JPH10309298A - Absorbing article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorbing article which optimizes its absorbing structure to quickly absorb wine, body fluid, etc., reduces backflow and residual on the top sheet, and does not cause stickiness or leakage to make a user feel comfortable. SOLUTION: This absorbing article has an absorbing body 2 between a permeable top sheet 1 and an impermeable back sheet 6. The absorbing body 2 is composed of the first absorbing area 3 of 0.01 to 0.2 g/cm<3> density arranged at the permeable top sheet 1, the third absorbing area 5 of 0.01 to 0.2 g/cm<3> density arranged at the impermeable back sheet 1, and the second absorbing area 4 of 0.1 to 0.4 g/cm<3> density arranged between the first absorbing area 3 and the third absorbing area 5. Absorbing substances 7 are substantially distributed equally on the first, second, and third absorbing areas, and a density gradient of the absorbing body 2 is increased to the center of the absorbing body 2 (non-layer absorbing structure).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorbent article, and more particularly, to an absorbent article used for diapers, incontinent pads, sanitary napkins, bed sheets, pet sheets, and the like.

[0002]

2. Description of the Related Art Conventionally, a disposable diaper, which is one of absorbent articles, comprises a cotton-like pulp and an absorbent material (for example, between a liquid-permeable top sheet and a liquid-impermeable back sheet). ,
It has a configuration in which an absorber made of a superabsorbent polymer), a hydrophilic sheet, or the like is arranged, and urine, body fluid, and the like are absorbed by the absorber through the top sheet. In this case, the absorber needs to receive urine, body fluid, etc. and hold the skin without re-wetting the skin.

[0003] As the absorbent used here, an absorbent substance is dispersed in cotton-like pulp and the whole is compressed to form an absorbent, or an absorbent substance is put between cotton-like pulp and cotton-like pulp. Absorber uniformly spread over the entire surface of the absorbent in a layered form, Absorber in which absorbent material is sandwiched and fixed between two absorbent papers, Absorbent in which absorbent material is fixed to the surface of absorbent paper with adhesive It is used for absorbent articles by forming an absorbent body in which an absorbent substance is integrally formed between a body and a top sheet and a back sheet.

However, in conventional absorbent articles, the speed until urine, body fluid, etc. are completely absorbed (hereinafter referred to as absorption speed) is slow, and further, the return of urine, body fluid, etc. from the absorber to the surface (hereinafter, referred to as absorption speed). , Wet back).
This also contributes to skin rash, especially when the wearer of the absorbent article is an infant. In addition, the absorbent substance moves between the absorbers, which gives the wearer an uncomfortable feeling such that the liquid is not sufficiently absorbed and leaks.

[0005] In recent years, from the viewpoint of ease of use and reduction of distribution costs, thinning and compactness have been progressively advanced, and as a result, the use ratio of large-volume cotton-like pulp used in the absorbent has been reduced. There is a tendency to increase the proportion of absorbent material having a small volume and a large absorption capacity. However, since absorbent materials absorb urine and bodily fluids slowly, disposable diapers composed of thin absorbers with a high percentage of absorbent materials have a slow absorption rate, which results in leakage of urine and bodily fluids. There is a problem of putting out.

[0006] Various methods have been proposed to solve these problems. For example, an absorbent structure having a fibrous upper layer and a fibrous lower layer has been proposed to quickly absorb urine of a wearer. The upper layer is about 0.03-
It has a density of about 0.14 g / cm ³ and the lower layer has a density of about 0.1 g / cm ³ .
14 has a density of about 0.3 g / cm ^3. Here, it can be seen that there is a density gradient formed by the lower density upper layer and the higher density lower layer. Such a structure quickly absorbs the liquid discharged in the upper layer,
It is said to be suitable for transporting this liquid to the lower layer where it is transported from the point where it is discharged.

Similarly, there has been proposed a non-layered absorption structure having a concentration gradient of an absorbing substance in a thickness (Z) direction. Absorbable substances are contained in floc pulp. It is said that the density of the absorbent material dispersed in the floppy pulp increases from one plane to the opposite plane. Where a flat surface having a relatively low density of the absorbent material is located closest to the body of the wearer, it is said that such a composition of the absorbent material prevents gel blocking.

Japanese Patent Application Laid-Open No. 6-205806 discloses an absorbing structure in which a concentration gradient of an absorbing substance is provided twice in the thickness (Z) direction. The absorbing structure includes a fibrous matrix having a dual gradient in the Z direction, wherein the concentration of the absorbing material is the first of the fibrous matrix.
The density of the fibrous matrix decreases from the first main plane to the second main plane opposite to the second main plane.
Discloses an absorbing structure that increases toward a major plane. This seeks to optimize the above two proposals.

[0009]

As described above, in the conventional absorbent articles, the absorption rate of the top sheet for absorbing urine, body fluid, and the like into the absorber is slow, and the dry touch property of the top sheet is good. There was no problem.
As mentioned above, both the gradient of density and the gradient of absorbent material are well known in the art and are effective in improving the performance of the absorbent article, but have an absorbent structure suitable for use in the absorbent article. Further optimization is desired.

Accordingly, an object of the present invention is to solve the above problems and optimize the absorbing structure.
That is, an object of the present invention is to provide an absorbent article in which the top sheet has a high spot absorbability and a high absorption rate for absorbing urine, body fluid, and the like into the absorber, and the top sheet has a remarkably improved dry touch property.

[0011]

SUMMARY OF THE INVENTION An absorbent article according to the present invention for solving the above-mentioned problems has an absorbent structure in which an absorbent is disposed between a liquid-permeable top sheet and a liquid-impermeable back sheet. In the non-transparent article, the absorbent includes a first absorbent region having a density of 0.03 to 0.20 g / cm ³ disposed on the liquid-permeable top sheet side, and the liquid-impermeable backsheet. A third absorption region having a density of 0.03 to 0.20 g / cm ³ disposed on the side, and 0.20 to 0.40 g / cm3 disposed between the first absorption region and the third absorption region.
consists secondary absorbent region having a density of cm ^3, the first, second, absorbent material in the third the absorption region of substantially evenly distributed, and the density gradient of the absorbent absorber An absorbent article characterized by being formed in a structure (non-layered absorption structure) that increases toward the center.

Further, the first absorption region is constituted by a fiber layer in the range of 100 to 300 parts by weight per 100 parts by weight of the absorbent material, and the second absorption region is formed by 1 to 50 parts by weight per 100 parts by weight of the absorbent material. An absorbent article, wherein the third absorbent region is constituted by a fiber layer in a range of 50 to 200 parts by weight per 100 parts by weight of the absorbent substance. Exist.

[0013] The absorbent article of the present invention is constituted by an absorber located between a liquid-permeable top sheet and a liquid-impermeable back sheet. This absorber has a first absorption region,
The first, second, and third absorption regions are formed in an integrated structure (non-layered absorption structure). The absorber is
A first absorption region arranged on the liquid-permeable topsheet side, a third absorption region arranged on the liquid-impermeable backsheet side, and a second absorption region between the first absorption region and the third absorption region. It has an integrated structure (non-layered absorption structure) consisting of an absorption region.

In the present invention, in each of the first, second and third absorption regions, the absorptive substance is substantially uniformly dispersed. The absorbent material increases non-stepwise or stepwise along the thickness direction toward the center of the absorber. The absorber is constituted by a high concentration of absorbent material towards the center. That is, the first absorption region or the second absorption region is made of a higher density absorbent material than the third absorption region.

In the absorbent article of the present invention having the above-mentioned structure, urine, body fluid and the like in the liquid-permeable top sheet are spot-absorbed in the first absorption region first and pass at a high speed, so that the first absorption region The urine, body fluid, and the like are immediately diffused at the interface between the first and second absorption regions, and are stored in the second and third absorption regions. Further, the top sheet and the urine, body fluid, and the like in the first absorption region are collected in the second absorption region. Therefore, urine, bodily fluids, loose stools, and the like do not stagnate in the top sheet, and urine, bodily fluids, and the like diffused in the absorber do not return to the top sheet again, and the dry touch property of the top sheet is significantly improved. It is. In addition, the absorber formed in a structure in which the first, second, and third absorption regions are integrated (hereinafter, sometimes referred to as a non-layered absorption structure) accompanies movement of the body. The present invention eliminates the discomfort of the user without tearing of the absorber and leakage of the absorbent material. The non-layered absorption structure referred to here is constituted by one layer in which the absorber is integrally formed.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the absorbent article of the present invention will be described in detail with reference to the drawings, taking a disposable diaper as an example, but the present invention is not limited to these.

FIG. 1 is a plan view showing a state in which the diaper is unfolded after use. As shown in FIG. 1, the disposable diaper comprises an absorbent body 2 disposed between a liquid-permeable top sheet 1 and a liquid-impermeable back sheet 6. FIG. 2 is a cross-sectional view of the disposable diaper shown in FIG. 1 taken along line xx ′. As shown in FIG. 2, the disposable diaper comprises a liquid-permeable top sheet 1 and a liquid-impermeable back sheet 6.
Absorber 2 is arranged between them. In addition, the absorber 2
The first absorption region 3 is disposed on the liquid-permeable top sheet 1 side, and the third absorption region 5 is disposed on the liquid-impermeable backsheet 6 side. Area 5
It is formed in a structure (non-layered absorption structure) in which the second absorption region 4 is disposed. The circle shown in FIG.
2 shows an enlarged cross-sectional view of FIG. From the liquid-permeable top sheet 1 to the liquid-impermeable back sheet 6, the first absorption region 3, the second absorption region 4, and the third absorption region 5 are provided. The density of the absorbent 7 is higher in the second absorption region 4 than in the region 5.

The disposable diaper having the above-mentioned structure is characterized in that urine, body fluid, etc. in a liquid-permeable top sheet are
The spot is quickly absorbed by the first absorption region, passes at a high speed, is immediately diffused at the interface between the first absorption region and the second absorption region, and urine and body fluids are stored in the second and third absorption regions. . Further, the top sheet and the urine, body fluid, and the like in the first absorption region are collected in the second absorption region. Therefore, urine, bodily fluids, etc. do not stagnate in the top sheet, and urine, bodily fluids, etc. diffused in the absorber do not return to the top sheet again, so that the dry touch property of the top sheet is significantly improved. . In addition, the absorber in which the first, second, and third absorption regions are formed as an integrated structure (non-layered absorption structure) is capable of tearing the absorber due to the movement of the body, No material leaks out,
This is to eliminate the discomfort of the user.

Hereinafter, the configuration of the disposable diaper of the present invention will be described. Liquid permeable topsheet The liquid permeable topsheet used is nonwoven fabric, woven fabric,
Liquid permeable sheets such as mesh sheets, porous foams, and porous films. The constituent fibers may be polypropylene, polyethylene, polyester, or composite fibers composed of two or more components such as polyester, polypropylene, and polyethylene. In particular, polyester / polyester, polyester / polyethylene, and polypropylene / polyethylene composite fibers have high strength. However, there is no particular limitation. Further, natural fibers (for example, wood fibers and cotton-like fibers) may be used, and can be manufactured from a wide range of materials such as a combination of synthetic fibers and natural fibers. The manufacturing method and shape are not limited,
In any case, since the liquid-permeable top sheet is a portion that directly contacts the skin, it is appropriate that the liquid-permeable top sheet is soft and comfortable. The basis weight of the liquid-permeable top sheet is preferably from 10 to 60 g / m ² . Basis weight of 10 g / m ²
If it is less than 1, the wet back from the absorber deteriorates, which is not appropriate. On the other hand, when the basis weight exceeds 60 g / m ² , the moisture remaining on the top sheet increases, so that the dry touch property is deteriorated, not only giving the wearer discomfort but also causing dermatitis and the like. The fiber diameter of the constituent fibers is preferably 0.5 to 10 denier. The fiber diameter is 0.
If it is less than 5 denier, the density becomes high, and the absorption rate is reduced, so that it becomes easy to leak. On the other hand, if the fiber diameter exceeds 10 denier, the feel becomes poor, which is not appropriate.

Absorber In the absorber, an absorber is disposed between a liquid-permeable topsheet and a liquid-impermeable backsheet, and the absorber is provided on the liquid-permeable topsheet side. 0.03 placed
A first absorption area having a density of about 0.20 g / cm ³ , and a 0.03 to 0.20 placed on the liquid-impermeable backsheet side.
a third absorption region having a density of g / cm ³ , and 0.20 to 0.40 g / c disposed between the first absorption region and the third absorption region.
It consists of a second absorption region with a density of m ³ . The density used here indicates the density in the structure of the low-density layer or the high-density layer, and does not indicate the actual fiber density. It represents the measured value of the sample measured across the length and width of the absorber. This density was determined under a load of 12 g / cm ² based on the weight of the fiber layer and the absorbent material. This absorber has a density gradient in the thickness (Z) direction and a density gradient of the absorbent material in the thickness (Z) direction. In the first absorption region, the second absorption region, the third absorption region,
The absorbent material is formed in a structure in which the absorbent material is substantially evenly dispersed and the density gradient of the absorber increases toward the center of the absorber.

The first absorption region is constituted by a fiber layer in the range of 100 to 300 parts by weight per 100 parts by weight of the absorbent material, and the second absorption region is in the range of 1 to 50 parts by weight per 100 parts by weight of the absorbent material. And the third absorption region is 50 to 2 per 100 parts by weight of the absorbent substance.
It is constituted by a fiber layer in the range of 00 parts by weight.

When the density of the first absorbent region disposed on the liquid-permeable top sheet side exceeds 0.20 g / cm ³ , or is constituted by a fiber layer of less than 100 parts by weight per 100 parts by weight of the absorbent material. Then, since the density of the absorbent substance dispersed in the first absorption region becomes high, the absorption substance gel is blocked, so that the absorbent substance is continuously contacted to form a permeation barrier, thereby preventing the absorption of excrement. , The absorption rate decreases. Further, the density of the first absorption region is 0.03 g / cm.
^When it is less than ³ , or when constituted by a fiber layer exceeding 300 parts by weight per 100 parts by weight of the absorbent substance,
Since the density of the absorbent substance dispersed in the first absorption region becomes low, excrement accumulates in the first absorption region or cannot be quickly absorbed from the top sheet, so that the dry touch property of the top sheet is poor. The first absorption area is 0.03
Suitably constituted by a fiber layer with a density of ０．２0.20 g / cm ^{3 and} in the range of 100-300 parts by weight per 100 parts by weight of absorbent material. When the absorbent absorbs the excrement and swells, the mutual interference of the absorbent is minimized, and the absorbent does not form a permeation barrier due to continuous contact. Permeate and absorb.

When the density of the second absorption region disposed between the first absorption region and the third absorption region exceeds 0.40 g / cm ³ or less than 1 part by weight of fiber per 100 parts by weight of the absorbent material When constituted by a layer, the second absorbent region becomes a layer of an absorbent substance, so that the movement of the wearer's body is similar to an absorbent body in which the absorbent substance is sandwiched and fixed between the upper and lower fiber layers. As a result, the absorbent body is torn, the absorbent body is displaced, and the absorbent substance leaks out, so that the absorbing performance is not obtained and the absorbent tends to leak. Further, the density of the second absorption region is 0.20 g.
/ Cm ³ or 5 per 100 parts by weight of absorbent material
If it is constituted by a fiber layer exceeding 0 parts by weight, the density of the absorbent substance dispersed in the second absorption region becomes low, so that excrement cannot be attracted to the second absorption region, Since the excrement accumulates in the absorption area, the return from the absorber to the top sheet increases, and the top sheet has a poor salat feeling and rash on the skin. The second absorption region is
Absorbent substance 1 at a density of 0.20 to 0.40 g / cm ³
Suitably it is constituted by a fibrous layer in the range of 1 to 50 parts by weight per 00 parts by weight. Since the density of the absorbent material is high, the excrement is sufficiently absorbed and the excrement in the first absorption region is attracted. Further, excrement can be diffused in the boundary between the first absorption region and the second absorption region. Furthermore, the fiber layer of the second absorption region has a structure in which the first absorption region and the third absorption region are integrated (non-layered absorption structure), so that the absorber does not tear, and the absorbent material does not leak. Eliminate user discomfort.

When the density of the third absorbing region disposed on the liquid impermeable back sheet side exceeds 0.20 g / cm ³ ,
Or, when the density of the third absorption region is constituted by a fiber layer of less than 50 parts by weight per 100 parts by weight of the absorbent material,
Since the density of the absorbent material dispersed in the third absorption region increases, a large amount of the absorbent material is disposed on the backsheet side, and the backsheet has a rough feel, which is not preferable. Further, the density of the third absorption region is 0.03 g /
less than cm ³ or 20 per 100 parts by weight of absorbent material
If the fiber layer exceeds 0 parts by weight, the concentration of the absorbent substance in the third absorption region becomes low, so that the absorber does not serve as a storage layer, so that the absorbent tends to leak. Suitably, the third absorbent region is constituted by a fibrous layer having a density of 0.03 to 0.20 g / cm ^{3 and} in the range of 50 to 200 parts by weight per 100 parts by weight of the absorbent substance. As the storage layer of the absorber, the softness of the absorbent article is further improved, and the discomfort of the wearer is eliminated.

The material of the fiber layer used for the absorbent can be selected from a wide range. For example, natural fibers (wood fibers, cotton fibers) may be used, and synthetic fibers or a combination of natural fibers and synthetic fibers may be used. Suitable natural fibers include cottony pulp and the like. The flocculent pulp is a chemical pulp sheet or a mechanical pulp sheet having a fiber length of 5 mm or less obtained by defibrating with a crusher. Pulp raw materials are not limited to conifers,
Hardwood, straw, bamboo and kefna also apply. The synthetic fiber may be polypropylene, polyethylene, polyester, or a composite fiber composed of two or more components such as polyester, polypropylene, and polyethylene. In particular, a composite fiber of polyester / polyester, polyester / polyethylene, or polypropylene / polyethylene is preferably used. It is preferable from the viewpoint of. The fiber diameter of the constituent fibers is preferably 1.5 to 10 denier, and the length is preferably 3 mm or more from the viewpoint of production. As a method of hydrophilizing these synthetic fibers and composite fibers, there are methods of applying a hydrophilic agent to the synthetic fibers and composite fibers by spraying, foaming, impregnating, or the like.

Further, by containing a large amount of synthetic fibers having an irregular cross section, a material having a low absorption region density can be obtained.
The reason for this is that, for example, in the case of the same denier, the synthetic fiber having a modified cross section has a larger cross-sectional area than the synthetic fiber having a circular cross section. There is also a method of increasing the fiber diameter of a synthetic fiber having a modified cross section than a synthetic fiber having a circular cross section. Examples of the synthetic fiber having an irregular cross-section include polypropylene, polyethylene, polyester, acrylic resin, and nylon resin, and the cross-sectional shape thereof is preferably T-type, W-type, H-type, rhombus, or amoeboid-like. There is no particular restriction.

Considering that the heat-fusible substance is mixed with natural fibers, a fibrous material is preferable. Examples of the heat-fusible substance include polypropylene, polyethylene, polyester, polyvinylidene, acrylic resin, and nylon resin. Alternatively, a composite fiber composed of two or more components such as polyester, polypropylene, and polyethylene may be used. In particular, a composite fiber of polyester / polyester, polyester / polyethylene, and polypropylene / polyethylene is preferable in terms of strength. A fiber diameter of about 1 to 5 denier is preferable, and a fiber length of 3 to 30 mm is suitable for mixing with natural fibers, but is not particularly limited. By heat-treating these fiber layers, a skeletal structure made of a heat-fusible substance is formed, and it is possible to have the strength of the fiber layers themselves even when wet. The heat treatment method is not particularly limited, such as a hot press roll, a hot emboss press roll, a hot air dryer, a microwave heater, an infrared heater, etc., but heat is uniformly transmitted to the mat layer, and the heat-fusible substance is melted. What is necessary is just to be able to form a skeleton structure.

Further, fibers such as rayon and cellulose acetate are also suitable for forming the absorber. The amount of the fiber layer used in the absorbent may be, for example, generally 40 to 3500 g / m ² depending on the intended absorbent.
To be.

The absorbent used in the absorber includes:
Examples include starch-based, cellulose-based, and synthetic polymer-based. That is, a starch-acrylic acid (salt) graft copolymer, a saponified product of starch-ethyl acrylate graft copolymer, a saponified product of starch-methyl methacrylate graft copolymer, and a saponified product of starch-acrylonitrile graft copolymer Saponified product of starch-acrylamide graft copolymer, saponified product of starch-acrylonitrile 2-acrylamide-2-methylpropanesulfonic acid graft copolymer, acrylic acid (salt) polymer,
Examples include a crosslinked product of polyethylene oxide crosslinked with acrylic acid, a crosslinked product of sodium carboxymethyl cellulose, and a crosslinked product of a polyvinyl alcohol-maleic anhydride reactant. It absorbs urine, body fluid, and water at least 20 times its own weight, and sodium polyacrylate is most suitable from the viewpoint of absorption performance.

The absorber can be formed by a spun bond or melt blow step, a carding step, a wet laid step, or an air laid step. The absorbent contains an absorbent material. Methods for incorporating this absorbent material into the absorbent are well known to those skilled in the art. For example, by simultaneously laying the fibers of the absorbent and the absorbent substance, the absorbent substance can be contained in the absorbent body. Further, a method of forming a density gradient of the absorbent material in the thickness (Z) direction of the absorber is obtained by changing the supply method of the absorbent material in the air-laid apparatus. The forming method is not particularly limited. Although the absorber is formed integrally, it may be in the form of a composite composed of a plurality of layers. For example, if the absorber is composed of a plurality of layers, these layers are in fluid communication with each other, so that liquid present in one absorption region can flow to another absorption region.

Further, as shown in FIG. 2, it may be wrapped with a hydrophilic sheet depending on the intended absorber. For example, a hydrophilic sheet such as a tissue, an absorbent paper, or a hydrophilic nonwoven fabric may be used.

As a method of compressing the absorber, compression by a press roll is advantageously performed. However, a continuous flat surface is used to make the absorber substantially uniform over the entire absorber by a roll having a smooth peripheral surface. Alternatively, a pattern arrangement may be used in which embossing is performed by a roll or the like having an uneven peripheral surface, the density of the absorber is partially different, and urine, bodily fluids, and the like are guided in the vertical and oblique directions. . In the case of embossing, the compressed portion and the non-compressed portion may be continuous or discontinuous.

As shown in FIG. 1, the size of the absorbent may be equal to or smaller than the size of the absorbent article. If the place where urine, body fluid, etc. are excreted is known, only that part may be installed.

Liquid-impermeable back sheet The liquid-impermeable back sheet used is a material in which a non-woven fabric, a woven fabric, or the like is bonded to a liquid-impermeable film such as polyethylene, or a moisture-proof back sheet. Any non-woven fabric or woven fabric may be used. Further, it may be embossed in a pattern to give a cloth-like appearance, or may be further matte-finished. When a film is used, a known air-permeable film that is permeable to water vapor only while being impermeable may be used, and it is more preferable to prevent stuffiness.

In the above-described members, for example, the entire surface or a part of the liquid-permeable top sheet and the absorber, and the liquid-impermeable back sheet are bonded by hot-melt bonding or the like between the absorber and the liquid-impermeable back sheet. And as an adhesive,
A water-soluble glue such as starch or CMC (carboxymethylcellulose) or a highly fluid adhesive may be used. In the disposable diaper (absorbent article) of the present invention, the effect of the present invention can be achieved only by combining the liquid-permeable top sheet and the absorber described above.

[0036]

The effects of the present invention will be described below in detail with reference to examples. As shown in the cross-sectional view of FIG. 2, a liquid-impermeable backsheet made of polyethylene is provided on the outer surface when the device is mounted, and an absorbent material (highly absorbent polymer) and cotton-like pulp are provided inside the backsheet. An absorbent body covered with a hydrophilic sheet (tissue) is provided, and these are covered with a liquid-permeable top sheet made of polyester / polyethylene coated with hydrophilic fibers, and the overlapping peripheral portions of the back sheet and the top sheet are attached to each other. It was configured by bonding. Further, as shown in FIG. 1, the planar shape of the disposable diaper had the largest area between the back sheet and the top sheet, and provided a stretchable elastic body which was in close contact with the crotch portion when worn. Further, the absorber had the same shape.

The evaluation items in the embodiment are as follows.
Using artificial urine, the absorption rate, wetback, and salat feeling were evaluated. The absorption rate is as follows: Place a perforated stainless steel plate (9 mm thick, 25 mm in diameter of the hole) in the center of the diaper and use it every 30 minutes until 50 cc of artificial urine is absorbed into the diaper. The measurement was repeated three times. Wet back refers to a method of measuring the absorption rate (absorbing 50 cc three times), leaving the diaper to stand for 30 minutes, and then using a 10 × 10
Ten pieces of filter paper of cm square (No. 63, manufactured by Toyo Roshi Kabushiki Kaisha) were stacked, left under a pressure of 0.05 kg / cm ² for 5 minutes, and the amount of liquid transferred to the filter paper was measured.

The "sarat feeling" was determined by measuring the absorption rate (5
After absorbing 0 cc three times), the surface of the top sheet was lightly touched by hand, and the dryness (salat feeling) was determined by sensory evaluation. The judgment criteria were classified into the following three stages (段 階, Δ, ×). Sarat feeling criterion ○: dry △: moist ×: considerably moist The artificial urine used here is as follows. Artificial urine composition (% by weight) Urea 1.9% NaCl 0.8% CaCl ₂ 0.1% MgSO ₄ 0.1% The balance is water

Example 1 As an absorber, a cotton-like pulp prepared by pulp sheeting made of NBKP with a defibrating machine and a superabsorbent polymer made of sodium polyacrylate were formed into a thickness (Z) by an air-laid manufacturing apparatus. It was manufactured such that three absorption regions were distributed in the directions. As a first absorbing region, a cotton-like pulp 100 g / m ^2, the superabsorbent polymer 100 g / m ² uniformly distributed to, 12 g / cm ² having a thickness of about 1.0mm under a load, the average density of 0.20 g / cm Formed into ³ ,
As the second absorption region, 5 g / m ^{2 of} flocculent pulp and 100 g / m ² of the superabsorbent polymer were uniformly distributed to obtain 12 g / m ^2.
The thickness under a load of ² cm is about 0.5 mm and the average density is 0.
21 g / cm ³ , and as the third absorption region, 50 g / m ^{2 of} flocculent pulp and 100 g / m ^{2 of} superabsorbent polymer
And a thickness under a load of 12 g / cm ^{2 of} about 1.
An absorber having a thickness of 0 mm and an average density of 0.15 g / cm ³ and having a structure in which the first, second, and third absorption regions were integrated (non-layered absorption structure) was obtained. Next, a disposable diaper having the structure shown in FIGS. 1 and 2 having the absorber between the liquid-permeable top sheet and the liquid-impermeable back sheet was produced.

Example 2 An absorber was produced in the same manner as in Example 1. 100 g / m ^{2 of} cottony pulp as the first absorption region of the absorber;
35 g / m ² of the superabsorbent polymer is uniformly distributed, and 12
g / cm ^{2, a} thickness under a load of about 1.0 mm and an average density of 0.14 g / cm ³ .
50 g / m ^{2 of} flocculent pulp and 100 g of superabsorbent polymer
/ M ² is uniformly distributed to form a thickness of about 0.5 mm under a load of 12 g / cm ² , an average density of 0.30 g / cm ³ , and a flocculent pulp of 100 g / m ² as a third absorption region.
And 50 g / m ² of superabsorbent polymer were distributed, and 12 g
Structure with a thickness of about 1.0 mm and an average density of 0.15 g / cm ³ under a / cm ² load, and the first, second, and third absorption regions are integrated (non-layered absorption structure) A diaper was prepared in the same manner as in Example 1 except that the absorbent was formed.

Comparative Example 1 An absorber was produced in the same manner as in Example 1. As the first absorption area of the absorber, 100 g / m ^{2 of} flocculent pulp is uniformly distributed, is formed to a thickness of about 1.0 mm under a load of 12 g / cm ² and an average density of 0.10 g / cm ³ ,
As the second absorption region, 50 g / m ^{2 of} flocculent pulp and 100 g / m ² of the superabsorbent polymer are uniformly distributed, and 12 g
/ Cm ² under a load of about 0.5 mm and an average density of 0.30 g / cm ³ .
100 g / m ^{2 of} cottony pulp and 85 g of superabsorbent polymer
/ M ² was distributed, a thickness of about 1.0mm under 12 g / cm ² load, is formed to an average density of 0.19 g / cm ^3,
A disposable diaper was prepared in the same manner as in Example 1, except that the first, second, and third absorption regions were formed into an integrated structure (non-layered absorption structure). .

Comparative Example 2 An absorber was produced in the same manner as in Example 1. 100 g / m ^{2 of} cottony pulp as the first absorption region of the absorber;
85 g / m ² of the superabsorbent polymer is uniformly distributed,
g / cm ² under a load of about 1.0 mm and an average density of 0.19 g / cm ³ .
50 g / m ^{2 of} flocculent pulp and 100 g of superabsorbent polymer
/ M ² is uniformly distributed to form a thickness of about 0.5 mm under a load of 12 g / cm ² , an average density of 0.30 g / cm ³ , and a flocculent pulp of 100 g / m ² as a third absorption region.
And a thickness under a load of 12 g / cm ^{2 of} about 1.
0 mm, formed with an average density of 0.10 g / cm ³ , except that the first, second and third absorption regions were formed into an integrated structure (non-layered absorption structure). Example 1
A diaper was prepared in the same manner as described above.

COMPARATIVE EXAMPLE 3 An absorber was arranged such that an absorbent was disposed between an upper layer and a lower layer. A pulp sheet made of NBKP is applied to the upper layer by a defibrating machine, and 100 g of cotton pulp is formed by an air laid process.
/ M ² is evenly distributed, and a pulp sheet having a thickness of about 1.0 mm under a load of 12 g / cm ² and an average density of 0.10 g / cm ³ , which is also made of NBKP in the lower layer, is subjected to a defibrating machine by an airlaid process. 150g of cottony pulp
/ M ² is uniformly distributed to form a thickness of about 1.0 mm under a load of 12 g / cm ² , an average density of 0.15 g / cm ³ , and a superabsorbent polymer made of sodium polyacrylate as an upper layer and a lower layer. A disposable diaper was prepared in the same manner as in Example 1 except that the absorbent was spread in layers.

Comparative Example 4 An absorber was produced in the same manner as in Example 1. As an absorber, 250 g / m ^{2 of} flocculent pulp produced by subjecting a pulp sheet made of NBKP to a defibrating machine and 185 g / m ² of a superabsorbent polymer made of sodium polyacrylate are uniformly distributed, and under a load of 12 g / cm ^2. Was formed to have a thickness of about 2.5 mm and an average density of 0.17 g / cm ³ in the same manner as in Example 1, except that a single-layer absorber was used.

The above-mentioned characteristics were evaluated using the disposable diapers prepared in Examples 1 and 2 and Comparative Examples 1 to 4. Table 1 shows the test results.

[Table 1]

As shown in Table 1, the characteristics of Comparative Examples 1 to 4 were considerably inferior to those of Examples 1 and 2, and the effect of the present invention was confirmed.

[0047]

As described above, by using the absorbent article of the present invention, urine, body fluid, and the like in the top sheet touching the user's skin are spot-absorbed quickly in the first absorption region of the absorber. At a high speed, followed by immediate diffusion at the interface between the first absorption region of the absorber and the second absorption region of the absorber, urine in the second absorption region of the absorber and the third absorption region of the absorber, Body fluids are stored. further,
The top sheet and the urine, body fluid, etc. of the first absorption region of the absorber are collected in the second absorption region of the absorber. Therefore, urine, bodily fluids, loose stools, and the like do not stagnate in the top sheet, and urine, bodily fluids, and the like diffused in the absorber do not return to the top sheet again, and the dry touch property of the top sheet is significantly improved. It is. In addition, the absorber in which the first, second, and third absorption regions are formed as an integrated structure (non-layered absorption structure) is capable of tearing the absorber due to the movement of the body, No material leaks out,
This is to eliminate the discomfort of the user.

[Brief description of the drawings]

FIG. 1 shows a plan view of a partially cut-out diaper of the present invention.

FIG. 2 shows a cross-sectional view of the disposable diaper of FIG. 1 taken along line xx ′. The circle shown in the absorber in FIG.
FIG. 3 shows an enlarged cross-sectional view of the absorber.

[Explanation of symbols]

 1. 1. Liquid permeable topsheet Absorber 3. First absorption region 4. Second absorption region 5. Third absorption region 6. 6. Liquid-impermeable backsheet 7. Absorbable substance 8. floc pulp Hydrophilic sheet 10. Elastic elastic body 11. Tape fastener

Claims (2)

[Claims] 1. An absorbent article in which an absorber is disposed between a liquid-permeable top sheet and a liquid-impermeable backsheet, wherein the absorber is disposed on the liquid-permeable top sheet side. the has a density of 0.03~0.20g / cm ³ which is disposed on the up side - a first absorbent region having a density of 0.03~0.20g / cm ^3, wherein the liquid impermeable Bakkushi was Three absorption regions, and a second absorption region having a density of 0.20 to 0.40 g / cm ³ disposed between the first absorption region and the third absorption region; Absorbent material is characterized in that the absorbent material is substantially evenly dispersed in each of the third absorption regions, and the density gradient of the absorber is increased toward the center of the absorber. Goods. 2. The first absorption region includes an absorbent material 100
Per 100 parts by weight per 100 parts by weight of the fibrous layer, wherein the second absorbent region is made of an absorbent material 100
The first absorbent region is constituted by a fiber layer in the range of 1 to 50 parts by weight per part by weight.
The absorbent article according to claim 1, wherein the absorbent article is constituted by a fiber layer in a range of 50 to 200 parts by weight per 0 parts by weight.