RU2299054C2 - Absorbing article (versions) - Google Patents

Abstract

FIELD: medicine and medical equipment, in particular, articles which may be used as hygienic and absorbing means for liquid released by organism.

SUBSTANCE: absorbing article has liquid-impermeable surface sheet positioned on upper side, liquid-impermeable rear sheet positioned on lower side, and absorbing layer comprising superabsorbing polymer for absorbing of released liquid, said layer being arranged between surface and rear sheets. Absorbing article is equipped with channel allowing part or total amount of released liquid directed to surface sheet to be forced out to side surface of rear sheet.

EFFECT: increased efficiency by preventing essential reduction in absorption rate with time, from initial usage stage to final stage, when absorbing capacity of article reaches maximum value, and reduced probability of repeated wetting.

34 cl, 30 dwg, 9 tbl, 3 ex

Description

The scope of the invention

The present invention relates to an absorbent article. More specifically, it relates to the creation of an absorbent article capable of preventing a substantial decrease in the rate of absorption of the released liquid over time and having a very low level of re-wetting.

BACKGROUND OF THE INVENTION

Conventional absorbent articles (see, for example, JP 3-251244 A) have a liquid permeable top sheet located on the upper side (on the side closest to the user's body), a liquid impervious back sheet located on the lower side (on the side remote from the user's body), and an absorber located between them. In the case of the release of a fluid, such as urine, feces and blood (hereinafter simply referred to as “the excreted fluid” or “the fluid”) entering the absorbent article, the excreted fluid first passes through the upper fluid-permeable sheet and enters the scavenger. In the absorber, the released liquid diffuses to the lower side, and when it reaches the liquid-tight back sheet, diffusion ceases. All conventional absorbent articles utilize such a mechanism for absorbing released fluid.

However, conventional absorbent articles that utilize the aforementioned absorption mechanism cause two important inherent problems. The first problem is that the absorption rate decreases as the absorption volume of the selected liquid absorber increases. The second problem is that the amount of liquid returned from the absorber to the top sheet, or the level of re-wetting, increases as the volume of absorbed released liquid increases, especially in the immediate vicinity of the absorption limit. This leads to an increase in the percentage of moisture on the surface of the user's body during and after the liquid is released, creates inconvenience for the user, increases the likelihood of sweating, and also becomes the first cause of skin irritation from wearing an absorbent product.

On the other hand, in trying to solve these problems, various solutions have already been proposed regarding characteristics, structure, breathability, etc. top sheet and absorber, however no final decision was found.

SUMMARY OF THE INVENTION

In connection with the stated objective of the present invention is the creation of an absorbent article, which is able to prevent a significant decrease in the rate of absorption during the time from the start of use to the final stage, when the limit of absorbent capacity of the product, and having a very low level of re-wetting.

The authors of the present invention as a result of studies aimed at achieving the above objectives, found that it is possible, due to the installation on the upper side of the absorber of a liquid-impervious surface sheet instead of a liquid-permeable top sheet to which the selected liquid flows, and by developing a structure ( design), in which a channel is provided, going from the upper side of the surface sheet to the lower portion of the absorber, to create an absorption mechanism that allows differential undirovat part or all of the discharged liquid discharged liquid from the lower side to the upper side of the absorber. Moreover, the inventors of the present invention have found that due to this absorption mechanism, the absorption rate does not decrease significantly over time, and the rewetting level becomes very low. Based on the above results of the studies, the present invention was carried out.

In other words, in accordance with the present invention, the following is proposed: from (1) to (34).

An absorbent article with a liquid impervious surface sheet located on the upper side, a liquid impermeable back sheet located on the lower side, and an absorber containing a superabsorbent polymer for absorbing the released liquid located between the surface sheet and the back sheet in which a channel is provided allowing part or all of the selected fluid supplied to the surface sheet, leak to the side surface of the back sheet of the absorber.

An absorbent article in which a channel is provided in at least one of the following sections of the absorber: at both front and rear ends, at both left and right ends and in the center.

An absorbent article in which a surface sheet is formed from a single layer of synthetic resin film.

An absorbent article in which the surface sheet is formed of a layered material consisting of a film of synthetic resin and a nonwoven material provided on the surface of the upper side of the film of synthetic resin.

An absorbent article in which a synthetic resin film has concave and convex portions that form a channel.

An absorbent article in which the surface sheet is positioned so that at least one surface portion of the upper side of the absorber is exposed (exposed).

An absorbent article in which a surface sheet comprises a liquid-permeable portion.

An absorbent article in which a liquid-permeable guide sheet with a channel is laminated to at least one surface portion of the upper side of the surface sheet.

An absorbent article in which the guide sheet covers at least one portion of the sides of the absorber directly or through (on top) the surface sheet.

An absorbent article in which the guide sheet has concave and convex portions that form a channel and has openings in some or all of the convex portions.

An absorbent article in which a skin contact sheet formed from a liquid-permeable nonwoven material is laminated to at least one surface portion of an upper side of a surface sheet or a guide sheet.

An absorbent article in which the backsheet is formed from a synthetic resin film.

An absorbent article in which a synthetic resin film that forms the backsheet is breathable.

An absorbent article in which the backsheet is formed of a laminate consisting of a film of synthetic resin and a nonwoven material provided on the surface of the lower side of the film of synthetic resin.

An absorbent article in which both the synthetic resin film and the non-woven material that form the back sheet are breathable.

An absorbent article in which a synthetic resin film that forms the backsheet has concave and convex portions and also has openings in some or all of the convex portions, and the non-woven material that forms the backsheet is a waterproof laminate having two or more layers, containing one layer or more layers of a knitted nonwoven material and one layer or more layers of meltblown nonwoven material.

An absorbent article in which a synthetic resin film that forms the back sheet has concave and convex portions forming a liquid trapping portion on the surface of its upper side.

An absorbent article in which an absorber is formed from a mixture of a superabsorbent polymer and whipped pulp wrapped in a liquid-permeable core wrapping sheet.

An absorbent article in which the absorber has two layers of liquid-permeable nonwoven material and a super-absorbent polymer introduced between them.

An absorbent article in which the absorber comprises a superabsorbent polymer supported by a coating on a liquid-permeable nonwoven material.

An absorbent article in which the content of the super absorbent polymer in the absorber is 50% by weight or more.

An absorbent article in which:

the main body of the absorbent product, which can form an internal space to accommodate a given area of the user's body when worn;

a cavity for the absorber block adjacent to the main body of the absorbent product, continuing the inner space and containing a back sheet on its inner wall; and

an absorber block formed by combining at least a surface sheet and an absorber inserted with the possibility of removal into the cavity for the absorber block.

An absorbent article in which a guide sheet is inserted in at least one portion between the main body of the absorbent article and the cavity for the absorber unit.

An absorbent article in which a liquid-permeable skin contact sheet is inserted in at least one portion between the main body of the absorbent article and the cavity for the absorber unit.

Absorbent product

in which a plurality of laminated absorbent blocks are inserted into the cavity for the absorber block (from the description of the invention, it can be understood more precisely: “in which a multilayer absorber formed using a plurality of identical absorbent blocks forming layers is inserted into the cavity for the absorber.” - Note translator).

An absorbent article in which:

the main body of the absorbent product, which can form an internal space to accommodate a given area of the user's body when worn;

the cavity for the absorber adjacent to the main body of the absorbent product, continuing the inner space and containing a back sheet on its inner wall;

an absorber introduced with the possibility of removal into the cavity for the absorber; and besides,

a surface sheet that is inserted in at least one portion between the main body of the absorbent article and the cavity for the absorber.

An absorbent article in which a guide sheet is laminated on the surface of the upper side of the surface sheet.

An absorbent article in which a liquid-permeable skin contact sheet is provided on at least one surface portion of an upper side of a surface sheet or a guide sheet.

An absorbent article in which a plurality of laminated absorbers are introduced into the cavity for the absorber.

An absorbent product in which there is provided a plot for placing (removing) urine, going from the center to the front section (body part), and a plot for placing feces, going from the center to the back section (body part), and the surface sheet is provided only on the plot for placement urine.

An absorbent article in which a liquid impermeable or waterproof, preventing backflow, sheet is inserted inside the absorber and / or mounted on the upper side of the absorber, at least in the area for placement of feces.

An absorbent article in which the rewet level, measured under a load of 0.1 psi (psi), 5 minutes after the start of absorption, which allows the absorber to absorb a solution of 0.9 wt.% Sodium chloride at 25 ° C and in the absence of load the amount equivalent to 50% of the absorbent capacity of the absorber is 5 ml or less.

An absorbent article in which the rewet level is 2 ml or less.

Absorbent product

in which the absorption capacity of the absorber upon absorption of a solution of 0.9 wt.% sodium chloride is 300 ml or more,

moreover, when the saline solution is added for absorption by means of a scavenger in an amount of 100 ml in each of three separate additives, carried out in the absence of load at intervals of 10 minutes, the average level of re-wetting after three additives is 5 ml or less,

wherein the root mean square (standard) deviation of the rewet level is 3 ml or less;

moreover, when the saline solution is added for absorption by means of a scavenger in an amount of 100 ml in each of three separate additives, conducted under a load of 0.1 psi at intervals of 10 minutes,

then the average absorption time of the three additives is 30 seconds or less,

and the standard deviation of the absorption time is 2 seconds or less.

Brief Description of the Drawings

Figure 1 shows a set of explanatory cross-sections, where you can see a plot of an example of an absorbent product in accordance with the present invention.

Figure 2 shows a group of explanatory top views and cross-sections, where you can see a plot of examples of an absorbent product in accordance with the present invention.

FIG. 3 (A) shows an explanatory perspective view of an example of a surface sheet with a large number of protrusions, and FIG. 3 (B) shows an explanatory cross section thereof.

Figures 4 (A) and (B) show explanatory cross sections, each of which shows an example of a surface sheet with V-grooves, and figure 4 (C) and (D) shows explanatory cross sections, each from which you can see an example of a ribbed surface sheet.

5 (A) and (B) show explanatory perspective views, each of which shows an example of a surface sheet with V-grooves.

Figure 6 shows a group of explanatory cross-sections, on each of which you can see a plot of examples of an absorbent product in accordance with the present invention.

7 shows a group of explanatory top views, on each of which you can see a plot of examples of an absorbent product in accordance with the present invention.

Fig. 8 is an explanatory perspective view where you can see an example of a guide sheet that has concave and convex portions forming channels, each convex portion having an opening.

Fig.9 shows a group of explanatory cross-sections (Fig.9 (A) - (D)) and a perspective view (Fig.9 (E)), where you can see a plot of examples of absorbent products in accordance with the present invention.

Figure 10 shows a group of explanatory cross-sections, on each of which you can see a plot of examples of an absorbent product in accordance with the present invention.

11 shows a set of explanatory top views, on each of which you can see a plot of examples of an absorbent product in accordance with the present invention.

On Fig shows a set of explanatory views from above, where you can see examples of the back sheet used in accordance with the present invention.

On Fig shows a set of explanatory cross-sections, on each of which you can see a plot of examples of an absorbent product in accordance with the present invention.

On Fig shows an explanatory top view where you can see a portion of an example of an absorbent product in accordance with the present invention.

On Fig shows a set of explanatory cross-sections, where you can see examples of the plot of the absorbent product in accordance with the present invention.

On Fig shows an explanatory top view where you can see a portion of an example of an absorbent product in accordance with the present invention.

On Fig shows a group of explanatory views from above, on each of which you can see an example of a preferred configuration of the back sheet, in the case when the element forming the back sheet itself forms a cavity for the absorber.

On Fig (A) shows an explanatory cross section where you can see an example of many laminated blocks of absorbers. FIG. 18 (B) shows an explanatory cross section where an example of a plurality of laminated absorbers can be seen, and FIG. 18 (C) shows an explanatory cross section where an example of a portion of an absorbent article according to the present invention comprising a plurality of laminated blocks can be seen. absorbers.

On Fig shows a group of explanatory drawings, each of which you can see an example of an absorbent product in accordance with the present invention, equipped with an element for drawing.

On Fig shows a group of explanatory top views, on each of which you can see an example of a plot of an absorbent product in accordance with the present invention.

On Fig shows an explanatory longitudinal section, where you can see an example of a plot of an absorbent product in accordance with the present invention.

On Fig shows an explanatory longitudinal section, where you can see an example of a plot of an absorbent product in accordance with the present invention.

23 is a cross-sectional view for explaining the behavior of the recovered liquid when it is supplied to an absorbent article.

On Fig shows an explanatory cross section of an absorbent product used in the Examples.

On Fig shows a set of explanatory drawings, allowing to understand the method of measuring the absorption rate in the Examples.

On Fig shows an explanatory front view and an explanatory top view, where you can see used in the Examples of the absorbent product, which contains many blocks of absorbers.

On Fig shows a set of explanatory cross-sections of blocks of absorbers used in the Examples.

On Fig shows a set of explanatory cross-sections of absorbent products, which used blocks of absorbers, shown in Fig.

On Fig shows explanatory drawings, allowing to understand used in the Examples, the method of measuring the level of re-wetting of absorbent products for the case of urine, and for the placement of feces.

On Fig shows a set of explanatory cross-sections, where you can see a portion of an example of a conventional absorbent product.

DETAILED DESCRIPTION OF THE INVENTION

In the following, absorbent articles in accordance with the present invention will be described in more detail with reference to preferred embodiments shown in the accompanying drawings. It should be borne in mind that all the drawings that are used to describe the present invention are explanatory drawings, in which the thickness of the absorbent product is shown exaggerated.

Figure 1 shows a set of explanatory cross-sections, where you can see a plot of an example of an absorbent product in accordance with the present invention. 1, the direction perpendicular to the surface of the sheet (page) is the anteroposterior direction of the absorbent article (in other words, the direction equivalent to the front to back direction for the user's body when he is wearing the article) (hereinafter, the same applies to all cross sections) . Figure 1 (A) is an explanatory drawing of the structure (structure) of an absorbent article in accordance with the present invention, and Figure 1 (B) is an explanatory drawing of an absorbent article in accordance with the present invention when used.

As shown in FIG. 1 (A), the absorbent article according to the present invention comprises a liquid impermeable surface sheet 10, a liquid impervious back sheet 12, and an absorber 14 containing a superabsorbent polymer (hereinafter also referred to as “SPP”), that the selected liquid can be absorbed by it, and the absorber 14 is located between the surface sheet 10 and the back sheet 12.

When the released liquid enters the absorbent product in accordance with the present invention, as shown in FIG. 1 (B), because the surface sheet 10 located on the upper side is liquid impermeable, the released liquid moves along the surface of the surface sheet 10 to its end sections. The released liquid, which has moved to the end portions of the surface sheet 10, because the back sheet 12 is impervious to liquid, moves along the inner surface of the back sheet 12 in the channel 16 formed between the absorber 14 and the back sheet 12, while part the liquid is absorbed by the absorber 14, mainly on the lower side of the absorber 14. Thus, the released liquid is absorbed on the lower side of the absorber 14 and then diffuses to the upper side.

As already mentioned here, the absorbent article in accordance with the present invention is characterized by the presence of a channel that allows part or all of the extracted liquid supplied to the surface sheet to move in the direction of the back sheet. This channel is preferably provided at least in one of the following sections of the absorber: at both front and rear ends, at both left and right ends and in the center.

Figure 2 shows a group of explanatory top views (figure 2 (A) and (B)) and cross sections (figure 2 (C) and (D)), where you can see a plot of examples of absorbent products in accordance with the present invention. In FIGS. 2 (A) and (B), the top to bottom direction of the page corresponds to the front to back direction of the absorbent article (hereinafter, the same applies to all top views). 2 (A) and (C), for convenience of explanation, only one surface sheet 10, one back sheet 12, and one absorber 14 are shown.

In the absorbent article shown in FIGS. 2 (A) and (C), the surface sheet 10 completely covers the upper surface of the absorber 14, and its sides and lower surface are completely covered by the back sheet 12. This absorbent article has channels in all of the following sections of the absorber 14: in the front end portion A, in the rear end portion B, in the left end portion C and on the right end portion D.

In the absorbent article shown in FIGS. 2 (B) and (D), two absorbers 14 are located next to each other, with a gap between them. Each of the two surface sheets 10 completely covers the corresponding upper surface of each of the two absorbers 14, the outer side surfaces and the lower surfaces of the absorbers being completely covered by one back sheet 12. This absorbent article has channels in all of the following sections of the absorber 14: at the front end portion A, in the rear end portion B, in the left end portion C, in the right end portion D and in the central portion E.

On Fig shows a set of explanatory cross-sections, where you can see a portion of an example of a conventional (known) absorbent product. FIG. 30 (A) shows an explanatory drawing of a structure (structure) of a conventional absorbent article, and FIG. 3 (B) shows an explanatory drawing of a conventional absorbent article when used.

A typical absorbent article typically comprises a liquid-permeable topsheet 11, a liquid-impervious backsheet 12, and an absorber 14 located between the topsheet 11 and the backsheet 12.

When the extracted liquid enters a conventional absorbent article, as shown in FIG. 30 (B), for the reason that the upper sheet 11 located on the upper side passes liquid, the released liquid that passes through the upper sheet 11 is absorbed when help the absorber on its upper side and then diffuses to the lower side.

In contrast, the absorbent article in accordance with the present invention is characterized as realizing an absorption mechanism in which a part of the extracted liquid or all of the released liquid diffuses from the lower side to the upper side of the absorber 14, using the structure described above. This absorption mechanism prevents a significant reduction in absorption rate over time and provides a very low level of re-wetting.

The surface sheet 10, which is used in accordance with the present invention, is impervious to liquid. In the description of the present invention, the term "liquid impermeable" means a property that ensures the absence of effective leakage of the selected liquid.

There are no restrictions associated, in particular, with the choice of material or structure of the surface sheet 10, provided that it is impervious to liquid. For example, a single layer synthetic resin film and a laminate formed from a synthetic resin film and a nonwoven fabric provided on the surface of the upper side of the synthetic resin film can advantageously be used. As a synthetic resin film, a film that allows air to pass through but not liquid, in other words, a breathable film made from a polymer such as PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), polyurethane or crosslinked, can usually be used. (network structure) PVA (polyvinyl alcohol).

One preferred embodiment of the synthetic resin film used to make the surface sheet 10 is the concave and convex portions forming the channels 16. However, when the absorbent article according to the present invention has a guide sheet, as discussed below in more detail, even if the synthetic resin film does not have concave and convex portions for forming the channels 16, it is also suitable for use.

Moreover, when a flat, smooth and relatively soft synthetic resin film is used as the surface sheet 10, then if the surface of the absorber on which the surface sheet is located has concave and convex portions, then the film can deform and form concave and convex portions for holding excreted fluid. However, in this case, the released liquid can quickly move due to the pressure-sensitive connection of a synthetic resin film and the upper surface of the absorber to smooth them, or by designing a roof-like structure with a convex central section and slopes on both sides of it.

Examples of concave and convex configurations include the following: a configuration with a large number of protrusions, a configuration with grooves such as V-shaped or U-shaped grooves, a lapped configuration (such as flakes), and a ribbed configuration.

Figure 3 (A) shows an explanatory perspective view of an example of a surface sheet with a large number of protrusions, and figure 3 (B) shows an explanatory cross section of such a sheet.

On the surface sheet 10a, continuous rows of a large number of concave portions are provided that act as channels 16 for the selected fluid. The surface sheet 10a shown in FIG. 3 has a large number of protrusions 18 forming convex portions.

As for the dimensions of the concave and convex sections of the surface sheet 10a, if we take into account its transportation, cost, etc., then the protrusions 18 forming the convex sections should mainly have a height of 0.3 mm or more, and even better, should have a height from 0.5 to 1.5 mm.

The advantage of the surface sheet 10a is that it does not inhibit (does not inhibit) the flow of the released liquid, even if the convex portions are slightly deformed during use.

Fig. 4 (A) and (B) show explanatory cross sections, each of which shows an example of a surface sheet with corresponding V-grooves, and Fig. 4 (C) and (D) shows explanatory cross sections, each of which an example of a ribbed surface sheet is shown.

5 (A) and (B) are explanatory perspective views, each of which shows an example of a surface sheet with V-grooves. In FIG. 5 (A), V-grooves are formed in only one direction, while in FIG. 5 (B), V-grooves are formed in two mutually perpendicular directions. It should be borne in mind that there are no restrictions regarding, in particular, the size, direction, number of grooves and the spaces between them. The same goes for ribs.

Next, the relative position of the surface sheet 10 and the absorber 14 will be explained.

As already mentioned here, the surface sheet 10 is located on the upper side of the absorber 14. The following examples show (but without limitation) various possible relative positions.

Figure 6 shows a group of explanatory cross-sections, each of which shows a portion of examples of an absorbent article in accordance with the present invention. 6 (A) to (D), for convenience of explanation, only one surface sheet 10 and one absorber 14 are shown.

6 (A) shows the surface sheet 10, which completely covers, from left to right, the upper surface of the absorber 14. In this case, the released liquid supplied to the surface sheet 10 quickly moves along the surface of the surface sheet 10 to the upper portion of the right and left end of the absorber 14.

6 (B) shows a surface sheet 10 that completely covers, from left to right, the upper surface of the absorber 14 and further covers its right and left side surfaces. In this case, the released liquid supplied to the surface sheet 10 quickly moves along the surface of the surface sheet 10 to the lower portion of the right and left ends of the absorber 14. Therefore, the proportion of the released fluid absorbed by the lower portion of the absorber 14 will be larger in comparison with the case shown in FIG. .6 (A).

6 (C) shows a surface sheet 10, which completely covers, from left to right, the upper surface of the absorber 14 and further covers both its right and left side surfaces, and a portion of its lower surface. In this case, the released liquid supplied to the surface sheet 10 quickly moves along the surface of the surface sheet 10 to the lower surface of the absorber 14. Thus, the released liquid is more easily absorbed in the central portion of the lower surface of the absorber 14 than in the case shown in Fig. 6 ( AT).

6 (D) shows a surface sheet 10, which partially covers, from left to right, the upper surface of the absorber 14. In this case, the released liquid supplied to the surface sheet 10 quickly moves along the surface of the surface sheet 10 to the upper surface close to the ends of the absorber 14. Consequently, part of the extracted liquid is absorbed through the upper surface of the absorber 14, however, the rest is absorbed through the side surfaces and the lower surface of the absorber 14. In accordance with this of by acquiring, as already mentioned here earlier, part of the isolated liquid can be absorbed not only through the lower surface of the absorber 14, but also through its other sections.

6 (E) shows two absorbers 14 that are located next to each other, with a channel 16 formed between them, each of the two surface sheets 10 completely covering in the left-to-right direction the upper surface of each of the two absorbers 14, also as are the side surfaces on their respective right and left sides. Moreover, the surface sheet 10 enters the channel 16. In this case, the released liquid supplied to the surface sheet 10 quickly moves along the surface of the surface sheet 10 to the lower portion of the channel 16, while a portion of the fluid moves to the lower portion of the outer ends. Thus, the released liquid is easily absorbed through the absorber portions equivalent to the central portion, as well as through the outer portions on both sides of the absorbent article.

6 (F) shows two absorbers 14 which are located next to each other, with a channel 16 formed between them, each of the two surface sheets 10 completely covering the upper surface of each of the two absorbers 14. In this case, the released liquid, fed to the surface sheet 10, quickly moves along the surface of the surface sheet 10 to the upper portion of the outer end of each absorber 14, and also passes through the channel 16 to the lower portion of the channel 16. In this case, the released liquid is easily absorbed through the side surface, as well as through the lower surface of each absorber 14.

7 shows a group of explanatory top views, each of which shows a portion of examples of an absorbent article in accordance with the present invention. 7, for convenience of explanation, only one surface sheet 10 and one absorber 14 are shown.

7 (A) shows a surface sheet 10, which completely covers the upper surface of the absorber 14.

7 (B) shows two absorbers 14, which are located side by side, with a channel 16 between them, each of the two surface sheets 10 completely covering the upper surface of each of the two absorbers 14.

7 (C) shows a surface sheet 10 that completely covers, from left to right, a portion in the anteroposterior direction of the upper surface of the absorber 14. A portion of the upper surface of the absorber 14 is open at the front and rear end portions of the surface sheet 10.

7 (D) shows a surface sheet 10, which completely covers in the anteroposterior direction, a portion in the direction from left to right of the upper surface of the absorber 14. The upper surface of the absorber 14 is partially open at the right and left end portions of the surface sheet 10.

7 (E) shows two surface sheets 10 that cover the right and left end portions of the upper surface of the absorber 14, with one portion of the upper surface of the absorber open in the central part of the absorber.

7 (F) shows a surface sheet 10 that completely covers the upper surface of the absorber 14, however, the surface sheet 10 has a liquid-permeable portion 20 in the center, from left to right.

Fig. 7 (G) shows a surface sheet 10 that completely covers the upper surface of the absorber 14, however, the surface sheet 10 has liquid-permeable portions 20 in two predetermined (predetermined) portions from left to right.

There are no restrictions associated, in particular, with the choice of material, structure, etc. fluid passing portions 20 shown in FIGS. 7 (F) and (G), provided that they are fluid passing. For example, a surface sheet 10 with openings that make it liquid-permeable can be used, or one portion of the surface sheet 10 can be made of a liquid-permeable material (e.g., a knotted non-woven material) and the like. In the description of the present invention, the term "fluid permeable" reflects the characteristic that allows the seepage of the selected fluid.

In both cases shown in Figs. 7 (A) and (B), the separated liquid supplied to the surface sheet 10 is absorbed through the side and lower surfaces of the absorber 14, without being absorbed by its upper surface.

In all cases shown in Figs. 7 (C) - (G), part of the extracted liquid supplied to the surface sheet 10 is absorbed from the upper surface of the absorber 14 through open sections of the absorber 14 or through the liquid-passing sections 20, and the remainder of the liquid is absorbed through side surfaces and through the bottom surface of the absorber 14.

As already mentioned here, options in which the released liquid is absorbed through all areas, including through the upper, lateral and lower surfaces of the absorber 14, are preferred since they allow an increase in the absorption rate, however, they somewhat worsen the level of re-wetting. In another embodiment of the absorbent article in accordance with the present invention, a surface sheet is arranged so as to open a portion of the upper surface of the absorber, the surface sheet being located only partially in the immediate vicinity of the urine excretion area of the user's body in order to ensure dryness of this local area.

The relative arrangements shown in FIGS. 6 (A) to (F) and the relative arrangements shown in FIGS. 7 (A) to (G) can be grouped in very different ways to obtain different layouts. Moreover, the surface sheet 10 and the absorber 14 may also have other relative positions different from those described above.

In accordance with one preferred embodiment of the present invention, there is provided a liquid-permeable guide sheet with a channel that is laminated to at least one portion of a surface of an upper side of a surface sheet. A guide sheet facilitates the movement of the supplied liquid to the underside of the absorber through its channel. Therefore, in the case of a laminated guide sheet, even if the synthetic resin film forming the surface sheet does not have concave and convex portions for forming channels, then due to the guide sheet, the selected liquid will quickly diffuse to the lower side of the absorber.

The separated liquid moves through the channels of the guide sheet due to capillary action, wetting, penetration and diffusion. To ensure effective movement of the selected fluid, the guide sheet preferably has hydrophilicity and a certain thickness. More specifically, for example, a concave-convex foil producing a liquid distribution effect or a concave-convex molded plastic netting producing a liquid distribution effect (for example, as proposed by the present inventors in International Publication No. 02/065965) can be used; and bulk laminated non-woven materials (for example, a composite sheet obtained by combining a layer of paper or non-woven material having a flat and smooth surface, and a layer of fiber web having a volume surface with concave and convex portions, proposed by the authors of the present invention in the description of patent JP 2001 -297161 A and in the description of the patent JP 2001-297162 A).

One preferred embodiment of the guide sheet has concave and convex portions forming channels, and also has openings on part of the convex portions or on all convex portions.

Fig. 8 is an explanatory perspective view where you can see an example of a guide sheet that has concave and convex portions forming channels, each convex portion having an opening.

On the guide sheet 22, a continuous row of a large number of concave portions acts as channels 26 for the selected fluid. The guide sheet 22 shown in FIG. 8 has a large number of protrusions 24 forming convex portions, each protrusion 24 having an opening 26 in the upper part.

In the case of a guide sheet with holes in the convex sections, as shown in Fig. 8, even if it is made of a hydrophobic material, these holes will act as channels for the selected liquid. In other words, the released liquid will pass through these openings from one side to the other side of the guide sheet.

Holes can only be provided in some convex sections or in all convex sections. Moreover, although there are no restrictions on the number of holes per unit area, a number from 1.0 to 100 holes per cm ² is preferred.

As for the dimensions of the concave and convex sections of the guide sheet 22, if we take into account its transportation, cost, etc., the protrusions 24 forming the convex sections should preferably have a height h of 0.3 mm or more, and even better, must have a height of 0.5 to 1.5 mm.

An advantage of the guide sheet 22 is that it does not inhibit the flow of the released fluid, even if the convex portions are slightly deformed during use.

The protrusions of the guide sheet 22 should preferably be facing down. In this case, the channels formed between the protrusions 24 and the surface of the surface sheet become wider (downward. - Translator's note), which leads to a smoother flow of the released liquid from the surface of the guide sheet to the surface of the surface sheet.

In accordance with one preferred embodiment of the present invention, there is provided a skin contact sheet made of a liquid permeable nonwoven material laminated with at least a portion of a surface of an upper side of a surface sheet or a guide sheet. The skin contact sheet is a portion that directly touches the skin of the user, and due to the presence of such a skin contact sheet, the comfort of the user can be improved. For the manufacture of a skin contact sheet, a material that is commonly used as a top sheet in conventional absorbent products can be used, and it can be imparted a skin care ability, such as an antibacterial effect. Moreover, a special contact sheet may also be used, such as that proposed by the present inventors in International Publication No. 02/00154.

Next, preferred examples of the structure of the aforementioned surface sheet, guide sheet and skin contact sheet will be described in detail.

Fig.9 shows a group of explanatory cross-sections (Fig.9 (A) - (D)) and a perspective view (Fig.9 (E)), where you can see a plot of examples of absorbent products in accordance with the present invention. 9, for convenience of explanation, only one surface sheet 10, one absorber 14, one guide sheet 22 and one skin contact sheet 28 are shown.

Fig. 9 (A) shows a surface sheet 10 which is formed of a laminate consisting of a film of synthetic resin and a nonwoven material provided on the surface of the upper side of the film of synthetic resin.

Fig. 9 (B) shows a surface sheet 10 which is formed of a single layer synthetic resin film, the synthetic resin film having concave and convex portions that form the channels 16, and also a skin contact sheet 28 made of a liquid permeable is shown non-woven material that is laminated (forms a layer of layered material. - Approx. translator) on the surface of the upper side of the surface sheet 10.

Fig. 9 (C) shows a surface sheet 10, which is formed from a single layer film of synthetic resin, as well as a liquid-permeable guide sheet 22 with channels 16, which is laminated on the surface of the upper side of the surface sheet 10.

Fig. 9 (D) shows a skin contact sheet 28, which is made of a liquid-permeable nonwoven material and is laminated on the surface of the upper side of the guide sheet shown in Fig. 9 (C).

Fig. 9 (E) shows a surface sheet 10, which is formed from a single layer of synthetic resin film, as well as a liquid-permeable guide sheet 22 with a large number of holes 26 and channels 16, which is laminated on the surface of the upper side of the surface sheet 10. Surface sheet 10 and the guide sheet 22 are combined using the connection sections 22a.

Figure 10 shows a group of explanatory cross-sections, on each of which you can see a plot of examples of an absorbent product in accordance with the present invention. 10, for convenience of explanation, only one surface sheet 10, one absorber 14, and one guide sheet 22 are shown.

10 (A) shows a surface sheet 10 that covers the upper surface, as well as the left end and right end sections of the absorber 14, and shows a guide sheet 22 that covers the upper surface, as well as the left end and right end sections of the absorber 14 and in addition, part of its lower surface.

10 (B) shows a surface sheet 10 that covers the upper surface of the absorber 14, and a guide sheet 22 that covers the upper surface, as well as the left end and right end sections of the absorber 14.

10 (C) shows a surface sheet 10 that covers the upper surface of the absorber 14, and a guide sheet 22 that covers the lower surface, as well as the left end and right end sections of the absorber 14, and, in addition, part of its upper surface.

As shown in FIGS. 10 (A) to (C), when the guide sheet 22 covers at least a portion of the side surface of the absorber 14, directly or through the surface sheet 10, the diffusion of the released liquid becomes faster.

11 shows a set of explanatory top views, on each of which you can see a plot of examples of an absorbent product in accordance with the present invention. 11, for convenience of explanation, only one surface sheet 10, one absorber 14, and one guide sheet 22 are shown.

11 (A) shows the surface sheet 10, which completely covers in the anteroposterior direction, the section in the left-to-right direction of the upper surface of the absorber 14. A portion of the upper surface of the absorber 14 is open on the right and left end sections of the surface sheet 10, and the guide sheet 22 completely in the direction from left to right, the portion in the anteroposterior direction of the upper surface of the surface sheet 10, while the portion of the upper surface of the absorber 14 and the portion of the upper surface of the surface sheet 10 Access the.

11 (B) shows the surface sheet 10 and the absorber 14, which are located similarly to that shown in 11 (A), but since the guide sheet 22 has the shape of a cross, the portion of the upper surface of the absorber 14 and the portion of the upper surface of the surface sheet 10 open differently than shown in FIG. 11 (A).

The back sheet 12, which is used in accordance with the present invention, is impervious to liquid. There are no restrictions associated, in particular, with the choice of material, structure, etc. the back sheet 12, provided that it is impervious to liquid, and the same type of back sheet that is used in conventional absorbent articles can be used. Preferred examples of the material for manufacturing the backsheet are a single layer synthetic resin film and a layered material consisting of a synthetic resin film and a nonwoven fabric provided on the surface of the underside of the synthetic resin film.

As a synthetic film, for example, a matte PE film and a porous breathable film can be used. The breathable film is a synthetic resin film that is made porous by the addition of filler and polymer mixing at MVTR (water vapor transfer rate) in the range from 1000 to 6000 l / (m ² · 24 hours). Typical breathable films contain Espoir (manufactured by Mitsui Chemicals Inc.) and Porum (manufactured by Tokuyama Corp.), both of which are obtained by adding CaCO ₃ as a filler in a PE polymer.

According to the present invention, when the back sheet is formed of a single layer of synthetic resin film, then the synthetic resin film is advantageously breathable, and when the back sheet is formed of a laminate comprising a synthetic resin film and non-woven materials provided on the surface of the lower side of the film made of synthetic resin, then predominantly both a synthetic resin film and non-woven materials are breathable. When the back sheet is breathable, the comfort of the user is improved. Moreover, by using a stretchable composite sheet (such as described in JP ID 195746 A), the fit of the article in the figure is further improved in some or all parts of the back sheet.

In accordance with the present invention, the synthetic resin film forming the back sheet advantageously has concave and convex portions that form liquid trapping portions on the surface of the upper side. According to the present invention, since the extracted liquid is first absorbed through the lower side and only later through the upper side of the absorber, the released liquid uniformly diffuses over the entire region of the lower side of the absorber due to the presence of concave and convex portions on the back sheet.

Regarding the configuration of concave and convex sections, the following examples can be given: a configuration with a large number of protrusions, a configuration with grooves (such as V-shaped or U-shaped grooves), a configuration with overlapping (like flakes), and a ribbed configuration.

On Fig shows a set of explanatory views from above, where you can see examples of the back sheet used in accordance with the present invention. The back sheet 12 shown in FIG. 12 (A) has a large number of grooves 30 forming concave portions. The back sheet 12 shown in FIG. 12 (B) has a large number of protrusions 32 forming convex portions.

In one preferred embodiment, the backsheet is a film on which concave and convex portions are formed (for example, the film proposed by the present inventors in the description of JP 2001-135239 A), wherein the synthetic resin film that forms the backsheet has concave and convex sections and has openings in some or all of the convex sections, while the non-woven material that forms the back sheet is a waterproof laminate of two layers or more, soda holding one or more layers of knitted nonwoven materials and one or more layers of meltblown nonwoven materials

As for the layered material, as preferred examples of the layered material, it is possible to cite a layered material formed from a film with concave and convex portions and a waterproof SMS non-woven material (three-layer non-woven material, meshed / meltblown / knotted), proposed the authors of the present invention in the description of patent JP 2001-124237 A.

Next, the relative position of the surface sheet 10, the absorber 14 and the back sheet 12 will be explained.

As already mentioned here, the back sheet 12 is located on the underside of the absorber 14. More specifically, in the following examples, various relative arrangements of the above elements are shown (but not limited).

On Fig shows a set of explanatory cross-sections, on each of which you can see a plot of examples of an absorbent product in accordance with the present invention. 13, for convenience of explanation, only one surface sheet 10, one absorber 14, one back sheet 12, and one guide sheet 22 are shown.

13 (A), a back sheet 12 is shown which covers both the lower surface and both right and left side surfaces of the absorber 14, the upper surface of which is closed by the surface sheet 10.

13 (B), a back sheet 12 is shown which covers both the lower surface and both right and left side surfaces of the absorber 14, the upper surface of which is closed by the surface sheet 10, the upper surface, both right and left side surfaces, and the portion of the bottom surface of the absorber 14 is closed by a guide sheet 22.

On Fig shows an explanatory top view where you can see a portion of an example of an absorbent product in accordance with the present invention. 14, for convenience of explanation, only one surface sheet 10, one absorber 14, and one back sheet 12 are shown.

On Fig shows a surface sheet 10, which covers a portion of the upper surface of the absorber 14, and a back sheet 12, which completely covers the absorber 14 and the lower surface of the surface sheet 10.

As an absorber for the implementation of the present invention, a conventional absorber can be used. More specifically, the absorber that is used in currently absorbent products is formed by wrapping a mixture of SPP and beaten pulp with a liquid permeable core wrapping sheet made from a material such as tissue paper, knotted non-woven material, and a film with holes.

In addition, a sheet with high water absorption obtained by the air-laying method can also be used, for example. The air-laying method is a method of producing a sheet with high water absorption by mixing pulverized pulp and SPP, adding a binder (such as heat-densified fiber) to the mixture, and molding from the mixture by heating the sheet. As examples of sheets with high water absorption, obtained using this method, you can cite the sheet NovaThin (registered trademark of the United States), manufactured by Rayonier Inc. (USA), and KINOCLOTH (Japan registered trademark) leaflet from Oji Kinocloth Co., Ltd. (Japan).

Other examples can be given of obtaining a sheet with high water absorption, for example, by introducing SPP into a dispersion suspension, as well as by using a coating method in which SPP is held on at least one of the two surfaces of a liquid-permeable non-woven permeable sheet material. Such a sheet with high water absorption was proposed by the authors of the present invention and described in Japanese patents JP 10-168230 A, JP 10-314217 A and JP 2000-201975 A. In this case, the preferred dispersion suspension of SPP is a suspension obtained by dispersing SPP and microfiber cellulose (MFC) in a mixture of water and ethanol. For example, MegaThin (a registered trademark of Japan), manufactured by Japan Absorbent Technology Institute, is a high water absorption sheet made using this method.

You can also give other examples of obtaining a sheet with high water absorption, for example, by introducing a large amount of SPP into a whipped nonwoven material and delaminating it using hot-melt adhesive, emulsion binder, water-soluble fiber, etc .; and obtaining a sheet with high water absorption due to the mixing of fiber SPP and PET fibers (polyethylene terephthalate) and molding from a mixture of canvas; and also obtaining a sheet with high water absorption, containing two layers of liquid-permeable non-woven materials and SPP, held between these layers.

The thickness of the sheet with high water absorption is predominantly 1.5 mm or less, and even better, 1 mm or less.

The content of SPP in the aforementioned absorber is preferably 50 wt.% Or more, and even better, from 60 to 95 wt.%.

The absorbent article of the present invention described below can have many absorbers, however, if a mixture of SPP and whipped pulp is used as the absorber, as in the embodiments described above, the absorber has a large volume and high absorbency, but a relatively low retention ability, so usually use a single layer of the mixture. A conventional absorbent article using such an absorber has a high rewet level, however, according to the present invention, a liquid impervious surface sheet is used, whereby the rewet level can be reduced to a small percentage of the level of conventional absorbent articles.

In those cases where the aforementioned sheet with high water absorption is used, since the sheet with high water absorption is extremely thin and has a relatively high holding capacity compared to the absorption capacity and its required wettability is high, in accordance with one of the preferred options proposed the authors of the present invention in patent JP 2002-113800 A, its structure contains many layers of a large number (set) of absorbers, and the absorption of the selected liquid at power absorber starts from the lower layer and gradually moved to the upper layers.

Next, embodiments of an absorbent article in accordance with the present invention will be explained.

An absorbent article in accordance with the present invention can be easily obtained using a conventional absorbent article such as a baby diaper such as a tape and a type of diapers (panties) and an incontinence control diaper for adults, a sanitary napkin for women, and other incontinence control products. In other words, an absorbent article in accordance with the present invention with substantially improved performance can be obtained by introducing a surface sheet, and preferably a surface sheet in combination with a guide sheet, between the top sheet and the absorber.

One preferred embodiment of an absorbent article in accordance with the present invention is an absorbent article that has a main body of an absorbent article that can form an internal space for containing a predetermined area of the wearer’s body when worn; a cavity for the absorber block adjacent to the main body of the absorbent product, communicating with the inner space and containing a back sheet on its inner walls; and an absorber unit formed by combining at least one surface sheet and an absorber inserted with the possibility of removal into the cavity for the absorber.

On Fig shows a set of explanatory cross-sections, where you can see examples of a portion of the above absorbent products.

The absorbent article 50 shown in FIG. 15 (A) comprises a main body 52 of an absorbent article that can form an interior space for containing a predetermined area of the wearer’s body when worn; a cavity 54 for the absorber block adjacent to the main body 52 of the absorbent product, communicating with the interior and containing a back sheet 12 on its inner walls; and an absorber unit 56 formed by combining a surface sheet 10 and an absorber 14 inserted removably into a cavity for the absorber unit. It should be borne in mind that FIG. 15 shows only part of the main body 52 of the absorbent article, with the space on the upper side of the drawing representing the aforementioned interior space. The surface sheet 10, the back sheet 12, and the absorber 14 are as previously described.

In Fig. 15 (A), the element forming the main body 52 of the absorbent article also forms a cavity 54 for the absorber unit, the back sheet 12 formed by another element being provided inside the cavity 54 for the absorber unit. However, in accordance with the present invention, it is possible if the cavity for the absorber block contains a back sheet inside it, that the element forming the back sheet, for example, can also form a cavity for the absorber block.

As for the main body 52 of the absorbent article, the main body of the absorbent article made of a washable material that can be reused, such as a regular diaper cover, can be used. The main body 52 of the absorbent article is advantageously a simple knit article, such as a knit article, since it improves the fit on the figure during wear.

Both on the right and left end portions of the back sheet 12 shown in FIG. 15, side members 58 are provided for assembly. The structure of the side members 58 for assembly may be a conventional structure that contains a bundle of polyurethane fibers, an elastic film, and the like.

The absorbent article 51 shown in FIG. 15 (B) mainly corresponds to the absorbent article 50, except that it includes a guide sheet 22 shown in the drawing.

The absorbent articles 50 and 51 in accordance with the present invention shown in FIGS. 15 (A) and (B) have an absorbent article main body 52 and a cavity 54 for the absorber unit directly communicating with each other (in other words, the surface sheet 10 or the guide sheet 22 is open), however, the aforementioned liquid-permeable skin contact sheet may be introduced in at least one portion of the space between them.

On Fig shows one block of the absorber introduced into the cavity 54 for the block of the absorber, however, in accordance with the present invention, as described below, in the specified cavity can be entered many laminated blocks of absorbers.

One preferred embodiment of an absorbent article in accordance with the present invention is an absorbent article that has a main body of an absorbent article that can form an internal space for containing a predetermined area of the wearer’s body when worn; the cavity for the absorber adjacent to the main body of the absorbent product, communicating with the inner space and containing a back sheet on its inner walls; and an absorber introduced with the possibility of removal into the cavity for the absorber; and a surface sheet that is present in at least one portion of the space between the main body of the absorbent article and the cavity for the absorber.

On Fig shows an explanatory top view where you can see a portion of an example of the above absorbent products.

The absorbent article 60 shown in FIG. 16 comprises a main body 52 of the absorbent article, which may form an interior space for containing a predetermined area of the wearer's body when worn; the cavity 55 for the absorber adjacent to the main body 52 of the absorbent product, communicating with the inner space and containing a back sheet (not shown) on its inner walls; an absorber 14 introduced with the possibility of removal into the cavity 55 for the absorber; and a surface sheet 10 attached to the absorber cavity 55 in order to wrap the absorber 14 over its upper surface. It should be borne in mind that FIG. 16 shows only a portion of the main body 52 of the absorbent article, with the space on the upper side of the drawing representing the aforementioned interior space. The surface sheet 10, the back sheet 12, and the absorber 14 are as previously described herein.

In accordance with the present invention, the element forming the main body of the absorbent article typically forms an absorber cavity 55; however, it is possible that if the cavity for the absorber contains a back sheet inside it, that another element forming the back sheet, for example, can also form a cavity for the absorber.

On Fig shows a group of explanatory top views, on each of which you can see an example of a preferred configuration of the back sheet, when the element forming the back sheet itself forms a cavity for the absorber. In such a structure, a durable and water-resistant material, such as, for example, Gore-Tex, is mainly used for the manufacture of the backsheet.

Each back sheet 12 shown in FIGS. 17 (A) to (E) has a large number of protrusions 32 forming convex portions. The back sheet 12 shown in FIG. 17 (F) has a large number of narrow and long grooves 30 forming concave portions. For this, quilted fabric, for example, can be used. The back sheet 12 shown in FIG. 17 (G) has a large number of point projections 32 forming convex portions.

In this case, the main body 52 of the absorbent article and the side members 58 for assembly are not different from those used for the absorbent article 50 shown in FIG.

In addition, even if the back sheet is formed from another material inside the cavity for the absorber, the same effect can be obtained as in the presence of concave and convex sections on the back sheet, due to the use of concave and convex sections on the profile of the element forming the cavity for the absorber , and achieving the effect of concave and convex sections on the back sheet, which is laminated on it.

An absorbent article 60 with the aforementioned guide sheet laminated on the surface of the upper side of the surface sheet 10 is one of the preferred embodiments of the present invention. In accordance with this embodiment, the guide sheet can be laminated so as to cover the surface sheet on its upper side, and also wrap the side surfaces of the absorber on its lower side.

In addition, the absorbent article 60 may include a liquid-permeable skin contact sheet, the same as in the case of the absorbent articles 50 and 51.

Moreover, the absorbent article 60 may comprise a plurality of laminated absorbers 14, as described hereinafter.

One of the preferred options for the absorbent product in accordance with the present invention, as already described here before, contains many laminated blocks of absorbers or absorbers. Particularly preferred is a thin and compact absorber of a material with a high content of SPP, when using, for example, the aforementioned sheet with high water absorption.

There are no restrictions associated, in particular, with the number of blocks of absorbers or absorbers in the laminate, if the laminate has 2 layers or more layers, however, the laminate mainly has 5 layers or less. Since the number of layers does not exceed 5, this allows you to get a compact absorbent product that does not become too bulky (bulky).

Fig. 18 (A) is an explanatory cross-sectional view showing an example of a plurality of laminated absorbent blocks, and Fig. 18 (B) is an explanatory cross-sectional view showing an example of a plurality of laminated absorbers. FIG. 18 (A) shows three layers of laminated absorbent blocks 56, and FIG. 18 (B) also shows three layers of laminated absorbers 14.

Fig. 18 (C) is an explanatory cross-sectional view showing an example of a portion of an absorbent article in accordance with the present invention containing a plurality of laminated absorbent blocks. In the absorbent article 70 shown in FIG. 18, an absorber unit 56 used as a single layer in the absorbent article 50 shown in FIG. 5 (A) is used by laminating such absorbent blocks to form three layers, as shown in FIG. .18 (A).

When a laminated (layered) absorber containing several layers is used in an absorbent article in accordance with the present invention, the frequency of replacing an absorbent article, for example, from three to five times a day to one to two times a day, is reduced in accordance with the number of layers. The following explains the reason why this becomes possible.

In an absorbent article in accordance with the present invention described above herein, the released liquid is absorbed mainly through the lower side of the absorber and then diffuses to its upper side. Most of the released liquid is absorbed through the lower side of the absorber until the absorption limit of the lowest absorber reaches the limit, after which the released liquid begins to be absorbed by the second absorber from below. Thus, the absorption of the released liquid gradually moves upward until the absorption limit of the uppermost absorber is reached. Thus, it becomes possible to use a plurality of scavengers and to separate, in due time, the scavenger, which has reached the limit of its absorbing capacity of the recovered liquid, from the rest of scavengers. This eliminates not only the sensation of volume or weight experienced by the user, but also does not reduce the absorption capacity, which can be caused by the pressure of the weight of the absorber with its absorbed selected liquid.

In contrast to this, if a plurality of layers of absorbers are used in a conventional absorbent article with a liquid-permeable top sheet, then the absorption will gradually move from top to bottom, however, before reaching the absorption limit of the absorber on the upper side, absorption begins in the absorber lying on them. Thus, in this case, the released liquid will be absorbed simultaneously by all absorbers, especially in the area in the center, starting from the upper surface, where the released liquid first arrives. Since all absorbers begin to swell gradually at the initial stage of use, the resulting liquid cannot completely diffuse into the individual absorber, and therefore, separating the individual absorber from other absorbers does not make sense, and separating the absorber in this case greatly reduces the utilization rate. Since it is impossible to separate an individual absorber, the total weight of the absorber increases. Therefore, the use of a multilayer absorber in a conventional absorbent article does not make sense.

Moreover, it should be borne in mind that even if multiple absorbers are used in the absorbent article according to the present invention, the rewetting level will still be very low, as in the case of a single-layer absorber, with the upper surface of the highest absorber remaining from the beginning until the end of use it is almost as dry as before use, which increases user comfort.

There are no restrictions associated, in particular, with the choice of a structure that allows us to separate the used absorber from other absorbers, however, such a structure should preferably have a section with a hole, for example, a section with a hole in the outer space from the cavity for the absorber block or from the cavity for the absorber . Suitable are the structures proposed by the authors of the present invention in the description of patent JP 2002-233209 A.

Particularly preferred is a structure that contains an element for drawing. In the structure described in JP 7-12117 U, one of the preferred examples of such an element for drawing.

On Fig shows a group of explanatory drawings, each of which you can see an example of an absorbent product in accordance with the present invention, equipped with an element for drawing. Fig. 19 (A) shows a top view, Fig. 19 (B) shows a longitudinal section, and Fig. 19 (C) shows another longitudinal section of an absorbent article containing an absorber. In FIGS. 19 (B) and (C), the left side of the drawing corresponds to the front side of the absorbent article, and the right side of the drawing corresponds to the back side of the absorbent article. On Fig (A) - (C) the back sheet is not shown, and the letter M denotes the user's body.

The absorbent article 80, shown in FIG. 19, has a tape-pulling member 62 located on the upper portion of the front end of the absorber 14. The pulling-off member 62 preferably has an adhesive layer 64 on its lower surface. In this case, a separation layer 66 is advantageously provided in the area corresponding to the adhesive layer 64, the separation layer 66 being in close contact with the adhesive layer 64 before it is introduced into the absorbent article 80. In the absorber 14 introduced into the cavity 54 for the absorbent product absorbent blocks 80 , the pulling member 62 extends from the portion with the opening of the cavity 54 for the absorber block, to its outer side, and then to the side of the main body 52 of the absorbent article, and the pulling member 62 is fixed to the main body Absorbent article 52 using the adhesive layer 64. After the lowermost absorber 14 absorbs a discharged liquid to the limit of its absorption capacity, the lowermost absorber 14 can be easily separated from the other sinks by pulling using said element for pulling 62.

In addition to the surface sheet, the back sheet and the absorber, the absorbent article according to the present invention may also contain such elements as standing gathers, waist gathers, a fastening mechanism (tape, fastener with hooks and loops, etc.) .p.) and a mechanism with tape for wrapping used during removal. For this, any suitable elements may be used.

The absorbent article of the present invention is suitable for use as a baby diaper, adult incontinence control diaper, sanitary napkin for women, and the like.

When an absorbent article according to the present invention is used as a diaper, it can only be used to place (remove) urine, or both to place urine and to place feces. When an absorbent article is used both for placing urine and for placing feces, it is preferable that the area for placing urine goes from the center to the front of the body of the user, and the area for placing feces goes from the center to the back of the body of the user, and the surface sheet should be provided only on the site for urine.

On Fig shows a group of explanatory top views, on each of which you can see an example of a plot of an absorbent product in accordance with the present invention. 20 (A) to (D), the upper side of the drawing corresponds to the front side of the absorbent article, and the lower side of the drawing corresponds to the rear side of the absorbent article.

In all of FIGS. 20 (A) to (D), the surface sheet 10 is provided only in the urine storage area located on the front side of the absorber 14, and is not provided in the feces storage area located on the back side.

As for structures that are different on the front side and on the rear side of the absorber, and the method of their manufacture, one of the preferred options for possible manufacturing techniques was proposed by the authors of the present invention in JP 6-343660 A. When using a structure of this kind, collections on the leg (leg gathers) etc. can only be provided on the front side.

A mixture of urine and feces is one of the causes of odor and rash. Therefore, it is possible to recommend the use of a means for separating urine and feces, such as a urine and feces separator described in JP 7-299092 A, in an absorber in accordance with the present invention.

On Fig shows an explanatory longitudinal section, where you can see an example of a plot of an absorbent product in accordance with the present invention. 21, the left side of the drawing corresponds to the front side of the absorbent article, and the right side of the drawing corresponds to the rear side of the absorbent article.

21, a surface sheet 10 is provided only in the urine receiving portion 34 located on the front side of the absorber 14, and is not provided in the feces receiving portion 36 located on the back side. The surface sheet 10 forms a crease on the guide sheet 22 (bent around it) in the immediate vicinity of the boundary between the urine receiving portion 34 and the feces of the absorber 14 receiving portion 36, wherein the folded portion may temporarily hold the urine entering the urine receiving portion 34, from moving to a plot 36 for placement of feces.

The absorbent article, which comprises a urine storage area and a feces storage area, advantageously contains, at least in the feces storage area, a liquid impermeable or waterproof sheet to prevent urine backflow located inside and / or on the upper surface of the indicated area.

On Fig shows an explanatory longitudinal section, where you can see an example of a plot of an absorbent product in accordance with the present invention. 22, the left side of the drawing corresponds to the front side of the absorbent article, and the right side of the drawing corresponds to the rear side of the absorbent article.

The absorbent article in accordance with the present invention shown in FIG. 22 comprises a liquid-impermeable or water-resistant urine backflow prevention sheet 38 located inside the absorber 14 in the feces receiving area 36. The operation of this urine backflow prevention sheet 38 is explained below.

In the case of an absorbent article that does not have a urine backflow sheet 38, such as the product shown in FIG. 21, the surface sheet 10 prevents the urine from moving on the upper side of the absorber 14 from the urine receiving portion 34 to the feces receiving portion 36 however, urine absorbed through the lower side of the scavenger 14 can still penetrate the upper side of the scavenger 14 and reach the surface of the upper side of the fecal site 36. In other words, there is some reverse flow (counterflow) of urine. When this happens, the effect of the separation of urine and feces disappears, and problems such as contamination of the buttocks and the development of skin irritation from diapers can occur.

In contrast, when the absorbent article contains urine backflow prevention sheet 38, as shown in FIG. 22, the surface sheet 10 prevents urine from moving on the upper side of the scavenger 14 from the urine receiving portion 34 to the feces receiving portion 36 and in addition to this, even if urine is absorbed through the lower side of the absorber 14 and seeps to the upper side of the absorber 14, then, since a liquid impervious or waterproof sheet 38 to prevent back flow of urine is provided Inside the absorber 14, urine is prevented from entering a portion of the top side surface 36 to accommodate the feces. In other words, the reverse flow of urine is prevented and the desired result is achieved without the above problems.

There are no restrictions associated, in particular, with the choice of material or structure of the sheet 38 to prevent back flow of urine, provided that it is impervious to liquids or waterproof, and a film similar to that used for the aforementioned surface sheet can be used as material. 10 and back sheet 12, as well as waterproof non-woven fabric. In this description, the term “waterproof” refers to a characteristic of a material that does not allow water to pass under a pressure of 100 mm water column (9.807 × 10 ² Pa) or lower. It is desirable that the water-resistant non-woven material is watertight at a pressure of 200 mm water column (1.961 × 10 ³ Pa) or lower.

The urine backflow prevention sheet 38 is advantageously set so that it covers at least a portion 36 for storing feces in the anteroposterior direction of the absorber 14, as shown in FIG. Moreover, also in the direction from left to right of the absorber 14, it is desirable that it covers the faecal area 36 in order to prevent the flow of urine to the surface of the upper side of the absorber 14.

An urine backflow prevention sheet 38 may be provided inside the absorber 14, as shown in FIG. 22, however, it may also be provided on the surface of the feces section 36, as well as above it. Moreover, a plurality of said sheets may be provided. There are no restrictions associated, in particular, with the method of placing the urine backflow prevention sheet 38 inside the scavenger 14. If, for example, the scavenger 14 is formed of a plurality of laminated sheets with high water absorption, then the urine backflow prevention sheet 38 can be inserted between these sheets with high water absorption.

As already mentioned here, the absorbent article in accordance with the present invention is significantly different from conventional absorbent articles, in which part of the extracted liquid or all of the released liquid supplied to the surface sheet moves down. This is discussed in more detail below.

23 is a cross-sectional view for explaining the movement of the recovered liquid when it enters the absorbent article. 23 shows only one absorber 14, the sheet completely covering it from left to right (this sheet is a liquid-permeable top sheet 11 in the case of a conventional absorbent article and a liquid-impervious surface sheet 10 in the case of an absorbent article in accordance with the present invention )

The total amount of released liquid supplied to the sheet 10 or sheet 11 is indicated by the letter Q, the total released amount absorbed through the side surfaces or through the lower surface is indicated as Q ₁ , and the total amount of released liquid absorbed through the upper surface is indicated as Q ₂ (provided that Q = Q ₁ + Q ₂ ).

In a conventional absorbent article, for the reason that almost the total amount of liquid released to the top sheet 11 passes through the top sheet 11 and is absorbed by the absorber 14, usually Q ₁ is approximately 1 to 10%, Q ₂ is approximately 99 up to 90%, and the ratio of Q ₁ / Q ₂ is approximately from 0.01 to 0.1.

In contrast, in the embodiment of the absorbent article according to the present invention, in which the surface sheet 10 completely covers the upper surface of the absorber 14 (for example, in the case of the absorbent article shown in FIGS. 7 (A) and (B)), for that reason that almost the total amount of liquid released to the surface sheet 10 moves from the upper surface of the surface sheet 10 to the lower side of the absorber 14 through the end sections of the surface sheet 10, usually Q ₁ is approximately 90 to 99%, Q ₂ state approximately 10 to 1%, and the ratio Q ₁ / Q ₂ is approximately 9 to 99.

Moreover, in the embodiment of the absorbent article in accordance with the present invention, in which the surface sheet 10 covers only a portion of the upper surface of the absorber 14 (for example, in the case of the absorbent article shown in Figs. 7 (C) to (G)), for that reason that part of the selected liquid supplied to the surface sheet 10 moves from the upper surface of the surface sheet 10 to the lower side of the absorber 14 through the end portions of the surface sheet 10, and the remaining amount is absorbed directly on the upper surface of the surface Titel 14 through its open areas, Q ₁ is, for example, depending on the particular design, approximately 50 to 70%, Q ₂ is from about 50 to 30%, and the ratio Q ₁ / Q ₂ is from about 1.0 to 2.5.

As already mentioned here, the absorbent product in accordance with the present invention differs significantly from conventional absorbent products in terms of the absorption mechanism of the released liquid, thereby preventing a decrease in the rate of absorption over time and reducing the level of re-wetting.

Further, the advantages of the present invention will be explained in more detail with reference to Examples.

Examples

1. The rate of absorption and the level of re-wetting of absorbent products

(1) Production of absorbent articles (Example 1)

The absorber was taken from a commercially available Kao Corporation's Merries diaper with a top sheet adhered to it.

As shown in FIG. 24, the absorber 14 taken from the diaper was turned upside down and covered with a breathable PE film (manufactured by Tokuyama Corp., thickness 20 μm), which is used as a back sheet in commercially available diapers and which here used as a liquid impervious surface sheet 10.

The upper surface, side surfaces and the portion of the lower surface of the absorber 14 were covered with a porous PE film (manufactured by Tredeger Co., trademark "T10650-1 TEC"), which is used here as a guide sheet 22.

Moreover, the absorber was covered with a breathable PE film (manufacturer Tokuyama Corp., thickness 20 μm), which is used as a back sheet in commercially available diapers and which is used here as a liquid impervious back sheet 12. As a result of these operations, an absorbent article 90 is obtained.

(Example 2)

The absorbent article 90 in this Example was obtained using a method similar to that used in Example 1, except that here a diaper from Unicharm Corporation's Mamypoko-Cotton was used as a commercially available diaper.

(Example 3)

The absorbent article 90 in this Example was obtained using a method similar to that used in Example 1, except that instead of a commercially available diaper, a comparison diaper with a MegaThin absorber (high water absorption sheet) manufactured by Japan Absorbent Technology Institute was used here.

It should be borne in mind that the diapers of Kao Corporation's Merries, Unicharm Corporation's Mamypoko-Cotton, as well as the diaper of comparison, obtained using an absorber MegaThin, manufactured by Japan Absorbent Technology Institute, were used in their original form in Comparative Examples 1-3 to measure the absorbent capacity and rewet level, as described here below.

(2) Absorbency Measurement

The following describes the method of measuring the absorbent capacity of each absorber of two types of commercially available diapers and one diaper of comparison used in Examples 1-3.

Diapers, the weight of which was previously determined, were immersed in a solution of 0.9 wt.% Sodium chloride for 30 minutes. Then the diapers were removed from the solution, left in this state for 30 seconds and dried. To do this, they were placed on a wire mesh of a dehydration apparatus with the top sheet facing down, and an acrylic plate was placed on top to apply a load to the diapers; moreover, a load (10 kg) was placed on top of an acrylic plate, after which the diaper was left for 20 minutes, and then removed. After that, the diapers were weighed and weight gain was determined as absorbent capacity. (The specific gravity of the sodium chloride solution was taken as 1). The measurement was performed under conditions n = 2.

The absorbent capacity of Kao Corporation's Merries diaper was 707 ml, Unicharm Corporation's Mamypoko-Cotton diaper was 606 ml, and Japan Absorbent Technology Institute's diaper comparison using a MegaThin absorber was 756 ml.

(3) Measurement of absorption rate

The following describes the method of measuring the absorption rate of each of the absorbent products of Examples 1-3 and Comparative examples 1-3.

As shown in Fig. 25, a plate 92 for supplying liquid (made of plastic with dimensions of 7.5 cm × 10 cm), which has a cylindrical section for supplying liquid with an inner diameter of 2.0 cm, and a load 94 located around the perimeter of the section for supplying liquid, placed in the center of the upper surface of the absorbent article 90, and a load of 0.1 psi (6.895 × 10 ² Pa) was applied. It should be borne in mind that FIG. 25 (A) shows a perspective view, and FIG. 25 (B) shows a longitudinal section.

100 ml of a solution of 0.9 wt% sodium chloride was supplied to the liquid supply section, and the time until the sodium chloride solution inside the liquid supply section disappeared by visual observation was measured. This time measurement operation was repeated 3 times with appropriate fluid inlets at 10 minute intervals.

The results are shown in Table 1

Table 1 Compares. example 1 Example 1 Compares. example 2 Example 2 Compares. example 3 Example 3 ^* ) 1st measurement 28 eleven 49 17 eighteen 12 2nd measurement 35 12 81 16 fourteen fourteen 3rd measurement 43 13 102 16 16 fifteen Average for three measurements (s) 35 12 77 16 16 fourteen Standard deviation (s) 6.1 0.8 21.8 0.5 1.6 1.2 ^* ) Absorption rate (s)

As the results shown in Table 1 show, absorbent articles in accordance with the present invention (Examples 1-3) have significantly higher absorption rates than conventional absorbent articles (Comparative Examples 1-3); and, moreover, their absorption rates change little over time. The absorption rate is particularly low and its change over time is significant when using a conventional mixture of SPP and whipped pulp as an absorber (Comparative Examples 1 and 2), however, these parameters are significantly improved in absorbent products in accordance with the present invention (Examples 1 and 2).

(4) Measurement of rewet level

(a) The level of re-wetting at 100 ml of fluid

The following describes the method of measuring the level of re-wetting at 100 ml of supplied fluid for absorbent products of Examples 1 and 3 and Comparative examples 1 and 3.

In the absence of load, 100 ml of a solution of 0.9 wt.% Sodium chloride was introduced dropwise at a rate of 13 ml / s into the center of the upper surface of the absorbent article using a burette located 10 mm above the surface. 5 minutes after the start of the solution introduction, a paper filter, the weight of which was measured in advance, was set so that its center coincides with the spot into which the solution entered dropwise and a load of 0.1 psi (6.895 × 10 ² Pa) was applied to it from above. After 3 minutes, the load was removed, the paper filter was weighed and the level of re-wetting was measured for 100 ml of the supplied liquid. The process was repeated 7 times with appropriate supply of the solution at intervals of 10 minutes. The results are shown in Table 2.

table 2 Comparative Example 1 Example 1 Comparative Example 3 Example 3 ^* ) 1st dimension 0.3 6.1 0.6 0.6 2nd dimension 8.2 3.8 0.7 0.1 3rd dimension 16.7 1.5 0.4 2.8 4th dimension 23.2 2.2 3.3 0.1 5th dimension 25.9 0.6 12.6 0.3 6th dimension 39.5 1.9 22.3 0.6 7th dimension 49.1 0.7 41.0 0.6 Average for the first three measurements (ml) 8.4 3.8 0.6 1.2 Standard deviation for the first three measurements (ml) 6.7 1.9 0.1 1.2 Average for seven measurements (ml) 23.3 2.4 11.6 0.7 Standard deviation for seven measurements (ml) 15.7 1.8 14.2 0.9 ^* ) Re-wetting level (ml)

(b) Re-wetting level for the case when the amount of liquid equivalent to 1/2 of the absorbing capacity is supplied (when 50% of the liquid is supplied)

The following describes the method of measuring the level of re-wetting for each of the absorbent articles of Examples 1 and 3 and Comparative examples 1 and 3, when the amount of liquid equivalent to 1/2 of the absorbing capacity is supplied.

In the absence of load, 100 ml of a solution of 0.9 wt.% Sodium chloride was introduced dropwise at a rate of 13 ml / s into the center of the upper surface of the absorbent product using a burette located 10 mm above the surface. This operation was repeated at intervals of 5 minutes until the amount of the solution introduced by drops reached the amount equivalent to 1/2 of the absorbing capacity (350 ml in Examples 1 and 3 and in Comparative Examples 1 and 3, and 300 ml in Example 2 and Comparative example 2). It should be borne in mind that in the case when 1/2 of the absorbing capacity is 350 ml, the amount of sodium chloride solution introduced by drops in the fourth operation is 50 ml. Five minutes after the start of the last operation of introducing the solution in drops, a paper filter, the weight of which was measured in advance, was set so that its center coincides with the spot into which the solution entered drops, and a load of 0.1 psi (6.895 × 10 ² Pa ) After 3 minutes, the load was removed, the paper filter was weighed and the level of re-wetting was measured for the case when the amount of liquid supplied was equivalent to 1/2 of the absorbing capacity.

The rewet level was measured 3 times in this way and the average value was calculated.

Moreover, the load was varied to apply a load of 0.5 psi (3.448 × 10 ² Pa) and the rewet level was measured when the amount of liquid supplied was equivalent to 1/2 of the absorption capacity. The measurements were carried out 3 times in the above manner and the average value was calculated.

The results are shown in Table 3.

Table 3 Load (psi) Comparative Example 1 Example 1 Reference Example 2 Example 2 Reference Example 3 Example 3 0.1 24.1 0.5 34.1 0.1 3.3 0.1 0.5 37.3 0.6 39.3 0.8 10.0 1.5

As the results shown in Table 2 and Table 3 show, absorbent articles in accordance with the present invention (Examples 1-3) have a significantly lower level of re-wetting than conventional absorbent products (Comparative examples 1-3); and, moreover, their rewet levels do not change much over time.

2. Characteristics of an absorbent article containing multiple absorbent blocks

(1) Production of absorbent articles (Example 4 and Comparative Examples 4 and 5)

Absorbent articles corresponding to the absorbent article 100 shown in FIG. 26 comprising a plurality of absorbent units were manufactured. As the main body 52 of the absorbent product, sewn knitted women's panties (manufactured by Gunze Ltd.) were used, to which an cavity for the absorber containing a liquid-tight back sheet was added. Fig. 26 (A) shows a front view, and Fig. 26 (B) shows a top view. The view shown in FIG. 26 (A) corresponds to the view on the front side of the absorbent article.

Absorbent articles 100 were obtained by introducing into the cavity 54 for absorbent blocks in the main body 52 of the absorbent article the layered absorbers shown in FIG. 28, which were obtained by laminating the three absorbent blocks shown in FIG. 27. In all Fig.27 and Fig.28 shows a cross section.

The absorber block used in Example 4, such as that shown in FIG. 27 (A), was obtained by covering a liquid-tight surface sheet of the upper surface, side surfaces, and a portion of the lower surface of the absorber 14, wherein sheet 10 was obtained by folding in half (half) a superabsorbent sheet containing an SPP layer 102 on one side thereof, so that the surface of the SPP faces the inside of the fold.

The absorber block used in Comparative Example 4, such as that shown in FIG. 27 (B), was obtained by covering the liquid-permeable sheet 104 of the bottom surface, side surfaces, and the portion of the upper surface of the absorber 14, the same as that used in Example 4.

The absorber unit used in Comparative Example 5, such as that shown in FIG. 27 (C), was obtained by covering with a liquid-permeable sheet 104 used in place of the liquid-impervious surface sheet 10 used in Example 4.

In Example 4, 3 absorber blocks were used, similar to those shown in FIG. 27 (A), which were laminated (of which a three-layer absorber was formed. - Translator's note) (starting from the top, the layers are called the first layer, second layer and third layer, respectively ) The connection between the first layer and the second layer, as well as between the second layer and the third layer, was achieved in a simple and quick manner by using a layer of hot-melt adhesive 106 at their left and right end sections. The upper surface, side surfaces, and most of the lower surface of the layered absorber formed from three blocks of absorbers were covered with a guide sheet 22.

In Comparative Example 4, 3 absorber blocks were used, similar to those shown in FIG. 27 (B), which were laminated (starting from the top, the layers are called the first layer, second layer and third layer, respectively). The connection between the first layer and the second layer, as well as between the second layer and the third layer, was achieved in a simple and quick manner by using a layer of hot-melt adhesive 106 at their left and right end sections.

In Comparative Example 5, 3 absorbent blocks were used, similar to those shown in FIG. 27 (C), which were laminated (starting from the top, the layers are called the first layer, second layer and third layer, respectively). The connection between the first layer and the second layer, as well as between the second layer and the third layer, was achieved in a simple and quick manner by using a layer of hot-melt adhesive 106 at their left and right end sections.

(2) Absorption Capability Test

Absorbent articles of Example 4 and Comparative Examples 4 and 5 were worn by the user, the user urinating twice, each time in a standing position. The second urination was done after one predetermined absorber layer was removed after the first urination. The amount of urine excreted each time was about 200 ml. The amount of urine absorbed by each layer of the scavenger after each urination was measured, and the utilization rate was calculated.

The results obtained after the first urination in Example 4 are shown in Table 4.

Table 4 Layer Valid
absorbed
amount (ml) Estimated quantity
takeover
(ml) Power
use of
(%) 1st layer 0 200 0 2nd layer 0 200 0 3rd layer 180 200 90

As shown in Table 4, only the third layer, which is the lowest layer, absorbs urine, while the first and second layers do not absorb urine. In addition, in accordance with visual observations, while absorption occurs almost uniformly over the entire surface area of the third layer, no wetting is observed in the first and second layers.

After the first urination, the third layer of the absorber was removed from the cavity for the blocks of absorbers. In this case, the first layer and the second layer remain closed by the guide sheet in the cavity for the blocks of absorbers. In other words, the removal of the third layer of the absorber is easy, without any problems.

The results obtained after the second urination in Example 4 are shown in Table 5.

Table 5 Layer First
really
absorbed
amount (ml) Second
really
absorbed
amount (ml) Estimated
quantity
absorption (ml) Coefficient
utilization (%) 1st layer 0 10 200 5 2nd layer 0 210 200 105

As shown in Table 5, the second layer, which in this case is the lowest layer, absorbs urine almost to the limit of its absorption capacity, while the first layer absorbs the amount of urine that was not absorbed by the second layer.

The second absorber layer was removed after the second urination. Removing the second layer was also easy, without any problems.

The results obtained after the first urination in Comparative Example 4 are shown in Table 6.

Table 6 Layer Really absorbed amount (ml) Estimated Absorption Amount (ml) Utilization rate (%) 1st layer 95 200 47.5 2nd layer 65 200 32.5 3rd layer 35 200 17.5

As shown in Table 6, the first layer, which is the uppermost layer, absorbs approximately half of the urine, and the second and third layers also absorb some urine. Moreover, visual observations show that absorption occurs over the entire surface, with the exception of approximately 1/5 of the total area located on the front side. However, the thickness of the back side was greater, and more precisely, was 1.5 cm. It can be assumed that this is the result of temporary retention of urine, which was not absorbed at first, and then gradually absorbed. In the second layer, absorption takes place to a level that thickens the absorber to about 1 cm, in an area equivalent to about 1/3 of the total area located on the back side. Moreover, it can be assumed that some areas on the front side are saturated with urine coming from the first layer. In the third layer, absorption also takes place to a level that thickens the absorber to approximately 1 cm, on an area equivalent to approximately 1/3 of the total area located on the back side.

The first absorber layer was removed from the cavity for the absorber blocks after the first urination. Moreover, since it is impossible to remove only one first layer, the second and third layers also left the cavity. After separating the first layer, the second and third layers were reintroduced into the cavity for the blocks of absorbers. In other words, removing the first layer is difficult.

The results obtained after the second urination in Comparative Example 4 are shown in Table 7.

Table 7 Layer First
really
absorbed
amount (ml) Second
really
absorbed
amount (ml) Estimated
quantity
absorption (ml) Coefficient
utilization (%) 2nd layer 65 125 200 95 3-layer interface 35 75 200 55

As shown in Table 7, the second layer, which in this case is the uppermost layer, absorbs approximately 2/3 of the urine, and the third layer also absorbs some urine.

The second layer of the absorber was removed from the cavity for the blocks of absorbers after the second urination, and the removal of the second layer was also difficult.

The results obtained after the first urination in Comparative Example 5 are shown in Table 8.

Table 8 Layer Really
absorbed
amount (ml) Estimated
quantity
absorption (ml) Coefficient
use of
(%) 1st layer 60 200 thirty 2nd layer 60 200 thirty 3rd layer fifty 200 25

As shown in Table 8, absorption occurs almost uniformly in all of the first to third layers. Therefore, continued use due to the removal of layers seems unlikely. Second urination for this reason was not performed.

It should be borne in mind that the expression "Estimated Absorption Amount" in Tables 4-8 reflects the absorbing capacity of each absorber for a solution of 0.9 wt.% Sodium chloride under a load of 0.5 psi (3.448 × 10 ² Pa).

As follows from the consideration of the above Examples, one of the preferred options for an absorbent product in accordance with the present invention is one whose rewet level, measured under a load of 0.1 psi, 5 minutes after the start of absorption, after taking a solution of 0.9 wt.% Sodium chloride in the amount equivalent to 50% of the absorption capacity of the absorber absorbed by the absorber at a temperature of 25 ° C in the absence of load is 5 ml or less, or mainly 2 ml or less.

Moreover, one of the preferred options for an absorbent article in accordance with the present invention is one in which the absorbent capacity of the absorber for a solution of 0.9 wt.% Sodium chloride is 300 ml or more, and when the saline solution is added for absorption using an absorber in an amount of 100 ml in each of the three separate additives carried out in the absence of load at intervals of 10 minutes, its average rewet level after three additives is 5 ml or less, and the mean square deviation ix rewet level is 3 ml or less; and when the brine is added for absorption by means of an absorber in an amount of 100 ml in each of three separate additives conducted under a load of 0.1 psi at 10 minute intervals, its average absorption time of the three additives is 30 seconds or less, and the standard deviation of the absorption time is 2 seconds or less.

3. Characteristics of absorbent articles containing backflow prevention sheet

A comparison was made of the rewetting level in the fecal site of the absorbent article without the backflow prevention sheet shown in FIG. 21 and the rewetting level in the fecal area of the absorbent article with the backflow prevention sheet shown in FIG. 22. Both of these absorbent articles are designed to hold both urine and feces. The width from left to right of the surface sheet 10, the absorber 14, the guide sheet 22 and the backflow prevention sheet 38 was the same for all of these absorbent articles.

As shown in FIG. 29, a liquid supply plate 92, which comprises a cylindrical liquid supply portion with an inner diameter of 2.0 cm, and a load 94 located along the perimeter of the liquid supply portion, were installed in the portion 34 for receiving urine of the absorbent article 14 , and a load of 0.1 psi was applied. At the same time, a paper filter 96 with a pre-measured weight was placed on the plot 36 to accommodate the feces of the absorbent article 14, and an additional acrylic plate 98 was placed on it; moreover, a load was placed on top of it to apply a 0.1 psi load.

100 ml of a solution of 0.9 wt.% Sodium chloride was supplied to the liquid supply section and 3 minutes after the liquid supply started, the paper filter was removed for weighing. This operation was repeated 3 times, so that the fluid supply began at intervals between operations of 10 minutes.

The results are shown in Table 9.

Table 9 Without sheet
prevent
reverse flow With sheet
prevent
reverse flow Rewet level at
feces site (ml) 1st
operation 0.5 0.0 2nd
operation 1.8 0.1 3rd
operation 2.9 0.7

As shown in Table 9, the rewetting level at the feces site is extremely low when the absorbent article intended for both urine placement and feces placement contains a backflow prevention sheet.

Industrial applicability

The absorbent product according to the present invention is suitable for use as a baby diaper, an incontinence control diaper for adults, a sanitary towel for women and the like, since it can prevent a significant decrease in the absorption rate of the released liquid over time and has a very low rewet level.

Claims (34)

1. An absorbent article comprising a liquid impervious surface sheet located on the upper side, a liquid impervious back sheet located on the lower side, and an absorber comprising a polymer for absorbing the released liquid located between the surface sheet and the rear sheet and having a channel, allowing part or all of the selected fluid supplied to the surface sheet to move to the back sheet. 2. The absorbent product according to claim 1, in which the channel is provided at least in one of the following sections of the absorber: at the front or rear ends, on the left or right sides, or in the center. 3. The absorbent article of claim 1, wherein the surface sheet is formed from a single layer film of synthetic resin. 4. The absorbent product according to claim 1, in which the surface sheet is formed of a layered material consisting of a film of synthetic resin and non-woven material provided on the surface of the upper side of the film of synthetic resin. 5. The absorbent article of claim 3 or 4, wherein the synthetic resin film has concave and convex portions that form a channel. 6. The absorbent product according to claim 1, in which the surface sheet is located so that the open surface area of the upper side of the absorber. 7. The absorbent article of claim 1, wherein the surface sheet comprises a liquid-permeable portion. 8. The absorbent product according to claim 1, which is further provided with a guide sheet adjacent at least one surface area to the upper side of the surface sheet. 9. The absorbent article of claim 8, wherein the guide sheet covers at least one portion of the sides of the absorber, directly or on top of the surface sheet. 10. The absorbent article of claim 8 or 9, wherein the guide sheet has concave and convex portions that form a channel and has openings in some or all of the convex portions. 11. The absorbent article according to claim 1, which is further provided with a skin contact sheet made of a liquid-permeable nonwoven material adjacent at least one surface portion to the upper side of the surface sheet or guide sheet. 12. The absorbent product according to claim 1, in which the back sheet is formed of a film of synthetic resin. 13. The absorbent product of claim 12, wherein the synthetic resin film that forms the back sheet has breathability. 14. The absorbent product according to claim 1, in which the back sheet is formed of a layered material consisting of a film of synthetic resin and non-woven material provided on the surface of the lower side of the film of synthetic resin. 15. The absorbent article of claim 14, wherein the synthetic resin film and nonwoven material that form the back sheet have breathability. 16. The absorbent article of claim 14, wherein the synthetic resin film that forms the back sheet has concave and convex portions and also has holes in some or all of the convex portions, and the non-woven material is a waterproof laminate having two or more layers, of which there are more layers of interlaced nonwoven fabric and one or more layers of meltblown nonwoven fabric. 17. An absorbent article according to one of claims 12 to 16, wherein the synthetic resin film that forms the back sheet has concave and convex portions forming a liquid trapping portion on the surface of its upper side. 18. The absorbent product according to claim 1, in which the absorber is made of a mixture of polymer and whipped pulp, wrapped in a liquid-permeable sheet. 19. The absorbent product according to claim 1, in which the absorber has two layers of liquid-permeable non-woven material and a polymer introduced between them. 20. The absorbent product according to claim 1, in which the absorber contains a polymer supported by coating on a liquid-permeable non-woven material. 21. The absorbent product according to claim 1, in which the polymer content in the absorber is at least 50 wt.%. 22. An absorbent article comprising a body of an absorbent article that forms an internal space for containing a predetermined area of a wearer's body when worn; a cavity for the absorber block adjacent to the body of the absorbent product, continuing the specified inner space and containing a back sheet on its inner wall; and an absorber unit, formed by combining at least a surface sheet and an absorber, introduced with the possibility of removal into the cavity for the absorber unit. 23. The absorbent product according to item 22, in which at least one section between the main body of the absorbent product and the cavity for the block of the absorber introduced a guide sheet. 24. The absorbent product according to item 22, in which between the main body of the absorbent product and the cavity for the absorber unit is introduced, at least in one area, a liquid-permeable skin contact sheet. 25. An absorbent article according to one of claims 22-24, wherein a plurality of blocks of absorbers are introduced into the cavity for the absorber block. 26. An absorbent article comprising a body of an absorbent article that forms an internal space for containing a predetermined area of a wearer's body when worn; the cavity for the absorber adjacent to the body of the absorbent product, continuing the specified inner space and containing a back sheet on its inner wall; an absorber introduced with the possibility of removal into the cavity for the absorber; and a surface sheet that is in at least one portion between the body of the absorbent article and the cavity for the absorber. 27. An absorbent product according to claim 26, which is further provided with a guide sheet adjacent to the upper side of the surface sheet. 28. An absorbent article according to claim 26 or 27, wherein at least one surface portion of the upper side of the surface sheet or the guide sheet is provided with a liquid-permeable skin contact sheet. 29. An absorbent article according to one of claims 26 to 28, wherein a plurality of absorbers are introduced into the cavity for the absorber. 30. The absorbent article of claim 26, wherein a urine distribution portion extending from the center to the front section and a feces placement portion extending from the center to the rear section are provided, wherein a surface sheet is provided only in the urine distribution portion. 31. The absorbent product according to claim 30, in which an inside of the absorber is introduced and / or mounted on the upper side of the absorber, at least in the area for storing feces, liquid permeable to prevent back flow of the sheet. 32. An absorbent product in which the re-wetting level, measured under a load of about 0.007 kg / cm ² , 5 minutes after the start of absorption is such that it allows the absorber to absorb a solution of 0.9 wt.% Chloride at a temperature of 25 ° C and in the absence of load sodium in an amount equivalent to 50% of the absorbent capacity of the absorber is not more than 5 ml. 33. The absorbent article of claim 32, wherein the rewet level is not more than 2 ml. 34. An absorbent article in which the absorption capacity of the absorber when absorbing a solution of 0.9 wt.% Sodium chloride is 300 ml or more, and when adding salt solution for absorption with the absorber in an amount of 100 ml in each of three separate additives carried out in the absence of loads at intervals of 10 min, the average level of re-wetting after three additions is not more than 5 ml, while the mean square deviation of the level of re-wetting is not more than 3 ml; moreover, when the saline solution is added for absorption by means of a scavenger in an amount of 100 ml in each of three separate additives, carried out under a load of about 0.007 kg / cm ² at intervals of 10 minutes, the average absorption time of the three additives is not more than 30 s, and the mean square the deviation of the absorption time is not more than 2 s.

Images