embodiment, the second laminated structure 6 is composed of a double-layer structure of the inner layer sheet 13 (folded portion 16) and the hydrophilic sheet 4, and has a first surface 6a composed of the inner layer sheet 13, and a second surface 6b located on the opposite side of the first surface 6a and composed of the hydrophilic sheet 4. The first surface 6a of the second laminated structure 6 forms the outer surface (skin-facing surface) of the second region D4, and the second surface 6b of the second laminated structure 6 forms the inner surface (non-skin-facing surface) of the second region D4.

[0073] A plurality of welded portions 17 are distributed on both surfaces (the first surface 6a and the second surface 6b) of the second laminated structure 6. The welded portions 17 of the second laminated structure 6 are basically the same as the welded portions 17 of the first laminated structure 5 described above, and unless otherwise specified, the above description of the welded portions 17 is applicable. The same is true for the welded portions 17 of the third laminated structure 7.

[0074] The second laminated structure 6 has a high-density portion formed by the welded portion 17 and a low-density portion formed by the peripheral portion (non-welded portion) of the welded portion 17, and a density difference is generated between the first surface 6a and the second surface 6b.

[0075] The first surface 6a (the surface subjected to the compression process) of the second laminated structure 6 has a concavo-convex structure consisting of a plurality of concave portions 60 located at the weld 17 (with the weld 17 as the bottom) and convex portions 61 located at the periphery of each of the concave portions 60 (weld 17).

[0076] The inner layer sheet 13 and the hydrophilic sheet 4 constituting the second laminated structure 6 are sheets extending from the first laminated structure 5 in the first region D3 , respectively, and the first laminated structure 5 and the second laminated structure 6 exist continuously.

[0077] In this embodiment, as described above, the second laminated structure 6 does not contain the outer layer sheet 12. That is, the front end side (the opposite side of the bending position 11F side) of the folded portion 16 of the outer body 11 does not contain the outer layer sheet 12 but is formed only by the inner layer sheet 13, and the second laminated structure 6 includes a portion of the folded portion 16 that is composed only of the inner layer sheet 13.

[0078] However, in the present invention, in the second laminate structure 6 , the outer layer sheet 12 may be disposed on the skin-facing surface of the inner layer sheet 13 (the surface opposite to the surface facing the hydrophilic sheet 4 ).

[0079] The outer layer sheet 12 and the inner layer sheet 13 constituting the third stacked structure 7 are sheets extending from the first stacked structure 5 in the first region D3 , respectively, and the first stacked structure 5 and the third stacked structure 7 exist continuously.

[0080] In the present embodiment, as described above, the third layered structure 7 does not include the hydrophilic sheet 4 , but includes the outer layer sheet 12 and the inner layer sheet 13 .

[0081] The third laminated structure 7 is basically constructed in the same manner as the second laminated structure 6 of a double-layer structure except that the combination of the sheets constituting the third laminated structure 7 is different. That is, the third laminated structure 7 is composed of a double-layer structure of an outer layer sheet 12 and an inner layer sheet 13, and has a first surface 7a composed of the outer layer sheet 12, and a second surface 7b composed of the inner layer sheet 13 located on the opposite side of the first surface 7a. The first surface 7a of the third laminated structure 7 forms the outer surface (non-skin facing surface) of the third area D5, and the second surface 7b of the third laminated structure 7 forms the inner surface (skin facing surface) of the third area D5. The third laminated structure 7 has a high-density portion composed of a fusion bond 17 and a low-density portion composed of a peripheral portion (non-fusion bond) of the fusion bond 17, and a density difference is generated on both surfaces (the first surface and the second surface) of the third laminated structure 7. In addition, a concave-convex structure consisting of a plurality of concave portions located at the welding portion 17 (with the welding portion 17 as the bottom) and convex portions located at the peripheral portions of each of the concave portions (welding portion 17) is formed on the first surface (the surface subjected to the compression processing) of the third stacked structure 7.

[0082] In this embodiment, if Figure 4 As shown in the enlarged view, the pattern (shape and arrangement when viewed from above) of the welded portions 17 in the first region D3 to the third region D5 is a pattern in which a plurality of welded portions 17 are all circular (dot-shaped) when viewed from above and are arranged in a scattered manner, but the pattern of the welded portions 17 in the present invention is not limited thereto, and any pattern can be selected within the scope of the present invention. For example, an elliptical shape, a quadrilateral shape, a diamond shape, a cross shape, etc. can be used instead of Figure 4 In addition, for example, a grid-like pattern in which a plurality of top-view (straight or curved) welded portions 17 are arranged to intersect each other can be adopted.

[0083] The hydrophilic sheet 4 is bonded to the inner surface of the portion of the outer body 11 that is located outside the longitudinal end 23E of the absorbent body 23 in the longitudinal direction X (the surface on the inner layer sheet 13 side). The hydrophilic sheet 4 is typically in a shape that is long in one direction (e.g., a rectangular shape) when viewed from above, with its long side direction aligned with the transverse direction Y, and extends continuously over the entire length of the transverse direction Y (between a pair of side seals S, S) at least in the waist portion D of the back portion C. In this embodiment, as shown in FIG. Figure 4 As shown, the hydrophilic sheet 4 is disposed on the waist wing portion D1 and the crotch waist portion D2.

[0084] The hydrophilic sheet 4 is hydrophilic as the wording indicates, and functions as a sweat-absorbent sheet that absorbs sweat of the wearer of the diaper 1. On the other hand, the outer sheet 12 and the inner sheet 13 may be either hydrophilic or hydrophobic.

[0085] In the present invention, whether a sheet is hydrophilic or hydrophobic can be determined based on the contact angle of the constituent fibers of the sheet measured by the following method. The "contact angle" mentioned in this specification refers to the contact angle measured by the following method unless otherwise specified. The smaller the contact angle, the more the sheet can be evaluated as highly hydrophilic (low hydrophobic), and the larger the contact angle, the more the sheet can be evaluated as less hydrophilic (high hydrophobic). In the present invention, if the contact angle is less than 90 degrees, the sheet is defined as hydrophilic, and if the contact angle is greater than 90 degrees, the sheet is defined as hydrophobic.

[0086] <Contact Angle Measurement Method>

[0087] Fibers are taken out from the sheet of the measurement object, and the contact angle of water relative to the fibers is measured. Scissors and tweezers are used to take out the fibers. In addition, the fiber removal sites in the sheet of the measurement object are the two sides of the sheet (two surface layers) and the part sandwiched by them (the central part in the thickness direction). As a measuring device, an automatic contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. is used. Deionized water is used for the measurement of the contact angle. The amount of liquid discharged from the inkjet water droplet discharge part (produced by CLUSTER TECHNOLOGY, the pulse injector CTC-25 with a discharge part aperture of 25μm) is set to 15 picoliters, and water drops are dripped directly above the fibers. The dripping state is recorded on a high-speed video device connected to a horizontally arranged camera. From the viewpoint of subsequent image analysis, it is desired that the video recording device is a personal computer equipped with a high-speed capture device. In this measurement, the image is recorded every 17msec. In the recorded video, the initial image of the water drop dripping on the fiber is analyzed by the attached software FAMAS (software version is 2.6.2, measurement method is drop method, analysis method is θ / 2 method, image processing algorithm is non-reflection, image processing image mode is frame, threshold level is 200, and curvature correction is not performed.) to calculate the angle between the surface where the water drop contacts the air and the fiber as the contact angle. The fiber taken out from the piece of the measurement object is cut into a fiber length of 1 mm, and the fiber is placed on the sample stage of the contact angle meter and maintained horizontally. The contact angle of two different places is measured for one fiber. The contact angle of N=5 roots is calculated to one decimal place, and the value obtained by averaging the measured values ​​at a total of 10 places (rounded off to the second decimal place) is defined as the contact angle of the fiber with water. The measurement environment is set to room temperature of 22±2℃ and humidity of 65±2%RH. The smaller the value of the contact angle, the higher the hydrophilicity.

[0088] In the case of disposable diapers, when the sheet to be measured is joined to other parts by adhesive, welding, etc., the joined portion is removed after removing the adhesive force by blowing cold air with a cold jet, etc., within a range that does not affect the contact angle of the fibers. This method of removing the measured object from the disposable diaper can also be used for other measurements.

[0089] The waist wing D1 (waist end) of the waist portion D is a portion where the wearer's sweat is more likely to accumulate, especially the waist wing D1 of the back portion C. Since the wearer of the diaper 1 lies on his back for a long time, sweat is very likely to accumulate, and it is a portion where skin problems caused by sweat may occur. On the other hand, the waist portion D is a portion that can come into contact with the wearer's skin of the diaper 1. In addition, since there is an absorber 23 that absorbs and retains excreta such as urine, it is required to have a good feel (skin feel), excellent leakage resistance, and prevent excreta from leaking to the outside of the diaper 1.

[0090] In view of this, in the present invention, taking into account the ease of sweat accumulation, the frequency of contact with excrement other than sweat such as urine and feces (excrement excreted in the crotch portion B), and the frequency of contact with the wearer's skin, the outer body 11 forming the outer surface of the waist portion D is divided into the first area D3 to the third area D5, and each area D3 to D5 is appropriately constructed to achieve improvements in hand feel, leakage resistance, and sweat absorption. Specifically, in the present invention, focusing on the "welding portion" that is arranged on the surface of the stacked structure of multiple sheets and connects the multiple sheets to each other, the more the number of welded portions per unit area (the higher the density of welded portions), the faster the sweat absorption speed of the stacked structure (the speed of introducing sweat present on the surface of the stacked structure), the stacked structures 5 to 7 of the first area D3 to the third area D5 of the outer body 11 are designed.

[0091] That is, in the diaper 1, in order to improve the sweat absorption speed of the first area D3 of the outer body 11 in the waist portion D where sweat is most likely to accumulate, the size relationship of "the first laminated structure 5> the second laminated structure 6" is established with respect to the number of welded portions 17 per unit area (weld density). With such a size relationship established, the sweat absorbed by the second area D4 is easily transferred to the first area D3 due to capillary force, thereby improving the air permeability with the first area D3 and the second area D4 as the center, and as a result, the sweat can be moved to the waist wing D1 (waist end) of the waist portion D, which is the part of the diaper 1 where sweat is most likely to evaporate, and thus the overall sweat absorption performance of the waist portion D is improved with the waist wing D1 as the center. Corresponding to the lower density of the welded portion compared to the first laminated structure 5, the second laminated structure 6 has excellent breathability. Therefore, the second laminated structure 6 has excellent quick-drying properties, and the absorbed sweat can be dried relatively quickly. The sweat absorbed by the first laminated structure 5 can be transferred to the second laminated structure 6 when there is still surplus sweat absorption capacity of the second laminated structure 6. Therefore, due to the excellent quick-drying properties of the second laminated structure 6, the overall sweat absorption of the waistline D can be improved.

[0092] Furthermore, the effect of the above-mentioned relationship of “first stacked structure 5 > second stacked structure 6” regarding the density of the welded portions is not only the improvement of the sweat absorption performance.

[0093] That is, since the second region D4 of the outer body 11 is a part that contacts the skin of the wearer of the diaper 1, the surface (skin-opposing surface) of the second laminated structure 6 preferably has an excellent hand feel and a good skin touch, but the above-mentioned size relationship is established, and the density of the welded portion of the second laminated structure 6 is lower than that of the first laminated structure 5 in the first region D3 closer to the waist opening WH, so that the second region D4 becomes softer than the first region D3, and thus the touch can be made good for the wearer. In addition, since the second region D4 is arranged at a position close to the absorbent body 23, it is preferred to avoid the attraction of moisture from the excrement absorbed and retained by the absorbent core 24. In this regard, in addition to the size relationship established in the diaper 1, the first region D3 is located at a position farther outside the longitudinal direction X than the longitudinal end 23E of the absorbent body 23, and the first stacking structure 5 constituting the first region D3 does not overlap with the absorbent body 23. Therefore, through the synergistic effect of these structures, it is difficult for water-containing excrement to reach the first stacking structure 5 from the absorbent body 23, and it is difficult for excrement to leak from the waist end.

[0094] As described above, the diaper 1 has a good feel, is less likely to leak excrement, and has excellent sweat absorption properties at the waist end portion (waist wing portion D1).

[0095] In particular, in the present embodiment, not only the waist portion D of the dorsal portion C but also the waist portion D of the ventral portion A adopts the above-mentioned characteristic structure, so that compared with the existing products, the feel, leakage resistance and sweat absorption of the waist portion D are greatly improved.

[0096] As an index of the "weld density" (the number of welds 17 per unit area), the ratio of the total area of ​​the welds 17 present in the region to the area of ​​the region (the first region D3, the second region D4) (hereinafter also referred to as "weld area ratio") can be used. The larger the weld area ratio, the greater the weld density in the region. Unless otherwise specified in this specification, "weld density" can be replaced by "weld area ratio".

[0097] From the viewpoint of more reliably achieving the effect of the relationship of "the first stacked structure 5> the second stacked structure 6" concerning the density of the welded portion, the difference between the welded portion area ratio of the first region D3 (the first stacked structure 5) and the welded portion area ratio of the second region D4 (the second stacked structure 6) is preferably 3% or more, more preferably 5% or more, when the latter is subtracted from the former. The upper limit of the difference is not particularly limited, but is preferably 22% or less, more preferably 20% or less, when the latter is subtracted from the former.

[0098] Furthermore, from the viewpoint of the balance between absorption performance and flexibility, the area ratio of the welded portion of each of the first region D3 and the second region D4 is preferably set as follows.

[0099] The weld area ratio of the first region D3 (first stacked structure 5) is preferably greater than that of the weld area ratio of the second region D4 (second stacked structure 6), and is preferably greater than 9%, more preferably greater than 11%, and is preferably less than 28%, more preferably less than 26%.

[0100] The weld area ratio of the second region D4 (second stacked structure 6) is preferably 6% or more, more preferably 8% or more, and preferably 25% or less, more preferably 23% or less, on the premise that it is smaller than the weld area ratio of the first region D3 (first stacked structure 5).

[0101] From the viewpoint of more reliably achieving the effect of the relationship of "first stacked structure 5> second stacked structure 6" regarding the density of the welded portion, it is preferred that the outer layer sheet 12 is hydrophilic and the inner layer sheet 13 is hydrophobic. That is, it is preferred that the contact angle of the outer layer sheet 12 is less than 90 degrees, and the contact angle of the inner layer sheet 13 is greater than 90 degrees.

[0102] According to this preferred embodiment, it can be expected that the hydrophilic outer sheet 12 located in the first region D3 closer to the wearer's skin absorbs sweat at the waist wing D1 (waist end) of the waist D where the wearer's sweat is particularly likely to accumulate, and the absorbed sweat is transferred to the hydrophilic sheet 4. Such an ideal sweat absorption system works, and the sweat absorption performance of the diaper 1 is further improved. In addition, depending on the posture of the wearer of the diaper 1, a gap sometimes occurs between the wearer's skin and the second region D4 facing the skin. At this time, there is a concern about the reduction of the sweat absorption performance of the second region D4 (second laminated structure 6). There is also a similar concern when the sweat droplets attached to the wearer's skin are small, such as those that can be seen at the beginning of sweating. However, by making the outer sheet 12 hydrophilic and the inner sheet 13 hydrophobic, the sweat absorption function of the outer sheet 12 works effectively, and such concerns can be eliminated.

[0103] Furthermore, from the viewpoint of making the transfer of aqueous liquids such as sweat from the outer layer sheet 12 to the hydrophilic sheet 4 smoother as described above, the hydrophilic sheet 4 is preferably higher in hydrophilicity than the outer layer sheet 12. That is, the magnitude relationship of "contact angle of the hydrophilic sheet 4 <contact angle of the outer layer sheet 12" is preferably established.

[0104] The contact angle of the hydrophilic sheet 4 is preferably 50 degrees or more, more preferably 55 degrees or more, provided that it is smaller than the contact angle of the outer layer sheet 12, and is preferably 84 degrees or less, more preferably 79 degrees or less.

[0105] The contact angle of the outer layer sheet 12 is preferably greater than that of the hydrophilic sheet 4, and is preferably 70 degrees or greater, more preferably 75 degrees or greater, and is preferably 89 degrees or less, more preferably 85 degrees or less.

[0106] The difference between the contact angle of the outer layer sheet 12 and the contact angle of the hydrophilic sheet 4 is preferably 5 degrees or more, more preferably 10 degrees or more, when the latter is subtracted from the former.

[0107] The upper limit of the difference between the contact angle of the outer layer sheet 12 and the contact angle of the hydrophilic sheet 4 is not particularly limited, but is preferably 39 degrees or less, more preferably 34 degrees or less, when the latter is subtracted from the former.

[0108] The sweat absorption capacity of the first region D3 (first laminated structure 5) is preferably larger than that of the second region D4 (second laminated structure 6). Since the magnitude relationship of "first laminated structure 5>second laminated structure 6" is established with respect to the density of the welded portion, and the same magnitude relationship is established with respect to the sweat absorption capacity, the sweat absorption performance of the entire waist portion D centered on the waist wing portion D1 can be further improved. The sweat absorption capacity is measured by the following method.

[0109] <Method for measuring sweat absorption capacity>

[0110] A portion of a top-view quadrilateral shape with a longitudinal length of 50 mm and a lateral length of 50 mm is cut from the measurement object area of ​​the disposable diaper in a manner that includes the entire area in the thickness direction of the portion as a sample, and its weight is measured. Ion exchange water is injected into the culture dish, and the sample is immersed in the ion exchange water for 5 minutes. When the sample is immersed in the ion exchange water, the sample is brought close to the ion exchange water and immersed in this state while the skin-facing surface of the sample is opposite to the ion exchange water. After immersion for 5 minutes, the sample is removed from the ion exchange water with tweezers, and the sample is allowed to dry naturally until the ion exchange water absorbed by the sample no longer drips due to its own weight. After drying, the weight of the sample is measured, and the weight of the sample before immersion in the ion exchange water is subtracted from the measured value to calculate the absorption capacity (unit: mg).

[0111] The procedure is performed five or more times for one measurement target area, and the average value of the five absorption capacities is defined as the sweat absorption capacity of the measurement target area.

[0112] The sweat absorption capacity of the first region D3 (first stacked structure 5) is preferably greater than the sweat absorption capacity of the second region D4 (second stacked structure 6), and is preferably greater than 23 mg, more preferably greater than 30 mg, and is preferably less than 75 mg, more preferably less than 68 mg.

[0113] The sweat absorption capacity of the second region D4 (second stacked structure 6) is preferably 15 mg or more, more preferably 20 mg or more, and preferably 50 mg or less, more preferably 45 mg or less, provided that it is smaller than the sweat absorption capacity of the first region D3 (first stacked structure 5).

[0114] When the sweat absorption capacity of the first region D3 and the second region D4 is to be increased, the thickness of the hydrophilic member such as the hydrophilic sheet 4 that helps to increase the sweat absorption capacity tends to increase, and this tendency leads to a decrease in softness. Considering such a trade-off, from the perspective of taking into account both the sweat absorption capacity and softness, it is preferred that the sweat absorption capacity of the two regions D3 and D4 is within the above range.

[0115] As an example of a structure in which the magnitude relationship of “first stacked structure 5 > second stacked structure 6” holds true with respect to sweat absorption capacity, the following structure A can be cited.

[0116] Structure A: The outer layer sheet 12 is hydrophilic (contact angle less than 90 degrees), and the first stacked structure 5 (first region D3) includes the outer layer sheet 12 and the hydrophilic sheet 4, and the second stacked structure 6 (second region D4) includes the hydrophilic sheet 4 but does not include the outer layer sheet 12.

[0117] In the structure A, the first laminated structure 5 has a hydrophilic double-layer structure formed by overlapping the hydrophilic sheets 12 and 4, while the second laminated structure 6 does not have such a hydrophilic double-layer structure because it does not contain the hydrophilic outer sheet 12. Due to such a difference in structure, the relationship of "first laminated structure 5> second laminated structure 6" is established with respect to sweat absorption capacity.

[0118] As mentioned above, if Figure 5 and Figure 6 As shown, on the surfaces of the first laminated structure 5 and the second laminated structure 6, respectively, specifically, on the first surface 5a of the first laminated structure 5 forming the outer surface of the first region D3 and the first surface 6a of the second laminated structure 6 forming the outer surface (skin-opposing surface) of the second region D4, a concave-convex structure of concave portions 50, 60 located at the welded portion 17 and convex portions 51, 61 located at the peripheral portions of the concave portions 50, 60 is formed. From the viewpoint of further improving the sweat absorption speed of the first region D3, it is preferred that the concave-convex height difference T5 (refer to Figure 5 ) is greater than the height difference T6 between the convex portion 61 and the concave portion 60 of the second stacked structure 6 (refer to Figure 6 )Small.

[0119] According to the present inventors' understanding, the fewer the unevenness of the surface of the stacked structure of multiple sheets and the higher the smoothness, the faster the sweat absorption speed of the stacked structure (the speed of sweat introduction on the surface of the stacked structure) is, and the sweat absorption is improved. Therefore, in order to improve the sweat absorption speed of the first area D3, it is preferred that the above-mentioned size relationship "the uneven height difference T5 of the first stacked structure 5 < the uneven height difference T6 of the second stacked structure 6" is established. In other words, it is preferred that the smoothness of the surface that will contact the skin in the first area D3 (first stacked structure 5) is higher than that in the second area D4 (second stacked structure 6). The uneven height differences T5 and T6 can be measured by the following method.

[0120] <Method for measuring unevenness>

[0121] From the measurement target area (e.g., the first stacked structure 5) of the disposable diaper, a portion of a top-view quadrilateral shape with a longitudinal length of 10 mm and a lateral length of 50 mm is cut as a sample in a manner that includes the entire area in the thickness direction of the portion. The sample is cut in the thickness direction. At this time, the cut surface is made to pass through the top of the convex portion (e.g., convex portion 51) of the concave-convex structure on the surface of the sample. The cut surface of the sample is observed under a microscope, and the spacing distance between the top of the convex portion in the surface of the sample with the concave-convex structure and the bottom of the concave portion adjacent to the convex portion along the thickness direction of the sample is measured, and the measured value is taken as the concave-convex height difference. The concave-convex height difference is measured at any 10 locations in one measurement target area, and the average value of these measured values ​​is taken as the concave-convex height difference of the measurement target area.

[0122] From the viewpoint of the balance between the absorption performance and the flexibility of the first stacked structure 5 and the second stacked structure 6, it is preferable that the uneven height differences T5 and T6 are respectively within the following ranges.

[0123] The unevenness T5 (see Figure 5 ) is greater than the uneven height difference T6 (refer to Figure 6 ) is small, preferably 70 μm or more, more preferably 90 μm or more, and preferably 190 μm or less, more preferably 170 μm or less.

[0124] The unevenness T6 of the second stacked structure 6 (second region D4) is preferably greater than the unevenness T5 of the first stacked structure 5 (first region D3), and is preferably greater than 80 μm, more preferably greater than 100 μm, and is preferably less than 200 μm, more preferably less than 180 μm.

[0125] In the present embodiment, as described above, the third region D5 forms a concave-convex structure on the first surface (the surface on which the compression processing is performed) of the third stacking structure 7, which is composed of a plurality of concave portions located at the welding portion 17 (with the welding portion 17 as the bottom) and convex portions located at the peripheral portions of each of the concave portions (welding portion 17). However, from the viewpoint of ensuring a balance between softness and preventing the absorbed sweat and other liquids from seeping to the outside, the height difference of the concave-convex portion of the third stacking structure 7 (third region D5) is preferably greater than 100 μm, more preferably greater than 120 μm, and preferably less than 220 μm, more preferably less than 200 μm.

[0126] The height difference of the concavo-convex structure of each of the stacked structures 5, 6, 7 (each region D3, D4, D5) can be adjusted by adjusting the pressure of the compression process performed on the stacked structures 5, 6, 7 to form the welded portion 17. Generally, by increasing the pressure on the compressed object (stacked structures 5, 6, 7) during the compression process, the depth of the concavo-convex structure, such as the concave portions 50, 60 formed corresponding to the welded portion 17, becomes deeper, and the height (apparent thickness) of the convex portions, such as the convex portions 51, 61 located at the peripheral portion of the concave portion, becomes higher. Therefore, by adjusting the pressure, the height difference of the concavo-convex structure between the convex portions and the concave portions can be adjusted.

[0127] In this embodiment, as described above, Figure 4As shown, the plurality of sheets 12 and 13 constituting the third stacked structure 7 in the third region D5 are joined to each other at the welded portions 17 dispersed on the surface of the third stacked structure 7, and the number of welded portions 17 per unit area of ​​the third stacked structure 7 is preferably the same as the number of welded portions 17 per unit area of ​​the second stacked structure 6 in the second region D4, or is less than the number of welded portions 17 per unit area of ​​the second stacked structure 6. That is, with respect to the welded portion density, the magnitude relationship of "first stacked structure 5>second stacked structure 6≥third stacked structure 7" is preferably established.

[0128] In the present embodiment, regarding the density of the welded portion, the magnitude relationship of “first stacked structure 5 > second stacked structure 6 > third stacked structure 7” holds.

[0129] The third region D5 (third stacking structure 7) forms the outer surface (outermost layer) of the diaper 1, so it is required to have a good skin touch. In addition, it is required that the sweat, urine, feces and other excreta absorbed by the second region D4 (second stacking structure 6) are transferred to the third region D5 and do not seep out to the outside of the diaper 1. By establishing the size relationship of the weld density "second stacking structure 6 ≥ third stacking structure 7", the size relationship of the hydrophilicity "second stacking structure 6>third stacking structure 7" is also easily established, so that such required performance can be easily met.

[0130] From the viewpoint of more reliably achieving the effect of establishing the magnitude relationship of "the second stacked structure 6 ≥ the third stacked structure 7" with respect to the density of the welded portion, the difference between the welded portion area ratio of the second region D4 (the second stacked structure 6) and the welded portion area ratio of the third region D5 (the third stacked structure 7) is preferably 3% or more, more preferably 5% or more, when the latter is subtracted from the former. The upper limit of the difference is not particularly limited, but is preferably 22% or less, more preferably 20% or less, when the latter is subtracted from the former.

[0131] In addition, from the perspective of achieving a balance between softness and preventing liquid from leaking to the outside of the diaper 1, the weld area ratio of the third region D5 (third laminated structure 7) is preferably 3% or more, more preferably 5% or more, and is preferably 22% or less, more preferably 20% or less.

[0132] It is preferred that there is no adhesive between the inner sheet 13 and the hydrophilic sheet 4 overlapping the inner sheet 13. That is, in the outer body 11 of the waist region D, it is preferred that the inner sheet 13 and the hydrophilic sheet 4 are joined via the welded portion 17 without adhesive at the overlapping portion of the inner sheet 13 and the hydrophilic sheet 4 (in this embodiment, the first region D3 and the second region D4). This is because the adhesive disposed between the sheets may hinder the transfer of excrement such as sweat, urine, and feces between the sheets.

[0133] From the same point of view, it is preferred that there is no adhesive between the inner layer sheet 13 and the outer layer sheet 12 overlapping the inner layer sheet 13. That is, in the outer body 11 of the waist portion D, it is preferred that the inner layer sheet 13 and the outer layer sheet 12 are joined via the welded portion 17 without an adhesive at the overlapping portion of the inner layer sheet 13 and the outer layer sheet 12 (in the present embodiment, the first region D3 and the third region D5).

[0134] In this embodiment, if Figure 4 As shown, the inner layer sheet 13 extends outward in the longitudinal direction X from the longitudinal end (inner end in the longitudinal direction X) on the opposite side to the first region D3 (first stacked structure 5) side of the second stacked structure 6 . Figure 4 The reference numeral 13E in the figure indicates an extension portion of the inner sheet 13 from the inner end in the longitudinal direction X of the second laminated structure 6. That is, the inner sheet 13 has an extension portion 13E, which together with the inner sheet 13 extends from the inner end in the longitudinal direction X of the hydrophilic sheet 4 constituting the second laminated structure 6 to the outer side in the longitudinal direction X. The inner sheet 13 is hydrophobic, and by adopting this structure, the entire area of ​​the skin-facing surface of the hydrophilic sheet 4 in the second area D4 (second laminated structure 6) is covered by the hydrophobic inner sheet 13, so that the unfavorable situation that the excretions such as urine and feces (excretions other than sweat) excreted in the crotch B are absorbed by the hydrophilic sheet 4 in the second area D4 can be effectively prevented, and the leakage-proof property can be improved.

[0135] In this embodiment, as described above, the absorbent body 23 includes the absorbent core 24 mainly composed of a water-absorbent material. Figure 4 As shown, the absorbent core 24 and the hydrophilic sheet 4 of the second stacking structure D4 do not overlap when viewed from above (projected along the thickness direction Z). When the absorbent core 24 and the hydrophilic sheet 4 of the second stacking structure D4 overlap when viewed from above, there is a concern that urine, feces and other excreta absorbed and retained by the absorbent core 24 will be absorbed by the hydrophilic sheet 4, thereby inducing leakage of excreta, but in this embodiment, by adopting the above-mentioned structure, this concern is eliminated.

[0136] The length of the first region D3 to the third region D5 in the longitudinal direction X is not particularly limited, but is preferably set as follows from the viewpoint of more reliably achieving the above-mentioned effects.

[0137] In the unfolded and stretched state of the diaper 1, the length of the first region D3 (first layered structure 5) in the longitudinal direction X is preferably 10% or more, more preferably 15% or more, and preferably 40% or less, more preferably 35% or less, relative to the length of the waistline D in the longitudinal direction X.

[0138] In the unfolded and stretched state of the diaper 1, the length of the second region D4 (second layered structure 6) in the longitudinal direction X is preferably 10% or more, more preferably 15% or more, and preferably 90% or less, more preferably 85% or less, relative to the length of the waistline D in the longitudinal direction X.

[0139] The length of the first region D3 (first stacked structure 5) in the longitudinal direction X is preferably 10 mm or more, more preferably 15 mm or more, and is preferably 40 mm or less, more preferably 35 mm or less.

[0140] The length of the second region D4 (second stacked structure 6) in the longitudinal direction X is preferably 10 mm or more, more preferably 15 mm or more, and is preferably 90 mm or less, more preferably 85 mm or less.

[0141] In this embodiment, if Figure 4 As shown, the absorbent body 23 includes a core wrapper 25 covering the outer surface of the absorbent core 24, and has an absorbent core non-existence area where the absorbent core 24 does not exist but the core wrapper 25 exists at a position farther outside the longitudinal direction X than the longitudinal end 24E of the absorbent core 24, and the absorbent core non-existence area and the second stacking structure 6 overlap when viewed from above.

[0142] In this way, by overlapping the absorbent core non-existing area of ​​the absorbent body 23 and the second stacking structure 6 (second area D4) in the thickness direction, the situation where excretions other than sweat such as urine and feces reach the second stacking structure 6 is suppressed, and the moisture such as sweat absorbed by the second stacking structure 6 is first temporarily retained in the absorbent core non-existing area in the space between the core sheets 25 and 25 relative to each other in the thickness direction, and then transferred from the space to the third stacking structure 7 (third area D5), and then transferred to the outside of the diaper 1. Therefore, especially in the summer when the wearer of the diaper 1 sweats a lot, the sweat is not easy to remain in the hydrophilic sheet 4.

[0143] Especially in this embodiment, if Figure 4 As shown, the absorbent core non-existing region and the second stacking structure 6 (second region D4) overlap each other with their parts (ends in the longitudinal direction X), and the longitudinal end 24E of the absorbent core 24 and the second stacking structure 6 are spaced apart in the longitudinal direction X. By adopting this structure, for example, when the diaper 1 is worn for a long time, even if the moisture from body fluids such as sweat absorbed by the absorbent core 24 is transferred to the second region D4 side through the core packing 25, since the first stacking structure 5 (first region D3) and the core packing 25 are spaced apart in the longitudinal direction X, the breathability of the second region D4 is not easily impaired, and moisture such as sweat can be efficiently discharged to the outside of the diaper 1.

[0144] In addition, there may be a small amount of water-absorbent polymer that has fallen off from the absorbent core 24 in the region where the absorbent core does not exist. In this case, moisture such as sweat absorbed by the second region D4 (second stacked structure 6) may be transferred to the water-absorbent polymer present in the region where the absorbent core does not exist, so the hydrophilic sheet 4 constituting the second stacked structure 6 is easier to dry than when the water-absorbent polymer does not exist, so it is easy to get a refreshing feeling (dry feeling) at any time.

[0145] The weight of the water-absorbent polymer present in the non-absorbent core region is 0.5 g / m 2 Above and 3g / m 2 When the amount is less than 10%, it is preferable because it can further avoid the inconvenience of excretion other than sweat such as urine and feces transferring to the region without the absorbent core, and the sweat can be preferentially transferred to the region without the absorbent core.

[0146] The content of the water-absorbent polymer in the absorbent core non-existing region is preferably 1% by mass or less, and more preferably 0.5% by mass or less, based on the mass of the water-absorbent polymer contained in the absorbent core 24 .

[0147] Moreover, in this invention, the said absorbent core non-existing area|region does not need to overlap with the 2nd area|region D4 at all.

[0148] In this embodiment, as described above, the inner sheet 13 is hydrophobic and mainly composed of hydrophobic fibers. Here, "mainly" means that the content of hydrophobic fibers in all the constituent fibers of the sheet is at least 50% by mass. The content of hydrophobic fibers in the inner sheet 13 may be 100% by mass, or all the constituent fibers of the inner sheet 13 may be hydrophobic fibers.

[0149] As the hydrophobic fiber, it is preferred to use a hydrophobic thermoplastic fiber (thermoplastic fiber). As its raw material (hydrophobic thermoplastic resin), for example, polyolefins such as polyethylene and polypropylene can be listed; polyesters such as polyethylene terephthalate; polyamides such as nylon 6 and nylon 66; polyacrylic acid, polyalkyl methacrylate, polyvinyl chloride, polyvinylidene chloride, etc., and one of them can be used alone or in combination of two or more. The hydrophobic fiber can be a single fiber composed of a blended polymer of one synthetic resin or a mixture of two or more synthetic resins, or it can also be a composite fiber. The composite fiber mentioned here is a synthetic fiber (thermoplastic fiber) obtained by combining two or more synthetic resins with different components in a spinneret and spinning them at the same time, with a structure in which multiple components are continuous in the length direction of each fiber, and are combined with each other in a single fiber. The morphology of the composite fiber includes core-sheath type, parallel type, etc., without special restrictions.

[0150] The hydrophilic sheet 4, i.e., the sweat-absorbent sheet, is mainly composed of hydrophilic fibers. In this embodiment, as described above, the outer sheet 12 is also hydrophilic and is mainly composed of hydrophilic fibers. The meaning of "mainly" mentioned here is the same as that of the hydrophobic fibers. The content of the hydrophilic fibers in the two sheets 4 and 12 may be 100% by mass, or all the constituent fibers of the two sheets 4 and 12 may be hydrophobic fibers.

[0151] As the hydrophilic fiber, a hydrophilic thermoplastic fiber (thermal fusion fiber) can be used, for example, a thermoplastic fiber that is hydrophilic in nature, such as polyacrylonitrile fiber, or a fiber that has been hydrophilized on a hydrophobic thermoplastic fiber that can be used as the hydrophobic fiber, and one of them can be used alone or in combination of two or more. As the latter "thermoplastic fiber that has been hydrophilized", for example, thermoplastic fibers that have been mixed with a hydrophilizing agent, thermoplastic fibers that have a hydrophilizing agent attached to the surface, thermoplastic fibers that have been plasma treated, etc. can be listed. The hydrophilizing agent is not particularly limited as long as it is a common hydrophilizing agent used for sanitary products.

[0152] As the hydrophilic sheet 4 and the outer layer sheet 12, the contact angle is less than 90 degrees, and any material that can be used as a sweat-absorbent sheet in the technical field can be used without particular limitation. As a sweat-absorbent sheet applicable to the present invention, for example, the sheet described in Japanese Patent Publication No. 2017-213360 can be exemplified.

[0153] The outer layer 12 preferably has a grammage of 8 g / m 2 More preferably 10 g / m 2 More than 30g / m 2 Below, more preferably 28g / m 2 the following.

[0154] The weight of the inner layer 13 is preferably 8 g / m 2 More preferably 10 g / m 2 More than 25g / m 2 Below, more preferably 23g / m 2 the following.

[0155] The weight of the hydrophilic sheet 4 is preferably 10 g / m 2 More preferably 12 g / m 2 More than 25g / m 2 Below, more preferably 23g / m 2 the following.

[0156] The outer body 11 having the waist portion D having the above-mentioned first region D3 to third region D5 can basically be manufactured according to the usual method using the existing publicly known manufacturing technology, as described above, as long as the density of the weld portion (weld portion area ratio) is such that "the first stacking structure 5 (first region D3)>the second stacking structure 6 (second region D4)", and further the size relationship of "the first stacking structure 5 (first region D3)>the second stacking structure 6 (second region D4)≥the third stacking structure 7 (third region D5)" is established.

[0157] For example, in the manufacturing process of the outer body 11 of the waist portion D, a method can be cited in which the number of times of welding treatment such as embossing for forming the welded portion 17 is different in each region D1 to D3. More specifically, for example, a method can be cited in which the number of times of welding treatment in the first region D3 (first stacked structure 5) having the highest density of welded portions in the outer body 11 forming the waist portion D is greater than the number of times in the other regions D2 and D3.

[0158] The following is based on Figure 7 An example of a method for manufacturing the outer body 11 of the waist portion D will be described.

[0159] Figure 7 The manufacturing method of the outer casing 11 shown has the following steps:

[0160] Step 1: a step of disposing a hydrophilic sheet 4 on a portion of one surface of an inner layer sheet 13 being conveyed in one direction (machine direction MD), performing a first welding treatment on the overlapping portion of the two sheets 13, 4, thereby forming a second laminated structure 6 (an integrated product of the inner layer sheet 13 and the hydrophilic sheet 4), and obtaining a first intermediate sheet 65 in which the inner layer sheet 13 and the second laminated structure 6 are continuously present in the machine direction MD;

[0161] The second step: the step of arranging the outer layer sheet 12 on the other surface of the inner layer sheet 13 in the first intermediate sheet 65 (the surface on the opposite side of the arrangement surface of the hydrophilic sheet 4) so ​​as to overlap with one end (rear end) of the second laminated structure 6 (the hydrophilic sheet 4) in the processing direction MD when viewed from above, performing a second welding treatment on the overlapping portion of the outer layer sheet 12 and the inner layer sheet 13, forming the third laminated structure 7 (an integrated product of the outer layer sheet 12 and the inner layer sheet 13) at the non-arrangement portion of the second laminated structure 6 in the overlapping portion, and forming the first laminated structure 5 (an integrated product of the outer layer sheet 12, the inner layer sheet 13 and the hydrophilic sheet 4) at the arrangement portion of the second laminated structure 6 in the overlapping portion, thereby obtaining a second intermediate sheet 66 in which the third laminated structure 7, the first laminated structure 5 and the second laminated structure 6 are continuous in the processing direction MD; and

[0162] Third step: a step of folding the second intermediate sheet 66 in the one direction (machine direction MD) at the position of the first laminated structure 5 so that the hydrophilic sheet 4 is located inside.

[0163] In the first step and the second step, the first stacked structure 5 to the third stacked structure 7 are formed by welding a plurality of sheets to each other through a welding process, and a plurality of welded portions 17 are dispersed on the surface. As the welding process, the above-mentioned compression process can be used, and specifically, for example, a known embossing process such as an embossing process accompanied by heat, ultrasonic embossing, etc. can be used. In the outer casing 11 as the manufacturing target, regarding the number of welded portions 17 per unit area between the first stacked structure 5 to the third stacked structure 7 (weld portion density), at least the size relationship of "the first stacked structure 5> the second stacked structure 6" is required to hold, and it is further preferred that the size relationship of "the second stacked structure 6≥ the third stacked structure 7" holds, as described above.

[0164] The second intermediate sheet 66 is substantially the same as the outer body 11 as the manufacturing target except that it is not folded back (does not have the folded back portion 16). The third step may be performed after the second intermediate sheet 66 is disposed at a predetermined position of the absorbent body 2.

[0165] As one of the main features of the present manufacturing method, it is possible to form three patterns of welded portions 17 having different welded portion densities by two welding processes (first welding process and second welding process). That is, in the first welding process and the second welding process used in the present manufacturing method, the number of welded portions 17 per unit area (weld portion density) formed by the welding process is in the order of "first welding process > second welding process", and by subjecting a part of the portion subjected to the first welding process in the first process, that is, one end portion (rear end portion) in the machine direction MD of the second laminated structure 6 (hydrophilic sheet 4) to the second welding process in the second process, the welded portion density of the one end portion is made higher than that of other portions, so that the one end portion becomes the first laminated structure 5 having the highest welded portion density. That is, the welded portions 17 of the first laminated structure 5 formed by the present manufacturing method are formed by two processes, the first process (first welding process) and the second process (second welding process).

[0166] According to the present manufacturing method, the exterior body 11 having the above-described characteristic structure can be efficiently manufactured in-line.

[0167] As mentioned above, although this invention was demonstrated based on embodiment of this invention, this invention is not limited to the said embodiment, It can change suitably.

[0168] For example, the diaper 1 of the embodiment is a shorts type with a waist opening and leg openings pre-formed, but the disposable diaper of the present invention is not limited to the shorts type, for example, it can also be an unfolded type without a waist opening and leg openings pre-formed, and including a fixing mechanism in the non-configuration part (wing part) of the absorbent body.

[0169] In addition, in the embodiment, the outer body 11 has a continuous shape such as an hourglass shape that covers the range of the ventral part A, the crotch part B and the dorsal part C, but the outer body 11 may include a ventral outer body arranged on the ventral side of the wearer, a crotch outer body arranged on the crotch of the wearer, and a dorsal outer body arranged on the dorsal side of the wearer, and the outer bodies are joined to each other at the ends of the longitudinal direction X to replace the above structure. The structures of the outer bodies may be the same or different from each other. Alternatively, the outer body 11 may have the ventral outer body and the dorsal outer body, but not the crotch outer body, and the absorbent body 2 may be mounted on the two outer bodies and fixed. As other embodiments of the outer body 11, it can be listed that the ventral outer body and the dorsal outer body respectively have a stacked structure of two sheets that are the same as the outer body 11 of the above-mentioned diaper 1 (a structure comprising an outer sheet 12, an inner sheet 13 and a plurality of elastic components 14 arranged between the two sheets 12, 13), and the crotch outer body is a single-layer structure composed of non-woven fabric.

[0170] All of the parts that are included in only one embodiment described above can be utilized mutually as appropriate.

[0171] The following contents are further disclosed regarding the above-mentioned embodiments of the present invention.

[0172] <1> A disposable diaper having a longitudinal direction extending from the wearer's ventral side to the back side via a crotch portion and a lateral direction orthogonal to the longitudinal direction, and being divided into a crotch portion arranged at the crotch portion, an ventral portion arranged at the wearer's ventral side relative to the crotch portion, and a dorsal portion arranged at the wearer's dorsal side relative to the crotch portion, the disposable diaper comprising an absorbent body for absorbing and retaining body fluids and an outer body arranged at the non-skin-opposing side of the absorbent body, the ventral portion and the dorsal portion having a waist portion arranged at the wearer's waist, and in the disposable diaper,

[0173] The outer body includes: an outer layer sheet arranged at a position relatively far from the absorbent body; and an inner layer sheet arranged at a position relatively close to the absorbent body.

[0174] The outer body of the waist portion of at least the back portion has a folded portion, which is formed by folding back a portion of the outer body located on the outer side in the longitudinal direction than the longitudinal end of the absorbent body toward the inner layer sheet, and is divided into:

[0175] A first region including a bending position of the outer body for forming the folded portion, and located outside the longitudinal direction of the absorbent body relative to the longitudinal end thereof;

[0176] a second region located on the inner side in the longitudinal direction than the first region and closer to the skin of the wearer than the folded position; and

[0177] a third region located on the inner side in the longitudinal direction than the first region and on the side farther from the skin of the wearer than the bending position,

[0178] The first region includes a first laminated structure including a portion in which the outer layer sheet, the inner layer sheet, and the hydrophilic sheet are sequentially laminated from the outer side to the inner side in the longitudinal direction, and a plurality of sheets constituting the first laminated structure are bonded to each other at welded portions dispersed on the surface of the first laminated structure.

[0179] The second region includes a second laminated structure in which the hydrophilic sheet is arranged on the non-skin facing surface of the inner layer sheet constituting the folded portion, and a plurality of sheets constituting the second laminated structure are bonded to each other at welded portions dispersed on the surface of the second laminated structure.

[0180] The first stacked structure has a larger number of the welded portions per unit area than the second stacked structure.

[0181] <2>

[0182] As mentioned above <1> In the disposable diaper, the area ratio of the welded portion in the first laminated structure (the first region) is 9 to 28%, preferably 11 to 26%.

[0183] <3>

[0184] As mentioned above <1> or <2> In the disposable diaper, the area ratio of the welded portion in the second layered structure (the second region) is 6 to 25%, preferably 8 to 23%.

[0185] <4>

[0186] As mentioned above <1> ~ <3> The disposable diaper according to any one of claims 1 to 5, wherein the sweat absorption capacity of the first region is greater than the sweat absorption capacity of the second region.

[0187] <5>

[0188] As mentioned above <1> ~ <4> The disposable diaper according to any one of claims , wherein the sweat absorption capacity of the first region (first layered structure) is 23 to 75 mg, preferably 30 to 68 mg.

[0189] <6>

[0190] As mentioned above <1> ~ <5> The disposable diaper according to any one of the claims 1 to 5, wherein the sweat absorption capacity of the second region (second layered structure) is 15 to 50 mg, preferably 20 to 45 mg.

[0191] <7>

[0192] As mentioned above <1> ~ <6> The disposable diaper according to any one of claims 1 to 5, wherein a concave portion located at the welded portion and a convex portion located at a peripheral portion of the concave portion are formed on the surface of each of the first laminate structure and the second laminate structure,

[0193] The first stacked structure has a smaller height difference between the convex portion and the concave portion than the second stacked structure.

[0194] <8>

[0195] As mentioned above <7> The disposable diaper, wherein the convex portions and the concave portions of the first laminated structure are formed on the outer surface of the first laminated structure, and the convex portions and the concave portions of the second laminated structure are formed on the outer surface (skin-facing surface) of the second laminated structure.

[0196] <9>

[0197] As mentioned above <7> or <8> In the disposable diaper, the height difference of the first layered structure is 70 to 190 μm, preferably 90 to 170 μm.

[0198] <10>

[0199] As mentioned above <7> ~ <9> The disposable diaper according to any one of claims 1 to 5, wherein the height difference of the second laminated structure is 80 to 200 μm, preferably 100 to 180 μm.

[0200] <11>

[0201] As mentioned above <1> ~ <10> The disposable diaper according to any one of claims 1 to 5, wherein the third region includes a third laminated structure formed by laminating the outer layer sheet and the inner layer sheet, and a plurality of sheets constituting the third laminated structure are bonded to each other at a plurality of welded portions dispersed on the surface of the third laminated structure,

[0202] The number of the welded portions per unit area of ​​the third stacked structure is the same as or smaller than the number of the welded portions per unit area of ​​the second stacked structure.

[0203] <12>

[0204] As mentioned above <11> In the disposable diaper, the area ratio of the welded portion in the third laminated structure (the third region) is 3 to 22%, preferably 5 to 20%.

[0205] <13>

[0206] As mentioned above <11> or <12> The disposable diaper, wherein the difference between the area ratio of the welded portion of the second stacking structure (the second region) and the area ratio of the welded portion of the third stacking structure (the third region) is 3% or more, preferably 5% or more, when the latter is subtracted from the former.

[0207] <14>

[0208] As mentioned above <11> ~ <13> The disposable diaper according to any one of claims 1 to 5, wherein a concave portion located at the welded portion and a convex portion located at a peripheral portion of the concave portion are formed on the surface of the third laminated structure,

[0209] The height difference between the convex portion and the concave portion of the third stacked structure (the third region) is 100 to 220 μm, preferably 120 to 200 μm.

[0210] <15>

[0211] As mentioned above <11> ~ <14> The disposable diaper according to any one of claims 1 to 5, wherein the third stacked structure is a double-layer structure of the outer layer sheet and the inner layer sheet.

[0212] <16>

[0213] As mentioned above <1> ~ <15> The disposable diaper according to any one of claims , wherein no adhesive is present between the inner layer sheet and the hydrophilic sheet superimposed on the inner layer sheet.

[0214] <17>

[0215] As mentioned above <1> ~ <16> The disposable diaper according to any one of claims , wherein no adhesive is present between the inner layer sheet and the outer layer sheet overlapped on the inner layer sheet.

[0216] <18>

[0217] As mentioned above <1> ~ <17> The disposable diaper according to any one of claims 1 to 5, wherein the outer sheet is hydrophilic and the inner sheet is hydrophobic.

[0218] <19>

[0219] As mentioned above <18> The disposable diaper described above, wherein the inner layer sheet extends outward in the longitudinal direction from a longitudinal end of the second laminated structure on the side opposite to the first region side.

[0220] <20>

[0221] As mentioned above <1> ~ <19> The disposable diaper according to any one of claims , wherein the hydrophilicity of the hydrophilic sheet is higher than the hydrophilicity of the outer sheet.

[0222] <21>

[0223] As mentioned above <1> ~ <20> The disposable diaper according to any one of claims 1 to 5, wherein the absorbent body includes an absorbent core mainly composed of a water-absorbent material, and the absorbent core and the hydrophilic sheet of the second laminated structure do not overlap in a plan view.

[0224] <22>

[0225] As mentioned above <21> The disposable diaper described above, wherein the absorbent body includes a core sheet covering the outer surface of the absorbent core, and has an absorbent core non-existence area on the outer side of the longitudinal direction of the longitudinal end of the absorbent core where the absorbent core does not exist but the core sheet exists, and the absorbent core non-existence area and the second stacking structure overlap when viewed from above.

[0226] <23>

[0227] As mentioned above <22> The disposable diaper is characterized in that the absorbent core non-existing region and the second stacked structure partially overlap each other, and a longitudinal end of the absorbent core and the second stacked structure are spaced apart in the longitudinal direction.

[0228] <24>

[0229] As mentioned above <22> or <23> The disposable diaper, wherein the absorbent core non-existing region has 0.5 g / m 2 Above and 3g / m 2 The following water-absorbent polymers.

[0230] <25>

[0231] As mentioned above <22> ~ <24> The disposable diaper according to any one of claims 1 to 5, wherein the content of the water-absorbent polymer in the absorbent core non-existing region is 1% by mass or less, preferably 0.5% by mass or less, based on the mass of the water-absorbent polymer contained in the absorbent core.

[0232] <26>

[0233] As mentioned above <1> ~ <25> The disposable diaper according to any one of claims 1 to 5, wherein the first laminate structure is a three-layer structure of the outer layer sheet, the inner layer sheet, and the hydrophilic sheet.

[0234] <27>

[0235] As mentioned above <1> ~ <26> The disposable diaper according to any one of claims , wherein the second laminate structure is a double-layer structure of the inner layer sheet and the hydrophilic sheet.

[0236] Industrial Applicability

[0237] According to the present invention, it is possible to provide a disposable diaper which has a good hand feel, is less likely to cause leakage of excrement, and has excellent sweat absorbency at the waist end portion.

Claims

1. A disposable diaper having a longitudinal direction extending from the wearer's ventral side to the back side via a crotch portion and a transverse direction orthogonal to the longitudinal direction, and being divided into a crotch portion arranged at the crotch portion, an ventral portion arranged at the wearer's ventral side relative to the crotch portion, and a dorsal portion arranged at the wearer's dorsal side relative to the crotch portion, the disposable diaper comprising an absorbent body for absorbing and retaining body fluids and an outer body arranged at the non-skin facing side of the absorbent body, and having a waist portion arranged at the waist of the wearer at the ventral portion and the dorsal portion, the disposable diaper being characterized in that: The outer body includes: an outer layer sheet arranged at a position relatively far from the absorbent body; and an inner layer sheet arranged at a position relatively close to the absorbent body. The outer body of the waist portion of at least the back portion has a folded portion, which is formed by folding back a portion of the outer body located on the outer side in the longitudinal direction than the longitudinal end of the absorbent body toward the inner layer sheet, and is divided into: A first region including a folded position of the outer body for forming the folded portion, and located outside the longitudinal direction of the absorbent body; a second region located on the inner side in the longitudinal direction than the first region and closer to the skin of the wearer than the folded position; and a third region located on the inner side in the longitudinal direction than the first region and on the side farther from the skin of the wearer than the bending position, The first region includes a first laminated structure including a portion in which the outer layer sheet, the inner layer sheet, and the hydrophilic sheet are sequentially laminated from the outer side to the inner side in the longitudinal direction, and a plurality of sheets constituting the first laminated structure are bonded to each other at welded portions dispersed on the surface of the first laminated structure. The second region includes a second laminated structure in which the hydrophilic sheet is arranged on the non-skin facing surface of the inner layer sheet constituting the folded portion, and a plurality of sheets constituting the second laminated structure are bonded to each other at welded portions dispersed on the surface of the second laminated structure. The first stacked structure has a larger number of welded portions per unit area than the second stacked structure. The ratio of the total area of ​​the welded portions existing in the first region to the area of ​​the first region is greater than the ratio of the total area of ​​the welded portions existing in the second region to the area of ​​the second region, The area ratio of the welded portion of the first stacked structure is 9 to 28%, The area ratio of the welded portion of the second stacked structure is 6 to 25%.

2. The disposable diaper according to claim 1, characterized in that: The sweat absorption capacity of the first region is greater than the sweat absorption capacity of the second region.

3. The disposable diaper according to claim 1 or 2, characterized in that: The sweat absorption capacity of the first region is 23 to 75 mg.

4. The disposable diaper according to claim 1 or 2, characterized in that: The sweat absorption capacity of the second region is 15 to 50 mg.

5. The disposable diaper according to claim 1 or 2, characterized in that: A concave portion located at the welded portion and a convex portion located at a peripheral portion of the concave portion are formed on the surface of each of the first stacked structure and the second stacked structure. The first stacked structure has a smaller height difference between the convex portion and the concave portion than the second stacked structure.

6. The disposable diaper according to claim 5, characterized in that: The convex portion and the concave portion of the first stacked structure are formed on an outer surface of the first stacked structure, and the convex portion and the concave portion of the second stacked structure are formed on an outer surface of the second stacked structure.

7. The disposable diaper according to claim 5, characterized in that: The height difference of the first stacked structure is 70 to 190 μm.

8. The disposable diaper according to claim 5, characterized in that: The height difference of the second stacked structure is 80 to 200 μm.

9. The disposable diaper according to claim 1 or 2, characterized in that: The third region includes a third laminated structure formed by laminating the outer layer sheet and the inner layer sheet, wherein a plurality of sheets constituting the third laminated structure are bonded to each other at a plurality of welded portions dispersed on the surface of the third laminated structure. The number of the welded portions per unit area of ​​the third stacked structure is the same as or smaller than the number of the welded portions per unit area of ​​the second stacked structure.

10. The disposable diaper according to claim 9, characterized in that: The area ratio of the welded portion of the third stacked structure is 3 to 22%.

11. The disposable diaper according to claim 9, characterized in that: The difference between the area ratio of the welded portion of the second stacked structure and the area ratio of the welded portion of the third stacked structure is 3% or more when the latter is subtracted from the former.

12. The disposable diaper according to claim 9, characterized in that: A concave portion located at the welded portion and a convex portion located at a peripheral portion of the concave portion are formed on the surface of the third laminated structure. The height difference between the protrusions and the recesses of the third stacked structure is 100 to 220 μm.

13. The disposable diaper according to claim 9, characterized in that: The third laminated structure is a double-layer structure of the outer layer sheet and the inner layer sheet.

14. The disposable diaper according to claim 1 or 2, characterized in that: There is no adhesive between the inner layer sheet and the hydrophilic sheet superimposed on the inner layer sheet.

15. The disposable diaper according to claim 1 or 2, characterized in that: There is no adhesive between the inner layer sheet and the outer layer sheet overlapped on the inner layer sheet.

16. The disposable diaper according to claim 1 or 2, characterized in that: The outer sheet is hydrophilic and the inner sheet is hydrophobic.

17. The disposable diaper according to claim 16, characterized in that: The inner layer sheet extends outward in the longitudinal direction from a longitudinal end of the second stacked structure on the side opposite to the first region side.

18. The disposable diaper according to claim 1 or 2, characterized in that: The hydrophilicity of the hydrophilic sheet is higher than that of the outer layer sheet.

19. The disposable diaper according to claim 1 or 2, characterized in that: The absorbent body includes an absorbent core mainly composed of a water-absorbent material, and the absorbent core and the hydrophilic sheet of the second stacked structure do not overlap in a plan view.

20. The disposable diaper according to claim 19, characterized in that: The absorbent body includes a core sheet covering the outer surface of the absorbent core, and has an absorbent core non-existing region where the core sheet does not exist but the absorbent core does not exist, on the outer side of the longitudinal end of the absorbent core in the longitudinal direction. The absorbent core non-existing region and the second stacked structure overlap each other in a plan view.

21. The disposable diaper according to claim 20, characterized in that: The absorbent core non-existing region and the second stacked structure partially overlap each other, and a longitudinal end of the absorbent core and the second stacked structure are spaced apart in the longitudinal direction.

22. The disposable diaper according to claim 20, characterized in that: In the non-absorbent core region, there is 0.5 g / m 2 Above and 3g / m 2 The following water-absorbent polymers.

23. The disposable diaper according to claim 20, characterized in that: The content of the water-absorbent polymer in the absorbent core non-existing region is 1% by mass or less relative to the mass of the water-absorbent polymer contained in the absorbent core.

24. The disposable diaper according to claim 1 or 2, characterized in that: The second laminated structure is a double-layer structure of the inner-layer sheet and the hydrophilic sheet.

Images