RU2748689C1 - Absorbent product - Google Patents

Abstract

FIELD: hygiene.SUBSTANCE: present invention relates to a disposable diaper (1) comprised of a liquid holding absorbent core (40) and a skin-facing fibrous structure (10) located on the side of the surface of the absorbent core (40) facing the skin. In a plan view of the disposable diaper (1) from the skin-facing surface the skin-facing fibrous structure (10) has multiple low density regions (LR) with a relatively low fiber density and a high density region (HR) with a relatively high fiber density, and each of the low density regions (LR) is surrounded by a high density region (HR). The skin-facing fibrous structure (10) comprises a top sheet (2) located on the side of the surface facing the skin.EFFECT: improved design of a disposable diaper.12 cl, 5 dwg, 1 tbl

Description

The technical field to which the invention relates

[0001]

The present invention relates to an absorbent article such as a disposable diaper.

Prior art

[0002]

Improving the absorption characteristics of loose stools has traditionally been one technical problem associated with absorbent articles. Loose stools are often present, especially in children who are several months old, and are lumps of heterogeneous excrement with different viscosities than normal stools. Accordingly, if the liquid stool absorption capacity of the diaper is insufficient, the liquid stool remains in contact with the wearer's skin for a long period of time and may irritate the skin and cause skin problems such as skin inflammation.

[0003]

Patent Document 1 discloses an absorbent article including a sublayer between a topsheet having a large number of pores and an absorbent core as a technical solution to reduce such contact with stools and prevent skin inflammation. In addition, Patent Documents 2 and 3 disclose absorbent articles including an intermediate sheet, which is the same as the sublayer between the topsheet and the absorbent member.

List of links

Patent documents

[0004]

Patent Document 1: JP 2011-235115A

Patent Document 2: JP 2008-100106A

Patent Document 3: JP 2011-200443A

The essence of the invention

[0005]

The present invention is directed to an absorbent article including a liquid retention absorbent core and a skin-facing fibrous structure located on the skin-facing surface of the absorbent core. In a plan view of the skin-facing surface of an absorbent article, the skin-facing fibrous structure has a plurality of low density zones having a relatively low fiber density and a high density zone having a relatively high fiber density, and each of the low density zones is surrounded by high density area.

Brief Description of Drawings

[0006]

[Fig. 1] Fig. 1 is a plan view schematically showing a skin-facing surface, that is, a side of the topsheet of a disposable diaper, which is an embodiment of an absorbent article according to the present invention, and is a plan view in an unfolded state, in which the diaper is flattened with the elastic members of the respective portions in a stretched state.

[Fig. 2] Fig. 2 is a horizontal sectional view schematically showing a section taken along line II-II in Fig. 1.

[Fig. 3] Fig. 3 is a partially enlarged plan view showing a low density area and a high density area included in the disposable diaper of this embodiment.

[Fig. 4] Fig. 4 is a partially enlarged cross-sectional view showing an enlarged portion of a horizontal cross-sectional view of the disposable diaper of this embodiment.

[Fig. 5] Fig. 5 is a partially enlarged cross-sectional view showing an enlarged portion of a horizontal cross-sectional view of a disposable diaper according to another embodiment of the present invention (corresponding to Fig. 4).

Description of embodiments

[0007]

Patent Document 1 does not mention the fiber density of the topsheet and the fiber density of the sublayer at all, and does not mention the relationship between the fiber density of the topsheet and the fiber density of the sublayer at all.

[0008]

In addition, Patent Documents 2 and 3 disclose that an absorbent article includes an intermediate sheet with a higher fiber density than the topsheet. With such a disposable diaper in which a high fiber density intermediate sheet is disposed adjacent to the back surface side of the topsheet, which has a lower fiber density than the intermediate sheet and has openings for fluid passage, there is a possibility that loose stools will occur. remain on the topsheet in the portions thereof not including liquid passages and having a low fiber density, and there is concern that the remaining loose stools will irritate the wearer's skin and cause skin problems such as skin inflammation.

[0009]

Accordingly, the present invention relates to an absorbent article that efficiently absorbs heterogeneous loose stools of different viscosities and suppresses adhesion of liquid stools to the skin of a wearer.

[0010]

In the following, an absorbent article according to the present invention will be described based on a preferred embodiment with reference to the drawings. 1 and 2 show a disposable diaper 1, which is an embodiment of an absorbent article according to the present invention. The diaper 1 has a front part 1F, which is placed on the ventral side of the wearer, and a back part 1R, which is placed on the dorsal side when worn, and a crotch part 1M, which is located between the front part and the back, and has a longitudinal direction X extending from the front portion 1F through the crotch portion 1M to the rear portion 1R and corresponding to the direction from the front side to the back side of the wearer, and the lateral direction Y orthogonal to the longitudinal direction X. Thus, the direction from the front side to the back side of the wearer is a direction extending from the front part 1F through crotch part 1M to back part 1R. When dividing the diaper 1 in half in the longitudinal direction X, the crotch portion 1M covers an area corresponding to 25-60% and preferably 30-50% of the total length of the diaper 1 relative to the center line CL. In addition, the crotch portion 1M has a portion that faces the excretory portion and which is located both opposite the wearer's body portion intended for urine discharge and opposite the wearer’s body portion (anus) intended for stool release when wearing the diaper 1, and a portion , facing the discharge part, is usually located in the center or near the center of the diaper 1, defined in the longitudinal direction X.

[0011]

As shown in FIGS. 1 and 2, the diaper 1 includes a liquid-retaining absorbent core 40, a skin-facing fibrous structure 10, which is located on the side of the skin-facing surface of the absorbent core 40, and a liquid-impervious or minimally liquid-permeable back sheet 3, which is located on the non-skin-facing surface of the absorbent core 40. The skin-facing fibrous structure 10 includes a liquid-permeable topsheet 2 that is located on the skin-facing side and can come into contact with the skin of the wearer. and a liquid-permeable intermediate sheet 5 that is located adjacent to the non-skin-facing surface of the topsheet 2. The skin-facing fibrous structure 10 is formed by stacking the topsheet 2 and the intermediate sheet 5 on top of each other. In the diaper 1, the absorbent core 40 is wrapped in a core wrap sheet 41, whereby the absorbent member 4. In the plan view of FIG. 1, the diaper 1 has the shape of a longitudinally elongated hourglass that is tapered inwardly substantially at the center the crotch portion 1M defined in the longitudinal direction X and is elongated in one direction, that is, in the longitudinal direction X.

[0012]

It should be noted that, as used herein, a "skin-facing surface" is the surface of an absorbent article or its constituent element (e.g. topsheet 2) that faces the skin of the wearer, that is, the side relatively close to the wearer's skin when the absorbent article is worn. , and the “non-skin-facing surface” is the surface of the absorbent article or a component thereof that faces toward (the garment side) opposite the skin, that is, the side relatively distant from the wearer's skin when the absorbent article is worn. It should be noted that the expression “when worn” means a normal and proper wearing position, that is, a state in which the absorbent article is maintained in the correct position when worn, and does not encompass a state in which the absorbent article is in an incorrect wearing position.

[0013]

Each of the topsheet 2 and the backsheet 3 is larger than the size of the absorbent member 4 and protrudes outward from the outer edge of the absorbent member 4. The topsheet 2 will be described in detail later. The back sheet 3 forms the outer shape of the diaper 1 in its open and uncontracted state shown in FIG. 1. Various types of backsheets that are traditionally used in this type of absorbent article can be used as the backsheet 3 without particular limitation. Examples of the backsheet 3 include resin film, resin film-nonwoven laminate, and the like. The backsheet 3 may, for example, be in the form in which the liquid-impermeable film sheet is used by itself, or the form in which the outer sheet is applied to the non-skin surface of the film sheet, that is, to the outer surface side of the film sheet. , and is placed thereon, and the outer sheet may be, for example, a nonwoven fabric.

[0014]

In the plan view shown in Fig. 1, the absorbent member 4 has a shape that is elongated in the longitudinal direction X and extends from the front portion 1F to the rear portion 1R. The absorbent core 40 and the core wrap sheet 41 are bonded by a known bonding means such as a hot melt adhesive.

[0015]

The absorbent core 40 has a single layer structure, and in the plan view of FIG. 1, the absorbent core 40 has an hourglass shape that is tapered inwardly substantially in the center in the length direction, that is, in the longitudinal direction X. The absorbent core 40 is formed by laying fibers from a core material containing an absorbent material. An absorbent material that has traditionally been used to form an absorbent core of this type can be used as an absorbent material without particular limitation. For example, wood pulp, hydrophilic fibers such as synthetic fibers that have been treated with a hydrophilizing agent, and absorbent polymer particles can be used. That is, the absorbent core 40 may be formed from a fiber stack formed from hydrophilic fibers or from absorbent polymer particles that rest on the fiber stack. As the core wrapping sheet 41, a liquid-permeable sheet material can be used, and examples thereof include paper, nonwoven fabric, and the like.

[0016]

The intermediate sheet 5 is a sheet that is separate from the absorbent body 4 and is located between the topsheet 2 and the absorbent body 4, and is a sheet that is also called a sub-layer or second sheet. The intermediate sheet 5 is rectangular in the plan view shown in FIG. 1. The intermediate sheet 5 has a length direction corresponding to the longitudinal direction X and preferably covers 30-70% and more preferably 40-60% of the skin-facing surface of the absorbent member 4. In the diaper 1, the intermediate sheet 5 is located in the crotch portion 1M. The length of the intermediate sheet 5 in the lateral direction Y (width of the intermediate sheet 5) is the same as the length of the absorbent member 4 in the lateral direction Y, or less than the length of the absorbent member 4 in the lateral direction Y. As described above, the crotch portion 1M has a portion facing towards the release portion, and the intermediate sheet 5 is disposed in the portion facing the release portion. The intermediate sheet 5 and each of the topsheet 2 and the absorbent member 4 (core wrap sheet 41) are fully or partially joined by a known bonding means such as an adhesive. Intermediate sheet 5 will be described in detail later.

[0017]

Side sheets 6 are respectively provided on the right and left sides of the topsheet 2 extending in the longitudinal direction X. Each of the side sheets 6 includes an inner edge portion that extends in the longitudinal direction X and an outer edge portion that is located on the outer side. in the lateral direction Y with respect to the inner edge portion, and extends in the longitudinal direction X. In the plan view of FIG. 1, the inner edge portions overlap the absorbent member 4 and, as shown in FIG. 2, the outer edge portions extend outwardly in the lateral direction Y from the side edges of the absorbent member 4 extending in the longitudinal direction X and attached to the backsheet 3. The vein elastic 60 is fixed in a stretched state so that it extends in the longitudinal direction X between the side sheet 6 and back sheet 3 in each of the parts that are intended for the right and left legs and are to be placed around the legs of the wearer. With this configuration, in the leg portions of the diaper 1, two leg cuffs are formed during wearing due to the contraction of the elastic members 60. In addition, the vein elastic 61 is fixed in a stretched state so that it extends in the longitudinal direction X, in the inner the edge portion of each side sheet 6. In this configuration, when wearing the diaper 1, due to the contraction of the elastic members 61, at least in the crotch portion 1M, each of the side sheets 6 forms a cuff for preventing leakage as a result of the inner edge portion being lifted towards to the wearer's skin from the portion at which the side sheet 6 and the back sheet 3 are connected. The leakage cuffs can prevent the discharged liquid such as urine from leaking outward in the lateral direction Y, that is, the so-called lateral leakage. The topsheet 2, the backsheet 3, the absorbent member 4, the intermediate sheet 5, the side sheets 6, and the elastic members 60 and 61 are bonded to each other by a known bonding means such as a hot melt adhesive or the like.

[0018]

The diaper 1 is a disposable diaper of the so-called opening type, and as shown in Fig. 1, two pieces of fastening tape 7 are respectively provided adjacent to two side edge portions of the rear portion 1R of the diaper 1 that extend in the longitudinal direction X. Not shown fastening portion, which is the male mechanical Velcro element is attached to each fastening tape 7. In addition, the target area 8, which is the female mechanical Velcro element, is formed on the non-skin-facing surface of the front 1F of the diaper 1. The target area 8 is formed by attaching and attaching a female mechanical Velcro member to the non-skin surface of the backsheet 3, which forms the non-skin surface of the front portion 1F, by using a known joining means, for example, such as an adhesive, or by heat sealing and making nena with the possibility of receiving the fastening parts of the pieces of the fastening tape 7 with the possibility of their separation.

[0019]

Next, the topsheet 2 and the intermediate sheet 5 described above will be described in detail with reference not only to FIGS. 1 and 2, but also to FIGS. 3 and 4. FIG. 3 is a partially enlarged plan view showing the zones The low density LR and the high density area HR included in the diaper 1, in a plan view of the diaper 1 from the topsheet 2 side. Fig. 4 is a partially enlarged sectional view showing, on an enlarged scale, part of a horizontal sectional view of the diaper 1.

[0020]

As shown in FIGS. 1 and 2, the topsheet 2 has a plurality of holes 2h that pass through the topsheet 2. The holes 2h can be formed in the entire topsheet 2, but in the diaper 1 they are formed in the crotch portion 1M of the topsheet 2. Since the topsheet 2 is provided with a plurality of holes 2h so that in the diaper 1 the skin-facing surface of the intermediate sheet 5 is exposed in the region of the holes 2h, as shown in FIGS. 3 and 4. As described above, the crotch portion 1M has a portion facing the discharge part, and the part facing towards the discharge part has a part 2R that faces the part for discharging the stool and is located opposite the body part of the wearer intended for discharging the stool on the back side 1R in the part facing towards the discharge part. In the diaper 1, the plurality of openings 2h of the topsheet 2 are preferably located only in the portion 2R that faces the portion intended for separating the chair, as shown in FIG. 1. If the openings 2h are located, for example, only in the part 2R that faces the part intended for stool discharge, it is possible to efficiently trap excrement, such as loose stools, from the openings 2h and suppress the return of liquid from the collected excrement from areas other than part 2R. that faces the part dedicated to the stool.

[0021]

The holes 2h may be dispersed in the in-plane direction of the topsheet 2, as shown in FIG. 1, but in the diaper 1, the plurality of holes 2h are evenly distributed in the in-plane direction of the topsheet 2. In particular, rows of holes in which the plurality of holes 2h are arranged in series at regular intervals along the lateral direction Y, are at regular intervals along the longitudinal direction X. In the diaper 1, a plurality of holes 2h are arranged in a zigzag / staggered pattern such that between the holes 2h forming one row of holes and adjacent to each other in the lateral in the Y direction, a hole 2h is formed, forming another row of holes adjacent to this one row of holes.

[0022]

There is no particular limitation on the shape of each hole 2h, but to prevent excrement such as loose stools from flowing out in the lateral direction Y and therefore to prevent leakage, it is preferable that each hole 2h is elongated in the longitudinal direction X in the view in plan view of the topsheet 2. For example, it is preferable that each hole 2h has the shape of an ellipse, the direction of the major axis of which corresponds to the longitudinal direction X, or the shape of a rectangle, the length direction of which corresponds to the longitudinal direction X. In the diaper 1, each hole 2h has a rectangular shape is elongated in the longitudinal direction X.

[0023]

In the plan view of the topsheet 2, the percentage of the area of the holes 2h is preferably 5% or more, and more preferably 10% or more, preferably 20% or less and more preferably 18% or less, and particularly preferably 5 to 20 % and more preferably from 10 to 18% for reasons related to improving the absorption characteristics of excrements such as loose stools. The percentage of the area of the holes 2h is determined using the method below.

Method for determining the percentage of hole area 2h

[0024]

First, a zone formed by a 7 cm × 7 cm (49 cm ² ) square in a plan view and having holes 2h is cut from the top sheet 2. Next, in a plan view of this zone, the areas of the holes 2h included in this zone are measured, and the sum of the hole areas 2h is obtained. The percentage of the area of the holes is obtained using the expression below.

Percentage of hole area 2h (%) =

(the sum of the hole areas 2h / the area of the cut area

(49 cm ² )) × 100

[0025]

In the plan view of the topsheet 2, the area (surface area) of each hole 2h formed in the crotch portion 1M is preferably 5 mm ² or more, and more preferably 7 mm ² or more, preferably 20 mm ² or less, and more preferably 15 mm ² or less, and is preferably 5 to 20 mm ^2, and more preferably 7 to 15 mm ² for the same reasons.

[0026]

The basis weight of the topsheet 2 is preferably 20 g / m ² or more, and more preferably 25 g / m ² or more, preferably 36 g / m ² or less, and more preferably 32 g / m ² or less, and preferably 20 to 36 g / m ^2, and more preferably 25 to 32 g / m ² . The basis weight of the topsheet 2 is a value determined in the non-apertured state 2h.

[0027]

The density of the fibers (fibers per mm ² ) of the fibers forming the top sheet 2 is higher than the density of the fibers of the fibers forming the intermediate sheet 5. In particular, the density of the fibers of the top sheet 2 is preferably 100 fibers per 1 mm. ² or more, and more preferably 150 fibers per mm ² or more, preferably 300 fibers per mm ² or less, and more preferably 250 fibers per mm ² or less, and preferably 100 to 300 fibers per mm ² or more preferably 150 to 250 fibers per mm ² for reasons of efficient absorption of low viscosity stools. The fiber density of the topsheet 2 is determined using the determination method below. The fiber density of the topsheet 2 is a value determined in the non-apertured state 2h.

[0028]

Fiber density determination method

The section of the topsheet 2 is viewed at magnification (adjusted to a magnification at which approximately 30-60 fiber cross-sections can be measured; at 150-500x magnification) using a scanning electron microscope. Next, the number of fiber cross-sections cut along the cross-sectional plane is counted over a certain area (approximately 0.5 mm ² ), and the area of the field of view is obtained over which the number of fiber cross-sections was counted. This number is then converted to the number of fiber cross-sections per mm ² and used as the fiber density, defined as the number of fibers per mm ² . The measurements are taken at three locations and the average is used as the fiber density of the sample. For example, JCM-5100 (product name) supplied by JEOL, Ltd. can be used as a scanning electron microscope.

[0029]

In addition, as shown in FIGS. 3 and 4, the outer edges of the holes 2h of the topsheet 2 are formed with the outer edge portions 2h1 having a higher fiber density than the portion of the topsheet 2 having no holes 2h. The fiber density (fibers per mm ² ) of the fibers forming the outer edge portions 2h1 is preferably 300 fibers per mm ² or more, and more preferably 350 fibers per mm ² or more, preferably 500 fibers per mm ² or less, and more preferably 450 fibers per mm ² or less, and is preferably from 300 to 500 fibers per mm ^2, and more preferably from 350 to 450 fibers per mm ^2, for reasons related to more efficient absorption of loose stools onto the top sheet 2. The fiber density of the fibers forming the outer edge portions 2h1 is determined using a method similar to the above-described fiber density determination method.

[0030]

In the diaper 1, the entire intermediate sheet 5 consists of a non-woven fabric formed from synthetic fibers. The basis weight of the entire intermediate sheet 5 is preferably 15 g / m ² or more, and more preferably 25 g / m ² or more, preferably 50 g / m ² or less, and more preferably 40 g / m ² or less, and preferably from 15 up to 50 g / m ^2, and more preferably from 25 to 40 g / m ² .

[0031]

The density of the fibers of the fibers forming the intermediate sheet 5 is lower than the density of the fibers of the fibers forming the topsheet 2. As shown in FIG. 4, in the diaper 1, the intermediate sheet 5 has a two-layer structure consisting of a high density layer 51 having a relatively high fiber density and a low density layer 52 adjacent to the non-skin-facing surface of the high density layer 51 and having a relatively low fiber density. The low density layer 52 is located on the topsheet 2 side (skin-facing side), and the high density layer 51 is located on the absorbent 4 side (non-skin side). That is, the intermediate sheet 5 is such that the density of the fibers of the topsheet 2 side (the skin-facing surface) is relatively low, and the density of the fibers of the surface-side fibers, not facing the skin is relatively high. Since the fiber density of the fibers of the intermediate sheet 5 located on the side of the absorbent 4 (the non-skin side) is relatively high, it is possible to smoothly suck up liquid stool by the absorbent 4 through the capillary force generated by the fibers.

[0032]

The difference between the density of the fibers (fibers per 1 mm ² ), which are the fibers of the intermediate sheet 5, forming the layer 52 of low density, and the density of the arrangement of the fibers (fibers per 1 mm ² ), which are the fibers forming the layer 51 of high density, is preferably 5 fibers per mm ² or more, and more preferably 10 fibers per mm ² or more, preferably 50 fibers per mm ² or less and more preferably 30 fibers per mm ² or less, and is preferably 5 to 50 fibers per 1 mm ² and more preferably from 10 to 30 fibers per mm ² for reasons related to the smooth absorption of liquid stool by the absorbent element 4. The density of the fibers constituting the fibers forming the intermediate sheet 5 is determined using a method similar to the method described above determination of the density of the arrangement of fibers.

[0033]

The density of the fibers (fibers per mm ² ) of the fibers forming the high density layer 51 is lower than the density of the fibers of the fibers forming the topsheet 2. The density of the fibers of the fibers forming the high density layer 51 is preferably is 20 fibers per mm ² or more, and more preferably 25 fibers per 1 mm ² or more, preferably 50 fibers per 1 mm ² or less and more preferably 30 fibers per 1 mm ² or less, and is preferably 20 to 50 fibers per mm ^2, and more preferably 25 to 30 fibers per mm ² for similar reasons.

[0034]

The density of the fibers (fibers per mm ² ) of the fibers forming the low density layer 52 is lower than the density of the fibers of the fibers forming each of the high density layer 51 and the topsheet 2. The density of the fibers of the fibers, forming the low density layer 52, preferably 3 fibers per mm ² or more, and more preferably 5 fibers per mm ² or more, preferably 45 fibers per mm ² or less, and more preferably 10 fibers per mm ² or less, and preferably 3 to 45 fibers per mm ^2, and more preferably 5 to 10 fibers per mm ² for similar reasons.

[0035]

A topsheet 2 having openings 2h with the above-described physical properties and an intermediate sheet 5 with a lower fiber density than the fiber density, which are the fibers forming the topsheet 2 form low density regions LR and a high density region HR in the diaper 1. Specifically, in a plan view of the diaper 1 from the topsheet 2 side, in a portion in which the topsheet 2 and the intermediate sheet 5 are superimposed in the thickness direction, the low density regions LR are composed of the skin-facing surface of the intermediate sheet 5, exposed in the region of the holes 2h of the topsheet 2. In the portion in which the topsheet 2 and the intermediate sheet 5 are superimposed in the thickness direction, the high density zone HR consists of a portion of the topsheet 2 having no holes 2h. In addition, in the portion in which the topsheet 2 and the intermediate sheet 5 are superimposed on each other in the thickness direction, the boundary portions H1 between the low density regions LR and the high density region HR surrounding the low density regions LR are composed of the outer edge portions 2h1 of the holes 2h in the top sheet 2 and have a higher fiber density compared to the high density HR zone.

[0036]

Thus, in the diaper 1, in a plan view from the skin-facing surface, the skin-facing fibrous structure 10 has a plurality of low density regions LR and a high density region HR, and each of the low density regions LR is surrounded by a high density region HR. Accordingly, even when the excrement excreted by the carrier is a non-uniform liquid stool, the problem of non-uniform liquid stool of different viscosity can be effectively solved, and such liquid stool can be absorbed by allowing the low-viscosity stool to be retained and absorbed through the HR high density zone. and allowing high viscosity stool to be retained and absorbed by the low density LR zones. Thus, it is possible to ensure effective absorption of non-uniform liquid stools with different viscosities, and therefore, the liquid stools are unlikely to adhere to the skin of the wearer, and the occurrence of skin problems such as skin inflammation can be prevented. It should be noted that a state in which “each of the low-density regions LR is surrounded by a high-density region HR” means not only a state in which each of the periphery of the low-density regions LR is completely surrounded by a high-density region HR, but also a state in which not each of the periphery of the low-density regions LR is completely surrounded by a high-density region HR, and 50% or more of the entire periphery of the low-density regions LR is surrounded by a high-density region HR, for example, a state in which the outer edges of the low-density regions LR are located on the outer edge facing fibrous skin 10.

[0037]

Since the low density areas LR are composed of an intermediate sheet 5 exposed to the area of the holes 2h of the topsheet 2, the shape of the low density areas LR is the same as the above-described shape of the holes 2h of the topsheet 2. When each of the low density areas LR has, for example, a rectangular shape that is elongated in the longitudinal direction, the low-viscosity chair is likely to be held in the low-density areas LR until it spreads out in the lateral direction Y, and hence leakage from the crotch portion 1M can be effectively suppressed. Especially in the case where each of the low density regions LR has a rectangular shape that is elongated in the longitudinal direction X, leakage can be suppressed more effectively.

[0038]

In addition, since the low density areas LR are composed of an intermediate sheet 5 exposed to the area of the holes 2h of the topsheet 2, the area of each low density area LR is the same as the above-described area of each hole 2h of the topsheet 2, and this area is preferably 5 mm ² or more, and more preferably 7 mm ² or more, preferably 20 mm ² or less, and more preferably 18 mm ² or less, and preferably 5 to 20 mm ² and more preferably 7 to 18 mm ² for reasons related with improved absorption characteristics of excrements such as loose stools.

[0039]

In addition, the proportion of the total area of the low density zones LR (holes 2h) of the surface area of the skin-facing fibrous structure 10 formed by the superposition of the topsheet 2 and the intermediate sheet 5 (the area of the portion in which the topsheet 2 and the intermediate sheet 5 are superposed each other), preferably 5% or more, and more preferably 10% or more, preferably 20% or less, and more preferably 18% or less, and particularly preferably 5 to 20% and more preferably 10 to 18% for reasons related to improved absorption of faeces such as loose stools. The proportion of the total area of the low density zones LR to the surface area of the skin-facing fibrous structure 10 is determined using the method below.

[0040]

The fraction of the total area of the low density LR zones of the surface area of the fibrous structure 10 facing the skin

First, a zone formed by a 7 cm × 7 cm (49 cm ² ) square in a plan view and having low density LR zones is cut from the top sheet 2. Next, in a plan view of this zone, the areas of low density LR zones included into this zone, and the sum of the areas of the LR zones of low density is obtained. The fraction of the total area of the low density zones LR relative to the surface area of the skin-facing fibrous structure 10 is obtained using the expression below.

Share of total area of low density LR zones (%) =

(sum of low density LR areas / cut area

zone (49 cm ² )) × 100

[0041]

In addition, when the low density LR zones are located in the portion 2R that faces the stool discharge portion as shown in FIG. 1, it is possible to suppress the return of accumulated fluid from loose stools, urine or the like from the high density HR zone to the other than the portion 2R which faces the portion for separating the stool. In addition, when the low density LR zones are arranged in a zigzag pattern, high viscosity stool can be effectively retained and absorbed.

[0042]

In addition, as shown in FIG. 3, the boundary portions H1 between the low density regions LR and the high density region HR surrounding the low density LR regions have a higher fiber density than the high density region HR. Accordingly, low-viscosity stools are more likely to pass from low-density LR zones or high-density HR zones to high fiber density boundary portions H1 due to capillary phenomena, and therefore the absorption characteristics of feces such as loose stools are improved.

[0043]

Hereinafter, the low density zones LR, the high density zone HR, and the border portions H1 will be described in more detail. The contact angle of the fibers forming the skin-facing surface with the ion-exchange water is such that, for reasons of improving the absorption of excreta, such as low-viscosity stools, towards the side of the absorbent member 4 and reducing the amount of excrement remaining on the skin-facing surface of the diaper 1, it is preferable that the contact angle in the high density region HR, which is the portion of the topsheet 2 not including the holes 2h, is less than the contact angle in the edge portions H1, which are the outer edge portions 2h1 of the holes 2h in the topsheet 2. In addition, it is preferable that the contact angle in the low-density regions LR consisting of the intermediate sheet 5 exposed in the region of the holes 2h of the topsheet 2 is less than the contact angle in the high-density region HR, which is part of the topsheet 2 not including holes 2h. Specifically, the contact angle in the edge portions H1, in other words, the contact angle of the fibers forming the skin-facing surface of the outer edge portions 2h1 of the holes 2h in the topsheet 2 is preferably 75 degrees or more, and more preferably 80 degrees or more, is preferably 95 degrees or less, and more preferably 90 degrees or less, and preferably 75 to 95 degrees, and more preferably 80 to 90 degrees. In addition, the contact angle in the high density region HR, in other words, the contact angle of the fibers forming the skin-facing side of the topsheet portion 2 not including the holes 2h, is preferably 65 degrees or more, and more preferably 70 degrees or more. preferably 90 degrees or less, and more preferably 80 degrees or less, and preferably 65 to 90 degrees, and more preferably 70 to 80 degrees. The contact angle in the low density regions LR, in other words, the contact angle of the fibers forming the skin-facing side of the intermediate sheet 5, at least in the portions exposed to exposure in the region of the holes 2h, is preferably 60 degrees or more, and more preferably 65 degrees. or more, preferably 85 degrees or less, and more preferably 75 degrees or less, and preferably 60 to 85 degrees, and more preferably 65 to 75 degrees. The contact angle in the boundary portions H1, the contact angle in the high density HR zone and the contact angle in the low density LR zones are determined using the following determination method.

[0044]

Method for determining the angle of contact of fibers with ion-exchange water

A fiber is cut from a specified portion and the angle of contact of that fiber with water is measured. As the measuring device, an MCA-J automatic contact angle measuring instrument manufactured by Kyowa Interface Science Co., Ltd. was used. Distilled water is used to measure the contact angle. The amount of fluid discharged from the outlet of a jet type ejector for ejecting water droplets (PulseInjector CTC-25 manufactured by Cluster Technology Co., Ltd. and having an outlet opening diameter of 25 μm) was set to 20 picoliters, and a drop of water drips directly onto the fiber. In this case, images of how the water drop falls are recorded on a high-speed image recording / recording device connected to a horizontally mounted camera. For reasons related to the subsequent performance of image analysis, it is desirable that the image recording apparatus is a personal computer in which the high-speed image capturing apparatus is included. With this measurement, the image is recorded every 17 ms. The first image from the recorded images, in which a water drop is deposited on a fiber cut from a nonwoven fabric, is analyzed using the accompanying FAMAS software (software version: 2.6.2; analysis method: resting drop method; analytical method: Ɵ / 2 method; image processing algorithm: non-reflective; image type in image processing: frame; threshold level: 200, and curvature correction: no correction), and the angle formed by the surface of a water droplet that is in contact with air and fiber are calculated and used as contact angle. The fiber cut from the top sheet 2 is cut with a fiber length of 1 mm, and the fiber is placed on a sample holder in the contact angle tester and held horizontally. The contact angle is measured at two different locations on the same fiber. For each of the different parts described above, the contact angle is measured to the first decimal place for N = 5 fibers, and the mean (rounded to the first decimal place) of the measured values measured at a total of 10 locations is defined as the contact angle at of this part.

[0045]

Examples of the topsheet 2 with the above-described physical properties include various nonwovens such as carded nonwovens, breathable nonwovens, spunbond nonwovens, meltblown nonwovens, hydroentangled nonwovens, and nonwovens. needlepunched materials containing thermally bondable synthetic resins such as polyethylene, polyethylene terephthalate, and polypropylene, and films formed to be permeable with a perforating means. For reasons related to making it easier to pass liquid stool through the topsheet 2 without degrading the texture of the skin-facing surface, it is preferable to use as the topsheet 2, for example, nonwovens, bonded through air through, or spunbond nonwovens. In addition, the holes 2h formed in the topsheet 2 can be formed by using various aperture methods commonly used for this type of absorbent article without being particularly limited, and for example if the holes 2h are formed by heating and cutting or cutting and squeezing. , the outer edge portions 2h1 are formed with a relatively high fiber density.

[0046]

In addition, examples of the intermediate sheet 5 with the above-described physical properties include nonwovens bonded by passing air through, nonwovens bonded by heating rollers, spunbonded nonwovens, SMS nonwovens (spunbond layer (S) - layer ( M) meltblown - spunbond layer (S)), SMMS nonwovens, resin bonded nonwovens, needle punched nonwovens, hydroentangled nonwovens and airlaid nonwovens a web-forming method containing thermally bonded synthetic resins such as polyethylene, polyethylene terephthalate and polypropylene. It is preferable to use air-through nonwoven fabrics as the intermediate sheet.

[0047]

The intermediate sheet 5, consisting of the above-described nonwovens, bonded by passing air through, can be obtained, for example, by using a method in which fibers introduced into an air jet are lowered and deposited on a web to form a web, and a jet of hot air is allowed to pass through, or high pressure water jets through the web on the mesh on the side opposite to the surface facing the mesh, so that the canvas is bonded. Nonwoven fabrics obtained using the mesh are characterized in that these nonwoven fabrics have a surface facing the mesh that was in contact with the mesh during manufacture and a surface (a surface "facing" air) that was not in contact with the mesh. mesh, has been processed by supplying directly to it a jet of hot air or a jet of water under high pressure, and is located on the side opposite to the surface facing the mesh. In a nonwoven fabric having a surface that was facing the mesh and a surface that was “facing” the air, the density of the fibers on the surface that was facing the mesh is higher than the density of the fibers on the surface that was “facing” the air ... The temperature of the hot air jet or the pressure of the high pressure water jet, the web speed, and the like are controlled so that the resulting nonwoven fabric has the desired fiber density and contact angle on the side of the surface that was "facing" the air. Thus, it is possible to obtain an intermediate sheet 5 having a two-layer structure of a high density layer 51 and a low density layer 52.

[0048]

In the above description, the absorbent article according to the present invention has been described by means of a preferred embodiment, but the absorbent article according to the present invention is not limited to the above embodiment, and can be changed accordingly.

For example, as shown in FIGS. 3 and 4, the diaper 1 described above has border portions H1 with a higher fiber density than the fiber density of the high density zone HR, at the boundaries between the low density zones LR and the high density zone HR. the surrounding low density area LR, but as seen in the case of the diaper 1 shown in FIG. 5, there is no absolute need for the border portions H1. The diaper 1 shown in FIG. 5 can also effectively absorb non-uniform loose stools.

[0049]

In addition, in the diaper 1 shown in FIGS. 1 to 4 and the diaper 1 shown in FIG. 5, which are described above, the fiber structure 10 facing the skin is formed by overlapping two sheets of topsheet 2 and intermediate sheet 5, but there is no absolute need for it to be formed by overlapping two sheets consisting of a topsheet 2 and an intermediate sheet 5. For example, a configuration may be used in which the skin-facing fibrous structure 10 consists of one sheet having low density LR zones and high density HR zones.

[0050]

In addition, in the diaper 1 described above, the skin-facing fibrous structure 10 includes a topsheet 2 and an intermediate sheet 5, and the low density regions LR consist of the skin-facing surface of the intermediate sheet 5 exposed in the region of the holes 2h of the upper sheet 2, but there is no absolute need to include an intermediate sheet 5. For example, a configuration may be used in which the skin-facing fibrous structure 10 does not include an intermediate sheet 5, but includes a topsheet 2 and a core wrap sheet 41, covering the skin-facing surface of the absorbent core, and the low-density regions LR consist of that surface of the core wrapping sheet 41 that faces the skin and is exposed in the region of the openings 2h of the topsheet 2. In this case, it is necessary that the core-wrapping sheet 41 consisted of a non-woven material formed from synthetic fibers, while the density is located The density of the fibers constituting the fibers forming the core wrap sheet 41 should be below the density of the fibers constituting the fibers constituting the topsheet 2.

[0051]

In addition, in the diaper 1 described above, a nonwoven fabric having a two-layer structure of a high-density layer 51 and a low-density layer 52 is used as the intermediate sheet 5, but there is no absolute need for a nonwoven fabric having a two-layer structure, and for example, it is also possible to use a nonwoven fabric having a single layer structure with a lower fiber density compared to the topsheet 2.

[0052]

In addition, the absorbent article of the present invention is not limited to the above-described open-type disposable diapers, and can be applied to a wide variety of articles such as pull-on disposable diapers, sanitary napkins, sanitary pants and the like that are used to absorb body fluids (urine, loose stools, menstrual blood, etc.) secreted from the human body.

[0053]

In connection with the above embodiment according to the present invention, the following absorbent article is further disclosed.

<1> Absorbent article comprising a liquid-retaining absorbent core and a skin-facing fibrous structure located on the side of the skin-facing surface of the absorbent core,

wherein, in a plan view from the side of the skin-facing surface of the absorbent article, the skin-facing fibrous structure has a plurality of low density zones having a relatively low fiber density and a high density zone having a relatively high fiber density, and each of the zones low density is surrounded by a high density zone.

<2> The absorbent article of <1>, wherein, in a plan view from the side facing the skin of the absorbent article, the area of each of the low density zones is 5 to 20 mm ² .

<3> The absorbent article of <1> or <2>, wherein, in a plan view from the skin-facing surface of the absorbent article, the proportion of the total area of the plurality of low density zones is 5 to 15% of the surface area of the fibrous structure, facing the skin.

<4> An absorbent article according to any one of items <1> to <3>, wherein, in a plan view from the side of the skin-facing surface of the absorbent article, boundary portions are provided at the boundaries between the low-density zones and the high-density zone surrounding the low-density zones. density, and the border portions have a higher fiber density than the high density zone.

<5> The absorbent article of <4>, wherein the contact angle of the fibers forming the skin-facing surface with the ion-exchange water is such that the contact angle in the high density zone is less than the contact angle in the boundary portions, and the contact angle in the low density zones is less contact angle in the high density area.

<6> The absorbent article according to any one of items <1> to <5>, having a longitudinal direction corresponding to a direction from the front side to the back side of the wearer, and a lateral direction orthogonal to the longitudinal direction, wherein each of the low density zones has a shape, which is elongated in the longitudinal direction.

<7> An absorbent article according to any one of <1> to <6>, wherein a plurality of low density zones are provided in the portion that faces the stool delivery portion and is opposite the stool delivery portion of the wearer.

<8> An absorbent article according to any one of items <1> to <7>, wherein the skin-facing fibrous structure includes a topsheet located on the skin-facing side and a liquid-permeable intermediate sheet adjacent to the non-facing to the skin with the surface of the topsheet, the topsheet has holes dispersed in the in-plane direction, the high density zone consists of a portion of the topsheet not including the holes, and the low density zone consists of the skin facing surface of the intermediate sheet exposed to the zone holes.

<9> The absorbent article of <8>, wherein the fiber density of the fibers on the side of the skin-facing surface of the intermediate sheet is lower than the density of the fibers of the fibers on the non-skin side thereof.

<10> An absorbent article according to any one of items <1> to <7>, wherein the skin-facing fibrous structure includes a topsheet disposed on a skin-facing surface side and a core wrap sheet disposed between the topsheet and the absorbent core and covering the skin-facing surface of the absorbent core, the topsheet has openings dispersed in a plane direction, the high density zone consists of a portion of the topsheet not including openings, and the low density zone consists of the skin-facing surface of the core wrap sheet open for exposure in the area of the holes.

[0054]

<11> An absorbent article according to any one of items <8> to <10>, wherein the plurality of holes are arranged in a zigzag pattern such that an opening is formed between the holes forming one row of holes and adjacent to each other in the lateral direction. a row of holes adjacent to a given row of holes.

<12> An absorbent article according to any one of <8> to <11>, wherein in a plan view of the topsheet, the percentage of aperture area is preferably 5% or more, and more preferably 10% or less, and preferably 20% or less, and more preferably 18% or less.

<13> An absorbent article according to any one of items <8> to <12>, including a front portion that is located on the ventral side of the wearer, and a back portion that is located on the dorsal side when worn, and a crotch portion that is located between the front part and rear, while in the plan view of the topsheet, the area (surface area) of each of the holes formed in the crotch portion is preferably 5 mm ² or more, and more preferably 7 mm ² or more, and preferably 20 mm ² or less and more preferably 15 mm ² or less.

<14> An absorbent article according to any one of <8> to <13>, wherein the basis weight of the topsheet, determined by excluding openings, is preferably 20 g / m ² or more, and more preferably 25 g / m ² or more, and preferably is 36 g / m ² or less, and more preferably 32 g / m ² or less.

<15> An absorbent article according to any one of <8> to <14>, wherein the fiber density of the topsheet is preferably 100 fibers per mm ² or more, and more preferably 150 fibers per mm ² or more, and preferably 300 fibers per 1 mm ² or less, and more preferably 250 fibers per 1 mm ² or less.

<16> An absorbent article according to any one of <8> to <15>, wherein the outer edges of the topsheet openings are provided with the outer edge portions having a higher fiber density than the topsheet portion not including the openings, and the density of the fibers (fibers per mm ² ) constituting the fibers forming the outer edge portions is preferably 300 fibers per mm ² or more, and more preferably 350 fibers per mm ² or more, and preferably 500 fibers per mm ² or less, and more preferably 450 fibers per mm ² or less.

<17> An absorbent article according to any one of <8> to <16>, wherein the intermediate sheet is composed of a nonwoven fabric formed from synthetic fibers, and the basis weight of the entire intermediate sheet is preferably 15 g / m ² or more, and more preferably 25 g / m ² or more, and is preferably 50 g / m ² or less, and more preferably 40 g / m ² or less.

<18> An absorbent article according to any one of <8> to <17>, wherein the intermediate sheet has a two-layer structure consisting of a high density layer having a relatively high fiber density and a low density layer adjacent to the non-skin-facing surface a high density layer and having a relatively low fiber density, and the difference in the density of the fibers (fibers per 1 mm ² ), which are the fibers forming the low density layer in the intermediate sheet, and the density of the fibers (fibers per 1 mm ² ), which are the fibers forming the high density layer is preferably 5 fibers per mm ² or more, and more preferably 10 fibers per mm ² or more, and preferably 20 fibers per mm ² or less, and more preferably 15 fibers per mm ² or less ...

<19> The absorbent article of <18>, wherein the density of fibers (fibers per mm ² ) of the fibers forming the high density layer is lower than the density of the fibers of the fibers forming the topsheet, and the density of the fibers constituting the fibers forming the high density layer is preferably 20 fibers per mm ² or more, and more preferably 25 fibers per mm ² or more, and preferably 35 fibers per mm ² or less, and more preferably 30 fibers 1 mm ² or less.

<20> An absorbent article according to <18> or <19>, in which the density of the fibers (fibers per 1 mm ² ) of the fibers forming the low density layer is lower than the density of the fibers of the fibers, forming each of the high density layer and the topsheet, and the fiber density of the fibers forming the low density layer is preferably 3 fibers per mm ² or more, and more preferably 5 fibers per 1 mm ² or more, and preferably 15 fibers per 1 mm ² or less, and more preferably 10 fibers per 1 mm ² or less.

[0055]

<21> An absorbent article according to any one of <8> to <20>, wherein the area of each of the low density zones is the same as the area of each of the openings of the topsheet, and is preferably 5 mm ² or more, and more preferably 7 mm ² or more, and is preferably 20 mm ² or less, and more preferably 18 mm ² or less.

<22> The absorbent article of <21>, wherein the proportion of the total area of the plurality of low density zones (holes) is preferably 5% or more, and more preferably 10% or more, and preferably 20% or less, and more preferably 18% or less from the surface area of the skin-facing fibrous structure formed by overlapping the topsheet and the intermediate sheet (area of the portion formed by overlapping the topsheet and the intermediate sheet).

<23> An absorbent article according to any one of <8> to <22>, wherein the contact angle of the fibers forming the skin-facing surface of the outer edge portions of the openings in the topsheet is preferably 82 degrees or more, and more preferably 83 degrees, or more and preferably 87 degrees or less, and more preferably 86 degrees or less, with the outer edge portions being the boundary portions between the low-density regions and the high-density regions.

<24> An absorbent article according to any one of <8> to <23>, wherein the contact angle of the fibers forming the skin-facing side of the topsheet portion not including openings is preferably 78 degrees or more, and more preferably 79 degrees or more, and preferably 82 degrees or less, and more preferably 81 degrees or less, the contact angle being the contact angle in the high density zone.

<25> An absorbent article according to any one of <8> to <24>, wherein the contact angle of the fibers forming the skin-facing side of the intermediate sheet at least in the portions exposed to exposure in the region of the openings is preferably 70 degrees or more, and more preferably 73 degrees or more, and preferably 78 degrees or less, and more preferably 77 degrees or less.

<26> An absorbent article according to any one of items <8> to <25>, including a front portion that is positioned on the ventral side of the wearer, and a back portion that is positioned dorsally when worn, and a crotch portion that is located between the front a part and a rear part, it is preferred that the crotch part has a part that faces the excretory part and which, when worn, is located opposite the part of the wearer's body intended for urine excretion, and opposite the part of the wearer's body intended for excretion of stool, while the part facing the discharging part has on the rear side a part which faces the part for discharging the stool and is located opposite the body part of the wearer intended for isolating the chair, and a plurality of openings of the topsheet are made only in the part that faces the part designed to highlight the stool.

<27> An absorbent article according to any one of <8> to <26>, wherein the interlayer is rectangular in a plan view.

<28> An absorbent article according to any one of <8> to <27>, having a longitudinal direction corresponding to a direction from the front side to a back side of the wearer and a lateral direction orthogonal to the longitudinal direction, the intermediate sheet having a length direction corresponding to the longitudinal direction direction, and preferably covers 30-70% and more preferably 40-60% of the skin-facing surface of the absorbent body, wherein in the absorbent body the absorbent core is wrapped in a core wrap sheet.

Examples of

[0056]

Hereinafter, the present invention will be described in more detail by way of examples, but the invention is not limited to these examples.

[0057]

Example 1

A diaper was manufactured having a configuration similar to that of the diaper 1 shown in FIGS. 1 and 2 and including a skin-facing fiber structure 10 having a topsheet 2 and an intermediate sheet 5 shown in FIGS. 3 and 4. As the top sheet was a spunbond nonwoven fabric with a basis weight of 26 g / m ² containing a polypropylene resin. Furthermore, as the intermediate sheet was used a nonwoven fabric with a basis weight of 35 g / ^m2, bonded by passing air through and manufactured by using a method in which fibers containing polyethylene resin and introduced into an air jet descended and settled on the wire to form canvas, and provided the passage of air having a temperature of 135 ° C and an air flow rate of 1 m / s through the canvas on a mesh moving at a speed of 80 m / s from the side opposite to the surface facing the mesh. Table 1 below shows the physical properties and the like of the topsheet and interlayer.

The density of the fibers and the angle of contact of the fibers with the ion-exchange water were determined using a method similar to the above-described determination method.

[0058]

Example 2

A diaper was made with a configuration similar to that in Example 1, except that a spunbond nonwoven material was used as the topsheet, in which the edge portions H1 with a higher fiber density and a larger contact angle with ion-exchange water than HR high density were provided at the boundaries between the low density LR zones and the high density HR zone, and a top sheet and an intermediate sheet were used whose physical properties and the like were changed. Table 1 below shows the physical properties and the like of the topsheet and interlayer.

[0059]

Example 3

A diaper was made with a configuration similar to that in Example 1, except that a spunbond nonwoven fabric used in Example 2 was used as the topsheet, an intermediate sheet was used in which the fiber density on the skin-facing surface was lower fiber densities on the non-skin side surface, and a topsheet and an intermediate sheet were used whose physical properties and the like were changed. As the intermediate sheet, a nonwoven fabric, bonded by passing air through and through and obtained by using a method in which fibers containing polyethylene resin and introduced into an air jet, were lowered and deposited on a mesh to form a canvas, and an air having a temperature of 135 ° was allowed C and an air flow velocity of 1 m / s through the web on the mesh moving at a speed of 100 m / s from the side opposite to the surface facing the mesh and the surface of the resulting nonwoven fabric, bonded by passing air through, which located on the side facing the mesh was used as the side facing the skin. Table 1 below shows the physical properties and the like of the topsheet and interlayer.

[0060]

Comparative example 1

A diaper was made with a configuration similar to that in Example 1, except that a topsheet and an intermediate sheet with the same fiber density were used. Table 1 below shows the physical properties and the like of the topsheet and interlayer.

[0061]

Estimating the amount of WB loose stools

The diapers of Examples 1-3 and Comparative Example 1 were placed horizontally so that the skin-facing side (topsheet 2 side) was oriented upward when each diaper was flattened. Thereafter, 5 g of pseudo-stool liquid (with a viscosity of 40 mPa ∙ s) was injected at a time using a metering pump at a flow rate of 6 g / s into a zone located 30 mm backward from the midline CL, which represents is the center of the diaper, defined in the longitudinal direction X (the area corresponding to the part 2R, which faces the part intended for stool release, in Fig. 1), immediately after this, 5 g of liquid pseudo-stool (with a viscosity of 240 mPa ∙ s) was introduced into the same site, and a pressure of 3 kPa, were applied to the injection site for one minute by placing a liquid-impermeable, 10 × 10 cm plastic film at the injection site and, in addition, placing the weight on the plastic film. The pressure of "3 kPa" is assumed to be the pressure (pressure to be sustained) that will be applied to the back of the diaper when a child who is several months old and wearing the diaper is asleep face up. In addition, the pseudo-chair liquid used was a suspension obtained by dissolving or dispersing bentonite in water. The concentration of bentonite was adjusted so that the viscosity of the high-viscosity pseudo-stool liquid was 40 mPa ∙ s and the viscosity of the low-viscosity pseudo-stool liquid was 240 mPa ∙ s. After applying the pressure, the weight and the polymer film were removed, and the mass of the liquid pseudo-chair adhered to the film was measured. For each type of diaper to be measured, three measurement samples were prepared and subjected to the above-described measurements. The average of the measured values was taken as the amount of liquid stool WB for a given diaper. Less WB loose stool meant better liquid stool absorption performance, resulting in a higher score. The results are shown in Table 1.

[0062]

Table 1

unit of measurement Ex. 1 Ex. 2 Ex. 3 Comp. Ex. 1 Top sheet (high density area) Fiber density fibers per 1 mm ² 200 200 200 80 Percentage of the area of holes (areas of low density) in the crotch) % 10 fourteen 12 10 Hole shape (low density zones) - Round Rectangular Rectangular Round Hole size (low density areas) mm Diameter 3.2 1.5 * 5 1.5 * 5 Diameter 4.4 Hole area (low density areas) mm ² eight 6 7 fifteen Angle of contact of fibers with ion-exchange water degrees 85 75 75 85 Surface density g / m ² 26 28 32 36 Outside edge of the topsheet hole (outer edge zone of high density) Fiber density fibers per 1 mm ² - 400 400 - Contact angle
fiber with ion exchange water degrees - 85 85 - Intermediate sheet (low density area) Total fiber density fibers per 1 mm ² 80 80 twenty 80 Contact angle
fiber with ion exchange water degrees 70 70 70 85 The density of the fibers on the side facing the skin, (low density layer) fibers per 1 mm ² 40 35 7 40 Fiber density on the non-skin side, (high density layer) fibers per 1 mm ² 40 40 27 40 Surface density g / m ² 35 twenty 32 twenty Assessment WB liquid stool quantity r 1,2 0.9 0.6 2

[0063]

As can be seen from Table 1, a comparison between the amount WB (g) of loose stools in the case of diapers of Examples 1-3 and the amount WB (g) of loose stools in the case of the diaper of Comparative Example 1 shows that the disposable diapers of Examples 1-3 provide less the amount of WB adhered liquid stool than the diaper of Comparative Example 1. Accordingly, it is expected that the disposable diapers of Examples 1-3 will be able to efficiently absorb non-uniform liquid stools of different viscosities as opposed to the diaper of Comparative Example 1, and will be able to reduce the occurrence of skin problems carrier.

Industrial applicability

[0064]

With the absorbent article of the present invention, it is possible to effectively absorb non-uniform liquid stools with different viscosities, and therefore, the liquid stools are unlikely to adhere to the wearer's skin.

Claims (17)

1. An absorbent article comprising a liquid-retaining absorbent core and a skin-facing fibrous structure located on the skin-facing side of the surface of the absorbent core, wherein the skin-facing fibrous structure includes a liquid-permeable topsheet disposed on the skin-facing side of the surface and a liquid-permeable intermediate sheet disposed adjacent to a non-skin-facing surface of the topsheet, in a plan view of the skin-facing side of the surface of an absorbent article, the skin-facing fibrous structure has a plurality of low density zones having a relatively low fiber density and a high density zone having a relatively high fiber density, each of the low density zones being surrounded by a zone high density, the intermediate sheet has a high density layer having a relatively high fiber density and a low density layer having a relatively low fiber density, the high density layer is disposed on the non-skin-facing surface and the low-density layer is disposed on the skin-facing surface, and the density of the fibers constituting the fibers forming the high density layer is lower than the density of the fibers constituting the fibers forming the topsheet. 2. An absorbent article according to claim 1, wherein in a plan view from the side facing the skin of the absorbent article, the area of each of the low density zones is 5 to 20 mm ² . 3. An absorbent article according to claim 1, wherein in a plan view of the skin-facing surface of the absorbent article, the proportion of the total area of the plurality of low density zones is 5 to 15% of the surface area of the fibrous structure facing the skin. 4. An absorbent article according to claim 1, wherein, in a plan view from the side facing the skin of the absorbent article, the boundary portions are provided at the boundaries between the low density zones and the high density zone surrounding the low density zones, and the border portions have a higher density. fibers than the fiber density of the high density zone. 5. An absorbent article according to claim 4, wherein the contact angle of the fibers forming the skin-facing surface with the ion-exchange water is such that the contact angle in the high-density zone is less than the contact angle in the boundary portions and the contact angle in the low-density zones is less than the contact angle in a high density area. 6. Absorbent article according to claim 1, having a longitudinal direction corresponding to the direction from the front side to the back side of the wearer, and a lateral direction orthogonal to the longitudinal direction, wherein each of the low density zones has a shape that is elongated in the longitudinal direction. 7. An absorbent article according to claim 1, wherein said plurality of low density zones are provided in a portion that faces the stool delivery portion and is opposite the stool delivery portion of the wearer. 8. Absorbent article according to claim 1, wherein the topsheet has holes dispersed in a plane direction and the low density zones consist of a skin-facing surface of the intermediate sheet that is exposed to the area of the holes. 9. The absorbent article of claim 8, wherein the density of the fibers on the skin-side surface of the intermediate sheet is lower than the density of the fibers on the non-skin side of the intermediate sheet. 10. The absorbent article of claim 8, wherein the contact angle of the fibers forming the skin-facing surface of the outer edge portions of the openings in the topsheet is 82 to 87 degrees, the outer edge portions being the boundary portions between low density zones and a high density area. 11. The absorbent article of claim 8, wherein the contact angle of the fibers forming the skin-facing side of the fiber-free portion of the topsheet is 78 to 82 degrees, the contact angle being the high density contact angle ... 12. The absorbent article of claim 8, wherein the skin-facing fibrous structure includes a liquid-permeable intermediate sheet disposed adjacent to the non-skin-facing surface of the topsheet and a contact angle of fibers forming the skin-facing side of the intermediate sheet at parts exposed to impact in the area of the holes is from 70 to 78 degrees.

Images