JP3178053B2 - Disposable diapers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disposable disposable diaper, and more particularly to a disposable disposable diaper having a three-dimensional elastic gather for preventing urine leakage at a crotch position of a topsheet.

[0002]

2. Description of the Related Art A nonwoven fabric made of a hydrophobic fiber such as polypropylene or polyester is used for a surface sheet used for a disposable diaper in order to reduce wet back (return of the excrement through the surface sheet). In general, a hydrophilic treatment is performed using a hydrophilic agent such as a surfactant to impart permeability. However, due to the hydrophilization treatment, urine reaches both ends in the width direction and both ends in the longitudinal direction of the diaper along the surface sheet layer, oozes out, and leaks.

[0003] Many proposals have been made to prevent this leakage of urine, but the present applicants have previously disclosed Japanese Patent Application No. 63-253869 (Japanese Patent Application Laid-open No. 2-1).
No. 02649), the central region of the surface material of the disposable diaper is formed of a hydrophilic sheet, and the adjacent left and right side portions are formed of a hydrophobic sheet, thereby improving the above-mentioned problems of the conventional diaper with leakage and reversion. Suggested diapers. However, this conventional example does not have a gather structure that stands upright at the crotch position of the topsheet, so that urine leakage from the crotch is not sufficiently prevented.

On the other hand, a structure in which three-dimensional gathers are provided outside an absorber is disclosed in, for example, Japanese Patent Application Laid-Open No. 62-223303. As shown in FIG. 6, the three-dimensional gather of the diaper is generally provided with a second flap 32 for forming a three-dimensional gather separately from the top sheet 31 on the upper side of the side flap 30, and the second flap is folded back. The end of the folded portion is bonded and fixed at the end flap position (abdominal part, back part), and an elastic elastic body 34 (elastic band) is adhered to the inside of the loop 33 in an extended state. Is provided at the crotch position. That is, when the diaper is worn, the folded portion of the second flap is pulled upward when the elastic body is contracted. However, this conventional three-dimensional gather requires a wide second flap in addition to the side flaps as described above, and the end of the second flap is folded back at the time of manufacture into a loop shape, and an elastic band is formed in the loop. Complicated processing such as wrapping and bonding. In addition, since the terminal of the folded portion is bonded at the end flap position (abdominal part, back part), the position and length of the three-dimensional gather are determined by the length of the end flap bonding and fixing with respect to the entire length of the disposable diaper and the length of the elastic sealing. There was a restriction to come.

[0005]

SUMMARY OF THE INVENTION In view of the above circumstances, the present inventors have improved the prior application, Japanese Patent Application No. 63-253869, to provide a diaper having a function of preventing urine leakage more easily than conventional diapers. It is intended to be provided by. That is, a disposable diaper having a three-dimensional elastic gathering provided with a urine leakage prevention function at the crotch position of the topsheet can be obtained by using simple means and methods with little change in the conventional mechanical production process, in other words, very simple. It is a first object of the present invention to propose a diaper that can be manufactured economically. Further, it is possible to improve the problem of the above-mentioned Japanese Patent Application Laid-Open No. 62-223303 and to form a three-dimensional gather as in the related art without complicated processing, and to simply set the position, length and rising height of the gather. A second object is to propose a new diaper that can be changed and adjusted.

[0006]

In order to achieve the above-mentioned object, the present invention superimposes a hydrophilic surface material provided in the center and a hydrophobic surface material provided on both sides thereof, and installs an elastic body between them. By cutting the center surface material to an appropriate length along the elastic body, the cut both sides are raised by expansion and contraction of the elastic body, so that a three-dimensional elastic gather that prevents urine leakage is formed. The gist is that.

That is, a diaper according to the present invention is a disposable diaper in which an absorbent is disposed between a top sheet and a liquid-impermeable back sheet, wherein the upper surface of the absorbent is covered with a water-permeable sheet. The topsheet comprises a hydrophilic center surface material disposed in a central region and hydrophobic side surface materials disposed in both widthwise side regions, and a side edge of the center surface material and a side edge of the side surface material. Are overlapped with each other, and an elastic elastic body is interposed between the overlapped side edges in an extended state along the overlapped portion, and both sides of the center surface material are slit cut along the overlapped portion. And joining the area inside the two slit cut portions to the water permeable sheet, and joining the area of the center surface material outside the slit cut portion to the water permeable sheet. As no free part, upon reduction of the stretchable elastic material, it is characterized in that the free portion is so resiliently launch upward.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the diaper of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 to 5, the disposable diaper of the present invention includes a top sheet 2 having a hydrophilic central region, a liquid-impermeable back sheet 3, an absorber 1 disposed therebetween, and a crotch. Elastic body 18 provided in the region,
24 and fastening tapes 5 at both ends of the upper portion of the diaper. As is well shown in the plan view of FIG. 1, the topsheet 2 includes a hydrophilic center surface member 15 disposed in the center region of the diaper and two side surface members disposed in both widthwise regions of the diaper. 16 and 16. By providing slit cut portions 19 on both sides of the hydrophilic center surface material 15 in the crotch region, three-dimensional elastic gathers 6 and 6 serving as weirs capable of preventing lateral leakage of excretions along the diaper longitudinal direction are formed. I have.

Hereinafter, this point will be described in detail. As shown in FIG. 2, the absorber 1 constituting the central layer of the diaper is fixed to the center position of the back sheet 3. The absorber 1 includes a mat-shaped absorbent core 12 and a tissue 12a provided below the absorbent core 12. A water-permeable sheet 13 (second surface material) is provided on the upper side of the core 12 so as to cover the core 12.
Is arranged. The role of the water permeable sheet 13 will be described later.

As the core 12, absorbent fibers such as flap pulp, cottony pulp, rayon and the like having excellent liquid absorbing power are used.
Used in multiple layers or more. In addition, a sheet containing a highly absorbent polymer or a granular material obtained by mixing activated carbon, carboxymethylcellulose, zeolite, or the like with the sheet containing a highly absorbent polymer is disposed between the fiber layers constituting the core body 12 to increase the absorption capacity as needed. Is also possible.

As described above, at least one water-permeable sheet 13 (second surface material) is disposed on the upper surface of the core body 12 so as to cover it. As described above, the main reason for superposing the water-permeable sheet having strength, instead of tissue, on the core body 12 is that when the both sides of the surface material 15 are raised, the absorber has low strength. The surface material 13 should not be exposed and the return of urine absorbed by the absorber
This is to reduce the number by two sheets of No. 15 and No. 15. The water-permeable sheet 13 is preferably one having a strength higher than that of a tissue paper usually used for the above-mentioned reason. For example, a hydrophilic nonwoven fabric, a perforated plastic film, or the like is used.

As shown in FIG. 1, the absorber 1 has a rectangular shape without constriction or a so-called hourglass shape (not shown) in which both sides of the central portion are constricted.

As the back sheet 3, a sheet material having a waterproof property is used, and preferably, a sheet material having both air permeability is used. Specifically, a polyethylene film having water permeability and a water-repellent nonwoven fabric are used.

As described above, the topsheet 2 is composed of the center surface member 15 disposed in the center region of the diaper and the side surface members 16 disposed in both widthwise regions of the diaper. The surface material 15 is formed in a rectangular shape having a full length in the vertical direction of the diaper as shown in FIG. As the center surface material 15, a dry nonwoven fabric is usually used, but a hydrophobic nonwoven fabric (for example, a polypropylene spunbonded nonwoven fabric) obtained by subjecting a central region to a hydrophilic treatment with a surfactant or the like can also be used. On the other hand, as the side surface material 16 arranged on both side regions in the width direction of the diaper, a hydrophobic material having the same length as the center surface material having a concave notch for a leg hole formed on one of the left and right side edges is used. As the hydrophobic material, for example, polypropylene, polyethylene, spunbonded nonwoven fabric that has not been subjected to a hydrophilic treatment made of synthetic fibers such as polyester, meltblown nonwoven fabric, and the like are preferable.
Of course, it is not limited to this.

Center surface material 15 arranged in the central region
And the side surface materials 16 and 16 arranged on both sides thereof, the side edges adjacent to each other are wrapped (overlapping).
The wrap portions 17, 17 may be partially adhered and fixed by a hot melt adhesive or a heat sealing method,
Alternatively, the center surface material 15 and the side surface material 16 are overlapped, and the surface materials may be bonded to each other by interposing a stretchable elastic body (for example, an elastic band or the like) 18 coated with an adhesive therebetween in an extended state. .

In the case of a disposable diaper having a width of 320 mm, in the present embodiment, the sheet width of the center surface material is set to 1
70 mm, the sheet width of the side surface material is set to 115 mm, and the wrap width of both surface materials is set to 40 mm. The width of the wrap may be 40 mm or less as long as the two types of surface materials 15 and 16 are joined to each other with sufficient strength, and the wrap width is not particularly limited. Considering that they are interposed in parallel, it is preferable that they overlap with each other, preferably with a wrap width of 20 mm or more. Also, when wrapping two kinds of surface materials,
In the illustrated embodiment, the side surface material 16 is overlaid on the center surface material 15, but the reverse is also possible.

On both sides of the center surface member 15, a slit cut portion 1 is formed along the elastic band 18.
9 and 19 are formed. Then, as shown in FIG. 2, an appropriate region between the slit cut portions of the center surface material 15, that is, an appropriate region inside the two slit cut portions is partially adhered to the water-permeable sheet 13 using a hot melt adhesive or the like. A portion outside the slit cut portion 19, that is, a region outside the slit cut portion 19 of the center surface member 15 is formed as a free portion (non-adhesive portion) 20 not joined to the water-permeable sheet 13. In FIG. 1, a hatched portion represents a top sheet adhesive portion, and a white portion represents a top sheet release portion.

In this way, when the elastic band 18 attached to the inside of the wrap portion 17 is reduced, the release portion is elastically raised upward, and the elastic portion 18 is laterally moved along the longitudinal direction of the diaper. The three-dimensional elastic gathers 6 serving as weirs that can prevent leakage are formed. The position and length of the slit cut portion 19 are as shown in FIG.
(B), it can be easily changed and adjusted. 5 (A) and FIG. 5 (B), the cut positions are different, and the rise height of gathers is higher in FIG. 5 (B).

Reference numerals 21 and 21 in the drawing denote recessed portions for leg holes formed by cutting out both side edges of the side surface materials 16 and 16 and the back sheet 3 in the width direction. An elastic body (eg, an elastic band) 24 forming the leg gathers 23, 23 is adhered in an extended state along the inner edges of the portions 21, 21. When the diaper is worn, the leg gathers 23 come into contact with the user's legs and maintain a sealed state.

FIG. 3 and FIG. 4 are explanatory views showing the outline of the method for producing a disposable diaper according to the present invention. As is clear from the above figure, after bonding the absorbent body 1 constituting the central layer of the diaper covered with the water-permeable sheet on the back sheet 3 and the elastic elastic body 24 forming the leg gathers 23, 23. As described above, the surface sheet 2 formed by superposing the hydrophilic center surface material 15 and the hydrophobic side surface material 16 thereon and adhering the elastic band 18 in the stretched state during the polymerization is used as described above. Paste. Note that a slit cut portion 19 is provided in advance near the wrap portion 17 side of the hydrophilic center surface member 15 by intermittently performing slit cut along the wrap portion.

[0021]

As described above, according to the diaper of the present invention, the hydrophilic center surface material and the hydrophobic side surface material are overlapped, an elastic body is provided therebetween, and the center is formed along the elastic body. By simply slitting the surface material to an appropriate length, the cut free portions on both sides stand up due to expansion and contraction of the elastic body, and a three-dimensional elastic gather that prevents leakage of urine can be easily formed. In addition, since the absorbent core is not exposed when the upper surface is raised by superimposing the surface material on two sheets substantially on the core, and the surface material becomes thicker, It is possible to reduce the reversion of absorbed urine. Therefore, it is possible to provide a diaper having a higher urine leakage prevention function than conventional ones. In addition, an excellent effect is exhibited in that the rising position, the rising position, and the rising height of the three-dimensional elastic gathering can be easily adjusted depending on the position and length of the slit cut portion.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of the diaper of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of the above.

FIG. 3 is an explanatory view schematically showing a method for manufacturing a diaper of the present invention.

FIG. 4 is an exploded view of the same.

FIG. 5 is a plan view showing another example of the diaper of the present invention in which a slit position is changed.

FIG. 6 is a sectional view of a conventional product.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Absorbent body 2 Top sheet 3 Back sheet 4 Side flap 5 Fastening tape 6 Three-dimensional elastic gather 12 Mat-shaped core 13 Water-permeable sheet 15 Center surface material 16 Side surface material 17 Lapping part 18 Elastic elastic body 19 Slit cut part 20 Free Part 21 concave notch part 23 leg gather 24 elastic body 30 side flap 31 surface sheet 32 second flap 33 loop 34 elastic body 35 solid elastic gather

Claims (1)

(57) [Claims] 1. A disposable diaper in which an absorber is disposed between a topsheet and a liquid-impermeable backsheet, wherein the top surface of the absorber is covered with a water-permeable sheet, and the topsheet is formed in a central region. It is composed of a hydrophilic center surface material and a hydrophobic side surface material arranged on both side regions in the width direction, and a side edge of the center surface material and a side edge of the side surface material overlap with each other. An elastic elastic body is interposed between the overlapped side edges in an extended state along the overlapping portion, and both sides of the center surface material are slit-cut along the overlapping portion, and
The area inside the two slit cut portions is joined to the water permeable sheet, and the area outside the slit cut portion of the center surface material is a free portion that is not joined to the water permeable sheet, when the elastic elastic body is reduced. A disposable diaper characterized in that the release portion is elastically raised upward.