AU2015265210B2

AU2015265210B2 - Disposable diaper

Info

Publication number: AU2015265210B2
Application number: AU2015265210A
Authority: AU
Inventors: Tomomi Isogai; Maki MIYAKE; Satoru Sakaguchi
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2014-05-27
Filing date: 2015-02-20
Publication date: 2016-12-08
Anticipated expiration: 2035-02-20
Also published as: WO2015182179A1; JP5838240B2; KR101688109B1; AU2015265210A1; CN106413652A; TW201607519A; MY159742A; KR20160124234A; TWI646948B; CN106413652B; JP2015223253A; BR112016026709A8

Abstract

A disposable diaper (1) for children with body weights of 3000 g or less, the disposable diaper comprising: side flaps (14); a pair of fastening tapes (30) provided on the side flaps (14); and a target region (29) capable of fastening to the fastening tapes (30). The pair of fastening tapes (30) can be fastened by overlaying one of the fastening tapes (30) on the other fastening tape (30). If the fastening force between the target region (29) and one of the fastening tapes (30) is P1 and the fastening force between the one fastening tape (30) and the other fastening tape (30) is P2, the relationship P1 > P2 > 0.1 N/10 mm holds. When the paired fastening tapes (30) are overlaid with the centers of the fastening tapes (30) in the tape width direction aligned, the upper fastening tape (30) can fasten to the target region (29) at the two sides that straddle the end of the lower fastening tape (30) in the tape width direction.

Description

1 2015265210 20 Oct 2016

DESCRIPTION

Title of Invention DISPOSABLE DIAPER 5 Technical Field [0001]

The present invention relates to disposable diapers.

Background Art [0002] 10 The following discussion of the background to the 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. 15 [0002a]

Throughout the description and claims of the specification, the word "comprise" and variations of the word, such as "comprising" and "comprises", is not intended to exclude other additives, components, integers or steps. 20 [0002b]

An open-type disposable diaper has been widely used conventionally. With the open-type disposable diapers, fastening tapes are provided to side flaps, and a target tape that engages with the fastening tapes is provided to a front portion (a part to a stomach side, also 25 referred to as a front part of a body) . Such an open-type disposable diaper is widely used particularly for newborns and babies and infants because of their ease to attach and detach.

Citation List Patent Literature 30 [0003] [Patent Literature 1] Patent Application Laid-open Publication No. 2013-212212 [Patent Literature 2] Patent Application Laid-open Publication No. 2013-138702 35 [Patent Literature 3] Patent Application Laid-open Publication No. 2 2015265210 20 Oct 2016 2013-230256 [Patent Literature 4] Patent Application Laid-open Publication No. 2013-158573 [Patent Literature 5] International Publication WO 2013/077360 5 [0004]

With babies having a weight equal to or less than 3000 g (hereafter, referred to as a low birth weight infant), sometimes it is required for the babies to be not touched as much as possible from the point of view of minimum handling. Therefore, the fastening 10 tapes of the disposable diapers for low birth weight infants are required to be "easy to unfasten".

On the other hand, particularly in the case of low birth weight infants, it is necessary to not only prevent leakage of body wastes, but also to prevent the fastening tapes that have been unfastened 15 from contacting the baby, and to prevent the baby from receiving stress such as discomfort and pain. Thus, the fastening tapes of the disposable diapers for low birth weight infants are also required to be "not easy to unfasten".

For this reason, the fastening tapes of the disposable diapers for 20 low birth weight babies are required to maintain mutually contradictory functions ("easy to unfasten" and "difficult to unfasten").

[0005]

It is desirable to maintain mutually contradictory functions of the 25 fastening tapes.

Summary of the Invention [0006]

In an aspect of the present invention, there is provided a disposable diaper for a baby having a weight equal to or smaller than 30 3000 g, the disposable diaper including: side flaps; a pair of fastening tapes provided to the side flaps; and a target region that is engageable with the fastening tapes, one of the fastening tapes, of the pair of the fastening tapes, 2015265210 20 Oct 2016 2a being engageable in an overlapping manner with another of the fastening tapes, in the case where an engaging force of the target region and the one of the fastening tapes is PI, and an engaging force of the 5 one of the fastening tapes and the other of the fastening tapes is P2, a relation being PI > P2 > 0.1 N/10 mm, in the case where the pair of the fastening tapes are overlapped in a state where centers of the fastening tapes in a tape width direction are matched, an upper side fastening tape being 10 engageable to the target region, in both sides of the upper side fastening tape straddling over an end portion of a lower side fastening tape in the tape width direction, wherein each of the fastening tapes has an engaging region that engages with the target region, 15 in the case where the pair of the fastening tapes is overlapped, in a state where an end portion of the upper side fastening tape is matched to a position of an end portion to the side flap side in the engaging region of the lower side fastening tape, and in a state where centers of the fastening tapes in the tape width 20 direction are matched, the upper side fastening tape is engageable to the target region, in both sides of the upper side fastening tape straddling over an end portion of the lower side fastening tape in the tape width direction.

[0007] 25 Other feathers of this invention will become clear from descriptions 3 of this specification and attached drawings.

Advantageous Effects of Invention [0008]

With this invention, the mutually contradictory functions ("easy to unfasten" and "difficult to unfasten") of the fastening tapes can be maintained.

Brief Description of Drawings [0009]

Fig. 1 is a developed plan view of a disposable diaper 1 for low birth weight babies.

Fig. 2A to Fig. 2C are exploded explanatory views of each part of the disposable diaper 1 for low birth weight babies. 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. 3A and Fig. 3B are explanatory views of a fastening tape 30 of the present embodiment mode.

Fig. 4A is an explanatory view of a state where another fastening tape 30 is overlapped on to one of the fastening tapes 30. Fig. 4B is a comparative explanatory view of the case where a pair of fastening tapes 30 is fixed in a staggered manner.

Fig. 5 is an explanatory view of measuring an engaging force.

Fig. 6A is an explanatory view where a fastening tape 30 to be in a lower side has been fixed to a target tape 29. Fig. 6B is an explanatory view where another fastening tape 30 has been fixed on the fastening tape 30 in Fig. 6A.

Fig. 7A and Fig. 7B are explanatory views of the shape of fastening tapes 30 in a comparative example.

Fig. 8A and Fig. 8B are explanatory views of the shape of the fastening tapes 30 in a first modified example.

Fig. 9A and Fig. 9B are explanatory views of the shape of the fastening tapes 30 in a second modified example.

Fig. 10 is an explanatory view of a pattern of a target tape 29 and a pattern of a target sheet 36 of the fastening tapes 30. 4

Fig. 11 is an explanatory view of a guiding pattern formed on the target tape 29.

Fig. 12 is an explanatory view of a positioning posture.

Fig. 13A and Fig. 13B are explanatory views showing a typical positional relation of a leg and the fastening tape.

Description of Embodiments [0010]

At least the following matters will become clear from the descriptions in this specification and the attached drawings.

[0011] A disposable diaper for a baby having a weight equal to or smaller than 3000 g will become clear, the disposable diaper including: side flaps; a pair of fastening tapes provided to the side flaps; and a target region that is engageable with the fastening tapes, one of the fastening tapes, of the pair of the fastening tapes, being engageable in an overlapping manner with another of the fastening tapes, in the case where an engaging force of the target region and the one of the fastening tapes is Pi, and an engaging force of the one of the fastening tapes and the other of the fastening tapes is P2, a relation being PI > P2 > 0.1 N/10 mm, in the case where the pair of the fastening tapes are overlapped in a state where centers of the fastening tapes in a tape width direction are matched, an upper side fastening tape being engageable to the target region, in both sides of the upper side fastening tape straddling over an end portion of a lower side fastening tape in the tape width direction.

According to such a disposable diaper, the contradictory functions of the fastening tape ("easy to unfasten" and "difficult to unfasten") can be maintained.

[0012]

It is preferable that, each of the fastening tapes has an engaging region that engages with the target region, in the case where the pair of the fastening tapes is overlapped, in a state where an end portion of the upper side fastening tape is matched to a position of an end portion to 5 the side flap side in the engaging region of the lower side fastening tape, and in a state where centers of the fastening tapes in the tape width direction are matched, the upper side fastening tape is engageable to the target region, in both sides of the upper side fastening tape straddling over an end portion of the lower side fastening tape in the tape width direction. According to such a disposable diaper, the contradictory functions of the fastening tape ("easy to unfasten" and "difficult to unfasten") can be maintained.

[0013]

It is preferable that, each of the fastening tapes has an engaging region that engages with the target region, a width of an end portion to the side flap side of the engaging region is greater than a width of an end portion of the fastening tape. For this reason, in the case where the pair of the fastening tapes is overlapped, the upper side fastening tape becomes engageable to the target region, in both sides of the upper side fastening tape straddling over the end portion of the lower side fastening tape in the tape width direction.

[0014]

It is preferable that, each of the fastening tapes has a target sheet that is engageable with another fastening tape, and a common pattern is provided to surfaces of the target region and the target sheet. For this reason, the texture of both members becomes common, and the aesthetic beauty becomes better, and also the patterns of both members can be naturally guided to match and to engage.

[0015]

It is preferable that, a striped pattern configured with depressions and protrusions is provided on surfaces of the target region and the target sheet, and depressions and the protrusions are arranged alternately along a tape length direction of the fastening tapes. For this reason, the fastening tape is easy to bend in the tape length direction and is difficult to bend in the tape width direction.

[0016]

It is preferable that, a guiding pattern that guides an engaging position of the fastening tapes is formed on the target region, and a size of the guiding pattern in a product width direction is one of a same size and 6 a smaller size than a size of an absorbent body in the product width direction. For this reason, the engaging positions of the fastening tapes are guided to a central portion, and as a result, the pair of the fastening tapes can be guided to be engaged in an overlapping manner.

[0017] == The Present Embodiment Mode = <Problems typical of low birth weight babies>

In the case of babies having a weight equal to or less than 3000 g (hereinafter, referred to as low birth weight babies), particularly in the case of low birth weight babies having a weight of less than 2500 g, as shown in Fig. 12, they are sometimes required to maintain a posture in which the back is curved roundly in a C-shape, and the legs are deeply bent in an M-shape. This posture is close to a posture of a fetus in a mother's body, and is a posture in which the baby can rest. In the below explanation, the posture shown in Fig. 12 is sometimes referred to as a "positioning posture". It should be noted that, Fig. 12 shows the positioning posture of a baby in a facing-down state, but there may also be cases where the baby is facing sideways or facing up.

[0018]

Further, in the case of the low birth weight babies, it is sometimes required to not touch the body as much as possible and to not put stress on the babies (hereinafter, referred to as "minimum handling"). In minimum handling, for example, it is required not only that body wastes do not leak from the disposable diaper, but also that the baby is not touched as much as possible during changing of the diaper.

[0019]

When complying with the concept of minimum handling, it is preferable that the disposable diaper for low birth weight babies is easy to wear. Supposing that the fastening tapes are difficult to unfasten during changing of the diaper, there is a possibility that the force of removing the fastening tapes will put a strain on the baby, thus the fastening tapes of the disposable diapers for low birth weight babies is required to be "easy to unfasten".

[0020]

On the other hand, in the case where the legs have moved in the positioning 7 posture in which the legs are bent in an M-shape as shown in Fig. 13B, compared to the case where the legs have moved in a state where the legs are extended as shown in Fig. 13A, a large force is applied that turns up the fastening tapes from around the groin of the baby, and thus the fastening tapes become easy to unfasten. In the case where the fastening tapes come off, however, it becomes a cause of leakage of body wastes, and also when the tape that has been unfastened contacts the baby, stress such as discomfort or pain is given to the baby, and this is contrary to minimum handling. Thus, the fastening tapes of the disposable diapers for low birth weight babies are required to be "difficult to unfasten".

[0021]

In other words, the fastening tapes of disposable diapers for low birth weight babies are required to maintain the mutually contradictory functions of "easy to unfasten" and "difficult to unfasten".

[0022] <Outline shape of Disposable diaper 1> A disposable diaper 1 of this embodiment mode is a disposable diaper for low birth weight babies having a weight equal to or less than 3000 g, and is preferably used particularly for low birth weight babies having a weight of less than 2500 g. It should be noted that, low birth weight babies include not only low birth weight babies (weight of less than 2500 g), but also very low birth weight babies (weight of less than 1500 g) and extremely low birth weight babies (weight of less than 1000 g).

[0023]

Fig. 1 is a developed plan view of the disposable diaper 1 for low birth weight babies. Fig. 2A to Fig. 2C are exploded explanatory views of each part of the disposable diaper 1 for low birth weight babies. 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.

[0024]

The disposable diaper 1 of this embodiment mode is a so-called open-type disposable diaper, and as shown in Fig. 1, the diaper 1 has the front portion 3, the crotch portion 5, and the rear portion 7. The front portion 3 is a part to be positioned in the front portion (a stomach side, a front 8 part of the body) of a wearer. Further, the rear portion 7 is a part to be positioned in the rear portion (a back side, a back part of the body) of the wearer. The crotch portion 5 is a part to be positioned in between the front portion 3 and the rear portion 7.

[0025]

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", and a direction orthogonal to the product longitudinal direction L is referred to as a "product width direction W". Further, as shown in Fig. 2, a direction orthogonal to the product longitudinal direction L and the product width direction W is referred to as a "thickness direction", and a side to the skin of a wearer is referred to as a "skin-side" and an opposite side is referred to as a "non-skin-side".

[0026]

The disposable 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 provided with a fastening tape 30.

[0027]

The central strip region 12 is a strip region positioned in a central portion in the product width direction W that is 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 liguid. The central strip region 12 has an oblong shape (a shape along the product longitudinal direction L) including an absorbent body 21 that has a liquid retention property. The central strip region 12 mainly has the absorbent body 21, a top sheet 22, a leak prevention sheet 23, and a back sheet 24 (refer to Fig. 2A to Fig. 2C).

[0028]

The absorbent body 21 is arranged over the front portion 3, the crotch portion 5, and the rear portion 7. A hatched region in Fig. 1 shows a region occupied by the absorbent body 21. The absorbent body 21 has a sand-glass shape in which a width in the 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 9 simple rectangle. 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.

The top sheet 22 is a liquid permeable member arranged to the skin-side of the absorbent body 21 (the upper side in the drawing) . The leak prevention sheet 23 is a liquid non-permeable member arranged to the non-skin-side of the absorbent body 21 (the lower side in the drawing) . The back sheet 24 is a member that configures an exterior of the non-skin-side of the disposable diaper 1 (an exterior sheet), and is configured from nonwoven fabric. The back sheet 24 is arranged to the non-skin-side of the leak prevention sheet 23.

[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.

[0030]

The side flaps 14 are parts positioned to both side edge portions 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 width of the side flaps 14 in the crotch portion 5 is narrower than the width of the side flaps 14 in the front portion 3 and the rear portion 7. It should be noted that, the side flaps 14 do not have to be provided over the entire region in the product longitudinal direction L, and for example, may be provided to only the rear portion 7. Each of the pair of the side flaps 14 is provided with a leg gather 15 (leg surrounding stretchable portion) that stretches along the product longitudinal direction L.

[0031]

The side flaps 14 are configured mainly 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 the sheet is configured from nonwoven fabric. The skin-side sheet 26 is a member configuring the leg side gathers 16 (stand-up gathers) , and the outer side parts of the skin-side 10 sheet 26 (the outer side parts than joining portions 26A in thick dotted lines in Fig. 1) configure the side flaps 14.

In the crotch portion 5 of the side flaps 14, a stretchable member 27 is arranged between the skin-side sheet 26 and the back sheet 24. The stretchable member 27 is a strip member that stretches along the product longitudinal direction L. The leg gathers 15 are configured by the stretchable members 27 applying stretchability to the skin-side sheets 26 and the back sheet 24 of the crotch portion 5. The stretchable member 27 is configured from stretchable nonwoven fabric, but it maybe configured from rubber thread or the like.

[0032]

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

[0033]

The leg side gathers 16 are configured mainly from parts to the inner side of the skin-side sheet 26 (refer to Fig. 2) . The inner edges of the skin-side sheets 26 in the crotch portion 5 have stretchability with the rubber thread and the like. The skin-side sheet 26 is joined along the product longitudinal direction L in the j oining portions 2 6A between the central strip region 12 and the side flaps 14 (the thick dotted lines in Fig. 1) . The region to the inner side than the joining portions 26A of the skin-side sheet 26 configures the leg side gathers 16 (the stand-up gathers) with the joining portions 26A as the supporting points.

[0034]

The waist gathers 18 are stretchable portions around the body arranged along the product width direction W in the rear portion 7 (refer to Fig. 1) . In the rear portion 7, the 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 strip stretchable member that stretches along the product width direction W. The waist gathers 18 are configured by the waist gather film 28 applying strechability to the back sheet 24 and the 11 like. The length in the product width direction W of the waist gather film 28 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.

[0035]

The fastening tape 30 is attached to the side flaps 14 in the rear portion 7 (refer to Fig. 1) . Apart of the fastening tape 30 is sandwiched between the skin-side sheet 26 and the back sheet 24, which configure the side flap 14 (refer to Fig. 2C), and thus the fastening tape 30 is attached thereto.

[0036]

The front portion 3 is provided with a target tape 29 (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 tapes 30, and the tape is formed from nonwoven fabric. The target tape 29 configures a target region to which the fastening tapes 30 are to be engaged. 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 in the nonwoven fabric which is an outermost layer of the back sheet 24.

[0037]

By engaging the fastening tapes 30 to the target tape 29, the disposable diaper 1 can be worn. It should be noted that, as will be described in detail later, the fastening tape 30 can be engaged on another fastening tape 30.

[0038] A product length in the product longitudinal direction L of the disposable diaper 1 for low birth weight babies in this embodiment mode (the size of the diaper in a state in which the product has been extended without creases) is in a range of 210 to 330 mm. For example, the product length of the disposable diaper 1 for low birth weight babies with a weight of less than 2500 g is 310 mm, the product length of the disposable diaper 1 for very low birth weight babies with a weight of less than 1500 g is 270 mm, and the product length of the disposable diaper 1 for extremely 12 low birth weight babies with a weight of less than 1000 g is 230 mm.

Further, the waist size of the disposable diaper 1 for low birth weight babies in this embodiment mode is in a range of 160 to 295 mm. It should be noted that, the waist size is a size in a state in which the product has been extended without creases, and in a state where an end portion of one fastening tape 30 is matched to an end portion to the side flap 14 side in a hook sheet region C of the other fastening tape 30 (for example, in the case where the waist gathers 18 are provided, in a state where the waist gathers 18 are in an extended state in the product width direction W) . For example, the waist size of the disposable diaper 1 for low birth weight babies is 273.5 mm, and the waist size of the disposable diaper 1 for very low birth weight babies with a weight of less than 1500 g is 220 mm.

[0039] «Configuration of Fastening tape 30>

Fig. 3A and Fig. 3B are explanatory views of the fastening tape 30 of this embodiment mode. Fig. 3A is a view of the fastening tape 30 seen from a hook sheet 34 side. Fig. 3B is a sectional view of the periphery of the fastening tape 30.

[0040]

As shown in Fig. 3A, the fastening tape 30 can be divided into a base end region A, an intermediate region B, a hook sheet region C, and a tip region D. Further, as shown in Fig. 3B, the fastening tape 30 has a base sheet 32, a hook sheet 34, and a target sheet 36.

[0041]

The base end region A is a region to be joined with the side flap 14. The base end region A is sandwiched with two sheets (the skin-side sheet 26 and the back sheet 24), which configure the side flap 14, and both surfaces of the base end region A are joined with the side flap 14. It should be noted that, the base end region A is joined on to the surface to the non-skin-side of the side flap 14, and only one surface of the base end region A may be joined to the side flap 14. The regions other than the base end region A (the intermediate region B, the hook sheet region C, and the tip region D) are arranged so as to protrude to the outer side in the product width direction W from the side flap 14 in the 13 rear portion 7.

[0042]

The intermediate region B is a region between the base end region A and the hook sheet region C. The hook sheet region C is a region provided with the hook sheet 34 and is a region that engages with the target tape 29 (engaging region) . The intermediate region B does not include the hook sheet 34, thus the bending rigidity of the intermediate region B is smaller than that of the hook region, and the intermediate region B is easy to bend. It should be noted that, in the case that the intermediate region B is bent in the product shipping stage, and the hook sheet 34 is engaged to the side flap 14, the engaging surface of the hook sheet 34 is not exposed, and is thus preferable. The tip region D is a region to the outer side than the hook sheet 34 . The tip region D functions as a "grip" that is grasped with fingers when detaching the fastening tape 30. It should be noted that, a region X in Fig. 3A is the region of the side flap 14.

[0043]

The base sheet 32 is a sheet to be a base of the fastening tape 30. The base sheet 32 is configured from a sheet made of a nonwoven fabric or a nonwoven fabric laminated with a film. Further, the base sheet 32 is configured from a sheet made of one sheet or a plurality of sheets layered on one another (a sheet made of a nonwoven fabric or a nonwoven fabric laminated with a film) . The base sheet 32 is arranged over an entire region from the base end region A to the tip region D of the fastening tape 30.

[0044]

The hook sheet 34 is a sheet that engages with the target region (here, the target tape 29) . The hook sheet 34 is engageable with the other fastening tape 30. Multiple engaging hooks (not shown) are provided on the surface of the hook sheet 34 (a surface in an opposite side to the base sheet 32 side), and with the engaging hooks hooking onto the target region, the fastening tapes 30 will engage with the target tape 29. The hook sheet 34 is joined to the base sheet 32. In joining the hook sheet 34 and the base sheet 32, a hot-melt adhesive is used, but the joining method is not limited to this, and for example, the hook sheet 34 and the base sheet 32 may be joined with a heat shield and the like.

[0045] 14

The target sheet 36 is a sheet that is engageable with the hook sheet 34 of the other fastening tape 30. The target sheet 36 is configured from a sheet made of one sheet or a plurality of sheets layered one on another of the nonwoven fabric. The target sheet 36 is joined to the base sheet 32 in the opposite side to the hook sheet 34.

The target sheet 36 is arranged in at least the hook sheet region C and the tip region D. The target sheet 36 in the drawing is arranged in a part of the base end region A (a part of the base end region A to the intermediate region B side), the intermediate region B, the hook sheet region C, and the tip region D. In this way, in the case that the target sheet 36 is provided from the base end region A to the tip region D, and also the target sheet 36 is joined to the base sheet 32 in the base end region A and also to the side flaps 14, the target sheet 36 becomes difficult to come off from the base sheet 32 during detaching of the other fastening tape 30, and thus is preferable.

[0046]

The target sheet 36 is not provided to a part of the base end region A (a part in an opposite side to the intermediate region B side). The region in which the target sheet 36 is not provided is arranged with the waist gather film 28 (refer to Fig. 2C) . In other words, between the base end region A and the back sheet 24, the end portion of the target sheet 36 and the end portion of the waist gather film 28 are sandwiched in a manner not overlapping each other. Thus, between the base end region A of the base sheet 32 and the back sheet 24, a difference in level can be reduced, and both of the target sheet 36 and the waist gather film 28 may be easily sandwiched.

It should be noted that, the target sheet 36 may be arranged in the entire region from the base end region A to the tip region D, similar to the base sheet 32. Further, the target sheet 36 may not be arranged in the base end region A or the intermediate region B. Further, in the case that the engaging force to be described later (equal to or greater than 0.1 N/10 mm) can be achieved, the target sheet 36 may be omitted, and the other fastening tape 30 may be engaged to the base sheet 32.

[0047]

Fig. 4A is an explanatory view of the manner in which the other fastening 15 tape 30 is overlapped on to one fastening tape 30.

[0048]

As shown in Fig. 4A, in the case where the pair of the fastening tapes 30 is overlapped, first the lower side fastening tape 30 is engaged to a central portion of the target tape 29 in the front region 3, and on such a fastening tape 30 the other fastening tape 30 is to be engaged. Thus, the pair of the fastening tapes 30 is naturally positioned in the central portion of the front portion 3 of the wearer. As a result of this, the parts that extend out from the side flaps 14 of the fastening tapes 30 (the intermediate region B, the hook sheet region C, the tip region D) are in positions away from the groin of the wearer, when compared to the case shown in Fig. 13B. Thus, even if the legs have moved in the positioning posture in which the legs are bent in an M-shape, when compared to the case shown in Fig. 13B, the fastening tapes 30 are less prone to receiving a force that turns up the tapes from the groin.

[0049]

It should be noted that, supposing that the fastening tape 30 cannot be engaged on to the fastening tape 30, in the case where the pair of the fastening tapes 30 can be fixed in a staggered manner as shown in Fig. 4B, the fastening tapes 30 can be fixed in positions away from the groin of the wearer. In this case, however, as shown in Fig. 4B, gaps and distortions are made with the disposable diaper 1, and there is a possibility that body wastes will leak, or movement of the baby will be inhibited and stress will be given to the baby, and this is contrary to minimum handling of low birth weight babies.

On the contrary, in the case where the pair of the fastening tapes 30 is overlapped, as shown in Fig. 4A, there is an advantage that gaps and distortions will be difficult to be made with the disposable diaper 1.

[0050] <Engaging force of Fastening tape 30>

In order to fix the fastening tapes 30 (specifically, the hook sheets 34 of the fastening tapes 30) , the engaging force of the fastening tapes 30 need to be equal to or greater than 0.1 N/10 mm. It should be noted that, in the case where the engaging force of the fastening tape 30 is smaller than 0.1 N/10 mm, supposing that the fastening tapes 30 can be 16 engaged, the fastening tapes 30 become unfastened in the case of receiving a force, and the fixing of the fastening tapes 30 become insufficient. Here, engaging with the engaging force equal to or greater than 0.1 N/10 mm is referred to as "fixing".

[0051]

The fastening tapes 30 are to be fixed to the target region (here, the target tape 29) of the front portion 3. Thus, in the case that the engaging force between the fastening tapes 30 (the hook sheet 34) and the target tape 29 of the front portion 3 is PI (unit: N/10 mm), it is required that PI is equal to or greater than 0.1 N/10 mm.

[0052]

Further, the fastening tape 30 of this embodiment mode is to be fixed also to the target sheet 36 of the other fastening tape 30. Thus, in the case that the engaging force between the fastening tape 30 (the hook sheet 34) and the target sheet 36 of the other fastening tape 30 is P2 (unit: N/10 mm), P2 is also required to be equal to or greater than 0.1 N/10 mm.

[0053]

On the other hand, in order to make the fastening tapes 30 easy to unfasten, the engaging force of the fastening tapes 30 is preferably equal to or smaller than 0.5 N/10 mm. This is because supposing that the engaging force of the fastening tape 30 exceeds 0.5 N/10 mm, the fastening tapes 30 become difficult to unfasten, and a strain is given to the baby with the force to unfasten the fastening tapes 30, and this is contrary to minimum handling of low birth weight babies. Thus, the engaging force of the fastening tapes 30 is preferably in a range of 0.1 to 0.5 N/10 mm.

[0054]

Further, in this embodiment mode, in the case where the engaging force of the fastening tapes 30 and the target tape 29 of the front portion 3 is PI, and the engaging force of the fastening tape 30 and the target sheet 36 of the other fastening tape 30 is P2, the relation is Pi > P2. In order to have such a relation, it is necessary to suppress rigidity of the fastening tapes 30, so that even when the fastening tapes touch the wearer a stress given to the wearer can be suppressed, and there is 17 a restriction on the material and thickness of the target sheet 36 of the fastening tapes. Here, PI is 0.5 to 0.7 N/30 mm (in the case where the unit is N/10 mm, the numerical value is 1/3), and P2 is 0.8 to 1.1 N/30 mm.

[0055]

The engaging force of the fastening tapes 30 that is adopted has been measured using an Autograph testing apparatus (AG-XIOplus) manufactured by Shimadzu Corporation. Specifically, a sample is prepared which has been cut out in a rectangular shape with as wide a width as possible from a hook sheet region C of a fastening tape 30 subject to be measured. Likewise, a sample is prepared which has been cut out in a larger size than the hook sheet 34 of a target (a target tape 29 or a target sheet 36) that is to be engaged with the fastening tapes 30.

Next, a 700 g roller (with a diameter of 85 mm, and a width of 45 mm) is moved along in a detaching direction of a main fastening tape 30 with a speed of 5 mm/min, and both samples are fixed by applying pressure. Both samples that have been fixed by applying pressure are set in the Autograph testing apparatus, and the engaging force of both samples in a pulling speed of 300 mm/min is measured, and a value that has been converted to an engaging force around a 10 mm unit width based on the width size of the samples is the engaging force (unit: N/10 mm) . Here, as shown in Fig. 5, the pulling direction is set so that a hook sheet surface is in a 135 degrees angle, with respect to a target sheet (a jig surface on which the target sample is placed) . A peel direction of the hook sheet is a main detaching direction during handling (detaching) of the fastening tape 30.

[0056] <A state in which the Fastening tapes 30 are overlapped^·

Fig. 6A is an explanatory view of the case where the fastening tape 30 to be in the lower side is fixed to the target tape 29. Fig. 6B is an explanatory view of the case where the other fastening tape 30 is fixed on to the fastening tape 30 in Fig. 6A.

[0057]

As shown in Fig. 6B, in the case where the pair of the fastening tapes 30 is overlapped in the state where the center in the tape width direction 18 of the fastening tapes 30 are matched, the upper side fastening tape 30 straddles over the end portion of the lower side fastening tape 30 in the tape width direction, and is fixed to the target tape 29 at both sides of the upper side fastening tape 30 that straddles over the lower side fastening tape 30. In the drawing, the region in which the upper side fastening tape 30 (the hook sheet 34) is fixed to the target tape 29 is hatched.

[0058]

As described previously, the engaging force PI with the target tape 29 is greater than the engaging force P2 with the other fastening tape 30 (Pi > P2) . Under such situation, the upper side fastening tape 30 in this embodiment mode engages with the target tape 29 in the hatched regions in Fig. 6B, thus the engaging force becomes higher, when compared to the case of engaging with only the lower side fastening tape 30.

In addition, a base side (a side flap 14 side) of the fastening tape 30 is positioned nearer to the groin than the end portion, thus the base side of the fastening tape 30 receives greater force to turn up, compared to the end portion. In this embodiment mode, however, in the base side of the fastening tape 30 (a part that strongly receives the force to turn up), the upper side fastening tape 30 is fixed to the target tape 29 straddling over the lower side fastening tape 30 (refer to the hatching in Fig. 6B), thus the engaging force to the base side of the fastening tape 30 is high, and it is difficult for the fastening tape 30 to unfasten.

[0059]

On the other hand, due to the structure in which the upper side fastening tape 30 straddles over the end portion of the lower side fastening tape 30 in the tape width direction, on the contrary, the structure is such that the end portion of the upper side fastening tape 30 is positioned only above the lower side fastening tape 30. The end portion of the upper side fastening tape 30, compared to the base side that is engaged with the target tape 29, has a low engaging force. Thus, the fastening tape 30 is easy to unfasten by holding the end portion of the fastening tape 30.

[0060]

As described above, in this embodiment mode, the fastening tape 30 can 19 maintain mutually contradictory functions of "easy to unfasten" and "difficult to unfasten". Since the fastening tapes 30 are easy to unfasten, the fastening tapes 30 can be unfastened without giving the baby stress, thus the disposable diaper 1 of this embodiment mode is preferable for low birth weight babies (babies with a weight equal to or smaller than 3000 g) that are required to be handled with minimum handling. On the other hand, the fastening tapes 30 are difficult to unfasten even in the case where the legs that are in a state bent in an M-shape, thus the disposable diaper 1 of this embodiment mode is preferable for low birth weight babies that are required to be in the positioning posture.

[0061]

In this embodiment mode, as shown in Fig. 6B, each of the pair of the fastening tapes 30 is overlapped in a state with the end portion of the upper side fastening tape 30 matched, in the position of the end portion to the side flap 14 side in the hook sheet region C of the lower side fastening tape 30, and with the center in the tape width direction of the fastening tapes 30 matched. Then, in the case where the pair of the fastening tapes 30 has been overlapped in this way, in this embodiment mode, the upper side fastening tape 30 is fixed to the target tape 29 in both sides straddling over the end portion of the lower side fastening tape 30 in the tape width direction. It should be noted that, in this embodiment mode, the waist size in the design of the disposable diaper 1 has as a standard the state where the end portion of one fastening tape 30 is matched to the end portion to the side flap 14 side in the hook sheet region C of the other fastening tape 30, thus under this design standard, the upper side fastening tape 30 is fixable to the target tape 29 in both sides straddling over the end portion of the lower side fastening tape 30 in the tape width direction. The position of the upper side fastening tape 30 with respect to the lower side fastening tape 30, however, is not limited to the position shown in Fig. 6B. Even if the upper fastening tape 30 is shifted to either the left or the right from the position shown in Fig. 6B, as long as the upper fastening tape 30 is fixed to the target tape 29 in both sides straddling over the end portion of the lower side fastening tape 30 in the tape width direction, the engaging force in the base side of the fastening tape 30 is high, and the fastening 20 tape 30 is difficult to unfasten.

[0062]

Further, in this embodiment mode, the width of the end portion to the side flap 14 side in the hook sheet region C (the size in the tape width direction) is greater than the width in the end portion of the fastening tape 30. By making the fastening tapes 30 into such a shape, when the pair of the fastening tapes 30 is overlapped in the state with the center in the tape width direction of the fastening tapes 30 matched, the upper side fastening tape 30 can be fixed to the target tape 29 in both sides straddling over the end portion of the lower side fastening tape 30 in the tape width direction.

[0063]

Fig. 7 A and Fig. 7B are explanatory views of the shape of a hook sheet region C of fastening tapes 30 in a comparative example. In the comparative example, opposite to this embodiment mode, a width of an end portion to a side flap 14 side in the hook sheet region C is smaller than a width of an end portion of the fastening tape 30 (refer to Fig. 7A). As a result, in the comparative example, the end portion of the upper side fastening tape 30 is fixed to the target tape 29, and thus the engaging force of the end portion of the upper side fastening tape 30 is large, and the upper side fastening tape 30 becomes difficult to unfasten. Further, in the comparative example, the engaging force to the base side of the upper side fastening tape 30 is small, and in the case where the legs in a state bent in an M-shape move, the upper side fastening tape 30 is easy to unfasten with a force received from the groin.

[0064] <Modified Example of shape of Fastening tapes 30>

Fig. 8A and Fig. 8B are explanatory views of a first modified example of the shape of fastening tapes 30. In the first modified example, the size of the fastening tape 30 in the tape width direction is configured smaller toward an end portion. Further, in the first modified example, the size of a hook sheet 34 in the tape width direction is also configured smaller toward the end portion.

Also in the first modified example, in the case where the pair of the fastening tapes 30 is overlapped in the state where centers of the 21 fastening tapes 30 in the tape width direction are matched, an upper side fastening tape 30 straddles over an end portion of a lower side fastening tape 30 in the tape width direction, and the upper side fastening tape 30 is fixable to a target tape 29 in both sides of the upper side fastening tape straddling over the end portion of the lower side fastening tape. Thus, also in the first modified example, the fastening tape 30 can maintain the mutually contradictory functions of "easy to unfasten" and "difficult to unfasten".

[0065]

It should be noted that, in the first modified example, the size of the fastening tape 30 in the tape width direction is configured smaller toward the end portion. Thus, in the first modified example, even in the state where not an end portion of the upper side fastening tape 30 but an end portion of the hook sheet region C (the end portion in the opposite side to the side flap 14 side) is matched to a position of the end portion to the side flap 14 side in the hook sheet region C of the lower side fastening tape 30, the hook sheet 34 of the upper side fastening tape 30 can be fixed to the target tape 29 in both sides of the upper side fastening tape straddling over the lower side fastening tape 30 in the tape width direction.

[0066]

Fig. 9A and Fig. 9B are explanatory views of a second modified example of the shape of fastening tapes 30. The fastening tape 30 in the second modified example has a narrow part in a central portion, and thus a tape width does not become smaller toward an end portion. In the second modified example, however, in the case where the pair of the fastening tapes 30 is overlapped in the state where the centers of the fastening tapes 30 in the tape width direction are matched, the upper side fastening tape 30 straddles over the end portion of the lower side fastening tapes 30 in the tape width direction, and the upper side fastening tape 30 is fixable to the target tape 29 in both sides of the upper side fastening tape 30 straddling over the lower side fastening tape 30. Thus, also in the second modified example, the fastening tape 30 can maintain the mutually contradictory functions of "easy to unfasten" and "difficult to unfasten". 22 [0067] <Pattern of Target>

Fig. 10 is an explanatory view of the pattern of the target tape 29 and the pattern of the target sheet 36 of the fastening tape 30.

[0068] A surface of the target tape 29 is provided with a striped pattern configured from depressions and protrusions. These depressions and protrusions are configured by forming, on an outermost layer of a nonwoven fabric of the nonwoven fabric having equal to or greater than two layers configuring the target tape 29, protrusions with a large fiber amount and depressed grooves with a small fiber amount in an alternate manner.

[0069]

The surface of the target sheet 36 of the fastening tape 30 is also given striped patterns configured with the depressions and the protrusions. The depressions and the protrusions of the target sheet 36 are also configured by forming in an alternate manner on the outermost layer of the nonwoven fabric of the target sheet 36, the protrusions with a large fiber amount and the depressed grooves with a small fiber amount. In this embodiment mode, the target sheet 36 configured with the nonwoven fiber becomes comparatively thick since the engaging force P2 between the fastening tape 30 and the fastening tape 30 needs to be equal to or greater than 0.1 N/10 mm, and thus forming such depressions and protrusions can be achieved.

[0070]

In this embodiment mode, the width and the interval of the depressions and the protrusions on the surface of the target tape 29 are approximately the same as the width and the interval of the depressions and the protrusions on the surface of the target sheet 36 of the fastening tape 30. In other words, in this embodiment mode, a common depression and protrusion pattern is provided on the surfaces of the target tape 29 and the target sheet 36. In this way, by making the pattern of the target tape 29 and the fastening tape 30 common, the texture of both members becomes common, and the texture after both members are joined does not change, thus its aesthetic beauty becomes better. Further, the patterns of the target tape 29 and the fastening tape 30 can be naturally guided 23 so as to match and be engaged, thus the fastening tape 30 can be suppressed from being engaged extremely diagonally to the target tape 29.

[0071]

It should be noted that, the common depressed and protruded pattern on the surfaces of the target tape 29 and the target sheet 36 may not be completely the same. For example, the target tape 29 having the depressed and protruded pattern may be further provided with embossing, and the target sheet 36 having the depressed and protruded pattern may not be provided with embossing. Even in such a case, as long as the depressed and protruded pattern is common, the texture will be common, and also the patterns of the target tape 29 and the fastening tape 30 can be guided so as to match and be engaged. Further, the common pattern of the surfaces of the target tape 29 and the target sheet 36 is not limited to the depressed and protruded pattern, and may be other patterns. Further, the common pattern on the surfaces of the target tape 29 and the target sheet 36 is not limited to the depressed and protruded pattern, but may be other patterns. Further, the common pattern on the surfaces of the target tape 29 and the target sheet 36 is not limited to the pattern with the same size, and may be a pattern similar in shape with a different size.

[0072]

Further, in this embodiment mode, the protrusions and the depressed grooves configuring the depressed and protruded pattern of the fastening tape 30 are formed along the tape width direction, and the depressions and the protrusions are arranged alternately along the tape length direction. Thus, the fastening tape 30 can be easily bent in the tape length direction and difficult to bend in the tape width direction. Since the tape length direction of the fastening tape becomes easy to bend, the fastening tape 30 becomes easy to unfasten. On the other hand, since the tape width direction of the fastening tape becomes difficult to bend, the fastening tape 30 can have rigidity with respect to the force to be received from the groin (a force received from below).

[0073]

The guiding pattern is a pattern for guiding to an engaging position 24 of the fastening tape 30. Here, the guiding pattern is a pattern where a range in a rectangular shape is colored. It should be noted that, the guiding pattern is not limited to this, and the guiding pattern may be configured as a rectangular outline shape, four L-shaped patterns showing four corners of a rectangular shaped region, and the like, or the guiding pattern may be configured by drawing letters, numbers, symbols, patterns, character designs and the like within the rectangular region. Further, the guiding pattern is not limited to the rectangular shape, and may be an oval shape.

[0074]

As shown in Fig. 11, the size of the guiding pattern in the product width direction W is the same as or smaller than the size of the absorbent body 21 in the product width direction W. In other words, the size of the guiding pattern in the product width direction W is equal to or smaller than the product width direction W of the absorbent body 21. In this way, the engaging position of the fastening tape 30 is guided to a central portion of the front portion 3, and as a result, the other fastening tape 30 can be guided to engage on the lower side fastening tape 30.

[0075]

By the way, since the absorbent body 21 is a comparatively thick member (refer to Fig. 2) , when the wearer in the positioning posture moves, such force can be absorbed (eased). Thus, as long as the fastening tape 30 is engaged to an inner side in the product width direction W than the absorbent body 21, even if the wearer in the positioning posture moves, such a force is difficult to be conveyed to the fastening tape 30, and the fastening tape 30 becomes difficult to unfasten. Thus, in the case that the size of the guiding pattern in the product width direction W is equal to or smaller than the size of the absorbent body 21 in the product width direction W, an effect that the fastening tape 30 becomes difficult to unfasten is obtained.

[0076]

Further, in this embodiment mode, the target region (here, the target tape 29) is in a wider range than the guiding pattern. Thus, even if the fastening tapes 30 extend off the guiding pattern, the fastening tapes 30 can be engaged with a sufficient engaging force. 25 [0077] = Other points

The above embodiment modes are for facilitating the understanding of this invention, and are not for limiting the understanding of this 5 invention in any way. This invention may be altered and modified without departing from the spirit thereof, and it is needless to say that this invention includes its equivalents.

[0078] 10 Reference Signs List 1 disposable diaper, 3 front portion, 5 crotch portion, 7 rear portion, 12 central strip region, 14 side flap(s), 15 leg gathers, 16 leg side gathers, 18 waist gathers, 15 21 absorbent body, 22 top sheet, 23 leak prevention sheet, 24 back sheet (exterior sheet), 25 stretchable film, 26 skin-side sheet, 26A joining portion, 27 stretchable member, 28 waist gather film, 29 target tape, 30 fastening tape, 32 base sheet, 20 34 hook sheet, 36 target sheet, A base end region, B intermediate region, C hook sheet region (engaging region), D tip region

Claims

The claims defining the invention are as follows:

1. A disposable diaper for a baby having a weight equal to or smaller than 3000 g, the disposable diaper comprising: side flaps; a pair of fastening tapes provided to the side flaps; and a target region that is engageable with the fastening tapes, one of the fastening tapes, of the pair of the fastening tapes, being engageable in an overlapping manner with another of the fastening tapes, in the case where an engaging force of the target region and the one of the fastening tapes is PI, and an engaging force of the one of the fastening tapes and the other of the fastening tapes is P2, a relation being PI > P2 > 0.1 N/10 mm, in the case where the pair of the fastening tapes are overlapped in a state where centers of the fastening tapes in a tape width direction are matched, an upper side fastening tape being engageable to the target region, in both sides of the upper side fastening tape straddling over an end portion of a lower side fastening tape in the tape width direction, wherein each of the fastening tapes has an engaging region that engages with the target region, in the case where the pair of the fastening tapes is overlapped, in a state where an end portion of the upper side fastening tape is matched to a position of an end portion to the side flap side in the engaging region of the lower side fastening tape, and in a state where centers of the fastening tapes in the tape width direction are matched, the upper side fastening tape is engageable to the target region, in both sides of the upper side fastening tape straddling over an end portion of the lower side fastening tape in the tape width direction.
2. A disposable diaper according to claim 1, wherein a width of an end portion to the side flap side of the engaging region is greater than a width of an end portion of the fastening tape.
3. A disposable diaper according to claim 1 or 2, wherein each of the fastening tapes has a target sheet that is engageable with another fastening tape, and a common pattern is provided to surfaces of the target region and the target sheet.
4. A disposable diaper according to claim 3, wherein a striped pattern configured with depressions and protrusions is provided on surfaces of the target region and the target sheet, and the depressions and the protrusions are arranged alternately along a tape length direction of the fastening tapes.
5. A disposable diaper according to any of claims 1 to 4, wherein a guiding pattern that guides an engaging position of the fastening tapes is formed on the target region, and a size of the guiding pattern in a product width direction is one of a same size and a smaller size than a size of an absorbent body in the product width direction.