Absorbent article

Abstract

To provide an absorbent article excellent in body fluid leakage prevention performance.SOLUTION: An absorbent article 1 includes a high-basis-weight portion 55 in which the basis weight of an absorbent core 5 is within a predetermined range, and a back-side low-basis-weight portion 56R which is located in a back-side portion R and in which the basis weight of the absorbent core 5 is smaller than that of the high-basis-weight portion 55. The back-side low-basis-weight portion 56R is located outward of the high-basis-weight portion 55 in the longitudinal direction X and adjacent to the high-basis-weight portion 55. Each of the pair of vertical stretchable parts 7070 has a portion at the same position as the back-side low-basis-weight portion 56R in the vertical direction X. When the absorbent article 1 is worn, a back side pleat 20 formed by deformation of a part positioned at the back side low basis weight part 56R in the front surface sheet 3 extends in the lateral direction Y on a skin facing face of the part.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to absorbent articles such as disposable diapers. [Background technology]

[0002] A known absorbent article includes an absorbent core that absorbs and retains bodily fluids, a topsheet that is disposed on the skin-facing side of the absorbent core and that comes into contact with the wearer's skin when worn, and a pair of leakage-preventing cuffs that are disposed on both sides of the absorbent core in the longitudinal direction (the direction corresponding to the front-to-back direction of the wearer).Patent Documents 1 to 3 describe disposable diapers having such a configuration.

[0003] The diapers described in Patent Documents 1 and 2 have laterally extending pleats on the skin-facing surface of the topsheet in the region sandwiched between one and the other of a pair of leakage-proof cuffs. In the diapers described in Patent Documents 1 and 2, the absorbent core has a uniform basis weight, and the pleats are positioned so as to overlap the uniform basis weight absorbent core in a plan view. The pleats function as a leakage barrier that blocks relatively fluid body fluids, such as loose stools. According to the diapers described in Patent Documents 1 and 2, the pleats prevent the inconvenience of body fluids leaking out from the longitudinal ends of the diaper. The pleats in the diaper described in Patent Document 1 are formed by tucks in the topsheet. In the diaper described in Patent Document 2, multiple topsheets are arranged so as to overlap in the longitudinal direction, and the free edges of the topsheets (portions of the topsheet not fixed to other components) located at the overlapping portions of the multiple topsheets form the pleats.

[0004] The diaper shown in Figures 19 and 20 of Patent Document 3 has folded-back sections 19 formed by folding back the longitudinal end of the absorbent body main body 2 (absorbent) toward the topsheet 3 along a folding line 18 at a widthwise bent structural section 7' ​​formed on the absorbent body main body 2. Despite the folded-back sections 19, the diaper is characterized by its compact size (see paragraphs

[0067] ,

[0068] , and

[0004] of Patent Document 3). The folded-back sections 19 function as leak-barriers. According to the diaper described in Patent Document 3, the leak-barrier has a large absorbent surface area for absorbing bodily fluids, and the entire surface of the section that contacts the wearer's skin contributes to absorbing urine, thereby eliminating waste of material. The widthwise bent structural section 7' ​​is a linear section of the absorbent body main body 2 that is processed to allow the absorbent body main body 2 to be easily folded back; specifically, it is a slit or a cut-off section (see paragraphs

[0027] and

[0028] of Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2017-29597 [Patent Document 2] Japanese Patent Application Publication No. 10-314226 [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-23365 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide an absorbent article that has excellent performance in preventing leakage of body fluids. [Means for solving the problem]

[0007] The present invention provides an absorbent article comprising an absorbent core having a ventral portion that is arranged on the ventral side of a wearer when worn, a dorsal portion that is arranged on the dorsal side of the wearer, and a crotch portion located therebetween, and having a vertical direction extending from the ventral portion via the crotch portion to the dorsal portion and a horizontal direction perpendicular to the vertical direction, the absorbent core absorbing and retaining bodily fluids, a topsheet that is arranged on the skin-facing side of the absorbent core and comes into contact with the wearer's skin when worn, and a pair of vertically stretchable portions that are arranged corresponding to both side portions of the absorbent core along the vertical direction and extend in the vertical direction from the ventral portion to the dorsal portion. In one embodiment of the absorbent article of the present invention, the absorbent article has a high basis weight section in which the basis weight of the absorbent core is within a predetermined range, and a back low basis weight section located in the back section and in which the basis weight of the absorbent core is smaller than that of the high basis weight section, and it is preferable that the back low basis weight section is located outward in the longitudinal direction from the high basis weight section and adjacent to the high basis weight section. In one embodiment of the absorbent article of the present invention, it is preferable that each of the pair of longitudinally extensible portions has a portion that is located at the same position in the longitudinal direction as the back-side low basis weight portion. In one embodiment of the absorbent article of the present invention, it is preferable that when worn, the skin-facing surface of the portion of the top sheet located in the low back basis weight portion has a back pleat formed by deformation of the portion extending in the lateral direction. Other features, advantages and embodiments of the present invention are described below. [Effects of the Invention]

[0008] According to the present invention, an absorbent article having excellent performance in preventing leakage of body fluids is provided. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic perspective view of the back side of a pants-type disposable diaper, which is one embodiment of the absorbent article of the present invention. [Figure 2] FIG. 2 is a developed plan view of the skin-facing side of the diaper shown in FIG. 1 in a developed and stretched state. [Figure 3]Figure 3(a) is a cross-sectional view schematically showing a cross-section along line II of the diaper shown in Figure 2 (a cross-section along the horizontal and thickness directions in the crotch area), and Figure 3(b) is the same cross-sectional view of the diaper when worn. [Figure 4] FIG. 4 is a cross-sectional view schematically showing a cross section of the diaper shown in FIG. 2 taken along line II-II (a cross section taken along the longitudinal and thickness directions at the central portion in the lateral direction). [Figure 5] FIG. 5 is an enlarged view of a part (the back pleat and its vicinity) of the view corresponding to FIG. 4 of another embodiment of the absorbent article of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described below based on preferred embodiments with reference to the drawings. The same parts in the drawings are designated by the same reference numerals. The drawings are essentially schematic, and the dimensions and dimensional ratios of certain parts to other parts may differ from those of the actual product.

[0011] 1 to 4 show a pants-type disposable diaper 1, which is one embodiment of the absorbent article of the present invention. The diaper 1 has a ventral portion F that is positioned on the ventral side of a wearer when worn, a dorsal portion R that is positioned on the dorsal side of the wearer, and a crotch portion M located between the ventral portion F and the dorsal portion R. The diaper 1 also has a longitudinal direction X that extends from the ventral portion F through the crotch portion M to the dorsal portion R, corresponding to the front-to-back direction of the wearer, and a lateral direction Y that is perpendicular to the longitudinal direction X. The diaper 1 also comprises an absorbent core 5 that absorbs and retains bodily fluids, a topsheet 3 that is disposed on the skin-facing side of the absorbent core 5 and comes into contact with the wearer's skin when worn, and a pair of longitudinally stretchable portions 70, 70 that are disposed corresponding to both sides of the absorbent core 5 along the longitudinal direction X and extend in the longitudinal direction X from the ventral portion F to the dorsal portion R.

[0012] In this embodiment, as shown in Figures 2 and 3, the diaper 1 is provided with leak-proof cuffs 7 that are arranged on the skin-facing side of the absorbent core 5 and have standing portions that stand up toward the wearer's skin when worn, and these standing portions are vertically stretchable portions 70.

[0013] The crotch portion M extends in the longitudinal direction X across the longitudinal centerline CL1 of the diaper 1. The longitudinal centerline CL1 is an imaginary line extending in the transverse direction Y, dividing the diaper 1 in the unfolded and stretched state as shown in FIG. The crotch portion M includes an excretory portion facing portion (not shown) facing the wearer's excretory portion such as the penis, and typically includes the portion of the diaper 1 that has the shortest length (width) in the lateral direction Y. In the present invention, the abdominal portion F, the crotch portion M, and the back portion R may be each of the regions obtained by dividing the absorbent article in a developed and stretched state into three equal parts in the longitudinal direction X.

[0014] In this specification, the term "unfolded and stretched state" refers to a state in which the absorbent article is spread out flat and in an unfolded state, and the elastic members of each part of the unfolded absorbent article are stretched until the absorbent article reaches the designed dimensions, i.e., the dimensions when unfolded flat and in a state in which the influence of the elastic members is completely eliminated. In the case of an absorbent article having side seals, such as a pants-type disposable diaper, the absorbent article is separated at the side seals and spread out flat to the unfolded state.

[0015] In this embodiment, the diaper 1 comprises an absorbent main body 2 including an absorbent core 5, and an exterior body 10 disposed on the non-skin-facing side of the absorbent main body 2. The absorbent main body 2 and the exterior body 10 are joined together by a known joining means such as an adhesive.

[0016] In this specification, the "skin-facing side" refers to the side of the absorbent article or its constituent member (e.g., absorbent core) that faces the skin of the wearer when the absorbent article is worn, i.e., the side that is relatively close to the wearer's skin, and the "non-skin-facing side" refers to the side of the absorbent article or its constituent member that faces the opposite side from the skin when the absorbent article is worn, i.e., the side that is relatively far from the wearer's skin. Note that "when worn" here refers to the normal, appropriate wearing position, i.e., a state in which the correct wearing position of the absorbent article is maintained.

[0017] The absorbent body 2 comprises a liquid-permeable topsheet 3 positioned relatively close to the wearer's skin, a liquid-impermeable, poorly liquid-permeable, or water-repellent backsheet 4 positioned relatively far from the wearer's skin, an absorbent core 5 interposed between the two sheets 3, 4, and a core wrap sheet 6 having a portion that contacts the skin-facing or non-skin-facing surface of the absorbent core 5. These components that make up the absorbent body 2 are joined together by known joining means such as adhesives. The topsheet 3 forms the outermost layer on the skin-facing side of the diaper 1 and can come into contact with the wearer's skin while the diaper 1 is being worn.

[0018] The core wrap sheet 6 includes a skin-side sheet 6A having a portion that contacts the skin-facing surface of the absorbent core 5, and a non-skin-side sheet 6B having a portion that contacts the non-skin-facing surface of the absorbent core 5. In this embodiment, the core wrap sheet 6 is a single sheet, and the skin-side sheet 6A and the non-skin-side sheet 6B are each part of that single sheet, but in the present invention, the form of the core wrap sheet is not limited to this, and the skin-side sheet 6A and the non-skin-side sheet 6B may be separate sheets. In other words, the core wrap sheet 6 may be composed of multiple sheets 6A, 6B.

[0019] In this embodiment, the topsheet 3, the backsheet 4 and the core wrap sheet 6 each have an extension portion that extends outward from the periphery of the absorbent core 5. That is, the top sheet 3 covers the entire skin-facing surface of the absorbent core 5, and as shown in FIG. 3, extends from the skin-facing surface side of the absorbent core 5 to the non-skin-facing side of the absorbent core 5 via both side edges (both ends in the horizontal direction Y) along the vertical direction X of the absorbent core 5, and as shown in FIG. 4, extends outward in the vertical direction X from the vertical ends 5X of the absorbent core 5 in the ventral side portion F and the dorsal side portion R. The backsheet 4 covers the entire non-skin-facing surface of the absorbent core 5, and as shown in FIG. 3, extends outward in the transverse direction Y from both side edges of the absorbent core 5 along the longitudinal direction X, and as shown in FIG. 4, extends outward in the longitudinal direction X from the longitudinal ends 5X of the absorbent core 5 in the ventral side portion F and the dorsal side portion R. As shown in Figure 4, the core wrap sheets 6 (6A, 6B) extend outward in the longitudinal direction X from the longitudinal ends 5X of the absorbent core 5 in the ventral portion F and the dorsal portion R. In this technical field, the overlapping portion of the absorbent core 5 and the core wrap sheet 6 is sometimes called the "absorbent body."

[0020] The top sheet 3, back sheet 4, and core wrap sheet 6 can be any sheet commonly used in this type of absorbent article, without any particular restrictions. The top sheet 3 and core wrap sheet 6 can be made of various liquid-permeable sheets, such as nonwoven fabric, woven fabric, and paper. The back sheet 4 can be made of a leak-proof sheet, specifically a liquid-impermeable sheet (a sheet that does not allow liquid to pass through at all) or a sheet that is poorly liquid-permeable (a sheet that is not liquid-impermeable but does not allow liquid to pass through easily), such as a moisture-permeable resin film or a laminate of such a resin film and a nonwoven fabric.

[0021] The absorbent core 5 is mainly composed of a water-absorbent material. Examples of the water-absorbent material include hydrophilic fibers and water-absorbent polymers, and these can be used alone or in combination of two or more. Examples of the hydrophilic fibers include natural fibers such as wood pulp and hydrophilic synthetic fibers. Examples of the water-absorbent polymers that can be used include those conventionally used in this type of absorbent body, without particular limitation, and examples thereof include polymers or copolymers of acrylic acid or alkali metal acrylates.

[0022] In this embodiment, as shown in Fig. 2, the absorbent core 5 has a shape that is elongated in one direction in a plan view, specifically a rectangular shape, and extends from the ventral region F through the crotch region M to the dorsal region R, with its longitudinal direction aligned with the longitudinal direction X of the diaper 1. Since the crotch region M is a region where bodily fluids excreted from the wearer's excretory area are concentrated, it is preferable that the absorbent core 5, which has the ability to absorb and retain bodily fluids, be located at least in the crotch region M. In this embodiment, the absorbent core 5 has a single-layer structure, but may have a layered structure in which a plurality of layers are layered in the thickness direction.

[0023] In this embodiment, the absorbent core 5 has recesses 51 extending in the longitudinal direction X, as shown in Figures 2 and 3. The recesses 51 are located at least in the crotch region M and are formed symmetrically on one side and the other side with respect to the transverse centerline CL2. The transverse centerline CL2 is an imaginary line extending in the longitudinal direction X, dividing the diaper 1 in the unfolded and stretched state into two equal parts in the transverse direction Y. The recesses 51 may have an opening on at least one of the skin-facing and non-skin-facing surfaces, and may be of a through type having an opening on both the skin-facing and non-skin-facing surfaces, or of a non-through type having an opening on one of the skin-facing and non-skin-facing surfaces and a bottom on the other. The through-type recesses 51 are spaces that are substantially free of the material (water-absorbent material) that forms the absorbent core 5. In this embodiment, the recesses 51 are of a through-type. The recesses 51 function as flow paths for body fluids such as urine, and also as bending guide portions for the absorbent core 5. Therefore, by providing the absorbent core 5 with the recesses 51, the liquid permeability or liquid diffusibility of the absorbent core 5 is appropriately controlled, which is expected to improve the leakproofness of the diaper 1, and also to promote favorable deformation of the absorbent core 5 while the diaper 1 is being worn, which is expected to improve the wearing comfort of the diaper 1. One example of a method for forming the recesses 51 is a method in which the forming material (water-absorbing material) of the absorbent core 5 is not deposited in the areas where the recesses 51 are to be formed during the manufacturing process of the absorbent core 5. Another example of a method for forming the recesses 51 is a method in which a precursor of the absorbent core 5 with a uniform amount of deposited forming material is manufactured, and the forming material is removed from the areas where the recesses 51 are to be formed in the precursor.

[0024] As shown in Figures 2 and 3, the diaper 1 of this embodiment includes core-expanding elastic members 52 arranged in the crotch region M to correspond to both side edges of the absorbent core 5 along the longitudinal direction X, allowing the elastic members 52 to expand and contract in the longitudinal direction X. One purpose of arranging the core-expanding elastic members 52 is to, when the diaper 1 is worn, cause both side edges (the side edges and their vicinity) of the absorbent core 5 in the crotch region M in the transverse direction Y, more specifically, the portions of the absorbent core 5 located outward in the transverse direction Y from the recesses 51, to rise toward the wearer's skin, as shown in Figure 3(b). This is expected to further improve the fit and leakproofness of the diaper 1. The core-expanding elastic members 52 are arranged at least in the crotch region M, and may extend from the crotch region M toward the ventral region F and / or the dorsal region R. The core-expanding elastic members 52 are arranged corresponding to the side edges of the absorbent core 5 along the longitudinal direction X, i.e., at or near the side edges, and do not necessarily need to be in contact with the side edges. For example, in the illustrated embodiment, the core stretching elastic member 52 is disposed between the absorbent core 5 and the core wrap sheet 6, but it may also be disposed between the core wrap sheet 6 and the topsheet 3. The core stretching elastic member 52 is fixed in a stretched state to other members such as the absorbent core 5 by known fixing means such as an adhesive.

[0025] The outer cover 10 includes an outer layer sheet 11 that forms the outer surface of the diaper 1, and an inner layer sheet 12 that forms the inner surface of the diaper 1. The two sheets 11, 12 are bonded together and integrated with an adhesive. The outer cover 10 forms the outer shape of the diaper 1 in an unfolded and stretched state as shown in Figure 2, and the periphery of the outer cover 10 forms the outline of the diaper 1 in the unfolded and stretched state. The outer cover 10 has a constricted portion in the crotch region M.

[0026] As shown in Fig. 1, the diaper 1 has a pair of side seals S, S, which are formed by joining both side edges of the ventral side portion F and the dorsal side portion R of the outer casing 10 along the longitudinal direction X by a known joining method such as fusion bonding using heat sealing, ultrasonic sealing, or adhesives. The annular portion of the diaper 1 including the pair of side seals S, S is a waist portion that is placed around the waist of the wearer. The diaper 1 has a waist opening WH through which the wearer's torso is passed, and a pair of leg openings LH, LH below the waist portion (towards the crotch portion M) through which the wearer's lower legs are passed.

[0027] The waist portion has a plurality of thread-like waist elastic members 13 extending in the horizontal direction Y between the pair of side seal portions S, S and spaced apart in the vertical direction X. The waist elastic members 13 are fixed in a stretched state in the horizontal direction Y to the surface of at least one of the outer sheet 11 and the inner sheet 12, are elastically stretchable in the horizontal direction Y, and are contracted in their natural state. When the diaper 1 is worn, the contraction of the waist elastic members 13 causes the waist portion to fit closely around the wearer's waist, forming a plurality of pleats (waist gathers) on the surfaces (skin-facing and non-skin-facing surfaces) of the waist portion that extend in a direction intersecting the extension direction (lateral direction Y) of the waist elastic members 13. Thread-like leg elastic members 14 are also arranged at the edges of each of the pair of leg openings LH, LH. The leg elastic members 14 are fixed in a stretched state to the sheets (in this embodiment, the outer sheet 11 and the inner sheet 12) that constitute the locations where they are arranged, and are contracted in their natural state. When the diaper 1 is worn, the contraction of the leg elastic members 14 forms multiple folds (leg gathers) around the entire periphery of the opening edge of the leg opening LH. In order to prevent unintended deformation of the absorbent core 5 due to the expansion and contraction of the waist elastic members 13 and the leg elastic members 14, the portions of the elastic members 13, 14 that overlap with the absorbent core 5 in a plan view may be divided into multiple parts, thereby inhibiting their stretchability.

[0028] In this embodiment, as shown in Figures 1, 2 and 4, a disposal tape 15 is disposed on the non-skin-facing surface of the exterior body 10 (outer layer sheet 11) in the back portion R. The disposal tape 15 is used to maintain the rolled-up state of the diaper 1 when the diaper 1 is rolled up and disposed of, and includes a fixed portion to the exterior body 10 and a free portion arranged so as to be able to unfold from the fixed portion. Any disposal tape used in this type of absorbent article can be used as the disposal tape 15 without any particular restrictions.

[0029] 2 and 3, a pair of leakage preventing cuffs 7 are arranged on the skin-facing side of the absorbent core 5, corresponding to both sides of the absorbent core 5 in the lateral direction Y. The pair of leakage preventing cuffs 7, 7 are formed symmetrically on one side and the other side with respect to the lateral centerline CL2. The leakage preventing cuffs 7 include a cuff sheet 8 extending in the longitudinal direction X from the abdominal side portion F through the crotch region M to the dorsal side portion R, and a cuff elastic member 9 fixed to the cuff sheet 8 and stretchable in the longitudinal direction X at least in the crotch region M.

[0030] The cuff sheet 8, together with the topsheet 3, forms the outermost layer on the skin-facing side of the diaper 1 and can come into contact with the wearer's skin while the diaper 1 is being worn. As shown in FIG. 2, the cuff sheet 8 has a pair of fastening parts 80 at both ends in the longitudinal direction X, which are connected to another member (the topsheet 3 in this embodiment). One of the pair of fastening parts 80 is located in the ventral side portion F, and the other is located in the dorsal side portion R. As shown in FIG. 3, the portion of the cuff sheet 8 sandwiched between the pair of fastening parts 80 has a fastening part 81 at one end in the lateral direction Y to another member (the topsheet 3 and the backsheet 4 in this embodiment), and the other end is a free edge 82. The one end of the cuff sheet 8 is located on the non-skin-facing side of the absorbent core 5. The means for fastening the cuff sheet 8 to another member at the fastening parts 80, 81 is not particularly limited and may be, for example, an adhesive or fusion bonding.

[0031] In this embodiment, the cuff elastic members 9 include a first cuff elastic member 9A arranged at the free edge 82 of the cuff sheet 8, and a second cuff elastic member 9B arranged between a fixing portion 81 (fixing portion 81 located at the outermost position in the lateral direction Y) and the free edge 82. More specifically, the cuff sheet 8 has a two-layer structure in which the cuff sheet 8 is folded in the lateral direction Y, and thread-like cuff elastic members 9 are fixed in a stretched state in the longitudinal direction X between the opposing cuff sheets 8, 8 that make up the two-layer structure.

[0032] As described above, the leakage-barrier cuffs 7 have longitudinally stretchable sections 70 as upright sections, and the longitudinally stretchable sections 70 are the sections of the leakage-barrier cuffs 7 where the cuff elastic members 9 are fixed in a stretched state (the sections where the cuff elastic members 9 are located, shown by dotted lines in Fig. 2). The longitudinally stretchable sections 70 are disposed in correspondence with the sides of the absorbent core 5 along the longitudinal direction X, and extend in the longitudinal direction X from the ventral section F to the dorsal section R. When the diaper 1 is worn, the longitudinally stretchable sections 70 stand upright toward the wearer's skin, as shown in Fig. 3(b), thereby effectively preventing excreted body fluids, such as urine, from leaking outward in the lateral direction Y from the diaper 1 (so-called side leakage). Furthermore, although not shown, when the vertically stretchable portion 70 is in the upright state, the contraction of the cuff elastic member 9 causes the entire diaper 1 to curve and deform so that the central portion of the absorbent body 2 in the vertical direction X becomes convex toward the non-skin-facing side (the back sheet 4 side), making it easier for the diaper 1 to fit the wearer's body shape.

[0033] As the cuff sheet 8, any material used as a leak-proof cuff in this type of absorbent article can be used without any particular restrictions, such as a single-layer or multi-layer water-repellent nonwoven fabric, a laminate of a resin film and a nonwoven fabric, etc. There is no particular restriction on the number of cuff elastic members 9 arranged in each of a pair of leakage preventing cuffs 7, 7, and there may be one or more. One of the main purposes of the cuff elastic members 9 is to make the leakage preventing cuffs 7 (cuff sheets 8) stand up toward the wearer's skin when the diaper 1 is worn, and in order to achieve this purpose, it is sufficient that at least one or more cuff elastic members 9 are arranged on the free edge portion 82 of the cuff sheet 8. Therefore, the second cuff elastic member 9B may be omitted.

[0034] 4, the diaper 1 has a high basis weight portion 55 in which the basis weight of the absorbent core 5 is within a predetermined range, and a back-side low basis weight portion 56R located in the back side portion R and in which the basis weight of the absorbent core 5 is smaller than that of the high basis weight portion 55. The back-side low basis weight portion 56R is located outward in the longitudinal direction X from the high basis weight portion 55 and adjacent to the high basis weight portion 55. In this embodiment, the high basis weight portion 55 is located in the back side portion R, but in the present invention, the position of the high basis weight portion 55 is not limited to the back side portion R, and it may be located in the crotch portion M.

[0035] In this embodiment, the basis weight of the absorbent core 5 in the back-side low basis weight portion 56R is zero. Specifically, in this embodiment, the basis weight of the absorbent core 5 is uniform except for the recessed portion 51. As shown in FIG. 4 , the uniform basis weight absorbent core 5 extends in the longitudinal direction X over the entire length of the crotch portion M in the longitudinal direction X and further extends to each of the ventral portion F and the back-side portion R. In the back-side portion R, a high basis weight portion 55 (region where the absorbent core 5 is present) and a back-side low basis weight portion 56R (region where the absorbent core 5 is absent) are present, and the longitudinal end 5X of the absorbent core 5 on the back-side portion R side is the boundary between them. In the back-side low basis weight portion 56R, the material forming the absorbent core 5 (water-absorbent material) is not present, but instead, the topsheet 3, backsheet 4, core wrap sheet 6 (skin-side sheet 6A, non-skin-side sheet 6B), and exterior body 10 (outer-layer sheet 11, inner-layer sheet 12) are present.

[0036] When the basis weight of the absorbent core 5 in the back low basis weight portion 56R is not zero, the ratio of the basis weight of the absorbent core 5 in the back low basis weight portion 56R to the basis weight of the absorbent core 5 in the high basis weight portion 55 is preferably 0.2 or more, more preferably 0.3 or more, and preferably 0.8 or less, more preferably 0.7 or less, assuming that the former is less than the latter, in order to appropriately adjust the difference in rigidity between the back low basis weight portion 56 and the high basis weight portion 55 and further ensure the formation of the back pleats 20 described below. The basis weight of the absorbent core 5 in the high basis weight portion 55 is preferably 250 g / m 2 from the viewpoint of the balance between the liquid absorption capacity of the absorbent core 5 and the wearing comfort of the diaper 1. 2 More than 700g / m 2 The following is the result.

[0037] In this embodiment, the diaper 1 has low-basis weight portions, such as the back-side low-basis weight portion 56R, in which the absorbent core 5 has a relatively low basis weight, not only in the back-side portion R but also in the ventral-side portion F. That is, as shown in FIG. 4 , the diaper 1 of this embodiment has, in the ventral-side portion F, a high-basis weight portion 55 and a ventral-side low-basis weight portion 56F in which the absorbent core 5 has a basis weight smaller than that of the high-basis weight portion 55. The ventral-side low-basis weight portion 56F is located outward in the longitudinal direction X from the high-basis weight portion 55 and adjacent to the high-basis weight portion 55. In this embodiment, the basis weight of the absorbent core 5 in the ventral-side low-basis weight portion 56F is zero. That is, in this embodiment, the ventral-side portion F has both the high-basis weight portion 55 and the ventral-side low-basis weight portion 56F (area where the absorbent core 5 is absent), and the longitudinal end 5X of the absorbent core 5 on the ventral-side portion F side is the boundary between them.

[0038] 2, the pair of longitudinally stretchable portions 70, 70 each have a portion that is in the same position as the back-side low basis weight portion 56R in the longitudinal direction X. In other words, when the pair of longitudinally stretchable portions 70, 70 and the back-side low basis weight portion 56R are each projected in the lateral direction Y, the projected image of each of the pair of longitudinally stretchable portions 70, 70 at least partially overlaps with the projected image of the back-side low basis weight portion 56R.

[0039] 2 and 4, the diaper 1 is characterized in that, when worn, a portion of the topsheet 3 located in the back-side low-basis-weight portion 56R is deformed to form a back-side pleat 20 extending in the transverse direction Y on the skin-facing surface of the topsheet 3. As described above, the back-side low-basis-weight portion 56R is adjacent to the high-basis-weight portion 55 in the longitudinal direction X. Therefore, in the diaper 1 having such a feature, there is a difference in basis weight between the formation region of the back-side pleat 20 (the region surrounded by the smallest area of ​​an imaginary rectangle that encloses the entire back-side pleat 20 in a plan view of the skin-facing side of the diaper 1 as shown in FIG. 2) and an area (the high-basis-weight portion 55) located inward of the formation region in the longitudinal direction X. The back pleats 20 are typically formed by folding a portion of the topsheet 3 located in the back-side low basis weight portion 56R in the longitudinal direction X with its non-skin-facing surface facing inward, as shown in Figure 4, in other words, by folding it along an imaginary line extending in the transverse direction Y. The reason why the back-side pleats 20 are formed in the back-side low basis weight portion 56R is that a pair of longitudinally stretchable portions 70, 70 that are stretchable in the longitudinal direction X are arranged at the same position in the longitudinal direction X as the back-side low basis weight portion 56R. As described above, the pair of longitudinally stretchable portions 70, 70 are arranged corresponding to both sides of the absorbent core 5 along the longitudinal direction X, so that the back-side low basis weight portion 56R has a portion sandwiched between one and the other of the pair of longitudinally stretchable portions 70, 70. Therefore, when the pair of longitudinally stretchable portions 70, 70 contract in the longitudinal direction X while the diaper 1 is being worn, the contractile force acts on the region sandwiched between the pair of longitudinally stretchable portions 70, 70, and a back-side pleat 20 is formed in that region of the topsheet 3 in the back-side low basis weight portion 56R, where the absorbent core 5 has a relatively low basis weight and therefore a relatively low rigidity. The back-side pleats 20 function as a leakage barrier that blocks bodily fluids, such as loose stools, that flow along the skin-facing surface of the topsheet 3. Therefore, the diaper 1 prevents the inconvenience of bodily fluids leaking out from the end of the back-side portion R in the longitudinal direction X. In particular, since fecal leakage tends to occur more frequently on the back-side portion R than on the ventral portion F, the back-side pleats 20 are effective in preventing fecal leakage.

[0040] Leak-barriers such as the back pleats 20 for preventing leakage from the longitudinal edges of an absorbent article are also described in Patent Documents 1 to 3. However, the leak-barriers described in these documents are formed by folding a topsheet to form tucks, arranging multiple topsheets to overlap longitudinally, or folding the absorbent body at linearly bent structural portions such as slits. All of these methods are formed through a folding process of components of the absorbent article, regardless of the presence of longitudinally stretchable portions such as the longitudinally stretchable portions 70. In contrast, the back pleats 20 are formed in the back low basis weight portion 56R by contraction of the longitudinally stretchable portions 70 in the longitudinal direction X, and are not formed through the folding process. Furthermore, the longitudinally stretchable portions 70 are originally employed as standing portions of the leakage-barrier cuffs 7, as described above, and are not employed solely for forming the back pleats 20. In other words, the back pleats 20 can be formed using only general components of absorbent articles such as leak-proof cuffs, without requiring a special process, such as the folding process, for the purpose of forming the back pleats 20. Therefore, the absorbent article of the present invention, represented by the diaper 1, has a relatively simple structure similar in basic structure to conventionally known absorbent articles, but can be said to have superior performance in preventing leakage of bodily fluids compared to conventionally known absorbent articles.

[0041] When worn, ventral pleats (not shown) formed by deformation of the ventral low basis weight portion 56F on the skin-facing surface of the topsheet 3 may extend in the transverse direction Y, but the dorsal pleats 20 are typically taller than the ventral pleats. The reason for this is that, as shown in Figure 2, the ventral low basis weight portion 56F is located outward in the longitudinal direction X from each of the pair of longitudinally stretchable portions 70, 70, and does not have any portions at the same position as these portions in the longitudinal direction X, making it less susceptible to the contractile force when these portions contract in the longitudinal direction X. In other words, the dorsal pleats 20 can be distinguished from ordinary pleats (wrinkles) formed in the topsheet of this type of absorbent article in that they are typically taller than these pleats (wrinkles).

[0042] As shown in Fig. 2, the back pleats 20 are typically present only in the back low basis weight portion 56R and not in the high basis weight portion 55. That is, typically, in a plan view of the skin-facing side (topsheet 3 side) of the diaper 1 as shown in Fig. 2, the entire back pleats 20 overlap the back low basis weight portion 56R. However, depending on the stretch characteristics of the longitudinally stretchable portions 70, the type of topsheet 3, etc., the back pleats 20 may be present across both the back low basis weight portion 56R and the high basis weight portion 55.

[0043] The height 20H of the back pleats 20 (see FIG. 4) is preferably as high as possible to improve leak-proofing performance. Specifically, it is preferably 1 mm or more, and more preferably 3 mm or more. The "height of the back pleats 20" referred to here refers to the maximum height of the back pleats 20, regardless of whether the diaper 1 is in a natural state (a state in which no external force is applied to the diaper 1) or in a stretched state. There is no particular upper limit to the height 20H of the back pleats 20. However, as mentioned above, the back pleats 20 are formed primarily by arranging a pair of longitudinally stretchable portions 70, 70 at the same position in the longitudinal direction X as the back low basis weight portion 56R. From the viewpoint of stably forming the back pleats 20 with sufficient leak-proofing performance with such a relatively simple absorbent article configuration, the height 20H is preferably 12 mm or less, and more preferably 10 mm or less. The height 20H of the back pleats 20 can be adjusted, for example, by appropriately adjusting the stretch characteristics of the longitudinally stretchable section 70 and the type of topsheet 3. The stretch characteristics of the longitudinally stretchable section 70 can be adjusted, for example, by adjusting the elongation rate, thickness, etc. of the cuff elastic member 9 that constitutes the longitudinally stretchable section 70.

[0044] The back-side pleats 20 are typically curved convexly outward in the longitudinal direction X in a plan view, as shown in Fig. 2. The peak of the convexity of the back-side pleats 20 in a plan view is located at the center of the back-side low basis weight portion 56R in the transverse direction Y, and both ends of the back-side pleats 20 in the transverse direction Y are located at or near the boundary between the high basis weight portion 55 and the back-side low basis weight portion 56R, which is located inward in the longitudinal direction X from the peak (in this embodiment, at the longitudinal end 5X on the back portion R side of the absorbent core 5). The back-side pleats 20 having such a curved shape in a plan view can further improve the function of the back-side pleats 20 in blocking bodily fluids. Such a curved dorsal fold 20 in a plan view may have a form consisting of a single dorsal fold 20 that is continuous in the transverse direction Y, as shown in Fig. 2, or may have a form (not shown) in which a plurality of small folds are substantially connected in the transverse direction Y to form a single dorsal fold 20 as a whole. In the form shown in Fig. 2, only a part of the dorsal fold 20 (both ends in the transverse direction Y) is at the same position in the longitudinal direction X as the pair of longitudinally stretchable portions 70, 70, but there may also be cases in which the entire dorsal fold 20 is at the same position in the longitudinal direction X as the pair of longitudinally stretchable portions 70, 70. The planar shape of the back pleats 20 can be adjusted by, for example, appropriately adjusting the stretch characteristics of the longitudinally stretchable portions 70, the type of topsheet 3, and the like.

[0045] The length 20Ly (see Figure 2) of the back pleat 20 along the lateral direction Y is preferably 40% or more, more preferably 50% or more, and preferably 100% or less, more preferably 95% or less of the maximum length of the absorbent core 5 in the lateral direction Y. The length 20Ly of the dorsal fold 20 is preferably 50 mm or more, more preferably 60 mm or more, and preferably 135 mm or less, more preferably 130 mm or less. The length 20Ly of the back pleat 20 can be adjusted by, for example, appropriately adjusting the stretch characteristics of the longitudinally stretchable portion 70, the type of topsheet 3, and the like.

[0046] As shown in Figure 4, the back pleats 20 are preferably oriented so that their tip ends 20T face the crotch area M, in other words, the back pleats 20 are inclined toward the crotch area M. Bodily fluids such as loose stools normally flow from the crotch area M toward the back pleats 20, and by oriented the back pleats 20 in this way, it is expected that the leak-proofing function of the back pleats 20 will be further improved. Such orientation of the back pleats 20 can be adjusted, for example, by appropriately adjusting the stretch characteristics of the longitudinally stretchable portions 70, the type of topsheet 3, etc.

[0047] In this embodiment, as described above, the diaper 1 includes the core wrap sheet 6 (6A, 6B) having a portion that contacts the skin-facing surface or the non-skin-facing surface of the absorbent core 5, and the back-side pleats 20 overlap the core wrap sheet 6 in a planar view. More specifically, in this embodiment, as shown in Fig. 4, the back-side low basis weight portion 56R has a non-placement region of the core wrap sheet 6, in which only the outer casing 10 is disposed, located outward in the longitudinal direction X from the placement region of the core wrap sheet 6. However, the back-side pleats 20 overlap the placement region of the core wrap sheet 6 in a planar view, but do not overlap the non-placement region of the core wrap sheet 6 in a planar view. Thus, the presence of the back-side pleats 20 in a position that overlaps the core wrap sheet 6 in a planar view can be expected to further improve the leakage prevention effect provided by the back-side pleats 20.

[0048] In the form shown in Figure 4, the back pleats 20 are composed only of the top sheet 3, but depending on the stretch characteristics of the vertical stretch section 70 and the type of other components other than the top sheet 3 present in the back low basis weight section 56R, it is possible that such other components may be present inside the back pleats 20.

[0049] For example, in the configuration shown in Fig. 5, the core wrap sheet 6 is present inside the back fold 20. More specifically, in the configuration shown in Fig. 5, the core wrap sheet 6 includes a skin side sheet 6A and a non-skin side sheet 6B, and both sheets 6A and 6B are folded inside the back fold 20, i.e., between one side and the other side of the folded two-layer topsheet 3. In the present invention, a modified example of the configuration shown in Fig. 5 includes a configuration in which only the skin side sheet 6A is present inside the back fold 20 and the non-skin side sheet 6B is not present. The core wrap sheet 6 (6A, 6B) is typically formed from a material capable of absorbing body fluids (nonwoven fabric, woven fabric, paper, etc.), and therefore the presence of the core wrap sheet 6 inside the back fold 20 improves the body fluid absorption ability of the back fold 20, which is expected to further improve the leak prevention function.

[0050] As described above, in this embodiment, the basis weight of the absorbent core 5 in the back-side low basis weight portion 56R is zero, and no absorbent core 5 is disposed in the back-side low basis weight portion 56R. However, in the present invention, there are cases where an absorbent core 5 is disposed in the back-side low basis weight portion 56R. In such cases, there may be a configuration (hereinafter also referred to as "Configuration A") in which the absorbent core 5 (specifically, a portion of the absorbent core 5 having a smaller basis weight than the portion disposed in the high basis weight portion 55) is present inside the back-side pleats 20. One example of Configuration A is a configuration in which the skin-side sheet 6A, the absorbent core 5, and the non-skin-side sheet 6B are folded into the back-side pleats 20 in order of proximity to the topsheet 3 that constitutes the back-side pleats 20. According to the above-mentioned form A, since the absorbent core 5 is present inside the back pleats 20, the bodily fluid absorption capacity of the back pleats 20 is improved, and further improvement in the leak prevention function can be expected.

[0051] As described above, in this embodiment, the back sheet 4 is disposed on the non-skin-facing side of the absorbent core 5, but the present invention may have a configuration in which the back sheet 4 is present inside the back pleats 20 (hereinafter also referred to as "Configuration B"). An example of Configuration B is a configuration in which the core wrap sheet 6 (6A and / or 6B) and the back sheet 4 are folded into the back pleats 20 in order of proximity to the top sheet 3 that constitutes the back pleats 20. Another example of Configuration B is a configuration in which the absorbent core 5 is folded between the skin side sheet 6A and the non-skin side sheet 6B that constitute the core wrap sheet 6 in one example of Configuration B. Since the back sheet 4 is typically formed from a sheet having leak-proof properties, according to the above-mentioned form B, it is expected that the leak-proof function of the back-side pleats 20 will be further improved.

[0052] As described above, in this embodiment, the diaper 1 includes the absorbent main body 2 and the exterior body 10. However, the present invention may also include a configuration (hereinafter also referred to as "Configuration C") in which the exterior body 10 (outer layer sheet 11 and / or inner layer sheet 12) is present inside the back-side pleats 20. One example of Configuration C is a configuration in which the core wrap sheet 6 (6A and / or 6B), the back sheet 4, and the exterior body 10 are folded into the back-side pleats 20 in order of proximity to the topsheet 3 that constitutes the back-side pleats 20. Another example of Configuration C is a configuration in which the absorbent core 5 is folded between the skin-side sheet 6A and the non-skin-side sheet 6B in the example of Configuration C. The presence of the outer casing 10 inside the dorsal fold 20 makes the size (height, etc.) of the dorsal fold 20 larger than if it were not present, so according to form C, further improvement in the leak-proofing function of the dorsal fold 20 can be expected.

[0053] A modified example of the above-mentioned form C in which the exterior body 10 is present inside the back pleats 20 is a form in which a disposal tape, which is used when disposing of the absorbent article, is fixed to the non-skin-facing surface of the exterior body 10 in a portion that overlaps the back pleats 20 in a plan view. For example, in the diaper 1, as shown in FIG. 2, the back pleats 20 and the disposal tape 15 overlap in a plan view, and a form (not shown) in which the exterior body 10 is present inside this back pleat 20 corresponds to a modified example of the above-mentioned form C. In the modified example of the above-mentioned form C, one side of the exterior body 10 having a two-layer structure folded inside the back pleats 20 is fixed by the disposal tape 15. Therefore, regardless of whether the absorbent article is in a natural state, a worn state, or an expanded and stretched state as shown in FIG. 2, the back pleats 20 are always present, and therefore the leakage prevention effect provided by the back pleats 20 is more reliably achieved.

[0054] The present invention can be applied to absorbent articles in general. The term "absorbent article" as used herein broadly encompasses articles used to absorb body fluids (urine, loose stools, menstrual blood, sweat, etc.) discharged from the human body, and includes, in addition to the pants-type disposable diaper of the above embodiment, for example, flat-type disposable diapers, sanitary shorts, incontinence pads, etc. The flat-type disposable diaper is a disposable diaper in which the ventral side and back side portions are not connected in an unused state, and the waist portion that is placed around the wearer's waist is not annular, and typically has a fastening tape on the back side portion, and when in use, the fastening tape is fastened to the non-skin-facing surface of the ventral side portion to put on the body.

[0055] The present invention has been described above based on its preferred embodiments, but the present invention is not limited to the above embodiments and can be modified as appropriate within the scope that does not impair the intended effects of the present invention. For example, in the above embodiment, the upright portions of the leakage preventing cuffs 7 were the longitudinally stretchable portions according to the present invention, but the longitudinally stretchable portions may be any portions that are arranged corresponding to the sides of the absorbent core 5 along the longitudinal direction X, extend in the longitudinal direction X from the ventral portion F to the dorsal portion R, and are stretchable in the longitudinal direction X, and are not limited to being parts of the leakage preventing cuffs 7. For example, the core stretching elastic members 52 may be longitudinally stretchable portions according to the present invention, provided that the core stretching elastic members 52 have portions that are in the same position in the longitudinal direction X as the dorsal low basis weight portions 56R. In addition, in the above embodiment, the outer casing 10 was a type of outer casing that was continuous from the ventral portion F through the crotch portion M to the dorsal portion R, but it may also be a split type outer casing that is split into a member arranged on the ventral side and a member arranged on the dorsal side.

[0056] The following supplementary notes are further disclosed regarding the above-described embodiment of the present invention. <1> The garment has a ventral side portion that is arranged on the ventral side of a wearer when worn, a dorsal side portion that is arranged on the dorsal side of the wearer, and a crotch portion located therebetween, and also has a vertical direction that extends from the ventral side portion through the crotch portion to the dorsal side portion and a horizontal direction that is perpendicular to the vertical direction, An absorbent article comprising: an absorbent core that absorbs and retains bodily fluids; a topsheet that is disposed on the skin-facing side of the absorbent core and that comes into contact with the wearer's skin when worn; and a pair of longitudinally stretchable sections that are disposed corresponding to both side sections along the longitudinal direction of the absorbent core and extend in the longitudinal direction from the ventral section to the dorsal section, The absorbent core has a high basis weight portion in which the basis weight is within a predetermined range, and a back-side low basis weight portion located in the back side portion and having a basis weight of the absorbent core smaller than that of the high basis weight portion, the back-side low basis weight portion being located outward in the longitudinal direction from the high basis weight portion and adjacent to the high basis weight portion, The pair of longitudinally stretchable sections each have a portion that is at the same position in the longitudinal direction as the back-side low basis weight section, When worn, the back-side low basis weight portion of the topsheet has a portion thereof deformed to form a back-side pleat on the skin-facing surface thereof, the back-side pleat extending in the lateral direction. <2> The absorbent core has a leak-proof cuff disposed on the skin-facing side thereof and having a standing portion that stands up toward the wearer's skin when worn, and the standing portion is the longitudinally stretchable portion. <1> The absorbent article according to claim 1. <3> the abdominal portion has the high basis weight portion and an abdominal-side low basis weight portion having a basis weight of the absorbent core smaller than that of the high basis weight portion, the abdominal-side low basis weight portion being located outward in the longitudinal direction from the high basis weight portion and adjacent to the high basis weight portion, When worn, a portion of the topsheet located in the ventral-side low basis weight portion has a skin-facing surface on which ventral-side pleats are formed by deformation of the portion, the ventral-side pleats extending in the lateral direction, The dorsal fold is taller than the ventral fold. <1> or <2> The absorbent article according to claim 1.

[0057] <4> the back-side pleats are present only in the back-side low basis weight portion; <1> ~ <3> 10. The absorbent article according to claim 1, wherein the absorbent article is a fibrous material. <5> The height of the dorsal fold is 1 mm or more. <1> ~ <4> 10. The absorbent article according to claim 1, wherein the absorbent article is a fibrous material. <6> The dorsal fold is curved convexly outward in the longitudinal direction in a plan view. <1> ~ <5> 10. The absorbent article according to claim 1, wherein the absorbent article is a fibrous material. <7> The back pleats are oriented such that the leading ends of the back pleats face the crotch portion. <1> ~ <6> 10. The absorbent article according to claim 1, wherein the absorbent article is a fibrous material. <8> a core wrap sheet having a portion that contacts the skin-facing surface or the non-skin-facing surface of the absorbent core, and the back pleats overlap the core wrap sheet in a plan view; <1> ~ <7> 10. The absorbent article according to claim 1, wherein the absorbent article is a fibrous material. <9> The core wrap sheet is present inside the dorsal fold. <8> The absorbent article according to claim 1.

[0058] <10> A portion of the absorbent core located in the back-side low basis weight portion is present inside the back-side pleat. <1> ~ <9> 10. The absorbent article according to claim 1, wherein the absorbent article is a fibrous material. <11> A backsheet is provided on the non-skin-facing side of the absorbent core, The back sheet is present inside the dorsal fold. <1> ~ <10> 10. The absorbent article according to claim 1, wherein the absorbent article is a fibrous material. <12> an absorbent body including the topsheet and the absorbent core, and an exterior body disposed on the non-skin-facing side of the absorbent body, the exterior body is present inside the back fold, and a disposal tape, which is used when disposing of the absorbent article, is fixed to a non-skin-facing surface of a portion of the exterior body that overlaps with the back fold in a plan view; <1> ~ <11> 10. The absorbent article according to claim 1, wherein the absorbent article is a fibrous material. <13> The basis weight of the absorbent core in the back-side low basis weight portion is zero. <1> ~ <12> 10. The absorbent article according to claim 1, wherein the absorbent article is a fibrous material. [Explanation of symbols]

[0059] 1. Pants-type disposable diapers (absorbent articles) 2. Absorbent body 3 Surface sheet 4 Back sheet 5 absorbent core 51 Recess 6 Core wrap sheet 6A Skin side sheet 6B Non-skin side sheet 7 Leak proof cuff 70 Vertical stretch section 10. Exterior body 15 Disposal tape 20 dorsal fold 55 High basis weight part 56R Dorsal low basis weight part 56F Ventral low basis weight part X vertical direction Y horizontal direction F ventral part M Inseam R dorsal part

Claims

1. The garment has a ventral side portion that is arranged on the ventral side of a wearer when worn, a dorsal side portion that is arranged on the dorsal side of the wearer, and a crotch portion located therebetween, and also has a vertical direction that extends from the ventral side portion through the crotch portion to the dorsal side portion and a horizontal direction that is perpendicular to the vertical direction, An absorbent article comprising: an absorbent core that absorbs and retains bodily fluids; a topsheet that is disposed on the skin-facing side of the absorbent core and that comes into contact with the wearer's skin when worn; and a pair of longitudinally stretchable sections that are disposed corresponding to both side sections along the longitudinal direction of the absorbent core and extend in the longitudinal direction from the ventral section to the dorsal section, The absorbent core has a high basis weight portion in which the basis weight is within a predetermined range, and a back-side low basis weight portion located in the back side portion and having a basis weight of the absorbent core smaller than that of the high basis weight portion, the back-side low basis weight portion being located outward in the longitudinal direction from the high basis weight portion and adjacent to the high basis weight portion, The pair of longitudinally stretchable sections each have a portion that is at the same position in the longitudinal direction as the back-side low basis weight section, When worn, the back-side low basis weight portion of the topsheet has a portion thereof deformed to form a back-side pleat on the skin-facing surface thereof, the back-side pleat extending in the lateral direction.

2. 2. The absorbent article according to claim 1, further comprising a leak-proof cuff disposed on the skin-facing side of the absorbent core and having an upstanding portion that stands up toward the wearer's skin when worn, the upstanding portion being the longitudinally stretchable portion.

3. the abdominal portion has the high basis weight portion and an abdominal-side low basis weight portion having a basis weight of the absorbent core smaller than that of the high basis weight portion, the abdominal-side low basis weight portion being located outward in the longitudinal direction from the high basis weight portion and adjacent to the high basis weight portion, When worn, a portion of the topsheet located in the ventral-side low basis weight portion has a skin-facing surface on which ventral-side pleats are formed by deformation of the portion, the ventral-side pleats extending in the lateral direction, The absorbent article according to claim 1 or 2, wherein the dorsal pleats are taller than the ventral pleats.

4. The absorbent article according to claim 1 or 2, wherein the height of the back pleats is 1 mm or more.

5. The absorbent article according to claim 1 or 2, wherein the back-side pleats are convexly curved outward in the longitudinal direction in a plan view.

6. The absorbent article according to claim 1 or 2, wherein the back pleats are oriented such that the tips of the back pleats face the crotch portion.

7. The absorbent article according to claim 1 or 2, comprising a core wrap sheet having a portion that contacts the skin-facing surface or the non-skin-facing surface of the absorbent core, and the back pleats overlap the core wrap sheet in a planar view.

8. The absorbent article according to claim 7 , wherein the core wrap sheet is present within the back pleat.

9. The absorbent article according to claim 1 or 2, wherein a portion of the absorbent core located in the back-side low basis weight portion is present inside the back-side pleat.

10. A backsheet is provided on the non-skin-facing side of the absorbent core, The absorbent article according to claim 1 or 2, wherein the back sheet is present inside the back pleat.

11. an absorbent body including the topsheet and the absorbent core, and an exterior body disposed on the non-skin-facing side of the absorbent body, The absorbent article according to claim 1 or 2, wherein the outer body is present inside the dorsal fold, and a disposal tape is fixed to the non-skin-facing surface of the outer body in a portion that overlaps with the dorsal fold in a planar view, the disposal tape being used when disposing of the absorbent article.

12. The absorbent article according to claim 1 or 2, wherein the basis weight of the absorbent core in the back-side low basis weight portion is zero.

Images