RU2676993C1 - Disposable diaper - Google Patents

Abstract

FIELD: satisfaction of human vital requirements.

SUBSTANCE: disposable diaper (1) of the present invention includes a front waist flap (FA) and a rear waist flap (FB) extending in lateral direction (Y) and located outside front and rear ends (23A) and (23B) of absorbent element (23), respectively, defined in the longitudinal direction (X). Rear waist flap (FB) has hydrophobic sheet (4) located on the side facing the skin, and hydrophilic sheet (5) located on the side not facing the skin. Sheet (4), located on the side facing the skin, includes depressed portions (41), pressed in toward sheet (5), located on the side not facing the skin, and holes (44) formed in sheet (4) located on the side facing the skin, respectively, in depressed portions (41). Each indented portion (41) of sheet (4) located on the side facing the skin has a thickness which decreases towards opening (44).

EFFECT: present invention effectively absorbs sweat, thereby effectively preventing eczema, prickly heat, rashes, and the like.

43 cl, 6 dwg

Description

FIELD OF THE INVENTION

[0001]

The present invention relates to a disposable diaper.

State of the art

[0002]

A disposable diaper is traditionally known, the surface of which comes in contact with the skin is provided with a sheet or the like for absorbing sweat, whereby eczema, sweating, rash and the like are effectively prevented (e.g., Patent Literature 1).

[0003]

Patent Literature 1 discloses a disposable diaper, end valves and side valves of which are provided with a composite sheet in which a hydrophobic first fibrous nonwoven material on a surface facing the skin and a hydrophilic second fibrous nonwoven material on a surface not facing the skin are superimposed on top of each other and attached to each other in areas fused together to absorb sweat. In addition, Patent Literature 1 discloses that a large number of holes are formed in the first fibrous nonwoven composite laminate.

[0004]

As another technical solution, the applicant of the present invention has previously proposed a pull-on disposable diaper, the outer covering element of which is formed of tubular parts extending in the longitudinal direction and arranged in series along the width direction, and a plurality of holes that communicate with the inner side of the tubular parts are formed at intervals along the longitudinal direction in the protrusions of the sheet forming the tubular parts and located on the side of the surface in contact with burns (e.g. patent literature 2).

List of links

Patent Literature

[0005]

Patent Literature 1: JP 2004-298467A

Patent Literature 2: JP 2011-78477A

SUMMARY OF THE INVENTION

[0006]

The present invention is directed to a disposable diaper comprising, in a longitudinal direction, a front zone, a rear zone and a crotch zone located between the front zone and the rear zone, having an absorbent element extending from the front zone to the rear zone, and having a front waist valve and a rear waist valve, passing in the lateral direction and located outside of the front and rear end portions of the absorbent element in the longitudinal direction. At least the back waist valve has a hydrophobic sheet located on the side facing the skin, which forms a surface in contact with the skin, and a hydrophilic sheet located on the side not facing the skin, which is located on the side not facing the skin of the sheet located on the side facing the skin. The sheet located on the side facing the skin includes a plurality of depressed portions depressed towards the sheet located on the side not facing the skin, and holes formed in the sheet located on the side facing the skin, respectively, in the depressed plots. Each indented portion of the sheet located on the side facing the skin has a thickness that decreases toward the hole.

Brief Description of the Drawings

[0007]

[Fig. 1] Fig. 1 is a perspective view showing a stretchable disposable diaper in a natural state according to an embodiment of the present invention.

[Fig. 2] Fig. 2 is a detailed plan view of the diaper of Fig. 1 in its flat unfolded unstretched condition when viewed from the side of the surface in contact with the skin.

[Fig. 3] Fig. 3 (a) is an enlarged top view of the main part of the portion of the outer covering element of the diaper shown in Fig. 2, when viewed from the side of the surface in contact with the skin, and Fig. 3 (b) is an enlarged a top view of the depressed portion shown in FIG. 3 (a).

[Fig. 4] Fig. 4 is a section taken along line IV-IV shown in Fig. 2.

[Fig. 5] Fig. 5 is a perspective view showing a spatially separated state of a part of the outer covering diaper member shown in Fig. 2.

[Fig. 6] Fig. 6 is an enlarged sectional view showing a section taken along the lateral direction (Y direction) of the waist elastic portion in the diaper shown in Fig. 1.

Description of Embodiments

[0008]

The disposable diaper disclosed in Patent Literature 1 is such that the parts fused together are formed while maintaining the shape of the fibers for the fibers constituting them to also sweat from them through capillary action. If the parts bonded by the fusion method are formed while maintaining the shape of the fibers for their constituent fibers in this way, the thickness of the peripheral edges of the parts bonded by the fusion method cannot be sufficiently small, the capillary action is unstable, and therefore the sweat cannot be sufficiently absorbed through holes.

[0009]

In addition, in patent literature 2 there is no mention of the thickness of the peripheral edges of the through holes formed in the outer covering element.

[0010]

The present invention relates to a disposable diaper, which allows to solve the above problems in the prior art.

[0011]

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

The disposable diaper of the present invention includes, along the longitudinal direction X, the front zone A, the rear zone B and the crotch zone C, which is located between the front zone A and the rear zone B, has an absorbent element 23 extending from the front zone A to the rear zone B, and has a front waist valve FA and a rear waist valve FB extending laterally Y and located respectively outside of the front and rear ends 23A and 23B of the absorbent element 23 defined in the longitudinal direction X. The front zone A pre resents a zone that "carry" around the front of the wearer when wearing the disposable diaper, and the rear zone B is a zone which is "wear" around the rear side of the wearer when wearing the disposable diaper. The front waist valve FA refers to the zone obtained by adding a zone extending in the lateral direction Y and located externally in the longitudinal direction X from the edge of the front end 23A of the absorbent element 23 defined in the longitudinal direction X from the front zone A, and the zones extending in the lateral direction Y from the front end 23A of the absorbent element 23, defined in the longitudinal direction X from the side of the front zone A. In addition, the rear waist flap FB refers to the zone obtained by adding the zone passing in b in the longitudinal direction Y and located externally in the longitudinal direction X from the edge of the rear end 23B of the absorbent element 23 defined in the longitudinal direction X from the side of the rear zone B and the zones extending in the lateral direction Y from the rear end 23B of the absorbent element 23 defined in the longitudinal direction X from the back zone B.

[0012]

Figures 1 and 2 show a pull-on disposable diaper 1 (hereinafter referred to alternatively as "diaper 1"), which is a disposable diaper according to an embodiment of the present invention. As shown in FIGS. 1 and 2, the diaper 1 includes an absorbent kit 2 and an outer cover member 3, which is located on the non-skin side of the absorbent kit 2 and secures the absorbent kit 2. The outer cover member 3 has a front waist flap FA and the rear waist flap FB extending laterally Y and located outside of the longitudinally defined X front and rear ends 23A and 23B of the absorbent element 23 forming the absorbent assembly Object 2. The diaper 1 is a disposable diaper in which both side edges 3a1, 3a1 of the front zone A of the outer covering element 3 and both side edges 3b1, 3b1 of the back zone B of the outer covering element 3 are connected to each other and form a pair of side seams S, S, hole WO for the waist and two holes LO, LO for the legs. As shown in FIG. 2, in a plan view of the diaper 1 in its flat, unstretched state, the outer covering member 3 is preferably divided into a front zone A that is “worn” around the front side of the wearer when worn, a rear zone B that is “worn” around the back of the carrier when worn, and the crotch zone C, which is located between the front zone A and the rear zone B.

[0013]

The above-described flat unfolded, unstretched state of the diaper 1, as shown in FIG. 2, is a state in which the side seams S are separated so that the diaper 1 is in the flat unfolded state, elastic elements in the corresponding parts of the diaper 1 in the flat unfolded state are not tightened, so that the size of the diaper corresponds to its design dimensions (i.e., such dimensions as the dimensions in the state when the diaper 1 is flattened with the elimination of the influence of elastic elements at).

[0014]

As used herein, a “skin contact surface” refers to the surface of the diaper 1 or its constituent element (for example, the outer covering element 3) that is in contact with the skin of the wearer when the diaper 1 is worn. In addition, the “surface facing the skin ", Represents the surface of the diaper 1 or its constituent element, which is facing the skin of the wearer when wearing the diaper 1, and" the surface not facing the skin "is the surface of the diaper 1 or its constituent element, which I am facing the opposite side of the wearer's skin (side of the garment) while wearing the diaper 1. In the diaper 1, the longitudinal direction (X direction) is the direction from the front zone A to the back zone B in a plan view of the diaper 1 in its flat unfolded, unstretched condition. In addition, the lateral direction (Y direction) is a direction that is orthogonal to the longitudinal direction (X direction) and represents the width direction of the diaper 1 in a plan view of the diaper 1 in its flat unfolded, unstretched state.

In addition, the diaper 1 is bilaterally symmetrical with respect to the longitudinal center line CL1 extending in the longitudinal direction (X direction) and shown in FIG. 2. Line CL2 in FIG. 2 is a transverse center line extending laterally (Y direction) and dividing the diaper 1 into two halves, and orthogonal to the longitudinal center line CL1.

[0015]

As shown in FIG. 2, in the diaper 1, the absorbent assembly 2 has an elongated shape that is relatively elongated in the longitudinal direction (X direction) in the flat, unstretched condition of the diaper 1. The absorbent assembly 2 includes a liquid permeable top sheet 21 which forms a surface facing the skin, minimally permeable to liquids (or water repellent), a back sheet 22, which forms a surface not facing the skin, and holding a liquid, an absorbent element 23, which is distributed laid between the sheets 21 and 22. In addition, as shown in figure 2, the cuffs 24, 24, protecting against leakage and having elastic elements 25, which form the cuffs, protecting against leakage, and placed in a state in which they are stretched in the longitudinal direction (direction X), provided on both sides along the longitudinal direction (direction X) of the absorbent assembly 2. In particular, the cuffs 24, which protect against leakage, are formed of a liquid-impermeable or water-repellent and breathable material, and elastic elements 25 form ue cuff protecting against leakage, placed in a state in which they are stretched in the longitudinal direction (direction X), adjacent to the free ends of the sleeves 24 to protect against leakage. When the diaper is worn, the free ends of the cuffs 24, which protect against leakage, rise upward as a result of the elastic elements 25 forming the cuffs that protect against leakage, thereby preventing leakage of the fluid released by the body in the lateral direction (Y direction).

[0016]

As shown in FIG. 2, an absorbent assembly 2 having such a configuration is attached to the middle of the outer covering member 3 by using an adhesive to fix the assembly so that the longitudinal direction (X direction) of the absorbent assembly 2 corresponds to the longitudinal direction (X direction) of the diaper 1 in its flat, unstretched state. Thus, the outer covering member 3 is located on the non-skin side of the surface and is attached by adhesive to the non-skin side surface of the back sheet 22 forming the absorbent assembly 2 in the thickness direction of the disposable diaper 1. Accordingly, in the diaper 1, the absorbent member 23 forming the absorbent assembly 2 is arranged so that it extends from the front zone A to the rear zone B.

[0017]

At least a back waist valve FB from the front waist valve FA and the rear waist valve FB extending laterally Y and located outside of the longitudinally defined X front and rear ends 23A and 23B of the absorbent member 23 includes a hydrophobic a sheet 4 located on the side facing the skin, which forms a surface in contact with the skin, and a hydrophilic sheet 5, located on the side not facing the skin, which is located on the side not facing the skin ty sheet 4, located on the side facing the skin. As shown in FIG. 2, in the diaper 1, the front waist valve FA and the rear waist valve FB have a sheet 4 located on the side facing the skin and a sheet 5 located on the side not facing the skin, and further have a hydrophobic outer sheet 6 on the non-skin side of the surface of the sheet 5 located on the non-skin side.

[0018]

As shown in FIG. 2, in the diaper 1, the outer covering member 3 preferably includes a front waist valve FA and a rear waist valve FB extending laterally Y and located outside of the longitudinally defined X front and rear ends 23A and 23B of the absorbent member 23. As shown in FIGS. 2 and 4, the outer covering member 3 includes an outer sheet 6 on the surface side not facing the skin that forms the outer surface of the diaper 1, sheets 4 located on the side s facing the skin, on the side which is closest to the surface facing the skin, and the inner sheet, which is placed between the outer sheet 6 and the sheet 4 disposed on the side facing the skin. In the diaper 1, the inner sheet corresponds to the sheet 5 located on the side not facing the skin.

[0019]

More preferably, as shown in FIG. 2, in the diaper 1, the sheet material forming the outer sheet 6, both in the front zone A and in the rear zone B, is folded back (bent) to the skin-facing surface of the sheet 5 located on the side not facing the skin, along the peripheral edges of the waist opening WO, and the folded portions 6R cover the longitudinally defined (X direction) front and rear ends 23A and 23B of the absorbent element 23 forming the absorbent assembly 2. Sheets 4 located on the side facing to the skin, sheet (internal top sheet) 5, located on the side not facing the skin, and the outer sheet 6 may be separate sheets, but in the diaper 1, the sheets 4, located on the side facing the skin, are formed from the folded parts 6R of the outer sheet 6. Thus , in the diaper 1, sheets 4 located on the skin-facing side are located on the skin-facing side of the sheet 5 located on the non-skinning side of the rear waist flap FB and the front waist flap FA. As shown in FIG. 2, in the diaper 1, the outer sheet 6 in an area other than the folded parts 6R and the sheet 5 located on the side not facing the skin are tapering inward towards the longitudinal center line CL1 in the middle in the longitudinal direction ( X direction) and are formed so that they have the same shape and the same size. Each of the sheets 4 located on the side facing the skin and formed from the folded portions 6R of the outer sheet 6 is formed with a rectangle shape that is elongated in the lateral direction (Y direction).

[0020]

As shown in FIG. 4, the sheets 4 located on the side facing the skin include a plurality of depressed portions 41 pressed in toward the sheet 5 located on the side not facing the skin, and through holes 44 formed in the sheets 4 located on the side facing the skin, respectively, in the depressed portions 41. In the diaper 1, sheets 4 located on the side facing the skin include bonded sections 42 in which the constituent fibers of the sheets 4 are located on the side facing the skin attached to yz other, in the respective depressed parts 41. Bonded portions 42 include the portions in which the fibers constituting the sheet 4 disposed on the side facing the skin, are fused and fixed to each other without a gap therebetween. Parts that are bonded relate to parts in which the constituent fibers are fused without a gap between them to such an extent that the constituent fibers do not return to their original shape even when they are separated from the parts that are bonded. The parts that are bonded are liquid impermeable parts that do not allow liquids to pass through them. In the fastened portions 42 of the diaper 1, the parts that are fastened are in the form of a film. As shown in FIGS. 3 and 4, in the diaper 1, openings 44 are formed inside the fastened portions 42.

[0021]

To improve sweat absorption, the holes 44 (bonded sections 42 in which the holes 44 are located) are arranged in sheets 4 located on the side facing the skin, preferably at least on the side located externally in the longitudinal direction X from the edge of the detected in the longitudinal direction (X direction), the rear end 23B (from the side opposite to the transverse center line CL2) of the absorbent element 23 forming the absorbent assembly 2, and in the diaper 1, the openings 44 are spaced the entire length of the sheet 4 disposed on the side facing the skin, as shown in Figure 2. The bonded portions 42 in which the openings 44 are located are preferably spaced apart in a row along the longitudinal direction (X direction), and the plurality of rows of bonded portions 42L formed from the plurality of bonded portions 42 are spaced along the lateral direction (Y direction). To improve perspiration dispersibility, as shown in FIGS. 2 and 3, the bonded portions 42 in which the openings 44 are located are preferably located in places that do not overlap the bonded zones 8, which will be described later, and in the diaper 1 the rows 42L bonded of plots and rows 8L of later described connected zones formed from a plurality of connected zones 8 are alternately arranged in a lateral direction (Y direction).

[0022]

The bonded sections 42 in which the holes 44 are located can be formed by hot stamping only sheets 4 located on the side facing the skin and heating sheets 4 located on the side facing the skin until they are formed through holes. The hot stamping device may be a device including an embossing roller and a support roller, while the outer peripheral surface of the embossing roller has a protrusion that corresponds in shape to the bonded sections 42. Instead of hot stamping, the technology for forming the bonded sections 42 may be used ultrasonic welding, laser and the like. In the formation of bonded sections 42, in which the holes 44 are located, by means of hot stamping, the stamping intensity during the formation of bonded sections 42 is preferably higher than the stamping intensity when forming bonded zones 8, which will be described later.

[0023]

To increase the ability to absorb sweat and prevent sweat from returning from the sheet 5, located on the side not facing the skin, to the skin, in a plan view of the diaper 1 in its flat unfolded, unstretched condition shown in FIG. 2, the interval between fastened sections 42, 42 adjacent to each other in the longitudinal direction (X direction) and forming rows of 42L fastened sections extending in the longitudinal direction (X direction), is preferably 1 mm or more and more preferably 3 mm or more, preferably the composition yaet 20 mm or less and more preferably 18 mm or less, and particularly preferably from 1 to 20 mm and more preferably from 3 to 18 mm.

In addition, to increase the dispersibility of perspiration in a top view of the diaper 1 in its flat unfolded, unstretched state shown in FIG. 2, the interval between rows of fastened portions 42L, 42L adjacent to each other in the lateral direction (Y direction), preferably is 4 mm or more and more preferably 6 mm or more, preferably is 20 mm or less and more preferably 16 mm or less and, in particular, is preferably 4 to 20 mm and more preferably 6 to 16 mm.

[0024]

As shown in FIGS. 4 and 5, each depressed portion 41 has a thickness that decreases towards the hole 44. A state in which the thickness decreases towards the hole 44 has a value that encompasses a state in which the thickness is continuously reduced in the direction to the hole 44, and a state in which the thickness decreases stepwise towards the hole 44. As shown in FIGS. 4 and 5, the outer periphery 43 of each hole 44 in the indented portion 41 included in the sheets 4 located on the side facing the skin has a thickness that gradually decreases towards the inner peripheral wall 42e (the peripheral edge of the hole 44) of the bonded portion 42 in which the hole 44 is formed. The outer periphery 43 refers to the portion from the inner peripheral wall 42e of the bonded portion 42, which is the peripheral edge (contour) of the hole 44, to the bonded portion 42 from the outside. Each outer periphery 43 is preferably formed with a ring shape starting from the inner peripheral wall 42e (the peripheral edge of the hole 44) of the bonded portion 42 in the indented portion 41. To move the sweat of the wearer towards the sheet 5 located on the side not facing the skin, if take the depth of each indented portion 41 at the inner peripheral wall 42e of the bonded portion 42 to be d3 (see FIG. 4), then the thickness at the location that is outside of the inner peripheral wall 42e of the bonded portion 42 at a distance from it of 0.50 from the depth (d3), preferably is from 20 to 75% and more preferably from 30 to 65% of the thickness d2 of the parts other than the depressed portions 41, and the thickness in the place that is outside from the inner peripheral wall 42e of the bonded portion 42 at a distance from it exceeding 1.5 times the depth (d3), preferably is from 55 to 95% and more preferably from 70 to 90% of the thickness d2 of the portions other than the depressed portions 41. Depth (d3) of each depressed portion 41 at the inner peripheral wall 42 bonded portion 42 and a thickness at a location which is at a distance from it, measured according to the method of measuring the thickness d5 of the inner peripheral wall 42e bonded portion 42, which will be described later.

In addition, the thickness d2 of the portions other than the depressed portions 41 included in the sheets 4 located on the side facing the skin is measured using a thickness gauge in a state where a pressure of 0.05 kPa is applied to the sheets 4 located on the side facing the skin to the skin. A laser displacement sensor manufactured by Omron Corporation is used as a thickness gauge. The thickness is measured at ten points, and the average value calculated for them is taken as the thickness of the sections other than the depressed sections 41.

The state in which the outer periphery 43 of the hole 44 has a thickness that gradually decreases towards the inner peripheral wall 42e of the bonded portion 42 can be seen based on the fact that the thickness at a distance that is outside the inner peripheral wall 42e of the bonded portion 42 is at a distance from it, which is 0.50 of the depth (d3), is less than the thickness in the place that is located outside the inner peripheral wall 42e of the bonded portion 42 at a distance from it, which is 1.5 times the depth (d3).

[0025]

To move the sweat of the carrier towards the sheet 5, located on the side not facing the skin, in the diaper 1, each of the holes 44 of the sheets 4 located on the side facing the skin is such that the inner peripheral wall 42e of the bonded portion 42 has a thickness d5 (see FIG. 4), which is preferably 60 μm or less and more preferably 45 μm or less, and its lower limit is 10 μm. The thickness d5 of the inner peripheral wall 42e of the bonded portion 42 is measured as follows. The part including the hole 44 is cut in the thickness direction using a knife, cutter, razor or the like so that the side of the inner peripheral wall 42e of the fastened portion 52 obtained by cutting is not wrinkled, and the section obtained by cutting is examined using a microscope and thus, the thickness of the inner peripheral wall 42e of the bonded portion 42 is measured. The thickness is measured on ten different inner peripheral walls 42e, and the average value calculated for them is taken as the thickness of the inner 42e bonded eriferiynoy wall portion 42.

[0026]

In addition, to move the sweat of the carrier towards the sheet 5 located on the non-skin side in the diaper 1, each hole 44 of the sheets 4 located on the skin side has a diameter L1 (see FIG. 3), which is preferably 0.5 mm or more and more preferably 1 mm or more, preferably 3 mm or less and more preferably 2.5 mm or less and, in particular, preferably from 0.5 to 3 mm and more preferably from 1 to 2.5 mm. The diameter L1 (see FIG. 3) of each hole 44 refers to the length of the hole 44 at its narrowest point.

[0027]

In addition, in the diaper 1 to move the sweat of the carrier towards the sheet 5 located on the side not facing the skin, each inner peripheral wall 42e of the fastened portions 42 of the sheets 4 located on the side facing the skin has a thickness d5 (see 4), which is preferably 1/10 or less and more preferably 1/30 or less of the diameter L1 (see FIG. 3) of the hole 44, and its lower limit is 1/50 of the diameter L1 of the hole 44.

[0028]

In addition, in the diaper 1 of the hole 44 of the sheets 4 located on the side facing the skin, such that the area of the inlet portion of one hole 44 is preferably 0.5 mm ² or more and more preferably 0.75 mm ² or more to move the sweat the carrier towards the sheet 5, located on the side not facing the skin, and, in addition, the area of the inlet portion of the part is preferably 5 mm ² or less and more preferably 4 mm ² or less in order to prevent sweat from returning from the sheet 5 located on the side not facing the skin, the skin, and, in particular, the inlet area is preferably from 0.5 to 5 mm ² and more preferably from 0.75 to 4 mm ² .

[0029]

In addition, in a top view of the diaper 1 in its flat unfolded, unstretched state shown in FIG. 2, the back waist valve FB of the diaper 1 is such that the fraction of the area of all openings 44 with respect to the total area of the sheet 4 located on the side facing the skin is preferably 1% or more and more preferably 3% or more to effectively transfer the sweat of the carrier to the sheet 5 located on the side not facing the skin, and, in addition, this proportion is preferably 15% or less and more preferably 10% or less in order to prevent the return of sweat from the sheet 5, located on the side not facing the skin, to the skin, and, in particular, this proportion is preferably from 1 to 15% and more preferably from 3 to 10%.

[0030]

In addition, in the diaper 1 for moving the sweat of the wearer towards the sheet 5 located on the side not facing the skin, each hole 44 of the sheets 4 located on the side facing the skin is preferably formed in a thin zone 43T with a thickness that is 70% or less of the thickness d2 (see FIG. 4) of sections other than the depressed portion 41 in sheets 4 located on the skin-facing side within the outer periphery 43 and more preferably formed in a thin zone 43ST located on the side holes and having thicknesses Which is 40% or less of the thickness d2 (See FIG. 4), in a thin zone 43T. In the diaper 1, not only each hole 44 is formed in the thin zone 43T, but also each bonded portion 42 is formed in the thin zone 43T.

In addition, in order to prevent sweat from returning from the sheet 5 located on the side not facing the skin to the skin, the thickness d2 (see FIG. 4) of the sections other than the depressed sections 41 in the sheets 4 located on the side facing to the skin, is preferably 600 μm or less, and more preferably 350 μm or less, and its lower limit is 100 μm.

[0031]

In the diaper 1, each thin zone 43T of the outer periphery 43 of the holes 44 in the depressed portions 41 is formed with a ring shape, as in the case of the outer periphery 43. To move the sweat of the wearer towards the sheet 5, located on the side not facing the skin, each thin the region 43T of the depressed portions 41 has a diameter L2 (see FIGS. 3 (a) and 3 (b)), which preferably exceeds the diameter L1 of the hole 44 (see FIGS. 3 (a) and 3 (b)) by 1.5 times or more and more preferably 2 times or more, and its upper limit exceeds the hole diameter L1 by 3 times. The diameter L2 (see FIGS. 3 (a) and 3 (b)) of each annular thin zone 43T refers to the length of the thin zone 43T at its narrowest point on its outer periphery.

[0032]

The sheets 4 located on the side facing the skin have a base weight that is 30 g / m ² or less, preferably 20 g / m ² or less to move the sweat of the wearer toward the sheet 5 located on the side not facing to the skin is preferably 9 g / m ² or more and more preferably 10 g / m ² or more so that the sheets 4 located on the side facing the skin can preserve the space between the sheet 5, which is located on the side, not facing the skin, and which absorbed the liquid, and skin, as a result of which the perspiration of the carrier which has been transferred to the sheet 5 located on the side not facing the skin to the skin is further reliably prevented, and the adhesion of the sheet that has absorbed sweat to the skin is prevented, and in particular is preferably from 9 to 30 g / m ² and more preferably from 10 to 20 g / m ² . The weight of the base sheets 4, located on the side facing the skin, can be determined based on the area and mass of the sheet, which can be measured. This measurement is carried out at 23 ± 2 ° C and a relative humidity of 50 ± 5% on a sample that has been stored in the same medium for 24 hours or more before measurement.

[0033]

In addition, in the outer covering element 3, sheets 4 located on the side facing the skin and sheet 5 located on the side not facing the skin can be attached to each other, for example, by means of connected zones 8 obtained by hot stamping, which will be described later, but in the diaper 1, they are attached to each other by adhesive 9, as shown in Fig.4. Adhesive 9 is applied to the non-skin surface of sheets 4 located on the skin side, or to the skin surface of sheet 5 located on the skin side, for example, in the form of a spiral. To move the sweat of the carrier towards the sheet 5 located on the side not facing the skin, the place where the adhesive 9 is placed preferably overlaps the fastened portions 42 of the sheets 4 located on the side facing the skin, as viewed in cross section in FIG. four.

[0034]

In addition, in the diaper 1, as shown in FIGS. 2 and 3, the outer covering element 3 has a plurality of elastic elements 71 placed in a state in which they are stretched in the lateral direction (Y direction), between the sheet 5 located on the side, not facing the skin, and the outer sheet 6 and placed at intervals along the longitudinal direction (X direction). In the diaper 1, the waist elastic portions G1 and lower belts, the lower elastic portions G2 are formed by providing a plurality of elastic elements 71. In addition, in the diaper 1, as shown in FIG. 2, a plurality of elastic leg elements 72 are placed in a stretched state between a sheet 5 located on the non-skin side and an outer sheet 6. In the diaper 1, the elasticized leg portions G3 are formed by providing a plurality of elastic leg elements 72.

[0035]

As shown in FIG. 2, in the diaper 1, waist elastic portions G1 are formed in the end valves, which are located externally in the longitudinal direction X with respect to the edges determined in the longitudinal direction (X direction) of the front and rear ends 23A and 23B of the absorbent element 23, forming the absorbent assembly 2 (from the side opposite to the transverse center line CL2) in the longitudinal direction (X direction). In addition, in the diaper 1, the lower elasticated parts G2 are formed in the side flaps located between the lower ends of the elasticated waist parts G1 located on the side of the transverse center line CL2 and the lower ends of the side seams S defined in the longitudinal direction (direction X). The back lap flap FB and the front lap flap FA described above are areas obtained by “summing” the end flaps (waist elastic portions G1) and the side flap parts (located below the waist, lower elastic portions G2). In addition, as shown in FIG. 2, in the diaper 1, the elasticized leg portions G3 are formed along the peripheral edges of the leg openings LO.

[0036]

As shown in FIGS. 2 and 3, in the diaper 1, the outer covering member 3 includes a plurality of connected zones 8 that connect the sheet 5 located on the non-skin side and the outer sheet 6. As described above, in the diaper 1 connected zones 8 are not formed in sheets 4 located on the side facing the skin. In the diaper 1, the back waist valve FB and the front waist valve FA are formed by joining and attaching a sheet 5 located on the non-skin side and the outer sheet 6 to each other by a plurality of connected zones 8 obtained by fusion bonding and dispersed .

[0037]

As shown in FIG. 2, in the diaper 1, the connected zones 8 obtained by bonding the sheet 5 located on the non-skin side and the outer sheet 6 by fusion are preferably arranged at intervals in a row along the longitudinal direction (X direction) in an area extending from the waist elastic portion G1 to below the waist, the lower elastic portion G2 of each of the front zone A and the rear zone B, and the plurality of rows 8L of connected zones formed from the plurality of connected zones 8 are spaced along the lateral direction (Y direction).

[0038]

The connected zones 8 are formed by superposing on each other a sheet 5 located on the non-skin side and the outer sheet 6 and melting and curing the multilayer parts by hot stamping. The hot stamping device may be a device including an embossing roller and a support roller, while the outer peripheral surface of the embossing roller has a protrusion that corresponds in shape to the connected zones 8. Instead of hot stamping, as a technology for forming the connected zones 8, there can be used ultrasonic welding, laser and the like.

[0039]

To improve perspiration dispersibility in the diaper 1, the interval between the connected zones 8, 8 adjacent to each other in the longitudinal direction (X direction) and forming rows of 8L connected zones extending in the longitudinal direction (X direction) is preferably 1 mm or more and more preferably 3 mm or more, preferably 20 mm or less and more preferably 18 mm or less and, in particular, preferably 1 to 20 mm and more preferably 3 to 18 mm.

In addition, in order to increase the evaporation capacity of the sweat that has been absorbed, the interval between rows of 8L, 8L connected zones adjacent to each other in the lateral direction (Y direction) is preferably 4 mm or more and more preferably 6 mm or more, preferably is 20 mm or less, and more preferably 16 mm or less, and in particular, is preferably 4 to 20 mm and more preferably 6 to 16 mm.

[0040]

The diaper 1 includes a plurality of elastic elements 71 placed in a state in which they are stretched in the lateral direction (Y direction), and spaced apart along the longitudinal direction (X direction) between the sheet 5 located on the side not facing the skin, and an outer sheet 6 attached to each other by connected zones 8. As shown in FIG. 2, in the diaper 1 in the zone extending from the waist elastic portion G1 to the lower elastic portion G2 of each of the front zone, located below the waist A and the rear zone B, the plurality of elastic members 71 are preferably arranged in a state in which they are laterally stretched (Y direction) in the gaps between the connected zones 8 of the plurality of rows 8L of connected zones. As shown in FIGS. 2 and 3, in order to prevent sweat from returning from the sheet 5 located on the non-skin side to the skin, in the diaper 1, the fastened sections 42 are preferably located and the openings 44 of the sheets 4 located on the side facing the skin skin are also preferably located between the elastic elements 71, 71 adjacent to each other in the longitudinal direction (X direction).

[0041]

In addition, as shown in FIG. 2, in the diaper 1, two fixation zones 3T1, 3T1 located on the outside, formed by joining the sheet 5 located on the non-skin side and the outer sheet 6 by using an adhesive for fixing elastic elements are located on both side edges 3a1, 3a1 of the front zone A of the outer covering element 3 and both side edges 3b1, 3b1 of the back zone B of the outer covering element 3, and two fixation zones 3T2, 3T2 located on the set side, formed Uteem compounds sheet 5 disposed on the side not facing the skin, and the outer sheet 6 by using the adhesive for fixing the elastic elements are arranged next to both lateral sides of the absorbent kit 2 extending along the longitudinal direction (direction X).

[0042]

In each of the waist elastic parts G1 of the diaper 1, a plurality of elastic elements 71 are arranged so that they extend between two fixation zones 3T1, 3T1 located on the outside, and the elastic elements 71 are fixed between the sheet 5 located on the side not facing the skin, and an outer sheet 6 in both fixation zones 3T1, 3T1 located on the outside, but not attached to either the sheet 5 located on the side not facing the skin or the outer sheet 6 between two fixation zones 3T1, 3T1 one hundred ones.

In addition, in each of the lower elasticated parts G2 of the diaper 1 located below the belt, a plurality of elastic elements 71 are arranged so that they extend from the fixation zone 3T1 located on the outside to the fixation zone 3T2 located on the kit side and the elastic elements 71 fixed between the sheet 5, located on the side not facing the skin, and the outer sheet 6 in all zones 3T1 fixation, located on the outside, and zones 3T2 fixation, located on the side of the kit, but not attached to the sheet 5, located decomposition on the side not facing the skin, or to the outer sheet 6 between the fixing zones 3T1 disposed on the outer side, and 3T2 fixing zones located toward the kit. In each of the lower elasticated parts G2 of the diaper 1 located below the belt, the elastic elements 71 are not located between the two fixation zones 3T2, 3T2 located on the side of the kit, or are located between them in a state in which they are cut into small parts so that they do not manifest its elasticity.

[0043]

In each of the leg-adapted, elasticized portions G3 of the diaper 1, a plurality of leg elastic members 72 arranged in a state in which they are stretched along the peripheral edges of the leg openings LO are secured between the sheet 5 located on the non-skin side, and the outer sheet 6 by means of an adhesive for fixing elastic elements, placed with a flat shape along the peripheral edges of the holes LO for the legs.

[0044]

As shown in FIGS. 1 and 6, the diaper 1 includes an assembled portion G formed by deforming the sheets 4 located on the side facing the skin so that they are curved inwardly into the diaper 1, due to the contraction of the plurality of elastic elements 71, placed in a state in which they are stretched in the lateral direction (Y direction), between the sheet 5, located on the side not facing the skin, and the outer sheet 6 and placed at intervals along the longitudinal direction (X direction). In the outer covering element 3 of the diaper 1, the assembled portion G is preferably formed by deforming the outer sheet 6 between rows of connected zones 8L, 8L adjacent to each other in the lateral direction (Y direction), by bending outward and deforming the sheets 4 located on the side facing to the skin, and the sheet 5, located on the side not facing the skin, which are attached to each other by adhesive 9, by arching inward as a result of pulling together many elastic elements 71 placed in a the line in which they are stretched in the lateral direction (Y direction), between the sheet 5, located on the side not facing the skin, and the outer sheet 6 and placed at intervals along the longitudinal direction (X direction), in the elasticated waist parts G1 and located below the waist, lower elastic parts of G2. The folds 3F formed from the outer sheet 6 or sheets 4 located on the side facing the skin and the sheet 5 located on the side not facing the skin are formed between the rows 8L, 8L of connected zones adjacent to each other and the hollow parts 3H, surrounded by folds 3F and folds 3F, are formed between the outer sheet 6 and sheets 4 located on the side facing the skin and the sheet 5 located on the side not facing the skin.

[0045]

To move the sweat of the wearer towards the sheet 5, located on the side not facing the skin, when viewed in cross section of the assembled portion G formed by tightening the elastic elements 71 as in FIG. 6, preferably 60% or more of all the bonded sections 42 and more preferably 75% or more of all the bonded sections 42 are located from a place that is halfway deep d4 of the recesses recessed towards the non-skin side of the sheets 4 located on the skin side, d on the side with protrusions (the side of the surface facing the skin), and the upper limit is preferably 100%.

[0046]

Subsequently, materials for forming the constituent elements of the diaper 1 will be described.

The sheets 4 located on the side facing the skin are sheets formed from a hydrophobic nonwoven material or the like formed from a hydrophobic fiber, and the sheet 5 located on the side not facing the skin is a sheet formed from a hydrophilic nonwoven a material or the like formed from a hydrophilic fiber.

In the diaper 1, sheets 4 located on the side facing the skin and forming the outer covering element 3 are formed from folded parts 6R of the outer sheet 6, and therefore, the entire outer sheet 6, including the back folded parts 6R (sheets 4 located on the side facing the skin) is formed from a hydrophobic sheet formed from a hydrophobic fiber, and a sheet 5 located on the side not facing the skin, which is separate from the outer sheet 6, is formed from a hydrophilic sheet.

[0047]

The hydrophobic fiber forming the hydrophobic sheet used for the outer sheet 6 (including sheets 4 located on the side facing the skin) may be a synthetic fiber and, in particular, may be fibers commonly used as constituent fibers of various nonwoven materials and examples thereof include: polyolefin fibers, such as polyethylene (PE) fiber and polypropylene (PP) fiber, fibers that use a thermoplastic resin, such as polyethylene terephthalate (PET) or liamide separately, and multicomponent fibers, such as multicomponent fibers with a core and cladding and with the arrangement of components side by side.

[0048]

The hydrophilic fiber forming the hydrophilic sheet used for the sheet 5 located on the side not facing the skin may be a fiber obtained by hydrophilization of a synthetic fiber, and in particular, may be a fiber obtained by treating a hydrophobic synthetic fiber with a hydrophilicity improver or fiber obtained by interfering with a hydrophilicity agent in the fiber. In addition, a composite non-woven material obtained by mixing a hydrophilic fiber in a natural state, such as natural or semi-natural fiber, with synthetic fiber can be used. There is no particular limitation on synthetic fibers, and examples thereof include: polyolefin fibers such as polyethylene (PE) fiber and polypropylene (PP) fiber, fibers that use a thermoplastic resin such as polyethylene terephthalate (PET) or polyamide according to separately, and multicomponent fibers, such as multicomponent fibers with a core and cladding and with the arrangement of components side by side. There is no particular limitation on the hydrophilicity enhancing agent used to impart hydrophilicity to the synthetic fiber, provided that it is a conventional hydrophilicity enhancing agent used on hygiene products. Specific examples of the hydrophilic fiber include: natural cellulosic fibers, such as fibers of wood pulp and non-wood pulp, for example, cotton pulp and straw pulp, and hydrated cellulose fibers, such as viscose fiber and dome-fiber. In addition, examples of a hydrophilic sheet may include hydrophilic fabrics in addition to hydrophilic non-woven materials. Examples of types of hydrophilic non-woven materials include a nonwoven fabric bonded through air through, a non-woven fabric spunbond production method, a non-woven fabric bonded by heated rollers, a hydro-entangled non-woven fabric, and a melt-woven nonwoven fabric.

[0049]

Whether the sheet forming fiber is hydrophilic or hydrophobic can be determined based on the contact angle of the constituent fiber determined using the “Method for Measuring the Contact Angle of the Fiber”, which will be described later. In particular, if the contact angle is 90 ° or more, it will be determined that the fiber is a hydrophobic fiber with low hydrophilicity, and if the contact angle is less than 90 °, it will be determined that the fiber is hydrophilic with a high hydrophilicity

Fiber contact angle measurement method

The contact angle is determined, for example, by using the MCA-J instrument for measuring the contact angle manufactured by Kyowa Interface Science Co., Ltd. In particular, immediately after the ion-exchange water (about 20 picoliters) is dripped onto the surface of the fiber forming the outer periphery 43, the contact angle is measured using a contact angle measuring device. The measurement is performed at five or more points on the fiber forming a section near the inner peripheral walls 42e of the bonded sections 42, or on the fiber forming a section near the outer edges of the depressed sections 41, and the average value calculated for them is taken as the contact angle. It should be noted that the temperature of the medium in which the measurements are performed is set to 20 ° C.

[0050]

As the topsheet 21, backsheet 22, absorbent member 23, leakproof cuffs 24, and the like components forming the absorbent assembly 2, various types of elements commonly used for absorbent articles, such as disposable diapers, can be used without any particular limitation. For example, the topsheet 21 may be a single layer or multilayer nonwoven material, a foil with holes, or the like. The backsheet 22 may be a moisture permeable polymer film or the like. The absorbent member 23 may be an absorbent core formed from absorbent polymer particles and fibrous materials wrapped in tissue paper. In addition, leakage protection cuffs 24 may be a water repellent single layer or multilayer nonwoven material or the like.

[0051]

Examples of material for forming elastic elements (elastic elements 25 forming cuffs that protect against leakage, elastic elements 71, elastic elements for legs 72, etc.) include synthetic rubber such as styrene butadiene, butadiene, isoprene and neoprene, natural rubber, ethylene vinyl acetate copolymer (EVA), flexible polyolefin and polyurethane. Regarding the shape of the elastic elements, thread-like elastic elements (rubber thread, etc.) or cord-shaped elastic elements (flat rubber cord, etc.) having a rectangular, square, round, elliptical or polygonal transverse shape can preferably be used. sections or the like.

[0052]

The various types of hot-melt adhesives and the like commonly used for absorbent articles, such as disposable diapers, can be used without any particular limitation as an adhesive for fixing elastic elements, namely, adhesive 9 for fixing elastic elements (elastic elements 25 forming cuffs that protect against leakage, elastic elements 71, elastic elements 72 for legs, etc.) and adhesive for fixing the kit designed to fix the outer covering e ementa 3, the absorbent kit 2 and the like.

[0053]

In the following, the effects and effects obtained by using the diaper 1 according to the above embodiment of the present invention will be described.

As shown in FIGS. 2-5, in the diaper 1, at least the back waist valve FB has a hydrophobic sheet 4 located on the side facing the skin and a hydrophilic sheet 5 located on the side not facing the skin, the hydrophobic sheet 4, located on the side facing the skin, includes depressed portions 41 depressed towards the sheet 5 located on the side not facing the skin, and holes 44 in the corresponding depressed portions 41. The thickness of each depressed portion 41 of the sheets 4, located on the side facing to Auger, decreases towards the hole 44. That is, the interfiber distance between the constituent fibers gradually decreases towards the holes 44. Accordingly, when the diaper 1 is worn, the sweat of the carrier is likely to be drawn from areas other than the depressed sections 41 in the direction to the indented portions 41, and the thickness of the indented portions 41 decreases towards the hole 44, and therefore, sweat is likely to quickly move from the holes 44 to the hydrophilic sheet 5, located on the side not facing to same. It is unlikely that the sweat of the carrier thus moved inside the hydrophilic sheet 5 located on the side not facing the skin will return to the hydrophobic sheets 4 located on the side facing the skin or the skin. Thus, the sweat of the wearer that has been moved to the sheet 5 located on the non-skin side, the non-skin surface side is likely to not come into contact with the skin, and therefore skin problems can be reduced. such as eczema, prickly heat, and rash.

[0054]

In addition, as shown in FIGS. 2 and 4, in the diaper 1 there are fastened portions 42 in which the constituent fibers of the sheets 4 located on the side facing the skin are attached to each other, are located in the corresponding depressed portions 41. In addition, fastened sections 42 include sections in which the constituent fibers of sheets 4 located on the side facing the skin are molten and attached to each other without a gap between them. In the diaper 1, holes 44 are formed inside the bonded sections 42. The fiber density of the bonded sections 42 is higher than the density of the outer periphery fibers 43 of the holes 44 in the depressed portions 41, and the fiber density of the outer peripheries 43 is higher than the fiber density of the portions other than the pressed portions 41. The portions that are bonded without a gap between the fibers, are areas that are not permeable to liquids that do not allow liquids to pass through them, but are areas with relatively high hydrophilicity, and therefore flaxly, when wearing the diaper 1, the sweat of the carrier is more likely to be pulled from areas other than the depressed portions 41 towards the depressed portions 41, and the sweat is more likely to quickly move from the outer peripheries 43 with a high fiber density through the openings 44 of the fastened portions 42 into a hydrophilic sheet 5 located on the side not facing the skin. Thus, the sweat of the wearer is more likely to move to the sheet 5 located on the side not facing the skin, on the side not facing the skin, and therefore skin problems such as eczema, sweating and rash can be further reduced. In addition, in the diaper 1, the portions that are fastened without a gap between the fibers are made in the form of a film, and therefore, the above effects are achieved in a more reliable manner. In addition, if the basis weight of the sheets 4 located on the side facing the skin is 30 g / m ² or less, the above effects are achieved in a more reliable manner.

[0055]

In addition, as shown in FIG. 2, in the diaper 1, the hydrophobic outer sheet 6 is located on the non-skin side of the surface of the sheet 5 located on the non-skin side, and a plurality of elastic elements 71 are placed in the state in which they are stretched in the lateral direction (Y direction), and pass through the gaps between the connected zones 8 of the plurality of rows 8L of connected zones in zones extending respectively from the waist elastic parts G1 to the lower elastic parts G2 located below the belt. As shown in FIG. 6, when the elastic elements 71 are pulled together in a stretched state, the folds 3F formed from sheets 4 located on the side facing the skin and a sheet 5 located on the side not facing the skin and the outer sheet 6 are created between rows 8L, 8L of connected zones adjacent to each other, and hollow parts 3H surrounded by folds 3F and folds 3F are formed between sheets 4 located on the side facing the skin and sheet 5 located on the side not facing the skin, and the outer sheet 6. Accordingly, p The ability to evaporate the perspiration of the carrier, which was transferred to the sheet 5 located on the side not facing the skin, is increased, and skin problems such as eczema, prickly heat and a rash can be further reduced.

[0056]

To facilitate reliable movement of the sweat of the carrier in the sheet 5, located on the side not facing the skin, the interfiber distance between the constituent fibers forming the sheets 4, located on the side facing the skin, in the depressed portions 41 is preferably less from the side of the holes 44 than the side outer with respect to the holes 44. More specifically, the interfiber distance between the fibers forming the thin zones 43ST located on the side of the holes on the outer peripheries 43 is preferably 4/5 or less and more preferably 2/5 or less of the interfiber distance between the fibers forming the portions located adjacent to the outer edges of the depressed portions 41, on the outer peripherals 43.

The interfiber distance between the fibers forming the thin zones 43ST located on the side of the holes on the outer periphery 43, and the interfiber distance between the fibers forming the areas located near the outer edges of the depressed portions 41, is determined using the method below. A smaller interfiber distance determined using the method below indicates a higher hydrophilicity.

[0057]

Method for determining the interfiber distance

For each measurement site, the basis weight, density, thickness and weight number of the fiber are determined, and the interfiber distance is calculated according to Formula 1. When measuring different sections of the same sheet, the basis weight and the weight number of the sheet fibers do not change, and only the thickness of the sections changes. The thickness is measured as follows. The thickness of the sheet is measured by cutting the sheet including the measurement portion in the thickness direction using a knife, cutter, razor or the like so that the side obtained by cutting does not wrinkle, and inspecting the section obtained by cutting using a microscope, and thus measure the thickness of the plot for measurements. The thickness is measured at ten different points, and the average value calculated for them is taken as the thickness of the section for measurements.

[0058]

To facilitate the effects described above, the contact angle between the sheets 4 located on the side facing the skin in the depressed portions 41 and the ion exchange water is preferably smaller on the side of the holes 44 than on the side external to the holes 44. In other words, the hydrophilicity of the sheets 4, located on the side facing the skin in the depressed portions 41 is preferably larger on the side of the holes 44 than on the side external to the holes 44. More specifically, sheets located on the side facing the skin, and about the side-forming openings 44 (thin zones 43ST located on the side of the openings) on the outer peripheries 43 have a contact angle with respect to ion-exchanged water, which is preferably 120 ° or less and more preferably 110 ° or less. There is no particular limitation on the lower limit of the contact angle of sheets located on the side facing the skin and having such a configuration, but the lower limit is 90 °, since the sheets located on the side facing the skin are hydrophobic.

In addition, the sheets located on the side facing the skin and forming a side external to each hole (near the outer edges of the depressed portions 41 on the outer periphery 43) have a contact angle with respect to ion exchange water, which is preferably 120 ° or more and more preferably 130 ° or more. If the upper limit value of the contact angle of sheets located on the side facing the skin and having such a configuration is 180 °, fairly satisfactory results are obtained.

In addition, the difference in the contact angle of the sheets located on the side facing the skin, on the side of the holes 44 (in thin zones 43ST located on the side of the holes) and the ion exchange water and the contact angle between the side external to the hole 44, (next to the outer edges of the depressed portions 41 on the outer periphery 43) and the ion exchange water is preferably large. More specifically, the difference in contact angles is preferably 10 ° or more, and more preferably 20 ° or more.

The contact angle between the sheets located on the side facing the skin and forming thin zones 43ST located on the side of the holes on the outer periphery 43, or the sheets located on the side facing the skin, and forming sections near the outer edges of the depressed sections 41 on the outer periphery 43, and ion exchange water is measured using the method below. A smaller contact angle measured using the method below indicates a higher hydrophilicity.

[0059]

Method for measuring sheet contact angle

The measurement was carried out using a zoom lens with an average magnification, tilted at an angle of 90 ° relative to the VHX-100 microscope manufactured by Keyence Corporation. As a sample for measurements, we used a part of the sheet cut with a size in the direction of MD of the movement of the semi-finished product in the machine, which is 150 mm, and a size in the direction of CD, transverse to the direction of MD, of 70 mm. The parameters of the medium in which the measurements were carried out were set as follows: 20 ° C / relative humidity 50%, and the sample for measurements was placed on the measuring table with the measuring surface oriented upwards so that the sheet could be examined in its direction CD . After that, 3 μl of ion-exchanged water was supplied to the measurement portions (thin zones 43ST located on the side of the holes on the outer periphery 43 and areas near the outer edges of the depressed portions 41 on the outer periphery 43) in a measurement sample placed on the measurement table , and their image was recorded. The contact angle was measured at ten points at which when viewed, both ends or one end of the water droplet on the sheet were clearly in focus, and the average value for them was calculated as the “contact angle".

[0060]

To absorb large amounts of sweat and reduce the amount of sweat that comes in contact with the skin, and to prevent sweat from returning from the sheet located on the side not facing the skin to the skin, sheet 5 located on the side not facing the skin has weight a base which is preferably 10 g / m ² or more and more preferably 20 g / m ² or more, preferably 50 g / m ² or less and more preferably 30 g / m ² or less and, in particular, is preferably from 10 to 50 g / m ² and more preferably 20 to 30 g / m ² .

For the same reasons, the sheet 5 located on the side not facing the skin is such that its portions other than the depressed portions 41 have a thickness that is preferably 100 μm or more and more preferably 150 μm or more, preferably 800 μm or less and more preferably 500 microns or less and, in particular, preferably is from 100 to 800 microns and more preferably from 150 to 500 microns. The thickness of the sheet 5 located on the side not facing the skin is measured using a thickness gauge in a state where a pressure of 0.05 kPa is applied to the sheet 5 located on the side not facing the skin. A laser displacement sensor manufactured by Omron Corporation is used as a thickness gauge. The thickness is measured at ten points, and the average value calculated for them is taken as the thickness.

[0061]

To facilitate reliable transfer of the carrier sweat to the sheet 5 located on the non-skin side, the sheet 5 located on the non-skin side has a hydrophilic fiber content with respect to all constituent fibers, preferably 80% by weight. or more and more preferably 90% of the mass. or more, and the lower limit of the content of hydrophilic fibers is preferably 70% of the mass.

[0062]

In addition, in order to facilitate reliable movement of the sweat of the carrier to the sheet 5 located on the side not facing the skin, the sheet 5 located on the side not facing the skin has a height of 30 mm with a width of 30 mm of water rise during the absorption test according to the Clem method, measured according to JIS (JIS - Japanese Industrial Standard) P 8141, preferably constituting 20 mm or more in 60 seconds and more preferably 25 mm or more in 60 seconds. There is no particular limitation with respect to the upper limit of the height of the water in the absorption test according to the Clem method for sheet 5 located on the side not facing the skin, however, satisfactory results are obtained if it is 30 mm in 60 seconds.

The height of the water in the absorption test according to the Klemm method for a sheet 5 located on the side not facing the skin is measured using the method below.

[0063]

Klemm method for determining the height of water rise

when tested for absorption

If, when removing sheet 5 located on the side not facing the skin from the outer covering element of the pull-on disposable diaper, sheets 4 located on the side facing the skin, sheet 5 located on the side not facing the skin, and the outer sheet 6 is fused or bonded to each other by adhesive, bonded portions are removed by fusion or the like using a solvent or heated air from a dryer or the like, and thereby Article 5, located on the side not facing the skin. The extracted sheet 5, located on the side not facing the skin, is taken as a sample, and the height of the water in the absorption test according to the Klemm method is determined for it according to the test method defined in JIS P 8141. In particular, from the extracted sheet 5, located on the side not facing the skin, a part with a width (length in the longitudinal direction (X direction) of the diaper 1) of 30 mm and a length (length in the lateral direction (Y direction) of the diaper 1) of 150 mm is cut out. When performing cutting, cutting methods in which the sample may flatten due to pressure, such as methods that use a pressure cutter, are not preferred because they can seriously affect the results. Thus, when performing cutting, the sample is cut using a knife, cutter, razor or the like so that its side obtained by cutting does not wrinkle. After that, the cut-out sample is placed on the device defined in JIS P 8141, and the height of the water in the Klemm absorption test is measured after 60 seconds using water as the test liquid. The test fluid can be colored appropriately by using a dye such as No. 1 Blue or methylene blue, so that the lifting height when absorbed can be easily seen. This measurement is performed five times, and the average value is calculated as the height of the water in the absorption test according to the Clem method for sheet 5, located on the side not facing the skin. It should be noted that the temperature of the medium in which the measurements are performed is set equal to 22 ° C.

[0064]

In addition, to facilitate reliable transfer of the sweat of the carrier to the sheet 5 located on the side not facing the skin, the sheet 5 located on the side not facing the skin has an amount of absorbed ion-exchange water when saturated, preferably 75 g / m ² or more and more preferably 100 g / m ² or more. There is no particular limitation with respect to the upper limit of the amount of water absorbed by the sheet 5, located on the side not facing the skin, when saturated, but fairly satisfactory results are obtained if it is 300 g / m ² .

The amount of water absorbed by the sheet 5, located on the side not facing the skin, when saturated, is determined using the method below.

[0065]

Method for determining the amount of absorbed water at saturation

A sample for measurements is obtained by cutting from a sheet located on the side not facing the skin a part with a width of 50 mm and a length of 50 mm. The measurement sample is immersed in ion-exchange water, the temperature of which is adjusted to 25 ° C. The sample is removed from the ion exchange water five minutes after the start of the dive, and then it is drained by suspension in a vertical state for 30 seconds. The mass of the sample that has absorbed the water is measured, and the desired amount of absorbed water at saturation is calculated using the formula below. The calculation is performed as follows: Amount (g / m ² ) of absorbed water at saturation = (mass (g) of the sample after water absorption - mass (g) of the sample before water absorption) / (area 0.05 m × 0.05 m of sample measurements). This measurement is performed five times, and the average value is calculated as the amount of water absorbed by the sheet 5, located on the side not facing the skin, when saturated.

[0066]

Although the present invention has been described above, the present invention is not limited to the above embodiment, and changes can be made accordingly.

For example, the above-described diaper 1 is such that the sheets 4 located on the side facing the skin and forming the outer covering element 3 are formed from folded sections 6R of the outer sheet 6, as shown in FIG. 2, but they can be hydrophobic sheets ( nonwovens), separate from the outer sheet 6. If such sheets 4, located on the side facing the skin, are arranged as separate elements, it is sufficient that at least the back waist valve FB from the front waist valve FA and the back waist valve FB was made with such a sheet 4, located on the side facing the skin, as a separate element.

[0067]

In addition, as shown in FIG. 4, in the diaper 1, the number of hydrophilic sheets 5 located on the non-skin side and provided at least in the back waist flap FB is one, but may be two or more. If the number of hydrophilic sheets 5 located on the side not facing the skin is two or more in this way, their hydrophilicity preferably increases in accordance with an increase in the distance from the skin of the carrier. That is, in comparison with the sheet located on the side not facing the skin, which is adjacent to the sheet 4, located on the side facing the skin, at least any value of the above hydrophilic fiber content with respect to all constituent fibers, the above weight of the base of the sheet, located on the side not facing the skin, the above height of rise of water when tested for absorption by the method of Clem, and the above amount of absorbed water when saturated, will preferably increase compared with the corresponding value for a sheet disposed on the side not facing the skin, which is adjacent to the sheet 4 disposed on the side facing the skin, in accordance with increasing distance from the sheet 4 disposed on the side facing the skin. In addition, compared with the sheet located on the side not facing the skin, which is adjacent to the sheet 4, located on the side facing the skin, at least any value from the interfiber distance between the fibers forming the sheet located on the side , not facing the skin, and the contact angle between the fibers forming a sheet located on the side not facing the skin, and ion exchange water will preferably decrease compared with the corresponding value for the sheet located on the side, not about facing the skin, which is adjacent to the sheet 4, located on the side facing the skin, in accordance with the increase in the distance from the sheet 4, located on the side facing the skin. The contact angle between the fibers forming the sheet, located on the side not facing the skin, and ion exchange water is measured using the method described above. In addition, the interfiber distance between the fibers forming the sheet located on the side not facing the skin is determined using the method below.

[0068]

Method for determining the interfiber distance

The interfiber distance can be obtained by using the formula 1 below.

(1)Interfiber distance (μm) = 10 ⁴

(one)

wherein L represents the thickness (cm) of the sheet ( sheet 4 located on the side facing the skin, sheet 5 located on the side not facing the skin or outer sheet 6 ), w represents the weight of the base (g / m ² ) of the sheet, Di represents the weight number of the fiber in denier for the component fiber i forming the sheet, and αi represents the percentage (%) of the mass of the component fiber i expressed as a percentage.

[0069]

In addition, as shown in FIG. 2, in the outer covering element 3 of the diaper 1, the outer sheet 6 and the sheet 5 located on the side not facing the skin are connected and attached to each other by a plurality of connection zones 8 obtained by fusion bonding, and sheets 4 located on the side facing the skin and sheet 5 located on the side not facing the skin are attached to each other by adhesive 9, but adhesive 9 may not be provided. In addition, as shown in FIG. 2, in the outer covering element 3 of the diaper 1, elastic elements 71 are placed between the outer sheet 6 and the sheet 5 located on the side not facing the skin, but the elastic elements 71 may not be provided between them.

[0070]

In addition, as shown in FIG. 2, the above-described disposable diaper 1 is a pull-on disposable diaper in which the outer covering member 3 is hourglass or the like and runs continuously from the front zone A through the crotch zone C to the back zone B, but it may be a pull-on disposable diaper in which the outer covering element 3 is a separate type element and is divided into separate elements consisting of a front outer covering element nta, the back outer covering element and the perineal outer covering element.

[0071]

In addition, as shown in FIG. 1, the above-described disposable diaper 1 is a pull-on disposable diaper having an outer covering member 3, but it may be a disposable diaper of the type disclosed. In the case of a disposable diaper type including a liquid permeable top sheet, a minimum liquid permeable top sheet, a back sheet and an absorbent element between these sheets, the top sheet corresponds to the sheet 5 located on the side not facing the skin. It is sufficient that at least a rear waist valve FB from the front waist valve FA and the rear waist valve FB extending laterally Y and located outside of the front and rear ends of the absorbent element, respectively defined in the longitudinal direction X, is provided with hydrophobic sheet 4, located on the side facing the skin, as a separate element, which forms a surface in contact with the skin.

[0072]

In connection with the above embodiments, the following disposable diapers will be further disclosed.

[0073]

<1> A disposable diaper comprising, in a longitudinal direction, a front zone, a rear zone and a crotch zone located between the front zone and the rear zone, having an absorbent element extending from the front zone to the rear zone, and having a front waist valve and a rear waist valve extending in the lateral direction and located outside of the front and rear end portions of the absorbent element in the longitudinal direction, respectively, while at least the rear waist valve has a hydrophobic sheet located on the side facing the skin, which forms the surface in contact with the skin, and a hydrophilic sheet located on the side not facing the skin, which is located on the side not facing the skin of the surface of the sheet located on the side facing the skin, the sheet located on the side facing the skin includes a plurality of depressed portions depressed towards the sheet located on the side not facing the skin, and holes formed in the sheet located on the side facing the skin, respectively in the depressed portions, and each depressed portion of the sheet located on the side facing the skin has a thickness that decreases towards the hole.

<2> A disposable diaper according to paragraph <1>, in which each hole of the sheet located on the side facing the skin has a diameter that is from 0.5 to 3 mm.

<3> A disposable diaper according to <1> or <2>, wherein the peripheral edge of each hole of the sheet located on the side facing the skin has a thickness that is 1/10 or less of the diameter of the hole.

<4> A disposable diaper according to any one of <1> to <3>, in which each hole of the sheet located on the side facing the skin is formed in a thin zone of the depressed portion with a thickness that is 70% or less of the thickness of the parts, different from the depressed area, in a sheet located on the side facing the skin.

[0074]

<5> A disposable diaper according to <4>, wherein the thin zone of each depressed portion has a ring shape and has a diameter that is 1.5 times or more greater than the diameter of the opening.

<6> A disposable diaper according to any one of <1> to <5>, wherein the sheet located on the side facing the skin includes, in each depressed portion, a bonded portion in which the constituent fibers of the sheet located on the side facing to the skin, are attached to each other, while the bonded section includes a section in which the constituent fibers of the sheet located on the side facing the skin are fused and attached to each other without a gap between them, and a hole is formed inside the bonded section.

<7> A disposable diaper according to any one of <1> to <6>, in which the sheet located on the side facing the skin in the depressed portion has hydrophilicity, which is greater on the side of the hole than on the side external to the hole .

<8> A disposable diaper according to any one of <1> to <7>, wherein the disposable diaper includes a hydrophobic outer sheet on the non-skin side of the sheet located on the non-skin side and a plurality of elastic elements, placed in a state in which they are stretched in the lateral direction of the disposable diaper, between the sheet located on the side not facing the skin and the outer sheet and placed at intervals along the longitudinal direction of the disposable diaper, and each hole of the sheet and, located on the side facing the skin, is located between the elastic elements adjacent to each other in the longitudinal direction.

<9> A disposable diaper according to any one of <1> to <8>, wherein the sheet located on the side facing the skin includes in each depressed portion a bonded portion in which the constituent fibers of the sheet located on the side facing attached to each other, a sheet located on the side facing the skin, and a sheet located on the side not facing the skin are attached to each other by adhesive, and the portion in which the adhesive is placed overlaps the bonded portion of the sheet located on the part of Rotate to the skin.

[0075]

<10> A disposable diaper according to any one of <1> to <9>, wherein the sheet located on the side facing the skin includes in each depressed portion a bonded portion in which the constituent fibers of the sheet located on the side facing to the skin, are attached to each other, and the bonded portion is made so that the portion that is bonded is made in the form of a film.

<11> A disposable diaper according to any one of <1> to <10>, wherein the disposable diaper has a hydrophobic outer sheet on the non-skin side of the sheet located on the non-skin side and a sheet located on the side facing the skin, formed from the folded back part of the outer sheet.

<12> A disposable diaper according to any one of <1> to <11>, wherein the sheet located on the side facing the skin includes, in each depressed portion, a bonded portion in which the constituent fibers of the sheet located on the side facing to the skin, attached to each other, and

holes (bonded areas in which the holes are located) are spaced on the entire sheet located on the side facing the skin.

<13> A disposable diaper according to any one of <1> to <12>, wherein the sheet located on the side facing the skin includes in each depressed portion a bonded portion in which the constituent fibers of the sheet located on the side facing attached to each other, the bonded sections respectively have holes and are spaced apart in a row along the longitudinal direction, and the plurality of rows of bonded sections formed from the plurality of bonded sections are spaced along the side about direction.

<14> A disposable diaper according to <13>, wherein the interval between the fastened portions adjacent to each other in the longitudinal direction and forming rows of fastened portions extending in the longitudinal direction is preferably 1 mm or more, and more preferably 3 mm or more, preferably 20 mm or less, and more preferably 18 mm or less.

[0076]

<15> A disposable diaper according to <13> or <14>, wherein the interval between the rows of fastened portions adjacent to each other in the lateral direction is preferably 4 mm or more and more preferably 6 mm or more, preferably 20 mm or less and more preferably 16 mm or less.

<16> A disposable diaper according to any one of <1> to <15>, wherein the sheet located on the side facing the skin includes, in each depressed portion, a bonded portion in which the constituent fibers of the sheet located on the side facing attached to each other, and when the depth of the depressed portion at the inner peripheral wall of the bonded portion is d3, then the thickness at a location outside of the inner peripheral wall of the bonded portion is 0.50 of the depth d3 is preferably from 20 to 75% and more preferably from 30 to 65% of the thickness d2 of the sections other than the depressed section.

<17> A disposable diaper according to any one of <1> to <16>, wherein the sheet located on the side facing the skin includes, in each depressed portion, a bonded portion in which the constituent fibers of the sheet located on the side facing to the skin are attached to each other, and the thickness at a location that is outside the inner peripheral wall of the bonded portion at a distance from it exceeding 1.5 times the depth d3 is preferably 55 to 95% and more preferably 70 to 90 % of thickness d2 of parts other than depressed area.

<18> A disposable diaper according to any one of <1> to <17>, wherein the sheet located on the side facing the skin includes in each depressed portion a bonded portion in which the constituent fibers of the sheet located on the side facing attached to each other, a bonded portion of the sheet located on the side facing the skin is such that the inner peripheral wall of the bonded portion has a thickness d5, which is preferably 60 μm or less and more preferably 45 μm or less, and its lowerthe limit is 10 μm.

<19> A disposable diaper according to any one of <1> to <18>, in which each hole of the sheet located on the side facing the skin has a diameter L1, which is preferably 0.5 mm or more and more preferably 1 mm or more preferably 3 mm or less and more preferably 2.5 mm or less and, in particular, preferably 0.5 to 3 mm and more preferably 1 to 2.5 mm.

[0077]

<20> A disposable diaper according to any one of <1> to <19>, wherein the sheet located on the side facing the skin includes, in each depressed portion, a bonded portion in which the constituent fibers of the sheet located on the side facing attached to the skin, and the inner peripheral wall of the bonded portion has a thickness d5, which is preferably 1/10 or less and more preferably 1/30 or less of the hole diameter L1, and its lower limit is 1/50 of the diameter L1 holes.

<21> A disposable diaper according to any one of <1> to <20>, wherein the openings of the sheet located on the side facing the skin are such that the area of the inlet portion of one opening is preferably 0.5 mm ² or more and more preferably 0.75 mm ² or more, preferably 5 mm ² or less, and more preferably 4 mm ² or less.

<22> A disposable diaper according to any one of <1> to <21>, wherein the proportion of the area of all openings relative to the total area of the sheet located on the side facing the skin is preferably 1% or more, and more preferably 3% or more preferably 15% or less and more preferably 10% or less.

<23> A disposable diaper according to any one of <1> to <22>, in which each hole of the sheet located on the side facing the skin is preferably formed in a thin zone of the depressed portion with a thickness that is 70% or less of the thickness d2 areas other than the depressed portion in the sheet located on the side facing the skin, inside the outer periphery of the depressed portion, and more preferably formed in a thin zone located on the hole side and having a thickness that is 40% or less of the thickness d2,thin zone.

<24> A disposable diaper according to any one of <1> to <23>, wherein the thickness d2 of the portions other than the depressed portion in the sheet located on the side facing the skin is preferably 600 μm or less, and more preferably 350 μm or less, and its lower limit is 100 μm.

[0078]

<25> A disposable diaper according to any one of <1> to <24>, wherein a thin area of the outer periphery of each hole in the depressed portions is formed with a ring shape, as in the case of the outer periphery.

<26> A disposable diaper according to any one of <1> to <25>, wherein the thin zone of each depressed portion has a diameter L2 that preferably exceeds the hole diameter L1 by 1.5 times or more and more preferably 2 times or more, and its upper limit exceeds the hole diameter L1 by 3 times.

<27> A disposable diaper according to any one of <1> to <26>, wherein the sheet located on the side facing the skin has a base weight of 30 g / m ² or less, preferably 20 g / m ² or less, is preferably 9 g / m ² or more and more preferably 10 g / m ² or more.

<28> A disposable diaper according to any one of <1> to <27>, wherein the back waist valve and the front waist valve are formed by connecting and attaching the sheet 5 located on the non-skin side and the outer sheet 6 to each other by a plurality of connected zones 8 distributed dispersively.

<29> A disposable diaper according to any one of <1> to <28>, wherein the hydrophobic outer sheet is provided on a non-skin side of a sheet located on a non-skin side, the connected zones of a sheet located on a non-skin side facing the skin and the outer sheet are arranged at intervals in the form of a row along the longitudinal direction in the area extending from the waist elastic portion to the lower elastic portion of each of the front zone and the rear zone, and a plurality of rows are connected GOVERNMENTAL zones formed from a plurality of bonded areas are spaced along the lateral direction.

[0079]

<30> A disposable diaper according to <29>, wherein the interval between the connected zones adjacent to each other in the longitudinal direction and forming rows of connected zones extending in the longitudinal direction is preferably 1 mm or more, and more preferably 3 mm or more, preferably 20 mm or less, and more preferably 18 mm or less.

<31> A disposable diaper according to <29> or <30>, wherein the interval between the rows of connected zones adjacent to each other in the lateral direction is preferably 4 mm or more and more preferably 6 mm or more, preferably 20 mm or less and more preferably 16 mm or less.

<32> A disposable diaper according to any one of <1> to <31>, wherein the disposable diaper includes a hydrophobic outer sheet on the non-skin side of the sheet located on the non-skin side and a plurality of elastic elements, placed in a state in which they are stretched in the lateral direction of the disposable diaper, between the sheet located on the side not facing the skin and the outer sheet and placed at intervals along the longitudinal direction of the disposable diaper, and the sheet located on the side facing the skin, it has a bonded portion in each of the depressed portions, and

the bonded sections are preferably located and the openings of the sheet located on the side facing the skin are also preferably located between the elastic elements adjacent to each other in the longitudinal direction.

<33> A disposable diaper according to any one of <1> to <32>, wherein the disposable diaper includes a hydrophobic outer sheet on the non-skin side of the sheet located on the non-skin side and a plurality of elastic elements, placed in a state in which they are stretched in the lateral direction of the disposable diaper, between the sheet located on the side not facing the skin and the outer sheet and placed at intervals along the longitudinal direction of the disposable diaper, and the sheet located on the side facing the skin, it has a bonded portion in each of the depressed portions, and

when viewed in cross-section of the assembled portion formed by tightening the elastic elements, preferably 60% or more of all the bonded sections and more preferably 75% or more of all bonded sections are located from a place that is half the depth d4 of the recesses recessed towards not the skin side of the sheet located on the side facing the skin to the side with protrusions (the side of the surface facing the skin), and the upper limit is preferably 100%.

<34> A disposable diaper according to any one of <1> to <33>, wherein the interfiber distance between the constituent fibers forming the sheet located on the skin side in each depressed portion is preferably less on the hole side than on the external to the hole.

[0080]

<35> A disposable diaper according to any one of <1> to <34>, wherein the interfiber distance between the fibers forming a thin zone located on the hole side and having a thickness that is 40% or less of the thickness d2 of sections other than the depressed a portion on the outer periphery of the hole within a thin zone with a thickness that is 70% or less of the thickness d2, preferably 4/5 or less, and more preferably 2/5 or less of the interfiber distance between the fibers forming a portion near the outer edge eat a dent on the outer periphery.

<36> A disposable diaper according to any one of <1> to <35>, in which the sheet located on the side facing the skin and forming a thin zone located on the side of the hole, with a thickness that is 40% or less of the thickness d2 of sections other than the depressed portion on the outer periphery of the hole within a thin zone with a thickness that is 70% or less of the thickness of d2 has a contact angle with respect to ion exchange water that is preferably 120 ° or less and more preferably 110 ° or less.

<37> A disposable diaper according to any one of <1> to <36>, in which the sheet located on the side facing the skin and forming a portion near the outer edge of the depressed portion on the outer periphery of the hole has a contact angle with respect to the ion exchange water, which is preferably 120 ° or more and more preferably 130 ° or more.

<38> A disposable diaper according to any one of <1> to <37>, wherein the sheet located on the side facing the skin includes in each depressed portion a bonded section in which the constituent fibers of the sheet located on the side facing to the skin, attached to each other, and the difference in the contact angle between the area adjacent to the bonded area and the ion-exchange water and the contact angle between the area located near the outer edge of the indented area on the outer periphery of the hole and the ion-exchange water before ochtitelno it is large, and the difference of the contact angle is preferably 10 ° or more and more preferably 20 ° or more.

<39> A disposable diaper according to any one of <1> to <38>, wherein the sheet located on the side not facing the skin has a base weight that is preferably 10 g / m ² or more and more preferably 20 g / m ² or more, preferably 50 g / m ² or less, and more preferably 30 g / m ² or less.

[0081]

<40> A disposable diaper according to any one of <1> to <39>, wherein the sheet located on the side not facing the skin is such that its portions other than the depressed portions have a thickness that is preferably 100 μm or more and more preferably 150 μm or more, preferably 800 μm or less, and more preferably 500 μm or less.

<41> A disposable diaper according to any one of <1> to <40>, in which the sheet located on the side not facing the skin has a hydrophilic fiber content with respect to all constituent fibers, preferably 80% by weight. or more and more preferably 90% of the mass. or more, and the lower limit of the content of hydrophilic fibers is preferably 70% of the mass.

<42> A disposable diaper according to any one of <1> to <41>, in which the sheet, located on the side not facing the skin, has a water height of 30 mm when absorbing test according to the Clem method, measured according to JIS P 8141, preferably constituting 20 mm or more in 60 seconds, and more preferably 25 mm or more in 60 seconds.

<43> A disposable diaper according to any one of <1> to <42>, in which the sheet, located on the side not facing the skin, has an amount of absorbed ion exchange water when saturated, preferably 75 g / m ² or more, and more preferably 100 g / m ² or more.

Industrial applicability

[0082]

According to the present invention, the sweat that has been absorbed can be quickly moved to the side of the surface not facing the skin, and the severity of skin problems such as eczema, sweating and rash can be reduced.

Claims (51)

1. A disposable diaper comprising, in a longitudinal direction, a front zone, a rear zone and a crotch zone located between the front zone and the rear zone, having an absorbent element extending from the front zone to the rear zone, and having a front waist valve and a rear waist valve extending into lateral direction and located outside of the front and rear end portions of the absorbent element, respectively, in the longitudinal direction, however, at least the back waist valve has a hydrophobic sheet located on the side facing the skin, which forms a surface in contact with the skin, and a hydrophilic sheet located on the side not facing the skin, which is located on the side not facing the skin of the surface of the sheet located on the side facing the skin, the sheet from the side facing the skin includes a plurality of depressed portions depressed towards the sheet from the side not facing the skin, and holes formed in the sheet from the side facing the skin, respectively, in the depressed portions, and each depressed portion of the sheet from the side facing the skin has a thickness that decreases toward the hole. 2. The disposable diaper according to claim 1, in which each hole of the sheet located on the side facing the skin has a diameter that is from 0.5 to 3 mm. 3. The disposable diaper according to claim 1, in which the peripheral edge of each hole of the sheet located on the side facing the skin has a thickness that is 1/10 or less of the diameter of the hole. 4. The disposable diaper according to claim 1, in which each hole of the sheet located on the side facing the skin is formed in a thin zone of the depressed portion with a thickness that is 70% or less of the thickness of the sections other than the depressed portion in the sheet, located on the side facing the skin. 5. The disposable diaper according to claim 4, in which the thin zone of each depressed portion has the shape of a ring and has a diameter that exceeds the diameter of the hole by 1.5 times or more. 6. The disposable diaper according to claim 1, in which the sheet located on the side facing the skin includes in each depressed portion a bonded section in which the constituent fibers of the sheet located on the side facing the skin are connected to each other, moreover, the bonded section includes a section in which the constituent fibers of the sheet located on the side facing the skin are fused and connected to each other without a gap between them, and a hole is formed inside the bonded section. 7. The disposable diaper according to claim 1, in which the sheet located on the side facing the skin in the indented portion has hydrophilicity, which is greater on the side of the hole than on the outside of the hole. 8. The disposable diaper according to claim 1, in which the disposable diaper includes a hydrophobic outer sheet on the non-skin side of the sheet located on the non-skin side, and a plurality of elastic elements placed in the state in which they are stretched in the lateral direction of the disposable diaper, between the sheet located on the side not facing the skin, and the outer sheet and placed at intervals along the longitudinal direction of the disposable diaper, and each hole of the sheet located with the side facing the skin is located between elastic elements that are adjacent to each other in the longitudinal direction. 9. The disposable diaper according to claim 1, wherein the sheet located on the side facing the skin includes, in each depressed portion, a fastened portion in which the constituent fibers of the sheet located on the side facing the skin are attached to each other, moreover, the sheet located on the side facing the skin and the sheet located on the side not facing the skin are attached to each other by adhesive, and the portion in which the adhesive is placed overlaps the bonded portion of the sheet located on the side facing the skin e. 10. The disposable diaper according to claim 1, in which the sheet located on the side facing the skin includes, in each depressed portion, a bonded portion in which the constituent fibers of the sheet located on the side facing the skin are attached to each other, and the bonded portion is configured such that the portion that is bonded is in the form of a film. 11. The disposable diaper according to claim 1, wherein the disposable diaper has a hydrophobic outer sheet on the non-skin side of the sheet located on the non-skin side, and the sheet located on the skin side is formed from folded back section of the outer sheet. 12. The disposable diaper according to claim 1, wherein the sheet located on the side facing the skin includes, in each depressed portion, a fastened portion in which the constituent fibers of the sheet located on the side facing the skin are attached to each other, and holes are spaced throughout the sheet located on the side facing the skin. 13. The disposable diaper according to claim 1, wherein the sheet located on the side facing the skin includes, in each depressed portion, a fastened portion in which the constituent fibers of the sheet located on the side facing the skin are attached to each other, wherein the bonded portions respectively have holes and are spaced apart in a row along the longitudinal direction, and the plurality of rows of bonded portions formed from the plurality of bonded portions are spaced along the lateral direction. 14. The disposable diaper of claim 13, wherein the interval between the fastened portions adjacent to each other in the longitudinal direction and forming rows of fastened portions extending in the longitudinal direction is from 1 to 20 mm. 15. The disposable diaper according to item 13, in which the interval between the rows of fastened sections adjacent to each other in the lateral direction is from 4 to 20 mm 16. The disposable diaper according to claim 1, in which the sheet located on the side facing the skin includes, in each depressed portion, a bonded portion in which the constituent fibers of the sheet located on the side facing the skin are attached to each other to a friend, and when the depth of the depressed portion at the inner peripheral wall of the bonded portion is d3, then the thickness at a location that is outside of the inner peripheral wall of the bonded portion at a distance from it of 0.50 from depth d3 is from 20 to 75% of the thickness d2 of the sections other than the depressed section. 17. The disposable diaper according to claim 1, in which the sheet located on the side facing the skin includes in each depressed portion a bonded section in which the constituent fibers of the sheet located on the side facing the skin are attached to each other, and the thickness at a location that is outside the inner peripheral wall of the bonded portion at a distance from it that is 1.5 times greater than the depth d3 is 55 to 95% of the thickness d2 of the parts other than the depressed portion. 18. The disposable diaper according to claim 1, in which the sheet located on the side facing the skin includes, in each depressed portion, a bonded portion in which the constituent fibers of the sheet located on the side facing the skin are attached to each other friend, moreover, the bonded section of the sheet located on the side facing the skin is made so that the inner peripheral wall of the bonded section has a thickness d5 from 10 to 60 μm. 19. The disposable diaper according to claim 1, in which each hole of the sheet located on the side facing the skin has a diameter L1 of from 0.5 to 3 mm. 20. The disposable diaper according to claim 1, in which the sheet located on the side facing the skin includes, in each depressed portion, a bonded portion in which the constituent fibers of the sheet located on the side facing the skin are attached to each other friend, and the inner peripheral wall of the bonded section has a thickness d5, which is from 1/50 to 1/10 of the diameter L1 of the hole. 21. The disposable diaper according to claim 1, in which the holes of the sheet located on the side facing the skin are such that the area of the inlet of one hole is from 0.5 to 5 mm ² . 22. The disposable diaper according to claim 1, in which the proportion of the area of all holes relative to the total area of the sheet located on the side facing the skin is from 1 to 15%. 23. The disposable diaper according to claim 1, in which each hole of the sheet located on the side facing the skin is formed in a thin zone and a thin zone located on the side of the hole, the thin zone is a portion enclosed within the outer periphery of the depressed portion and having a thickness that is 70% or less of the thickness d2 of the parts other than the depressed portion in a sheet located on the side facing the skin, and the thin zone located on the hole side is a portion of the thin zone having a thickness that is 40% or less of the thickness d2. 24. The disposable diaper according to claim 1, in which the thickness d2 of the parts other than the depressed portion in the sheet located on the side facing the skin is from 100 to 600 microns. 25. The disposable diaper according to claim 1, in which a thin zone of the outer periphery of each hole in the depressed portions is formed in the form of a ring, as in the case of the outer periphery. 26. The disposable diaper according to claim 1, wherein the thin zone of each depressed portion has a diameter L2 that exceeds the hole diameter L1 by 1.5-3 times. 27. The disposable diaper according to claim 1, in which the sheet located on the side facing the skin has a base weight of 9 to 30 g / m ² . 28. The disposable diaper according to claim 1, in which the rear waist valve and the front waist valve are formed by connecting and attaching a sheet located on the side not facing the skin and the outer sheet to each other through a plurality of connected zones arranged dispersed. 29. The disposable diaper according to claim 1, in which the hydrophobic outer sheet is provided on the non-skin side of the sheet surface located on the non-skin side, wherein the connected zones of the sheet located on the non-skin side and the outer sheet arranged at intervals in a row along a longitudinal direction in a zone extending from a waist elastic portion to a lower elastic portion of each of the front zone and the rear zone, and a plurality of rows of connected zones formed op ponents of the plurality of bonded areas are spaced along the lateral direction. 30. The disposable diaper according to clause 29, in which the interval between the connected zones adjacent to each other in the longitudinal direction and forming rows of connected zones extending in the longitudinal direction is from 1 to 20 mm 31. The disposable diaper according to clause 29, in which the interval between the rows of connected zones adjacent to each other in the lateral direction is from 4 to 20 mm 32. The disposable diaper according to claim 1, wherein the disposable diaper includes a hydrophobic outer sheet on the non-skin side of the sheet located on the non-skin side, and a plurality of elastic elements placed in the state in which they are stretched in the lateral direction of the disposable diaper, between the sheet located on the side not facing the skin, and the outer sheet and placed at intervals along the longitudinal direction of the disposable diaper, and the sheet located on the side, about extended to the skin, has a bonded area in each of the depressed areas, and the bonded section and the hole of the sheet located on the side facing the skin are located between the elastic elements adjacent to each other in the longitudinal direction. 33. The disposable diaper according to claim 1, in which the disposable diaper includes a hydrophobic outer sheet on the non-skin side of the sheet located on the non-skin side, and a plurality of elastic elements placed in the state in which they are stretched in the lateral direction of the disposable diaper, between the sheet located on the side not facing the skin, and the outer sheet and placed at intervals along the longitudinal direction of the disposable diaper, and the sheet located on the side, about torn to the skin, has a bonded area in each of the depressed areas, and, when viewed in cross-section of the assembled area formed by tightening the elastic elements, 60-100% of all bonded areas are located from a place that is half the depth d4 of the recesses, recessed towards the non-skin side of the sheet, located on the side facing skin, up to the side with protrusions. 34. The disposable diaper according to claim 1, in which the inter-fiber distance between the constituent fibers forming a sheet located on the side facing the skin in each depressed portion is less from the side of the hole than from the side external to the hole. 35. The disposable diaper according to claim 1, wherein the interfiber distance between the fibers forming a thin zone located on the hole side and having a thickness that is 40% or less of the thickness d2 of parts other than the depressed portion on the outer periphery of the hole inside the thin zone with a thickness of 70% or less of the thickness d2 is 4/5 or less of the inter-fiber distance between the fibers forming a section near the outer edge of the depressed portion on the outer periphery. 36. The disposable diaper according to claim 1, in which the sheet located on the side facing the skin, and forming a thin zone located on the side of the hole, with a thickness that is 40% or less of the thickness d2 of parts other than the depressed portion, on the outer periphery of the hole within a thin zone with a thickness that is 70% or less of the thickness d2, has a contact angle with respect to ion exchange water that is 120 ° or less. 37. The disposable diaper according to claim 1, in which the sheet, located on the side facing the skin, and forming a section near the outer edge of the depressed portion on the outer periphery of the hole, has a contact angle with respect to ion exchange water that is 120 ° or more . 38. The disposable diaper according to claim 1, wherein the sheet located on the side facing the skin includes, in each depressed portion, a bonded portion in which the constituent fibers of the sheet located on the side facing the skin are attached to each other, and the difference in the contact angle between the portion adjacent to the bonded portion and the ion exchange water and the contact angle between the portion adjacent to the outer edge of the depressed portion on the outer periphery of the hole and the ion exchange water is 10 ° or more. 39. The disposable diaper according to claim 1, in which the sheet, located on the side not facing the skin, has a base weight of 10 to 50 g / m ² . 40. The disposable diaper according to claim 1, in which the sheet located on the side not facing the skin is such that its parts other than the depressed portions have a thickness of 100 to 800 microns. 41. The disposable diaper according to claim 1, in which the sheet, located on the side not facing the skin, has a hydrophilic fiber content of from 70 to 80% of the mass. in relation to all constituent fibers. 42. The disposable diaper according to claim 1, in which the sheet, located on the side not facing the skin, has a width of 30 mm for lifting water when tested for absorption according to the Klemm method, measured according to JIS P 8141, of 20 mm or more per 60 seconds. 43. The disposable diaper according to claim 1, in which the sheet, located on the side not facing the skin, has an amount of absorbed ion-exchange water at saturation of 75 g / m ² or more.

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