WO2018020693A1

WO2018020693A1 - Absorbent article

Info

Publication number: WO2018020693A1
Application number: PCT/JP2016/072821
Authority: WO
Inventors: 拓也深山; 匡志宇田; 坂口　智
Original assignee: ユニ・チャーム株式会社
Priority date: 2016-07-29
Filing date: 2016-08-03
Publication date: 2018-02-01
Also published as: JP2018015472A; CN109561997B; JP6033981B1; CN109561997A

Abstract

Provided is an absorbent article that includes a surface sheet which is capable of adequately transferring a weak acidifier to a wearer's skin and which is capable of maintaining the pH on the surface of a skin-facing side of the absorbent article so as to be weakly acidic even when excreted fluid such as urine is being repeatedly expelled. This absorbent article includes a surface sheet (2) that comprises non-woven fabric which has base portions (12) and projections that project toward the skin facing side of the absorbent article from the base portions (12). Each projection has an apex (13) and side wall portions (15) and contains the weak acidifier in the apex (13) and side wall portions (15), the fiber density of the side wall portions (15) being lower than that of the apex (13).

Description

Absorbent articles

The present invention relates to absorbent articles such as disposable diapers, sanitary napkins and incontinence pads.

In absorbent articles such as disposable diapers and sanitary napkins, in order to improve rash (dermatitis) that occurs on the skin of the wearer, the surface of the surface sheet that can be in direct contact with the wearer's skin is made weakly acidic Is being considered.

For example, Patent Document 1 has a predetermined water permeability, and the pH of the surface layer is 4.0 or more and 6.5 or less, and the pH of the surface layer after 20 mL of water per unit area is 4.0 or more and 6 or less. A weakly acidic water-permeable nonwoven fabric that is .8 or less is disclosed. The water-permeable nonwoven fabric disclosed in Patent Document 1 is weakly acidic for absorbent articles such as disposable diapers, incontinence pads, and sanitary napkins because the acidic water-permeable agent (treatment agent) is not easily washed away by moisture such as urine and sweat. It can be suitably used as a top sheet.

JP 2014-091899 A

However, since the water-permeable nonwoven fabric disclosed in Patent Document 1 has a flat structure, when such a water-permeable nonwoven fabric is used as a surface sheet of an absorbent article, the absorbent article is worn. Contact unevenness between the surface of the face sheet on the skin facing surface side and the wearer's skin surface due to bending or deformation caused by the wearer's movement, and is included in the surface of the face sheet on the skin facing surface side There was a possibility that the treatment agent (weak acidifying agent) could not be sufficiently transferred to the wearer's skin.
Furthermore, in the water-permeable nonwoven fabric disclosed in Patent Document 1, the pH of the surface layer after water permeation of 20 mL is 4.0 or more and 6.8 or less, and the treatment agent is less likely to be washed away by moisture such as urine and sweat. However, no consideration is given to the structure of the non-woven fabric (surface sheet) that makes the treatment agent difficult to be washed away, so depending on the structure of the non-woven fabric, excretion liquid such as urine that is repeatedly supplied (especially the wearer ), The pH on the surface of the topsheet may not be maintained weakly acidic.

Therefore, the present invention can sufficiently transfer the weak acidifying agent to the wearer's skin, and the pH on the surface on the skin-facing surface side even when excretion liquid such as urine is repeatedly supplied. It aims at providing the absorbent article provided with the surface sheet which can be maintained weakly acidic.

One aspect (aspect 1) of the present invention is an absorbent article provided with a topsheet, wherein the topsheet has a base and a convex portion protruding from the base toward the skin-facing surface of the absorbent article. The convex part has a top part and a side wall part, and includes a weak acidifying agent in the top part and the side wall part, and the fiber density of the side wall part is higher than the fiber density of the top part. The absorbent article is also small.

The absorbent article of this aspect contains the weak acidifying agent on the top and side walls of the convex portion of the surface sheet that easily comes into direct contact with the skin of the wearer. The weak acidifying agent can be sufficiently transferred to the wearer's skin. Furthermore, since the absorbent article of this aspect has a fiber density in the side wall portion of the convex portion that is lower than the fiber density at the top portion, when the excretory fluid such as urine is supplied from the wearer to the surface of the topsheet, the excretory fluid Even when the weak acidifying agent contained in the top part and the side wall part elutes during the excretion liquid containing the above weak acidifying agent permeates from the skin facing surface side of the surface sheet to the non-skin facing surface side. A certain amount of excreted liquid tends to remain as a residual liquid on the side wall portion having a low fiber density, and the pH of the convex portion can be kept weakly acidic by the weak acidifying agent contained in the residual liquid. As a result, the absorbent article according to the present aspect always retains the excretory liquid containing a certain weak acidifying agent as the residual liquid on the above-mentioned side wall portion even when excretion liquid such as urine is repeatedly supplied from the wearer. Since it is easy to do, pH of a convex part can be maintained weakly acidic.
As described above, the absorbent article according to this aspect can sufficiently transfer the weak acidifying agent to the skin of the wearer, and the skin of the topsheet even when excretion liquid such as urine is repeatedly supplied. The pH on the surface on the opposite surface side can be kept weakly acidic.
In the present specification, the surface on the skin facing surface side of the surface sheet may be simply referred to as “surface of the surface sheet”.

In an absorbent article according to another aspect (aspect 2) of the present invention, in the absorbent article according to aspect 1, the convex portion has a hollow internal structure.

In the absorbent article of this aspect, since the convex part of the topsheet has a hollow internal structure, the excretory liquid containing the above-described weakly acidifying agent is close to the skin of the wearer in the convex part. It tends to remain on the surface layer portion on the opposite surface side (more specifically, the surface layer portion on the side wall portion of the convex portion), and the weak acidifying agent can be more easily brought into contact with the skin of the wearer. The agent can be transferred to the wearer's skin more reliably.

In an absorbent article according to still another aspect (aspect 3) of the present invention, in the absorbent article according to

aspect

1 or 2, the base portion includes a high-density portion having a fiber density higher than that of the side wall portion.

In the absorbent article according to this aspect, since the base portion of the topsheet includes a high density portion having a fiber density higher than that of the side wall portion of the convex portion, the excretory liquid containing the weak acidifying agent described above is more relative to the base portion. In particular, it tends to remain on the side wall of the convex portion having a low fiber density, and the effect of the above-described aspect 1 (that is, “the weak acidifying agent can be sufficiently transferred to the wearer's skin, and urine, etc. Even when the excretory liquid is repeatedly supplied, the effect of “the pH on the surface of the face sheet facing the skin facing side can be kept weakly acidic”) is more reliably and efficiently exhibited. Can do.
In addition, in this specification, the effect of the above-mentioned aspect 1 may be called "the effect concerning the transferability and durability of a weak acidifying agent."

In an absorbent article according to still another aspect (Aspect 4) of the present invention, in the absorbent article according to any one of Aspects 1 to 3, the base portion includes the weak acidifying agent.

The absorbent article of the present aspect includes the weak acidifying agent described above even in the base part of the topsheet on which the excretion liquid supplied from the wearer is likely to temporarily accumulate. Therefore, the weak acidifying agent contained in the base part Is eluted in the excretion fluid that temporarily accumulates on the base portion of the topsheet, and remains on the side wall portion of the convex portion when the excretion fluid permeates from the skin facing surface side to the non-skin facing surface side of the topsheet. The amount (that is, concentration) of the weak acidifying agent contained in the excretory liquid (hereinafter, excretory liquid remaining on the side wall portion may be simply referred to as “residual liquid”) can be relatively increased. As a result, the absorbent article according to the present aspect can exhibit the effects and effects related to the migration and durability of the weak acidifying agent better and more reliably.

In an absorbent article according to yet another aspect (Aspect 5) of the present invention, in the absorbent article according to any one of Aspects 1 to 4, the base portion is recessed toward the non-skin facing surface side of the absorbent article. Has a recess.

Since the absorbent article of this aspect has a concave portion in which the base portion of the topsheet is recessed toward the non-skin facing surface side of the absorbent article, the side wall portion and the topsheet in the convex portion of the topsheet are formed by the concave portion. Even if the convex part of the topsheet is crushed by the wearer's body pressure or the like, it remains on the side wall part as described above. It is possible to make it difficult for the excretory fluid (residual fluid) to be drawn into the non-skin facing surface side. Thereby, in the absorbent article of this aspect, since the excretion liquid containing the eluted weak acidifying agent is more likely to remain on the side wall portion of the convex portion, the above-described weak acidifying agent can be transferred and durable. Such operational effects can be more reliably exhibited.

In an absorbent article according to still another aspect (Aspect 6) of the present invention, in the absorbent article according to any one of Aspects 1 to 5, the convex portion extends continuously in a predetermined first direction and the first It consists of a plurality of first direction flanges arranged in the second direction intersecting the direction.

The absorbent article according to this aspect is configured by a plurality of first-direction flanges arranged in a second direction in which the convex portion of the topsheet continuously extends in a predetermined first direction and intersects the first direction. The excretory fluid supplied to the surface of the top sheet is diffused in the first direction described above, and between the convex portions adjacent in the second direction (that is, between the first direction collars adjacent in the second direction). It is possible to make it easy to temporarily store. Thereby, in the absorbent article of the present aspect, the excretory liquid containing the eluted weak acidifying agent described above easily comes into contact with a wider range of side wall portions (specifically, a wide range of side wall portions in the first direction). Since the excretion liquid containing the weak acidifying agent can be left in a wider range of the side wall portion, the effects of the above-described weak acidifying agent in terms of migration and durability are exhibited in a wider area of the surface sheet. be able to.

In an absorbent article according to yet another aspect (aspect 7) of the present invention, in the absorbent article according to any one of the aspects 1 to 5, the convex portion extends continuously in a predetermined first direction and the first A plurality of first direction flanges arranged in a second direction intersecting the direction and two first direction flanges adjacent to each other in the second direction and continuously extending in the second direction and the first direction. And a plurality of second direction ridges arranged in a row.

The absorbent article according to this aspect includes a plurality of first direction flanges arranged in a second direction in which convex portions of the topsheet continuously extend in a predetermined first direction and intersect the first direction, and the second direction. A plurality of second direction flanges that continuously extend in the second direction between the two first direction flanges adjacent to each other. The excretory fluid supplied to each of the above-described convex portions adjacent to each direction (that is, between the two first direction collars adjacent to each other in the second direction and the two first direction collars adjacent to each other). It is possible to make it easier to collect between two second direction flanges adjacent to each other in the first direction, and it is possible to secure a certain number of side wall portions.
Therefore, in the absorbent article of this aspect, the excretory liquid containing the weakly acidifying agent that has been eluted is a side wall portion (more specifically, the side wall portion of the first direction collar portion and the side wall portion of the second direction collar portion). Each of which is more easily contacted, and the excretory liquid containing the weak acidifying agent can be more reliably left on the side wall portion of the convex portion, and the excretory liquid containing the weak acidifying agent is allowed to remain in the first direction heel part. It can be made to remain in each of the side wall part and the side wall part of the 2nd direction collar part (that is, securing the amount of excretion fluid containing the above-mentioned weak acidifying agent remaining in the side wall part of a convex part more than a fixed. Therefore, the effects of the above-described weak acidifying agent in terms of migration and durability can be exhibited more reliably and more remarkably.

In an absorbent article according to yet another aspect (Aspect 8) of the present invention, in the absorbent article according to any one of Aspects 1 to 7, the weak acidifying agent comprises only a plant-derived component.

Since the above-mentioned weak acidifying agent consists only of a plant-derived component, the absorbent article of this aspect, such as a wearer and a user (for example, a caregiver) of the absorbent article (hereinafter simply referred to as “wearer etc.”) In contrast, the use of only plant-derived components as weak acidifying agents can provide a sense of security. And, since such a sense of security can psychologically encourage long-term wearing of the absorbent article, the absorbent article of this aspect relates to the migration and durability of the weak acidifying agent described above by long-term wearing. The effect can be more steadily exhibited, and the effect can be easily recognized by the wearer.

In the absorbent article of still another aspect (Aspect 9) of the present invention, the non-woven fabric contains a cotton fiber in a content of 35% by mass or less.

In the absorbent article of this embodiment, since the nonwoven fabric constituting the top sheet contains hydrophilic cotton fibers in a content of 35% by mass or less, the nonwoven fabric has a structure and fiber density having the above-mentioned convex portions and base portions. While maintaining the above relationship, it is easier to retain the excretion fluid from which the weak acidifying agent is eluted (particularly, it is easier to retain in the side wall portion), and as a result, the above weak acidifying agent is retained. It is possible to more reliably and satisfactorily exhibit the effects related to the transferability and durability.

According to the present invention, the weak acidifying agent can be sufficiently transferred to the wearer's skin, and the pH on the surface on the skin-facing surface side can be reduced even when excretion liquid such as urine is repeatedly supplied. An absorptive article provided with a surface sheet which can be maintained in weak acidity can be provided.

FIG. 1 is a plan view of a disposable diaper according to the first embodiment of the present invention. 2 is an enlarged cross-sectional view taken along line II-II shown in FIG. 1 of the disposable diaper according to the first embodiment of the present invention. FIG. 3 is a perspective view of a nonwoven fabric constituting the top sheet of the disposable diaper according to the first embodiment of the present invention. FIG. 4 is an enlarged plan view of a main part of the top sheet of the disposable diaper according to the first embodiment of the present invention. FIG. 5 is an enlarged sectional view taken along line VV shown in FIG. 4 of the disposable diaper according to the first embodiment of the present invention. 6 is an enlarged cross-sectional view taken along the line VI-VI shown in FIG. 4 of the disposable diaper according to the first embodiment of the present invention. Fig.7 (a) is an important section expanded sectional view of the convex part in the surface sheet of the disposable diaper shown in FIG. 6, FIG.7 (b) supplies excretion liquid to the disposable diaper shown in Fig.7 (a). FIG. 7C is a main part enlarged cross-sectional view schematically showing a state immediately after the discharge, and FIG. 7C is a state after the excretion liquid has shifted from the state shown in FIG. 7B to the non-skin facing surface side of the topsheet. It is a principal part expanded sectional view which shows typically. FIG. 8 is an enlarged sectional view taken along line VIII-VIII shown in FIG. 4 of the disposable diaper according to the first embodiment of the present invention. FIG. 9 is a perspective view of a nonwoven fabric constituting the top sheet of the disposable diaper according to the second embodiment of the present invention. FIG. 10 is an enlarged plan view of a main part of the nonwoven fabric shown in FIG. FIG. 11 is an enlarged cross-sectional view along the line XI-XI of the nonwoven fabric shown in FIG. FIG. 12 is an enlarged cross-sectional view along the line XII-XII of the nonwoven fabric shown in FIG. FIG. 13: is a perspective view of the nonwoven fabric which comprises the surface sheet of the disposable diaper which concerns on 3rd embodiment of this invention. 14 is an enlarged cross-sectional view of the nonwoven fabric shown in FIG. 13 taken along line XIV-XIV. FIG. 15 is a perspective view of a nonwoven fabric constituting the top sheet of the disposable diaper according to the fourth embodiment of the present invention. FIG. 16: is a perspective view of the nonwoven fabric which comprises the surface sheet of the disposable diaper which concerns on 5th embodiment of this invention.

Hereinafter, preferred embodiments of the absorbent article of the present invention will be described in detail with reference to the drawings. In this specification, unless otherwise specified, “an object placed on a horizontal surface in an unfolded state (for example, an absorbent article, a surface sheet (nonwoven fabric), an absorbent body, etc.) “Looking in the thickness direction of the object” is called “plan view”. In particular, when the object is an absorbent article, viewing the absorbent article in the thickness direction from the top sheet side in a state where the absorbent article is unfolded may be simply referred to as “plan view”.

Various directions and the like used in this specification are as follows unless otherwise specified.
In this specification, “longitudinal direction” refers to “a direction in which the length of a vertically long object in plan view is long”, and “width direction” refers to “a direction in which the length of a vertically long object in plan view is short (short side). Direction) ”and“ thickness direction ”means“ perpendicular direction with respect to the object placed on the horizontal plane in the unfolded state ”. The longitudinal direction, the width direction, and the thickness direction are orthogonal to each other.
Further, in the present specification, “in the width direction of a vertically long object (for example, an absorbent article, a surface sheet (nonwoven fabric), an absorbent body, etc.) is relatively proximal to the widthwise central axis extending in the longitudinal direction. The “side” is referred to as the “inward side in the width direction”, and the “distal side relative to the central axis in the width direction in the width direction of the vertically long object” is referred to as the “outer side in the width direction”. . The same applies to the inner side and the outer side in the longitudinal direction.
In this specification, unless otherwise specified, in the thickness direction of the absorbent article, “relatively proximal to the wearer's skin surface when the absorbent article is worn” is defined as “skin facing surface”. "Side", and "the distal side relative to the skin surface of the wearer when the absorbent article is worn" is referred to as "the non-skin facing surface side".
In the present specification, “when wearing” means that the wearer wears the absorbent article (that is, when the wearable state is formed) and maintains that state (wears). "While wearing" is synonymous.

<First embodiment>
1, FIG. 2 and FIGS. 4 to 8 are views schematically showing the disposable diaper 1 (absorbent article) according to the first embodiment of the present invention, and FIG. 3 is a top sheet 2 of the disposable diaper 1. It is a perspective view which shows typically the nonwoven fabric which comprises. In addition, in the disposable diaper 1 of FIG. 1, the area | region of the upper side of drawing corresponds to the back part side area | region which becomes proximal with respect to a wearer's back at the time of wearing of the disposable diaper 1, and the area | region of the lower side of drawing is It corresponds to an abdominal region that is proximal to the wearer's abdomen when the disposable diaper 1 is worn.

The disposable diaper 1 according to the first embodiment of the present invention has a longitudinal direction L, a width direction W, and a thickness direction T that are orthogonal to each other, as shown in FIGS. 1, 2, and 4 to 8. In the thickness direction T, the liquid-permeable surface sheet 2 located on the skin-facing surface side of the wearer and having a first direction flange 11 (convex portion) and a base 12 described later, and the wearer's non-skin facing A liquid-impermeable back sheet 3 positioned on the surface side and an absorbent body 4 positioned between the two sheets are provided as a basic configuration.
1 and 2, the disposable diaper 1 absorbs a pair of

side sheets

5 and 5 that can form a leak-proof wall portion by standing up an edge on the inner side in the width direction W. An elastic member 6 made of rubber or the like for extending and contracting in the longitudinal direction L on the left and right legs, which are located on the outer side in the width direction W with respect to the body 4 and abuts on the wearer's thigh, In some cases, the disposable diaper 1 further includes a connecting tape 7 for connecting the abdomen-side region and the back-side region of the disposable diaper 1 and an exterior sheet (not shown) disposed on the non-skin facing surface side of the back sheet 3.

In the present embodiment, as shown in FIG. 2, the back sheet 3 is at least the surface of the absorbent body 4 on the non-skin facing surface side on the non-skin facing surface side of the disposable diaper 1 (the lower side of the absorbent body 4 in FIG. 2). It is comprised by the liquid-impermeable sheet | seat member which is arrange | positioned so that it may cover and prevents permeation | transmission of excretion liquids, such as urine discharged | emitted from the wearer, and prevents this excretion liquid leaking outside. In addition, this back surface sheet 3 has the vertically long outer shape formed in the longitudinal direction L of the disposable diaper 1 in plan view, and extends from the above-described abdomen side region to the back side region. Are arranged as follows.

In the present invention, the liquid-impermeable sheet member constituting the back sheet is particularly suitable as long as it has various characteristics that can be used as the back sheet of the absorbent article (for example, liquid impermeability, air permeability, flexibility, etc.). Without limitation, for example, an arbitrary liquid-impermeable sheet member such as a resin film such as polyethylene or polypropylene having air permeability, or a laminate in which a nonwoven fabric is bonded to the resin film can be used.

Among these, it is preferable to use a liquid-impermeable sheet member having a predetermined air permeability, although the back sheet does not transmit liquid such as excretory liquid. When the back sheet has such air permeability, moisture released from the absorbent that has absorbed excretory fluid such as urine can be released to the outside through the back sheet, Alternatively, the amount of moisture remaining between the absorbent article and the wearer's skin can be reduced.
In general, if the wearer's skin (skin) is kept wet by excreted fluid such as urine or its moisture, the wearer's skin will be swollen and maintain resistance to chemical and physical irritation. (I.e., the protective function against various skin irritation is reduced), so that it receives alkaline chemical stimulation by ammonia components derived from urine and other excretory fluids, and physical stimulation by friction with the surface sheet. When it is received, the skin cannot withstand these irritation and it is easy to cause rash (dermatitis), but the back sheet is constituted by the liquid-impermeable sheet member having air permeability as described above. As described above, the amount of moisture remaining in the absorbent article or between the absorbent article and the wearer's skin can be reduced, so that the wearer's skin is unlikely to become wet. (I.e., difficult to maceration of the skin of the wearer), consequently, it can be difficult to cause more and skin irritation.

Further, in the present invention, the dimensional shape of the back sheet is not particularly limited as long as it can prevent leakage of excretory fluid, and any size according to the size, sex, use, etc. of the person who wears the absorbent article. Shape can be adopted. Further, the thickness of the back sheet is not particularly limited as long as the effect of the present invention is not impaired. For example, a thickness in the range of 0.001 mm to 5.0 mm can be adopted, but the liquid impermeability and flexibility are not limited. The thickness is preferably within the range of 0.003 mm to 3.0 mm from the viewpoint of the property and air permeability.

As shown in FIG. 2, the absorbent body 4 in the first embodiment of the present invention is disposed between the top sheet 2 and the back sheet 3 in the thickness direction T of the disposable diaper 1 and transmits the top sheet 2. It is constituted by an absorptive member having a function of absorbing and holding excretory fluid such as urine. As shown in FIG. 1, the absorbent body 4 is formed long along the longitudinal direction L of the disposable diaper 1 in a plan view, and the substantially central portion of the longitudinal direction L is inward in the width direction W. In the central region including a widthwise central axis (not shown) extending in the longitudinal direction L of the disposable diaper 1 and extending from the above-mentioned abdomen side region to the back side region. Are arranged to be. Further, the absorber 4 is formed so that the surface on the surface sheet 2 side (that is, the skin facing surface side) and the surface on the back sheet 3 side (that is, the non-skin facing surface side) are both substantially flat. 4 has a substantially constant thickness.
In the present invention, the absorbent body is not limited to the above-described embodiment, and the absorbent body may have an arbitrary external shape such as a rectangle or an oval, or may be closer to the front in the longitudinal direction of the absorbent article or They may be arranged at a position closer to the rear, and may have partially different thicknesses.

In the present invention, the absorbent member constituting the absorbent body is not particularly limited as long as the effect of the present invention is not impaired, and any absorbent member known in the art can be used. As such an absorbent member, for example, an absorbent material including at least one of a water-absorbing fiber such as pulp and a superabsorbent polymer is covered with at least one liquid-permeable covering sheet such as tissue. Can be mentioned.

The thickness, basis weight, and the like of the absorbent body are not particularly limited, and may be appropriately adjusted according to various properties (for example, absorbency, strength, flexibility, etc.) that the absorbent body of the absorbent article such as a disposable diaper should have. it can. For example, the thickness of the absorber is in the range of 0.1 to 15 mm, preferably in the range of 1 to 10 mm, and the basis weight of the absorber is in the range of 20 to 1000 g / m ² , preferably 50 to 800 g. / M ² . In addition, the thickness, basic weight, etc. of an absorber may be constant over the whole absorber, and may differ partially.

In the present embodiment, the absorber 4 is bonded to the top sheet 2 on the skin facing surface side and the back sheet 3 on the non-skin facing surface side by an adhesive such as a hot-melt adhesive. Has been.

As shown in FIG.1 and FIG.2, the surface sheet 2 in 1st embodiment of this invention is the skin opposing surface side (above the absorber 4 in FIG. 2) of the disposable diaper 1 which can contact a wearer's skin directly. Side), the excretion fluid absorbed and retained by the absorber 4 is disposed so as to cover at least the surface of the absorber 4 on the skin-facing surface side and allows the excretion fluid such as urine discharged from the wearer to pass therethrough. It is composed of a liquid-permeable nonwoven fabric that prevents contact with the wearer's skin. As shown in FIG. 1, the surface sheet 2 has a vertically long outer shape that is formed long along the longitudinal direction L of the disposable diaper 1 in a plan view, from the abdomen side region to the back side region. It arrange | positions so that it may extend over.

In the present embodiment, as shown in FIGS. 3 to 8, the topsheet 2 has a first direction and a first direction which are parallel to the longitudinal direction L, the width direction W and the thickness direction T of the disposable diaper 1, respectively. It consists of a nonwoven fabric which has a 2nd direction and a 3rd direction, and has the 1st surface 2a which forms the surface by the side of the skin opposing surface of the disposable diaper 1, and the 2nd surface 2b which forms the surface by the side of a non-skin opposing surface. . As shown in FIGS. 3 to 8, the non-woven fabric extends in the first direction (longitudinal direction L), the base 12 positioned at the reference position in the third direction (thickness direction T) of the topsheet 2, and the A plurality of first direction ridges 11 projecting from the base 12 toward the skin-facing surface side of the disposable diaper 1, formed so as to be arranged at predetermined intervals in a second direction (width direction W). Yes. In addition, this 1st direction collar part 11 is an example of the "convex part" in this invention.

In the present embodiment, as shown in FIGS. 3 to 6 and 8, the base 12 includes a first base 22 having a first bottom 22 serving as a reference surface in the third direction (thickness direction T) of the topsheet 2. 21 and a plurality of hollow structures that are intermittently formed in the first base portion 21 along the first direction (longitudinal direction L) and open to the first surface 2a of the first bottom portion 22. A recess 26 (second base). Further, as shown in FIGS. 3, 5, and 8, the concave portion 26 includes a peripheral wall portion 27 extending from the first bottom portion 22 toward the absorber 4 side (that is, the non-skin facing surface side), and the peripheral wall. And a second bottom portion 28 formed so as to close the end portion of the portion 27 on the non-skin facing surface side.

In the present embodiment, as shown in FIGS. 3 to 8, the first direction flange 11 includes a top portion 13 that is located closest to the skin facing surface side of the topsheet 2, and the top portion 13 and the first bottom portion 22. And a side wall 15 extending in the first direction (longitudinal direction L), and the first direction flange 11 is provided on the top sheet 2 on the non-skin facing surface side. It has a void 14 facing the second surface 2b of the (nonwoven fabric). By providing the gap portion 14, the first direction flange portion 11 of the topsheet 2 has a hollow internal structure.
In the present specification, the “top” of the convex portion such as the first direction ridge portion 11 is the apex located on the most skin facing surface side in the convex portion (in the case where the convex portion is composed of a plurality of types of ridge portions). , Each of the ridges includes the most apex located on the skin facing surface side, and the height of the convex portion from the apex (that is, the first surface of the base (in this embodiment, the first base 21 The position of 70% of the distance from the first surface 2a) of the first bottom portion 22 to the apex of the convex portion (here, the position of 70% of the height of the convex portion is convex starting from the first surface of the base portion). It refers to the position up to 70% of the total height of the part.)

And in this embodiment, the 1st direction collar part 11 contains the weak acidifying agent in the top part 13 and the side wall part 15, and also the fiber density of the side wall part 15 is shown in Fig.7 (a). It is comprised so that it may become smaller than the fiber density of the top part 13. FIG.
Since the disposable diaper 1 in this embodiment contains the weak acidifying agent in the top part 13 and the side wall part 15 of the 1st direction collar part 11 (convex part) of the surface sheet 2 which can contact a wearer's skin directly. The weak acidifying agent can be easily brought into contact with the wearer's skin, and the weak acidifying agent can be sufficiently transferred to the wearer's skin. Furthermore, since the fiber density in the side wall part 15 of the 1st direction collar part 11 is smaller than the fiber density of the top part 13, as shown in FIG.7 (b), the disposable diaper 1 is shown in FIG.7 (b). Even if the weak acidifying agent contained in the top portion 13 and the side wall portion 15 is eluted in the excretion fluid U when the excretion fluid U such as urine is supplied onto the top sheet 2 from the wearer, the above-mentioned When the excretory liquid U containing a weak acidifying agent permeates from the skin facing surface side of the top sheet 2 to the non-skin facing surface side, a certain amount of excreted liquid is transferred to the side wall portion 15 having a low fiber density (more specifically, The residual liquid R is likely to remain as a residual liquid R (between the fibers of the constituent fibers forming the side wall 15) (see FIG. 7C). The pH of part 11 can be kept weakly acidic.
Thereby, even if the disposable diaper 1 in this embodiment is a case where excretion liquid U, such as urine, is repeatedly supplied from a wearer, the excretion liquid always containing a certain weak acidifying agent is used as the residual liquid R. Since it is easy to remain in the above-mentioned side wall part 15, pH of the above-mentioned 1st direction collar part 11 can be maintained in weak acidity.
Further, as a result, the disposable diaper 1 has the effect of the weak acidifying agent (that is, the wearer's skin is weakly acidified and hardly changed to alkaline, and the skin irritation caused by chemical irritation is hardly caused. Effect) can be demonstrated continuously.
Moreover, when the topsheet 2 has the first direction ridges 11 (convex portions) as described above, the wearer's skin is easily separated from the absorbent body 4 holding the excretory fluid, and the absorbent body 4. It is difficult for the wearer's skin to become wet due to the return of the excretory fluid from the wearer, so the wearer's skin is difficult to swell (that is, the protective function against various irritation of the wearer's skin is reduced) As a result, it is possible to make it more difficult to cause skin irritation.

Here, the determination of the size of the fiber density in each part (top, side wall, etc.) of the nonwoven fabric is carried out using a scanning electron microscope or the like for each of the target parts (for example, size of 1 mm × 1 mm) for comparing the fiber density. Magnification is observed at a magnification of about 20 to 100 times, and it can be judged visually from the number of fibers per certain area.

In addition, although it is not an indispensable structural requirement in the absorbent article of this invention that the convex part of a surface sheet is a collar part like this embodiment, a convex part is predetermined | prescribed like this embodiment. It is preferable to include a plurality of first direction flanges that extend continuously in the first direction and are arranged in the second direction intersecting the first direction. When the convex portion of the topsheet is configured by a plurality of first direction flanges that extend continuously in a predetermined first direction and are arranged in a second direction intersecting the first direction, the surface sheet is supplied to the surface of the topsheet The discharged fluid is temporarily accumulated between the convex portions adjacent in the second direction (that is, between the two first direction flanges adjacent in the second direction) while diffusing in the first direction. Since it can be made easier (see FIG. 7 (b)), the excreted liquid containing the eluted weak acidifying agent is spread over a wider range of side walls (specifically, a wide range of side walls in the first direction). It is easy to contact and the excretory liquid containing the weak acidifying agent can be left in a wider range of the side wall. Thereby, the effect which concerns on the transferability and durability of the above-mentioned weak acidifying agent can be exhibited in a wider area | region of a surface sheet.

Moreover, as above-mentioned, in this embodiment, although the 1st direction and 2nd direction of the surface sheet 2 have a parallel relationship with the longitudinal direction L and the width direction W of the disposable diaper 1, respectively, in this invention, The first direction and the second direction of the topsheet are not limited to the form of the present embodiment as long as they intersect each other on the same plane (that is, on the topsheet), and any direction can be adopted. .
In the present specification, the “second direction intersecting the first direction” means that the angle formed with the first direction on the same plane (on the top sheet) is in the range of 45 ° or more and 90 ° or less. Thus, the second direction intersecting the first direction is meant.

As the weak acidifying agent that can be used in the absorbent article of the present invention, at least the surface of the topsheet facing the skin (specifically, at least the convex portions (ie, the top and side walls) of the topsheet) and the wearer The skin is not particularly limited as long as the skin can be weakly acidified, and examples thereof include organic acids such as fatty acids and oils such as plant-derived oils. Examples of the organic acid include saturated fatty acids such as succinic acid and lactic acid; fatty acids such as unsaturated fatty acids such as fumaric acid, oleic acid, and undecylenic acid. The oils include coconut oil, palm kernel oil, Examples include plant-derived fats and oils mainly containing saturated fatty acids such as palm oil; plant-derived oils and fats mainly containing unsaturated fatty acids such as castor oil, tall oil and olive oil. The fatty acid described above may contain an appropriate amount of an alkali metal salt such as a sodium salt or a potassium salt of the fatty acid.
Among these, it is preferable to use unsaturated fatty acids or oils having a melting point of 40 ° C. or less, because they are difficult to oxidatively decompose and easily act at the temperature of excretion discharged from the wearer, and the melting point is 30 ° C. or less. More preferably, unsaturated fatty acids or oils are used.
Furthermore, among these, what consists only of a plant-derived component is especially preferable. If the weak acidifying agent is composed only of plant-derived components, it is possible to foster a sense of security by using only plant-derived components as weak acidifying agents for wearers of absorbent articles, etc. it can. Since such a sense of security can psychologically promote long-term wearing of the absorbent article, the absorbent article of the present invention has the effects of migrating and durability of the weak acidifying agent described above by long-term wearing. In addition to being able to exhibit more steadily, it is possible to make the wearer and the like easily recognize such operational effects.

The above-mentioned organic acids and oils may be used alone or in combination of two or more, and any additive (for example, antioxidant, emollient, colorant, fragrance, etc.) May be included.
Examples of weak acidifying agents other than the organic acids and oils described above include water permeability imparting agents disclosed in Japanese Patent Application Laid-Open Nos. 2014-109078 and 2014-231666. Since this water permeability imparting agent can also impart durable water permeability to the nonwoven fabric, it can be suitably used as the weak acidifying agent of the present invention.

In the present specification, “weak acidification” means changing the pH so that an object (for example, a surface sheet (nonwoven fabric), a wearer's skin, etc.) exhibits weak acidity. Further, in the present specification, “weakly acidic” means that the pH is in the range of 3.0 to 6.0. Here, the evaluation of whether or not the object is weakly acidic is performed by measuring the pH of the surface of the nonwoven fabric with the following <weak acidity evaluation method> or a commercially available pH meter when the object is a nonwoven fabric. Moreover, when a target object is a wearer's skin, it can carry out by measuring pH of the skin surface with a commercially available pH measuring device.

<Weak acidity evaluation method>
(1) A bromothymol blue solution (BTB solution) is diluted with a neutral buffer to prepare a pH indicator for weak acidity evaluation.
(2) The pH indicator is dropped on the surface of the nonwoven fabric to be measured with a one drop dropper or sprayed with a spray.
(3) The surface of the nonwoven fabric to which the pH indicator is attached is lightly pressed with a glass rod so that the fibers constituting the nonwoven fabric and the pH indicator are mixed.
(4) The non-woven fabric is checked by visually checking the color of the surface of the non-woven fabric 10 seconds after the pH indicator is adhered, and by comparing the color sample and color prepared for each pH in advance. Determine the pH of the surface.
The color sample for each pH described above is prepared as follows.
(i) A plurality of types of solutions whose pHs are known in advance (for example, a plurality of types having different pH values such as different pH by 1.0 or 0.5) (for example, a plurality of pH buffer solutions having different pHs) Or a diluted solution of the pH buffer solution or the like) is prepared as a color sample standard solution.
(ii) A color sample for each pH is prepared by dropping an appropriate amount of the pH indicator into each prepared color sample standard solution to cause coloration.

In the present invention, the position where the weak acidifying agent is attached to the surface sheet (nonwoven fabric) is not particularly limited as long as the weak acidifying agent is attached to at least the top and the side wall of the convex portion. You may make it adhere only to a side wall part, or may adhere to the whole nonwoven fabric including both a convex part and a base. Since the above-mentioned convex part (especially the top part) has less chance of contact with excretion fluid such as urine than the base part and the contact time is short, when a weak acidifying agent is attached to such convex part, At least in the convex portion, it is difficult for the weak acidifying agent to flow out of the surface sheet with the excretion liquid, even if the weak acidifying agent flows with the excretion liquid, in the present invention, Since the fiber density in the side wall part of the convex part is relatively small, excretory liquid containing a certain weak acidifying agent tends to remain on the side wall part as a residual liquid (FIGS. 7B and 7C). )), And the pH of the convex portion can be kept weakly acidic. As a result, the absorbent article of the present invention can exhibit better and more reliably the effects related to the migration and durability of the weak acidifying agent described above.

In the absorbent article of the present invention, it is preferable that the weak acidifying agent described above is also contained in the base portion of the topsheet. Since the base portion of the topsheet is a portion where the excretion fluid supplied from the wearer is likely to temporarily accumulate, if such a weak acidifying agent is also included in such a base portion, the weakness included in the base portion The acidifying agent elutes in the excretion liquid temporarily accumulated on the base of the topsheet, and remains on the side wall portion when the excretion liquid permeates from the skin facing surface side to the non-skin facing surface side of the topsheet. The amount (that is, concentration) of the weak acidifying agent contained in the excretory fluid can be relatively increased. As a result, the absorbent article of the present invention can exhibit better and more reliably the effects related to the migration and durability of the weak acidifying agent described above.

When the weak acidifying agent is applied to the surface of the surface sheet (nonwoven fabric), the application method is not particularly limited. For example, an extrusion apparatus equipped with a discharge nozzle; a spiral coater, a curtain coater, a spray coater, a dip coater Any coating device such as a non-contact type coater such as a contact type coater can be used. In addition, when a weak acidifying agent is attached to the entire surface sheet, an impregnation method in which the nonwoven fabric constituting the surface sheet is impregnated with a solution containing the weak acidifying agent or the constituent fibers of the nonwoven fabric are previously coated with the weak acidifying agent. It is also possible to adopt a method to The amount of the weak acidifying agent attached to the top sheet (nonwoven fabric) is not particularly limited as long as the effect of the present invention can be achieved, and for example, an arbitrary amount within the range of 0.01 to 30 g / m ² is adopted. can do.

Next, the structure of the topsheet 2 of the disposable diaper 1 according to the first embodiment of the present invention (that is, the structure having the first directional flange 11 and the base 12) will be described in more detail.

In the present embodiment, as shown in FIGS. 5, 6, and 8, the top sheet 2 is not joined to the absorber 4 in the second surface 2 b in the first direction flange 11, and the first base in the base 12. A part of the second surface 2b of the first bottom portion 22 of 21 and the second surface 2b of the second bottom portion 28 of the recess 26 (second base portion) are on the surface sheet 2 side of the absorbent body 4 (that is, the skin facing surface). The adhesive layer 8 is joined to the surface. In the present embodiment, the first direction flange 11 extends beyond both edges of the absorbent body 4 in the longitudinal direction L (first direction), but in the present invention, It is not limited to such an aspect, The 1st direction collar part may be extended in the longitudinal direction of the absorbent article to the at least one edge of an absorber, or beyond one edge. When the first direction buttock is extended in this way, even if the excretion liquid retained in the absorber returns from the absorber, the excretion liquid is less likely to contact the wearer's skin, and the wearer's skin It is difficult for the wearer's skin to become wet (that is, the wearer's skin does not have a low protective function against various irritation), resulting in skin irritation. It can be made harder to cause.
In addition, the direction where a 1st direction collar part is extended is not limited to the longitudinal direction of the above-mentioned absorbent article, The 1st direction collar part may be extended in arbitrary directions, such as the width direction of an absorbent article.

In the present embodiment, the interval between the adjacent first direction flanges 11 is not particularly limited as long as the effect of the present invention is not hindered, and is preferably in the range of 0.25 to 5.0 mm, for example. Is in the range of 0.5 to 3.0 mm. Here, “the interval between adjacent first direction hooks” means the distance between the substantially central positions in the width direction of each first direction hook (substantially the apex of the top of the first direction hook). Point to. When the distance between the adjacent first direction ridges is within the above range, the surface of the surface sheet (nonwoven fabric) has a good surface feel and it is difficult to give physical irritation to the wearer's skin. In addition, it can make it more difficult to cause skin irritation.

The height of the first direction ridge is not particularly limited as long as the effect of the present invention is not impaired, and is, for example, in the range of 0.25 to 5.0 mm, preferably in the range of 0.5 to 3.0 mm. It is. If the height of the first direction heel portion is 0.25 mm or more, the area of the side wall portion can be secured above a certain level, so that the excretory liquid containing the weak acidifying agent described above remains more reliably on the side wall portion. Can be made. On the other hand, if the height of the first direction collar is 5.0 mm or less, the protrusion of the first direction collar does not become excessively large and does not form a sharp structure, so it is difficult to give physical irritation to the wearer's skin. As a result, skin irritation and the like can be made more difficult to cause.

In the present embodiment, the first direction flange 11 has a hollow internal structure provided with a gap 14 facing the second surface 2b of the topsheet 2. Although it is not an essential constituent in the absorbent article of the present invention that the convex portion (first direction flange) of the top sheet has such a hollow internal structure (that is, the convex portion of the top sheet is Although it may have a solid internal structure), it is preferable that the convex portion of the topsheet has a hollow internal structure like the first direction flange 11 of the present embodiment. When the convex part of the topsheet has such a hollow internal structure, the excretory liquid containing the above-described eluted weak acidifying agent is the surface layer on the skin facing surface side close to the skin of the wearer in the convex part. Since it tends to remain on the portion (more specifically, the surface layer portion on the side wall portion of the convex portion) and the weak acidifying agent can be more easily brought into contact with the wearer's skin, the weak acidifying agent can be more reliably It can be transferred to the skin of the wearer.

Further, in the present embodiment, the first direction collar 11 is formed integrally with the first base 21 in the base 12 in the width direction W of the disposable diaper 1 as shown in FIGS. As shown in FIGS. 3 to 6, the first base portions 21 are formed in a plurality of rows in the width direction W so as to sandwich the first direction flanges 11 therebetween. The flanges are also formed in parallel with each other and with the same width.

Furthermore, the first base portion 21 is configured such that the fiber density of the first bottom portion 22 is larger than the fiber density of the first direction flange portion 11 (that is, the top portion 13 and the side wall portion 15). In addition, this 1st bottom part 22 is an example of the "high density part whose fiber density is higher than a side wall part" in this invention. When the base part of the topsheet includes a high-density part having a higher fiber density than the side wall part of such a convex part (first direction flange), the excretory fluid containing the weak acidifying agent described above Since it becomes easier to remain on the side wall portion of the convex portion having a lower fiber density than the above, it is possible to more reliably and more efficiently exhibit the effects related to the transferability and durability of the weak acidifying agent described above. Can do.

Moreover, as shown in FIG.3 and FIG.4, in the 1st bottom part 22 of this 1st base 21, it has a substantially rectangular opening by planar view, and the non-skin opposing surface side of the surface sheet 2 as a whole A plurality of concave portions 26 (second base portions) having a substantially rectangular parallelepiped internal space protruding toward the top are formed. As shown in FIG. 4, the plurality of recesses 26 are intermittently formed along the longitudinal direction L at regular intervals in each of the plurality of first bottom portions 22 arranged in the width direction W. They are arranged in a staggered arrangement form.

As shown in FIGS. 3, 5, and 8, the recess 26 includes a peripheral wall portion 27 that extends from the first bottom portion 22 toward the non-skin facing surface side, and a non-skin facing surface side of the peripheral wall portion 27. A second bottom portion 28 formed so as to close the end portion at the end portion, and the peripheral wall portion 27 is formed so as to be along the longitudinal direction L of the topsheet 2 so as to face each other. A pair of first

peripheral wall portions

29, 29 and a pair of second

peripheral wall portions

30, 30 facing each other formed along the width direction W of the topsheet 2 are provided. Moreover, since the nonwoven fabric which comprises the surface sheet 2 is formed by the 2nd bottom part 28 being compressed toward the direction of the 2nd surface 2b from the 1st surface 2a, the nonwoven fabric which comprises the surface sheet 2 Has the highest fiber density. The second bottom portion 28 is also an example of the “high density portion having a higher fiber density than the side wall portion” in the present invention.

Although it is not an essential component in the absorbent article of the present invention that the base portion of the topsheet has such a recess, if the top portion of the topsheet has such a recess, Since the side wall portion of the convex portion of the topsheet and the absorber disposed on the non-skin facing surface side of the topsheet can be separated more reliably, the convex portion of the topsheet is crushed by the body pressure of the wearer, etc. Even in such a case, it is possible to make it difficult for the excretory liquid (residual liquid) remaining on the side wall portion to be drawn into the non-skin facing surface side. Thereby, since the excretion liquid containing the above-mentioned weak acidifying agent is more likely to remain on the side wall portion of the convex portion, the action and effects relating to the transferability and durability of the above-mentioned weak acidifying agent are more reliably exhibited. be able to. Furthermore, when the base portion of the topsheet is provided with such a recess, when the pressure such as the body pressure of the wearer is applied from the skin facing surface side of the topsheet, the above-described first base portion is not supported with the recess as a fulcrum. By bending to the skin facing surface side, the above-mentioned pressure can be buffered, so that it is difficult to give physical irritation to the wearer's skin, and as a result, it is more difficult to cause skin irritation.

Further, the depth of the recess (that is, the distance from the first surface at the first bottom of the first base to the first surface at the second bottom of the recess) is not particularly limited as long as the effect of the present invention is not impaired. , 0.05 to 2.0 mm, and preferably 0.075 to 1.5 mm. When the depth of the recess is in such a range, the operational effects exhibited by the above-described recess can be more satisfactorily exhibited.
Further, the length of the concave portion in the first direction (longitudinal direction) is not particularly limited, and is, for example, in the range of 0.25 to 5.0 mm, preferably in the range of 0.5 to 3.0 mm. . Similarly, the length of the concave portion in the second direction (width direction) is not particularly limited, and is, for example, in the range of 0.25 to 5.0 mm, preferably in the range of 0.5 to 3.0 mm. . When the lengths of the recesses in the first direction and the second direction are within the above ranges, the operational effects exhibited by the above-described recesses can be more satisfactorily exhibited.

In the present embodiment, each of the pair of first

peripheral wall portions

29, 29 of the peripheral wall portion 27 constituting the concave portion 26 is provided with a surface sheet from the internal space of the concave portion 26 as shown in FIGS. A hole 31 communicating with the second second surface 2b is formed. One such hole portion 31 is provided in each of the pair of first

peripheral wall portions

29, 29, and these hole portions 31 are close to the second bottom portion 28 in the thickness direction T in the first peripheral wall portion 29. It is formed at the position. On the other hand, in the pair of second

peripheral wall portions

30, 30, there is no equivalent to the hole portion 31, and each of the second peripheral wall portions 30 has an end portion located on the non-skin facing surface side as a second bottom portion. 28 is connected. When such a hole is formed in the recess, the tensile force of the fiber of the protrusion (first direction collar) adjacent to the base where the hole is provided is released, and the entire protrusion or protrusion Therefore, the flexibility in the thickness direction and the surface direction of the surface sheet at the convex portion is improved, and a smooth feel can be obtained. Therefore, the surface sheet including the concave portion in which such a hole is formed can reduce physical irritation due to friction when rubbed with the wearer's skin, and therefore, the skin sheet caused by such physical irritation. It can be made difficult to cause a rash.

In the present embodiment, the hole 31 is formed by breaking the constituent fibers of the topsheet 2 (nonwoven fabric) without melting the constituent fibers. As shown in FIG. 8, the broken end portion of the constituent fiber is included. This broken end is not like a fiber that melts and breaks the fiber and melts and rounds the end of the fiber to increase the fiber diameter. It has a structure with little or no change in fiber diameter. As a result, even if the wearer's skin touches the periphery of the hole 31, there is no thermoplastic resin fiber cured by melting, so that it is difficult to physically irritate the wearer's skin. It can make it more difficult to cause rash.

Further, as shown in FIG. 7, in the internal space of the hole portion 31, a part of the constituent fibers of the topsheet 2 (nonwoven fabric) is bridged, while the broken end portion of the part of the constituent fibers is the hole portion. The internal space of the hole 31 is not a completely open space. Thereby, even if a wearer's skin touched the hole part 31, the level | step difference between the hole part 31 and the 1st surrounding wall part 29 and the 2nd bottom part 28 of the recessed part 26 by the structure fiber in the above-mentioned internal space. Therefore, it is difficult to give physical irritation to the wearer's skin, and as a result, it is possible to further prevent skin irritation and the like.

In addition, since it is not an indispensable constituent requirement in the absorbent article of this invention that such a hole is formed in the recessed part of a surface sheet, such a hole is formed in the recessed part of a surface sheet. It does not have to be.

The above structure of the top sheet 2 in the present embodiment, that is, the structure having the first direction flange portion 11 and the base portion 12 is described in any uneven shape forming method (for example, Japanese Patent No. 5829349 and Japanese Patent No. 5829326). As disclosed, it can be formed by using a method of forming a flat nonwoven fabric between a pair of shaping rolls provided with pins and ridges. In addition, the relationship of the fiber density of the top sheet (nonwoven fabric) (such as the relationship between the fiber density of the top portion and the side wall portion) can be obtained by appropriately adjusting the placement, height, etc. of the pins and ridges of the shaping roll. it can.

In the present invention, the nonwoven fabric constituting the surface sheet is not particularly limited as long as it has various properties (for example, liquid permeability, flexibility, touch, etc.) that can be used as the surface sheet of the absorbent article. Arbitrary nonwoven fabrics, such as a spunlace nonwoven fabric and an air through nonwoven fabric, formed using arbitrary hydrophilic fibers, such as cellulosic fibers such as thermoplastic resin fibers subjected to hydrophilic treatment, and the like can be used.
Among these, it is preferable to use the non-woven fabric constituting the surface sheet that contains cotton fibers at a content of 35% by mass or less. Such a nonwoven fabric easily retains the excreted liquid from which the above weak acidifying agent is eluted due to the hydrophilicity of the cotton fibers (particularly easily retained in the side wall), and further, the cotton fibers are contained in an amount of 35% by mass or less. (The lower limit of the content is not particularly limited and is, for example, 0.1% by mass), so that the nonwoven fabric has a relatively high rigidity and melts with thermoplastic resin fibers and the like. Even if it contains cotton fibers that are difficult to bond, the structure having the above-mentioned convex portions and base portions in the nonwoven fabric and the relationship of fiber density can be sufficiently maintained. Therefore, the absorbent article provided with such a non-woven fabric as a surface sheet can more reliably and satisfactorily exhibit the effects of the above-described weak acidifying agent in terms of migration and durability.
In addition, in this specification, content of a cotton fiber points out the ratio (mass%) of the mass of the cotton fiber with respect to the mass (namely, total mass of the constituent fiber in a nonwoven fabric) except the weak acidifying agent.

Further, the nonwoven fabric constituting the surface sheet may be constituted by a single fiber layer or may be constituted by a fiber laminate composed of two or more fiber layers. For example, the second surface (surface on the non-skin facing surface side) of the topsheet is formed by a fiber layer (first fiber layer) made of cotton capable of absorbing and holding excretory fluid such as urine, and When the first surface (surface on the skin-facing surface side) of the topsheet is formed of a fiber layer (second fiber layer) that does not contain cotton or hydrophilic fibers, excretion fluid returns from the absorbent body. Since the excreted fluid that has returned to the liquid can be absorbed and retained by the first fiber layer, the excreted fluid is less likely to come into contact with the wearer's skin due to the presence of the second fiber layer. It is difficult for a person's skin (skin) to become wet and soft (that is, it is difficult for the wearer's skin to protect against various irritation), resulting in more skin irritation. Can be difficult.

The basis weight of the nonwoven fabric constituting the surface sheet is not particularly limited as long as the effect of the present invention is not impaired, but is preferably in the range of 10 to 100 g / m ² from the viewpoint of strength, flexibility, absorbability and the like of the nonwoven fabric. More preferably, it is in the range of 15 to 75 g / m ² . Further, the thickness of the nonwoven fabric is not particularly limited as long as it does not impair the effects of the present invention, but is preferably in the range of 0.1 to 5.0 mm from the viewpoint of the strength, flexibility, and absorbability of the nonwoven fabric, Preferably, it is in the range of 0.5 to 3.0 mm.

In addition, in this invention, if the structure containing the convex part and base part of a surface sheet can have the effect of this invention, it will not be limited to the structure of the above-mentioned 1st embodiment, Arbitrary structures containing a convex part and a base part are included. A structure can be adopted.

Hereinafter, another embodiment (second embodiment to fifth embodiment) of the present invention, which differs from the first embodiment described above only in the structure including the convex portion and the base portion of the topsheet, will be described with reference to the drawings. To do. Note that configurations other than the configuration different from the first embodiment (including configurations that differ only in name) are basically the same as those in the above-described embodiment, and thus the description thereof is omitted.

<Second embodiment>
9 to 12 are diagrams schematically showing a nonwoven fabric constituting the surface sheet 200 of the disposable diaper (absorbent article) according to the second embodiment of the present invention.
In the second embodiment, the topsheet 200 is similar to the first embodiment described above in the first direction and the second direction, which are parallel to the longitudinal direction L, the width direction W, and the thickness direction T of the disposable diaper. It has a direction and a third direction, and is made of a non-woven fabric having a first surface 200a that forms a surface on the skin facing surface side of the disposable diaper and a second surface 200b that forms a surface on the non-skin facing surface side. As shown in FIGS. 9 to 12, the non-woven fabric extends in the first direction (longitudinal direction L), the base 212 located at the reference position in the third direction (thickness direction T) of the topsheet 200, and the A plurality of first direction ridges 211 projecting from the base 212 toward the skin-facing surface side of the disposable diaper, which are arranged in a second direction (width direction W) at predetermined intervals, and in the width direction W Projecting toward the skin-facing surface side of the disposable diaper from the base 212, which is formed so as to extend in the width direction W between the two adjacent first direction flanges 211 and to be arranged in the longitudinal direction L at a predetermined interval. And a plurality of second direction ridges 216. The first direction flange 211 and the second direction flange 216 are examples of the “convex portion” in the present invention.

In the second embodiment, as shown in FIGS. 9 to 12, the base 212 includes a first base 221 including a first bottom 222 that serves as a reference surface in the third direction (thickness direction T) of the topsheet 200. And the first direction flange 211 adjacent to the second direction (width direction W) and the second second direction flange 216 adjacent to the first direction (longitudinal direction L). In the region within the base portion 221, six concave portions 226 (second shape) that are intermittently formed in the longitudinal direction L and the width direction W and have a hollow structure opening in the first surface 200 a of the first bottom portion 222. Base). Further, as shown in FIG. 9, the concave portion 226 includes a peripheral wall portion 227 extending from the first bottom portion 222 toward the non-skin facing surface side, and an end portion of the peripheral wall portion 227 on the non-skin facing surface side. And a second bottom portion 228 formed so as to close the portion. In the second embodiment, as shown in FIGS. 9 to 12, the second bottom portion 228 is formed from the first surface 200a of the topsheet 200 to the second portion at a substantially central portion of the second bottom portion 228 in plan view. A hole 231 that penetrates the surface 200b is provided.

In the second embodiment, as shown in FIGS. 9 and 11, the first direction flange 211 has a top 213 that is located closest to the skin facing surface in the topsheet 200, the top 213, and the first bottom 222. A side wall portion 215 extending in the longitudinal direction L, and the first direction flange portion 211 is provided on the non-skin facing surface side of the topsheet 200 on the topsheet 200 (nonwoven fabric). The second surface 200b is provided with a gap 214 facing the second surface 200b. By providing the gap portion 214, the first direction flange portion 211 of the topsheet 200 has a hollow internal structure. In addition, as above-mentioned, since it is not an essential structural requirement in the absorbent article of this invention that the 1st direction collar part (convex part) of a surface sheet has a hollow internal structure, this 1st direction collar part is this May have a solid internal structure.

In the second embodiment, as shown in FIGS. 9 and 12, the second direction ridge portion 216 is positioned on the skin facing surface side next to the top portion 213 of the first direction ridge portion 211 in the topsheet 200. A top portion 217, and a side wall portion 219 extending in the width direction W between the top portion 217 and the first bottom portion 222, and the second direction flange portion 216 is formed on the surface sheet 200. On the skin facing surface side, a gap portion 218 facing the second surface 200b of the topsheet 200 (nonwoven fabric) is provided. By providing the gap 218, the second direction flange 216 of the topsheet 200 also has a hollow internal structure. In addition, as mentioned above, since it is not an essential constituent requirement in the absorbent article of the present invention that the second direction flange (convex portion) has a hollow internal structure, the second direction flange is It may have a solid internal structure.

And in this 2nd embodiment, the 1st direction collar part 211 and the 2nd direction collar part 216 of the surface sheet 200 are the top part 213 and side wall part of the 1st direction collar part 211 similarly to the above-mentioned 1st embodiment. 215, and the top part 217 and the side wall part 219 of the second direction collar part 216 each contain a weak acidifying agent, and the fiber density in the side wall part 215 of the first direction collar part 211 is more than the fiber density of the top part 213. And the fiber density in the side wall portion 219 of the second direction flange 216 is configured to be smaller than that of the top portion 217.
Therefore, in the disposable diaper (absorbent article) according to the second embodiment, in addition to obtaining the same effect as the first embodiment, in the disposable diaper according to the second embodiment, A plurality of first direction flanges 211 in which the convex portions of the topsheet 200 continuously extend in a predetermined first direction (longitudinal direction L) and are arranged in a second direction (width direction W) intersecting the first direction; A plurality of second direction flanges 216 that continuously extend in the second direction between the two first direction flanges 211 adjacent to each other in the second direction and are arranged in the first direction. Therefore, the excretion fluid supplied to the surface of the top sheet 200 is disposed between the convex portions adjacent to each other in the above-described directions (that is, the first direction flange 211 adjacent to the second direction and the adjacent first Between the one-way collar 211 Between) the second direction ridges 216 adjacent in one direction, on which can be more easily reservoir, it is possible to secure the side wall portions of a predetermined number or more.
As a result, in the disposable diaper according to the second embodiment, the excretory liquid containing the above-dissolved weak acidifying agent has a side wall portion (specifically, the side wall portion 215 and the second direction wrinkle of the first direction hook portion 211). Each of the side wall portions 219 of the portion 216 is more easily contacted, and the excretory fluid containing the weak acidifying agent can be more reliably left on the side wall portion of the convex portion, and the excretory fluid containing the weak acidifying agent Can remain on each of the side wall portion 215 of the first direction flange portion 211 and the side wall portion 219 of the second direction flange portion 216 (that is, the excretion liquid containing the weak acidifying agent described above is applied to the side wall portion of the convex portion. Since the remaining amount can be ensured above a certain level), the above-described effects of the weak acidifying agent on the transferability and durability can be more reliably and more prominently exhibited.

Hereinafter, the structure of the topsheet 200 in the second embodiment (that is, the structure having the first direction flange 211, the second direction flange 216, and the base 212) will be described in more detail.

In the second embodiment, the height of the first direction flange 211 is not particularly limited as long as the effect of the present invention is not hindered, and is, for example, in the range of 0.25 to 5.0 mm, preferably 0.8. It is in the range of 5 to 3.0 mm. Further, the width of the first direction flange portion 211 (length in the width direction W) is not particularly limited as long as the effect of the present invention is not impaired, and is within a range of, for example, 0.3 to 2.5 mm, preferably Within the range of 0.5 to 1.5 mm. When the height and width of the first heel portion are within each of these ranges, the area of the side wall portion can be secured above a certain level, and the excretory liquid containing the weak acidifying agent described above can be more reliably added to the side wall portion. In addition, the protrusion of the first direction heel portion does not become excessively large, and it is difficult to give physical irritation to the wearer's skin, and as a result, it is more difficult to cause skin irritation and the like. can do. Furthermore, when the height and width of the first direction collar are within these ranges, the first direction collar is not easily crushed. The effect concerning the transferability and durability of the acidifying agent can be exhibited more reliably.

Further, the interval between the first direction flanges adjacent to each other in the second direction (width direction W) is not particularly limited as long as the effect of the present invention is not hindered. For example, it is within a range of 1.0 to 5.0 mm. Yes, preferably in the range of 2.0 to 4.0 mm. When the distance between the first direction ridges adjacent to each other in the second direction is within such a range, the number (area) of the side wall portions can be secured above a certain level, and excretion includes the weak acidifying agent described above. In addition to allowing the liquid to remain on the side wall more reliably, it is easy to secure a storage space for temporarily storing excretion liquid such as urine, which will be described later, and the excretion liquid stored in the storage space contacts the wearer's skin. As a result, it is possible to make it more difficult to cause skin irritation or the like.

In the second embodiment, the height of the second ridge 216 is not particularly limited as long as the effect of the present invention is not hindered. For example, the height is in the range of 0.3 to 3.0 mm, preferably 0. It is in the range of 5 to 2.5 mm. Further, the width of the second direction flange 216 (length in the longitudinal direction L) is not particularly limited as long as the effect of the present invention is not impaired, and is within a range of, for example, 0.6 to 5.0 mm, preferably It is in the range of 1.0 to 4.0 mm. When the height and width of the second direction heel are within these ranges, the area of the side wall can be secured above a certain level, and the excretory fluid containing the weak acidifying agent can be more reliably added to the side wall. In addition, the protrusion of the second direction heel portion does not become too large, and it is difficult to give physical irritation to the wearer's skin, and as a result, it is more difficult to cause skin irritation and the like. can do. Furthermore, if the height and width of the second direction collar are within these ranges, not only the second direction collar but also the first direction collar will not easily collapse. The effect which concerns on the transferability and durability of the above-mentioned weak acidifying agent show | played by providing a 2-way collar part can be exhibited more reliably.

Further, the interval between the second direction flanges adjacent to each other in the first direction (longitudinal direction L) is not particularly limited as long as the effect of the present invention is not impaired, and is within a range of, for example, 1.0 to 10.0 mm. Yes, preferably in the range of 2.0 to 6.0 mm. When the interval between the second direction ridges adjacent to each other in the first direction is within such a range, the number (area) of the side wall portions can be secured above a certain level, and excretion includes the weak acidifying agent described above. In addition to allowing the liquid to remain on the side wall portion more reliably, not only the second direction collar but also the first direction collar can be prevented from being crushed. Therefore, the first direction collar and the second direction collar are The effect which concerns on the transferability and durability of the above-mentioned weak acidifying agent show | played by providing can be demonstrated more reliably.

Furthermore, in the second embodiment, the second direction flange 216 is formed with a height lower than that of the first direction flange 211. Such a configuration is not an essential component in the absorbent article of the present invention, but when the height of the second direction collar is configured to be lower than the height of the first direction collar, The second heel portion having a low height is not easily affected by the body pressure of the wearer and is not easily crushed. Therefore, the second direction heel portion is supported from the second direction side (the width direction W side). The buttock can be made more difficult to collapse. Thereby, the surface sheet provided with such a configuration has the effects of the above-described weak acidifying agent migratory and durable, which are exhibited by providing the first direction flange and the second direction flange. It can be demonstrated more reliably.
Moreover, the surface sheet provided with such a configuration is adjacent to the above-described first bottom, two first-direction flanges adjacent in the second direction (width direction W), and the first direction (longitudinal direction L). Since the excretion liquid which accumulates in the below-mentioned storage space surrounded by two 2nd direction collars which fit can be delivered to another storage space adjacent to the 1st direction, it was supplied to the surface of a surface sheet It is easy to temporarily store the excretory liquid between the convex portions (that is, between the two first direction flanges adjacent in the second direction and the two second direction flanges adjacent in the first direction). However, it can be diffused in the first direction described above. As a result, the absorbent article having the surface sheet having such a configuration has a wider range of side wall portions (more specifically, the first direction ridge portion and the first direction heel portion) containing the above-dissolved weak acidifying agent. It is easy to contact each side wall part of the second direction heel part, and the excretory fluid can remain in a wider range of the side wall part. , It is possible to exert more reliably and more remarkably.

In the second embodiment, each of the plurality of second direction flanges 216 is between two first direction flanges 211 adjacent in the second direction (width direction W), as shown in FIGS. 9 and 10. It is formed to extend in the width direction W and to be arranged at a predetermined interval in the first direction (longitudinal direction L), and each of the plurality of second direction flanges 216 has both ends in the width direction W. The portion is formed so as to be connected to two first direction flanges 211 adjacent in the width direction W. Thereby, as shown in FIG. 10, the surface sheet 200 in the second embodiment includes two first direction flanges 211 adjacent to the width direction W and two second directions adjacent to the longitudinal direction L. The lattice unit A surrounded by the flanges 216 is a minimum structural unit, and the lattice unit A has a lattice-like convex structure in which a plurality of lattice units A are arranged in the longitudinal direction L and the width direction W, respectively.

In the second embodiment, as shown in FIG. 10, the lattice unit A is centered on the first bottom portion 222, and the top portions of the first bottom portion 211 adjacent to the first bottom portion 222 and the width direction W are the top portions. Two imaginary planes (not shown) passing through the vertex of 213 and extending in the thickness direction T, and passing through the vertex of the top portion 217 of the first bottom portion 222 and the two second direction flange portions 216 adjacent to the longitudinal direction L. The first bottom 222, the two first direction flanges 211 adjacent to the width direction W, and the longitudinal direction L are separated by two virtual surfaces (not shown) extending in the thickness direction T. A storage space for temporarily storing excretion fluid such as urine, which is surrounded by two matching second direction flanges 216, is formed.

In the second embodiment, the second direction flange 216 is formed so that both ends in the width direction W are connected to two first direction flanges 211 adjacent to the width direction W. However, in the present invention, the second direction flange is not limited to such an aspect, and only one end of the second direction (width direction W) is connected to the first direction flange, The other end in the two directions may be formed so as not to be connected to the first direction flange. By forming the second direction collar in this way, it becomes easier to transfer the excretion liquid temporarily stored in the above-described storage space to another storage space adjacent to the first direction, and thus is supplied to the surface of the topsheet. The excreted liquid can be quickly diffused in the first direction as described above while temporarily accumulating between the buttocks (that is, the storage space). Thereby, since it becomes possible to leave the excretion liquid in a wider range of the side wall portion, it is possible to satisfactorily exhibit the effects related to the transferability and durability of the weak acidifying agent. Such an effect is also the same in the aspect in which the second direction collar is intermittently extended in the second direction (for example, the aspect in which the height of the second direction collar is partially reduced). Can play.
Note that, as in the second embodiment, both end portions in the second direction of the second direction flange are formed so as to be connected to two first direction flanges adjacent in the second direction. Then, since the excretion liquid supplied to the surface of the top sheet can be more reliably stored between the ridges (that is, the storage space), the excretion liquid is stored in the side wall portions of the ridges (convex portions). In addition, it is possible to more reliably remain, and it is possible to more reliably exhibit the above-described effects related to the transferability and durability of the weak acidifying agent.

In the second embodiment, the first bottom 222 that forms the bottom of the storage space of the lattice unit A has a fiber density of the first direction flange 211 (that is, the top portion 213 and the side wall portion 215) and the second direction flange. It is comprised so that it may become larger than any fiber density of 216 (namely, the top part 217 and the side wall part 219). In addition, this 1st bottom part 222 is an example of the "high density part whose fiber density is higher than a side wall part" in this invention. When the base portion of the topsheet includes a high-density portion having a higher fiber density than the side wall portions of such convex portions (the first direction ridge portion and the second direction ridge portion), the weak acidifying agent described above is included. Since the excretion fluid is more likely to remain in the side wall portion of the convex portion having a fiber density relatively lower than that of the base portion, the action and effect relating to the transferability and durability of the weak acidifying agent described above can be more reliably and It can be exhibited more efficiently.

In the second embodiment, as shown in FIGS. 9 to 12, the lattice unit A has a substantially circular opening in plan view and faces the non-skin facing surface side of the topsheet 200 as a whole. Six concave portions 226 (second base portions) having a substantially cylindrical internal space protruding in the first bottom portion 222 are formed. As shown in FIGS. 9 and 10, the six recesses 226 are arranged along the peripheral edge of the lattice unit in plan view (that is, along the first direction hook and the second direction hook). And a predetermined interval in the longitudinal direction L and the width direction.

As shown in FIGS. 9, 11, and 12, the recess 226 includes a substantially cylindrical peripheral wall portion 227 that extends from the first bottom portion 222 toward the non-skin facing surface side, and a non-skin of the peripheral wall portion 227. A substantially circular second bottom portion 228 formed so as to close the end portion on the opposite surface side, and the second bottom portion 228 further extends from the first surface 200a of the topsheet 200. A hole 231 that penetrates through the second surface 200b is provided. Moreover, since the 2nd bottom part 228 is formed by the nonwoven fabric which comprises the surface sheet 200 being compressed toward the direction of the 2nd surface 200b from the 1st surface 200a, the nonwoven fabric which comprises the surface sheet 200 Has the highest fiber density. The second bottom portion 228 is also an example of the “high density portion having a higher fiber density than the side wall portion” in the present invention.

In the second embodiment, the concave portion 226 includes a hole portion 231 that penetrates from the first surface 200a of the topsheet 200 to the second surface 200b in the second bottom portion 228. While the supplied excretion fluid is temporarily stored between the ridges (that is, the storage space), a certain amount of excretion fluid is transferred to the non-skin facing surface side of the topsheet 200 by the above-described hole portion 231. be able to. Thereby, the surface sheet 200 in this 2nd embodiment can ensure fixed liquid permeability, exhibiting the effect which concerns on the transferability and durability of the above-mentioned weak acidifying agent favorably.

Note that the number, shape, size, and the like of the recesses in the lattice unit A are not limited to those of the second embodiment, and are arbitrarily set in consideration of the retention of liquid excretion, liquid permeability, and the like. can do. Moreover, since it is not an indispensable structural requirement in the absorbent article of this invention that a recessed part has the above-mentioned hole part, the recessed part does not need to have the above-mentioned hole part.

<Third embodiment>
Next, a third embodiment of the present invention will be described with reference to the drawings. Note that configurations other than the configurations different from the above-described embodiments (including configurations that differ only in name) are basically the same as those of the above-described embodiments, and thus description thereof is omitted.

FIG.13 and FIG.14 is a figure which shows typically the nonwoven fabric which comprises the surface sheet 200 of the disposable diaper (absorbent article) which concerns on 3rd embodiment of this invention.
As shown in FIGS. 13 and 14, the top sheet 200 according to the third embodiment has the same structure as that of the second embodiment described above except that the first direction gavel 232 described later is provided. is doing.

As shown in FIGS. 13 and 14, the top sheet 200 according to the third embodiment extends in the first direction (longitudinal direction L) and skins from the first bottom portion 222 in each of the lattice units (not shown). A first direction gavel 232 that protrudes toward the facing surface is provided. In addition, the 1st direction collar part 211, the 2nd direction collar part 216, and the 1st direction small collar part 232 in this 3rd embodiment are examples of the "convex part" in this invention.

In the third embodiment, as shown in FIGS. 13 and 14, the first direction edge 232 is located on the skin facing surface side next to the top 217 of the second direction edge 216 in the topsheet 200. And a side wall portion 235 extending in the first direction (longitudinal direction L) between the top portion 233 and the first bottom portion 222. Further, the first direction gavel portion 232 includes The surface sheet 200 is provided with a gap 234 facing the second surface 200b of the surface sheet 200 (nonwoven fabric) on the non-skin facing surface side. By providing this gap portion 234, the first direction gavel portion 232 also has a hollow internal structure. As described above, the fact that the first direction gavel 232 also has a hollow internal structure is not an essential component in the absorbent article of the present invention. It may have a real internal structure.

The first direction small flange 232 also includes the weak acidifying agent in the top portion 233 and the side wall portion 235, similarly to the first direction flange 211 and the second direction flange 216, and the side wall portion 235. The fiber density at is lower than the fiber density at the top 233.
Therefore, since the disposable diaper (absorbent article) according to the third embodiment can secure a larger number of collars (convex portions) than the second embodiment described above, the second embodiment described above. The effects of the above can be obtained more advantageously.

Further, in the third embodiment, the first direction gavel portion 232 is connected to two second direction collar portions 216 whose both ends in the first direction (longitudinal direction L) are adjacent to each other in the first direction. And the height H ₃ of the first direction collar 232 is lower than the height H _{1 of} the first direction collar 211 and the height (not shown) of the second direction collar 216. It is formed to become. Furthermore, in the third embodiment, the height H ₁ of the first direction flange 211 is between the first direction flange 211 and the first direction small flange 232 adjacent in the second direction (width direction W). to be larger than the interval PI ₁ of topsheet 200 is configured. Thus, even if the first direction collar 211 falls in the second direction due to the wearer's body pressure or the like, the first direction collar 211 comes to lean against the first direction collar 232, Since the first direction collar 211 can be supported by the first direction collar 232, the first direction collar 211 easily returns to the original position, and is provided by including the first direction collar 211. The effect concerning the transferability and durability of the weak acidifying agent described above can be exhibited more advantageously and reliably.

In the present invention, the direction in which the first direction gavel extends is not particularly limited (that is, it may be the second direction gavel), but the first direction gavel has the third direction mentioned above. As in the embodiment, it is preferable to extend along the first direction. When the first direction collar portion extends along the first direction, even if the first direction collar portion having the highest height in the topsheet falls in the second direction, the first direction collar as described above. Since the portion can be easily returned to the original position, the effect of the above weak acidifying agent on the transferability and durability, which is achieved by providing the first directional flange, can be more advantageously and reliably achieved. Can be demonstrated.

In the third embodiment, the height of the first direction gavel 232 is not particularly limited as long as the effect of the present invention is not hindered, and is, for example, in the range of 0.1 to 2.5 mm, preferably 0. Within the range of 25-2.0 mm. When the height of the first direction gavel portion is within such a range, the area of the side wall portion can be secured above a certain level, and the excretory fluid containing the weak acidifying agent described above can be more reliably applied to the side wall portion. In addition to being able to remain, since the first direction collar also becomes more difficult to fall down, the effects of the above weak acidifying agent migratory and durable, which are exhibited by providing the first direction collar, It can be exhibited more advantageously and reliably.
In addition, the 1st direction gavel part may have a part with the partially low height.

Moreover, the space | interval between the 1st direction collar part 211 adjacent to a 2nd direction (width direction W) and the 1st direction small collar part 232 is not restrict | limited unless the effect of this invention is inhibited, for example, 0. It is within the range of 5 to 2.5 mm, preferably within the range of 1.0 to 2.0 mm. In addition, it is preferable that this space | interval is smaller than the height of the 1st direction collar part 211 as above-mentioned.

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described with reference to the drawings. Note that configurations other than the configurations different from the above-described embodiments (including configurations that differ only in name) are basically the same as those of the above-described embodiments, and thus description thereof is omitted.
FIG. 15: is a perspective view of the nonwoven fabric which comprises the surface sheet 200 of the disposable diaper which concerns on 4th embodiment of this invention.

As shown in FIG. 15, the topsheet 200 according to the fourth embodiment has a substantially circular opening in a plan view in each of the above-described lattice units (not shown), and the topsheet 200 as a whole. Four concave portions 226 (second base portions) having a substantially cylindrical inner space protruding toward the non-skin facing surface side are formed in the first bottom portion 222, and the first direction gavel portion 232 has A recessed portion 236 that is recessed toward the non-skin facing surface side of the topsheet 200 is formed in a substantially central portion of the top portion 233 in the first direction (longitudinal direction L).
In the fourth embodiment, since the first direction gavel portion 232 includes the above-described hollow portion 236, it is difficult to be crushed by a wearer's body pressure or the like. Thus, it can be exhibited more advantageously and reliably.

<Fifth embodiment>
Next, a fifth embodiment of the present invention will be described with reference to the drawings. Note that configurations other than the configurations different from the above-described embodiments (including configurations that differ only in name) are basically the same as those of the above-described embodiments, and thus description thereof is omitted.
FIG. 16: is a perspective view of the nonwoven fabric which comprises the surface sheet of the disposable diaper which concerns on 5th embodiment of this invention.

As shown in FIG. 16, the topsheet 200 according to the fifth embodiment has the same structure as that of the above-described second embodiment except that there is no recess.
Also in the fifth embodiment, since the specific first direction flange portion 211 and the second direction flange portion 216 are provided, the above-described effects of the weak acidifying agent in terms of transferability and durability are sufficiently exhibited. In addition, since there is no recess, the contact area between the topsheet 200 and the absorber (specifically, the second surface 200b of the first bottom 222 and the surface of the absorber facing the skin) Contact area) can be secured above a certain level, so that excretion fluid such as urine supplied to the surface of the topsheet 200 can be quickly transferred to the absorbent body through the first bottom portion 222, and the wearer's skin is wetted. It is even less likely to happen.

The structure of the top sheet 200 in the second to fifth embodiments described above, that is, the structure having at least the first direction flange 211, the second direction flange 216, and the base 212 is the first embodiment described above. Similar to the form, any uneven shape forming method (for example, an uneven shape forming method in which a flat non-woven fabric is sandwiched between a pair of forming rolls having pins and ridges, or such an uneven shape forming method is stepwise. It can be formed using a shaping method performed multiple times). In addition, the relationship of the fiber density of the top sheet (nonwoven fabric) (such as the relationship between the fiber density of the top portion and the side wall portion) can be obtained by appropriately adjusting the placement, height, etc. of the pins and ridges of the shaping roll. it can.

Further, in the absorbent article of the present invention, the structure including the convex portion and the base portion of the surface sheet is formed on the entire surface sheet as in the above-described embodiments, but a part of the surface sheet (for example, wearing) The region corresponding to the person's excretion opening, the region corresponding to the buttocks, etc.).
And in this invention, if the structure containing the convex part and base part of a surface sheet can have the effect of this invention, it will be limited to each above-mentioned embodiment (Namely, the form whose convex part is a collar part etc.). Instead, any structure can be employed. For example, the convex portion of the top sheet closes the end portion of the substantially cylindrical peripheral surface portion (side wall portion) protruding from the base portion toward the skin facing surface side and the end portion of the peripheral surface portion on the skin facing surface side. And having a top surface portion (top portion) that is formed in a substantially circular shape and having a substantially cylindrical solid shape, such as an elliptical column shape or a polygonal column shape, a truncated cone shape, or a pyramid shape. You may be comprised by arbitrary solid shapes, such as truncated cone shape, such as a trapezoid, and substantially hemisphere. Even in the convex part having such a structure, if the top part and the side wall part of the convex part include a weak acidifying agent, and the fiber density of the side wall part is configured to be smaller than the fiber density of the top part, The effect which concerns on the transferability and durability of the above-mentioned weak acidifying agent can be show | played.

In addition, the absorbent article of the present invention is not limited to the above-described embodiments, and can be appropriately combined, substituted, changed, and the like without departing from the object and spirit of the present invention.
In addition to the tape-type disposable diaper as in each of the embodiments described above, the present invention provides various absorbent articles such as a pant-type disposable diaper, a sanitary napkin, a panty liner, and a (light) incontinence pad. Can be applied to.
In this specification, ordinal numbers such as “first” and “second” are used to distinguish items with the ordinal numbers, and mean the order, priority, importance, etc. of each item. Not what you want.

1 disposable diaper (absorbent article)
2,200

Top sheet

2a, 200a

1st surface

2b, 200b 2nd surface 3 Back sheet 4 Absorber 8

Adhesive layer

11, 211 1st direction collar (convex part)
12, 212

Base portion

13, 213

Top portion

14, 214

Gap portion

15, 215

Side wall portion

21, 221

First base portion

22, 222 First

bottom portion

26, 226 Recessed portion (second base portion)
27, 227

Peripheral wall portion

28, 228 Second bottom portion 29 First peripheral wall portion 30 Second

peripheral wall portion

31, 231 Hole portion 216 Second direction flange (convex portion)
217 Top part 218 Cavity part 219 Side wall part 232 First direction gavel part 233 Top part 234 Cavity part 235 Side wall part 236 Dimple part

Claims

An absorbent article provided with a surface sheet,
The top sheet is made of a nonwoven fabric having a base and a convex portion protruding from the base toward the skin facing surface side of the absorbent article,
The convex part has a top part and a side wall part, and includes a weak acidifying agent in the top part and the side wall part,
The fiber density of the side wall part is smaller than the fiber density of the top part,
The absorbent article.
The absorbent article according to claim 1, wherein the convex portion has a hollow internal structure.
The absorbent article according to claim 1 or 2, wherein the base portion includes a high-density portion having a fiber density higher than that of the side wall portion.
The absorbent article according to any one of claims 1 to 3, wherein the base includes the weak acidifying agent.
The absorbent article according to any one of claims 1 to 4, wherein the base has a recess that is recessed toward the non-skin facing surface side of the absorbent article.
6. The projecting portion according to claim 1, wherein the convex portion includes a plurality of first-direction flange portions that continuously extend in a predetermined first direction and are arranged in a second direction intersecting the first direction. Absorbent articles.
A plurality of first-direction flanges extending in a second direction that continuously extends in a predetermined first direction and intersects the first direction;
A plurality of second direction hooks that continuously extend in the second direction and are arranged in the first direction between the two first direction hooks adjacent to each other in the second direction. The absorbent article as described in any one of these.
The absorbent article according to any one of claims 1 to 7, wherein the weak acidifying agent comprises only a plant-derived component.
The absorbent article according to any one of claims 1 to 8, wherein the non-woven fabric contains a cotton fiber in a content of 35% by mass or less.