JP2000354760A - Absorber and throw-away diaper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorber 4 which is light in weight and compact and has excellent absorption performance and a throw-away diaper which is light, compact, is easy to carry and is excellent in the effect of preventing urine leakage even when the diaper is formed as a package by packaging of plural sheets. SOLUTION: The absorber 4 contains a highly water absorptive polymer A of >=8 g/30 second/0.3 g absorption rate by a DW method and a highly water absorptive polymer B of <=5 g/30 second/0.3 g absorption rate by the DW method at 90/10 to 10/90 by weight (the polymer A/the polymer B) and the content of fluff pulp is 0 to 30 wt.%. The throw-away diaper 1 is formed by interposing the absorber 4 between a liquid permeable front surface sheet 2 and a liquid impermeable rear surface sheet 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorbent body that is lightweight, compact and excellent in absorbing performance, and is lightweight and compact having the absorbent body, and is easy to carry as a package by packaging a plurality of sheets. And a disposable diaper excellent in urine leakage prevention effect.

[0002]

2. Description of the Related Art Disposable diapers have been made more compact and convenient to carry because of improvements in the construction and materials used. However, the weight of the package body in which a plurality of disposable diapers are still stored is quite heavy, and some of them exceed 3 kg, so that the burden of carrying the package body is considerably large. As a method of reducing the weight of the package, it is conceivable to reduce the number of disposable diapers per package, but the distribution efficiency is reduced, which leads to an increase in the unit price and an increase in the number of purchases by the user. Would.

[0003] Further, simply reducing the number of water-absorbing members in order to reduce the weight per disposable diaper results in a large amount of leakage, which is unusable.

Accordingly, an object of the present invention is to provide a light and compact absorbent having excellent absorption performance, and a lightweight and compact light and easy to carry even when a plurality of sheets are wrapped to form a package. Another object of the present invention is to provide a disposable diaper having an excellent effect of preventing urine leakage.

[0005]

The present invention relates to a superabsorbent polymer A having an absorption rate of at least 8 g / 30 sec / 0.3 g according to the DW method and a high water absorbing rate of at most 5 g / 30 sec / 0.3 g according to the DW method. By providing the absorbent containing the water-absorbing polymer B in a weight ratio (polymer A / polymer B) of 90/10 to 10/90 and having a fluff pulp content of 0 to 30% by weight, The purpose has been achieved.

The present invention has achieved the above object by providing a disposable diaper in which the absorber is interposed between a liquid-permeable top sheet and a liquid-impermeable back sheet. .

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on one preferred embodiment of a disposable diaper. As shown in FIGS. 1 to 4, a disposable diaper 1 according to one embodiment of the present invention includes a liquid-permeable top sheet 2, a liquid-impermeable back sheet 3, and a liquid interposed between the sheets 2 and 3. A so-called deployable disposable, comprising the absorbent body 4 having a retaining property, and fastening fastener tapes 11 disposed on both left and right side edges B1 and B2 of the back part B located on the back side of the wearer. It is a diaper.

In detail, the disposable diaper 1 of the present embodiment
Has an absorber 4, a back sheet 3 having substantially the same size as the absorber 4, and a top sheet 2 arranged to cover the surface and side surfaces of the absorber 4, as shown in FIGS. are doing.
The outer layer nonwoven fabric 5 is arranged on the back surface side of the back sheet 3, and the water repellent nonwoven fabric 61 for forming the three-dimensional gathers 6 is arranged on the top sheet 2 on the side edge side of the absorber 4. The outer nonwoven fabric 5 and the water-repellent nonwoven fabric 61 are both extended to the left and right side edges of the absorber 4, and hold and fix the leg elastic members 71 to form a pair of left and right leg gathers 7. At the free edge portion 62 of the water-repellent nonwoven fabric 61, a three-dimensional gather elastic member 63 for forming the three-dimensional gather 6 is arranged. At both longitudinal ends of the disposable diaper 1, the outer nonwoven fabric 5 and the topsheet 2 extend from both longitudinal ends of the absorber 4 to form a pair of waist portions 8. The waist portion 8 has a sheet-like waist elastic member 8.
1 are arranged and fixed by the topsheet 2 and the outer layer nonwoven fabric 5. The absorber 4 is made of an absorbent polymer 42
And a backing sheet 43 for wrapping the nonwoven fabric 41, and a compression-recoverable uneven sheet 44 is disposed between the absorber 4 and the back sheet 3. . On the surface of the outer layer nonwoven fabric 5 in the abdominal part A,
A fastening portion 51 for fastening the fastening tape 11 is provided.

Thus, in the disposable diaper of the present embodiment, the absorbent body 4 is made of DW
Superabsorbent polymer A having an absorption rate of 8 g / 30 sec / 0.3 g or more according to the DW method (hereinafter sometimes simply referred to as superabsorbent polymer A) and an absorption rate of 5 g / 30 sec / 0.
3 g or less of superabsorbent polymer B (hereinafter sometimes simply referred to as superabsorbent polymer B) in a weight ratio (polymer A
/ Polymer B) 90/10 to 10/90, preferably weight ratio (polymer A / polymer B) 80/20 to 20/8
It is contained at 0. The content of fluff pulp in the absorber 4 is 0 to 30% by weight, preferably 0 to 20% by weight. The absorber 4 is a preferred embodiment of the absorber of the present invention.

Superabsorbent polymer A and superabsorbent polymer B
If the weight ratio (A / B) is more than 90/10, the excreted urine is fixed to the superabsorbent polymer without diffusing in the absorber, and the absorber is not widely used effectively. , Absorption performance is reduced. On the other hand, when the weight ratio (A / B) of both superabsorbent polymers A and B is less than 10/90,
It is difficult to reduce fluff pulp, and it is difficult to reduce the weight and size of disposable diapers.

The superabsorbent polymers A and B are superabsorbent polymers, for example, sodium polyacrylate, (acrylic acid-vinyl alcohol) copolymer,
Conventionally known products such as a crosslinked product of sodium polyacrylate, (starch-acrylic acid) graft copolymer, (isobutylene-maleic anhydride) copolymer and a saponified product thereof, and polyaspartic acid can be used. Among these superabsorbent polymers, those having an absorption rate of 8 g / 30 seconds / 0.3 g or more by the DW method and DW
Absorption rate of 5 g / 30 sec / 0.3 g or less by the method is used in combination at the above specific weight ratio. Thus, by using the superabsorbent polymers A and B together in a specific ratio,
Even if fluff pulp is significantly reduced, disposable diapers maintain high absorption rates and high saturated absorption.

The superabsorbent polymer B preferably has an absorption rate by the DW method of 0.5 g / 30 sec / 0.3 g or more, and the superabsorbent polymer A preferably has a higher absorption rate by the DW method. The total content of the superabsorbent polymer A and the superabsorbent polymer B in the absorber 4 is preferably 50% by weight or more, more preferably 50 to 99% by weight,
Particularly preferably, it is 60 to 95% by weight.

The absorption rate by the DW method (g / 30 seconds / 0.
3g), using a device (Demand Wettability Tester) generally known as a device for performing the DW method, using a polymer spray table [7] in which the liquid level of physiological saline was set at the same water level.
0 mmφ, a table on which No. 2 filter paper was placed on a glass filter No. 1) on which 0.3 g of the superabsorbent polymer to be measured was sprayed, and the water absorption at the time of spraying the superabsorbent polymer was set to 0, It is the value of this absorption obtained by measuring the amount of water absorption after 30 seconds (this absorption is measured on a burette scale indicating the decrease in the level of the physiological saline).

In the present invention, the content of fluff pulp in the absorber 4 is set to 0 to 30% by weight. If the content of fluff pulp in the absorber exceeds 30% by weight, it will be difficult to significantly reduce the weight and size of the disposable diaper.
The fluff pulp content may be 0%.
In addition, from the viewpoint of obtaining a high absorption rate and a high saturated absorption amount in the disposable diaper, the superabsorbent polymer A
And the superabsorbent polymer B are preferably contained in the absorber in a mixed state.

The absorbent in the present invention can be formed by using a water-absorbing polymer, a fiber assembly, and a mount for packaging these as main components, and the relationship between the absorbent polymer and the fiber assembly is particularly limited. However, in this embodiment, a mixture of the above-mentioned superabsorbent polymers A and B is used as the absorbent polymer 42, and the mixture is held in the inter-fiber gap of the nonwoven fabric 41 as a fiber aggregate. It is.

Examples of the fiber aggregate include fluff pulp, rayon fiber, hydrophilic fibers such as cotton and cellulose acetate, polyolefin fibers such as polyethylene and polypropylene, condensed fibers such as polyester and polyamide, and vinyl chloride. And fibers of a vinyl monomer polymer such as vinyl acetate. These can be single or 2
It may be a fiber obtained by laminating seeds or more, or compounding them into a core-sheath. Among these fibers, hydrophobic ones may be used after being made hydrophilic by treatment with an oil agent or the like. Further, in the case of using a fiber having heat fusibility, it is preferable to use the fiber aggregate as a non-woven fabric by heat treatment or the like, since the strength of the absorber is improved. In addition, as the backing paper, those usually used for disposable diapers can be used without any particular limitation.

The material for forming each component of the disposable diaper 1 having the above-mentioned structure will be described. Can be used. As the leg elastic member, the three-dimensional gather elastic member, and the waist elastic member, those usually used for disposable diapers can be used without any particular limitation. As a material for forming the fastening tape, in addition to a tape material to which an adhesive is applied, a male material tape of a mechanical fastener or the like is used. In addition, when the fastening tape is a tape material to which an adhesive is applied, a tape that has been subjected to a peeling treatment is used, and when the fastening tape is a male material tape, a tape of a normal mechanical fastener is used. A tape material used as a female material is used without any particular limitation. The uneven sheet 44 does not have to be provided.

The disposable diaper according to the present embodiment is configured as described above, so that it is lightweight and compact. Even when a plurality of pieces are stored in a packaging bag in a laminated and compressed state to form a package, they are lightweight and portable. Is easy. Moreover, it has a high urine leakage prevention effect, and can effectively prevent urine leakage in both cases where urine is discharged vigorously and urine is discharged in large quantities over time.

In the above-described embodiment, a baby disposable diaper has been described as an example. However, the disposable diaper of the present invention can be a baby pants-type disposable diaper or an adult disposable diaper. Also, the present invention is applicable to pants-type disposable diapers. Further, the absorbent of the present invention is particularly useful as an absorbent for absorbent articles used for absorbing body fluids, such as disposable diapers, sanitary napkins, panty liners, and further, drip sheets, kitchen absorbent sheets, and home use. It can also be used as an absorbent in cleaning sheets for pets, sheets for pets and the like.

[0020]

[Example 1] Absorption rate by DW method 11.8
g / 30 sec / 0.3 g superabsorbent polymer A (manufactured by Sumitomo Seika, trade name "10SH-P") and a superabsorbent polymer B having an absorption rate of 3.6 g / 30 sec / 0.3 g by DW method. (Manufactured by Nippon Shokubai Co., Ltd., trade name "CA-W4") at a weight ratio (polymer A / polymer B) of 30/70 to obtain a superabsorbent polymer mixture. Then, the obtained superabsorbent polymer mixture, fluff pulp and core / sheath = PP
/ PE heat-welding conjugate fiber is blended in a ratio (weight ratio) of 85/10/5, and the basis weight of each of the superabsorbent polymer mixture, fluff pulp and heat-welding conjugate fiber is 2 in order.
The sheets were laid in a sheet shape so as to be 00 g / m ² , 24 g / m ² and 12 g / m ² . Next, the upper and lower surfaces of the obtained piled body were wrapped with a tissue having a basis weight of 15 g / m ² , and then heat-treated to obtain an absorber. The content of fluff pulp in the absorber is 9% by weight, and the total content of both superabsorbent polymers A and B in the absorber is 75% by weight. Next, a nonwoven fabric made of PP / PE was provided as a top sheet on one surface of the absorber, and a PE film was provided as a back sheet on the other surface. Furthermore, a known fastening tape, a waist elastic member, a leg elastic member, and the like were disposed to obtain a baby-sized M-size disposable diaper shown in FIG.

Example 2 The two superabsorbent polymers A and B in Example 1 were mixed at a weight ratio (polymer A / polymer B) = 50/50 to obtain a superabsorbent polymer mixture. . The obtained superabsorbent polymer mixture is sprayed onto the adhesive-coated surface of the tissue coated with the hot melt adhesive so as to have a basis weight of 200 g / m ^2, and a sheet-like product of fluff pulp 80 g / m ² thereon. Layered fines. Further, a tissue coated with a hot melt adhesive was overlaid to obtain an absorber. The content of fluff pulp in this absorber was 26% by weight, and the total content of both superabsorbent polymers A and B in this absorber was 65% by weight. A disposable diaper was obtained in the same manner as in Example 1 except that this absorbent was used.

[Comparative Example 1] Absorption rate 3.6 by DW method
g / 30 seconds / 0.3 g superabsorbent polymer (manufactured by Nippon Shokubai Co., Ltd., trade name “CA-W4”) and fluff pulp are mixed at a weight ratio (polymer / pulp) = 40/60, and water-absorbing polymer, fluff pulp each basis weight, in order to fiber stacking the sheet so that the 200 g / m ^2, 300 g / m ^2, then the basis weight 15g the upper and lower surfaces / m
Wrapped with ² tissues to obtain an absorber. The content of fluff pulp in this absorber is 57% by weight. A disposable diaper was obtained in the same manner as in Example 1 except that this absorbent was used.

Comparative Example 2 The same superabsorbent polymer and fluff pulp as in Comparative Example 1 were mixed at the same ratio as in Comparative Example 1, and the basis weight of each of the superabsorbent polymer and fluff pulp was 80 g / m 2 in order. ^{2. The} sheet is laid in a sheet form so as to have a weight of 120 g / m ^2, and then the upper and lower surfaces are weighed at 15 g / m ^2.
Wrapped in a tissue to obtain an absorber. The fluff pulp content in this absorber is 52% by weight. A disposable diaper was obtained in the same manner as in Example 1 except that this absorbent was used.

The disposable diapers of Examples 1 and 2 and Comparative Examples 1 and 2 were measured for weight, basis weight, absorption rate and saturated absorption amount, and the results are shown in Table 1. Incidentally, the product basis weight, absorption rate and saturated absorption amount are values obtained as follows, respectively. Product basis weight: The disposable diaper was spread in a plane, and the area (m ² ) in that state was measured. Then, the weight (g) of the disposable diaper is divided by the measured area to obtain a product basis weight (g).
/ M ² ). The area of the fastening tape was not included in the area serving as the basis for calculating the grammage.

Absorption speed: The disposable diaper is spread in a plane, and in this state, the diaper crotch is 100 mm × 1.
A test piece was cut out at a size of 00 mm. The obtained test piece was allowed to stand on a horizontal table with the top sheet side up. Then, an acrylic cylinder having an inner diameter of 50 mm was placed vertically at the center of the test piece, and 50 g of physiological saline was added into the cylinder at one time. The time until the added physiological saline was absorbed by the test piece and disappeared from the top sheet was measured, and the amount of physiological saline absorbed per second from the time when the physiological saline was added to the time when the physiological saline disappeared ( g) was calculated to be the body fluid absorption rate (g / sec).

Saturated absorption amount: A test piece obtained in the same manner as in the measurement of the absorption rate was put in a 150 mm × 150 mm nylon mesh (250 mesh) bag, and the mesh bag was immersed in physiological saline. This was pulled up after 1 minute and drained for 5 minutes. From the weight (g) after draining, the weight (g) before immersion, and the area (cm ² ) of the test piece, absorption of physiological saline per 100 cm ^{2 of} the test piece was performed. The amount (g) was calculated and defined as the saturated absorption amount (g / 100 cm ² ).

Further, each disposable diaper was evaluated for urine leakage. The evaluation was performed by using a total of 200 use tests for each disposable diaper for 10 monitors. And of each of the 200
Table 1 shows the ratio of the disposable diaper that caused urine leakage as “the ratio of urine leakage”.

[0028]

[Table 1]

The disposable diapers of Examples 1 and 2 have a high urine leakage prevention ability despite their weight being 30 g or less and the weight per piece being significantly lighter than the conventional disposable diapers. Have maintained. The disposable diaper of Comparative Example 1 has a high content of fluff pulp in the absorbent and has a high urine leakage prevention ability, but is heavy in weight and is difficult to carry in a package. In the disposable diaper of Comparative Example 2, the fluff pulp and the superabsorbent polymer of the absorbing member were respectively reduced by 60% by weight from that of Comparative Example 1, but the urine leakage preventing ability was reduced although it was lightweight. . The disposable diaper according to the present invention (Examples 1 and 2)
Despite its light weight, high urine leakage prevention ability is maintained because the function of fluff pulp, which was previously taken by fluff pulp to quickly take in urine discharged into the absorbent, was absorbed by the DW method at a rate of 8 g / 30 seconds. It is considered that the superabsorbent polymer of /0.3 g or more is substituted.

[0030]

The absorbent of the present invention is lightweight and compact, has a high absorption rate and a high saturated absorption amount, and has excellent absorption performance. The disposable diaper of the present invention is lightweight and compact, is light and easy to carry even when a plurality of wrappers are packaged, and has excellent urine leakage prevention ability.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a disposable diaper according to the present invention.

FIG. 2 is a sectional view schematically showing a section taken along line XX of FIG. 1;

FIG. 3 is a cross-sectional view schematically showing a YY cross section of FIG. 1;

FIG. 4 is a sectional view schematically showing a ZZ section of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disposable diaper 11 Fastening tape 2 Top sheet 3 Back sheet 4 Absorber 41 Polymer fixed nonwoven fabric 42 Absorbent polymer 43 Mount 44 Uneven sheet 5 Outer nonwoven fabric 51 Fastening part 6 Solid gather 61 Water repellent nonwoven fabric 62 Free edge 63 Solid gather elasticity Member 7 Leg gather 71 Leg elastic member 8 Waist portion 81 Waist elastic member A Abdominal side B Back side

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) A61F 13/551

Claims (4)

[Claims] 1. An absorption rate by the DW method of 8 g / 30 seconds /
0.3 g or more of superabsorbent polymer A and DW method absorption rate of 5 g / 30 sec / superabsorbent polymer B of 0.3 g or less
And a weight ratio (polymer A / polymer B) of 90/10 to 10
10/90 and fluff pulp content is 0
An absorber that is 30% by weight. 2. The total content of the superabsorbent polymer A and the superabsorbent polymer B in the absorber is 50.
2. The absorbent according to claim 1, which is at least about 10% by weight. 3. A disposable diaper in which the absorbent body according to claim 1 is interposed between a liquid-permeable top sheet and a liquid-impermeable back sheet. 4. The superabsorbent polymer A and the superabsorbent polymer B are mixed in the absorber.
The disposable diaper described.