RU2606570C2 - Absorbent product - Google Patents

Abstract

FIELD: hygiene.

SUBSTANCE: absorbent product is developed, comprising liquid permeable top sheet, located at side of surface, contacting with skin, back sheet, located at side of surface, not contacting with skin, and absorbing element, located between two sheets, wherein upper sheet is made from non-woven material and absorbing element has absorbing core and cover sheet, which covers core. Multiple concave sections of back surface, which form cavities, directed to side of surface, contacting with skin, are distributed next to each other on side of upper sheet surface, not contacting with skin, cover sheet passes inside concave sections of back surface, and there is spatial part between cover sheet, extending inside recesses and absorbing core.

EFFECT: absorption of fluid.

25 cl, 35 dwg, 6 tbl

Description

FIELD OF TECHNOLOGY

The present invention relates to an absorbent article, such as a disposable diaper, pads used for urinary incontinence, a sanitary napkin or panty liner used for mild incontinence.

BACKGROUND OF THE INVENTION

In the development of absorbent products, such as disposable diapers, attempts have been made to improve performance and increase wearing comfort by improving the materials and designs of the individual components. In addition, for example, topsheets and absorbent bodies have been developed as components aimed at providing such an improvement, and in particular, proposals have recently been made regarding various absorbent products that are functionally improved in consideration of the method of use and type of product. In addition, to ensure good wearing comfort, the apparent / visible thickness of the component was increased by maintaining the distance between the part of the diaper in contact with the skin and the absorbent body. As a result, the backflow of liquid to the side of the skin-contacting surface of the article and the increase in humidity in the diaper can be prevented. In particular, there are absorbent articles in which the sublayer is laid under the top sheet, in which the top sheet is concave-convex in shape by embossing, and in which the shaped sheet is bonded and attached to another sheet of nonwoven material by compression bonding.

Patent Literature 1 discloses an absorbent article in which the absorbent body itself is brought into close contact with the top sheet to form a concave-convex shape. Due to this, the ability to move the fluid inside can be increased to obtain a soft texture. In patent literature 2, a sanitary napkin is disclosed in which the absorbent body in the zone facing the excretory zone has a large number of concave portions extending inward from the side of the surface in contact with the skin. This gasket has a good point-wise absorption capacity, since the surface area of the absorbent body from the surface contacting with the skin increases, so that the concave portions trap and draw fluid into them, as a result of which liquid diffusion on the skin-contacting surface side can be prevented. . This can be achieved by performing the absorbent body itself with a specific shape.

A patent diaper 3 discloses a diaper formed with waist assemblies including complex stretch and contract areas in the abdomen and in the area on the back of the diaper to improve fit, increase air permeability and softness of the waist of the diaper. In each complex stretching and contracting section, a plurality of elastic elements located between two sheets in the waist part are not fixed anywhere except for the parts end in the width direction, as a result of which there are no obstacles to stretching and pulling. By tightening the elastic elements, both surfaces of the two sheets will protrude in opposite directions to form multiple folds in the longitudinal direction. Due to this, breathability and softness can be ensured.

A diaper is disclosed in Patent Literature 4, in which two waist flap portions are located in the rear side zone of the waist portion so that they protrude outward in a width direction, with a stretch zone of the waist portion being provided on the inside of each waist flap portion. As a result, the stretch zone is stretched to compensate for the difference in circumference between the waist part and the femoral part, so that the fit can be improved.

In Patent Literature 5, a two-layer top sheet having a concave-convex structure is disclosed. The top sheet has a central zone formed with a large number of concave and convex sections, and side zones on both sides of the central zone. The concave portions in the central region of the top sheet are heated and squeezed together with the bottom sheet by means of a heated roller, so that the two layers are firmly fixed. Therefore, the top sheet, in which protruding convex portions are stably stored in the central zone, has good ability to prevent backflow of liquid. The topsheet can also provide good leakage prevention, since the side zones provide good fluid movement into the absorbent body.

Patent Literature 6 discloses a two-ply top sheet having a concave-convex shape formed by a bead with protrusions. The top sheet has good breathability and springability, since liquid retractors, concave portions formed on the surface side of the top sheet in contact with the skin, can provide a reduction in fluid flow on the surface side in contact with the skin.

LIST OF LINKS

Patent Literature

Patent Source 1: JP-A-2009-119022 (“JP-A” means Japanese Unexamined Published Patent Application)

Patent Source 2: JP-A-2008-18048

Patent Source 3: JP-A-2008-132023

Patent Source 4: WO 2009/104581

Patent Source 5: JP-A-2009-118920

Patent Source 6: JP-A-2009-89965

SUMMARY OF THE INVENTION

The absorbent article of the present invention has a top sheet having a concave portion of a rear surface connected to and interacting with another component.

The present invention consists in an absorbent article that has a liquid-permeable top sheet located on the side of the surface in contact with the skin, a back sheet located on the side of the surface not in contact with the skin, and an absorbent body located between both sheets, the top sheet formed of a nonwoven material, the absorbent body has an absorbent core and a covering sheet covering the absorbent core; in which a plurality of concave portions of the back surface, recessed towards the side of the surface in contact with the skin, are arranged in a certain order next to each other and dispersively on the side of the non-skin surface of the top sheet. The cover sheet extends into each concave portion of the back surface, while the spatial portions between the inward cover sheet and the absorbent core are retained. In addition, having a convex shape, deformed as a whole, formed by the top sheet and the back sheet, is located outside the part of the absorbent body, end in the longitudinal direction, in which the absorbent body is not placed between the top sheet and the back sheet. In addition, the sublayer is located between the top sheet and the absorbent body, while the sublayer is brought into contact with each convex portion of the back surface in the top sheet adjacent to each concave portion of the back surface, and the density of the fibers of the sublayer in this section is higher than the density of the fibers of the sublayer in another section .

Other and additional objectives, features and advantages of the invention will appear with greater completeness from the following description, presented with corresponding links to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[FIG. 1] FIG. 1 is a partially exploded perspective view schematically showing a disposable diaper visible from a skin contact surface in accordance with a preferred embodiment of an absorbent article of the present invention.

[FIG. 2-1] FIG. 2-1 (a) is a section taken along line II-II shown in FIG. 1, FIG. 2-1 (b) is a partially enlarged section, partially enlarging and schematically showing a cross section of a top sheet, and FIG. 2-1 (c) is a partially enlarged sectional view schematically showing the relative position of the top sheet and the cover sheet.

[FIG. 2-2] FIG. 2-2 is a photograph replacing the drawing, in which there is an image of a section of a disposable diaper according to this embodiment.

[FIG. 3] FIG. 3 (a) and 3 (b) are explanatory views schematically showing the relative position of the top sheet, the cover sheet and the absorbent core in a concave portion of the rear surface.

[FIG. 4] FIG. 4 is a perspective view schematically showing a partial section of a top sheet used for a diaper according to this embodiment.

[FIG. 5] FIG. 5 is a partially enlarged section, partially increasing a predetermined section of FIG. 2-1 (a).

[FIG. 6] FIG. 6 is an explanatory view schematically showing the relationship between the concave portion of the rear surface and the convex portion of the rear surface on the side of the non-skin surface of the top sheet in a plan view.

[FIG. 7] FIG. 7 is a photograph replacing a drawing in which there is an image of a section of a top sheet of this embodiment.

[FIG. 8] FIG. 8 (a) to 8 (d) are explanatory views showing a modified example of sectional configurations of each concave portion of the rear surface.

[FIG. 9] FIG. 9 (a) and 9 (b) are explanatory views showing a modified example of configurations of a section of a top sheet.

[FIG. 10] FIG. 10 (a) and 10 (b) are explanatory views showing a modified example of an absorbent core.

[FIG. 11] FIG. 11 is an explanatory view schematically showing the states of liquid diffusion according to examples 1 and 2 and comparative examples 1 and 2.

[FIG. 12] FIG. 12 is an explanatory view schematically showing the states of liquid diffusion according to examples 1 and 2 and comparative examples 1 and 2.

[FIG. 13] FIG. 13 is a partially exploded perspective view schematically showing a disposable diaper visible from a skin contact surface in accordance with another preferred embodiment (second embodiment) of an absorbent article of the present invention.

[FIG. 14] FIG. 14 is a partially enlarged, partially exploded perspective view schematically enlarging each multilayer end portion of a disposable diaper according to the second embodiment.

[FIG. 15] FIG. 15 (A) is a cross-section taken along line AA shown in FIG. 14 and FIG. 15 (B) is a section taken along line BB shown in FIG. fourteen.

[FIG. 16] FIG. 16 is a partially enlarged sectional view schematically showing a partially enlarged cross section of the multilayer end portion shown in FIG. 15 (A) and 15 (B).

[FIG. 17] FIG. 17 (A) and 17 (B) are explanatory views schematically showing the upper parts, the inflection points and the bending directions in the contact zone of each section deformed as a whole, in FIG. 15 (A) and 15 (B).

[FIG. 18-1] FIG. 18-1 (1) and 18-1 (2) are schematic diagrams corresponding to FIG. 15 (A), 15 (B), 17 (A) and 17 (B), showing a modified example of the multilayer end portion of the second embodiment.

[FIG. 18-2] FIG. 18-2 (1) and 18-2 (2) are schematic diagrams corresponding to FIG. 15 (A), 15 (B), 17 (A) and 17 (B), showing another modified example of the multilayer end portion of the second embodiment.

[FIG. 18-3] FIG. 18-3 (1) and 18-3 (2) are schematic diagrams corresponding to FIG. 15 (A), 15 (B), 17 (A) and 17 (B), showing yet another modified example of the multilayer end portion of the second embodiment.

[FIG. 19] FIG. 19 is a plan view schematically showing another preferred example of the arrangement in the plane of the parts of the multilayer end parts deformed as a whole according to the second embodiment.

[FIG. 20] FIG. 20 (a) and 20 (b) are explanatory views showing the stretched and contracted states of the multilayer end portion of the second embodiment.

[FIG. 21] FIG. 21 is a partially enlarged section schematically showing a cross section of a multilayer end portion in which the top sheet of FIG. four.

[FIG. 22] FIG. 22 is a partially enlarged sectional view showing a state in which a sheet of nonwoven fabric is disposed between the top sheet and the back sheet in the multilayer end portion of the second embodiment.

[FIG. 23] FIG. 23 (a) -23 (d) are explanatory views schematically showing sectional shapes of the multilayer end portion of the respective testable elements of Example 21 and Comparative Examples 21-23.

[FIG. 24] FIG. 24 shows photographs replacing the drawing, showing the respective states of the tested elements of Example 21 and Comparative Examples 21-23 after dripping and after tilting.

[FIG. 25] FIG. 25 is a partially exploded perspective view schematically showing a disposable diaper visible from a skin contact surface in accordance with yet another preferred embodiment (third embodiment) of an absorbent article of the present invention.

[FIG. 26-1] FIG. 26-1 (a) is a section taken along line II-II shown in FIG. 25, and FIG. 26-1 (b) is a partially enlarged section schematically showing the relative position of the top sheet and the sublayer.

[FIG. 26-2] FIG. 26-2 is a photograph replacing the drawing, in which there is an image of a cross section of a disposable diaper according to the third embodiment.

[FIG. 27] FIG. 27 is an explanatory view schematically showing the relationship between the top sheet, the underlayer and the absorbent body in a convex portion of the rear surface.

[FIG. 28] FIG. 28 is a partially enlarged section, partially increasing the predetermined cross section of FIG. 26-1.

[FIG. 29] FIG. 29 (a) and 29 (b) are explanatory views schematically showing a modified example of cross-sectional configurations of the top sheet.

[FIG. 30] FIG. 30 (a) to 30 (c) show photographs replacing the drawing, in which there are images of the states of the tested top sheet of Example 31.

[FIG. 31] FIG. 31 (a) -31 (c) show photographs replacing the drawing, in which there are images of the states of the tested top sheet of comparative example 31.

DESCRIPTION OF EMBODIMENTS

The present invention relates to the development of an absorbent article, which can provide an additional increase in the absorbing capacity of a conventional absorbent article, can prevent the spreading of repeatedly released liquid and the spreading of a large amount of released liquid on the top sheet, and can provide quick absorption of liquid into it for diffusion of the liquid in the absorbent body as a result of which the liquid is effectively absorbed and retained. In addition, the present invention relates to the development of an absorbent article that can provide an improvement in the ability to prevent leakage in the part in which the absorbent body is not located. In addition, the present invention relates to the development of an absorbent article, which can have, in addition to a great ability to absorb liquid, the ability to prevent backflow, achieved by increasing the usual thickness by connecting the components by lamination, can provide an additional reduction in the backflow of liquid and humidity in product and can provide an additional reduction in the amount of the liquid that remains on the side of the surface facing the skin and the presence of which minutes may be due to the state of the use and the chosen amount, thereby further reducing the load on the wearer's skin.

Hereinafter, the present invention will be described in detail based on preferred embodiments (first to third embodiments) with reference to the drawings.

Since the distinction in the present invention is based, in particular, on a specific arrangement, the concave portion 7 of the rear surface and the convex portion 8 of the rear surface according to the first embodiment are called the concave portion 7v of the rear surface located above the absorbent body and the convex portion 8v of the rear surface located above the absorbent body, and the concave portion 7 of the rear surface and the convex portion 8 of the rear surface according to the second embodiment are called the concave portion 7w of the rear surface rhnosti disposed in the end portion, and a convex portion 8w rear surface disposed at the end portion. On the other hand, the concave portion 7 of the rear surface and the convex portion 8 of the rear surface according to the third embodiment are called the concave portion 7v of the rear surface located above the absorbent body and the convex portion 8v of the rear surface located above the absorbent body, based on positions similar to those in the first embodiment. Furthermore, without distinguishing, the concave portion 7 of the rear surface and the convex portion 8 of the rear surface are called simply the concave portion 7 of the rear surface and the convex portion 8 of the rear surface.

Furthermore, in the present invention, when distinguishing between the first and third embodiments, especially with respect to the structure of the components, the spatial portion 72 of the first embodiment is called the spatial portion 72v located in the absorbent body, and the spatial portion 72 of the third embodiment is called spatial a portion 72w of the concave portion or a spatial portion 72w located above the sublayer. In addition, the spatial part 72 is simply called the spatial part 72.

First Embodiment

FIG. 1 is a partially exploded perspective view schematically showing a disposable diaper visible from a skin contact surface in accordance with one preferred embodiment (first embodiment) of an absorbent article of the present invention. The diaper illustrated in the drawing is a disposable diaper provided with a tape (open-type diaper). The diaper, visible from the inside (from the side of the surface in contact with the skin), is flattened and curved to some extent.

A general description will be given of the disposable diaper 10 of the first embodiment.

The disposable diaper 10 of the first embodiment has a liquid-permeable topsheet 1 located on the skin-contacting surface side, a backsheet 2 located on the non-skin-contacting surface and an absorbent body 3 provided between the two sheets. The absorbent body 3 has an absorbent core 31 and cover sheets 32 and 33. The surface in contact with the skin (facing the skin) and not in contact with the skin (not facing the skin) the surface of the absorbent core 31 are flat. The side of the surface in contact with the skin (facing the skin) is covered with a cover sheet 32, the side of the surface in contact with the skin (not facing the skin) is covered with a cover sheet 33, and the cover sheets and the absorbent core 31 are coated with hot-melt adhesive, applied by spraying to ensure intermittent connection. In addition, portions of the covering sheets end in the width direction are connected outside of both side edges of the absorbent core.

In the expanded state, the back sheet 2 is essentially in the form of sand sheets due to the fact that both of its lateral edges are biased inwardly in a part central in the longitudinal direction (Y direction), which ensures the formation of an external diaper configuration. The outer configuration of the diaper 10 in the expanded state is divided in the longitudinal direction (Y direction) into a zone F on the abdomen side located on the stomach side of the wearer, a zone R on the back side located on the back side of the wearer, and a crotch zone C located between them. The crotch zone C includes a zone corresponding to the excretory zone of the carrier (the zone facing the excretory zone). The back sheet 2 may include one sheet or multiple sheets. The top sheet 1 and the absorbent body 3 are located on the back sheet 2 so that the top sheet 1 covers the upper side of the absorbent body 3. The top sheet 1 and the absorbent body 3 have a substantially rectangular shape with a smaller width than the back sheet 2, and a longitudinal direction the top sheet 1 and the absorbent body 3 coincides with the longitudinal direction of the back sheet 2. In addition, two side sheets 4 and 4 are connected by lamination from the outside in the width direction (X direction) from both side edges of the top sheet 1 in the longitudinal direction ui. The side sheet 4 is formed with a cuff 41 to prevent leakage, in the end part of which there is an elastic element offset to the center in the width direction, and with leg assemblies 42 in which the elastic element is located outside in the width direction. Through these elements, fluid leakage in the lateral direction at the junction of the baby's hips caused by movement can be effectively prevented. In the diaper 10 of this embodiment, it is possible to further provide a functional structural part, sheet material or the like.

The abdominal region F and the diaphragm zone R provided on the rear side 10 are formed respectively with the valve part 17 on the rear side and the valve part 18 on the abdomen, each of these parts having a side sheet 4 and a back sheet 2 connected by lamination and protruding outward in the width direction. A fastening tape 19 is provided in the valve portion 17 from the rear side. The tape 19 can be attached to the part (not shown) intended for attaching the tape and provided on the valve part 18 from the abdomen, as a result of which the diaper can be worn and fixed in a predetermined position. At this stage, the diaper smoothly bends inwardly in a part central in the longitudinal direction and is worn in a state in which the absorbent body 3 corresponds to the zone from the femoral part to the lower abdomen of the child. Due to this, the released substance can be absorbed properly and retained by the absorbing body 3.

The materials of the top sheet 1, the back sheet 2 and the absorbent body 3 will be described in further detail below. In this embodiment, the top sheet 1 is formed by using a hydrophilic, aerodynamically-formed canvas, non-woven material that rapidly absorbs the fluid released by the body to move the fluid into the absorbent body and has a good texture. In addition, the backsheet 2 includes a liquid impervious element and is formed, for example, by using a liquid impermeable, moisture permeable film having air permeability. In the present invention, the ability to resist the penetration of liquids means a characteristic in which the penetration of liquids is difficult, and covers water resistance, water repellent ability and impermeability to liquids. In the absorbent body 3, the absorbent core 31 includes cellulosic fibers and a super absorbent polymer, and the cover sheets 32 and 33 are formed by using a material with high hydrophilicity.

In the present invention, unless otherwise indicated, the surface on the side in contact with the human body is called the surface on the skin side, the surface in contact with the skin or the upper surface, and the opposite surface is called the surface not on the skin side, the surface not in contact with the skin , or back surface. On these two surfaces, the side closer to the surface from the skin is called the side of the surface facing the skin, the side of the surface in contact with the skin, or the side of the upper surface, and the side closer to the surface is not from the skin and is called the side a surface not facing the skin, a side of the surface not in contact with the skin, or a side of the back surface. When wearing an absorbent article, the place located on the front side of the human body is called the front part, its edge is called the front edge and the place located on the back side is called the back part, and its edge is called the back edge. The direction of the normal to the top surface or the back surface of the absorbent article is called the direction of the thickness, and the size in this direction is called the thickness. In the plane view of the absorbent article, the direction from the ventral zone to the rear side zone passing through the crotch zone is called the length direction or the longitudinal direction, and the direction perpendicular to the length direction (the longitudinal direction) is called the width direction. The longitudinal direction, as a rule, corresponds to the direction from front to back with respect to the body of a person wearing an absorbent article.

The sectional shape of the diaper 10 will be described with reference to FIG. 2-1 and 2-2. FIG. 2-1 (a) is a section taken along line II-II shown in FIG. 1, FIG. 2-1 (b) is a partially enlarged section, partially enlarging and schematically showing a cross section of a top sheet, and FIG. 2-1 (c) is a partially enlarged sectional view schematically showing the relative position of the top sheet and the cover sheet. FIG. 2-2 is a photograph replacing the drawing, in which there is a cross-sectional image of the disposable diaper 10 of this embodiment, the entire cross-section shown in the central photograph and one concave portion 7 of the rear surface (one concave portion 7v of the rear surface located above the absorbing body) is enlarged in the photograph located on the lower right side. In an enlarged view of the concave portion 7 of the rear surface, the spatial portion 72 (the spatial portion 72v located in the absorbent body) located under the inwardly extending portion of the covering sheet (the inward extending portion 71) is a portion enclosed in a closed loop shown by a dashed line. The absorbent core 31 is a collection of fibers including cellulosic fibers and has small corrugations on its outer surface, so that the fibers on the outer edge are fluffy. In FIG. 2-1 (a), the contour defining the outer shape of the absorbent core 31 is shown with alternating long and two short strokes within the main limits of the fiber population (the same applies to FIGS. 3 and 5).

As shown in FIG. 2-1 (a), the cross-sectional shape of the diaper 10 is such that the top sheet 1 and the cover sheet 32 have a concave-convex shape next to the absorbent core 31. This shape, in particular, the configuration of the concave portion 7 of the rear surface and the component below it, can provide an improvement in the ability to absorb liquid, the ability to diffuse the liquid and increase the rate of “binding” of the liquid in the absorbent body, as will be described later. The cross-sectional shape of the top sheet 1 and the cover sheet 32 will be described further with reference to FIG. 2-1 (b) and 2-1 (s).

As shown in FIG. 2-1 (b), on the side of the surface of the non-contacting skin of the top sheet 1, a concave portion 7 of the rear surface is formed, which is recessed from the side (z ₂ ) of the surface not in contact with the skin, to the side (z ₁ ) of the surface in contact with the skin . A large number of concave portions 7 of the rear surface are arranged at periodic intervals so that they are at substantially equal distances from each other in the plane direction, while this arrangement allows the side of the surface of the upper sheet 1 not in contact with the skin to have a concave-convex shape. That is, the convex portion 8 of the rear surface is formed between the concave portions of the rear surface and protrudes from the side (z ₁ ) of the surface in contact with the skin, to the side (z ₂ ) of the surface not in contact with the skin. In this case, the expression “a plurality of concave portions of the rear surface are adjacent to each other and with scattering” means that the later described upper part 7a, which is the bottom of the recess of the concave portion 7 of the rear surface, and the adjacent upper part 7a are points separated by a lower part 7c, thereby separate concave portions 7 of the rear surface will be located separately from each other in respective directions in a plan view. They are not a plurality of strip-shaped recesses arranged in parallel. In this embodiment, the convex upper surface portion 78 is formed on the side of the skin contact surface of the upper sheet 1 at a location corresponding to the concave rear surface portion 7, and the concave upper surface portion 88 is formed on the side of the skin contact surface of the upper sheet 1 at the location corresponding to the convex section 8 of the rear surface.

As shown in FIG. 2-1 (c) and 2-2, the concave portion 7 of the rear surface (the concave portion 7v of the rear surface located above the absorbent body) in the top sheet 1 is formed with an inwardly extending portion 71, with a portion of the covering sheet 32 covering the side in contact with skin surface of the absorbent body 3, protrudes upward and extends into the interior of this part 71. In the case where the cover sheet 32 and the absorbent core 31 are intermittently connected by means of a hot-melt solvent-free adhesive, as in the diaper 10 of this embodiment , the covering sheet 32 is preferably “raised” between the glue application areas to form the inwardly extending portion 71. As shown in FIG. 2-1 (c) and 2-2, the spatial portion 72 (the spatial portion 72v located in the absorbent body) is formed between the cover sheet 32 and the absorbent core 31 in the concave portion 7 of the rear surface (the concave portion 7v of the rear surface located above the absorbent body ) The spatial portion 72 is formed by forming the inwardly extending portion 71 due to the upwardly extending cover sheet 32. The inwardly penetrating portions 71, 71, ... need not have the same inward depth (h ₂ ) and are not limited to the deeper portions, as shown in FIG. 2-2, so that the inwardly extending portion 71 may have a depth determined by a relationship such as: the depth (h ₁ ) of the recess of the concave portion 7 of the rear surface> the depth (h ₂ ) of the passage inwardly of the inwardly extending part 71 (see Fig. 2-1 ( from)). On the concave portion 7 of the rear surface, a gap is preferably formed between the top sheet 1 and the cover sheet 32, which is a buffer portion 73 in the form of a gap that reduces the effect of the force acting on the side of the top sheet 1.

The concave portion 7 of the rear surface is a recess in the non-skin contact surface of the top sheet 1 and is formed by parts 7b representing side walls extending from the upper part 7a to the lower part 7c and formed along the recess in the upper sheet 1 (see Fig. 2 -1 (b)). The concave portion 7 of the rear surface, which is formed of a soft nonwoven material, may not necessarily have the shape of a finished geometric figure, but the sectional shape of the concave portion 7 of the rear surface formed by the side wall portions 7b is a shape similar to a parabola, so that the shape the space inside the concave portion 7 of the rear surface has a shape similar to a round cone or a round truncated cone with a rounded top 7a. The three-dimensional shape of the concave portion 7 of the rear surface is not limited to this embodiment, may have any concave shape, and may have, for example, a conical or prismatic shape. As an embodiment, when the side of the skin contact surface of the top sheet has a concave-convex shape, the three-dimensional shape of the concave portion 7 of the back surface preferably has a conical shape (round cone shape, round truncated cone shape, pyramid shape, truncated pyramid shape, the shape of an inclined round cone or the like) corresponding to the shape of the side of the surface in contact with the skin.

In this embodiment, the upper part 7a is the part that represents the highest place (in the Z ₁ direction) of the side of the non-skin contact surface of the top sheet 1, which forms the inner wall in the three-dimensional space of the concave portion 7 of the back surface, and the lower part 7c represents is the part corresponding to the lowest place (in the Z ₂ direction) in the same space. Therefore, in the concave-convex configuration in which the concave portion 7 of the rear surface and the convex portion 8 of the rear surface alternate, the lower portion 7c of the concave portion of the rear surface coincides with the upper portion 8a of the convex portion 8 of the rear surface. The upper part 7a and the lower part 7c (the upper part 8a of the convex portion of the rear surface) of the concave portion 7 of the rear surface are the vertices of the curved surface, but they are not limited to this, and their periphery can be formed flat. In this case, the upper part 7a can be defined as the center point on the plane or the highest point on the plane, and the lower part 7c (the upper part 8a of the concave portion of the rear surface) can be defined as the center point on the plane or the lowest point on the plane. With this definition, the depth (h ₁ ) of the concave portion 7 of the back surface is determined by the height difference of the surface of the upper sheet 1 not in contact with the skin and represents the distance from the upper part 7a to the lower part 7c (see Fig. 2-1 (b)). Similarly, the depth (h ₂ ) of the inwardly extending portion 71 is the distance between the lower portion 7c and the highest point of the inwardly extending portion 71 from the surface in contact with the skin (see Fig. 2-1 (c)).

With reference to FIG. 3, the concave portion 7 of the rear surface (the concave portion 7v of the rear surface located above the absorbent body), which is the basic structural part of this embodiment, will be described in more detail, and its operation and effect will be described. FIG. 3 are explanatory views schematically showing the relationship between the top sheet 1, the cover sheet 32 and the absorbent core 31 in the concave portion 7 of the rear surface (in the concave portion 7v of the rear surface located above the absorbent body), FIG. 3 (a) and 3 (b) show two configurations. In the configuration of FIG. 3 (a) the depth (h ₂ ) of the inwardly extending portion 71 is less than the depth (h ₁ ) of the recess of the concave portion 7 of the rear surface (h ₂ <h ₁ ), and the buffer part 73, which is a gap and having a depth (h ₃ ), is formed together with the spatial part 72 (spatial part 72v located in the absorbing body). The configuration of FIG. 3 (b) shows that (h ₁ = h ₂ ), and the buffer portion 73, which is a gap, is not formed, although the spatial part 72 is formed.

In the configurations in both of FIG. 3 (a) and 3 (b) the concave portion 7 of the rear surface (the concave portion 7v of the rear surface located above the absorbent body) is formed in the top sheet 1 from the side z _{2 of} the non-skin surface in the direction of the side z _{1 of the} surface, in contact with the skin, so that the inner space of the retaining liquid of the absorbent body 3 under the top sheet will be formed next to the skin of the carrier. Therefore, the distance covered by the liquid as it enters the interior can be reduced, which is effective to improve the ability to absorb liquids. The inwardly extending portion 71 is located in the concave portion 7 of the rear surface, so that a coating sheet having high hydrophilicity is located next to the skin, and the liquid released can be reliably and quickly absorbed into the absorbent core 31. For reasons related to the ability to absorb liquids , portions 7b of the concave portion 7 of the rear surface, which are side walls, and the inwardly extending portion 71 are preferably brought into close contact to connect them without a gap on the contact surface between E (hereinafter called the bonded portion 74). This allows the inwardly extending portion 71 to directly suction the liberated liquid located in the topsheet 1. Although the bonding method using the hot-melt adhesive is acceptable for forming the bonded portion 74, the fibers are preferably point bonded to each other by spray coating without film formation from adhesive. Due to this, the distance between the loosely arranged fibers in the parts 7b, which are the side walls and formed from a liquid-permeable non-woven material (top sheet), can be maintained to ensure quick transmission of the liquid, and the portion passing inside, formed from a material having high hydrophilicity ( cover sheet 32), creates a fluid suction force to trap the liquid and move it directly inward, that is, into the absorbent core 31. For reasons, it is connected With the rapid absorption of the fluid being released without diffusion, the configuration between the components on the concave portion 7 of the rear surface is preferably provided at least in the crotch area C of the diaper 10.

To provide effective liquid absorption capacity, the depth (h ₂ ) of the inwardly extending portion 71 is preferably 50% or more, more preferably 75% or more of the depth (h ₁ ) of the recess of the concave portion 7 of the rear surface (concave portion 7v of the rear surface located over the absorbing body). With a lower limit value or a larger value, the amount of liquid remaining, in particular in the upper part 7a in the upper sheet 1, can be reduced. In fact, the depth (h ₂ ) of the inwardly extending portion 71 extending into the concave portion 7 of the rear surface may not necessarily be constant in all the concave portions 7 of the rear surface, and in some cases, concave portions 7 of the rear surface may also occur in which the inwardly, the portion 71 is not substantially formed. In this case, the number of concave portions of the rear surface in which the depth (h ₂ ) of the inwardly extending portion 71 is 50% or more, preferably 50% or more, more preferably 70% or more of the total number of concave portions of the rear surface. With a lower limit value or a larger value after absorption of the liquid, the amount of liquid in contact with the skin can be reduced.

With a preferred range of values in configuration (a) with the ratio shown (h ₂ <h ₁ ), an increase in the ability to absorb liquids can preferably be achieved, and the presence of a buffer portion 73, which is a gap, can provide an effect specific to it. In particular, the effect of the force exerted by the top sheet 1 on the absorbent body 3 can be reduced. In addition, the upper portion 7a of the concave portion 7 of the rear surface (the concave portion 7v of the rear surface located above the absorbent body), which is closest to the skin, is not brought into contact with the inwardly extending portion 71, so that backflow of liquid can even be prevented then, when moisture is contained in the inwardly extending portion 71, thereby providing a good feeling of dryness of the top sheet 1. On the other hand, the configuration (b) with the ratio shown (h ₂ = h ₁ ) is preferred for reasons related to about the ability to absorb liquid, since the inside portion 71 extends inwardly from the sidewall portions 7b to the upper portion 7a. Therefore, with respect to the ratio (a) / (b) of the configuration (a) and the configuration (b) in all the concave portions 7 of the back surface formed in the top sheet 1, it should be noted that the proportion of the configuration (b) is preferably higher next to the highlight , in which the ability to absorb liquids is important, and the proportion of configuration (a) is preferably higher next to the femoral part, in which preventing backflow of fluid is important. For reasons related to the importance of the ability to absorb liquids, the ratio (a) / (b) of the configuration (a) and configuration (b) in all the concave portions 7 of the back surface formed in the top sheet next to the excretory part is preferably 4 / 6 or more, more preferably 2/8 or more. In addition, the ratio (a) / (b) is preferably 0/10 or less. For reasons related to the importance of preventing backflow, the ratio (a) / (b) of configuration (a) and configuration (b) in all concave portions 7 of the rear surface formed in the top sheet 1 near the femoral part is preferably 6 / 4 or more, more preferably 8/2 or more. In addition, the ratio (a) / (b) is preferably 10/0 or less.

As described above, the spatial portion 72 (the spatial portion 72v located in the absorbent body) is formed in a concave portion 7 of the rear surface (FIGS. 3 (a) and 3 (b)). The spatial portion 72 may allow diffusion of the recovered fluid, sucked by the inwardly extending portion 71, in the absorbent body 3, so that the fluid can be directly and effectively absorbed on a large surface of the absorbent core. Thus, the absorption rate of the extracted liquid from the top sheet 1 can be increased, so that diffusion of the liquid on the side of the skin contacting surface of the top sheet 1 can be prevented. In addition, even when the amount of the released liquid becomes larger at some point in time , the spatial part 72 can provide temporary retention of liquid from the top sheet 1, and in this case is a "valve" regulating the absorption of liquid. Unlike the absorbent core 31 formed from cellulosic fibers, the spatial portion 72 has a low water retention capacity, so that it can provide rapid fluid transfer to the absorbent core 31. Thus, the spatial portion 72 can provide temporary fluid retention similar to a flow control valve liquid and can be quickly restored, so that it can cope sufficiently not only with a large number of secretions, but also with repeated secretions. In addition, when the skin-contacting surface of the absorbent core 31 is substantially flat, the action of the spatial portion 72 is preferably more effective. However, it is not required that the skin-contacting surface of the absorbent core 31 be smooth, and for reasons related to the rapid movement of fluid into the absorbent core, it is preferable that the cellulosic fibers fluff (see small circle diagram (ii) in FIG. . 2-1 (a)) reached the spatial part 72.

A method for measuring the depth (h ₁ ) of the concave portion 7 of the rear surface, the depth (h ₂ ) of the inwardly extending portion 71, and the depth (h ₃ ) of the buffer portion 73, which is a gap

The depth measurement (h ₁ ) of the concave portion 7 of the rear surface is performed by increasing the cross section of the top sheet 1 passing through the upper part 7a and the lower part 7c, and by measuring the distance between the line t tangent to the neighboring lower parts 7c (see Fig. 2 -1 (s)), and the upper part 7a. The depth measurement (h ₂ ) of the inwardly extending portion 71 is performed by measuring the distance between the upper portion 71a of the convex portion of the inwardly extending portion 71 on the surface of the skin contact and the line tangent to the lower portions 7c. The difference is the depth (h ₃ ) of the buffer portion 73, which is the gap (h ₃ = h ₁ -h ₂ ). Measurement is performed by magnification with a VH-3000 microscope manufactured by Keyence Corporation and a two-point measurement method after calibration adjustment. An electron microscope may be used.

The diaper 10 has both a large liquid suction force, which is provided by the concave portion 7 of the rear surface (the concave portion 7v of the rear surface located above the absorbent body) and the inwardly extending portion 71, and the ability to efficiently transport the fluid possessed by the spatial portion 72 (spatial portion 72v located in the absorbing body). That is, the configurations of the concave portion 7 of the back surface extending inwardly of the portion 71 in the cover sheet 32, the spatial portion 72, and the absorbent core 31 “interact” with each other, and despite the fact that liquid diffusion on the surface facing the skin can be prevented provides diffusion of the liquid in the absorbent core 31 of the absorbent body for reliable absorption, retention and "binding" of the liquid. Thereby, a situation where the liquid remains on the side of the top sheet 1 can be prevented, and a backflow of liquid to the side of the top sheet 1 can be prevented to provide a good dry feeling on the skin of the carrier.

In addition, in the absorbent core 31, which can absorb and hold the liquid over a large area, the area over which the liquid reaches the side of the back sheet 2 becomes larger, so that moisture can be effectively released from the back sheet 2 to the outside. As a result, lowering the temperature of the diaper due to the heat of evaporation of moisture can be ensured over a large area from the side of the back sheet 2 to effectively prevent evaporation of moisture in the diaper 10 (in the part surrounded by the back sheet 2 and the skin of the wearer), so that vaporization in the diaper 10 will be difficult.

To ensure functioning and efficiency, the ratio (r ₁ / h ₁ ) of the distance (r ₁ ) between the lower part 7c and the lower part 7c of the concave portions 7 of the rear surface and the depth (h ₁ ) of the concave portion of the rear surface shown in FIG. 2-1 (b) is preferably 1/1 or more, more preferably 10/8 or more. The ratio (r ₁ / h ₁ ) is preferably 3/1 or less, more preferably 10/4 or less. The ratio (w ₁ / h ₁ ) of the pitch (w ₁ ) between the upper parts 7a-7a of the concave portions of the rear surface and the depth (h ₁ ) of the concave portion of the rear surface is preferably 1/1 or more, more preferably 10/8 or more. The ratio (w ₁ / h ₁ ) is preferably 3/1 or less, more preferably 10/4 or less. With a lower limit or a larger value, a structure of the upper sheet can be provided into which the covering sheet can easily “fit”, and with an upper limit or a lower value, a large volume of the spatial part 72 can be provided.

As described above, in the top sheet 1, a convex rear surface portion 8 is formed between the concave rear surface portions 7 and 7, and the convex rear surface portion 8 preferably has an upper portion 8a. As shown in FIG. 3, in the convex portion 8 of the rear surface, the top sheet 1 and the absorbent core 31 are brought into contact with each other in the upper part 8a by means of the cover sheet 32, so that the contact area can preferably be reduced. By reducing the contact area of the top sheet 1 and the absorbent core 31, the liquid diffusion in the absorbent core 31 can be smooth, which causes a decrease in the absorption rate, the liquid backflow to the side of the top sheet 1 after absorption of the liquid can be prevented, and due to the configuration of the concave portion 7 the back surface can be more effectively prevented moisture on the top sheet 1.

The skin contact side of the surface of the top sheet 1 preferably has a concave-convex shape in which the convex portion of the upper surface 78 and the concave portion 88 of the upper surface are repeated in accordance with the corrugation provided by the concave portion 7 of the rear surface and the convex portion 8 of the rear surface. Many concave-convex configurations formed in the upper surface and the rear surface are preferably provided in the direction in the plane so that concave and convex sections will be formed repeatedly on the entire top sheet 1 in many directions (see Fig. 4). The shape of the top sheet 1 can provide a reduction not only of the contact area between the absorbent core 31 and the top sheet 1, but also of the contact area between the skin of the wearer and the top sheet 1. The reduction of the contact area is effective in preventing moisture on the skin, and breathability can be increased in concave and convex areas, so that it can be more effective in preventing vaporization. In addition, the top sheet 1, which has a concave-convex shape on both surfaces, can well repeat three-dimensional movement to exhibit the ability to three-dimensional springing with point support on both surfaces. When the upper portion 78a of the convex portion 78 of the upper surface has a rounded curved surface, a soft texture with springability can be provided.

Furthermore, as shown in FIG. 4, in the concave-convex configuration of the top sheet 1, sidewall surfaces 88b (= 78b) are preferably formed that slope downward from the convex portion of the upper surface 78 to the concave portion 88 of the upper surface, and the concave portion 88 of the upper surface has an independent cup or cup shape . Thus, it can be provided in a more efficient way to improve the ability to capture the released fluid and the ability to absorb liquid. This aspect will be described with reference to FIG. 5.

FIG. 5 is a partially enlarged section, partially increasing a predetermined cross section of FIG. 2-1 (a). To provide an understanding of the liquid permeability, a concave-convex line (line k ₁ ) is shown in the cross section, while a concave-convex line behind it (line k ₂ ) is omitted to avoid complication, and the convex section of the back surface is omitted, and only the convex section is shown top surface. In this embodiment, for example, the emitted liquid a ₁ will flow down along the side walls 78b (= 88b), which are the side walls, from the upper part 78a of the convex portion 78 of the upper surface (arrows b ₁ ), with a high probability it will stop near the upper part 88a of the concave portion 88 of the upper surface and is unlikely to move in a plane direction. Thus, the spreading of the released liquid on the side of the skin contacting surface of the top sheet 1 can be further prevented, so that the released liquid can be moved to a place remote from the skin in the thickness direction. In addition, the liquid released into the concave portion 88 of the upper surface is sucked out from the side wall portions 88b (= portions 7b representing the side walls of the concave portion 7 of the rear surface) through the connected portion 74 to the inwardly extending portion 71 (b ₂ ) and then absorbed into the spatial part 72. The diffusion of the liquid from the spatial part 72 in the direction in the plane (arrows b ₃ ) is ensured and its subsequent movement into the absorbent core 31 (arrows b ₄ ) for its binding. Arrows b ₂ -b ₄ show the mechanism of action of the concave portion of the rear surface as the base portion of the structure. The concave-convex shape of the convex portion 78 of the upper surface and the concave portion 88 of the upper surface can make the effect of the concave portion 7 of the rear surface more effective.

On the side of the non-skin surface of the top sheet 1, each convex portion 8 of the rear surface is preferably surrounded by concave portions 7 of the rear surface to ensure that they are arranged in a certain order independently from each other in the plane direction, and the spaces of the individual concave portions 7 of the rear surface are connected to each other the other in the direction of the plane. The independent arrangement is not limited to a structure in which the convex portions 8 and 8 of the rear surface are completely removed from each other so that they are completely separated from each other, and also encompasses partially connected convex portions 8 of the rear surface, provided that at least the peripheries of the upper parts 8a are divided. This preferred arrangement will be described with reference to FIG. 6.

FIG. 6 is an explanatory view schematically showing the relative position of the concave portion of the rear surface and the convex portion of the rear surface on the side of the surface of the upper sheet not in contact with the skin in a plan view, wherein the mutual arrangement is simplified and modeled based on the relative position of the upper parts 7a and 8a. In particular, the upper part 7a of the concave portion 7 of the rear surface is shown by a white circle, and the upper part 8a of the convex portion 8 of the rear surface is shown by a black circle. In FIG. 6, the area between the upper parts 8a, 7a and 8a, between the upper parts 7a and 7a or between the upper parts 8a and 8a is a part that is a side wall. To provide an understanding of the preferred arrangement, the side wall portion in the region between the upper portions 8a and 8a is shown as a narrow hourglass shape and is denoted by m. A side wall portion is a portion that continuously forms a concave portion 7 of the rear surface and a convex portion 8 of the rear surface and “denotes” both portions 7b and 8b representing the side walls.

As shown in FIG. 6, the side wall portion m is located between the upper portions 8a and 8a of the convex portions 8 of the rear surface. The side wall portion m is not shaped so that the upper portions 8a of the convex portions 8 of the rear surface are completely connected, and preferably has a shape where it is narrowed in the portion central in the sheet thickness direction (direction from z ₂ to z ₁ Fig. 2-1 (b)), like the shape of the narrow hourglass shown in Fig. 6. The convex portions 8 and 8 of the rear surface are completely separated in the narrowed portion to ensure their independence, and the spaces of the concave portions 7 of the rear surface are connected in the narrowed portion of the m-side portion. That is, on the side of the surface of the top sheet 1 not in contact with the skin, not only the area between the upper parts 8a, 7a and 8a, but also the area between the upper parts 8a and 8a has a concave-convex shape, as a result of which spaces connecting the concave sections 7 and 7 back surface. For example, as shown in FIG. 7, a side wall portion m is preferably formed in an arcuate shape. As indicated by the bright arrows in FIG. 6 and 7, the spaces of the concave portions 7 of the rear surface can freely “move” back and forth along the arcuate configuration of the side m portion m. The inwardly extending portions 71 of the cover sheet 32 are formed along this preferred configuration of the topsheet 1, and the spatial portions 72 below them are also connected to each other. Thus, as shown by the bright arrows shown in FIG. 6 and 7, the liquid emitted sucked into the spatial parts 72 can diffuse unhinderedly because it “makes its way” through the compressible elements of the concave portions 7 of the rear surface, so that the liquid emitted can be effectively absorbed, retained and bound over a large area absorbent core 31.

In the process of absorbing liquid in the diaper 10 shown in FIG. 3 and 5, there is preferably a difference in density or density gradient, in which the fiber density of the nonwoven fabric of the top sheet 1 on the concave portion of the back surface increases from the upper part 7a to the lower part 7c. Due to this, the liquid can quickly pass from the side of the surface in contact with the skin, with its stronger absorption inward. For example, in a predetermined cross section of the concave portion 7 of the rear surface shown in FIG. 2-1 (b), a difference in density or a density gradient can be shown / shown by dividing the top sheet 1 from the top 7a to the bottom 7c in the direction of the height (h ₁ ) of the concave portion 7 of the back surface into three zones (part A, part B and part C) and comparing the average values of the respective fiber densities (n ₁ , n ₂ and n ₃ ) of these zones. The ratio of the fiber densities of part A, part B and part C is preferably: (n ₁ ) <(n ₂ ) <(n ₃ ), and the ratio (n ₁ / n ₂ / n ₃ ) is preferably 2/6/10 or more more preferably 3/5/10 or more. The ratio (n ₁ / n ₂ / n ₃ ) is preferably 8/9/10 or less, more preferably 5/7/10 or less. With a lower limit or a larger value, a good texture can be provided, and with an upper limit or a lower value, the amount of liquid remaining on the top sheet 1 can be reduced.

Density Measurement Method

The density values (n ₁ , n ₂ and n ₃ ) of the upper part 7a, the parts 7b representing the side walls, and the lower part 7c of the concave portion 7 of the rear surface of the upper sheet 1 can be measured in the following way.

In the depth direction (h ₁ ) of the concave portion 7 of the rear surface, the parts obtained by dividing part of the upper sheet 1 from the upper part 7a to the lower part 7b in water are part A, part B and part C, and the cut surface passing through the upper part 7a and the lower part 7b in the upper sheet are examined with magnification by using the scanning electron microscope below (which is adjusted to magnification, in which from 30 to 60 cross-sections of the fibers can be measured from 150- to 500-fold increase), after which the number of cross-sections of the fibers cut by the cut plane is counted into a constant area. Then this value is converted into the number of cross-sections of the fibers per 1 mm ² , and this number is determined as the density of the fibers (fibers per mm ² ). The measurement is performed at three points, and the average value is determined as the density of the fibers of the sample.

* Scanning electron microscope: JCM-5100 (trade name) manufactured by JEOL Ltd.

A modified example of the configuration of the cross section of the concave portion of the rear surface and the top sheet

The cross-sectional shape of the concave portion 7 of the rear surface of the diaper 10 is not limited to the shape (see FIGS. 2-1 (b)) and may be of any shape provided that it provides the ability to absorb liquids similar to that described above. For example, in FIG. 8 (a) the concave portion 7 of the rear surface has the shape of a pointed peak-like upper portion 7a; in FIG. 8 (b) the concave portion 7 of the rear surface has a plurality of upper parts 7a; in FIG. 8 (c) the concave portion 7 of the rear surface has a flat upper portion 7a; and in FIG. 8 (d), the concave portion 7 of the rear surface has an upper portion 7a expanded to a width between the side walls 7b and 7b. Similarly, the cross-sectional shape of the top sheet 1 is not limited to the concave-convex shape of this embodiment and can be of any shape provided that it provides a certain relative position of the concave portion of the rear surface and the cover sheet 32 and the absorbent core 31 below it. For example, in FIG. 9 (a) the side of the skin contact surface is flat; and in FIG. 9 (b), the concave portions 7 of the rear surface are spaced apart, and the upper portion of the concave portion of the rear surface is flat. In the configuration of FIG. 9 (b) the lower portion 7c of the concave portion 7 of the rear surface is the portion in which the plane intersects the upper portion 8a of the convex portion 8 of the rear surface and the portion of the side walls of the parts 7b of the concave portion 7 of the rear surface.

Modified Absorbent Core Example

In the diaper 10, the shape of the absorbent core is not limited to the shape in which the skin contacting surface is flat in this embodiment, and forms that can allow diffusion of the sucked-in liquid over a large area for quick absorption, retention can be used as an option. and fluid binding. For example, as described with reference to FIG. 10, absorbent cores 90 (FIG. 10 (a)) and 90a (FIG. 10 (b)) can be used, each of which includes a concave portion 91 with a groove shape, a protruding absorbent portion 93 with a block shape divided by a concave part, and a concave absorbing part 94, connecting that side of one surface of the protruding absorbing part 93, which corresponds to the concave part 91.

When using an absorbent core, the fluid sucked into the spatial portion 72 diffuses along the concave portion 91 and the concave absorbent portion 94 located beneath it to distribute, absorb, hold and bind the fluid in the protruding absorbent portion 93. Such a trajectory enables reliable fluid binding to a wide area, so that the occurrence of a reverse fluid flow to the side of the top sheet will be hindered. In the case where the concave absorbent portion 94 has a lower surface density in the absorbent cores 90 and 90a as compared to the protruding absorbent portion 93, the resistance to liquid passage in the concave absorbent portion 94 can be reduced, so that easy diffusion of the fluid can be ensured, and the ability to the fluid retention is reduced, so that the liquid can be easily moved to the protruding absorption part 93. For the same reasons, the concave absorbing part 94 having a low surface density, pre respectfully has a lower density than the absorbent projecting portion 93 having a higher surface density. In the absorbent cores 90 and 90a, either the surface with the concave portion 91, or the surface with the concave absorbent portion 94 having a low surface density, may be on the side of the surface in contact with the skin and may be located anywhere according to the purpose of the absorbent article.

In the case where an absorbent core 90 or 90a is used, the concave portion 91 or the concave absorbent portion 94 is preferably overlapped by the spatial portion 72 (the spatial portion 72 located in the absorbent body) in the concave portion 7 of the back surface in the crotch zone C including at least a portion facing the excretory zone. Thus, the liquid located in the spatial part 72 can be easily moved to the concave part 91 or the concave absorbing part 94 and its rapid diffusion can be ensured in order to ensure binding in a simple manner.

A method of forming a concave portion 7 of the rear surface and the inwardly extending portion 71

An absorbent article having a concave portion 7 of the rear surface and an inwardly extending portion 71 similar to those shown in FIG. 2-2 can be obtained in a typical manufacturing process for a similar product. For example, at the stage of connecting the absorbent body and the top sheet by lamination during the assembly of the diaper, the lamination-connected body is introduced into the zone between the press roll formed with concave and convex parts and the support shaft located opposite the press roll, so that the top sheet 1 is inserted in contact with the pressing shaft to ensure partial compression and heating. In this case, the nonwoven fabric of the top sheet 1 and the covering sheet are preferably spaced apart by spray coating of the hot-melt adhesive without adhesive by means of slotted devices or by spiral coating of the hot-melt adhesive without adhesive so that they are brought into close contact with each other to form concave portion of the back surface. In addition, the cover sheet and the absorbent core are preferably bonded by spiral coating in a less accurate manner. The density (q ₁ ) of the adhesive coating between the top sheet and the cover sheet is preferably higher than the density (q ₂ ) of the hot-melt adhesive coating between the cover sheet and the absorbent core, and the ratio (q ₁ / q ₂ ) is preferably 2/1 or more, more preferably 3/1 or more. The ratio (q ₁ / q ₂ ) is preferably 10/1 or less, more preferably 5/1 or less. In the case where the concave portion of the rear surface is formed by means of a press roll and a profiled sheet is used that previously had a concave-convex shape similar to that shown in FIG. 4, or a concave-convex shape similar to that shown in FIG. 9, and using a cover sheet having fluffy fibers, wrinkles, wrinkles, and stretch and pull, the contact between the top sheet 1 and the inside portion 71 in the concave portion of the rear surface can preferably be increased to form the inside portion 71 that extends inside the concave portion of the back surface more deeply.

Profiled sheet can be made as follows. The fibrous canvas before bonding by fusion is fed from the card machine to the device for shaping the canvas to obtain a predetermined thickness and then fixed on a base having a large number of protrusions and having air permeability. After that, a stream of hot air is directed to a fibrous canvas placed on the base at a temperature at which the fibers can be moderately bonded by fusion to give a certain shape to the fibrous canvas along the protrusions on the base, so that the fibers are fused together. At this stage, the temperature of the hot air stream is preferably higher than the melting temperature of the thermoplastic fiber forming the fibrous web, and the temperature difference is preferably 0 ° C or more, more preferably 5 ° C or more. In addition, the temperature difference is preferably 70 ° C or less, more preferably 50 ° C or less. Examples of thermoplastic fibers may include polyolefins, such as polypropylene and polyethylene; polyesters; polyamides such as nylon 6 and nylon 66; polyacrylonitriles and the like, or bicomponent / multicomponent fibers such as fibers with a core and cladding and fibers with the arrangement of components side by side, consisting of two or more of these fibers, and the like. When using a bicomponent fiber containing a component with a low melting point and a component with a high melting point, as the thermoplastic fiber, the temperature of the hot air stream directed onto the fibrous web is preferably equal to the melting temperature or exceeds the melting temperature of the component with a low melting point and lower than the melting temperature of the component with a high melting point. The temperature of the hot air stream directed onto the fibrous web is preferably equal to the melting point of the component with a low melting point + (plus) 0 ° C or more, more preferably the melting point of the component with a low melting point + (plus) 5 ° C or more, preferably equal to the melting point of the component with a high melting point - (minus) 10 ° C or less, and more preferably the melting point of the component with a high melting point - (minus) 20 ° C or less. The fibrous canvas and nonwoven fabric preferably contain thermoplastic fiber in an amount of 30 weight percent or more, more preferably 40 weight percent or more, preferably 100 weight percent or less, and more preferably 80 weight percent or less. Fibrous canvas and non-woven material may contain fiber that in the initial state does not have the ability to heat-fuse (for example, natural fibers such as cotton and cellulose fiber, viscose and acetate fiber, etc.).

For reasons of formability and touch, when profiling a fibrous web, the flow of hot air is preferably 20 m / s or more, more preferably 30 m / s or more, preferably 130 m / s or less, and more preferably 100 m / s or less. When the speed of the air stream is equal to the lower limit value or exceeds the lower limit value, the cubic effect will be sufficient, and the effects provided by the ability to spring and the ability to pick up excrement will be manifested to a sufficient degree, which is preferred. When the speed of the air stream is equal to the upper limit value or less than the upper limit value, the sheet will have no holes and good compression resistance is maintained. Thus, the effects provided by the ability to spring and the ability to capture excrement can be manifested to a sufficient degree, which is preferred.

When considering continuous production, the aforementioned base is preferably a conveyor type base that is movable, or a drum type base. Preferably, a method is provided in which the shaped non-woven material to be moved is wound onto a shaft. In the nonwoven fabric in this embodiment, the MD direction (machine direction is the direction of movement in the machine) and the direction CD (cross direction is the direction perpendicular to the direction of movement in the machine) can be directed in either of two directions.

As the materials forming the top sheet 1, the back sheet 2, the absorbent body 3 and the side sheet 4, materials that are commonly used for the absorbent article can be used.

As the top sheet 1, for example, a hydrophilic non-woven material is preferred, and non-woven materials called a non-woven fabric obtained by aerodynamic method of forming a canvas, a nonwoven fabric with pin bonding of a canvas, a nonwoven fabric of a spunbond production method, non-woven can be used as a hydrophilic nonwoven material, for example. hydroentangling material and a three-dimensional nonwoven material in which the nonwoven fibers are oboj natural fibers of cotton, polypropylene filaments, bicomponent fibers made from polypropylene and polyethylene and bicomponent fibers made of polyethylene terephthalate and polyethylene, which have been subjected to a treatment for imparting hydrophilicity, and data nonwoven materials can be preferably used a surface density is 15 g / m ² or more and 50 g / m ² or less. In addition, in the crotch area of the top sheet 1, the hydrophilic film with holes and the hydrophilic non-woven material may partially overlap on the side of the surface of the top sheet 1 not in contact with the skin.

There are no specific restrictions with respect to the back sheet 2, provided that it is waterproof and moisture permeable. For example, a porous film obtained by melt-mixing a hydrophobic thermoplastic resin and a finely divided inorganic filler containing calcium carbonate and the like, or an organic polymer that is not compatible, and the like for forming a film and subjecting the film to uniaxial or biaxial stretching, can be cited as an example. . Examples of thermoplastic resins may include polyolefins. Examples of polyolefins may include high to low density polyethylenes, linear low density polyethylenes, polypropylene, polybutylene and the like, and these polyolefins can be used individually or in a mixture.

As the absorbent body 3, those materials that are commonly used for the absorbent article can be used. In particular, as the absorbent core, for example, those absorbent cores that use a fiber bundle or a fiber bundle and an absorbent polymer in combination, and the like, can be used. As the fibers that make up the aggregate, hydrophilic natural fibers, such as cellulose fibers, and synthetic fibers (preferably fibers that have been processed to give them hydrophilicity) and the like can be used. Although the surface density is not particularly limited, it is preferably 150 g / m ² or more and 500 g / m ² or less.

In addition, thin paper (sanitary paper), such as hydrophilic sanitary paper, creped paper, non-woven materials formed from hydrophilic fibers such as cotton and viscose, non-woven, can be used as a covering sheet covering the absorbent core. materials formed from synthetic polymer fibers subjected to hydrophilicity processing, for example, non-woven material obtained by the aerodynamic method of forming the canvas (pass through air), nonwoven fabric with pin bonding of canvas, nonwoven fabric obtained by hydro-entangling (spunlace), nonwoven fabric of spunbond production method (spunbond) and nonwoven fabric with SMS structure: layer obtained by spunbond production method (S - spunbond), layer, obtained by the aerodynamic method from a melt (M - meltblown), a layer obtained by a spinneret production method (S).

For the side sheet 4, it is preferable to use, for example, a water-repellent non-woven material, and in particular, a non-woven material of a spinneret production method, a non-woven material with a structure of SM are used: a layer obtained by a spinneret of a production method (S), a layer obtained by an aerodynamic method from a melt (M ), a nonwoven material with an SMS structure: a layer obtained by a spinneret production method (S), a layer obtained by an aerodynamic method from a melt (M), a layer obtained by a spinneret production method (S), and the like. As elastic elements for three-dimensional assemblies and leg assemblies on the side sheet 4, typical elastic elements used for such a product can be used. Examples of such elastic materials include synthetic rubbers such as styrene butadiene, butadiene, isoprene and neoprene, natural rubber, ethylene vinyl acetate copolymer (EVA), elastic polyolefins and polyurethane. The shapes of the elastic elements preferably include a thread or strip (flat rubber thread) with a rectangular, square, round or polygonal section or a multifilament thread.

In the absorbent article of the present invention, the presence of a concave portion of the rear surface of the cover sheet extending inside it and the spatial portion between the cover sheet and the absorbent core can prevent liquid diffusion on the side of the top sheet to increase the force of absorption of the liquid inside it and can provide diffusion of the sucked fluid in the absorbent core for quick binding of the fluid in it. Therefore, the absorbent article of the present invention can provide an increase in absorbency compared to a conventional absorbent article, can prevent diffusion of repeatedly released liquid and a large amount of liquid released on the top sheet side, can provide quick absorption of liquid into the absorbent body and liquid diffusion in the absorbent body and can provide effective absorption and retention of fluid. Thus, excellent functioning and effect can be provided that can prevent skin hydration and can provide good wearing comfort.

In the absorbent article of the present invention, the absorbent core is not limited to this embodiment, provided that it can fulfill the function of absorbing, retaining and binding the liquid therein, and may be, for example, a thin sheet-like core. In the absorbent article of the present invention, the cover sheet is not limited to this embodiment, provided that it can function to cover at least one side of the skin contact surface of the absorbent core to allow fluid to move into the absorbent core, and may be a component having the ability to ensure diffusion of the liquid, and to have many layers, not being limited by the presence of one layer.

The absorbent article of the present invention is not limited to a disposable type diaper according to this embodiment, and encompasses an article having a certain relationship between the top sheet, the cover sheet and the absorbent core. The absorbent article of the present invention can be, for example, a panty-type disposable diaper, a panty-type diaper that can be used as a diaper fastened by a tape by tearing a portion of a panty-type disposable diaper, a pad used for urinary incontinence, a sanitary napkin, panty liner for everyday use and mild incontinence pad. In addition, the absorbent article of the present invention is effective not only for menstrual blood, but also for urine, vaginal discharge and loose stool. The absorbent article of the present invention may include the inclusion of another component in the absorbent article of this embodiment, if necessary, in accordance with the application and functionality.

A disposable diaper 20 as a second embodiment of an absorbent article in accordance with the present invention is described with reference to FIG. 13 - FIG. 22. The diaper 20 of the second embodiment has, in addition to the structure of the diaper 10 of the first embodiment, comprising a top sheet having a concave portion of the back surface deformed as a single portion 51 of the top sheet 1 and the back sheet 2 outside the absorbent body 3 in the longitudinal direction (in the multilayer end part 5).

Hereinafter, a second embodiment of the present invention will be explained with the exception of components that match the components of the aforementioned first embodiment. The aforementioned first embodiment and this second embodiment are not separate and mutually exclusive with respect to each other, and, for example, the second embodiment can be considered as being covered by more specific ideas related to the aforementioned first embodiment. In addition, the invention in accordance with the first embodiment and the invention in accordance with the second embodiment are in technical interconnection, in which the inventions are connected so as to form one idea of the invention due to the presence of similar or corresponding special technical features in these embodiments. The same reference numbers are provided for the same and similar elements, and explanations for them are sometimes omitted (however, the dimensions and special relative positions correspond to the drawings, which correspond to the corresponding options for implementation).

FIG. 13 is a partially exploded perspective view schematically showing a disposable diaper visible from a skin contact surface in accordance with a preferred embodiment (third embodiment) of an absorbent article of the present invention. The diaper illustrated in the drawing is a disposable diaper fastened with a tape. The diaper, visible from the inside (the side of the surface in contact with the skin), is laid out in a plane and curved to some extent.

A general description will be given of the disposable diaper 10 of the second embodiment.

The disposable diaper 20 of the second embodiment basically has the same structure as the diaper 10 of the first embodiment (top sheet 1, back sheet 2, absorbent body 3 and side sheet 4 and the like). However, to avoid complexity in FIG. 13, the absorbent core and the cover sheet forming the absorbent body 3 are not separated, and the entire absorbent body 3 is shown as one component.

The disposable diaper 20 according to the second embodiment differs from the disposable diaper 10 according to the first embodiment in that the deformed whole portion 51 is located outside the absorbent body 3 in the longitudinal direction. This aspect will be described below.

The lengths of the top sheet 1 and the back sheet 2 in the longitudinal direction (Y direction) coincide with each other and are longer than the length of the absorbent body 3. The top sheet 1 and the back sheet 2 are connected by lamination and fastened without placing the absorbent body 3 between them outside of parts 3a and 3a of the absorbent body 3, endwise in the longitudinal direction (these zones outside the end parts 3a are called multilayer end parts 5). The bonding method used for such a product can be selected, and, for example, the top sheet 1 and the back sheet 2 can be spaced together by spray-coating of a hot-melt adhesive without adhesive. When spray coating is applied, the amount of coating material and the density of the coating are controlled so that when the stiffness decreases, both sheets can be firmly bonded and combined into a single unit. The multilayer end parts 5 are located in the zone F on the side of the abdomen and in the zone R on the back side of the diaper 20 and are located around the waist of the wearer while wearing the diaper 20. When wearing the diaper 20, the multilayer end parts 5 are from the side of the parts 3a of the absorbent body 3, end in in the longitudinal direction, up to the diaper parts 20a and 20a, endwise in the longitudinal direction, are arranged in accordance with the direction of the height of the wearer. The multilayer end portion 5 will be described in detail later.

The multilayer end portion 5 of the diaper 20 will be described with reference to FIG. 14. As shown in FIG. 14, the multilayer end portion 5 of the diaper 20 has a plurality of sections 51 deformed as a whole, in which the bonded facing each other surfaces of the top sheet 1 and the back sheet 2 are deformed integrally to form a convex shape in the thickness direction. When the top sheet 1 and the back sheet 2 are deformed in the same thickness direction in the sections 51 deformed as a whole, it is not necessary that the strain values of the sections 51, 51, ... deformed as a whole coincide with each other. In the diaper 20, each portion 51 deformed as a unit includes a portion deformed as a single portion 52 on a skin facing side, protruding to a skin contacting surface and deformed as a single portion 53 on a non-skin facing side, protruding to the side of the surface not in contact with the skin. In the section 51, deformed as a whole, two sheets are partially bent to the side facing the skin, or to the side not facing the skin, relative to the horizontal plane of the absorbing body 3 from the side not facing the skin. The term “as a whole” in the expression “section 51 deformed as a whole” means that one convex section is formed in which the top sheet 1 and the back sheet 2 are connected as a whole as a multilayer element, and there is no restriction, namely that the top sheet 1 and the back sheet 2 must be brought into tight contact with each other without a gap, and they can have a very small gap of such a size that it was possible to prevent liquid diffusion on the contact surface between the two sheets. In addition, from another point of view, the term “as a whole” means that two sheets are brought into tight contact with each other to form a convex section so that the two sheets have essentially the same deformation in the section 51, deformed as a whole, even when various pressures are applied to the multilayer end portion 5, and the shape of the portion 51 deformed as a whole can be substantially restored when the load is removed. Provided that a combination into one can be ensured, another component can be placed between two sheets.

As shown in FIG. 14, sections 51 deformed as a whole are arranged with scattering in a direction in the plane of the laminated end part 5. When placing sections 51 deformed as a whole, “with scattering”, sections 51 deformed as a whole are spaced so that they are scattered in each direction in a plan view. In the second embodiment, the sections of two types deformed as a single unit alternately form a plurality of lines in the longitudinal direction (Y direction) and in the width direction (X direction), and ordered sets consisting of two types of sections deformed as a whole in adjacent lines represent are ordered sets arranged in a checkerboard pattern and shifted from each other by half a step. As a result, the sections 51 deformed as a whole are scattered over a wide range in the direction of the surface of the multilayer end portion 5.

As shown in FIG. 15, the arrangement of the portion 51 deformed as a whole will be described with particular attention to the longitudinal sectional shape of the multilayer end portion 5. FIG. 15 shows a portion of the cross section in the longitudinal direction from the end portion 3a of the absorbent body 3 to the end portion 20a of the diaper 20 (see FIG. 13), with FIG. 15 (A) is a partially enlarged section taken along line AA in FIG. 14 and FIG. 15 (B) is a partially enlarged section taken along line BB in FIG. fourteen.

In FIG. 15 (A) as part of the multilayer end portion 5, five portions 52 deformed as a whole on the skin facing side and four sections 53 deformed as a whole on the skin non-facing side are arranged in a certain order alternately to form row A in the longitudinal direction. In FIG. 15, the portions 52 deformed as a whole, on the side facing the skin, are convex portions curved to the side Z ₁ , and the portions deformed as a whole, 53 on the side not facing the skin, are convex portions curved to the side Z ₂ . The portions 52 deformed as a whole on the side facing the skin, and the portions 53 deformed as a whole on the side not facing the skin are alternately arranged alternating with another portion deformed as a whole. In FIG. 15 (B), a section of row B adjacent to row A is shown as part of a multilayer end portion 5. In row B, four sections 52 deformed as a single unit on the skin side and three sections 53 deformed as a single unit on the side not facing the skin, arranged in a specific order alternately. A plurality of deformed sections arranged in a certain order in a row B are offset from a plurality of deformed sections arranged in a certain order in a row A by half a step so that the sections deformed as a whole, curved in the same direction, do not overlap in the width direction.

Due to the many arranged in a certain order of sections from rows A and B, the longitudinal section of the multilayer end portion 5 as a whole has a tortuous shape like wavy bends in the directions Z ₁ and Z ₂ in the thickness direction relative to the horizontal plane of the absorbent body 3 on the side not facing the skin. Due to deformation as a single whole, the space between the facing surfaces of the top sheet 1 and the back sheet 2, forming a multilayer end portion 5, becomes small. Similarly, the contact area in which space is reduced is tortuous. Even when liquid flows out of the absorbent body 3, and sweat released from the skin and moisture in the diaper are trapped from the top sheet 1, as shown by the separated arrows J shown in FIG. 16, the fluid does not move unhindered. That is, a very small space formed by combining into a single whole, and a tortuous configuration of the contact zone provide the creation of a resistance force to extrusion and spread of fluid in the contact zone. In addition, due to the tortuous configuration, the length of the contact zone in the longitudinal direction is greater than the length of the multilayer end portion 5, as a result of which the resistance force increases. Therefore, fluid diffusion and fluid leakage can be effectively prevented. Rows A and B, offset half a step from each other, are alternating in the width direction, so that fluid diffusion can be effectively prevented in the width direction due to the same effect.

In particular, when a person wearing a diaper lays down and flips on his / her back to change his / her position, the absorbent body 3 and the multilayer end portion 5 may be substantially parallel to the floor surface, or the multilayer end portion 5 will be tilted down. In this case, under the action of gravity and pressure of the human body on the absorbing body 3, the liquid can enter the zone between the facing surfaces of two sheets in the multilayer end part 5.

When the back sheet 2 is flat, as in conventional products according to the prior art, the resistance to the movement of the liquid is small, and there is a possibility of wet spreading of the liquid due to the surface tension of the liquid-impermeable back sheet 2 and capillary forces on the contact surface. In addition, when there is some space, there is a possibility of fluid flowing into it.

In conventional products according to the prior art, which provide improved fit in the waist part, as shown in patent literature 3 and 4, the number of components is increased, the manufacturing process is complicated, and the cost may increase. In contrast, when the waist portion includes a top sheet that has concave and convex portions and a back sheet that is flat, a constant ability to stretch and contract can be provided without adding any complicated operations and increasing the number of components. However, the space in which the liquid stagnates and passes through is created between the top sheet and the back sheet. In this part, the absorbent body is not located, so that the function of absorption and retention of the liquid is “absent”. Thus, for example, when a child or caregiver who wears a diaper moves his body in a prone position, fluid can flow and leak in accordance with his / her posture.

However, as shown in FIG. 15, in the diaper 20 of the second embodiment, even with a carrier position similar to that described above, the tortuous configuration of the multilayer end portion 5 in the thickness direction in the contact zone can provide resistance to the passage of liquid flow and liquid suction in the thickness direction under the influence of gravity (Z ₁ → Z ₂ ), thereby serving as a barrier to fluid movement or wet spreading (see FIG. 16). This can provide effective prevention of fluid diffusion and fluid leakage in a space minimized by combining the elements into a single unit. For these reasons, the surfaces of the two sheets facing each other in the area 53 deformed as a whole on the side not facing the skin, in particular in the upper part 53a, are firmly connected to eliminate any gap.

The tortuous configuration of the present invention is a configuration that has portions deformed in different directions with respect to a constant horizontal plane formed in the entire multilayer end portion 5. From another point of view, the tortuous configuration can also be a configuration in which a plurality of inflection points in the direction thickness in the multilayer end portion 5 is formed relative to the horizontal plane of the absorbent body 3 on the side not facing the skin. Each inflection point is a starting point at which the facing surfaces of the top sheet 1 and the back sheet 2 are bent relative to a horizontal plane. This aspect will be described with reference to FIG. 17. FIG. 17 schematically conceptually shows the upper parts of each portion 51 deformed as a whole and shown in FIG. 15 (the upper portion 52a on the side of the surface in contact with the skin, and the upper portion 53a on the side of the surface in contact with the skin), the inflection point 54 and the bending direction G. The horizontal lines FA and FB are lines that are a continuation of the lower side of the absorbent body 3, as well as lines located in the middle of the thickness of the multilayer end part 5. The arrows at the left end of the horizontal lines FA and FB indicate the direction from the absorbent body 3 to the end part 20a ( see Fig. 13) of the diaper 20. The inflection point 54 is a point at which a portion 51 deformed as a whole intersects the horizontal planes FA and FB and is shown as a black dot. The bending direction G is a direction in which the contact area between two sheets in the multilayer end portion 5 bends with respect to the arrow direction of the horizontal lines FA and FB at the inflection point 54, and is shown by an arrow. Each of the upper parts in the portion 51 deformed as a whole (the upper part 52a on the surface side in contact with the skin and the upper part 53a on the side of the surface not in contact with the skin) is shown as a black dot. For reasons related to “illustrating” the resistance to fluid movement between two sheets, the upper parts and the inflection point of the portion 51 deformed as a whole are shown using the boundary between the two facing each other surfaces, and for convenience, the part in which there is a gap between surfaces facing each other, is shown using the back sheet 2 on the side of the surface in contact with the skin. For the same reasons, the direction of bending is indicated by an arrow using the longitudinal direction from the absorbent body 3 to the side of the diaper end portion 20a.

FIG. 17 (A) shows row A shown in FIG. 15 (A). Row A has ten inflection points 54. In the bending direction G at each inflection point 54, the bending direction G1 oriented in the direction Z ₁ and the bending direction G2 oriented in the direction Z ₂ alternate. FIG. 17 (B) shows row B shown in FIG. 15 (B). Row B has eight inflection points 54. In the bending direction G at each inflection point 54, the bending direction G1 oriented in the direction Z ₁ and the bending direction G2 oriented in the direction Z ₂ alternate. Thus, despite the fact that the contact area of the two sheets completely coincides with the direction of the arrow of the horizontal line FA, it has many starting points, which are alternately located at the top and bottom relative to the horizontal line.

As shown in FIG. 17, the bending directions at the inflection points alternate in the Z ₁ direction and the Z ₂ direction, so that the cross section of the multilayer end portion 5 in the longitudinal direction has a tortuous / serpentine configuration and can effectively provide the above effect. That is, when the inflection points 54 having different inflection directions are arranged in a certain order, the number of sections 51 deformed as a whole can be optionally selected, and the scattering arrangement is not limited to regular, such as shown in FIG. 14 and 15, and may be another regular arrangement or an irregular arrangement. As another regular arrangement, for example similar to that shown in FIG. 18-1, the horizontal portion 55 may be located between adjacent deformed sections 51 as a whole; as shown in FIG. 18-2, the horizontal portion 55 may be combined with the portion 52 deformed as a unit on the side facing the skin and, as shown in FIG. 18-3, the horizontal portion 55 may be combined with the portion 53 deformed as a whole, on the side not facing the skin. In all cases, the plurality of sections deformed as a whole, in the Z ₁ direction and in the Z ₂ direction, at the set of inflection points when the horizontal section 55 is placed between them are continuously arranged, and the cross section of the multilayer end portion 5 has a tortuous configuration relative to the horizontal line.

In addition, the arrangement of the sections 51 deformed as a whole with scattering in a plane direction is not limited to a regular arrangement similar to that shown in FIG. 14, and may be another regular arrangement or an irregular arrangement. As another regular arrangement, for example, a plurality of combinations in which sections 51 deformed as a whole and bent in the same thickness direction are arranged radially, can be located in the surface direction. In particular, as shown in FIG. 19, a plurality of combinations consisting of a portion 53 deformed integrally on the non-skin side and centrally located and six integrally deformed portions 52 on the skin side that surround the deformed integrally portion 53 on the side not facing the skin can be arranged in a certain order in the direction in the plane. In this case, a concave-convex configuration is preferably formed in which the cross section of the multilayer end portion 5 not only in the longitudinal direction and in the width direction, but also in all directions has a tortuous configuration / shape with respect to a horizontal line.

Furthermore, as shown for the ordered set in the width direction shown in FIG. 14 and the combinations of FIG. 15 (A) and 15 (B), deformed as a single section 52 on the side facing the skin, and deformed as a whole section 53 on the side not facing the skin, in the multilayer end portion 5 alternate in the width direction. Thus, as shown in FIG. 20, when a tensile force is applied to the multilayer end portion 5, it is deformed as a whole section 51, in which the top sheet 1 and the back sheet 2 are integrated, stretched to a horizontal state (see Fig. 20 (b)) and pulled together to return to the original shape of the section 51, deformed as a whole, when removing the load (see Fig. 20 (a)). That is, the sections 51, deformed as a whole, provide the ability to stretch and contract the entire multilayer end part 5. As a result, even when the diaper 20 is firmly fixed and fixed so that there is no slack around the waist part while wearing the diaper 20, the ability by stretching and contracting the multilayer end portion 5 can provide a fit around the waist zone of the wearer without unduly squeezing the waist zone. Therefore, good wearing comfort can be provided. Thus, the diaper 20 can satisfy the requirement of a high ability to prevent leakage and fit due to the tensile and tensile forces acting around the waist at the same time.

When forming the multilayer end portion 5 in the disposable diaper 20 of the second embodiment, the top sheet 1 is preferably a nonwoven fabric used for the first embodiment (see FIG. 4), and the concave portion 7 of the rear surface is located in the region of the multilayer end portion 5 In this case, in the multilayer end portion, a convex rear surface portion 8 is formed around concave rear surface portions 7, so that a large number of concave rear surface portions 7 and Olsha number of convex portions 8 of the rear surface are alternated at regular intervals so that they will be adjacent with substantially equal spaces in a direction in the plane.

As described above, in the second embodiment, in accordance with the location, the concave portion of the rear surface and the convex portion of the rear surface in the laminated end portion 5 are called the concave portion 7w of the rear surface located in the end portion and the convex portion 8w of the rear surface located in the end portion , and they differ from the concave portion 7v of the rear surface located above the absorbent body, and the convex portion 8w of the rear surface located above the absorbent body, the first in Rianta embodiment. Alternatively, the concave portion of the rear surface and the convex portion of the rear surface in the laminated end portion 5 are called "the concave portion 7w of the rear surface located in the multilayer end portion 5" and the "convex portion 8w of the rear surface located in the end portion 5" and without distinction are called simply a “concave rear portion 7w” and a “convex rear portion 8w”.

In this case, an upwardly extending portion 21 is formed in which a portion of the backsheet 2 made of a film preventing the penetration of liquids (non-permeable to liquids, a moisture-permeable films) protrudes upward and extends into the concave portion 7w of the rear surface located at the end of the upper sheet 1 (see FIG. 21). The concave back surface portion 7w located at the end portion and the upwardly extending portion 21 are brought into close contact with each other and are combined to form a portion 52 deformed as a whole on the side facing the skin. At the same time, due to the formation of the upwardly extending portion 21, the backsheet 2 is deformed along the configuration of the topsheet 1 from the side walls of the parts 7b of the concave portion 7w of the rear surface located in the end portion to the upper portion 8a of the convex portion 8w of the rear surface located in the end portion, resulting in a deformed as a whole section 53 is formed on the side not facing the skin. That is, the back sheet 2 is given a concave-convex shape matching the concave-convex shape on the side of the skin contact surface of the top sheet 1. Therefore, when the concave back surface portion 7w located in the end portion and the convex back surface portion 8w located in the end parts of the top sheet 1, have a substantially conical shape, in particular the shape of a round cone and a circular truncated cone, deformed as a whole section 52 on the side facing the skin, and deformed as a whole the portion 53 on the non-skin side has a shape close to the same round conical shape, together with the upwardly extending portion 21 of the back sheet 2. Such a shape can preferably prevent liquid diffusion not only in the longitudinal direction (X direction) and in the width direction (Y direction), but also in many directions, and can easily provide the ability to stretch and contract in many directions. For reasons related to this effect of the sections 51 deformed as a whole, the depth of the passage inwardly of the upwardly extending portion 21 preferably “reaches” the upper portion 7a of the concave portion 7w of the rear surface located in the end portion so that there is no possible gap, but the configuration is optional is limited by this configuration, and there are some upwardly extending portions 21 in which the depth (h ₄ ) of their passage inward may be less than the depth (h ₁ ) of the recessed concave portion 7w of the rear surface, located at the end. Preferably, there are some small gaps, since the contact of the top sheet and the skin can be suppressed due to the softness of the nonwoven material forming the top sheet.

The shape and size of the top sheet 1 and the back sheet 2 of the second embodiment are not particularly limited, but to effectively provide a preferred feel when using the depth (h ₁ ) of the concave portion 7w of the rear surface located in the end portion is preferably 0.4 mm or more, more preferably 1 mm or more, although it varies slightly according to the size and application of the absorbent article used. The depth (h ₁ ) of the concave portion 7 of the rear surface located in the end portion is preferably 4 mm or less, more preferably 3 mm or less. The depth (h ₄ ) of the upwardly extending portion 21 of the back sheet 2 is preferably 0.2 mm or more, more preferably 0.5 mm or more. The depth (h ₄ ) of the upwardly extending portion 21 is preferably 3.5 mm or less, more preferably 2 mm or less. The depth (h ₄ ) of the upwardly extending portion 21 is preferably 30% or more, more preferably 50% or more of the depth (h ₁ ) of the concave portion 7w of the rear surface located in the end portion. With a lower limit value or a larger value, the amount of liquid remaining, in particular in the upper part 7a in the upper sheet 1, can be reduced. The percentage expressed as the number of concave rear surface portions 7w located at the end portion in which the depth (h ₄ ) of the upwardly extending portion 21 is 50% or more, as described above, preferably 50% or more, more preferably 70% or more, most preferably 90% or more of the total number of concave rear surface portions 7w located at the end portion. The percentage expressed as the number of concave rear surface portions 7w located at the end portion in which the depth (h ₄ ) of the upwardly extending portion 21 is 100% or more, preferably 5% or more, more preferably 10% or more of the total concave sections 7w of the rear surface located in the end part. With a lower limit value or a larger value, the amount of liquid coming into contact with the skin after absorption of the liquid can be reduced.

To implement the above effects, the ratio (w ₂ / h ₁ ) of the step (w ₂ ) between the upper parts 7a and 7a of the concave portions 7w of the rear surface located in the end part and the depth (h ₁ ) of the concave portion 7w of the rear surface located in the end part is preferably 1/1 or more, more preferably 10/8 or more. The ratio (w ₂ / h ₁ ) is preferably 3/1 or less, more preferably 10/4 or less. With a lower limit or a larger value, a configuration of the upper sheet can be provided in which the covering sheet can easily pass into it, and with an upper limit or a lower value, the volume of the spatial part Q can be provided to a large extent.

Method for measuring the depth (h ₁ ) of the concave portion 7w of the rear surface located in the end portion and the depth (h ₄ ) of the upwardly extending portion 21

The depth measurement (h ₁ ) of the concave portion 7w of the rear surface located in the end portion is performed by increasing the cross section of the upper sheet 1 passing through the upper part 7a and the lower part 7c, and by measuring the distance between the line t tangent to the neighboring lower parts 7c (see Fig. 21), and the upper part 7a. The depth measurement (h ₄ ) of the upwardly extending portion 21 is performed by measuring the distance between the convex portion 21a of the upwardly extending portion 21 from the surface in contact with the skin and a line t tangent to the lower parts 7c. The difference is the depth (h ₅ ) of the buffer portion 73, which is a gap (h ₅ = h ₁ -h ₄ ). Measurement is performed by magnification with a VH-3000 microscope manufactured by Keyence Corporation and a two-point measurement method after calibration adjustment. An electron microscope may be used.

A modified example of the configuration of the cross section of the concave portion 7w of the rear surface located in the end part and the top sheet

The cross-sectional configuration of the concave portion 7w of the rear surface located in the end portion and the top sheet 2 is not limited to the above shape and can be of any shape provided that it provides the above effect. For example, the forms described with reference to FIG. 8 and 9 for the first embodiment.

A method of forming a portion 51 deformed as a unit

An absorbent article in which sections 51 deformed as a whole (deformed as a whole section 52 on a skin facing side and deformed as a whole section 53 on a skin non-facing side) similar to those shown in FIG. 14 and 15, formed in the multilayer end portion 5, can be obtained in a typical manufacturing process for such a product. For example, at the stage where the top sheet 1 and the back sheet 2 are connected by lamination when placing the absorbent body 3 between them, the part of the top sheet 1 and the back sheet 2, in which the absorbent body is not located between them, connected by lamination, is introduced into the zone between a pressing shaft formed with concave and convex parts, and a support shaft located opposite the pressing shaft, so that the top sheet 1 is brought into contact with the pressing shaft to ensure its compression and heating. In this case, the top sheet 1 and the back sheet 2 are preferably stitched at intervals by spray coating of the hot-melt solvent-free adhesive by means of slot devices or by coating of the hot-melt solvent-free adhesive in a spiral so that they are brought into close contact with each other to form a portion 51, deformed as a whole. Preferably, in the shaping process, as shown in the first embodiment, in the case where a non-woven fabric has been used which has previously been concave-convex (see FIG. 4), preferably deformed as a single integral portion 52 on the side can be formed facing the skin, and deformed as a single section 53 on the side not facing the skin, which are respectively combined into a single whole.

Profiled non-woven material can be manufactured by the method described in the description of the first embodiment.

In the second embodiment, the facing surfaces of the top sheet 1 and the back sheet 2 in the multilayer end portion 5 are preferably brought into close contact with each other, but within such limits as not to impair the functioning of the portion 51 deformed as a whole, the other component may be placed between two sheets. In this case, the contact zone between two sheets means the part between the surfaces of two sheets facing each other, including another component placed between them.

As another component, for example, an elastic element (not shown) can be used, designed to enhance the ability to stretch and tighten the waist part, including the multilayer end part 5 of the diaper 20. Strengthen the ability to stretch and pull in the waist part, aimed at improving the fit of the diaper to the wearer can be achieved by placing a plurality of elastic elements in a specific order in the width direction between the top sheet 1 and the back sheet 2. In the diaper 20, before wearing, the rear valve portions 17 and 17 (see FIG. 13) on both sides of the zone R are stretched from the rear side and attached to the zone from the abdomen. In this case, due to the ability of the multilayer end portion 5 to stretch and contract, and the ability of the elastic elements to stretch and contract, the diaper 20 is stretched to ensure that it adheres without difficulty to the body of the carrier having a certain shape, thereby providing a feeling of good fit due to moderate contraction during fixation. Even while the body is moving while wearing, the diaper 20 can easily flexibly follow shape changes in the region around the waist of the wearer to ensure a good fit. When the elastic elements are pulled together, wrinkles and folds are likely to occur in the top sheet 1 and the back sheet 2 in the multilayer end part 5. In this case, in the multilayer end part 5 of the second embodiment, the top sheet 1 and the back sheet 2 are brought into tight contact with each other and combined into a single whole, and the sections 51 deformed as a whole, bent in the thickness direction, are scattered in the plane so that the formation of wrinkles and folds in the longitudinal direction will be difficult. Wrinkles and folds will be “divided and scattered” due to the section 51, deformed as a whole. This preferably can effectively provide enhanced good tensile and constrictive properties and prevent fluid diffusion and fluid leakage.

As an example of another component located between the sheets, a nonwoven sheet 9 having a size within the size of the multilayer end portion 5 is located between the top sheet 1 and the back sheet 2. The nonwoven sheet 9 can make the abdominal region F and the region R c the back, forming the waist of the diaper 20, are thicker to provide a soft texture. Furthermore, as shown in FIG. 22, the nonwoven sheet 9 is shaped in a certain way and it forms integrally along the concave and convex portions formed by the portion 51 deformed as a unit (deformed as a unit of the side 52 on the side facing the skin and deformed as a unit of the portion 53 on the side not facing the skin). Thus, the nonwoven sheet 9 fills even a small gap to prevent the passage of liquid flow, so that liquid diffusion and liquid leakage can preferably be prevented in a more efficient manner.

As the materials forming the top sheet 1, the back sheet 2, the absorbent body 3 and the side sheet 4, materials that are commonly used for the absorbent article can be used.

In particular, the materials given as examples in the first embodiment can be used. In addition, the absorbent body 3 is not limited to the above, provided that it has the ability to absorb, retain and bind the fluid in it, and may be an absorbent body, for example, of a thin sheet type.

The absorbent article of the present invention provides excellent exposure and effect, which can provide an improvement in the ability to prevent leakage in the part in which the absorbent body is not located.

The absorbent article of the present invention is not limited to a folding type disposable diaper according to this embodiment, and is widely applicable to a configuration in which the top sheet and the back sheet are connected by lamination outside the absorbent body. In this case, the top sheet and the back sheet can be defined as a liquid-permeable sheet on the surface side in contact with the skin, and a sheet on the side of the surface not in contact with the skin, which are connected directly or indirectly by lamination and integrated into one end parts of the product in which the absorbent body is not located between them. The shape of the top sheet and the back sheet is not limited to this embodiment, provided that they meet this definition and various configurations can be selected. The absorbent article of the present invention can be, for example, a panty-type disposable diaper, a panty-type diaper that can be used as a tape-fastened diaper by tearing a portion of a panty-type disposable diaper, an incontinence pad, a sanitary napkin, a panty liner for cowards designed for everyday use and a gasket used for mild incontinence. In addition, the absorbent article of the present invention is effective not only for menstrual blood, but also for urine, vaginal discharge and loose stool.

Another aspect of an absorbent article in accordance with the present invention will be described with reference to a pad used for weak incontinence, as an example. The pad used for weak incontinence includes a liquid-permeable top sheet located on the side of the surface facing the skin while wearing, a back sheet located on the side of the surface not in contact with the skin, and an absorbent body located between the two sheets, and has an elongated shape in the longitudinal direction (not shown). The incontinence pad is used by gluing a side of the non-skin surface formed by the back sheet to a fabric underwear. In this case, the incontinence pad will be located in the longitudinal direction from the lower abdomen to the femoral part of the wearer. In that part of the incontinence pad that is longitudinally longitudinal, a multilayer end is formed in which the top sheet and the back sheet are directly or indirectly joined by lamination and bonded without placing an absorbent body between them. The multilayer end portion is thinner than the zone in which the absorbent body is located between two sheets. Therefore, when the conventional incontinence pad is glued to the underwear, there is a possibility of a gap between the incontinence pad and the skin, so that liquid can flow and leak.

However, as in the embodiment of the disposable diaper 20, in the present invention, the multilayer end portion is formed with the portion deformed as a whole, in which the top sheet and the back sheet are integrated as a multilayer element to be deformed to form a convex shape in the direction sheet thickness. In addition, sections deformed as a whole alternate in the width direction. Thus, the areas deformed as a whole provide the ability to stretch and contract the entire multilayer end part to ensure that it is brought into close contact with the skin, so that at the same time the requirements of providing a high ability to prevent leakage and fit due to force can be satisfied stretching and pulling.

A disposable diaper 30 as a third embodiment of an absorbent article in accordance with the present invention is described with reference to FIG. 25 - FIG. 28. As in the diaper 10 of the first embodiment, the diaper 30 of the third embodiment uses the top sheet 1, in which the concave portion 7 of the rear surface and the convex portion 8 of the rear surface are arranged in a specific order. In the third embodiment, for reasons related to improving the ability to absorb liquids, the diaper 30 has a special design in which, in addition to the concave portion 7 of the rear surface, the convex portion 8 of the rear surface surrounded by the concave portions 7 of the rear surface is connected to the underlayer 6.

The aforementioned first and second embodiments and this third embodiment are not separate and mutually exclusive with respect to each other, and, for example, the third embodiment may be considered as being covered by more specific ideas related to the aforementioned first and second embodiments. In addition, the inventions in accordance with the first and second embodiments and the invention in accordance with the third embodiment are in technical relationship, in which the inventions are connected so as to form one general idea of the invention due to the presence of similar or corresponding special technical features of these embodiments . The same reference numbers are provided for the same and similar elements, and explanations for them are sometimes omitted (however, the dimensions and special relative positions correspond to the drawings, which correspond to the corresponding options for implementation).

FIG. 25 is a partially exploded perspective view schematically showing a disposable diaper visible from a skin contact surface in accordance with a preferred embodiment (third embodiment) of an absorbent article of the present invention. The diaper illustrated in the drawing is a disposable diaper fastened with a tape. The diaper, visible from the inside (the side of the surface in contact with the skin), is laid out in a plane and curved to some extent.

A general description will be given of the disposable diaper 30 of the third embodiment.

The disposable diaper 30 of the third embodiment basically has the same structure as the diaper 10 of the first embodiment (top sheet 1, back sheet 2, absorbent body 3 and side sheet 4 and the like). However, to avoid complexity in FIG. 25, the absorbent core and the cover sheet forming the absorbent body 3 are not separated, and the entire absorbent body 3 is shown as one component.

The disposable diaper 30 of the third embodiment differs from the disposable diaper 30 of the first embodiment in that the liquid-permeable underlayer 6 is located between the top sheet 1 and the absorbent body 3. The underlayer 6 has a substantially rectangular shape with a smaller width compared to the back sheet 2, so that the sublayer 6 in the longitudinal direction coincides with the back sheet 2 in the longitudinal direction to cover the side of the skin contact surface of the absorbent body 3.

The sublayer 6 is a component that provides an increase in the absorption capacity due to the rapid absorption of liquid from the top sheet 6, diffusion of the liquid in a plane direction, and effective movement of the liquid into the absorbent body 3. In addition, the sublayer 6 can increase the thickness of the component by providing a predetermined the distance between the side of the skin-contacting surface of the diaper 30 and the absorbent body 3. In this way, the backflow of liquid to the side of the top sheet 1 can be prevented it is effective to reduce humidity in the diaper 30.

The same materials of the top sheet 1, the back sheet 2 and the absorbent body 3 can be selected as in the first embodiment. The material of the sublayer 6, described in detail later, includes a sheet, which is mainly a liquid-permeable fibrous material. In addition, for reasons related to liquid permeability and diffusion, the sublayer 6 preferably has a lower fiber density compared to the top sheet.

The cross-sectional shape of the diaper 30 and the configuration of the top sheet 1 and the sublayer 6 will be described with reference to FIG. 26-1 and 26-2. FIG. 26-1 (a) is a section taken along line II-II shown in FIG. 25, and FIG. 26-1 (b) is a partially enlarged sectional view schematically showing the relative position of the top sheet and the sublayer 6. FIG. 26-2 shows a photograph replacing the drawing, in which a sectional image of a disposable diaper 30 is shown. In the photograph replacing the drawing in FIG. 26-2, each part in which the convex portion 8 of the rear surface of the upper sheet 1 is surrounded by a sublayer 6 is surrounded by a circle indicated by a dashed line.

As shown in the cross-sectional configuration of the diaper 30 in FIG. 26-1 (a) and 26-2, the top sheet 1 has a concave-convex shape in which the convex portion 8 of the rear surface (the convex portion 8v of the rear surface located above the absorbent body) and the concave portion 7 of the rear surface (concave portion 7v of the rear surfaces located above the absorbent body) alternate with respect to the absorbent body 3. The top sheet 1 and the sublayer 6 are brought into contact with each other on the convex portion 8 of the rear surface (the convex portion 8v of the rear surface located above the absorbent body).

In the present invention, the configuration of the contact portion of the top sheet 1 and the sublayer 6 (hereinafter the contact part is denoted by 63) provides an additional reduction in fluid retention, as described later, while maintaining the ability of the sublayer to absorb liquid, the ability of the sublayer to provide fluid diffusion and the ability of the sublayer to preventing backflow of fluid. The configuration of the top sheet 1 and the sublayer 6 will be further described with reference to FIG. 26-1 (b).

As shown in FIG. 26-1 (b), the convex portion 8 of the rear surface is formed on the side of the non-skin surface of the top sheet 1 and protrudes from the side (Z ₁ ) of the surface in contact with the skin to the side (Z ₂ ) of the surface not in contact with the skin. A large number of convex portions 8 of the rear surface are arranged at periodic intervals so that adjacent convex portions 8 of the rear surface are at substantially equal distances from each other in the plane direction. A concave portion 7 of the rear surface is provided between the convex portions 8 of the rear surface and is recessed from the side (Z ₂ ) of the non-skin surface to the side (Z ₁ ) of the skin contact. With this arrangement, individual convex sections 8 of the rear surface are “scattered” in the respective directions in plan view. As a result, the side of the surface of the upper sheet 1 not in contact with the skin has a concave-convex shape. In the third embodiment, the concave portion 88 of the upper surface is formed on the side of the skin-contacting surface of the top sheet 1 at a location corresponding to the convex portion 8 of the rear surface, and the convex portion 78 of the upper surface is formed on the side of the skin-contacting surface of the top sheet 1 in the position corresponding to the concave section 7 of the rear surface.

As described above, the convex portion 8 of the rear surface is a portion protruding toward the side of the absorbent body 3 on the side of the surface of the upper sheet 1 not in contact with the skin. The convex portion 8 of the rear surface is brought into contact with the underlayer 6 in the contact portion 63 (see Fig. 27). The contact portion 63 fills the gap between the absorbent body 3 and the upper sheet 1, so that the suction force acting on the side of the absorbent body 3 is easily transmitted to the upper sheet 3 through the sublayer 6. In addition, the fiber density of the sublayer 6 in the contact part 63 is higher than the density of fibers in the rest of the sublayer (hereinafter, the part of the sublayer 6, having a high density of fibers, is called the dense part 61, and the part of the sublayer 6, having a low density of fibers, is called the scarce part 62). Due to this structure, the capillary forces created by the dense part 61 of the sublayer 6 provide easier absorption of liquid compared to the loose part 62 of the sublayer 6, and together with the suction force created by the absorbing body 3, can provide active absorption of even liquid, which is likely to will remain in the top sheet 1, in particular in the convex portion 8 of the rear surface. Thus, the sublayer 6 provides an effective transfer of fluid into the absorbent body 3. As a result, the ability to prevent fluid retention in the upper sheet 1 can be further improved, so that the ability to reduce moisture in the area between the skin and the upper sheet 1 can be further improved.

In the third embodiment, the convex portion 8 of the rear surface has a rounded upper portion 8a, so that preferably the area in contact with the underlayer 6 in the contact portion 63 can be prevented. In this way, the backflow of liquid can be prevented, thereby reducing the amount of liquid remaining in the contact portion 63. In addition, the reduction of the contact zone avoids preventing the manifestation of absorption in the concave portion 7 of the rear surface, as described later, which effective to prevent moisture on the top sheet 1. The convex portion 8 of the rear surface of the top sheet 1 is not limited to the presence of the upper part 8a of the third embodiment, provided that it provides this effect and can have a flat shape.

In the present invention, for reasons of reducing the amount of remaining liquid, the fibers forming the convex portion 8 of the rear surface, brought into contact with the contact portion 63 and the dense portion 61 of the sublayer 6, do not form a film, so that a gap between the fibers is maintained. This differs from the formation of a film of fibers due to heat sealing according to the prior art, and there is no obstacle to the movement of liquid. The liquid located in the top sheet 1 can be forcedly directed into the absorbent body 3 due to the action of capillary forces created by the dense part 61 of the sublayer 6. Since the fibers do not form a film, the contact part 63 cannot be rigid, resulting in a good texture. There is no possibility of reducing the volume of the upper sheet 1 and the sublayer 6 and the manifestation of their ability to spring, so that good wearing comfort can be ensured. The contact portion 63, which does not have the rigidity due to film formation, cannot transmit a downward force, thereby reducing compression in the thickness direction from the side of the top sheet 1. Therefore, this is preferable, since the reverse flow of liquid will be even more difficult, caused by squeezing.

The contact portion 63 of the convex portion 8 of the rear surface and the sublayer 6 preferably has a portion that is joined by hot-melt adhesive, and a portion that is not bonded by hot-melt adhesive. In this way, both a reduction in the amount of remaining liquid and stabilization of the contact portion 63 can be achieved in a balanced manner. Preferably, if the minimum number of sections is connected by means of glue / adhesive, and as regards the area, then the number of sections connected is preferably reduced in the area facing the excretory zone. This prevents the later described obstruction of the smooth flow of liquid into the absorbent body resulting from the adhesive, so that wearing comfort due to flexibility can be ensured. In addition, it is not required that parts in which the convex portions 8 of the rear surface and the dense portions 61 of the sublayer 6 are brought into contact with each other are provided in the entire topsheet 1, and these parts are preferably provided in the crotch zone C, including at least a zone facing the excretory zone. The zone facing the excretory zone is the part that directly receives excretion, such as urine or feces, and the part located next to it.

Based on these considerations, the ratio (g ₁ / g ₂ ) of the number (g ₁ ) of contact parts connected by adhesive and the number (g ₂ ) of contact parts not connected by adhesive is preferably 1/1 or more, more preferably 1/2 or more. The ratio (g ₁ / g ₂ ) is preferably 1/8 or less, more preferably 1/4 or less. With a lower limit or a higher value, the connection of the top sheet 1 and the sublayer 6 becomes stable, and with an upper limit or a lower value, the adhesion caused by the adhesive can be prevented. In the contact portion 63, connected by a hot-melt adhesive, the fibers of both elements are preferably point-wound by spray coating without forming an adhesive film. Thus, even when the fibers of the convex portion 8 of the rear surface and the dense portion 61 of the sublayer 6 are connected, a gap between the fibers of both elements can be easily maintained.

As shown in FIG. 27, for reasons related to the stabilization of the contact portion 63, the dense portion 61 of the sublayer 6 preferably forms a concave portion deepened to the side of the non-skin surface, and the convex portion 8 of the rear surface extends into the interior of this concave portion and is brought into contact with this concave plot. In this state, it will be difficult to flatten the contact zone without strong bonding of the dense part 61 and the convex portion 8 of the rear surface, and this zone is easy to stabilize. The area in which the convex portion 8 of the rear surface is brought into contact with the dense portion 61 in the inwardly extending portion is moderately expanded without increasing the area of the area of the dense portion 61, so that the efficiency of moving (liquid) into the absorbent body 3 can be improved. in the later concave portion 7 of the rear surface described later, the loose portion 62 of the sublayer 6 is preferably bulky and extends to a small extent into the spatial portion 72w of the concave portion (the spatial portion 72w above the underlay) in 7-mentioned portion of the rear surface to allow easy fluid direction in the spatial part of the concave portion 72w. The thickness of the concave portion of the dense portion 61 is preferably 30% or more, more preferably 50% or more of the thickness of the loose portion 62. The thickness of the concave portion of the dense portion 61 is preferably 90% or less, more preferably 70% or less of the thickness of the loose portion 62. With a lower limit value or a larger value, backflow of liquid in the contact part and evaporation of water vapor in the diaper can be prevented, and with a higher limit value or a lower value, the contact state of the upper l Ista 1 and sublayer 6 can be stably maintained.

On the other hand, the concave portion 7 of the rear surface is a recess in the non-skin contact surface of the top sheet 1 and is formed by parts 7b representing the side walls and extending from the upper part 7a to the lower part 7c in the upper sheet 1 along the recess (see FIG. . 26-1 (b)). The loose portion 62 of the sublayer 6 is located at the location of the concave portion 7 of the rear surface. The spatial portion 72w of the concave portion is formed between the concave portion 7 of the rear surface and the loose portion 62 of the sublayer 6. The spatial portion 72w of the concave portion is a substantially empty portion even when the fibrous material of the top sheet 1 and the sublayer 6 passes slightly into it. Since the spatial portion 72w of the concave portion is an empty space, the resistance to passage of liquid that extends from the top sheet 1 is low. The spatial portion 72w of the concave portion in the concave portion 7 of the rear surface is at a location relatively close to the side facing the skin, so that fluid can be easily and quickly absorbed from the upper portion 7a and the sidewall portions 7b to allow easy active the transmission of fluid received by the topsheet 1. The spatial portion 72w of the concave portion preferably becomes a buffer portion that reduces the effect of the force exerted by the topsheet 1.

In addition, the loose part 62 of the sublayer 6, the fiber density of which is not increased compared to the dense part 61, may have the ability to absorb liquid and the ability to ensure diffusion of the liquid, similar to the original functions of the sublayer 6. The loose part 62 can provide rapid fluid movement, captured in the spatial portion 72w of the concave portion into the absorbent body 3 over a large area. On this basis, the fiber density of the sublayer 6 is preferably lower than the density of the fibers in the area adjacent to the concave portion 7 of the rear surface of the top sheet 1. In addition, the configuration of the top sheet 1, the spatial portion 72w of the concave portion and the loose portion 62 of the sublayer 6 can increase the distance between the skin carrier and absorbent body to provide thickness. Thus, preferably, a fluid backflow to the skin-facing side can be prevented.

As described above, in the concave portion 7 of the rear surface due to the combination of the spatial portion 72w of the concave portion and the loose portion 62 of the sublayer 6, the absorption rate of the released liquid from the top sheet 1 can be increased, so that diffusion of the liquid on the side of the skin contacting surface of the top can be prevented. of sheet 1. In addition, even when the amount of liquid released becomes larger at some point in time, the spatial portion 72w of the concave portion can provide temporary liquid retention from the top sheet 1 is similar to a fluid absorption control valve. In contrast to the absorbent body 3 formed from cellulose fibers, the spatial portion 72w of the concave portion provides a small force of water retention, so that it can provide quick movement of the liquid into the absorbent body 3 when exposed to the sublayer 6, causing the diffusion of the liquid. The combination of the spatial portion 72w of the concave portion and the loose portion 62 of the sublayer 6 can provide temporary fluid retention similar to a fluid flow control valve and quickly restore spatial shape, so that these components can sufficiently cope not only with a large number of precipitates, but also with multiple secretions. In addition, this effect can preferably be more effective when the surface of the absorbent body 3 in contact with the skin has a substantially flat shape.

For reasons of absorption rate, in the configuration of the concave portion 7 of the rear surface, the sectional shape of the concave portion 7 of the rear surface formed by the side wall portions 7b is preferably essentially a parabola shape, and the spatial shape of the concave portion 7 of the rear surface together with the rounded top 7a has the shape of a round cone or a round truncated cone or a shape close to a cone (round cone, round truncated cone, pyramid truncated a pyramid and an inclined round cone and the like). A smooth taper of the conical shape allows fluid to pass in the thickness direction without decreasing pressure during fluid release and can quickly absorb more fluid into the spatial portion 72w of the concave portion.

In the concave portion 7 of the rear surface, the upper portion 7a is the portion at the highest point (in the Z ₁ direction) of the non-skin surface of the top sheet 1 forming the inner wall of the three-dimensional space of the concave portion 7 of the rear surface, and the lower portion 7c is the portion in lowest place (in the direction of Z ₂ ) in the same space. The lower portion 7c of the concave portion of the rear surface coincides with the upper portion 8a of the convex portion 8 of the rear surface. The upper part 7a and the lower part 7c (the upper part 8a of the convex portion of the rear surface) of the concave portion 7 of the rear surface are shown as the apex of the curved surface, but their shape is not limited to this, and their periphery may have a flat shape. In this case, the upper part 7a can be defined as the center point on the plane or the highest point on the plane, and the lower part 7c can be defined as the center point on the plane or the lowest point on the plane. In this definition, the depth (h ₁ ) of the concave portion 7 of the back surface is the height difference relative to the surface of the upper sheet 1 not contacting the skin and represents the distance between the upper part 7a and the lower part 7c (see Fig. 26-1 (b)) .

The depth (h ₁ ) of the concave portion 7 of the rear surface varies depending on the size and use of the absorbent article and cannot be determined unambiguously, but preferably it is 0.5 mm or more, more preferably 1 mm or more. In addition, the depth (h ₁ ) of the concave portion 7 of the rear surface is preferably 4 mm or less, more preferably 3 mm or less. The depth measurement (h ₁ ) of the concave portion 7 of the rear surface is performed by increasing the cross section of the upper sheet 1 passing through the upper part 7a and the lower part 7c, and by measuring the distance between the line t tangent to the neighboring lower parts 7c (see Fig. 26 -1 (b)), and the upper part 7a. Measurement is performed by magnification with a VH-3000 microscope manufactured by Keyence Corporation and a two-point measurement method after calibration adjustment. An electron microscope may be used.

As described above, the area of the concave portion 7 of the rear surface (the combination of the spatial portion 72w of the concave portion and the loose portion 62) and the area of the convex portion 8 of the rear surface (contact portion 63 of the convex portion 8 of the rear surface and the solid portion 61) interact to increase liquid absorption capacity so that the liquid can be quickly transferred to the absorbent body 3 to prevent the backflow of liquid, as a result of which the presence of the remaining liquid (in the top sheet) is simultaneously prevented. Thus, the contact of the liquid with the skin of the wearer can be further prevented, so that the effect of reducing moisture in the area between the skin and the surface side of the diaper 30 facing the skin can be further enhanced. A configuration with a similar mutual arrangement of the components is preferably provided at least in the crotch area C of the diaper 30. A good dry feeling on the skin of the wearer can be provided.

In addition, the absorbent body 3 absorbs and retains the liquid, the diffusion of which was ensured by the sublayer 6 and the spatial parts 72w of the concave portions over a large area, so that the area on which the liquid reaches the side of the back sheet 2 becomes larger. In this case, moisture can be effectively released from the back sheet 2 to the outside. As a result, lowering the temperature of the diaper due to the heat of evaporation of moisture can be ensured over a large area from the side of the back sheet 2, so that evaporation of moisture inside the diaper 30 can be effectively prevented (in the part surrounded by the back sheet 2 and the skin of the wearer), thereby making it difficult vaporization in the diaper 30.

In the present invention, for reasons related to providing the above effect and effect, the density (m ₆₁ ) of the fibers of the dense portion 61 of the sublayer 6 is preferably 15 fibers per 1 mm ² or more, more preferably 20 fibers per 1 mm ² or more. The density (m ₆₁ ) of the fibers is preferably 120 fibers per 1 mm ² or less, more preferably 80 fibers per 1 mm ² or less. The density (m ₆₂ ) of the fibers of the loose portion 62 of the sublayer 6 is preferably 10 fibers per 1 mm ² or more, more preferably 15 fibers per 1 mm ² or more. The density (m ₆₂ ) of the fibers is preferably 100 fibers per 1 mm ² or less, more preferably 60 fibers per 1 mm ² or less. The ratio (m ₆₁ / m ₆₂ ) of the density (m ₆₁ ) of the fibers of the dense portion 61 and the density (m ₆₂ ) of the fibers of the dense portion 62 is preferably 6/5 or more, more preferably 7/5 or more. The ratio (m ₆₁ / m ₆₂ ) is preferably 3/1 or less, more preferably 2/1 or less.

For the same reasons, the ratio (n ₆₃ / n ₆ ) of the area of the dense part 61 and the area (n ₆ ) of the sublayer 6 on the surface in contact with the skin, determined in plan view of the area (n ₆₃ ), is preferably 1/20 or more, more preferably 1/10 or more. The ratio (n ₆₃ / n ₆ ) is preferably 2/5 or less, more preferably 1/5 or less. The area (n ₆₃ ) of the zone in the plan view is the area of the zone determined by looking at the sublayer 6 in the plan view from the side of the surface in contact with the skin, without taking into account the surface of the walls of the recesses in the thickness direction.

The method of separation of the dense part 61 and the loose part 62

The boundary defining a clear difference in density between the dense portion 61 and the loose portion 62 of the sublayer is generally difficult to determine. Therefore, the dense portion 61 can be defined as a recessed portion, or the dense portion 61 is a portion brought into contact with the convex portion 8 of the rear surface, which makes it possible to distinguish it from the loose portion 62.

More precisely, the section of the sublayer 6 passing through the adjacent dense parts 61 of the sublayer is increased so that the dense part 61 is a part located between zones in which the curved line of the upper surface of the sublayer 6 on the side facing the skin bends like a curved line, concave towards the side of the surface not in contact with the skin, for rounding. The profile of the upper surface of the sublayer on the side facing the skin has a concave-convex shape in which the portion of the curved line concave to the side of the surface not in contact with the skin and the portion of the curved line protruding to the side of the surface in contact with the skin are continuously repeated. The direction of the bend is changed by means of zones that form a substantially straight line at the boundaries between the concave portion and the protruding portion. The concave portion surrounded by the boundaries on which this straight line is bent to begin to round it is a recess.

Sublayer density measurement method 6

The cut surface is examined with magnification by using the scanning electron microscope below (which is adjusted to enlarge, in which 30 to 60 cross sections of the fibers can be measured; 150 to 500 times magnification), and then the number of cross sections of the fibers cut by the plane is calculated section, to a constant area. Then this value is converted into the number of cross-sections of the fibers per 1 mm ² , and this number is determined as the density of the fibers (fibers per mm ² ). The measurement is performed at three points, and the average value is determined as the density of the fibers of the sample.

* Scanning electron microscope: JCM-5100 (trade name) manufactured by JEOL Ltd.

As described with reference to FIG. 4 for the first embodiment, the side of the skin-contacting surface of the top sheet 1 preferably has a concave-convex shape in which the convex portion of the upper surface 78 and the concave portion 88 of the upper surface are repeated in accordance with the corrugation provided by the concave portion 7 of the rear surface and the convex portion 8 back surface. Many concave-convex configurations formed in the upper surface and the rear surface are preferably provided in the direction in the plane so that concave and convex sections will be formed repeatedly on the entire top sheet 1 in many directions (see Fig. 4). The shape of the top sheet 1 can provide a reduction not only in the contact zone between the top sheet 1 and the underlayer 6, but also in the contact zone between the skin of the wearer and the top sheet 1. The reduction of the contact zone is more effective in preventing moisture on the skin, and breathability can be increased in concave and convex areas, so that it can be more effective in preventing vaporization. In addition, the top sheet 1, which has a concave-convex shape on both surfaces, can well repeat three-dimensional movement to exhibit the ability to three-dimensional springing with point support on both surfaces. When the upper portion 78a of the convex portion 78 of the upper surface has a rounded shape with a curved surface, a soft texture with springability can be provided.

In addition, as shown in FIG. 4, in the concave-convex configuration of the top sheet 1, sidewall surfaces 88b (= 78b) are preferably formed that slope downward from the convex portion of the upper surface 78 to the concave portion 88 of the upper surface, and the concave portion 88 of the upper surface has an independent cup or cup shape . Thus, it can be provided in a more efficient way to improve the ability to capture the released fluid and the ability to absorb liquid. For example, the liquid emitted will flow down along the side wall portion 78b (= 88b) from the upper portion 78a of the convex upper surface portion 78 (arrows b ₁ ), with a high probability it will stop near the upper portion 88a of the concave upper surface portion 88 and is unlikely to move in a direction in the plane. Thus, the spreading of the released liquid on the side of the skin contacting surface of the top sheet 1 can be further prevented, so that the released liquid can be moved to a place remote from the skin in the thickness direction.

In this case, as shown in FIG. 28, the liquid released into the concave portion 88 of the upper surface is sucked from the sides 88b representing the side walls (= parts 7b representing the side walls of the concave portion 7 of the rear surface) to the spatial portion 72w (arrows b ₂ ) of the concave portion. The diffusion of the liquid from the spatial part 72w of the concave portion in the direction in the plane (arrows b ₃ ) and its subsequent movement into the absorbent core 31 (arrows b ₄ ) is ensured for its binding. In this part, it will not be possible to transmit a large amount of liquid stagnant in the concave portion 88 of the rear surface, so that a situation easily arises in which the liquid remains.

However, on the surface side not facing the skin, the convex portion 8 of the rear surface is brought into contact with the dense portion 61 of the sublayer 6 in the contact portion 63, so that due to the greater suction force acting from the side of the sublayer 6, and the suction force acting from the side absorbing body 3, the situation in which the liquid remains (in the top sheet) can be effectively eliminated (arrows b ₅ ). The concave-convex shape of the convex portion 78 of the upper surface and the concave portion 88 of the upper surface can make the impact of the convex portion 8 of the rear surface, the concave portion 7 of the rear surface and the underlayer 6 more effective.

As described with reference to FIG. 6 for the first embodiment, on the side of the non-skin surface of the top sheet 1, each convex portion 8 of the rear surface is preferably surrounded by concave portions 7 of the rear surface to ensure that they are placed in a certain order independently from each other in the plane direction, and the space of the individual concave portions 7 of the rear surface are connected to each other in a plane direction. Thus, as indicated by the bright arrows shown in FIG. 6 and 7, the emitted fluid sucked into the spatial portion 72w of the concave portion can diffuse unhinderedly because it “paves its way” through the compressible elements of the concave portions 7 of the rear surface, so that the emitted fluid can be effectively absorbed, retained and bound to a large area of the absorbent core 31.

In the process of absorbing liquid in the diaper 30 shown in FIG. 27 and 28, there is preferably a difference in density or density gradient in which the density of the nonwoven fibers of the top sheet 1 in the concave portion of the back surface increases from the upper part 7a to the lower part 7c. Due to this, the liquid can quickly pass from the side of the surface in contact with the skin, with its stronger absorption inward. For example, in a predetermined cross section of the concave portion 7 of the rear surface shown in FIG. 26-1 (b), a difference in density or a density gradient can be shown / shown by dividing the top sheet 1 from the top 7a to the bottom 7c in the direction of the height (h ₁ ) of the concave portion 7 of the back surface into three zones (part A, part B and part C) and comparing the average values of the respective fiber densities (n ₁ , n ₂ and n ₃ ) of these zones. The ratio of the fiber densities of part A, part B and part C is preferably: (n ₁ ) <(n ₂ ) <(n ₃ ), and the ratio (n ₁ / n ₂ / n ₃ ) is preferably 2/6/10 or more more preferably 3/5/10 or more. The ratio (n ₁ / n ₂ / n ₃ ) is preferably 8/9/10 or less, more preferably 5/7/10 or less. With a lower limit or a larger value, a good texture can be provided, and with an upper limit or a lower value, the amount of liquid remaining on the top sheet 1 can be reduced.

Method for measuring the density of the concave portion 7 of the rear surface of the top sheet 1

The density values (n ₁ , n ₂ and n ₃ ) of the upper part 7a, the parts 7b representing the side walls, and the lower part 7c of the concave portion 7 of the rear surface of the upper sheet 1 can be measured in the following way.

In the depth direction (h ₁ ) of the concave portion 7 of the rear surface, the parts obtained by dividing part of the upper sheet 1 from the upper part 7a to the lower part 7b in water are part A, part B and part C, and the cut surface passing through the upper part 7a and the lower part 7b in the upper sheet are examined with magnification by using the scanning electron microscope below (which is adjusted to magnification at which 30 to 60 fiber cross-sections can be measured; from 150- to 500-fold zoom), then count the number of cross sections of fibers of the cut plane cut at a constant area. Then this value is converted into the number of cross-sections of the fibers per 1 mm ² , and this number is determined as the density of the fibers (fibers per mm ² ). The measurement is performed at three points, and the average value is determined as the density of the fibers of the sample.

* Scanning electron microscope: JCM-5100 (trade name) manufactured by JEOL Ltd.

A modified example of the configurations of the section of the upper sheet

In the diaper 30, the sectional shape of the top sheet 1 is not limited to the concave-convex shape of the third embodiment and can be of any shape provided that it allows a certain relative position of the convex section 8 of the back surface, the concave section 7 of the back surface and the underlayer 6 located under them. For example, in FIG. 29 (a) the side of the skin contact surface is flat, and in FIG. 29 (b) the upper portion of the convex portion 8 of the rear surface is flat in shape. In the configuration of FIG. 29 (b) the lower portion 7c of the concave portion 7 of the rear surface is the portion in which the plane intersects the upper portion 8a of the convex portion 8 of the rear surface and the portion of the side walls of the parts 7b of the concave portion 7 of the rear surface.

In a modified example of the top sheet 1, the convex portion 8 of the rear surface has a greater thickness than the concave portion 7 of the rear surface. Therefore, there is a likelihood of fluid stagnation in the convex portion of the back surface. However, in this case, the convex portion 8 of the rear surface is brought into contact with the dense portion 61 of the sublayer 6, so that due to the greater suction force acting from the side of the sublayer 6 and the suction force acting from the side of the absorbing body 3, fluid stagnation can be effectively eliminated . In addition, in the modified example, there is preferably a difference in density or density gradient, in which the fiber density of the nonwoven fabric of the top sheet 1 on the concave portion of the back surface increases from the upper part 7a to the lower part 7c. Due to this, the liquid can quickly pass from the thin part of the top sheet 1 to the spatial part 72w of the concave portion, and the sublayer 6 can provide a forced movement of the liquid into the absorbent body.

A modified example of an absorbing body

In the diaper 30, the shape of the absorbent core forming the absorbent body is not limited to the shape in which the skin contacting surface of the third embodiment is flat, and forms that can allow diffusion of the liquid sucked inwards over a large area can be used as an option. for fast absorption, retention and binding of liquids. For example, as described with reference to FIG. 10 for the first embodiment, absorbent cores 90 (FIG. 10 (a)) and 90a (FIG. 10 (b)) can be used, each of which includes a concave portion 91 with a groove shape protruding from the absorbent portion 93 with a shape block, separated by a concave part, and a concave absorbing part 94, connecting that side of one surface of the protruding absorbing part 93, which corresponds to the concave part 91.

In the case where an absorbent core 90 or 90a is used, the concave portion 91 or the concave absorbent portion 94 is preferably overlapped by the spatial portion 72w of the concave portion in the concave portion 7 of the rear surface in the crotch area C including at least a portion facing excretory zone. Thus, the liquid located in the spatial portion 72w of the concave portion can be easily moved to the concave portion 91 or the concave absorbent portion 94, and its rapid diffusion can be ensured to ensure binding in a simple manner.

A method of forming a concave portion 7 of the rear surface, a convex portion 8 of the rear surface and the contact portion 63

An absorbent article having a concave portion 7 of the rear surface, a convex portion 8 of the rear surface, and a contact portion 63 similar to those shown in FIG. 26-2 can be obtained in a typical manufacturing process for such a product. For example, at the stage of connecting the absorbent body and the top sheet by lamination during the assembly of the diaper, the lamination-connected body is introduced into the zone between the press roll formed with concave and convex parts and the support shaft located opposite the press roll, so that the top sheet 1 is inserted in contact with the pressing shaft to ensure its partial compression.

However, squeezing and heating are performed to give a certain shape to the top sheet 1 and to form a contact portion 63, so that, unlike fastening and fixing the sheets during squeezing, the squeezing force is not large so as not to cause the formation of a film of fibers. In this case, the pressure during compression is preferably 0.2 MPa or more, more preferably 0.3 MPa or more. The pressure is preferably 0.8 MPa or less, more preferably 0.6 MPa or less. When excess heating is performed by compression, the heating temperature is preferably an indoor temperature or a higher temperature, more preferably 40 ° C or more. The heating temperature is preferably 100 ° C. or less, more preferably 80 ° C. or less.

Furthermore, in the case where the concave portion of the rear surface is formed by the press roll and a profiled sheet is used that previously had a concave-convex shape similar to that shown in FIG. 4, and a concave-convex shape similar to that shown in FIG. 29, the formation of a portion 63 in which the convex portion 8 of the rear surface is in contact with the underlayer 6 can be more reliable, and in this case, the part of the underlayer 6 in the contact portion 63 can preferably be depressed to form a concave shape and may have a high density.

The profiled sheet may be made by the method described for the first embodiment.

As the materials forming the top sheet 1, the sublayer 6, the back sheet 2, the absorbent body 3 and the side sheet 4, materials that are commonly used for the absorbent article can be used. In particular, materials can be used, examples of which are given in the description of the first embodiment.

In view of the fact that the sublayer 6 must fulfill the function of diffusion and transmission of liquid, as the sublayer 6, for example, non-woven material and a sheet with a high cellulose content are preferably used. Specific examples of non-woven material include non-woven material obtained by the aerodynamic method of forming the canvas (passing through the air), non-woven material obtained by hydro-entangling, non-woven material of spunbond production method and non-woven material obtained by the aerodynamic method from melt. When these nonwoven materials are formed from hydrophobic fibers, they are preferably subjected to a hydrophilicity treatment by a hydrophilicity preparation. The surface density of the sublayer 5 is preferably 20 g / m ² or more, more preferably 30 g / m ² or more. The surface density is preferably 100 g / m ² or less, more preferably 80 g / m ² or less.

The absorbent article of the present invention can provide excellent functioning and effect in which the absorption capacity of a conventional absorbent article can be further enhanced and, to a greater extent, prevention of backflow of liquid and prevention of moisture in the article can be provided, and the amount of that liquid can be further reduced. which remains on the side of the surface facing the skin, and the presence of which may be due to the condition in use and the allocated amount ohm, so that the load on the wearer's skin can be further reduced.

In the absorbent article of the present invention, the absorbent body is not limited to this embodiment, provided that it has the function of absorbing, retaining, and binding liquid therein and may be, for example, an absorbent body such as a thin sheet. In the absorbent article of the present invention, the sublayer is not limited to this embodiment, provided that it has the function of covering at least one side of the surface of the absorbent body in contact with the skin to move the fluid into the absorbent body, and may be a plurality of layers without being limited by the presence of one layer.

The absorbent article of the present invention is not limited to a disposable type diaper according to this embodiment, and encompasses an article having a certain relationship between the top sheet, the underlayer and the absorbent body. The absorbent article of the present invention can be, for example, a panty-type disposable diaper, a panty-type diaper that can be used as a diaper fastened by a tape by tearing a portion of a panty-type disposable diaper, a pad used for urinary incontinence, a sanitary napkin, panty liner for everyday use and mild incontinence pad. In addition, the absorbent article of the present invention is effective not only for menstrual blood, but also for urine, vaginal discharge and loose stool. The absorbent article of the present invention may include the inclusion of another component in the absorbent article of the third embodiment, if necessary, in accordance with the application and functionality.

In connection with the aforementioned embodiments, the absorbent articles mentioned below are further disclosed in the present invention.

<1> An absorbent article that has a liquid-permeable top sheet located on the side of the surface in contact with the skin, a back sheet located on the side of the surface not in contact with the skin, and an absorbent body located between both sheets, the top sheet being formed of nonwoven material, the absorbent body has an absorbent core and a covering sheet covering the absorbent core; in which a plurality of concave portions of the back surface, recessed towards the side of the skin contacting surface, are arranged in a certain order next to each other and dispersively on the side of the surface of the non-skin contacting top sheet, and the cover sheet extends into the concave portions the back surface, while retaining the spatial portions (space portions) that exist between passing inward, the covering sheet and the absorbent core.

<2> An absorbent article according to <1>, in which the side of the surface of the upper sheet not in contact with the skin has a concave-convex shape due to the placement of concave portions of the back surface in a certain order at periodic intervals.

<3> An absorbent article according to <1> or <2>, wherein the side of the skin contacting surface of the top sheet has a concave-convex shape.

<4> An absorbent article according to any one of <1> to <3>, wherein the side of the skin-contacting surface of the absorbent core is flat.

<5> An absorbent article according to any one of <1> to <4>, wherein the depth of the inwardly extending portion in which the portion of the covering sheet extends into the concave portion of the rear surface is less than the depth of the recess of the concave portion 7 of the rear surface.

<6> An absorbent article according to any one of <1> to <5>, wherein the depth of passage of the cover sheet inside the concave portion of the back surface in the top sheet is 50% or more of the depth of the recess of the concave portion of the back surface.

<7> An absorbent article according to any one of <1> to <6>, wherein the percentage of concave portions of the back surface, in which the depth of passage of the cover sheet inwardly in the concave portion of the back surface in the top sheet, is 50% or more of the depth of the recess the concave portion of the rear surface is preferably 50% or more, more preferably 70% or more of the total number of concave portions of the rear surface.

<8> An absorbent article according to any one of <1> to <7>, wherein in the concave portion of the back surface there is a portion representing a gap between the top sheet and the inside portion of the cover sheet.

<9> An absorbent article according to any one of <1> to <8>, wherein in the concave portion of the rear surface there is a portion in which the cover sheet and the top sheet are connected.

<10> An absorbent article according to any one of <1> to <9>, wherein the concave portion of the back surface is a recess in a non-skin surface of the top sheet and is formed by portions representing side walls extending from the top to the bottom and formed along the recess in the top sheet.

<11> An absorbent article according to <10>, in which the concave portion of the rear surface has a shape in which the cross-sectional shape of the concave portion 7 of the rear surface formed by the side wall portions is similar to a parabola, and in which the space shape of the concave portion of the rear surface together with a rounded top has a shape similar to a round cone or a round truncated cone.

<12> An absorbent article according to <10> or <11>, in which a connected part is formed, in which the parts in the concave portion of the rear surface, which are the side walls, and the inward part are brought into contact with each other and connected.

<13> An absorbent article according to <12>, wherein the joined part is a part providing a point-wise connection of the fiber of the coating sheet and the fiber of the top sheet by spray coating of the adhesive.

<14> An absorbent article according to any one of <1> to <13>, wherein the plurality of concave portions of the rear surface and the plurality of convex portions of the rear surface are arranged in a specific order on the side of the surface of the upper sheet not in contact with the skin, with each convex portion of the rear surface surrounded by concave portions of the rear surface to ensure its independent placement, and the spaces of the concave portions of the rear surface are connected to each other.

<15> An absorbent article according to any one of <1> to <14>, wherein the concave portion of the back surface has an upper portion, a portion is a side wall, and a lower portion in the upper sheet, and there is a difference in density or density gradient of the nonwoven fibers material of the top sheet, in which the density increases from the top to the bottom.

<16> An absorbent article according to any one of <1> to <15>, wherein the absorbent core has a structure with a higher or lower density of fibers, and there is a part in which a part of the absorbent core having a low density and the spatial part overlap.

<17> An absorbent article according to any one of <1> to <16>, wherein the cover sheet and the absorbent core are intermittently connected by means of a hot-melt adhesive without adhesive.

<18> An absorbent article according to any one of <1> to <17>, wherein the fiber density in the cross section of the concave portion of the rear surface increases from the surface side facing the skin to the surface side not facing the skin.

<19> An absorbent article according to any one of <1> to <18>, wherein the absorbent article includes a multilayer end portion in which the top sheet and the back sheet are connected to each other directly or indirectly by lamination and fastened without placing the absorbent body between them outside the part of the absorbing body, end in the longitudinal direction, while the multilayer end part has many deformed as a whole sections in which facing each other, the surface of the upper sheet and the back sheet are deformed to to integrally to form a convex shape in a thickness direction, wherein the deformed portions are arranged in a specific order to the scattering in the multilayer end portion in a direction in the plane.

<20> An absorbent article according to <19>, wherein the facing surfaces of the top sheet and the back sheet in the multilayer end portion have a tortuous shape in the thickness direction due to deformation by means of a section deformed as a whole, in cross section in the longitudinal direction.

<21> An absorbent article according to <19> or <20>, in which concave portions of the back surface, recessed towards the side of the surface in contact with the skin, are arranged in a certain order next to each other and with scattering on the side of the surface not in contact with the skin the top sheet, while the back sheet extends into the concave portion of the back surface in the multilayer end portion to form a portion deformed as a unit.

<22> An absorbent article according to <21>, wherein the concave portion of the rear surface in the multilayer end portion is a recess of substantially conical shape.

<23> An absorbent article according to any one of <19> to <22>, wherein the top sheet is formed of a nonwoven material having a concave-convex shape on both surfaces.

<24> An absorbent article according to any one of <19> to <23>, wherein in the multilayer end portion, the elastic element is located in the width direction between the top sheet and the back sheet.

<25> An absorbent article according to any one of <19> to <24>, in which, in a multilayer end portion, a sheet formed from a nonwoven material is disposed between the top sheet and the back sheet.

<26> An absorbent article according to any one of <19> to <25>, wherein the depth of the passage inwardly of the upwardly extending portion, in which the portion of the backsheet extends into the concave portion of the rear surface, is less than the depth of the depression of the concave portion of the rear surface in the multilayer end portion.

<27> An absorbent article according to <26>, wherein the depth of passage into the concave portion of the rear surface in the multilayer end portion is 0.4 mm or more and 4 mm or less.

<28> An absorbent article according to any one of <1> to <27>, wherein the side of the non-skin surface of the top sheet has a concave-convex shape in which the convex portions of the back surface are punctate, with the liquid-permeable sublayer located between the upper the sheet and the absorbing body, while the sublayer and the convex portion of the rear surface in the upper sheet are brought into contact with each other in the contact part, while the density of the fibers of the sublayer in the contact part is higher than the density of the fibers of the sublayer in the other part.

<29> An absorbent article according to <28>, wherein the peripheral portion of the concave portion of the back surface on the non-skin-side surface of the top sheet forms a concave portion of the back surface, recessed from the side of the non-skin surface to the side of the skin contact wherein the spatial portion of the concave portion is formed between the concave portion of the rear surface and the underlayer, and the fiber density of the sublayer at the location of the spatial portion of the concave portion is less than n fibers of the sublayer brought into contact with a concave portion of the back surface.

<30> An absorbent article according to <28> or <29>, wherein the contact portion of the convex portion of the rear surface in the top sheet and the sublayer has a fiber structure in which a gap between the fibers of both components is maintained.

<31> An absorbent article according to any one of <28> to <30>, wherein the contact parts of the convex portions of the rear surface in the upper sheet and the sublayer have a part that is bonded and a part that is not bonded.

<32> An absorbent article according to any one of <28> to <31>, wherein in the contact portion of the convex portion of the rear surface in the upper sheet and the sublayer, the sublayer forms a concave portion deepened to the side of the non-skin surface and the convex portion of the rear surface in the top sheet passes into the concave portion in the sublayer and is brought into contact with the concave portion in the sublayer.

<33> An absorbent article according to any one of <28> to <32>, wherein the ratio of the area of the contact portion of the sublayer to the convex portion of the back surface and the area of the sheet of the sublayer is 1/20 or more and 2/5 or less.

<34> An absorbent article according to any one of <28> to <33>, wherein the density of the fibers of the sublayer in the portion in contact with the convex portion of the rear surface in the top sheet is 15 fibers per 1 mm ² or more and 120 fibers per 1 mm ² or less.

<35> An absorbent article according to any one of <28> to <34>, wherein the sublayer is formed of a nonwoven material obtained by the aerodynamic method of forming a canvas (passing air through).

<36> An absorbent article according to any one of <28> to <35>, wherein in the sublayer, the thickness of the dense part with a high fiber density in the contact part is 30% or more and 90% or less of the thickness of the dense part with a low fiber density in the contact parts.

<37> An absorbent article according to any one of <28> to <36>, in which there is a difference in density or a density gradient in which the density of the fibers of the nonwoven fabric of the top sheet in the concave portion of the back surface increases from the top to the bottom.

<38> An absorbent article according to any one of <1> to <37>, wherein the top sheet is made of a hydrophilic nonwoven material.

<39> An absorbent article according to any one of <1> to <38>, wherein the back sheet is made of a porous film having water resistance, moisture permeability, and breathability.

<40> An absorbent article according to any one of <1> to <39>, wherein the absorbent core is formed from cellulosic fibers and an ultra-high absorbency polymer.

<41> An absorbent article according to any one of <1> to <40>, wherein the cover sheet is made of hydrophilic tissue paper.

<42> An absorbent article according to any one of <1> to <41>, which is a disposable type diaper.

<43> An absorbent article according to any one of <1> to <41>, which is a panty type disposable diaper.

<44> An absorbent article according to any one of <1> to <41>, which is a diaper that can be used in the form of a diaper fastened by tape by tearing a portion of a disposable diaper such as a panty.

EXAMPLES

The present invention will be described in more detail based on the examples below, but it is contemplated that the invention is not limited to them.

For the first embodiment, the following examples 1 and 2 and comparative examples 1 and 2 were shown.

Example 1

A canvas formed from two-component fibers, such as fibers with a core and a sheath, having a core of polyethylene terephthalate and a sheath of polyethylene, was fixed in a device designed to give a specific shape to the canvas, this canvas was given a certain shape along the protrusions on the base of the device by blowing a jet of hot air and then the fibers were fused together to form a profiled sheet having the shape shown in FIG. 4, in which the upper and rear surfaces had a concave-convex configuration (with a step (w ₁ ) between the upper parts 7a and 7a of the concave portions of the rear surface of 5 mm and the depth (h ₁ ) of the concave portion of the rear surface of 2 mm) so that the resulting profiled sheet was used as the top sheet. A liquid-impermeable back sheet, an absorbent body, in which an absorbent core (with a surface cellulose density of 200 g / m ² and a surface density of a polymer with a high absorbency of 286 g / m ² ) was coated with hydrophilic paper, and the top the sheet was joined by lamination in this order, so that they were fastened by means of hot-melt solvent-free adhesive. The shape and structure of the backsheet and the absorbent body were the same as those in the currently manufactured and marketed diaper Merries Sara Sara Air-through, size M (trade name) manufactured by Kao Corporation. In this case, the density (q ₁ ) of the adhesive coating between the top sheet and the coating sheet was 15 g / m ² , and the density (q ₂ ) of the coating of the hot-melt solvent-free adhesive between the coating sheet and the absorbent core was 5 g / m ² . The laminated sample was bonded under pressure equivalent to the pressure of the diaper seal to be stored at room temperature for one month, resulting in the formation of passable portions of the covering sheet.

The depth (h ₁ ) of the concave portions of the rear surface averaged 1.5 mm. The depth (h ₂ ) of the inward passage, determined for the inwardly extending parts, averaged 1.3 mm. The percentage of the number of concave portions of the rear surface, in which the ratio (h ₂ ) / (h ₁ ) was 50% or more, was 95% of the total number of concave portions of the rear surface. The percentage of the number of concave portions of the rear surface, in which the part extending inwardly completely (to the entire depth) (100%), was 60% of the total number of concave portions of the rear surface in which the ratio (h ₂ ) / (h ₁ ) was 50% or more.

Example 2

The laminated sample of example 1 was bonded under pressure equivalent to the pressure of the diaper seal to be stored at room temperature for three days, as a result of which the sample of example 2 was formed.

(1) The depth (h ₁ ) of the concave portions of the rear surface averaged 2.0 mm.

(2) The depth (h ₂ ) of the inward passage, determined for the inwardly extending parts, averaged 0.8 mm.

(3) The percentage of the number of concave portions of the rear surface, in which the ratio (h ₂ ) / (h ₁ ) was 50% or more, was 30% of the total number of concave portions of the rear surface.

(4) The percentage expressed as a percentage of the number of concave portions of the rear surface in which the part extending inwardly completely (to the full depth) (100%) was 5% of the total number of concave portions of the rear surface in which the ratio (h ₂ ) / ( h ₁ ) was 50% or more.

Comparative Example 1

A hand-made product with the same characteristics as a commercially manufactured and marketed disposable diaper manufactured by Kao Corporation (trade name “Merries Sara Sara Air-through, size M”), in which only the sublayer is not placed, was sample of comparative example 1.

Reference Example 2

The top sheet was made of a flat non-woven material obtained by the aerodynamic method of forming the canvas (passing air through), which was formed from two-component fibers such as fibers with a core and a shell having a core of polyethylene terephthalate and a shell of polyethylene, and, as in examples 1 and 2, a liquid impermeable back sheet, an absorbent body in which an absorbent core (with a surface cellulose density of 200 g / m ² and a surface density of a polymer with a high absorbance 286 g / m ² ) was coated with hydrophilic paper, and the top sheet was joined by lamination in this order, so that they were bonded by hot-melt adhesive. Only the base of the device for shaping the fibrous canvas was taken and brought into contact with the top sheet of the sample, placed on the top sheet of the sample and pressed to the top sheet of the sample, while the protrusions of the base were in contact with the top sheet, after which it was possible to withstand it for one months, as a result of which a concave-convex configuration was formed in which the upper sheet and the absorbing body were combined into a single whole, as a result of which a relatively in Example 2.

Performance Assessment

For each sample (disposable diaper), the diffusion areas of the liquid in the corresponding layers of the upper sheet, the covering sheet and the absorbent core were measured using examples and comparative examples. The following two tests (1) and (2) were carried out for measurements. The liquid diffusion in the absorbing core was determined by the diffusion zone of the red artificial urine through which the light emitted from the projector placed under each sample passed.

Test 1

For each sample according to examples 1 and 2 and comparative examples 1 and 2, 40 g of artificial urine was injected at a speed of 5 g / s by using a pump at the injection site, which was the center of the absorbing body in the width direction, located at a distance of 155 mm from the end part of the absorbent body of the sample from the side of the abdomen, measured in the direction to that part of the rear side, which is end in the longitudinal direction, when the sample is deployed in a plane. The composition of artificial urine included 1.94 weight percent of urea, 0.795 weight percent of sodium chloride, 0.11 weight percent of magnesium sulfate, 0.062 weight percent of calcium chloride, 0.197 weight percent of potassium sulfate, 0.010 weight percent of red (dye) No. 2, 96.88 weight percent water and polyoxyethylene ether of lauryl alcohol (approximately 0.07%), and the surface tension was 53 ± 1 dyne / cm (23 ° C). It was possible to hold the sample with artificial urine for 10 minutes, and then a photograph was taken after the top sheet was separated, resulting in an image of its diffusion area on the film sheet for an overhead projector (OHP). Similarly, the cover sheet in the upper part of the absorbent body after the separation of the upper sheet was photographed to obtain an image of the diffusion zone of artificial urine on a sheet of film for an overhead projector. The sample was placed on the projector, and then an image of the diffusion zone of artificial urine was obtained on a film sheet for the projector of the upper location when light was emitted and transmitted from the side of the back sheet. The image on a film sheet for an overhead projector was captured by a scanner to calculate the diffusion area by using Image-Pro Plus image analysis software (manufactured by Nippon Roper K. K.).

Test 2

For each sample in Example 1 and Comparative Example 1, 40 g of artificial urine was injected at a speed of 5 g / s by using a pump at the injection site, which was the center of the absorbent body in the width direction, located at a distance of 155 mm from the end of the absorbent the body of the sample from the side of the abdomen, measured in the direction to that part of the rear side that is terminal in the longitudinal direction, when the sample is deployed in a plane. It was possible to soak a sample with 40 g of artificial urine for 10 minutes to photograph it from above, and an additional 40 g of artificial urine was injected from the same injection site at a speed of 5 g / s. In addition, it was possible to soak the sample with artificial urine for 10 minutes to analyze the diffusion area similar to test 1. In test 2, it is impossible to analyze the diffusion area of the injected 40 g of artificial urine. In test 2, it was confirmed that when using the photographic image obtained before the second injection of artificial urine, it could be seen that the diffusion state of the artificial urine on the top sheet due to the first injection of artificial urine was the same as in the sample from test 1.

The evaluation results were shown in Tables 1 and 2. The characteristics of the liquid diffusion in the samples used in the tests for evaluating the liquid diffusion were shown in FIG. 11 and 12. In table 1 and in FIG. 11 shows the measurement results for the above test 1, and in table 2 and in FIG. 12 shows the measurement results for the above test 2. For the values given for injected 40 g of artificial urine in table 2 and in FIG. 12, the values for Example 1 and Comparative Example 1 in Test 1 are also shown for comparison. In FIG. 11 and 12, each liquid diffusion zone on the top sheet is shown as a part in which a black circle is provided in the photographic image replacing the drawing, and each liquid diffusion zone in the cover sheet and the absorbent core is shown as a part surrounded by a black line. Changes in the area of liquid diffusion between the layers in the samples shown in FIG. 11 and 12, and the differences in area between examples 1 and 2 and comparative examples 1 and 2 correspond to the measurement results shown in tables 1 and 2.

Table 1 Diffusion area
(unit: cm ² ) Etc. one Etc. 2 Wed pr. 1 Wed pr. 2 Top sheet 26.02 35,99 59.05 64.60 Covering sheet
(The upper layer of the absorbing body) 72.10 71.42 71.67 88.06 Absorbent core 120.89 121.83 124.80 130.01 "Ex" means an example in accordance with this invention.
"Wed etc. "means a comparative example

table 2 Diffusion area
(unit: cm ² ) Etc. one Wed pr. 1 Injection
40 g Injection
80 g Injection
40 g Injection
80 g Top sheet 26.02 24.16 59.05 108.35 Covering sheet
(The upper layer of the absorbing body) 72.10 134.84 71.67 130.04 Absorbent core 120.89 162.72 124.80 160.88 "Ex" means an example in accordance with this invention
"Wed etc. "means a comparative example

As is apparent from the results shown in table 1 and in FIG. 11, the disposable diapers of Examples 1 and 2 prevented liquid diffusion on the top sheet compared to comparative example 1, and, on the other hand, in the inner structural part of the cover sheet and the absorbent core under the top sheet, liquid diffusion was sufficient like the comparative examples. As is apparent from the results shown in table 2 and in FIG. 12, in the disposable diaper of Example 1, the area / zone of liquid diffusion on the top sheet was essentially the same area / zone in the case of two injections of liquid in test 2 and in the case of only one injection of liquid in test 1. In the disposable diaper The use of Example 1 provided sufficient liquid diffusion corresponding to the amount of liquid accumulating in the absorbent body, regardless of the prevention of liquid diffusion in the top sheet. In contrast, in the comparative example, the area of liquid diffusion in the top sheet after two injections of liquid in test 2 was approximately two times greater than the area of liquid diffusion in the top sheet after only one injection of liquid in test 1.

Based on the foregoing, regardless of the amount of liquid, such as during repeated release, each disposable diaper according to the examples provided prevention of liquid diffusion on the top sheet, rapid absorption and diffusion of liquid in the absorbent body, and effective absorption and retention of liquid. Thereby, excellent exposure and effect have been demonstrated in which wetting of the skin can be prevented to ensure good wearing comfort.

For the second embodiment, the following example 21 and comparative examples 21-23 were shown.

Example 21

A canvas formed from two-component fibers, such as fibers with a core and a sheath, having a core of polyethylene terephthalate and a sheath of polyethylene, was fixed in a device designed to give a specific shape to the canvas, this canvas was given a certain shape along the protrusions on the base of the device by blowing a jet of hot air and then the fibers were fused together to form a profiled sheet having the shape shown in FIG. 4, in which the upper and rear surfaces had a concave-convex configuration (with a step (w ₁ ) between the upper parts 7a and 7a of the concave portions 7w of the rear surface located in the end parts, which was 5 mm, and the depth (h ₁ ) of the concave portion 7w of the rear surface located at the end portion, which was 1.3 mm), so that the resulting profiled sheet was used as the top sheet.

The top sheet of the Merries Sara Sara Air-through, size M diaper (trade name) manufactured by Kao Corporation has been replaced by the top sheet obtained from the above operation and to be attached. Parts located near the end parts in which the absorbent body was not located in the diaper area located on the back side and in the diaper area located on the abdomen side had a multilayer structure formed by the top sheet, back sheet and non-woven material of the outer layer. The multilayer end portions shown in FIG. 14 and 15, each of which was deformed as a single section on the side facing the skin, and deformed as a single section on the side not facing the skin, formed by movement and compression between the press shaft and the support shaft of the parts located near the end parts in the diaper area located on the back side and in the diaper area located on the abdomen, in which the absorbent body was not placed, as a result of which the test element 1A was formed according to example 21.

In each multilayer end portion, the depth (h ₁ ) of the concave portions 7w of the rear surface located in the end portion of the upper sheet was on average 1.0 mm. The depth (h ₄ ) of the inward passage, determined for the upwardly extending portions of the back sheet, averaged 0.8 mm. The percentage of the number of concave portions 7w of the rear surface located in the end portion, in which the ratio (h ₄ ) / (h ₁ ) was 50% or more, was 90% of the total number of concave portions 7w of the rear surface located in the end portion . The percentage of the number of concave portions 7w of the rear surface located in the end part, in which the part extending inwardly completely (all the way) (100%), was 50% of the number of concave portions 7w of the rear surface located in the end part, in which ratio (h ₄ ) / (h ₁ ) was 50% or more.

The area located on the rear side of the diaper element 1A to be tested was cut out at a distance of 40 mm from the side of the diaper portion endwise in the longitudinal direction and at a distance of 70 mm in the width direction, so that this cut out part was the element 1B intended for testing as described in Example 21. Regardless of the element 1B to be tested, the area located on the rear side of the diaper element 1A to be tested was cut at a distance of 45 mm from the side of the diaper part nick, end in the longitudinal direction, and at a distance of 130 mm in the width direction, so that the cut out part was the test element 1C as described in Example 21. The cross-sectional shapes of the test elements 1B and 1C had a concave-convex configuration similar to the model shown in FIG. 23 (a).

Reference Example 21

In the test element 1A of Example 21, the back sheet was left flat without the formation of all areas deformed as a whole on the side facing the skin and all areas deformed as a whole on the side not facing the skin by pressing to obtain the intended for testing the diaper element. In each multilayer end portion, the depth (h ₁ ) of the concave portions 7w of the rear surface located in the end portion of the upper sheet was on average 1.0 mm. The depth (h ₄ ) of the passage inward, determined for the upwardly extending portions of the back sheet, averaged 0 mm. This was the test piece 11A of comparative example 21. The area located on the rear side of the test piece 11A was cut out at a distance of 40 mm from the side of the diaper portion, end in the longitudinal direction, and at a distance of 70 mm in the width direction, so that the cut-out part was the test piece 11B of comparative example 21. Regardless of the test piece 11B, the area on the back of the test piece element 11A, was cut at a distance of 45 mm from the side of the diaper portion, the end in the longitudinal direction, and at a distance of 130 mm in the width direction, so that the cut out part was intended for testing element 11C in comparative example 21. The shape of the sections intended for testing Elements 11B and 11C had a concave-convex configuration similar to the model shown in FIG. 23 (b).

Reference Example 22

A hand-made product that was made by partially modifying the industrially manufactured and marketed disposable diaper (trade name “Merries Sara Sara Air-through, size M”) manufactured by Kao Corporation and by attaching the top sheet and back sheet directly to each other to a friend without placing an elastic element and a barrier non-woven material located outside the parts of the absorbing body, end in the longitudinal direction, in the area located from the back s hand, which were incorporated into industrially manufactured product intended to constitute a test element 12A of Comparative Example 22. In each end portion of the multilayer depth (h ₁₎ of the concave portions 7w rear surface disposed at the end portion in the upper layer of a dual layer topsheet averaged 0.4 mm. The depth (h ₄ ) of the passage inward, determined for the upwardly extending portions of the back sheet, averaged 0 mm. The area located on the rear side of the test piece 12A was cut out at a distance of 40 mm from the side of the diaper portion endwise in the longitudinal direction and at a distance of 70 mm in the width direction, so that this cut out part was a test piece 12B in comparative example 22. Regardless of the test element 12B, the area located on the rear side of the test element 12A was cut out at a distance of 45 mm from the side of the diaper portion, end in the longitudinal direction, and at a distance of 130 mm in the width direction, so that the cut out part was a test element 12C according to comparative example 22. The cross-sectional shapes of the test elements 12B and 12C had a concave-convex configuration similar to the model shown in FIG. . 23 (s).

The top sheet of this test item had a two-layer structure including a top layer having a concave-convex shape and a flat bottom layer, with the upper layer 11 and the lower layer 12 shown in a schematic representation of the model in FIG. 23 (s).

Reference Example 23

A diaper element for testing was obtained in which the top sheet of the test element 11A of comparative example 21 was replaced with a flat one without any concave-convex parts. This was the test element 13A of comparative example 23. The rear surface of the top sheet in each multilayer end portion did not have concave portions, so that the depth (h ₁ ) of each concave portion and the depth (h ₄ ) of the passage inward determined for each protruding up area of the back sheet was 0 mm. The area located on the rear side of the test piece 13A was cut out at a distance of 40 mm from the side of the diaper portion endwise in the longitudinal direction and at a distance of 70 mm in the width direction, so that this cut out part was a test piece 13B in comparative example 23. Regardless of the test element 13B, the area located on the rear side of the test element 13A was cut out at a distance of 45 mm from the side of the diaper portion, end in the longitudinal direction, and at a distance of 130 mm in the width direction, so that the cut out part was a test element 13C according to comparative example 23. The cross-sectional shapes of the test elements 13B and 13C had a configuration similar to the model shown in FIG. 23 (d).

Rating

The fluid flow property and the ability to stretch and pull together the prepared test items of disposable diapers were evaluated using the method below. The results are shown in table 3.

Test Method for Estimating Fluid Flow

An acrylic plate was used, which made it possible to tilt at a given angle. The test items 1B and 11B-13B were placed and fixed on a horizontal acrylic plate so that the top sheet was facing up. 500 μl of red artificial urine was introduced into each of the test elements 1B and 11B-13B placed on a horizontal acrylic plate, while the injection was carried out by smoothly dripping at a speed of 100 μl / s into an area 30 mm from the part corresponding to the end portion of the uncut diaper in the region located on the rear side in the longitudinal direction (end portion 20a of the diaper 20 in FIG. 13). Then it was provided with the possibility of holding samples with artificial urine for one minute to measure the extent of the diffusion zone at the moment, while the contour of the diffusion zone of the liquid was projected onto a sheet of transparent film for an overhead projector. The extent of the diffusion distance was the distance that the fluid traveled from the dripping point to the end portion (inclined side).

It was possible to hold the acrylic plate, inclined at an angle of 30 °, for three minutes, so that the part corresponding to the end part (end part 20a of diaper 20 in Fig. 13) in the area located on the rear side was facing down. The extent of the diffusion zone has now been measured again to obtain an image of the outline of the liquid diffusion zone on a sheet of transparent film for an overhead projector. The image on a film sheet for an overhead projector was captured by a scanner to calculate the diffusion area by using Image-Pro Plus image analysis software (manufactured by Nippon Roper K. K.).

The difference in the lengths of the diffusion zones between the length after dripping and the length after tilting was the spreading length, and the difference in diffusion areas between the area after dripping and the area after tilting was the spreading area.

The measurement was performed six times, and the average value of the measurement results was then shown in table 3 as the result of the evaluation obtained in the tests for estimating fluid flow. The state of liquid spreading in each test item after dripping and after tilting was shown in each photograph replacing the drawing, in FIG. 24. FIG. 24 shows each test item whose image is shown from the side of the top sheet. The liquid spreading zone is a zone with a color having a low brightness, such as black or gray, with respect to the white top sheet.

The diffusion area and the extent of the diffusion zone are determined for the diffusion zone of red artificial urine when light is emitted and radiation is transmitted from a projector located under each sample. The extent of the diffusion zone is the distance over which the artificial urine has spread from the central drip point to the end portion corresponding to the end portion 20a in the area located on the rear side. The composition of the artificial urine used included 1.94 weight percent urea, 0.795 weight percent sodium chloride, 0.11 weight percent magnesium sulfate, 0.062 weight percent calcium chloride, 0.197 weight percent potassium sulfate, 0.010 weight percent red (dye) No. 2, 96, 88 weight percent water and polyoxyethylene ether of lauryl alcohol with a mole of added EO of 41 (approximately 0.07%) and a surface tension of 53 ± 1 dyn / cm (23 ° C.).

Method for assessing the ability to stretch and contract

For each of the 1C and 11C-13C test pieces to be tested, the end parts in the direction corresponding to the width direction (X direction) of the uncut diaper were fastened to the clamping devices located on both ends of the Autograph series testing machine (manufactured by Shimadzu Corporation; trade name AG-X 1KN), so that the distance between the clamping devices was 70 mm. The operation of stretching each test item to a load of 6 N at a speed of 300 mm / min to return it to its original state was repeated for five cycles. The tensile value corresponding to a load of 1, 2, 3 or 4 N was measured during each operation from stretching (during stretching under the influence of loading) and returning to the initial state (during tightening when unloading) in the first cycle, and then the difference between the length when stretching and the length when returning to the initial state was recorded as "the difference corresponding to a change in values between stretching and returning to the initial state in the first cycle." In a similar manner, the tensile strength during stretching was measured in each of the first and fifth cycles corresponding to each load, and then the difference between both cycles was recorded as “the difference corresponding to the change in tensile strengths between the first and fifth cycles”. A small “change in magnitude during stretching and returning to the starting position in the first cycle” characterizes a good ability to recover with less deformation in the multilayer end parts of the diaper during stretching and pulling. Therefore, when the diaper is worn when it is stretched around the waist, a good fit can be achieved with less slackness. A small “change in magnitude when stretching between the first and fifth cycles” indicates a good ability to stretch and pull even with repeated stretching and pulling. Therefore, when worn, the diaper will repeat the changes in the area around the waist part due to the movement of the wearer, which ensures a good fit.

Table 4 shows the results of the assessment "the difference corresponding to the change in values between stretching and returning to the initial state in the first cycle". Table 5 shows the results of the assessment of "the difference corresponding to the change in values during stretching between the first and fifth cycles."

Table 3 Etc. 21 Wed pr 21 Wed pr 22 Wed pr 23 Test item 1B 11B 12V 13B Reference figure 23 (a) 23 (b) 23 (s) 23 (d) (The length of the diffusion zone: mm) After dripping 16 16.33 thirty 25.33 After tilting 22.67 thirty thirty thirty Spreading length 6.67 13.67 - 4.67 (Diffusion area: cm ² ) Spreading area 0.34 1.68 1,11 1.97 "Ex" means an example in accordance with this invention
"Wed etc. "means a comparative example

Table 4
(The difference corresponding to the change in values between stretching and resetting in the first cycle) Etc. 21 S Ave. 21 Wed pr 22 Wed pr 23 Test item 1C 11C 12C 13C Reference figure 23 (a) 23 (b) 23 (s) 23 (d)

1 N 2.09 2.08 2.27 3.29 2 N 1.84 1.88 2.09 3.19 3 N 1.46 1.45 1.72 2,4 4 N 1.12 1.09 1.27 1.42 "Ex." Means an example in accordance with this invention.
"Wed etc. "means a comparative example

Table 5
(The difference corresponding to the change in values during stretching between the first and fifth cycles) Etc. 21 Wed pr 21 Wed pr 22 Wed pr 23 Test item 1C 11C 12C 13C Reference figure 23 (a) 23 (b) 23 (s) 23 (d) 1 N 1,53 1,50 1.74 2,3 2 N 1.48 1.42 1.68 2.45 3 N 1.32 1.27 1,54 2.1 4 N 1.18 1,02 1.36 1.43 "Ex." Means an example in accordance with this invention
"Wed etc. "means a comparative example

As is evident from the test results for determining the extent of the diffusion zone shown in Table 3, after dripping (horizontal state without applying any external force), the lengths of the diffusion zones in the test elements of Example 21 and Comparative Example 21 were significantly less than the corresponding values for comparative examples 22 and 23, so that it was difficult to move the liquid. In comparative example 22, the liquid spread over a large area immediately after dripping and reached the end parts, thereby causing leakage. In comparative example 23, the liquid flowed almost to the end part immediately after dripping or reached the end part, which caused a leak. When an external force was applied after tilting in the test element of Example 21, the increase in the liquid diffusion zone was small compared to the zone after dripping (horizontal state without any external force), so that the liquid did not reach the end parts, thereby not causing no leakage. On the other hand, in comparative example 21, in which the diffusion was relatively small after dripping, and in comparative example 23, in which the liquid spread almost to the end part, the liquid reached the end part, thereby causing leakage.

As is evident from the test results for determining the diffusion area shown in Table 3, in the test element of Example 21, the flow resistance was large, so that there was no easy spreading of the liquid, and the liquid holding force was large. On the other hand, in comparative example 21, the fluid holding force was large in the horizontal state, but the flow resistance was small, so there was a possibility of increased diffusion due to deformation and tilt during application of external force. Since the back sheet was flat in comparative examples 22 and 23, the liquid diffusion resistance force was small, so that the liquid was diffused over a large area immediately after dripping.

These results were clearly shown by black or gray areas having low brightness and showing the spreading of liquid in photographs that replace the drawing, in FIG. 24. In the test element 1B of Example 21, both after dripping and after tilting, this zone was small and did not reach the end part. On the contrary, in comparative example 21, this zone was small after dripping, but after tilting, liquid diffused to the side of the end part, and in comparative example 22 this zone reached the side of the end part after dripping. In comparative example 23, this zone also reached almost to the end part. In particular, in comparative examples 22 and 23, these zones expanded widely after dripping.

As is evident from the results shown in tables 4 and 5, in the test element according to example 21 as "the difference corresponding to a change in values between stretching and resetting in the first cycle", and "the difference corresponding to a change in values when stretching between the first and fifth cycles "were small, while the same was characteristic of the test item in comparative example 21, in which a profiled canvas sheet was used. This indicates that in the test element of example 21 there were no obstacles to the ability to stretch and pull the profiled sheet from the canvas, the deformation in the sheet caused by stretching was small, and the ability to respond to stretching and pulling was good. Therefore, in a diaper having multilayer end parts corresponding to the structure of the element to be tested, the waist of the diaper easily “repeated” the change in the shape of the zone around the abdomen due to a change in posture and food intake by the wearer, relative to the state of fit during wear, so it was difficult the occurrence of any gaps.

For the third embodiment, the following example 31 and comparative examples 31-33 were shown.

Example 31

A canvas formed from two-component fibers, such as fibers with a core and a sheath, having a core of polyethylene terephthalate and a sheath of polyethylene, was fixed in a device designed to give a specific shape to the canvas, this canvas was given a certain shape along the protrusions on the base of the device by blowing a jet of hot air and then the fibers were fused together to form a profiled sheet having the shape shown in FIG. 4, in which the upper and rear surfaces had a concave-convex configuration (with a step (w ₁ ) between the upper parts 8a and 8a of the concave portions of the rear surface of 5 mm and the depth (h ₁ ) of the concave portion of the rear surface of 2 mm) so that the resulting profiled sheet was used as the top sheet.

A hydrophilic nonwoven material obtained by the aerodynamic method of forming the canvas and having a surface density of 40 g / m ² was used for the sublayer. A liquid impermeable back sheet, an absorbent body in which an absorbent core (with a surface cellulose density of 200 g / m ² and a surface density of a polymer with a high absorbency of 286 g / m ² ) was coated with hydrophilic paper, a sublayer and the top sheet was joined by lamination in this order, so that they were bonded by hot-melt solvent-free adhesive. The spiral pattern formed from hot-melt adhesive without adhesive was used to bond the underlayer and the top sheet, and in the contact part formed by the underlayer and the concave portion of the back surface of the top sheet, there were sections that were connected and parts that were not connected. The laminated specimen was bonded under a pressure equivalent to the same diaper seal pressure as in the case of the commercially manufactured and currently marketed Merries Sara Sara-Air-through, size M diaper (trade name) manufactured by Kao Corporation for storage at an indoor temperature for one month, as a result of which a concave-convex configuration and a fibrous structure of the sublayer with loose and dense parts were formed.

The ratio (m ₆₁ / m ₆₂ ) between the density (m ₆₁ ) of the fibers of the dense part and the density (m ₆₂ ) of the fibers of the dense part of the sublayer was 1.65.

Reference Example 31

The sample of comparative example 31 was a sample prepared in the same way as the multilayer sample of example 31, without bonding and storage. The sublayer of the sample did not have a concave-convex configuration and fibrous structure with loose and dense parts according to example 31 and remained flat.

Reference Example 32

The absorbent body and the top sheet of the multilayer sample according to example 31 were connected directly to each other without placing a sublayer between them, which was not bonded and not stored, as a result of which a sample was formed according to comparative example 32 (without a sublayer).

Reference Example 33

The industrially manufactured and marketed disposable diaper (trade name “Merries Sara Sara Air-through, size M”) manufactured by Kao Corporation was a sample of comparative example 33. The sample was a diaper made using a two-ply top sheet, in which the sheet on the surface side facing the skin was concave-convex in shape by heat sealing, and the sheet on the side of the surface not facing the skin was flat and the sublayer was placed m between them.

Performance Assessment

For each sample (disposable diaper), by the examples and comparative examples, the value of the liquid back flow and the absorption time, and the amount of liquid remaining in the top sheet, were measured for the case of divided injections under pressure. The two following tests (1) and (2) were performed to perform the measurements.

Test 1

In each sample according to example 31 and comparative examples 31-33, the injection site of the liquid was the center of the absorbing body in the width direction, located at a distance of 155 mm from the end part of the absorbing body of the sample from the abdomen, measured in the direction to that part of the back side, which is end in the longitudinal direction, when deploying the sample in the plane. An acrylic plate with a tubular part for injection was placed on the sample so that the place of injection of liquid into the sample was located in the center of the part of the acrylic plate intended for injection, and then the load was placed on the acrylic plate to apply a load of 2 kPa (20 kgf / cm ² ). The injection portion provided in the acrylic plate was formed with a tubular shape (53 mm high) with an inner diameter of 36 mm, and in addition, the acrylic plate was formed with a through hole having an inner diameter of 36 mm and providing the communication of the inner space of the tubular part intended for injection with the surface of the acrylic plate facing the top sheet, so that the central axis of the tubular part intended for injection coincides with the central axis of acrylic plates in the width direction at the portion corresponding to 1/3 of the length in the longitudinal direction.

A liquid column height of 10 mm from the portion intended for injection was maintained to inject 40 g of artificial urine. The time from the start of injection to the disappearance of artificial urine from the top sheet was the absorption time. The composition of artificial urine included 1.94 weight percent of urea, 0.795 weight percent of sodium chloride, 0.11 weight percent of magnesium sulfate, 0.062 weight percent of calcium chloride, 0.197 weight percent of potassium sulfate, 0.010 weight percent of red (dye) No. 2, 96.88 mass percent of water and polyoxyethylene ether of lauryl alcohol with the number of moles of added EO constituting 41 (approximately 0.07%), and the surface tension was 53 ± 1 dyne / cm (23 ° C).

Artificial urine was injected four times at intervals of 10 minutes to allow samples to soak for 10 minutes, and then the load and acrylic plate were removed to apply 16 layers of filter paper (ADVANTEC 5C 10 mm × 10 mm) to the sample to accommodate the load on them, after which a load of 3.4 kPa (35 kgf / cm ² ) was applied. Each sample was left in this state for two minutes, and then the mass of artificial urine that was absorbed by the filter paper was measured, so that the measured value was a value characterizing the return flow of the liquid.

Test 2

In each sample according to example 31 and comparative examples 31-33, the injection site of the liquid was the center of the absorbing body in the width direction, located at a distance of 155 mm from the end part of the absorbing body of the sample from the abdomen, measured in the direction to that part of the back side, which is end in the longitudinal direction, when deploying the sample in the plane.

The top sheet at the periphery (10 mm × 20 mm) of the injection site was previously incised to inject 80 g of artificial urine at a speed of 5 g / s by using a pump. It was possible to soak each sample for 10 minutes, and then the top sheet was smoothly separated to measure its mass. The artificial urine absorbed by the topsheet was absorbed by the Kimtowel product, and then the topsheet was left to dry for one night, whereby the value obtained by subtracting the mass after drying from the (measured) mass was a value characterizing the amount of remaining liquid.

Table 6 shows the results of the above assessment. FIG. 30 and 31 show the samples used in the test to determine the amount of remaining liquid. FIG. 30 shows the states of the tested top sheet of the test element of Example 1, and FIG. 31 shows the state of the tested top sheet of the test item in comparative example 31. FIG. 30 (a) and 31 (a) show the side of the skin contact surface of the top sheet, FIG. 30 (b) and 31 (b) show the side of the non-skin contact surface of the top sheet, and FIG. 30 (c) and 31 (c) are photographs replacing the drawings by partially enlarging the images in FIG. 30 (b) and 31 (b). In each photograph replacing the drawing, the black section shows the remaining liquid.

Table 6 Etc. 31 Wed pr 31 Wed pr 32 Wed pr 33 Return fluid flow after split injection 0.14 g 0.33 g 0.84 g 1.09 g Absorption time
(With the fourth injection) 38 s 65 s 92 s 33 s (The amount of injected liquid is 160 g, the time during which it is possible to soak is 10 minutes) The amount of fluid remaining in the top sheet 0.11 g 0.16 g 0.10 g 0.27 g (The amount of injected liquid is 80 g, the time during which it is possible to soak is 10 minutes) "Ex." Means an example in accordance with this invention
"Wed etc. "means a comparative example

As is evident from the results shown in table 6, in the diaper having a two-layer top sheet profiled by heat sealing (comparative example 33), the absorption rate was high, since the concave and convex portions on the side of the skin-facing surface of the top sheet did not “enter” into the sublayer was even under pressure, and the space was saved, but in the disposable diapers of Example 31 and Comparative Examples 31 and 32, the amount of liquid held in the form of liquid remaining in the upper material that and the amount of reverse fluid flow were less than in comparative example 33. This happened because in the disposable diapers of example 31 and comparative examples 31 and 32, each of which has a single-layer top sheet with a concave-convex shape, the thickness was reduced in particular, under pressure, and concave portions of the rear surface of the upper sheet “entered” into the absorbent body and the sublayer located under them.

In addition, when comparing the disposable diapers of Example 31 and Comparative Example 31 having a sublayer with the disposable diaper of Comparative Example 32 without a sublayer, it should be noted that the underlayer played a large role in preventing backflow of liquid, so the presence of a sublayer provided a significant reduction in the amount of returning liquid, in particular, with divided injections under pressure. In addition, the presence of a sublayer made the diaper bulky for temporary fluid retention, as a result of which the liquid was diffused in the plane direction, so that the absorption time was shorter than in the case of comparative example 32 without a sublayer.

In addition, in the disposable diaper of Example 31, when compared to comparative example 31, the amount of liquid backflow was further reduced and the absorption time was reduced to such an extent that it became the same as in the case of comparative example 33, thereby improving performing the original function of the sublayer. Furthermore, in comparison with comparative example 31, liquid stagnation can be prevented. This was discovered by analyzing a state in which black color showing the remaining liquid in FIG. 30 (Example 31) was as if lighter than in FIG. 31 (comparative example 31). With the result of preventing stagnation of the liquid in Example 1, it was possible to overcome the disadvantage (comparative example 31) that “the presence of a sublayer made the top sheet farther away from the absorbent body, as a result of which the water absorption force acting on the absorbing side of the body, it was unlikely that it could “reach” the upper sheet, and there was a significant probability that the amount of liquid remaining in the upper sheet would be large, ”and, therefore, it was possible reducing stagnation of the liquid to a level such as in comparative example 32 without a sublayer. That is, the disposable diaper that used the concave-convex sublayer of Example 1 was excellent because it provided both the benefits of having a sublayer and the benefits of not having a sublayer.

After the description of the invention in connection with the options for its implementation according to the authors of the invention, it should be indicated that the invention should not be limited to any of the details of the description, unless otherwise indicated, but should be considered in a broad sense within its essence and scope defined by the accompanying claims .

This application claims priority to patent application No. 2011-151210 filed in Japan on July 7, 2011, patent application No. 2011-258584 filed in Japan November 28, 2011, and patent application No. 2012-025123 filed in Japan on February 8. 2012, each of which is fully incorporated herein by reference.

DESCRIPTION OF SYMBOLS (reference numerals)

1 top sheet

2 back sheet

21 The upwardly protruding portion (the portion in which the backsheet 2 extends into the concave portion 7w of the rear surface located in the end portion of the topsheet 1)

3 Absorbing body

31 Absorbing core

32 and 33 Cover sheet

4 side sheet

5 Laminated end part

51 Deformed as a single unit

52 Deformed as a single area on the side facing the skin

53 Deformed as a single area on the side not facing the skin

6 sublayer

61 Dense part

62 Loose part

7 Concave back

7v Concave portion of the rear surface located above the absorbent body

7w Concave portion of the rear surface located in the end portion (concave portion of the rear surface of the upper sheet 1 located in the multilayer end portion 5)

71 Passing inward portion (portion in which the covering sheet 32 extends into the concave portion 7 of the rear surface of the upper sheet 1)

72 Space

72v The spatial part located in the absorbing body

72w The spatial portion of the concave portion (the spatial portion above the sublayer)

73 The buffer part, which is a gap

74 United part

8 Convex rear surface

8v A convex portion of the rear surface located above the absorbent body

8w Convex portion of the rear surface located in the end portion (convex portion of the rear surface of the upper sheet 1 located in the multilayer end portion 5)

78 Convex portion of the upper surface

88 Concave portion of the upper surface

10, 20 and 30 Disposable diaper

Claims (27)

1. An absorbent article that has a liquid-permeable top sheet located on the side in contact with the skin of the surface, a back sheet located on the side of the surface not in contact with the skin, and an absorbent body located between both sheets, the top sheet being formed of non-woven material, the absorbent body has an absorbent core and a covering sheet covering the absorbent core; wherein a plurality of concave portions of the back surface, recessed towards the side of the skin contacting surface, are arranged adjacent to each other and scattered on the side of the upper sheet not in contact with the skin, and the covering sheet extends into the concave portions of the back surface, while retaining spatial parts between the inwardly extending covering sheet and the absorbent core; wherein the absorbent product includes a multilayer end portion in which the top sheet and the back sheet are connected to each other directly or indirectly by lamination and fastened without placing the absorbent body between them outside the end part of the absorbent body in the longitudinal direction, while the multilayer end the part has a plurality of sections deformed as a whole, in which the facing surfaces of the top sheet and the back sheet are deformed as a whole with the formation of a convex shape s in the direction of thickness, while the deformed sections are scattered in the multilayer end part in the direction in the plane. 2. An absorbent product according to claim 1, in which the side not in contact with the skin of the surface of the upper sheet has a concave-convex shape due to the placement of concave portions of the rear surface at periodic intervals. 3. The absorbent product according to claim 1 or 2, in which the side in contact with the skin of the surface of the upper sheet has a concave-convex shape. 4. The absorbent product according to claim 1 or 2, in which the side in contact with the skin surface of the absorbent core has a flat shape. 5. The absorbent product according to claim 1 or 2, in which the depth of the passage covering the sheet inside the concave portion of the rear surface in the top sheet is 50% or more of the depth of the recess of the concave portion of the rear surface. 6. The absorbent product according to claim 1 or 2, in which in the concave portion of the rear surface there is a part representing a gap between the upper sheet and the part of the covering sheet extending inward. 7. The absorbent product according to claim 1 or 2, in which in the concave portion of the rear surface there is a part in which the covering sheet and the upper sheet are connected. 8. An absorbent article according to claim 1 or 2, wherein a plurality of concave portions of the rear surface and a plurality of convex portions of the rear surface are disposed on a side not in contact with the skin of the surface of the upper sheet, wherein each convex portion of the rear surface is surrounded by concave portions of the rear surface to provide its independent placement, and the space of concave portions of the rear surface are connected to each other. 9. The absorbent product according to claim 1 or 2, in which the concave portion of the rear surface has an upper part, a part representing a side wall and a lower part in the upper sheet, and there is a difference in the density or density gradient of the fibers of the nonwoven material of the upper sheet, wherein the density increases from the top to the bottom. 10. The absorbent article according to claim 1 or 2, in which the absorbent core has a structure with a higher or lower density of fibers, and there is a part in which a part of the absorbent core with a higher density and the spatial part overlap. 11. The absorbent product according to claim 1 or 2, in which the covering sheet and the absorbent core are intermittently connected by means of a hot-melt solvent-free adhesive. 12. The absorbent product according to claim 1 or 2, in which the density of the fibers in the cross section of the concave portion of the rear surface increases from the side of the surface facing the skin to the side of the surface not facing the skin. 13. The absorbent article of claim 1, wherein the facing surfaces of the top sheet and the back sheet in the multilayer end portion have a tortuous shape in the thickness direction due to deformation by means of a section deformed as a unit, in cross section in the longitudinal direction. 14. The absorbent product according to claim 1, in which the concave portions of the back surface, recessed towards the side of the surface in contact with the skin, are located next to each other and with scattering on the side that is not in contact with the skin of the surface of the top sheet, the back sheet passes into the concave portion of the rear surface in the multilayer end portion to form a portion deformed as a unit. 15. The absorbent article of claim 14, wherein the concave portion of the rear surface in the multilayer end portion is a recess of substantially conical shape. 16. The absorbent article of claim 1, wherein the top sheet is formed of a nonwoven material having a concave-convex shape on both surfaces. 17. The absorbent product according to claim 1, wherein in the multilayer end portion, the elastic element is located in the width direction between the top sheet and the back sheet. 18. An absorbent article according to claim 1, wherein in the multilayer end portion, a sheet formed from a nonwoven material is located between the top sheet and the back sheet. 19. An absorbent product according to claim 1 or 2, in which the side not in contact with the skin of the surface of the upper sheet has a concave-convex shape, in which the convex portions of the rear surface are dotted, while the liquid-permeable sublayer is located between the upper sheet and the absorbent body, the sublayer and the convex portion of the rear surface in the upper sheet are in contact with each other in the contact part, while the density of the fibers of the sublayer in the contact part is higher than the density of the fibers of the sublayer in the other part. 20. The absorbent product according to claim 19, in which the peripheral part of the concave portion of the rear surface on the side that is not in contact with the skin of the surface of the upper sheet, forms a concave portion of the rear surface, recessed from the side of the surface not in contact with the skin, to the side of the surface in contact with skin, while the spatial part of the concave portion is formed between the concave portion of the back surface and the underlayer, and the fiber density of the sublayer at the location of the spatial part of the concave portion is less than STI fiber sublayer contacting the rear surface of the concave portion. 21. The absorbent article of claim 19, wherein the contact portion of the convex portion of the rear surface in the top sheet and the sublayer has a fiber structure in which a gap between the fibers of both components is maintained. 22. The absorbent product according to claim 19, in which the contact parts of the convex portions of the rear surface in the upper sheet and the sublayer have a part that is bonded and a part that is not bonded. 23. The absorbent article of claim 19, wherein in the contact portion of the convex portion of the rear surface in the upper sheet and the sublayer, the sublayer forms a concave portion deepened to the side of the non-skin surface and the convex portion of the rear surface in the upper sheet extends into the concave portion in the sublayer and in contact with the concave portion in the sublayer. 24. The absorbent product according to claim 19, in which the ratio of the area of the zone of the contact part of the sublayer and the convex portion of the back surface relative to the area of the sheet of the sublayer is 1/20 or more and 2/5 or less. 25. An absorbent product according to claim 19, in which the density of the fibers of the sublayer in the part in contact with the convex portion of the rear surface in the top sheet is 15 fibers per 1 mm ² or more and 120 fibers per 1 mm ² or less.

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