Title of Invention

"ABSORBENT ARTICLE FOR DISPOSAL OF BODY FLUIDS"

Abstract The absorbent article for disposal of body fluids includes a topsheet 2 composed of an upper layer sheet 6 made of liquid-pervious plastic film and a lower layer sheet 7 made of liquid-pervious fibrous assembly, and the upper layer sheet 6 extends in one direction and formed with a plurality of crest 11 and troughs 12 alternating in a direction orthogonal to the first-mentioned direction.
Full Text -1A-
The invention relates to an absorbent article for receiving and containingbody fluids.
Japanese Patent Application Disclosure Gazette (Kokai) No. HeilO-272152 discloses an absorbent article for disposal of body fluids, in which a liquid-pervious topsheet comprises a heat-sealable and hydrophobic upper layer sheet having a plurality of liquid-passages extending therethrough and a heat-sealable and hydrophilic lower layer sheet underlying the upper layer. The topsheet protrudes upward to present an arc-shaped cross-section and/ in its protuberant region, said upper and lower layer sheets are sealed with each other by a plurality of debossing spots distributed in a pattern. The upper layer sheet may be formed/ for example, by a synthetic resin film and said lower layer sheet may be formed, for example, by a fibrous nonwoven fabric. According to a preferred embodiment, the liquid-passage comprises a tapered capillary formed integrally with the liquid-passage and extending downward until a lower end of the capillary comes in contact with the lower layer sheet- Such capillary functions to accelerate absorption of body fluids and to

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prevent the amount of body fluids once absorbed from flowing
back to the exterior of the article. The known article is certainly advantageous in that its upper surface protruding in arc-shape is kept under tension and therefore reliably placed against the wearer's crotch region with good fitting. In addition/ the liquid-passages extending downward from the upper layer sheet are not easily deformed because they are supported by the lower layer sheet. However/ the article having a good fitting may often be problematic in ventilation or breathability desired to be maintained between the wearer's, skin and the article and apt to cause stuffiness and/or eruption.
In view of the problem as has been described above, it is an object of this invention to provide an absorbent article for disposal of body fluids similar to the article in that the liquid-pervious topsheet comprises upper and lower layer sheets but distinguished from the known article in that the ventilation or breathability desired to be maintained between the topsheet and the wearer's skin is drastically improved .

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Accordingly, the present invention provides an absorbent article for receiving and containing body fluids, said article comprising:
a liquid-pervious topsheet defining a body facing surface;
a liquid-impervious backsheet defining an undergarment facing surface, a liquid-absorbent core disposed between said topsheet and said backsheet;
said topsheet being constituted of an upper sheet layer made of plastic film, and a lower sheet layer made of fibrous assembly, wherein said upper sheet layer is 0.01~0.1 mm thick and has a plurality of apertures formed therein, each of said plurality of apertures has a diameter of 0.2~6 mm, said upper sheet layer is provided with liquid-passages which extend from said plurality of apertures through said upper sheet layer, and each said liquid passage has a length of 0.2~4 mm and a lower end diameter of 0.1~5 mm; and wherein said lower sheet layer has a density of 0.01~0.1 g/cm3 and a basis weight of 10~80 g/m3, said lower sheet layer being bonded to a bottom surface of said upper sheet layer such that said liquid-passages extend from said upper sheet layer into said lower sheet layer;
said article also having;
a plurality of crests and troughs formed in the upper sheet layer and the lower sheet layer of the topsheet, said plurality of crests and troughs extending in a longitudinal direction of said article and alternating in a direction intersecting said longitudinal direction at right angles.
According to one embodiment of this invention, the upper layer sheet is of hydrophobic nature and the liquid- . passages are treated to become hydrophilic.
According to another embodiment of this invention, the lower layer sheet is a nonwoven fabric made pf thermoplastic synthetic fibers.

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According to still another embodiment of this invention, the nonwovea fabric is treated to become hydrophilic.
According to further another embodiment of this invention, a bottom surface of the lower layer sheet is
bonded to an upper surface of the absorbent core, BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Fig. 1 is a perspective view showing a partially cutaway sanitary napkin of this invention; and
Fig. 2 is a fragmentary sectional view taken along a line II-II in Fig. 1.
Details of an absorbent article for disposal of body fluids proposed by this invention will be more fully understood from the description of a sanitary napkin as a specific embodiment of this invention given here under with ' reference to the accompanying drawings .
A sanitary napkin 1 shown by Fig. 1 in a perspective view as partially cutaway comprises a liquid-pervious topsheet 2 defining a body facing surface, a liquid-impervious backsheet 3 defining an undergarment facing surface and a liquid-absorbent core 4 disposed between the topsheet and the backsheet 2, 3. The topsheet 2 comprises an

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upper layer sheet 6 and a lower layer sheet 7 bonded to the lower surface of the upper layer sheet 6. The topsheet 2 and the backsheet 3 are put flat together over their portions extending outward beyond a peripheral edge of the absorbent core 4 and bonded to each other along a line 8.
Fig. 2 is a fragmentary sectional view taken along a line II-II in Fig. 1 extending transversely of the napkin 1. The upper layer sheet 6 making a part of the topsheet 2 is made of a plastic film having a thickness of 0.01 - 0.1mm and forms a plurality of crests 11 and troughs 12 alternating transversely of the napkin 1 (See Fig. 1 also). A height H of the crest 11 (i.e., a depth of the trough 12) is in a range of 0.3 - 3mm and a pitch between apices' of adjacent crests 11 is in a range of 2 ~ 7rnm. The upper layer sheet 6 is formed with a plurality of apertures 13 and liquid-passages 14 extending from the top surface toward the bottom surface around the respective apertures 13. Each of the apertures 13 has a diameter of 0.2 - 6mm and a total area occupied by the apertures 13 corresponds to 20 - 70% of the surface area of the upper layer sheet 6. Each of the liquid-passages 14 has a length of 0.2 - 4mm and a diameter of 0.1 5mm at its lower end. The liquid-passages 14 are preferably of hydrophilic nature and if they are formed by a

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hydrophobic film, peripheral walls of the liquid-passages 14 are preferably treated by suitable means to become hydrophilic.'
The lower layer sheet 7 making a part of the topsheet 2 is preferably provided in the form of a fibrous assembly comprising semi-synthetic fibers such as thermoplastic synthetic fibers or rayon fibers or natural fibers such as pulp fibers intertwined or sealed together to have a density of 0.01 - 0.lg/cm3 and a basis weight of 10 - 80g/m2 and more preferably provided in the form of nonwoven fabric having a density of 0.01 - O.lg/cm3 containing 60% or more by weight of thermoplastic synthetic fibers with a fineness of 1 - 8 deniers and a basis weight of 10 - 80g/m2. The nonwoven fabric useful for this purpose includes a spun bond nonwoven fabric, a point bond nonwoven fabric, an air-through nonwoven fabric and a spun lace nonwoven fabric. The lower layer sheet 7 is preferably made of hydrophilic fibers or synthetic fibers treated to become hydrophilic. When a certain degree of bulkiness of a cushioning property is desired for the lower layer sheet 7, it is also possible to use a nonwoven fabric containing crimped conjugated fibers. Such lower layer sheet 7 is bonded to the bottom surface of the upper layer sheet 6 by means of adhesive agent or sealing technique

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and the liquid-passages 14 extend from the upper layer sheet
6 into interfiber gaps of the lower layer sheet 7.
Individual fibers of the lower layer sheet 7 surround the
respective liquid-passages 14 and serve to protect the
liquid-passages 14 from being collapsed. These individual
fibers are adhered to or sealed with outer surfaces of the
liquid-passage walls as well as their lower openings and thus
additionally serve to prevent the liquid-passages 14 from
being deformed. While the bottom surface of the lower layer
sheet 7 also may have the crests and the troughs similar to
those on its upper surface, the lower surface is preferably
planar as shown and closely placed against the upper surface
of the absorbent core 4. More preferably, the lower layer
sheet 7 is intermittently bonded to the upper surface of the
absorbent core 4 in a region extending inside the line 8 by
means of suitable adhesive agent such as hot melt adhesive
agent, sealing technique or embossing in the direction of
thickness. Once the upper layer sheet 6, the lower layer
sheet 7 and the absorbent core 4 have been bonded together,
the crests 11 as well as the troughs 12 can be shifted
neither longitudinally nor transversely of the napkin under
a wearer's body weight. Upon removal of the body weight, the
crests 11 and troughs 12 immediately restore their initial

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shapes.
The line 8 along which the topsheet 2 and the backsheet 3 are bonded together is a seal line along which the upper and lower layer sheets 6, 7 and the backsheet 3 are integrally bonded or sealed together and preferably functions to prevent body fluids discharged on the central region of the napkin from exuding toward a peripheral flap 18,
While the napkin 1 has been illustrated and described here in above, this invention is applicable also to the other absorbent article for disposal of body fluids such as panty liners, disposable diapers or urine-absorbent pads for incontinent users. It is also possible to use the topsheet 2 according to this invention selectively as a part of the body facing surface of the absorbent article, for example, in the central region of the napkin 1.
The absorbent article for disposal of body fluids such as the napkin arranged as has been described with reference to the accompanying drawings can effectively avoid stuffiness and/or eruption. This is achieved by the,body facing surface of the article comprising the crests adapted to be closely placed against the wearer's skin and the troughs adapted to form the ventilating channels. The upper layer sheet forming a part of the topsheet has a plurality of crests and troughs

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which advantageously makes an effective area of the upper layer sheet substantially larger than that in the case of the planar upper layer sheet. The effective area of the upper layer sheet thus enlarged enables correspondingly increased number of liquid-passages to be present on the surface of the article. In this manner, absorption of body fluids into the absorbent core can accelerated and stuffiness and/or eruption due to use of such article can be further reliably prevented. The upper layer sheet is backed by the lower layer sheet and therefore the topsheet comprising these two layer sheets has a high elastic restoring force in the direction of thickness particularly in the region defined by the crests In this manner, the napkin obtains a high cushioning property.

10 WE CLAIM:
1. An absorbent article (1) for receiving and containing body fluids, said article comprising:
a liquid-pervious topsheet (2) defining a body facing surface;
a liquid-impervious backsheet (3) defining an undergarment facing surface, a liquid-absorbent core (4) disposed between said topsheet (2) and said backsheet (3);
said topsheet (2) being constituted of an upper sheet layer (6) made of plastic film, and a lower sheet layer (7) made of fibrous assembly, wherein said upper sheet layer (6) is 0.01-0.1 mm thick and has a plurality of apertures (13) formed therein, each of said plurality of apertures (13) has a diameter of 0.2~6 mm, said upper sheet layer is provided with liquid-passages (14) which extend from said plurality of apertures (13) through said upper sheet layer (6), and each said liquid passage (14) has a length of 0.2~4 mm and a lower end diameter of 0.1~5 mm; and wherein said lower sheet layer (7) has a density of 0.01~0.1 g/cm3 and a basis weight of 10~80 g/m3, said lower sheet layer (7) being bonded to a bottom surface of said upper sheet layer (6) such that said liquid-passages (14) extend from said upper sheet layer (6) into said lower sheet layer (7);
said article (1) also having;
a plurality of crests (11) and troughs (12) formed in the upper sheet layer (6) and the lower sheet layer (7) of the topsheet (2), said plurality of crests and troughs extending in a longitudinal direction of said article (1) and alternating in a direction intersecting said longitudinal direction at right angles.

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2. The article (1) as claimed in Claim 1, wherein said upper
sheet layer (6) is hydrophobic and said liquid-passages (14) are
treated to become hydrophilic.
3. The article (1) as claimed in Claim 1 or 2, wherein said lower
sheet layer (7) is a nonwoven fabric made of thermoplastic
synthetic fibers.
4. The article (1) as claimed in any of the preceding Claims,
wherein the bottom surface of said lower sheet layer (7) is bonded
to the upper surface of said liquid-absorbent core (4).
5. An absorbent article for receiving and containing body fluids,
substantially as herein described, particularly with reference to,
and as illustrated in the accompanying drawings.
The absorbent article for disposal of body fluids includes a topsheet 2 composed of an upper layer sheet 6 made of liquid-pervious plastic film and a lower layer sheet 7 made of liquid-pervious fibrous assembly, and the upper layer sheet 6 extends in one direction and formed with a plurality of crest 11 and troughs 12 alternating in a direction orthogonal to the first-mentioned direction.

Documents:

00026-cal-2000 abstract.pdf

00026-cal-2000 claims.pdf

00026-cal-2000 correspondence.pdf

00026-cal-2000 description(complete).pdf

00026-cal-2000 drawings.pdf

00026-cal-2000 form-1.pdf

00026-cal-2000 form-18.pdf

00026-cal-2000 form-2.pdf

00026-cal-2000 form-3.pdf

00026-cal-2000 form-5.pdf

00026-cal-2000 g.p.a.pdf

00026-cal-2000 letters patent.pdf

00026-cal-2000 priority document others.pdf

00026-cal-2000 priority document.pdf

00026-cal-2000 reply f.e.r.pdf

26-CAL-2000-CORRESPONDENCE 1.1.pdf

26-CAL-2000-FORM 27.pdf


Patent Number 207092
Indian Patent Application Number 26/CAL/2000
PG Journal Number 21/2007
Publication Date 25-May-2007
Grant Date 23-May-2007
Date of Filing 18-Jan-2000
Name of Patentee UNI-CHARM CORPORATION
Applicant Address 182,SHIMOBUN,KINSEI-CHO,KAWANOE-SHI,EHIME-KEN
Inventors:
# Inventor's Name Inventor's Address
1 KASHIWAGI MASAHIRO C/O TECHNICAL CENTER UNI-CHARM CORPORATION 1531-7,TAKASUKA WADAHAMA,TOYOHAMA-CHO MITOYO-GUN,KAGAWA-KEN,
PCT International Classification Number A61F13/511
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11-12335 1999-01-20 Japan