Absorbent products

Abstract

This absorbent article (1) has, in a ventral side elastic portion (WA) and a dorsal side elastic portion (WB), a main body side sheet (32) which is joined to an absorbent body (2) and an outer surface side sheet (31). The main body side sheet (32) or the outer surface side sheet (31) is an elastic sheet. The elastic sheet has high stretch portions (31H) and low stretch portions (31L) alternately arranged in a Y direction. The elastic sheet is disposed in the ventral side elastic portion (WA) or the dorsal side elastic portion (WB), and in a region (23PT) that overlaps with an absorber (23), the high stretch portions (31H) of the elastic sheet are joined to form first joined portions (1JT). In a region (23NT) that does not overlap with the absorber (23), the low stretch portions (31L) of the elastic sheet are joined to form second joined portions (2JT), and second non-joined portions (2NJT) where the high stretch portions (31H) of the elastic sheet are not joined are formed.

Description

Absorbent articles

[0001] This invention relates to absorbent articles such as disposable diapers and sanitary napkins.

[0002] For example, in a pant-type disposable diaper, an outer casing is placed on the outside of a vertically elongated absorbent body containing an absorbent core. As an example of a stretchable composite sheet used for such an outer casing, the composite sheet described in Patent Document 1 is known.

[0003] The stretchable composite sheet described in Patent Document 1 is a sheet comprising a non-stretchable sheet, a stretchable nonwoven fabric, and an adhesive portion for bonding the non-stretchable sheet and the stretchable nonwoven fabric. If such a stretchable composite sheet is used, for example, as the outer casing of a disposable diaper of the pull-up type, the appearance of the disposable diaper will be improved and the user experience will be enhanced.

[0004] WO2008 / 066009 Pamphlet

[0005] The present invention relates to an absorbent article having an absorbent body comprising a ventral region and a dorsal region in the longitudinal direction, and a crotch region located between them, and an absorbent body comprising an absorbent material extending from the ventral region to the dorsal region, and having a ventral stretch portion and a dorsal stretch portion extending laterally from the ventral region and the dorsal region, respectively. The ventral stretch portion and the dorsal stretch portion each have a body-side sheet joined to the absorbent body and an outer-side sheet disposed on the non-skin-facing side of the body-side sheet. At least one of the body-side sheet and the outer-side sheet is a stretchable sheet that is stretchable in the lateral direction. The stretchable sheet has a relatively high-stretch portion and a relatively low-stretch portion alternately arranged in the lateral direction. The stretchable sheet is disposed in at least one of the ventral stretch portion and the dorsal stretch portion. In the region overlapping with the absorbent body, the body-side sheet and the outer-side sheet are joined at the high-stretch portion to form a first joining portion. In the region outside the absorbent that does not overlap with the absorbent, the main body sheet and the outer surface sheet form a second jointed portion where they are joined at the low-stretch portion, and a second non-jointed portion where they are not joined at the high-stretch portion.

[0006] Figure 1 is a perspective view of a pant-type disposable diaper, which is a preferred embodiment of the present invention. Figure 2 is a partially broken unfolded plan view of the diaper shown in Figure 1, viewed from the skin-contacting surface side, in an unfolded and stretched state. Figure 3 is an exploded perspective view schematically showing the diaper shown in Figure 1 disassembled. Figure 4 is a perspective view of the stretchable outer sheet constituting the diaper shown in Figure 1. Figure 5 is a cross-sectional view taken along the line V-V shown in Figure 2. Figure 6(a) is a cross-sectional view taken along the line VI-VI shown in Figure 2, and Figure 6(b) is a cross-sectional view showing Figure 6(a) in a contracted state. Detailed description of the invention

[0007] However, Patent Document 1 does not describe the joining position between an elastic composite sheet, which is made by bonding a non-stretchable sheet and an elastic nonwoven fabric at an adhesive portion, and an absorbent material, when such a composite sheet is used as an outer casing. For example, if the elastic composite sheet is simply joined to a position that overlaps with the absorbent material, the shrinkage of the composite sheet may cause wrinkles in the absorbent material, which could impair the absorbent material's absorption performance and lead to leakage.

[0008] The present invention relates to an absorbent article that can overcome the drawbacks of the prior art described above.

[0009] The present invention will now be described below with reference to the drawings, based on its preferred embodiments. The absorbent article of the present invention comprises a ventral region A and a dorsal region B in the longitudinal direction X, and a crotch region C located between A and B. It has an absorbent body 23 containing an absorbent material extending from the ventral region A to the dorsal region B, and each of the ventral region A and dorsal region B has a ventral stretch portion WA and a dorsal stretch portion WB extending in the transverse direction Y. Here, the ventral region A is the region located on the wearer's ventral side when wearing a disposable diaper, and the dorsal region B is the region located on the wearer's dorsal side when wearing a disposable diaper. The ventral stretch portion WA is formed in the ventral region A located on the wearer's ventral side. The dorsal stretch portion WB is formed in the dorsal region B located on the wearer's dorsal side.

[0010] Figures 1 and 2 show a pant-type disposable diaper 1 (hereinafter also referred to as "diaper 1"), which is one embodiment of the absorbent article of the present invention. As shown in Figures 1 and 2, diaper 1 comprises an absorbent body 2 and an outer body 3 disposed on the non-skin-facing side of the absorbent body 2 to fix the absorbent body 2. The outer body 3 has an ventral stretch portion WA and a dorsal stretch portion WB extending in the lateral direction Y in the ventral region A and dorsal region B, respectively. Diaper 1 is a disposable diaper in which the left and right side edges 3a1, 3a1 of the ventral region A of the outer body 3 and the left and right side edges 3b1, 3b1 of the dorsal region B of the outer body 3 are joined to form a pair of side seal portions 5, 5, a waist opening WH and a pair of leg openings LH, LH. Preferably, as shown in Figure 2, the outer casing 3 of the diaper 1, when viewed from above in its unfolded and extended state, is divided into a ventral region A that is positioned on the wearer's abdominal side when worn, a dorsal region B that is positioned on the wearer's back side when worn, and a crotch region C between the ventral region A and the dorsal region B.

[0011] The state described above, where the diaper 1 is unfolded and stretched, means, as shown in Figure 2, that the side seal portion 5 is peeled off to unfold the diaper 1, and then the elastic members of each part of the unfolded diaper 1 are stretched to the design dimensions (the same dimensions as when it is spread flat in a planar state with the influence of the elastic members completely eliminated).

[0012] In this specification, "skin-facing surface" refers to the surface of the diaper 1 or its components that faces the wearer's skin when worn, and "non-skin-facing surface" refers to the surface of the diaper 1 or its components that faces the opposite side (clothing side) of the wearer's skin when worn. In the diaper 1, the vertical direction (X direction) is the direction from the ventral region A to the dorsal region B when the diaper is unfolded and extended on a plane. The transverse direction (Y direction) is the direction perpendicular to the vertical direction (X direction), and refers to the width direction of the diaper 1 when it is unfolded and extended on a plane. The diaper 1 is also symmetrical with respect to the vertical center line CL1 extending in the vertical direction (X direction), as shown in Figure 2. In Figure 2, CL2 is a transverse center line extending in the transverse direction (Y direction) that divides the diaper 1 in the vertical direction (X direction), and is perpendicular to the vertical center line CL1.

[0013] In diaper 1, as shown in Figure 2, the absorbent body 2 has a vertically elongated shape with a relatively long vertical direction (X direction) when diaper 1 is unfolded and extended. The absorbent body 2 comprises a liquid-permeable surface sheet 21 that forms the skin-facing surface, a liquid-impermeable (including water-repellent) back sheet 22 that forms the non-skin-facing surface, and a liquid-retaining absorbent body 23 interposed between these two sheets 21 and 22. In diaper 1, the total length of the absorbent body 2 in the vertical direction (X direction) is the same as that of the absorbent body 23, and the positions of the outer ends 23A1 and 23B1 of the front and rear ends 23A and 23B of the absorbent body 23 are the same as the positions of the outer ends of the front and rear ends of the absorbent body 2, as shown in Figure 2. In addition, as shown in Figure 2, leak-proof cuffs 24, 24 having elastic members 25 arranged in an extended state in the vertical direction (X direction) are provided on both sides of the absorbent body 2 along the vertical direction (X direction). Specifically, the leak-proof cuff 24 is made of a material that is impermeable to liquids or water-repellent and breathable, and an elastic member 25 for forming the leak-proof cuff is positioned near the free end of each leak-proof cuff 24 in an extended state in the vertical direction (X direction). When the diaper is worn, the free end side of the leak-proof cuff 24 stands up due to the contraction of the elastic member 25 for forming the leak-proof cuff, preventing the outflow of bodily fluids in the horizontal direction (Y direction).

[0014] As shown in Figure 2, the absorbent body 2, configured as described above, is joined to the central part of the outer casing 3 by an adhesive 4 for fixing the body, with its longitudinal direction (X direction) aligned with the longitudinal direction (X direction) of the diaper 1 in its unfolded and extended state. As shown in Figure 3, the application positions of the adhesive 4 for fixing the body are formed at positions corresponding to at least both sides of the absorbent body 2 along the longitudinal direction X. In this way, the outer casing 3 is positioned on the non-skin-facing side of the back sheet 22 constituting the absorbent body 2 in the thickness direction of the disposable diaper 1 and is bonded and fixed by the adhesive 4 for fixing the body. Therefore, in the diaper 1, the absorbent material 23 constituting the absorbent body 2 is arranged across the ventral region A and the dorsal region B.

[0015] The ventral stretch portion WA and the dorsal stretch portion WB each have a main body sheet 32 ​​that is joined to the absorbent main body 2 and an outer surface sheet 31 that is placed on the non-skin-facing side of the main body sheet 32. In the present invention, at least one of the main body sheet 32 ​​and the outer surface sheet 31 is a stretchable sheet that is stretchable in the lateral direction, while in diaper 1, the outer surface sheet 31 is a stretchable sheet that is stretchable in the lateral direction (Y direction). Furthermore, in the present invention, it is sufficient for the stretchable sheet to be placed on at least one of the ventral stretch portion WA and the dorsal stretch portion WB, while in diaper 1, the stretchable sheet is placed on both the ventral stretch portion WA and the dorsal stretch portion WB. Note that in diaper 1, the main body sheet 32 ​​is a non-stretchable sheet and does not have elasticity.

[0016] In diaper 1, as shown in Figure 3, the outer casing 3 that adhesively fixes the absorbent body 2 has an outer sheet 31 that forms the outer surface, i.e., the non-skin-facing surface, of diaper 1 when worn, and a body sheet 32 ​​positioned opposite the skin-facing surface of the outer sheet 31, and is composed of a laminate of the outer sheet 31 and the body sheet 32. When diaper 1 is worn, the outer sheet 31 is located on the side farther from the wearer's body and forms the non-skin-facing surface (outer surface) of diaper 1, and the body sheet 32 ​​is located on the side closer to the wearer's body and forms the skin-facing surface (inner surface) of diaper 1. The outer sheet 31 and the body sheet 32 ​​are joined to each other at predetermined locations via joining means such as heat sealing, ultrasonic sealing, or adhesive.

[0017] In diaper 1, as shown in Figure 3, the main body sheet 32 ​​is made up of a single continuous sheet, while the outer surface sheet 31 is made up of multiple sheets combined together. Specifically, it includes a ventral outer surface sheet 31A that constitutes the ventral region A, a dorsal outer surface sheet 31B that constitutes the dorsal region B, and a crotch outer surface sheet 31C located between the two sheets 31A and 31C and constituting the crotch region C. The sheets 31A, 31B, and 31C that make up the outer surface sheet 31 are joined together at their ends in the longitudinal direction X, and are joined and integrated at the overlapping portion by known joining means such as adhesive, heat sealing, high-frequency sealing, and ultrasonic sealing. At the overlapping portion between sheets 31A, 31C and sheet 31B, sheet 31B, which is located in the center in the longitudinal direction X, is located relatively closer to the absorbent main body 2, and the non-skin facing surfaces at both ends of sheet 31B in the longitudinal direction X are covered by sheets 31A and 31C.

[0018] In diaper 1, as shown in Figure 3, the ventral outer sheet 31A has a ventral extension portion 31AE that extends outward from the end in the vertical direction X on the ventral region A side of the main body sheet 32, and the dorsal outer sheet 31B has a dorsal extension portion 31BE that extends outward from the end in the vertical direction X on the dorsal region B side of the main body sheet 32. Both extension portions 31AE and 31BE are folded back towards the main body sheet 32 ​​so as to cover both ends in the vertical direction X of the absorbent body 2 which is placed and fixed on the main body sheet 32, and are fixed with adhesive to the other components of diaper 1 (main body sheet 32, absorbent body 2, leak-proof cuff 24) that are opposite to both extension portions 31AE and 31BE.

[0019] As described above, the outer sheet 31 of diaper 1 is stretchable in the lateral direction Y, and in particular, in diaper 1, the outer sheet 31 is partially stretchable in the lateral direction Y. That is, in diaper 1, as shown in Figure 3, of the three outer sheets 31A (abdominal), 31B (back), and 31C (crotch), the 31A (abdominal) and 31B (back) are stretchable in the lateral direction Y, while the 31C (crotch) is not stretchable and is non-stretchable.

[0020] In the present invention, "having elasticity in the lateral direction Y" means that the maximum elongation of the elastic sheet in the lateral direction Y is 100% or more, and that the elongation recovery rate (elongation recovery rate when 100% elongated) when the sheet is deflated after being stretched to 100% elongation in the lateral direction Y is at least 70% or more. In diaper 1, both the ventral outer sheet 31A and the dorsal outer sheet 31B are sheets that have elasticity in the lateral direction Y. The elongation recovery rate of the sheet is measured by the following measurement method.

[0021] <Method for Measuring the Elongation Recovery Rate of a Sheet> Prepare a sample piece measuring 50 mm in length and 25 mm in width from the sheet to be measured. Fix the sample piece between the chucks (chuck spacing K0) of a tensile testing machine (Orientec Co., Ltd.'s "Tensilon" RTC-1150A), and stretch the sample piece by widening the chuck spacing at a tensile speed of 300 mm / min until it reaches the length K2 (= K0 × 2) at 100% elongation. Then, narrow the chuck spacing at the same speed as the tensile speed, and the length of the sample piece at the point when the tensile stress becomes 0 is defined as the length after elongation recovery, K1. Calculate the elongation recovery rate of the sheet to be measured at 100% elongation using the following formula: Elongation recovery rate at 100% elongation (%) = [(K2 - K1) / (K2 - K0)] × 100

[0022] In the present invention, a non-stretchable sheet means a sheet with an elongation recovery rate of 20% or less, as measured by the <Method for measuring the elongation recovery rate of a sheet>, or a sheet that breaks before being stretched to 100%. In diaper 1, both the crotch outer sheet 31C and the main body sheet 32 ​​are non-stretchable sheets.

[0023] As the stretchable ventral outer surface sheet 31A and dorsal outer surface sheet 31B of the diaper 1, for example, (1) a stretchable sheet in which a stretchable fiber layer is integrated on both sides or one side of an elastic fiber layer, (2) a stretchable sheet in which a stretchable fiber layer is integrated on both sides or one side of a net-like elastic sheet, (3) a stretchable sheet in which a stretchable fiber layer is integrated on both sides or one side of an elastic sheet made of an elastic film, (4) a stretchable sheet in which a large number of elastic filaments arranged to extend in one direction without crossing each other are joined to a stretchable non-woven fabric in a substantially non-stretched state over their entire length, etc. can be preferably used. Examples of the method of integrating the elastic fiber layer and the stretchable fiber layer include, for example, laminating them and entangling them with water flow, a method of entangling fibers by air-through or the like, a method of joining them by heat embossing, an adhesive, ultrasonic waves, or the like.

[0024] In the diaper 1, in the outer surface sheet 31 which is a stretchable sheet, a high stretchable portion 31H having relatively high stretchability and a low stretchable portion 31L having relatively low stretchability are alternately arranged in the lateral direction Y. Preferably, in the diaper 1, as shown in FIGS. 5 and 6, the stretchable ventral outer surface sheet 31A and dorsal outer surface sheet 31B constituting the outer surface sheet 31 are formed such that the high stretchable portion 31H and the low stretchable portion 31L are alternately arranged in the lateral direction Y.

[0025] Figure 4 shows a preferred example of a stretchable sheet used in diaper 1. The ventral outer sheet 31A and dorsal outer sheet 31B shown in Figure 4 correspond to the stretchable sheet described in (4) above, and have a structure in which thread-like elastic filaments are joined to one surface of an extendable fiber layer mainly composed of non-elastic fibers. The structure includes two fiber sheets 36 and 37 as the fiber layer, and an elastic member 38 as the elastic filament interposed between the two sheets 36 and 37. The stretchable ventral outer sheet 31A and dorsal outer sheet 31B having such a structure are formed, for example, by inserting them into the meshing portions of a pair of tooth groove rolls in which teeth and tooth roots are alternately formed in the circumferential direction, and stretching them according to the method described in Japanese Patent Application Publication No. 2009-61743. The highly stretchable portion 31H is the portion that is greatly stretched by the teeth of one tooth groove roll and the teeth of the other tooth groove roll, while the less stretchable portion 31L is the portion that comes into contact with the teeth of one tooth groove roll and the teeth of the other tooth groove roll, respectively, and is hardly stretched. In the ventral outer sheet 31A and the dorsal outer sheet 31B of the diaper 1, the highly stretchable portion 31H that extends continuously in the longitudinal direction X and the less stretchable portion 31L that extends continuously in the longitudinal direction X are arranged alternately in the transverse direction Y.

[0026] In diaper 1, the two sheets 36 and 37 (see Figure 4) that make up the stretchable ventral outer sheet 31A and the dorsal outer sheet 31B are both stretchable. Sheets 36 and 37 are stretchable in the same direction as the stretching direction (lateral direction Y) of the elastic member 38. Stretchability includes (a) cases where the constituent fibers of sheets 36 and 37 themselves stretch, and (b) cases where, even if the constituent fibers themselves do not stretch, the sheets 36 and 37 as a whole stretch due to the separation of fibers that were bonded at intersections, structural changes in the three-dimensional structure formed by multiple fibers due to bonding between fibers, or the tearing of constituent fibers.

[0027] In the diaper 1, the elastic members 38 (see FIG. 4) that constitute the stretchable ventral outer surface side sheet 31A and dorsal outer surface side sheet 31B are elastic filaments formed by stretching in a state where the elastic resin is melted or softened. The plurality of elastic members 38 are substantially continuous over the entire length of the ventral outer surface side sheet 31A and dorsal outer surface side sheet 31B (the entire length in the lateral direction Y of the exterior body 3). The plurality of elastic members 38 are arranged so as to extend in one direction (lateral direction Y) without crossing each other. The elastic members 38 are joined to the two sheets 36 and 37 in a substantially non-stretched state. The joining of the elastic members 38 to the sheets 36 and 37 in the ventral outer surface side sheet 31A and dorsal outer surface side sheet 31B is achieved by fusing the elastic members 38 with the fibers (non-elastic fibers) constituting the sheets 36 and 37 being buried in the elastic members 38, and is not achieved using an adhesive such as a hot melt adhesive. Therefore, there is no adhesive between the sheets 36 and 37 (stretchable fiber layer mainly composed of non-elastic fibers) and the elastic members 38 joined thereto.

[0028] In the diaper 1, the stretchable ventral outer surface side sheet 31A and dorsal outer surface side sheet 31B are stretchable in the same direction as the direction in which the elastic members 38 extend (lateral direction Y) (see FIG. 4). The stretchability of the ventral outer surface side sheet 31A and dorsal outer surface side sheet 31B is exhibited due to the elasticity of the elastic members 38 at the high stretch region 31H. When the ventral outer surface side sheet 31A and dorsal outer surface side sheet 31B are stretched in the same direction as the direction in which the elastic members 38 extend, the elastic members 38 and the sheets 36 and 37 at the high stretch region 31H extend, while the elastic members 38 and the sheets 36 and 37 at the low stretch region 31L do not extend. Then, when the stretching of the ventral outer surface side sheet 31A and dorsal outer surface side sheet 31B is released, the elastic members 38 at the high stretch region 31H contract, and along with the contraction, the sheets 36 and 37 at the high stretch region 31H return to the state before stretching.

[0029] With respect to the highly elastic portion 31H and the less elastic portion 31L, the length of the elastic member 38 when stretched in the direction of stretching (lateral direction Y) is preferably 130% or more, more preferably 300% or more, and preferably with an upper limit of 600% or less, assuming that the length in the lateral direction Y of the highly elastic portion 31H is longer than the length in the lateral direction Y of the less elastic portion 31L, when the length when contracted is set to 100%. The length of the less elastic portion 31L is preferably 200% or less, more preferably 170% or less, and preferably with a lower limit of 100% or more. The length when stretched is measured by the following measurement method.

[0030] <Length of the highly elastic portion 31H and the less elastic portion 31L when stretched in the lateral direction Y> A rectangular sample piece is cut from an expandable sheet in which highly elastic portions 31H and less elastic portions 31L are alternately arranged in the lateral direction Y, with dimensions of 200 mm in the direction of stretching of the elastic member 38 (lateral direction Y) and 50 mm in the vertical direction X. Then, using a pen or the like, marks are made on the highly elastic portion 31H and the less elastic portion 31L, and the length of the lateral direction Y of each portion of the highly elastic portion 31H and the less elastic portion 31L is measured in advance. The sample piece is mounted on an Orientec Tensilon RTC1210A. The distance between the chucks is 150 mm. The mounted sample piece is stretched at a speed of 100 mm / min in the direction of stretching of the elastic member 38 (lateral direction Y), and when the stretching of the sample piece stops, the length of the lateral direction Y of each portion of the highly elastic portion 31H and the less elastic portion 31L when stretched is measured. Then, let La be the length in the lateral direction Y of the highly elastic portion 31H, and let Lb be the length in the lateral direction Y of the highly elastic portion 31H when stretched. Then, {Lb / La} × 100 is calculated as the length (%) of the lateral direction Y of the highly elastic portion 31H when stretched. Similarly, the length (%) of the lateral direction Y of the low-elastic portion 31L when stretched is calculated in the same manner.

[0031] In diaper 1, the two sheets 36 and 37 (see Figure 4) that make up the ventral outer sheet 31A and the dorsal outer sheet 31B can each be made of short-fiber nonwoven fabric. Examples of nonwoven fabrics include air-through nonwoven fabric, heat-rolled nonwoven fabric, spunlace nonwoven fabric, spunbond nonwoven fabric, and meltblown nonwoven fabric. Sheets 36 and 37 may be of the same type or different types. Here, "sheets of the same type" means sheets in which the manufacturing process, the type of constituent fibers, the fiber diameter and length of the constituent fibers, the thickness and basis weight of the sheets, etc., are all the same. If at least one of these is different, they are "different types of sheets".

[0032] In diaper 1, the elastic member 38 (elastic filament) (see Figure 4) that constitutes the stretchable ventral outer sheet 31A and dorsal outer sheet 31B is made from materials such as thermoplastic elastomer or rubber. In particular, using thermoplastic elastomer as the raw material allows for melt spinning using an extruder, similar to ordinary thermoplastic resins, and the elastic filament obtained in this way is easily heat-fused, making it suitable for the ventral outer sheet 31A and dorsal outer sheet 31B. Examples of thermoplastic elastomers include styrene-based elastomers such as SBS (styrene-butadiene-styrene), SIS (styrene-isoprene-styrene), SEBS (styrene-ethylene-butadiene-styrene), and SEPS (styrene-ethylene-propylene-styrene), olefin-based elastomers (ethylene-based α-olefin elastomers, propylene-based elastomers copolymerized with ethylene-butene-octene, etc.), polyester-based elastomers, and polyurethane-based elastomers. These can be used individually or in combination of two or more. Furthermore, core-sheath type or side-by-side type composite fibers made from these resins can also be used.

[0033] On the other hand, in diaper 1, nonwoven fabrics manufactured by various methods are preferably used as the non-stretchable crotch outer sheet 31C and the main body sheet 32 ​​(see Figure 3), for example, spunbond nonwoven fabric, air-through nonwoven fabric, needle-punched nonwoven fabric, etc. Examples of constituent fibers of the nonwoven fabric used as the non-stretchable sheets 31C and 32 include polyester such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and polybutylene terephthalate (PBT), polyamide, etc. The fibers constituting the nonwoven fabric used as the non-stretchable crotch outer sheet 31C and the main body sheet 32 ​​may be short fibers or long fibers, and may be hydrophilic or hydrophobic. In addition, core-sheath type or side-by-side type composite fibers, split fibers, irregular cross-section fibers, crimped fibers, heat-shrinkable fibers, etc. can also be used. These fibers can be used individually or in combination of two or more types.

[0034] In diaper 1, as shown in Figures 2 and 3, multiple thread-like or strip-like waist elastic members 33 are arranged in an extended state in the lateral direction Y in the ventral region A and the dorsal region B, respectively, and these multiple waist elastic members 33 are intermittently arranged at predetermined intervals in the longitudinal direction X. Because the waist elastic members 33 are arranged in a state in which their elasticity is exhibited, a substantially continuous annular waist gather is formed around the entire circumference of the opening edge of the waist opening WH. In addition, one or more thread-like or strip-like leg elastic members 34 for forming leg gathers are arranged in an extended state at the leg edges that form the opening edges of each of the pair of leg openings LH, LH, thereby forming a substantially continuous annular leg gather around the entire circumference of the opening edges of each of the pair of leg openings LH, LH. Both of these elastic members 33 and 34 are sandwiched and fixed between the outer sheet 31 and the main body sheet 32 ​​that constitute the outer casing 3 by bonding means such as adhesive.

[0035] In diaper 1, the ventral stretch portion WA and the dorsal stretch portion WB are formed by an outer sheet 31, made from a stretchable sheet, being arranged in a stretched state in the lateral direction Y on the non-skin-facing surface of the main sheet 32, as shown in Figures 5 and 6(a). Preferably, the ventral stretch portion WA of diaper 1 is formed by an elastic ventral outer sheet 31A being arranged and fixed in a stretched state in the lateral direction Y on the non-skin-facing surface of the main sheet 32. Similarly, the dorsal stretch portion WB of diaper 1 is formed by an elastic dorsal outer sheet 31B being arranged and fixed in a stretched state in the lateral direction Y on the non-skin-facing surface of the main sheet 32. Here, arranging the outer sheet 31 in an extended state in the lateral direction Y means, as shown in Figure 2, extending the thread-like or strip-shaped waist elastic member 33 and leg elastic member 34, as well as the elastic filament elastic member 38, until they reach the design dimensions (the same dimensions as when spread out flat with the influence of the elastic members completely eliminated).

[0036] In the ventral stretch portion WA and the dorsal stretch portion WB of the diaper 1, a first joining portion 1JT is formed where the main body sheet 32 ​​and the outer sheet 31 are joined at the highly stretchable portion 31H of the stretchable sheet in the region 23PT that overlaps with the absorbent body 23, and a second joining portion 2JT is formed where the main body sheet 32 ​​and the outer sheet 31 are joined at the less stretchable portion 31L of the stretchable sheet in the region 23NT that is outside the absorbent body 23 and does not overlap with the absorbent body 23, and a second non-jointed portion 2NJT is formed where the main body sheet 32 ​​and the outer sheet 31 are joined at the less stretchable portion 31L of the stretchable sheet and are not joined at the highly stretchable portion 31H of the stretchable sheet. Preferably, in the ventral stretch portion WA and the dorsal stretch portion WB of the diaper 1, as shown in Figure 5, there is a non-stretchable main body sheet 32 ​​and a stretchable outer sheet 31, respectively, and in the region 23PT that overlaps with the absorbent 23, the main body sheet 32 ​​and the highly stretchable portion 31H of the outer sheet 31 are joined at the first joining portion 1JT. Furthermore, in the ventral stretch portion WA and the dorsal stretch portion WB of the diaper 1, in the region 23NT that is outside the absorbent 23 and does not overlap with the absorbent 23, the main body sheet 32 ​​and the less stretchable portion 31L of the outer sheet 31 are joined at the second joining portion 2JT, and the main body sheet 32 ​​and the highly stretchable portion 31H of the outer sheet 31 are not joined.

[0037] Preferably, in the ventral region A of the diaper 1, the stretchable ventral outer sheet 31A is arranged in a stretched state in the lateral direction Y on the non-skin-facing surface of the non-stretchable main body sheet 32. As shown in Figure 5, in the region 23PT where the main body sheet 32 ​​and the ventral outer sheet 31A overlap with the absorbent body 23, the stretched, highly elastic portion 31H of the main body sheet 32 ​​and the ventral outer sheet 31A are joined at the first joining portion 1JT to form the ventral stretch portion WA. Furthermore, in the region 23NT where the main body sheet 32 ​​and the ventral outer sheet 31A do not overlap with the absorbent body 23 beyond the absorbent body 23, as shown in Figure 6(a), the low-stretch portion 31L of the main body sheet 32 ​​and the ventral outer sheet 31A in their extended state are joined at the second joining portion 2JT, and the high-stretch portion 31H of the main body sheet 32 ​​and the ventral outer sheet 31A are not joined, forming the ventral stretch portion WA. In the ventral region A of the diaper 1, the "region 23NT that does not overlap with the absorbent body 23" is, as shown in Figure 2, the end flap portion located outward in the vertical X direction (opposite side from the horizontal center line CL2) from the outer end 23A1 of the front end portion 23AA of the absorbent body 23 constituting the absorbent body 23 in the vertical direction (X direction) of the absorbent body 23. Furthermore, in addition to the end flap portion, this refers to the region that includes the side flap portion located beyond the side portions along the vertical direction (X direction) of the absorber 23 in the lateral direction Y, and between the lower end of the end flap portion in the vertical direction X and the lower end of the side seal portion 5.

[0038] Similar to the ventral region A shown in Figure 5, in the dorsal region B of the diaper 1, the elastic dorsal outer surface sheet 31B is arranged in an extended state in the lateral direction Y on the non-skin-facing surface of the non-stretchable main body sheet 32. In the region 23PT where the main body sheet 32 ​​and the dorsal outer surface sheet 31B overlap with the absorbent material 23, the highly stretchable portion 31H of the main body sheet 32 ​​and the dorsal outer surface sheet 31B in an extended state is joined at the first joining portion 1JT to form the dorsal stretch portion WB. Furthermore, in the region 23NT where the main body sheet 32 ​​and the extended dorsal outer sheet 31B do not overlap with the absorbent body 23 beyond the absorbent body 23, similar to the ventral region A shown in Figure 6(a), the main body sheet 32 ​​and the low-stretch portion 31L of the extended dorsal outer sheet 31B are joined at the second joining portion 2JT, while the main body sheet 32 ​​and the high-stretch portion 31H of the extended dorsal outer sheet 31B are not joined, thus forming the dorsal stretch portion WB. In the dorsal region B of the diaper 1, the "region 23NT that does not overlap with the absorbent body 23" is, similar to the ventral region A of the diaper 1, the end flap portion located outward in the vertical X direction (opposite side to the horizontal center line CL2) from the outer end 23B1 of the rear end 23B of the absorbent body 23 constituting the absorbent body 23, as shown in Figure 2. Furthermore, in addition to the end flap portion, this refers to the region that includes the side flap portion located beyond the side portions along the vertical direction (X direction) of the absorber 23 in the lateral direction Y, and between the lower end of the end flap portion in the vertical direction X and the lower end of the side seal portion 5.

[0039] Thus, in the ventral stretch portion WA and the dorsal stretch portion WB of the diaper 1, as shown in Figure 5, the non-stretchable main body sheet 32 ​​and the stretchable outer sheet 31 are joined in the region 23PT overlapping with the absorbent material 23 at the highly stretchable portion 31H of the stretched state of the main body sheet 32 ​​and the outer sheet 31. Therefore, in the region 23PT overlapping with the absorbent material 23, even if the stretched state of the outer sheet 31 is released, the contraction of the highly stretchable portion 31H is easily inhibited, and wrinkles are less likely to occur in the absorbent material 23 of the diaper 1, and the absorption performance of the absorbent material 23 is less likely to be impaired.

[0040] Furthermore, in the ventral stretch portion WA and the dorsal stretch portion WB of the diaper 1, as shown in Figure 6(a), in the region 23NT that does not overlap with the absorbent material 23, the low-stretch portion 31L of the stretchable outer sheet 31 that forms the outer surface of the diaper 1 is joined to the main sheet 32 ​​when it is stretched, but the high-stretch portion 31H of the outer sheet 31 is not joined to the main sheet 32. Therefore, in the region 23NT that does not overlap with the absorbent material 23, as shown in Figure 6(b), when the stretched state of the outer sheet 31 is released, the contraction of the high-stretch portion 31H is not easily inhibited, wrinkles are less likely to occur in the outer sheet 31 that forms the outer surface of the diaper 1, and the outer surface of the diaper 1 looks good. Furthermore, when the stretched state of the outer sheet 31 is released, as shown in Figure 6(b), the contraction of the highly elastic portion 31H causes the portion of the main body sheet 32 ​​between the parts of the main body sheet 32 ​​joined by a pair of low-elastic portions 31L, 31L adjacent to the highly elastic portion 31H to easily deform so as to bulge towards the skin-facing side. As a result, a space G is easily formed between the highly elastic portion 31H and the main body sheet 32, which makes it easier to feel the skin, improves breathability, and enhances the user experience. In particular, in diaper 1, since the main body sheet 32 ​​is a non-elastic sheet, a space G is even more easily formed between it and the highly elastic portion 31H, making it easier to feel the skin, further improving breathability, and further enhancing the user experience.

[0041] In diaper 1, in the region 23PT overlapping with the absorbent material 23, the main body sheet 32 ​​and the outer sheet 31 form a first non-jointed area 1NJT where they are not joined at the low-stretch portion 31L of the stretchable sheet. That is, in the region 23PT overlapping with the absorbent material 23, as shown in Figure 5, the main body sheet 32 ​​and the low-stretch portion 31L of the outer sheet 31 formed from the stretchable sheet are not joined. Preferably, in the ventral region A of diaper 1, the main body sheet 32 ​​and the ventral outer sheet 31A are joined at the first jointed area 1JT, and in the region 23PT overlapping with the absorbent material 23, the main body sheet 32 ​​and the highly stretchable portion 31H of the ventral outer sheet 31A in its extended state are joined at the first jointed area 1JT, and the main body sheet 32 ​​and the low-stretch portion 31L of the ventral outer sheet 31A are not joined at the first non-jointed area 1NJT. Similarly, in the dorsal region B of diaper 1, the main body sheet 32 ​​and the dorsal outer sheet 31B are joined at the first joining portion 1JT in the region 23PT that overlaps with the absorbent material 23, and the highly stretchable portion 31H of the main body sheet 32 ​​and the dorsal outer sheet 31B in their extended state is joined at the first joining portion 1JT, while the less stretchable portion 31L of the main body sheet 32 ​​and the dorsal outer sheet 31B is not joined at the first non-jointing portion 1NJT.

[0042] In the region 23PT overlapping with the absorbent material 23 of the diaper 1, as shown in Figure 3, the first joining portion 1JT of the main body sheet 32 ​​and the outer sheet 31, and the first non-joint portion 1NJT of the main body sheet 32 ​​and the outer sheet 31 are formed continuously in the vertical direction X and are arranged alternately in the horizontal direction Y. Preferably, in the region 23PT overlapping with the absorbent material 23, the first joining portion 1JT between the highly elastic portion 31H of the ventral outer sheet 31A or the dorsal outer sheet 31B and the main sheet 32 ​​is continuous in the vertical direction X, and the first non-joint portion 1NJT between the low elastic portion 31L of the ventral outer sheet 31A or the dorsal outer sheet 31B and the main sheet 32 ​​is continuous in the vertical direction X. The first joining portion 1JT continuous in the vertical direction X and the first non-joint portion 1NJT continuous in the vertical direction X are arranged alternately in the horizontal direction Y.

[0043] In diaper 1, in the region 23PT overlapping with the absorbent material 23, as shown in Figure 5, the low-stretch portion 31L of the main body sheet 32 ​​and the outer sheet 31 are not joined at the first non-joint portion 1NJT, while the high-stretch portion 31H of the main body sheet 32 ​​and the outer sheet 31 are joined at the first joint portion 1JT. Furthermore, in the region 23PT overlapping with the absorbent material 23, as shown in Figure 3, the first joint portion 1JT of the main body sheet 32 ​​and the outer sheet 31 and the first non-joint portion 1NJT of the main body sheet 32 ​​and the outer sheet 31 are formed continuously in the vertical direction X and are arranged alternately in the horizontal direction Y. As a result, wrinkles are less likely to occur in the absorbent material 23 of diaper 1, and the absorption performance is less likely to be further impaired.

[0044] In diaper 1, in the region 23NT that is outside the absorbent core 23 and does not overlap with the absorbent core 23, as shown in Figure 6(a), the main body sheet 32 ​​and the low-stretch portion 31L of the outer sheet 31 are joined at the second joining portion 2JT, and the main body sheet 32 ​​and the high-stretch portion 31H of the outer sheet 31 are not joined at the second non-joint portion 2NJT. In the non-overlapping region 23NT, as shown in Figure 3, the second joining portion 2JT and the second non-joint portion 2NJT are continuous in the vertical direction X, and the second joining portion 2JT that is continuous in the vertical direction X and the second non-joint portion 2NJT that is continuous in the vertical direction X are arranged alternately in the horizontal direction Y. Similarly, in the folded portion of the waist, the second joining portion 2JT that is continuous in the vertical direction X and the second non-joint portion 2NJT that is continuous in the vertical direction X are arranged alternately in the horizontal direction Y. In diaper 1, as shown in Figure 3, at the vertical X boundary between the region 23PT overlapping the absorbent material 23 and the region 23NT not overlapping the absorbent material 23, the first joining portion 1JT and the first non-jointing portion 1NJT, which are continuous in the vertical X direction and located in the region 23PT overlapping the absorbent material 23, are not continuous with the second joining portion 2JT and the second non-jointing portion 2NJT, which are continuous in the vertical X direction and located in the region 23NT not overlapping the absorbent material 23, and are separated. When the first joining portion 1JT and the second joining portion 2JT, which are continuous in the vertical X direction, are separated at the vertical X boundary between the region 23PT overlapping the absorbent material 23 and the region 23NT not overlapping the absorbent material 23, wrinkles are less likely to occur in the absorbent material 23, and the absorption performance is less likely to be further impaired.

[0045] From the viewpoint of further reducing the likelihood of wrinkles forming on the absorbent material 23 in the region 23PT overlapping with the absorbent material 23, and further reducing the likelihood of impaired absorption performance, it is preferable that in the region 23PT overlapping with the absorbent material 23, the first joining portion 1JT of the main body sheet 32 ​​and the outer sheet 31 is formed over the entire area of ​​the highly elastic portion 31H of the outer sheet 31. Preferably, when the diaper 1 is unfolded and stretched, the first joining portion 1JT is formed over the entire area within the contour of the highly elastic portion 31H when viewed from above of the highly elastic portion 31H of the ventral outer sheet 31A or the dorsal outer sheet 31B.

[0046] Furthermore, in diaper 1, as shown in Figure 5, the positions of the fixing points between the absorbent body 2 and the outer body 3, i.e., the application positions of the adhesive 4 for fixing the body, overlap with the positions of the first joining portion 1JT of the body side sheet 32 ​​and the outer side sheet 31 in the region 23PT that overlaps with the absorbent body 23. If they overlap in this way, wrinkles are less likely to occur in the absorbent body 23 in the region 23PT that overlaps with the absorbent body 23. As shown in Figure 5, from the viewpoint of making it less likely for wrinkles to occur in the absorbent body 23 when viewed in cross-section, it is sufficient for the application portion of the adhesive 4 for fixing the body and the first joining portion 1JT to partially overlap in the lateral direction Y, but it is preferable that the entire lateral direction Y range of the first joining portion 1JT is included within the lateral direction Y range of the application portion of the adhesive 4 for fixing the body.

[0047] From the viewpoint of further enhancing the effects described above, it is preferable that diaper 1 comprises one or more of the following components.

[0048] As shown in Figure 2, when the diaper 1 is unfolded and extended, in a plan view, with respect to the ventral region A, the ratio of the length of the lateral Y direction of the region 23PT that overlaps with the absorbent material 23 to the sum of the lengths of the lateral Y direction of the region 23NT that does not overlap with the absorbent material 23 (sum of the lengths of the lateral Y direction of each of the side flap portions) ((L 23PT / L 23NTThe ratio of the length of the lateral Y direction of the region 23PT that overlaps with the absorbent 23 to the sum of the lengths of the lateral Y direction of the region 23NT that does not overlap with the absorbent 23 (sum of the lengths of the lateral Y direction of each of the side flap portions) ((L 23PT / L 23NT The ratio of (x 100) is preferably 20% or more, more preferably 30% or more, and more preferably 65% ​​or less, and more preferably 55% or less. Specifically, it is preferably 20% or more and 65% or less, and more preferably 30% or more and 55% or less.

[0049] As shown in Figure 2, when the diaper 1 is unfolded and extended, the area of ​​the region 23PT that overlaps with the absorbent material 23 in the ventral region A is (S 23PT The sum of the areas of each first joining portion 1JT, which is the joining portion between the main body side sheet 32 ​​and the highly elastic portion 31H of the ventral outer surface side sheet 31A, (S 1JT The proportion of (S 1JT / S 23PT The ratio of (x 100) is preferably 25% or more, more preferably 35% or more, and more preferably 70% or less, and more preferably 60% or less. Specifically, it is preferably 25% to 70%, and more preferably 35% to 60%. The same applies to the dorsal region B as to the ventral region A.

[0050] Furthermore, when the diaper 1 is unfolded and stretched, as shown in Figure 5, a cross-sectional view is taken. With respect to the region 23PT overlapping with the absorbent material 23 in the ventral region A, the ratio of the length of the lateral Y direction (W1) of the first joining portion 1JT, which is the joining portion between the main body sheet 32 ​​and the highly stretchable portion 31H of the ventral outer sheet 31A, to the length of the lateral Y direction (W2) of the highly stretchable portion 31H of the outer sheet 31 ((W1 / W2) × 100) is preferably 60% or more, more preferably 80% or more, more preferably 150% or less, and more preferably 120% or less. Specifically, it is preferably 60% or more and 150% or less, and more preferably 80% or more and 120% or less. The same applies to the dorsal region B as to the ventral region A. By setting the range in this manner, not only is it possible to prevent wrinkles from forming in the absorbent material, but gaps are created by making unadhered portions with the leak-proof sheet, which makes it easier to achieve the effect of improved breathability.

[0051] Furthermore, when the diaper 1 is unfolded and stretched, as shown in Figure 5, a cross-sectional view is taken, and with respect to the region 23PT overlapping with the absorbent material 23 in the ventral region A, the ratio of the length (W1) in the lateral direction Y of the first joining portion 1JT, which is the joining portion between the main body sheet 32 ​​and the highly stretchable portion 31H of the ventral outer sheet 31A, to the length (W3) in the lateral direction Y of the low-stretch portion 31L of the outer sheet 31 ((W1 / W3) × 100) is preferably 50% or more, more preferably 70% or more, more preferably 140% or less, and more preferably 120% or less. Specifically, it is preferably 50% or more and 140% or less, and more preferably 70% or more and 120% or less. The same applies to the dorsal region B as to the ventral region A.

[0052] Further, when the diaper 1 is viewed in cross-section in the state of being unfolded and stretched as shown in FIG. 5, with respect to the region 23PT overlapping the absorber 23 in the ventral region A, the ratio ((W2 / W4)×100) of the lateral length (W2) in the lateral direction Y of the highly stretchable part 31H of the outer surface side sheet 31 to the lateral length (W4) in the lateral direction Y of the body fixing adhesive 4, which is a fixing part between the absorbent main body 2 and the exterior body 3, is preferably 60% or more, more preferably 80% or more, and preferably 150% or less, more preferably 120% or less. Specifically, it is preferably 60% or more and 150% or less, more preferably 80% or more and 120% or less. Regarding the dorsal region B, it is the same as the ventral region A.

[0053] Further, when the diaper 1 is viewed in plan view in the state of being unfolded and stretched as shown in FIG. 2, with respect to the ventral region A, the area (S 23NT ) of the region 23NT that does not overlap the absorber 23, the total area (S 2JT ) of each second joining part 2JT, which is a joining part between the body side sheet 32 and the low stretchable part 31L of the outer surface side sheet 31, the ratio ((S 2JT / S 23NT )×100) is preferably 20% or more, more preferably 35% or more, and preferably 75% or less, more preferably 65% or less. Specifically, it is preferably 20% or more and 75% or less, more preferably 35% or more and 65% or less. Regarding the dorsal region B, it is the same as the ventral region A. By setting it within such a range, the hot melt coating amount can be reduced, and by reducing the rigidity, the effect of improving the texture is more likely to be achieved.

[0054] Further, when the diaper 1 is viewed in plan view in the state of being unfolded and stretched as shown in FIG. 2, with respect to the ventral region A, the area (S [[ID=*15]] 23NT ) of the region 23NT that does not overlap the absorber 23, the total area (S 2NJT ) of each second non-joining part 2NJT, which is a part where the body side sheet 32 and the highly stretchable part 31H of the outer surface side sheet 31 are not joined, the ratio ((S 2NJT / S 23NTThe ratio of (x 100) is preferably 25% or more, more preferably 35% or more, and more preferably 80% or less, and more preferably 65% ​​or less. Specifically, it is preferably 25% to 80%, and more preferably 35% to 65%. The same applies to the dorsal region B as to the ventral region A. By setting the range to this, it is easier to reduce the amount of hot melt coating and reduce rigidity, thereby improving the texture.

[0055] Furthermore, when the diaper 1 is unfolded and stretched, as shown in Figure 2, the sum of the areas of each second joining portion 2JT (S) is calculated with respect to the region 23NT of the ventral region A that does not overlap with the absorbent material 23. 2JT The sum of the areas of each second non-jointed portion 2NJT (S) 2NJT The proportion of (S 2NJT / S 2JT The ratio of (x 100) is preferably 100% or more, more preferably 200% or more, and more preferably 1000% or less, and more preferably 800% or less. Specifically, it is preferably 100% or more and 1000% or less, and more preferably 200% or more and 800% or less. The same applies to the region 23NT that does not overlap with the absorber 23 of the dorsal region B as to the region 23NT that does not overlap with the absorber 23 of the ventral region A.

[0056] Furthermore, when the diaper 1 is unfolded and stretched, as shown in Figure 6(a), a cross-sectional view is taken, and with respect to the region 23NT of the ventral region A that does not overlap with the absorbent material 23, the ratio of the length in the lateral direction Y (W5) of the second joining portion 2JT, which is the joining portion between the main body sheet 32 ​​and the low-stretch portion 31L of the outer sheet 31, to the length in the lateral direction Y (W2) of the highly stretchable portion 31H of the outer sheet 31 ((W5 / W2) × 100) is preferably 50% or more, more preferably 70% or more, more preferably 150% or less, and more preferably 100% or less. Specifically, it is preferably 50% or more and 150% or less, and more preferably 70% or more and 100% or less. The same applies to the dorsal region B as to the ventral region A.

[0057] Furthermore, when the diaper 1 is unfolded and stretched, as shown in Figure 6(a), a cross-sectional view is taken, and with respect to the region 23NT of the ventral region A that does not overlap with the absorbent material 23, the ratio of the length in the lateral direction Y (W5) of the second joining portion 2JT, which is the joining portion between the main body sheet 32 ​​and the low-stretch portion 31L of the outer sheet 31, to the length in the lateral direction Y (W3) of the low-stretch portion 31L of the outer sheet 31 ((W5 / W3) × 100) is preferably 40% or more, more preferably 70% or more, more preferably 140% or less, and more preferably 100% or less. Specifically, it is preferably 40% or more and 140% or less, and more preferably 70% or more and 100% or less. The same applies to the dorsal region B as to the ventral region A.

[0058] Furthermore, when the diaper 1 is unfolded and stretched, as shown in Figures 5 and 6(a), a cross-sectional view is taken. With respect to the ventral region A, the ratio ((W1 / W5) × 100) of the length in the lateral direction Y (W5) of the second joining portion 2JT, which is the joining portion between the main body sheet 32 ​​and the low-stretch portion 31L of the outer sheet 31, to the length in the lateral direction Y (W1) of the first joining portion 1JT, which is the joining portion between the main body sheet 32 ​​and the high-stretch portion 31H of the ventral outer sheet 31A, is preferably 50% or more, more preferably 70% or more, more preferably 200% or less, and more preferably 150% or less. Specifically, it is preferably 50% or more and 200% or less, and more preferably 70% or more and 150% or less. The same applies to the dorsal region B as to the ventral region A.

[0059] The materials used to form each part of the diaper 1 described above will now be explained. The surface sheet 21, back sheet 22, absorbent body 23, and leak-proof cuff 24 that constitute the absorbent body 2 can be any type of material that has been conventionally used in absorbent articles such as disposable diapers, without any particular limitations. For example, the surface sheet 21 can be a single-layer or multi-layer nonwoven fabric or a perforated film. The back sheet 22 can be a breathable resin film or the like. The absorbent body 23 can be an absorbent core made of absorbent material composed of absorbent polymer particles and fiber material, covered with tissue paper. The leak-proof cuff 24 can be a water-repellent single-layer or multi-layer nonwoven fabric or the like.

[0060] Examples of elastic members (such as the leak-proof cuff forming elastic member 25, waist elastic member 33, and leg elastic member 34) include synthetic rubbers such as styrene-butadiene, butadiene, isoprene, and neoprene, natural rubber, EVA, stretchable polyolefin, and polyurethane. Preferably, the elastic members can be in the form of threads (such as elastic threads) or strings (such as flat rubber) with a rectangular, square, circular, elliptical, or polygonal cross-section.

[0061] As the adhesive 4 for fixing the main body, or the strip-shaped adhesive (not shown) for fixing the leg elastic member 34, various hot-melt adhesives conventionally used for absorbent articles such as disposable diapers can be used without particular limitation. The adhesive 4 for fixing the main body is applied, for example, using a coater to one of the non-skin-facing surfaces of the back sheet 22 constituting the absorbent main body 2 and the skin-facing surface of the main body side sheet 32 ​​constituting the outer casing 3.

[0062] The first joint portion 1JT and the second joint portion 2JT of the main body sheet 32 ​​and the outer surface sheet 31 can be formed by applying various hot melt adhesives conventionally used for absorbent articles such as disposable diapers, for example, using a coater. Alternatively, the first joint portion 1JT and the second joint portion 2JT can be formed using thermal embossing, ultrasonic sealing, laser processing, etc.

[0063] Examples of processes for forming the side seal portion 5 include thermal embossing, ultrasonic sealing, and laser processing.

[0064] Although the present invention has been described above based on its preferred embodiments, the present invention is not limited to the embodiments described above and can be modified as appropriate. For example, in the diaper 1 described above, as shown in Figures 5 and 6, the outer sheet 31 is made of an elastic sheet that is stretchable in the lateral direction (Y direction), and the main sheet 32 ​​is made of a non-elastic sheet. However, the main sheet 32 ​​may be made of an elastic sheet that is stretchable in the lateral direction (Y direction), and the outer sheet 31 may be made of a non-elastic sheet, or both the main sheet 32 ​​and the outer sheet 31 may be made of an elastic sheet that is stretchable in the lateral direction. When the main sheet 32 ​​is an elastic sheet, a non-pleated elastic material touches the skin, making it less likely to leave gather marks.

[0065] Furthermore, in diaper 1, elastic sheets are provided in both the ventral elastic section WA and the dorsal elastic section WB, but it is sufficient if the elastic sheet is provided in either the ventral elastic section WA or the dorsal elastic section WB.

[0066] Furthermore, in diaper 1, as shown in Figure 5, in the region 23PT overlapping with the absorbent material 23, the main body sheet 32 ​​and the highly elastic portion 31H of the outer sheet 31 are joined at the first joining portion 1JT, and the main body sheet 32 ​​and the less elastic portion 31L of the outer sheet 31 are not joined at the first non-jointing portion 1NJT. However, not only the highly elastic portion 31H of the main body sheet 32 ​​and the outer sheet 31 may be joined, but the less elastic portion 31L of the main body sheet 32 ​​and the outer sheet 31 may also be joined. In other words, the first non-jointing portion 1NJT does not need to be formed in the region 23PT overlapping with the absorbent material 23.

[0067] Furthermore, in the disposable diaper 1 described above, as shown in Figure 2, the outer body 3 is a pant-type disposable diaper with a continuous shape such as an hourglass extending over the ventral region A, the crotch region C, and the dorsal region B. However, the outer body 3 may also be a split-type pant-type disposable diaper in which the outer body 3 is divided into a ventral outer body, a dorsal outer body, and a crotch outer body as separate components.

[0068] Furthermore, the disposable diaper 1 described above is a pant-type disposable diaper having an outer casing 3, as shown in Figure 1, but it may also be a deployable type disposable diaper.

[0069] Furthermore, the absorbent item mentioned above is a pant-type disposable diaper 1 as shown in Figure 1, but it may also be a women's panty-type sanitary napkin.

[0070] With regard to the embodiments described above, the following absorbent articles are further disclosed.

[0071] <1> An absorbent article having an absorbent body comprising a ventral region and a dorsal region in the longitudinal direction, and a crotch region located between them, and an absorbent body comprising an absorbent material extending from the ventral region to the dorsal region, and having a ventral stretch portion and a dorsal stretch portion extending laterally from the ventral region and the dorsal region, respectively, wherein the ventral stretch portion and the dorsal stretch portion each comprise a body-side sheet joined to the absorbent body and an outer-side sheet disposed on the non-skin-facing surface of the body-side sheet, and at least one of the body-side sheet and the outer-side sheet is a stretchable sheet having elasticity in the lateral direction, wherein the stretchable sheet has a relatively high-stretch portion and a relatively low-stretch portion alternately arranged in the lateral direction, An absorbent article wherein the stretchable sheet is provided on at least one of the ventral stretchable portion and the dorsal stretchable portion, and in the region overlapping with the absorbent, the main body side sheet and the outer side sheet are joined at the highly stretchable portion to form a first joining portion, and in the region outside the absorbent that does not overlap with the absorbent, the main body side sheet and the outer side sheet are joined at the low stretchable portion to form a second joining portion and a second non-jointed portion that is not joined at the highly stretchable portion.

[0072] <2> The absorbent article according to <1>, wherein in the region overlapping with the absorbent, the main body sheet and the outer surface sheet form a first non-jointed portion where they are not joined at the low-stretch portion, and the first non-jointed portion and the first joined portion are formed continuously in the vertical direction and arranged alternately in the horizontal direction. <3> The absorbent article according to <1> or <2>, wherein in the region overlapping with the absorbent, the first joined portion is formed over the entire area of ​​the high-stretch portion. <4> The absorbent article according to any one of <1> to <3>, wherein one of the main body sheet and the outer surface sheet is the stretchable sheet and the other is the non-stretchable sheet. <5> The absorbent article according to any one of <1> to <4>, wherein the absorbent article comprises an outer casing disposed on the non-skin-facing side of the absorbent body and fixing the absorbent body, the outer casing having a body-side sheet and an outer-side sheet, and the position of the fixing portion between the absorbent body and the outer casing overlaps with the position of the first joining portion in the region overlapping with the absorbent.

[0073] <6> The absorbent article according to any one of <1> to <5>, wherein the outer sheet is an expandable sheet having elasticity in the lateral direction, and the main body sheet is a non-stretchable sheet that does not have elasticity. <7> The absorbent article according to any one of <1> to <6>, wherein the outer sheet comprises a ventral outer sheet constituting the ventral region and a dorsal outer sheet constituting the dorsal region, and the expandable ventral outer sheet and the dorsal outer sheet are expandable in the same direction as the elastic member. <8> The absorbent article according to any one of <1> to <7>, wherein the ventral expandable portion and the dorsal expandable portion each have a first joining portion formed in the region where the non-stretchable main body sheet and the expandable outer sheet in an extended state overlap with the absorbent. <9> With respect to the folded portion of the waist, in the region that does not overlap with the absorbent material, the folded portion of the main body sheet and the outer surface sheet form the second joining portion, and the second joining portion and the second non-joint portion of the folded portion of the main body sheet and the outer surface sheet are formed continuously in the vertical direction and are arranged alternately in the horizontal direction, as described in <2> above. <10> At the vertical boundary between the region that overlaps with the absorbent material and the region that does not overlap with the absorbent material, the vertically continuous first joining portion and the first non-joint portion are not continuous with the vertically continuous second joining portion and the second non-joint portion, and are separated, as described in <9> above. <11> With respect to the ventral region, the ratio of the horizontal length of the region that overlaps with the absorbent material to the sum of the horizontal lengths of the region that does not overlap with the absorbent material ((L 23PT / L 23NT The absorbent article according to any one of <1> to <10> above, wherein the amount of () × 100) is 20% or more, preferably 30% or more, and 65% or less, preferably 55% or less.

[0074] <12> With respect to the dorsal region, the ratio of the lateral length of the region overlapping with the absorber to the sum of the lateral lengths of the region not overlapping with the absorber ((L 23PT / L 23NTThe absorbent article according to any one of <1> to <11> above, wherein the area of ​​the region overlapping with the absorbent (S) is 20% or more, preferably 30% or more, and 65% or less, preferably 55% or less. <13> With respect to at least one of the ventral region and the dorsal stretch portion, the area of ​​the region overlapping with the absorbent (S 23PT The sum of the areas of the first joint portion (S) 1JT The proportion of (S 1JT / S 23PT The absorbent article according to any one of <1> to <12> above, wherein (W1 / W2) × 100 is 25% or more, preferably 35% or more, and 70% or less, preferably 60% or less. <14> With respect to the region of the ventral region or the region of the dorsal stretch portion that overlaps with the absorbent, the absorbent article according to any one of <1> to <13> above, wherein the ratio ((W1 / W2) × 100) of the lateral length (W1) of the first joining portion, which is the joining portion between the main body sheet and the highly stretchable portion of the outer sheet, to the lateral length (W2) of the highly stretchable portion of the outer sheet is preferably 60% or more, 80% or more, and 150% or less, preferably 120% or less. <15> With respect to the region of the ventral region or the region of the dorsal stretch portion that overlaps with the absorbent, the ratio of the lateral length (W1) of the first joining portion to the lateral length (W3) of the low stretch portion of the outer sheet ((W1 / W3) × 100) is 50% or more, preferably 70% or more, and 140% or less, preferably 120% or less, according to any one of <1> to <14> above.

[0075] <16> With respect to the region of the ventral region or the dorsal stretchable portion that overlaps with the absorbent, the ratio of the lateral length (W2) of the highly stretchable portion of the outer sheet to the lateral length (W4) of the adhesive for fixing the main body, which is the fixing portion between the absorbent main body and the outer body ((W2 / W4) × 100) is 60% or more, preferably 80% or more, and 150% or less, preferably 120% or less, as described in <5> above. <17> With respect to at least one of the ventral region and the dorsal stretchable portion, the area (S) of the region that does not overlap with the absorbent 23NT The sum of the areas of the second joint portion (S) 2JT The proportion of (S2JT / S 23NT The absorbent article according to any one of <1> to <16> above, wherein the area of ​​the region of the ventral or dorsal stretchable portion that does not overlap with the absorbent material (S 23NT The sum of the areas of the second non-jointed portion (S) 2NJT The proportion of (S 2NJT / S 23NT The absorbent article according to any one of <1> to <17> above, wherein the area of ​​the second joining portion (S) is 25% or more, preferably 35% or more, and 80% or less, preferably 65% ​​or less. <19> With respect to the region of the ventral or dorsal stretch portion that does not overlap with the absorbent, 2JT The sum of the areas of the second non-jointed portion (S) 2NJT The proportion of (S 2NJT / S 2JTThe absorbent article according to any one of <1> to <18> above, wherein (W5 / W2) × 100 is 100% or more, preferably 200% or more, and 1000% or less, preferably 800% or less. <20> With respect to the area of ​​the ventral region or the dorsal stretch portion that does not overlap with the absorbent, the absorbent article according to any one of <1> to <19> above, wherein the ratio of the lateral length (W5) of the second joining portion to the lateral length (W2) of the highly stretch portion of the outer sheet (W5 / W2) × 100 is 50% or more, preferably 70% or more, and 150% or less, preferably 100% or less. <21> With respect to the region of the ventral region or the region of the dorsal stretch portion that does not overlap with the absorbent, the ratio of the lateral length (W5) of the second joining portion to the lateral length (W3) of the low stretch portion of the outer sheet ((W5 / W3) × 100) is 40% or more, preferably 70% or more, and 140% or less, preferably 100% or less, according to any one of <1> to <20> above. <22> With respect to at least one of the ventral region and the dorsal stretch portion, the ratio of the lateral length (W1) of the first joining portion to the lateral length (W5) of the second joining portion ((W1 / W5) × 100) is 50% or more, preferably 70% or more, and 200% or less, preferably 150% or less, according to any one of <1> to <21> above.

[0076] <23> The absorbent article according to any one of <1> to <22> above, wherein of the three outer sheets constituting the outer sheet, the ventral outer sheet and the dorsal outer sheet are stretchable in the lateral direction, and the crotch outer sheet is not stretchable and is non-stretchable. <24> The absorbent article according to <23> above, wherein the ventral outer sheet and the dorsal outer sheet have a structure in which thread-like elastic filaments are joined to one surface of an extendable fiber layer mainly composed of non-elastic fibers, and are composed of two fiber sheets as the fiber layer and an elastic member as the elastic filament interposed between the two sheets. <25> The absorbent article according to <24> above, wherein the plurality of elastic members are arranged so as to extend in one direction (lateral direction) without intersecting each other. <26> The absorbent article according to <24> or <25>, wherein the elastic member is joined to two of the fiber sheets in a substantially non-stretched state. <27> The absorbent article according to any one of <24> to <26>, wherein there is no adhesive between the fiber sheet (stretchable fiber layer mainly composed of non-elastic fibers) and the elastic member joined thereto. <28> The absorbent article according to any one of <24> to <27>, wherein, with respect to the highly stretchable portion and the less stretchable portion, the length of the elastic member when stretched in the stretching direction is 130% or more, preferably 300% or more, with an upper limit of 600%, and the length of the highly stretchable portion when stretched is 130% or more, preferably 300% or more, with an upper limit of 600%, and the length of the less stretchable portion when stretched is 200% or less, preferably 170% or less, with a lower limit of 100%, with respect to the highly stretchable portion and the less stretchable portion, assuming that the length of the highly stretchable portion when stretched is 100%, is longer than the length of the less stretchable portion when contracted.

[0077] According to the present invention, the absorbent material is less prone to wrinkles, its absorption performance is less likely to be impaired, and the appearance of the absorbent article is improved, resulting in a better user experience.