JP2004065716A - Absorptive article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an absorptive article excellent in terms of absorbability and mountability, which can be manufactured at a low cost. <P>SOLUTION: The absorptive article is provided with a liquid permeable top sheet, a liquid non-permeable back sheet and an absorbent interposed between the sheets. The main body of the absorbent consists mainly of pulp fibers and highly water absorptive polymer. Then, the absorbent is constituted so that the content of the highly water absorptive polymer is ≥55 wt.% , the content of the pulp fibers is <45 wt.% and the highly water absorptive polymer satisfies the following absorption performance conditions (1)-(3): (1) an absorption rate is ≤50 seconds for 30cc of artificial urine; (2) an absorption amount is ≥28 cc/g for the artificial urine under 20 g/cm<SP>2</SP>pressurization; and (3) moisture absorption blocking is ≤50%. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an absorbent article such as a disposable disposable diaper or a sanitary napkin, and more particularly to an absorbent article which is excellent in absorbability and wearability and can be manufactured at low cost.
[0002]
[Prior art]
Conventionally, absorbent articles such as disposable disposable diapers or sanitary napkins usually include a liquid-permeable top sheet covering a surface side in contact with a wearer's body, a liquid-impermeable back sheet covering the back side, and the sheet. And an absorber interposed therebetween. For such absorbent articles, general users are demanding ones that are particularly excellent in absorbency and wearability and can be obtained at low cost.
[0003]
FIG. 6 is a plan view of a tape-type disposable paper diaper 100, which is an example of a conventional absorbent article, as viewed from the front side, and FIG. 7 is a cross-sectional view taken along line AA of FIG. As shown in the figure, the disposable diaper 100 is formed by forming a disposable diaper main body constituted by an absorber 103 interposed between a liquid-permeable top sheet 101 and a liquid-impermeable back sheet 102 into a pseudo hourglass shape. A fastening tape 104 and an elastic elastic member 105B for holding and closely attaching the diaper main body to the body, an elastic elastic member 105F on the abdominal side, and an elastic elastic member 105S around the leg are similarly provided on the back side. Each is provided.
[0004]
[Problems to be solved by the invention]
As shown in FIG. 7, the absorber 103 has a mixed layer of pulp fiber 107 and superabsorbent polymer 108 covered with crepe paper 106. In the disposable diaper 100 configured as described above, the bodily fluid such as urine which has entered through the liquid-permeable top sheet 101 is temporarily held by the pulp fiber 107 and then held by the superabsorbent polymer 108. At this time, the superabsorbent polymer 108 swells and the volume of the absorber 103 increases. Therefore, when the amount of the superabsorbent polymer 108 is increased, the amount of the pulp fiber 107 in the absorber 103 is relatively reduced, the absorption speed is reduced, and the entanglement of the fibers is reduced, so that the absorption of the absorber 103 is reduced. There is a disadvantage that the formability is deteriorated.
[0005]
Conversely, in order to improve the shape retention, the amount of the superabsorbent polymer 108 in the absorber 103 is reduced, and the amount of the pulp fiber 107 is relatively increased to form the disposable diaper 100. In addition, there are disadvantages such as the crotch part being bulky, the movement function of the leg part being deteriorated, the appearance being deteriorated, and the production cost being increased. Therefore, in consideration of such absorptivity, wearability, cost, and the like, the actual thickness of the conventional absorptive article is generally about 5 to 10 mm.
[0006]
However, such absorbent articles are far less than ideal absorbent articles desired by general users, which are excellent in both absorbability and wearability and can be obtained at a low price, and recently have a thickness particularly close to a sheet. There has been a strong demand for the appearance of a lightweight, compact absorbent article.
[0007]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an absorbent article which is excellent in absorbability and wearability and can be manufactured at low cost.
[0008]
[Means for Solving the Problems]
The object of the present invention is to provide a liquid-permeable topsheet, a liquid-impermeable backsheet, and an absorbent interposed between the sheets, wherein the absorbent is mainly composed of pulp fibers and a superabsorbent polymer. In the absorbent article, in the absorbent, the content of the superabsorbent polymer is 55% by weight or more, the content of the pulp fiber is less than 45% by weight, and the superabsorbent polymer is 1) to This is achieved by an absorbent article characterized by satisfying the absorption performance condition of 3).
1) The absorption rate is 50 seconds or less for 30 cc of artificial urine.
2) The absorption amount is 28 cc / g or more for artificial urine under a pressure of 20 g / cm ² .
3) The moisture absorption blocking rate is 50% or less.
[0009]
Further, the above object of the present invention is to provide an absorbent article, wherein the absorber is constituted by a single layer of the pulp fiber and a mixed layer of the pulp fiber and the superabsorbent polymer. Is achieved more effectively.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the content of the present invention will be described in detail based on an embodiment in which the absorbent article is a disposable disposable diaper as described above. It should be noted that the present invention is not necessarily limited to the following embodiments, and it is needless to say that the configuration can be arbitrarily changed without departing from the scope of the claims.
[0011]
FIG. 1 is a plan view of a disposable disposable diaper 10 according to an embodiment of the present invention, which is developed and viewed from the front side, FIG. 2 is a cross-sectional view taken along the line BB of FIG. 1, and FIG. is there. As shown in the drawing, the present paper diaper 10 has substantially the same configuration as the above-described conventional paper diaper 100 except for the internal configuration of the absorber 13. For this reason, the components corresponding to the disposable diaper 100 are denoted by the corresponding numbers and symbols in the tens.
[0012]
That is, in the paper diaper 10, the paper diaper main body is constituted by the absorber 13 interposed between the liquid-permeable top sheet 11 and the liquid-impermeable back sheet 12, and the entire back is formed in a pseudo hourglass shape. Is an elastic elastic member 15B made of a fastening tape 14 and a rubber string for holding and making the diaper main body adhere to the body, an elastic elastic member 15F on the abdomen side, and an elastic elastic member 15S on the leg circumference. Is provided.
[0013]
For the liquid-permeable top sheet 11, a material having liquid permeability, such as a woven fabric, a non-woven fabric, or a porous sheet, which is soft and comfortable to the touch is used. The liquid-impermeable back sheet 12 is made of a liquid-impermeable and soft material such as polyethylene, a waterproof film, a composite material of these materials, or a composite material such as a film and a woven fabric.
[0014]
2 and 3, the absorbent body 13 has a single layer L1 of pulp fiber 17, a mixed layer L2 of pulp fiber 17 and superabsorbent polymer 18, and a single layer of pulp fiber 17 from the surface side. The three layers L1 are covered with the crepe paper 16. The layer thicknesses of the single layer L1 of the pulp fiber 17 and the mixed layer L2 of the pulp fiber 17 and the superabsorbent polymer 18 are L1 = 0 to 4 mm and L2 = 1 to 8 mm, respectively. The overall thickness of the diaper 13 is set to 1 to 10 mm, and is considerably thinner than that of the conventional paper diaper 100 described above.
[0015]
As the material of the pulp fiber 17, cottony pulp or another known material is applied. As the superabsorbent polymer 18, sodium polyacrylate or vinyl acrylate copolymer is preferably used.
[0016]
Here, the absorbent 13 has a total content of the superabsorbent polymer 18 contained in the three layers of 55% by weight or more and a total content of the pulp fibers 17 of less than 45% by weight. 18 is designed to satisfy the following absorption performance conditions 1) to 3).
1) The absorption rate is 50 seconds or less for 30 cc of artificial urine.
2) The absorption amount is 28 cc / g or more for artificial urine under a pressure of 20 g / cm ² .
3) The moisture absorption blocking rate (gel strength) is 50% or less.
[0017]
Here, the absorption performance of the superabsorbent polymer 18 is measured by the analysis method shown in FIG. FIG. 4A is an explanatory diagram schematically showing a method of analyzing an absorption rate, FIG. 4B an absorption amount under pressure, and FIG. 4C a method of analyzing a moisture absorption blocking rate.
[0018]
First, as shown in FIG. 4 (A), the absorption rate of the superabsorbent polymer 18 is such that 1 g of the superabsorbent polymer 18 is sprayed into a petri dish 20 having a diameter of 90 mm, and 30 cc of artificial urine is placed therein ( A1) The time (second) until the artificial urine is absorbed by the superabsorbent polymer 18 is measured (A2). As a result of intensive experiments conducted by the present inventors, it has been revealed that the superabsorbent polymer 18 having an absorption rate of 50 seconds or less is preferable in terms of absorption performance. If the absorption rate exceeds 50 seconds, the hydrophilicity of the superabsorbent polymer 18 increases, and wet back of the urine becomes conspicuous and the skin is easily rash.
[0019]
Next, as shown in FIG. 4 (B), the amount of absorption of the superabsorbent polymer 18 is within a range of 40 mm in diameter on a filter paper 21 having a diameter of 50 mm under a pressure of 20 g / cm ² (B1). Then, 0.2 g of the superabsorbent polymer 18 was sprayed, and this was immersed in artificial urine to measure the amount of absorption (cc / g) (B2). As in the above, as a result of experiments, it has been clarified that the superabsorbent polymer 18 having an absorption amount of 28 cc / g or more is preferable in terms of absorption performance. If the amount of absorption is less than 28 cc / g, as in the case of the absorption speed, wet back of urine becomes remarkable and the skin is easily rash.
[0020]
Further, as shown in FIG. 3 (C), the moisture absorption blocking rate of the superabsorbent polymer 18 is such that 2 g of the superabsorbent polymer 18 is sprayed in a range of 100 mm × 10 mm on a steel plate 22 of 150 mm × 150 mm (square). Then, it is stored for 30 seconds in a constant temperature and high humidity bath at a temperature of 40 ° C. and a humidity of 90% (C1), and the steel plate 22 is turned upside down and stopped for 1 minute (C2).
The moisture-absorbing blocking rate of the superabsorbent polymer 18 is measured based on the calculation formula, that is, the superabsorbent polymer remaining on the steel plate 22 / total weight × 100 = moisture-absorbing blocking rate (%) (C3). As in the above, as a result of experiments, it has been revealed that the superabsorbent polymer 18 having a moisture absorption blocking ratio of 50% or less is preferable. When the moisture absorption blocking ratio exceeds 50%, when the superabsorbent polymer 18 is transported to a diaper manufacturing machine, the polymer particles adhere to each other and solidify in an atmosphere of normal humidity, resulting in poor dispersibility. This is because uniform spraying of the superabsorbent polymer 18 cannot be performed. In addition, it has also been clarified that the polymer particles adhere to the inside of the transport pipe and the diaper manufacturing equipment and the like to cause rust, which often requires overhaul, and that the production equipment has to be stopped each time, which is costly. .
[0021]
According to the paper diaper 10 made using the absorber 13 configured as described above,
Since the pulp fibers 17 and the superabsorbent polymer 18 are appropriately contained, bodily fluids such as urine are quickly absorbed into the absorber 13. Further, since the total thickness can be made as thin as 5 mm or less, it is possible to manufacture the lightweight and compact disposable diaper 10 at a low cost.
[0022]
In the above embodiment, the absorber 13 has a three-layer structure. However, the present invention is not necessarily limited to this, and the content of the superabsorbent polymer and the pulp fiber constituting the absorber 13 may be: Under the conditions of 55% by weight or more and less than 45% by weight, respectively, it can be changed as shown in FIGS. 5 (A) and 5 (B).
[0023]
That is, the absorbent body 13 shown in FIG. 5 (A) has two layers, a mixed layer L2 of the pulp fiber 17 and the superabsorbent polymer 18 on the surface side and a single layer L1 of the lower pulp fiber 17 on the crepe paper. 16. In addition, the layer thickness of the mixed layer L2 of the pulp fiber 17 and the superabsorbent polymer 18 is set to L2 = 1 to 6 mm, and the layer thickness of the single layer L1 of the pulp fiber 17 is set to L1 = 0 to 4 mm. .
[0024]
Similarly, the absorber 13 shown in FIG. 5 (B) crepes two layers, a single layer L1 of the pulp fiber 17 on the surface side and a mixed layer L2 of the pulp fiber 17 and the superabsorbent polymer 18 on the lower side. It is covered with paper 16. In addition, the layer thickness of the single layer L1 of the pulp fiber 17 is set to L1 = 0 to 4 mm, and the layer thickness of the mixed layer L2 of the pulp fiber 17 and the superabsorbent polymer 18 is set to L2 = 1 to 6 mm. .
[0025]
Even when the superabsorbent polymer 18 satisfies the conditions of the above-mentioned 1) to 3), the same effects as those of the above-described embodiment can be obtained by the absorbent 13 composed of two layers as described above. Has been found.
[0026]
Although the content of the present invention has been described above with respect to disposable disposable diapers, it goes without saying that the present invention can be applied to other known absorbent articles such as sanitary napkins and urine absorbing pads.
[0027]
【The invention's effect】
As described in detail above, according to the present invention, it is possible to provide an absorbent article which is excellent in absorbability and wearability and can be manufactured at low cost. In particular, since the thickness of the absorber can be reduced, the absorbent article can be made lightweight and compact as a whole, and can provide a comfortable wearing feeling and a free exercise function of the legs to the wearer. In addition, a remarkable effect that the manufacturing cost can be reduced can be obtained.
[Brief description of the drawings]
FIG. 1 is an exploded plan view of a disposable paper diaper according to an embodiment of the present invention.
FIG. 2 is a sectional view taken along line BB of FIG.
FIG. 3 is an enlarged view of a main part (layer structure of an absorber) of FIG. 2;
FIGS. 4A and 4B are diagrams illustrating a method for analyzing the absorption performance of a superabsorbent polymer according to the present invention, wherein FIG. 4A is a diagram illustrating an absorption rate, FIG. 4B is an absorption amount, and FIG.
FIGS. 5A and 5B are cross-sectional views each showing another configuration of the absorber according to the present invention.
FIG. 6 is a plan view of a conventional disposable disposable diaper developed from the front side.
FIG. 7 is a sectional view taken along line AA of FIG. 6;
[Explanation of symbols]
10,100 Disposable disposable diapers (absorbent articles)
11, 101 Top sheet 12, 102 Back sheet 13, 103 Absorber 14, 104 Fastening tape 15B, F, S, 105B, F, S Elastic elastic member 16, 106 Crepe paper 17, 107 Pulp fiber 18, 108 High absorbency Polymer 20 Petri dish 21 Filter paper 22 Steel plate L1 Single layer of pulp fiber L2 Mixed layer of pulp fiber and superabsorbent polymer

Claims (2)

An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent interposed between the sheets, wherein the absorbent is mainly composed of pulp fiber and a superabsorbent polymer. Is that the content of the superabsorbent polymer is 55% by weight or more, the content of the pulp fiber is less than 45% by weight, and the superabsorbent polymer has the following absorption performance conditions 1) to 3). An absorbent article characterized by being satisfied.
1) The absorption rate is 50 seconds or less for 30 cc of artificial urine.
2) The amount of absorption is 28 cc / g or more for artificial urine under a pressure of 20 g / cm ² .
3) The moisture absorption blocking rate is 50% or less. 2. The absorbent article according to claim 1, wherein the absorber comprises a single layer of the pulp fiber and a mixed layer of the pulp fiber and the superabsorbent polymer. 3.

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