Disposable diapers

Abstract

To provide a disposable diaper in which an absorbent sheet adheres closely to the wearer's skin and absorbency is improved. [Solution] A disposable diaper (10) has an absorbent sheet (70) arranged in a first waist region, which is one of the front and rear waist regions, and a side joint portion (60). The first waist region has a first region (R1) that extends in the width direction from one outer edge of the first waist region to the other outer edge and that extends in the longitudinal direction from the inner edge of the absorbent sheet to the outer edge of the absorbent sheet. A second waist region, which is the other of the front and rear waist regions, has a second region (R2) that is contiguous with the first region in the width direction and extends in the width direction from one outer edge of the second waist region to the other outer edge. The contractile force in the width direction of the first region is lower than the contractile force in the width direction of the second region.

Description

[Technical Field]

[0001] The present invention relates to a disposable diaper having a water-absorbent sheet. [Background technology]

[0002] Disposable diapers with an absorbent core and a separate absorbent sheet are known. The absorbent sheet is disposed on the skin-facing side of the waist region, which comes into contact with the wearer's skin. Therefore, the absorbent sheet comes into contact with the skin when worn and absorbs sweat. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2009-148531 Summary of the Invention

[0004] Absorbent sheets absorb sweat by coming into contact with the skin. Therefore, if the absorbent sheet is separated from the skin, the absorbency of the absorbent sheet for body fluids will decrease, and the absorbent sheet may not be able to fully function.

[0005] Therefore, there is a demand for a disposable diaper in which the absorbent sheet can be closely attached to the wearer's skin, thereby improving absorbency.

[0006] A disposable diaper according to one embodiment has a longitudinal direction and a width direction which are perpendicular to each other, a front waist region, a rear waist region, and a crotch region disposed between the front waist region and the rear waist region, an absorbent body disposed at least in the crotch region, a water-absorbent sheet disposed in a first waist region which is one of the front waist region and the rear waist region, a liquid-impermeable backsheet disposed on the non-skin-facing side of the water-absorbent sheet, and a side joining portion joining an outer edge portion of the front waist region to an outer side portion of the rear waist region, The first waist region has a first region that extends in the width direction from one outer edge of the first waist region to the other outer edge and that extends in the longitudinal direction from the inner edge of the absorbent sheet to the outer edge of the absorbent sheet, and the second waist region, which is the other of the front waist region and the rear waist region, is continuous with the first region in the width direction and has a second region that extends in the width direction from one outer edge of the second waist region to the other outer edge, and the contractile force in the width direction of the first region is lower than the contractile force in the width direction of the second region.

[0007] A disposable diaper according to another embodiment has a longitudinal direction and a width direction which are perpendicular to each other, a front waist region, a rear waist region, and a crotch region disposed between the front waist region and the rear waist region, an absorbent body disposed at least in the crotch region, an absorbent sheet disposed in a first waist region which is one of the front waist region and the rear waist region, a liquid-impermeable backsheet disposed on the non-skin-facing side of the absorbent sheet, and side joining portions joining outer sides of the front waist region and the rear waist region. When the disposable diaper, in which the second waist region, which is the other of the front waist region and the rear waist region, and the first waist region are continuous in the width direction, is worn on a tubular body so that the length is 77% of the stretched state, the ratio of the length between the side joints of the first waist region to the length between the side joints of the second waist region in the worn state is higher than the ratio of the length between the side joints of the first waist region to the length between the side joints of the second waist region in the stretched state. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a front view of a disposable diaper according to an embodiment. [Figure 2] 2 is a plan view of the disposable diaper shown in FIG. 1, viewed from the skin-facing side. [Figure 3] 2 is a plan view of the disposable diaper shown in FIG. 1, viewed from the non-skin-facing side. [Figure 4] FIG. 3 is a cross-sectional view taken along the line AA shown in FIG. [Figure 5] FIG. 3 is a cross-sectional view taken along line BB shown in FIG. [Figure 6] FIG. 2 is a cross-sectional view taken along line CC shown in FIG. [Figure 7] FIG. 2 is a cross-sectional view taken along line DD shown in FIG. [Figure 8] FIG. 2 is a cross-sectional view taken along line EE shown in FIG. [Figure 9] 2 is a diagram showing a state in which the disposable diaper shown in FIG. 1 is attached to a cylindrical body. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] (1) Overview of the embodiment At least the following matters will become clear from the description of this specification and the accompanying drawings. A disposable diaper according to one embodiment has a longitudinal direction and a width direction which are perpendicular to each other, a front waist region, a rear waist region, and a crotch region disposed between the front waist region and the rear waist region, an absorbent body disposed at least in the crotch region, a water-absorbent sheet disposed in a first waist region which is one of the front waist region and the rear waist region, a liquid-impermeable backsheet disposed on the non-skin-facing side of the water-absorbent sheet, and side joining portions joining outer sides of the front waist region and the rear waist region, The first waist region has a first region that extends in the width direction from one outer edge of the first waist region to the other outer edge and that extends in the longitudinal direction from the inner edge of the absorbent sheet to the outer edge of the absorbent sheet, and the second waist region, which is the other of the front waist region and the rear waist region, is continuous with the first region in the width direction and has a second region that extends in the width direction from one outer edge of the second waist region to the other outer edge, and the contractile force in the width direction of the first region is lower than the contractile force in the width direction of the second region.

[0010] According to this aspect, when the first and second regions contract, the first region is pulled toward the second region, reducing wrinkles in the first region and allowing the first region to adhere more closely to the skin. This allows the absorbent sheet to adhere more closely to the skin, improving the absorbency of body fluids such as sweat.

[0011] According to another aspect, there is provided a disposable diaper having longitudinal and width directions perpendicular to each other, a front waist region, a rear waist region, and a crotch region disposed between the front waist region and the rear waist region, an absorbent body disposed at least in the crotch region, an absorbent sheet disposed in a first waist region which is one of the front waist region and the rear waist region, a liquid-impermeable back sheet disposed on the non-skin-facing side of the absorbent sheet, and side joining portions joining outer sides of the front waist region and the rear waist region, When the disposable diaper, in which the second waist region, which is the other of the front waist region and the rear waist region, and the first waist region are continuous in the width direction, is worn on a tubular body so that the length is 77% of the stretched state, the ratio of the length between the side joints of the first waist region to the length between the side joints of the second waist region in the worn state is higher than the ratio of the length between the side joints of the first waist region to the length between the side joints of the second waist region in the stretched state.

[0012] According to this aspect, when the garment is worn in a contracted state compared to the stretched state, the ratio of the length between the side seams of the first waist region to the length between the side seams of the second waist region is higher. Therefore, the first waist region moves toward the second waist region when contracting from the stretched state to the worn state. This results in fewer wrinkles than the second waist region, making it easier to fit closely to the skin. This allows the absorbent sheet to fit closely to the skin, improving the absorption of body fluids such as sweat.

[0013] According to one preferred embodiment, the first waistline region is the rear waistline region.

[0014] A wearer tends to sweat more on the back side than on the ventral side, and by locating the absorbent sheet in the rear waist area, which is worn on the back side of the wearer, sweat absorption can be further improved.

[0015] According to a preferred embodiment, the disposable diaper further comprises a tape member for disposing of the disposable diaper, the tape member being arranged to overlap at least a portion of the water-absorbent sheet when viewed in a plan view in the thickness direction.

[0016] The area of ​​the water-absorbent sheet that overlaps with the tape member is made more rigid by the tape member, which makes the water-absorbent sheet less likely to wrinkle and makes it easier to fit the water-absorbent sheet to the skin.

[0017] According to one preferred embodiment, the inner edge of the tape member is located inward in the longitudinal direction from the center of the water-absorbent sheet in the longitudinal direction.

[0018] According to this aspect, the tape member is positioned inward from the longitudinal center of the water-absorbent sheet and is easily positioned at a position corresponding to the wearer's intergluteal cleft, so that the water-absorbent sheet overlapping the tape member fits snugly into the cavity of the intergluteal cleft, improving absorbency.

[0019] According to one preferred embodiment, the inner edge of the tape member is located more inward in the longitudinal direction than the inner edge of the water-absorbent sheet.

[0020] The tape member is located inside the inner longitudinal edge of the absorbent sheet and is easily positioned in a position corresponding to the wearer's intergluteal cleft, so that the absorbent sheet overlapping the tape member fits snugly into the cavity of the intergluteal cleft, improving absorbency.

[0021] According to a preferred embodiment, the tape member overlaps the center of the rear waistband region in the width direction in a plan view in the thickness direction.

[0022] The tape member overlaps the widthwise center of the rear waist region, and easily fits into the gluteal cleft of the wearer when worn, thereby providing close contact between the absorbent sheet and the tape member, further improving absorbency.

[0023] In a preferred embodiment, the absorbent sheet has an outer region extending outward in the longitudinal direction from the outer edge of the absorbent sheet in the longitudinal direction, and an inner region extending inward in the longitudinal direction from the inner edge of the absorbent sheet in the longitudinal direction, and the widthwise contraction force of the region in which the absorbent sheet is arranged is higher than the widthwise contraction force of at least one of the outer region and the inner region.

[0024] Since the contractile force of the region where the absorbent sheet is arranged is higher than that of the outer region or the inner region, the region where the absorbent sheet is arranged easily fits to the body without floating above the wearer's skin. The absorbent sheet fitting to the body allows efficient absorption of bodily fluids, improving absorbency.

[0025] In one preferred embodiment, the contractile force in the width direction of the region where the water-absorbent sheet is disposed is higher than the contractile force in the width direction of the outer region and the contractile force in the width direction of the inner region.

[0026] According to this aspect, the region where the water-absorbent sheet is arranged fits the body better than the outer and inner regions, making it less likely for the water-absorbent sheet to lift up from the periphery of the sheet and ensuring good adhesion of the water-absorbent sheet.

[0027] According to one preferred embodiment, the first waist region has a lower contractile force in the width direction than the second waist region.

[0028] When the first waist region and the second waist region contract, the first waist region is pulled toward the second waist region, reducing wrinkles in the first waist region and allowing the first waist region to fit more closely to the skin. This allows the absorbent sheet to fit more closely to the skin, improving absorbency.

[0029] According to one preferred embodiment, the length between the outer edge of the first waist region and the outer edge of the front absorbent main body in the longitudinal direction is longer than the length between the outer edge of the second waist region and the outer edge of the front absorbent main body.

[0030] According to this aspect, the first waist region is less susceptible to the effects of the absorbent main body being compressed by the wearer's legs, making it easier to maintain the close contact of the water-absorbent sheet disposed in the first waist region.

[0031] (2) Embodiment of disposable diaper Hereinafter, a disposable diaper according to an embodiment will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the dimensional ratios and the like may differ from those of the actual product. Therefore, specific dimensions and the like should be determined with reference to the following description. Furthermore, the drawings may include parts whose dimensional relationships and ratios differ from one another.

[0032] FIG. 1 is a front view of a disposable diaper 10 according to this embodiment. FIG. 2 is a plan view of the disposable diaper 10 as viewed from the skin-facing side, and FIG. 3 is a plan view of the disposable diaper as viewed from the non-skin-facing side. FIG. 4 is a cross-sectional view taken along line AA in FIG. 2, and FIG. 5 is a cross-sectional view taken along line BB in FIG. 2. The plan views shown in FIGS. 2 and 3 show the disposable diaper in a stretched state. The stretched state in the present invention refers to a state in which the disposable diaper 10 is stretched to a state in which no wrinkles are formed with the side seam 60 (described later) unfolded. The natural state in the present invention refers to a state in which, in the case of a disposable diaper housed in a package, the disposable diaper is removed from the package and left for 24 hours in an atmosphere of 20°C±2°C and a relative humidity of 60%±5%RH.

[0033] The disposable diaper 10 has a longitudinal direction L and a width direction W that are perpendicular to each other. The longitudinal direction L is defined by the direction extending from the front side to the back side of the body. In other words, the longitudinal direction L is the direction extending from front to back when the disposable diaper 10 is laid out. The disposable diaper 10 also has a thickness direction T that is perpendicular to both the longitudinal direction L and the width direction W. The thickness direction T extends from a skin-facing side T1 that faces the wearer to a non-skin-facing side T2 that faces away from the wearer.

[0034] The disposable diaper 10 has a front waist region S1, a rear waist region S2, and a crotch region S3. The front waist region S1 faces the wearer's front waist (abdomen). The rear waist region S2 faces the wearer's rear waist (back). The crotch region S3 is located between the front waist region S1 and the rear waist region S2, between the crotch of the wearer. In this embodiment, a water-absorbent sheet 70 (described later) is disposed in the rear waist region S2. Therefore, the rear waist region S2 constitutes the first waist region, and the front waist region S1 constitutes the second waist region. In a modified example, the water-absorbent sheet 70 may be disposed in the front waist region S1, the rear waist region S2 constitutes the second waist region, and the front waist region S1 constitutes the first waist region.

[0035] The disposable diaper 10 may have a front waistline member 20, a rear waistline member 30, and an absorbent body 40. The front waistline member 20 is arranged in the front waistline region S1, and the region where the front waistline member 20 is arranged is the front waistline region. The rear waistline member 30 is arranged in the rear waistline region S2, and the region where the rear waistline member 30 is arranged is the rear waistline region. The front waistline member 20 constitutes the second waistline member of the present invention, and the rear waistline member 30 constitutes the first waistline member of the present invention. The front waistline member 20 and the rear waistline member 30 may be made of, for example, nonwoven fabric sheets. Specifically, the front waistline member 20 and the rear waistline member 30 may have a first outer nonwoven fabric sheet 35 arranged on the side closest to the skin-facing side T2 of the disposable diaper, and a second outer nonwoven fabric sheet 36 arranged on the skin-facing side T1 of the first outer nonwoven fabric sheet 35. The first exterior nonwoven fabric sheet 35 and the second exterior nonwoven fabric sheet 36 constitute the nonwoven fabric sheets of the present invention. The first exterior nonwoven fabric sheet 35 and the second exterior nonwoven fabric sheet 36 contain thermoplastic fibers. In this embodiment, the basis weight of the first exterior nonwoven fabric sheet 35 and the basis weight of the second exterior nonwoven fabric sheet 36 are each 10 g / m 2 ~35g / m 2The first outer nonwoven fabric sheet 35 and the second outer nonwoven fabric sheet 36 may be made of a spunbonded nonwoven fabric, an SMS nonwoven fabric, or a point-bonded nonwoven fabric. The first outer nonwoven fabric sheet 35 extends outward in the longitudinal direction L from the inner edge of the front waistline member 20 and the inner edge of the rear waistline member 30, and is folded back toward the skin-facing side T1 from the waist-line opening 62 as a base point. The folded-back portion 35F of the first outer nonwoven fabric sheet 35 may be disposed on the skin-facing side T1 of the disposable diaper near the waist-line opening 62 described below. The folded-back portion 35F of the first outer nonwoven fabric sheet 35 covers the outer edge of the absorbent sheet described below. A first back sheet 51 described below may be disposed between the first outer nonwoven fabric sheet 35 and the second outer nonwoven fabric sheet 36. Here, the outer edge in the present invention refers to an edge located on the outer side in the longitudinal direction L, and the inner edge refers to an edge located on the inner side in the longitudinal direction.

[0036] The disposable diaper 10 may be provided with a side joining portion 60 joining the outer side portions of the front waistline member 20 and the rear waistline member 30. The side joining portion 60 is defined by a portion where the outer side portions of the front waistline member 20 and the rear waistline member 30 are engaged with each other. Here, the "outer side portion" in the present invention refers to a portion occupying a certain range in the width direction including an edge in the width direction W, and the "outer edge" refers to an edge in the width direction. The side joining portion 60 may be located widthwise inward of the outer edge 20E of the front waistline member 20 (the outer edge of the front waistline region S1) and the outer edge 30E of the rear waistline member 30 (the outer edge of the rear waistline region S2). Specifically, the outer edge of the side joining portion 60 may be located 5 mm or more inward of the outer edge 20E of the front waistline member 20 and the outer edge 30E of the rear waistline member 30. 1, with the side seam 60 formed, the disposable diaper 10 is provided with a waist opening 62 through which the wearer's waist is inserted and a pair of leg openings 66 through which the wearer's legs are inserted. The waist opening 62 may be defined by the front edge of the front waist region S1 and the rear edge of the rear waist region S2.

[0037] 2 shows the disposable diaper 10 in an unfolded state after the side joint portions 60 have been released. The side joint portions 60 may extend along the longitudinal direction L in each of the front waistline member 20 and the rear waistline member 30. In this case, the boundary between the front waistline region S1 and the crotch region S3 may be defined by the rear end edge of the side joint portion 60 provided in the front waistline member 20. Similarly, the boundary between the rear waistline region S2 and the crotch region S3 may be defined by the front end edge of the side joint portion 60 provided in the rear waistline member 30.

[0038] The front waistline region S1 and the rear waistline region S2 may be provided with stretchable members 32 that are stretchable in the width direction W. The stretchable members 32 may be made of, for example, rubber thread that is stretchable in the width direction W, or an elastic sheet that is stretchable in the width direction W. Alternatively, the stretchable members 32 may be made of, for example, the front waistline member 20 itself and the rear waistline member 30 itself that are made of a stretchable sheet.

[0039] The contractile force in the width direction W of the front waistband region S1 constituting the second waistband region may be higher than the contractile force in the width direction W of the rear waistband region S2 constituting the first waistband region. Because the contractile force of the front waistband region S1 is higher than that of the rear waistband region S2, the outer edge of the rear waistband region S2 in the width direction W is pulled toward the front waistband region S1 when worn. This makes the outer edge of the rear waistband region in the width direction W more visible to the wearer when viewed from the front. Furthermore, when the front waistband region S1 and the rear waistband region S2 contract, the rear waistband region S2 is pulled toward the front waistband region S1. Fewer wrinkles are formed in the rear waistband region S2 than in the front waistband region S1, making the rear waistband region S2 more likely to fit snugly against the skin.

[0040] In this embodiment, the contractile force refers to the ease of shrinkage in the width direction, and can be measured as follows. First, the side seams of the disposable diaper are torn to lay the disposable diaper out in an unfolded state. The diaper is cut along the rear edge of the front waistband member and the front edge of the rear waistband member, and the crotch region is separated. This allows samples of the front waistband region and the rear waistband region to be obtained. When measuring the contractile force of the first and second regions, which will be described later, the first and second regions are cut out from the front and rear waistband regions to obtain samples of the first and second regions.

[0041] Then, for each sample, 10 mm of each widthwise end was designated as a gripping portion, and the remaining portion was designated as the remaining portion. The widthwise dimension LA (mm) of the remaining portion when unfolded without wrinkles in the longitudinal and widthwise directions (100% stretched dimension) was measured in advance. Then, the gripping portions of the sample were held by the upper and lower chucks of a tensile tester (e.g., Shimadzu Autograph AGS-X, etc.), and the space between the upper and lower chucks was widened to stretch the contracted sample in the width direction to 85% of the LA at a pulling rate of 100 mm / min. The space between the chucks was then narrowed to 70% of the LA. The force exerted in this narrowed state was designated the contraction force (N).

[0042] The disposable diaper 10 may have a tape member 80 for disposal of the disposable diaper. The tape member 80 may be arranged on the side T2 closest to the non-skin-facing surface of the disposable diaper 10. The tape member 80 may be configured to be extendable in the longitudinal direction L when disposed of compared to its state before disposal. Specifically, the tape member 80 may be folded around a fold along the width direction W as a base point. The bending rigidity of the tape member 80 in the longitudinal direction L may be higher than the bending rigidity of other components constituting the disposable diaper in the longitudinal direction, and the bending rigidity of the tape member 80 in the width direction may be higher than the bending rigidity of other components constituting the disposable diaper in the width direction.

[0043] The absorbent main body 40 may be disposed in at least the crotch region S3. The absorbent main body 40 may extend into the front waistline region S1 and the rear waistline region S2. The absorbent main body 40 may be configured as a separate body from the front waistline member 20 and the rear waistline member 30. In this case, the absorbent main body 40 may be joined to the front waistline member 20 and the rear waistline member 30 in the front waistline region S1 and the rear waistline region S2, respectively. As shown in FIG. 2 , in the longitudinal direction L, the length L12 between the outer edge of the rear waistline region and the outer edge of the absorbent main body may be longer than the length L11 between the outer edge of the front waistline region S1 and the outer edge of the absorbent main body.

[0044] The absorbent body 40 includes at least an absorbent core 45. The absorbent core 45 may contain, for example, fluff pulp, superabsorbent polymer (SAP), or a mixture thereof. The absorbent core 45 is located at least in the crotch region S3. Preferably, the absorbent core 45 may extend from the front waist region S1 to the rear waist region S2 in the longitudinal direction L. The absorbent core 45 may be covered by a core wrap. Furthermore, the absorbent body 40 may have a topsheet 41 located on the skin-facing side of the absorbent core 45.

[0045] The absorbent main body 40 may have leg flaps 46. The leg flaps 46 may be arranged outboard of the absorbent core 45 in the width direction W. The leg flaps 46 may have at least two leg sheets 47 and leg elastic members 48 arranged between the leg sheets 47. The leg sheet 47 may be part of the top sheet 41, part of a back sheet (not shown), or a sheet separate from the top sheet 41 and the back sheet. The leg elastic members 48 are fixed to the leg sheets 47 in a longitudinally stretched state. The leg elastic members 48 may be composed of a plurality of rubber threads (320 to 620 dtex) arranged at intervals in the width direction. The leg elastic members 48 are arranged in a stretched state in a predetermined longitudinal region of the leg flaps 46. In the region where the leg elastic members 48 are stretched, a longitudinal contraction force acts on the leg flaps 46, while in the region where the leg elastic members 48 are not stretched, no longitudinal contraction force acts on the leg flaps 46. In this specification, the longitudinal length of the region where the longitudinal contraction force acts is also referred to as the "effective length" of the leg elastic members 48. The effective length portion is the portion where wrinkles are formed due to the contraction of the leg elastic members when the diaper is in its natural state. Figure 2 shows the effective length portion 49 of the leg elastic members 48. The absorbent main body 40 is joined to the front waistline member 20 and the rear waistline member 30 at the joining region R40 shown in Figure 2. The effective length portion 49 may overlap the joining region R40.

[0046] An absorbent sheet 70 is disposed in one of the front waist region S1 and the rear waist region S2. The absorbent sheet 70 is a sheet capable of absorbing bodily fluids such as sweat. The absorbent sheet 70 may be disposed in the rear waist region S2. A wearer is more likely to sweat on the back side than on the ventral side. By disposing the absorbent sheet 70 in the rear waist region S2, which is worn on the back side of the wearer, sweat absorption can be further improved. The absorbent sheet 70 may have a pulp sheet 71 containing at least pulp fibers. Examples of pulp fibers include wood pulp and non-wood pulp. Examples of wood pulp include softwood pulp and hardwood pulp, and examples of non-wood pulp include cotton pulp, hemp pulp, straw pulp, bamboo pulp, bagasse pulp, reed pulp, and kenaf pulp. The pulp sheet 71 may contain hydrophilic fibers other than pulp fibers. Examples of hydrophilic fibers include natural fibers such as regenerated cellulose fibers (rayon, viscose rayon, etc.), semi-synthetic cellulose fibers (acetate fibers, etc.), and refined cellulose fibers.

[0047] The water-absorbent sheet 70 may further include a water-absorbent nonwoven fabric sheet 72. The water-absorbent nonwoven fabric sheet 72 constitutes the nonwoven fabric sheet of the present invention. The water-absorbent nonwoven fabric sheet 72 may be disposed with a pulp sheet 71 sandwiched therebetween in the thickness direction T. The water-absorbent sheet 70 of this embodiment has a density of 10 to 35 g / m 2 and 10 to 25 g / m pulp sheets 71 arranged on both sides of the pulp sheet 71 in the thickness direction. 2and the water-absorbent nonwoven fabric sheet 72. The pulp sheet 71 may contain pulp fibers but not thermoplastic fibers. The water-absorbent nonwoven fabric sheet 72 contains thermoplastic fibers. Examples of thermoplastic resin fibers include polyolefin polymers (polyethylene, polypropylene, polyester, polyethylene terephthalate, etc.), polyamide polymers, acrylic polymers, fibers using these, and fibers formed by combining these. The water-absorbent sheet 70 may be colored. The color may be the color of the pulp sheet itself that constitutes the water-absorbent sheet 70, or it may be colored by printing or the like, or a colored portion may be provided in part of the water-absorbent sheet 70. The colored portion may have a design or picture, or a pattern such as stripes. The absorbent sheet of this embodiment is colored throughout the entire water-absorbent sheet 70.

[0048] The water-absorbent sheet 70 is disposed on the closest skin-facing side T1 of the disposable diaper 10. Therefore, the water-absorbent sheet 70 comes into contact with the wearer's skin when worn. The water-absorbent sheet 70 comes into contact with the skin and absorbs body fluids such as sweat. The water-absorbent sheet 70 may overlap at least the first outer nonwoven fabric sheet 35 and the second outer nonwoven fabric sheet 36 in the thickness direction. The water-absorbent sheet 70 is joined to a member such as a sheet located on the non-skin-facing side T2 of the water-absorbent sheet 70 by an adhesive or other bonding means.

[0049] The absorbent sheet 70 does not need to overlap the effective length portions of the leg flaps 46 in a plan view in the thickness direction. In a pants-type diaper with a structure in which the front waistline member and the rear waistline member are spaced apart in the longitudinal direction, as in this embodiment, the leg flaps 46 extend outward in the width direction W from the absorbent core 45 and are fixed to the front waistline member 20 and the rear waistline member 30, thereby fitting the leg-area region of the disposable diaper to the wearer's legs. However, when the absorbent core absorbs bodily fluids, the weight of the bodily fluids generates a downward force on the absorbent main body, and the longitudinal contraction of the leg flaps 46 may apply a downward force to the front waistline member and the rear waistline member. Because the effective length portions 49 of the leg flaps 46 and the absorbent sheet 70 do not overlap in the thickness direction, the downward force transmitted via the leg flaps 46 is less likely to be applied to the absorbent sheet 70, making it easier to prevent the absorbent sheet from shifting downward. This prevents the water-absorbent sheet from shifting in the longitudinal direction, making it easier to keep the water-absorbent sheet around the wearer's waist. This allows the water-absorbent sheet 70 to be positioned appropriately for the wearer, making it easier to maintain its sweat-absorbing effect.

[0050] Furthermore, among the leg elastic members of the leg flaps, the leg elastic members 482 located on the outer side in the width direction may not overlap the joining region R40, while the leg elastic members 481 located on the inner side in the width direction may overlap the joining region R40. Because the leg elastic members 482 located on the outer side in the width direction do not overlap the joining region R40, the leg flaps can flexibly deform when fitted around the wearer's legs, making it easier for the wearer to move their legs. Furthermore, the leg elastic members 481 located on the inner side in the width direction are adjacent to the absorbent core that absorbs bodily fluids and are therefore more likely to be weighted by bodily fluids. Because the leg elastic members 481 located on the inner side in the width direction overlap the joining region R40, even when the absorbent core becomes heavy due to the absorption of bodily fluids, the leg elastic members can easily continue to pull the absorbent main body toward the waistband member.

[0051] The water absorbent sheet 70 may be provided over a portion of the entire rear waistband region S2 in the longitudinal direction L. The outer edge 702 of the water absorbent sheet 70 may be located more inward in the longitudinal direction L than the outer edge 602 of the side joint portion 60. The inner edge 701 of the water absorbent sheet 70 may be located more inward in the longitudinal direction L than the inner edge 601 of the side joint portion 60. The rear waistband region S2 may have a first region R1 extending from one outer edge to the other outer edge of the rear waistband region S2 in the width direction W, and extending from the inner edge of the water absorbent sheet 70 to the outer edge of the water absorbent sheet 70 in the longitudinal direction L. In other words, the first region R1 is a region that combines the region where the water absorbent sheet 70 is disposed and a region in the rear waistband region S2 that extends in the width direction from the region where the water absorbent sheet 70 is disposed. The front waist region S1 may have a second region R2 that is continuous with the first region R1 in the width direction W and extends from one outer edge of the front waist region S1 to the other outer edge in the width direction W. The first region R1 and the second region may be continuous with each other in the width direction W in the pants-type state shown in FIG. 1 . The absorbent sheet 70 may be disposed over the entire width direction W of the rear waist region S2. The absorbent sheet 70 may have an extension 75 that is disposed outward in the width direction W of the side joint 60. The extension 75 is a portion between the outer edge 70E of the absorbent sheet 70 and the side joint 60.

[0052] The disposable diaper 10 has a liquid-impermeable backsheet 50 arranged on the non-skin-facing side T2 of the absorbent sheet 70. The backsheet 50 may have at least a portion overlapping the absorbent sheet in a plan view in the thickness direction T. This prevents bodily fluids absorbed by the absorbent sheet from leaking to the non-skin-facing side (outside the diaper). It is sufficient that at least a portion of the backsheet 50 is arranged on the non-skin-facing side T2 of the absorbent sheet. The backsheet 50 may have a portion that is not arranged on the non-skin-facing side T2 of the absorbent sheet 70.

[0053] As shown in FIG. 4 , the backsheet 50 may have a first backsheet 51 and a second backsheet 52 located closer to the skin-facing side T1 than the first backsheet 51. The first backsheet 51 may be disposed in each of the front waistline region S1 and the rear waistline region S2. The first backsheet 51 may be located between the first outer nonwoven fabric sheet 35 and the second outer nonwoven fabric sheet 36. The inner edge 511 of the first backsheet 51 may be located outward in the longitudinal direction L from the inner edge of the rear waistline region S2 or the front waistline region S1. The inner edge 511 of the first backsheet 51 in the rear waistline region S2 may be located inward in the longitudinal direction L from the inner edge 701 of the water-absorbent sheet 70. The outer edge 512 of the first backsheet 51 may be located inward in the longitudinal direction L from the outer edge of the rear waistline region S2 or the front waistline region S1. The outer edge 512 of the first backsheet 51 in the rear waistline region S2 may be located longitudinally inward of the outer edge 702 of the water-absorbent sheet 70, or may be located longitudinally outward of the outer edge 522 of the second backsheet 52. In this embodiment, the outer edge 512 of the first backsheet 51 forms the outer edge of the backsheet. In a modified example, the outer edge 522 of the second backsheet 52 may form the outer edge of the backsheet.

[0054] The second backsheet 52 may be disposed across the front waistline region S1, the rear waistline region S2, and the crotch region S3. The second backsheet 52 may be disposed on the non-skin-facing side T2 of the absorbent core 45, closer to the skin-facing side T1 than the front waistline member 20 and the rear waistline member 30. The outer edge 522 of the second backsheet 52 is located more inward in the longitudinal direction L than the outer edges of the rear waistline region S2 or the front waistline region S1. The outer edge 522 of the second backsheet 52 in the rear waistline region S2 may be located more inward than the outer edge 702 of the absorbent sheet 70, or more inward than the outer edge 512 of the first backsheet. The first backsheet 51 and the second backsheet 52 are disposed in the center of the disposable diaper 10 in the width direction W, and do not necessarily have to be disposed at the sides of the disposable diaper 10 in the width direction W.

[0055] In a plan view in the thickness direction, at least a portion of the backsheet 50 may overlap the water-absorbent sheet 70. The water-absorbent sheet 70 may overlap at least a portion of the first backsheet 51, or at least a portion of the second backsheet 52, or may overlap both the first backsheet 51 and the second backsheet 52. The water-absorbent sheet 70 overlaps the backsheet 50 in a region inward in the longitudinal direction L from the outer edge 512 of the first backsheet 51. The water-absorbent sheet 70 overlaps both the first backsheet 51 and the second backsheet 52 in a region inward in the longitudinal direction L from the outer edge 522 of the second backsheet 52. In addition, the water-absorbent sheet 70 overlaps the backsheet 50 in a region inward in the width direction W from the outer edge of the first backsheet 51 or the outer edge of the second backsheet 52. Since at least a portion of the absorbent sheet 70 overlaps the back sheet 50, leakage of body fluids absorbed by the absorbent sheet 70 can be prevented. Furthermore, when viewed from outside the diaper, the user can tell that at least a portion of the absorbent sheet 70 overlaps the back sheet by the difference in color intensity of the absorbent sheet 70. This makes it easier for the user to feel secure about leakage of body fluids absorbed by the absorbent sheet 70.

[0056] The absorbent sheet 70 may have a longitudinally extending portion 77 extending outward in the longitudinal direction L beyond the outer edge of the backsheet 50. In FIG. 3, the longitudinally extending portion 77 and a laterally extending portion 78 (described later) are indicated by different diagonal lines. The longitudinally extending portion 77 is a portion between the outer edge 512 of the first backsheet 51 and the outer edge 702 of the absorbent sheet 70. The longitudinally extending portion 77 extends outward in the longitudinal direction L beyond the backsheet 50, making it easily visible from outside the diaper without the backsheet 50 in between. The absorbent sheet 70 is also colored, making it easily visible from outside the diaper. The user can easily recognize the presence of the absorbent sheet 70 by viewing the longitudinally extending portion 77 from outside the diaper. When the absorbent sheet has a colored portion, the user can easily recognize the presence of the absorbent sheet based on the colored portion of the absorbent sheet 70. This provides the user with a sense of security regarding the absorbency of body fluids such as sweat. The water-absorbent sheet 70 is colored and has areas where it overlaps with the back sheet 50 and areas where it does not, so it is possible to achieve both visibility of the water-absorbent sheet and prevention of leakage of bodily fluids, making it easier for the user to feel secure about both leakage and absorbency.

[0057] As shown in FIG. 3 , the length L21 of the overlapping region between the water-absorbent sheet 70 and the backsheet 50 in the longitudinal direction L may be longer than the length L22 of the longitudinal extension 77. The length L21 of the overlapping region between the water-absorbent sheet 70 and the backsheet 50 is the distance in the longitudinal direction L between the outer edge 512 of the first backsheet 51 and the inner edge 701 of the water-absorbent sheet 70. The length L of the longitudinal extension 77 is the distance in the longitudinal direction L between the outer edge 512 of the first backsheet 51 and the outer edge 702 of the water-absorbent sheet 70. The overlapping region between the water-absorbent sheet 70 and the backsheet 50 is longer than the longitudinal extension 77, which can enhance the effect of suppressing leakage of bodily fluids. The water-absorbent sheet 70 is colored, making it easily noticeable against other sheets. Therefore, even if the longitudinal extension 77 is short, the user can easily recognize the presence of the water-absorbent sheet 70 and feel reassured about its absorbency. More preferably, the length of the longitudinal extensions 77 in the longitudinal direction L may be less than 30% of the total length of the water-absorbent sheet 70 in the longitudinal direction L. The water-absorbent sheet 70 overlaps the back sheet 50 over an area in the longitudinal direction L that is 70% or more of the total length of the water-absorbent sheet 70, ensuring the prevention of leakage of bodily fluids. This makes it easier to achieve both visibility and leak-proofness of the water-absorbent sheet 70.

[0058] The water-absorbent sheet 70 may have a widthwise extension 78 extending outward in the width direction beyond the outer edge of the backsheet 50. The widthwise extension 78 is a portion between the outer edge of the first backsheet 51 and the outer edge of the water-absorbent sheet, located longitudinally outward from the outer edge 522 of the second backsheet 52. The widthwise extension 78 is a portion between the outer edge of the first backsheet 51 and the outer edge of the second backsheet, the outer edge of which is located outward in the width direction, and the outer edge of the water-absorbent sheet, located longitudinally inward from the outer edge 522 of the second backsheet 52. The positional relationship between the outer edge of the first backsheet 51 and the outer edge of the second backsheet is not limited. The provision of the widthwise extension 78 allows the user to visually recognize the water-absorbent sheet 70 extending outward in the width direction W beyond the backsheet 50 from outside the diaper, making it easy for the user to recognize the presence of the water-absorbent sheet. This provides a sense of security regarding absorbency.

[0059] As shown in FIG. 3, the widthwise extensions 78 may extend outward in the width direction from the center CL between the outer edges of the backsheet and the disposable diaper. The widthwise extensions 78 are arranged in at least half of the region outward in the width direction W from the backsheet 50. This makes it easier for users to see the absorbent sheet extending outward in the width direction from the backsheet. More preferably, the water absorbent sheet 70 may be arranged across the entire width of the disposable diaper. Since the water absorbent sheet is arranged across the entire width of the disposable diaper, it becomes easier for users to see the water absorbent sheet. This makes it easier for users to recognize the presence of the water absorbent sheet, and gives them a sense of security about its absorbency.

[0060] The longitudinally extending portions 77 and the widthwise extending portions 78 of the water-absorbent sheet 70 form non-overlapping regions that do not overlap with the backsheet. In a stretched state, the area of ​​the non-overlapping regions is preferably 60% or more of the total area of ​​the water-absorbent sheet. In a stretched state, the water-absorbent sheet does not overlap with the backsheet over an area that is 60% or more of the total area. This makes it easier to ensure the visibility of the water-absorbent sheet 70.

[0061] In a plan view in the thickness direction, the stretchable member 32 may overlap the longitudinally extending portion 77 and may be disposed on the non-skin-facing side of the longitudinally extending portion 77. The L value of the longitudinally extending portion 77 in the L*a*b* color space when the disposable diaper in its natural state is viewed from the non-skin-facing side may be 82 or more, preferably 85 or more. The L value of the longitudinally extending portion 77 in the L*a*b* color space is not the L value of the absorbent sheet 70 itself, but the L value measured from the non-skin-facing side of the disposable diaper. The state when the disposable diaper in its natural state is viewed from the non-skin-facing side refers to the state when the disposable diaper is left for 24 hours in an atmosphere of 60%±5% RH relative humidity with the non-skin-facing side of the rear waist region facing up and then visually observed. The longitudinally extending portions 77 of the water-absorbent sheet 70 are visible through the first outer nonwoven fabric sheet 35 and the second outer nonwoven fabric sheet 36. When viewing the water-absorbent sheet 70 from outside the diaper, the user can see the longitudinally extending portions 77 as well as the stretchable members 32. If the stretchable members 32 are too prominent, the user may feel uncomfortable due to the stretchable members 32. Specifically, if the stretchable members 32 are too prominent, the stretchable members may be emphasized, which may cause discomfort compared to diapers in which the stretchable members are less prominent, or the stretchability may be overemphasized, leaving marks on the skin due to the stretch, making the diaper feel unfriendly to the skin, or giving the user a chemical-like, unfriendly feel. By ensuring that the L value of the longitudinally extending portions in the L*a*b* color space when viewed from the non-skin-facing side of the diaper is 85 or greater, the stretchable members 32 are prevented from being too prominent, and the discomfort caused by the stretchable members 32 is reduced. More preferably, the L value in the L*a*b* color space of the longitudinal extension 77 may be equal to or less than 91.6, which is the L value of the stretchable member 32. This makes the stretchable member 32 less noticeable compared to the longitudinal extension 77. The L value of the longitudinal extension can be determined by measuring the color of the object to be measured using a commercially available colorimeter and quantifying the value based on the CIE 1976 (L*a*b*) color space specified in JIS Z 8729.

[0062] Preferably, the water absorbent sheet 70 may have a blue base color. When the water absorbent sheet 70 has a blue base color, it has a cool appearance and provides an improved feeling of freshness. Furthermore, the stretchable members 32 may have a white base color. When the stretchable members 32 have a white base color, they are less noticeable against the water absorbent sheet 70, which makes it easier to reduce the sense of incongruity. Note that a white base is an L value of 90.0 or more in the (L*a*b*) color space, and a blue base is an L value of 0 or less and an a value of 20 or less in the (L*a*b*) color space.

[0063] Next, an evaluation of the discomfort felt by the absorbent sheet thus constructed will be described. Ten subjects who normally wear disposable diapers were asked to visually inspect the disposable diapers of Examples 1 to 5 and Comparative Examples 1 and 2 in their natural state, and a questionnaire was conducted regarding the discomfort felt by the stretchable member in accordance with the following evaluation criteria. The (L*a*b*) values ​​of the disposable diapers used in the evaluation are values ​​of the longitudinally extending portions measured from the non-skin-facing side of the disposable diaper in its natural state. In this evaluation, the L value of the stretchable member 32 in the (L*a*b*) color space was 91.6, the a value was -0.62, and the b value was -1.81. (Judgment criteria) Good: The stretchable material cannot be recognized, or the stretchable material can be recognized but does not cause discomfort. Poor: The elastic material is recognizable and causes discomfort. From the survey results, diapers for which 80% or more of the 30 subjects gave a "good" rating were given an overall rating of ◎, diapers for which 60% or more of the subjects gave a "good" rating were given an overall rating of ○, and diapers for which less than 60% of the subjects gave a "good" rating were given an overall rating of ×.

[0064] [Table 1]

[0065] As shown in Table 1, the disposable diapers of Examples 1 to 5 are less likely to experience discomfort due to the stretchable members. Therefore, it is preferable that the L value of the longitudinal extension 77 is 82 or more. It was also found that the disposable diapers of Examples 1 to 4 are less likely to cause discomfort in 80% or more of users. Therefore, more preferably, the L value of the longitudinal extension 77 may be 85 or more.

[0066] Next, the joining of the front waist region S1 and the rear waist region S2 in the vicinity of the side joining portion of the disposable diaper constructed as above will be described with reference to Fig. 6 to Fig. 8. Fig. 6 shows the CC cross section shown in Fig. 1, Fig. 7 shows the DD cross section shown in Fig. 1, and Fig. 8 shows the EE cross section shown in Fig. 1. Figs. 6 and 7 show cross sections of the region where the water-absorbent sheet 70 is arranged, and Fig. 8 shows a cross section of the region where the water-absorbent sheet 70 is not arranged.

[0067] The disposable diaper 10 has a non-joined region NR where the front waistline region S1, which is the second waistline region, is not joined to the extended region 75 of the water absorbent sheet 70. The non-joined region NR is a region where, in the pants-type state, the surface of the extended region 75 facing the front waistline region S1 is not joined to the surface of the front waistline member 20 facing the rear waistline region S2. The non-joined region NR may be located in a region extending from the outer edge of the extended region 75 toward the inside in the width direction W, or may be continuous from the outer edge of the extended region 75 to the side joint region 60. The outer edge of the non-joined region NR is the outer edge of the extended region 75, i.e., the outer edge 70E of the water absorbent sheet 70. The inner edge of the non-joined region NR may be adjacent to the side joint region 60 or may be spaced apart from the side joint region 60 in the width direction W.

[0068] In the region extending from the outer edge of the extension portion 75 toward the inside in the width direction W, the extension portion 75 is not joined to the front waist region S1. Therefore, in the region extending from the outer edge of the extension portion 75 toward the inside in the width direction W, the extension portion 75 is spaced apart from the front waist region S1, making it easier to see from outside the diaper. In particular, as shown in cross section CC in FIG. 6 , in the region where the absorbent sheet 70 is not covered by the folded-back portion 35F of the first outer nonwoven fabric sheet 35, the extension portion 75 is exposed and easily visible from outside the diaper. Furthermore, because the absorbent sheet 70 is colored, the user can easily recognize the absorbent sheet 70. The extension portion 75 of the absorbent sheet 70 makes it easy for the user to recognize the presence of the absorbent sheet 70. The user can recognize that the absorbent sheet 70, which can absorb body fluids, is provided separately from the absorbent core, and can feel reassured about the absorbency of body fluids such as sweat. Furthermore, the user can identify the outer widthwise edge of the disposable diaper using the extensions 75 of the absorbent sheet 70 as a landmark, making it easier to grasp any misalignment of the disposable diaper in the widthwise direction when putting it on. This allows the user to put the disposable diaper on in the appropriate position relative to their body.

[0069] Furthermore, the contractile force in the width direction W of the front waist region S1 constituting the second waist region may be higher than the contractile force in the width direction W of the rear waist region S2 constituting the first waist region. Because the front waist region S1 is more likely to contract in the width direction than the rear waist region S2, the outer edge of the rear waist region S2 is pulled toward the front waist region S1 when worn. Therefore, the extension portions 75 of the absorbent sheet 70 are pulled toward the front, making them more visible when viewed from the front. That is, the extension portions 75 are biased toward the front or rear rather than the sides of the wearer's body, making them more visible than when positioned on the sides. This makes the extension portions 75 of the absorbent sheet 70 more easily recognizable, and thus more reassuring for the absorbency of bodily fluids. To ensure that the extension portions 75 are easily recognizable by the user, the length of the extension portions 75 in the width direction W is preferably 5 mm or greater.

[0070] Disposable diapers configured as described above can be manufactured, for example, by the following manufacturing method. First, a front continuous body in which the front waistline member is continuous in the width direction and a rear continuous body in which the rear waistline member is continuous in the width direction are transported, and components such as the absorbent main body 40 are arranged so as to straddle the front continuous body and the rear continuous body. Next, the front continuous body and the absorbent main body are folded along a fold line extending in the width direction so that the front continuous body and the rear continuous body overlap. Then, side joints are formed, and the continuous body is cut along the outer edges of the front waistline region and the outer edges of the rear waistline region. This allows a pants-type disposable diaper to be obtained.

[0071] When cutting the front and rear continuous bodies, the front and rear continuous bodies are cut with a cutting device such as a cutter while they are overlapping. Therefore, the front and rear continuous bodies are welded together during cutting, forming a second side joint 61 where the front continuous body (front waistband region) and the rear continuous body (rear waistband region) are joined together widthwise outward of the side joint (see FIGS. 1 and 8). At this time, it is difficult to join the pulp sheet 71 containing pulp fibers to the exterior nonwoven fabric sheet, but it is easy to join the exterior nonwoven fabric sheets together. Therefore, as shown in FIGS. 6 and 7, the second side joint 61 is not formed by cutting in the area where the water-absorbent sheet 70 having the pulp sheet 71 is arranged. On the other hand, as shown in FIG. 8, the second side joint 61 is formed by cutting in the area where the water-absorbent sheet 70 is not arranged.

[0072] A second side joint 61 may be formed in regions outside and inside the absorbent sheet 70 in the longitudinal direction L. The second side joint 61 is a portion where the front waist region S1 and the rear waist region S2 are joined, outside the side joint 60 in the width direction W. The second side joint 61 may be spaced apart in the width direction W from the side joint 60. With this configuration, the side joint 60 and the second side joint 61 are provided in regions outside the absorbent sheet 70 in the longitudinal direction L. In regions outside the absorbent sheet in the longitudinal direction, it is difficult for fingers or the like to be inserted between the first waist region and the second waist region from the outside of the diaper, and the second side joint 61 protects the joined state of the side joint 60. This prevents the side joint 60 from unintentionally breaking during use.

[0073] The nonwoven fabric sheet has a first-side nonwoven fabric sheet arranged closer to the first waistline region in the thickness direction than the pulp sheet 71 in the region where the side joints 60 are provided, and a second-side nonwoven fabric sheet arranged closer to the second waistline region in the thickness direction than the pulp sheet 71 in the region where the side joints 60 are provided. In the region shown in Fig. 6, the first-side nonwoven fabric sheet is composed of a water-absorbent nonwoven fabric sheet 72, a first exterior nonwoven fabric sheet 35 in the rear waistline region S2, and a second exterior nonwoven fabric sheet 36 in the rear waistline region S2, and the second-side nonwoven fabric sheet is composed of a water-absorbent nonwoven fabric sheet 72, a first exterior nonwoven fabric sheet 35 in the front waistline region S1, and a second exterior nonwoven fabric sheet 36 in the front waistline region S1. In the region shown in Fig. 7, the first-side nonwoven fabric sheet is composed of the water-absorbent nonwoven fabric sheet 72, one first exterior nonwoven fabric sheet 35 in the front waist region S1, two first exterior nonwoven fabric sheets 35 in the rear waist region S2, and a second exterior nonwoven fabric sheet 36 in the rear waist region S2. In the region shown in Fig. 7, the second-side nonwoven fabric sheet is composed of the water-absorbent nonwoven fabric sheet 72, the first exterior nonwoven fabric sheet 35 in the front waist region S1, and the second exterior nonwoven fabric sheet 36 in the front waist region S1. In addition, when the water-absorbent sheet 70 does not have a water-absorbent nonwoven fabric sheet, the first-side nonwoven fabric sheet and the second-side nonwoven fabric sheet may be composed of at least one of the first exterior nonwoven fabric sheet and the second exterior nonwoven fabric sheet.

[0074] The basis weight of the first-side nonwoven fabric sheet and the basis weight of the first-side nonwoven fabric sheet may be higher than the basis weight of the pulp sheet 71. The basis weight of the first-side nonwoven fabric sheet is the total basis weight of the nonwoven fabric sheets that make up the first-side nonwoven fabric sheet. The basis weight of the second-side nonwoven fabric sheet is the total basis weight of the nonwoven fabric sheets that make up the second-side nonwoven fabric sheet. Because the basis weights of the first-side nonwoven fabric sheet and the second-side nonwoven fabric sheet are relatively high, it is easy to form the second side joint portion 61 by joining the nonwoven fabric sheets together when cutting, and it is also easy to maintain the joined state of the second side joint portion 61. It becomes easy to maintain the joined state of the outer edge of the front waistline region S1 and the outer edge of the rear waistline region while maintaining the body fluid absorbency of the pulp sheet 71.

[0075] The side joints 60 are formed on the non-skin-facing side T2 of the diaper by heat welding or the like. The formation of the side joints 60 fuses thermoplastic fibers such as nonwoven fabric. The pulp sheet 71 contains pulp fibers and is less susceptible to welding than nonwoven fabric. Therefore, the bond strength of the portions of the side joints 60 that do not overlap with the pulp sheet 71 is higher than the bond strength of the portions of the side joints that do overlap with the pulp sheet 71. The portions of the side joints 60 that do not overlap with the pulp sheet 71 are located on the outer side of the absorbent sheet 70 in the longitudinal direction and on the inner side of the absorbent sheet 70 in the longitudinal direction. As shown in FIG. 6 and other figures, in the region where the side joints 60 are formed, the pulp sheet 71, the absorbent nonwoven fabric sheet 72, the first exterior nonwoven fabric sheet 35, and the second exterior nonwoven fabric sheet 36 overlap in the thickness direction T.

[0076] The water-absorbent sheet 70 is disposed in the rear waistband region S2 and is bonded to the rear waistband region S2 with an adhesive or the like. Therefore, with the side joints 60 formed, the bonded state between the water-absorbent sheet 70 and other sheets is more likely to be maintained on the rear waistband region S2 side in the thickness direction T than the pulp sheet 71. On the other hand, the bonded state between the water-absorbent sheet 70 and other sheets may be less likely to be maintained on the front waistband region S1 side in the thickness direction T than the pulp sheet 71. To maintain the bonded state between the water-absorbent sheet 70 and the front waistband region S1, the basis weight of the pulp sheet 71 is preferably lower than that of the second-side nonwoven fabric sheet disposed closer to the second waistband region than the pulp sheet 71. Because the basis weight of the pulp sheet 71 is lower than that of the second-side nonwoven fabric sheet, the second-side nonwoven fabric sheet maintains the bonded state of the side joints 60, thereby preventing unintentional tearing of the side joints 60 during use.

[0077] 2, the distance L1 between the outer edge 702 of the water absorbent sheet 70 and the outer edge 602 of the side joint portion 60 may be shorter than the distance L2 between the inner edge 701 of the water absorbent sheet 70 and the inner edge 601 of the side joint portion 60. When removing a disposable diaper from a wearer, the side joint portion 60 is generally torn from the outer edge 602 of the side joint portion 60 toward the inside in the longitudinal direction L. At this time, the user will notice that the strength of the side joint portion is relatively high in the region outside the water absorbent sheet 70 in the longitudinal direction L, and that the strength of the side joint portion 60 is relatively low in the region where the water absorbent sheet 70 is located. Since the distance L1 between the outer edge 702 of the water absorbent sheet 70 and the outer edge 602 of the side joint 60 is shorter than the distance between the inner edge 701 of the water absorbent sheet 70 and the inner edge 601 of the side joint 60, when tearing the side joint from the outer edge in the longitudinal direction of the side joint toward the inside in the longitudinal direction, the user can quickly reach the easy-to-tear area, thereby making it easier for the user to tear the side joint 60.

[0078] The disposable diaper 10 is also constructed so that the absorbent sheet 70 can easily adhere to the skin. The close contact of the absorbent sheet 70 with the skin improves the absorbency of body fluids such as sweat. Next, the construction that allows the absorbent sheet 70 to easily adhere to the skin will be described in detail.

[0079] The contractile force of the first region R1 in the width direction W may be lower than the contractile force of the second region R2 in the width direction. In the worn state, the first region R1 and the second region R2 contract in the width direction W compared to the stretched state shown in Fig. 2 etc., and the first region R1 is pulled toward the second region R2. Fewer wrinkles are formed in the first region R1 compared to the second region R2, and the contact area between the first region R1 and the skin increases. This allows the absorbent sheet 70 to adhere closely to the skin, improving the absorbency of body fluids such as sweat.

[0080] Furthermore, the contractile force in the width direction W of the rear waistband region S2 may be lower than the contractile force in the width direction W of the front waistband region S1. When worn, the rear waistband region S2 is pulled toward the front waistband region S1. This reduces the number of wrinkles formed in the rear waistband region S2, making it easier for the rear waistband region S2 to fit snugly against the skin. This allows the absorbent sheet 70 to fit snugly against the skin, improving absorbency.

[0081] The wearing state in the present invention refers to a state in which a disposable diaper in which the front waist region S1 and the rear waist region S2 are continuous in the width direction W via the side joining portion 60 is worn on the tubular body 100 so that the diaper is 77% of the stretched state. Fig. 9 is a diagram schematically showing the state in which the disposable diaper is worn on the tubular body 100 so that the diaper is 77% of the stretched state. Fig. 9 shows the disposable diaper and the tubular body as viewed from an extension of the central axis of the tubular body 100. The state in which the disposable diaper is worn on the tubular body 100 so that the diaper is 77% of the stretched state is as follows. The front waist region S1 and the rear waist region S2 are stretched in the width direction W to remove wrinkles in the front waist region S1 and the rear waist region S2, and the length L31 (see FIG. 2) between the side joints 60 in the front waist region S1 (the length between the inner edge of the left side joint and the inner edge of the right side joint) and the length L32 between the side joints 60 in the rear waist region S2 are measured. The sum of the length L31 between the side joints 60 in the front waist region S1 and the length L32 between the side joints 60 in the rear waist region S2 is defined as the length of the disposable diaper 10 in a stretched state when attached to the tubular body 100. Next, the disposable diaper 10 is attached to the tubular body 100 whose periphery is 77% of the length in the stretched state. This state is defined as the state when the disposable diaper 10 is attached to the tubular body 100 so that the periphery is 77% of the length in the stretched state. The length L of the cylindrical body 100 in the longitudinal direction is at least equal to or greater than the longitudinal length of the side joint portion 60. Silicone PET separator (Nippa Corporation, PET38*1-B, C70905-13) can be used as the surface material of the cylindrical body 100, and its friction coefficient may be less than 1 μs. The friction coefficient is a static friction coefficient and can be measured by applying a measuring element to the surface of the cylindrical body using a portable friction meter Muse (Heidon, Nisshin Machinery Co., Ltd.). Measurements are taken at 5 to 10 locations, and the average value is taken as the friction coefficient.

[0082] When the diaper is worn on a tubular body so that the length is 77% of the stretched length, the length L41 (see FIG. 9) between the side seams 60 in the front waist region S1 may be shorter than the length L42 between the side seams 60 in the rear waist region S2. When designing a disposable diaper, it is assumed that the waist circumference dimension that is 77% of the widthwise length in the stretched state is included in the waist circumference dimension of the wearer when the diaper is worn. The ratio of the length L42 between the side seams 60 in the rear waist region S2 to the length L41 between the side seams 60 in the front waist region S1 when worn is higher than the ratio of the length L32 between the side seams 60 in the rear waist region S2 to the length L31 between the side seams 60 in the front waist region S1 when stretched.

[0083] In this embodiment, the length L31 between the side joints 60 in the front waistband region S1 in the stretched state and the length L32 between the side joints 60 in the rear waistband region S2 in the stretched state are the same, as shown in FIG. 2. Therefore, the ratio of the length between the side joints 60 in the rear waistband region S2 to the length between the side joints 60 in the front waistband region S1 in the stretched state is 1.0. Furthermore, as shown in FIG. 9, the side joints 60 are biased toward the front waistband region S1 in the worn state. The length L42 between the side joints 60 in the rear waistband region S2 in the worn state is longer than the length L41 between the side joints 60 in the front waistband region S1 in the worn state. Therefore, the ratio of the length L42 between the side joints 60 in the rear waistband region S2 to the length L41 between the side joints 60 in the front waistband region S1 in the worn state is greater than 1.0. In this way, because the side joints 60 are biased toward the front waistband region S1 when worn, the rear waistband region S2 has fewer wrinkles than the front waistband region S1 and is more likely to fit snugly against the skin. This allows the absorbent sheet 70 to fit snugly against the skin, improving its ability to absorb bodily fluids such as sweat. Furthermore, when worn on a cylindrical body so that the sheet is 77% stretched, the extensions 75 of the absorbent sheet 70 are biased toward the front waistband region S1. This makes the extensions 75 more easily visible from the front of the body when worn.

[0084] The contractile force in the width direction of the region where the water-absorbent sheet 70 is disposed may be higher than that of the region located on the outer side in the longitudinal direction. As shown in FIG. 4 , the region extending from the outer edge 702 in the longitudinal direction L of the water-absorbent sheet 70 to the outer side in the longitudinal direction L is referred to as the outer region R4, and the region extending from the inner edge 701 in the longitudinal direction L of the water-absorbent sheet 70 to the inner side in the longitudinal direction L is referred to as the inner region R3. The contractile force in the width direction of the region where the water-absorbent sheet 70 is disposed may be higher than the contractile force in the width direction W of at least one of the outer region R4 and the inner region R3. The region where the water-absorbent sheet 70 is disposed is the region that overlaps with the water-absorbent sheet 70 in a plan view in the thickness direction. Because the contractile force of the region where the water-absorbent sheet 70 is disposed is higher than that of the outer region R4 or the inner region R3, the region where the water-absorbent sheet 70 is disposed easily fits the body without floating off the wearer's skin. Preferably, the contractile force in the width direction W of the region where the water-absorbent sheet 70 is arranged may be higher than the contractile force in the width direction W of the outer region R4. The region where the water-absorbent sheet 70 is arranged fits the body better than the outer region R4, making it less likely for the water-absorbent sheet 70 to lift up from the skin on the outer region R4 side, and preventing body fluid absorbed by the water-absorbent sheet from leaking through the waist-opening 62. More preferably, the contractile force in the width direction of the region where the water-absorbent sheet is arranged may be higher than the contractile force in the width direction of the outer region R4 and the contractile force in the width direction of the inner region R3. This allows the water-absorbent sheet to fit the body more easily. This allows the water-absorbent sheet to absorb body fluid more efficiently, improving absorbency.

[0085] In a plan view in the thickness direction, the tape member 80 may be disposed so as to overlap at least a portion of the water-absorbent sheet 70. The tape member increases the rigidity of the water-absorbent sheet 70 in the area where it overlaps with the tape member. This makes it less likely for wrinkles to form in the water-absorbent sheet 70, and allows the water-absorbent sheet 70 to adhere more closely to the skin.

[0086] As shown in FIG. 3 , the inner edge 801 of the tape member 80 may be located inward in the longitudinal direction L from the center of the water-absorbent sheet 70 in the longitudinal direction L. The water-absorbent sheet 70 is preferably located in an area that easily absorbs sweat, and is preferably located across the wearer's gluteal cleft and back. The tape member 80 is located inward in the longitudinal direction L from the center of the water-absorbent sheet 70, and is easily located in a position corresponding to the wearer's gluteal cleft. More preferably, the inner edge 801 of the tape member 80 may be located inward in the longitudinal direction from the inner edge 701 of the water-absorbent sheet 70. The tape member 80 is easily located in a position corresponding to the wearer's gluteal cleft. Therefore, the water-absorbent sheet 70 overlapping the tape member 80 fits into the hollow of the gluteal cleft, improving absorbency.

[0087] In a plan view in the thickness direction, the tape member 80 may overlap the widthwise center of the rear waistline region S2. The tape member 80 overlaps the widthwise center of the rear waistline region S2, and easily fits into the hollow of the gluteal cleft when worn by the wearer. More preferably, the tape member 80 may be arranged across the center of the width direction W of the rear waistline region S2. The tape member 80 easily fits into the hollow of the gluteal cleft within a certain range extending left and right from the widthwise center of the gluteal cleft. The absorbent sheet 70 overlapping the tape member 80 fits more closely to the skin, further improving absorbency.

[0088] In a plan view in the thickness direction, at least a portion of the absorbent sheet 70 may overlap the outer longitudinal edge of the absorbent core 45 on the skin-facing side of the absorbent core 45. More specifically, the absorbent sheet 70 and the absorbent core 45 may overlap in the region from the inner edge of the absorbent sheet to the outer edge of the absorbent core in the longitudinal direction L, and in the width direction W, in a region inside the outer edge of the absorbent core 45. The absorbent core 45 is layered with an absorbent material that absorbs bodily fluids, and the thickness of the absorbent core is generally greater than the thickness of other diaper components such as the backsheet. The absorbent sheet 70 overlaps the outer longitudinal edge of the absorbent core and is positioned closer to the wearer due to the thickness of the absorbent core. This allows the absorbent sheet to fit closely to the wearer, improving absorbency. The outer edge of the absorbent core is generally positioned to overlap the vicinity of the wearer's gluteal cleft. The absorbent sheet overlaps the outer edge of the absorbent core and is positioned so as to fit into the gluteal cleft. Therefore, the absorbency can be further improved.

[0089] In a modified example, the absorbent sheet 70 may be spaced apart from the absorbent core 45 in the longitudinal direction L. When the absorbent core 45 and the absorbent sheet 70 are spaced apart in the longitudinal direction, i.e., when the absorbent core 45 and the absorbent sheet 70 do not overlap in a plan view in the thickness direction, the body fluid absorbed by the absorbent core 45 is less likely to be transferred to the absorbent sheet 70. This further reduces leakage of body fluid from the absorbent sheet 70.

[0090] The length L12 between the outer edge of the rear waistband region S2 and the outer edge of the absorbent main body 40 may be longer than the length L11 between the outer edge of the front waistband region S1 and the outer edge of the absorbent main body 40. The absorbent main body 40 is arranged in the crotch region S3, and is held between the legs when worn, and is easily compressed in the width direction W. The absorbent main body 40 is arranged biased toward the front waistband region S1 in the longitudinal direction L than the rear waistband region S2. Therefore, the rear waistband region S2 is less affected by compression of the absorbent main body 40. The absorbent sheet 70 arranged in the rear waistband region S2 is easily maintained in close contact with the skin.

[0091] Although the present invention has been described in detail using the above-described embodiments, it is clear to those skilled in the art that the present invention is not limited to the embodiments described in this specification. The present invention can be implemented in modified and altered forms without departing from the spirit and scope of the present invention as defined by the claims. Therefore, the description in this specification is intended to be illustrative and does not have any limiting meaning on the present invention. [Industrial Applicability]

[0092] According to the present invention, there is a need for a disposable diaper in which the absorbent sheet adheres closely to the wearer's skin, thereby improving absorbency. [Explanation of symbols]

[0093] 10. Disposable diapers 20 Front waistband member 30 Rear waistband member 35 First exterior nonwoven fabric sheet (nonwoven fabric sheet) 36 Second exterior nonwoven fabric sheet (nonwoven fabric sheet) 40 Absorbent body 45 Absorption Core 46 Leg Flap 49 Effective length 50 Back Seat 51 No. 1 back seat 52 Second back seat 60 Side joint 70 Water-absorbent sheet 71 Pulp Sheet 72 Absorbent nonwoven fabric sheet (nonwoven fabric sheet) 75 Extension part 80 Tape material S1 Front waist area S2 Rear waist area S3 Inseam area L Longitudinal direction W width direction T1 Skin-facing side T2 Non-skin facing side

Claims

1. a longitudinal direction and a width direction that are perpendicular to each other; a front waist region, a rear waist region, and a crotch region disposed between the front waist region and the rear waist region; an absorbent main body disposed at least in the crotch region; a water-absorbent sheet disposed in a first waist region, which is one of the front waist region and the rear waist region; a liquid-impermeable back sheet disposed on the non-skin-facing side of the water-absorbent sheet; A disposable diaper having a side joining portion joining an outer portion of the front waist region and an outer portion of the rear waist region, the absorbent sheet has at least one of an outer region extending from an outer edge of the absorbent sheet in the longitudinal direction to the outside in the longitudinal direction, and an inner region extending from an inner edge of the absorbent sheet in the longitudinal direction to the inside in the longitudinal direction, The disposable diaper has a contractile force in the width direction of the region where the water-absorbent sheet is arranged that is higher than a contractile force in the width direction of at least one of the outer region and the inner region.

2. 2. The disposable diaper according to claim 1, wherein the absorbent sheet is bonded to a member located on the non-skin-facing side of the absorbent sheet by an adhesive means.

3. the water-absorbent sheet has a longitudinally extending portion that extends outward in the longitudinal direction beyond the outer edge of the back sheet, 3. The disposable diaper according to claim 1, wherein the length in the longitudinal direction of the region where the absorbent sheet and the back sheet overlap is longer than the length in the longitudinal direction of the longitudinally extending portion.

4. the water-absorbent sheet has a widthwise extending portion extending outward in the width direction beyond the outer edge of the back sheet, and a lengthwise extending portion extending outward in the lengthwise direction beyond the outer end edge of the back sheet, The longitudinally extending portion and the widthwise extending portion have a non-overlapping region that does not overlap with the backsheet, 4. The disposable diaper according to claim 1, wherein the area of ​​the non-overlapping region is 60% or more of the area of ​​the entire absorbent sheet in a stretched state.

5. 5. The disposable diaper according to claim 1, wherein the distance between the outer edge of the absorbent sheet and the outer edge of the side joint portion in the longitudinal direction is shorter than the distance between the inner edge of the absorbent sheet and the inner edge of the side joint portion.

6. the first waist region includes a first exterior nonwoven fabric sheet, a second exterior nonwoven fabric sheet disposed closer to the skin than the first exterior nonwoven fabric sheet, and a stretchable member stretchable in the width direction; the first exterior nonwoven fabric sheet has a folded-back portion that is folded back toward the skin-facing surface from the waist-opening as a base point, The disposable diaper according to claim 1 , wherein the folded-back portion overlaps the absorbent sheet and the stretchable member.

7. The first waist region has a stretchable member that is stretchable in the width direction, The disposable diaper according to claim 1 , wherein a plurality of the stretchable members are arranged in the outer region.

8. The absorbent main body has an absorbent core and leg flaps arranged on the outer side of the absorbent core in the width direction and having leg elastic members that stretch in the longitudinal direction, the absorbent main body is joined to a first waist member disposed in the first waist region at a joining region; The disposable diaper according to claim 1 , wherein, in a plan view in the thickness direction, effective length portions of the leg flaps do not overlap the absorbent sheet but overlap the joining region.

9. The absorbent main body has an absorbent core and leg flaps arranged on the outer side of the absorbent core in the width direction and having leg elastic members that stretch in the longitudinal direction, the absorbent main body is joined to a first waist member disposed in the first waist region at a joining region; 8. The disposable diaper according to claim 1, wherein, in a plan view in the thickness direction, outer leg elastic members located on the outer side in the width direction among the leg elastic members do not overlap the joining region, and inner leg elastic members located on the inner side in the width direction among the leg elastic members overlap the joining region.

10. A laminated region in which the back sheet overlaps in the thickness direction is provided, The disposable diaper according to claim 1 , wherein at least a portion of the laminated region overlaps the absorbent sheet.

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