Underpants-type disposable diaper

Abstract

An underpants-type disposable diaper according to one aspect of the present invention comprises: an absorbent body that includes a ventral portion positioned on the ventral side of a wearer when worn, a dorsal portion positioned on the dorsal side of the wearer when worn, and a crotch portion disposed between the ventral portion and the dorsal portion, and that extends in a longitudinal direction between the ventral side and the dorsal side; and a waistline portion that includes a ventral waistline portion connected to the ventral portion and a dorsal waistline portion connected to the dorsal portion, and extends in the waistline direction of the wearer. At least one of the ventral waistline portion and the dorsal waistline portion includes a first high-elastic region, a second high-elastic region disposed apart from the first high-elastic region in the waistline direction, and a low-elastic region that is disposed between the first high-elastic region and the second high-elastic region and has an elasticity lower than those of the first high-elastic region and the second high-elastic region. The low-elastic region has through holes extending through the waistline portion in a thickness direction thereof.

Description

Pants-type disposable diapers

[0001] The present disclosure relates to pant-type disposable diapers.

[0002] Patent Document 1 describes a diaper that includes an absorbent main body having an absorbent body, a ventral outer member that covers the ventral side of the wearer, and a dorsal outer member that covers the dorsal side of the wearer, and that has through-holes that pass through the ventral outer member and the dorsal outer member from the skin side to the non-skin side so as to overlap with the elastic members of the ventral outer member and the dorsal outer member. Patent Document 2 describes a pants-type diaper that has multiple auxiliary openings formed in the ventral side that is located on the ventral side of the wearer when worn.

[0003] International Publication No. 2017 / 175289 Japanese Patent Application Laid-Open No. 2004-267335

[0004] In the diaper described in Patent Document 1, through-holes are formed in the ventral and dorsal outer members to improve the breathability of the diaper. Increasing the opening area of ​​the through-holes is considered as a way to further improve breathability. However, if the opening area of ​​the through-holes is increased, the through-holes are likely to close due to the contractile force of the elastic members depending on the wearer's body shape or posture. Closing the through-holes makes it difficult to achieve the desired breathability.

[0005] Therefore, an object of the present disclosure is to provide a pants-type diaper that can improve breathability.

[0006] A pants-type disposable diaper according to one aspect includes a ventral portion that is positioned on the ventral side of a wearer when worn, a dorsal portion that is positioned on the dorsal side of the wearer when worn, and a crotch portion located between the ventral portion and the dorsal portion, and includes an absorbent main body that extends longitudinally between the ventral side and the dorsal side when worn, and a waist portion that includes a ventral waist portion connected to the ventral portion and a dorsal waist portion connected to the dorsal portion, and extends in a waist direction of the wearer, wherein at least one of the ventral waist portion and the dorsal waist portion includes a first high-elasticity region, a second high-elasticity region that is spaced apart from the first high-elasticity region in the waist direction, and a low-elasticity region that is positioned between the first high-elasticity region and the second high-elasticity region and has lower elasticity than the first high-elasticity region and the second high-elasticity region, and the low-elasticity region has a through-hole that penetrates the waist portion in a thickness direction.

[0007] In the above-mentioned pants-type disposable diaper, the through-holes are provided in the low-elasticity region, which has lower elasticity than the first and second high-elasticity regions, and therefore the through-holes are prevented from closing due to contraction of the waistband, allowing air to enter and exit through the through-holes, thereby improving the breathability of the pants-type diaper.

[0008] At least one of the ventral waist portion and the dorsal waist portion may include a third high-elasticity region adjacent to the low-elasticity region in the longitudinal direction and having higher elasticity than the low-elasticity region. In this case, the third high-elasticity region, in addition to the first and second high-elasticity regions, stretches in the waist direction to fit closely around the waist of the wearer, thereby improving the fit of the pants-type disposable diaper.

[0009] The low-elasticity region may have a plurality of through-holes, including a through-hole, which can improve the breathability of the pants-type disposable diaper.

[0010] The back waist portion may include a lower edge located on the crotch portion side and an upper edge located on the opposite side of the lower edge in the longitudinal direction, and the through-hole may be formed in the back waist portion between the back edge of the absorbent main body and the upper edge of the back waist portion. By positioning the through-hole at a position that does not overlap the absorbent main body, the through-hole is prevented from being blocked by the absorbent main body, thereby improving the breathability of the pants-type disposable diaper.

[0011] When the region of the low-elasticity region that is closer to the upper edge than the center line of the low-elasticity region in the longitudinal direction is defined as the upper region, and the region of the low-elasticity region that is closer to the lower edge than the center line is defined as the lower region, the opening area of ​​the through-holes in the upper region may be larger than the opening area of ​​the through-holes in the lower region. Because wearers tend to sweat particularly on their backs, increasing the opening area of ​​the through-holes in the upper region, which is closer to the wearer's back, can further improve breathability. On the other hand, reducing the opening area of ​​the through-holes in the lower region can suppress urine leakage through the through-holes.

[0012] The waist portion includes a skin-facing sheet disposed on the wearer's skin side, a non-skin-facing sheet disposed on the non-skin-facing side, and a plurality of elastic members disposed between the skin-facing sheet and the non-skin-facing sheet, and the pants-type disposable diaper may further include a cover sheet attached to the skin-facing sheet from the skin-facing side so as to cover the through-holes. By providing the cover sheet so as to cover the through-holes, the feel of the diaper can be improved and urine leakage from the through-holes can be suppressed.

[0013] The airflow resistance of the first air passage passing through the cover sheet and the through-holes may be equal to or less than half of the airflow resistance of the second air passage passing through the cover sheet, the skin-facing sheet, and the non-skin-facing sheet. By making the airflow resistance of the first air passage relatively small, air inside the diaper is discharged to the outside via the first air passage, thereby improving breathability.

[0014] The cover sheet may be colored a different color from the non-skin-facing sheet, and the color difference ΔE between the cover sheet and the non-skin-facing sheet may be 4 or more. By increasing the color difference between the cover sheet and the non-skin-facing sheet, the colored cover sheet can be seen through the through-holes when viewing the diaper from the non-skin-facing side, improving the visibility of the through-holes. As a result, the user can recognize that the diaper has high breathability.

[0015] The cover sheet may be a sweat-absorbent sheet having a higher absorbency than the skin-facing sheet and the non-skin-facing sheet, in which case the cover sheet absorbs moisture inside the diaper, thereby preventing the diaper from becoming stuffy when worn.

[0016] At least a portion of the cover sheet may be disposed on the skin-facing side of the absorbent main body and may have standing portions that stand up relative to the absorbent main body due to the contractile force of an elastic member disposed along the edge of the cover sheet on the crotch side. In this case, urine discharged into the absorbent main body is blocked by the standing portions of the cover sheet, thereby suppressing urine leakage from the through-holes.

[0017] The non-skin-facing sheet includes a folded portion that is folded in the thickness direction and arranged on the skin-facing side of the absorbent main body, and the folded portion may have a standing portion that stands up relative to the absorbent main body due to the contractile force of an elastic member arranged along the edge of the folded portion on the crotch side. In this case, urine discharged into the absorbent main body is blocked by the standing portion of the folded portion, thereby suppressing urine leakage from the through-holes.

[0018] The pants-type disposable diaper may further include a post-treatment tape for holding the pants-type disposable diaper in a rolled-up state when the diaper is disposed of, and the post-treatment tape may be positioned so as not to overlap the through-hole, thereby preventing the through-hole from being blocked by the post-treatment tape.

[0019] The plurality of elastic members may be arranged at predetermined intervals in the longitudinal direction in the first and second high-elasticity regions, and the maximum width of the through holes in the longitudinal direction may be greater than the predetermined interval. By making the maximum width of the through holes in the longitudinal direction greater than the predetermined interval, the opening area of ​​the through holes can be increased, thereby improving the breathability of the pants-type disposable diaper.

[0020] The non-skin-contact sheet may be made of a porous nonwoven fabric having a higher porosity than the skin-contact sheet. By making the porosity of the skin-contact sheet that comes into contact with the wearer's skin relatively low, the feel of the pants-type disposable diaper can be improved.

[0021] The through-holes may be formed by cutting out a part of the skin-facing sheet and the non-skin-facing sheet, which allows the opening area of ​​the through-holes to be increased, thereby improving the breathability of the pants-type disposable diaper.

[0022] The absorbent main body may include an outer sheet including a decoration that evokes high breathability, which can impress upon the user that the pants-type disposable diaper has high breathability.

[0023] The width of the low-elasticity region in the waist direction may be smaller than the width of the absorbent main body in the direction perpendicular to the longitudinal direction. In this case, when the first high-elasticity region and the second high-elasticity region contract, the high rigidity of the absorbent main body suppresses contraction of the low-elasticity region. As a result, the through-holes are less likely to close, ensuring breathability of the pants-type disposable diaper.

[0024] The low-elasticity region waist portion has a joint portion connecting an end of the ventral waist portion in the waist direction to an end of the dorsal waist portion in the waist direction, and the width of the low-elasticity region in the longitudinal direction may be ¼ or less of the length of the joint portion in the longitudinal direction. By making the width of the low-elasticity region in the longitudinal direction relatively small, the fit of the pants-type disposable diaper can be ensured.

[0025] The absorbent body may include an absorbent core having absorbent properties, the absorbent core having a pair of longitudinally extending channel portions, the basis weight of the pair of channel portions being lower than that of the other portions of the absorbent core, and two of the plurality of through holes being arranged on an extension line of the pair of channel portions. In this case, an air path is formed in the diaper that passes through the pair of channels toward the two through holes, thereby further improving the breathability of the pants-type disposable diaper.

[0026] The pair of channels may be non-through grooves recessed in the thickness direction of the absorbent core. By forming the pair of channels as non-through grooves, the rigidity of the absorbent core can be ensured and contraction of the low-elasticity region can be suppressed. This makes it difficult for the through holes to close, thereby ensuring breathability of the pants-type disposable diaper.

[0027] According to various aspects of the present invention, the breathability of a pants-type disposable diaper can be improved.

[0028] 5 is a perspective view schematically illustrating a pants-type disposable diaper according to one embodiment; FIG. 6 is a plan view of the pants-type disposable diaper as viewed from the skin-facing side; FIG. 7 is a plan view of the pants-type disposable diaper as viewed from the non-skin-facing side; FIG. 8 is a schematic cross-sectional view of the absorbent main body taken along line A-A in FIG. 2; FIG. 9 is a schematic plan view of the back waist portion as viewed from the non-skin-facing side; FIG. 10 is a schematic cross-sectional view of the back waist portion taken along line B-B in FIG. 5; (a) to (d) are diagrams showing examples of opening shapes of through-holes; FIG. 11 is a cross-sectional view of a pants-type disposable diaper according to another embodiment; FIG. 12 is a cross-sectional view of a pants-type disposable diaper according to yet another embodiment.

[0029] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate explanations will be omitted. The drawings may be partially simplified or exaggerated for ease of understanding, and the dimensional ratios are not limited to those shown in the drawings.

[0030] A pants-type disposable diaper 1 (hereinafter referred to as "diaper 1") according to one embodiment will be described below. Fig. 1 is a perspective view of the diaper 1 according to one embodiment. Fig. 2 is a plan view of the diaper 1 as viewed from the skin-facing side Z1, and Fig. 3 is a plan view of the diaper 1 as viewed from the non-skin-facing side Z2.

[0031] The skin-facing side Z1 is the side that faces the wearer's skin when the diaper 1 is worn, and the non-skin-facing side Z2 is the side that faces away from the wearer's skin when the diaper 1 is worn. In the following description, a person who wears the diaper 1 will be referred to as a "wearer," and a person who helps the wearer put the diaper 1 on will be referred to as a "user." Typically, the wearer is a child or a person being cared for, and the user is a parent or caregiver.

[0032] 2 and 3 show the diaper 1 in an unfolded state in which the diaper 1 has been cut at side end portions 34 of the ventral waistband portion 3 and side end portions 44 of the back waistband portion 4, which will be described later, and stretched to a state in which no wrinkles are formed. As shown in FIGS. 2 and 3, the diaper 1 in the unfolded state extends in a transverse direction X and a longitudinal direction Y. The longitudinal direction Y corresponds to the longitudinal direction L of the diaper 1, which extends between the ventral side and the back side of the wearer when the diaper 1 is worn. The transverse direction X is a direction perpendicular to the longitudinal direction Y, and is a width direction extending from side to side of the wearer when the diaper 1 is worn. The thickness direction Z is a direction perpendicular to the transverse direction X and the longitudinal direction Y.

[0033] The diaper 1 includes a ventral waistband portion 3, a rear waistband portion 4, and an absorbent body 10. The absorbent body 10 has a generally rectangular planar shape that is elongated in the longitudinal direction Y of the diaper 1. As shown in FIGS. 2 and 3 , the absorbent body 10 includes a ventral portion 10a disposed at one end of the longitudinal direction Y, a rear portion 10b disposed at the other end of the longitudinal direction Y, and a crotch portion 10c disposed between the ventral portion 10a and the rear portion 10b in the longitudinal direction Y. The ventral portion 10a is positioned on the ventral side of the wearer when worn, and the rear portion 10b is positioned on the rear side of the wearer when worn. The crotch portion 10c is positioned to cover the crotch of the wearer when worn. In the following description, the direction from the ventral portion 10a to the rear portion 10b in the longitudinal direction Y may be referred to as the "rear side," and the direction from the rear portion 10b to the ventral portion 10a may be referred to as the "rear side."

[0034] The ventral waist portion 3 is joined to the ventral portion 10a of the absorbent main body 10 from the non-skin-facing side Z2. The back waist portion 4 is joined to the back portion 10b of the absorbent main body 10 from the non-skin-facing side Z2. The diaper 1 is formed by folding the absorbent main body 10 in half so that the ventral waist portion 3 and the back waist portion 4 face each other, and joining the lateral end portions 34 of the ventral waist portion 3 in the lateral direction X to the lateral end portions 44 of the back waist portion 4 in the lateral direction X at the joining portions 18, thereby connecting the ventral waist portion 3 and the back waist portion 4 in a belt-like manner. As a result, the diaper 1 is formed into a pants-type diaper, as shown in FIG. 1 . In the following description, the state in which the ventral waist portion 3 and the back waist portion 4 are connected in a belt-like manner as described above will be referred to as a "connected state." The ventral waist portion 3 and the back waist portion 4 in the connected state constitute the waist portion 2 that extends in the waist circumference direction R of the wearer when worn. The waist portion 2 expands and contracts in the waist direction R in response to expansion and contraction of a plurality of elastic members 33, 43, which will be described later. As shown in Fig. 1, the diaper 1 in the connected state has a waist opening BH through which the wearer's waist passes and a pair of leg openings LH through which the wearer's legs pass.

[0035] Figure 4 is a schematic cross-sectional view of the absorbent main body 10 taken along line A-A in Figure 2. As shown in Figure 4, the absorbent main body 10 includes a topsheet 11, a backsheet 12, an exterior sheet 13, and an absorbent body 14. The topsheet 11 constitutes the surface of the absorbent main body 10 that contacts the wearer, and is disposed on the skin-facing side Z1. The topsheet 11 is made of a water-permeable nonwoven fabric such as a spunbond nonwoven fabric, and covers the absorbent body 14 from the skin-facing side Z1. The topsheet 11 is adhered to the surface of the skin-facing side Z1 of the absorbent body 14 with, for example, a hot melt adhesive HM.

[0036] The backsheet 12 is disposed closer to the non-skin-facing side Z2 than the topsheet 11. The backsheet 12 is made of a water-impermeable film and covers the absorbent body 14 from the non-skin-facing side Z2. The backsheet 12 is adhered to the surface of the non-skin-facing side Z2 of the absorbent body 14 with, for example, a hot melt adhesive HM.

[0037] The exterior sheet 13 is disposed on the non-skin-facing side Z2 of the back sheet 12 and constitutes the outermost layer of the absorbent body 10. The exterior sheet 13 is made of, for example, a water-impermeable nonwoven fabric. Typically, the exterior sheet 13 is plain white. The width of the exterior sheet 13 in the lateral direction X is greater than the width of the back sheet 12, and the exterior sheet 13 extends beyond the back sheet 12 on both sides in the lateral direction X.

[0038] The absorbent body 14 is disposed between the topsheet 11 and the backsheet 12 of the absorbent main body 10, and absorbs the wearer's urine that has permeated through the topsheet 11. As shown in Fig. 4, the absorbent body 14 includes an absorbent core 15 and a core wrap 16. The absorbent core 15 contains pulp fibers and a superabsorbent polymer (SAP) and absorbs the wearer's urine. In one embodiment, the absorbent core 15 has a layered structure in which a lower covering sheet 15a, a lower SAP layer 15b, an intermediate sheet 15c, an upper SAP layer 15d, and an upper covering sheet 15e are layered in this order from the bottom up.

[0039] The lower covering sheet 15a is a hydrophilic sheet containing pulp and covers the lower surface of the lower SAP layer 15b. The lower SAP layer 15b is a water-absorbing layer containing super absorbent polymers (SAP) and is disposed between the lower covering sheet 15a and the intermediate sheet 15c. The intermediate sheet 15c is a water-permeable sheet such as a nonwoven fabric and is disposed between the lower SAP layer 15b and the upper SAP layer 15d. The upper SAP layer 15d is a water-absorbing layer containing super absorbent polymers and is disposed between the intermediate sheet 15c and the upper covering sheet 15e. The upper covering sheet 15e is a hydrophilic sheet containing pulp and covers the upper surface of the upper SAP layer 15d.

[0040] Pulp constituting the lower covering sheet 15a and the upper covering sheet 15e may be, for example, chemical pulp, or cellulose fibers such as rayon or acetate. Superabsorbent polymers may be, for example, particulate or fibrous starch-, acrylic acid-, or amino acid-based polymers. The core wrap 16 is, for example, a tissue or nonwoven fabric sheet, and covers the skin-facing side Z1 and non-skin-facing side Z2 of the absorbent core 15. The core wrap 16 is adhered to the non-skin-facing side Z2 of the lower covering sheet 15a and the skin-facing side Z1 of the upper covering sheet 15e, for example, with a hot melt adhesive HM. Urine and other excrement excreted in the absorbent body 10 passes through the topsheet 11 and the upper covering sheet 15e and is absorbed by the upper SAP layer 15d. Excrement not absorbed by the upper SAP layer 15d passes through the intermediate sheet 15c and is absorbed by the lower SAP layer 15b.

[0041] As shown in Figures 2 and 4, a pair of channel portions 20 are formed in the upper SAP layer 15d of the absorbent core 15. The basis weight of the pair of channel portions 20 is set lower than the basis weight of the remaining portions of the absorbent core 15. That is, the density of the superabsorbent polymer in the pair of channel portions 20 is lower than the density of the superabsorbent polymer in the remaining portions of the absorbent core 15. In one embodiment, as shown in Figure 4, the pair of channel portions 20 are non-penetrating grooves recessed from the surface of the skin-facing side Z1 of the upper SAP layer 15d toward the non-skin-facing side Z2. Note that the pair of channel portions 20 may also be slits penetrating the upper SAP layer 15d in the thickness direction Z.

[0042] As shown in Fig. 2, the pair of channel portions 20 are disposed symmetrically with respect to the center line CW of the absorbent main body 10 in the transverse direction X, and extend linearly in the longitudinal direction Y across substantially the entire area of ​​the absorbent core 15. The formation of the pair of channel portions 20 in the absorbent core 15 allows urine excreted by the wearer to be diffused in the longitudinal direction Y. In other words, the pair of channel portions 20 have the function of controlling the flow direction of urine. Two of the multiple through holes 50 described below are disposed on an extension line of the pair of channel portions 20. This forms a path for air to pass through the pair of channel portions 20 and head toward the two through holes 50 within the diaper 1.

[0043] As shown in Fig. 2, the absorbent main body 10 has a pair of leak-proof gathers 80. The leak-proof gathers 80 are arranged on the outer sides of the absorbent core 15 in the lateral direction X, and prevent urine excreted into the absorbent core 15 from leaking in the lateral direction X. As shown in Fig. 4, the leak-proof gathers 80 are formed by folding inward both left-right side portions of the outer sheet 13. The pair of leak-proof gathers 80 are upright three-dimensional gathers and are provided on the absorbent main body 10 along the longitudinal direction Y.

[0044] The leak-proof gathers 80 include a pair of elastic members 22 extending in the vertical direction Y, an upright portion 81 that stands up due to contraction of the pair of elastic members 22, a horizontal fixing portion 82 that serves as an upright fulcrum for the upright portion 81 in the horizontal direction X, and a vertical fixing portion 83 that serves as an upright fulcrum for the upright portion 81 in the vertical direction Y.

[0045] The pair of elastic members 22 are disposed between the inwardly folded outer sheet 13 and extend in the longitudinal direction Y. The pair of elastic members 22 are, for example, rubber threads or flat elastic members that are contractible in the longitudinal direction. The pair of elastic members 22 are disposed spaced apart from each other across a center line CW that divides the absorbent main body 10 into two in the transverse direction X, and are fixed to the outer sheet 13 in a stretched state in the longitudinal direction Y. The ventral side ends of the pair of elastic members 22 are disposed in the ventral side portion 10a, and the dorsal side ends of the pair of elastic members 22 are disposed in the dorsal side portion 10b.

[0046] The lateral fixing parts 82 are formed on the outer sides of the standing parts 81 in the lateral direction X, over substantially the entire area of ​​the absorbent main body 10 in the longitudinal direction Y. The lateral fixing parts 82 are part of the exterior sheet 13, and are joined to the topsheet 11 or the backsheet 12. For example, a hot melt adhesive HM is used to join the lateral fixing parts 82 (see FIG. 4 ). The lateral fixing parts 82 serve as standing fulcrums for the standing parts 81 in the lateral direction X.

[0047] The vertical fixing portions 83 are formed at positions inside the horizontal fixing portions 82 in the horizontal direction X. The vertical fixing portions 83 are part of the exterior sheet 13 and are joined to the top sheet 11 or the back sheet 12. For example, a hot melt adhesive is used to join the vertical fixing portions 83. The vertical fixing portions 83 include a ventral side fixing portion 84 and a dorsal side fixing portion 85. The ventral side fixing portion 84 is formed on the ventral side portion 10a of the absorbent main body 10. The dorsal side fixing portion 85 is formed on the dorsal side portion 10b of the absorbent main body 10. The vertical fixing portions 83 serve as standing fulcrums for the standing portions 81 in the vertical direction Y.

[0048] The standing portion 81 is formed between the ventral fixing portion 84 and the dorsal fixing portion 85. That is, the standing portion 81 is positioned more inward in the lateral direction X than the lateral fixing portion 82, and more inward in the longitudinal direction Y than the longitudinal fixing portion 83. The standing portion 81 is a part of the exterior sheet 13 that is not fixed to the topsheet 11 or the backsheet 12. An elastic member 22 stretched in the longitudinal direction Y is connected to the standing portion 81. When the elastic member 22 contracts in the longitudinal direction Y, the standing portion 81 stands up from the lateral fixing portion 82 as a starting point. In this way, the standing portion 81 stands up so as to sandwich the absorbent core 15 from the lateral direction X, thereby preventing urine leakage.

[0049] As shown in FIG. 2 , the diaper 1 further includes a plurality of leg elastic members 40 that are stretchable in the longitudinal direction. The leg elastic members 40 are arranged outward in the transverse direction X from the pair of elastic members 22. The ventral ends of the leg elastic members 40 are arranged in the ventral portion 10a, and the dorsal ends of the leg elastic members 40 are arranged in the dorsal portion 10b. The leg elastic members 40 are made of a stretchable material, such as rubber or spandex, that is stretchable in the longitudinal direction. They are connected to the outer sheet 13 of the absorbent main body 10 along the side edges 10S of the absorbent main body 10 in a stretched state in the longitudinal direction Y. When the diaper 1 is worn, the leg elastic members 40 contract in the longitudinal direction Y, allowing the side edges 10S of the absorbent main body 10 to fit the legs of the wearer.

[0050] As shown in Fig. 3, the diaper 1 may have an indicator 72 that changes color upon contact with moisture. The indicator 72 is disposed at a position overlapping the absorbent body 14 when viewed from the thickness direction Z, and is provided on the outer sheet 13 so as to be visible from the non-skin-facing side Z2 of the absorbent main body 10. The indicator 72 changes color upon reaction with bodily fluid absorbed by the absorbent body 14. The color change of the indicator 72 allows the user to know the wetness of the absorbent body 14.

[0051] As shown in Fig. 3, the diaper 1 includes a post-treatment tape 24 for holding the diaper 1 in a rolled state when discarding it. The post-treatment tape 24 is a strip-shaped fastening tape provided on the outer surface of the back waistband 4 of the diaper 1. When discarding the diaper 1, the user tears the connected diaper 1 along the side end portions 34 of the ventral waistband 3 and the side end portions 44 of the back waistband 4, rolls the diaper 1 with the topsheet 11 facing inward, and adheres the post-treatment tape 24 to the outer surface of the diaper 1. This keeps the diaper 1 in a rolled state. The post-treatment tape 24 may be provided on the ventral waistband 3 or the outer sheet 13, as long as it is on the outer surface of the diaper 1. The post-treatment tape 24 is positioned so as not to overlap the multiple through-holes 50, which will be described later.

[0052] The ventral waist portion 3 has a generally rectangular planar shape with its longitudinal direction aligned with the transverse direction X of the diaper 1, and is disposed closer to the non-skin-facing side Z2 than the ventral portion 10a of the absorbent main body 10. The ventral waist portion 3 includes a skin-facing sheet 31 disposed on the skin-facing side Z1, a non-skin-facing sheet 32 ​​disposed on the non-skin-facing side Z2, and a plurality of elastic members 33. The ventral portion 10a of the absorbent main body 10 is adhered to the skin-facing sheet 31 of the ventral waist portion 3 via an adhesive layer. The adhesive layer may extend continuously in the waist-surrounding direction R.

[0053] Typically, the skin-facing sheet 31 and the non-skin-facing sheet 32 ​​are made of a plain white nonwoven fabric. For example, the skin-facing sheet 31 and the non-skin-facing sheet 32 ​​are made of an SMS nonwoven fabric in which spunbond, meltblown, and spunbond are laminated in this order, a spunbond nonwoven fabric, an air-through nonwoven fabric, or a laminate of these nonwoven fabrics. The skin-facing sheet 31 and the non-skin-facing sheet 32 ​​are joined to each other with a hot melt adhesive applied to the multiple elastic members 33. Therefore, non-adhesive regions are formed between the multiple elastic members 33 where the skin-facing sheet 31 and the non-skin-facing sheet 32 ​​are not directly adhered to each other.

[0054] In one embodiment, the non-skin-facing sheet 32 ​​may be made of a nonwoven fabric having numerous apertures, and the skin-facing sheet 31 may be made of a nonwoven fabric having no apertures. Note that the apertures referred to here do not refer to gaps between the fibers of the nonwoven fabric, but rather to through-holes formed by perforation processing. Therefore, the non-skin-facing sheet 32 ​​has a higher aperture rate than the skin-facing sheet 31. By making the aperture rate of the skin-facing sheet 31 relatively low, the feel of the diaper 1 against the skin is improved.

[0055] The plurality of elastic members 33 are disposed between the skin-facing sheet 31 and the non-skin-facing sheet 32, and are arranged at intervals d1 in the longitudinal direction Y. These plurality of elastic members 33 extend in the lateral direction X between the lateral end portions 34 of the ventral waistband 3. Therefore, the ventral waistband 3 stretches in the lateral direction X, i.e., in the waist-circumference direction R, while fitting around the waist of the wearer. The plurality of elastic members 33 are made of an elastic material such as rubber or spandex.

[0056] 2 and 3 , the ventral waist portion 3 has an upper edge 3a located on one side in the longitudinal direction Y and a lower edge 3b located on the other side in the longitudinal direction Y. In the longitudinal direction Y, the upper edge 3a is located closer to the ventral side than the ventral edge 10F of the absorbent main body 10. The lower edge 3b is located closer to the dorsal side than the ventral edge 10F of the absorbent main body 10. When worn, the longitudinal direction Y of the ventral waist portion 3 is oriented in a vertical direction perpendicular to the waist circumference direction R of the wearer, with the upper edge 3a located on the ventral side of the wearer and the lower edge 3b located on the crotch side of the wearer. The multiple elastic members 33 of the ventral waist portion 3 are arranged at intervals d1 in the longitudinal direction Y between the upper edge 3a and the lower edge 3b.

[0057] 3, the ventral waistline portion 3 includes a first highly elastic region R31, a second highly elastic region R32, a third highly elastic region R33, and a low-elastic region R34. The first highly elastic region R31, the second highly elastic region R32, and the third highly elastic region R33 are regions in which a plurality of elastic members 33 are arranged between the skin-facing sheet 31 and the non-skin-facing sheet 32, and are stretchable in the lateral direction X.

[0058] 3 , the first high-elasticity region R31 is disposed adjacent to the side edge 34 of the ventral waistline portion 3. The second high-elasticity region R32 is disposed adjacent to the side edge 34 and is spaced apart from the first high-elasticity region R31 in the lateral direction X (waistline direction R). The third high-elasticity region R33 is disposed at a position offset from the first high-elasticity region R31 and the second high-elasticity region R32 in the longitudinal direction Y, and is provided across the entire ventral waistline portion 3 in the lateral direction X. For example, the third high-elasticity region R33 is disposed between the low-elasticity region R34 and the upper edge 3 a of the ventral waistline portion 3.

[0059] The low-elasticity region R34 is disposed between the first high-elasticity region R31 and the second high-elasticity region R32. The low-elasticity region R34 is a region where the multiple elastic members 33 are not substantially disposed between the skin-facing sheet 31 and the non-skin-facing sheet 32, and has lower elasticity than the first high-elasticity region R31, the second high-elasticity region R32, and the third high-elasticity region R33. The low-elasticity region R34 is formed, for example, by cutting some of the multiple elastic members 33 midway in the lateral direction X. Note that some of the cut multiple elastic members 33 may remain in the low-elasticity region R34. The low-elasticity region R34 is disposed in a position overlapping the absorbent main body 10 when viewed from the thickness direction Z. By arranging the low-elasticity region R34 so as to overlap the absorbent main body 10, the contractile force of the multiple elastic members 33 is less likely to act on the absorbent main body 10, thereby suppressing contraction of the absorber 14 in the lateral direction X.

[0060] As described above, the low-elasticity region R34 is disposed adjacent to the first high-elasticity region R31 and the second high-elasticity region R32 in the lateral direction X, and adjacent to the third high-elasticity region R33 in the longitudinal direction Y. Typically, the low-elasticity region R34 is disposed in the central portion of the ventral waistline portion 3 in the lateral direction X. The width W2 of the low-elasticity region R34 in the lateral direction X may be smaller than the width W1 of the ventral side edge 10F of the absorbent main body 10 in the lateral direction X.

[0061] 1, a decoration 25 may be applied to the exterior sheet 13 in a position overlapping the low-stretch region R34. The decoration 25 may have a design that evokes high breathability. Examples of the decoration 25 that evokes high breathability include an illustration of an open window or an illustration of wavy lines representing wind.

[0062] The back waist portion 4 has a generally rectangular planar shape that is elongated in the lateral direction X of the diaper 1, and is disposed closer to the non-skin-facing side Z2 than the back portion 10b of the absorbent main body 10. The back waist portion 4 includes a skin-facing sheet 41 disposed on the skin-facing side Z1, a non-skin-facing sheet 42 disposed on the non-skin-facing side Z2, and a plurality of elastic members 43. The back portion 10b of the absorbent main body 10 is adhered to the skin-facing sheet 41 of the back waist portion 4 via an adhesive layer. The adhesive layer may extend continuously in the lateral direction X (waist-surrounding direction R).

[0063] Typically, the skin-facing sheet 41 and the non-skin-facing sheet 42 are made of a plain white nonwoven fabric. For example, the skin-facing sheet 41 and the non-skin-facing sheet 42 are made of an SMS nonwoven fabric in which spunbond, meltblown, and spunbond are laminated in this order, a spunbond nonwoven fabric, an air-through nonwoven fabric, or a laminate of these nonwoven fabrics. The skin-facing sheet 41 and the non-skin-facing sheet 42 are joined to each other with a hot melt adhesive applied to multiple elastic members 43. Therefore, non-adhesive regions where the skin-facing sheet 41 and the non-skin-facing sheet 42 are not directly adhered to each other are formed between the multiple elastic members 43.

[0064] In one embodiment, the non-skin-facing sheet 42 may be made of a porous nonwoven fabric having numerous openings, and the skin-facing sheet 41 may be made of a nonwoven fabric having no openings. Note that the openings referred to here do not refer to gaps between the fibers of the nonwoven fabric, but rather to through-holes formed by perforation. Therefore, the opening rate of the non-skin-facing sheet 42 is higher than that of the skin-facing sheet 41. By making the opening rate of the skin-facing sheet 41 relatively low, the feel of the diaper 1 against the skin is improved.

[0065] The plurality of elastic members 43 are disposed between the skin-facing sheet 41 and the non-skin-facing sheet 42 and are arranged at intervals d2 in the longitudinal direction Y. The plurality of elastic members 43 extend in the lateral direction X between the lateral end portions 44 of the back-side waistband portion 4 in the lateral direction X. Therefore, the back-side waistband portion 4 stretches in the lateral direction X, i.e., in the waist-circumference direction R, while fitting around the waist of the wearer. The plurality of elastic members 43 are made of an elastic material such as rubber thread or spandex.

[0066] 2 and 3, the back waist portion 4 has an upper edge 4a located on one side in the longitudinal direction Y and a lower edge 4b ​​located on the other side in the longitudinal direction Y. In the longitudinal direction Y, the upper edge 4a is located on the dorsal side of the dorsal edge 10R of the absorbent main body 10. The lower edge 4b ​​is located on the ventral side of the dorsal edge 10R of the absorbent main body 10. When worn, the longitudinal direction Y of the back waist portion 4 is oriented in a vertical direction perpendicular to the waist direction R of the wearer, with the upper edge 4a located on the dorsal side of the wearer and the lower edge 4b ​​located on the crotch side of the wearer. The multiple elastic members 33 of the back waist portion 4 are arranged at a predetermined interval d2 in the longitudinal direction Y between the upper edge 4a and the lower edge 4b.

[0067] Fig. 5 is a schematic plan view of the back waist portion 4 as seen from the non-skin-facing side Z2. Fig. 6 is a schematic cross-sectional view of the back waist portion 4 taken along line B-B in Fig. 5. Note that in the cross-sectional view shown in Fig. 6, for ease of explanation, the components are shown spaced apart in the thickness direction Z, but in reality, they are in contact with each other in the thickness direction Z. In one embodiment, as shown in Fig. 6, the non-skin-facing sheet 42 includes a folded-back portion 45 folded back toward the skin-facing side Z1 at the upper edge 4a. At least a portion of the folded-back portion 45 is positioned closer to the skin-facing side Z1 than the skin-facing sheet 41.

[0068] 3 and 5, the back waist portion 4 includes a first highly elastic region R41, a second highly elastic region R42, a third highly elastic region R43, and a low-elastic region R44. The first highly elastic region R41, the second highly elastic region R42, and the third highly elastic region R43 are regions in which a plurality of elastic members 43 are arranged between the skin-facing sheet 41 and the non-skin-facing sheet 42, and are stretchable in the lateral direction X.

[0069] 5 , the first high-elasticity region R41 is disposed adjacent to a side edge 44 of the back waistline portion 4. The second high-elasticity region R42 is disposed adjacent to the side edge 44 and is spaced apart from the first high-elasticity region R41 in the lateral direction X (waistline direction). The third high-elasticity region R43 is disposed at a position offset from the first high-elasticity region R41 and the second high-elasticity region R42 in the longitudinal direction Y and is provided across the entire back waistline portion 4 in the lateral direction X. For example, the third high-elasticity region R43 is disposed between the low-elasticity region R44 and the upper edge 4a of the back waistline portion 4.

[0070] The low-elasticity region R44 is disposed between the first high-elasticity region R41 and the second high-elasticity region R42. The low-elasticity region R44 is a region where substantially no elastic members 43 are disposed between the skin-facing sheet 41 and the non-skin-facing sheet 42, and has lower elasticity than the first high-elasticity region R41, the second high-elasticity region R42, and the third high-elasticity region R43. The low-elasticity region R44 is formed, for example, by cutting some of the elastic members 43 midway in the lateral direction X. Note that some of the cut elastic members 43 may remain in the low-elasticity region R44.

[0071] As described above, the low-elasticity region R44 is disposed adjacent to the first high-elasticity region R41 and the second high-elasticity region R42 in the lateral direction X, and adjacent to the third high-elasticity region R43 in the longitudinal direction Y. Typically, the low-elasticity region R44 is disposed in the center of the back waistband portion 4 in the lateral direction X. As shown in FIG. 3 , the width W3 of the low-elasticity region R44 in the lateral direction X may be smaller than the width W4 of the back edge 10R of the absorbent main body 10 in the lateral direction X. By making the width W3 of the low-elasticity region R44 smaller than the width W4 of the back edge 10R of the absorbent main body 10 in the lateral direction X, contraction of the low-elasticity region R44 is suppressed by the rigidity of the absorbent main body 10.

[0072] Furthermore, the width L2 of the low-elasticity region R44 in the longitudinal direction Y may be equal to or less than one-fourth the length of the side end portion 44 of the back waist portion 4 in the longitudinal direction Y, i.e., the length L1 of the joint portion 18 (see FIG. 3 ). By making the width L2 of the low-elasticity region R44 in the longitudinal direction Y relatively small, the contractile force of the waist portion 2 in the waist direction R is ensured, thereby improving the fit of the diaper 1.

[0073] As shown in Fig. 5, the low-elasticity region R44 is formed with a plurality of through-holes 50 that penetrate the back waistband 4 in the thickness direction Z. As shown in Fig. 6, the through-holes 50 penetrate the skin-facing sheet 41 and the non-skin-facing sheet 42 of the back waistband 4 in the thickness direction Z. The through-holes 50 have the function of discharging air from within the diaper 1 to the outside of the diaper 1, thereby improving breathability. In particular, since a wearer is prone to sweating on their backs, forming the through-holes 50 in the back waistband 4 can improve comfort when wearing the diaper 1.

[0074] The through-hole 50 is formed by making an annular cut in the low-elasticity region R44 and hollowing out a portion of the skin-facing sheet 41 and the non-skin-facing sheet 42 in the low-elasticity region R44. That is, the through-hole 50 has a certain opening area. Note that the annular cut means cutting a portion of the low-elasticity region R44 of the back waistline portion 4 all the way around, and the planar shape is not limited to a circular ring, but may include any ring shape such as a rectangular ring or a polygonal ring.

[0075] For example, as shown in FIG. 5 , the through hole 50 has a heart-shaped opening. As shown in FIGS. 7( a ) to 7 ( d ), the opening shape of the through hole 50 is not limited to a heart shape and can have various other shapes. FIG. 7( a ) shows a round through hole 50, and FIG. 7( b ) shows an animal (cat)-shaped through hole 50. FIG. 7( c ) shows a wing-shaped through hole 50, and FIG. 7( d ) shows a through hole 50 with a shape combining a heart and a wing. The opening shape of the through hole 50 may be elliptical, semicircular, teardrop-shaped, diamond-shaped, polygonal, or the like. Because the through hole 50 is formed in the low-elasticity region R44, there is a region around the through hole 50 where the multiple elastic members 43 are not arranged. Therefore, the contractile force of the multiple elastic members 43 prevents the through hole 50 from closing.

[0076] The contour line of the through hole 50 may be a smooth curve having a continuous curvature. For example, the contour line of the through hole 50 may have a radius of curvature of 2.5 mm or more. The radius of curvature of the contour line refers to the minimum radius of curvature of the contour line of the through hole 50. When the contour line of the through hole 50 is a smooth curve, peeling of the skin-contact sheet 41 and the non-skin-contact sheet 42 of the back waistline portion 4 from the portions corresponding to the corners of the through hole 50 is suppressed. Furthermore, the portions corresponding to the corners are prevented from coming into contact with the wearer, thereby preventing the diaper 1 from feeling uncomfortable against the skin.

[0077] Furthermore, the opening width H of the through-holes 50 in the vertical direction Y (the up-down direction when worn) may be larger than the predetermined spacing d2 between the multiple elastic members 43 in the vertical direction Y. The opening width H means the maximum width of the through-holes 50 in the vertical direction Y. By increasing the opening width H of the multiple through-holes 50, the opening area of ​​the multiple through-holes 50 increases, thereby improving the breathability of the diaper 1.

[0078] In one embodiment, as shown in FIG. 5 , the plurality of through holes 50 are arranged in the horizontal direction X (the waist-circumference direction R) within the low-stretch region R44. The plurality of through holes 50 may also be arranged in the vertical direction Y, or in a direction inclined relative to the horizontal direction X and the vertical direction Y. The plurality of through holes 50 may also be arranged along an arch-shaped curve, or may be distributed two-dimensionally within the low-stretch region R44. The opening areas of the through holes 50 may be equal to or different from each other. The opening area of ​​the through holes 50 can be measured as follows. First, the diaper 1 is removed from the package, and the waist portion 2 is pulled left and right to smooth out any wrinkles in the low-stretch region R44. Next, a photograph is taken from directly above the through hole 50. Finally, the photographed image is analyzed using general area analysis software to measure the opening area of ​​the through hole 50. It is sufficient that at least one through hole 50 is formed in the low-stretch region R44. 5, four through holes 50 are arranged in the horizontal direction X. Of the four through holes 50, the two central through holes 50 in the horizontal direction X are arranged on an extension line of a pair of channel portions 20 (see FIG. 2).

[0079] When the upper region 46 of the low-elasticity region R44 is located closer to the upper edge 4a than the center line CL of the low-elasticity region R44 in the longitudinal direction Y, and the lower region 47 is located closer to the lower edge 4b ​​than the center line CL of the low-elasticity region R44 in the longitudinal direction Y, the opening area of ​​the plurality of through holes 50 in the upper region 46 may be larger than the opening area of ​​the plurality of through holes 50 in the lower region 47. For example, when the plurality of through holes 50 are arranged in the longitudinal direction Y, the opening area of ​​each through hole 50 may decrease from the back side to the ventral side. This increases the opening area of ​​the plurality of through holes 50 on the back side where sweating is more likely, allowing moisture inside the diaper 1 to be efficiently discharged through the plurality of through holes 50.

[0080] The skin-facing sheet 41 and the non-skin-facing sheet 42 in the low-elasticity region R44 are directly bonded to each other at least around the through-holes 50. Direct bonding of the skin-facing sheet 41 and the non-skin-facing sheet 42 means that the skin-facing sheet 41 and the non-skin-facing sheet 42 are bonded in contact with each other without an elastic member 43 interposed between them. In one embodiment, the skin-facing sheet 41 and the non-skin-facing sheet 42 may be directly bonded to each other with an adhesive throughout substantially the entire low-elasticity region R44. As described above, in the first high-elasticity region R41, the second high-elasticity region R42, and the third high-elasticity region R43, the skin-facing sheet 41 and the non-skin-facing sheet 42 are bonded to each other via the elastic member 43, whereas in the low-elasticity region R44, the skin-facing sheet 41 and the non-skin-facing sheet 42 are directly bonded to each other with an adhesive.

[0081] 3 and 6 , the plurality of through-holes 50 are arranged in the longitudinal direction Y between the back edge 10R of the absorbent main body 10 and the upper edge 4a of the back waistline portion 4. That is, the plurality of through-holes 50 are arranged at positions that do not overlap with the absorbent main body 10 when viewed from the thickness direction Z. As a result, the flow of air through the plurality of through-holes 50 is not obstructed, and the breathability of the diaper 1 can be improved.

[0082] In one embodiment, the diaper 1 further includes a cover sheet 60. As shown in Fig. 2, the cover sheet 60 includes a ventral cover sheet 61 attached to the skin-facing sheet 31 of the ventral waist portion 3 from the skin-facing side Z1, and a back cover sheet 62 attached to the skin-facing sheet 41 of the back waist portion 4 from the skin-facing side Z1. The ventral cover sheet 61 has a long strip shape in the lateral direction X and is joined to the absorbent main body 10 and the skin-facing sheet 31 of the ventral waist portion 3 so as to cover the ventral edge 10F of the absorbent main body 10. The back cover sheet 62 has a long strip shape in the lateral direction X and is joined to the absorbent main body 10 and the skin-facing sheet 41 of the back waist portion 4 so as to cover the back edge 10R of the absorbent main body 10. The widths in the horizontal direction X of the ventral cover sheet 61 and the back cover sheet 62 are substantially equal to the widths in the horizontal direction X of the ventral waistline portion 3 and the back waistline portion 4, respectively, and the widths in the vertical direction Y of the ventral cover sheet 61 and the back cover sheet 62 are smaller than the widths in the vertical direction Y of the ventral waistline portion 3 and the back waistline portion 4, respectively. The ventral cover sheet 61 and the back cover sheet 62 are arranged along the waist of the wearer when connected. Hereinafter, when there is no need to particularly distinguish between the ventral cover sheet 61 and the back cover sheet 62, the ventral cover sheet 61 and the back cover sheet 62 may be collectively referred to as cover sheet 60.

[0083] The cover sheet 60 is made of, for example, polyethylene terephthalate (PET) fibers, polypropylene (PP) fibers, or mixtures thereof, rayon, fibrillated rayon, or other regenerated cellulose fibers, cotton, or natural cellulose fibers such as ground pulp, whose fiber surfaces have been hydrophilically treated. The cover sheet 60 may be a sweat-absorbent sheet having a higher water absorbency than the skin-facing sheets 31, 41 and the non-skin-facing sheets 32, 42. The high water absorbency of the cover sheet 60 allows moisture in the diaper 1 to be absorbed by the cover sheet 60, thereby preventing the diaper from becoming stuffy during wear.

[0084] 2 and 6 , the back cover sheet 62 is disposed so as to overlap at least a portion of the low-elasticity region R44 as viewed in the thickness direction Z, and covers the through-holes 50 from the skin-facing side Z1. In one embodiment, the ventral edge 62F of the back cover sheet 62 is disposed more ventrally than the back edge 10R of the absorbent main body 10, and the back edge 62R of the back cover sheet 62 is disposed more dorsally than the low-elasticity region R44. As a result, the back cover sheet 62 is disposed so as to overlap a portion of the absorbent main body 10, the first high-elasticity region R41, the second high-elasticity region R42, and the low-elasticity region R44 as viewed in the thickness direction Z. Covering the through-holes 50 with the back cover sheet 62 improves the feel of the diaper 1 against the skin and suppresses urine leakage through the through-holes 50.

[0085] The back cover sheet 62 may include an adhesive region 63 that is bonded to the absorbent main body 10 and the skin-facing sheet 41 with an adhesive, and a non-adhesive region 64 that is not bonded to the skin-facing sheet 41 with an adhesive (see FIGS. 2 and 6 ). The adhesive region 63 of the back cover sheet 62 is a region of the back cover sheet 62 that overlaps a portion of the absorbent main body 10, the first high-elasticity region R41, and the second high-elasticity region R42, when viewed from the thickness direction Z. The adhesive region 63 is bonded to a portion of the absorbent main body 10, the first high-elasticity region R41, and the second high-elasticity region R42 with a hot melt adhesive HM. The non-adhesive region 64 of the back cover sheet 62 overlaps the low-elasticity region R44 when viewed from the thickness direction Z. The non-adhesive region 64 is not bonded to the low-elasticity region R44 with the hot melt adhesive HM. Instead, the non-adhesive region 64 is pressure-bonded to the low-elasticity region R44 of the skin-facing sheet 41 by embossing. Here, when the non-adhesive region 64 of the back cover sheet 62 is pressed against the skin-facing sheet 41, the recesses or protrusions formed by embossing may be arranged along a direction inclined with respect to the waist-circumference direction R. By pressing the non-adhesive region 64 against the low-elasticity region R44 by embossing, leakage of the hot melt adhesive HM from the multiple through-holes 50 is prevented.

[0086] The cover sheet 60 may be colored a different color from the non-skin-facing sheets 32, 42. For example, the cover sheet 60 may have a color difference ΔE of 4 or more relative to the non-skin-facing sheets 32, 42 in the L*a*b* color space. The color difference ΔE is calculated using the following formula. The larger the color difference ΔE, the greater the color difference. ΔE=((L2-L1) ２ + (a2-a1) ２ + (b2-b1) ２ ) １／２ L2: L value of non-skin-facing sheets 32, 42 L1: L value of cover sheet 60 a2: a value of non-skin-facing sheets 32, 42 a1: a value of cover sheet 60 b2: b value of non-skin-facing sheets 32, 42 b1: b value of cover sheet 60

[0087] Increasing the color difference ΔE between the cover sheet 60 and the non-skin-facing sheets 32, 42 allows the colored cover sheet 60 to be seen through the multiple through-holes 50 when viewing the diaper 1 from the non-skin-facing side Z2. This improves the visibility of the multiple through-holes 50, thereby impressing on the user that the diaper 1 has high breathability. The color difference ΔE can be measured, for example, using a spectrophotometer 3nh (model number: CR8) manufactured by Shenzhen Threenh Technology Co., Ltd. For example, 10 cm x 10 cm test pieces are cut from each of ten diapers 1 and placed on a reference plate with sample number No. 502515 in a constant temperature and humidity chamber. The color difference ΔE is then measured using the spectrophotometer 3nh described above, and the average value is taken as the color difference ΔE.

[0088] Moisture-laden air within the diaper 1 is discharged to the outside through the back cover sheet 62 and the through-holes 50. The portion of the back waist portion 4 where the plurality of through-holes 50 are formed has higher breathability than other portions. For example, the airflow resistance of the first air passage P1 passing through the back cover sheet 62 and the through-holes 50 may be half or less of the airflow resistance of the second air passage P2 passing through the back cover sheet 62, the skin-facing sheet 41, and the non-skin-facing sheet 42 (see FIG. 6 ). The airflow resistance can be determined, for example, by cutting test pieces of predetermined dimensions from the back waist portion 4 of three diapers 1, measuring the airflow resistance of each of the three test pieces using a Kato Tech Co., Ltd. air permeability tester (KES-F8) or an equivalent air permeability tester, and calculating the average value.

[0089] When putting the diaper 1 on a wearer, the wearer first places both legs through the waist opening BH and the pair of leg openings LH, and then pulls up the diaper 1. This positions the waist section 2 around the wearer's waist, and positions the crotch section 10c of the absorbent main body 10 so as to cover the wearer's crotch. Since the multiple through-holes 50 formed in the back waist section 4 are positioned on the back side of the wearer, moisture, including sweat, from the wearer is expelled to the outside of the diaper 1 through the back cover sheet 62 and the multiple through-holes 50. This prevents the diaper 1 from becoming stuffy. In particular, since the multiple through-holes 50 are formed in the low-stretch region R44, which has low stretchability, the multiple through-holes 50 are prevented from closing due to contraction of the multiple elastic members 43. As a result, air can enter and exit through the multiple through-holes 50, improving the breathability of the diaper 1.

[0090] Next, a diaper according to another embodiment will be described. Fig. 8 is a cross-sectional view of a diaper according to another embodiment. As shown in Fig. 8, a standing portion 65 is provided at the edge on the ventral side (the crotch portion 10c side) of the back coversheet 62. The standing portion 65 is part of the back coversheet 62 and is not joined to the absorbent main body 10. The standing portion 65 includes an elastic member 66 arranged along the ventral edge of the back coversheet 62, and stands up relative to the absorbent main body 10 as the elastic member 66 contracts in the lateral direction X. By having the standing portion 65 standing up relative to the absorbent main body 10, urine discharged into the absorbent main body 10 and flowing toward the back waistband portion 4 is blocked by the standing portion 65, thereby suppressing urine leakage from the multiple through-holes 50.

[0091] Fig. 9 is a cross-sectional view of a diaper according to yet another embodiment. As shown in Fig. 9, the folded-back portion 45 of the non-skin-facing sheet 42 is folded back at its upper edge 4a toward the skin-facing side Z1 and extends further toward the ventral side than the back-side edge 10R of the absorbent main body 10 when viewed in the thickness direction Z. A standing portion 48 is provided at the edge of the ventral side (the crotch portion 10c side) of the folded-back portion 45. The standing portion 48 is part of the non-skin-facing sheet 42 and is not joined to the absorbent main body 10. The standing portion 48 includes an elastic member 49 disposed along the ventral side edge of the folded-back portion 45. The elastic member 49 contracts in the lateral direction X, causing the standing portion 48 to stand up relative to the absorbent main body 10. By having the standing portion 48 stand up relative to the absorbent main body 10, urine discharged into the absorbent main body 10 and flowing toward the back waistband portion 4 is blocked by the standing portion 48, thereby suppressing urine leakage through the multiple through-holes 50.

[0092] While the diaper 1 according to various embodiments has been described above, the present invention is not limited to the above-described embodiments and various modifications can be made without departing from the spirit of the invention. In other words, it should be noted that the above-described embodiments are for illustrative purposes only and do not limit the scope of the present invention. The above-described various embodiments can be combined within a consistent range.

[0093] For example, in the above embodiment, a plurality of through holes 50 are formed in the low-elasticity region R44 of the back-side waistline portion 4, but it is sufficient that at least one through hole 50 is formed in the back-side waistline portion 4. Furthermore, it is sufficient that the through hole 50 is formed in at least one of the ventral waistline portion 3 and the back-side waistline portion 4. For example, one or more through holes 50 may be formed only in the low-elasticity region R34 of the ventral waistline portion 3, or one or more through holes 50 may be formed in both the low-elasticity region R34 of the ventral waistline portion 3 and the low-elasticity region R44 of the back-side waistline portion 4.

[0094] In the embodiment shown in Fig. 2, the cover sheet 60 is attached to the skin-facing sheets 31, 41 of the waistline portion 2 from the skin-facing side Z1, but the cover sheet 60 does not have to be attached to the skin-facing sheets 31, 41 as long as it is attached to the waistline portion 2 so as to overlap the through-hole 50 when viewed from the thickness direction Z. For example, the cover sheet 60 may be attached to the non-skin-facing sheets 32, 42 from the non-skin-facing side Z2 so as to cover the through-hole 50. The cover sheet 60 may also be disposed between the skin-facing sheet 31 and the non-skin-facing sheet 32, and between the skin-facing sheet 41 and the non-skin-facing sheet 42. Even in such cases, providing the cover sheet 60 so as to overlap the through-hole 50 can prevent urine leakage from the through-hole 50.

[0095] The present disclosure includes the following: [1] A pants-type disposable diaper comprising: an absorbent main body including a abdominal portion located on the abdominal side of a wearer when worn, a dorsal portion located on the dorsal side of the wearer when worn, and a crotch portion disposed between the abdominal portion and the dorsal portion, and extending in a longitudinal direction between the abdominal side and the dorsal side when worn, and a waist portion including a abdominal waist portion connected to the abdominal portion and a dorsal waist portion connected to the dorsal portion, and extending in a waist direction of the wearer, wherein at least one of the abdominal waist portion and the dorsal waist portion includes a first high-elasticity region, a second high-elasticity region spaced apart from the first high-elasticity region in the waist direction, and a low-elasticity region disposed between the first high-elasticity region and the second high-elasticity region and having lower elasticity than the first high-elasticity region and the second high-elasticity region, and wherein the low-elasticity region has a through-hole penetrating the waist portion in a thickness direction.

[0096] [2] The pants-type disposable diaper according to [1], wherein at least one of the ventral waistband portion and the dorsal waistband portion includes a third high-elasticity region adjacent to the low-elasticity region in the longitudinal direction and having higher elasticity than the low-elasticity region.

[0097] [3] The pants-type disposable diaper according to [1] or [2], wherein the low-elasticity region has a plurality of through-holes including the through-hole.

[0098] [4] The pants-type disposable diaper according to any one of [1] to [3], wherein the rear waist portion includes a lower edge located on the crotch portion side and an upper edge located on the opposite side of the lower edge in the longitudinal direction, and the through-hole is formed in the rear waist portion between the rear edge of the absorbent main body and the upper edge of the rear waist portion.

[0099] [5] The pants-type disposable diaper according to [4], wherein, when the region of the low-elasticity region that is closer to the upper edge than the center line of the low-elasticity region in the longitudinal direction is defined as an upper region, and the region of the low-elasticity region that is closer to the lower edge than the center line is defined as a lower region, the opening area of ​​the through hole in the upper region is larger than the opening area of ​​the through hole in the lower region.

[0100] [6] The pants-type disposable diaper according to any one of [1] to [5], wherein the waist portion includes a skin-facing sheet arranged on the skin-facing side of the wearer, a non-skin-facing sheet arranged on the non-skin-facing side of the wearer, and a plurality of elastic members arranged between the skin-facing sheet and the non-skin-facing sheet, and the pants-type disposable diaper further includes a cover sheet attached to the waist portion so as to overlap the through-hole when viewed in the thickness direction.

[0101] [7] The pants-type disposable diaper according to [6], wherein the cover sheet is attached to the skin-facing sheet from the skin-facing side so as to cover the through-holes.

[0102] [8] The pants-type disposable diaper according to [6], wherein the cover sheet is attached to the non-skin-facing sheet from the non-skin-facing side so as to cover the through-holes.

[0103] [9] The pants-type disposable diaper according to [6], wherein the cover sheet is disposed between the skin-facing sheet and the non-skin-facing sheet.

[0104]

[10] The pants-type disposable diaper according to [6], wherein the air resistance value of the first air passage passing through the cover sheet and the through-hole is 1 / 2 or less of the air resistance value of the second air passage passing through the cover sheet, the skin-facing sheet, and the non-skin-facing sheet.

[0105]

[11] The pants-type disposable diaper according to [6] or [7], wherein the cover sheet is colored in a color different from that of the non-skin-facing sheet, and the color difference ΔE between the cover sheet and the non-skin-facing sheet is 4 or more.

[0106]

[12] The pants-type disposable diaper according to any one of [6] to

[11] , wherein the cover sheet is a sweat-absorbent sheet having a water absorbency higher than that of the skin-facing sheet and the non-skin-facing sheet.

[0107]

[13] The pants-type disposable diaper according to any one of [6] to

[12] , wherein at least a part of the cover sheet is disposed on the skin-facing side of the absorbent main body and has a standing part that stands up relative to the absorbent main body due to the contraction force of an elastic member disposed along the edge of the cover sheet on the crotch side.

[0108]

[14] The pants-type disposable diaper according to any one of [6] to

[12] , wherein the non-skin-facing sheet includes a folded-up portion that is folded in the thickness direction and is arranged on the skin-facing side of the absorbent main body, and the folded-up portion has a standing portion that stands up against the absorbent main body due to the contractile force of an elastic member that is arranged along the edge of the folded-up portion on the crotch side.

[0109]

[15] The pants-type disposable diaper according to any one of [1] to

[14] , further comprising a post-treatment tape for holding the pants-type disposable diaper in a rolled-up state when the pants-type disposable diaper is disposed of, the post-treatment tape being positioned so as not to overlap the through-hole.

[0110]

[16] The pants-type disposable diaper according to any one of [6] to

[14] , wherein the plurality of elastic members are arranged at predetermined intervals in the longitudinal direction in the first high-elasticity region and the second high-elasticity region, and the maximum width of the through holes in the longitudinal direction is greater than the predetermined intervals.

[0111]

[17] The pants-type disposable diaper according to any one of [6] to

[14] , wherein the non-skin-facing sheet is made of a porous nonwoven fabric having a higher porosity than the skin-facing sheet.

[0112]

[18] The pants-type disposable diaper according to any one of [6] to

[14] , wherein the through-holes are formed by cutting out parts of the skin-facing sheet and the non-skin-facing sheet.

[0113]

[19] The pants-type disposable diaper according to any one of [1] to

[18] , wherein the absorbent body includes an exterior sheet including a decoration that evokes high breathability.

[0114]

[20] The pants-type disposable diaper according to any one of [1] to

[19] , wherein the width of the low-elasticity region in the waist direction is smaller than the width of the absorbent body in a direction perpendicular to the longitudinal direction.

[0115]

[21] The pants-type disposable diaper according to any one of [1] to

[20] , wherein the waist portion has a joint portion connecting an end of the ventral waist portion in the waist circumference direction and an end of the dorsal waist portion in the waist circumference direction, and the width of the low-elasticity region in the longitudinal direction is ¼ or less of the length of the joint portion in the longitudinal direction.

[0116]

[22] The pants-type disposable diaper according to [3], wherein the absorbent body includes an absorbent core having absorbent properties, the absorbent core has a pair of channel portions extending in the longitudinal direction, the basis weight of the pair of channel portions is lower than that of other portions of the absorbent core, and two of the plurality of through holes are arranged on extensions of the pair of channel portions.

[0117]

[23] The pants-type disposable diaper according to

[22] , wherein the pair of channel portions are non-penetrating grooves recessed in the thickness direction of the absorbent core.

[0118] 1...Pants-type disposable diaper, 2...Waist portion, 3...Ventral waist portion, 4...Dorsal waist portion, 13...Outer sheet, 15...Absorbent core, 18...Joint portion, 20...Channel portion, 49, 66...Stretchable member, 24...Post-treatment tape, 25...Decoration, 31, 41...Skin-facing sheet, 32, 42...Non-skin-facing sheet, 33, 43...Elastic member, 45...Fold-up portion, 46...Upper region, 47... Lower region, 48, 65...standing portion, 50...through hole, 60...cover sheet, R31, R41...first high-elasticity region, R32, R42...second high-elasticity region, R33, R43...third high-elasticity region, R34, R44...low-elasticity region, P1...first ventilation path, P2...second ventilation passage, R...waist direction, X...horizontal direction, Y...vertical direction, Z...thickness direction, Z1...skin-facing side, Z2...non-skin-facing side.

Claims

1. A pants-type disposable diaper comprising: an absorbent main body including a abdominal portion located on the abdominal side of a wearer when worn, a dorsal portion located on the dorsal side of the wearer when worn, and a crotch portion located between the abdominal portion and the dorsal portion, and extending longitudinally between the abdominal side and the dorsal side when worn; and a waist portion including a abdominal waist portion connected to the abdominal portion and a dorsal waist portion connected to the dorsal portion, and extending in the waist direction of the wearer, wherein at least one of the abdominal waist portion and the dorsal waist portion includes a first high-stretch region, a second high-stretch region spaced apart from the first high-stretch region in the waist direction, and a low-stretch region located between the first and second high-stretch regions and having lower stretchability than the first and second high-stretch regions, and wherein the low-stretch region has a through-hole that passes through the waist portion in the thickness direction.

2. A pants-type disposable diaper as described in claim 1, wherein at least one of the ventral waistband portion and the dorsal waistband portion includes a third high-elasticity region adjacent to the low-elasticity region in the longitudinal direction and having higher elasticity than the low-elasticity region.

3. The pants-type disposable diaper according to claim 1, wherein the low-elasticity region has a plurality of through-holes including the through-hole.

4. A pants-type disposable diaper as described in claim 1, wherein the rear waistband portion includes a lower edge located on the crotch side and an upper edge located opposite the lower edge in the longitudinal direction, and the through-hole is formed in the rear waistband portion between the rear edge of the absorbent main body and the upper edge of the rear waistband portion.

5. A pants-type disposable diaper as described in claim 4, wherein, when the region of the low-elasticity region that is closer to the upper edge than the center line of the low-elasticity region in the longitudinal direction is defined as an upper region, and the region of the low-elasticity region that is closer to the lower edge than the center line is defined as a lower region, the opening area of ​​the through hole in the upper region is larger than the opening area of ​​the through hole in the lower region.

6. A pants-type disposable diaper as described in claim 1, wherein the waist portion includes a skin-facing sheet arranged on the skin-facing side of the wearer, a non-skin-facing sheet arranged on the non-skin-facing side of the wearer, and a plurality of elastic members arranged between the skin-facing sheet and the non-skin-facing sheet, and the pants-type disposable diaper further includes a cover sheet attached to the waist portion so as to overlap the through-hole when viewed in the thickness direction.

7. The pants-type disposable diaper according to claim 6, wherein the cover sheet is attached to the skin-facing sheet from the skin-facing side so as to cover the through-holes.

8. The pants-type disposable diaper according to claim 6, wherein the cover sheet is attached to the non-skin-facing sheet from the non-skin-facing side so as to cover the through-hole.

9. The pants-type disposable diaper according to claim 6, wherein the cover sheet is disposed between the skin-facing sheet and the non-skin-facing sheet.

10. A pants-type disposable diaper as described in claim 6, wherein the air resistance value of the first air passage passing through the cover sheet and the through hole is less than half the air resistance value of the second air passage passing through the cover sheet, the skin-facing sheet and the non-skin-facing sheet.

11. The pants-type disposable diaper according to claim 6, wherein the cover sheet is colored a different color from the non-skin-facing sheet, and the color difference ΔE between the cover sheet and the non-skin-facing sheet is 4 or more.

12. The pants-type disposable diaper according to claim 6, wherein the cover sheet is a sweat-absorbent sheet having a higher water absorbency than the skin-facing sheet and the non-skin-facing sheet.

13. A pants-type disposable diaper as described in claim 6, wherein at least a portion of the cover sheet is positioned on the skin side of the absorbent body and has a standing portion that stands up against the absorbent body due to the contraction force of an elastic member positioned along the edge of the cover sheet on the crotch side.

14. A pants-type disposable diaper as described in claim 6, wherein the non-skin-facing sheet includes a folded portion that is folded in the thickness direction and is positioned on the skin-facing side of the absorbent main body, and the folded portion has a standing portion that stands up against the absorbent main body due to the contraction force of an elastic member positioned along the edge of the folded portion on the crotch side.

15. The pants-type disposable diaper according to claim 1, further comprising a post-treatment tape for holding the pants-type disposable diaper in a rolled-up state when the diaper is disposed of, the post-treatment tape being positioned so as not to overlap the through-hole.

16. A pants-type disposable diaper as described in claim 6, wherein the plurality of elastic members are arranged at predetermined intervals in the longitudinal direction in the first high-elasticity region and the second high-elasticity region, and the maximum width of the through holes in the longitudinal direction is greater than the predetermined intervals.

17. The pants-type disposable diaper according to claim 6, wherein the non-skin facing sheet is made of a porous nonwoven fabric having a higher porosity than the skin facing sheet.

18. The pants-type disposable diaper according to claim 6, wherein the through-holes are formed by cutting out a part of the skin-facing sheet and the non-skin-facing sheet.

19. The pants-type disposable diaper according to claim 1, wherein the absorbent body includes an exterior sheet including a decoration that evokes high breathability.

20. The pants-type disposable diaper according to claim 1, wherein the width of the low-elasticity region in the waist direction is smaller than the width of the absorbent body in a direction perpendicular to the longitudinal direction.

21. A pants-type disposable diaper as described in claim 1, wherein the waist portion has a joint portion connecting an end of the ventral waist portion in the waist direction and an end of the dorsal waist portion in the waist direction, and the width of the low-elasticity region in the longitudinal direction is 1 / 4 or less of the length of the joint portion in the longitudinal direction.

22. A pants-type disposable diaper as described in claim 3, wherein the absorbent body includes an absorbent core having absorbent properties, the absorbent core has a pair of channel portions extending in the longitudinal direction, the basis weight of the pair of channel portions is lower than that of other portions of the absorbent core, and two of the plurality of through holes are arranged on extensions of the pair of channel portions.

23. The pants-type disposable diaper according to claim 22, wherein the pair of channels are non-penetrating grooves recessed in the thickness direction of the absorbent core.

Images