RU2568863C2 - Absorbent article - Google Patents

Abstract

FIELD: personal use articles.

SUBSTANCE: absorbent article long in the longitudinal direction, comprising a fluid-permeable upper sheet located on the surface side in contact with the skin, a lower sheet located on the surface side not in contact with the skin, and an absorbent element located between the two sheets, at that the absorbent element has a longitudinal direction and a width direction that are perpendicular to each other; the absorbent element has structures which provide the passage of fluids and which are arranged respectively in the longitudinal direction and in the width direction of the absorbent element in the zone facing the emission area, and each of which is formed by concave portions having the shape of grooves and sunken from the surface side not in contact with the skin in the thickness direction, and the concave absorbent portions containing cellulosic fibres, located at the surface side in contact with the skin, the lower parts of the concave portions, and the absorbent element has projecting absorbent parts having shape of blocks which protrude toward the surface side not in contact with the skin, comprise cellulose fibres and have a higher basis weight compared to the basis weight of the concave absorbent parts, in the areas surrounded by structures providing the passage of fluids, and the concave absorbent parts of the structures providing the passage of fluids, have low density, and the protruding absorbent parts having shape of blocks have high density relative to the concave absorbent parts.

EFFECT: increase in reliability of absorption.

7 cl, 13 dwg, 1 tbl

Description

FIELD OF TECHNOLOGY

The present invention relates to an absorbent article, such as a sanitary napkin, disposable diaper or incontinence panties.

BACKGROUND

For absorbent products, such as sanitary napkins, attempts have been made to improve performance and wearing comfort by improving the materials and structures of the individual components. Also, suggestions were made regarding the functional improvement of absorbent elements, taking into account the mode of use and the type of product.

For example, a gasket has been proposed having a top sheet, a bottom sheet and an absorbent member, in which the absorbent member is formed with a plurality of point compressed parts that are depressed relative to the rear side of the absorbent member (see Patent Literature 1). Compressed parts and uncompressed parts that are not compressed form a continuous roughness due to a gradual change in thickness, resulting in a density gradient that increases from uncompressed parts to compressed parts. Due to this, the fluid, which is directed from the top sheet into the absorbent element, is quickly absorbed, so that the prevention of backflow of the fluid and the prevention of leaks can be enhanced while ensuring sufficient retention of the absorbed fluid. In addition, an absorbent article having an absorbent member comprising high density portions and low density portions that extend in the longitudinal direction with a strip configuration and has alternatively been divided into sections has been disclosed (see Patent Literature 2). This absorbent element contributes to the diffusion of the fluid in the longitudinal direction, so that the absorbent element provides excellent ability to absorb fluids and can flexibly deform under the action of pressure acting in the width direction.

LIST OF LINKS

Patent Literature

Patent Literature 1: JP-A-2006-55352 (“JP-A” means Japanese Unexamined Published Patent Application)

Patent Literature 2: JP-A-2010-136899

SUMMARY OF THE INVENTION

TECHNICAL PROBLEM

The present invention is aimed at further improving the absorbent characteristics of the aforementioned conventional absorbent products to obtain an absorbent product, which more effectively prevents the presence of residual fluid and back flow of fluid on the top sheet, helps to reduce sweating, can quickly cope with the strong release of fluid released organism at one time, and has excellent flexibility, due to which the absorbent product adheres to the user's body and is deformed in a favorable way, "following" the movement of the user.

SOLUTION

The present invention solves the above problem by means of a longitudinally long absorbent article comprising a fluid permeable top sheet located on the surface of the skin contacting surface, a bottom sheet located on the surface of the skin non-contact and an absorbent element arranged between two sheets

wherein the absorbent element has a longitudinal direction and a width direction that are perpendicular to each other; the absorbent element has structures that allow the passage of fluids and which are located respectively in the longitudinal direction and in the direction of the width of the absorbent element in the zone facing the discharge zone, and each of which is formed by concave sections having the shape of grooves and pressed from the side not in contact with the skin surface in the direction of thickness, and concave absorbent sections containing cellulose fiber, located on the side of the surface in contact with the skin, the lower parts of the concave chastkov; and the absorbent element has protruding absorbent sections in the form of blocks that protrude toward the side of the non-skin contact surface, contain cellulose fiber and have a higher base weight than concave absorbent sections in areas surrounded by flowable structures environments and

wherein the concave absorbent portions of the structures providing the passage of fluids have a low density, and the protruding absorbent portions in the form of blocks have a high density relative to the concave absorbent portions.

EFFECTS OF THE INVENTION

The absorbent article of the present invention functions and provides effects such that the absorbent article more effectively prevents the presence of residual fluid on the top sheet and back flow of fluid toward the top sheet to reduce sweating. In addition, the absorbent article of the present invention functions in such a way that it provides effects that allow the absorbent article to quickly counteract the strong release of fluid emitted by the body at one time, and has excellent flexibility by which the absorbent article adheres to the wearer's body and deforms favorably, " following ”the movement of the user.

Other and further features and advantages of the invention will become more apparent from the description below, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially exploded perspective view showing a sanitary napkin in accordance with one embodiment of an absorbent article of the present invention when viewed from the surface of the skin contact.

Figure 2 shows a section taken along the line II-II in figure 1.

FIG. 3 is a drawing schematically showing only an absorbent element in accordance with this embodiment of the present invention, wherein (A) is a plan view in which the absorbent element is visible from the side of the skin contact surface, (B) is the section taken along line BB in view (A) and (C) is a plan view in which the absorbent element is visible from the side of the surface not in contact with the skin.

FIG. 4 is a drawing for explaining process steps that schematically shows states before crimping and after crimping by means of a rotating roller during manufacture for a preferred manufacturing method of an absorbent member in accordance with this embodiment of the present invention.

FIG. 5 is a sectional view schematically showing a method of forming an absorbent element blank on a concave portion for accumulating on the surface of a rotary drum for a preferred method of manufacturing an absorbent element in accordance with this embodiment of the present invention.

6 is a partially exploded perspective view showing a sanitary towel in accordance with one embodiment (second embodiment) of an absorbent article of the present invention when viewed from the side of the skin contact surface.

Fig.7 shows a section taken along the line II-II in Fig.8.

Fig. 8 is a partial sectional view showing an enlarged portion of a predetermined sectional surface of the sanitary napkin shown in Fig.6.

Fig. 9 is a partially exploded perspective view showing a sanitary towel in accordance with one embodiment (third embodiment) of an absorbent article of the present invention when viewed from the side of the skin contact surface.

Figure 10 shows a section taken along the line II-II in figure 9.

11 is a plan view schematically showing the absorbent element of the sanitary napkin shown in FIG. 9 from a surface non-skin contact side.

FIG. 12 is a partial sectional view showing an enlarged portion of a predetermined sectional surface of the sanitary napkin shown in FIG. 9.

13 shows schematic sections, respectively, showing part of embodiments of absorbent elements prepared in the Test Example and Comparative Example.

DESCRIPTION OF EMBODIMENTS

Hereinafter, the present invention is described in detail with reference to the drawings based on the preferred first to third embodiments.

[First Embodiment]

FIG. 1 is a partially exploded perspective view showing a sanitary towel in accordance with a first embodiment of an absorbent article of the present invention when viewed from the surface in contact with the skin. Figure 2 shows a section taken along the line II-II in figure 1. Figure 3 is a drawing schematically showing only an absorbent element in accordance with this embodiment of the present invention, wherein (A) is a top view in which the absorbent element is visible from the side of the skin contact surface, (B) is a section made along the line BB in view (A), and (C) is a top view in which the absorbent element is visible from the side of the surface not in contact with the skin. In these drawings, the absorbent member sheet intended for wrapping the core is omitted to avoid complication. In addition, in FIG. 3, a leakage-preventing groove is omitted to enable understanding of the shape of the absorbent member.

In the sanitary napkin 10 of this embodiment, the absorbent member 3 is placed on that side of the bottom sheet 2, which is the side of the skin contact surface by attachment with an adhesive or the like. In addition, the side sheets 4 are brought into contact with the bottom sheet 2 and attached to the bottom sheet 2 outside of the left and right sides in the longitudinal direction of the absorbent element 3 from that side of the bottom sheet 2, which is the side of the skin contact surface. The top sheet 1 is located between the bottom sheet 2 and the side sheet 4 in the part in which the bottom sheet and the side sheet are in contact, and in the direction inward in the direction of its width (X direction), the top sheet 1 is located so that it will be closer to the side a surface in contact with the skin than the absorbent element 3. The above-mentioned corresponding sheet elements, which are layered in a similar manner, are bonded by heat sealing or the like from the outside of the absorbent element 3 without introducing the absorbent element and 3 therebetween, thereby to form the outer peripheral portion 6 of the gasket 10. This outer peripheral portion 6 does not impair the overall extensibility and is fastened to such an extent that the fluid, which has been once absorbed, does not flow. Each of the side sheets 4 has a free end 41 on which a pocket (not shown) is formed in the direction of the outer peripheral part 6, and the pocket has the effect of preventing leakage of fluid or the like in the lateral direction. In addition, the pterygoid parts 42, each of which is formed by the side sheet 4, extend outward in the width direction of the sanitary towel 10 on the left and right sides in the width direction of the sanitary towel 10 in this embodiment, and by folding these parts towards the crotch side part of the panties, which is the side of the surface that is not in contact with the skin, the sanitary towel 10 is fixed to the panties.

The leakage-preventing groove 5, which is obtained by indentation from the skin-contacting surface of the top sheet 1 towards the absorbent member 3, is formed from the skin-contacting surface of the sanitary napkin 10 (see FIGS. 1 and 2). The shape of the leakage preventing groove 5, in plan view, in plan view, is such that the depressed portions, each of which has a certain length in the longitudinal direction, are located on the left and right sides in the direction of the width of the zone facing the discharge zone, for receiving menstrual blood or the like in the central part in the longitudinal direction of the absorbent element 3, while the corresponding left and right depressed portions gradually bend towards the center of the absorbent element 3 as they approach zheniya to the front and rear ends of the absorbent element 3 and are connected at the front and rear ends. That is, the leakage preventing groove 5 has a shape in which two depressed portions that are located on a side in contact with the skin surface on both side parts in the longitudinal direction of the sanitary towel 10 extend in the forward and backward directions and continue in the form of an endless “ring” "In the top view (see figure 1).

Thus, leakage of the released fluid laterally when the gasket is attached and used can be effectively prevented. The zone facing the discharge zone is a part that directly receives the excreted menstrual blood, or vaginal discharge, or the like, and a zone near this part and is located in the center in the longitudinal direction on the pad 10 of this embodiment, and is also located in the location where the pterygoid portions 42 are located. The shape of the leakage preventing groove 5 in the plan view in this embodiment is not limited to the aforementioned shape, and the groove portions may intersect each other at the front end and rear end of the form as an endless ring, and it is preferable that this form has been defined appropriately depending on the intended use.

Details will be mentioned below regarding materials, sizes and the like for the top sheet 1, the bottom sheet 2, the side sheet 4 and the absorbent member 3. In this embodiment, a hydrophilic non-woven fabric obtained in the through air stream is used in the top sheet 1 for reasons associated with the rapid absorption of the selected fluid and passing it into the absorbent element, and for reasons related to the fine texture. In addition, as the bottom sheet 2, a moisture-permeable film having breathability is used as a single layer. The absorbent element 3 is formed by coating cellulosic fibers and the like and a polymer with an ultra-high absorbency (a polymer with high water absorption capacity) by a sheet for wrapping a core, such as paper (not shown). In addition, an adhesive (not shown) intended to secure the sanitary napkin 10 to the clothes is applied to the side of the surface of the lower sheet 2 not in contact with the skin. The sanitary napkin 10 is fixed to the wearer's clothing by means of an adhesive. The sanitary napkin 10 of this embodiment is worn by guiding the side of its upper sheet to the side in contact with the skin of the clothing surface, and placing it in the longitudinal direction from the lower abdomen to the buttocks, and placing it in the width direction in the direction of the line that connects the left and right foot.

In the present invention, unless otherwise indicated, the surface on the side in contact with the human body is called the surface on the side facing the skin, the surface in contact with the skin, or the upper surface, and the opposite surface is called the surface on the side not facing the skin, surface not in contact with the skin, or the back surface. On these two surfaces, the side closer to the surface facing the skin and the strike direction are referred to as the surface facing the skin, the surface contacting side of the skin, or the upper surface side, and the side closer to the non facing surface to the skin, and the direction of strike are called the side of the surface not facing the skin, the side of the surface not in contact with the skin, or the side of the back surface. When wearing the pad, 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 back surface of the absorbent article is called the direction of the thickness, and its value is called the thickness. In the top absorbent article, a direction extending from the ventral zone to the rear side zone through the inner zone between the hips is called a longitudinal direction, and a direction that is perpendicular to the longitudinal direction is called a width direction. The longitudinal direction, as a rule, corresponds to the direction of the body of the person wearing the pad from front to back.

The absorbent element 3 of this embodiment is formed by coating a mixed fiber mass containing cellulosic fiber and an ultra-high absorbency polymer with a core wrap sheet. The absorbent element 3 has high density zones 38 in which the absorbent element materials (its constituent fiber and super absorbent polymer) are in a dense state, and low density zones 39 in which the absorbent element materials are in a loose state compared to zones 38 high density, at least in the area facing the discharge. As shown in FIG. 3 (A), the absorbent member 3 is in the form of an “island in the sea” type structure in which low density zones 39 extend continuously in a plane direction and high density zones 38 are dispersed and surrounded by low density zones 39.

In the direction of the thickness of the low-density zones 39, as shown in FIG. 3 (B), concave portions 31 that are concave from the side of the non-skin surface are directed towards that side of the absorbent member 3, which is the side of the surface in contact with leather, made to form voids, and concave absorbent sections 34 containing cellulosic fiber are provided on the lower parts of the concave sections 31 from the side of the surface in contact with the skin. As shown in FIGS. 3 (B) and 3 (C), the concave portions 31 extend both in the longitudinal direction and in the width direction of that side of the absorbent member, which is the side of the non-skin surface in accordance with the zones 39 low density. The arrangement in the longitudinal direction and the width direction means that numerous strips of concave portions 31 are provided at predetermined intervals in the form of an absorbent element 3 from above. Therefore, concave portions of the rows extending in the longitudinal direction are arranged at predetermined intervals in the width direction, and concave portions of the rows extending in the longitudinal direction are arranged at predetermined intervals in the longitudinal direction.

The rows of concave portions 31 may be continuous or discontinuous. The concave absorbent portions 34 are aligned with the concave portions 31, as shown in FIGS. 3 (A) and (B). These concave portions 31 and concave absorbent portions 34 form fluid passage structures whereby the fluid present on the skin side of the absorbent element 3 is rapidly absorbed in the thickness direction, so that it effectively contributes to the capture and retention of fluid on the protrusions absorbent sections 33 without creating the possibility of a reverse flow of fluid. This will be explained below. In addition, in the thickness direction of the high-density zones 38, the parts surrounded by the concave portions 31 are divided into a plurality of protruding absorbent portions 33 in the form of blocks that protrude towards the side of the lower sheet 2 (see FIG. 3 (B) and (C )). The protruding absorbent portions 33 comprise cellulosic fiber and an absorbent polymer, thereby thereby absorbing and retaining the released fluid.

In this embodiment, each protruding absorbent portion 33 has a shape approximately representing the shape of a rectangular parallelepiped having a longitudinal length direction. The protruding absorbent portions 33 are arranged along the lines in the longitudinal direction and in the width direction so that they are separated by predetermined gaps s and r in the natural state (see FIG. 3 (C)), as seen from a top view from that side of the absorbent element 3, which is the side of the surface that is not in contact with the skin. This arrangement is such that projected images of many protruding absorbent portions 33 appear to overlap in both directions when the protruding absorbent portions are projected in the longitudinal direction and the width direction. An absorbent element 3 comprising concave absorbent portions 34 and protruding absorbent portions 33 forms a generally seamless integrated structure.

The protruding absorbent portions 33, located in the high density zones 38, comprise an absorbent material with a higher density than the absorbent element material in the concave absorbent portions 34 and thus create a large capillary force, and are portions with a high surface density, which are thicker than the concave absorbent portions 34 and therefore absorb and retain a large amount of fluid. In particular, the function of the protruding absorbent portions 33 is mainly to play a role in capturing and retaining the fluid. On the other hand, concave absorbent portions 34 located in the low density zones 39 are portions that have a relatively lower density than the density of the protruding absorbent portions 33 and are portions that are thinner and have a lower surface density over compared to the surface density of the protruding absorbent portions 33. Consequently, the concave absorbent portions 34 have a lower resistance to the passage of the fluid compared to the protruding of absorbent portions 33, and hence allow rapid penetration of fluid in the thickness direction of the absorbent element 3 without loss of fluid pressure.

This is explained with reference to FIG. 3 (B) as follows: the low-density absorbent element regions 39 in which the concave portions 31 and the concave absorbent portions 34 are located have a lower surface density and lower density compared to the surface density and density in high density areas 38 of the absorbent member 3, in which there are protruding portions of the absorbent 33. The concave portions 34 absorbent quickly absorb fluid (Figure 3 (B), and the arrow _1), and numerous neighboring Venue Payuschie absorbent portions 33 absorb the fluid within the capillary due to their strength (Figure 3 (B), arrow _1), and thus, the fluid can be captured and held in place, which is removed from that side of the absorbent element 3, which is represents the side of the surface facing the skin.

In addition, the concave absorbent portions 34 and portions 33a on the side of the protruding absorbent portions 33, which is the side of the skin contacting surface, are aligned in a plane direction to form a continuous portion 35 on the side of the absorbent element 3, which is the surface side in contact with the skin (see figure 3 (B)). The continuous portion 35 has a flat shape at the top sheet 1. Since the flat continuous portion 35 forms that side of the absorbent element 3, which is the side of the surface in contact with the skin, the top sheet is in tight contact with the absorbent element, and the fluid that has passed through the top sheet 1, is easily guided to the absorbent element 3.

The continuous portion 35 is explained with reference to FIG. 3 (A) as follows: as mentioned above, the continuous portion 35 is divided into low density zones 39 formed from concave absorbent portions 34 and high density zones 38 formed from protruding absorbent portions 33a 33. In this continuous portion 35, low density zones 39 formed from concave absorbent portions 34 having low surface density and low density become fluid passageways in which the presence of residual fluid is reduced medium and low density zones 39 extend continuously in the direction in the plane of the absorbent element 3, which makes it possible to quickly absorb fluid from the top sheet 1 into the absorbent element 3 over a large area (Fig. 3 (A), arrows b ₁ ).

The fluid that has passed through the concave absorbent portions 34 is distributed to the numerous protruding absorbent portions 33 and is sucked by the numerous protruding absorbent portions 33 for gripping and holding there (Fig. 3 (B), arrows ₁ ), while the fluid only temporarily held by concave portions 31 (FIG. 3 (B), arrows c ₂ ). The fluid absorbed by the concave portions 31 is subsequently absorbed and held by the protruding absorbent portions 33. Naturally, the fluid can also be absorbed and held directly by the portions 33a (which form the continuous portion 35) of the protruding absorbent portions 33. However, when the fluid having a high viscosity, such as menstrual blood, is released in large quantities at one time / at a time or is released repeatedly, even if the fluid cannot be absorbed and retained ohm absorbent projecting portions 33, fluid is quickly absorbed by absorbent concave portions 34 and concave portions 31 operate as a buffer for temporarily retaining the fluid. In addition, as mentioned above, since the concave portions 31 are connected continuously from the side of the absorbent element 3, which is the side of the surface not in contact with the skin (see FIG. 3 (C)), the fluid can move in a plane direction in places remote from the top sheet 1 (Fig. 3 (C), arrows d ₁ ), to enable reliable absorption and retention of it on the numerous protruding absorbent portions 33, which are distributed over a wide area (Fig. 3 (C), arrows d ₂ ).

Due to this, the fluid can be quickly absorbed into the inner part of the absorbent element 3 from the side of the top sheet 1 by means of "conductive" structures that allow the passage of fluid and formed from concave absorbent sections 34 and concave sections 31, and can be reliably absorbed and held by the protruding absorbent sections 33. Consequently, the presence of residual fluid on that side of the absorbent element 3, which is the side of the surface in contact with the skin, and is unlikely to be reduced, is reduced. Reverse zniknovenie fluid flow from the interior of the absorbent member 3 to the topsheet 1.

Even if, while wearing the pad 10 of this embodiment, pressure is applied acting in the thickness direction, it will be difficult to produce a backflow of the selected fluid, such as menstrual blood, to the side of the top sheet 1. One factor is that the aforementioned island-at-sea type structure, in which high density zones 38 are located within low density zones 39, enables rapid retraction of the fluid in the thickness direction and retention and binding of the fluid on numerous protruding absorbent sections 33, and the fluid does not remain on the top sheet and on that side of the absorbent element 3, which is the side of the surface in contact with the skin. In addition, the aforementioned fluid flow structures formed from concave absorbent portions 34 and concave portions 31 facilitate the absorption and movement of the fluid, thereby effectively affecting the suppression of the backflow of fluid.

In particular, it is believed that such an effect is provided by the following many actions: concave absorbent portions 34 quickly suck the fluid into the concave portions 31 without holding the fluid; a fluid that has not been sucked in by the concave portion quickly spreads in the plane direction due to corresponding diffusion provided by continuously changing the density created by the concave absorbent portions 34 as low density zones and the protruding absorbent portions 33 as high density zones 38 ( the location of the constituent elements, due to which a high degree of diffusion of a large amount of fluid can be ensured); a fluid that has already been sucked in by the concave portions 31 is located at locations that are relatively distant from that side of the absorbent element 3, which is the side of the skin contact surface; the amount of fluid accumulated in the concave portions 31 themselves does not remain large, since the fluid quickly moves to that side of the absorbent element 3, which is the side of the surface not in contact with the skin, due to the structures that allow the passage of the fluid and having concave portions 31, and is absorbed and held by the protruding absorbent portions 33; etc. In addition, it is also believed that another factor is that the pressure applied to the concave portions 31 is “buffered” due to the presence of concave absorbent portions 34, and the movement of fluid in structures that allow fluid to pass through and have concave portions 31 is accelerated by account of this pressure.

In addition, since the absorbent element 3 has a shape in which the protruding absorbent portions 33 of the high density zones 38 provide support from the skin contacting surface to the non-contacting surface of the absorbent element, its deformation under pressure acting in the thickness direction is difficult, and thus, it effectively suppresses the backflow of fluid and prevents twisting. Thus, since the fluid is rapidly absorbed by the concave portions 31 and the fluid does not remain on the side of the absorbent member 3 facing the top sheet 1, the backflow of fluid to the side of the top sheet 1 is also effectively suppressed even if pressure exists in thickness direction, and thus a good dry feeling can be provided. In addition, since the absorbent element 3 has a concave-convex shape, which is divided by longitudinal and transverse concave portions 31 on the side of the absorbent element 3, which is the side of the surface not facing the skin, the absorbent element has flexibility in the longitudinal direction and in the width direction in this part, and, thus, the “ability to fit to the body”, due to which the sanitary towel 10 adheres to the bumps of the skin surface, and the “ability to follow the movement”, due to which The sanitary napkin 10 “follows” the user's movement and the formation of partial gaps with respect to the skin is prevented; they are improved to a very significant extent.

In the present invention, the arrangement of the protruding absorbent portions 33 is an arrangement according to this embodiment, or may be any arrangement that can be appropriately selected depending on the intended use and function, and, for example, the arrangement may be a staggered arrangement (arrangement in which the aforementioned projected images are staggered approximately half a step in the longitudinal direction and / or and width direction). Furthermore, the shape of the protruding absorbent portion 33 is the shape of this embodiment, or may be any shape that can be selected appropriately depending on the intended use and function.

Thus, so that the concave absorbent portions 34 do not hold the absorbed amount of fluid and allow rapid movement of the fluid to the concave portions 31 and that the concave portions 31 function as a temporary accumulation of the extracted fluid to prevent the fluid from returning to the side of the top sheet 1, an absorbent component the element in concave absorbent portions 34 as low density zones 39 has an average density (m ₁ ), preferably of 0.02 to 0.09 g / cm ³ , more preferably - from 0.03 to 0.08 g / cm ³ . In addition, to ensure fluid retention and binding, the structural element of the absorbent element in the protruding absorbent portions 33 as high density zones 38 has an average density (m ₂ ) of 0.10 to 0.25 g / cm ³ , more preferably from 0.10 to 0.20 g / cm ³ . In addition, despite the fact that the protruding absorbent portions 33 are portions whose density is increased by pressing / compression during manufacture, even if a uniform density in the direction of their thickness is not ensured, it is sufficient that the density as a whole is higher compared with a density of concave portions 34 absorbent, and the ratio (m ₁ / m ₂₎ of the average density (m ₁₎ of the concave portions 34 as the absorbent zones 39 of low density and medium density (m ₂₎ of the projecting portions 33 absorbent as the high density zones 38 redpochtitelno is 0.80 or less, more preferably - 0.60 or less. By adjusting the ratio (m ₁ / m ₂ ) so that it does not exceed the upper limit, an absorption mechanism is provided in which the fluid is temporarily held in the low density zones 39 and the fluid is effectively absorbed and held in the high density zones 38 by capillary force, which acts between zones 39 low density and zones 38 high density.

Furthermore, for the same reason, the constituent element of the absorbent element in the low density zones 39 having concave absorbent portions 34 and concave portions 31 (see FIG. 3 (B)) has an average base weight (w ₁ ), preferably between 10 and up to 160 g / m ² , more preferably from 20 to 150 g / m ² . The constituent element of the absorbent element in high density zones 38 having protruding absorbent portions 33 (see FIG. 3 (B)) has an average base weight (w ₂ ), preferably of 160 to 400 g / m ² , more preferably of 200 to 350 g / m ² . In addition, the ratio (w ₁ / w ₂ ) of the average basis weight of the two types of zones of the absorbent element is preferably from 0.01 to 0.90, more preferably from 0.1 to 0.7. The ratio (%) of height / depth (h ₂ ) of the concave portion 31 to the thickness (h ₁ ) of the absorbent member 3 (thickness of the protruding absorbent portions 33) (see FIG. 2) is preferably from 20 to 98%, more preferably from 30 up to 70%.

In the present invention, concave portions 31 are portions that become voids due to indentation from the bottom of the absorbent element 3 toward the side of the skin contact surface. Concave absorbent portions 34 are portions of the absorbent element 3 that are located on the upper parts of the concave portions 31 and which are separated by virtual lines t and t that extend in the thickness direction from the lower wall portions 31a and 31a (see FIG. 3 (B)) . The protruding absorbent portion 33 is a portion extending from the upper portion to the lower portion of the absorbent member, which is adjacent to zones 39 and surrounded by zones 39, each of which comprises a concave portion 31 and a concave absorbent portion 34 that are located in the thickness direction (see figure 2 and figure 3 (B)).

[Method for determining the average density of zones 38 high

density and average density of low density zones 39]

In the above definitions, the density of the high density zones 38 and the density of the low density zones 39 is the combination density of cellulosic fibers and a super absorbent polymer, which are constituent elements of the absorbent element 3. The absorbent element 3 is cut along virtual lines t and t that extend into the thickness direction from the lower parts 31a and 31a of the walls of the concave sections 31 to obtain protruding absorbent sections 33 of the high density zones 38 and concave absorbent sections s 34 39 low density zones, and each cut to a size of a length of 50 mm and a size of a width of 5 mm, to prepare samples. Then, the mass of each sample is determined using an electric balance (GR-300, manufactured by A & D company, Limited, accuracy: 4 decimal places). The thickness of the samples is measured by using a thickness gauge operating at constant pressure, and the mass of the measured sample is divided by the volume of the sample (thickness × length × width) to calculate the density of the entire material at the location of each zone. The measurement is carried out by means of a thickness gauge operating at constant pressure, at a pressure of 0.5 g / cm ² . The average density is obtained by calculating the average of ten samples prepared in randomly selected parts.

[Method for determining the average weight of the base zones 38

high density and low density zones 39]

The method of determining the average weight of the base (w ₂ ) of the high density zones 38 and the average weight of the base (w ₁ ) of the low density zones 39 includes measuring in advance the surface area of each zone to be measured, cutting out the measured zone from the aforementioned virtual lines t and t by means of a cutting device, and measurement of the mass of the cut out part. The measured mass is divided by the surface area to thereby determine the average surface density of the zone with each density. The average surface density is obtained by the average of ten samples prepared in randomly selected parts.

[Measurement of the thickness of the protruding absorbent sections 33 and

concave absorbent sections 34 (and concave sections 31)]

First, the concave portion 31 may be separated in the form of a part that has become empty due to indentation from the bottom side of the absorbent element 3 towards the side of the skin contact surface, and the concave absorbent portion 34 may be separated in the form of a part formed from the material of the absorbent element 3, which is located on the side of the upper part of the concave portion 31 (FIG. 3 (B)). The protruding absorbent portion 33 may be separated as a part that is formed from the material of the absorbent element 3 from top to bottom and which is adjacent to the low density zones 39 and surrounded by low density zones 39 containing concave portions 31 and concave absorbent portions 34 that are arranged in the direction thickness (Fig. 3 (B)). The boundary between the protruding absorbent portion 33 and both the concave absorbent portions 34 and the concave portions 31 can be defined as virtual lines t and t that extend from the lower parts 31a and 31a of the walls of the concave portions 31 (FIG. 3 (B)) .

The thickness (h ₃ = h ₁ -h ₂ ) of the concave absorbent portions 34 and the thickness (h ₁ ) of the protruding absorbent portions 33, divided as described above, are measured by placing an acrylic polymer plate having dimensions of 37 mm × 37 mm and a thickness of 3 mm on the absorbent core 3, thickness measurements (h ₁ ) of the protruding absorbent portions 33 by using a non-contact laser displacement meter manufactured by KEYENCE Corporation (laser head: LK-G30, displacement meter: LK-GD500), and thickness measurements ( h ₃₎ of the concave absorbent uch stkov measurement section 34 through the surface 2 corresponding to the absorbent body by using the microscope VHX-1000, manufactured by KEYENCE Corporation.

Hereinafter, a preferred manufacturing method of the aforementioned sanitary napkin 10 is described with reference to FIGS. 4 and 5. The shape of the absorbent element 3 and the number, shape, arrangement and the like of the concave portions 31 and the protruding absorbent portions 33 are illustrated schematically and are not necessarily the same as illustrated in figures 1 and 2.

FIG. 4 is a drawing showing equipment 60 for manufacturing absorbent bodies, which is preferably used in the manufacture of the absorbent element 3 of the sanitary towel 10. As shown in FIG. 4, process equipment 60 includes a rotary drum 62 having a plurality of concave storage portions 9 ( parts for deposition), which are formed at predetermined intervals on the outer peripheral surface, channel 63, which is configured to allow the supply of fibrous material S in a scattered / divided state towards the outer peripheral surface of the rotary drum 62, a portion 64 for supplying fibrous material, which is configured to allow the supply of fibrous material S to the channel 63, the abrasive roller 65, which is configured to allow scraping of excess the amount of fibrous material that is deposited with overflow in the concave parts of the drives 9, the covering mechanism (not shown), which is configured to sintering the ability to cover the upper and lower surfaces of the deposited elements 70 (blanks of absorbent bodies), which come out of the concave parts of the drives 9, sheet 3b for wrapping the core, compressing equipment 66, which is configured to allow the compression and compression of the absorbent continuous body, which obtained by coating blanks 70 of absorbent bodies with sheet 3b for wrapping the core between two press rolls 66a and 66b, and cutting equipment (not shown), which made with a configuration that allows cutting the compressed absorbent continuous body in size, which is used in a separate sanitary pad, to obtain a processed absorbent element 3.

The rotary drum 62 is cylindrical in shape and functions to rotate at a constant speed in the direction of arrow A in FIG. 4. Numerous concave storage parts 9 are formed on the outer peripheral surface of the rotating drum 62. An air suction fan (not shown) is connected to a non-rotating part located on the inside (from the axis of rotation) of the rotating drum 62, and in the separated spaces B and E inside the rotating drum is negative the pressure is maintained by actuating the air suction fan. The part forming the lower surface of each concave storage part 9 is formed by a mesh plate and has many small pores. During the passage of each concave storage part 9 over spaces B and E in which negative pressure is maintained, the small pores in the part forming the lower surface of each concave storage part 9 function as suction pores.

Channel 63 has a discharge end portion 63a covering a portion of the outer peripheral surface of the rotary drum 62 and a discharge end portion 63b connected to the equipment 64 for supplying fibrous material, and channel 63 is configured so that an air stream that flows towards the outer the peripheral surface of the rotating drum 62, is created in the channel 63 due to the suction from the side forming the lower surface of the parts of the concave storage parts 9, which are located above the space B. Part 6 4 for supplying fibrous material comprises a refiner 64e and is configured such that a sheet-like feed material S ', such as cellulose, is introduced into the refiner 64e by a pinch roller 64d for feeding the feed materials, and the fibrillated fibrous material S is fed into the channel 63.

The abrasive roller 65 has brushes on the periphery, and the fibrous material S that has poured out from the concave storage portions 62 is scraped off by brushes. Precipitated elements (blanks of absorbent elements) 70, which remain in the concave parts of the drives 9 and are not removed by the abrasive roller 65, are released from the concave parts of the drives 9 at the location of the lower part of the rotating drum 62. The release from the concave parts of the drives 9 maintaining positive pressure in the separated space D in the rotating drum with the help of means (not shown) that creates high pressure, to allow air to escape from small pores in the image the lower surfaces of the parts of the concave storage parts 9 and the air suction from the side of the vacuum conveyor 67. The aforementioned coating mechanism has a known conveying mechanism, which is configured to feed the core sheet 3b to the vacuum conveyor 67, and is made with such a structure, that the deposited element (blank of the absorbent element) 70 is placed on the sheet for wrapping the core, and both side parts of the sheet for wrapping the core are then folded onto the deposited element (blank of the absorbent element) 70 to thereby cover the upper and lower surfaces of the deposited element (blank of the absorbent element) 70 with a sheet 3b for wrapping the core. 4, details related to the folding step are omitted, and the state of the folded core wrapping sheet 3b is shown simply in two lines.

A method of manufacturing the aforementioned absorbent element 3 will be described, which involves the use of equipment 60 for the manufacture of absorbent bodies, shown in Fig.4.

First, the rotary drum 62 and the abrasion roller 65 are rotated, and the aforementioned air suction fan and the aforementioned pressure generating means are activated to thereby create a negative pressure in spaces B and E and create a positive pressure in space D. In addition, the vacuum conveyor 67, compression equipment 66, and the aforementioned cutting equipment are driven. By actuating the air-suction fan, a suction force is created on the lower surface forming portions of the concave storage portions 9 that are located above the space B, and an air flow that flows towards the outer peripheral surface of the rotary drum 62 is created in the channel 63. In addition when the equipment 64 for supplying fibrous material is driven and the fibrous material S (cellulosic fiber 41 and ultra absorbent polymer 42) is supplied to cash 63, the fibrous material S is brought into a “diffuse” state and is introduced into the air flow that passes through the channel 63 and is fed towards the outer peripheral surface of the rotating drum 62.

During the passage of each concave storage portion 9 over the space B in which negative pressure is maintained, the fibrous material S supplied from the channel 63 is sucked in by each concave storage portion 9 and deposited therein. In each concave storage part 9, the fibrous material is deposited in a slightly higher amount, and the fibrous material that falls out of the concave storage part 9 is scraped off by the abrasive roller 65. The deposited element (blank of the absorbent member) 70 remaining in the concave storage part 9 and not scraped off by the abrasive roller 65, is released and placed on the core wrapping sheet 3b fed to the vacuum conveyor 67.

The formation of the absorbent element blank 70 will be explained with reference to FIG. In Fig. 5, in order to facilitate understanding of the unevenness of the shape of the absorbent element, instead of the full image of the concave part of the storage device 9, a part in which two protruding parts 51 are located is illustrated and illustrated.

The fibrous material S, which is a mixture of cellulosic fiber 41 and polymer 42 with ultra-high absorbency, is stacked in the interior of the concave storage portion 9 shown in FIG. 5 (a), but does not accumulate on the protruding parts 51 as shown in FIG. 5 (a), and as the fibrous material gradually precipitates, the fibrous material accumulates beyond the height of the protruding portions 51, as shown in FIG. 5 (b), to thereby obtain a blank 70 of the absorbent element according to phi g. 5 (s). The stacked parts 74 located on the protruding parts 51 become concave absorbent portions 34 of the absorbent element 3, and the parts 71 in which the protruding parts 51 are located become concave portions 31 of the absorbent element 3. Parts 73 located in the concave storage portions between the protrusions, become protruding absorbent sections 33 'before compression. In addition, the part 75, which is superimposed in the form of a foot over the protruding parts 51, becomes a continuous part 35 of the absorbent element 3.

The deposited member (absorbent member blank) 70 located on the core wrapping sheet 3b is closed by both sides of the core wrapping sheet 3b that are folded, and then the deposited member (absorbent member blank) 70 is inserted into the compression equipment 66 and exposed compression between two press rolls 66a and 66b. Thus, the protruding absorbent portions 33 'are compressed and converted to the protruding absorbent portions 33 of the high density zones. After that, the deposited element is cut with an unshown cutting means to obtain an absorbent element 3 having a size used in each sanitary napkin. The method of the aforementioned compression may be a method involving the use of compression rollers 66 or compression by means of a flat pressing equipment. Regardless of the compression / compression means, the compression mode preferably corresponds to a pressure of from 0.5 to 5 kgf / cm ² , more preferably from 1 to 4 kgf / cm ² .

Thus, the absorbent element 3 is molded as a whole, and concavity and convexity are formed in accordance with the shape and arrangement of the protruding parts 51 in the concave storage part. The concave absorbent portions 34 have a lower surface density compared to the surface density of the protruding absorbent portions 33 due to their small thickness, and unlike the concave absorbent portions formed by compression, such as embossing, the concave absorbent portions 34 have a low resistance to passage of fluids, which makes it possible to quickly move the fluid in the thickness direction. In addition, the absorbent element 3 provides a fine / good texture, since the absorbent element 3, which is molded as a unit in this way, has no part that is hard due to compression, such as embossing. When wearing a pad 10 having such an absorbent element 3, the wearer can feel the softness of the absorbent element 3 because there is no hard part that touches the user through the top sheet 1. In addition, since the pad has flexibility at the locations of the concave portions 31, the pad snug to the body and provides a good level of comfort.

Despite the fact that the polymer with ultra-high absorbency inside the absorbent element 3 is present in a uniformly distributed form in this embodiment, to effectively suppress the backflow of fluid, it is preferable to place the polymer with ultra-high absorbency so that it is biased towards the protruding absorbent portions 33 in more than to the continuous portion 35 containing concave absorbent portions 34, and it is more preferable that the polymer with an ultrahigh absorbent method was placed so that it was shifted to a greater extent to that side of the protruding absorbent portions 33, which is the side of the surface not facing the skin than to the continuous portion 35 containing concave absorbent portions 34. In addition, for the same reasons it is also preferable to place the polymer with ultra-high absorbency on the side of the concave portions 31, which is the side of the surface not facing the skin.

In addition, in the absorbent element 3 of this embodiment, it is preferable to place structures that allow fluid to pass and have concave portions 31 so as to encompass portions located externally in the width direction with respect to leakage groove 5. This arrangement also provides flexibility on both sides of the absorbent element 3, where leakage easily occurs in the lateral direction, and thus the absorbent element can be deformed so that the absorbent element surrounds the inside of the legs of the user to ensure that the absorbent element adheres to the crotch. and can “follow” the movement of the user's body, thereby preventing the formation of gaps.

Although the dimensions and shapes of the protruding absorbent portion 33 and the concave portion 31 in this embodiment are not particularly limited and vary to some extent depending on the intended use of the absorbent article used, the length k _{1 of} each protruding absorbent portion 33 in the longitudinal direction ( see figure 3 (C)) is preferably from 5 to 40 mm, more preferably from 10 to 25 mm. Its length k ₂ in the width direction is preferably from 3 to 40 mm, more preferably from 5 to 15 mm. In addition, the length s of each concave portion in the longitudinal direction is preferably from 1 to 5 mm, more preferably from 1 to 3 mm. The length r in the width direction is preferably from 1 to 5 mm, more preferably from 1 to 3 mm.

[Second Embodiment]

A sanitary napkin as a second embodiment of an absorbent article in accordance with the present invention is described with reference to FIGS. 6 to 8. 6 is a partially exploded perspective view showing a sanitary napkin in accordance with a second embodiment of an absorbent article of the present invention when viewed from the surface in contact with the skin. Fig.7 shows a section taken along the line II-II in Fig.6. Fig. 8 is a partial sectional view showing an enlarged portion of a predetermined sectional surface of the sanitary napkin shown in Fig.6.

Hereinafter, a second embodiment of the present invention will be explained with the exception of parts that “overlap” with corresponding parts of the above first embodiment. The aforementioned first embodiment and this second embodiment are not in particular and exclusive relationship, and, for example, the second embodiment can be considered as being within the framework of more specific ideas of 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 communication, in accordance with which the invention is connected so as to form one idea of the invention, due to the presence of the same or corresponding special technical feature. The same and similar elements are denoted by the same reference numerals, and their explanations are sometimes excluded (nevertheless, the dimensions and special mutual arrangements correspond to the drawings, which correspond to the respective embodiments).

The sanitary napkin 20 of the second embodiment is the same as the sanitary napkin 10 of the aforementioned first embodiment, except that among the constituent elements of the sanitary napkin 10, only the top sheet is different. The top sheet in the second embodiment is shown by the symbol 21. The top sheet 21 has many parts that protrude at equal intervals on the surface side in contact with the skin and on the side of the surface not in contact with the skin, and the protruding sections are located in the same places on the side of the surface in contact with the skin, and on the side of the surface not in contact with the skin (see Fig.6-8). The features of the top sheet 21 are as follows.

As shown in FIG. 7, the top sheet of this embodiment is formed by bonding by laminating two fibrous layers: an upper layer 11 on the surface side of the skin contact surface and a lower layer 12.

The upper layer 11 and the lower layer 12 are connected by pressure connection using the embossing element in many depressed areas 15. The upper layer 11 and the lower layer 12 are made with relief elements in the same places in the top view and depressed in the depressed sections 15 for thereby forming many plots in the form of depressions. The non-squeezed portions between the depressions, that is, the zones surrounded by the depressed portions 15, form convex portions 14. The convex portions 14a of the upper layer 11 protrude in the direction of the surface side in contact with the skin, and the convex portions 14b of the lower layer 12 protrude in the direction of the surface side, not in contact with skin. A plurality of convex portions 14a and 14b are spaced at equal intervals in the same places of the upper layer 11 and the lower layer 12 in a plan view as the aforementioned depressed portions 15, and thus a plurality of concave-convex portions are formed over the entire area of the upper layer 11 and the lower layer 12. In addition, many concave-convex sections are formed over the entire area of the upper sheet 21.

The depressed portions 15, which become depressions of the upper layer 11 and the lower layer 12, are portions in which the fibers of the upper sheet 21 are densified and the density of the fibers is higher and the capillary strength is greater than the density of the fibers and capillary force in the convex portions 14 of the upper sheet 21. This enables efficient and rapid passage of the separated fluid from the top sheet 21 to the absorbent element 3. In particular, the means described in paragraphs [0007] to [0045] of the description from JP-A-2004-166849 can be used.

In this embodiment, each depressed portion 15 has approximately such a cruciform shape in which two long axes intersect (see FIG. 6). The adjacent two depressed sections 15 and 15, which are located at the smallest distance from each other, are located so that they are approximately on the line of continuation of each other in the direction of the long axis. Due to this, the density gradient of the constituent fibers is formed between the depressed portions 15 and the convex portions 14 in a plurality of directions on the top sheet 21, and thus, the distribution of the fluid and the penetration of the fluid in the thickness direction of the top sheet 21 are improved. The shapes and arrangement of the depressed portions 15 may be the shapes and arrangement of this embodiment, or may be such that the relief elements of a circular or square shape are randomly distributed, and may s arbitrarily chosen any shape and layout, which is provided by density gradient constituent fibers and hence to carry out distribution and rapid penetration of fluid in the direction of thickness.

In this case, the dynamic characteristics of the aforementioned sectioned absorbent element 3 and the top sheet 21 in the sanitary napkin 20 are described in detail based on FIG. Fig. 8 is a partial sectional view showing an enlarged portion of a predetermined sectional surface of the sanitary napkin shown in Fig.6. The bottom sheet 2 and the side sheet 4 are not illustrated in order to avoid complicating the drawing, and the shape of the top sheet 21 is shown schematically and may not be the same shape as the illustrated form when practicing the present invention.

The top sheet 21 gives high mobility to the selected fluid when it is moved in the thickness direction due to capillary force using a density gradient similar to the above, and thus can provide a quick movement of the fluid released from the body into the absorbent element 3. In addition Moreover, since the convex portions 14a of the upper layer 11 and the convex portions 14b of the lower layer 12 are formed at the same places in the thickness direction (see FIG. 8), the fluid moves easily to accumulate in one place in the plane, and this is preferable since even a small amount of fluid is directed into the absorbent element 3, and it is possible to effectively pass this small amount of fluid towards the absorbent element 3. In particular, if the fiber density in the upper layer 11 and the lower layer 12 differs and the density of the fibers of the lower layer is higher, the fluid easily remains on the side of the lower layer of the upper sheet, but the structure in which the fluid accumulates creates the effect of improving the feeling of dryness in quently topsheet shielding properties and its ability to provide a small reverse flow of fluid. As mentioned above, the absorbent element 3 has numerous concave portions 31 on the surface side not in contact with the skin, and the concave absorbent portions 34 are located on the surface side in contact with the skin. Since the concave absorbent portions 34 have less resistance to the passage of fluid compared to portions of other parts of the absorbent element, by using these portions as chambers, the extracted fluid a _{1 is} rapidly absorbed in the thickness direction of the absorbent element 3. The part of the fluid that has moved in the direction the thickness of the absorbent element 3, becomes a moving fluid a ₂ , which extends towards the surrounding protruding absorbent sections 33, 33, and the other part l becomes accumulated fluid a ₃ , which is captured by the concave portion 31. Thus, since the fluid that has penetrated from the top sheet 21 is absorbed by the concave absorbent portions 34 and is divided into the fluid a ₂ and the fluid a ₃ , the degree of retention on the side the front surface of the absorbent element is reduced, and the resistance to passage of the fluid is further reduced. Therefore, the backflow of fluid towards the top sheet 21 can also be effectively suppressed.

Thus, the sanitary napkin 20 of this embodiment can sufficiently exhibit the characteristics of the topsheet 21, which is capable of good fluid transmission in the thickness direction, due to the large ability to transmit fluid in the thickness direction of the absorbent element 3 having concave sections 31 to thereby provide an effect of suppressing the backflow of fluid to the skin for the sucked-in fluid, which provides a preferred dryness tions for users.

As mentioned above, since in the gasket 20, the top sheet 21 can allow fluid to move while “collecting” the fluid, the amount of fluid remaining on the top sheet 21 can be reduced (the feeling of dryness can be improved), and since the top sheet 21 has lower sections that contact directly with the absorbent body 3, it can provide suppression of the reverse fluid flow. In addition, when the low density zones 39 and the high density zones 38 of the absorbent member 3 are formed on the skin contact surface in the top sheet 21, the feeling of dryness of the top sheet 21 can be further improved by exhibiting corresponding diffusivity due to the continuous change in density created the concave absorbent portions 34 of the low density zones 39 and the protruding absorbent portions 33 of the high density zones 38, among the aforementioned continuous effects. In addition, since the above-mentioned density change of the absorbent element 3 is only due to the periphery of the high density zones 38, excessive diffusion does not occur, and leakage can be suppressed.

Materials and a preferred method for manufacturing the topsheet 21 will be described below.

The top sheet 21 consists, for example, of the top layer 11, which is formed from heat-resistant heat-shrinkable fibrous material or fibers having a higher heat-shrink temperature than the heat-shrink temperature of the fibers in the lower layer, and from the lower layer 12, which is formed from not subjected shrink, a heat shrinkable fibrous material that has a higher heat shrink temperature than the heat shrink temperature of the fibers in the upper layer.

The upper layer 11 and the lower layer 12 are fused partially or completely to a predetermined pattern by compression / embossing under the influence of heat or the like, and heat is supplied to them to enable heat shrinkage of the lower layer 12 in the horizontal direction. Then, due to the combination of the upper layer 11 and the lower layer 12 during embossing during shrinkage of the lower layer 12, the upper layer 11 also tends to shrink under the action of the lower layer 12, since the upper layer 11 is integrated with the lower layer 12 by embossing. However, curvature deformation occurs because heat shrinkage does not occur in the upper layer 11 or occurs to a lesser extent in the upper layer 11 as compared to the heat shrink of the lower layer 12, and the deformation appears as a convex protrusion on the upper layer 11. Accordingly, the deformation also appears in in the form of a convex protrusion on the lower layer 12, since the deformation in the upper layer 11 is also transmitted to the lower layer 12. It should be specially mentioned that the hot-stamping connection is carried out by hot stamping nil surfaces, on which a plurality of embossing rods, each of which has a predetermined shape, are arranged with a predetermined arrangement (on the peripheral surfaces of the embossing rollers and the like), in contact with both sides of the upper layer 11 and the lower layer 12 in the laminated element consisting from the upper layer 11 and the lower layer 12, due to the application of pressure and fusion of the constituent fibers in the upper layer 11 and the lower layer 12 in places that are compressed by the respective rods when applying heat. The convex portions 14, which are formed by the upper layer 11 and the lower layer 12, may have parts that are “pushed” so that they cover the depressed portions.

Heat shrinkage of the lower layer 12 is performed by forming a lower layer 12 of heat-shrinkable fibers or by incorporating heat-shrinkable fibers into the lower layer 12 in advance and heat treat the middle layer 12 simultaneously with the upper layer 11 and the lower layer 12 being fused or after the two layers are fused . By thermally shrinking the lower layer 12 in the horizontal direction in a similar manner, the ability of the convex portions formed on the upper layer 11 and the lower layer 12 to form protruding parts is improved, and thus, the upper sheet 21, which is more bulky and has more fine / good texture. In the case where the top sheet 21 is formed by bonding two fibrous layers by lamination in a similar manner, from the viewpoint of improving the fluid transmission ability of the top sheet 21 in the thickness direction of the top sheet, it is preferable that no boundary is formed between the two fibrous layers.

As the upper layer 11 and the lower layer 12, it is preferable to use, for example, a carded web or a bulk non-woven material. A carded cloth refers to a collection of fibers before converting it into a nonwoven material. Namely, this means a collection of fibers in a state in which the fibers are rather weakly mixed with each other and which corresponds to a state where the collection of fibers has not yet undergone subsequent processing of a carded web that is used in the manufacture of a nonwoven material, such as processing for fusion bonding through a process for passing through an air stream or a calendaring process. When the carded webs are used as the upper layer 11 and the lower layer 12, the fibers in the upper layer 11 and the lower layer 12 are thermally fused simultaneously with or after the connection of the upper layer 11 and the lower layer 12. In addition, to examples of bulk non-woven material may include non-woven material obtained by passing a through stream of air, non-woven material obtained by laying in the air stream, non-woven material bonded with resin, and the like. The constituent fibers of the upper layer 11 are preferably fibers that are not substantially heat-shrinkable, or fibers that are not heat-shrinkable at a temperature equal to the heat-shrink temperature of the constituent fibers of the lower layer 12 or lower than the heat-shrink temperature of the constituent fibers of the lower layer 12. The surface density of the upper layer 11 is preferably from 10 to 50 g / m ^2, more preferably - 15 to 40 g / m ^2, from the viewpoint of formation of sufficient density gradient from the viewpoint st chsheniya texture topsheet 21.

As the lower layer 12, a carded web or heat-shrinkable nonwoven fabric can be used. The constituent fibers of the lower layer 12 are preferably fibers formed from a thermoplastic polymeric material, as well as heat-shrinkable / heat-shrinkable. Examples of such a fiber may include a fiber with a hidden crimp. The level of fibers with hidden crimp in the lower layer 12 is preferably from 40 to 100 weight percent. Fiber with a hidden crimp can be processed similarly to conventional fibers for non-woven materials before heating, and fiber with a hidden crimp are fibers that undergo shrinkage with the formation of spiral twists under the action of heating to a given temperature.

A fiber with a hidden crimp is formed, for example, of two-component fibers such as fibers with an eccentric core and cladding or fibers with the arrangement of components side by side, containing two types of thermoplastic polymeric materials with different degrees of shrinkage. Examples thereof may include fibers described in JP-A-H9-296325 and JP-B-2759331. The middle layer may shrink, for example, by incorporating pre-shaped fibers with hidden crimp into it and ensuring that the fibers are crimped by heating at the same time as the upper layer 11 and the lower layer 12 are fused together or after the upper layer 11 and the lower layer 12 have been fused. The middle layer 12 has a surface density of preferably 10 to 50 g / m ² , more preferably 15 to 40 g / m ² .

The upper sheet 21 formed from the data of the upper layer 11 and the lower layer 12 has a surface density of 20 to 100 g / m ² , more preferably 35 to 80 g / m ² . Since many concave-convex portions are formed on the top sheet 21, the sheet 1 has a large thickness and is voluminous.

The topsheet 21 is not limited to the aforementioned embodiment, and may be modified accordingly provided that it does not deviate from the object of the present invention. For example, the top sheet 21 may be formed by a fibrous sheet with a three-layer structure. In this case, it is desirable to form a middle layer 13 of heat-shrinkable fibers and form an upper layer 11 and a lower layer 12 of fibers that do not have heat-shrinkability. In addition, from the point of view of increasing permeability with respect to the fluid, it is desirable that the upper layer 11 has a higher surface density compared to the surface density of the lower layer 12.

[Third Embodiment]

Further, another embodiment (third embodiment) of the sanitary napkin of the second embodiment as an absorbent article of the present invention will be explained below. In the sanitary napkin of the third embodiment, the absorbent element 3 is used together with the topsheet 21 of the second embodiment, and the zones A of the protruding absorbent portions 38 are such that they have a higher surface density compared to the surface density of the zones B of the concave absorbent portions 34 and concave sections 31.

The aforementioned first and second embodiments and this third embodiment are not in particular and exclusive relationship, and, for example, the third embodiment may be considered as being within the framework of more specific ideas of 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 communication, in accordance with which the inventions are connected so as to form one general idea of the invention due to the presence of the same or corresponding special technical feature . The same and similar elements are denoted by the same reference numbers, and their explanations are sometimes excluded (nevertheless, the dimensions and special relative positions correspond to the drawings, which correspond to the respective embodiments).

Fig. 9 is a partially exploded perspective view showing a sanitary towel in accordance with a third embodiment when viewed from the side of the skin contact surface. Figure 10 shows a section taken along the line II-II in figure 9. 11 is a plan view schematically showing the absorbent element of the sanitary napkin shown in FIG. 9 from a surface side not in contact with the skin, and elements other than the absorbent element are not shown in order to avoid complicating the drawing. In these drawings, an absorbent member sheet for wrapping a core is omitted to avoid complication. FIG. 12 is a partial sectional view showing an enlarged portion of a predetermined sectional surface of the sanitary napkin shown in FIG. 9.

In the sanitary napkin 30 of this embodiment, the absorbent member 3 is placed on that side of the bottom sheet 2, which is the side of the skin contact surface by attachment with an adhesive or the like. In addition, the side sheets 4 are brought into contact with the bottom sheet 2 and attached to the bottom sheet 2 outside of the left and right sides in the longitudinal direction of the absorbent element 3 from that side of the bottom sheet 2, which is the side of the skin contact surface. The top sheet 21 is held between the bottom sheet 2 and the side sheet 4 in that part in which the bottom sheet and the side sheet are in contact and inwardly in the direction of its width (X direction), the top sheet 21 is located so that it will be closer to the side a surface in contact with the skin than the absorbent element 3. The above-mentioned corresponding sheet elements, which are layered in a similar manner, are bonded by heat sealing or the like from the outside of the absorbent element 3 without introducing the absorbent element cient 3 therebetween to thereby form the outer peripheral portion 6 of the gasket 30. This outer peripheral portion 6 does not impair the overall extensibility and is fastened to such an extent that the fluid, which has been once absorbed, does not flow. Each of the side sheets 4 has a free end 41 on which a pocket (not shown) is formed in the direction of the outer peripheral part 6, and the pocket has the effect of preventing leakage of fluid or the like in the lateral direction. In addition, the pterygoid parts 42, each of which is formed by the side sheet 4, extend outward in the width direction of the sanitary towel 30 on the left and right sides in the width direction of the sanitary towel 30 in this embodiment, and by bending these parts towards that crotch side part of the panties, which is the side of the surface that is not in contact with the skin, the sanitary towel 30 is fixed to the panties.

The leakage-preventing groove 5, which is obtained by indentation from the skin-contacting surface of the top sheet 21 towards the absorbent body 3, is formed from the skin-contacting surface of the sanitary napkin 30. The shape of the leakage-preventing groove 5, in a plan view, is such a shape, that the depressed sections, each of which has a certain length in the longitudinal direction, are located on the left and right sides in the direction of the width of the zone facing the discharge area for menstrual cramps vi or the like in the central portion in the longitudinal direction of the absorbent member 3, the respective left and right indented portions gradually curve towards the center of the absorbent member 3 as they approach the front and rear ends of the absorbent body 3 and are joined at the front and rear ends. That is, the leakage preventing groove 5 has a shape in which two depressed portions that are located on a side in contact with the skin of the surface on both sides in the longitudinal direction of the sanitary towel 30 extend in the forward and backward directions and continue in the form of an endless “ring” "In the top view (see Fig.9). Thus, leakage of the released fluid laterally when the gasket is attached and used can be effectively prevented. The area facing the discharge area is a part that directly receives the excreted menstrual blood, or vaginal discharge, or the like, and an area close to that part, and is located in the center in the longitudinal direction on the pad 30 of this embodiment, and is also located in the same place where the pterygoid portions 42 are located. The shape of the leakage preventing groove 5 in the plan view in this embodiment is not limited to the aforementioned shape, and the groove portions may intersect each other with the other at the front end and the rear end of the configuration in the form of an endless ring, and it is preferable that this form be determined accordingly depending on the intended use.

Details will be mentioned below regarding materials, sizes and the like for the top sheet 21, the bottom sheet 2, the side sheet 4 and the absorbent member 3. In this embodiment, a fluid permeable, non-woven material having convex fiber portions on the surface side contacting the skin and on the surface not in contact with the skin is used in the top sheet 21 for reasons related to the rapid absorption of the selected fluid and passing it into the absorbent element, and for reasons related th with a fine texture. In addition, as the bottom sheet 2, a moisture-permeable film having breathability is used as a single layer. The absorbent member 3 is formed by coating the cellulosic fibers and the like and the absorbent polymer with a sheet for wrapping a core, such as paper (not shown). In addition, an adhesive (not shown) intended to secure the sanitary napkin 30 to the clothes is applied to the side of the surface of the lower sheet 2 not in contact with the skin. The sanitary napkin 30 is fixed to the wearer's clothing by means of an adhesive. The sanitary napkin 30 of this embodiment is worn by guiding the side of its upper sheet to the side in contact with the surface of the skin of the user, and placing it in the longitudinal direction from the lower abdomen to the buttocks, and placing it in the width direction in the direction of the line that connects the left and right foot.

In the present invention, unless otherwise indicated, the surface on the side in contact with the human body is called the surface on the side facing the skin, the surface in contact with the skin, or the upper surface, and the opposite surface is called the surface on the side not facing the skin, a surface not in contact with the skin, or a lower surface. On these two surfaces, the side closer to the surface from the side facing the skin and the direction of continuation are 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 not facing to the skin, and the direction of continuation is called the side of the surface not facing the skin, the side of the surface not in contact with the skin, or the side of the lower surface. When wearing the pad, 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 back surface of the absorbent article is called the direction of the thickness, and its value is called the thickness. In the top absorbent article, a direction extending from the ventral zone to the rear side zone through the inner zone between the hips is called a longitudinal direction, and a direction that is perpendicular to the longitudinal direction is called a width direction. The longitudinal direction, as a rule, corresponds to the direction of the body of the person wearing the pad from front to back.

As shown in FIG. 10, the top sheet 21 of this embodiment is formed by bonding by laminating two fibrous layers: an upper layer 11 on the surface of the skin contact surface and a lower layer 12.

The upper layer 11 and the lower layer 12 are connected by pressure connection using the embossing element in many depressed areas 15. The upper layer 11 and the lower layer 12 are made with relief elements in the same places in the top view and depressed in the depressed sections 15 for thereby forming many areas in the form of depressions. The non-squeezed portions between the depressions, that is, the zones surrounded by the depressed portions 15, form convex portions 14. The convex portions 14a of the upper layer 11 protrude in the direction of the surface side in contact with the skin, and the convex portions 14b of the lower layer 12 protrude in the direction of the surface side, not in contact with skin. A plurality of convex portions 14a and 14b are spaced at equal intervals in the same places of the upper layer 11 and the lower layer 12 in a plan view as the aforementioned depressed portions 15, and thus a plurality of concave-convex portions are formed over the entire area of the upper layer 11 and the lower layer 12. In addition, many concave-convex sections are formed over the entire area of the upper sheet 21.

The depressed portions 15, which have become depressions of the upper layer 11 and the lower layer 12, are portions in which the fibers of the upper sheet 21 are densified and the fiber density is higher and the capillary force is greater than the fiber density and capillary force in the convex portions 14 of the upper sheet 21 This makes it possible to efficiently and quickly pass the selected fluid from the topsheet 21 into the absorbent element 3. In particular, the means described in paragraphs [0007] to [0045] of the description from JP-A-2004-166849 can be used.

In this embodiment, each depressed portion 15 has approximately a sectional shape in which two long axes intersect (see FIG. 6). The adjacent two depressed sections 15 and 15, which are located at the smallest distance from each other, are located so that they are approximately on the line of continuation of each other in the direction of the long axis. Due to this, the density gradient of the constituent fibers is formed between the depressed portions 15 and the convex portions 14 in a plurality of directions on the top sheet 21, and thus, the distribution of the fluid and the penetration of the fluid in the thickness direction of the top sheet 21 are improved. The shapes and arrangement of the depressed portions 15 may be the shapes and arrangement of this embodiment, or may be such that the relief elements of a circular or square shape are randomly distributed, and may s arbitrarily chosen any shape and layout, which is provided by density gradient constituent fibers and hence to carry out distribution and rapid penetration of fluid in the direction of thickness.

The absorbent element 3 of this embodiment is formed by coating a bale of fibers containing cellulosic fiber and an absorbent polymer with a core wrapping sheet. In the absorbent element 3, numerous concave portions 31 that are concave from the side of the non-skin surface in the thickness direction to the skin surface are located at least in the area facing the discharge area. The concave portions 31 are arranged respectively in the longitudinal direction and in the width direction of the absorbent member 3. The longitudinal arrangement and the width direction mean that numerous strips of concave portions 31 are provided at predetermined intervals in the form of the absorbent member 3 from above, and in particular, means that rows of concave sections that extend in the longitudinal direction are arranged at predetermined intervals in the width direction, and rows of concave sections that extend in the width direction are arranged enes at predetermined intervals in the longitudinal direction. The rows of concave portions 31 may be continuous or discontinuous. Concave absorbent sections 34 containing cellulosic fibers are located on the lower parts on the side of the concave sections 31, which is the side of the surface in contact with the skin. The concave portions 31, which are plurally arranged in the longitudinal direction and the transverse direction, and the corresponding concave absorbent portions 34 are aligned in the thickness direction to form structures for the absorbent element 3, allowing fluid passage. The parts of the absorbent element 3 surrounded by concave portions 31 are divided into a plurality of protruding absorbent portions 33, in the form of blocks that protrude towards the side of the bottom sheet 2. The protruding absorbent portions 33 contain cellulose fiber and an absorbent polymer to thereby absorb and hold selected fluid. In this embodiment, each protruding absorbent portion 33 has a shape approximately representing the shape of a rectangular parallelepiped having a longitudinal length direction. The protruding absorbent portions 33 are located along the lines in the longitudinal direction and in the width direction so that they are separated by predetermined gaps s and r in the natural state (see FIG. 11), as seen in a plan view from the side of the absorbent element 3, which is side of the surface not in contact with the skin. This arrangement is such that projected images of many protruding absorbent portions 33 appear to overlap in both directions when the protruding absorbent portions are projected in the longitudinal direction and the width direction. By means of the aforementioned fluid passage structures having concave portions 31, a fluid such as menstrual blood can be transferred to the corresponding protruding absorbent portions 33 and quickly absorbed and can be held therein from the non-skin side of the surface of the absorbent element 3 which is removed from the top sheet 21.

As mentioned above, the concave absorbent portions 34, which are thinner than the protruding absorbent portions 33, are arranged as part of the absorbent element 3 on the side of the concave portions 31, which is the side of the surface facing the skin. The concave absorbent portions 34 and portions 33a on the side of the protruding absorbent portions 33, which is the side of the skin contacting surface, are aligned in a plane direction to form a continuous portion 35 on the side of the absorbent element 3, which is the side of the contacting surface skin. The continuous portion 35 has a flat shape at the top of the sheet 21. The absorbent element 3 comprising concave absorbent portions 34 and protruding absorbent portions 33 forms a generally seamless integrated structure. The density is approximately uniform almost everywhere, in particular in the area facing the discharge area, with the exception of the indented portion of the groove 5, which prevents leakage. The fact that the density is approximately uniform in practice means that the absorbent element 3 does not have any part in which the density is excessively increased due to compression by embossing or the like during molding of the absorbent element 3, and also means that it is also permissible / possible cases when there is a slight change in density during manufacture or a slight change in density due to displacement of elements during the movement of products, for example, when wrapping in individual packaging. In addition, the zones B of the absorbent element in which the concave portions 31 and the concave absorbent portions 34 are located (FIG. 10) have a lower surface density compared with the surface density of the zones A of the absorbent element 3 in which the protruding absorbent portions 33 are located (FIG. 10).

Since in the absorbent element 3 of this embodiment, that side of the absorbent element 3, which is the side of the skin contacting surface and has a continuous portion 35, has a flat shape, the top sheet 21 is precisely in contact with the absorbent element 3, and a fluid that passed through the top sheet 21, is easily inserted into the absorbent element 3 over a large area. As mentioned below, the protruding absorbent sections 33 having a block shape and the concave absorbent portions 34 are formed such that the concave absorbent portions 34 and the upper portions 33a of the protruding absorbent portions 33, similar to the blocks, form a continuous plane on the skin contact surface side, and in the interface between the concave absorbent portions 34 and the protruding absorbent portions 33 having a block shape, there is no excessively large difference in density that can be seen in conventional grooves obtained indentation, and the like, and both types of sections have approximately uniform density and are formed from approximately the same material; in addition, the interface / interface zone is flat when viewed from the side of the surface in contact with the skin in a plan view, and it cannot be seen by visual observation.

In addition, in the aforementioned structure allowing the passage of fluid, in particular in the concave absorbent portions 34, the density is not increased and the thickness is small, and thus, the surface density is reduced, and therefore, the resistance to passage of the fluid is low. In this way, the concave absorbent portions 34 become fluid passageways in which the degree of fluid retention is reduced, and thus the fluid from the top sheet 21 can be quickly drawn into the inside of the absorbent element 3. On the other hand, the fluid, which passed through the concave absorbent portions 34, easily moves to the upper portions 33a of the protruding absorbent portions 33 in the continuous portion 35, which has no boundary zone and has approximately uniform density, and is quickly absorbed INDICATES in absorbent plural protruding portions 33, moves in the thickness direction and is held. On the other hand, the fluid present in the concave absorbent portions 34 is also captured by the concave portions 31, which are portions of the space. The fluid that has passed into the concave portions 31 is absorbed and held in the lower parts of the protruding absorbent portions 33. It goes without saying that the fluid can also be absorbed and held directly by the portions 33a (portions of the continuous portion 35) of the protruding absorbent portions 33. However, in that case when a fluid having a high viscosity, such as menstrual blood, is released in large quantities at one time / at a time or is released repeatedly, even if the fluid cannot be absorbed and retained and again projecting portions 33 absorbent, fluid is quickly absorbed by absorbent concave portions 34 and concave portions 31 operate as a buffer for temporarily retaining the fluid. In addition, as mentioned above, since the concave portions 31 are connected continuously from the side of the absorbent element 3, which is the side of the surface not in contact with the skin, the fluid can move in those places that are removed from the top sheet 21, to enable reliable absorbing and retaining the fluid in the respective protruding absorbent portions 33. Thus, the fluid can be quickly absorbed into the interior of the absorbent element 3 from the side of the top sheet 21 pos by means of fluid passage structures formed from concave absorbent portions 34 and concave portions 31, and can be reliably absorbed and held by the protruding absorbent portions 33. Consequently, the presence of residual fluid on that side of the absorbent element 3 that is the surface side is reduced, in contact with the skin, and it will be difficult for the backflow of fluid from the inside of the absorbent element 3 to the top sheet 21.

Furthermore, even if pressure acting in the thickness direction is applied while the gasket 30 is being worn, it will be difficult to return the released fluid, such as menstrual blood, to the side of the upper sheet 21 due to the presence of structures that allow fluid to pass and are formed from concave absorbent sections 34 and concave sections 31. It is believed that this effect is provided by many actions: concave absorbent sections 34 provide a quick movement of the fluid in the concave sections 31, not holding fluid; a fluid that has already been sucked in by the concave portions 31 is located at locations that are relatively distant from that side of the absorbent element 3, which is the side of the skin contact surface; the amount of fluid accumulated in the concave portions 31 themselves does not remain large, since the fluid quickly moves to that side of the absorbent element 3, which is the side of the surface not in contact with the skin, due to the structures that allow the passage of the fluid and having concave portions 31, and is absorbed and held by the protruding absorbent portions 33; etc. In addition, it is also believed that another factor is that the pressure applied to the concave portions 31 is “buffered” due to the presence of concave absorbent portions 34, and the movement of fluid in structures that allow fluid to pass through and have concave portions 31 is accelerated by account of this pressure. Thus, since the fluid is rapidly sucked into the concave portions 31 and the fluid does not remain on the side of the absorbent member 3 facing the top sheet 21, the backflow of fluid to the side of the top sheet 21 is also effectively suppressed even if the pressure acts thickness direction, and thus a good dry feeling can be provided. In addition, since the absorbent element 3 has a concave-convex shape, which is divided by longitudinal and transverse concave sections 31 on the side of the absorbent element 3, which is the side of the surface not facing the skin, the absorbent element has flexibility in this part, and thus thus, the “ability to fit to the body”, due to which the sanitary towel 30 adheres to the bumps of the skin surface, and the “ability to follow the movement”, due to which the sanitary towel 30 “follows” the movement the user and prevents the formation of partial gaps relative to the skin, are improved to a very significant extent.

In the present invention, the arrangement of the protruding absorbent portions 33 is an arrangement according to this embodiment, or may be any arrangement that can be appropriately selected depending on the intended use and function, and, for example, the arrangement may be a staggered arrangement (arrangement in which the aforementioned projected images are staggered approximately half a step in the longitudinal direction and / or and width direction). Furthermore, the shape of the protruding absorbent portion 33 is the shape of this embodiment, or may be any shape that can be selected appropriately depending on the intended use and function. In addition, a conventional leakage-preventing groove may be formed by applying a pressing force from the top sheet side of the aforementioned absorbent member of the present invention. In addition, a conventional leakage-preventing groove may be formed by embossing on the top sheet of the aforementioned absorbent member of the present invention.

As the manufacturing method of the absorbent element 3, there can be mentioned a method according to which the absorbent element 3 can be manufactured, for example, by using a machine for stacking fibers in a stack, a machine for stacking mixed fibers in a stack, or the like (not shown), which provides " dispersion "of the material of the absorbent element containing cellulosic fibers or cellulosic fibers and a polymer with ultra-high absorbency in air and absorption of this material in parts Ithel mold 50 having the plural protruding portions 51 which are arranged on the peripheral surface of the drum for placing filaments into a stack or the like to enable the deposition of material on them (see Fig. 5).

For example, as shown in FIG. 5, a mixture of cellulosic fibers 61 and ultra-absorbent polymer 62 is stacked in the form of a stack while avoiding the protruding portions 51 of FIG. 5 (a), and as the mixture gradually settles, the stack is stacked, leaving the height limits of the protruding parts 51, as shown in FIG. 5 (b), thereby obtaining a blank 70 of the absorbent element of FIG. 5 (c). The stacked parts 74 located on the protruding parts 51 become concave absorbent portions 34 of the absorbent element 3, and the parts 71 in which the protruding parts 51 are located become concave portions 31 of the absorbent element 3. Parts 73 housed in the concave storage portions between the protrusions, become protruding absorbent sections 33 before compression. In addition, the part 75, which is stacked in the form of a stack over the protruding parts 51, becomes the continuous part 35 of the absorbent element 3. The stack is closed from the fibrous mixture of cellulose fibers and the absorbent polymer formed in this way with a sheet (not shown) for wrapping the core formed from paper, such as sanitary paper, from various nonwoven materials or the like, to form an absorbent member 3.

Since the concave absorbent portions 34 and the protruding absorbent portions 33 of the absorbent element 3, which are integrally formed in this way, are formed without compression / squeezing or the like, the fiber density does not become high, and thus, the absorbent element 3 will have an approximately uniform density . In addition, the concave absorbent portions 34 have a lower surface density compared to the surface density of the protruding absorbent portions 33 due to their fineness. Unlike concave absorbent portions formed by compression, such as embossing, concave absorbent portions 34 have little resistance to the passage of fluids, which makes it possible to quickly move the fluid in the thickness direction. In addition, the absorbent element 3 provides a fine / good texture because the absorbent element 3, which is molded integrally in this way, has no part that is hard due to compression, such as embossing. When wearing the pad 10 having the specified absorbent element 3, the carrier may feel the softness of the absorbent element 3 because there is no hard part that touches the user through the top sheet 21. In addition, since the pad has flexibility in the locations of the concave portions 31, the pad snug to the body and provides a good level of comfort.

In order for the concave absorbent portions 34 to provide a reduction in the degree of fluid retention and the rapid movement of the fluid into the concave portions 31, and for the concave portions 31 to temporarily hold the separated fluid and prevent the back flow of fluid to the side of the top sheet 21, as mentioned above, ratio (%) height / depth (h ₂₎ of the concave portions 31 to the thickness (h ₁₎ of the absorbent element 3 (thickness of the protruding portions 31 of the absorbent) (see. Figure 10) is preferably from 40 to 98%, particularly preferably - from 30% to 70%, and even more preferably - from 40% to 60%. By adjusting this ratio so that it matches the aforementioned lower limit or a larger value, it is possible to more effectively reduce the presence of residual fluid on the upper sheet and backflow to the upper sheet, and by adjusting this ratio so that it matches the upper limit or a lower value , it can be ensured that the fluid received from the top sheet is moved to the protruding absorbent portions 33 without spreading too wide. For the same reasons, the constituent material of zones B having concave absorbent portions 34 and concave portions 31 (see FIG. 10) has a base weight (w ₁ ), preferably from 30 to 160 g / m ² , more preferably from 50 up to 150 g / m ² . Zones A having protruding absorbent portions 33 (see FIG. 10) have a base weight (w ₂ ) of preferably 180 to 400 g / m ² , more preferably 200 to 300 g / m ² . In addition, the ratio (w ₁ / w ₂ ) of the basis weight of the two zones is preferably from 0.1 to 0.8, more preferably from 0.3 to 0.6.

In the present invention, concave portions 31 are portions that become voids due to indentation from the bottom of the absorbent element 3 toward the side of the skin contact surface. The concave absorbent portions 34 are portions of the absorbent element 3 that are located on the upper parts of the concave portions 31 and which are separated by virtual lines s and s that extend in the thickness direction from the lower wall portions 31a and 31a (see FIG. 12). The protruding absorbent portion 33 is a portion extending from the upper portion to the lower portion of the absorbent element, which is adjacent to zones B and surrounded by zones B, each of which contains a concave portion 31 and a concave absorbent portion 34 that are located in the thickness direction (see figure 10 and figure 12).

The thickness (h ₃ ) of the concave absorbent portions 34 and the thickness (h ₁ ) of the protruding absorbent portions 33, defined as described above, were measured by placing an acrylic polymer plate having dimensions of 37 mm × 37 mm and a thickness of 3 mm by the absorbent core 10, measuring the thickness (h ₁ ) of the protruding absorbent portions 33, including the upper parts 33a, by using a non-contact laser displacement meter manufactured by KEYENCE Corporation (laser head: LK-G30, displacement meter: LK-GD500), and thickness measurements ( h ₃ ) in bent absorbent portions 34 by measuring a sectional surface corresponding to FIG. 10 for an absorbent element using a VHX-1000 microscope manufactured by KEYENCE Corporation.

Furthermore, the method for determining the weight of the base (w ₁ ) of the concave absorbent portions 34 and the weight of the base (w ₂ ) of the protruding absorbent portions 33 is as follows: the weight of the base (w ₁ ) was calculated by cutting the concave absorbent portions in the concave portions by pressing a razor manufactured by FEATHER Safety Razor Co., Ltd. (FEATHER Razor S, with one cutting edge), mass measurements and mass dividing by the surface area of the parts that were cut, and in addition, the weight of the base (w ₂ ) was calculated by cutting the protruding absorbent sections 33, including the upper parts 33a, mass measurements and mass dividing on the surface area of those parts that have been cut.

Despite the fact that the absorbent polymer inside the absorbent element 3 is present in a uniformly distributed form in this embodiment, to more effectively suppress the backflow of fluid, it is preferable to place the absorbent polymer so that it is more biased towards those portions of the protruding absorbent portions 33, which are below the continuous portion 35 containing concave absorbent portions 34, and more preferably, the absorbent polymer is placed so that it is displaced in a larger heat to the side of the protruding absorbent portions 33, which is the side of the surface not facing the skin, than to the continuous portion 35 containing the concave absorbent portions 34. In addition, for the same reasons, it is also preferable to place the absorbent polymer on the other side of the concave portions 31 , which is the side of the surface not facing the skin.

In addition, in the absorbent body 3 of this embodiment, it is preferable to place structures that allow fluid to pass and have concave portions 31 so as to encompass portions located externally in the width direction with respect to leakage groove 5. Due to this arrangement, the stiffness of the product when bending in the direction of the width of the product as an axis decreases, and the product is easily deformed in accordance with the curvature of the user's body in the direction from the perineum to the buttocks, and this arrangement can also provide flexibility on both sides of the absorbent element 3, where leakage easily occurs laterally, thereby ensuring that the absorbent element snugly fits the wearer's crotch, and the absorbent element can “follow” the movement of the body Vatel, to thereby prevent the formation of gaps.

In this case, the dynamic characteristics of the aforementioned sectioned absorbent element 3 and the top sheet 21 in the sanitary napkin 30 are described in detail based on FIG. FIG. 12 is a partial sectional view showing an enlarged portion of a predetermined sectional surface of the sanitary napkin shown in FIG. 9. The bottom sheet 2 and the side sheet 4 are not illustrated in order to avoid complicating the drawing, and the shape of the top sheet 21 is shown schematically and may not be the same shape as the illustrated form when practicing the present invention.

The topsheet 21 of this embodiment provides high mobility to the isolated fluid when it is moved in the thickness direction due to capillary force using a density gradient similar to the above, and thus can provide a quick movement of the fluid released from the body into the absorbent element 3. In addition, since the convex portions 14a of the upper layer 11 and the convex portions 14b of the lower layer 12 are formed at the same places in the thickness direction (see FIG. 12), the fluid can be easily moved is allowed to accumulate in one place in the plane, and this is preferable since even a small amount of fluid is directed into the absorbent element 3, and it is possible to efficiently pass this small amount of fluid towards the absorbent element 3. In particular, if the density of the fibers in the upper layer 11 and the lower layer 12 is different and the density of the fibers of the lower layer is higher, the fluid easily remains on the side of the lower layer of the upper sheet 21, but the structure in which the fluid accumulates creates It has the effect of improving the feeling of dryness due to the shielding property of the top sheet 21 and its ability to provide a small backflow of fluid. As mentioned above, the absorbent element 3 has numerous concave portions 31 on the surface side not in contact with the skin, and the concave absorbent portions 34 are located on the surface side in contact with the skin. Since the concave absorbent portions 34 have less resistance to the passage of fluid compared to the portions of other parts of the absorbent element, by using these portions as chambers, the extracted fluid a _{1 is} rapidly absorbed in the thickness direction of the absorbent element 3. The portion of the fluid that has moved to the thickness direction of the absorbent member 3, becomes a moving fluid ₂ which extends towards the surrounding absorbent protruding portions 33, 33, and another hour s becomes accumulated fluid and _3, which is captured by the concave portion 31. Thus, since the fluid that has penetrated from the upper sheet 21 is sucked absorbent concave portions 34 and separated into a fluid and the fluid ₂ and _3, the retention side the front surface of the absorbent element is reduced, and the resistance to passage of the fluid is further reduced. Therefore, the backflow of fluid towards the top sheet 21 can also be effectively suppressed.

Thus, the sanitary napkin 30 of this embodiment can sufficiently exhibit the characteristics of the topsheet 21, which is capable of good fluid transmission in the thickness direction, due to the large fluid transmission ability in the thickness direction of the absorbent element 3 having concave sections 31 to thereby provide an effect of suppressing the backflow of fluid to the skin for the sucked-in fluid, which provides a preferred dryness tions for users.

The sizes and shapes of the protruding absorbent portions 33 and the concave portions 31 in this embodiment are not particularly limited. Even though the dimensions vary slightly depending on the intended use of the absorbent product used, the length k _{1 of the} protruding absorbent portion 33 in the longitudinal direction (see FIG. 11) is preferably from 10 to 30 mm, more preferably from 15 to 25 mm, for reasons related to improving the gradual bending of the absorbent element along the axis of the concave portions toward the skin contact surface and the deformation of the absorbent element along the shape of the wearer's body. The length k _{2 of the} protruding absorbent portion 33 in the width direction is preferably from 5 to 20 mm, more preferably from 7 to 15 mm, for reasons related to the fact that the concave portions weaken the compressive force acting in the width direction that is applied to absorbent body while wearing. In addition, the length s of the concave portion 31 in the longitudinal direction is preferably from 1 to 5 mm, more preferably from 1 to 3 mm. The length r in the width direction is preferably from 1 to 5 mm, more preferably from 1 to 3 mm.

Materials and a preferred method for manufacturing the topsheet 21 will be described below.

The top sheet 21 consists, for example, of the top layer 11, which is formed from heat-resistant heat-shrinkable fibrous material or fibers having a higher heat-shrink temperature than the heat-shrink temperature of the fibers in the lower layer, and from the lower layer 12, which is formed from not subjected shrink, a heat shrinkable fibrous material that has a higher heat shrink temperature than the heat shrink temperature of the fibers in the upper layer.

The upper layer 11 and the lower layer 12 are fused partially or completely to a predetermined pattern by compression / embossing under the influence of heat or the like, and heat is supplied to them to enable heat shrinkage of the lower layer 12 in the horizontal direction. Then, due to the combination of the upper layer 11 and the lower layer 12 during embossing during shrinkage of the lower layer 12, the upper layer 11 also tends to shrink under the action of the lower layer 12, since the upper layer 11 is integrated with the lower layer 12 by embossing. However, curvature deformation occurs because heat shrinkage does not occur in the upper layer 11 or occurs to a lesser extent in the upper layer 11 as compared to the heat shrink of the lower layer 12, and the deformation appears as a convex protrusion on the upper layer 11. Accordingly, the deformation also appears in in the form of a convex protrusion on the lower layer 12, since the deformation in the upper layer 11 is also transmitted to the lower layer 12. It should be specially mentioned that the hot-stamping connection is carried out by hot stamping nil surfaces, on which a plurality of embossing rods, each of which has a predetermined shape, are arranged with a predetermined arrangement (on the peripheral surfaces of the embossing rollers and the like), in contact with both sides of the upper layer 11 and the lower layer 12 in the laminated element consisting from the upper layer 11 and the lower layer 12, due to the application of pressure and fusion of the constituent fibers in the upper layer 11 and the lower layer 12 in places that are compressed by the respective rods when applying heat. The convex portions 14, which are formed by the upper layer 11 and the lower layer 12, may have parts that are “pushed” so that they cover the depressed portions.

Heat shrinkage of the lower layer 12 is performed by forming a lower layer 12 of heat-shrinkable fibers or by incorporating heat-shrinkable fibers into the lower layer 12 in advance and heat treat the middle layer 12 simultaneously with the upper layer 11 and the lower layer 12 being fused or after the two layers are fused . By thermally shrinking the lower layer 12 in a horizontal direction in a similar manner, the ability of the convex portions formed on the upper layer 11 and the lower layer 12 to form protruding parts is improved, and thus, the upper sheet 21, which is more bulky and has finer / better texture. In the case where the top sheet 21 is formed by bonding two fibrous layers by lamination in a similar manner, from the viewpoint of improving the fluid transmission ability of the top sheet 21 in the thickness direction of the top sheet, it is preferable that no boundary is formed between the two fibrous layers.

As the upper layer 11 and the lower layer 12, it is preferable to use, for example, a carded web or a bulk non-woven material. A carded cloth refers to a collection of fibers before converting it into a nonwoven material. Namely, this means a collection of fibers in a state in which the fibers are rather weakly mixed with each other and which corresponds to a state where the collection of fibers has not yet undergone subsequent processing of a carded web that is used in the manufacture of a nonwoven material, such as processing for fusion bonding through a through flow process or a calendaring process. When the carded webs are used as the upper layer 11 and the lower layer 12, the fibers in the upper layer 11 and the lower layer 12 are thermally fused simultaneously with or after the connection of the upper layer 11 and the lower layer 12. In addition, to examples of bulk non-woven material may include non-woven material obtained by passing a through stream of air, non-woven material obtained by laying in the air stream, non-woven material bonded with resin, and the like. The constituent fibers of the upper layer 11 are preferably fibers that are not substantially heat-shrinkable, or fibers that are not heat-shrinkable at a temperature equal to the heat-shrink temperature of the constituent fibers of the lower layer 12 or lower than the heat-shrink temperature of the constituent fibers of the lower layer 12. The surface density of the upper layer 11 is preferably from 10 to 50 g / m ^2, more preferably - 15 to 40 g / m ^2, from the viewpoint of formation of sufficient density gradient from the viewpoint st chsheniya texture topsheet 21.

As the lower layer 12, a carded web or heat-shrinkable nonwoven fabric can be used. The constituent fibers of the lower layer 12 are preferably fibers formed from a thermoplastic polymeric material, as well as heat-shrinkable / heat-shrinkable. Examples of such a fiber may include a fiber with a hidden crimp. The level of fibers with hidden crimp in the lower layer 12 is preferably from 40 to 100 weight percent. Fiber with a hidden crimp can be processed similarly to conventional fibers for non-woven materials before heating, and fiber with a hidden crimp are fibers that undergo shrinkage with the formation of spiral twists under the action of heating to a given temperature.

A fiber with a hidden crimp is formed, for example, of two-component fibers such as fibers with an eccentric core and cladding or fibers with the arrangement of components side by side, containing two types of thermoplastic polymeric materials with different degrees of shrinkage. Examples thereof may include fibers described in JP-A-H9-296325 and JP-B-2759331. The middle layer may shrink, for example, by incorporating pre-shaped fibers with hidden crimp into it and ensuring that the fibers are crimped by heating at the same time as the upper layer 11 and the lower layer 12 are fused together or after the upper layer 11 and the lower layer 12 have been fused. The middle layer 12 has a surface density of preferably 10 to 50 g / m ² , more preferably 15 to 40 g / m ² .

The upper sheet 21 formed from the upper layer 11 and the lower layer 12 has a surface density of 20 to 100 g / m ² , more preferably 35 to 80 g / m ² . Since many concave-convex portions are formed on the top sheet 21, the sheet 1 has a large thickness and is voluminous.

The topsheet 21 is not limited to the aforementioned embodiment, and may be modified accordingly provided that it does not deviate from the object of the present invention. For example, the top sheet 21 may be formed by a fibrous sheet with a three-layer structure. In this case, it is desirable to form a middle layer 13 of heat-shrinkable fibers and form an upper layer 11 and a lower layer 12 of fibers that do not have heat-shrinkability. In addition, from the point of view of increasing permeability with respect to the fluid, it is desirable that the upper layer 11 has a higher surface density compared to the surface density of the lower layer 12.

Subsequently, materials for forming the elements that form the sanitary napkins 10, 20 and 30 according to these embodiments will be explained.

As materials for the formation of the top sheet 1, the bottom sheet 2, the absorbent element 3 and the side sheet 4, those materials that are selected for the product of this type can be used without particular limitation. For example, as the top sheet 1, a structure is used in which various non-woven materials (for example, non-woven material obtained by passing through an air stream, non-woven material of a spunbond production method (spunbond) and the like) are superposed on each other, a composite sheet formed from a laminate from a nonwoven material and a film on which a plurality of open pores are formed, or the like. In addition, the top sheet may be a sheet formed of three layers: the upper layer, the middle layer and the lower layer, each of the upper layer and the lower layer having a shape with a surface roughness formed by protruding portions and parts pressed by embossing, and connected to a flat middle layer.

The side sheet 4 is preferably a water-repellent non-woven material, and water-repellent non-woven material or various non-woven materials that have been processed to give them water-repellent properties can be used, and they are selected from carded non-woven materials, spunbond non-woven materials, non-woven materials made by melt blowing, non-woven materials made by hydro-entangling, non-woven materials, manufacturing made using heated rolls, needle-punched non-woven materials, and the like. For example, non-woven materials of a spunbond production method, non-woven materials with an SM structure consisting of a layer obtained by a spunbond production method and a layer obtained by melt blowing, non-woven materials with an SMS structure consisting of a layer obtained by a spunbond production method, a layer, obtained by blowing from the melt, and a layer obtained by a spinneret production method, and the like.

The material for forming the absorbent parts 3 is not particularly limited, and fibrous materials, porous materials and combinations thereof and the like can be used. Examples of fibrous material that can be used include: natural fibers, such as wood pulp fibers, cotton fibers and hemp fibers; elementary fibers consisting of synthetic resins, including, for example, polyolefin-based resins such as polyethylene and polypropylene; polyester resins such as polyethylene terephthalate and polyvinyl alcohol resins; bicomponent fibers containing two or more types of these resins, and semi-synthetic fibers such as acetate and hydrate cellulose / viscose. In cases where synthetic resin fibers are used, the fibers can be heat-shrinkable fibers that are deformed by heat. For example, you can use fibers whose fineness increases, but whose length decreases under the influence of heat, or fibers whose fineness changes insignificantly under the influence of heat, but whose apparent length, which the fibers have, decreases due to their deformation with the formation of a serpentine shape. Examples of porous materials that can be used include sponges, non-woven materials, and combinations of polymers with ultra-high absorbency (i.e., combinations of polymers with ultra-high absorbency and fibers), and the like.

As the bottom sheet 2, a moisture-permeable film per se, a moisture-proof film per se, or a film and non-woven material that are bonded, water-repellent non-woven material with an SMS structure (layer obtained by spunbond production method, layer obtained by melt blowing, layer can be used) can be used obtained by a spinneret production method), with the structure of SMMS (a layer obtained by a spinneret production method, a layer obtained by blowing from a melt, a layer obtained by blowing from a melt, a layer obtained by lernym production method, and the like) or the like. From the point of view of combination with an anti-slip adhesive and the like, it is most preferable to use a moisture-permeable film or a moisture-proof film per se as a material for preventing leakage. Examples of a moisture-permeable film material may include a film obtained by plasticizing during melting and extrusion of a thermoplastic resin and an inorganic filler that is not compatible with the thermoplastic resin, drawing the extruded film to a predetermined size and the formation of small pores in the film, or a non-porous film that is essentially has high moisture compatibility and can release water vapor like a semi-permeable / osmotic membrane. In order to obtain a leak prevention layer that sufficiently has the property of releasing moisture and ensures that no fluid leakage is associated with the present invention, the moisture permeability is preferably in the range of 0.7 to 3.0 g / 100 (cm ² · h), more preferably 1.0 to 2.5. From the point of view of increasing dryness, providing comfort, it is most preferably most preferred that the moisture permeability is in the range from 1.5 to 2.5. In addition, in order to be able to use the film without problems, such as tearing the film, the film has a surface density of 18 to 70 g / m ² , more preferably 25 to 60 g / m ² . In addition, the preferred content of the inorganic filler is from 30 to 65 weight percent, more preferably from 40 to 60 weight percent, determined based on the percentage of the weight of the filler to the weight of the entire film.

As mentioned above, since the absorbent article of the present invention has an absorbent element having the aforementioned structure, the fluid is absorbed through portions located on that side of the concave absorbent portions and the protruding absorbent portions of the absorbent element, which is the side of the skin contacting surface, is rapidly absorbed with simultaneous distribution in the direction in the plane, it is absorbed and held (fixed) on shaped blocks that protrude absorbent stkah. Since the structures providing the passage of the fluid, which are located in the longitudinal direction and in the transverse direction in the absorbent body, have concave absorbent sections on the side of the concave sections (recesses), which is the side of the surface in contact with the skin, this contributes to the movement of the fluid, rather than retaining the fluid, and thus the fluid is quickly and easily absorbed and held by a plurality of protruding absorbent portions. In the aforementioned concave portions, a fluid that has passed through the concave absorbent portions can be temporarily held, and thus, the presence of residual fluid on the side of the top sheet is reduced. Since the fluid held in the concave portions is absorbed and held on the side of the protruding absorbent portions, which is the side of the surface not in contact with the skin, the occurrence of a reverse fluid flow is difficult. By means of fluid passage structures such as those mentioned above, the fluid can be reliably absorbed and held in each of the plurality of protruding absorbent sections in the form of blocks that are arranged with “dispersion”. In addition, in the second embodiment, the protruding portions on the lower surface side of the top sheet allow fluid to flow smoothly into the absorbent element and can prevent reverse wetting, that is, a reverse flow of fluid that has already passed into the absorbent element toward the skin side. That is, the combination of a top sheet having regularly extending protruding portions and an absorbent element having fluid passage structures formed from concave portions and concave absorbent portions provides excellent fluid transmission ability in the thickness direction and provides guaranteed absorption and retention of fluid Wednesday.

In the present invention, the structures of the high-density zones 38 and the low-density zones 39 of the absorbent element and the structures that allow the passage of fluids and formed from the concave sections 31 and the concave absorbent sections 34 are not limited to structures located along the entire length in the longitudinal direction, as in This embodiment, and can only be located in the area facing the area of secretions. The absorbent article of the present invention is not limited to the aforementioned embodiments, and the present invention can be applied to this type of sanitary napkins, such as daily incontinence pads and incontinence pads. In addition, the present invention is also effective not only for menstrual blood, but also for urine, vaginal discharge, loose stool, and the like. Furthermore, in addition to the upper sheets 1 and 21, the absorbent parts 3, the lower sheet 2 and the side sheet 4, other elements can be appropriately included in accordance with the intended use and operation. The materials for the upper sheets 1 and 21, the absorbent element 3 and the lower sheet 2 of sanitary napkins according to the above embodiments, the modes in the manufacturing method and product size data are not particularly limited, and various materials that are used in conventional sanitary napkins can be used.

EXAMPLES

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to them.

{Example 1}

A mixture of cellulosic fiber and an ultra-absorbent polymer was deposited by suction in storage parts having protruding parts that are longitudinally and transversely spaced at equal intervals on the peripheral surface of the drum for stacking fibers in a stacking machine fibers in the foot to obtain a stack of fibers consisting of cellulose fiber and a polymer with ultra-high absorbency, with a total surface density of cellulose of a large fiber in an absorbent body of 200 g / m ² and a total surface density of an ultra-high absorbency polymer in an absorbent body of 52 g / m ² (FIG. 5 (c)) (total surface density of cellulose fiber and total surface density polymers with ultra-high absorbency mean surface density values taking into account the entire length of the concave and convex parts). This stack of fibers was covered with a core wrapping sheet, passed through a pair of compression rollers and compressed under a pressure of 3.0 kgf / cm ² to obtain an absorbent element, and the absorbent element was used as sample 1 in Example 1. In this sample 1, protruding absorbent portions 33 as high density zones 38 had an average density (m ₂ ) of 0.12 g / cm ³ , and concave absorbent portions 34 as low density zones 39 had an average density (m ₁ ) of 0.08 g / cm ³ . Zones 38 of high density had an average base weight (w ₂ ) of 240 g / m ² , and zones 39 of low density had an average weight of the base (w ₁ ) of 100 g / m ² . In addition, the concave absorbent portions 34 had a thickness (h ₃ ) of 1.2 mm, and the protruding absorbent portions 33 had a thickness (h ₁ ) of 2.0 mm. Each of the protruding absorbent sections 33 had a length k ₁ in the longitudinal direction of 20 mm and a length k ₂ in the width direction of 10 mm, and each of the concave sections 31 had a length s in the longitudinal direction of 2.0 mm, and a length r in the width direction of 1.0 mm.

The absorbent element was removed from a commercially available and commercially available sanitary towel manufactured by Kao Corporation (trade name: “Laurier F for heavy flow daytime and regular flow days”), and sample 1 of the above absorbent element was placed in the place from which the absorbent element was removed, and other elements were returned to their original position to obtain a sanitary napkin for evaluation. The top sheet of the aforementioned industrially manufactured and commercially available sanitary napkin is formed of a nonwoven material having the following composition / structure.

Non-woven material: a laminated non-woven material of a two-layer structure having upper and lower fibrous layers, in which the upper layer consists of 100% bicomponent fibers with a core and a sheath, containing polyethylene terephthalate as a core and polyethylene as a sheath, and the lower layer consists of 100% fibers with hidden spiral crimp (NBF-L (V) manufactured by Daiwabo Co., Ltd., which are bicomponent fibers with a core and a sheath, containing polyethylene as a core and polypropylene as a sheath, which do not show spiral tortuosity when heated). The mass ratio of the upper and lower layers (upper layer / lower layer) is 50/50. The upper and lower layers are connected by means of dot embossed / pressed parts, which are located in the form of "scattered" points, and the fibers with hidden crimp in the lower layer are in such a state that crimp appears when heated.

{Comparative example 1}

The aforementioned industrially manufactured and commercially available sanitary napkin manufactured by Kao Corporation was used as a sanitary napkin in the Comparative Example. In the absorbent body (sample 2) of this industrially manufactured and commercially available sanitary towel, round embossed parts, each of which has a diameter of 2 mm, were staggered over the entire area. The pitch between the centers of the embossed parts is 7 mm. The surface density (mass per part area) was 250 g / m ² .

In addition, as a Control Example and Comparative Examples 2-4, samples of 3-6 absorbent bodies having the cross-sectional surfaces shown in Figs. 13 (a) to (d) were each used for the aforementioned industrially manufactured and commercially available gaskets and evaluated.

{Test Case}

A mixture of cellulosic fiber and an ultra-absorbent polymer was deposited by suction in storage parts having protruding parts that are longitudinally and transversely spaced at equal intervals on the peripheral surface of the drum for stacking fibers in a stacking machine fibers in the foot to obtain a stack of fibers, consisting of cellulose fiber and an absorbent polymer, with a surface density of the protruding absorbent sections, was as high as 240 g / m ² and a surface density of concave absorbent portions of 115 g / m ² (FIG. 13 (a)). This stack of fibers was covered with a core wrapping sheet to obtain an absorbent element, and the absorbent element was used as a sample in Example 1 (sample 3). The stack of fibers used consisted of cellulosic fibers and a highly absorbent polymer, and each of the protruding parts used had the following dimensions: 20 mm (in the longitudinal direction) × 10 mm (in the width direction).

{Comparative example 2}

The absorbent element was obtained similarly (including dimensions) to the absorbent body according to Example 1 except that the depth (h ₂ ) of the concave portions was 30% of the thickness of the absorbent element (thickness of the protruding absorbent portions), the surface density of the protruding absorbent portions was 240 g / m ² and the surface density of the concave absorbent portions was 160 g / m ² in the absorbent body of this embodiment, and the absorbent element was used as the sample of Comparative Example 1 (sample 4) (see Fig. 13 (b)).

{Comparative example 3}

The absorbent element was obtained similarly (including dimensions) to the absorbent body according to Example 1, except that the concave portions were not made in the absorbent body, and the surface density of the entire absorbent element was 200 g / m ² , and the absorbent element was used as a sample according to Comparative example 2 (sample 5) (see Fig.13 (c)).

{Comparative example 4}

The high-pressure-compressed portions 35 were formed on the side of the absorbent member of Comparative Example 2, which is the side of the skin contacting surface by compressing the absorbent member from the non-contacting surface of the skin using rod-shaped embossing elements. An absorbent element similar to Example 1 (including dimensions) was obtained, except as described above, and the absorbent element was used as a sample in Comparative Example 3 (sample 6) (see FIG. 13 (d)).

[Performance evaluation]

<1> For the aforementioned Example, Comparative Examples 1-4 and Control Example 3 g of blood was injected three times into each sanitary napkin at intervals of 3 minutes from the top of the sheet, and the evaluation was carried out in an environment with a temperature of 25 ° C. The backflow of fluid on the surface layer was evaluated at the time when 6 g (total amount injected) of horse blood was absorbed, and the surface area of the fluid spreading was the surface area after absorption of 9 g of horse blood. In this case, horse blood was used as the blood introduced into the pad. In particular, defibrinated horse blood manufactured by Nippon Biotest Laboratories Inc. was used. Defibrinated horse blood had a viscosity of less than 15 mPa · s, measured with a Type B TVB-10M viscometer manufactured by Toki Sangyo Co., Ltd. (measurement temperature: 25 ° С, with adapter and rotor L). The horse blood used was the same in all the examples from Example and Comparative Examples.

<2> Method for measuring the value of the reverse flow of fluid on the surface layer

3 g of horse blood was introduced by using a fluid injection plate having a fluid injection portion with an open pore size of 10 mm. 1 minute after the introduction of the fluid, sanitary-hygienic paper, the mass of which was measured, was placed on the surface of the gasket, a metal plate with a mass of 125 g was additionally placed on it, pressed down for 5 seconds (with a pressure of 4.5 g / cm ² ), and the amount of fluid absorbed by the sanitary paper was measured. In addition, the amount of fluid adhered to the surface of the insert plate in contact with the gasket was also measured, and a total value, the sum of the two amounts, was used as the amount of fluid backflow to the surface layer when 3 g of horse blood was injected. . 3 g of horse blood was reintroduced 3 minutes after the first administration, and operations similar to the above were repeated 1 minute after administration to obtain a return fluid flow to the surface layer if only 6 g of horse blood was injected. 3 g of horse blood was introduced again, and operations similar to the above were repeated 1 minute after injection to obtain the amount of back flow of fluid on the surface layer if only 9 g of horse blood was injected.

<3> Method for measuring the surface area of the spreading fluid

The surface area of the fluid spreading on the surface layer (top sheet side) of the absorbent pad member that was evaluated for the return flow of fluid on the surface layer (after introducing 6 g of horse blood) was measured using an image analyzer and determined as the surface area of the fluid spreading .

The results of the above estimates are shown in table 1 below.

[Method of measurement]

The sanitary pad was placed horizontally, an acrylic polymer plate with a cylinder having an input channel with a diameter of 1 cm was placed on the bottom surface on a sanitary pad, 3 g of defibrinated horse blood (manufactured by Nippon Biotest Labo) was introduced from the input channel , and after entering this state remained for 1 minute. After this, an acrylic polymer plate with a cylinder was removed, and 16 sheets of absorbent paper (industrially manufactured and commercially available, sanitary paper) with a size of 6 cm × 9.5 cm and a surface density of 13 g / m ² were superimposed on each other and placed on the upper surface of the top sheet. In addition, a load was placed on them, so that a pressure of 4.0 × 10 ² Pa was applied, and pressure was applied for 5 seconds. After the application of pressure, the absorbent paper sheets were removed, the paper weight before and after the application of pressure was measured, and the mass of defibrated horse blood absorbed by the paper was measured and determined as the amount of fluid remaining on the surface.

The results of the above estimates are shown in table 1 below.

Table 1 The present invention Comparative Example 1 Test case Reference Example 2 Reference Example 3 Reference Example 4 The magnitude of the reverse fluid flow on the surface layer (in the case of absorption of 6 g of horse blood, after 1 minute) 50 mg 200 mg 120 mg 260 mg 390 mg 190 mg The surface area of the spreading fluid (the surface side of the absorbent element, not facing the skin, after absorption of 9 g of horse blood) 36 cm ² 39 cm ² 37 cm ² 39 cm ² 36 cm ² 40 cm ² The average density of the protruding absorbent areas 0.12 g / cm ³ 0.125 g / cm ³ 0.12 g / cm ³ 0.12 g / cm ³ 0.125 g / cm ³ 0.12 g / cm ³ The average density of concave absorbent areas 0.08 g / cm ³ 0.125 g / cm ³ 0.12 g / cm ³ 0.11 g / cm ³ 0.125 g / cm ³ 0.16 g / cm ³ Thickness ratio (thickness of concave sections / thickness of protruding absorbent sections) 40% There is no difference in concave and convex areas 43% thirty% There is no difference in concave and convex areas fifty%

As is clear from the results shown in table 1, it is obvious that the surface area of the spreading fluid is reduced, the backflow of the fluid is small, and the occurrence of a backflow wetting the skin in the absorbent article of Example is hindered.

[Flexibility]

Each of the sanitary napkins of the Example and Comparative Examples was fastened to underpants and attached to a female body model. A pressure sensor (a pressure sensor device manufactured by Pressure Profile System) was inserted into the groin area of the human body model, and the maximum pressure value was determined in the pressure measurement area with dimensions of 25 mm × 25 mm when the legs of the female body model were bent inside.

As a result, the maximum pressure applied to the inguinal zone of the model from the side of the sanitary towel in Example 1 was 0.7 kPa, while the maximum pressure applied to the inguinal zone of the model from the side of the sanitary towel in Comparative Examples was 1.4 kPa.

From these results it was found that the sanitary napkin of Example 1 provides less pressure that is applied to the inguinal area of the user when the wearer moves to bring the legs together while wearing, compared with the pressures created by the sanitary napkins of the Comparative Examples, it creates a slight feeling inconvenience, which is felt by the wearer when wearing a sanitary towel, and creates a feeling of more comfortable wearing.

[The ability to prevent twisting]

Each of the sanitary napkins of Example 1 and Comparative Examples was fastened to underpants and attached to a dynamic model of the human body. When observing the cross-sectional area in the width direction of the sanitary napkin when performing the exercise while walking the dynamic model for 30 minutes, the cross-section surface was bent with an M-shape in the absorbent bodies of the sanitary napkins according to Comparative Examples, while the absorbent element of the sanitary napkin according to Example was bent with approximately trapezoidal shape in a state where the part, central in the direction of the width, remained relatively flat, and in the Example a small indentation of prices was noted tra in the direction of the width in comparison with Comparative examples.

From these results, it was found that the sanitary napkin according to Example 1 had a greater ability to prevent twisting and improved adherence to the skin of the user compared with sanitary napkins according to Comparative examples.

After describing the invention in connection with embodiments, applicants specifically indicate that the invention should not be limited to any of the details of the description, unless otherwise indicated, but should be construed broadly within its spirit and scope as set forth in the accompanying claims.

This application has priority to patent application No. 2010-282455, filed in Japan on December 17, 2010, and Patent Application No. 2010-282456, filed in Japan on December 17, 2010, each of which is incorporated herein by reference in its entirety.

DESCRIPTION OF REFERENCE POSITIONS

1 top sheet

2 bottom sheet

3 Absorbent element

31 Concave section

33 Protruding absorbent area

34 Concave absorbent area

4 side sheet

5 Leakage prevention groove

10 Sanitary pad

Claims (7)

1. A longitudinally long absorbent article comprising a fluid-permeable top sheet located on a side of a skin contacting surface, a bottom sheet located on a non-skin contact surface and an absorbent member disposed between the two sheets,
wherein the absorbent element has a longitudinal direction and a width direction, which are located at right angles to each other; the absorbent element has structures that allow the passage of fluids and which are located respectively in the longitudinal direction and in the direction of the width of the absorbent element in the area facing the discharge area, and each of which is formed by concave sections having the shape of grooves and pressed from the side of the non-contacting surface with the skin, in the direction of thickness, and concave absorbent portions containing cellulose fiber, on the lower parts located on the side of the surface in contact with the skin bent sections; and the absorbent element has protruding absorbent sections in the form of blocks that protrude towards the side of the non-skin contact surface, contain cellulose fiber and have a higher base weight than the base weight of the concave absorbent sections in areas surrounded by structures providing the passage of fluids, and
wherein the concave absorbent portions of the structures providing the passage of fluids have a low density, and the protruding absorbent portions in the form of blocks have a high density relative to the concave absorbent portions. 2. The absorbent product according to claim 1, in which the constituent element of the concave absorbent sections has an average density of 0.02-0.09 g / cm ³ and the constituent element of the protruding absorbent sections has an average density of 0.10-0, 25 g / cm ³ . 3. The absorbent article of claim 1, wherein the grooved concave portions of the absorbent member have a depth in the thickness direction of 40% of 98% of the thickness of the block-shaped protruding absorbent portion. 4. The absorbent product according to claim 1, wherein the top sheet has a plurality of portions that protrude at equal intervals on the surface side in contact with the skin and the side of the surface not in contact with the skin, and the protruding sections are located in the same parts on the side of the surface in contact with the skin, and the side of the surface that is not in contact with the skin. 5. The absorbent article of claim 1, wherein the absorbent element comprises a polymer with super absorbency, and a polymer with super absorbency is disposed so as to shift toward a surface side of the protruding absorbent portions that are not in contact with the skin. 6. The absorbent article of claim 1, wherein the absorbent member comprises a polymer with super absorbency and a polymer with super absorbency that is positioned so as to shift toward a surface side of the protruding absorbent portions that are not in contact with the skin, the polymer with super absorbency being placed on concave absorbent areas. 7. The absorbent article of claim 1, wherein the absorbent article is a sanitary napkin.

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