TWM513015U - Disposable diaper - Google Patents

Abstract

To provide a disposable diaper excellent in fit of the crotch section, prevention of leakage, and prevention of rewet. A disposable diaper 1 of the invention includes a top sheet 2 defining the skin facing side, an outer sheet 3 defining the non-skin facing side, and an absorbent member 4 between these sheets. The absorbent member 4 includes an absorbent core 40 oblong in the longitudinal direction X corresponding to the front-to-rear direction of a wearer. The absorbent core 40 contains an absorbent polymer. Upon defining an absorbent crotch region 40c in a narrowed portion of the absorbent core 40, the absorbent core 40 has a large area region 40a and a small area region 40b different in area from each other, one forward and the other rearward of the absorbent crotch region 40c. The absorbent core 40 has a slit 7 extending in the longitudinal direction from the absorbent crotch region 40c to the large area region 40a. The slit 7 intersects a transverse centerline CL of the outer sheet 3, with at least 80% of the total length of the slit 7 located in the side of the large area region 40a of the centerline CL. The width W2 of the slit 7 in the large area region is larger than the width W1 in the crotch region 40c.

Description

Disposable diaper

This creation is about a disposable diaper.

As the absorbent body of the disposable diaper, it is known that the portion disposed in the lower portion of the wearer's crotch is formed into an indented shape from the viewpoint of improving the conformability. However, it is difficult to ensure a sufficient absorption capacity in the lower portion of the absorbent body, and it is easy to cause a liquid leakage from the lower portion of the crotch or a so-called liquid return of the absorbed liquid to the skin of the wearer.

As a technique for providing a slit in an absorbent core constituting an absorbent body, Patent Document 1 discloses that the lower absorbent layer has an absorbent structure having an upper absorbent layer and a lower absorbent layer. The opening and the upper absorbent layer cover the absorbent structure at the rear end of the opening. Moreover, in the patent document 2, it is described that the absorptive core body has the slit which has the opening part in the non-skin opposite surface side so that it may extend in the longitudinal direction of an absorptive core.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2012-040260

Patent Document 2: Japanese Patent Laid-Open Publication No. 2012-143542

Patent Document 1 discloses that urine or the like diffuses in the forward and backward directions in the opening of the lower absorbent layer, and urine which is diffused toward the side of the absorbent structure after opening is accommodated in the side of the opening. The bag is formed by covering the upper absorbent layer. However, the opening of the lower absorbent layer is formed only in the vicinity of the central portion of the absorbent article, and the portion on the front side is long, so that the liquid tends to stay in the vicinity of the lower portion of the crotch. Further, since the width of the opening is fixed, when the opening is made narrow, the opening is entirely closed during liquid absorption, and the diffusion function of the liquid in the front-rear direction is easily impaired, so that the width of the opening is widened. There is a decrease in the absorption capacity in the lower part of the crotch, but it is easy to leak.

The slit in Patent Document 2 extends long in the front-rear direction of the absorbent core. However, it is effective to make the absorbent core have a front-back asymmetry and to make the absorption capacity different in the front-rear direction or to make the slit width different. The contents of the grounding to the area where the absorption capacity is large are not described.

The present invention relates to a disposable diaper having a front sheet which forms a facing surface of the skin, a non-skin facing outer sheet, and an absorbent body between the two sheets. The absorbent body has an absorbent core having a shape elongated in the longitudinal direction of the disposable diaper, and the absorbent core comprises a water-absorptive polymer. The absorptive core has a contraction portion in a plan view shape, and the absorbent body is disposed in the longitudinal direction when the absorbent core is set in the lower region of the absorbent body having the same length as the minimum width of the contracted core portion. A large-area region and a small-area region having different areas from each other before and after the region are formed in the absorbent core, and a slit extending in the longitudinal direction is formed from the region in which the absorber is squatted to the large-area region. The slit intersects with a center line dividing the entire length of the disposable diaper in the longitudinal direction into two equal portions, and 80% or more of the total length of the slit is located closer to the large-area region side than the center line, and the large-area region The width in the middle is greater than the width in the underarm region.

1‧‧‧ diapers

1A‧‧‧ diapers

1B‧‧‧ diapers

2‧‧‧Front sheet

2A‧‧‧Front sheet

2B‧‧‧Front sheet

3‧‧‧ outer sheet

4‧‧‧Acceptor

5‧‧‧Buckle belt

6‧‧‧Three-dimensional folds

7‧‧‧Slit

7A‧‧‧2nd slit

7B‧‧‧ transverse slit

8‧‧‧Flexible sheet

9‧‧‧ Leg elastic members

21‧‧‧Uplift

22‧‧‧Slots

40‧‧‧Absorbable core

40'‧‧‧Absorbable core

40a‧‧‧Large area

40b‧‧‧Small area

40c‧‧‧Absorbing area

40s‧‧‧slit area

41‧‧‧Package

42‧‧‧Package

43‧‧‧Slit cushion sheet

51‧‧‧Fixed area

61‧‧‧Flexible components

62‧‧‧Sheet for the formation of three-dimensional pleats

71‧‧‧Narrow section

72‧‧‧ wide section

75‧‧‧Small Absorption Department

76‧‧‧Small Absorption Department

91‧‧‧Cylinder

92‧‧‧Cylinder

93‧‧‧ fixture

94‧‧‧ cushion

A‧‧‧ ventral side

A‧‧‧width

B‧‧‧Back side

B‧‧‧ Length

C‧‧‧胯下下

C‧‧‧ Length

CL‧‧‧Central Line

L‧‧‧Full length

L1‧‧‧ Full length

L2‧‧‧ length

P‧‧‧ contracted part

W‧‧‧Artificial urine

W1‧‧‧Width

W2‧‧‧Width

X‧‧‧ length direction

Y‧‧‧Width direction

Fig. 1 is a partially broken plan view showing a disposable diaper according to an embodiment of the present invention.

Figure 2 is a cross-sectional view taken along line II-II of Figure 1.

3(a) and 3(b) are explanatory views of the underarm region, the large-area region, the small-area region, and the slit region of the absorber.

Fig. 4 is a cross-sectional view showing a section (a section along the line III-III of Fig. 1) in the vicinity of a slit in a large area of the disposable diaper of Fig. 1.

Fig. 5 (a) and Fig. 5 (b) are perspective views respectively showing an example of a front sheet which is preferably used in the disposable diaper of the present invention.

Fig. 6 (a) is a schematic plan view showing a sheet of a disposable diaper according to another embodiment of the present invention, which is a surface of a skin facing surface and an elastic member, and Fig. 6 (b) is shown in Fig. 6 (a) The disposable diaper is equivalent to the figure of Figure 2.

Fig. 7 is a view corresponding to Fig. 2 of a disposable diaper according to still another embodiment of the present invention.

Fig. 8 is a plan view showing an absorbent core of a disposable diaper according to still another embodiment of the present invention.

Fig. 9 (a) is a plan view showing an absorbent core of the absorbent body used in the examples, and Fig. 9 (b) is a plan view showing a state in which the absorbent core is swollen by liquid absorption.

Fig. 10 (a) is a plan view showing an absorbent core of the absorbent body used in the comparative example, and Fig. 10 (b) is a plan view showing a state in which the absorbent core is swollen by liquid absorption.

Fig. 11 is a view showing an apparatus used in a liquid permeability test.

This creation is about a disposable diaper which is excellent in the conformity, leak-proof property of the underarm and excellent in preventing liquid back to the wearer's skin.

Hereinafter, the present invention will be described with reference to the drawings based on preferred embodiments thereof.

As shown in Fig. 1 and Fig. 2, the disposable diaper 1 (hereinafter also referred to as diaper 1) which is one embodiment of the present invention has a front sheet 2 which forms a liquid permeability to the skin facing surface, and forms a non-skin contrast. The outer layer sheet 3 and the liquid retaining body 4 located between the two sheets 2 and 3. The opposite side of the skin is facing the side of the wearer's skin when wearing a diaper. The skin facing surface is the side opposite to the skin side of the wearer when the diaper is worn. In the present creation, the longitudinal direction of the diaper is also referred to as the direction of the ventral side (front side) and the back side (rear side) of the wearer, that is, the front-rear direction.

The diaper 1 has a direction corresponding to the front and rear directions of the wearer, more specifically, a longitudinal direction X which is a direction in which the wearer wears the front and rear directions, and a state in which the diaper 1 is flattened as shown in FIG. The width direction Y intersecting the length direction X described above.

The diaper 1 has a front side portion A disposed on the abdomen side of the wearer when worn, a back side portion B disposed on the back side of the wearer when worn, and a lower portion C disposed on the wearer's crotch during wearing. . Further, the diaper 1 of the present embodiment is an unfolded disposable diaper as shown in Fig. 1, and the adhesive tapes 5 and 5 are provided on both side edges of the back side portion B, and the outer surface of the front side portion A is provided with a surface. The fixing area 51 of the fastening strips 5, 5 is fixed. Further, the diaper 1 is formed in an arc shape on both side edges of the crotch portion C, and has a shape in which the central portion in the longitudinal direction X is contracted in plan view.

The outer layer sheet 3 is a sheet which forms a non-skin opposing surface (outer surface) of the diaper 1, and the outer shape sheet 3 has a shape conforming to the outer shape of the diaper 1 as viewed from the non-skin facing side of the diaper 1. . As the outer layer sheet 3, for example, a resin film containing a liquid impervious property or a non-skin facing layer on the non-skin facing side of the resin film is preferably used. The outer layer sheet 3 may be one in which two or three or more sheets are joined in the longitudinal direction of the diaper 1.

The front sheet 2 contains various known sheets of liquid permeability. As shown in FIGS. 1 and 2, the front sheet 2 in the present embodiment has a width narrower than that of the outer layer sheet 3, and is disposed on the central portion in the width direction of the outer layer sheet 3. An absorber 4 having a shape elongated in the longitudinal direction X of the diaper 1 is interposed between the front sheet 2 and the outer sheet 3.

The absorbent body 4 includes an absorbent core 40 including a fiber assembly including a fiber material such as pulp fibers and water-absorbent polymer particles held therein, and a coated core material 41, 42 covering the absorbent core 40 . As the packaged core materials 41 and 42, various known ones can be used, and for example, a water-permeable tissue such as toilet paper or a water-permeable nonwoven fabric or the like is preferably used. The absorbent core 40 has a substantially planar shape similar to that of the absorbent body 4. The packaged core materials 41 and 42 have the same position at the same position as the both ends 40a and 40b of the absorbent core 40 in the longitudinal direction, or have two ends in the longitudinal direction X from the positions where the both ends 40a and 40b are slightly extended in the longitudinal direction X.

As shown in FIGS. 1 and 2, the leg elastic members 9 are disposed in an extended state on both side portions of the crotch portion C of the diaper 1. The leg elastic members 9 are respectively disposed in one or a plurality of strips on both sides in the longitudinal direction of the diaper 1. The leg elastic member 9 is fixed between the outer layer sheet 3 and the sheet 62 for forming the three-dimensional pleats 6, 6 via an adhesive. The leg elastic members 9 are contracted to form leg gathers on the legs disposed in the leg circumference of the wearer. Further, a sheet 62 for forming a three-dimensional gather having an elastic member 61 is disposed on both sides in the longitudinal direction of the diaper 1, and when the diaper is worn, the elastic member 61 is contracted to form a three-dimensional shape that is raised toward the wearer's skin. Pleats 6.

In the diaper 1 of the present embodiment, as shown in Fig. 1, the absorbent core 40 has a contracted portion P in a plan view.

The contracted portion P is a portion sandwiched by a portion having a width larger than the portion in the longitudinal direction of the absorbent core 40 in the longitudinal direction X of the diaper 1.

In the present invention, the "absorbent region of the absorbent body" is set such that the contracted portion of the absorbent core is the same length as the minimum width of the contracted portion.

Specifically, the "absorbent area" in this creation is specifically described. Further, since the longitudinal direction of the absorbent core 40 is the same as the longitudinal direction X of the diaper 1, the longitudinal direction of the absorbent core 40 is also expressed as the longitudinal direction X.

As shown in Fig. 3 (a), the portion where the width of the indented portion P of the absorbent core 40 is the narrowest is centered, and the length b of the longitudinal direction X has the width a of the portion having the narrowest width (the minimum). The region of the same length as the width is set as the absorber underarm region 40c.

Further, when the portion having the narrowest width is continuously present in the longitudinal direction X of the absorbent core 40, the absorbent body crotch region 40c is set as follows.

When the length c of the range in which the narrowest width is continuously continuous in the X direction is the width a (minimum width) of the portion having the narrowest width (c≦a), the length c is divided The region in which the length b of the longitudinal direction X is the same as the width a (the minimum width) of the portion having the narrowest width is the center of the absorbent body. On the other hand, as shown in Fig. 3(b), when the length c of the range in which the narrowest width continuously exists is longer than the width a (minimum width) of the portion having the narrowest width (c>a), it will be the narrowest. The entire range of the range in which the width continuously exists is set as the absorber underarm region 40c.

In the diaper 1 of the present embodiment, the contracted portion P of the absorbent core 40 is formed in the lower portion C of the diaper 1 in which the both side edges are concave. Further, the minimum width portion (the portion having the smallest width) of the crotch portion C of the diaper 1 is set to have the same length in the longitudinal direction of the diaper 1 as the minimum width a of the contraction portion P of the absorbent core. (In the range of the diaper), the portion where the width of the contraction portion P of the absorbent core 40 is the smallest is present in this range. Further, the center length CL of the diaper 1 in the longitudinal direction is divided into two equal parts, and the length of the diaper 1 is set to the same length as the minimum width a of the contraction portion P of the absorbent core. In the range of (the range of the diaper), the portion where the width of the contraction portion P of the absorbent core 40 is the smallest is also present in this range.

The absorbent core 40 of the present embodiment has a large-area region 40a and a small-area region 40b having different areas before and after the absorbent body crotch region 40c defined in the longitudinal direction X as described above. As shown in FIG. 3, the areas of the large-area region 40a and the small-area region 40b are plane areas in a state in which the absorptive core is expanded into a planar shape, and the area of each of them also includes the area of the slit 7.

The absorbent core 40 shown in Fig. 1 and Fig. 3(b) has a large-area region 40a on the side of the front side portion A and a small-area region 40b on the side of the back side portion B with respect to the absorbent body crotch region 40c. Therefore, it is suitable for children who are used for high months and months after the month when the amount of urine is relatively increased. On the other hand, the absorbent core 40 in the disposable diaper of the present invention may have a large-area region 40a on the side of the back side portion B with respect to the absorbent body crotch region 40c and a small-area region on the side of the ventral side portion A. 40b. In this case, it is suitable for infants of low age who have a large amount of excretion of liquid stools.

As will be described further in the absorbent core 40 of the present embodiment, as shown in Fig. 1, the slit 7 extending in the longitudinal direction X of the absorbent core 40 extends from the absorbent body crotch region 40c to the large-area region 40a. And formed. Further, the slit 7 intersects with the center line CL which divides the entire length L of the diaper in the longitudinal direction into two equal portions, and 80% or more of the total length L1 of the slit 7 is located closer to the large-area region 40a than the center line CL.

In the present invention, the term "slit" refers to a portion formed in a portion of the absorbent core and having no material for forming the absorbent core, and has a shape that is long in one direction. The absorbent core forming material which is a material for forming the absorbent core may be present at the slit at a low basis weight. However, the slit preferably penetrates the absorbent core. Further, in the case where the absorbent core forming material is present at a low basis weight in the slit portion, the basis weight thereof is preferably 15% or less of the basis weight of the other portion of the absorbent core (for example, a portion adjacent to the slit). More preferably 5% or less.

The slit 7 and the second slit 7A described below have a shape elongated in the longitudinal direction of the absorbent core in the same direction as the longitudinal direction of the diaper 1, and the following lateral slit 7B has a length with the absorbent core. The direction in which the direction intersects is longer in Y.

The absorber underarm region 40c has a slit 7 intersecting the center line CL, and the slit 7 extends to the large-area region 40a, and 80% or more of the total length L1 thereof is located on the side of the larger-area region 40a than the center line CL. This allows the urine or liquid stool (hereinafter referred to as urine or the like) which is discharged to the lower armrest region 40c of the absorbent body having a narrow width and a small absorption capacity to be efficiently diffused to a large extent of the large-area region 40a and absorbed. . In particular, the width W2 in the large-area region 40a of the slit 7 is larger than the width W1 in the underarm region 40c of the absorber, so that even if the large-area region 40a absorbs liquid to swell the water-absorbing polymer, at least the large-area region 40a is maintained. The opening state of the slit 7 [see FIG. 9] satisfactorily maintains the liquid diffusion function by the slit 7 described above.

According to the disposable diaper 1 of the present embodiment, the high absorption capacity of the large-area region 40a in the absorbent core 40 can be effectively utilized, the good conformability of the crotch portion can be maintained, and the lower portion of the crotch can be effectively suppressed. The liquid leaks, or the absorbed liquid returns to the liquid returning to the wearer's skin.

From the viewpoint of more effectively exerting such an effect, the absorbent core 40 preferably satisfies one or more of the following conditions.

The length L2 (refer to FIG. 1) of the portion of the slit 7 located on the side closer to the large-area region 40a than the center line CL is preferably 80 to 95% of the total length L1 of the slit (refer to FIG. 1), and further preferably 85~95%.

Further, the total length L1 of the slit 7 is preferably 40 to 70%, more preferably 50 to 60%, of the total length L of the outer layer sheet 3.

As shown in Fig. 1, the slit 7 of the absorbent core 40 of the present embodiment has a narrow portion 71 having a relatively narrow width and a wide portion 72 having a relatively wide width, and the narrow portion 71 is mainly present in the absorbent body. The crotch region 40c, the wide portion 72 is mainly present in the large-area region 40a.

In the present embodiment, the boundary between the narrow portion 71 and the wide portion 72 of the slit 7 is located closer to the large-area region 40a than the boundary between the absorbent underarm region 40c and the large-area region 40a, but the narrow portion 71 and the width are wide. The boundary of the web portion 72 may also be at the same position as the boundary between the absorbent body underarm region 40c and the large-area region 40a.

Further, as for the slit 7, the width W2 of the wide portion 72 is preferably 1.5 to 4.0 times the width W1 of the narrow portion 71, and more preferably 2.0 to 3.0 times.

Further, the width W1 of the narrow portion 71 of the slit 7 is preferably 20 mm or less, more preferably 15 mm or less, and is preferably 3 mm or more, and further preferably 5 mm or more. Further, the width W2 of the wide portion 72 of the slit 7 is preferably 4.5 mm or more, more preferably 7.5 mm or more, and is preferably 30 mm or less, and further preferably 20 mm or less. Further, the difference (W2-W1) between the width W2 of the wide portion 72 and the width W1 of the narrow portion 71 is preferably 2 mm or more, more preferably 5 mm or more, and is preferably 30 mm or less, and further preferably 20 mm or less. .

The area of the large-area region 40a is preferably 150% or more, more preferably 200% or more, and further preferably 500% or less, further preferably 400% or less, and preferably 150%. 500%, and more preferably 200 to 400%.

The area of the large-area region 40a is preferably 300% or more, more preferably 400% or more, and further preferably 600% or less, and further preferably 500% or less, of the area of the absorbent body underarm region 40c. The area of the small-area region 40b is preferably 110% or more, more preferably 120% or more, and further preferably 300% or less, and further preferably 200% or less, of the area of the absorbent body underarm region 40c.

Further, as shown in FIG. 2 and FIG. 4, the slit 7 in the present embodiment penetrates the absorbent core 40 in the thickness direction in either of the absorber crotch region 40c and the large-area region 40a. Further, the narrow portion 71 and the wide portion 72 are uniform in width over the entire length direction X, respectively. Further, it is preferable that the slit 7 does not extend in the small-area region 40b as in the present embodiment.

Further, as shown in FIG. 2, the upper side of the skin facing surface side of the absorbent core 40 and the side of the non-skin opposing side of the side of the coated core material 42 may overlap the slit 7. As shown in FIG. 3, the upper side clad core material 41 and the lower side clad core material 42 are joined to each other in a portion overlapping the slit 7, but in terms of the diffusibility of the excrement, as shown in FIG. Preferably, the upper package core material 41 and the lower package core material 42 are joined to each other in the narrow portion 71 of the absorber underarm region 40c, and in terms of the diffusibility of the excrement, preferably via the slit 7 The upper package core material 41 and the lower package core material 42 are joined to each other in the wide portion 72 of the large area 40a. In the example shown in FIG. 4, the upper package core material 41 and the front surface sheet 2 are caught in the slit 7, and are integrated with the lower package core material 42 and the outer layer sheet 3.

As the front sheet 2, various sheets and the like which have been used as the front sheet of the disposable diaper can be used without particular limitation, and for example, an open-pored film or a non-woven fabric made by various processes using a single-layer or multi-layer structure can be used. However, as the front sheet 2, the ridges 21 extending in the longitudinal direction X of the diaper and the ridges 21 and 21 are provided as in the front sheets 2A and 2B shown in Figs. 5(a) and 5(b). The groove portion 22 can further promote the diffusion of urine or the like excreted to the large-area region 40a of the absorbent body crotch region 40c, which is preferable.

The front sheet 2A shown in Fig. 5(a) imparts a solid to a non-woven fabric of a single layer or a multilayer structure. The shape of the cross-sectional shape in the width direction Y intersecting the longitudinal direction X of the diaper is continuous and undulating, and a cavity is formed in the ridge portion 21. The front sheet 2A is preferably such that the lower surface of the groove portion 22 is joined to a sheet disposed therebelow, for example, a packaged core material 41 or a second sheet disposed between the front sheet 2 and the packaged core material. As such a front sheet 2A, for example, those described in JP-A-1996-302555, JP-A-1996-246321, and JP-A-2004-275296 can be used.

The cross-sectional shape of the front sheet 2B shown in Fig. 5(b) intersecting the longitudinal direction X of the diaper has a continuous wave shape on the upper surface, and the lower surface is substantially flat, and the inside of the ridge portion 21 is substantially flat. Be solid. As such a front sheet 2B, for example, those described in JP-A-2009-299227, JP-A-2001-095845, and JP-A-2008-025079 can be used.

The disposable diaper of the present invention is also preferably such that, as in the disposable diaper 1A shown in Fig. 6, the absorbent core 40 and the outer layer sheet 3 have a length X in the diaper or intersect with the length direction. The stretchable sheet 8 which is stretched in the direction Y is disposed at least at a position where the stretchable sheet 8 overlaps the slit 7 in the absorbent body crotch region 40c. In the disposable diaper 1A, the stretchable sheet 8 is disposed between the core sheet 42 and the outer layer sheet 3 on the lower side of the non-skin opposing surface side of the coated absorbent core 40. Regarding the disposable diaper 1A, the aspect which is not particularly described is the same as that of the diaper 1 described above.

By arranging the stretchable sheet 8 in the longitudinal direction X of the diaper as the stretchable sheet 8, the absorbent body 4 or its absorbent core 40 is contracted in the longitudinal direction of the diaper, and the absorbent body 4 or the absorbent core 40 can be increased. Absorption capacity per unit area. Thereby, it is possible to more reliably prevent liquid leakage from the lower portion C or the like. From the viewpoint of more effectively exhibiting the effect, the stretchable sheet 8 is preferably joined to at least one of the upper and lower members sandwiched in the longitudinal direction X. Further, from the same viewpoint, the stretchable sheet 8 is preferably disposed from the absorber crotch region 40c to the large-area region 40a so as to overlap the slit 7 as shown in Fig. 6(a). As the bonding method, various known methods such as an adhesive can be employed, and The joints may be joined over the entire surface or may be partially joined in a particular pattern.

On the other hand, when the stretchable sheet 8 is stretched in the direction Y intersecting the longitudinal direction X of the diaper, preferably in the direction Y orthogonal to the longitudinal direction X, the absorbent body 4 or the absorbent body 4 is used. The absorbent core 40 is contracted in the width direction of the diaper to improve the conformability of the crotch portion C and the like to the wearer's skin. Further, the front sheet 2 also has wrinkles extending in the longitudinal direction X, and the diffusibility of the liquid in the longitudinal direction X is improved. Therefore, it is possible to more reliably prevent urine and the like from remaining in the lower portion C of the absorbent body underarm region 40c. .

From the viewpoint of exerting this effect, the stretchable sheet 8 is preferably joined to at least one of the upper and lower members sandwiched in the state of being elongated in the width direction Y. Further, from the same viewpoint, the stretchable sheet 8 is preferably disposed from the absorber crotch region 40c to the large-area region 40a so as to overlap the slit 7 as shown in Fig. 6(a). As the bonding method, various known methods such as an adhesive may be employed, and the bonding may be performed over the entire surface or partially bonded in a specific pattern.

As the elastic sheet 8, an elastic sheet containing a polyurethane or an elastomer may be used, but in terms of suppressing liquid leakage from the lower portion of the crucible, it is preferably used, for example, as disclosed in Japanese Patent Laid-Open Publication No. 2013 In the case of the stretchable sheet as described in the above-mentioned Japanese Patent Publication No. Hei. No. 2013-81715, the thickness of the stretchable sheet is thin and adheres to the wearer's body. Moreover, it is preferable that the stretchable sheet 8 is stretchable in both the longitudinal direction X of the diaper and the direction in which it crosses.

The disposable diaper of the present invention is also preferably a disposable diaper 1B as shown in Fig. 7, and the absorbent body 4 has a coated core material 41, 42 covering the absorbent core 40, and the absorbent core 40 is located The slit-pad layer sheet 43 excellent in liquid diffusibility is disposed between the non-skin-facing side cladding sheets 42 in a state of being overlapped with the slits 7. The liquid high-diffusing sheet 43 in the disposable diaper 1B is disposed in the plan view of the absorbent core 40 in the same manner as the stretchable sheet 8 in the disposable diaper 1A, and is disposed not only in the absorbent body underarm region 40c, but also in the absorbent core 40. And overlapping with the slit 7 of the self-absorbing body underarm region 40c to the large-area region 40a Set.

In the slit-cushion sheet 43, "excellent liquid diffusibility" means that the Klemm water absorption obtained by the "Water absorption test method using the Klemm method for paper and paper sheets" prescribed in JIS P8141 is The range of 100 mm or more, especially 150 mm or more, is 10 minutes.

As in the case of the disposable diaper 1B, the slit cushion layer sheet 43 is disposed so that the non-skin opposing surface side of the absorbent core 40 covers the slit 7 portion, and the liquid diffuses into the longitudinal direction X through the slit 7. Further improvement can more reliably suppress liquid leakage or liquid return.

As the slit underlayer sheet 43, for example, a non-woven fabric comprising synthetic fibers and a non-woven fabric comprising two kinds of fibers of synthetic fibers and cellulose-based fibers described in Japanese Patent Laid-Open Publication No. 2004-298384, or Japanese Patent Laid-Open No. 2013 can be used. Non-woven fabrics including beaten pulp and regenerated cellulose described in -150799.

As described above, the absorbent core 40 in the diapers 1, 1A, and 1B includes a fiber assembly containing a fibrous material such as pulp fibers and particles of a water-absorbent polymer held therein. As the fiber material constituting the fiber assembly, hydrophilic fibers such as pulp fibers, ray fibers, cotton fibers, and cellulose acetate, polyolefin fibers such as polyethylene and polypropylene, and condensed fibers such as polyester and polyamide can be used. Wait. As the particles of the water-absorbent polymer, for example, various water-absorbent polymers previously used for disposable diapers can be used without particular limitation, and examples thereof include sodium polyacrylate, (acrylic acid-vinyl alcohol) copolymer, and sodium polyacrylate cross-linking. A body, a (starch-acrylic acid) graft copolymer, an (isobutylene-maleic anhydride) copolymer, a saponified product thereof, a particle of polyaspartic acid, or the like.

The absorbent core 40 is preferably obtained by a fiber stacking step of depositing the fiber material supplied with the air flow into the fiber stacking recess of a specific shape, and more preferably the water-absorbing polymer and the fiber. The material is supplied together with the flow of air, and is produced by being deposited in a specific stacked state such as a mixed state. The slit 7 can be formed by a non-breathable convex portion having a shape corresponding to the slit 7 in the concave portion for fiber accumulation of the fiber stacking roller. It is easy to form.

The absorbent core in the present invention is preferably a viewpoint that it is less likely to cause a water-absorptive polymer which swells due to liquid absorption to become a gel, and a phenomenon called gel agglomeration which hinders subsequent absorption of liquid is preferable. The water-absorbent polymer and the pulp fiber are contained, and the ratio of the mass of the pulp fiber to the total mass of the absorbent core is 40% or more. The ratio of the mass of the pulp fiber to the total mass of the absorbent core is more preferably 50% or more, and is preferably 70% or less, further preferably 60% or less, and more specifically, preferably 40 to 70%. Further preferably 50 to 60%. The ratio of the total mass of the pulp fibers and the water-absorbing polymer to the total mass of the absorbent core is preferably from 90 to 100%, more preferably from 95 to 100%.

Further, it is preferable that the absorbent core 40 of the absorber 4 is coated with the core sheets 41 and 42 having high diffusibility to further improve the diffusibility of the liquid passing through the slit 7. Here, the high-diffusion property of the packaged chip material means that the Kleem water absorption amount measured by the following method is preferably 0.2 g/30 sec ‧ 15 mm or more, and more preferably 0.2 to 0.4 g / 30 sec ‧ 15 mm The scope.

[Method for measuring Klime water absorption]

The measurement target sheet (thin paper) was allowed to stand in an environment of 23 ° C ± 2 ° C and a relative humidity of 50% RH ± 2% for 12 hours, and the humidity was adjusted so as to be in a fixed state. The sheet after the humidity adjustment was cut into a rectangular shape having a MD (machine direction) of 150 mm and a CD (cross direction) of 15 mm, and the cut rectangular shape was used as a sample. A straight line (marking line) parallel to the short side is drawn by a pencil at a position separated from the short side of the sample by 5 mm in the longitudinal direction. Then, the sample was suspended from the lower portion of the electronic balance so that the long side of the sample became vertical, and the sample was quickly placed in the measurement liquid (physiological saline) to the above-mentioned reticle while maintaining the suspended state. Further, the sample was suspended in such a manner that the above-mentioned reticle (a straight line drawn by a pencil) was close to the above-mentioned measuring liquid. Then, the weight increase amount of the sample after the sample was placed in the measurement liquid for 30 seconds was measured by an electronic balance, and the measured value was taken as the Kreem water absorption amount (g/30 sec ‧ 15 mm). The more water absorption of Klim More, the higher the assessment. Furthermore, a personal computer equipped with a commercially available electronic balance data acquisition software (trade name: RsCom Ver 2.40: A&D COMPANY, LIMITED) is attached to the electronic balance to record the weight change of the sample.

In the diapers 1 , 1A, and 1B, the core sheet 41 covering the upper side of the skin facing surface side of the absorbent core 40 and the coated core material covering the lower side of the non-skin facing side of the absorbent core 40 are covered. 42 is a sheet of a different body, but it is preferable that at least the coated core material 42 covering the non-skin facing side is a "highly diffusible" sheet.

Further, in the present invention, the absorbent core 40 is a basis weight of the slit region 40s (see FIG. 3) which is a range in which the slit 7 is formed in the region where the absorbent body underarm region 40c and the large-area region 40a are combined. The basis weight is higher than the basis weight of the small-area region 40b, and it is preferable to increase the absorption capacity of the region in which the diffusion property of the liquid is formed by the slit, thereby preventing leakage and suppressing liquid return. Here, the basis weight of the slit region 40s and the small-area region 40b is calculated by dividing the mass by the area for each region. The mass is set to the total mass of all the components constituting the absorbent core. The area of the slit region 40s also includes the area of the slit 7 portion.

The absorbent core in the present invention is preferably such that the surface on the side of the front sheet is covered with a core material having a low liquid permeability. When the urine or the like supplied to the portion overlapping the slit is absorbed by the absorbent core from the inner wall surface of the slit, the urine or the like is easily diffused in the longitudinal direction X, and the absorption capacity of the absorbent body can be effectively utilized. Here, the low dielectric permeability of the packaged chip material means that the liquid permeation time measured by the following method is 10 seconds or longer, preferably 15 seconds or longer.

[Method for measuring liquid permeation time]

As shown in Fig. 11, two cylinders 91 and 92 having an inner diameter of 35 mm in the upper and lower end openings are arranged vertically so that the axes of the two cylinders 91 and 92 are aligned, and a metal mesh having a diameter of 55 mm and a cutting of 40 mm square are provided. A sample piece was placed on the upper side of a filter paper of a diameter of 55 mm manufactured by Advantec Co., Ltd., and sandwiched between the upper and lower cylinders 91 and 92. At this time, it is preferable that the jig 93 and the cylinder 92 provided on the lower end and the lower side of the cylinder 91 on the upper side are The upper end annular flange portion is fitted to connect the upper and lower cylinders 91 and 92. Reference numeral 94 is a gasket made of rubber or the like having through holes having the same diameter and the same diameter as the inner diameters of the cylinders 91 and 92. In the state in which the cut sample piece is held by the upper and lower cylinders 91 and 92, 40 g of the artificial urine shown by the symbol W in Fig. 11 is supplied into the upper cylinder 91. The supplied artificial urine flows through the cut sample piece from the lower end of the cylinder 92 through the lower side cylinder 92. The change in the weight of the artificial urine flowing down from the lower cylinder 92 was observed using an electronic equal weight measuring mechanism, and the time from the start of the supply of artificial urine to the time when the mass reached 20 g was measured. For liquid penetration time. In a plurality of measurements, a new cut sample piece is prepared each time. The measurement was performed three times, and the average value was made into the measured value.

The composition of the artificial urine used in the measurement of the liquid permeation time is as follows.

1.94% by mass of urea, 0.7954% by mass of sodium chloride, 0.11058% by mass of magnesium sulfate (hexahydrate), 0.06208% by mass of calcium chloride (dihydrate), 0.19788 mass% of potassium sulfate, 0.0035 mass% of polyoxyethylene lauryl ether and Ion exchange water (remaining amount).

In the diapers 1 , 1A, and 1B, the core sheet 41 covering the upper side of the skin facing surface side of the absorbent core 40 and the coated core material covering the lower side of the non-skin facing side of the absorbent core 40 are covered. 42 is a sheet of a different body, but it is preferable that at least the coated core material 41 covering the opposite side of the skin is a sheet having a low liquid permeability.

The liquid permeation time of the sheath material having a low liquid permeability is preferably 10 seconds or longer, more preferably 15 seconds or longer, and is preferably 60 seconds or shorter, and more preferably 50 seconds or shorter.

Fig. 8 is a plan view showing an absorbent core of another example of the absorbent core which can be used in the present creation. The absorbent core 40' shown in Fig. 8 can be used, for example, in place of the absorbent core 40 in the diapers 1, 1A, 1B.

In the absorbent core 40', in the same manner as the absorbent core 40 in the diaper 1, the slit 7 extending in the longitudinal direction X in the central portion in the width direction Y of the absorbent core 40 is self-contained. The absorbent body underarm region 40c is formed over the large-area region 40a having a narrow portion 71 in the absorbent body crotch region 40c and a wide portion in the large-area region 40a. 72.

In addition to the slit 7, the absorptive core 40' further includes a second slit 7A and a lateral slit 7B which are different from the slit 7 as an auxiliary slit. Each of the slits and the auxiliary slits penetrates the absorbent core 40' in the thickness direction.

Further, in the absorbent core body 40', the second slits 7A and 7A extending in the longitudinal direction X and the direction Y extending in the longitudinal direction X are formed in the absorbent body crotch region 40c and the large-area region 40a. The plurality of horizontal slits 7B are formed with a plurality of small absorbing portions 75 and 76 surrounded by the slit and the auxiliary slit in the absorbent core 40'. More specifically, each of the second slits 7A is formed on each of both sides of the slit 7 disposed at the center in the width direction Y. The horizontal slit 7B is formed in one or a plurality of strips in the absorbent body crotch region 40c, and a plurality of strips are formed in the large-area region 40a, and the horizontal slits 7B are cross-shapedly intersected with the slit 7 in the center, respectively, and Each of the second slits 7A and 7A located on both sides of the slit 7 in the center is connected. The lateral slit 7B formed in the large-area region 40a includes a cross that also crosses the second slit 7A.

If an absorbent core having an auxiliary slit including the second slit 7A and the lateral slit 7B and having a plurality of small absorbing portions 75 and 76 surrounded by the slit and the auxiliary slit is used, the absorbing underarm region is combined The diffusibility of the liquid in the slit and the auxiliary slit region after 40c and the large-area region 40a is further improved.

In the constituent members of the diaper 1, 1A, 1B and the like, the members used in the absorbent article such as disposable diapers are not particularly limited.

Although the present invention has been described above based on its preferred embodiment, the present invention is not limited to the above embodiment, and can be appropriately changed.

Moreover, the absorbent article of the present invention may be a disposable diaper for children or adults, in addition to a disposable (fixed) disposable diaper for children or adults.

Further, the description of the above-described embodiments and the requirements of only one embodiment can be appropriately applied to other embodiments, and the requirements of the respective embodiments can be It is appropriate to replace each other in the implementation form.

With regard to the above-described embodiment of the present invention, the following supplementary note (disposable diaper) is further disclosed.

<1>

A disposable diaper having a disposable diaper which forms a front sheet of the opposite side of the skin, a non-skin facing outer sheet and an absorbent body between the two sheets, and the absorbent body has An absorbent core having a shape elongated in the longitudinal direction of the disposable diaper, the absorbent core comprising a water-absorbing polymer, wherein the absorbent core has a contracted portion in a plan view shape, and the absorbent core is in the absorbent core When the body is set to the underarm region of the absorber having the same length as the minimum width of the indented portion, a large area and a small area having different areas from each other in the longitudinal direction of the underarm region of the absorber are formed. The absorbent core has a slit extending in the longitudinal direction formed from the crotch region of the absorbent body to the large-area region, and the slit intersects with a center line dividing the entire length of the disposable diaper into two equal portions. 80% or more of the total length of the slit is located closer to the large-area region than the center line, and the width of the large-area region is larger than the width of the underarm region

<2>

A disposable diaper according to <1>, wherein the front sheet has a ridge extending in the longitudinal direction and a groove portion located between the ridges.

<3>

The disposable diaper according to <1> or <2>, wherein the stretchable core and the outer layer sheet have a stretchable sheet stretched in the longitudinal direction, and the stretchable sheet is disposed at least under the armpit The position of the region overlapping the slit.

<4>

The disposable diaper according to any one of <1> to <3>, wherein the absorbent core and the outer layer sheet have a stretchable sheet stretched in a direction intersecting the longitudinal direction, and the stretchable sheet is stretched. The sheet is disposed at least at a position overlapping the slit in the region of the underarm of the absorber.

<5>

The disposable diaper according to any one of <1> to <4> wherein the absorbent body has a coated core material covering the absorbent core, and the absorbent core is located on the non-skin opposing side of the absorbent core. A slit cushion sheet excellent in liquid diffusibility is disposed between the packaged core materials in a state of being overlapped with the slit.

<6>

The disposable diaper according to any one of <1> to <5> wherein the absorbent core comprises a water-absorbing polymer and a pulp fiber, and the ratio of the mass of the pulp fiber to the total mass of the absorbent core is above 50.

<7>

The disposable diaper according to any one of <1> to <6> wherein the absorbent core of the absorbent body is coated with a coated core material having a high diffusibility.

<8>

The disposable diaper according to any one of <1> to <7> wherein the absorbent core is combined with the region of the underarm of the absorbent body and the large-area region to be in the range in which the slit is formed. The basis weight of the inner slit region is higher than the basis weight of the small area region.

<9>

The disposable diaper according to any one of <1> to <8> wherein the surface of the absorbent core on the side of the front sheet is coated with a sheath material having a low liquid permeability.

<10>

A disposable diaper according to any one of <1> to <9>, wherein the absorbent body is The lower region and the large-area region are formed with an auxiliary slit including a second slit extending in the longitudinal direction apart from the slit and a plurality of transverse slits extending in a direction intersecting the longitudinal direction, and the absorption is performed The core body is formed with a plurality of small absorbing portions surrounded by the slit and the auxiliary slit.

<11>

The disposable diaper according to any one of <1> to <10> wherein the slit of the underarm region of the absorbent body disappears after the liquid absorbing and swelling of the absorbent core, and on the other hand, the slit of the large area is It does not disappear after the liquid absorption of the absorbent core.

<12>

The disposable diaper according to any one of <1> to <11> wherein the outer layer sheet has a shape in a plan view from the non-skin opposite side of the diaper having a shape conforming to the outer shape of the diaper as an outer layer sheet. Any one of a resin film containing a liquid impervious property or a non-woven fabric on the non-skin facing side of the resin film.

<13>

The disposable diaper according to any one of <1> to <12, wherein the packaged chip material is any one of a water permeable tissue or a water permeable non-woven fabric.

<14>

The disposable diaper according to any one of <1> to <13> wherein the narrowest portion of the indented portion of the absorbent core is continuously present in a straight line in the longitudinal direction of the absorbent core.

<15>

The disposable diaper of any one of <1> to <13>, wherein the length L2 of the portion of the slit which is located on the side of the larger area than the center line CL is 80 to 95% of the total length L1 of the slit. Further preferably, it is 85 to 95%, and the total length L1 of the slit is 40 to 70%, preferably 50 to 60%, of the total length L of the outer layer.

<16>

The disposable diaper according to any one of <1> to <15, wherein the width W2 of the wide portion of the slit is 1.5 to 4.0 times, preferably 2.0 to 3.0 times, the width W1 of the narrow portion. The width W1 of the narrow portion of the slit is 20 mm or less, preferably 15 mm or less, and 3 mm or more, preferably 5 mm or more, and the width W2 of the wide portion of the slit is 4.5 mm or more, preferably 7.5 mm. The above is 30 mm or less, preferably 20 mm or less, and the difference (W2-W1) between the width W2 of the wide portion and the width W1 of the narrow portion is 2 mm or more, preferably 5 mm or more, and 30 mm or less. It is preferably 20 mm or less.

<17>

The disposable diaper according to any one of <1> to <15, wherein the area of the large-area area is 150% or more, preferably 200% or more, and 500% or less, preferably 500% or less. It is 400% or less, and preferably 150 to 500%, and more preferably 200 to 400%, and the area of the large-area region is 300% or more, preferably 400% or more, of the area of the underarm region of the absorber. 600% or less, preferably 500% or less, the area of the small-area region is 110% or more, preferably 120% or more, and preferably 300% or less, preferably 200% or less, of the area of the underarm region of the absorbent body.

<18>

The disposable diaper according to any one of <1> to <17> wherein the slit penetrates the absorbent core in the thickness direction in any of the underarm region and the large-area region of the absorber. The width of the web portion and the wide portion are uniform over the entire length direction X, and the slit does not extend in a small area as in the present embodiment.

<19>

The disposable diaper according to any one of <1> to <18, wherein the upper surface of the skin of the absorbent core is opposite to the side of the skin and the side of the non-skin opposite side is coated with the core material. a portion overlapping the slit is in a non-joined or separated state, or the upper package core and the lower package core are joined to each other at a portion overlapping the slit, or The slit has a narrow portion having a relatively narrow width and a wide portion having a relatively wide width, and the upper side clad core and the lower side clad core are joined to each other in the narrow portion of the underarm region of the absorbent body.

<20>

The disposable diaper according to any one of <1> to <19> wherein the upper side of the packaged chip material and the front side sheet are caught in the slit, and the like is integrated with the lower side of the packaged chip material and the outer layer sheet. .

<21>

The disposable diaper according to any one of <1> to <20> wherein the absorbent core comprises a fiber assembly containing a fibrous material such as pulp fibers and particles of a water-absorbent polymer held therein as a constituent fiber assembly. As the fibrous material of the body, any of the hydrophilic fibers of any of pulp fibers, rayon fibers, cotton fibers, and cellulose acetate, polyethylene, polypropylene, polyester, and polyamide A condensed fiber, the particle of the water-absorbing polymer comprises sodium polyacrylate, (acrylic acid-vinyl alcohol) copolymer, sodium polyacrylate crosslinked body, (starch-acrylic acid) graft copolymer, (isobutylene-methylene carbonate) An acid anhydride) copolymer and particles of any of the saponified product and polyaspartic acid.

<22>

The disposable diaper according to any one of <1> to <21, wherein a ratio of the mass of the pulp fiber to the total mass of the absorbent core is 40% or more, preferably 50% or more, and 70%. Hereinafter, it is preferably 60% or less, preferably 40% to 70%, more preferably 50% to 60%, and the ratio of the total mass of the pulp fibers and the water-absorbent polymer to the total mass of the absorbent core is 90%. 100%, preferably 95~100%.

<23>

A disposable diaper according to any one of <1> to <22, wherein three-dimensional pleats and leg pleats are disposed.

<24>

The disposable diaper of any one of <1> to <23> which is an unfolding type diaper which is provided with a fastening tape on both side edges of the back side portion, and is fixed on the outer surface of the abdominal side portion. The fixed area of the adhesive strip.

Example

Hereinafter, the present invention will be further described using the examples, but the present creation is not limited by the examples.

[Examples]

An absorbent body having the absorbent core 40 having the shape shown in Fig. 9 (a) was produced. The absorbent core 40 is formed as a mixed fiber deposit of pulp fibers and a water-absorptive polymer, and the ratio of the pulp fibers is set to 50% by mass. As the pulp fiber, a usual fluff pulp is used. The following is used as the sheathing material covering the skin facing side of the absorbent core 40.

Package chip: thin paper with a basis weight of 13.5g/m ²

The dimensions of the respective portions of the absorbent core 40 used in the examples are shown in Table 1.

The absorbent body was sandwiched between the front sheet and the outer sheet, and the two sheets were joined around the absorbent to obtain an evaluation diaper.

Front sheet: hot air non-woven fabric with a basis weight of 36g/m ²

[Comparative example]

A diaper for evaluation was produced in the same manner as in the Example except that the slit was replaced with a uniform width as shown in Fig. 10 (a).

[assessment]

The amount of liquid return and the liquid diffusion area were measured by the following methods, and the results are shown in Table 1.

[return amount]

Each of the evaluation diapers of the examples and the comparative examples was fixed on the flat plate which was inclined at 5° with the large-area region side as the inclined lower end side. 120 g of artificial urine colored in red was divided into three times and 40 g was injected every 10 minutes. After the third injection was completed, after standing for 10 minutes, four pieces of the collagen film (Naturin, trade name COFFIJ) were cut into 70 mm squares. The things of the people. Further, a weight was placed thereon so that the pressure became 7 kPa, and the pressure was applied for 30 seconds. After the pressurization, the collagen membrane was taken out, and the weight of the collagen membrane before and after the pressurization was measured, and the weight of the liquid absorbed by the collagen membrane was measured to determine the amount of liquid returned.

[Liquid diffusion area]

Immediately after the measurement of the amount of liquid return, the film for OHP (Overhead Projector) was placed on the front sheet, and the outline of the portion in which the front sheet was expanded red was written. A dedicated software (Image-ProPlus: manufactured by NIPPON ROPER Co., Ltd.) which can measure the area inside the outline is used, and an image written in the OHP film is taken into a personal computer by a scanner to determine a liquid diffusion area.

As can be seen from the results shown in Table 1, the diaper of the embodiment in which the wide portion 72 of the width of the slit is provided in the large-area region 40a is compared with the diaper of the comparative example in which the slit having the uniform width over the entire length is provided. The liquid diffusion area is large, and the diaper of the embodiment more effectively utilizes the absorption capacity of the absorbent core. Moreover, it can be seen that the diaper of the example has a smaller amount of liquid return than the comparative example, and the diaper of the example is excellent in liquid-repellent property against the skin. Moreover, it is understood that the diaper of the example can utilize the absorption capacity more effectively, and therefore, it is superior in leakproofness to the diaper of the comparative example. Further, in the diaper of the examples and the absorbent core of the diaper of the comparative example, the absorbent core of the diaper has a contraction portion, and therefore the enamel portion has excellent conformability.

Further, in the liquid diffusion area, the outline of the portion in which the front sheet was expanded reddish was written on the film for OHP, and the front sheet was peeled off, and the state of the slit of the absorbent core was observed. As a result, the absorbability of the example was obtained. As shown in Fig. 9(b), the core body disappears in the region of the underarm of the absorber, and on the other hand, in the large area, the wide portion 72 of the slit 7 does not disappear. On the other hand, in the absorbent core of the comparative example, as shown in FIG. 10(b), the slit 7 disappeared in the underarm region and the large-area region of the absorber.

By making the width of the wide portion formed in the large-area region swelled by the absorbent core, the width of the slit can be maintained, and the liquid diffusibility can be maintained when the liquid is repeatedly absorbed.

The disposable diaper of the present invention is preferably such that the slit in the underarm region of the absorbent body disappears after the liquid swell of the absorbent core, and on the other hand, the slit in the large area is sucked by the absorbent core. After the liquid swells, it will not disappear.

Further, the absorbent core was swelled by the following method, and it was observed whether or not the slit in the underarm region and the large-area region of the absorbent body disappeared after the liquid swelled by the absorbent core. Moreover, the disappearance of the slit means that the width of the slit is 0 mm.

<Absorbing conditions of absorbent core>

In each of the evaluation diapers of the examples and the comparative examples, 120 g of artificial urine which was colored in red was placed in a flat plate on a flat plate, and 40 g was injected every 10 minutes. After 5 minutes from the end of the injection, the skin was abutted from the skin contact surface side. The slit was visually observed to see if the slit disappeared.

[Industrial availability]

The disposable diaper of the present invention is excellent in the conformability, leak-proof property, and liquid-repellent prevention property to the skin.

1‧‧‧ diapers

2‧‧‧Front sheet

3‧‧‧ outer sheet

4‧‧‧Acceptor

5‧‧‧Buckle belt

7‧‧‧Slit

9‧‧‧ Leg elastic members

40‧‧‧Absorbable core

40a‧‧‧Large area

40b‧‧‧Small area

40c‧‧‧Absorbing area

41‧‧‧Package

42‧‧‧Package

51‧‧‧Fixed area

61‧‧‧Flexible components

62‧‧‧Sheet for the formation of three-dimensional pleats

71‧‧‧Narrow section

72‧‧‧ wide section

A‧‧‧ ventral side

B‧‧‧Back side

C‧‧‧胯下下

CL‧‧‧Central Line

L‧‧‧Full length

L1‧‧‧ Full length

L2‧‧‧ length

P‧‧‧ contracted part

W1‧‧‧Width

W2‧‧‧Width

X‧‧‧ length direction

Y‧‧‧Width direction

Claims (24)

A disposable diaper having a disposable diaper which forms a front sheet of the opposite side of the skin, a non-skin facing outer sheet and an absorbent body between the two sheets, and the absorbent body has An absorbent core having a shape elongated in the longitudinal direction of the disposable diaper, the absorbent core comprising a water-absorbing polymer, wherein the absorbent core has a contracted portion in a plan view shape, and the absorbent core is in the absorbent core When the body is set to the underarm region of the absorber having the same length as the minimum width of the indented portion, a large area and a small area having different areas from each other in the longitudinal direction of the underarm region of the absorber are formed. The absorbent core has a slit extending in the longitudinal direction formed from the crotch region of the absorbent body to the large-area region, and the slit intersects with a center line dividing the entire length of the disposable diaper into two equal portions. 80% or more of the total length of the slit is located closer to the large-area region side than the center line, and the width of the large-area region is larger than the underarm region of the absorber Width. The disposable diaper according to claim 1, wherein the front sheet has a ridge extending in the longitudinal direction and a groove portion between the ridges. The disposable diaper according to claim 1, wherein the stretchable core and the outer layer sheet have a stretchable sheet stretched in the longitudinal direction, and the stretchable sheet is disposed at least in the underarm region and The position where the slits overlap. The disposable diaper according to claim 1, wherein the absorbent core and the outer layer sheet have a stretchable sheet stretched in a direction crossing the longitudinal direction, and the stretchable sheet is disposed at least in the absorbent body. The position of the underarm region that overlaps with the slit. The disposable diaper according to claim 1, wherein the absorbent body has a coated core material covering the absorbent core, and the absorbent core and the coated core material on the non-skin opposing side thereof are A slit cushion sheet excellent in liquid diffusibility is disposed in a state in which the slits are overlapped. The disposable diaper according to claim 1, wherein the absorbent core comprises a water-absorbing polymer and a pulp fiber, and a ratio of a mass of the pulp fiber to a total mass of the absorbent core is 50% or more. The disposable diaper according to claim 1, wherein the absorbent core of the absorbent body is coated with a coated core material having a high diffusibility. The disposable diaper according to claim 1, wherein a basis weight of the slit region in a region in which the slit is formed in a region where the absorbent core is combined with the underarm region and the large-area region is formed. Above the basis weight of the small area mentioned above. The disposable diaper according to claim 1, wherein the surface of the absorbent core on the side of the front sheet is covered with a sheath material having a low liquid permeability. The disposable diaper according to claim 1, wherein the absorbent body has a second slit extending in the longitudinal direction apart from the slit and extending in a direction crossing the longitudinal direction in the region of the underarm of the absorbent body and the large-area region. The auxiliary slit of the plurality of horizontal slits is formed with a plurality of small absorbing portions surrounded by the slit and the auxiliary slit in the absorbent core. The disposable diaper according to claim 1, wherein the slit of the absorbent region of the absorbent body is swollen by the liquid absorbing and swelling of the absorbent core, and the slit of the large-area region is applied to the absorbent core. After the liquid is swollen, it will not disappear. The disposable diaper according to claim 1, wherein the outer layer sheet has a shape in a plan view from the non-skin opposing side of the disposable diaper having a shape conforming to the outer shape of the disposable diaper as the outer sheet A resin film containing a liquid impervious property, or a non-woven fabric layer on the non-skin facing side of the resin film Either. The disposable diaper according to claim 1, wherein the absorbent body has a coated core material covering the absorbent core, and the coated core material is a water-permeable tissue or a water-permeable nonwoven fabric. The disposable diaper according to claim 1, wherein the portion of the absorbent core having the narrowest portion of the innermost portion of the absorbent core is continuously continuous in the longitudinal direction of the absorbent core. The disposable diaper according to claim 1, wherein the length (L2) of the portion of the slit which is located on the side of the larger area than the center line (CL) is 80 to 95% of the total length (L1) of the slit, The total length (L1) of the slit is 40 to 70% of the total length (L) of the outer layer sheet. A disposable diaper according to claim 1, wherein said slit has a narrow portion having a relatively narrow width and a wide portion having a relatively wide width, and a width (W2) of said wide portion is a width of said narrow portion (W1) 1.5 to 4.0 times, the width (W1) of the narrow portion is 20 mm or less and 3 mm or more, and the width (W2) of the wide portion is 4.5 mm or more and 30 mm or less, and the width of the wide portion is further The difference (W2-W1) between (W2) and the width (W1) of the narrow portion is 2 mm or more and 30 mm or less. The disposable diaper of claim 1, wherein the area of the large area is 150 to 500% of the area of the small area, and the area of the large area is more than 300% of the area of the area under the absorber. % or less, the area of the small area is 110% or more and 300% or less of the area of the underarm area of the absorber. The disposable diaper according to claim 1, wherein the slit has a narrow portion having a relatively narrow width and a wide portion having a relatively wide width, and the slit is in the lower region of the absorbent body and the large-area region. One of the above-mentioned absorbent cores penetrates in the thickness direction, the above-mentioned narrow portion and the upper portion The width portion is uniform in width over the entire length direction of the absorbent core, and the slit does not extend over the small area. The disposable diaper according to claim 1, wherein the upper side of the skin on the opposite side of the skin of the absorbent core and the side of the non-skin facing side are covered with the slit. Non-joined or separated from each other, or the upper side clad chip and the lower side clad material are joined to each other at a portion overlapping the slit, or the slit has a narrow portion having a relatively narrow width and a relatively wide width In the wide portion, the upper side clad core material and the lower side clad core material are joined to each other in the narrow portion of the underarm region of the absorber. The disposable diaper according to claim 1, which has a side cladding material on the opposite side of the skin of the absorbent core and a side cladding material on the side opposite to the non-skin opposite side, the upper side of the packaged chip and the front side. The sheet is caught in the slit, and is integrated with the lower package core material and the outer layer sheet. The disposable diaper according to claim 1, wherein the absorbent core comprises a fiber assembly containing a fiber material such as pulp fibers and particles of a water-absorbent polymer held therein, and as a fiber material constituting the fiber assembly, pulp fibers are used. Any one of the hydrophilic fibers of any of the fibers, the cotton fiber, the cellulose acetate, the polyethylene fiber, the polypropylene, the polyester, the polyamine, the water-absorbing polymerization The particles of the material include sodium polyacrylate, acrylic acid-vinyl alcohol copolymer, sodium polyacrylate crosslinked body, starch-acrylic acid graft copolymer, isobutylene-maleic anhydride copolymer and saponified product thereof, polyaspartic acid Particles of any of them. The disposable diaper according to claim 6, wherein the ratio of the mass of the pulp fibers to the total mass of the absorbent core is 40% or more and 70% or less, pulp fibers and water absorption. The ratio of the total mass of the polymers to the total mass of the absorbent core is from 90 to 100%. A disposable diaper according to claim 1, wherein three-dimensional pleats and leg pleats are disposed. The disposable diaper according to claim 1, wherein the detachable diaper is provided with a fastening tape on both side edges of the back side portion, and a fixing region for fixing the fastening tape is provided on the outer surface of the abdominal side portion.