WO2015076136A1

WO2015076136A1 - Disposable diaper

Info

Publication number: WO2015076136A1
Application number: PCT/JP2014/079737
Authority: WO
Inventors: 亜由香南崎
Original assignee: 花王株式会社
Priority date: 2013-11-21
Filing date: 2014-11-10
Publication date: 2015-05-28
Also published as: CN206063313U; RU170417U1; JP2015100412A; JP5848312B2; TWM513015U

Abstract

This disposable diaper (1) is provided with a front sheet (2) which forms a skin-facing surface, an outer sheet (3) which forms a non-skin-facing surface, and an absorbent body (4) disposed between both sheets. The absorbent body (4) has an absorbent core (40) that is longer in a lengthwise direction (X) corresponding to the front-back direction of a wearer, and the absorbent core (40) contains a water-absorbing polymer. The absorbent core (40) has a large-area region (40a) and a small-area region (40b) which have different surface areas and which are located to the front and the back respectively when an absorbent-body crotch region (40c) is positioned in a narrowed portion. In the absorbent core (40), a slit (7) extending in the lengthwise direction (X) is formed from the absorbent-body crotch region (40c) to the large-area region (40a). The slit (7) intersects the center line (CL) of the outer sheet (3), and at least 80% of the whole length of the slit (7) is located on the large-area region (40a) side of the center line (CL). The width (W2) of the slit (7) in the large-area region (40a) is larger than the width (W1) thereof in the absorbent-body crotch region (40c).

Description

Disposable diapers

The present invention relates to a disposable diaper.

From the viewpoint of improving fit, a disposable diaper absorbent body having a shape in which a portion disposed on the wearer's crotch portion is confined is known. However, it is difficult to secure a sufficient absorption capacity in the crotch part by making the absorbent body constricted, so that liquid leakage from the crotch part and so-called liquid return that the absorbed liquid returns to the wearer's skin Is likely to occur.
As a technique for providing a slit in the absorbent core constituting the absorber, Patent Document 1 relates to an absorbent structure having an upper absorbent layer and a lower absorbent layer, and has an opening in which the lower absorbent layer extends in the front-rear direction. An absorbent structure is described in which an upper absorbent layer covers the rear end of the opening. Patent Document 2 describes that a slit having an opening on the non-skin facing surface side is formed in the absorbent core so as to extend in the longitudinal direction of the absorbent core.

JP2012-040260A JP 2012-143542 A

In Patent Document 1, urine or the like diffuses in the front-rear direction at the opening of the lower absorbent layer, and urine or the like diffused toward the rear absorbent structure side of the opening is covered with the upper absorbent layer at the rear end of the opening. It is described that it is accommodated in a pocket formed. However, the opening of the lower absorbent layer is formed only in the vicinity of the central portion of the absorbent article, and since the portion located on the front side is longer, the liquid tends to stay near the crotch. In addition, since the width of the opening is constant, if the opening is narrow, the entire opening is closed during liquid absorption, and the function of diffusing liquid in the front-rear direction is likely to be impaired. If the width is widened, the absorption capacity in the crotch part is lowered, and there is a risk that leakage tends to occur.
The slit in Patent Document 2 extends long in the front-rear direction of the absorbent core. However, the absorbent core is asymmetrical in the front-rear direction so that the absorption capacity is different between the front and rear, and the slit width is varied to absorb the slit. There is no mention of effectively guiding to high capacity areas.

The present invention relates to a vertically long disposable diaper provided with a surface sheet that forms a skin facing surface, an outer layer sheet that forms a non-skin facing surface, and an absorbent body positioned between both sheets. The absorbent body has an absorbent core having a shape elongated in the longitudinal direction of the disposable diaper, and the absorbent core contains a water-absorbing polymer. The absorbent core has a constricted portion in a plan view shape, and when the absorbent inseam region having the same length as the minimum width of the constricted portion is set in the absorbent core, Before and after the absorber crotch region, a large area region and a small area region having different areas are provided, and a slit extending in a longitudinal direction is formed in the absorbent core from the absorber crotch region to the large area region. It is formed over. The slit intersects a central line that bisects the overall length in the longitudinal direction of the disposable diaper, and 80% or more of the total length of the slit is located on the large area region side from the central line, and the large area region Is wider than the width in the crotch region.

FIG. 1 is a partially cutaway plan view showing a disposable diaper according to an embodiment of the present invention. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is an explanatory diagram of an absorber crotch region, a large area region, a small area region, and a slit region. 4 is a cross-sectional view showing a cross section (cross section taken along line III-III in FIG. 1) in the vicinity of the slit of the large-area region of the disposable diaper in FIG. Fig.5 (a) and FIG.5 (b) are perspective views which respectively show the example of the surface sheet preferably used for the disposable diaper of this invention. Fig.6 (a) is a schematic top view which excludes the sheet | seat and elastic member which comprise the skin opposing surface of the disposable diaper which is other embodiment of this invention, FIG.6 (b) is FIG. It is FIG. 2 equivalent drawing of the disposable diaper shown to a). FIG. 7 is a view corresponding to FIG. 2 of a disposable diaper that is 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 top view which shows the absorptive core in the absorber used for the Example, FIG.9 (b) is a top view which shows the state after the liquid absorption swelling of the absorptive core. Fig.10 (a) is a top view which shows the absorptive core in the absorber used for the comparative example, FIG.10 (b) is a top view which shows the state after the liquid absorption swelling of the absorptive core. FIG. 11 is a diagram showing an instrument used in the liquid permeability test.

Detailed Description of the Invention

The present invention relates to a disposable diaper having excellent crotch fit, leakage prevention, and liquid return prevention to the wearer's skin.

Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings.
A disposable diaper 1 (hereinafter also simply referred to as diaper 1) as an embodiment of the present invention includes a liquid-permeable surface sheet 2 and a non-skin facing surface that form a skin facing surface, as shown in FIGS. And a liquid-retaining absorbent 4 positioned between the two

sheets

2 and 3. The skin facing surface is a surface directed toward the wearer's skin when the diaper is worn, and the non-skin facing surface is a surface directed toward the opposite side of the wearer's skin when the diaper is worn. In the present invention, the longitudinal direction of the diaper is also referred to as the abdomen side (front side) and back side (rear side) of the wearer, that is, the front-rear direction.

The diaper 1 is a direction corresponding to the longitudinal direction of the wearer, more specifically, the longitudinal direction X, which is the direction that coincides with the wearer's longitudinal direction when worn, and the diaper 1 is expanded in a flat shape as shown in FIG. In the state, it has a width direction Y intersecting the longitudinal direction X.
The diaper 1 has, in the longitudinal direction X, an abdominal side A that is disposed on the abdomen of the wearer when worn, a back side B that is disposed on the back of the wearer when worn, and a crotch of the wearer when worn. The crotch part C is arranged. Moreover, the diaper 1 of this embodiment is a deployment type disposable diaper, as shown in FIG. 1, and the

fastening tapes

5 and 5 are provided in the both-sides edge part of the back side part B, and the outer side of the abdominal side part A is provided. A landing zone 51 for

fastening fastening tapes

5 and 5 is provided on the surface. Further, the diaper 1 has both side edges of the crotch portion C formed in an arc shape, and has a shape in which a central portion in the longitudinal direction X is constricted in a plan view.

The outer layer sheet 3 is a sheet that forms a non-skin facing surface (outer surface) of the diaper 1, and the plan view shape of the outer layer sheet 3 viewed from the non-skin facing surface side of the diaper 1 is the outer shape of the diaper 1. It has a matching shape. As the outer layer sheet 3, for example, a sheet made of a liquid hardly permeable resin film or a sheet obtained by laminating and bonding a nonwoven fabric on the non-skin facing surface side of the resin film is preferably used. The outer layer sheet 3 may be formed by connecting two or more sheets in the longitudinal direction of the diaper 1.
The top sheet 2 is made of various known liquid-permeable sheets. As shown in FIGS. 1 and 2, the surface sheet 2 in the present embodiment is narrower than the outer layer sheet 3, and is disposed on the central portion in the width direction of the outer layer sheet 3. Between the surface sheet 2 and the outer layer sheet 3, an absorbent body 4 having a long shape in the longitudinal direction X of the diaper 1 is interposed.

The absorbent body 4 includes an absorbent core 40 made of a fiber assembly made of a fiber material such as pulp fiber and water-absorbing polymer particles held therein, and

core wrap sheets

41 and 42 covering the absorbent core 40. Consists of. As the

core wrap sheets

41 and 42, various known ones can be used. For example, a water-permeable thin paper such as tissue paper or a water-permeable nonwoven fabric is preferably used. The absorbent core 40 has substantially the same planar view shape as the absorbent body 4. The

core wrap sheets

41, 42 have both ends in the longitudinal direction X at the same positions as the

longitudinal ends

40a, 40b of the absorbent core 40 or at positions slightly extending in the longitudinal direction X from the both

ends

40a, 40b. Yes.

As shown in FIGS. 1 and 2, leg elastic members 9 are arranged in an extended state on both sides of the crotch part C of the diaper 1. One or a plurality of leg elastic members 9 are arranged on both sides of the diaper 1 in the longitudinal direction. The leg elastic member 9 is fixed between the outer layer sheet 3 and the sheet material 62 for forming the three-

dimensional gathers

6 and 6 via an adhesive. The leg elastic member 9 contracts to form a leg gather in the leg part arranged around the wearer's leg. Moreover, the sheet | seat material 62 for solid gathering which has the elastic member 61 is distribute | arranged to the both sides of the longitudinal direction in the diaper 1, and when wear | wearing a diaper, by the contraction of the elastic member 61, toward a wearer's skin A standing three-dimensional gather 6 is formed.

In the diaper 1 of this embodiment, the absorptive core 40 has the part P constricted in planar view shape, as shown in FIG.
The constricted part P is a part sandwiched between a part wider than the part in the longitudinal direction of the absorbent core 40 along the longitudinal direction X of the diaper 1.

The “absorber crotch region” in the present invention is set in the constricted portion of such an absorbent core as a region having the same length as the minimum width of the constricted portion.
The “absorber crotch region” in the present invention will be described more specifically. In addition, 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. 3A, the length b in the longitudinal direction X is the width a (minimum width) of the narrowest portion with the narrowest portion in the constricted portion P of the absorbent core 40 as the center. ) Is the absorber crotch region 40c.
When the narrowest part is continuously present in a straight line in the longitudinal direction X of the absorbent core 40, the absorbent crotch region 40c is set as follows.
When the length c of the range in which the narrowest width continuously exists linearly in the X direction is equal to or smaller than the width a (minimum width) of the narrowest portion (c ≦ a), the length c A region where the length b in the longitudinal direction X is the same as the width a (minimum width) of the narrowest portion is defined as an absorber crotch region 40c. On the other hand, as shown in FIG. 3B, when the length c of the range where the narrowest width is continuously present is longer than the width a (minimum width) of the narrowest portion (c> a). The entire region where the narrowest width continuously exists is defined as an absorber crotch region 40c.

In the diaper 1 of the present embodiment, the constricted portion P of the absorbent core 40 is formed in the crotch portion C of the diaper 1 whose both side edges are concave. In addition, a range of the same length as the minimum width a of the constricted portion P of the absorbent core in the longitudinal direction of the diaper 1 around the minimum width portion (the portion having the minimum width) in the crotch part C of the diaper 1 (diaper When the range is set, a portion having a minimum width in the constricted portion P of the absorbent core 40 exists in the range. In addition, a range of the same length as the minimum width a of the constricted portion P of the absorbent core in the longitudinal direction of the diaper 1 around the center line CL that bisects the overall length L in the longitudinal direction of the diaper 1 (diaper Even when the (range) is set, a portion having the smallest width in the constricted portion P of the absorbent core 40 exists in the range.

The absorbent core 40 in the present embodiment includes a large area region 40a and a small area region 40b having different areas before and after the absorber crotch region 40c defined as described above in the longitudinal direction X. ing. As shown in FIG. 3, the areas of the large area region 40 a and the small area region 40 b are flat areas in a state where the absorbent core is flattened, and each area includes the area of the slit 7 portion. .
The absorbent core 40 shown in FIG.1 and FIG.3 (b) has the large area area | region 40a by the side of the stomach side A with respect to the absorber crotch area | region 40c, and has the small area area | region 40b by the back side part B side. Have. Therefore, it is suitable for infants for older children after the month when the amount of urination is relatively increased. On the other hand, the absorptive core 40 in the disposable diaper of this invention has the large area area | region 40a on the back side part B side with respect to the absorber crotch area | region 40c, and the small area area | region 40b on the abdominal side part A side. Also good. In that case, it becomes suitable for infants of a low age with a large amount of excretion of liquid stool.

The absorbent core 40 according to the present embodiment will be further described. In the absorbent core 40, as shown in FIG. 1, the slit 7 extending in the longitudinal direction X is formed from the absorber crotch region 40c to the large area region 40a. Has been. The slit 7 intersects the central line CL that bisects the total length L in the longitudinal direction of the diaper, and 80% or more of the total length L1 of the slit 7 is located on the large area region 40a side from the central line CL. Yes.
In the present invention, the slit is a portion formed in a part of the absorbent core where the material for forming the absorbent core does not exist, and has a shape that is long in one direction. The slit may have an absorbent core forming material, which is an absorbent core forming material, having a low basis weight. However, it is preferable that the slit penetrates the absorbent core. Moreover, when the absorbent core forming material is present at a low basis weight in the slit portion, the basis weight may be 15% or less of the basis weight of another portion of the absorbent core (for example, a portion adjacent to the slit). Preferably, it is 5% or less.
The slit 7 and the second slit 7A, which will be described later, have a shape that is long in the longitudinal direction of the absorbent core, which is the same as the longitudinal direction of the diaper 1. The lateral slit 7B, which will be described later, is a longitudinal direction of the absorbent core. It has a long shape in the direction Y that intersects with.

The absorber crotch region 40c has a slit 7 that intersects the center line CL, and the slit 7 extends to the large area region 40a, and 80% or more of the total length L1 is larger than the center line CL on the large area region 40a side. The urine and liquid stool (hereinafter referred to as urine) excreted on the absorber crotch region 40c having a small width and a small absorption capacity are efficiently diffused over a wide area of the large area region 40a. Can be absorbed. In particular, since the slit 7 has a width W2 in the large area region 40a wider than a width W1 in the absorber crotch region 40c, even if the large area region 40a absorbs liquid and the water absorbing polymer swells, at least, The opening state of the slit 7 in the large area 40a is maintained [see FIG. 9], and the liquid diffusion function by the slit 7 described above is maintained well.
According to the disposable diaper 1 of the present embodiment, the high absorption capacity of the large area 40a in the absorbent core 40 can be effectively utilized, and liquid leakage from the crotch can be maintained while maintaining good fit in the crotch. Moreover, the liquid return which returns to the state which the absorbed liquid touches a wearer's skin can also be suppressed effectively.

From the viewpoint of ensuring such an effect, the absorbent core 40 preferably satisfies one or more of the following conditions.
In the slit 7, the length L2 (see FIG. 1) of the portion located on the large area area 40a side from the center line CL is preferably 80 to 95% of the total length L1 (see FIG. 1), more preferably 85-95%.
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 in 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. Exists mainly in the absorber crotch region 40c, and the wide portion 72 exists mainly in the large area region 40a.
In the slit 7 according to the present embodiment, the boundary between the narrow portion 71 and the wide portion 72 is located closer to the large area 40a than the boundary between the absorber crotch region 40c and the large area 40a. And the boundary of the wide part 72 may be in the same position as the boundary of the absorber crotch region 40c and the large area region 40a.

Further, in the slit 7, the width W2 of the wide portion 72 is preferably 1.5 to 4.0 times, more preferably 2.0 to 3.0 times the width W1 of the narrow portion 71.
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 preferably 3 mm or more, more 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 preferably 30 mm or less, more 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 preferably 30 mm or less, more preferably 20 mm. It is as follows.

The area of the large area region 40a is preferably 150% or more, more preferably 200% or more, preferably 500% or less, more preferably 400% or less of the area of the small area region 40b. Preferably, it is 150 to 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 preferably 600% or less, more preferably 500% or less, of the area of the absorber crotch region 40c. The area of the small area region 40b is preferably 110% or more, more preferably 120% or more, and preferably 300% or less, more preferably 200% or less, of the area of the absorber crotch region 40c.

Moreover, as shown in FIG.2 and FIG.4, the slit 7 in this embodiment has penetrated the absorptive core 40 in the thickness direction in any of the absorber crotch region 40c and the large area region 40a. Further, the narrow width portion 71 and the wide width portion 72 have a uniform width along the longitudinal direction X, respectively. Moreover, it is preferable that the slit 7 does not extend to the small area region 40b as in the present embodiment.
2, the upper core wrap sheet 41 located on the skin facing surface side of the absorbent core 40 and the lower core wrap sheet 42 located on the non-skin facing surface side overlap with the slit 7. In FIG. 3, the upper core wrap sheet 41 and the lower core wrap sheet 42 may be joined to each other at a portion overlapping the slit 7 as shown in FIG. However, the upper core wrap sheet 41 and the lower core wrap sheet 42 are preferably joined to each other at the narrow portion 71 in the absorber crotch region 40c from the viewpoint of diffusibility of excrement, and through the slit 7. The upper core wrap sheet 41 and the lower core wrap sheet 42 are joined together at the wide portion 72 in the large area 40a. From the viewpoint of diffusivity. In the example shown in FIG. 4, the upper core wrap sheet 41 and the top sheet 2 are recessed into the slit 7, and they are integrated with the lower core wrap sheet 42 and the outer layer sheet 3.

As the surface sheet 2, various sheets conventionally used as a surface sheet of disposable diapers can be used without particular limitation, and for example, a non-woven fabric by various production methods of a perforated film or a single layer or a multilayer structure can be used. However, as the surface sheet 2, as shown in the

surface sheets

2A and 2B shown in FIGS. 5A and 5B, the surface sheet 2 is positioned between the flange portion 21 and the

flange portions

21 and 21 extending in the longitudinal direction X of the diaper. It is preferable to use the one having the groove portion 22 because the diffusion of the urine excreted on the absorber crotch region 40c to the large area region 40a is further promoted.

The surface sheet 2A shown in FIG. 5 (a) is obtained by giving a three-dimensional shape to a nonwoven fabric having a single layer or a multilayer structure, and the cross-sectional shape in the width direction Y intersecting the longitudinal direction X of the diaper is the upper and lower surfaces. A continuous wave shape is formed, and a cavity is generated in the flange portion 21. In the surface sheet 2A, it is preferable that the lower surface of the groove portion 22 is bonded to a sheet disposed below the groove portion 22 such as a core wrap sheet 41 or a second sheet disposed between the surface sheet 2 and the core wrap sheet. As such a surface sheet 2A, for example, those described in JP-A-1996-302555, JP-A-1996-246321, and JP-A-2004-275296 can be used.
In the topsheet 2B shown in FIG. 5B, the cross-sectional shape in the width direction Y intersecting the longitudinal direction X of the diaper has a continuous wave shape on the top surface, while the bottom surface is substantially flat, and the inside of the collar portion 21 is It is solid. As such a surface sheet 2B, for example, those described in JP 2009-299227 A, JP 2001-095845 A, and JP 2008-025079 A can be used.

The disposable diaper of the present invention is stretchable in the longitudinal direction X of the diaper or in the direction Y intersecting the longitudinal direction between the absorbent core 40 and the outer layer sheet 3 as in the disposable diaper 1A shown in FIG. It is also preferable that the sheet 8 is provided and the stretchable sheet 8 is disposed at a position overlapping the slit 7 in at least the absorber crotch region 40c. In the disposable diaper 1 A, the stretchable sheet 8 is disposed between the lower core wrap sheet 42 that covers the non-skin facing surface side of the absorbent core 40 and the outer layer sheet 3. About the disposable diaper 1A, the point which is not demonstrated in particular is the same as that of the diaper 1 mentioned above.

As the stretchable sheet 8, a material that stretches in the longitudinal direction X of the diaper is disposed, and the absorbent body 4 and the absorbent core 40 are contracted in the longitudinal direction of the diaper, whereby the absorbent body 4 and the absorbent core 40. The absorption capacity per unit area can be increased. Thereby, the liquid leak from the crotch part C etc. can be prevented more reliably. From the viewpoint of ensuring such an effect more reliably, the stretchable sheet 8 is preferably joined to at least one of the upper and lower members sandwiching the stretchable sheet 8 in the longitudinal direction X. From the same point of view, the stretchable sheet 8 is preferably arranged so as to overlap the slit 7 from the absorber crotch region 40c to the large area region 40a as shown in FIG. 6 (a). . As the joining means, various known methods such as an adhesive can be adopted, and the joining may be wholly joined or partially joined in a specific pattern.

On the other hand, when the stretchable sheet 8 is arranged to stretch in the direction Y intersecting the longitudinal direction X of the diaper, and preferably in the direction Y perpendicular to the longitudinal direction X, the absorbent body 4 and the absorbent core 40 are provided. By contracting in the width direction of the diaper, the fit of the crotch part C and the like to the wearer's skin can be improved. In addition, wrinkles extending in the longitudinal direction X are generated in the top sheet 2 and the diffusibility of the liquid in the longitudinal direction X is improved, so that urine or the like stays in the crotch part C where the absorber crotch region 40c exists. Can be more reliably prevented.
From the viewpoint of achieving such an effect, the stretchable sheet 8 is preferably joined to at least one of the upper and lower members sandwiching the stretchable sheet 8 in the width direction Y. From the same point of view, the stretchable sheet 8 is preferably arranged so as to overlap the slit 7 from the absorber crotch region 40c to the large area region 40a as shown in FIG. 6 (a). . As the joining means, various known methods such as an adhesive can be adopted, and the joining may be wholly joined or partially joined in a specific pattern.

As the stretchable sheet 8, an elastic sheet made of polyurethane or an elastomer can be used. For example, stretchable sheets such as stretchable sheets described in JP2013-189745A, JP2013-81715A, and the like can be used. It is preferable from the viewpoint of suppressing liquid leakage from the crotch part that is thin at the time and is in close contact with the wearer's body. Moreover, as the elastic sheet 8, it is also preferable to use a sheet having elasticity in both the longitudinal direction X of the diaper and its crossing direction.

In the disposable diaper of the present invention, like the disposable diaper 1B shown in FIG. 7, the absorbent body 4 has

core wrap sheets

41 and 42 that wrap the absorbent core 40, and the absorbent core 40 and its non-skin facing It is also preferable that a slit underlay sheet 43 excellent in liquid diffusibility is disposed in a state of being overlapped with the slit 7 between the core wrap sheet 42 positioned on the surface side. The liquid high diffusibility sheet 43 in the disposable diaper 1B has the same arrangement range in the plan view of the absorbent core 40 as the elastic sheet 8 in the disposable diaper 1A. They are arranged so as to overlap with the slits 7 extending from the region 40c to the large area region 40a.

Regarding the slit underlay sheet 43, “excellent in liquid diffusibility” means that the Klem water absorption obtained by the “water absorption test method by the Krem method of paper and paperboard” defined in JIS P8141 is 100 mm or more in 10 minutes, It means that it exists in the range of 150 mm or more especially.

Like the disposable diaper 1B, by disposing the slit underlay sheet 43 so as to cover the slit 7 portion on the non-skin facing surface side of the absorbent core 40, the diffusibility of the liquid in the longitudinal direction X through the slit 7 is improved. This further improves liquid leakage and liquid return more reliably.
Examples of the slit underlay sheet 43 include a synthetic fiber described in JP-A No. 2004-298384 and a nonwoven fabric made of both synthetic fibers and cellulosic fibers, or a non-woven fabric made of beaten pulp and regenerated cellulose described in JP-A-2013-150799. Etc. can be used.

As described above, the absorbent core 40 in the

diapers

1, 1 A, 1 B includes a fiber assembly made of a fiber material such as pulp fiber and water-absorbing polymer particles held by the fiber assembly. As the fiber material constituting the fiber assembly, hydrophilic fibers such as pulp fibers, rayon fibers, cotton fibers, and cellulose acetate, polyolefin fibers such as polyethylene and polypropylene, and condensation fibers such as polyester and polyamide can be used. . As the water-absorbing polymer particles, for example, various water-absorbing polymers conventionally used in disposable diapers can be used without particular limitation, such as sodium polyacrylate, (acrylic acid-vinyl alcohol) copolymer, Examples thereof include cross-linked sodium polyacrylate, (starch-acrylic acid) graft copolymer, (isobutylene-maleic anhydride) copolymer and saponified product thereof, particles made of polyaspartic acid, and the like.
The absorbent core 40 is preferably obtained through a fiber-laying step in which the fiber material supplied in an air flow is sucked and deposited in a fiber-shaped concave portion having a predetermined shape. It is more preferable to manufacture the product by supplying it in a flow and depositing it in a predetermined deposition state such as a mixed state. The slit 7 described above can be easily formed by providing a non-breathable convex portion or the like having a shape corresponding to the slit 7 in the concave portion for stacking of the stacking drum.

The absorbent core according to the present invention includes a water-absorbing polymer and pulp fibers, and the ratio of the mass of the pulp fibers to the total mass of the absorbent core is 40% or more. Is preferable from the viewpoint of becoming a gel and making it difficult to cause a phenomenon called gel blocking which inhibits the subsequent liquid absorption. The ratio of the mass of the pulp fiber to the total mass of the absorbent core is more preferably 50% or more, preferably 70% or less, more preferably 60% or less, and more specifically, preferably 40 to 70%, more preferably 50 to 60%. The ratio of the total mass of pulp fibers and water-absorbing polymer to the total mass of the absorbent core is preferably 90 to 100%, more preferably 95 to 100%.

Further, in the absorbent body 4, it is preferable that the absorbent core 40 is covered with

core wrap sheets

41 and 42 having high diffusibility because the diffusibility of the liquid through the slit 7 can be further improved. Here, regarding the core wrap sheet, high diffusibility means that the water absorption amount of Klem measured by the following method is preferably 0.2 g / 30 sec · 15 mm or more, more preferably 0.2 to 0.4 g / 30 sec · 15 mm. Means a range.

[Measurement method of water absorption by Clem]
The sheet to be measured (thin paper) is allowed to stand for 12 hours in an environment with a room temperature of 23 ° C. ± 2 ° C. and a relative humidity of 50% RH ± 2% so as to be in a constant state. A rectangular shape having a size of 150 mm for MD and 15 mm for CD is cut out from the moisture-conditioned sheet, and the cut out rectangular shape is used as a sample. A straight line (marked line) parallel to the short side is drawn with a pencil at a position 5 mm inward in the longitudinal direction from one short side of the sample. Then, the sample is suspended at the bottom of the electronic balance so that the long side of the sample is vertical, and the sample is quickly put into the measuring solution (saline) while maintaining the suspended state up to the marked line. . The sample is hung so that the marked line (straight line drawn with a pencil) is close to the measurement solution. Then, an increase in the weight of the sample 30 seconds after the sample is put in the measurement solution is measured with an electronic balance, and the measured value is defined as a Krem water absorption (g / 30 sec. 15 mm). The higher the Krem water absorption, the higher the rating. The electronic balance is electrically connected to a personal computer on which a commercially available electronic balance data capturing software (trade name RsCom Ver2.40: manufactured by A & D Co., Ltd.) is installed. The change in weight of the sample can be recorded.

In the

diapers

1, 1 A, 1 B described above, the upper core wrap sheet 41 that covers the skin facing surface side of the absorbent core 40 and the lower core wrap sheet that covers the non-skin facing surface side of the absorbent core 40. 42 is a separate sheet, but at least the core wrap sheet 42 covering the non-skin facing surface side is preferably a “highly diffusible” sheet here.

Moreover, the absorptive core 40 in this invention is the grammage of the slit area | region 40s (refer FIG. 3) which is the range in which the slit 7 is formed in the area | region which combined the absorber crotch area 40c and the large area area | region 40a. It is preferable that the amount is higher than the basis weight of the small area region 40b, because the absorption capacity of the region where the diffusibility of the liquid is increased due to the formation of slits can prevent the leakage and suppress the liquid return. Here, the basis weight of the slit area 40s and the small area area 40b is calculated by dividing the mass by the area for each area. The mass is the total mass of all components constituting the absorbent core. The area of the slit region 40s includes the area of the slit 7 portion.

In the absorbent core of the present invention, the surface sheet side surface is preferably covered with a core wrap sheet having low liquid permeability. By increasing the time until the urine etc. supplied to the part overlapping the slit is absorbed from the inner wall surface of the slit to the absorbent core, the urine etc. is easily diffused in the longitudinal direction X, and the absorption capacity of the absorber Can be used effectively. Here, regarding the core wrap sheet, the low liquid permeability means that the liquid permeation time measured by the following method is 10 seconds or longer, preferably 15 seconds or longer.

[Measurement method of liquid permeation time]
As shown in FIG. 11, two cylinders 91 and 92 having an inner diameter of 35 mm open at the upper and lower ends are arranged up and down with the axes of both cylinders 91 and 92 aligned, and a metal mesh net having a diameter of 55 mm, A 40 mm square cut sample piece and a piece of filter paper having a diameter of 101 mm and a diameter of 101 mm are set on the upper side and sandwiched between upper and lower cylinders 91 and 92. At this time, it is preferable that the upper and lower cylinders 91 and 92 are connected by fitting the clip 93 to an annular flange portion provided at the lower end of the upper cylinder 91 and the upper end of the lower cylinder 92. Reference numeral 94 denotes a rubber packing having a through hole having the same diameter and the same shape as the inner diameters of the cylinders 91 and 92. In this manner, with the cut sample pieces sandwiched and fixed between the upper and lower cylinders 91 and 92, 40 g of artificial urine indicated by the symbol W in FIG. The supplied artificial urine passes through the cut sample piece, passes through the lower cylinder 92, and flows down from the lower end of the cylinder 92. Observe the time-dependent change in the weight of the artificial urine flowing down from the lower cylinder 92 using a weight measuring means such as an electronic balance, and measure the time from the start of supplying the artificial urine until the mass reaches 20 g, This time is defined as the liquid permeation time. In multiple measurements, a new cut sample piece is prepared each time. The measurement is performed three times, and the average value is taken as the measured value.
The composition of the artificial urine used for measuring 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 (septahydrate), 0.06208% by mass of calcium chloride (dihydrate), 0.19788% by mass of potassium sulfate , Polyoxyethylene lauryl ether 0.0035 mass% and ion-exchanged water (remaining amount).

In the

diapers

1, 1 A, 1 B described above, the upper core wrap sheet 41 that covers the skin facing surface side of the absorbent core 40 and the lower core wrap sheet that covers the non-skin facing surface side of the absorbent core 40. 42 is a separate sheet, but at least the core wrap sheet 41 covering the skin facing surface side is preferably the “low liquid permeability” sheet here.
The core wrap sheet having low liquid permeability has a liquid permeation time of preferably 10 seconds or longer, more preferably 15 seconds or longer, and preferably 60 seconds or shorter, more preferably 50 seconds or shorter.

FIG. 8 is a plan view of an absorbent core showing another example of the absorbent core that can be employed in the present invention. 8 can be used in place of the absorbent core 40 in the

diapers

1, 1A, 1B described above, for example.
In the absorbent core 40 ′, similarly to the absorbent core 40 in the diaper 1 described above, a vertically long slit 7 extending in the longitudinal direction X is formed at the center of the absorbent core 40 in the width direction Y, and the absorber crotch region 40 c. The slit 7 has a narrow portion 71 in the absorber crotch region 40c and a wide portion 72 in the large area region 40a.
In addition to the slit 7 described above, the absorbent core 40 ′ further includes a second slit 7 A and a lateral slit 7 B as auxiliary slits separately from the slit 7. These slits and auxiliary slits both penetrate the absorbent core 40 'in the thickness direction.
Further, in the absorbent core 40 ', the absorbent crotch region 40c and the large area region 40a are provided with

second slits

7A and 7A extending in the longitudinal direction X and a plurality of lateral portions extending in the direction Y intersecting the longitudinal direction X. A slit 7B is formed, and a plurality of small absorbing

portions

75 and 76 surrounded by the slit and the auxiliary slit are formed in the absorbent core 40 ′. More specifically, one second slit 7A is formed on each side of the slit 7 arranged in the center in the width direction Y. One or a plurality of horizontal slits 7B are formed in the absorber crotch region 40c, and a plurality of horizontal slits 7B are formed in the large area region 40a. Each of the horizontal slits 7B intersects the central slit 7 in a cross shape, The second slits 7A and 7A located on both sides of the central slit 7 are also connected to each other. The horizontal slit 7B formed in the large area region 40a includes a cross that intersects the second slit 7A in a cross shape.

When an absorbent core having a plurality of small absorbing

portions

75 and 76 surrounded by the slits and the auxiliary slits is used, the absorber crotch region 40c and the large area are provided. The diffusibility of the liquid in the slit and auxiliary slit region combined with the region 40a is further improved.

Among the constituent members in the above-described

diapers

1, 1A, 1B, etc., those not particularly described can be used without particular limitation as those used for absorbent articles such as disposable diapers.

As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to embodiment mentioned above, It can change suitably.
Moreover, the absorbent article of the present invention may be a pants-type disposable diaper for infants or adults, in addition to a deployable (tape-clamped) disposable diaper for infants or adults.
In addition, the description omitted in one embodiment and the requirements of only one embodiment can be applied to other embodiments as appropriate, and the requirements in each embodiment can be appropriately applied between the embodiments. Can be substituted for each other.

Regarding the above-described embodiment (aspect) of the present invention, the following additional notes (disposable diapers) are further disclosed.
<1>
A vertically long disposable diaper comprising a surface sheet that forms a skin facing surface, an outer layer sheet that forms a non-skin facing surface, and an absorber positioned between both sheets,
The absorbent body has an absorbent core having a shape elongated in the longitudinal direction of the disposable diaper, and the absorbent core contains a water-absorbing polymer,
The absorbent core has a constricted portion in a plan view shape,
When an absorbent crotch region having the same length as the minimum width of the constricted portion is set in the absorbent core, a large area region and a small area that have different areas before and after the absorbent crotch region in the longitudinal direction. Has an area area,
In the absorbent core, a slit extending in the longitudinal direction is formed from the absorber crotch region to the large area region,
The slit intersects a central line that bisects the overall length in the longitudinal direction of the disposable diaper, and 80% or more of the total length of the slit is located on the large area region side from the central line, and the large area region The disposable diaper whose width | variety in is wider than the width | variety in the said crotch area | region.
<2>
<1> The disposable diaper according to <1>, wherein the topsheet has a ridge extending in the longitudinal direction and a groove positioned between the ridges.
<3>
Between the absorbent core and the outer layer sheet, there is an elastic sheet that expands and contracts in the longitudinal direction, and the elastic sheet is disposed at a position that overlaps at least the slit in the crotch region, < Disposable diaper according to 1> or <2>.
<4>
Between the absorbent core and the outer layer sheet, it has an elastic sheet that expands and contracts in a direction intersecting the longitudinal direction, and the elastic sheet is at a position that overlaps at least the slit in the absorber crotch region. The disposable diaper according to any one of <1> to <3>, which is arranged.
<5>
The absorbent body has a core wrap sheet that wraps the absorbent core, and a slit underlay sheet excellent in liquid diffusibility between the absorbent core and the core wrap sheet positioned on the non-skin facing surface side. The disposable diaper according to any one of <1> to <4>, wherein the disposable diaper is arranged so as to overlap the slit.

<6>
Any one of <1> to <5>, wherein the absorbent core includes a water-absorbing polymer and pulp fibers, and a ratio of the mass of the pulp fibers to the total mass of the absorbent core is 50% or more. The disposable diaper described.
<7>
The disposable diaper according to any one of <1> to <6>, wherein the absorbent core is covered with a highly diffusible core wrap sheet.
<8>
In the absorbent core, the basis weight of the slit area in the area where the slit is formed in the area where the absorber crotch area and the large area area are combined is the basis weight of the small area area. The disposable diaper according to any one of <1> to <7>, which is higher than the amount.
<9>
The disposable diaper according to any one of <1> to <8>, wherein a surface of the absorbent core on the surface sheet side is covered with a core wrap sheet having low liquid permeability.
<10>
In the absorber crotch region and the large area region, a second slit extending in the longitudinal direction separately from the slit and an auxiliary slit formed of a plurality of lateral slits extending in a direction intersecting the longitudinal direction are formed, The disposable diaper according to any one of <1> to <9>, wherein a plurality of small absorbent parts surrounded by the slit and the auxiliary slit are formed in the absorbent core.

<11>
Any one of <1> to <10>, wherein the slit in the absorbent crotch region disappears after liquid absorption and swelling of the absorbent core, while the slit in the large area region does not disappear after liquid absorption and swelling of the absorbent core. The disposable diaper according to 1.
<12>
The outer layer sheet has a shape corresponding to the outer shape of the diaper when viewed from the non-skin facing surface side of the diaper, and the outer layer sheet is made of a liquid hardly permeable resin film or a resin film. The disposable diaper according to any one of <1> to <11>, which is one obtained by laminating and adhering a nonwoven fabric to the non-skin facing surface side.
<13>
The disposable diaper according to any one of <1> to <12>, wherein the core wrap sheet is either water-permeable thin paper or water-permeable nonwoven fabric.
<14>
The disposable diaper according to any one of <1> to <13>, wherein the narrowest portion of the constricted portion of the absorbent core continuously exists linearly in the longitudinal direction of the absorbent core.
<15>
In the slit, the length L2 of the portion located on the large area side from the center line CL is 80 to 95%, more preferably 85 to 95% of the total length L1 of the slit. The disposable diaper according to any one of <1> to <13>, which is 40 to 70%, preferably 50 to 60%, of the total length L of the outer layer sheet.

<16>
In the slit, the width W2 of the wide portion is 1.5 to 4.0 times, preferably 2.0 to 3.0 times the width W1 of the narrow portion, and the width W1 of the narrow portion of the slit is 20 mm. In the following, preferably 15 mm or less, 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 or more, 30 mm or less, preferably 20 mm. 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, preferably 20 mm or less <1> ~ <15> The disposable diaper described in any one of the above.
<17>
The area of the large area region is 150% or more of the area of the small area region, preferably 200% or more, 500% or less, preferably 400% or less, and preferably 150 to 500%. More preferably 200 to 400%, and the area of the large area is 300% or more, preferably 400% or more, and 600% or less, preferably 500% of the area of the absorber crotch region. The area of the small area region is 110% or more, preferably 120% or more, and 300% or less, preferably 200% or less of the area of the absorber crotch region <1> to < The disposable diaper according to any one of 15>.
<18>
The slit penetrates the absorbent core in the thickness direction both in the absorber crotch region and the large area region, and the narrow portion and the wide portion are each uniform in width in the longitudinal direction X, The slit is a disposable diaper according to any one of <1> to <17>, which does not extend to a small area as in the present embodiment.
<19>
Whether the upper core wrap sheet positioned on the skin-facing surface side of the absorbent core and the lower core wrap sheet positioned on the non-skin facing surface side are in a non-bonded or spaced state from each other in a portion overlapping the slit ,
The upper core wrap sheet and the lower core wrap sheet are joined to each other at a portion overlapping with the slit, or the slit has a relatively narrow width portion and a relatively wide width portion. The disposable core according to any one of <1> to <18>, wherein the upper core wrap sheet and the lower core wrap sheet are joined to each other at the narrow portion in the absorber crotch region Diapers.
<20>
Any one of <1> to <19>, wherein an upper core wrap sheet and a top sheet are inserted into the slit and integrated with a lower core wrap sheet and an outer layer sheet. Disposable diapers.

<21>
The absorbent core is composed of a fiber assembly made of fiber material such as pulp fiber and water-absorbing polymer particles held by the fiber core. The fiber material constituting the fiber assembly includes pulp fiber, rayon fiber, and cotton fiber. , Hydrophilic fiber of any cellulose acetate, polyolefin fiber of any of polyethylene or polypropylene, condensed fiber of any of polyester or polyamide, and the water-absorbing polymer particles are sodium polyacrylate (acrylic acid-vinyl alcohol) <1> Particles made of any one of (1) copolymer, crosslinked sodium polyacrylate, (starch-acrylic acid) graft copolymer, (isobutylene-maleic anhydride) copolymer and saponified product thereof, and polyaspartic acid. ~ <20> The disposable diaper described in any one of the above.
<22>
The ratio of the pulp fiber mass to the total mass of the absorbent core is 40% or more, preferably 50% or more, 70% or less, preferably 60% or less, preferably 40 to 70%, more preferably. The ratio of the total mass of the pulp fibers and the water-absorbing polymer to the total mass of the absorbent core is from 90 to 100%, preferably from 95 to 100%. <1> to <21> The disposable diaper according to any one of the above.
<23>
The disposable diaper according to any one of <1> to <22>, wherein a three-dimensional gather and a leg gather are arranged.
<24>
<1> to <23> A deployable disposable diaper, in which a fastening tape is provided on both side edges of the dorsal side, and a landing zone for fastening the fastening tape is provided on the outer surface of the abdominal side. The disposable diaper according to any one of the above.

Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited to the examples.

〔Example〕
The absorber provided with the absorptive core 40 of the shape shown to Fig.9 (a) was manufactured. The absorbent core 40 was formed as a mixed fiber of pulp fibers and water-absorbing polymer, and the proportion of pulp fibers was 50% by mass. As the pulp fiber, ordinary fluff pulp was used. As the core wrap sheet for covering the skin facing surface side of the absorbent core 40, the following was used.
Core wrap sheet: thin paper with a basis weight of 13.5 g / m ² Table 1 shows the dimensions of each part of the absorbent core 40 used in the examples.

The absorbent body was sandwiched between the top sheet and the outer layer sheet, and the two sheets were joined around the absorbent body to obtain a diaper for evaluation.
Top sheet: Air-through nonwoven fabric with a basis weight of 36 g / m ² [Comparative Example]
A diaper for evaluation was manufactured in the same manner as in the example except that the slit was replaced with one having a uniform width as shown in FIG.

[Evaluation]
The liquid return amount and the liquid diffusion area were measured by the following method, and the results are shown in Table 1.
[Liquid return amount]
The diapers for evaluation of the examples and comparative examples were fixed on a flat plate with a 5 ° inclination, with the large area region side being the inclined lower end side. 120 g of artificial urine colored red was divided into 3 portions and 40 g was injected every 10 minutes. After the completion of the third injection, the mixture was allowed to stand for 10 minutes, and a collagen film (Naturin, trade name COFFIJ) cut into 70 mm square was stacked on top of each other. Further, a weight was placed thereon so that the pressure became 7 kPa, and pressure was applied for 30 seconds. After pressurization, the collagen film was taken out, the weight of the collagen film before and after pressurization was measured, and the weight of the liquid absorbed in the collagen film was measured to obtain the liquid return amount.

[Liquid diffusion area]
Immediately after the measurement of the amount of liquid return was completed, the OHP film was placed on the top sheet, and the outline of the portion where the top sheet spread in red was written. Using dedicated software (Image-ProPlus: manufactured by Nippon Roper Co., Ltd.) that can measure the area inside the contour, the image written on the OHP film was taken into a personal computer with a scanner and the liquid diffusion area was determined.

From the result shown in Table 1, the diaper of the example which provided the wide part 72 which expanded the width | variety of the slit in the large area area | region 40a is compared with the diaper of the comparative example which provided the slit with a uniform width over the full length, It can be seen that the liquid diffusion area is large, and the diaper of the example utilized the absorption capacity of the absorbent core more effectively. Moreover, the diaper of an Example has little liquid return amount compared with a comparative example, and it turns out that the diaper of an Example is excellent also in the liquid return prevention property to skin. Moreover, since the diaper of an Example can utilize absorption capacity more effectively, it turns out that it is excellent also in the leak prevention property compared with the diaper of a comparative example. In addition, since the diaper of an Example and the diaper of a comparative example all have the part which the absorbent core was constricted, it is excellent in the fit property of a crotch part.

Moreover, after copying the outline of the portion where the surface sheet spreads in red in the liquid diffusion area, the surface sheet was peeled off, and the state of the slit of the absorbent core was observed. As shown in FIG. 9B, the slit 7 disappears in the absorber crotch region, while the wide portion 72 of the slit 7 did not disappear in the large area region. On the other hand, in the absorbent core of the comparative example, as shown in FIG. 10B, the slits 7 disappeared in both the absorber crotch region and the large area region.
Maintaining liquid diffusibility when absorbing liquid repeatedly by setting the width of the wide part formed in the large area to such a width that the slit remains even after the absorbent core absorbs and swells. Can do.

Thus, in the disposable diaper of the present invention, the slit in the absorber crotch region disappears after liquid absorption swelling of the absorbent core, while the slit in the large area region does not disappear after liquid absorption swelling of the absorbent core. preferable.
Whether or not the slits in the absorber crotch region and the large area region disappear after the absorbent core is swollen is observed by swollen the absorbent core by the following method. The disappearance of the slit means that the width of the slit becomes 0 mm.

<Liquid absorption swelling condition of absorbent core>
In each of the diapers for evaluation in Examples and Comparative Examples, 120 g of red-colored artificial urine was injected into a flat plate in three portions every 40 minutes, and 40 g was injected every 10 minutes. A plan view is taken from the surface side, and the presence or absence of the slit is visually observed.

The disposable diaper of this invention is excellent in the fit property of a crotch part, leak prevention property, and the liquid return prevention property to skin.

Claims

A vertically long disposable diaper comprising a surface sheet that forms a skin facing surface, an outer layer sheet that forms a non-skin facing surface, and an absorber positioned between both sheets,
The absorbent body has an absorbent core having a shape elongated in the longitudinal direction of the disposable diaper, and the absorbent core contains a water-absorbing polymer,
The absorbent core has a constricted portion in a plan view shape,
When an absorbent crotch region having the same length as the minimum width of the constricted portion is set in the absorbent core, a large area region and a small area that have different areas before and after the absorbent crotch region in the longitudinal direction. Has an area area,
In the absorbent core, a slit extending in the longitudinal direction is formed from the absorber crotch region to the large area region,
The slit intersects a central line that bisects the overall length in the longitudinal direction of the disposable diaper, and 80% or more of the total length of the slit is located on the large area region side from the central line, and the large area region The disposable diaper whose width | variety in is wider than the width | variety in the said crotch area | region.
The disposable diaper according to claim 1, wherein the top sheet has a ridge extending in the longitudinal direction and a groove positioned between the ridges.
Between the absorbent core and the outer layer sheet, there is an elastic sheet that expands and contracts in the longitudinal direction, and the elastic sheet is arranged at a position that overlaps at least the slit in the crotch region. The disposable diaper of claim | item 1 or 2.
Between the absorbent core and the outer layer sheet, it has an elastic sheet that expands and contracts in a direction intersecting the longitudinal direction, and the elastic sheet is at a position that overlaps at least the slit in the absorber crotch region. The disposable diaper according to any one of claims 1 to 3, wherein the disposable diaper is arranged.
The absorbent body has a core wrap sheet that wraps the absorbent core, and a slit underlay sheet excellent in liquid diffusibility between the absorbent core and the core wrap sheet positioned on the non-skin facing surface side. The disposable diaper according to any one of claims 1 to 4, wherein the disposable diaper is arranged so as to overlap the slit.
The absorbent core according to any one of claims 1 to 5, wherein the absorbent core includes a water-absorbing polymer and pulp fibers, and a ratio of the mass of the pulp fibers to the total mass of the absorbent core is 50% or more. Disposable diapers.
The disposable diaper according to any one of claims 1 to 6, wherein the absorbent core is covered with a highly diffusible core wrap sheet.
In the absorbent core, the basis weight of the slit area in the area where the slit is formed in the area where the absorber crotch area and the large area area are combined is the basis weight of the small area area. The disposable diaper according to any one of claims 1 to 7, wherein the disposable diaper is higher than the amount.
The disposable diaper according to any one of claims 1 to 8, wherein a surface of the absorbent core on the surface sheet side is covered with a core wrap sheet having low liquid permeability.
In the absorber crotch region and the large area region, a second slit extending in the longitudinal direction separately from the slit and an auxiliary slit formed of a plurality of lateral slits extending in a direction intersecting the longitudinal direction are formed, The disposable diaper according to any one of claims 1 to 9, wherein a plurality of small absorbent portions surrounded by the slit and the auxiliary slit are formed in the absorbent core.
The slit in the absorbent crotch region disappears after liquid absorption swelling of the absorbent core, while the slit in the large area region does not disappear after liquid absorption swelling of the absorbent core. Disposable diapers described in 1.
The outer layer sheet has a shape that corresponds to the outer shape of the disposable diaper when viewed from the non-skin facing surface side of the disposable diaper, and the outer layer sheet is made from a liquid-impermeable resin film. The disposable diaper according to any one of claims 1 to 11, wherein the disposable diaper is one obtained by laminating and bonding a non-woven fabric to the non-skin facing surface side of the resin film.
The disposable diaper according to any one of claims 1 to 12, wherein the core wrap sheet is either water-permeable thin paper or water-permeable nonwoven fabric.
The disposable diaper according to any one of claims 1 to 13, wherein the narrowest portion of the constricted portion of the absorbent core continuously exists linearly in the longitudinal direction of the absorbent core.
In the slit, the length L2 of the portion located on the large area side from the center line CL is 80 to 95% of the total length L1 of the slit,
The disposable diaper according to any one of claims 1 to 13, wherein a total length L1 of the slit is 40 to 70% of a total length L of the outer layer sheet.
The slit has a narrow portion having a relatively narrow width and a wide portion having a relatively wide width,
The width W2 of the wide portion is 1.5 to 4.0 times the width W1 of the narrow portion, 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 not less than 4.5 mm and not more than 30 mm, and the difference (W2−W1) between the width W2 of the wide width portion and the width W1 of the narrow width portion is not less than 2 mm and not more than 30 mm. The disposable diaper of Claim 1.
The area of the large area region is 150 to 500% of the area of the small area region, the area of the large area region is 300% or more and 600% or less of the area of the absorber crotch region, The disposable diaper according to any one of claims 1 to 15, wherein an area of the small area is 110% or more and 300% or less of an area of the absorber crotch area.
The slit has a narrow portion having a relatively narrow width and a wide portion having a relatively wide width,
The slit penetrates the absorbent core in the thickness direction both in the absorber crotch region and the large area region, and the narrow portion and the wide portion are respectively in the longitudinal direction of the absorbent core. The disposable diaper according to any one of claims 1 to 17, wherein the slit has a uniform width and the slit does not extend into the small area region.
Whether the upper core wrap sheet positioned on the skin-facing surface side of the absorbent core and the lower core wrap sheet positioned on the non-skin facing surface side are in a non-bonded or spaced state from each other in a portion overlapping the slit ,
The upper core wrap sheet and the lower core wrap sheet are joined to each other at a portion overlapping with the slit, or the slit has a relatively narrow width portion and a relatively wide width portion. The disposable diaper according to any one of claims 1 to 18, wherein the upper core wrap sheet and the lower core wrap sheet are joined to each other at the narrow portion in the absorber crotch region. .
The upper core wrap sheet and the top sheet are inserted into the slit, and are integrated with the lower core wrap sheet and the outer layer sheet. Disposable diapers.
The absorbent core is composed of a fiber assembly made of fiber material such as pulp fiber and water-absorbing polymer particles held by the fiber core. The fiber material constituting the fiber assembly includes pulp fiber, rayon fiber, and cotton fiber. , Hydrophilic fiber of any cellulose acetate, polyolefin fiber of any of polyethylene or polypropylene, condensed fiber of any of polyester or polyamide, and the water-absorbing polymer particles are sodium polyacrylate (acrylic acid-vinyl alcohol) 2. A particle comprising any one of a copolymer, a crosslinked sodium polyacrylate, a (starch-acrylic acid) graft copolymer, an (isobutylene-maleic anhydride) copolymer, a saponified product thereof, and polyaspartic acid. The disposable diaper according to any one of to 20.
The ratio of the mass of the pulp fiber to the total mass of the absorbent core is 40% or more and 70% or less, and the ratio of the total mass of the pulp fiber and the water absorbent polymer to the total mass of the absorbent core is 90 to 100%. The disposable diaper according to any one of claims 1 to 21, wherein
The disposable diaper according to any one of claims 1 to 22, wherein a three-dimensional gather and a leg gather are arranged.
A deployment type disposable diaper, wherein a fastening tape is provided on both side edges of the back side portion, and a landing zone for fastening the fastening tape is provided on the outer surface of the abdominal side portion. The disposable diaper of Claim 1.