JPH11318982A - Absorptive article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorptive article which is optimized in an absorbing structure and can be comfortably used. SOLUTION: An absorbent 1 is arranged between a liquid-permeable top sheet 2 and a liquid-impermeable back sheet 3. The absorbent 1 is constituted of an upper layer part 4 located on the side of the top sheet 2 and a lower layer part 5 located on the side of the back sheet 3. The upper layer part 4 is formed by mixing and arranging absorptive substance in plural rows of parallel muscle shapes in a fiber layer. The lower layer part 5 is constituted of a first absorbing area 6 on the side of the upper layer part 4, a third absorbing area 8 on the side of the back sheet 3 and a second absorbing area 7 between the first and third absorbing areas 6, 8. In each absorbing area, fiber substance and absorptive substance are uniformly blended, the second absorbing area 7 is higher than the first absorbing area 6 and the third absorbing area 8 in density. Space among each absorbing area is formed into a continuous integral structure without boundary lines.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an absorbent article,
More specifically, the present invention relates to an absorbent article used for a diaper, an incontinence pad, a sanitary napkin, a bed sheet, a pet sheet, and the like using an absorbent substance.

[0002]

2. Description of the Related Art Conventionally, a disposable diaper, which is one of absorbent articles, has a cotton-like pulp, an absorbent material (for example, It has a configuration in which an absorber made of a highly absorbent 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, after receiving the urine, body fluid, and the like, the absorber needs to hold the skin without re-wetting the skin.

[0003] The absorbent used here is to disperse an absorbent material in floc pulp and compress the whole into an absorbent,
Or, an absorbent body in which an absorbent material is uniformly spread in a layered manner between cottony pulp and cottony pulp, an absorbent body in which the absorbent material is sandwiched between two absorbent papers, and fixed. It is used for an absorbent article by forming an absorbent body having an absorbent material fixed on the surface of the body with an adhesive, or an absorbent body having an absorbent material integrally formed between 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 contributes to skin rash, especially when the wearer of the absorbent article is an infant. In addition, the absorbent substance moves between the absorbers, and the liquid is not sufficiently absorbed and leaks, thereby causing discomfort to the wearer.

[0005] In recent years, thinning and compactness have been promoted from the viewpoint of ease of use and reduction of distribution costs. As a result, the proportion of large-volume cotton-like pulp used in the absorbent has been reduced, and the volume has been reduced. There is a tendency to increase the proportion of small and large absorbent materials. 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 a density gradient exists in the thickness (Z) direction in the absorber formed by the lower density upper layer and the higher density lower layer. Such a structure is said to be suitable for quickly absorbing and retaining the liquid discharged on the surface of the upper layer in the upper layer and transporting the liquid to the lower layer.

[0007] Similarly, a non-layered absorbent structure having a density gradient of the absorbent material in the thickness (Z) direction has been proposed, wherein the absorbent material is dispersed in a cotton-like pulp layer. 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 absorbent material density is located closest to the body of the wearer, it is said that such an arrangement of the absorbent material prevents gel blocking.

Japanese Patent Application Laid-Open No. 6-205806 discloses an absorption structure having a double gradient in the thickness (Z) direction. That is, the absorbent structure includes a fibrous matrix, and the distribution concentration of the absorbent material decreases from the first major plane of the fibrous matrix toward the opposing second major plane, while the density of the fibrous matrix itself is reduced. Disclosed is an absorbing structure that increases from the first main plane to the second main plane.

Further, Japanese Utility Model Application Laid-Open No. Sho 56-11210 discloses that at least two quadrants including the center line among three quadrants which divide the longitudinal direction of the absorption pad into four quarters. Disposable diapers containing a superabsorbent polymer sheet divided and disclosed are disclosed in JP-A-62-170246 and JP-A-62-170247. In the absorbent body of absorbent sanitary articles in which particles are mixed, the superabsorbent polymer particles form a group of vertical stripes, wavy patterns, etc. in the fiber web, and are intermittent in the plane direction and continuous in the thickness direction. There are proposed absorbers that are distributed uniformly.

[0010]

As described above, in a conventional absorbent article, the absorption rate for absorbing urine, body fluid, and the like excreted on the top sheet surface to the absorber is slow, and the absorbent sheet is in contact with the top sheet. However, there is a problem that the so-called dry touch is not good when the user feels dry. Further, as described above, providing a density gradient in the fiber layer, providing a density gradient in the absorbent material, and arranging the absorbent material layer in a vertical stripe pattern, a wave pattern, or the like in the fiber layer. Although is effective in improving the performance of absorbent articles, it is desirable to further optimize the absorbent structure suitable for use in absorbent articles.

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

[0012]

The present invention for solving the above problems includes the inventions specified by the following technical items.

(1) In an absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber disposed between these two sheets, the absorber is on the top sheet side The upper layer portion is formed by arranging a plurality of rows of absorbent materials in a layer made of a fibrous material, and the lower layer portion is formed of a fiber layer. The part comprises a first absorption region arranged on the upper layer side, a third absorption region arranged on the back sheet side, and a second absorption region arranged between the first absorption region and the third absorption region. A fiber material and an absorbent material are uniformly blended in each absorption region, and the second absorption region has a higher density than the first absorption region and the third absorption region, and
The distribution density of the absorbent substance is higher than that of the first absorption region and the third absorption region, and furthermore, between each absorption region, it is characterized in that it is formed in a continuous integrated structure without boundaries. Absorbent articles.

(2) The densities of the first absorption region, the second absorption region and the third absorption region measured under a pressure of 12 g / cm ² are 0.03 to 0.20 g / cm ³ and 0.20 to 0.20 g / cm ³ , respectively.
0.40 g / cm ³ and 0.03 to 0.20 g / cm ³
The absorbent article according to the above (1), wherein (3) In the first absorption region, 100 to 300 parts by weight of a fiber substance is blended per 100 parts by weight of the absorbent substance,
The second absorbent region contains 1 to 50 parts by weight of a fiber material per 100 parts by weight of the absorbent material, and the third absorbent region contains 50 to 200 parts by weight of the fiber material per 100 parts by weight of the absorbent material.
The absorbent article according to the above (1) or (2), wherein the absorbent article is blended in parts by weight. (4) The upper layer of the absorber contains an absorbent material in the fiber.
The absorbent article according to any one of the above (1) to (3), which is formed in a structure arranged in a parallel streak having a width of about 50 mm.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In an absorbent article according to the present invention, an absorber comprises an upper layer and a lower layer, and the upper layer is formed by arranging a plurality of rows of absorbents in a layer made of a fibrous material. The lower layer portion is composed of first, second, and third absorption regions, and a fiber material and an absorbent material are uniformly mixed in each absorption region, and the second absorption region is composed of the first and second absorption regions. The density is higher than the three absorption regions, and the distribution density of the absorbent material is higher than the first absorption region and the third absorption region. The structure is formed.

The absorbent article according to the present invention having the absorbent having the above-described structure is characterized in that urine, body fluid, etc., which have penetrated the liquid-permeable top sheet, are spot-absorbed in the upper layer of the absorber. Has a structure in which the absorbent material is arranged in a plurality of rows in a layer made of a fibrous material, so that the material is immediately diffused, passes at a high speed, and moves to the lower layer of the absorber. further,
In the lower part of the absorber, urine, body fluids, etc. penetrating from the upper part of the absorber pass through the first absorption region at a high speed and are diffused at the interface between the first absorption region and the second absorption region, and Absorbed and retained in the region and the third absorption region. In this case, urine, body fluid, and the like absorbed and retained in the third absorption region are prevented from returning to the upper layer portion by the action of the absorbent substance in the second absorption region.

Therefore, urine, bodily fluids, etc. do not stagnate on the top sheet, and urine,
Since there is little so-called wet back that bodily fluids return to the top sheet again, the so-called dry touch property that feels dry when touching the top sheet is significantly improved, and it prevents the wearer's skin from rash and itching Can be.

The absorbent substance arranged in a plurality of rows in the upper layer of the absorbent body expands and gels when absorbing urine, body fluid, and the like. However, since the absorbent material does not come into contact with adjacent muscles, the remaining urine, body fluid, etc., which has not been absorbed by the upper layer, can move to the lower layer from the interval between the muscles of the absorbent material. Therefore, even when a large amount of urine, bodily fluid, and the like are excreted at one time, the urine and body fluid are smoothly absorbed and retained, so that leakage can be prevented.

Furthermore, since the respective absorption areas in the lower layer are formed in a continuous and integral structure without boundaries, there is no possibility that the absorber is broken by the movement of the body or the absorbent substance leaks out. Therefore, no discomfort is given to the wearer.

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 (P) includes an absorber 1 disposed between a liquid-permeable top sheet 2 and a liquid-impermeable back sheet 3. FIG. 2 is a cross-sectional view of the disposable diaper shown in FIG. 1 taken along line XX ′, and FIG.
FIG. 2 is a partially enlarged view of a cross-sectional view of FIG.

As shown in FIGS. 2 and 3, the used diaper (P) has an absorber 1 disposed between a liquid-permeable top sheet 2 and a liquid-impermeable back sheet 3. The absorber 1 is composed of an upper layer 4 and a lower layer 5. The upper layer 4 of the absorber is formed by arranging an absorbent material 9 in a plurality of rows in a layer made of a fibrous material 10. I have. further,
The lower layer portion 5 of the absorber includes a first absorption region 6 disposed on the upper layer portion 4 side of the absorber, a third absorption region 8 disposed on the liquid impermeable back sheet 3 side, and a first absorption region. 6 and a second absorption region 7 disposed between the third absorption region 8.

FIG. 3 is an enlarged cross-sectional view of the absorbent body 2, from the liquid-permeable top sheet 2 to the liquid-impermeable back sheet 3, The lower layer 5 is composed of a first absorption region 6, a second absorption region 7, and a third absorption region 8, and a fiber material and an absorbent material are uniformly mixed in each absorption region. Are formed in a continuous and integral structure without boundaries, and the first absorption region 6 and the third absorption region 8
Shows a state where the distribution density of the absorbent material 9 is higher.

In the absorbent article of the present invention, the liquid-permeable top sheet includes a nonwoven fabric, a woven fabric, a mesh sheet,
A liquid permeable sheet such as a porous film and a porous film is used. As the liquid permeable sheet, a sheet made of synthetic fibers such as polypropylene, polyethylene, and polyester, or composite fibers composed of two or more components such as polyester, polypropylene, and polyethylene can be used. In particular, polyester / polyester, polyester / Polyethylene, polypropylene / polyethylene composite fibers are preferable from the viewpoint of strength. Further, it may be manufactured from a wide range of materials such as natural fibers (for example, wood fibers and cotton-like fibers) and a combination of synthetic fibers and natural fibers. There is no limitation on the manufacturing method and shape, but in any case, the liquid-permeable topsheet is a portion that directly contacts the skin, so that a soft and comfortable one is suitable.

The liquid-permeable topsheet has a basis weight of 10
What is 60 g / m < ² > is preferable. Basis weight 10g /
If it is less than m ² , wet back from the absorber deteriorates, which is not appropriate. Conversely, if the basis weight exceeds 60 g / m ² , the moisture remaining on the top sheet increases, so that the dry touch property deteriorates and not only causes discomfort to the wearer but also causes dermatitis and the like, which is preferable. Absent.
The fiber diameter of the constituent fibers is preferably 0.5 to 10 denier. If the fiber diameter is less than 0.5 denier, the density increases,
Since the absorption rate is low, it is easy to leak and the fiber diameter is 1
If it exceeds 0, the skin feels bad and is not suitable.

The absorbent in the absorbent article of the present invention is disposed between a liquid-permeable top sheet and a liquid-impermeable back sheet. Further, the absorber includes an upper layer located on the top sheet side and a lower layer located on the back sheet side. The upper layer portion is formed by arranging an absorbent material in a plurality of lines in a layer made of a fiber material. The arrangement width of the absorbent material is preferably from 5 to 50 mm, and in this range, even if the absorbent material absorbs urine, bodily fluids, and gels, and expands in volume, adjacent absorbent materials can be separated from each other. Since there is no contact, the absorber does not lose its shape and can prevent lateral leakage of urine, body fluid, etc. due to the shape loss. It is possible to reliably maintain the passage interval.

When the arrangement width of the absorbent material is less than 5 mm, the width is too small to make the arrangement of the absorbent material difficult, so that the absorbent material is liable to be blocked and the absorption performance is reduced.
On the other hand, when the arrangement width exceeds 50 mm, the interval between the absorbent materials becomes too large, and effective absorption of urine, body fluid, and the like cannot be performed.

The arrangement direction of the absorbent material may be the width direction of the absorbent article, the longitudinal direction, or the oblique direction, and may be appropriately determined depending on the absorbent article used. Further, the arrangement intervals of the absorbent materials may be parallel or non-parallel to each other, may differ depending on the location, and may be appropriately determined depending on the absorbent article.

The lower layer portion includes a first absorption region disposed on the upper layer side, a third absorption region disposed on the back sheet side,
Consisting of a second absorption region arranged between the first and third absorption regions, a fiber material and an absorbent material are uniformly blended in each absorption region, and there is no border between each absorption region It is formed into a continuous, integral structure.

In each of the absorption regions constituting the lower layer, the density of the second absorption region is higher than that of the first and third absorption regions. That is, when measured under a pressure of 12 g / cm ² , the density of the first absorption region is 0.03 to 0.2.
20 g / cm ³ and the density of the second absorption region is 0.20
０．４0.40 g / cm ³ , and the density of the third absorption region is preferably 0.03〜0.20 g / cm ³ .

The density indicated here is the average value of the pressure applied to the absorbent article when the baby as the wearer wears the absorbent article, and is applied to the absorbent body under a load of 12 g / cm ^2. It is a value when measured and does not represent the actual density of the absorbent body of the absorbent article before use. Therefore, hereinafter, unless otherwise specified, the density is 12 g / c.
The value under m ² under pressure is shown.

Further, in each of the absorption regions, the distribution density of the absorbent in the second absorption region is higher than in the first and third absorption regions. That is, 100 to 300 parts by weight of the fiber substance is blended per 100 parts by weight of the absorbent substance in the first absorption area, and the absorbent substance 10 is contained in the second absorption area.
It is preferable that 1 to 50 parts by weight of the fiber substance is blended per 0 parts by weight, and 50 to 200 parts by weight of the fiber substance is blended per 100 parts by weight of the absorbent substance in the third absorption region.

With the lower layer having such a structure, urine, body fluid, and the like penetrating from the upper layer pass through the first absorption region at a high speed and diffuse at the interface between the first absorption region and the second absorption region. The urine, body fluid, etc. absorbed and retained in the second absorption region and the third absorption region, and further absorbed and retained in the third absorption region, are moved to the upper layer by the action of the absorbent substance in the second absorption region. Is prevented, the dry touch property of the top sheet is improved. In addition, since there is no border between the absorption regions, the absorption region is formed by a continuous integrated structure, so that the absorber does not break due to the movement of the body, and the absorbent material does not leak out. Does not give any discomfort.

As described above, the first absorbent region has a density of 0.03 to 0.20 g / cm ³ and the absorbent material 10
It is preferable that 100 to 300 parts by weight of a fiber substance is blended per 0 parts by weight. If the density and the mixing ratio of the absorbent substance are within this range, when the absorbent substance swells by absorbing urine, body fluid, etc., interference between the absorbent substances is minimized, and the absorbent substance is continuously contacted. There is little formation of a permeation barrier, and excrement can be efficiently absorbed and transmitted in three-dimensional directions.

When the density is increased beyond 0.20 g / cm ³ , or when the amount of the fibrous substance per 100 parts by weight of the absorbent is less than 100 parts by weight, the distribution density of the absorbent is high. In order to form a permeation barrier by contacting continuously by blocking the gel of the absorbent material,
Absorption of urine, body fluids, etc. is hindered, and the absorption rate is reduced.
On the other hand, when the density is less than 0.03 g / cm ³ , or when the amount of the fiber material per 100 parts by weight of the absorbent material exceeds 300 parts by weight, the distribution density of the absorbent material decreases. In addition, urine, body fluid, and the like that have infiltrated from the upper layer cannot be quickly absorbed and retained, so that the dry touch property of the top sheet deteriorates.

The second absorption region has a density of 0.20 to 0.20.
0.40 g / cm ³ , and preferably 1 to 50 parts by weight of a fiber material per 100 parts by weight of the absorbent material. When the density and the blending ratio of the absorbent substance are in this range, since the density is higher than that of the first absorption region, urine and body fluids that have passed through the first absorption region are transferred to the interface between the first absorption region and the second absorption region. In addition, since the distribution density of the absorbent substance is higher than that of the first absorption region, urine and body fluid can be sufficiently absorbed and retained, and further, urine and body fluid from the third absorption region Can be prevented from returning to the top sheet, so that there is little wet back to the top sheet, and the dry touch property is good.

When the density is increased beyond 0.40 g / cm ³ , or when the amount of the fiber material per 100 parts by weight of the absorbent material is less than 1 part by weight, the absorbent material in the second absorption region Since the distribution density of the absorber becomes too large, as in the case of the absorber having a structure in which only the absorbent material is sandwiched between the upper and lower fiber layers, the displacement of the absorber due to the movement of the wearer,
Breakage or leakage of the absorbent material is liable to occur, absorption performance is reduced, and leakage of urine, body fluid, etc. is liable to occur. On the other hand, when the density is less than 0.20 g / cm ³ , or when the amount of the fiber material per 100 parts by weight of the absorbent material is 50
When the amount exceeds the weight part, the distribution density of the absorbent substance becomes low, urine, body fluid, etc. cannot be sufficiently absorbed and retained, and further, urine from the third absorption region,
Since it is not possible to prevent the backflow of the body fluid or the like, urine, body fluid, or the like easily accumulates in the first absorption region, and the wet back from the absorber to the top sheet increases, and the dry touch property of the top sheet deteriorates.

Further, the third absorption region has a density of 0.03
０．２0.20 g / cm ³ , and preferably 50 to 200 parts by weight of a fiber material per 100 parts by weight of the absorbent material. When the density and the blending ratio of the absorbent substance are within this range, urine, body fluid, and the like that have passed through the second absorption region can be sufficiently absorbed and retained.

When the density is increased beyond 0.20 g / cm ³ , or when the amount of the fibrous substance per 100 parts by weight of the absorbent is less than 50 parts by weight, the distribution density of the absorbent is large. The absorption rate of the absorbent material is lower than that of the fiber material, and urine and body fluids that have passed through the second absorption region are not immediately absorbed by the absorbent material, so that the wet-back of the absorbent material increases, Poor touch characteristics. On the other hand, when the density is less than 0.03 g / cm ³ , or when the amount of the fiber material per 100 parts by weight of the absorbent material exceeds 200 parts by weight, the distribution density of the absorbent material decreases. In addition, since the absorption performance is reduced, the function as a storage layer is lost, and leakage is likely to occur.

The fibrous substance used in the absorbent can be selected from a wide range, and for example, natural fibers, synthetic fibers, or a combination of natural fibers and synthetic fibers can be used. As a suitable natural fiber, a chemical pulp sheet or a linear pulp having a fiber length of 5 mm or less obtained by defibrating a mechanical pulp sheet with a crusher is advantageously used. The pulp raw material is not limited to softwoods, but hardwoods, straws, bamboos, and kenafs are also applicable.

The synthetic fiber may be a composite fiber composed of two or more components such as polypropylene, polyethylene, polyester, or polyester, polypropylene, and polyethylene. In particular, a composite fiber of polyester / polyester, polyester / polyethylene, or polypropylene / polyethylene may be used. It is preferable from the viewpoint of strength. The fiber diameter of the constituent fibers is 1.5 to 10 denier, and the length is 1
Those having a thickness of 0 mm or more are preferable in terms of production. These synthetic fibers and composite fibers are preferably subjected to a hydrophilic treatment. As the hydrophilic treatment method, a method in which a hydrophilic agent is applied to the synthetic fibers and the composite fibers by spraying, foam coating, impregnation, or the like is used. There is.

Further, by using synthetic fibers having a modified cross section as the synthetic fibers, the density of the absorption region can be reduced. For example, in the case of the same denier, a synthetic fiber having a modified cross section has a larger cross-sectional area than a 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.

A heat fusible substance can be added to the fiber layer, especially the fiber layer made of natural fibers. The heat-fusible substance is preferably a fibrous substance. Examples of the heat-fusible substance include polypropylene, polyethylene, polyester, polyvinylidene, acrylic resin, and nylon resin. In addition, polyester, polypropylene, polyethylene, etc.
Composite fibers composed of more than one component may be used. In particular, polyester / polyester, polyester / polyethylene, and polypropylene / polyethylene composite fibers are preferable from the viewpoint of strength. The fiber diameter is preferably about 1 to 5 denier and the fiber length is 3 to 30 mm, as long as it is suitable for mixing with natural fibers, and there is no particular limitation. Fibers such as rayon and cellulose acetate can also be suitably used.

By heat-treating these heat-fusible substance-containing fiber layers, inter-fiber bonds are formed by the heat-fusible substances, and the strength of the fiber layers themselves can be maintained even when wet. The heat treatment method is not particularly limited, such as a hot press roll, a hot embossing 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 to form a skeleton. It suffices if a structure can be formed. The amount of fiber layer used in this absorber is
Depending on the target absorber, for example, generally 30 to
It is 1000 g / m ² .

The absorbent used in the absorber includes:
Examples include starch-based, cellulose-based, and synthetic polymer-based. Specifically, a starch-acrylic acid (salt) graft copolymer, a saponified starch-ethyl acrylate graft copolymer, a saponified starch-methyl methacrylate graft copolymer, a starch-acrylonitrile graft copolymer Combined saponified product, saponified starch-acrylamide graft copolymer, saponified starch-acrylonitrile-2-acrylamide-2-methylpropanesulfonic acid graft copolymer, acrylic acid (salt) polymer, cross-linked with acrylic acid Polyethylene oxide, crosslinked product of sodium carboxymethylcellulose, crosslinked product of polyvinyl alcohol-maleic anhydride reactant, etc., among these, absorb urine, body fluid and water at least 20 times its own weight, Sodium polyacrylate based on absorption performance It is also suitable.

The absorber can be formed by a spun bond or melt blow step, a carding step, a wet laid step, an air laid step, or the like. The method of containing the absorbent material in the absorber,
It is well known to those skilled in the art. For example, by simultaneously laying the fibers of the absorber and the absorbent material, the absorbent material can be contained in the absorber. Further, in the absorber, a method of forming a parallel streaky absorbent material,
As a method for forming the density gradient of the absorbent substance in the thickness (Z) direction of the absorber, there is a method of changing the method of supplying the absorbent substance in the air-laid apparatus, but the forming method is not particularly limited.

It is preferable that the absorber is formed as an integral type (non-layered absorption structure) in consideration of the shape of the absorber.
After separately manufacturing and laminating the upper layer and lower layer of the absorber,
It may be integrated. Further, these may be in the form of a composite composed of a plurality of layers. For example, if the absorber comprises a plurality of layers, these layers are in communication with each other, so that liquid present in one absorption region can flow to another absorption region.

Further, as shown in FIG. 2, the sheet may be wrapped with a hydrophilic sheet 11 depending on the intended absorber. For example,
Any hydrophilic sheet such as tissue, absorbent paper, hydrophilic nonwoven fabric, etc. can be used as the hydrophilic sheet.

As a method for compressing the absorber, compression by a press roll is advantageously performed. As a compression method, a method of forming a substantially continuous surface over the entire absorbent body by a roll having a smooth peripheral surface or the like may be used, or embossing may be performed by a roll or the like having an uneven peripheral surface. Alternatively, a method of forming a pattern arrangement in which the density of the absorber is partially different and urine, body fluid, and the like are guided in the vertical and horizontal directions and in the oblique direction may be used. In the case of embossing, the compressed portion and the non-compressed portion may be continuous or discontinuous.

Further, as shown in FIG. 1, the size of the absorber 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, it may be installed only in that part.

The liquid-impermeable sheet used for the liquid-impermeable back sheet may be a material in which a nonwoven fabric, a woven fabric, or the like is bonded to a liquid impermeable film such as polyethylene, or a moisture-proof nonwoven fabric. It may be made of a woven fabric.
Further, it may be embossed in a pattern to give a cloth-like appearance, or may be further matte-finished.
In the case of using a film, a known air-permeable film that allows only water vapor to pass while being liquid-impermeable may be used, and such a liquid-impermeable and air-permeable sheet prevents stuffiness. Therefore, it is more preferable.

Between the above-described members, for example, between the liquid-permeable top sheet and the absorber, and between the absorber and the liquid-impermeable back sheet, the entire surface or a part thereof is bonded by hot melt bonding or the like. Has been done. In addition to the hot melt, the adhesive may be a starch-based or water-soluble glue such as CMC (carboxymethylcellulose), or an adhesive having a higher fluidity.

[0052]

EXAMPLES The absorbent article of the present invention will be described in detail with reference to examples of disposable diapers. As shown in the plan view of FIG. 1, the cross-sectional view of FIG. 2, and the enlarged cross-sectional view of FIG. 3, the disposable diaper P as an absorbent article has a liquid impervious surface made of polyethylene on the outer surface when worn. Back sheet 3 is provided, and an absorbent body 1 composed of an absorbent material 9 (highly absorbent polymer) and cotton-like pulp 10 and covered entirely with a hydrophilic sheet 11 (tissue) is provided on the inside thereof. Is covered with a liquid-permeable top sheet 2 made of a polyester / polyethylene fiber non-woven fabric subjected to a hydrophilic treatment, and the overlapping peripheral portions of the back sheet and the top sheet are adhered to each other.

As shown in FIG. 1, the disposable diaper 1 is made of a stretchable elastic body 12 which comes into close contact with the crotch when worn.
, And fasteners 13 are attached to both side edges of the back body. The disposable diaper thus formed was evaluated for absorption rate, wet back, and dry touch using artificial urine.

The absorption speed was determined by placing a perforated stainless steel plate (thickness 9 mm, diameter of the hole 25 mm) at the center of the diaper, and until 50 cc of artificial urine was absorbed into the diaper. Was measured three times every 30 minutes and evaluated. What is wet back?
After leaving the used diaper for 30 minutes in which the absorption rate was measured (50 cc was absorbed three times), 10 pieces of 10 × 10 cm square filter paper (manufactured by Toyo Filter Paper, No. 63) were stacked on the center of the used diaper. Further, after the mixture was left for 5 minutes while applying a pressure of 0.05 kg / cm ^2, the amount of liquid transferred to the filter paper was measured.

The dry touch property was determined by measuring the absorption rate (absorbing 50 cc three times) by lightly touching the surface of the top sheet of the disposable diaper with a hand, and determining the dryness by sensory evaluation. The criterion is the following three steps (○, △,
X). Judgment criteria for dry touch: Dry: ○ Wet: △ Very wet: ×

The composition of the artificial urine used in this example is as follows. Artificial urine composition (% by weight): urea 1.9%, NaCl 0.1.
8%, CaCl ₂ 0.1%, MgSO ₄ 0.1%, the rest being water.

Example 1 A cotton-like pulp obtained by treating a pulp sheet made of softwood bleached kraft pulp (NBKP) with a defibrating machine and a superabsorbent polymer made of sodium polyacrylate were made into a cotton-like material by an air-laid manufacturing apparatus. The superabsorbent polymer is arranged in the pulp layer in a streak parallel to each other to form an upper layer portion of the absorbent body. Further, the cotton-like pulp and the superabsorbent polymer are arranged so that three absorption regions are distributed in the thickness direction. To form a lower layer of the absorber. However, cotton-like pulp 1
The superabsorbent polymer 200 g / m ² placed parallel and streaks in the longitudinal direction to 20mm spacing of the absorbent article to the cotton-like pulp layer made of 00g / m ^2, a thickness of about at 12 g / cm ² pressure 1.0 mm, average density 0.30 g / cm ³
Was formed. Further, as the lower layer, a cotton-like pulp 100 g / m ² and the superabsorbent polymer 100 g / m ² was uniformly blended, about the thickness of 12 g / cm ² pressure 1.
0 mm, a first absorbent area having an average density of 0.20 g / cm ³ , and 5 g / m ^{2 of} flocculent pulp and
0 g / m ² is uniformly blended to form a second absorbent region having a thickness of about 0.5 mm under an applied pressure of 12 g / cm ² and an average density of 0.30 g / cm ³ , and a high fuzzy pulp of 5 g / m ^2. Absorbent polymer 100g / m ² is blended uniformly, 12g / c
a thickness of about 1.0mm in m ² under pressure, an average density of 0.1
A third absorption area of 5 g / cm ³ was formed. Further, an absorbent body having a continuous crotch width of 10 cm and a length of 40 cm in the longitudinal direction and having a shape as shown in FIG. .

Example 2 An absorber was produced in the same manner as in Example 1. However, 200 g / m ² of the superabsorbent polymer was arranged in a cotton-like pulp layer composed of 100 g / m ² of cotton-like pulp as the upper layer in parallel and streaks at intervals of 10 mm in the longitudinal direction of the absorbent article.
An absorber having a thickness of about 1.0 mm and an average density of 0.30 g / cm ³ under a pressure of ² g / cm ² was formed. As the lower layer, 100 g / m ^{2 of} flocculent pulp and 35 g / m ² of a superabsorbent polymer are uniformly blended, and a first layer having a thickness of about 1.0 mm and an average density of 0.14 under a pressure of 12 g / cm ² is used. An absorption area is formed, and 50 g / m ^{2 of} flocculent pulp and 100 g / m ² of a superabsorbent polymer are uniformly blended to form 12 g / cm ²
Approximately 0.5mm thick under pressure, average density 0.21g
/ Cm ³ to form a second absorbent area, and 100 g of floc pulp
/ M ² and the highly absorbent polymer 50 g / m ² are uniformly blended, and the thickness under pressure of 12 g / cm ^{2 is} about 1.0 mm,
A third absorption region having an average density of 0.15 g / cm ³ was formed. Further, the lower layer portion is formed in a continuous integrated structure having no boundary between the absorption regions, and the upper layer portion is laminated thereon, and the crotch width 10 cm and the length in the longitudinal direction are 40 cm.
An absorber having the shape shown in was prepared.

Comparative Example 1 An absorber was produced in the same manner as in Example 1 except that the upper layer was not formed.

Comparative Example 2 An absorber was produced in the same manner as in Example 1 except that the lower layer was not formed.

Comparative Example 3 An absorber was produced in the same manner as in Example 1. However, as the upper layer, 100 g / m ^{2 of} flocculent pulp and 200 g / m ² of a superabsorbent polymer were uniformly blended, the thickness under pressure of 12 g / cm ^{2 was} about 1.0 mm, and the average density was 0.30 g / c.
An m ³ absorber was formed.

Comparative Example 4 An absorber was produced in the same manner as in Example 1. However, as the lower layer portion, the cotton-like pulp 100 g / m ² and the superabsorbent polymer 100 g / m ² was uniformly blended, a thickness of about 1.0mm at 12 g / cm ² pressure, the average density of 0.20 g / c
m ³ , forming a first absorption area, and floc pulp 50 g / m ²
And 100 g / m ² of the superabsorbent polymer,
A second absorbent area having a thickness of about 0.5 mm and an average density of 0.30 g / cm ³ under pressure of ² g / cm ² is formed, and 50 g / m ^{2 of} flocculent pulp and 100 g / m ² of superabsorbent polymer are uniformly formed. It was blended to form a third absorbing region having a thickness of about 0.5 mm under a pressure of 12 g / cm ² and an average density of 0.30 g / cm ³ .

Comparative Example 5 An absorber was produced in the same manner as in Example 1. However, as the lower layer portion, the cotton-like pulp 100 g / m ² and the superabsorbent polymer 100 g / m ² was uniformly blended, a thickness of about 1.0mm at 12 g / cm ² pressure, the average density of 0.20 g / c
m ³ , forming a first absorption area, and floc pulp 50 g / m ²
And 100 g / m ² of the superabsorbent polymer,
A second absorbent area having a thickness of about 0.5 mm under pressure of ² g / cm ² and an average density of 0.20 g / cm ³ is formed, and 100 g / m ^{2 of} flocculent pulp and 50 g / m ² of superabsorbent polymer are uniformly formed. It was blended to form a third absorption region having a thickness of about 1.0 mm under a pressure of 12 g / cm ² and an average density of 0.10 g / cm ³ .

Comparative Example 6 An absorber was produced in the same manner as in Example 1. However, as the lower layer, 155 g / m ^{2 of} cottony pulp and 300 g / m ² of a superabsorbent polymer were uniformly blended, and the thickness under pressure of 12 g / cm ^{2 was} about 2.5 mm, and the average density was 0.20 g / c.
An m ³ absorber was formed.

Using the absorbents produced in Examples 1 and 2 and Comparative Examples 1 to 6, disposable diapers were produced, and the above-mentioned characteristics were evaluated. Table 1 shows the test results.

[0066]

[Table 1]

[0067]

As shown in Table 1, the characteristics of Comparative Examples 1 to 6 are considerably inferior to those of Examples 1 and 2, and the effects of the present invention can be confirmed. As described above, the absorbent article of the present invention has a structure in which the upper layer of the absorbent body has a structure in which the absorbent substance is arranged in a plurality of lines in the fiber layer, so that the top sheet touches the skin of the user. Urine and bodily fluids excreted in the body are spot-absorbed quickly in the upper layer, pass through at a high speed, and immediately diffuse to the lower layer of the absorber.
Furthermore, in the lower layer of the absorber, urine, body fluids, etc., which have passed through the upper layer of the absorber, are diffused at a high speed into the first absorption region, and quickly diffuse into the second and third absorption regions. And stored. As a result, urine, bodily fluids, loose stools, etc. excreted on the top sheet do not stagnate,
Further, urine, body fluid, and the like diffused into the absorber do not return to the top sheet again, and the dry touch property of the top sheet is remarkably improved. Therefore, it is possible to prevent skin irritation and itching.

The absorbent substance arranged in the form of a streak in the upper layer of the absorber absorbs urine, body fluid, etc., and expands in volume to gel. Since there is no mutual contact, the remaining urine, bodily fluids, etc., which have exceeded the absorption capacity of the upper layer, move quickly to the lower layer through the permeation gap where the superabsorbent polymer does not exist. Therefore, even when a large amount of urine or bodily fluids is excreted at once, the absorption speed is high, urine, bodily fluids and the like are smoothly absorbed to prevent lateral leakage, and further, the first and second lower layers are formed. two,
The third absorber, which is formed in a continuous and integrated structure with no boundaries, is used without causing the absorber to tear due to the movement of the body and causing the absorbent to leak out. The structure does not cause discomfort to the person.

[Brief description of the drawings]

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

FIG. 2 shows a cross-sectional view of the disposable diaper of FIG. 1 taken along line x-x '.

FIG. 3 shows a partially enlarged view of the sectional view of FIG. 2;

[Explanation of symbols]

1: absorber, 2: top sheet, 3: back sheet,
4: Absorber upper layer, 5: Absorber lower layer, 6: Absorber lower layer first absorption area, 7: Absorber lower layer second absorption area, 8:
Absorber lower layer part third absorption region, 9: superabsorbent polymer, 1
0: fiber substance, 11: tissue, 12: elastic body around the leg,
P: Absorbent article.

Claims (4)

[Claims] 1. An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber disposed between these two sheets, wherein the absorber is provided on the top sheet side. An upper layer portion and a lower layer portion located on the back sheet side, wherein the upper layer portion is formed by arranging a plurality of rows of absorbent materials in a layer made of a fibrous material; Is a first absorption region arranged on the upper layer side,
It consists of a third absorption area arranged on the backsheet side and a second absorption area arranged between the first absorption area and the third absorption area, and each absorption area is uniformly blended with a fibrous substance and an absorbent substance. Is, the second absorption region is higher in density than the first absorption region and the third absorption region, and the distribution density of the absorbent material is higher than the first absorption region and the third absorption region. Further, an absorbent article characterized by being formed in a continuous and integral structure without boundaries between the respective absorption regions. 2. The density of the first absorption region, the second absorption region and the third absorption region measured under a pressure of 12 g / cm ² ,
0.03 to 0.20 g / cm ³ , 0.20 to 0.4 respectively
0 g / cm ³ and 0.03~0.20g / cm ³ The absorbent article of claim 1, wherein. 3. The method according to claim 1, wherein the first absorption region includes an absorbent material 100.
100 to 300 parts by weight of a fiber substance is blended per part by weight, 1 to 50 parts by weight of a fiber substance is blended per 100 parts by weight of the absorbent substance in the second absorbent region, and absorbent is contained in the third absorbent region. 50 fibrous substances per 100 parts by weight of substance
The absorbent article according to claim 1, wherein the absorbent article is blended in an amount of from 200 to 200 parts by weight. 4. The absorbent body according to claim 1, wherein an upper layer portion of the absorber is formed in a structure in which absorbent materials are arranged in a parallel streak having a width of 5 to 50 mm in the fiber. Absorbent articles.