JP3406229B2 - Disposable diapers - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a disposable diaper.

[0002]

2. Description of the Related Art In a disposable diaper disclosed in Japanese Patent Laid-Open No. 58-41902, superabsorbent polymer layers are arranged in strips on opposite ends or both sides of an absorbent body.
The superabsorbent polymer layer is arranged inside the absorber, between the absorber and the backsheet, or between the absorber and the topsheet. In this polymer layer, in addition to the polymer powder alone, the polymer powder is embossed into a band-shaped sheet sandwiched between two absorbent sheets, or the polymer powder and ground pulp. There is one in which a mixture of and is pressed into a band-shaped sheet.

[0003]

According to the above-mentioned known technique, the body fluid, which tends to exude from the peripheral portion of the absorbent body, can be captured by the superabsorbent polymer. The super-absorbent polymer does not easily release (separate) the absorbed body fluid even when the body pressure is applied, so it effectively prevents the body fluid from flowing out of the core when it is in the peripheral portion of the core. You can

However, in the above-mentioned prior art, when only the polymer powder is inside the absorber, the polymer powder is likely to spill from the edge of the absorber, which makes it difficult to achieve the intended purpose. It is also difficult to increase the amount used. Further, since the band-shaped sheet containing the polymer powder has a relatively high rigidity, the fact that it is located in the peripheral portion of the absorber makes the edge portion of the absorber, which is already high in rigidity, further rigid. It further reduces the flexibility of the diaper and makes it uncomfortable to wear.

Therefore, the present invention has an object to solve the problems of the prior art when the superabsorbent polymer powder is arranged in the peripheral portion of the absorber.

[0006]

In order to solve the above-mentioned problems, the present invention is premised on a liquid-permeable surface sheet,
A disposable diaper having a liquid-impermeable back sheet and an absorbent body interposed between the both sheets, and having superabsorbent polymer powder disposed on at least a part of a peripheral portion of the absorbent body.

On this premise, the present invention is characterized in that the absorber is a central member and an edge of the central member.
Consisting of an edge member arranged so as to be in close contact with the part,
The edge member is formed by encapsulating the superabsorbent polymer powder in a liquid-permeable sheet, and has a peripheral edge portion.
Forming at least a part of the

In a preferred embodiment of the present invention, the liquid-permeable sheet forms a substantial bag, and the superabsorbent polymer powder is 40 to 80% of the volume of the bag.
Occupy

[0009] In another one of the embodiments, the bag contains a strip of either a fiber or a film made of a hydrophobic thermoplastic synthetic resin, and the amount of the strip is the superabsorbent polymer powder. Equivalent to 0-20% of the weight of.

In another embodiment, the fibers are hollow fibers.

In another embodiment, the fibers are crimped.

In yet another embodiment, the film has a large number of irregularities on the surface.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the disposable diaper according to the present invention will be described below with reference to the accompanying drawings.

A disposable diaper 1 shown in a partially cutaway plan view in FIG. 1 includes a liquid-permeable top sheet 2, a liquid-impermeable back sheet 3, and an absorbent body 4 interposed between these sheets 2 and 3. It is a long hourglass type with front and back, and in the front and back direction,
It has a front waist region 6, a back waist region 7, and a crotch region 8 located between these both regions 6, 7. Front and back sheets 2, 3
Extend from the peripheral edge of the absorber 4 and overlap with each other, and the overlapping portions are bonded to each other via the hot melt adhesive 9. In the crotch region 8, the absorbent core 4 is curved inward of the diaper 1, and leg elastic members 11 extending along the absorbent core 4 are located between the front and back sheets 2 and 3, and these two sheets 2 and It is joined to at least one inner surface of No. 3 in a stretched state. Tape fasteners 12 are attached to both side edges of the rear waist region 7.

The absorbent body 4 has at least the central member 16 which occupies most of the surface area of the absorbent body 4 and the peripheral portion of the absorbent body 4 when the diaper 1 is viewed in plan as shown in the figure. The edge member 17 forms a part, and both members 16 and 17 are covered with tissue paper 18.
The central member 16 is a compression-molded product of crushed pulp, and can contain powder of a superabsorbent polymer up to 40% by weight. The edge member 17 is made of powder 2 of a superabsorbent polymer.
1 is enclosed in a bag 22 made of a liquid permeable sheet, which is added to the super absorbent polymer powder 21 and
Fibers 30 or film strips of hydrophobic thermoplastic synthetic resin can be included, up to an amount equivalent to 20% by weight of powder 21 (see FIGS. 2 and 3). The edge member 17 is arranged so as to be in close contact with the edge portion of the central member 16.

FIG. 2 is a view taken along the line II-II of FIG. The center member 16 and the edge member 17 are bonded to the tissue paper 18 that covers them through the hot-melt adhesive 23 so that their edges are in close contact with each other. However, when the central member 16 and the edge member 17 are in close contact with each other only by being sandwiched between the front and back sheets 2 and 3, the use of the hot melt adhesive 23 is omitted, or the tissue paper 18 is used. The covering of the edge member 17 can be omitted. In the edge member 17, it is preferable that the amount of the superabsorbent polymer powder 21 occupies 40 to 80% of the volume of the bag 22. In this way, the bag 22
Since the superabsorbent polymer powder 21 can move relatively freely in the inside, when the diaper 1 is worn, the edge member 17 is deformed and fits well to the wearer's body. Moreover, the powder 21 swollen by absorbing body fluid does not press the body.

FIG. 3 is a sectional view of the principal part taken along the line III-III in FIG. The bag 22 can be made of a liquid-permeable sheet, such as a woven cloth, a non-woven cloth, or a net. When the bag 22 is made of, for example, a nonwoven fabric made of thermoplastic synthetic fiber,
The superabsorbent polymer powder 21 can be enclosed by welding or adhering the end portion 27 of the bag 22. The non-woven fabric may form a bag in a substantial sense so that the polymer powder 21 can be held in the peripheral portion of the absorbent body 4.

In the diaper 1 thus constructed, the body fluid flowing on the topsheet 2 is filled with the superabsorbent polymer powder 21.
Can be absorbed to prevent leakage of body fluids. The powder 21 that has absorbed the body fluid and swelled forms a gel block at the edge of the absorbent body 4, and when the height (thickness) of the block exceeds the thickness of the central member 16, the gel block is placed on the surface sheet 2. It acts as a leak barrier against body fluids flowing through. Further, even if the body fluid absorbed by the body pressure acts on the central member 16 and exudes from the edge portion of the member 16, if the edge member 17 is provided, the body fluid can be absorbed again. Since the swollen superabsorbent polymer powder 21 hardly releases body fluid by the action of body pressure, the edge member 17
Is effective in preventing body fluid from seeping out from the edge portion of the absorbent body 4. It is preferable that the super absorbent polymer powder 21 exhibiting such an effect can absorb 5 times or more of its own weight in 3 seconds and 15 times or more of its own weight in 10 seconds.

When the powder 21 and the strips of the hydrophobic fiber 30 are mixed in the bag 22, the fiber 30 is interposed between the powders 21 swollen by absorbing the body fluid, and the powders 21 adhere to each other. Therefore, it is possible to form an air-permeable / water-permeable gap that communicates with the inside and outside of the gel block formed by the powder 21. If the body fluid penetrates into the gel block through the gap, the powder 21 can be effectively used when there is the powder 21 that is trapped inside the gel block and has not yet absorbed the body fluid. When hollow fibers or crimped fibers are used as the fibers 30, a relatively large gap can be formed in the gel block to enhance ventilation / water permeability. The fiber 30 preferably has a length of 2 to 50 mm. Fiber 3
Instead of 0, it is also possible to use a strip of a plastic film made of a hydrophobic thermoplastic synthetic resin. If many irregularities are formed on the surface of the film, it is useful for increasing the gap between the gel blocks.

FIG. 4 is a drawing similar to FIG. 1, showing an example of an embodiment of the present invention. In this diaper 1, the edge member 1
7 are arranged in the crotch region 8 of the absorber 4 so as to form an arc. In the front and rear waist regions 6 and 7, elastic members 31 and 32 extending in the waist direction are located between the front and back sheets 2 and 3, and are joined to at least one inner surface of the sheets 2 and 3 in an extended state. There is. The edge member 17, as shown in FIG.
In addition to forming the peripheral edge portion of the absorbent body 4 in a state of being in close contact with the central member 16 from the side, it is mounted on the inner surface of the edge portion of the central member 16 to form a part of the peripheral edge portion of the absorbent body 4. May be.

In the present invention, the topsheet 2 may be made of non-woven fabric or perforated plastic film. A plastic film can be used for the back sheet 3. The core 4 can be bonded to the topsheet 2 and / or the backsheet 3 with an adhesive such as a hot-melt adhesive, if necessary. Each member of the diaper 1 can be joined by adhesion, welding by heating, welding by ultrasonic waves, or the like. Examples of the superabsorbent polymer used in the present invention include starch-based ones such as starch acrylonitrile copolymer, cellulose-based ones using carboxymethylated cellulose, acrylic-based ones, and polyvinyl alcohol-based ones. Known materials such as acrylamide and acrylamide can be used. The shape of the diaper 1 is not limited to the hourglass shape shown in the figure, but may be a rectangular shape or a pants shape.

[0022]

In the disposable diaper according to the present invention, the super-absorbent polymer powder arranged in the peripheral portion of the absorbent body is wrapped in the liquid-permeable sheet so that it does not spill from the absorbent body. There is no need to make the absorber highly rigid. A gel block of superabsorbent polymer powder swollen with body fluid can form a leakproof ridge at the edge of the absorbent body. When super absorbent polymer powder and a strip of hydrophobic thermoplastic synthetic resin are mixed in the bag, the strip forms a water-permeable gap that communicates with the inside and outside of the gel block, and the body fluid is still inside the block. It allows the use of superabsorbent polymer powders which have not been absorbed.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view of a disposable diaper.

2 is a view taken along the line II-II of FIG.

FIG. 3 is a sectional view of a main part taken along the line III-III in FIG.

FIG. 4 is a partially cutaway plan view of a disposable diaper showing an example of an embodiment.

[Explanation of symbols]

1 disposable diapers 2 Top sheet 3 back sheet 4 absorber16 Central member 17 Edge member 21 Super absorbent polymer powder 22 Liquid-permeable sheet (bag) 30 Strips of synthetic resin (syntheticMade of resinfiber)

Continuation of the front page (56) Reference JP-A-1-292181 (JP, A) JP-A-9-136974 (JP, A) JP-A-2-283369 (JP, A) JP-A-11-19127 (JP , A) Actual development Sho 60-45017 (JP, U) Actual development 2-61326 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) A61F 13/15-13/84 A61F 5/44

Claims (6)

(57) [Claims] 1. A liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body interposed between these sheets, and a super-absorbent polymer powder on at least a part of a peripheral portion of the absorbent body. A disposable diaper in which the absorbent body is in close contact with a central member and an edge portion of the central member.
The edge member being arranged so that
Is a product in which the superabsorbent polymer powder is wrapped in a liquid-permeable sheet.
The diaper is characterized in that it also forms a part of the diaper. 2. The diaper according to claim 1, wherein the liquid-permeable sheet substantially forms a bag, and the superabsorbent polymer powder occupies 40 to 80% of the volume of the bag. 3. A strip of either a fiber or a film made of a hydrophobic thermoplastic synthetic resin is contained in the bag,
The amount of the particles is 0 to the weight of the superabsorbent polymer powder.
The diaper according to claim 1 or 2, which is equivalent to 20%. 4. The diaper according to claim 3, wherein the fibers are hollow fibers. 5. The diaper according to claim 3, wherein the fibers are crimped. 6. The diaper according to claim 3, wherein the film has a large number of irregularities on its surface.