AU2015265236B2

AU2015265236B2 - Disposable diaper

Info

Publication number: AU2015265236B2
Application number: AU2015265236A
Authority: AU
Inventors: Tomomi Isogai; Maki MIYAKE; Satoru Sakaguchi
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2014-05-27
Filing date: 2015-03-05
Publication date: 2018-10-04
Anticipated expiration: 2035-03-05
Also published as: CN106456404A; MY170691A; JP2015223257A; WO2015182205A1; TW201611798A; TWI643605B; BR112016023766A2; KR20170009834A; CN106456404B; JP6349148B2; KR101959901B1; AU2015265236A1

Abstract

An unfolding-type disposable diaper (1) for an infant having a body weight of 3000 g or less, having a longitudinal direction, a width direction, and a thickness direction orthogonal to each other, and being provided with a front waist-surrounding area (1a), a crotch area (1b), and a rear waist-surrounding area (1c), the unfolding-type disposable diaper (1) having an absorbent body (4), a pair of fastening members (10) extending outward in the width direction from the rear waist-surrounding area (1c), leg-surrounding stretchable members (6) provided along a pair of leg-surrounding openings (HL) formed by fastening of the pair of fastening members (10) to the front waist-surrounding area (1a) and provided further outside in the width direction than the absorbent body (4), and a target display part (15) for indicating the position at which to fasten the pair of fastening members (10) to the front waist-surrounding area (1a), the absorbent body (4) being provided with an overlap region (A) in the longitudinal direction which overlaps with the target display part (15) in the thickness direction, and the length (L1) of the target display part (15) in the width direction being equal to or less than the maximum length (L2) of the absorbent body (4) in the width direction in the overlap region (A).

Description

DESCRIPTION

Title of Invention

DISPOSABLE DIAPER

Technical Field [0001] The invention relates to an open-type disposable diaper for infants weighing 3000 g or less.

Background Art [0001a]

The following discussion of the background to the target tape of invention is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any aspect of the discussion was part of the common general knowledge as at the priority date of the application.

[0002] An open-type disposable diaper is brought into contact with the body of a wearer, and then is fixed to the wearer by fastening a pair of fastening tapes (fastening members) to a a front waist-circumference area; these fastening tapes extend outwards in the width direction from a back waist-circumference area. Some disposable diapers have an exterior sheet to the entire of which the fastening tapes can be fastened. But, this type of disposable diapers does not have a front target tape, which serves as a guide of the position at which the fastening tapes are fastened, and is difficult to wear. And, a disposable diaper has been proposed in which a target print (e.g., a number or an illustration), which serves as a guide of the position where the fastening tapes are fastened, is visible through the exterior sheet (see Patent Literature 1, for example).

Citation List [Patent Literature] [0003] [Patent Literature 1] Japanese Patent Application

Laid-open Publication No. 2002-253608

2015265236 31 Jul 2018

Summary of the Invention [0004] For wearers of various sizes, the target print is generally printed extending to both ends of the front waistcircumference area in the width direction. But, as for a baby weighing 3000 g or less, a user intends to put a disposable diaper loosely on the baby, and the fastening tapes are likely to be fastened to both ends of the front waist-circumference area in the width direction in accordance with the position of the target print. In this case, a gap is formed in a waist opening and/or leg openings, and there is a problem that excrement leakage is likely to happen.

[0005] The invention has been made in view of the above conventional problems, and an advantage thereof is to prevent excrement leakage from an open-type disposable diaper for infants weighing 3000 g or less.

[0006] According to one form of the invention there is provided an open-type disposable diaper for infants weighing 3000 g or less that has a longitudinal direction, a width direction, and a thickness direction perpendicular to one another, and that is composed of a front waist-circumference area, a crotch area and a back waist-circumference area, the diaper comprising: an absorbent body; a pair of fastening members that extend outwardly in the width direction from the back waist-circumference area; leg-circumference stretchable members that are respectively provided along a pair of leg openings that are to be formed by fastening the pair of fastening members to the front waist-circumference area, and that are provided outside in the width direction with respect to the absorbent body; and a target display section that indicates a position at which the pair of fastening members are to be fastened to the front waist-circumference area, the absorbent body having a longitudinal overlapping zone in which the absorbent body overlaps the target display section in the

2015265236 31 Jul 2018 thickness direction, a widthwise length of the target display section being equal to or smaller than a maximum widthwise length of the absorbent body within the overlapping zone, a pair of upstanding gathers that stand up toward a wearer side are provided along the longitudinal direction on both widthwise ends, and a stand-up point of each of the upstanding gathers is located , in the width direction, outside a widthwise outer end of the absorbent body and inside a widthwise outer end of a stretchable area in which the corresponding leg-circumference stretchable member is provided.

Other features of this invention will become apparent from the description in this specification and the attached drawings .

[0007] According to the invention, it is possible to prevent excrement leakage from an open-type disposable diaper for infants weighing 3000 g or less.

[0007a] Where any or all of the terms comprise, comprises, comprised or comprising are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components.

Brief Description of Drawings [0008] FIG. 1 is a schematic plan view of a disposable diaper on the wearer's skin side.

FIG. 2 is a schematic plan view of the disposable diaper on the non-skin side.

FIGS. 3A to 3C are cross-sectional views of the disposable diaper respectively along the line A-A, the line B-B and the line C-C in FIG. 2.

FIG. 4 is a schematic perspective view of the disposable diaper when being worn .

3a

2015265236 31 Jul 2018

FIG. 5A is an explanatory diagram showing how fastening tapes are fastened to an outer end of a front waist-circumference area in the width direction, and FIG. 5B is an explanatory diagram how fastening tapes are fastened to the central section of the front waist-circumference area in the width direction.

FIGS. 6A and 6B are explanatory diagrams of a low-weight infant's posture.

FIG. 7 is a diagram illustrating how sheet members located between an absorbent core and a leg-circumference stretchable member are folded.

FIG. 8 is an explanatory diagram showing how the fastening tapes are fastened to each other.

FIG. 9 is an explanatory diagram of a method of measuring fastening force.

Description of Embodiments [0009] At least the following matters will be made clear by the description in the specification and the accompanying drawings .

[0010] An open-type disposable diaper for infants weighing

3000 g or less that has a longitudinal direction, a width direction, and a thickness direction perpendicular to one another, and that is composed of a front waist-circumference area, a crotch area and a back waist-circumference area, the diaper including: an absorbent body; a pair of fastening members that extend outwardly in the width direction from the back waist-circumference area; leg-circumference stretchable members that are respectively provided along a pair of leg openings that are to be formed by fastening the pair of fastening members to the front waist-circumference area, and that are provided outside in the width direction with respect to the absorbent body; and a target display section that indicates a position at which the pair of fastening members are to be fastened to the front waist-circumference area, the absorbent body having a longitudinal overlapping zone in which the absorbent body overlaps the target display section in the thickness direction, a length of the target display section in the width direction being equal to or smaller than a maximum length of the absorbent body within the overlapping zone in the width direction.

With such a disposable diaper, since the absorbent body is stacked on the target display section in the thickness direction, a user can be guided so as to fasten the fastening member to the central section of the front waist-circumference area in the width direction. Fastening the fastening member to the central section of the front waist-circumference area in the width direction allows the waist opening and the leg opening to be smaller, and makes it possible to prevent excrement leakage from openings. Further, even if a wearer is in an M-shaped posture in which his/her legs are rigidly bent in M shape till his/her knees reach to his/her abdomen, the wearer's legs are not in contact with the fastening members and the fastening members are prevented to be removed. As a result, it is possible to prevent excrement leakage.

[0011] In such a disposable diaper, a pair of upstanding gathers that stand up out of a wearer side are provided along the longitudinal direction on both widthwise ends, and a standup point of each of the upstanding gathers is located between a widthwise outer end of the absorbent body and a widthwise outer end of a stretchable area in which the corresponding legcircumference stretchable member is provided.

With such a disposable diaper, the stand-up points of the upstanding gathers, together with the absorbent body and the leg-circumference stretchable members, are in close contact with a wearer, and this can prevent the upstanding gathers from being flattened. It is therefore possible to dam excrement by the upstanding gathers which are standing up, and excrement leakage can be prevented.

[0012] In such a disposable diaper, the stand-up point of the upstanding gather is located closer to the widthwise outer end of the absorbent body than to a widthwise inner end of the stretchable area.

With such a disposable diaper, the position of the absorbent body is steadier than those of the leg-circumference stretchable members, which move together with wearer's legs. Accordingly, if the stand-up points of the upstanding gathers are located at a position closer to the absorbent body than to the leg-circumference stretchable members, this makes the stand-up points of the upstanding gathers steadier. Consequently, this allows the upstanding gathers to stand up finely, and excrement leakage can be prevented.

[0013] In such a disposable diaper, the absorbent body includes an absorbent core and a wrap material of the absorbent core, and a length in the width direction from a widthwise outer end of the absorbent core to a widthwise inner end of a stretchable area in which the corresponding leg-circumference stretchable member is provided is equal to or more than a length of the stretchable area in the width direction.

With such a disposable diaper, it is possible to prevent the stretchable area from being drawn and flattened inwardly, and the stretchable area can be in close contact with the wearer's legs. Accordingly, the fitting on the wearer's legs improves, and excrement leakage can be prevented.

[0014] In such a disposable diaper, a one-side surface of either one of the pair of fastening members and an other-side surface of the other fastening member can be fastened to each other at a fastening force of 0.1 N/lOmm or more, the one-side surface being on one side in the thickness direction, the other-side surface being on the other side in the thickness direction.

With such a disposable diaper, the fastening members can be fastened at a position closer to the center of the front waistcircumference area in the width direction, and this enables the waist opening and the leg openings to be smaller. It is therefore possible to prevent excrement leakage if an extremely small low-weight infant wears the diaper.

[0015] === Schematic Configuration of Disposable Diaper ===

A disposable diaper of the present embodiment is an open-type disposable diaper for infants weighing 3000 g (gram) or less (hereinafter referred to as a low-weight infant), in particular, a diaper suitable for a low-birth-weight infant weighing less than 2500 g, a very-low-birth-weight infant weighing less than 1500 g, and an extremely-low-birth-weight infant weighing less than 1000 g.

[0016] FIG. 1 is a schematic plan view of the disposable diaper 1 on the wearer's skin side (inside) when the disposable diaper 1 is spread out and stretched. FIG. 2 is a schematic plan view of the disposable diaper 1 on the non-skin side (outside) when the disposable diaper 1 is spread out and stretched. FIGS. 3A to 3C are cross-sectional views of the disposable diaper 1 respectively along the line A-A, the line B-B and the line C-C in FIG. 2. FIG. 4 is a schematic perspective view of the disposable diaper 1 when being worn. As shown in the figures, the disposable diaper 1 has the longitudinal direction, the width direction and the thickness direction which are perpendicular to one another, and the disposable diaper 1 includes: a front waist-circumference area la which covers the ventral portion of a wearer; a back waistcircumference area lc which covers the dorsal portion of the wearer; and a crotch area lb placed between the front waistcircumference area la and the back waist-circumference area lc. [0017] As shown in FIG. 3, the disposable diaper 1 includes an absorbent body 4 between a liquid-permeable top sheet 2 and a liquid-impermeable back film 3. The absorbent body 4 includes: an absorbent core 41 and a liquid-permeable wrap material 42. The absorbent core 41 (composed of a material such as pulverized pulp or superabsorbent polymers) extends in the longitudinal direction from the front waist-circumference area la to the back waist-circumference area lc, and the core 41 absorbs and holds excrement. The wrap material 42 (e.g., tissue sheet or spunbonded nonwoven fabric) wraps the absorbent core 41. In the present embodiment, the absorbent body 4 has a rectangular planar shape, and the absorbent core 41 has an hourglass planar shape, in which its longitudinal central portion is narrower. On the non-skin side of the back film 3, an exterior sheet 5 (e.g., nonwoven fabric) is formed and constitutes the exterior of the entire disposable diaper 1. In order to improve the fitting on a wearer's waist, it is preferable that a stretchable member which can stretch in the width direction (e.g., stretchable sheet member and a threadlike stretchable member) is formed in the back waistcircumference area lc, but this is not shown in the figures. [0018] In the back waist-circumference area lc, a pair of fastening tapes 10 (fastening members) extending beyond both ends in the width direction are provided. As shown in FIG. 2, in the front waist-circumference area la on the non-skin-side surface of the exterior sheet 5, formed is a target tape 14 having a rectangular planar shape. The base material 11 of the fastening tape 10 includes a hook sheet 12 on the skin-side surface in the thickness direction (that is, a surface facing the target tape 14 when the fastening tape 10 is folded onto the front waist-circumference area la). On the other hand, on the non-skin-side surface of the base material 11, a target sheet 13 is provided. The hook sheet 12 (e.g., a sheet having a male component of a hook-and-loop fastener) is able to be fastened to and removed from the target sheet 13 and the target tape 14 (e.g., a piece of nonwoven fabric or a sheet having a female component of hook-and-loop fastener). It should be noted that the fastening tape 10 may be fastened directly to the exterior sheet 5, without the target tape 14. Also, the target sheet 13 may be different in material from the target tape 14.

[0019] In the front waist-circumference area la on the nonskin-side surface of the back film 3, a target display section 15 (e.g., a rectangle filled with a color different from the surrounding areas, the area indicated with hatchings in FIG. 2) is printed and indicates the position where the pair of fastening tapes 10 should be fastened in the front waistcircumference area la. The exterior sheet 5 and the target tape 14 placed on the non-skin side of the target display section 15 are parts through which the target display section 15 is visible from outside. In the present embodiment, the target tape 14 is a size larger than the target display section 15. However, the invention is not limited thereto. The target tape 14 may be equal in size to the target display section 15. [0020] When wearing the disposable diaper 1, the disposable diaper 1 is first two-folded in the longitudinal direction while being in contact with a wearer. And then, the pair of fastening tapes 10 and the surrounding areas are folded towards the center in the width direction, and the pair of fastening tapes 10 are fastened to the target tape 14 of the front waistcircumference area la. Then, as shown in FIG. 4, a waist opening HB and a pair of leg openings HL are formed.

[0021] As shown in FIG. 1, in the disposable diaper 1 which is spread out and stretched, the longitudinal central portion is narrower and both side edges of the crotch area lb in the width direction are curved in an arch shape. The curved portions become the pair of leg openings HL when the diaper 1 is worn. Also, in the disposable diaper 1, along the pair of leg openings HL (along the longitudinal direction in the present embodiment), leg-circumference stretchable members 6 are provided outside in the width direction with respect to the absorbent body 4, the leg-circumference stretchable members 6 being capable of stretching in the longitudinal direction. The leg-circumference stretchable members 6 are fixed between an upstanding-gather sheet 21 (to be described later) and the back film 3 and the exterior sheet 5 while stretching the longitudinal direction. Thus, when no external force is exerted on the disposable diaper 1, the leg-circumference stretchable members 6 contract and leg gathers are formed respectively around the leg openings HL, which fit on the wearer's legs .

[0022] In the present embodiment, the leg-circumference stretchable member 6 is composed of a stretchable sheet member (e.g., stretchable nonwoven fabric made of stretchable fiber, or stretchable film which is film made of a melted thermoplastic elastomer resin such as urethane or styrene). However, the invention is not limited thereto. For example, the leg-circumference stretchable member 6 may be composed of a plurality of thread-like stretchable members (e.g., thread-like stretchable fiber made of polyurethane or thread-like natural rubber) placed at intervals in the width direction.

[0023] In both sides of the disposable diaper 1 in the width direction (on the skin-side surface of the top sheet 2), a pair of upstanding gathers 20 which stand up out of the skin side (the wearer-facing side) are provided along the longitudinal direction. Each upstanding gathers 20 includes: the upstanding-gather sheet 21; and upstanding-gather stretchable members 22. As shown in FIG. 3, the widthwise outer end of the upstanding-gather sheet 21 coincides with that of the exterior sheet 5. On the other hand, the widthwise central end 21a of the upstanding-gather sheet 21 is folded towards the top sheet 2 (the non-skin side) and is two-layered, and the upstandinggather stretchable members 22 (e.g., a thread-like stretchable members; in the present embodiment, two stretchable members) are provided between the two-layered upstanding-gather sheet 21. The upstanding-gather stretchable members 22 are stretched in the longitudinal direction and are fixed to the upstandinggather sheet 21.

[0024] As shown in FIG. 1, the upstanding-gather sheet 21 is joined to the top sheet 2 on first joint sections 23 and a second joint section 24 (e.g., areas to which hot-melt adhesive is applied). The first joint sections 23 are provided in both of the longitudinal ends of the upstanding-gather sheet 21 and the top sheet 2 and are located near the center in the width direction with respect to the second joint section 24. In the present embodiment, in each of the longitudinal ends of each upstanding gather 20, three first joint sections 23 are placed lining in the width direction. The second joint section 24 extends from one-side longitudinal ends to the other-side longitudinal ends of the upstanding-gather sheet 21 and the top sheet 2. Thus, the upstanding-gather sheet 21 between the first joint sections 23 located in both of the longitudinal ends stands up from the top sheet 2 toward the skin side by contractile force of the upstanding-gather stretchable member 22; in this case, the second joint section 24 serves at a stand-up point where the upstanding-gather sheet 21 stands up. [0025] The disposable diaper 1 of the present embodiment is for low-weight infants. It is therefore preferable that a product size is set as follows: the product size is measured in a state where the product is stretched without creases, specifically, in a state where the size of a component constituting the disposable diaper 1 (e.g., the exterior sheet

5) is stretched so as to be substantially the same as the initial size of the component alone. The longitudinal product length in which the product is stretched in the longitudinal direction is in the range of 210 to 330 mm. More specifically, it is preferable that the product length for an infant weighing less than 2500 g is 310 mm, that the product length for an infant weighing less than 1500 g is 270 mm, and that the product length for an infant weighing less than 1000 g is 230 mm. The waist size (the circumference of the waist opening HB) is in the range of 160 to 295 mm. More specifically, it is preferable that the waist size for an infant weighing less than 2500 g is 273.5 mm, and that the waist size for an infant weighing less than 1500 g is 220 mm. The waist size is a size in a state where the widthwise top end of either one of the fastening tapes 10 coincides with the widthwise root end section of the hook sheet 12 of the other fastening tape 10. That is, when a stretchable member is provided for the circumference of waist, the waist size is size in a state where product is stretched in the width direction.

[0026] === Problem Unique to Low-Weight Infant ===

FIG. 5A is an explanatory diagram showing how the fastening tape 10 is fastened to an outer end of the front waistcircumference area la in the width direction, and FIG. 5B is an explanatory diagram how the fastening tape 10 is fastened to the central section of the front waist-circumference area la in the width direction. FIGS. 6A and 6B are explanatory diagrams of a low-weight infant's posture. A user intends to put the disposable diaper 1 loosely on a low-weight infant weighing 3000 g or less, and the fastening tapes 10 are likely to be fastened to the outer ends of the front waist-circumference area la in the width direction, as shown in FIG. 5A. In this case, the circumferences of the waist opening HB and the leg openings HL become larger than the case where the fastening tapes 10 are fastened to the central section of the front waist-circumference area la in the width direction as shown in FIG. 5B. Since low-weight infants weighing less than 2500 g at birth in particular are delivered before fat is formed on their body, the low-weight infants have a torso and legs which are thinner than those of normal newborn infants. Accordingly, if the disposable diaper 1 is put loosely on a baby, a gap becomes more likely to be formed in the waist opening HB and/or the leg openings HL, as shown in FIG. 5A.

[0027] A low-weight infant keeps the following posture (hereinafter referred to as a positioned posture): the posture being taken by the infant in his/her mother's womb, that is, the infant's back 30 bends roundly in C shape and the infant's legs 31 spread in M shape with the infant's knees being rigidly bent almost up to his/her abdomen as shown in FIGS. 6A and 6B. A gap hl is therefore likely to be formed between the back 30 and the disposable diaper 1. If the fastening tapes 10 are fastened to the outer ends of the front waist-circumference area la in the width direction (FIG. 5A) , the leg openings HL face outwardly in the width direction, and leg gathers is located on thin thighs, but not located on the top of thighs. Accordingly, a gap becomes more likely to be formed. If the low-weight infant is in the positioned posture, the leg openings HL which face outwardly in the width direction are placed near the central section in the width direction, and are pulled towards the infant's abdomen. In this case, a gap h2 is likely to be formed between the back sides of the legs 31 and the disposable diaper 1. Thus, if a gap is formed between the disposable diaper 1 and a wearer, excrement leaks from the gap. [0028] If the fastening tapes 10 are fastened to the outer ends of the front waist-circumference area la in the width direction, the legs 31 of a low-weight infant in the positioned posture come into contact with the fastening tapes 10 as shown in FIG. 6B, or this produces strong force which is exerted on the fastening tape 10 and the surrounding areas to remove them and to roll them towards the ventral side. In this case, it is possible that the fastening tapes 10 are removed from the target tape 14, which will result in excrement leakage.

[0029] It is, therefore, an object of the present embodiment is to prevent excrement leakage from an open-type disposable diaper for infants weighing 3000 g or less.

[0030] === Target Display Section 15 ===

In the disposable diaper 1 of the present embodiment, the absorbent body 4 is provided near the center in the width direction with respect to the leg-circumference stretchable member 6, and the absorbent body 4 has a longitudinal overlapping zone A in which the absorbent body 4 overlaps the target display section 15 in the thickness direction, as shown in FIG. 2. The overlapping zone A is a zone which indicates a longitudinal position. The end Al of the overlapping zone A coincides with a longitudinal end 15a of the target display section 15 on the side towards the back waist-circumference area lc, the end A2 of the overlapping zone A coincides with the longitudinal end 4a of the absorbent body 4 on the side towards the front waist-circumference area la. In the disposable diaper 1 of the present embodiment, the length Ll of the target display section 15 in the width direction is smaller than the length L2 of the absorbent body 4 within the overlapping zone A in the width direction. Since the widthwise central position CL of the target display section 15 is aligned with the widthwise central position CL of the absorbent body 4, a widthwise outer end 15b of the target display section 15 is located inside (near the center) in the width direction with respect to a widthwise outer end 4b (on the same side in the width direction) of the absorbent body 4 within the overlapping zone A.

[0031] Thus, when a user sees the target display section 15 accommodating inside (near the center) in the width direction with respect to the absorbent body 4 located in the central section in the width direction, the user is guided so as to fasten the fastening tapes 10 to the central section of the front waist-circumference area la in the width direction (FIG. 5B) . As for low-weight infants, whom a user intends to put a diaper loosely on, it is therefore possible to prevent the fastening tapes 10 from being fastened to the outer ends of the front waist-circumference area in the width direction.

[0032] By fastening the fastening tape 10 to the central section of the front waist-circumference area la in the width direction, the circumferences of the waist opening HB and the leg openings HL can be smaller. This prevents gaps from being formed between the wearer and the openings HB and HL, and can prevent excrement leakage. In addition, as shown in FIG. 5B, this enables the leg openings HL to face forward. That is, compared to those in FIG. 5A, the leg openings HL are located near the center in the width direction and can open in the thickness direction. Thus, the orientation of the legs of a low-weight infant in the positioned posture coincides with the orientation of the leg openings HL, and the leg-circumference stretchable members 6, which extend along the leg openings HL uniformly fit on the circumference of the wearer's legs. Further, the leg-circumference stretchable members 6 do not fit on the wearer's thighs, which are thin, but the member fit on the top of thighs. This prevents gaps from being formed on and around the leg openings HL, and can prevent excrement leakage from the leg openings HL. In addition, if the legcircumference stretchable members 6 fit on the top of thighs, which are less likely to move than thigh, this can make the positions of the leg-circumference stretchable members 6 steady. It can be said that this also makes it possible to prevent excrement leakage.

[0033] By fastening the fastening tape 10 onto the central section of the front waist-circumference area la in the width direction, the legs of a low-weight infant in the positioned posture are not in contact with the fastening tape 10, and the fastening tapes 10 can be prevented to be removed from the target tape 14. As a result, it is possible to prevent excrement leakage. Further, since the fastening tapes 10 are members which are relatively more rigid, chapping of a lowweight infant whose skin is weak can be prevented if the fastening tapes 10 do not come into contact with the legs of the low-weight infant.

[0034] According to the target display section 15 accommodating inside (near the center) in the width direction with respect to the absorbent body 4, the fastening tapes 10 are fastened to a zone, within the target tape 14, in which the absorbent body 4 overlaps the target tape 14. Consequently, from the legs of a low-weight infant in the positioned posture, the fastening tapes 10 are subjected to force which is exerted to remove and roll the fastening tapes 10, through the absorbent body 4, which are relatively more rigid. Thus, the force which is exerted to remove and roll the fastening tape 10 is absorbed by the absorbent body 4, and this allows the fastening tapes 10 to be further less likely to be removed from the target tape 14.

[0035] For low-weight infants, in order to stabilize respiratory or to prevent cerebral hemorrhage, it is desirable to avoid touching on infants' body as much as possible (the socalled minimum handling). Accordingly, if the number of times that the disposable diaper 1 is changed for a low-weight infant decreases by preventing excrement leakage from the diaper 1, this reduces load of nurses and mothers, and also this is effective in terms of low-weight infants' life support.

[0036] The length Ll of the target display section 15 in the width direction may be equal to the length L2 of the absorbent body 4 within the overlapping zone A in the width direction. That is, it is sufficient that the length Ll is equal to or less than the length L2, and a widthwise outer end 15b of the target display section 15 may coincide with a widthwise outer end 4b (on the same side in the width direction) of the absorbent body 4 within the overlapping zone A. In this case, since a user can also be guided so as to fasten the fastening tape 10 to the central section of the front waist-circumference area la in the width direction, the above-mentioned effects can be achieved.

[0037] Since the absorbent body 4 of the present embodiment has a rectangular planar shape, the length of the absorbent body 4 in the width direction is the same at all locations in the longitudinal direction. However, the invention is not limited thereto, and the length of the absorbent body 4 in the width direction may change depending on a location in the longitudinal direction. In this case, the length of the target display section 15 in the width direction is equal to or smaller than the maximum length of the absorbent body 4 within the overlapping zone A in the width direction, the fastening tapes 10 can be fastened to the central section of the front waist-circumference area la in the width direction.

[0038] In FIG. 2, a printed rectangular filled with a color different from the surrounding areas serves as the target display section 15. However, the invention is not limited thereto. The target display section 15 may be any printed item such as a number, a character, a line, an illustration, or an ellipse. In this case, the length of the target display section 15 in the width direction means the length in the width direction from an item printed at the position closest to one side in the width direction to an item printed at the position closest to the other side in the width direction. Further, it is not necessary to print the target display section 15 in the back film 3, and the target display section 15 may be printed in the exterior sheet 5 or the target tape 14. Furthermore, it is not necessary to form the target display section 15 by printing, and an area where a material different from the surrounding areas is provided may serve as the target display section 15. For example, the target tape 14 whose color is different from the surrounding areas may serve as the target display section 15.

[0039] Further, the central position CL of the target display section 15 in the width direction does not have to be aligned with the central position CL of the absorbent body 4 in the width direction, because of production error or the like. In this case, the widthwise end 15b of the target display section 15 on the one side is located outside in the width direction with respect to the widthwise end 4b of the absorbent body 4 within the overlapping zone A on the same side. But, even in this case, if the length of the target display section 15 in the width direction is set to equal to or less than the maximum length of the absorbent body 4 within the overlapping zone A in the width direction, the widthwise end 15b of the target display section 15 on the other side is located inside (near the center) in the width direction with respect to the widthwise end 4b of the absorbent body 4 within the overlapping zone A on the same side. Furthermore, the widthwise end 15b of the target display section 15 on the one side is not beyond the widthwise end 4b of the absorbent body 4 on the same side. Accordingly, the same effects as mentioned above can be achieved.

[0040] === Leg-Circumference Stretchable Member 6 ===

In the disposable diaper 1 of the present embodiment, a pair of the leg-circumference stretchable members 6 are provided on both outer sides in the width direction with respect to the absorbent body 4. More specifically, the widthwise innermost end 6a (nearest the center) of the leg-circumference stretchable member 6 is located outside in the width direction with respect to the widthwise outermost end 4a of the absorbent body 4. In other words, since the leg-circumference stretchable members 6 are provided in sheet members (the upstanding-gather sheet 21, the back film 3, and the exterior sheet 5) which are less rigid than the absorbent body 4, a space is formed between the leg-circumference stretchable member 6 and the absorbent body 4 which is to be in close contact with a wearer. Consequently, a shape like a puff sleeve is formed. Accordingly, whereas the absorbent body 4 remains in close contact with a wearer's body, the legcircumference stretchable members 6 follow the motion of the wearer's legs due to a flexibly-movable sheet members located between the stretchable members 6 and the absorbent body 4. A wearer is therefore likely to move legs and to be in the positioned posture (the leg openings HL are likely to face forward) . In other words, even when a wearer is in the positioned posture, the leg-circumference stretchable members 6 can maintain a state in which they fit on the wearer's legs while preventing the absorbent body 4 from creasing. It is therefore possible to prevent excrement leakage. Also, since excrement can be held in the space formed between the absorbent body 4 and the leg-circumference stretchable member 6, it can be said that excrement leakage can be prevented.

[0041] Further, in the disposable diaper 1 of the present embodiment, the length from the widthwise outer end 41a of the absorbent core 41 of the absorbent body 4 (on one side) to the widthwise inner end 6a (near the center) of the legcircumference stretchable member 6 (on the same side in the width direction) is defined as a length L3 in the width direction, as shown in FIG. 2. And, the length L3 is larger than the length L4 of the leg-circumference stretchable member 6 in the width direction. Accordingly, the length of a flexibly-movable sheet member which is located between the legcircumference stretchable member 6 and the absorbent core 4a which is more rigid (e.g., the upstanding-gather sheet 21) is long, and a wearer is likely to be in the positioned posture as mentioned above. In addition, the leg-circumference stretchable members 6 maintain a state in which they fit on the wearer's legs. It is therefore possible to prevent excrement leakage .

[0042] FIG. 7 is a diagram illustrating how sheet members between the absorbent core 41 and the leg-circumference stretchable member 6 (e.g., the upstanding-gather sheet 21) are folded. For the purpose of explanation, components such as the wrap material 42 of the absorbent body 4, the back film 3 and the exterior sheet 5 are omitted in the figure. With the disposable diaper 1 of the present embodiment, since a user is guided so as to fasten the fastening tape 10 to the central section of the front waist-circumference area la in the width direction as mentioned above, the upstanding-gather sheet 21, etc. are likely to enter inwardly (near the center) in the width direction from the position of the absorbent body 4, in particular, from the position of the widthwise outer end 41a of the absorbent core 41 which is more rigid, as shown in FIG. 7. Accordingly, if the length L3 in the width direction from the widthwise outer end 41a of the absorbent core 41 to the widthwise inner end 6a of the leg-circumference stretchable member 6 is smaller than the length L4 of the leg-circumference stretchable member 6 in the width direction, the legcircumference stretchable member 6 is drawn and flattened inwardly (non-skin side). In this case, the leg-circumference stretchable members 6 in the form of sheet cannot be in surface-to-surface contact with the wearer' legs, and the fitting of the leg openings HL deteriorates, which causes excrement leakage.

[0043] It is therefore preferable that, as in the disposable diaper 1 of the present embodiment, the length L3 in the width direction from the widthwise outer end 41a of the absorbent core 41 to the widthwise inner end 6a of the leg-circumference stretchable member 6 is equal to or larger than the length L4 of the leg-circumference stretchable member 6 in the width direction. Thus, the upstanding-gather sheet 21, etc. are folded in Z shape as shown in FIG. 7, and an area in which the leg-circumference stretchable member 6 is provided (stretchable area) is held in the form of a plane (a plane perpendicular to the thickness direction). This allows the leg-circumference stretchable members 6 to be in surface-to-surface contact with the wearer's legs, and the fitting of the leg openings HL can increase. Accordingly, excrement leakage can be prevented. [0044] The planar shape of the absorbent core 41 of the present embodiment is an hourglass shape. It is therefore sufficient that, if the length in the width direction from the widthwise nearest-the-center end of the widthwise outer end 41a of the absorbent core 41 (the outer end 41a of the narrowed portion) to the widthwise inner end 6a of the leg-circumference stretchable member 6 is defined as the length L3, the length L3 is equal to or larger than the length L4 of the legcircumference stretchable member 6 in the width direction. It is preferable that, as shown in FIG. 2, the length L5 in the widthwise direction from the widthwise outermost end 41a of the absorbent core 41 to the widthwise inner end 6a of the legcircumference stretchable member 6 is equal to or larger than the length L4 of the leg-circumference stretchable member 6 in the width direction. This allows the leg-circumference stretchable members 6 to further certainly be in surface-tosurface contact with the wearer' legs.

[0045] It is not necessary that the leg-circumference stretchable members 6 are stretchable sheet members, and the leg-circumference stretchable member 6 may be a plurality of thread-like stretchable members arranged in the width direction. This makes it possible to hold in the form of a plane the stretchable area in which a plurality of thread-like stretchable members are provided. And, the plurality of thread-like stretchable members (stretchable area) can be in contact with the wearer's legs. This can increase the fitting of the leg openings HL.

[0046] In the manufacturing line of disposable diapers 1, a disposable diaper 1 which is spread out is folded in the width direction or in the longitudinal direction. It is therefore preferable that the folding position in the width direction is a position where the leg-circumference stretchable member 6 does not exist. This can prevent the sheetlike legcircumference stretchable members 6 from having fold, and the leg-circumference stretchable members 6 become more likely to be in surface-to-surface contact with the wearer's legs. If a folding position is the widthwise outermost end 4a of the absorbent body 4, the upstanding-gather sheet 21, etc. are more likely to be folded in Z shape as shown in FIG. 7.

[0047] === Upstanding Gather 20===

In the disposable diaper 1 of the present embodiment, as shown in FIG. 1, the stand-up point of the upstanding gather 20 is the widthwise inner end 24a (near the center) of the second joint section 24 (on one side in the width direction) which joins the upstanding-gather sheet 21 to the top sheet 2. The widthwise inner end 24a of the second joint section 24 is located between the widthwise inner end 6a (near the center) of the leg-circumference stretchable member 6 (on the same side in the width direction) and the widthwise outer end 4a of the absorbent body 4 (on one side) . In other words, the stand-up points of the upstanding gathers 20 are provided between the absorbent body 4 which is to be in close contact with a wearer's body and the leg-circumference stretchable member 6 which is to be in close contact with a wearer's legs. This can prevent the upstanding gathers 20 from being flattened, and the upstanding gathers 20 can dam excrement. Consequently, excrement leakage can be prevented. In particular, if the wearer is a low-weight infant in the positioned posture, the disposable diaper 1 is likely to be in close contact with a wearer. In this case, the stand-up points of the upstanding gathers 20 are provided in a flexibly-movable sheet member which is located between the absorbent body 4 and the legcircumference stretchable member 6 (e.g., the upstanding-gather sheet 21), that is, a portion which is easy to separate from a wearer. This enables the upstanding gathers 20 to stand up in a space between the absorbent body 4 and the leg-circumference stretchable member 6, and this is effective.

[0048] Note that the widthwise outer ends 6b of the legcircumference stretchable members 6 are most likely to be in close contact with the wearer's legs. Accordingly, the same effects as mentioned above can be achieved if the stand-up points of upstanding gathers 20 are provided at least between the widthwise outer ends 6b of the leg-circumference stretchable member 6 (stretchable area) and the widthwise outer ends 4a of the absorbent body 4.

[0049] The leg-circumference stretchable members 6, which are to be in close contact with the wearer's legs, are more likely to shift and are less rigid than the absorbent body 4, which is to be in close contact with the wearer's body. As shown in FIG. 1, in the disposable diaper 1 of the present embodiment, the stand-up point (the widthwise inner end 24a of the second joint section 24) of one upstanding gather 20 (on one side in the width direction) is provided at a position closer to the widthwise outer end 4a of the absorbent body 4 (on the same side in the width direction) than to the widthwise inner end 6a of one leg-circumference stretchable member 6 (on the same side in the width direction). In other words, the length L6 in the width direction from the stand-up point 24a of the upstanding gather 20 to the widthwise outer and 4a of the absorbent body 4 is smaller than the length L7 in the width direction from the stand-up point 24a of the upstanding gather 20 to the widthwise inner end 6a of the leg-circumference stretchable member 6. This allows the position of the stand-up point 24a of the upstanding gather 20 to be steady, and also allows the upstanding gathers 20 to stand up finely. Accordingly, excrement leakage can be further certainly prevented.

[0050] In the present embodiment, the planar shape of the absorbent core 41, which significantly affects the rigidity of the absorbent body 4, is an hourglass shape. But, the invention is not limited thereto, for example, and the planar shape of the absorbent core 41 may be a rectangle. In this case, the stand-up point 24a of the upstanding gather 20 can be provided at a position closer to the widthwise outer end 41a of the absorbent core 41 than to the widthwise inner end 6a of the leg-circumference stretchable member 6. This can make the position of the stand-up point 24a of the upstanding gather 20 steadier, and this allows the upstanding gathers 20 to stand up finely.

[0051] === Fastening Tape 10===

FIG. 8 is an explanatory diagram showing how the fastening tapes are fastened to each other. As shown in FIG. 1, the fastening tape 10 of the present embodiment includes the hook sheet 12 and the target sheet 13 which can be fastened to the hook sheet 12; the hook sheet 12 being provided on the skinside surface (a surface facing the target tape 14 when the fastening tape 10 is folded onto the front waist-circumference area la) , the target sheet 13 being provided on the non-skinside surface. In the disposable diaper 1 of the present embodiment, as shown in FIG. 8, of the pair of fastening tapes 10, a surface of the fastening tape 10a on one side in the thickness direction (a surface facing outwardly when the fastening tape 10a is folded onto the front waist-circumference area la) can be fastened to a surface of the fastening tape 10b on the other side in the thickness direction (a surface facing inwardly when the fastening tape 10b is folded onto the front waist-circumference area la) . When the diaper 1 is worn, the hook sheet 12 of one fastening tape 10a is first fastened to the central section of the target tape 14 in the width direction, and then onto the target sheet 13 of one fastening tape 10a, the hook sheet 12 of the other fastening tape 10b is fastened.

[0052] Even if the fastening tapes 10 cannot be fastened to each other, shifting the fastening position of the fastening tapes 10 in the longitudinal direction enables the fastening tapes 10 to be fastened at a position closer to the center of the front waist-circumference area la in the width direction. However, in this case, a gap is formed on either one of the leg openings HL or the absorbent body 4 creases, and it is possible that excrement leaks. Accordingly, if the fastening tapes 10 can be fastened to each other as in the present embodiment, the waist opening HB and the leg openings HL can be smaller and it is possible to prevent the absorbent body 4 from creasing. It is also possible to more certainly prevent the legs of a low24 weight infant in the positioned posture from coming into contact with the fastening tape 10. This makes it possible to prevent excrement leakage even when putting the disposable diaper 1 on a smaller low-weight infant.

[0053] In order to keep the fastening tapes 10 fastened when the disposable diaper 1 is worn, the fastening force between the fastening tapes 10 (the fastening force between the hook sheet 12 and the target sheet 13) is set to 0.1 N/lOmm or more. On the other hand, if the fastening force is too strong, the fastening tapes 10 are difficult to remove when changing the disposable diaper 1. It is therefore desirable that the fastening force between the fastening tapes 10 is set to 0.5 N/lOmm or less. Similarly, it is desirable that the fastening force of the hook sheet 12 to the target tape 14 is 0.1 N/lOmm or more and 0.5 N/lOmm or less. And, the target sheet 13 may be provided only in either one of the fastening tapes 10, and this can reduce materials. But, if the target sheet 13 are provided on both of the fastening tapes 10, user can fasten the fastening tapes 10 without concerning the order of the fastening tapes 10.

[0054] Each fastening tape 10 of the present embodiment has a substantially trapezoidal shape, and its top end in the width direction is shorter in longitudinal length than its root end. Accordingly, as shown in FIG. 8, the upper fastening tape 10b has a zone (the hatched zone) on which the upper fastening tape 10b does not overlap the lower fastening tape 10a, and the nooverlapping zone can be fastened to the target tape 14. Further, the root end of the fastening tape 10b is more likely to be subject to force from legs of a low-weight infant in the positioned posture than the top end is. And, the fastening force of the fastening tape 10 to the target tape 14 may be greater than the fastening force between the fastening tapes 10. In this case, since the root end of the upper fastening tape 10b (the hatched zone) is fastened to the target tape 14 by a strong fastening force, the upper fastening tape 10b becomes more difficult to remove and this makes it possible to prevent excrement leakage. On the other hand, the top end of the upper fastening tape 10b is fastened to the lower fastening tape 10a by a relatively weak fastening force. Accordingly, when changing the disposable diaper 1, users easily pick up the top end of the upper fastening tape 10a and easily remove the fastening tapes 10.

[0055] FIG. 9 is an explanatory diagram of a method of measuring the fastening force. the fastening force (N/lOmm) between the fastening tapes 10 is measured as follow with an Autograph Tester AG-Xplus (Shimazu Corporation), which is an

First, prepare a sample from a to-be-measured example of a tensile strength tester.

which is obtained by cutting, fastening tape 10, a rectangular area including the hook sheet 12. Similarly, prepare a sample S2, which is obtained by cutting, from the fastening tape 10, a rectangular area including the target sheet 13. Next, align the samples SI and according to the longitudinal direction and the width direction of the disposable diaper 1, and then place the hook sheet 12 of the sample SI on the target sheet 13 of the sample S2. Roll a roller of 700 g on the samples SI and S2 at a speed of 5 mm/minute in the width direction of the disposable diaper 1 (a direction in which the fastening tape 10 is pulled and removed), and fasten the samples SI and S2.

[0056] Next, put the samples SI and S2, which are fastened to each other, onto the tensile strength tester. More specifically, fix the sample S2 to the tilt table 50a of a base 50, and hold the end section of the sample SI with a moving member 51. Align the width direction of the disposable diaper 1 with the tilt direction of the tilt table 50a. Then, move the moving member 51 upwards relative to the base 50 at a constant moving speed of 300 mm/minute, and pull apart the samples SI and S2. Obtain the load when the angle formed between the tilt table 50a and a direction in which the moving member 51 is pulling the sample SI (a direction of a pulling force which is exerted on the sample SI) has reached to 135 degrees .

[0057] Finally, convert the obtained load into a load under conditions in which the size of the sample SI (the hook sheet 12) in the longitudinal direction of the disposable diaper 1 is 10 mm; the converted load is the foregoing fastening force (N/lOmm) . The fastening force of the hook sheet 12 to the target tape 14 can be measured in the same way.

[0058] The above-described embodiments are intended to facilitate the understanding of the present invention, and the present invention is not to be construed as being limited to the embodiments. Needless to say, various modifications and improvements can be made to the present invention without departing from the gist thereof, and equivalents thereof fall within the present invention.

[0059] For example, the disposable diaper 1 does not have to include the upstanding gathers 20. Further, in the disposable diaper 1, the stand-up point 24a of the upstanding gather 20 may be located on the absorbent body 4 or may be located outside in the width direction with respect to the legcircumference stretchable member 6. Furthermore, in the disposable diaper 1, the stand-up point 24a of the upstanding gather 20 may be located at a position closer to the legcircumference stretchable member 6 than to the absorbent body 4. Furthermore, in the disposable diaper 1, the length in the width direction from the widthwise outer end 41a of the absorbent core 41 to the widthwise outer end 6a of the legcircumference stretchable member 6 may be smaller than the length of the leg-circumference stretchable member 6 in the width direction. Furthermore, in the disposable diaper 1, the fastening tape 10 does not have to have the target sheet 13.

Reference Signs List [0060] 1 disposable diaper, la front waist-circumference area, lb crotch area, lc back waist-circumference area, 2 top sheet, back film, 4 absorbent body, 41 absorbent core, 42 wrap material, 5 exterior sheet, 6 leg-circumference stretchable member (stretchable area), 10 fastening tape (fastening member), 11 base material, 12 hook sheet, 13 target sheet, 14 target tape, 15 target display section, 20 upstanding gather, 21 upstanding-gather sheet, 22 upstanding-gather stretchable member, 23 first joint section, 24 second joint section, 24a stand-up point of upstanding gather, 30 back, 31 leg, 50 base, 50a tilt table, 51 moving member, HB waist opening, HL leg opening, A overlapping zone

2015265236 31 Jul 2018

Claims

The claims defining the invention are as follows:

1. An open-type disposable diaper for infants weighing 3000 g or less

5 that has a longitudinal direction, a width direction, and a thickness direction perpendicular to one another, and that is composed of a front waist-circumference area, a crotch area and a back waist-circumference area, the diaper comprising:

10 an absorbent body;

a pair of fastening members that extend outwardly in the width direction from the back waist-circumference area;

leg-circumference stretchable members that are respectively provided along a pair of leg

15 openings that are to be formed by fastening the pair of fastening members to the front waist-circumference area, and that are provided outside in the width direction with respect to the absorbent body; and a target display section that indicates a position at which

20 the pair of fastening members are to be fastened to the front waist-circumference area, the absorbent body having a longitudinal overlapping zone in which the absorbent body overlaps the target display section in the thickness direction,

25 a widthwise length of the target display section being equal to or smaller than a maximum widthwise length of the absorbent body within the overlapping zone, a pair of upstanding gathers that stand up toward a wearer side are provided along the longitudinal direction on

30 both widthwise ends, and a stand-up point of each of the upstanding gathers is located , in the width direction, outside a widthwise outer end of the absorbent body and inside a widthwise outer end of a stretchable area in

2015265236 31 Jul 2018 which the corresponding leg-circumference stretchable member is provided.
2. A disposable diaper according to claim 1, wherein

5 the stand-up point of the upstanding gather is located closer to the widthwise outer end of the absorbent body than to a widthwise inner end of the stretchable area.
3. A disposable diaper according to claim 1 or 2, wherein

10 the absorbent body includes an absorbent core and a wrap material of the absorbent core, and a length in the width direction from a widthwise outer end of the absorbent core to a widthwise inner end of a stretchable area in which the corresponding leg-circumference stretchable

15 member is provided is equal to or more than a length of the stretchable area in the width direction.
4. A disposable diaper according to any one of claims 1 to 3, wherein

20 a one-side surface of either one of the pair of fastening members and an other-side surface of the other fastening member can be fastened to each other at a fastening force of 0.1 N/lOmm or more, the one-side surface being on one side in the thickness

25 direction, the other-side surface being on the other side in the thickness direction.

1/9

WIDTH

DIRECTION

CENTER

OUTER SIDE ** **· ,, _iE-_D ** OUTER SIDE

INNER

L7

FIG. 1

OUTER SIDE

WIDTH

DIRECTION

CENTER 'INNER

SIDE

OUTER SIDE

FIG. 2

3/9

SKIN SIDE

NON-SKIN

SIDE

WIDTH

DIRECTION

SKIN SIDE

V ₅3 ?

WIDTH

DIRECTION z

THICKNESS

DIRECTION

NON-SKIN

SIDE

SKIN SIDE

THICKNESS

DIRECTION

NON-SKIN

SIDE s

TP j iUi Ow

4/9

FIG. 4
5/9

DIRECTION

-►

OUTER SIDE

CENTER

LONGITUDINAL

DIRECTION

FIG. 5A

LONGITUDINAL

DIRECTION

WIDTH _____ DIRECTION OUTER SIDE’*-►CENTER

FIG. 5B
6/9

FIG. 6A

FIG. 6B
7/9

SKIN SIDE

THICKNESS

DIRECTION

NON-SKIN

SIDE

CENTER INNER SIDE

WIDTH

DIRECTION

OUTER SIDE

FIG. 7
8/9

FIG. 8
9/9

FIG. 9