AU2015265150A1

AU2015265150A1 - Disposable diaper

Info

Publication number: AU2015265150A1
Application number: AU2015265150A
Authority: AU
Inventors: Tomomi Isogai; Maki MIYAKE; Satoru Sakaguchi
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2014-05-27
Filing date: 2015-04-24
Publication date: 2016-09-29
Anticipated expiration: 2035-04-24
Also published as: KR101911758B1; MY168986A; AU2015265150B2; JP2015223255A; WO2015182307A1; KR20170009827A; BR112016023784A2; CN106456405B; JP6343495B2; CN106456405A

Abstract

A disposable diaper having a longitudinal direction and a width direction intersecting with the longitudinal direction, the disposable diaper having a central band-shaped region including an absorbent body for absorbing liquid, side flaps positioned on both sides in the width direction of the central band-shaped region, and band-shaped leg-surrounding elastic sheets for expanding and contracting along the longitudinal direction, the leg-surrounding elastic sheets being provided to the side flaps. Edge parts on the outer sides of the side flaps in the width direction are provided with wavy portions in which projections convex toward the outer side in the width direction and recesses concave toward the outer side in the width direction repeat in alternating fashion in the longitudinal direction, and the leg-surrounding elastic sheets are disposed on the inner side in the width direction relative to the recesses of the side flaps.

Description

[DESCRIPTION] [Title of Invention] DISPOSABLE DIAPER [Technical Field] [0001]

The present invention relates to disposable diapers. [Background Art] [0002]

Conventionally, open-type disposable diapers have been widely used. In open-type disposable diapers, a side flap is provided with a fastening tape, and a front portion (referred to as an abdomen side part, or a front part of the body) is provided with a target tape that engages with the fastening tape. Such open-type disposable diapers are widely used particularly with newborns and babies and infants since they are easy to attach and detach.

[Citation List] [Patent Literature] [0003] PTL 1: Japanese Patent Application Laid-open Publication

No. 2013-212212 PTL 2: Japanese Patent Application Laid-open Publication

No. 2013-138702 PTL 3: Japanese Patent Application Laid-open Publication

No. 2013-230256 PTL 4: Japanese Patent Application Laid-open Publication

No. 2013-158573 PTL 5: International Publication No. 2013/077360 pamphlet [Summary of the Invention] [Technical Problem] [0004]

In open-type disposable diapers, detaching and attaching is easy, however the fitting of the leg-surrounding part when wearing the diaper may become a problem. For example, when allowing babies and infants or the like to wear diapers, there may be a case where gaps between the leg surrounding opening portion of the diaper and the legs of the wearer are less likely to occur by fastening the fastening tape tightly so that the body wastes excreted inside the diaper are not leaked from the leg surrounding opening portion of the diaper to the outside. In such a case, the leg surrounding portion of the diaper easily bites into the skin of the wearer, an uncomfortable feeling is caused when the wearer moves his/her legs, and the deterioration of the texture may be caused. Further, in the case of newborns with sensitive skins, the tight fastening of the leg portion results in a deterioration of the baby's bloodstream, thereby causing a swelling and also an uncomfortable feeling.

The present invention has been made in view of the above problems, and this invention aims to provide a disposable diaper that has a good texture in the leg-surrounding part. [Solution to Problem] [0005]

An aspect of the invention is a disposable diaper having a longitudinal direction and a width direction intersecting the longitudinal direction, the disposable diaper including: a central strip region including an absorbent body that absorbs liquid; side flaps positioned in both side portions in the width direction of the central strip region; and a strip-shaped leg surrounding elastic sheet that is provided to the side flap and stretches along the longitudinal direction, an end edge portion in an outer side in the width direction of the side flap having a wave form part in which a projected portion projected to the outer side in the width direction and a depressed portion depressed to the outer side in the width direction are repeated alternately in the longitudinal direction, and the leg surrounding elastic sheet being arranged to the inner side in the width direction than the depressed portion of the side flap.

[0006]

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

[Effects of the Invention] [0007]

According to this invention, a disposable diaper having a good texture in the leg-surrounding part can be provided.

[Brief Description of Drawings] [0008] [Fig. 1] Fig. 1 is a developed plan view of a diaper 1.

[Fig. 2] Fig. 2A to Fig. 2C are exploded views of each parts of the diaper 1. Fig. 2A is an exploded explanatory view of a front portion 3. Fig. 2B is an exploded explanatory view of a crotch portion 5. Fig. 2C is an exploded explanatory view of a rear portion 7.

[Fig. 3] Fig. 3 is an explanatory view of a positioning posture .

[Fig. 4] Fig. 4 is a view illustrating a form of the diaper 1 when worn.

[Fig. 5] Fig. 5 is a side view showing the manner of the diaper 1 when worn.

[Fig. 6] Fig. 6 is a schematic plan view explaining a configuration of a side flap 14.

[Fig. 7] Fig. 7 is a view showing enlarged an end edge portion 14Lg of the side flap 14.

[Description of Embodiments] [0009]

At least the following matters will become clear with the description of this specification and the attached drawings. A disposable diaper having a longitudinal direction and a width direction intersecting the longitudinal direction, the disposable diaper including: a central strip region including an absorbent body that absorbs liquid; side flaps positioned in both side portions in the width direction of the central strip region; and a strip-shaped leg surrounding elastic sheet that is provided to the side flap and stretches along the longitudinal direction, an end edge portion in an outer side in the width direction of the side flap having a wave form part in which a projected portion projected to the outer side in the width direction and a depressed portion depressed to the outer side in the width direction are repeated alternately in the longitudinal direction, and the leg surrounding elastic sheet being arranged to the inner side in the width direction than the depressed portion of the side flap.

According to such a disposable diaper, a disposable diaper having a good texture in the leg-surrounding part can be provided.

[0010]

In the above disposable diaper, it is preferable that the leg surrounding elastic sheet is linearly arranged along the longitudinal direction.

According to such a disposable diaper, in the crotch portion, the leg surrounding elastic sheet is in a parallel positional relation to the end edge portion of the side flap, and thus the stretching force applied by the leg surrounding elastic sheet can uniformly act on the end edge portion of the side flap. In this way, the problem such that the fastening becomes tight in a partial region of the end edge portion of the side flap becomes less likely to occur.

[0011]

In the above disposable diaper, it is preferable that a distance between the projected portion and the depressed portion in the width direction is greater than a distance between the depressed portion and an outer side end portion in the width direction of the leg surrounding elastic sheet.

According to such a disposable diaper, the stretching force of the leg surrounding elastic sheet does not easily directly act on the end edge portion of the side flap that forms the leg surrounding opening portion, the depressed portion and the projected portion are easily maintained in respective shapes, and the wave form shape of this end edge portion becomes easily maintained even when wearing the diaper. In this way, the force acting on the end edge portion of the side flap is dispersed, and a good texture can be achieved while applying such stretchability that does not impair the fitting of the leg surrounding opening portion.

[0012]

In the above disposable diaper, it is preferable that the side flap has a front portion positioned to an abdomen side of a wearer when wearing the disposable diaper, a rear portion positioned to a back side of the wearer, and a crotch portion positioned between the front portion and the rear portion; and a distance between two adjacent projected portions in the longitudinal direction is constant in the crotch portion of the side flap.

According to such a disposable diaper, the force easily acts on each of the projected and depressed portions uniformly. This makes it hard to cause a problem such that the fastening becomes tight in a partial region of the end edge portion of the side flap.

[0013]

In the above disposable diaper, it is preferable that a maximum distance of the distances between the two adjacent projected portions in the longitudinal direction in the rear portion of the side flap is wider than the distance between the two adjacent projected portions in the longitudinal direction in the crotch portion of the side flap.

According to such a disposable diaper, the curve of the edge part that contacts with the buttocks of the wearer becomes smooth in the rear region of the side flap, and thus a good texture can be achieved by making the texture of the buttocks soft.

[0014]

In the above disposable diaper, it is preferable that a length in the width direction in the rear portion of the side flap is longer than a length in the width direction in the crotch portion of the side flap.

According to such a disposable diaper, the area where the side flaps cover the buttocks of the wearer in the region of the rear portion is widen when worn, and thus a comfortable feeling of wearing can be achieved.

[0015]

In the above disposable diaper, it is preferable that the absorbent body has, on each of a front side and a rear side in the longitudinal direction of the crotch portion, a pair of dart portions in which a basis weight of a liquid absorbent raw material is less than other parts; and the rear portion of the side flap is a region positioned to the rear side in the longitudinal direction of the dart portion provided to the rear side in the longitudinal direction of the crotch portion.

According to such a disposable diaper, the width of the side flap becomes narrow in the front portion side in the longitudinal direction of the rear side dart portion, and the width of the side flap becomes wide in the rear portion side thereof. Thereby, the wearer can easily move his/her legs to the front portion side in the longitudinal direction and the buttocks of the wearer can be restrained from extending over the side flap in the rear portion side.

[0016]

In the above disposable diaper, it is preferable that a front side end portion in the longitudinal direction of the leg surrounding elastic sheet and a rear side end portion in the longitudinal direction of the leg surrounding elastic sheet are in the same position in the width direction.

According to such a disposable diaper, the stretching force easily acts on the end edge portion of the side flap uniformly, and thus the fastening force of the leg surrounding portion is suppressed from being locally high, and thereby easily achieving a good texture. Further, even when the diaper is worn by reversing the front and rear, the force can act on the end edge portion uniformly without impairing the function of the diaper.

[0017]

In the above disposable diaper, it is preferable that the side flap has a liquid permeable top sheet arranged to a skin-side of the wearer, a back sheet arranged to a non-skin side of the wearer, and a liquid non-permeable leak prevention sheet arranged between the top sheet and the back sheet; and an outer side end portion in the width direction of the leak prevention sheet is positioned to the inner side in the width direction than the depressed portion of the side flap.

According to such a disposable diaper, the leak prevention sheet in which the raw material of the fabric is hard and the texture of which easily deteriorates is arranged apart from the end edge portion of the side flap, and thus the region of the end edge portion is kept soft and the texture of the leg surrounding portion when wearing the diaper can be improved.

[0018]

In the above disposable diaper, it is preferable that the side flap has, in a front side end portion and a rear side end portion in the longitudinal direction, a notched portion formed of a curve which protrudes to the inner side in the width direction.

According to such a disposable diaper, by providing a notched portion, the corner portion of the side flap hardly contacts the abdomen portion of the wearer, and thus the texture in the waist circumference can be improved.

[0019] ===Embodiments=== <Basic Configuration of Disposable Diaper 1> A disposable diaper 1 of the present embodiment (hereinafter, referred to simply as a diaper 1) is a disposable diaper that targets mainly newborns and babies and infants as wearers, and is preferably used in low weight infants with a weight equal to or smaller than 3000 grams, and in particular is preferably used in low birth weight infants with a weight of less than 2500 grams. It should be noted that, low weight infants include not only low birth weight infants (with a weight of less than 2500 grams), but also very low birth weight infants (with a weight of less than 1500 grams), and extremely low birth weight infants (with a weight of less than 1000 grams).

[0020]

Fig. 1 is a developed plan view of the diaper 1. Fig. 2A to Fig. 2C are exploded explanatory views of each portion of the diaper 1. Fig. 2A is an exploded explanatory view of a front portion 3. Fig. 2B is an exploded explanatory view of a crotch portion 5. Fig. 2C is an exploded explanatory view of a rear portion 7.

[0021]

The diaper 1 of the present embodiment is a disposable diaper of a so-called open type, and as shown in Fig. 1, the diaper has a front portion 3, a crotch portion 5, and a rear portion 7. The front portion 3 is a part that is to be positioned in the front portion (an abdomen side, a front part of the body) of a wearer. Further, the rear portion 7 is a part that is to be positioned in the rear portion (a back side, a back part of the body) of a wearer. The crotch 5 is a part to be positioned in between the front portion 3 and the rear portion 7.

[0022]

In the below explanation, as shown in Fig. 1, each direction is defined. In other words, a direction from the front portion 3 toward the rear portion 7 is referred to as a "product longitudinal direction L", a direction orthogonal to the product longitudinal direction L is referred to as a "product width direction W". CL shown in Fig. 1 is a line showing a center of the diaper 1 in the product longitudinal direction L. Further, as shown in Fig. 2, the direction orthogonal to the product longitudinal direction L and the product width direction W is referred to as a "thickness direction", and the side to the skin of the wearer is referred to as a "skin side", and the opposite side is referred to as a "non-skin side".

[0023]

The diaper 1 has a central strip region 12, side flaps 14, leg side gathers 16, and waist gathers 18. Each of the pair of the side flaps 14 is attached with a fastening tape 30.

[0024]

The central strip region 12 is a strip region positioned

in a central portion in the product width direction W configured with the front portion 3, the crotch portion 5, and the rear portion 7 (refer to Fig. 1). The central strip region 12 is a part that absorbs and retains liquid such as urine excreted by the wearer. The central strip region 12 has a vertically long shape (a shape along the product longitudinal direction L) including an absorbent body 21 that has liquid retainability. The central strip region 12 mainly has an absorbent body 21, a top sheet 22, a leak prevention sheet 23, and a back sheet 24 (refer to Fig. 2A to Fig. 2C).

[0025]

The absorbent body 21 is a member made by laminating liquid absorbent raw material that can absorb excretions such as urine, and the absorbent body 21 is arranged over the front portion 3, the crotch portion 5, and the rear portion 7. The region indicated as a shaded portion in Fig. 1 shows a region occupied with the absorbent body 21. The absorbent body 21 has an hourglass shape in which the width of a central portion in the product longitudinal direction L becomes narrow. The shape of the absorbent body 21 however is not limited to the shape shown in Fig. 1, and may be a simple rectangular shape. Further, the absorbent body 21 may be provided in at least the crotch portion 5. The absorbent body 21 is arranged sandwiched with the top sheet 22 and the leak prevention sheet 23. As the liquid absorbent material structuring the absorbent body 21, for example, a liquid absorbent fiber such as a pulp fiber, and liquid absorbent particles such as superabsorbent polymers can be used. Further, a liquid absorbent material other than the liquid absorbent fiber and the liquid absorbent particles may be included.

[0026]

The crotch portion 5 of the absorbent body 21 is formed with a pair of dart portions 211f near the front portion 3 in both end portions in the product width direction W. Similarly, a pair of dart portions 211b is formed near the rear portion 7 in both end portions in the product width direction W. The dart portions 211f and 211b are narrowed portions that are notched in a substantially bell shape as shown in Fig. 1. It should be noted that, the shape of the dart portions 211f and 211b is not limited to the shape shown in Fig. 1. Further, the absorbent body 21 may not be notched at the dart portions 211f and 211b, but the basis weight of the liquid absorbent raw material in the dart portions 211f and 211b may be less than that of other parts of the absorbent body 21. For example, the basis weight of the liquid absorbent raw material in the dart portions 211f and 211b may be less than or equal to one third of the basis weight of the other parts. In any case, rigidity of the absorbent body 21 in the dart portions 211f and 211b is lower than the other parts. In this way, the absorbent body 21 can be easily bent in the dart portion regions, and can also be easily deformed in a round dimension to fit the body (the crotch portion) of the wearer, and the fitting of the diaper 1 when worn can be improved.

[0027]

It should be noted that, with the diaper 1, the position of the crotch portion 5 is set so that the center portion of the groin of the wearer and the center portion of the crotch portion 5 match. The center portion of the groin of the wearer is the center position at the base of the legs, and is a position shifted to the front portion side of the central position CL of the diaper 1 in the product longitudinal direction L (refer to Fig. 1). Since the center portion of the crotch portion 5 is positioned to the front portion side of the central position CL of the diaper 1, the wearer can easily move his/her legs to the front side (the abdomen side), and further an area of the rear portion 7 of the diaper 1 can be made relatively wide, so that the buttocks of the wearer can be sufficiently covered.

[0028]

The top sheet 22 is a liquid permeable member arranged to the skin side of the absorbent body 21. The leak prevention sheet 23 is a liquid non-permeable member arranged to the nonskin side of the absorbent body 21. The back sheet 24 is a member that configures the exterior to the non-skin side of the diaper 1 (an exterior sheet), and is configured with for example, nonwoven fabric. The back sheet 24 is arranged to the non-skin side of the leak prevention sheet 23 (refer to Fig. 2A to Fig. 2C) .

[0029]

In the crotch portion 5 of the central strip region 12, a stretchable film 25 is arranged between the absorbent body 21 and the back sheet 24. The stretchable film 25 is a member that applies stretchability to the central strip region 12 of the crotch portion 5. In the present embodiment, the stretchable film 25 is attached in a state stretched in the product longitudinal direction L. In this way, the stretchable film 25 shows shrinkage force along the product longitudinal direction L with respect to the crotch portion 5 in the central strip region 12. When wearing the diaper 1, the crotch portion 5 contracts along the product longitudinal direction L, and thus with the above described dart portions 211f and 211b the central strip region 12 deforms dimensionally into a rounded shape to fit the body of wearer. In this way, the central strip region 12 is retained in a shape that surrounds the crotch portion of the wearer, and thus the fitting of the diaper 1 is improved, and leaking of excretions to outside of the diaper 1 can be easily suppressed.

[0030]

The side flaps 14 are parts positioned in both side portions of the central strip region 12 in the product width direction W. The side flaps 14 are formed over the front portion 3, the crotch portion 5, and the rear portion 7 (refer to Fig. 1) . The length (width) in the product width direction W of the side flaps 14 in the crotch portion 5 is narrower than the length (width) in the product width direction W of the side flaps 14 in the front portion 3 and the rear portion 7. Further, a length wb in the product width direction W of the rear portion 7 of the side flaps 14 is longer than a length wf in the product width direction W of the front portion 3 of the side flaps 14 (refer to Fig. 1). Each of the pair of the side flaps 14 is provided with leg gathers 15 (leg surrounding stretchable portion) that stretch along the product longitudinal direction L.

[0031]

The side flaps 14 are mainly configured from the skin-side sheet 26 and the back sheet 24 (refer to Fig. 2A to Fig. 2C) . The skin-side sheet 26 is a member to the skin side formed over the front portion 3, the crotch portion 5, and the rear portion 7, and for example, is configured from nonwoven fabric. The skin-side sheet 26 is a member structuring the leg side gathers 16 (stand-up gathers), and the outer side part of the skin-side sheet 26 (a part to the outer side of a joining portion 26A of a thick dotted line in Fig. 1) configures the side flaps 14.

[0032]

In between the skin-side sheet 26 and the back sheet 24 of the side flap 14 is arranged an elastic sheet 27. The elastic sheet 27 is a belt-like member that stretches along the product longitudinal direction L, and a member that applies stretchability to the leg surrounding opening portion, when wearing the diaper 1. In other words, the elastic sheet 27 is a leg surrounding elastic sheet that makes a leg surrounding portion of the diaper 1 fit the leg of the wearer. Further, the elastic sheet 27 applies stretchability to the skin-side sheet 26 and the back sheet 24 of the crotch portion 5, and thus the leg gathers 15 are configured. The elastic sheet 27 is configured with for example, nonwoven fabric.

[0033]

The leg side gathers 16 are stand-up gathers to prevent liquid leakage from gaps around the leg. The pair of the leg side gathers 16 is formed along the product longitudinal direction L over the front portion 3, the crotch portion 5, and the rear portion 7 (refer to Fig. 1). The leg side gathers 16 are formed so as to cover both edges of the central strip region 12 in the inner side of the side flaps 14.

[0034]

The leg side gathers 16 are configured from mainly the parts of the inner side of the skin-side sheet 26 (refer to Fig. 2) . The inner edges of the skin-side sheet 26 of the crotch portion 5 have stretchability with a rubber thread or the like. The skin-side sheet 26 is joined along the product longitudinal direction L in a joining portion 26A between the central strip region 12 and the side flaps 14 (thick dotted lines in Fig. 1) . A region to the inner side of the joining portion 26A of the skin-side sheet 26 configures the leg side gathers 16 (stand-up gathers) with the joining portion 26A as a supporting point.

[0035]

The waist gathers 18 are a waist circumference stretchable portion arranged along the product width direction W in the rear portion 7 (refer to Fig. 1) . In the rear portion 7, a waist gather film 28 is arranged between the absorbent body 21 and the back sheet 24 (refer to Fig. 2C) . The waist gather film 28 is a belt-like stretchable member that stretches along the product width direction W. The waist gather film 28 applies stretchability to such as the back sheet 24, and thus the waist gathers 18 are configured. The length of the waist gather film 28 in the product width direction W is longer than the absorbent body 21. Thus, the waist gathers 18 are formed protruding to the outer side in the product width direction W from the absorbent body 21. It should be noted that, the waist gathers 18 do not have to be provided.

[0036]

The fastening tapes 30 are attached to the side flaps 14 in the rear portion 7 (refer to Fig. 1). The fastening tape 30 is attached by sandwiching a portion of the fastening tape 30 between the skin-side sheet 26 and the back sheet 24 which configure the side flap 14 (refer to Fig. 2C).

[0037] A target tape 29 is provided in the front portion 3 (refer to Fig. 1) . The target tape 29 is arranged to the non-skin side of the back sheet 24 in the front portion 3 (refer to Fig. 2A) . The target tape 29 is a member that is engageable with the fastening tape 30, and is formed with for example nonwoven fabric. The target tape 29 configures a target region that engages with the fastening tape 30. It should be noted that, instead of arranging the target tape 29 to the non-skin side of the back sheet 24, the target region may be formed on a nonwoven fabric in the outermost layer of the back sheet 24.

[0038]

The fastening tape 30 is engaged to the target tape 29, and thus the diaper 1 is worn. It should be noted that, the fastening tape 30 can also be engaged to the other fastening tape 30 as described later.

[0039]

The length of the product of the diaper 1 in the product longitudinal direction L for low weight infants in the present embodiment is (a size of the product in a stretched state with no creases in the longitudinal direction) in a range of 210 to 330 mm. For example, the length of the product of the diaper 1 for low birth weight infants with a weight of less than 2500 grams is 310mm. The length of the product of the diaper 1 for very low birth weight infants with a weight of less than 1500 grams is 270mm. The length of the product of the diaper 1 for extremely low birth weight infants with a weight of less than 1000 grams is 230mm.

[0040]

Further, the waist size of the diaper 1 for low weight infants in the present embodiment is in a range of 160 to 295 mm. It should be noted that the waist size is a size in which an end portion of one of the fastening tape 30 is in a state matched to an end portion to the side flap 14 side in a hook sheet region C of the other fastening tape 30, and is in a state in which the product is spread out without creases. In other words, the size is of the product in a state extended in the width direction. For example, the waist size of the diaper 1 for low birth weight infants is 273.5 mm and the waist size of the diaper 1 for extremely low birth weight infants with a weight of less than 1500 grams is 220 mm.

[0041] <Regarding the Wearing of the Diaper 1>

In open-type disposable diapers, it is important to enhance the fitting of the leg surrounding opening portion and the waist circumference opening portion so that excretions such as urine are prevented from leaking to the outside when worn. In particular, as shown in Fig. 3, in a case where the wearer is a low body weight baby, it may be required that the back of the baby is curled up to be a C-shape and a posture strongly flexing the legs into an M shape is maintained. This posture is close to a fetal posture in the mother's body (fetus-like flexion posture), and is a posture that easily makes the baby lie quietly, also referred to as a "positioning posture". It should be noted that, in Fig. 3, although the positioning posture in a prone state is illustrated, a sideways posture or a supine posture may also be possible. In such a positioning posture, gaps easily occur in the leg surrounding portion of the diaper.

[0042]

Thus, the sufficient fitting is required to produce no gap in the leg surrounding portion. In this respect, in the diaper 1, the fitting can be enhanced by adjusting the fixed position of the fastening tape when worn. Fig 4 is a view illustrating a form of the diaper 1 when worn. Fig. 5 is a side view showing the manner of the diaper 1 when worn.

[0043]

When wearing open-type disposable diapers, in ordinary cases, a manner is general in which the diaper is fixed around the waist of the wearer by engaging a pair of the fastening tapes 30 provided to both end portions (rear portion protruding portions 14b to be described later) of the rear portion 7 of the side flaps 14 with respective target tapes 29 provided to the non-skin side of the front portion 3 of the central strip region 12. On the other hand, in the diaper 1 of the present embodiment, as shown in Fig. 4, one of the fastening tapes 30 (the left-side fastening tape 30 in Fig. 4) can be engaged with the target tape 29, and the other fastening tape 30 (the right-side fastening tape 30 in Fig. 4) can be further engaged on the former fastening tape 30. As stated above, the diaper 1 is configured so that the length wb in the product width direction W of the rear portion 7 of the side flaps 14 is longer than the length wf in the product width direction W of the front portion 3 (wb > wf) and the fastening tape 30 is easily extended around the front portion 3 side (the abdomen side of the wearer) , and thus, as shown in Fig. 4, it is easy to allow one of the fastening tapes 30 to be superposed by and engaged with the other fastening tape 30. In such a way, by engaging the fastening tapes 30 to each other, the rear portion 7 side of the central strip region 12 and side flaps 14 becomes in a state of being entirely pulled to the front portion 3 side, and the fitting of the waist circumference opening portion and the leg surrounding opening portion is improved. Thus, the gaps in the leg surrounding portion do not easily occur. It is a matter of course that, when wearing the diaper 1, the fastening tapes 30 may not be engaged to each other, but the right and left fastening tapes 30 may be engaged with the target tape 29, respectively.

[0044]

On the other hand, the improvement of the fitting in the leg surrounding opening portion of the diaper 1 also means that the fastening of the leg surrounding opening portion with respect to the leg portion of the wearer becomes tighter. In the example of Fig. 5, the side flap 14 that forms the leg surrounding opening portion is pulled to the abdomen side of the wearer (the front portion 3 side of the diaper 1), and thus the fastening force is strengthened in the leg surrounding opening portion. When the wearer moves his/her legs in this state, the end portions of the side flaps 14 easily bites into the inguinal region of the wearer with the region of the crotch portion 5 (the region shown by a hatched part in Fig. 5) as the center, and the texture of this portion may deteriorate. In the case of the low body weight baby with sensitive skin, the tight fastening of the inguinal region results in a deterioration of the baby's bloodstream to cause a swelling, and also causes an uncomfortable feeling.

[0045]

Then, in the diaper 1 of the present embodiment, the side flaps 14 are configured so as to improve the fitting when worn and achieve a good texture in the leg surrounding portion. Hereinafter, the detailed configuration of the side flaps 14 is explained.

[0046] <The Configuration of the Side Flaps 14>

Fig. 6 is a schematic plan view explaining a configuration of the side flaps 14 of the present embodiment. As stated above, the side flaps 14 of the present embodiment is a vertically long part along the product longitudinal direction L and is configured with the skin-side sheet 26 and the back sheet 24. A region of the front portion 3 of the side flap 14 has a front portion protruding portion 14f protruding toward the outer side in the product width direction W. Further, in the front portion side in the product longitudinal direction L of the front portion protruding portion 14f, a notched portion 14fR notched in a curved shape so as to project to the inner side in the product width direction W is formed. Similarly, a region of the rear portion 7 of the side flaps 14 has a rear portion protruding portion 14b protruding toward the outer side in the product width direction W. The rear portion protruding portion 14b is provided with the fastening tape 30 (refer to Fig. 1), and with the fastening tape 30 the rear portion protruding portion 14b is fixed overlapping the rear portion protruding portion 14f in the waist circumference of the wearer. Further, in the rear portion side in the product longitudinal direction L of the rear portion protruding portion 14b, a notched portion 14bR notched in a curved shape so as to project to the inner side in the product width direction W.

[0047]

The outer side end portion region in the product width direction W between the front portion protruding portion 14f and the rear portion protruding portion 14b of the side flap 14 is made from an end edge portion 14Lg that forms a leg surrounding opening portion of the diaper 1. The end edge portion 14Lg in the present embodiment is formed over the front portion 3 to the rear portion 7 with the crotch portion 5 as the center, and is a wave form shape in which a plurality of projected portions projected to the outer side in the product width direction W and a plurality of depressed portions depressed to the outer side in the product width direction W are alternately repeated in the product longitudinal direction L. In Fig. 6, a plurality of projected portions 145a and a plurality of depressed portions 145b are formed in the crotch portion 5 of the end edge portion 14Lg. Similarly, the front portion 3 of the end edge portion 14Lg is formed with a plurality of projected portions 143a and a plurality of depressed portions 143b, and the rear portion 7 of the end edge portion 14Lg is formed with a plurality of the projected portions 147a and a plurality of the depressed portions 147b.

[0048]

Fig. 7 is a drawing showing enlarged an end edge portion 14Lg of the side flap 14. The end edge portion 14Lg has five projected portions 145a and five depressed portions 145b in the region of the crotch portion 5. The projected portion 145a and the depressed portion 145b each have a slight curve in a predetermined curvature, and are so-called R shapes, and are formed with a curvature of, for example, approximately R=6mm to 10mm. In the present embodiment, the five projected portions 145a are each formed with the same curvature, and also the five depressed portions 145b are each formed with the same curvature. In other words, the projections and depressions formed in the region of the crotch portion 5 all have the same shape. Further, the projected portions 145a and the depressed portions 145b are each arranged to be in a linear positional relationship along the product longitudinal direction L. In other words, in the region of the crotch portion 5 of the end edge portion 14Lg, the tip positions of the five depressed portions 145b are each in the same position in the product width direction W, and as shown in Fig. 7, are positioned on the same line along the product longitudinal direction L. Similarly, the tip positions of the five projected portions 145a are each in the same position in the product width direction W, and are positioned on the same line along the product longitudinal direction L. In this way, the end edge portion 14Lg forms a waveform along the product width direction W in the crotch portion 5. In Fig. 7, the tip portion of the projected portion 145a and the tip portion of the depressed portion 145b are formed to retain the distance We therebetween with respect to the product width direction W. The length of We is, for example, approximately 2mm. Further, the distances (intervals) La5 between two adjacent projected portions 145a in the product longitudinal direction L are all the same. In other words, the pitch of the wave form shape of the end edge portion 14Lg in the crotch portion 5 is La5.

[0049]

It should be noted that, the shape, the size, and the arrangement number and the like of the projected portions 145a and the depressed portions 145b are not limited to the example shown in Fig. 6 and Fig. 7, and can be changed appropriately depending on the target wearer and the difference in size of the diaper 1. Further, the size of the two adjacent projected portions 145a in the product longitudinal direction L or the size of the two adjacent depressed portions 145b in the product longitudinal direction L may be different from each other.

[0050]

In Fig. 6, two projected portions 143a and two depressed portions 143b are formed in the region of the front portion 3 of the end edge portion 14Lg. The projected portions 143a and the depressed portions 143b have substantially the same configuration as each of the projected portions 145a and the depressed portions 145b. In the region of the front portion 3 however, the wave form shape formed with the projected portions 143a and the depressed portions 143b do not have to be formed along the product longitudinal direction L. In other words, the wave form shape of the end edge portion 14Lg with respect to the product longitudinal direction L may be inclined or bent. In the region of the front portion 3, the distance (interval) between two adjacent projected portions 143a in the product longitudinal direction L is represented by La3 (refer to Fig. 7) .

[0051]

In the region of the rear portion 7 of the end edge portion 14Lg, three projected portions 147a and three depressed portions 147b are formed. In this region, the end edge portion 14Lg becomes wider to the outer side in the product width direction W as it nears toward the rear portion side in the product longitudinal direction L, and is a slanted wave form shape with respect to the product longitudinal direction L. In other words, the width of the side flap 14 is made to be wider to the rear side in the product longitudinal direction L than the dart portion 211b on the rear portion side which is formed by the absorbent body 21. This is for widening the area where the side flaps 14 cover the buttocks of the wearer in the region of the rear portion 7 when wearing the diaper 1. In the diaper 1, the position of the crotch portion 5 is set to fit the middle position of the groin of the wearer, and the dart portion 221b is provided at the position near the rear portion of the crotch portion 5. Thus, the width of the side flap 14 becomes narrow in the front portion side of the dart portion 211b in the product longitudinal direction L, and the width of the side flap 14 becomes wide in the rear portion side thereof, and thus the wearer can easily move his/her legs in the front portion side (the region of the crotch portion 5) and the buttocks of the wearer can be restrained from extending over the side flap 14 in the rear portion side (the region of the rear portion 7).

[0052]

It should be noted that, as shown in Fig. 7, the three projected portions 147a and the depressed portions 147b provided in the region of the rear portion 7 each have different shapes (curvature and size). Then, the largest interval of the distances (intervals) between the two adjacent projected portions 147a is represented by La7.

[0053]

In the inner side of the end edge portion 14Lg of the side flaps 14 in the product width direction W, the elastic sheet 27 is arranged. The elastic sheet 27 has a predetermined length (width) in the product width direction W, is a belt-like stretchable member stretching along the product longitudinal direction L, and is formed with for example, stretchable nonwoven fabric as described above. As shown in Fig. 6 and Fig. 7, the elastic sheet 27 of the present embodiment is arranged at the position to the inner side in the product width direction W than the depressed portions 145b formed in the region of the crotch portion 5 of the end edge portion 14Lg. Then, the elastic sheet 27 is joined to the skin-side sheet 26 and the like in a stretched state along the product longitudinal direction L, and thereby stretchability occurs along the product longitudinal direction L with respect to the end edge portion 14Lg of the side flaps 14. Thus, when wearing the diaper 1, a stretching force acts in a direction in which the leg surrounding opening portion shrinks.

[0054]

Further, the elastic sheet 27 is linearly arranged along the product longitudinal direction L. In other words, the elastic sheet 27 is arranged substantially parallel to the end edge portion 14Lg of the side flaps 14 in the region of the crotch portion 5. In Fig. 7, the distance between the position of the depressed portions 145b of the end edge portion 14Lg and the position of the outer side end portion in the product width direction W of the elastic sheet 27 is represented by the distance of Ws. The length of Ws is, for example, approximately 1mm. Although the details will be described later, the elastic member is arranged apart from the end edge portion 14Lg in the diaper 1, and thus the texture of the leg surrounding portion can be made more comfortable when wearing the diaper 1.

[0055]

Further, linearly arranging the elastic sheet 27 along the product longitudinal direction L means that the front side end portion and rear side end portion of the elastic sheet 27 are positioned substantially in the same position in the product width direction W. With such an arrangement, when wearing the diaper 1, the elastic sheet 27 is in a state extended toward the groin of the wearer from the position in which the abdomen side and back side of the wearer are opposed with each other. Then, the elastic sheet 27 substantially uniformly contracts along the leg surrounding opening portion of the diaper 1, and thus it becomes easy to allow contractile force to uniformly act on the leg surrounding opening portion. In this way, the fastening of the leg surrounding portion of the diaper 1 is suppressed from being locally tight, and this makes it easy to achieve a good texture.

[0056]

The elastic sheet 27 is joined to the skin-side sheet 26 at the skin-side in the thickness direction and is joined to the back sheet 24 and the leak prevention sheet 23 at the nonskin side in the thickness direction. The leak prevention sheet 23 is a member that suppresses the permeation of the urine and the like excreted inside the diaper 1 to the non-skin side, and the leak prevention sheet 23 is joined to the elastic sheet 27, thereby hardly generating gaps therebetween. This makes it easy to restrain the leaking of excretions such as urine from the leg surrounding portion when wearing the diaper 1.

[0057] <Regarding the Texture of the Leg Surrounding Portion of the

Diaper 1>

Then, the effect of the configuration of the side flaps 14 on the texture in the leg surrounding portion of the diaper 1 will be described.

[0058]

It has been explained that, in the diaper 1, the fitting when worn can be improved by engaging the fastening tapes 30 with each other as in Fig. 4, whereas the fastening force in the leg surrounding portion enlarges accordingly. In the conventional diaper, the linear elastic member such as a rubber thread as an elastic member that applies stretchability to this leg surrounding portion is used in general. Thus, in a case where the fastening of the leg surrounding portion is tight, the pressure applied to the legs of the wearer is increased, and this has caused a sense of incongruity or an uncomfortable feeling when worn to be increased. On the other hand, in the diaper 1, the belt-like elastic sheet 27 having a predetermined width as an elastic member of the leg surrounding portion is used, and thus the fastening force applied to the legs of the wearer can be easily diffused. In other words, the pressure is reduced by widening the area where the fastening force acts on the legs of the wearer, and it is possible to restrain biting into the leg surrounding portion and to prevent an uncomfortable feeling from being easily given to the wearer.

[0059]

Further, by making the elastic sheet 27 in a belt-like shape, it is possible to prevent the gaps between the leg surrounding opening portion and the legs of the wearer from being easily generated when wearing the diaper 1. For example, in a case where the wearer is a low body weight baby and the baby is made to take the positioning posture as explained in Fig. 3, the shape of the leg surrounding opening portion of the diaper 1 is complicatedly deformed. Thus, in a case where the elastic member provided to the leg surrounding opening portion is a linear member such as a rubber thread, such member cannot completely fit the complicated deformation, and thus the gaps may easily occur in the leg surrounding portion. On the other hand, in diaper 1, by using the belt-like elastic member such as an elastic sheet 27, the contact area of the leg surrounding opening portion and the legs of the wearer is widened, and thus even in a case where the leg surrounding opening portion is complicatedly deformed, the elastic member can easily follow this deformation, and this makes it hard to generate the gaps in the leg surrounding portion.

[0060]

Further, in the diaper 1, by making the end edge portion 14Lg a wave form shape with the crotch portion 5 of the side flaps 14 as the center, an uncomfortable feeling when wearing the diaper can be decreased. In the conventional diapers, the end edge portion that forms the leg surrounding opening portion is often cut linearly or so as to draw a gentle curve having a small curvature. This end edge portion is a part that becomes an "edge" that directly contacts the skin of the wearer in the leg surrounding opening portion of the diaper 1, and thus when such a nearly linear edge is pressed against the skin, the shape of the edge part is liable to remain as a mark as is, thereby causing the wearer to have an uncomfortable feeling and a sense of incongruity. On the other hand, the end edge portion 14Lg of the diaper 1 is a wave form shape having projections and depressions in the product width direction W, and thus the length of the edge part is long compared with a case of the linear shape. Thereby, the force applied to the end edge portion 14Lg is diffused, and the mark does not easily remain on the skin of the wearer.

[0061]

ThenN in the present embodiment, the elastic sheet 27 that allows stretching force to act on the leg surrounding opening portion is arranged apart from the end edge portion 14Lg of the side flaps 14, so that the stretching force hardly influences the edge part of the end edge portion 14Lg. For example, in a case where the elastic sheet is joined in a state sandwiched between the skin-side sheet 26 and the back sheet 24 and the overlapped these three sheets are cut together into the wave form shape, and thereby allowing the stretching force to act on the projected and depressed portions of the end edge portion 14Lg as well, the end edge portion 14Lg may not maintain the wave form shape. Specifically, by allowing shrinkage force in the product longitudinal direction L to act on the edge part of the end edge portion 14Lg when wearing the diaper, the projected and depressed portions stand up in the thickness direction, and the difference between the projections and depressions becomes small due to the shrinkage of the projected portions, so that the wave form shape cannot be maintained in some cases. When the wave form shape cannot be maintained, the force acting on the end edge portion 14Lg is less likely to be dispersed, and thus marks of the edge are easily put on the skin of the wearer. On the other hand, in diaper 1, as explained in Fig. 7, the gaps of Ws are provided at least between the depressed portions 145b of the end edge portion 14Lg and the elastic sheet 27. In other words, the diaper 1 is configured so that the stretching force of the elastic sheet 27 is less likely to directly act on the end edge portion 14Lg. This makes it easy to allow the depressed portions and the projected portions to retain respective shapes and to maintain the wave form shape even when wearing the diaper 1. Further, in diaper 1, the distance We between the projected portion 145a and the depressed portion 145b in the product width direction W is made to become longer than Ws (We > Ws) . In other words, a certain extent of space is to be secured between the projected portion 145a of the end edge portion 14Lg and the elastic sheet 27. By providing this space, at least the parts of the projected portions 145a are less likely to be affected by the stretching force of the elastic sheet 27 than the parts of the depressed portions 145b, and the projected and depressed shapes are maintained more easily. Thus, when wearing the diaper 1, the wave form shape can be maintained while applying, on the end edge portion 14Lg, such stretchability which does not impair the fitting of the leg surrounding opening portion. Therefore, it is possible to achieve a good texture.

[0062]

Then, in the region of the crotch portion 5 of the end edge portion 14Lg, the stretching force applied by the elastic sheet 27 acts uniformly by equating each pitch between the projected portion and the depressed portion (shown by the interval La5 in the product longitudinal direction L in Fig.7). In this way, the tension is suppressed from being high locally at a part of the projected portions 145a or the depressed portions 145b, and a problem such that the fastening becomes tight at a partial region of the leg surrounding portion is less likely to occur when wearing the diaper 1. Further, in the diaper 1, the elastic sheet 27 is linearly arranged along the product longitudinal direction L and is in a parallel positional relation to the end edge portion 14Lg, and thus the diaper 1 has a structure where the force easily acts on the end edge portion 14Lg uniformly.

[0063]

On the other hand, in the rear portion 7 of the end edge portion 14Lg, the pitch La7 between the projected and depressed portions is made to be wider than La5. As described above, in the rear portion 7, the side flaps 14 widens to the outer side in the product width direction W, and the area covering the buttocks of the wearer is made to be large, and additionally, the stretching force applied by the elastic sheet 27 is not allowed to easily act on the end edge portion 14Lg. Thus, compared to the region of the crotch portion 5, in the region of the rear portion 7, even when the pitch La7 between the projections and depressions is enlarged, the texture when worn does not easily deteriorate. On the contrary, by enlarging the pitch La7 between the projections and depressions, the curve of the edge part that contacts with the buttocks of the wearer becomes smooth, and thus the texture at the buttocks can be made soft.

[0064]

Further, in diaper 1, the outer side end portion in the product width direction W of the leak prevention sheet 23 is positioned to the inner side in the product width direction W of the end edge portion 14Lg of the side flaps 14. In other words, a predetermined space is provided between the end edge portion 14Lg of the side flaps 14 and the outer side end portion in the product width direction W of the leak prevention sheet 23. In the case of Fig. 6, the position of the outer side end portion in the product width direction W of the leak prevention sheet 23 is arranged near the intermediate part in the product width direction W of the elastic sheet 27. The leak prevention sheet 23 is a liquid non-permeable sheet having waterproofness, and thus the fabric of the raw material is hard and the texture easily deteriorates compared with the skin-side sheet 26 and the back sheet 24 constituted by nonwoven fabric and the like. In a case where such a leak prevention sheet 23 is arranged in the region of the end edge portion 14Lg of the side flaps 14, the leg surrounding portion of the diaper 1 becomes hard and may cause the wearer to feel a sense of incongruity. However, in the present embodiment, the leak prevention sheet 23 is arranged apart from the end edge portion 14Lg, and thus the region of the end edge portion 14Lg is kept soft by such as nonwoven fabric that constitutes the skin-side sheet 26 and the back sheet 24, the texture of the leg surrounding portion in wearing the diaper 1 can be comfortable.

[0065]

Further, the deterioration of the texture in the waist portion (the abdomen portion) of the wearer can be restrained by the notched portion 14fR provided to the front portion protruding portion 14f and the notched portion 14bR provided to the rear portion protruding portion 14b in the side flaps 14. In a case where the low body weight baby who is a target wearer of diaper 1 takes the positioning posture as shown in Fig. 3, both end portions in the product longitudinal direction L of the side flaps 14 are just positioned to fit the abdomen portion. At this time, in a case where the shape of this end portion is pointed, the corner portion of the side flap 14 contacts the abdomen portion of the wearer, and thereby deteriorating the texture. Then, in the diaper 1, the notched portion 14fR or 14bR is provided to this end portion, so that the corner portion of the side flaps 14 does not contact the abdomen portion, and thus the texture is improved. It should be noted that, the notched portions 14fR and 14bR protrude inwardly, and thus projections of fabrics in this end portion are restrained when wearing the diaper 1. For this reason, the texture in the waist circumference can be further improved.

[0066] ===Other Points===

The above embodiment modes are to facilitate understanding of the present invention, and do not limit understanding of the present invention in any way. This invention may be changed and modified without departing from its scope thereof, and it is needless to say that this invention includes its equivalents .

[0067]

When wearing the diaper 1 described in the above-mentioned embodiment, the diaper 1 is generally fixed to his/her waist of the wearer by setting the front portion 3 to the abdomen side and setting the rear portion 7 to the back side. On the other hand, the diaper 1 may be worn by setting the front portion 3 of the diaper 1 to the back side and setting the rear portion 7 to the abdomen side. In other words, the diaper 1 can also be worn by reversing the front and rear.

[0068]

In a case where the wearer is a low body weight baby, "minimum handling" that tries not to touch the body as much as possible so as not to impose stress may be required. In this minimum handling, for example, it is required that not only excretions are not leaked from the disposable diaper, but also the stable posture is not changed as much as possible when changing the diaper. Thus, in a case where the low body weight baby as the wearer is taking a prone positioning posture as shown in Fig. 3, it is necessary to wear the diaper 1 without moving the body as much as possible. In this case, it is preferable to wear the diaper without changing the posture in such a manner that the diaper 1 is worn by reversing the front and back thereof and the fastening tapes 30 are engaged to be fixed in the back side of the low body weight baby.

[0069]

In diaper 1, the elastic sheet 27 that applies stretchability to the leg surrounding opening portion is linearly arranged along the product longitudinal direction L, the position of the front portion 3 side end portion and the position of the rear portion 7 side end portion of the elastic sheet 27 are each in the same position in the product width direction W. Thus, in a case where the diaper 1 is worn by reversing the front and back thereof, the stretching force applied by the elastic sheet 27 uniformly acts on the leg surrounding opening portion, and thus the texture of the leg surrounding portion of the diaper 1 does not deteriorate. In other words, when wearing the diaper 1 by reversing the front and back thereof, the function described in the above-mentioned embodiment is not easily impaired. Thus, in the diaper 1, it is possible to achieve both minimum handling and good texture (particularly, the texture in the leg surrounding portion) when worn.

[Reference Signs List] [0070] 1 disposable diaper (diaper), 3 front portion, 5 crotch portion, 7 rear portion, 12 central strip region, 14 side flaps, 14b rear portion protruding portion, 14bR notched portion, 14f front portion protruding portion, 14fR notched portion, 14Lg end edge portion, 143a, 145a, 147a projected portions, 143b, 145b, 147b depressed portions, 15 leg gathers, 16 leg side gathers, 18 waist gathers, 21 absorbent body, 211f dart portion, 221b dart portion, 22 top sheet, 23 leak prevention sheet, 24 back sheet (exterior sheet), 25 stretchable film, 26 skin-side sheet, 26A joining portion, 27 elastic sheet, 28 waist gather film, 29 target tape, 30 fastening tape

Claims

[CLAIMS] [Claim 1] A disposable diaper having a longitudinal direction and a width direction intersecting the longitudinal direction, the disposable diaper comprising: a central strip region including an absorbent body that absorbs liquid; side flaps positioned in both side portions in the width direction of the central strip region; and a strip-shaped leg surrounding elastic sheet that is provided to the side flap and stretches along the longitudinal direction, an end edge portion in an outer side in the width direction of the side flap having a wave form part in which a projected portion projected to the outer side in the width direction and a depressed portion depressed to the outer side in the width direction are repeated alternately in the longitudinal direction, and the leg surrounding elastic sheet being arranged to the inner side in the width direction than the depressed portion of the side flap. [Claim
2] A disposable diaper according to claim 1, wherein the leg surrounding elastic sheet is linearly arranged along the longitudinal direction. [Claim
3] A disposable diaper according to claim 1 or 2, wherein a distance between the projected portion and the depressed portion in the width direction is greater than a distance between the depressed portion and an outer side end portion in the width direction of the leg surrounding elastic sheet. [Claim
4] A disposable diaper according to any one of claims 1 to 3, wherein the side flap has a front portion positioned to an abdomen side of a wearer when wearing the disposable diaper, a rear portion positioned to a back side of the wearer, and a crotch portion positioned between the front portion and the rear portion; and a distance between two adjacent projected portions in the longitudinal direction is constant in the crotch portion of the side flap. [Claim
5] A disposable diaper according to claim 4, wherein a maximum distance of the distances between the two adjacent projected portions in the longitudinal direction in the rear portion of the side flap is wider than the distance between the two adjacent projected portions in the longitudinal direction in the crotch portion of the side flap. [Claim
6] A disposable diaper according to claim 4 or 5, wherein a length in the width direction in the rear portion of the side flap is longer than a length in the width direction in the crotch portion of the side flap. [Claim
7] A disposable diaper according to claim 6, wherein the absorbent body has, on each of a front side and a rear side in the longitudinal direction of the crotch portion, a pair of dart portions in which a basis weight of a liquid absorbent raw material is less than other parts; and the rear portion of the side flap is a region positioned to the rear side in the longitudinal direction of the dart portion provided to the rear side in the longitudinal direction of the crotch portion. [Claim
8] A disposable diaper according to any one of claims 1 to 7, wherein a front side end portion in the longitudinal direction of the leg surrounding elastic sheet and a rear side end portion in the longitudinal direction of the leg surrounding elastic sheet are in the same position in the width direction. [Claim
9] A disposable diaper according to any one of claims 1 to 8, wherein the side flap has a liquid permeable top sheet arranged to a skin-side of the wearer, a back sheet arranged to a non-skin side of the wearer, and a liquid non-permeable leak prevention sheet arranged between the top sheet and the back sheet; and an outer side end portion in the width direction of the leak prevention sheet is positioned to the inner side in the width direction than the depressed portion of the side flap. [Claim
10] A disposable diaper according to any one of claims 1 to 9, wherein the side flap has, in a front side end portion and a rear side end portion in the longitudinal direction, a notched portion formed of a curve which protrudes to the inner side in the width direction..