Absorbent article

Abstract

Provided is an absorbent article (1) having a waist part and an absorbent body (10). An end on one side in the left-right direction of the waist part is joined by a side joining part (2b), and a fastening part (5) is provided. The waist part has a waist stretchable member (23), and the absorbent body (10) has a leg-surrounding stretchable member (17). An abdomen-side waist part (20) has, on one side thereof in the left-right direction, a portion where the waist stretchable member (23) and the leg-surrounding stretchable member (17) intersect. The value obtained by dividing the force required to extend a lower stretchable region (BE) by a predetermined length in the left-right direction by the width in the top-bottom direction of the lower stretchable region (BE) is greater than the value obtained by dividing the force required to extend a leg-surrounding stretchable region (LE) by a predetermined length in the top-bottom direction by the width in the left-right direction of the leg-surrounding stretchable region (LE).

Description

absorbent articles

[0001] The present invention relates to an absorbent article.

[0002]

[0003] Conventionally, there has been known an absorbent article that has leg openings on one side in the left-right direction, and that can form a leg opening on the other side by engaging a fastening portion (locking tab) provided on the other side with a waist portion. Such an absorbent article can be put on by a wearer by passing one leg through the leg opening on one side, pulling it up to the crotch area, and then engaging the fastening portion on the other side. For example, Patent Document 1 discloses a disposable diaper that can be put on by a wearer by passing one leg through a leg hole (leg opening) formed on one side of a waist portion (waist portion), and then fastening the other side of the waist portion with a fastening means (locking tab).

[0003] Publication No. 7-17304

[0004] However, conventional absorbent articles such as those disclosed in Patent Document 1 have the problem that when a wearer puts one leg through the leg openings and pulls them up, it is difficult to sufficiently pull up the leg openings when pulling the waistband, making it difficult to securely fit the leg openings around the wearer's groin. Furthermore, the leg openings tend to shift position, which requires the wearer to repeatedly re-engage the fastening parts when putting on the article, resulting in the hassle of adjusting the position and fit of the leg openings.

[0005] The present invention has been made in consideration of the above-mentioned conventional problems, and its purpose is to improve the fit of the leg openings in absorbent articles that have leg openings on one side in the left-right direction and fastening parts on the other side, thereby reducing the effort required when putting them on.

[0006] The main invention for achieving the above object is an absorbent article having a waistline portion having a vertical direction, a horizontal direction, and a front-to-rear direction that intersect with one another, the waistline portion having a ventral waistline portion and a back waistline portion, and an absorbent main body, wherein one end of the ventral waistline portion and the back waistline portion in the horizontal direction are joined at a side joining portion, and the waistline portion has a fastening portion having an engaging portion that detachably engages with the non-skin side of the waistline portion, the waistline portion has waistline elastic members that stretch in the horizontal direction, the absorbent main body has leg elastic members that stretch in the vertical direction on both sides in the horizontal direction, and when viewed in the front-to-rear direction, the waistline elastic members stretch in the vertical direction on one side of the ventral waistline portion in the horizontal direction, and an area where the waist elastic member intersects with the leg elastic member or an extension thereof, and when the area where the waist elastic member is provided in the waist section below the vertical center of the side joint is defined as a lower elastic region, and the area where the leg elastic member is provided in the absorbent main body is defined as a leg elastic region, the value obtained by dividing the force required to stretch the lower elastic region by a predetermined length in the left-right direction by the vertical width of the lower elastic region is greater than the value obtained by dividing the force required to stretch the leg elastic region by the vertical width of the leg elastic region.

[0007] Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0008] According to the present invention, in an absorbent article having leg openings on one side in the left-right direction and a fastening portion on the other side, the fit of the leg openings can be improved and the effort required when putting the article on can be reduced.

[0009] 1 is a perspective view of the disposable diaper 1 in a worn state; 2 is a plan view of the diaper 1 in an unfolded and stretched state, as seen from the non-skin side; 3 is an enlarged view of portion X in FIG. 2; 4 is a diagram illustrating the separation of the ventral waistline portion 20 and the formation of waist-line openings; 5 is a diagram illustrating the cutting operation of the ventral waistline portion 20; 6 is an enlarged view of one side region in the left-right direction of the ventral waistline portion 20 and the absorbent main body 10 in a stretched state; 7A to 7C are diagrams illustrating a method for measuring the stretch force of the lower stretchable region BE; 8 is a partially enlarged view of the diaper 1 in a stretched state, illustrating the state when the fastening portion 5 is aligned with the position of the marker portion 60 and engaged with the ventral waistline portion 20; and 9 is an enlarged view of portion Y in FIG. 8. 10A and 10B are diagrams illustrating the length of the stretchable member along the periphery of the leg-openings LH.

[0010] At least the following matters will become clear from the description of this specification and the accompanying drawings.

[0011] (Aspect 1) An absorbent article having a waistline portion having a vertical direction, a horizontal direction, and a front-to-rear direction intersecting each other, the waistline portion including a ventral waistline portion and a back waistline portion, and an absorbent main body, wherein one end of the ventral waistline portion and the back waistline portion in the horizontal direction are joined at a side joining portion, and a fastening portion having an engaging portion that detachably engages with the non-skin side of the waistline portion, the waistline portion has waistline stretchable members that stretch in the horizontal direction, and the absorbent main body has leg stretchable members that stretch in the vertical direction on both sides in the horizontal direction, and when viewed in the front-to-rear direction, the waistline stretchable members and the leg stretchable members are stretched in the vertical direction on one side of the horizontal direction of the ventral waistline portion, and wherein the region where the waistline elastic member is provided on the waist portion below the vertical center of the side joint is defined as a lower elastic region, and the region where the leg-opening elastic members are provided on the absorbent main body is defined as a leg-opening elastic region, the value obtained by dividing the force required to stretch the lower elastic region by a predetermined length in the left-right direction by the vertical width of the lower elastic region is greater than the value obtained by dividing the force required to stretch the leg-opening elastic region by the vertical width of the leg-opening elastic region.

[0012] According to the absorbent article of Aspect 1, when putting on the absorbent article, after the wearer's legs are passed through the leg openings on one side in the left-right direction, when the waist portion (ventral waist portion) is grasped and pulled upward, force is transmitted to the leg elastic members via the waist elastic members, making it easier to pull up the leg elastic regions. Furthermore, the leg elastic regions are more likely to be stretched vertically with a force weaker than the force acting in the direction stretching the lower elastic region in the left-right direction, making it easier to pull up the leg elastic regions in conjunction with the lower elastic region compared to the reverse case. This makes it easier for the leg elastic regions and the leg openings along the lower elastic region to fit the wearer's groin, at least on the front side (ventral side) in the front-to-back direction. Furthermore, when engaging the fastening parts after pulling up the waist portion, the effort required to adjust the position of the leg openings by repeatedly attaching and detaching the fastening parts to improve fit around the groin is reduced.

[0013] (Aspect 2) The absorbent article according to Aspect 1, wherein, on one side in the left-right direction of the ventral waistline portion and the back waistline portion, when viewed in the front-to-back direction, the waistline elastic members and the leg line elastic members or their extensions intersect at the ventral waistline portion and the back waistline portion, respectively, and the force required to stretch the lower elastic region by a predetermined length along the left-right direction divided by the width of the lower elastic region in the up-down direction is greater than the force required to stretch the leg line elastic region by the predetermined length along the up-down direction divided by the width of the leg line elastic region in the left-to-right direction.

[0014] According to the absorbent article of Aspect 2, when the waist portion (ventral waist portion and rear waist portion) is grasped and pulled up during putting on the absorbent article, force is transmitted to the leg elastic members via the abdominal and rear waist elastic members, making it easier to pull up the leg elastic regions. Furthermore, the leg elastic regions are more likely to be stretched vertically with a force weaker than the force acting in the direction stretching the lower elastic region left and right, making it easier to pull up the leg elastic regions in conjunction with the lower elastic region compared to the reverse case. Therefore, the leg elastic regions and the leg openings along the lower elastic region fit more easily around the wearer's groin on both the abdominal and rear sides.

[0015] (Aspect 3) The absorbent article according to aspect 1 or 2, wherein at least one of the waist stretch members and one of the leg stretch members intersect on one side in the left-right direction of the ventral waist portion and the dorsal waist portion when viewed in the front-to-rear direction, and the force required to stretch one of the intersecting waist stretch members by a predetermined length in the left-right direction is greater than the force required to stretch one of the intersecting leg stretch members by the predetermined length in the up-down direction.

[0016] According to the absorbent article of aspect 3, when the waist portion is pulled up during putting on the absorbent article, a force is likely to act directly on the leg elastic members that intersect with the waist elastic members, and the leg elastic members are likely to be pulled up in conjunction with the waist elastic members, making it easier for the leg openings to fit closely to the groin area. As a result, when the fastening portions are engaged on the other side in the left-right direction, the position of the leg openings on one side in the left-right direction is less likely to shift, making it easier to put on the absorbent article.

[0017] (Aspect 4) The absorbent article according to any one of Aspects 1 to 3, wherein, on one side in the left-right direction of the ventral waistline portion and the dorsal waistline portion, when viewed in the front-to-rear direction, a plurality of the waistline stretch members and the legline stretch members intersect, and the force required to stretch the plurality of intersecting waistline stretch members by the predetermined length along the left-right direction is greater than the force required to stretch the plurality of intersecting legline stretch members by the predetermined length along the up-down direction.

[0018] According to the absorbent article of aspect 4, when the waist portion is pulled up during putting on the absorbent article, a larger force is likely to act on the multiple leg elastic members that intersect with the waist elastic members. This makes it easier for the multiple leg elastic members to be pulled up in conjunction with the multiple waist elastic members, and the leg openings LH are more likely to fit closely to the groin area, making it less likely for the leg openings to shift position when engaging the fastening parts, making putting on the absorbent article easier.

[0019] (Aspect 5) The absorbent article of any one of Aspects 1 to 4, wherein, on the one side in the left-right direction of the ventral waistline portion, when viewed in the front-to-rear direction, the force required to stretch the waistline stretch members, which have portions that intersect with the leg stretch members in the lower elasticized region, by a predetermined length along the left-right direction is smaller than the force required to stretch the waistline stretch members, which do not have portions that intersect with the leg stretch members in the lower elasticized region, by a predetermined length along the left-right direction.

[0020] According to the absorbent article of aspect 5, the region on one side of the ventral waistline in the left-right direction where the leg elastic members and the waist elastic members intersect near the periphery of the leg openings is more easily stretched in the left-right direction than other regions, making it easier for the leg openings to open. This makes it easier for the wearer to widen the leg openings when putting on the absorbent article, and also makes it less likely for the wearer's legs to get caught in the leg openings LH when putting their legs through the leg openings.

[0021] (Aspect 6) The absorbent article according to any one of Aspects 1 to 5, wherein, when viewed in the front-to-rear direction, on the ventral side in the front-to-rear direction and on one side in the left-to-right direction, the length in the up-down direction of the area where the waistline stretchable member and the legline stretchable member intersect is shorter than the length in the left-to-right direction of the waistline stretchable member provided on the other side in the left-to-right direction of the area where the waistline stretchable member and the legline stretchable member intersect.

[0022] In the absorbent article of aspect 6, the area where the waist stretchable member and the leg stretchable member intersect (the intersecting area) is more easily pulled to the other side in the left-right direction than in the opposite case. Therefore, when the fastening part is pulled to the other side in the left-right direction while being wrapped around the abdominal waist part to engage it during the putting action of the absorbent article, the intersecting area is more easily able to resist the force pulling to one side in the left-right direction. This makes it less likely that the position of the leg openings (the position of the intersecting area) will shift relative to the wearer's groin, and the fit of the leg openings will be less likely to deteriorate.

[0023] (Aspect 7) The absorbent article according to any one of Aspects 1 to 6, wherein the ventral waistline portion is provided with a marker portion for engaging with the fastening portion, and when the absorbent article is opened, the fastening portion is engaged on the other side in the left-right direction of the position of the marker portion, and when the absorbent article is opened, the other side in the left-right direction of the ventral waistline portion does not have a portion where the waistline elastic members and the leg line elastic members intersect when viewed in the front-to-back direction, but when the fastening portion is engaged with the ventral waistline portion in accordance with the position of the marker portion, when viewed in the front-to-back direction, there is a portion where the waistline elastic members and the leg line elastic members or extensions thereof intersect when viewed in the front-to-back direction.

[0024] According to the absorbent article of aspect 7, when the package is opened, the stretchable force of the leg stretchable members is less likely to act on the waist stretchable members on the other side in the left-right direction, making it easier to stably maintain the state in which the fastening parts are engaged with the engaged parts. On the other hand, when the fastening parts are engaged in accordance with the positions of the marker parts, the waist stretchable members and the leg stretchable members work together to make it easier for the stretchable force to act along the leg openings, making it easier for the leg openings to fit around the wearer's groin on the other side in the left-right direction.

[0025] (Aspect 8) The absorbent article according to any one of Aspects 1 to 7, wherein when viewed in the front-to-rear direction with the fastening portion engaged with the abdominal waistband portion in alignment with the position of the marker portion on the other side in the left-right direction, the end of one side of the waistline elastic member is located on the other side in the left-right direction relative to the leg line elastic member that is located closest to the one side.

[0026] According to the absorbent article of aspect 8, compared to the opposite case, the waist elastic member is less likely to exert an excessively large stretching force in the left-right direction, making it easier to align and engage the fastening part with the marker part, and making it less likely that the engaging part and the engaged part will come out of engagement. When the fastening part is aligned with and engaged with the marker part, the waist elastic member and the leg elastic member work together to exert a stretching force along the periphery of the leg openings, making it easier for the leg openings to fit around the wearer's groin on the other left-right side.

[0027] (Aspect 9) The absorbent article according to any one of Aspects 1 to 8, wherein when viewed in the front-to-rear direction with the fastening portion engaged with the abdominal waistband portion in alignment with the position of the marker portion on the other side in the left-right direction, the engaging portion provided on the fastening portion is located on the one side in the left-right direction relative to the leg opening stretchable member that is located furthest on the one side.

[0028] According to the absorbent article of Aspect 9, the stretching force of the leg elastic members is less likely to act on the region where the ventral waist portion (engaged portion) and the fastening portion (engaging portion) are engaged. Therefore, wrinkles and distortions are less likely to form in this region, and the region is more likely to maintain a flat shape, making it less likely for the engaged portion and the fastening portion (engaging portion) to disengage. This further improves the fit when worn.

[0029] (Aspect 10) The absorbent article according to any one of Aspects 1 to 9, wherein in a stretched state, with the fastening portion engaged with the ventral waist portion in alignment with the position of the marker portion, the total length of the waist stretchable member and the leg stretchable member arranged along the periphery of the leg openings on one side in the left-right direction is longer than the total length of the waist stretchable member and the leg stretchable member arranged along the periphery of the leg openings on the other side in the left-right direction.

[0030] According to the absorbent article of Aspect 10, when putting on the absorbent article, the perimeter of the leg opening on one side in the left-right direction, which is the opening through which the wearer's legs are passed first, is longer than the perimeter of the leg opening on the other side, making it less likely that the wearer's legs will get caught in the leg opening on one side in the left-right direction compared to the reverse case, which makes it easier to put on the absorbent article smoothly and makes it easier to fit the leg opening on one side in the left-right direction around the wearer's groin.

[0031] (Aspect 11) The absorbent article according to any one of Aspects 1 to 10, wherein in a natural state, with the fastening portion engaged with the ventral waist portion in alignment with the position of the marker portion, the total length of the waist stretchable member and the leg stretchable member arranged along the periphery of the leg opening on one side in the left-right direction is longer than the total length of the waist stretchable member and the leg stretchable member arranged along the periphery of the leg opening on the other side in the left-right direction.

[0032] According to the absorbent article of aspect 11, compared to the opposite case, even if the absorbent article is not sufficiently stretched when putting it on, the wearer's legs are less likely to get caught in the leg openings on one side in the left-right direction when putting the legs through them, which makes it easier to put on the absorbent article and makes it easier to fit the leg openings LH around the wearer's groin on one side in the left-right direction.

[0033] (Aspect 12) The absorbent article according to any one of Aspects 1 to 11, wherein, when viewed in the front-to-rear direction with the fastening portion engaged with the ventral waistline portion in alignment with the position of the marker portion, the length in the left-to-right direction of the portion where the waistline stretch member overlaps with the leg line stretch member on one side in the left-to-right direction is longer than the length in the left-to-right direction of the portion where the waistline stretch member overlaps with the leg line stretch member on the other side in the left-to-right direction.

[0034] In the absorbent article of aspect 12, the area where the waist elastic member and the leg elastic member intersect on one side in the left-right direction is larger than on the other side in the left-right direction. Therefore, the force pulling up the waist portion on the side where the wearer's legs pass through when putting on the absorbent article (one side in the left-right direction) is more likely to be transmitted to the leg openings, and the leg openings are more likely to be pulled up and fit better around the groin area than in the opposite case.

[0035] Embodiments Hereinafter, an embodiment of the absorbent article according to the present invention will be described using a pants-type disposable diaper for infants as an example. However, the absorbent article according to the present invention is not limited to disposable diapers for infants, and can also be used as disposable diapers for adults, sanitary shorts, etc.

[0036] <Configuration of disposable diaper 1> Fig. 1 is a perspective view of a disposable diaper 1 (hereinafter referred to as "diaper") in a worn state, as seen from the other left-right side. Fig. 2 is a plan view of the diaper 1 in an unfolded and stretched state, as seen from the non-skin side. The center line C-C in Fig. 2 is the center line in the left-right direction in the stretched state.

[0037] The "natural state" refers to the state of the diaper 1 after it has been left for a predetermined period of time. For example, the diaper 1 is taken out of the package and the back waist portion 30 is pulled outward in both the left and right directions to place the waist portions 20, 30 in a "stretched state." This stretched state is maintained for 15 seconds, after which the tension on the diaper 1 is released and the diaper 1 is placed on a flat surface such as a desk. The natural state is the state in which the diaper 1 is left lying flat for 5 minutes.

[0038] The "unfolded state" refers to a state in which both side portions of the diaper 1 in a pants-type state, i.e., the side joint portions 2a, 2b at both side ends of the ventral waistband portion 20 and the back waistband portion 30, are separated and opened, and the entire diaper 1 is unfolded in a flat plane. The "stretched state" refers to a state in which the elastic members of the diaper 1 are stretched to an extent that wrinkles in the diaper 1 are no longer visible. Specifically, this refers to a state in which the dimensions of each component constituting the diaper 1 (e.g., the ventral waistband portion 20, which will be described later) are stretched to the same dimensions as or close to the dimensions of the component alone.

[0039] In the pants-type state shown in Figure 1, the diaper 1 has a vertical direction, a horizontal direction, and a front-to-back direction that are perpendicular to one another, and is formed with a waist opening BH and a pair of leg openings LH, LH. In the vertical direction, the waist opening BH side is the upper side, and the crotch side is the lower side. In the front-to-back direction, the wearer's abdominal side is the front side, and the wearer's back side is the rear side. The direction in which the materials constituting the diaper 1 are layered is referred to as the thickness direction, and the side in contact with the wearer in the thickness direction is referred to as the skin side, and the side opposite the skin side is referred to as the non-skin side. The thickness direction also corresponds to the front-to-back direction in the natural state.

[0040] The diaper 1 is a so-called three-piece type and includes an absorbent main body 10, a ventral waist section 20, and a dorsal waist section 30. The ventral waist section 20 covers the wearer's ventral side, and the dorsal waist section 30 covers the wearer's dorsal side. Hereinafter, the ventral waist section 20 and the dorsal waist section 30 will be collectively referred to simply as the "waist section." The diaper 1 also includes a fastening section 5.

[0041] In the diaper 1 in the unfolded state shown in Fig. 2, the ventral waist portion 20 and the back waist portion 30 are arranged so that their longitudinal directions are aligned with the left-right direction of the diaper 1. One longitudinal end of the absorbent main body 10 is arranged in the center of the ventral waist portion 20 in the left-right direction, and the other longitudinal end of the absorbent main body 10 is arranged in the center of the back waist portion 30 in the left-right direction, thereby forming the crotch portion 40. The absorbent main body 10 is arranged closer to the skin than the ventral waist portion 20 and the back waist portion 30.

[0042] The diaper 1 in the unfolded state shown in Fig. 2 is folded in half at approximately the center CL of the absorbent body 10 in the longitudinal direction, with the longitudinal direction of the absorbent body 10 aligned with the up-down direction of the diaper 1, and both side ends of the ventral waistband portion 20 and both side ends of the dorsal waistband portion 30 in the left-right direction of the diaper 1 are joined by heat welding, ultrasonic welding, or the like to form a pair of side joints 2a, 2b, thereby producing the pants-type diaper 1 shown in Fig. 1. The side joint 2b is a joint provided on one side in the left-right direction, and the side joint 2a is a joint provided on the other side in the left-right direction.

[0043] However, the side joint 2a does not necessarily have to be formed on the other left-right side, as long as the side joint 2b is formed on at least one left-right side. That is, it is sufficient that the ventral waistline portion 20 and the back waistline portion 30 are joined by the side joint 2b at least at one end in the left-right direction. For example, the ventral waistline portion 20 and the back waistline portion 30 may not be joined to each other on the other left-right side, and a fastening portion 5 (described later) may be provided at the other end in the left-right direction of the back waistline portion 30.

[0044] Furthermore, since the diaper 1 of this embodiment is for infants, when the diaper 1 is in an unfolded and extended state (FIG. 2), the maximum longitudinal dimension of the diaper 1 (the length from the top of the ventral waistband 20 to the top of the dorsal waistband 30) is preferably in the range of approximately 395 mm to 425 mm. The longitudinal (vertical) length of the side joint portions 2a, 2b is preferably in the range of approximately 88.5 mm to 98.5 mm. However, diapers for infants having sizes outside the above range may also be used.

[0045] In this embodiment, the portions overlapping the pair of side joint portions 2a, 2b in the vertical direction are referred to as waistband portions 20, 30. The waistband portions 20, 30 include a ventral waistband portion 20, which is one of the waistband portions, and a back waistband portion 30, which is the other of the waistband portions. The portion below the waistband portions 20, 30 is referred to as a crotch portion 40. Note that the absorbent article may also include an extension portion extending downward from the ventral waistband portion 20 or the back waistband portion 30 as an outer covering material located on the non-skin side of the absorbent main body 10. The extension portion can cover the wearer's lower abdomen and buttocks. Furthermore, the ventral waistband portion 20 and the back waistband portion 30 are not necessarily separate and distinct members, and an outer covering material for the crotch portion may be provided between the ventral waistband portion 20 and the back waistband portion 30, and the ventral waistband portion 20 and the back waistband portion 30 may be a continuous, single member.

[0046] The absorbent body 10 comprises an absorbent body 11, a liquid-permeable top sheet 12 arranged closer to the skin than the absorbent body 11, a second sheet 13 arranged between the top sheet 12 and the absorbent body 11, a side sheet 14 arranged closer to the skin than the absorbent body 11 and the second sheet 13, a liquid-impermeable back sheet 15 arranged closer to the skin than the absorbent body 11, and an outer sheet 16 arranged closer to the skin than the back sheet 15.

[0047] The absorbent body 11 has a generally rectangular shape in plan view and includes an absorbent core 11A that absorbs and retains excretions such as urine, and a liquid-permeable core wrap sheet (not shown) that covers the absorbent core. Examples of the absorbent core 11A include a liquid-absorbent fiber molded product (liquid-absorbent fiber molded product) made from liquid-absorbent fibers such as pulp containing superabsorbent polymer (SAP) and molded into a predetermined shape, such as a generally hourglass shape in plan view, or a so-called SAP sheet made from a sheet of superabsorbent polymer (SAP). The absorbent core 11A may also be configured by stacking an SAP sheet and a liquid-absorbent fiber molded product in the thickness direction. For example, the absorbent core 11A may be configured by stacking an SAP sheet, a liquid-absorbent fiber molded product, and an SAP sheet in this order from the skin side in the thickness direction. The left-right length of the absorbent core 11A of the diaper 1 is approximately the same as the left-right length of the absorbent body 11. Examples of the core wrap sheet include a liquid-permeable sheet such as tissue paper or nonwoven fabric. It is also possible to have a configuration without a core wrap sheet.

[0048] As shown in Fig. 2, leg elastic members 17 provided on both lateral sides of the absorbent main body 10 constitute leg gathers. The leg gathers of the pants-type diaper 1 are provided along the leg openings LH, and the diaper 1 fits around the legs of the wearer by the elasticity of the leg elastic members 17. The leg elastic members 17 of the diaper 1 are made of a plurality of rubber threads, and are fixed in a stretched state in the longitudinal direction of the absorbent main body 10 between the back sheet 15 and the outer sheet 16, for example, between the outer sheets 16 that are folded inward in the lateral direction to form two layers.

[0049] The absorbent body 10 has leak-preventing wall elastic members 18 on both left-right sides thereof, inside the leg-hole elastic members 17. A plurality of leak-preventing wall elastic members 18 are fixed in a longitudinally stretched state between the two layers of side sheets 14 folded outward in the left-right direction, forming a pair of leak-preventing wall portions along the longitudinal direction. When the diaper 1 is worn, the leak-preventing wall portions rise up against the wearer's skin due to the elasticity exhibited by the leak-preventing wall elastic members 18, and fit snugly against the wearer's crotch area.

[0050] Examples of the leg-hole elastic members 17 and the leak-preventing wall elastic members 18 include rubber threads and elastic sheets.

[0051] The ventral waistband portion 20 includes a skin-side sheet 21, a non-skin-side sheet 22, and multiple waistband stretch members 23 that stretch in the left-right direction. The skin-side sheet 21 and the non-skin-side sheet 22 are laminated and joined together by a joining method such as an adhesive such as hot melt, or by heat or ultrasonic welding. The skin-side sheet 21 and the non-skin-side sheet 22 are sheet members of approximately the same size and shape, and in this embodiment, are approximately rectangular. The non-skin-side sheet 22 is positioned closer to the skin side than the skin-side sheet 21. The skin-side sheet 21 and the non-skin-side sheet 22 can be non-stretch sheets such as SMS nonwoven fabrics (spunbond, meltblown, spunbond nonwoven fabrics), spunbond nonwoven fabrics, air-through nonwoven fabrics, point-bond nonwoven fabrics, stretch nonwoven fabrics, plastic sheets, perforated plastic sheets, and laminate sheets thereof.

[0052] The multiple waistline elastic members 23 of the ventral waistline portion 20 are arranged vertically between the skin-side sheet 21 and the non-skin-side sheet 22 and are fixed in a stretched state in the left-right direction. Therefore, the ventral waistline portion 20 stretches left-right to fit the wearer's waist. Examples of the waistline elastic members 23 include elastic members such as rubber and spandex. The ventral waistline portion 20 has an engaged portion 25 on the non-skin-side surface of the non-skin-side sheet 22 that can engage with an engaging portion 51 (described below) of the fastening portion 5. The engaged portion 25 is a so-called target area, and examples thereof include a nonwoven fabric sheet. Furthermore, if a male hook-and-loop fastener is used for the engaging portion 51, it is desirable to select an engaged portion that corresponds to the engaging portion 51, such as a female hook-and-loop fastener, for the engaged portion 25. Furthermore, instead of providing a separate member on the non-skin side of the non-skin side sheet 22, the non-skin side sheet 22 may be made of a member (e.g., nonwoven fabric) that can engage with the engaging portion 51, and the engaging portion 25 may be directly engaged with the non-skin side of the non-skin side sheet 22. However, conversely to the above, the engaging portion 25 of the ventral waistline portion 20 may be a male member of a hook-and-loop fastener, and the engaging portion 51 of the fastening portion 5 (the surface facing the ventral waistline portion 20) may be a nonwoven fabric sheet, a female member of a hook-and-loop fastener, or the like.

[0053] In this embodiment, the skin-facing side of the engaged portion 25 is provided with a marker portion 60 that serves as a reference (marker) for the fastening position of the fastening portion 5 when engaging the engaging portion 51. In FIGS. 1 and 2 , the marker portion 60, which represents the outline of the fastening portion 5, is displayed so as to be visible from the outside (non-skin side). The marker portion 60 is adjusted so that, when putting the diaper 1 on a wearer, the outline of the fastening portion 5 is aligned with the marker portion 60 and engaged with the marker portion 60, thereby making the lateral lengths of the waist portions 20, 30, which extend outward in the lateral direction from the absorbent body 11 located in the crotch area of ​​the wearer, equal or similar lengths. That is, by engaging the fastening portion 5 with the marker portion 60, the contractile force and tightening force are well balanced on both the left and right sides of the waist portion, reducing discomfort for the wearer when putting on the diaper 1. Hereinafter, the state in which the fastening portion 5 is engaged with the marker portion 60 on the waist portion of the diaper 1 is also referred to as the "reference wearing state."

[0054] The shape of the marker part 60 is not limited to a shape that follows the entire outer contour of the fastening part 5, but may also be a shape that follows a part of the outer contour. Also, the marker part 60 may be a colored part in which the part inside the outer contour is colored, or may be configured by arranging small patterns such as dots, stars, flowers, etc.

[0055] The back waistband portion 30 includes a skin-side sheet 31, a non-skin-side sheet 32, and multiple waistband stretch members 33 that stretch in the left-right direction. The skin-side sheet 31 and the non-skin-side sheet 32 ​​are laminated and joined together using a joining method such as an adhesive such as hot melt, or welding using heat or ultrasound. The skin-side sheet 31 and the non-skin-side sheet 32 ​​are sheet members of approximately the same size and shape, and in this embodiment, are approximately rectangular. The non-skin-side sheet 32 ​​is positioned closer to the skin side than the skin-side sheet 31. Examples of non-stretch sheets that can be used as the skin-side sheet 31 and the non-skin-side sheet 32 ​​include polypropylene SMS nonwoven fabrics (spunbond, meltblown, spunbond nonwoven fabrics), spunbond nonwoven fabrics, air-through nonwoven fabrics, point-bond nonwoven fabrics, stretch nonwoven fabrics, plastic sheets, perforated plastic sheets, and laminates thereof.

[0056] The multiple waistline elastic members 33 of the back-side waistline portion 30 are arranged side by side in the vertical direction between the skin-side sheet 31 and the non-skin-side sheet 32, and are fixed in a stretched state in the left-right direction. Therefore, the ventral waistline portion 20 and the back-side waistline portion 30 each stretch in the left-right direction to fit the waist of the wearer. Examples of the waistline elastic members 33 include elastic members such as rubber and spandex.

[0057] The fastening part 5 is a so-called tab (knob) member, and is a member used to form a waist opening when the ventral waistline portion 20 is cut. Fig. 3 is an enlarged view of a portion X in Fig. 2. In the fastening part 5 of this embodiment, a base end portion of the fastening part 5 (the other side in the left-right direction in Fig. 2 etc.) is fixed to the other side of the center in the left-right direction of the ventral waistline portion 20, and a tip end portion of the fastening part 5 (one side in the left-right direction in Fig. 2 etc.) has an engaging part 51 that separably engages with the non-skin side surface of the ventral waistline portion 20.

[0058] The fastening part 5 is a gripping part that is grasped by the wearer or a person putting the diaper 1 on the wearer (hereinafter also referred to as the "wearer, etc."), and therefore it is preferable that the fastening part 5 itself has a strength sufficient to prevent breakage. For example, various films such as plastic film and nylon film, nonwoven fabric, and film made by laminating nonwoven fabric can be used as the fastening part 5. The fastening part 5 of the diaper 1 of this embodiment is a sheet-like member consisting of three layers, with nonwoven fabric of the same size layered on both sides of a plastic film.

[0059] The engaging portion 51 is provided on the skin-side surface of the fastening portion 5 and is a member that can detachably engage with the non-skin-side surface of the ventral waist portion 20 (specifically, the engaged portion 25). Examples of the engaging portion 51 include a male component of a hook-and-loop fastener or an adhesive material such as an adhesive sheet. While the engaging portion 51 in this embodiment has a substantially rectangular shape, it may have any shape, such as a round shape. When the diaper 1 of this embodiment is opened from the package, as shown in FIG. 2 , the fastening portion 5 (engaging portion 51) is engaged with the engaged portion 25 on the other side in the left-right direction of the marker portion 60. That is, before opening, the diaper 1 is distributed in a pants-like form with the fastening portion 5 temporarily attached on the other side in the left-right direction of the marker portion 60.

[0060] As shown in Fig. 3 and other figures, the fastening part 5 is fixed to the abdominal waistline part 20 by a fixing part F1 and an auxiliary fixing part F2. In this embodiment, the fixing part F1 and the auxiliary fixing part F2 are welded parts that join the fastening part 5 and the abdominal waistline part 20 in the thickness direction by heat welding, ultrasonic welding, or the like. The fastening part 5 is fixed to the abdominal waistline part 20 mainly by the fixing part F1, and the auxiliary fixing part F2 assists the fixation by the fixing part F1.

[0061] ===How to wear diaper 1=== The diaper 1 of this embodiment can be worn in the form of a so-called pants-type diaper (with leg openings LH formed) on one side in the left-right direction, and a tape-type diaper (without leg openings LH formed) on the other side in the left-right direction, by cutting the ventral waist portion 20 in advance at the cutting guide portion.

[0062] First, the ventral waist portion 20 is cut at the cutting guide portion, and one of the wearer's legs (the wearer's right leg in the case of diaper 1) is passed through the leg opening LH on one side in the left-right direction (in the case of a pants-type diaper), and then the diaper 1 is pulled up to the wearer's crotch area.After that, the engaging portion 51 of the fastening portion 5 is engaged with the ventral waist portion 20 so that the diaper fits the wearer's waist, forming a waist opening, and the diaper is ready to be worn.

[0063] By putting the diaper in this manner, even for infants who flap their legs and have difficulty passing both legs through the leg openings LH, LH of a pants-type disposable diaper, once the wearer can pass one leg through the leg opening LH, the fastening portion 5 (engaging portion 51) can be easily engaged to put the diaper on. Furthermore, when the wearer puts on the diaper 1, it may be difficult for the wearer to put on a typical tape-type diaper (a diaper with tapes on both the left and right sides) in a toilet, etc. However, by making one side of the diaper pants-type and the other side (tape-type) with the fastening portion 5, it becomes easier to put on and the fit around the waist can be adjusted. As described above, when engaging the fastening portion 5 (engaging portion 51) with the ventral waist portion 20, it is recommended to align the fastening portion 5 with the position of the marker portion 60 marked on the non-skin side of the ventral waist portion 20 (engaged portion 25).

[0064] Furthermore, when removing the diaper 1 from the body after use, the ventral waist portion 20 is separated at the cutting guide portion, the other left-right side of the diaper 1 is removed from the wearer's body, and one leg is pulled out from one of the left-right leg openings LH, thereby allowing the diaper 1 to be removed from the wearer's body.

[0065] ===Cutting of the ventral waistline portion 20=== Cutting of the ventral waistline portion 20 will be described using Figures 4 and 5. Figure 4 is a diagram illustrating the separation of the ventral waistline portion 20 and the formation of a waistline opening. Figure 5 is a diagram illustrating the operation of cutting the ventral waistline portion 20. Figure 4 is a diagram illustrating the cross-sectional configuration as viewed from the arrows A-A in Figure 3. Note that Figures 4 and 5 are schematic diagrams, and the dimensions etc. are not necessarily accurate.

[0066] Fig. 4A shows the diaper 1 in the pants-type state shown in Fig. 1 etc. In other words, the ventral waist portion 20 is not cut, and the ventral waist portion 20 and the back waist portion 30 form a continuous waist opening via the side joining portions 2a, 2b. Figs. 4B and 5A show the state in which the tip of the fastening portion 5 is grasped and pulled up toward the non-skin side from the state shown in Fig. 4A.

[0067] 5A , by grasping the ventral waist portion 20 with one hand and the fastening portion 5 with the other hand and pulling them outward in the left-right direction, the ventral waist portion 20 is cut along the cutting guide portion and separated into one side and the other side in the left-right direction as shown in FIGS. 4C and 5B . The "cutting guide portion" is a guide portion used when cutting at least a portion of the ventral waist portion 20. In the diaper 1, the fixing portion F1 that fixes the ventral waist portion 20 and the fastening portion 5 functions as the cutting guide portion. Specifically, as shown in Fig. 5A , when the abdominal waistline portion 20 and the fastening portion 5 are held and pulled in the left-right direction, the pulling force is first concentrated at the cutting induction starting point K (see Fig. 3 ), which is the tip-side end of the cutting induction portion (fixing portion F1) located closest to the tip, and then the force is transmitted along the inclined portion of the cutting induction portion that slopes upward and toward the base end from the cutting induction starting point K and the inclined portion that slopes downward and toward the base end from the cutting induction starting point K. Then, the abdominal waistline portion 20 is cut at the other left-right end CE of the fixing portion F1, and the abdominal waistline portion 20 is separated into the other side that has the fastening portion 5 and the one side that does not have the fastening portion 5.

[0068] Thereafter, as necessary, as shown in Fig. 4D , the engaging portion 51 of the fastening part 5 is engaged with the engaged portion 25 of the ventral waistline portion 20 to form a waist opening in the diaper 1. With the engaging portion 51 engaged with the engaged portion 25, the engaging portion 51 may be engaged with the engaged portion 25 so that one side and the other side of the separated ventral waistline portion 20 in the left-right direction overlap in the front-to-back direction (thickness direction), or the engaging portion 51 may be engaged with the engaged portion 25 so that the one side and the other side of the separated ventral waistline portion 20 in the left-to-right direction do not overlap in the front-to-back direction (thickness direction). The size of the waist opening in the diaper 1 can be adjusted by adjusting the position at which the engaging portion 51 is engaged.

[0069] However, the fixed portion F1 is not limited to being the cutting guide portion, and any other cutting guide portion capable of guiding the cutting of the ventral waist portion 20 may be provided, such as by providing perforations or a low basis weight portion. Furthermore, the diaper 1 does not necessarily have to be provided with a cutting guide portion. The wearer may cut the ventral waist portion 20 at a desired position using a blade or by hand.

[0070] In this embodiment, the diaper 1 is distributed in a state in which the ventral waist portion 20 and the back waist portion 30 are joined at the side joining portions 2a, 2b, and a user who removes the diaper 1 from the package separates the ventral waist portion 20 at the fastening portion F1, but this is not limited thereto. For example, the diaper 1 may be packaged in a state in which the portions where the waist portions are joined by the fastening portions are separated in advance.

[0071] Regarding the Fit of the Leg Openings LH When Wearing the Diaper 1: As described above, when wearing an absorbent article (diaper) having a pants-type construction on one side and a tape-type construction on the other side, the wearer passes their legs through the leg openings on one side and pulls the diaper up to their crotch area. However, with conventional diapers, the force applied by gripping and pulling up the waistband portion is not sufficiently transmitted to the leg openings, resulting in the leg openings not being pulled up properly and making it difficult to fit the diaper to the wearer's groin. Furthermore, because the leg openings are difficult to fit and prone to misalignment, it is often necessary to repeatedly re-engage the fastening portions on the other side to prevent gaps from forming between the wearer's body and the leg openings or to fine-tune the position of the leg openings, which requires a lot of effort.

[0072] In contrast, the diaper 1 of this embodiment can reduce the effort required for putting on the diaper 1 by improving the fit of the leg openings LH when putting on the diaper 1. The fit of the leg openings LH when putting on the diaper 1 will now be described. Figure 6 is an enlarged view of one side (one side of the center C) in the left-right direction of the ventral waist portion 20 and the absorbent main body 10 in a stretched state.

[0073] In Figure 6, the region of the ventral waistline portion 20 below the vertical center of the side joint 2b where the waistline elastic members 23 are provided is referred to as the lower waistline elastic region BE (hereinafter also referred to as the "lower elastic region BE"). Here, the "region where the waistline elastic members 23 are provided" refers to the region where the elastic force of the waistline elastic members 23 acts. Specifically, it refers to the region of the ventral waistline portion 20 below the vertical center of the side joint 2b, surrounded by the uppermost and lowermost waistline elastic members 23. In Figure 6, the lower elastic region BE is indicated by hatching with diagonal lines extending from the upper left to the lower right. This lower elastic region BE is a region along the periphery of the leg openings LH on one side of the diaper 1 in the horizontal direction, and provides lateral elasticity to the leg openings LH.

[0074] In addition, in Figure 6, the region of the absorbent main body 10 where the leg-hole elastic members 17 are provided is referred to as the leg-hole elastic region LE. The "region where the leg-hole elastic members 17 are provided" refers to the region where the elastic force of the leg-hole elastic members 17 acts. Specifically, it refers to the region surrounded by the leg-hole elastic member 17 provided on the most one side and the leg-hole elastic member 17 provided on the most other side in the left-right direction within one end region of the absorbent main body 10. In Figure 6, the region hatched with diagonal lines extending from the lower left to the upper right is the leg-hole elastic region LE. This leg-hole elastic region LE is a region along the periphery of the leg-hole opening LH on one side of the diaper 1 in the left-right direction, and provides vertical elasticity to the leg-hole opening LH.

[0075] The leg-around elastic member 17 is provided on one side and the other side of the absorbent body 10 in the left-right direction, and an elastic region is also formed on the other side in the left-right direction, but in this specification, unless otherwise specified, the elastic region formed on one side of the absorbent body 10 in the left-right direction will be referred to as the leg-around elastic region LE.

[0076] In the diaper 1, when viewed in the front-to-rear direction, a portion of the waist elastic members 23 and a portion of the leg elastic members 17 are arranged to intersect with each other, and there is a portion where the lower elastic region BE and the leg elastic region LE overlap (a portion corresponding to an intersection region IR, which will be described later). Therefore, when putting on the diaper 1, after the wearer has put their legs through the leg openings LH on one side in the left-right direction, when the waist portion (ventral waist portion 20) is grasped and pulled upward, a force is transmitted to the leg elastic members 17 via the waist elastic members 23, making it easier to pull up the leg elastic regions LE.

[0077] 6, when viewed in the front-to-back direction, portions of the waist elastic members 23 and portions of the leg elastic members 17 intersect with each other, but even if the leg elastic members 17 are short and do not directly intersect with the waist elastic members 23 and the leg elastic members 17, the same effect as described above may be expected. For example, if there is a portion where the extension of the leg elastic members 17 intersects with the waist elastic members 23, the force that grips and pulls the waist portion (ventral waist portion 20) upward is more easily transmitted from the waist elastic members 23 to the leg elastic members 17, making it easier to pull up the leg elastic regions LE, compared to when the two do not intersect at all.

[0078] Furthermore, in the diaper 1, the force required to stretch the lower elasticized region BE a predetermined length in the left-right direction divided by the vertical width WBE of the lower elasticized region BE is greater than the force required to stretch the leg elasticized region LE a predetermined length in the up-down direction divided by the left-right width WLE of the leg elasticized region LE. In other words, the force required to stretch the unit width of the lower elasticized region BE a predetermined length in the left-right direction is greater than the force required to stretch the unit width of the leg elasticized region LE a predetermined length in the up-down direction. Therefore, when the waistband portion (the abdominal waistband portion 20) is grasped and pulled upward, the leg elasticized region LE can be easily stretched in the up-down direction with a force weaker than the force acting in the left-right direction to stretch the lower elasticized region BE. Compared to the reverse case, the leg elasticized region LE can be easily pulled up in conjunction with the lower elasticized region BE. This allows the leg openings LH along the leg elasticized regions LE and the lower elasticized region BE to fit easily around the wearer's groin at least on the front side (belly side) in the front-to-back direction.

[0079] Furthermore, since the leg openings LH (the leg elasticized regions LE and the lower elasticized region BE) fit the wearer's groin area, gaps are less likely to form between the leg openings LH and the wearer's skin (groin area). Therefore, when engaging the fastening parts 5 (engaging parts 51) after pulling up the waist part (ventral waist part 20), the effort of repeatedly attaching and detaching the fastening parts to adjust the position of the leg openings LH in order to close the gap in the groin area is reduced, and the operation of engaging the fastening parts 5 (engaging parts 51) can be performed more stably and easily.

[0080] The operation of engaging the fastening part 5 (engaging part 51) with the abdominal waist part 20 (engaged part 25) is often performed with the wearer lying on their back. Therefore, the leg openings LH are pressed against the wearer's buttocks at the rear side (back side) in the front-to-rear direction, making it difficult for them to shift position. Therefore, by improving the fit of the leg openings LH (leg opening stretchable regions LE and lower stretchable region BE) at least at the front side (abdominal side) in the front-to-rear direction, the operation of engaging the fastening part 5 (engaging part 51) can be performed stably.

[0081] The force required to stretch the lower elastic region BE by a predetermined length in the left-right direction can be measured as follows: Figures 7A to 7C are diagrams illustrating a method for measuring the elastic force of the lower elastic region BE.

[0082] When measuring the stretch force of the lower elasticized region BE, first, as shown in Figure 7A, a sample of the region to be measured (the lower elasticized region BE) is cut out from the diaper 1. Specifically, the side seam regions 2a, 2b of the diaper 1 are peeled off to lay it out, and then the ventral waistline portion 20 is separated from the absorbent main body 10 to separate the ventral waistline portion 20. The portion corresponding to the lower elasticized region BE described in Figure 6 is then cut out. The cutout is performed so that portions that will become the gripping margins Ga remain on both lateral sides of the lower elasticized region BE. If it is not possible to secure a sufficiently large gripping margin Ga on one lateral side in Figure 7A, the gripping margin Ga may be formed by joining another member with an adhesive or the like.

[0083] After cutting out the sample, measurements are performed using a specified tensile testing machine 70 (e.g., Instron Model 5965 or equivalent). As shown in FIG. 7B , the initial distance L1 between a pair of chucks (fixing jigs) 71, 71 spaced apart in the tensile direction is adjusted to match the left-right length of the lower stretchable region BE of the sample, such that the sample (lower stretchable region BE) does not slacken or is slightly slackened. The gripping margin Ga of the sample (lower stretchable region BE) in its natural state is then clamped between the chucks 71. As previously mentioned, the "natural state" refers to a state in which the sample is left unloaded for a predetermined period of time. One chuck 71 clamps the gripping margin Ga on one side in the left-right direction, and the other chuck 71 clamps the gripping margin Ga on the other side in the left-right direction.

[0084] Next, as shown in Figure 7C, the distance between the pair of zippers 71, 71 is increased in the pulling direction at a speed of 100 mm / min. The lower elasticized region BE of the sample is stretched laterally until the distance between the pair of zippers 71, 71 reaches a predetermined length L2. For example, the stretching is performed within a range that includes at least a contraction rate corresponding to the minimum waist circumference of the wearer and a contraction rate corresponding to the maximum waist circumference of the wearer. Next, from the stretched state of the lower elasticized region BE, the distance between the pair of zippers 71, 71 is decreased at a speed of 100 mm / min until the distance between the pair of zippers 71, 71 returns to the initial distance L1. Note that the stretch force measurement for the lower elasticized region BE of the diaper 1 was performed under conditions of initial distance L1 = 30 mm and L2 = 90 mm, but the length of L2 can be adjusted appropriately depending on the length of the initial distance L1 in the sample's natural state.

[0085] This cycle is repeated twice. During the second stretching cycle, the horizontal length of the stretched lower stretchable region BE is recorded in association with the stretching force acting on the lower stretchable region BE at that time (the force required to stretch the lower stretchable region BE to that length). During the second contraction cycle, the contraction rate of the contracted lower stretchable region BE (the horizontal length of the lower stretchable region BE) is recorded in association with the contraction force acting on the lower stretchable region BE at that time (the force required to contract the lower stretchable region BE to that length). The recorded force is then divided by the vertical width of the lower stretchable region BE (L20 / 2), thereby determining the magnitude of the force per unit width when the lower stretchable region BE is stretched in the horizontal direction.

[0086] The magnitude of the stretching force of the leg-hole stretchable regions LE and other members can be determined in a similar manner.

[0087] Similarly to the ventral waist portion 20, the dorsal waist portion 30 also has a waist lower stretchable region BE (lower stretchable region BE) formed in a region below the vertical center of the side joint 2b, where the waist stretchable member 33 is provided (not shown in Figure 6).

[0088] 2, when the back waistband portion 30 is viewed in the front-to-back direction, a portion of the waist elastic member 33 and a portion of the leg elastic member 17 (or an extension thereof) are arranged to intersect with each other on one side in the left-right direction (one side of the center C). In the ventral waistband portion 20 and the back waistband portion 30, the force required to stretch the lower elastic region BE by a predetermined length in the left-right direction divided by the vertical width of the lower elastic region BE is greater than the force required to stretch the leg elastic region LE by a predetermined length in the up-down direction divided by the left-to-right width of the leg elastic region LE. In other words, the force required to stretch the unit width of the lower elastic region BE by a predetermined length in the left-to-right direction (the total force on the ventral and back sides) is greater than the force required to stretch the unit width of the leg elastic region LE by a predetermined length in the up-down direction.

[0089] As a result, when the waist portion (ventral waist portion 20 and rear waist portion 30) is grasped and pulled up during putting on the diaper 1, force is transmitted to the leg elastic members 17 via the ventral waist elastic member 23 and rear waist elastic member 33, making it easier to pull up the leg elastic regions LE. Furthermore, the leg elastic regions LE are more easily stretched in the vertical direction with a force weaker than the force acting in the direction stretching the rear and ventral lower elastic regions BE in the left-right direction, making it easier to pull up the leg elastic regions LE compared to the reverse case. Therefore, the leg openings LH along the leg elastic regions LE and the lower elastic regions BE fit more easily around the wearer's groin on both the ventral and rear sides.

[0090] In the diaper 1, at least one waist elastic member 23 (33) and at least one leg elastic member 17 intersect with each other on one left-right side of the ventral waist portion 20 and the back waist portion 30 when viewed in the front-rear direction (see FIGS. 2 and 6). The force required to stretch a single waist elastic member 23 (33) that intersects with a leg elastic member 17 by a predetermined length in the left-right direction is greater than the force required to stretch a single leg elastic member 17 that intersects with the waist elastic member 23 (33) by a predetermined length in the up-down direction.

[0091] That is, when the waist elastic members 23 (33) and the leg elastic members 17 intersect with each other, the waist elastic members 23 (33) have a greater elastic force than the leg elastic members 17. Therefore, when the waist portion is pulled up during putting on the diaper 1, a force is more likely to act directly on the leg elastic members 17 that intersect with the waist elastic members 23 (33), which in turn tends to pull up the leg elastic members 17 in conjunction with the waist elastic members 23 (33), making it easier for the leg openings LH to fit tightly against the groin area. As a result, when the fastening portion 5 (engagement portion 51) is engaged on the other side in the left-right direction, the leg openings LH are less likely to shift position on one side in the left-right direction, making it easier to put on the diaper 1.

[0092] In reality, when viewed in the front-to-back direction on one side in the left-to-right direction, a plurality of waistline elastic members 23 (33) intersect with the legline elastic members 17. The force required to extend the plurality of waistline elastic members 23 (33) that intersect with the legline elastic members 17 by a predetermined length in the left-to-right direction is preferably greater than the force required to extend the plurality of legline elastic members 17 that intersect with the waistline elastic members 23 (33) by a predetermined length in the up-down direction.

[0093] In this case, when the waist portion is pulled up during putting on the diaper 1, a greater force is likely to act on the leg elastic members 17 that intersect with the waist elastic members 23 (33). As a result, the leg elastic members 17 are likely to be pulled up in conjunction with the waist elastic members 23 (33) that intersect with each other, and the leg openings LH are likely to fit more closely to the groin area. Therefore, when engaging the fastening portion 5 (engagement portion 51), the leg openings LH are less likely to shift position, making it easier to put on the diaper 1.

[0094] Furthermore, when viewed in the front-to-back direction, the multiple waist elastic members 23, 23 provided in the lower elastic region BE have portions that intersect with the leg elastic members 17, while others do not. In Figure 6, of the multiple waist elastic members 23 provided in the lower elastic region BE, the two waist elastic members 23 located on the lower side have portions that intersect with the leg elastic members 17, while the three waist elastic members 23 located on the upper side do not have portions that intersect with the leg elastic members 17. Preferably, the force required to stretch the waist elastic members 23 that have portions that intersect with the leg elastic members 17 by a predetermined length in the left-to-right direction is smaller than the force required to stretch the waist elastic members 23 that do not have portions that intersect with the leg elastic members 17 by a predetermined length in the left-to-right direction. In other words, it is preferable that the waist stretchable member 23 having a portion that intersects with the leg stretchable member 17 be able to stretch in the left-right direction with a weaker force than the waist stretchable member 23 that does not have a portion that intersects with the leg stretchable member 17.

[0095] 6, the waist elastic members 23, which have portions that intersect with the leg elastic members 17, are positioned close to the periphery of the leg openings LH. Therefore, if the waist elastic members 23, which have portions that intersect with the leg elastic members 17, are made more stretchable, the region along the periphery of the leg openings LH on one side of the ventral waist portion 20 in the left-right direction will be more stretchable in the left-right direction than the other region, making it easier to open the leg openings LH. This allows the wearer to easily open the leg openings LH when putting on the diaper 1, and also makes it less likely that the wearer's legs will get caught on the periphery of the leg openings LH when putting their legs through the leg openings LH.

[0096] In addition, in the lower stretchable region BE, the area where the waist stretchable members 23 and the leg stretchable members 17 intersect when viewed in the front-to-back direction (the area surrounded by the thick line in Figure 6) is defined as an intersection area IR. In this case, the length LIR in the up-down direction of the intersection area IR is shorter than the length WA in the left-right direction of the waist stretchable member 23 provided on the other left-right side of the intersection area IR (LIR<WA).

[0097] With this configuration, the influence of the elastic force of the waist elastic member 23 (portion of length WA) is greater than in the opposite case (LI > RWA), and the intersecting area IR is more likely to be pulled to the other left-right side (toward the center C of the diaper 1). Therefore, when putting on the diaper 1, when the fastening portion 5 provided at the tip of the back-side waist portion 30 is pulled to the other left-right side and turned toward the ventral waist portion 20 to engage with the engaging portion 25, the intersecting area IR is more likely to resist the force pulling it to the other left-right side in conjunction with the back-side waist portion 30. This makes it less likely that the position of the leg openings LH (the position of the intersecting area IR) will shift relative to the wearer's groin, and the fit of the leg openings LH will be less likely to deteriorate.

[0098] Fig. 8 is a partially enlarged view of the diaper 1 in a stretched state, illustrating the state when the fastening parts 5 are aligned with the marker parts 60 and engaged with the ventral waist part 20. Fig. 9 is an enlarged view of part Y in Fig. 8. When the diaper 1 is viewed in the front-rear direction with the fastening parts 5 (engaging parts 51) aligned with the marker parts 60 and engaged, the waist elastic members 23 have portions that intersect with the leg elastic members 17 (or their extensions) on the other left-right side (the side where the fastening parts 5 are provided), as shown in Figs. 8 and 9.

[0099] 2 , when the diaper 1 is opened from the package (when the fastening portion 5 is engaged at a position on the other side of the marker portion 60 in the left-right direction), the waist elastic members 23 and the leg elastic members 17 do not intersect with each other. That is, on the other side of the left-right direction (the fastening portion 5 side), before the fastening portion 5 (engaging portion 51) is aligned with the position of the marker portion 60 and engaged, the vertical stretching force of the leg elastic members 17 does not act on the waist elastic members 23. Therefore, before the diaper 1 is opened from the package, the stretching forces of the waist elastic members 23 and the leg elastic members 17 are not easily linked, and unnecessary external forces are not easily applied to the fastening portion 5, making it easy to stably maintain the state in which the engaging portion 51 is engaged with the engaged portion 25.

[0100] On the other hand, when the fastening portion 5 (engagement portion 51) is aligned with the position of the marker portion 60 and engaged with the diaper 1 (the standard wearing state described above), the stretching force of the leg elastic members 17 is more likely to act on the waist elastic members 23 on the other side in the left-right direction. As a result, the stretching force in the left-right direction exerted by the waist elastic members 23 and the stretching force in the up-down direction exerted by the leg elastic members 17 work together to more likely act on the periphery of the leg openings LH. Therefore, the leg openings LH are more likely to fit around the wearer's groin on the other side in the left-right direction, improving the fit of the diaper 1 when worn.

[0101] Furthermore, in a state where the fastening portion 5 (engaging portion 51) is aligned with the position of the marker portion 60 and engaged (standard wearing state), when viewed in the front-to-rear direction as shown in Fig. 9, one end 23ei of the waist stretchable member 23 in the left-right direction is located on the other side of the leg stretchable member 17i that is located on the left-to-right side furthest from the other side. This makes it less likely that the waist stretchable member 23 will exert an excessively large left-to-right stretching force compared to when one end 23ei of the waist stretchable member 23 is located on one side of the leg stretchable member 17i in the left-to-right direction. This makes it easier to align the fastening portion 5 (engaging portion 51) with the position of the marker portion 60 and engage it, and also makes it less likely that the engagement between the engaging portion 51 and the engaged portion 25 will come loose.

[0102] When the fastening portion 5 (engagement portion 51) is aligned with the position of the marker portion 60 and engaged (standard wearing state), at least a portion of the waist stretchable member 23 and the leg stretchable member 17 intersect on the other side in the left-right direction of the leg stretchable member 17i. Therefore, the waist stretchable member 23 and the leg stretchable member 17 work together, making it easier for a stretching force to act along the periphery of the leg openings LH. Therefore, on the other side in the left-right direction, the leg openings LH fit more easily around the wearer's groin.

[0103] Furthermore, when the fastening portion 5 (engaging portion 51) is aligned with the position of the marker portion 60 and engaged (standard wearing state), as viewed in the front-to-rear direction as shown in Fig. 9 , the engaging portion 51 is located to one side in the left-right direction of the leg-hole stretchable member 17i located furthest to the left-right direction. The offset in the left-right direction between the engaging portion 51 and the leg-hole stretchable member 17 makes it difficult for the stretching force of the leg-hole stretchable member 17 to act on the region of the engaged portion 25 of the ventral waistline portion 20 that is engaged with the fastening portion 5 (engaging portion 51). Therefore, the region of the engaged portion 25 that is engaged with the fastening portion 5 (engaging portion 51) is less likely to wrinkle or distort and is more likely to maintain a flat shape, making it less likely for the engaged portion 25 to disengage from the engaging portion 51. This improves the fit of the diaper 1 when worn.

[0104] Furthermore, when the fastening portion 5 (engagement portion 51) is aligned with the position of the marker portion 60 and engaged (standard wearing state), as viewed in the front-to-rear direction of the ventral waist portion as shown in Fig. 8, the length CRr of the overlapping portion between the waist elastic member 23 and the leg elastic member 17 on one side in the left-right direction is longer than the length CRl of the overlapping portion between the waist elastic member 23 and the leg elastic member 17 on the other side in the left-right direction. In other words, the width of the region where the waist elastic member 23 and the leg elastic member 17 intersect on one side in the left-right direction is greater than that on the other side in the left-right direction. Therefore, when putting on the diaper 1, the force pulling up the waist portion is more easily transmitted to the leg openings LH on the side where the wearer's legs are passed through (one side in the left-right direction), and the leg openings LH are more easily pulled up, resulting in a better fit around the groin area, compared to the reverse case.

[0105] Figures 10A and 10B are diagrams illustrating the length of the elastic members along the periphery of the leg openings LH. Figure 10A shows the leg openings LH on one side in the left-right direction when the pants-type diaper 1 is viewed from one side in the left-right direction. Figure 10B shows the leg openings LH formed on the other side in the left-right direction when the diaper 1 is viewed from the other side in the left-right direction with the fastening parts 5 (engagement parts 51) aligned with the positions of the marker parts 60 and engaged. Note that both Figures 10A and 10B show the diaper 1 in a stretched state.

[0106] In FIG. 10A , on one side in the left-right direction, a waistline stretchable member 23r is arranged in the ventral waistline portion 20 along the periphery of the leg-opening LH. The waistline stretchable member 23r is the stretchable member that is arranged at the bottom in the vertical direction among the multiple waistline stretchable members 23, 23.... Similarly, on one side in the left-right direction, a waistline stretchable member 33r is arranged in the dorsal waistline portion 30 along the periphery of the leg-opening LH. The waistline stretchable member 33r is the stretchable member that is arranged at the bottom in the vertical direction among the multiple waistline stretchable members 33, 33.... Also, on one side in the left-right direction, a leg-opening stretchable member 17r is arranged in the absorbent main body 10 along the periphery of the leg-opening LH. The leg-opening stretchable member 17r is the stretchable member that is arranged at the left-right-most (outer) side among the multiple leg-opening stretchable members 17, 17....

[0107] Similarly, in FIG. 10B , on the other side in the left-right direction, a waistline elastic member 23l is arranged in the ventral waistline portion 20 along the periphery of the leg-opening LH. The waistline elastic member 23l is the elastic member arranged at the bottom in the vertical direction among the multiple waistline elastic members 23, 23.... Also, on the other side in the left-right direction, a waistline elastic member 33l is arranged in the dorsal waistline portion 30 along the periphery of the leg-opening LH. The waistline elastic member 33l is the elastic member arranged at the bottom in the vertical direction among the multiple waistline elastic members 33, 33.... Also, on the other side in the left-right direction, a leg-opening elastic member 17l is arranged in the absorbent main body 10 along the periphery of the leg-opening LH. The leg-opening elastic member 17l is the elastic member arranged at the other side (outside) in the left-right direction among the multiple leg-opening elastic members 17, 17....

[0108] In this case, in the diaper 1, the total length (L23r + L33r + L17r) of the waist elastic member 23r arranged along the periphery of the leg opening LH on one side in the left-right direction, the length L33r of the waist elastic member 33r, and the length L17r of the leg elastic member 17r is longer than the total length (L23l + L33l + L17l) of the waist elastic member 23l arranged along the periphery of the leg opening LH on the other side in the left-right direction, the length L33l of the waist elastic member 33l, and the length L17l of the leg elastic member 17l.

[0109] The leg openings LH on one side in the left-right direction are the openings through which the wearer's legs are first inserted when putting on the diaper 1. When the diaper 1 is stretched, the length of the elastic member along the periphery of the leg openings LH on one side in the stretched state is longer than the length of the elastic member along the periphery of the leg openings LH on the other side in the stretched state. This makes it easier for the leg openings LH on one side in the left-right direction to widen and less likely for the wearer's legs to get caught when putting them through, compared to the reverse case. This makes it easier to put on the diaper 1 and to fit the leg openings LH on one side in the left-right direction around the wearer's groin.

[0110] The length L23r of the waist stretchable member 23r corresponds to the distance (left-right distance) between the other left-right end of the side joint 2b and the leg stretchable member 17r in the unfolded state shown in Fig. 2. Similarly, the length L33r of the waist stretchable member 33r corresponds to the distance (left-right distance) between the other left-right end of the side joint 2b and the leg stretchable member 17r in the unfolded state shown in Fig. 2. Furthermore, the length L17r of the leg stretchable member 17r corresponds to the distance (up-down distance) between the waist stretchable member 23r and the waist stretchable member 33r in the unfolded state shown in Fig. 2. The same can be said for L23l, L33l, and L17l.

[0111] Although Figures 10A and 10B illustrate the diaper 1 in a stretched state, it is also preferable that the total length of the waist elastic member 23r arranged along the periphery of the leg opening LH on one side in the left-right direction, the length of the waist elastic member 33r, and the length of the leg elastic member 17r be longer than the total length of the waist elastic member 23l arranged along the periphery of the leg opening LH on the other side in the left-right direction, the length of the waist elastic member 33l, and the length of the leg elastic member 17l.

[0112] With this configuration, compared to the reverse case, even if the diaper 1 is not sufficiently pulled when putting on the diaper 1, the wearer's legs are less likely to get caught when passing them through the leg openings LH on one side in the left-right direction. This makes it easier to put on the diaper 1 and to fit the leg openings LH on one side in the left-right direction around the wearer's groin.

[0113] ===Other Embodiments= ...

[0114] DESCRIPTION OF SYMBOLS 1 Diaper (disposable diaper, absorbent article), 2a Side joint portion (other side), 2b Side joint portion (one side), 5 Fastening portion, 10 Absorbent body, 11 Absorbent body, 11A Absorbent core, 12 Top sheet, 13 Second sheet, 14 Side sheet, 15 Back sheet, 16 Outer sheet, 17 Leg opening elastic member, 18 Leak-proof wall elastic member, 20 Abdominal waist portion, 21 Skin side sheet, 22 Non-skin side sheet, 23 Waist elastic member (abdominal side), 25 Engaged portion, 30 Dorsal waist portion, 31 Skin side sheet, 32 Non-skin side sheet, 33 Waist elastic member (dorsal side), 51 Engagement portion, 60 Marking portion, 70 Tensile tester, 71 Zipper, BH Waist opening, LH Leg opening, F1 Fixed part, F2 auxiliary fixed part, BE waist stretch area, BE lower stretch area (lower waist stretch area), LE leg stretch area, IR intersection area

Claims

1. An absorbent article having a waist portion having a ventral waist portion and a rear waist portion, and an absorbent main body, the ends of the ventral waist portion and the rear waist portion on one side in the left-right direction being joined at a side joint, the waist portion having a fastening portion having an engagement portion that detachably engages with the non-skin-side surface of the waist portion, the waist portion having a waist stretch member that stretches in the left-right direction, the absorbent main body having leg stretch members that stretch in the up-down direction on both sides in the left-right direction, the one side in the left-right direction of the ventral waist portion having a portion where the waist stretch member and the leg stretch member or an extension thereof intersect when viewed in the front-to-back direction, when a region where the waist stretch member is provided on the waist portion below the center position in the up-down direction of the side joint is defined as a lower stretch region, and a region where the leg stretch member is provided on the absorbent main body is defined as a leg stretch region, an absorbent article characterized in that a value obtained by dividing a force required to stretch the lower stretchable region by a predetermined length along the left-right direction by the vertical width of the lower stretchable region is greater than a value obtained by dividing a force required to stretch the leg opening stretchable region by the vertical direction by the horizontal width of the leg opening stretchable region.

2. An absorbent article as claimed in claim 1, characterized in that, on one side in the left-right direction of the ventral waistband section and the rear waistband section, when viewed in the front-to-rear direction, there are portions where the waistband elastic member and the leg band member or an extension thereof intersect at the ventral waistband section and the rear waistband section, respectively, and a value obtained by dividing the force required to stretch the lower stretchable region by a predetermined length in the left-right direction by the vertical width of the lower stretchable region is greater than a value obtained by dividing the force required to stretch the leg stretchable region by the predetermined length in the up-down direction by the horizontal width of the leg stretchable region.

3. An absorbent article as claimed in claim 1 or 2, characterized in that, on one side in the left-right direction of the ventral waist section and the dorsal waist section, when viewed in the front-to-rear direction, at least one of the waistline elastic members and the legline elastic members intersect, and the force required to stretch one of the intersecting waistline elastic members by a predetermined length in the left-right direction is greater than the force required to stretch one of the intersecting legline elastic members by the predetermined length in the up-down direction.

4. An absorbent article as described in claim 3, characterized in that, on one side in the left-right direction of the ventral waist section and the dorsal waist section, when viewed in the front-to-rear direction, a plurality of the waist stretch members and the leg stretch members intersect, and the force required to stretch the plurality of intersecting waist stretch members by the specified length along the left-right direction is greater than the force required to stretch the plurality of intersecting leg stretch members by the specified length along the up-down direction.

5. An absorbent article as claimed in claim 1 or 2, characterized in that, on one side of the left-right direction of the ventral waist portion, when viewed in the front-to-rear direction, the force required to stretch the waist stretch member, which has a portion that intersects with the leg stretch member in the lower stretch region, by a predetermined length along the left-right direction is smaller than the force required to stretch the waist stretch member, which does not have a portion that intersects with the leg stretch member in the lower stretch region, by a predetermined length along the left-right direction.

6. An absorbent article as claimed in claim 1 or 2, characterized in that, on the ventral side in the front-to-rear direction and on one side in the left-to-right direction, when viewed in the front-to-rear direction, the length in the up-down direction of the area where the waistline elastic member and the legline elastic member intersect is shorter than the length in the left-to-right direction of the waistline elastic member provided on the other side in the left-to-right direction of the area where the waistline elastic member and the legline elastic member intersect.

7. An absorbent article as claimed in claim 1 or 2, characterized in that the ventral waist portion is provided with a marker portion for engaging the fastening portion, and when the absorbent article is opened, the fastening portion is engaged on the other side in the left-right direction of the position of the marker portion, and when the absorbent article is opened, the other side in the left-right direction of the ventral waist portion does not have a portion where the waist stretch member and the leg stretch member intersect when viewed in the front-to-rear direction, and when the fastening portion is engaged with the ventral waist portion in line with the position of the marker portion, when viewed in the front-to-rear direction, there is a portion where the waist stretch member and the leg stretch member or an extension thereof intersect when viewed in the front-to-rear direction.

8. An absorbent article as described in claim 7, characterized in that, when viewed in the front-to-rear direction with the fastening portion engaged with the ventral waist portion in line with the position of the marker portion on the other side of the ventral waist portion in the left-right direction, the end of one side of the waist elastic member is located on the other side in the left-right direction of the leg elastic member which is located furthest on the one side.

9. An absorbent article as described in claim 7, characterized in that, when viewed in the front-to-rear direction with the fastening portion engaged with the ventral waistband portion in line with the position of the marker portion on the other side in the left-right direction of the ventral waistband portion, in the left-right direction, the engaging portion provided on the fastening portion is located to the one side of the leg opening elastic member which is located furthest to the one side.

10. An absorbent article as claimed in claim 7, characterized in that in a stretched state, with the fastening portion engaged with the ventral waist portion in alignment with the position of the marker portion, the total length of the waist elastic member and the leg elastic member arranged along the periphery of the leg opening on one side in the left-right direction is longer than the total length of the waist elastic member and the leg elastic member arranged along the periphery of the leg opening on the other side in the left-right direction.

11. An absorbent article as claimed in claim 7, characterized in that, in a natural state, with the fastening portion engaged with the ventral waist portion in alignment with the position of the marker portion, the total length of the waist elastic member and the leg elastic member arranged along the periphery of the leg opening on one side in the left-right direction is longer than the total length of the waist elastic member and the leg elastic member arranged along the periphery of the leg opening on the other side in the left-right direction.

12. An absorbent article as claimed in claim 7, characterized in that, when viewed in the front-to-rear direction with the fastening portion engaged with the ventral waist portion in alignment with the position of the marker portion, the length in the left-right direction of a portion where the waistline elastic member overlaps with the legline elastic member on one side in the left-right direction is longer than the length in the left-right direction of a portion where the waistline elastic member overlaps with the legline elastic member on the other side in the left-right direction.

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