JP2004065300A - Absorber and disposable diaper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an absorber and a disposable diaper that are thin and leakproof, and can be manufactured at a low cost. <P>SOLUTION: In the absorber made by covering a mixed layer of a fiber and an absorptive polymer with an upper layer sheet and a lower layer sheet, the absorbent polymer is formed of a liquid permeable high absorbency polymer and a high absorbency polymer featuring a large absorption quantity is applied to the top face of the lower layer sheet. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an absorber and a disposable disposable diaper, and more particularly, to an absorber and a disposable disposable diaper which are thin, have an excellent leakage prevention effect, and can be manufactured at low cost.
[0002]
[Prior art]
Recently, disposable paper diapers for infants and incontinent persons, or absorbent articles such as absorbent pads and sanitary napkins, have excellent absorbency and no liquid leakage, and have no bulkiness when worn. Due to the demand for compact and inexpensive products, the art is working to reduce the thickness of the absorber, which is the main part of such absorbent articles, as thin as possible.
[0003]
In order to make the absorber thin, it is necessary to minimize the amount of fibers such as pulp and cotton constituting the absorber as compared to the water-absorbing polymer. However, when the mixing ratio of the water-absorbing polymer to the fiber is increased in this way, bodily fluids such as urine which have passed through the upper layer sheet of the absorber are absorbed by the water-absorbing polymer located in the upper layer portion of the mixed layer. There is a drawback that a so-called blocking phenomenon occurs in which the water-absorbing polymers gel and adhere to each other. When such a blocking phenomenon occurs, the bodily fluid is not absorbed into the interior of the absorber, but is pushed back out of the surface, thereby causing liquid leakage due to wet back.
[0004]
Therefore, for the purpose of preventing such a blocking phenomenon, Japanese Patent Application Laid-Open No. 2001-252307 discloses that an absorbent interposed between a liquid-permeable top sheet and a liquid-impermeable back sheet is provided with a liquid-permeable top sheet. A first absorbent layer formed by fixing and holding a good first superabsorbent polymer with a sheet such as a tissue, and a second superabsorbent polymer having a higher absorbency than the superabsorbent polymer are similarly fixed by a sheet. There has been proposed an absorbent article composed of a second absorbent layer formed by holding the second absorbent layer.
[0005]
[Problems to be solved by the invention]
However, in order to produce an absorbent having two layers using two types of superabsorbent polymers, two stages of fiber-laying equipment are required in the manufacturing process of the absorbent article, at least in the manufacturing process of the absorbent. Therefore, there is a disadvantage that the equipment cost and the installation space increase and the manufacturing cost increases. In addition, there is a limit to making the absorber thinner with a structure in which a mixed layer of a superabsorbent polymer and fibers such as pulp is laminated, and it is difficult to make the absorber extremely thin. Since the state is hard to be uniform, irregularities are generated on the surface of the absorber, and therefore, there are drawbacks such as a poor appearance and a poor fit. In particular, where the polymer is concentrated, adverse effects such as gel blocking occur and there is a disadvantage that the absorption performance is reduced.
[0006]
An object of the present invention is to provide an absorber and a disposable disposable diaper which solve the above-mentioned drawbacks of the prior art, are thin, have an excellent leakage prevention effect, and can be manufactured at low cost.
[0007]
[Means for Solving the Problems]
The object of the present invention is to provide an absorbent body in which a mixed layer of fibers and a water-absorbing polymer is covered with an upper layer sheet and a lower layer sheet, wherein the water-absorbing polymer is composed of a highly water-absorbing polymer having good liquid permeability, This is achieved by an absorber characterized in that the upper surface of the lower sheet is coated with a superabsorbent polymer having good absorption.
[0008]
Further, the object of the present invention is to provide an absorbent body in which a mixed layer of fibers and a water-absorbing polymer is covered with an upper layer sheet and a lower layer sheet, wherein the water-absorbing polymer is composed of a high water-absorbing polymer having a good absorption amount. This is achieved by an absorber characterized in that a high water-absorbing polymer having good liquid permeability is applied to the lower surface of the upper layer sheet.
[0009]
Further, the object of the present invention is to provide a disposable disposable diaper comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber interposed between the two sheets, wherein the absorbent is made of fiber A mixed layer of a highly water-absorbing polymer and a liquid-permeable high-absorbent polymer is covered by an upper sheet and a lower layer sheet coated with a high-absorbent polymer with a good absorption on the upper surface. Is done.
[0010]
Still further, the object of the present invention is a disposable disposable diaper comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber interposed between the two sheets, wherein the absorber is A disposable disposable diaper characterized by comprising a mixed layer of fibers and a superabsorbent polymer having a good absorption amount coated on the lower surface with an upper layer sheet coated with a superabsorbent polymer having good liquid permeability and a lower layer sheet. Achieved.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the contents of the present invention will be described in detail using a disposable paper diaper as an embodiment of the present invention as an example. The absorbent according to the present invention is not necessarily limited to the disposable paper diaper, and can be widely applied to known absorbent articles such as absorbent pads and sanitary napkins.
[0012]
FIG. 1 is a plan view of a tape-type disposable paper diaper (hereinafter referred to as “paper diaper”) 10 according to an embodiment of the present invention, which is developed and viewed from the front side. The disposable diaper 10 is generally well-known for its external shape, and includes a liquid-permeable top sheet 11, a liquid-impermeable back sheet 12, and an absorber 13 interposed between these sheets. The main body 14 has an hourglass shape in a plan view, and has a front body 15, a back body 16, and a crotch portion 17. A plurality of elastic members 18 are provided around the waist of the front body 15, an elastic member 19 is provided around the waist of the rear body 16, and an elastic member 20 is provided around the legs of the crotch 17. Are interposed between the liquid-permeable topsheet 11 and the liquid-impermeable backsheet 12, respectively, to form planar gathers. A fastening tape 21 for fixing the diaper main body 14 to the waist of the wearer is fixed to both ends of the back body 16.
[0013]
Here, the liquid-permeable top sheet 11 is formed of a nonwoven fabric, a woven fabric, a porous plastic film, or the like that has a good touch and is hydrophilic, and a single or composite fiber of polypropylene, polyethylene, polyester, or the like is preferably used.
[0014]
The liquid-impermeable back sheet 12 is formed of a liquid-impermeable nonwoven fabric, a woven fabric, a plastic film, or a laminate of these materials, and is preferably made of a material having air permeability or moisture permeability.
[0015]
The elastic members 18, 19, and 20 are formed of a material having expansion and contraction such as a rubber string, and the thickness and the number of the elastic members are appropriately set according to the application. As described above, these members form a flat gather at a predetermined portion of the diaper main body 14, whereby when the paper diaper 10 is worn, the diaper main body 14 is brought into close contact with the body and leakage of body fluid is prevented.
[0016]
The absorbent body 13 of the paper diaper 10 includes a liquid-permeable top sheet 11 and a waterproof film 22 welded to the upper surface of the liquid-impermeable back sheet 12, as shown in FIG. Is interposed between FIG. 3 is a cross-sectional view showing the absorber 13 in a further enlarged manner. As shown in the figure, the absorber 13 has an upper sheet 13 and an upper surface coated with a superabsorbent polymer 13p2 having a good absorption amount. The lower layer sheet 13b covers the mixed layer composed of the pulp fiber 13s and the highly water-absorbent polymer 13p1 having good liquid permeability.
[0017]
Here, the upper layer sheet 13a and the lower layer sheet 13b are formed of a sheet material such as a nonwoven fabric or a tissue, and the inside thereof is defibrated into a highly water-absorbing polymer 13p1 having good liquid permeability and a fiber length of 5 mm or less by a crusher. It is a mixed layer with the pulp fibers 13s. The mixing ratio between the superabsorbent polymer 13p1 and the pulp fiber 13s is set to 7: 3, and the fiber amount is set to half or less of the polymer amount. The mixing ratio of the superabsorbent polymer 13p1 and the pulp fiber 13s can be used in the range of 5: 5 to 7: 3. If the polymer ratio is higher than 7: 3, the quality tends to be poor, for example, the absorption rate becomes slow and the absorber 13 has many irregularities of the granular polymer. Such basis weight of the absorbent body 13 that is configured pulp fibers 13s is 80~250g / ^{m 2,} about 250~600g / ^{m 2} in the range superabsorbent polymer 13p1 of 170~520g / ^{m 2,} also The thickness is set to about 3 to 10 mm under a load of 0.5 g / cm ² .
[0018]
As the superabsorbent polymers 13p1 and 13p2 in the present invention, known superabsorbents each having a crosslinked structure and having a carboxyl group or the like as a component of the polymer are used.
[0019]
In particular, the superabsorbent polymer 13p1 has a liquid permeability of 50 ml / min / cm ² or more in a saturated swelling state and a maximum absorption rate of 0.1 ml / sec / g or more of the physiological saline. A water-absorbing polymer having good liquid properties is used.
[0020]
As the superabsorbent polymer 13p2, a superabsorbent polymer having an absorption capacity and a maximum absorption rate of 1.1 times or more of the superabsorbent polymer 13p1 and having a good absorption amount is used. The superabsorbent polymer 13p2 having such properties is sprayed on the upper surface of the lower sheet 13b fed out of a roll through a polymer spraying machine in the process of manufacturing the absorber 13, and the superabsorbent polymer is applied to the upper surface of the lower sheet 13b. A polymer layer is applied.
When the superabsorbent polymer 13p2 is layered by the spraying method, the polymer can be averaged and interposed, and as a result, a flat surface having a uniform thickness can be formed. It should be noted that only one simple spraying machine needs to be installed for such spraying, and the installation space can be reduced. It can be realized in space.
[0021]
Since the paper diaper 10 includes the absorber 13 having the above-described configuration, when the body fluid passes through the liquid-permeable top sheet 11 and reaches the upper layer sheet 13a of the absorber 13, the liquid diaper 10 has a liquid-permeable property. The body fluid quickly penetrates the mixed layer of the good superabsorbent polymer 13p1 and the pulp fiber 13s, and immediately after being blocked by the gelation of the superabsorbent polymer, is immediately absorbed and stored in the superabsorbent polymer 13p2 having a good absorption amount. . Therefore, according to the paper diaper 10, it is possible to provide a paper diaper having no body fluid returning.
[0022]
Moreover, since the absorber 13 can be formed in a thin and flat shape, the disposable diaper which is easy to wear and has a good appearance can be provided.
[0023]
As described above, the contents of the present invention have been described with reference to one embodiment. However, the present invention can be modified as follows.
[0024]
FIG. 4 is an enlarged cross-sectional view of an absorber 13 'used in a disposable diaper 10' (not shown) according to another embodiment of the present invention, and is shown corresponding to FIG.
Therefore, the same components as those shown in FIG. 3 are denoted by the same reference numerals.
[0025]
As shown in the figure, the absorbent body 13 ′ has a highly water-absorbent polymer 13 p 1 having good liquid permeability on the lower surface of an upper sheet 13 a, and a pulp fiber is provided between the upper sheet 13 a and the lower sheet 13 b. This is provided with a mixed layer of 13s and the superabsorbent polymer 13p2 having a good absorption amount. Here, the characteristics of the superabsorbent polymers 13p1 and 13p2, the mixing ratio of the mixed layer, and the like are substantially the same as those of the previous embodiment.
[0026]
According to the disposable diaper 10 ′ using the present absorbent body 13 ′ having such a configuration, the body fluid penetrates the liquid-permeable top sheet 11 and becomes the upper layer sheet 13 a of the absorbent body 13, similarly to the embodiment. When it reaches, the body fluid quickly penetrates into the mixed layer via the highly water-absorbent polymer 13p1 having good liquid permeability, and is absorbed and stored in the high-absorbent polymer 13p2 having a good absorption amount inside. Therefore, the present paper diaper 10 'can also provide a thin paper diaper without body fluid reversal, as described above.
[0027]
In the present invention, pulp fibers are preferable as the fibers forming the mixed layer, but it goes without saying that natural fibers such as cotton, hemp, wool, and silk or synthetic fibers can also be used.
[0028]
The lower sheet 13b having the superabsorbent polymer 13p2 coated on the upper surface and the upper sheet 13a having the superabsorbent polymer 13p1 coated on the lower surface are desirably nonwoven fabrics rather than tissue in terms of strength.
[0029]
【The invention's effect】
As described in detail above, the absorber according to the present invention is a thin, good-looking, and excellent absorbent, and in particular, according to the disposable diaper using such an absorbent, An inexpensive disposable diaper that does not have a bulky feeling when the diaper is performed and that does not leak due to the return of the body fluid can be provided to the user.
[Brief description of the drawings]
FIG. 1 is a plan view of a disposable paper diaper according to an embodiment of the present invention, which is developed and viewed from the front side.
FIG. 2 is a sectional view taken along line XX of FIG.
FIG. 3 is an enlarged sectional view of an absorber which is a main part of FIG.
FIG. 4 is an enlarged sectional view of an absorber according to another embodiment of the present invention.
[Explanation of symbols]
10, (10 ') disposable disposable diaper 11 liquid-permeable top sheet 12 liquid-impermeable back sheet 13, 13' absorber 13a upper layer sheet 13b lower layer sheet 13p1 (highly liquid-permeable) superabsorbent polymer 13p2 (absorption amount) Good) super absorbent polymer 14 diaper body 15 front body 16 back body 17 crotch part 18, 19, 20 elastic elastic member 21 fastening tape 22 waterproof film

Claims (4)

An absorbent body in which a mixed layer of fibers and a water-absorbing polymer is covered with an upper sheet and a lower layer sheet, wherein the water-absorbing polymer is composed of a highly water-absorbing polymer having good liquid permeability and is absorbed on the upper surface of the lower sheet. An absorber characterized by being coated with a good amount of superabsorbent polymer. In an absorbent body comprising a mixed layer of fibers and a water-absorbing polymer covered with an upper sheet and a lower layer sheet, the water-absorbing polymer is composed of a high water-absorbing polymer having a good absorption amount, and liquid is passed through the lower surface of the upper sheet. An absorbent body comprising a highly water-absorbing polymer having good properties. In a disposable disposable diaper including a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber interposed between the two sheets, the absorbent is made of a highly water-absorbent material having good liquid permeability with fibers. A disposable disposable diaper comprising a mixture layer of a polymer and an upper layer sheet and a lower layer sheet coated with a superabsorbent polymer having a good absorption on the upper surface. In a disposable disposable diaper including a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber interposed between the two sheets, the absorbent is made of a highly water-absorbing polymer having a good absorption amount with fibers. A disposable disposable diaper characterized by comprising a mixed layer comprising a lower layer and an upper layer sheet coated with a highly water-absorbing polymer having good liquid permeability on the lower side.

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