Underpants type absorbent article

Abstract

To provide an underpants type absorbent article which is capable of achieving both bedsore prevention and fitness at a high level.SOLUTION: A girth part 5 has: a waist end part 6 which defines a waist opening WH and has elasticity in a horizontal direction Y; and a waist end adjacent zone 7 adjacent to the waist end 6 in a vertical direction X. The waist end 6 includes an elastic member 45 which is fixed on the surfaces of sheet materials 41, 42 composing the girth part 5 and elastic in the horizontal direction Y, and the waist end adjacent zone 7 is an area where no elastic member 45 is disposed. In the waist end 6 and the waist end adjacent zone 7, no absorbent core 24 is disposed. An abdominal side exterior body 4F has a greater extension stress than a back side exterior body 4R in the horizontal direction Y of the waist end 6. In a natural state of the underpants type absorbent article 1, the waist end 6 has a total length in a girth direction shorter than in areas other than the waist end 6 in the girth part 5.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a pants-type absorbent article such as a pants-type disposable diaper.

Background Art

[0002] A pants-type disposable diaper typically includes an absorbent core that absorbs and holds body fluids, and an outer wrapper disposed on the non-skin-facing side of the absorbent core. A side region of a portion (ventral outer wrapper) disposed on the ventral side of the wearer in the outer wrapper and a side region of a portion (dorsal outer wrapper) disposed on the dorsal side of the wearer in the outer wrapper are joined to form a pair of side seal portions, and an annular body circumference portion, a waist opening, and a pair of leg openings are formed around the wearer's torso. In the ventral outer wrapper and the dorsal outer wrapper, a plurality of filamentous elastic members arranged to be stretchable in the lateral direction are intermittently arranged in the longitudinal direction in order to enhance the fit to the wearer's body, and the entire body circumference portion has elasticity in the body circumference direction.

[0003] Patent Document 1 describes that in a pants-type disposable diaper, a low-stretch region having a lower elongation stress than the remaining portion of the stretchable sheet is formed in a part of the portion of the stretchable sheet constituting the rear waist panel (corresponding to the dorsal outer wrapper) facing the absorbent core. According to the diaper described in the patent document, the entire waist region (corresponding to the body circumference portion) has an appropriate fit, does not inhibit the liquid absorption performance in the region where the absorbent core is present, and there is no possibility of deformation such as wrinkles occurring in the graphic sheet disposed in the region where the absorbent core is present in the waist region.

[0004] Patent Document 2 describes that in order to solve the problem that the crotch portion becomes stuffy during wearing in a conventional pants-type disposable diaper, a bent fit portion that bends so as to enter the wearer's gluteal cleft is provided at the portion facing the gluteal cleft in the back body, and in the front body and the back body, a lifting elastic member that exerts a contraction force in the longitudinal direction so as to lift the crotch portion toward the waist side is provided, and the tensile stress during elastic deformation in the longitudinal direction in the front body is made larger than that in the back body.

[0005] In Patent Document 3, in the region having a side seal portion in the front body of the pant-type disposable diaper, in order from the waist opening to the leg opening, a front waist edge region, an ilium contact region, and a lower abdomen contact region are arranged, and regarding the tensile force during lateral elastic deformation of these regions, the magnitude relationship of lower abdomen contact region > front waist edge region > ilium contact region is established. According to the diaper described in Patent Document 3, the rear lower end side region corresponding to the lower abdomen contact region in the rear body is strongly pulled forward by the lower abdomen contact region and expanded in the left-right direction, and the movement toward the gluteal cleft side is suppressed, so it is said that the displacement of the three-dimensional gathers in the rear body can be prevented.

[0006] In Patent Document 4, in the body circumference portion of the pant-type disposable diaper, in order from the waist opening to the leg opening, a first elastic region, a second elastic region, and a third elastic region are arranged, the shrinkage rate of the second elastic region is made smaller than the shrinkage rates of the first and third elastic regions, and when the first to third elastic regions are in an elastically relaxed state, the second elastic region is curved toward the outside of the diaper. According to the diaper described in Patent Document 4, when an elderly person wears this, it is said that the curved second elastic region can be grasped with a finger and easily pulled up.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0008] In the worn state of a conventional pants-type absorbent article, a large number of wrinkles are generated on the skin-facing surface of the outer body that constitutes the waist area due to the contraction of the outer body in the waist circumference direction. When these wrinkles occur in the back waist area where body pressure tends to concentrate when the wearer is in a lying or sitting position, there is a risk of causing bedsores (decubitus ulcers). In particular, the portion located outward in the longitudinal direction from the absorbent core in the back waist area does not have an absorbent core that can function as a cushion for dispersing body pressure. Therefore, the area of the wearer's skin that comes into contact with this portion is easily affected by the wrinkles generated in this portion and is likely to cause bedsores. On the other hand, as a method for preventing the occurrence of bedsores, a method of weakening the constriction of the wearer's body by the waist area, such as reducing the elongation stress of the elastic member disposed in the waist area, can be considered. However, this method may cause a decrease in the fit of the waist area. A pants-type absorbent article that can achieve both high-level prevention of bedsores and fit has not yet been provided.

[0009] An object of the present invention relates to providing a pants-type absorbent article that can achieve both high-level prevention of bedsores and fit.

Means for Solving the Problems

[0010] The present invention includes an absorbent core and an outer body disposed on the non-skin-facing surface side of the absorbent core. The outer body includes a ventral outer body disposed on the ventral side of the wearer and a dorsal outer body disposed on the dorsal side of the wearer. It has a longitudinal direction extending from the ventral outer body toward the dorsal outer body, a transverse direction orthogonal to the longitudinal direction, and a waist circumference direction along the wearer's waist during wearing. A pants-type absorbent article in which the side region of the ventral outer body and the side region of the dorsal outer body are joined to form an annular waist area, a waist opening, and a pair of leg openings disposed around the wearer's waist. In one embodiment of the pants-type absorbent article of the present invention, the waist area has a waist end portion that defines the waist opening and has elasticity in the transverse direction, and a waist end portion adjacent region adjacent to the waist end portion in the longitudinal direction. The waist end portion includes an elastic member that is fixed to the surface of the sheet material constituting the body circumference portion and is stretchable in the lateral direction, and it is preferable that the area adjacent to the waist end portion is a non-arrangement area of the elastic member. In one embodiment of the pant-type absorbent article of the present invention, it is preferable that the absorbent core is not arranged at the waist end portion and the area adjacent to the waist end portion. In one embodiment of the pant-type absorbent article of the present invention, it is preferable that the ventral exterior body has a greater lateral elongation stress at the waist end portion than the dorsal exterior body. In one embodiment of the pant-type absorbent article of the present invention, in the natural state of the pant-type absorbent article, it is preferable that the total length of the waist end portion in the body circumference direction is shorter than that of other regions in the body circumference portion other than the waist end portion. Other features, effects, and embodiments of the present invention will be described below.

Advantages of the Invention

[0011] According to the present invention, there is provided a pant-type absorbent article capable of achieving both high-level prevention of bedsores and good fit.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

BEST MODE FOR CARRYING OUT THE INVENTION

[0013] FIGS. 1 to 5 show a pant-type disposable diaper 1 which is an embodiment of the pant-type absorbent article of the present invention. The diaper 1 includes an absorbent core 24 and an outer wrapper 4 disposed on the non-skin facing surface side of the absorbent core 24.

[0014] In this specification, the "skin facing surface" is the surface of the absorbent article or its component member (for example, the absorber) that faces the wearer's skin side when the absorbent article is worn, that is, the side relatively close to the wearer's skin, and the "non-skin facing surface" is the surface of the absorbent article or its component member that faces the side opposite to the skin side when the absorbent article is worn, that is, the side relatively far from the wearer's skin. Here, the "when worn" means a normal proper wearing position, that is, a state in which the correct wearing position of the absorbent article is maintained.

[0015] The outer wrapper 4 includes a ventral outer wrapper 4F disposed on the ventral side of the wearer and a dorsal outer wrapper 4R disposed on the dorsal side of the wearer. In the present embodiment, as shown in FIGS. 1 to 3, the outer wrapper 4 further includes an undercrotch outer wrapper 4M located between the ventral outer wrapper 4F and the dorsal outer wrapper 4R in addition to the ventral outer wrapper 4F and the dorsal outer wrapper 4R, and these three outer wrappers 4F, 4M, 4R are integrated. The outer wrapper 4 of the present embodiment is continuous over the entire length in the longitudinal direction X of the diaper 1.

[0016] The diaper 1 has a longitudinal direction X extending from the ventral outer wrapper 4F toward the dorsal outer wrapper 4R and a lateral direction Y orthogonal to the longitudinal direction X. The longitudinal direction X corresponds to the direction extending from the ventral side of the wearer through the crotch portion to the dorsal side. The lateral direction Y corresponds to the body circumference direction along the body circumference of the wearer when worn.

[0017] In the diaper 1, the side regions of the ventral outer body 4F and the side regions of the dorsal outer body 4R are joined to form an annular body circumferential portion 5 arranged around the wearer's torso, as well as a waist opening WH and a pair of leg openings LH, LH. Specifically, the diaper 1 has a pair of side seal portions S, S which are the joints between a pair of side regions along the longitudinal direction X of the ventral outer body 4F and a pair of side regions along the longitudinal direction X of the dorsal outer body 4R. The joining form between the ventral outer body 4F and the dorsal outer body 4R in the side seal portion S is not particularly limited, and examples include fusion by heat seal, ultrasonic seal, etc.; adhesion by an adhesive.

[0018] The body circumferential portion 5 is a region in the diaper 1 that is in the same position as the side seal portion S in the longitudinal direction X. In other words, it is the region sandwiched between the pair of side seal portions S, S. Also, in the outer body 4, the portion constituting the body circumferential portion 5 of the ventral part F is the ventral outer body 4F, the portion constituting the body circumferential portion 5 of the dorsal part R is the dorsal outer body 4R, and the rest is the crotch outer body 4M.

[0019] As shown in FIGS. 1 to 3, the diaper 1 of the present embodiment has a ventral part F arranged on the ventral side of the wearer during wearing, a dorsal part R arranged on the dorsal side of the wearer, and a crotch part M located between the ventral part F and the dorsal part R. The crotch part M extends in the longitudinal direction X across the longitudinal center line CLx of the diaper 1. The longitudinal center line CLx is a virtual straight line that bisects the diaper 1 in the longitudinal direction X in the unfolded and maximum extended state as shown in FIG. S and extends in the transverse direction Y. The crotch part M includes an excretion part facing part (not shown) facing the excretion part such as the penis of the wearer, and typically includes the part where the length in the transverse direction Y is the shortest in the diaper 1. The ventral part F, the crotch part M, and the dorsal part R can be the respective regions when the absorbent article in the unfolded and maximum extended state is trisected in the longitudinal direction X.

[0020] As used herein, the "deployed and fully extended state" refers to a state in which the absorbent article is separated at the side seal portion to be in a deployed state, and the elastic member provided in the absorbent article is extended until the dimensions of the members other than the elastic member in a plan view become the designed dimensions, that is, until the influence of the elastic member is completely eliminated, and the absorbent article is spread out flat.

[0021] The diaper 1 of the present embodiment is symmetrically formed on one side and the other side with respect to the horizontal center line CLy. The horizontal center line CLy is a virtual straight line that bisects the diaper 1 in the deployed and fully extended state in the horizontal direction Y and extends in the vertical direction X.

[0022] The diaper 1 of the present embodiment has an absorbent main body 2 including an absorbent core 24. The outer cover 4 is fixed to the non-skin-facing surface of the absorbent main body 2 by known joining means such as an adhesive. As shown in FIG. 3, the absorbent main body 2 has a shape that is long in one direction in a plan view, specifically a rectangular shape. Its longitudinal direction is made to coincide with the vertical direction X of the diaper 1, and it is disposed at the center in the horizontal direction Y of the outer cover 4, and extends in the vertical direction X from the ventral side portion F through the crotch portion M to the dorsal side portion R. The absorbent main body 2 includes a liquid-permeable surface sheet 21 disposed at a position relatively close to the wearer's skin, a liquid-impermeable back sheet 22 disposed at a position relatively far from the wearer's skin, and an absorber 23 interposed between the two sheets 21 and 22. The absorber 23 includes an absorbent core 24 capable of absorbing and holding body fluids, a liquid-permeable skin-side core wrap sheet 25 covering the skin-facing surface of the absorbent core 24, and a liquid-permeable non-skin-side core wrap sheet 26 covering the non-skin-facing surface of the absorbent core 24. These members constituting the absorbent main body 2 are integrated by known joining means such as an adhesive.

[0023] As the constituent members of the absorbent body 2, those commonly used in this type of absorbent article can be used without particular limitation. Examples of the surface sheet 21 include various non-woven fabrics and perforated films. Examples of the back sheet 22 include resin films and laminates of resin films and non-woven fabrics. The absorbent core 24 is mainly composed of a water-absorbing material. Examples of the water-absorbing material include fiber materials such as wood pulp and water-absorbing polymers, and one or more of these can be used. Examples of the core wrap sheets 25, 26 include paper and non-woven fabrics. In this embodiment, both the skin-facing surface and the non-skin-facing surface of the absorbent core 24 are covered with two core wrap sheets 25, 26, but this may also be done with one core wrap sheet. Further, the core wrap sheets 25, 26 may be omitted, that is, the absorber 23 may be composed only of the absorbent core 24.

[0024] As shown in FIG. 3, a pair of leak-proof cuffs 3, 3 that stand up on the wearer's skin side when the diaper 1 is worn are provided on both sides along the longitudinal direction X on the skin-facing surface of the absorbent body 2. The leak-proof cuff 3 includes a liquid-impermeable cuff sheet that forms the main body of the leak-proof cuff 3 and a filamentous elastic member for the cuff fixed to the cuff sheet. The cuff sheet has a strip shape extending in the longitudinal direction X in a plan view, and is fixed to other members (such as the surface sheet 21 and the outer package 4) such that the inner edge portion extending in the longitudinal direction X near the horizontal center line CLy becomes a free edge portion. The elastic member for the cuff is fixed in an extended state in the longitudinal direction X at the free edge portion of the cuff sheet. When the diaper 1 is worn, due to the contraction of the elastic member for the cuff, at least in the crotch portion M, the cuff sheet stands up with the fixing portion to other members as the standing base end so that the free edge portion of the leak-proof cuff approaches the wearer's body. By thus standing up the pair of leak-proof cuffs 3, 3, the lateral outward flow of excrement such as urine is blocked.

[0025] The outer package 4 (including the ventral outer package 4F, the crotch outer package 4M, and the dorsal outer package 4R. The same shall apply hereinafter unless otherwise specified) includes an outer layer sheet 41 that forms the outer surface of the diaper 1, an inner layer sheet 42 that forms the inner surface of the diaper 1, and filamentous torso elastic members 45 and filamentous leg elastic members 46 fixed between both sheets 41 and 42. Both sheets 41 and 42 are joined and integrated with each other by an adhesive. In FIG. 4, the region 40 with a dot pattern indicates the adhesion region. The adhesion region 40 includes a plurality of members laminated in the thickness direction Z of the diaper 1 and an adhesive such as a hot melt adhesive, and the plurality of members are joined by the adhesive. Specifically, for example, in the adhesion region 40 including the outer layer sheet 41, the inner layer sheet 42, and the torso elastic member 45 disposed between both sheets 41 and 42, these plurality of members are joined by the adhesive.

[0026] In this embodiment, the outer layer sheet 41 has a longer length in the longitudinal direction X than the inner layer sheet 42 and has an extension portion that extends outward in the longitudinal direction X from one end of the inner layer sheet 42 in the longitudinal direction X. The extension portion of the outer layer sheet 41 is folded back to the skin-facing surface side of the inner layer sheet 42 to form a folded-back portion 41F. The folded-back portion 41F forms the waist end portion 6 of the torso portion 5 that defines the waist opening WH. At the waist end portion 6, there is a two-layer structure of the outer layer sheet 41 formed by the folded-back portion 41F and the outer layer sheet 41 disposed opposite thereto.

[0027] As the outer layer sheet 41 and the inner layer sheet 42, those used as the sheet materials constituting the exterior body in this type of absorbent article can be used without particular limitation, and for example, nonwoven fabrics produced by various manufacturing methods can be used. Both sheets 41 and 42 may each be a stretch sheet having elasticity in the lateral direction Y, or may be a non-stretch sheet having no elasticity. As an example of the stretch sheet, a "stretch sheet formed by joining a plurality of elastic filaments arranged to extend in one direction without intersecting each other to a stretchable nonwoven fabric containing inelastic fibers in a substantially non-extended state" described in JP-A-2009-61743 (hereinafter also referred to as "specific stretch sheet") can be exemplified. For example, the outer layer sheet 41 can be the specific stretch sheet and the inner layer sheet 42 can be a non-stretch sheet. In the present embodiment, both sheets 41 and 42 have no elasticity.

[0028] A plurality of body circumferential elastic members 45 are arranged in the body circumferential portion 5 (ventral exterior body 4F and dorsal exterior body 4R). The plurality of body circumferential elastic members 45 extend in the lateral direction Y between a pair of side seal portions S, S and are intermittently arranged in the longitudinal direction X. The body circumferential elastic member 45 is fixed in a state of being extended in the lateral direction Y on at least one surface of the outer layer sheet 41 and the inner layer sheet 42 which are the sheet materials constituting the body circumferential portion 5, has elastic stretchability in the lateral direction Y, and is contracted in a natural state (a state where no external force is applied). In the worn state of the diaper 1, due to the contraction of the body circumferential elastic member 45, a plurality of folds (gathers) extending in a direction intersecting the extending direction (lateral direction Y) of the body circumferential elastic member 45 are formed on the surfaces (skin-facing surface and non-skin-facing surface) of the body circumferential portion 5.

[0029] The body circumferential portion 5 has elasticity in the lateral direction Y due to the elastic stretchability of the body circumferential elastic member 45, excluding the arrangement region of the absorbent core 24 (the region overlapping the projection of the absorbent core 24 in the thickness direction in the body circumferential portion 5). In the arrangement region of the absorbent core 24 in the body circumferential portion 5, the body circumferential elastic member 45 is processed so that the elastic stretchability of the body circumferential elastic member 45 does not appear, such as being divided.

[0030] The leg-around elastic member 46 is arranged so as to surround the opening edges of the pair of leg openings LH, LH. Specifically, as shown in FIG. 3, the leg-around elastic member 46 extends from the inner ends in the longitudinal direction X of the ventral outer body 4F and the dorsal outer body 4R (the ends in the longitudinal direction X near the longitudinal center line CLx) to the vicinity of the longitudinal center line CLx, and is arranged along the side edges of the crotch outer body 4M. The leg-around elastic member 46 is fixed in a stretched state to the sheet materials (such as the outer layer sheet 41 and the inner layer sheet 42) constituting its arrangement site, and is contracted in its natural state. In the state of wearing the diaper 1, due to the contraction of the leg-around elastic member 46, a plurality of folds (leg gathers) are formed on the entire circumference of the opening edge of the leg opening LH.

[0031] As shown in FIGS. 3 and 4, the diaper 1 of the present embodiment includes an auxiliary sheet 43 that forms the skin-facing surface of the body-around portion 5. The auxiliary sheet 43 extends in the longitudinal direction X from the waist end 6 that defines the waist opening WH of the diaper 1 to a position inward in the longitudinal direction X from the longitudinal end 24X of the absorbent core 24, and extends in the lateral direction Y over the entire length in the lateral direction Y of the ventral outer body 4F and the dorsal outer body 4R, respectively. Also, as described above, a folded-back portion 41F of the outer layer sheet 41 exists at the waist end 6, thereby forming a two-layer structure of the outer layer sheet 41. A part of the auxiliary sheet 43 is interposed between the two layers of the outer layer sheet 41, 41 that constitute the two-layer structure. Also, a body-around elastic member 45 is arranged between the outer layer sheet 41 (the outer layer sheet 41 that forms the outermost layer of the diaper 1) that is not the folded-back portion 41F of the two layers of the outer layer sheet 41, 41 and the auxiliary sheet 43. The auxiliary sheet 43 is fixed to other members (such as the outer layer sheet 41, the inner layer sheet 42, and the surface sheet 21) that come into contact with it by known joining means such as an adhesive or heat fusion.

[0032] Except for the portion disposed at the folding portion 41F, the auxiliary sheet 43 has a sweat-absorbing function in that it can come into contact with the wearer's skin in the worn state of the diaper 1, and thus can absorb and hold the sweat excreted from the skin by contacting the wearer's skin. As the auxiliary sheet 43, a sheet material having a sweat-absorbing function can be used, for example, a non-woven fabric.

[0033] As shown in FIG. 2, the diaper 1 of the present embodiment includes a disposal tape 47. The disposal tape 47 is fixed to the non-skin-facing surface of the outer layer sheet 41 of the back outer body 4R that forms the outer surface of the back side portion R of the diaper 1. The disposal tape 47 is used to maintain the rolled-up state of the used diaper 1 after rolling up the used diaper 1. The disposal tape 47 has a long strip shape in the longitudinal direction X, and the unused disposal tape 47 shown in FIG. 2 is in a folded state. The disposal tape 47 is configured in the same manner as the disposal tape in this type of disposable diaper.

[0034] Hereinafter, the body circumferential portion 5, which is a main characteristic portion of the diaper 1, will be described in detail. The body circumferential portion 5 has a waist end portion 6 that defines a waist opening WH and has elasticity in the lateral direction Y, and a waist end adjacent region 7 that is adjacent to the waist end portion 6 in the longitudinal direction X. The waist end portion 6 of the body circumferential portion 5 (ventral body circumferential portion 5) including the ventral outer body 4F and the waist end portion 6 of the body circumferential portion 5 (dorsal body circumferential portion 5) including the dorsal outer body 4R are at the same position in the longitudinal direction X. The waist end adjacent region 7 of the ventral body circumferential portion 5 and the waist end adjacent region 7 of the dorsal body circumferential portion 5 are at the same position in the longitudinal direction X. The waist end portion 6 includes an "elastic member fixed to the surface of the sheet material constituting the body circumferential portion 5 and stretchable in the lateral direction Y" (hereinafter, also referred to as a "specific elastic member"), whereas the waist end adjacent region 7 does not include the specific elastic member and is a non-arrangement region of the specific elastic member. In the present embodiment, the specific elastic member is the body circumferential elastic member 45. The body circumferential elastic member 45 is an elastic member that is fixed to at least one surface of the outer layer sheet 41 and the inner layer sheet 42, which are sheet materials constituting the body circumferential portion 5, and is stretchable in the lateral direction Y.

[0035] As is clear from the description of "fixed to the surface of the sheet material", the specific elastic member is separate from the sheet material constituting the body circumferential portion 5 and is typically fixed to the surface of the sheet material with an adhesive. Therefore, by eliminating the adhesive, the specific elastic member can be separated from the sheet material. In the present invention, as the sheet material constituting the body circumferential portion 5, a stretchable sheet formed by laminating an elastic filament and a nonwoven fabric, such as the specific stretchable sheet, can be used. In that case, the elastic filament is not a specific elastic member. Since the elastic filament is a constituent member of the stretchable sheet that is the sheet material and is integrally inseparable from the stretchable sheet, it is not "fixed to the surface of the sheet material".

[0036] A plurality of body circumferential elastic members 45 (specific elastic members) are arranged at equal intervals in the longitudinal direction X at the waist end portion 6. On the other hand, the length in the longitudinal direction X of the region adjacent to the waist end portion 7, that is, the length in the longitudinal direction X of the region where the body circumferential elastic members 45 are not arranged, is longer than the interval in the longitudinal direction X between the body circumferential elastic members 45 at the waist end portion 6. Therefore, when observing the body circumferential portion 5 in order from the waist opening WH toward the leg opening LH, the region where the interval first becomes longer is the region adjacent to the waist end portion 7. The region adjacent to the waist end portion 7 is typically the region where the interval between the body circumferential elastic members 45 adjacent to each other in the longitudinal direction X in the body circumferential portion 5 is the widest.

[0037] Since the waist end adjacent region 7 does not include a specific elastic member, when a non-elastic sheet such as the outer layer sheet 41 and the inner layer sheet 42 of the present embodiment is used as the sheet material constituting the body circumference portion 5, the waist end adjacent region 7 is a non-elastic region that does not have elasticity in the lateral direction Y. On the other hand, when a sheet material having elasticity in the lateral direction Y such as the specific elastic sheet is used as the sheet material constituting the body circumference portion 5, the waist end adjacent region 7 has elasticity in the lateral direction Y, but the elongation stress of the waist end adjacent region 7 in the lateral direction Y is lower than that of the waist end 6 including the specific elastic member. That is, regardless of whether the sheet material constituting the body circumference portion 5 has elasticity in the lateral direction Y, between the waist end 6 and the waist end adjacent region 7 adjacent thereto, with respect to the elongation stress in the lateral direction Y, the magnitude relationship of waist end 6 > waist end adjacent region 7 is established.

[0038] The absorbent core 24 is not disposed in the waist end 6 and the waist end adjacent region 7. In other words, as shown in FIG. 3, in the body circumference portion 5 of each of the ventral side portion F and the dorsal side portion R, the waist end 6 and the waist end adjacent region 7 are located outside the longitudinal end 24X of the absorbent core 24 and its virtual extension line in the longitudinal direction X.

[0039] The diaper 1 is characterized in having the following configurations A to C. · Configuration A: The body circumference portion 5 has a waist end adjacent region 7 that does not include a specific elastic member at a position adjacent in the longitudinal direction X to a waist end 6 that includes a specific elastic member (body circumference elastic member 45) and has elasticity in the lateral direction Y. · Configuration B: The ventral side outer body 4F has a greater elongation stress in the lateral direction Y of the waist end 6 than the dorsal side outer body 4R. · Configuration C: In the natural state of the diaper 1, that is, in a state where no external force acts on the diaper 1, the waist end 6 has a shorter total length in the body circumference direction than other regions in the body circumference portion 5 other than the waist end 6. In other words, in the natural state of the diaper 1, the total length of the waist end 6 in the body circumference direction is shorter than the maximum length of the total length of other regions in the body circumference portion 5 in the body circumference direction.

[0040] When the diaper 1 is worn, a large number of wrinkles are generated on the skin-facing surface of the outer body 4 that constitutes the torso circumference portion 5 due to the contraction of the specific elastic member (torso circumference elastic member 45) in the lateral direction Y. In particular, the dorsal outer body 4R that constitutes the dorsal torso circumference portion 5 is likely to have concentrated body pressure when the wearer is in a lying or sitting position, so the wrinkles generated on the dorsal outer body 4R can cause bedsores. In particular, the dorsal waist end portion 6 and the area adjacent to the waist end portion 7 are areas where the absorbent core 24 that can function as a cushion for dispersing the body pressure of the wearer is not arranged. Therefore, the part of the wearer's skin that comes into contact with the absorbent core non-arrangement area is easily affected by the wrinkles generated in the absorbent core non-arrangement area, and there is a concern about the occurrence of bedsores. However, in the diaper 1, the above configuration A is adopted, and since the specific elastic member that is the cause of wrinkle generation is excluded from the area adjacent to the waist end portion 7, wrinkles are less likely to occur in the area adjacent to the waist end portion 7 and its vicinity. In addition, in the diaper 1, the above configuration B is adopted. Regarding the elongation stress in the lateral direction Y of the waist end portion 6, as shown in FIG. 5, the elongation stress Ff of the ventral outer body 4F > the elongation stress Fr of the dorsal outer body 4R. Therefore, the force for pulling the side seal portion S toward the ventral outer body 4F side is greater than the force for pulling the side seal portion S toward the dorsal outer body 4R side. As a result, the degree of contraction of the ventral outer body 4F in the lateral direction Y is greater than that of the dorsal outer body 4R. As a result, the occurrence situation of the wrinkle C on the surface of the torso circumference portion 5 is that there are relatively many on the ventral outer body 4F and relatively few on the dorsal outer body 4R. Such asymmetric elongation characteristics between the ventral and dorsal sides of the torso circumference portion are not seen in conventional general pants-type disposable diapers. In a conventional pants-type disposable diaper, as represented by the diaper 1Z shown in FIG. 6, since the elongation stress Ff of the ventral outer body 4F = the elongation stress Fr of the dorsal outer body 4R, the force for pulling the side seal portion S toward the dorsal outer body 4R side is the same as the force for pulling it toward the ventral outer body 4F side. Therefore, the occurrence situation of the wrinkle C on the surface of the torso circumference portion 5 is the same for both the ventral outer body 4F and the dorsal outer body 4R. Thus, the above-described Configurations A and B have the effect of suppressing the generation of wrinkles in the non-disposed area of the absorbent core 24 in the dorsal body circumferential part 5 (dorsal exterior body 4R), and contribute to the prevention of bedsores. On the other hand, by adopting the above-described Configurations A and B, there is a concern that the constriction of the wearer's body by the body circumferential part 5 becomes weaker than before their adoption, and the fit of the body circumferential part 5 deteriorates. In particular, introducing the waist end adjacent area 7 that does not contain a specific elastic member in the body circumferential part 5 can strengthen such a concern. However, in the diaper 1, the above-described Configuration C is adopted, and since the total length in the body circumferential direction of the waist end 6 in the natural state of the diaper 1 is shorter than that of the other areas of the body circumferential part 5 including the waist end adjacent area 7, the fit of the waist end 6 is higher than that of conventional pants-type disposable diapers of this kind. Therefore, even if the other areas of the body circumferential part 5 other than the waist end 6 are slightly inferior in fit, an excellent fit feeling can be obtained for the entire body circumferential part 5. As is clear from the above description, the diaper 1 having the above-described Configurations A to C can achieve both high-level prevention of bedsores and fit.

[0041] From the viewpoint of more surely achieving the action and effect of the above-described Configuration B, the ratio of the elongation stress in the lateral direction Y of the waist end 6 of the ventral exterior body 4F to that of the dorsal exterior body 4R is, on the premise that the former > the latter, the former / the latter, preferably 1.1 or more, more preferably 1.2 or more, and preferably 2.0 or less, more preferably 1.9 or less. On the premise that the elongation stress in the lateral direction Y of the waist end 6 of the ventral exterior body 4F is larger than that of the dorsal exterior body 4R, it is preferably 13.8 cN / mm or more, more preferably 14.0 cN / mm or more, and preferably 20.0 cN / mm or less, more preferably 19.0 cN / mm or less. On the premise that the elongation stress in the lateral direction Y of the waist end 6 of the dorsal exterior body 4R is smaller than that of the ventral exterior body 4F, it is preferably 12.0 cN / mm or more, more preferably 12.2 cN / mm or more, and preferably 13.6 cN / mm or less, more preferably 13.5 cN / mm or less.

[0042] The "elongation stress" is the load required to elongate each part of the body circumferential part 5 (for example, the waist end part 6) by a certain length along its expansion and contraction direction (lateral direction Y). The larger the value of the elongation stress, the more difficult it is for the corresponding part to elongate. The elongation stress is measured by the following method. The elongation stress in the lateral direction Y of each part of the body circumferential part 5 can be adjusted by appropriately adjusting the type, thickness, and arrangement (number of arrangements, arrangement intervals, etc.) of the elastic members (body circumferential elastic members 45) that can expand and contract in the lateral direction Y arranged in the corresponding part.

[0043] <Measurement method of elongation stress> Taking the case where the measurement target disposable absorbent article is the above-mentioned diaper 1 as an example for explanation. First, separate the ventral outer body 4F and the dorsal outer body 4R joined at the side seal part S, unfold the diaper 1 and expand it into a planar shape, and cut out a measurement target area along a straight line parallel to the lateral direction Y of the diaper 1 to obtain a measurement sample. For example, when the measurement target area is the waist end part 6, referring to FIG. 3, in the longitudinal direction X, with the longitudinal end 1X (the opening end of the waist opening WH) of the diaper 1 as the upper end, and among the elastic members 45 located between the longitudinal end 1X and the waist end adjacent area 7, a virtual straight line extending in the lateral direction Y passing through a position 2 mm away from the elastic member 45 closest to the waist end adjacent area 7 toward the waist end adjacent area 7 side is used as the lower end, and a quadrangular area in plan view is cut out from the diaper 1 to obtain a measurement sample of the waist end part 6. Before measuring the elongation stress, measure the length in the direction corresponding to the lateral direction Y and the length in the direction corresponding to the longitudinal direction X of the measurement sample. Clamp both ends (side seal S or its vicinity) in the longitudinal direction of the measurement sample (lateral direction Y of diaper 1) to a chuck of a tensile testing machine (for example, made by Orientec Co., Ltd., Tensilon universal testing machine "RTC-1210A"). The distance between the chucks at this time shall be 100 mm. Then, extend the measurement sample at a speed of 300 mm / min until the distance between the chucks becomes 240 mm, and then perform an operation to return the distance between the chucks to 100 mm to contract the measurement sample. The tensile load (cN) at the time when the distance between the chucks is 240 mm is defined as the elongation stress of the measurement sample. The elongation stress of the measurement sample is calculated as the average elongation stress by converting it per unit length in the direction orthogonal to the tensile direction (longitudinal direction of the measurement sample) of the measurement target area (longitudinal direction X of diaper 1). For one measurement target area (for example, waist end 6), prepare three measurement samples, measure their elongation stresses, and take their average as the elongation stress in the lateral direction Y of the measurement target area.

[0044] Regarding the Configuration B, as an example of a method for establishing a relationship of ventral outer body 4F > dorsal outer body 4R for the elongation stress in the lateral direction Y of the waist end 6, instead of making the elongation rate of a specific elastic member (waist circumference elastic member 45) at the waist end 6 the same between the ventral outer body 4F and the dorsal outer body 4R, a method (Method B1) is provided to establish a relationship of ventral outer body 4F > dorsal outer body 4R for the number per unit length in the longitudinal direction X of the specific elastic member (for example, the number per 30 mm in length in the longitudinal direction X). As another example of the method, instead of making the number per unit length in the longitudinal direction X of the specific elastic member at the waist end 6 the same between the ventral outer body 4F and the dorsal outer body 4R, a method (Method B2) is provided to establish a relationship of ventral outer body 4F > dorsal outer body 4R for the elongation rate of the specific elastic member.

[0045] In this embodiment, Method B1 is adopted. As shown in FIG. 4, the ventral outer body 4F has a greater number per unit length in the longitudinal direction X of the waist circumference elastic member 45 (specific elastic member) at the waist end 6 than the dorsal outer body 4R. The ratio of the number per unit length in the longitudinal direction X of the body circumference elastic member 45 at the waist end 6 of the ventral outer body 4F to the number per unit length in the longitudinal direction X of the body circumference elastic member 45 at the waist end 6 of the dorsal outer body 4R is, on the premise that the former > the latter, expressed as the former / latter, preferably 1.1 or more, more preferably 1.2 or more, and preferably 2.0 or less, more preferably 1.9 or less. On the premise that the number per unit length in the longitudinal direction X of the body circumference elastic member 45 at the waist end 6 of the ventral outer body 4F is more than that of the dorsal outer body 4R, it is preferably 6 pieces / 30 mm or more, more preferably 7 pieces / 30 mm or more, and preferably 12 pieces / 30 mm or less, more preferably 10 pieces / 30 mm or less. On the premise that the number per unit length in the longitudinal direction X of the body circumference elastic member 45 at the waist end 6 of the dorsal outer body 4R is less than that of the ventral outer body 4F, it is preferably 4 pieces / 30 mm or more, more preferably 5 pieces / 30 mm or more, and preferably 9 pieces / 30 mm or less, more preferably 8 pieces / 30 mm or less.

[0046] From the viewpoint of more surely achieving the operational effects of the said configuration C, the ratio of the total length in the body circumference direction of the waist end 6 in the natural state of the diaper 1 to the maximum length of the total length in the body circumference direction of the other regions of the body circumference part 5 in the same state is, on the premise that the former < the latter, expressed as the former / latter, preferably 0.4 or more, more preferably 0.5 or more, and preferably 0.9 or less, more preferably 0.8 or less. On the premise that the total length in the body circumference direction of the waist end 6 in the natural state of the diaper 1 is shorter than the maximum length of the total length in the body circumference direction of the other regions of the body circumference part 5 in the same state, it is preferably 180 mm or more, more preferably 190 mm or more, and preferably 270 mm or less, more preferably 260 mm or less.

[0047] Regarding the above-described configuration C, as an example of a method for making the total length in the circumferential direction of the waist end portion 6 in the natural state of the diaper 1 the shortest in the circumferential portion 5, instead of making the elongation rate of a specific elastic member (the circumferential elastic member 45) the same between the waist end portion 6 and other regions of the circumferential portion 5, there is a method of establishing a magnitude relationship between the waist end portion 6 and other regions with respect to the number per unit length in the longitudinal direction X of the specific elastic member. As another example of the above-described method, instead of making the number per unit length in the longitudinal direction X of the specific elastic member the same between the waist end portion 6 and other regions of the circumferential portion 5, there is a method of establishing a magnitude relationship between the waist end portion 6 and other regions with respect to the elongation rate of the specific elastic member. The total length in the circumferential direction of each part of the circumferential portion 5 can be measured using a ruler, a measuring tape, or the like.

[0048] In the unfolded and maximum elongation state of the diaper 1, the length in the longitudinal direction X of the waist end portion 6 is preferably 20 mm or more, more preferably 25 mm or more, and preferably 45 mm or less, more preferably 40 mm or less. In the unfolded and maximum elongation state of the diaper 1, the length in the longitudinal direction X of the region adjacent to the waist end 7 is preferably 18 mm or more, more preferably 20 mm or more, and preferably 60 mm or less, more preferably 55 mm or less.

[0049] Of the two longitudinal ends of the waist end portion 6 in the longitudinal direction X, the outer end in the longitudinal direction X (the end in the longitudinal direction X farthest from the longitudinal center line CLx) is the longitudinal end 1X of the diaper 1, and the inner end in the longitudinal direction X (the end in the longitudinal direction X closest to the longitudinal center line CLx) is the boundary with the waist end adjacent region 7. Therefore, the "length in the longitudinal direction X of the waist end portion 6 in the unfolded and maximum extended state of the diaper 1" can be measured by measuring the length along the longitudinal direction X between the outer end and the inner end in the same state. Here, as described above, the waist end adjacent region 7 is the region where the interval in the longitudinal direction X between specific elastic members (the body circumference elastic members 45) first becomes long when observing the body circumference portion 5 in order from the waist opening WH to the leg opening LH. Therefore, the boundary between the waist end portion 6 and the waist end adjacent region 7 (the inner end in the longitudinal direction X of the waist end portion 6) is a specific elastic member that is located closer to the waist opening WH than the region and adjacent to the region. Also, as described above, the waist end adjacent region 7 is the region where the interval first becomes long when observing the body circumference portion 5 in order from the waist opening WH to the leg opening LH. Therefore, the "length in the longitudinal direction X of the waist end adjacent region 7 in the unfolded and maximum extended state of the diaper 1" can be measured by measuring the length along the longitudinal direction X of the region in the same state.

[0050] In the present embodiment, the body circumference portion 5 has a non-arrangement region of a specific elastic member (the body circumference elastic member 45) separately from the waist end adjacent region 7. Specifically, as shown in FIG. 4, the ventral outer body 4F (the ventral body circumference portion 5) and the dorsal outer body 4R (the dorsal body circumference portion 5) each have, in order from the waist opening WH to the leg opening LH, a waist end portion 6, a waist end adjacent region 7, an intermediate portion 8, an intermediate portion adjacent region 9, and a crotch end portion 10. Here, the waist end portion 6, the intermediate portion 8, and the crotch end portion 10 all include the body circumference elastic member 45, while the waist end adjacent region 7 and the intermediate portion adjacent region 9 do not include the body circumference elastic member 45 and are non-arrangement regions of the specific elastic member. In this way, since the presence of a plurality of non-arrangement regions of the specific elastic member in the body circumferential portion 5 more effectively suppresses the generation of wrinkles that cause pressure sores on the surface of the body circumferential portion 5, the pressure sore prevention effect can be further improved.

[0051] The middle part 8 of the ventral body circumferential portion 5 and the middle part 8 of the dorsal side are in the same position in the longitudinal direction X. The middle part adjacent region 9 of the ventral body circumferential portion 5 and the middle part adjacent region 9 of the dorsal body circumferential portion 5 are in the same position in the longitudinal direction X. The lower thigh side end portion 10 of the ventral body circumferential portion 5 and the lower thigh side end portion 10 of the dorsal body circumferential portion 5 are in the same position in the longitudinal direction X.

[0052] The body circumferential elastic member 45 is disposed between the outer layer sheet 41 and the auxiliary sheet 43 at the waist end portion 6, and is disposed between the outer layer sheet 41 and the inner layer sheet 42 at the lower thigh side end portion 10, while at the middle part 8, it is disposed between the inner layer sheet 42 and the auxiliary sheet 43. The extension stress in the lateral direction Y of each of the middle part 8 and the lower thigh side end portion 10 can be appropriately set within a range that does not inhibit the diaper 1 from having the configuration C.

[0053] In the middle part 8, a plurality of circumferential elastic members 45 are arranged at equal intervals in the vertical direction X. On the other hand, the length in the vertical direction X of the region adjacent to the middle part 9, that is, the region located closer to the leg opening LH (vertical center line CLx) than the middle part 8 and where the circumferential elastic members 45 are not arranged, is longer than the interval in the vertical direction X between the circumferential elastic members 45 in the middle part 8. Therefore, when observing the circumferential part 5 in order from the waist opening WH toward the leg opening LH, the region where the interval first becomes long (waist end adjacent region 7), the region where the interval becomes narrow (middle part 8) are confirmed in this order, and then the region where the interval becomes wide is the middle part adjacent region 9. The length in the vertical direction X of the middle part adjacent region 9 in the unfolded and maximum stretched state of the diaper 1 is shorter than the length in the vertical direction X of the waist end adjacent region 7 in the same state. The middle part adjacent region 9 is a part where wrinkles that cause bedsores are relatively likely to occur on the surface due to including the overlapping part with the absorbent core 24. However, due to the establishment of such a size relationship with the waist end adjacent region 7, the generation of wrinkles can be more effectively suppressed.

[0054] In the present embodiment, as shown in FIG. 4, in the waist end adjacent region 7 and the middle part adjacent region 9, which are non-arrangement regions of the specific elastic member (circumferential elastic member 45), there are non-adhesive regions 44 where no adhesive is applied between two opposing sheet materials. The "two opposing sheet materials" may be any sheet materials existing in a region that overlaps with the non-arrangement region of the specific elastic member in a plan view, and the position in the thickness direction is not limited. In the present embodiment, the "two opposing sheet materials" are the outer layer sheet 41 and the inner layer sheet 42. The non-adhesive region 44 is a region where no adhesive is applied, and in the non-adhesive region 44, the two opposing sheet materials (the outer layer sheet 41 and the inner layer sheet 42 in the present embodiment) are not joined. In the present embodiment, between the outer layer sheet 41 and the inner layer sheet 42, which are the "two opposing sheet materials", an adhesive region 40 and a non-adhesive region 44 are mixed, and the two sheets 41 and 42 are joined at the adhesive region 40. Next, since the adhesion region 40 is harder than the region where the adhesive is not applied, there is a risk of causing pressure sores if the adhesion region 40 exists particularly in a region where body pressure tends to concentrate. On the other hand, in the present embodiment, since the non-adhesion region 44 is arranged in the non-arrangement region of the specific elastic member, the non-arrangement region of the specific elastic member has few wrinkles and maintains the original flexibility of the sheet material, and the pressure sore prevention effect is further enhanced. The non-adhesion region 44 may be the entirety of each of the waist end adjacent region 7 and the middle part adjacent region 9, or may be only a part thereof. Typically, the non-adhesion region 44 exists over the entire length in the lateral direction Y of the portion sandwiched between the pair of side seal portions S, S in the waist end adjacent region 7 and / or the middle part adjacent region 9.

[0055] The present invention can be applied to disposable diapers in general. The "absorbent article" referred to here includes articles used for absorbing body fluids (urine, soft feces, menstrual blood, sweat, etc.) discharged from the human body, and is not limited to the disposable diapers of the above-described embodiment.

[0056] As described above, the present invention has been described based on its embodiments, but the present invention can be appropriately modified without being limited to the above-described embodiments. In the above-described embodiment, the outer body 4 is in a form in which the ventral outer body 4F, the crotch outer body 4M, and the dorsal outer body 4R are integrated and continuous over the entire length in the longitudinal direction X of the diaper 1. Instead, it may be in a form in which the crotch outer body 4M is not provided and the ventral outer body 4F and the dorsal outer body 4R are arranged apart from each other in the longitudinal direction X. In that case, the absorbent main body 2 is fixed by spanning between the two outer bodies 4F, 4R.

Explanation of Reference Numerals

[0057] 1 Disposable diaper (pants-type absorbent article) 24 Absorbent core 4 Outer body 4F Ventral outer body 4M Crotch outer body 4R Dorsal outer body 40 Adhesion region 41 Outer layer sheet 42 Inner layer sheet 43 Auxiliary sheet 44 Non - adhesive area 45 Circumferential elastic member 5 Circumferential part 6 Waist end 7 Area adjacent to the waist end 8 Middle part 9 Area adjacent to the middle part 10 Lower crotch end X Longitudinal direction Y Transverse direction WH Waist opening LH Leg opening

Claims

1. An absorbent article comprising an absorbent core and an outer cover disposed on the non-skin-facing side of the absorbent core, wherein the outer cover includes a ventral outer cover disposed on the ventral side of the wearer and a dorsal outer cover disposed on the dorsal side of the wearer, having a longitudinal direction extending from the ventral outer cover toward the dorsal outer cover, a transverse direction orthogonal to the longitudinal direction, and a body circumferential direction along the body circumference of the wearer during wearing, a pair of side regions of the ventral outer cover and side regions of the dorsal outer cover are joined to form an annular body circumferential portion, a waist opening, and a pair of leg openings disposed around the body circumference of the wearer, which is a pant-type absorbent article, wherein the body circumferential portion has a waist end portion that defines the waist opening and has elasticity in the transverse direction, and a waist end adjacent region adjacent to the waist end portion in the longitudinal direction, wherein the waist end portion is fixed to the surface of the sheet material constituting the body circumferential portion and includes an elastic member that is stretchable in the transverse direction, and the waist end adjacent region is a region where the elastic member is not disposed, wherein the absorbent core is not disposed in the waist end portion and the waist end adjacent region, wherein the ventral outer cover has a greater transverse elongation stress in the waist end portion than the dorsal outer cover, wherein in the natural state of the pant-type absorbent article, the waist end portion has a shorter total length in the body circumferential direction than other regions of the body circumferential portion other than the waist end portion, which is a pant-type absorbent article.

2. The pant-type absorbent article according to claim 1, wherein the ventral outer cover has a greater number of the elastic members per unit length in the longitudinal direction in the waist end portion than the dorsal outer cover.

3. The pant-type absorbent article according to claim 1 or 2, wherein the body circumferential portion has a region where the elastic member is not disposed, separate from the waist end adjacent region.

4. The pant-type absorbent article according to claim 1 or 2, wherein there is a non-adhesive region in the region where the elastic member is not disposed, where no adhesive is applied between two opposing sheet materials.

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