Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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S P E C I F I CAT I O N
DISPOSABLE PANTS-TYPE DIAPER
TECHNICAL FIELD
[0001]
The present invention relates to disposable pants-type
diapers preventing the wearer's skin from being soiled with
urine and/or feces.
RELATED ART
[0002]
It is well known to provide diapers with a structure
serving to prevent urine and feces from being mixed with each
other inside the diaper put on the wearer's body.
[0003]
For example, the diaper described in JP 2002-11044 A
(PATENT DOCUMENT 1) has a skin-contact sheet above a
liquid-pervious inner sheet covering an absorbent structure
wherein, in a crotch region, the skin-contact sheet is formed
with an opening and provided with an elastic member attached
under tension thereto to surround this opening. In the case
of this diaper of prior art, the absorbent structure in the
crotch region is formed with a dam-like ridge to block flow of
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urine and/or feces.
[0004]
In the case of the disposable pants-type diaper described
in JP 2007-296314 A (PATENT DOCUMENT 2) , a sheet piece defining
a separator serving to prevent urine and feces from being mixed
with each other is provided in the crotch region and this sheet
piece is fixed along the opposite side edges thereof to the inner
surface of the diaper. The sheet piece has a front end and a
rear end both extending in the transverse direction of the
diaper and these two ends are integrated together on a center
line bisecting a width dimension of the diaper.
PATENT DOCUMENT 1: JP 2002-11044 A
PATENT DOCUMENT 2: JP 2007-296314 A
DISCLOSURE OF THE INVENTION
PROBLEM TO BE SOLVED BY THE INVENTION
[0005]
In the case of the diaper described in PATENT DOCUMENT
1, feces move to the inner sheet through the opening of the
skin-contact sheet. The skin-contact sheet extends across the
crotch region of the diaper in the front-back direction and
therefore feces did not properly pass through the opening will
flow forward on the skin-contact sheet until the diaper wearer's
external genital may be soiled with feces. Furthermore, urine
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may flow rearward on the skin-contact sheet until the wearer's
skin may be soiled with urine in the vicinity of the wearer's
anus.
[0006]
In the case of the diaper described in PATENT DOCUMENT
2, the front end and the rear end of the sheet piece defining
the separator are bonded to each other along the center line
of the diaper, allowing urine and feces to be separated from
each other. With this diaper of prior art, feces would not move
forward along the separator. However, considering that the
separator for anus and external genital is the integrated front
and rear ends, it has sometimes been difficult for this
separator to block a flow of loose passage.
[0007]
In view of the problem as has been described above, it
is a principal object of the present invention to improve the
disposable pants-type diaper so that the diaper wearer's skin
in the vicinity of external genital and/or anus would not be
soiled by body waste flowing in the direction from anus to
external genital or the inverse direction.
MEASURE TO SOLVE THE PROBLEM
[0008]
The object set forth above is achieved, according to the
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present invention, by an improvement in the disposable
pants-type diaper having a front-back direction, a transverse
direction and a vertical direction being orthogonal one to
another and comprising a crotch region, a front waist region
extending forward from the crotch region and a rear waist region
extending rearward from the crotch region wherein the crotch
region includes a bodily fluid absorbent structure comprising
a liquid-pervious inner sheet, a liquid-impervious outer sheet
and a bodily fluid absorbent core sandwiched between the inner
and outer sheets and curved with the inner sheet inside and the
crotch region is additionally formed with a separator adapted
to separate urine and feces from each other.
[00091
The improvement according to the present invention is
characterized in aspects as follow. An innermost sheet member
bonded to the inner sheet to be interposed between a pants-type
diaper wearer's skin and the inner sheet is adapted to be
partially spaced upward from the inner sheet in the vertical
direction and thereby to form a body waste retaining space
wherein the innermost sheet member includes a front opening
allowing urine to flow into the body waste retaining space and
a rear opening allowing feces to move into the body waste
retaining space. A portion of the innermost sheet member
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extending between the front opening and the rear opening in the
front-back direction sags toward a lowermost portion of the
crotch region and is bonded to itself in segments thereof
opposed to each other in the front-back direction to form the
separator.
[0010]
The present invention has three aspects from first to
third as described below.
[0011]
In the first aspect of the present invention, the
innermost sheet member is bonded to the inner sheet and segments
of the innermost sheet member defining at least respective parts
of peripheral edges of the front opening and the rear opening
and opposed to each other in the front-back direction are bonded
together via a pair of spacers spaced from each other in the
transverse direction to define a space having a required
dimension.
[0012]
In a preferable embodiment of the first aspect, each of
the two spacers is formed of a flexible and elastic material.
[0013]
In another preferable embodiment of the first aspect,
each of the two spacers has a dimension in a range of 1 to 30mm
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in the front-back direction and is spaced from each other by
a distance in a range of 5 to 70mm in the transverse direction.
[0014]
In the second aspect of the present invention, the bodily
fluid-absorbent structure has side f laps f ormed outboard of the
core in the transverse direction and end flaps formed outboard
of the core in the vertical direction. A region of the innermost
sheet member extending between the front opening and the rear
opening is folded along a fold line extending in the transverse
direction and defined by a center line bisecting a dimension
of the diaper in the transverse direction with a skin-facing
surface of the innermost sheet member inside so that the region
extending between the front and rear opening and folded to face
itself and partially bonded together and the innermost sheet
member extends downward from this bonded region toward the inner
sheet in the vertical direction to form the separator. The
innermost sheet member further includes elastic regions adapted
to be elastically contractible and respectively defined between
the region facing itself in the front-back direction and
partially bonded together and a top of the front opening as
viewed in the vertical direction and between the region facing
itself in the front-back direction and partially bonded
together and a top of the rear opening as viewed in the vertical
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direction, on one hand, and a non-elastic region defined by a
portion extending downward from the bonded regions, on other
hand.
[0015]
In a preferable embodiment of the second aspect, the
elastic regions extend in the transverse direction in the crotch
region and joined under tension to the side flaps of the bodily
fluid-absorbent structure.
[0016]
In another preferable embodiment of the second aspect,
the innermost sheet member is pant-shaped.
[0017]
In another preferable embodiment of the second aspect,
the side flaps are provided with elastic members extending in
the front-back direction attached under tension thereto and the
elastic regions intersect and overlap the elastic members.
[0018]
In another preferable embodiment of the second aspect,
the elastic regions and the elastic members are bonded together
in regions of intersecting and overlapping.
[0019]
In the third aspect of the present invention, a portion
of the innermost sheet member extending in the front-back
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direction between the front opening and the rear opening is
folded to be opposed to each other in the front-back direction
and directly or indirectly bonded to itself along a center line
extending in the transverse direction and bisecting a dimension
of the diaper in the front-back direction so that the portion
droops down toward the crotch region and a lower end thereof
is joined to the inner sheet to form the separator. The
separator is provided along the center line with a sheet member
having a thickness in the front-back direction in a range of
1 to 10mm, a width in the transverse direction in a range of
10 to 70mm and a height in the vertical direction in a range
of 30 to 100% of a dimension of the separator in the vertical
direction and functioning to restrict a degree of deformation
potentially occurring in the separator formed of the innermost
sheet material.
[0020]
In a preferable embodiment of the third aspect, the sheet
member has a level of stiffness in a range of 40 to 130N based
on Procedure D of Stiffness Measuring Method specified by
Section 6 of JIS K 6400-2.
[0021]
In another preferable embodiment of the third aspect, the
sheet member is attached to the separator on a front surface
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of the separator, a rear surface of the separator or between
the opposed and joined portions of the innermost sheet member.
EFFECT OF THE INVENTION
[0022]
In the disposable pants-type diaper according to the
present invention, the innermost sheet member sags toward the
lowermost portion of the crotch region to form the separator
adapted to separate urine and feces from each other and thereby
to prevent urine and feces from being mixed with each other.
[0023]
In one aspect of the disposable pants-type diaper
according to the present invention, is bonded to itself via the
spacers along a segment of the peripheral edge of the front
opening and a segment of the peripheral edge of the rear opening
both for the body waste retaining space to form the space of
a required dimension. The portion of the innermost sheet member
extending in the front-back direction between these segments
of the respective openings' peripheral edges sags toward the
lowermost portion of the crotch region. The portion of the
innermost sheet member sagging in this manner serves as the
barrier functioning to prevent urine excreted on the front half
of the crotch region and feces excreted on the rear half of the
crotch region from being mixed with each other. With the
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pants-type diaper put on the wearer's body, the segments of the
respective openings' peripheral edges defining the space
therebetween are put in close contact with the wearer's crotch
skin and thereby serve as the barriers against urine flowing
rearward and loose passage flowing forward along the wearer's
skin. In consequence, the wearer's skin in the vicinity of anus
would not be soiled with urine and the wearer's skin in the
vicinity of external genital would not be soiled with feces.
[0024]
In one aspect of the disposable pants-type diaper
according to the present invention, the innermost sheet member
is formed with the front opening and the rear opening and, in
the crotch region, the portion of the innermost sheet member
extending between these two openings is folded downward and
partially joined together to form the separator. The separator
serves to prevent urine passing through the front opening and
feces passing through the rear opening from being mixed with
each other on the liquid-pervious inner sheet. The innermost
sheet member further includes elastic regions adapted to be
elastically contractible and respectively defined between the
region facing itself in the front-back direction and partially
bonded together and a top of the front opening as viewed in the
vertical direction and between the region facing itself in the
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front-back direction and partially bonded together and a top
of the rear opening as viewed in the vertical direction, on one
hand, and a non-elastic region defined by a portion extending
downward from the bonded regions, on the other hand. With such
unique arrangement, with the diaper put on the wearer's body,
the presence of the innermost sheet member would not contract
the crotch region in the transverse direction to disengage the
side edges of the crotch region from the wearer's inguinal
region. In this embodiment, the diaper wherein the innermost
sheet member is pant-shaped facilitates the front and rear
openings to be aligned with the wearer's external genital and
anus, respectively, when the diaper is put on the wearer's body.
In the embodiment of the present invention wherein the elastic
regions adapted to be contractible in the transverse direction
intersect with the elastic members provided along the side flaps
of the bodily fluid-absorbent structure, these elastic regions
cooperate with the elastic members to assure reliable fitness
of the diaper around the wearer's thighs. In the embodiment
of the present invention wherein the innermost sheet member and
the side flaps are bonded together in the regions of
intersecting and overlapping, the side flaps are smoothly
curved along the side edges of the core so that the side flaps
may be smoothly put in contact with the wearer's inguinal
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region.
[0025]
In one aspect of the disposable pants-type diaper
according to the present invention, the innermost sheet member
forming the separator adapted to separate urine and feces from
each other and thereby to prevent urine and feces from being
mixed with each other is provided with the sheet member having
a thickness in the front-back direction in a range of 1 to 10mm,
a width in the transverse direction in a range of 10 to 70mm
and a height in the vertical direction in a range of 30 to 100%
of a dimension of the separator in the vertical direction and
functioning to restrict the separator from being deformed.
With this arrangement, the separator can fulfill its primary
function without being readily crooked even if the diaper
wearer's posture changes in various ways. The separator
provided with this sheet member serves also to restrict the
bodily fluid-absorbent core from being crooked to be pressed
against the diaper wearer's skin. In this way, the separator
is able to prevent the internal volume of the body waste
retaining space from being unacceptably reduced due to such
crooking of the core.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026]
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[FIG. 1] Fig. 1 is a partially cutaway perspective view of
an exemplary embodiment of the pants-type diaper according to
the present invention.
[FIG. 2] Fig. 2 is a plan view showing the pants-type diaper
having front and rear waist regions thereof unsealed from each
other and flatly developed.
[FIG. 3] Fig. 3 is a sectional view taken along the line
III-III in Fig. 1.
[FIG. 4] Fig. 4 is an overhead view of the pants-type diaper
as viewed from above in a direction indicated by the arrows IV-IV
in Fig. 3.
[FIG. 51 Fig. 5 is a partially cutout perspective view of one
preferred embodiment of the pants-type diaper according to the
present invention.
[FIG. 61 Fig. 6 is a sectional view taken along the line VI-VI
in Fig. 5.
[FIG. 7] Fig. 7 is a partially cutaway perspective view of
an embodiment of the disposable pants-type diaper according to
the present invention.
[FIG. 81 Fig. 8 is a sectional view taken along the line
VIII-VIII in Fig. 7.
[FIG. 9] Fig. 9 is a partially cutaway plan view of the diaper
having been flatly developed.
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[FIG. 10] Fig. 10 is a view similar to Fig. 9, illustrating
one preferred embodiment of the present invention.
[FIG. 11] Fig. 11 is a partially cutaway perspective view of
an embodiment of the pants-type diaper according to the present
invention.
[FIG. 121 Fig. 12 is a plan view showing the pants-type diaper
having front and rear waist regions thereof unsealed from each
other and flatly developed.
[FIG. 13] Fig. 13 is a sectional view taken along the line
XIII-XIII in Fig. 11.
[FIG. 14] Fig. 14 is an overhead view of the pants-type diaper
as viewed from above in a direction indicated by the arrows
XIV-XIV in Fig. 13.
[FIG. 15] Fig. 15 is a partially cutout perspective view of
one preferred embodiment of the pants-type diaper according to
the present invention.
[FIG. 16] Fig. 16 is a sectional view taken along the line
XVI-XVI in Fig. 15.
[FIG. 17] Fig. 17 is a view similar to Fig. 16, showing another
preferred embodiment of the present invention.
IDENTIFICATION OF REFERENCE NUMERALS USED IN THE DRAWINGS
[0027]
1 pants-type diaper
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2 inner sheet
3 outer sheet
4 absorbent core
6 crotch region
6a lowermost portion of crotch region
7 front waist region
8 rear waist region
chassis
12 leg-openings
10 13 peripheries of leg-openings
innermost sheet member
20a separator
21 portion of innermost sheet member (front end)
22 portion of innermost sheet member (rear end)
15 31 body waste retaining space
33 front opening
33b peripheral edge
33c segment (lower segment)
34 rear opening
20 34b peripheral edge
34c segment (lower segment)
36 portion extending in front-back direction
45 liquid-absorbent structure
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50 void space
71 spacers
120 innermost sheet member
201 pants-type diaper
206 crotch region
207 front waist region
208 rear waist region
220 innermost sheet member
220a tuck (separator)
222 bodily fluid-absorbent structure
222a side flaps
223a end flaps
223 inner sheet
224 outer sheet
231 body waste retaining space
231a body waste retaining space
231b body waste retaining space
231t opening's top
232t opening's top
233 front opening
234 rear opening
237 joint (joint region)
271 elastic region
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272 elastic region
273 non-elastic region
301 pants-type diaper
302 inner sheet
303 outer sheet
304 absorbent core
306 crotch region
306a lowermost portion of crotch region
307 front waist region
308 rear waist region
310 chassis
312 leg-openings
320 innermost sheet member
320a separator
331 body waste retaining space
333 front opening
334 rear opening
335 lower end
345 liquid-absorbent structure
381 sheet member (deformation restricting sheet)
A front-back direction
B transverse direction
C vertical direction
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K dimension of separator in vertical direction
L height
M width
N thickness
Q-Q folding line (transverse center line)
P-P center line (longitudinal center line)
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028]
Details of one or more embodiments of the disposable
pants-type diaper according to the present invention will be
more fully understood from the description given hereunder with
reference to Figs. 1-6.
[0029]
Fig. 1 is a partially cutaway perspective view showing
the disposable pants-type diaper 1 as put on the wearer's body
wherein a front-back direction, a transverse direction and a
vertical direction of the diaper 1 are respectively indicated
by double-headed arrows A, B and C which are orthogonal one to
another. The pants-type diaper 1 includes a pant-shaped
chassis 10 comprising a liquid-pervious inner sheet 2, a
liquid-impervious outer sheet 3 and a bodily fluid-absorbent
core 4. The chassis 10 has a crotch region 6, a front waist region
7 extending forward from the crotch region 6 and a rear waist
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region 8 extending rearward from the crotch region 6. The front
and rear waist regions 7, 8 are put flat and sealed together
along respective pairs of side edges 7a, 7a and 8a, 8a of these
waist regions 7, 8, more specifically, at joints 9 arranged
intermittently in the vertical direction as viewed in Fig. 1
along these side edges 7a, 7a and 8a, 8a and thereupon a
waist-opening 11 and a pair of leg-openings 12 are formed.
Along a periphery lla of the waist-opening 11, a plurality of
waist elastic members 14a extending in a circumferential
direction is sandwiched between the inner and outer sheets 2,
3 and bonded under tension to at least one of the inner and outer
sheets 2, 3. Along a periphery of each of the leg-openings 12,
a plurality of leg elastic members 14b extending in the
circumferential direction is sandwiched between the inner and
outer sheets 2, 3 and bonded under tension to at least one of
these inner and outer sheets 2, 3. Three components, i . e . , the
leg elastic members 14b and the inner and outer sheets 2, 3
cooperate together to define respective annular elastic regions
41 surrounding the wearer's legs. Of the pants-type diaper 1,
at least the crotch region 6 includes a bodily fluid absorbent
structure 45 comprising the inner and outer sheets 2, 3 and the
absorbent core 4 sandwiched therebetween. The bodily fluid
absorbent structure 45 extends in the front-back direction A
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and curves convexly downward to define a bottom portion 6a of
the crotch region 6.
[0030]
Fig. 2 is a partially cutaway perspective view showing
the pants-type diaper la as after the front and rear waist
regions 7, 8 of the diaper 1 have been unsealed at the joints
9 and flatly developed as a whole in the front-back direction
A as well as in the transverse direction B wherein such developed
diaper la is shown as viewed from its inner side. In the state
of such developed diaper la, the chassis 10 in Fig. 1 appears
as a concave shaped flattened chassis 10a. The periphery lla
of the waist-opening 11 in Fig. 1 appears herein as a front end
7b and a rear end 8b of the flattened chassis 10a and the
peripheries 13 of the respective leg-openings 12 appear herein
as the crotch region's side edges 13b of the flattened chassis
10a. While the crotch region's side edges 13b convexly curve
toward a center line P-P extending in the front-back direction
A to bisect a dimension of the flattened chassis 10a in the
transverse direction X, the respective pairs of side edges 7a,
7a and 8a, 8a of the front and rear waist regions 7, 8 extend
generally in parallel to this center line P-P. The absorbent
core 4 also is concave shaped and is formed of a mixture 4a of
fluff pulp fibers and super-absorbent polymer particles wrapped
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with a bodily fluid-absorbent and highly dispersant wrapping
sheet 4b such as a tissue paper. In the flattened chassis 10a,
the innermost sheet member 20 made of hydrophobic sheet material,
more preferably, hydrophobic and liquid-impervious sheet
material is attached to inner sheet 2 defining the inner surface
of the flattened chassis 10a in the crotch region 6 so that the
innermost sheet member 20 may define a separator 20a (See Fig.
3). Such flatly developed diaper la is formed symmetrically
about the center line P-P extending in the front-back direction
A. The lowermost portion 6a of the crotch region 6 lies on a
transverse center line Q-Q bisecting a dimension of the flatly
developed diaper la in the front-back direction A.
[0031]
The innermost sheet member 20 is attached to the flattened
chassis 10a so that the innermost sheet member 20 may be
interposed between the inner sheet 2 and the diaper wearer's
skin (not shown) when the pants-type diaper 1 is put on the
wearer's body. The innermost sheet member 20 has side edges
23 respectively fixed to the crotch region's side edges 13b by
hot melt adhesive 24, a front end 21 lying before the lowermost
portion 6a of the crotch region 6 and extending in the transverse
direction B between the side edges 23, 23 and a rear end 22 lying
behind the lowermost portion 6a of the crotch region 6 and
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extending in the transverse direction B between the side edges
23, 23. The innermost sheet member 20 in the illustrated
embodiment is not bonded to the inner sheet 2 and adapted to
be spaced from the inner sheet 2 except the side edges 23 so
that a tunnel- or pocket-like body waste retaining space 31
extending from the front end 21 to the rear end 22 may be defined
between the innermost sheet member 20 and the inner sheet 2.
Along the front end 21 and the rear end 22, the innermost sheet
member 20 is folded back to form a sleeve 21a and a sleeve 22a,
respectively. These sleeves 21a, 22a contain therein a front
elastic member 21b and a rear elastic member 22a attached under
extension thereto, respectively, to define front elastic region
42 and a rear elastic region 43 both extending between the crotch
region's side edges 13b. These elastic regions 42, 43 intersect
with the elastic regions 41 of the flattened chassis 10a. A
distance Hf from the transverse center line Q-Q to the front
end 21 is generally equal to a distance Hr from the transverse
center line to the rear end 22.
[0032]
The innermost sheet member 20 is provided on the front
end 21 with a pair of spacers 71 located symmetrically about
the center line P-P extending in the front-back direction A and
spaced from each other by a dimension M. Each of the spacers
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71 may be provided in the form of a block made of a sponge, a
foamed polyurethane, a foamed polystyrene, a foamed
polyethylene, a felt or a nonwoven fabric each having a
flexibility sufficient to be easily deformed under a body weight
of the wearer of the pants-type diaper 1 and, more preferably,
having an elastic recovery properties also sufficient for a
rapid recovery after deformation. The innermost sheet member
20 is provided on the rear end 22 with a pair of regions 72
indicated by imaginary lines which are also located
symmetrically about the center line P-P extending in the
front-back direction A and spaced from each other by a dimension
M in the transverse direction B. The pair of spacers 71 are
bonded to the innermost sheet member 20 at the pair of regions
72 indicated by the imaginary lines as the side edges 7a, 7a
and 8a, 8a of the flattened chassis la are joined together to
obtain the pants-type diaper 1 (See Figs. 3 and 4).
[00331
Fig. 3 is a sectional view taken along the line III-III
in Fig. 1 and the line III-III corresponds to the center line
P-P extending in the front-back direction A in Fig. 2. In the
pant-shaped flattened chassis 10, the front and rear waist
regions 7, 8 are joined together along the respective side edges
7a, 7a and 8a, 8a thereof . The crotch region 6 curves in U-shape
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as viewed in the front-back direction A and the lowermost
portion 6a of the crotch region 6 defines a bottom of this
U-shaped curve. The crotch region's side edges 13b appear in
Fig. 3 as the peripheral edges 13 defining the leg-openings 12.
The innermost sheet member 20 has the front end 21 and the rear
end 22 thereof bonded to each other via the spacers 71 and the
portion 36 shown in Fig. 2 to extend in the front-back direction
A between the front end 21 and the rear end 22 sags toward the
lowermost portion 6a to form the separator 20a partitioning the
crotch region 6 into a front half and a rear half. Each of the
spacers 71 has a dimension N in the front-back direction A and
is attached to the innermost sheet member 20 by adhesion or
sealing. The presence of the spacers 71 allows the front end
21 and the rear end 22 to leave between them a space 50 (See
Fig. 4) having a dimension N along the center line P-P extending
in the front-back direction A. The regions in which the spacers
71 are joined to the rear end 22 are designated by a reference
numeral 72. The separator 20a may be formed so that the portion
36 of the innermost sheet member 20 is put close to, or in contact
with or joined to the lowermost portion 6a or the inner sheet
2 in the vicinity of the portion 6a. Fig. 3 exemplarily shows
one of these three manners of implementation in which the
portion 36 of the innermost sheet member 20 is joined to the
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lowermost portion 6a or the inner sheet 2 in the vicinity of
the portion 6a. In the body waste retaining space 31 formed
by cooperation of the innermost sheet member 20 with the inner
sheet 2, the front end 21 is spaced from the inner sheet 2 to
define a front opening 33 and the rear end 22 is spaced from
the inner sheet 2 to define a rear opening 34.
[00341
Fig. 4 is an overhead view of the pants-type diaper 1 of
Fig. 1 as viewed from above the waist-opening 11 in a direction
indicated by the arrows IV-IV in Fig. 3. As viewed in the
transverse direction B of the pants-type diaper 1, the front
end 21 and the rear end 22 of the innermost sheet member 20
respectively have central segments 21c, 22c defined between a
pair of the spacers 71, right-hand segments 21R, 22R adapted
to be put in contact with a right leg of the diaper wearer (not
shown) and left-hand segments 21L, 22L adapted to be put in
contact with a left leg of the diaper wearer. The central
segments 21c, 22c extend in parallel to each other in the
transverse direction B to form a space having a dimension N in
the front-back direction A and a dimension M in the transverse
direction B. These central segments 21c, 22c are adapted to
come in contact with the diaper wearer's skin between his or
her external genital and anus as the pants-type diaper 1 is put
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on the wearer's body. The right-hand segments 21R, 22R
cooperate with each other to define a laterally facing V-shaped
space so that the wearer' s right leg may be guided through this
laterally facing V-shaped space. In a similar manner, the
left-hand segments 21L, 22L cooperate with each other to define
a laterally facing V-shaped space so that the wearer's left leg
may be guided through this laterally facing V-shaped space. As
illustrated, the respective leg-openings 12 of the chassis 10
have a right leg peripheral edge 13R and a left leg peripheral
edge 13L. The respective peripheral edges 13R, 13L comprise
upper segments 15a not overlapping the side edges 23 of the
innermost sheet member 20 and lower segments 15b overlapping
the side edges 23 and bonded thereto (See Fig. 3 also) . In Fig.
4, respective ranges of these upper segments 15a and lower
segments 15b are indicated by double-headed arrows G and H.
[0035]
Sequence in which the pants-type diaper 1 may be put on
the wearer's body will be described below together with behavior
of the pants-type diaper. First, the front and rear waist
regions 7, 8 of the chassis 10 may be spaced from each other
in the front-back direction A and then the waist-opening 11 may
be sufficiently broadened as seen in Figs. 1 and 4. Thereby
the front end 21 of the separator 20a formed of the innermost
CA 02719287 2010-09-22
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sheet member 20 is deformed so that the right-hand segment 21R
and the left-hand segment 21L are curved in V-shape facing
forward in the front-back direction A around a pair of the
spacers. In a similar manner, the rear end 22 is deformed so
that the right-hand segment 22R and the left-hand segment 22L
are curved in V-shape facing rearward in the front-back
direction A (See Fig. 4) . Consequently, the front opening 33
and the rear opening 34 for the body waste retaining space 31
are automatically broadened (See Fig. 3) . The left-hand
segments 21L, 22L are spaced from each other in the front-back
direction A at the same moment that the right-hand segments 21R,
22R are spaced from each other in the front-back direction A.
The respective central segments 21c, 22c of the front end 21
and the rear end 22 cooperate together to define the space 50.
Now the diaper wearer (not shown) may guide his or her right
leg into an opening 41R for the right leg defined by the upper
segment 15a of the right leg peripheral edge 13R, the right-hand
segment 21R of the front end 21 and the right-hand segment 22R
of the rear end 22. Then the wearer may guide his or her right
leg into the leg-opening 12 for the right leg defined by the
upper segment 15a and the lower segment 15b of the right leg
peripheral edge 13R. Without interruption, the wearer may
guide his or her left leg into an opening 41L for the left leg
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defined by the upper segment 15a of the left leg peripheral edge
13L, the left-hand segment 21L of the front end 21 and the
left-hand segment 22L of the rear end 22. Then the wearer may
guide his or her right leg into the leg-opening 12 for the left
leg defined by the upper segment 15a and the lower segment 15b
of the left leg peripheral edge 13L-
[003 61
In the pants-type diaper 1 after it has been put on the
wearer's body, the peripheral edges 13 of the respective
leg-openings 12, i.e., the right leg peripheral edge 13R and
the left leg peripheral edge 13L are elastically contractible
in a circumferential direction thereof, on one hand, and the
front end 21 and the rear end 22 of the separator 20a are
elastically contractible in the transverse direction B, on the
other hand. With such arrangement, the upper segment 15a of
the peripheral edge 13R for the right leg and the right-hand
segments 21R, 22R of the separator 20a are elastically put in
close contact around the right leg in the vicinity of the right
leg's inguinal region to form a primary seal 51R (See Fig. 4)
serving to prevent leak of bodily fluids . Below the primary seal
51R, the lower segment 15b and the upper segment 15a of the
peripheral edge 13R for the right leg are integrated to form
a secondary seal 52R (See Fig. 4) serving to prevent leakage
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of bodily fluids. Function of this secondary seal 52R is
similar to that of the leg seal in the conventional pants-type
diaper. The arrangement and function as have been described
just above are also true with respect to the left leg.
Specifically, the upper segment 15a of the peripheral edge 13L
for the left leg and the left-hand segments 21L, 22L of the
separator 20a are elastically put in close contact around the
left leg in the vicinity of the left leg's inguinal region to
form a primary seal 51L serving to prevent leakage of bodily
fluids. Below the primary seal 51L, the lower segment 15b and
the upper segment 15a of the peripheral edge 13L for the left
leg are integrated to form a secondary seal 52L serving to
prevent leak of bodily fluids. The pants-type diaper 1 having
been put on the wearer' s body may be sufficiently pulled up along
the body to assure that the central segments 21c, 22c in the
separator 20a come in contact with the wearer's skin between
the wearer's external genital and anus.
[00371
With the pants-type diaper 1 put on the wearer's body in
the state as has been described above, the portion 36 of the
separator20ais positioned to divide the wearer's crotch region
into a front half and a rear half. In the front half of the
wearer's crotch region, the wearer's external genital lying
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before the front end 21 is exposed in the front opening 33 and,
in the rear half of the wearer's crotch region, the wearer's
anus lying behind the rear end 22 is exposed in the rear opening
34. Consequentially, it is assure that urine discharged by the
wearer flows through the front opening 33 into the pocket-like
body waste retaining space 31 and feces excreted by the wearer
moves through the rear opening 34 into the body waste retaining
space 31. In this way, it is possible for the pants-type diaper
1 to prevent urine and/or feces from coming in contact with the
wearer's skin by the presence of the separator 20a. In addition,
the central segments 21c, 22c of the separator 20a is kept spaced
from each other in the font-back direction A to define dual
barriers adapted to prevent urine from flowing along the
wearer's skin toward the anus and simultaneously to define dual
barriers adapted to prevent loose passage from flowing along
the wearer's skin toward the wearer's external genital as long
as these central segments 21c, 22c are kept in contact with the
wearer's skin. Furthermore, even if these central segments 2 1c,
22c are not kept in contact with the wearer's skin, these central
segments 21c, 22c are adapted to prevent loose passage flowing
back from the body waste retaining space through the rear
opening 34 to the wearer's external genital, for example, when
the wearer sits flat on the floor unless the loose passage flows
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beyond the space 50. In other words, with the pants-type diaper
1 the wearer's skin in the vicinity of the anus would not be
stained with urine and wearer's skin in the vicinity of the
external genital would not be soiled with loose passage. Urine
and feces once retained in the body waste retaining space 31
can no more flow on the inner sheet 2 in the front-back direction
A and be mixed with each other since the separator 20a is kept
close to or in contact with or bonded to the inner sheet 2 at
the lowermost portion 6a of the crotch region 6. Therefore
fluidity of feces would not increase due to mixture with urine
and the wearer' s skin would not be readily soiled with such loose
passage. In addition, for the wearer's legs, the primary seals
51R, 51L and the secondary seals 52R, 52L are formed to prevent
urine and/or feces from readily leaking out of the pants-type
diaper 1 even if urine and/or feces do not flow into the body
waste retaining space 31 but flowing along the wearer's legs.
[0038]
In the pants-type diaper 1, the front end 21 of the
innermost sheet member 20 defining the separator 20a partially
defines the peripheral edge of the front opening 33. As viewed
in the front-back direction A, the front end 21 lies behind the
wearer's external genital and positioned so that the external
genital can be reliably exposed in the front opening 33. While
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the front end 21 is exemplarily illustrated to extend linearly
in the transverse direction B, it is also possible to form the
front end 21 to curve convexly toward the transverse center line
Q-Q. The rear end 22 of the innermost sheet member 20 partially
defines the peripheral edge of the rear opening 34. As viewed
in the front-back direction A, the rear end 22 lies before the
wearer's anus and positioned so that the anus can reliably face
the rear opening 34. While such rear end 22 is exemplarily
illustrated to extend linearly in the transverse direction B,
it is possible to form the rear end 22 to curve convexly toward
the transverse center line Q-Q.
(0039]
For the present invention, the shape of the spacers 71
defining the space 50 is not specified in particular. While
the dimension N of the spacer 71 is not specified but depends
on whether the pants-type diaper 1 is for baby or for adult,
for comprehensive application, the dimension N is preferably
in a range of 1 to 30mm and more preferably in a range of 1 to
5mm. The dimension N exceeding 30mm will progressively make it
difficult to expose the wearer's external genital in the front
opening 33 and to expose the wearer's anus in the rear opening
34. A distance dimension M between a pair of the spacers 71
is preferably in a range of 5 to 70mm and more preferably in
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a range of 25 to 30mm. The distance dimension M smaller than
5mm may sometimes make it difficult for body waste to pass
through the space 50 and the distance dimension M exceeding 70mm
may sometimes unacceptably broaden the width of the crotch
region 6.
[0040]
In the crotch region 6 of the flattened chassis 10a shown
by Fig. 2, the inner and outer sheets 2, 3 put flat together
define side flaps 25 outboard of the liquid-absorbent core 4.
When the crotch region 6 is curved in U-shape under contraction
of the elastic regions 41 and thereupon the pants-type diaper
1 is put into the state as illustrated by Fig. 1, the side flaps
25 behave to raise themselves along side edges 4c of the core
4 in the vicinity of the transverse center line Q-Q, i.e., in
the vicinity of the lowermost portion 6a of the crotch region
6. The innermost sheet member 20 having the side edges 23 bonded
to the inner surface of the elastic regions 41 pulls the side
flaps 25 inward in the transverse direction of the pants-type
diaper 1, i.e., toward the center line P-P extending in the
front-back direction as the waist-opening 11 is broadened. In
consequence, the behavior of the side flaps 25 to raise
themselves is further enhanced. Such behavior of the side flaps
becomes further significant as the front end 21 and the rear
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end 22 elastically contract. The side flaps 25 having such
behavior come in close contact with the wearer's thighs from
below with respect to the pants-type diaper 1 and thereby
effectively prevent bodily fluids from leaking out along the
wearer's thighs.
[0041]
To implement the present invention, liquid-pervious
sheet material such as nonwoven fabric or perforated plastic
film may be used as the inner sheet 2. Liquid-impervious sheet
material such as plastic film or composite sheet consisting of
plastic film and nonwoven fabric may be used as the outer sheet
3. Fluff pulp fibers or a mixture of fluff pulp fibers and
super-absorbent polymer particles wrapped with an appropriate
sheet material such as a tissue paper may be used as the
liquid-absorbent core 4. A hydrophobic sheet material such as
a nonwoven fabric or plastic film, more preferably, a
hydrophobic and liquid-impervious sheet material may be used
as the innermost sheet member 20. While the innermost sheet
member 20 are preferably provided along the front end 21 and
the rear end 22 with the elastic members 21b, 22b attached under
tension thereto so that the innermost sheet member 20 may be
elastically contracted, it is possible to eliminate use of the
elastic members 21b, 22b by using an elastic sheet material
CA 02719287 2010-09-22
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adapted to be elastically contracted in the transverse
direction B as the innermost sheet member 20. It should be
appreciated that the present invention includes an embodiment
according to which both the front end 21 and the rear end 22
are not elastically contractible in the transverse direction
B.
[0042]
Fig. 5 is a partially cutaway perspective view of one
preferred embodiment of the pants-type diaper 1 according to
the present invention. Regions and members of this embodiment
similar to those in the pants-type diaper 1 of Fig. 1 are
designated with similar reference numerals. Specifically, the
pants-type diaper 1 of Fig. 5 also has the crotch region 6, the
front waist region 7 and the rear waist region 8 wherein the
side edges 7a, 7a and 8a, 8a of the front and rear waist regions
7, 8 are put flat and sealed together at the joints 9 arranged
intermittently in the vertical direction to form the
waist-opening 11 and a pair of the leg-openings 12. The
pants-type diaper 1 according to this embodiment also includes
the innermost sheet member 120 facing the wearer' skin (not
shown) and a bodily fluid absorbent member 122 attached to the
outer surface 120b of the innermost sheet member 120 wherein
these innermost sheet member 120 and the bodily fluid absorbent
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member 122 are integrated with each other to form the
pant-shaped chassis 10. The innermost sheet member 120 is
preferably hydrophobic, more preferably hydrophobic and
liquid-impervious. Elasticized sheet pieces 52 are bonded
under tension to the inner surface of the innermost sheet member
120 in the front waist region 7 and the rear waist region 8,
respectively, so that the innermost sheet member 120 may be
elastically contracted in the circumferential direction. The
innermost sheet member 120 is formed in the crotch region 6 with
the front opening 33 and the rear opening 34. The front opening
33 has the peripheral edge 33b and is positioned in front of
the transverse center line Q-Q so that the wearer's external
genital can be exposed in this front opening 33. The rear
opening 34 has the peripheral edge 34b and is positioned behind
the transverse center line Q-Q so that the wearer's anus can
be exposed in this rear opening 34. Referring to Fig. 5, a pair
of spacers 71 are attached to the peripheral edge 34b by which
the innermost sheet member 120 is joined to itself along a lower
segment 33c of the peripheral edge 33b and a lower segment 34c
of the peripheral edge 34b (See Fig. 6 also).
[0043]
The bodily fluid absorbent member 122 has the bodily fluid
absorbent structure 45 comprising the liquid-pervious inner
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sheet 2, the liquid-impervious outer sheet 3 and the bodily
fluid absorbent core 4 sandwiched between the inner and outer
sheets 2, 3. These inner and outer sheets 2, 3 extend outward
beyond the periphery of the core 4 and put flat and bonded
together outside the periphery of the core 4 wherein at least
one of these inner and outer sheets 2, 3 is bonded to the
innermost sheet member 120 so that the front opening 33 and the
rear opening 34 may be covered with said one of the inner and
outer sheets 2, 3 from outside of the innermost sheet member
120. Along the side edges 13 of the crotch region 6, the inner
sheet 2, the outer sheet 3 and the innermost sheet member 120
are placed one on another and bonded together. Also along the
side edges 13, the leg elastic members 14b sandwiched between
the inner sheet 2 and the outer sheet 3 is bonded under tension
to at least one of these two sheets 2, 3. Between the side edges
13, the inner sheet 2 and the innermost sheet member 120 are
not bonded to each other so that the innermost sheet member 120
may be spaced from the inner sheet 2 in the thickness direction
of the core 4 to form the body waste retaining space 31 into
which urine flows through the front opening 3 and feces moves
through the rear opening 34.
[0044]
Fig. 6 is a sectional view taken along the line VI-VI in
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Fig. 1 wherein the line VI-VI corresponds to the center line
P-P extending in the front-back direction. The innermost sheet
member 120 is bonded to itself along the lower segment 33c of
the peripheral edge 33b defining the front opening 33 and the
lower segment 34c of the peripheral edge 34b defining the rear
opening 34 to form the space 50 having the dimension N in the
front-back direction A between these two segments 33c, 34c. The
space 50 has the dimension M in the transverse direction B (See
Fig. 5) . The portion 36 of the innermost sheet member 120
defined in the front-back direction A between the lower segments
33c, 34c sags toward the lowermost portion 6a of the crotch
region 6. The portion 36 of the innermost sheet member 120 may
be put close to, or in contact with or joined to the lowermost
portion 6a or the inner sheet 2 in the vicinity of the portion
6a. Fig. 6 exemplarily shows one of these three manners of
implementation in which the portion 36 of the innermost sheet
member 120 is joined to the lowermost portion 6a or the inner
sheet 2 in the vicinity of the portion 6a.
[0045]
With the pants-type diaper 1 implemented as illustrated
by Fig. 5 put on the wearer's body, the lower segments 33c, 34c
function as dual barriers one of which prevents urine from
flowing rearward along the wearer's skin in crotch region and
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the other of which prevents loose passage from flowing forward
along the wearer' s skin in the crotch region so long as the lower
segments 33c, 34c are kept in contact with the wearer's skin
in the crotch region. In this way, also with the pants-type
diaper 1 of Fig. 5, the wearer's skin in the vicinity of the
anus would not be soiled with urine and the wearer's skin in
the vicinity of the external genital would not be soiled with
loose passage. The innermost sheet member 120 sags toward the
lowermost portion 6a of the crotch region 6 and thereby divides
the body waste retaining space 31 into front and rear halves
to define the separator 20a adapted to prevent urine and feces
from being mixed together on the inner sheet 2. The lower
segments 33c, 34c in the pants-type diaper 1 of Fig. 5 provide
the function equivalent to that of the front edge 21 and the
rear edge 21 of the innermost sheet member 20 in the pants-type
diaper 1 of Fig. 1.
[0046]
Details of one or more embodiments of the disposable
pants-type diaper according to the present invention will be
more fully understood from the description given hereunder with
reference to Figs. 7-10.
[0047]
Fig. 7 is a partially cutaway perspective view of the
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disposable pants-type diaper 201 put on the wearer's body
wherein a front-back direction, a transverse direction and a
vertical direction are indicated by double-headed arrows A, B
and C extending orthogonally one to another. The diaper 201
has a crotch region 206, a front waist region 207 extending
forward from the crotch region 206 and a rear waist region 208
extending rearward from the crotch region 206 wherein
respective side edges of the front and rear waist regions 207,
208 are put flat and sealed together at joints 209 arranged
intermittently in the vertical direction C to form a
waist-opening 211 and a pair of leg-openings 212. In addition,
the diaper 201 includes the innermost sheet member 220 facing
the diaper's skin (not shown) and a bodily fluid-absorbent
structure 222 attached to the outer surface 221b of the
innermost sheet member 220. Of the innermost sheet member 220,
the respective portions defining the front and rear waist
regions 207, 208 are elastically contractible in the transverse
direction B and most of the portion defining the crotch region
206 is not contractible in the transverse direction B
elastically as well as non-elastically. While the innermost
sheet member 220 is preferably liquid-impervious over all and
more preferably air-permeable and liquid-impervious over all,
it is possible to form the innermost sheet member 220 in such
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a manner that the portions defining the front and rear waist
regions 207, 208, respectively, are liquid-impervious and the
portion defining the crotch region 206 is liquid-pervious.
[0048]
Referring to Fig. 7, the bodily f luid-absorbent structure
222 comprises a liquid-pervious inner sheet 223, a
liquid-impervious outer sheet 224 and a core 226 sandwiched
between these two sheets 223, 224 wherein the core 226 comprises,
in turn, a bodily fluid-absorbent material such as fluff pulp
fibers wrapped with a tissue paper. These two sheets 223, 224
extend outward from a periphery of the core 226 are bonded to
each other outboard of the periphery to form a pair of side flaps
222a and a pair of end flaps 222b. These side flaps 222a and
end flaps 222b are bonded to the innermost sheet member 220 (See
Figs. 8 and 9) . In the crotch region 206, for example, the side
flaps 222b and the innermost sheet member 220 are put flat
together to define side edges 227. Along these side edges 227,
leg elastic members 228 are sandwiched between the inner and
outer sheets 223, 224 and bonded under tension to at least one
of these sheets 223, 224 to define respective parts of leg
elastic regions. In a region extending in the transverse
direction B between the side edges 227, 227, the inner sheet
223 and the innermost sheet member 220 are spaced from each other
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in the vertical direction C to form a body waste retaining space
231. The end flaps 222b of the bodily fluid-absorbent structure
222 are bonded to the outer surface 221b of the innermost sheet
member 220 and therefore no more function as the flaps.
[0049]
The innermost sheet member 220 used in such manner is
formed before the transverse center line Q-Q extending in the
transverse direction B to bisect a dimension of the diaper 201
in the front-back direction A with a front opening 233 and behind
the transverse center line B with a rear opening 234. The front
opening 233 is positioned so that the wearer's external genital
can be exposed therein and the rear opening 234 is positioned
so that the wearer's anus can be exposed therein. In this way,
urine and feces excreted by the wearer directly flow or move
into the body waste retaining space 231 not through the
innermost sheet member 220. Urine and feces having flown or
moved in into the body waste retaining space 2.1 is retained
within the space defined between the innermost sheet member 220
and the inner sheet 223 spaced from each other and thereby
prevented from coming in contact with the wearer's skin. In
addition, the inner sheet 223 having absorbed such urine or
feces and being in wet condition is covered with the innermost
sheet member 220. The innermost sheet member 220 thus protects
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the wearer from uncomfortable feeling which would otherwise be
experienced by the wearer due to contact with the wet inner sheet
223.
[00501
Fig. 8 is a sectional view taken along the line VIII-VIII
in Fig. 7 wherein the line VIII-VIII corresponds to the central
line P-P extending in the front-back direction A to bisect a
dimension of the diaper 201 in the transverse direction B. The
portions of the innermost sheet member 220 in the front and rear
waist regions 207, 208, respectively, are bonded to each other
in parallel to the vertical center line R-R extending in the
vertical direction C and bisecting the dimension of the diaper
201 in the front-back direction A to define upper segments of
peripheral edges surrounding the respective leg-openings 212.
In the crotch region 206, the innermost sheet member 220 is
formed with a tuck 220a. The tuck 220a is formed by bonding
or sealing regions of the innermost sheet member 220 facing each
other along the vertical center line R-R at a joint 237. More
specifically, the innermost sheet member 220 is folded along
the vertical center line R-R in its region between the front
opening 233 and the rear opening 234 with the skin-facing inner
surface of the innermost sheet member 220 inside. In other
words, the tuck 220a extends downward from the portion of the
CA 02719287 2010-09-22
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innermost sheet member 220 spaced from the inner sheet 223
toward the inner sheet 223 to lie on the transverse center line
Q-Q (See Fig. 7) . While the joint 237 for the tuck 220a is
illustrated to be formed at least along the uppermost segment
238 of the tuck 220a as viewed in the vertical direction C, the
joint 236 may be enlarged by an appropriate dimension toward
a lower end 239 of the tuck 220a. While a dimension of the joint
237 in the transverse direction B is principally smaller than
a width dimension of the crotch region 206, the dimension of
the joint 237 may be enlarged unless the joint 237 prevents the
diaper 201 from being smoothly put on the wearer's body. For
example, in the case of the diaper 201 exclusively for baby,
the dimension of the joint 237 in the transverse direction B
is preferably in a range of 10 to 70mm. The lower end 239 of
the tuck 220a may be coated on its outer surface with joining
means such as adhesive and joined to the inner sheet 223. In
this case, the lower end 239 may be joined only along a middle
portion thereof in the transverse direction B or over all to
the inner sheet 223 (See Fig. 10).
[0051]
Between the innermost sheet member 220 and the inner sheet
223, the body waste retaining space 231 divided into a front
half and a rear half by the tuck 220a. Specifically, the body
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waste retaining space 231 is divided into a front body waste
retaining sub-space 231a defined before the transverse center
line Q-Q and a rear body waste retaining sub-space 231b defined
behind the transverse center line Q-Q. Between these two
sub-spaces 231a, 231b, the tuck 220a extends upward from the
inner sheet 223. The front opening 233 of the innermost sheet
member 220 communicates with the inside and the outside of the
front body waste retaining sub-space 231a and lets urine flow
thereinto. The rear opening 234 communicates with the inside
and the outside of the rear body waste retaining sub-space 231b
and legs feces move thereinto.
[0052]
Fig. 9 is a partially cutaway plan view showing the diaper
201a corresponding to the diaper 201 of Figs. 7 and 8 after the
front and rear waist regions 207, 208 have been unjoined from
each other at the joints 209, the respective halves of the
innermost sheet member 220 have been unjoined from each other
at the joint 237 for the tuck 220a and then the crotch region
206 and the front and rear waist regions 207, 208 have been
developed in the front-back direction A as well as in the
transverse direction B. It should be noted here that the
regions in the flatly developed diaper 201a which are common
to those in the diaper 201 are designated by same reference
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numerals as those used for the diaper 201.
[0053]
The innermost sheet member 220 is contoured by a pair of
side edges 221a, a front end 221b and a rear end 221c in a concave
shape curved inwardly and comprises a first sheet 251 defining
at least a central portion of the crotch region 206 as viewed
in the front-back direction A, a second sheet 252 defining at
least the front waist region 207 and a third sheet 253 defining
at least the rear waist region 208 arranged in the front-back
direction A. The first sheet 251 is not elastically
contractible and faces the inner sheet 223 according to the
embodiment of Fig. 9 and the same as the innermost sheet member
220 in shape and dimension. In other words, side edges, front
end and rear end of the first sheet 251 correspond to the side
edges 221a, the front end 221b and the rear end 221c of the
innermost sheet member 220. The second sheet 252 is elastically
contractible in the transverse direction B and bonded under
tension in the transverse direction B to the inner surface of
the first sheet 251 by hot melt adhesive 256 according to the
embodiment of Fig. 9. The second sheet 252 is contoured by a
pair of side edges 252a, a front end 252b and a rear end 252c
wherein the side edges 252a and the front ends 252b
substantially correspond to the side edges 251a and the front
CA 02719287 2010-09-22
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end 251b, respectively. The rear end 252c of the second sheet
252 lies in the crotch region 206 and extends across the front
opening 233. The third sheet 253 also is elastically
contractible in the transverse direction B and, according to
the embodiment of Fig. 9, bonded under tension in the transverse
direction B to the inner surface of the first sheet 251 by hot
melt adhesive 256. The third sheet 253 is contoured by a pair
of side edges 253a, a front end 253b and a rear end 253c wherein
the side edges 253a and the rear end 253c substantially
correspond to the side edges 251a and the rear end 251c of the
first sheet 251. The front end 253b of the third sheet 253 lies
in the crotch region 206 and extends across the rear opening
234. In this way, the innermost sheet member 220 is formed with
front and rear elastic regions 271, 272 both adapted to be
elastically contractible in the transverse direction B under
the effect of the second sheet 252 and the third sheet 253,
respectively. Between the rear end 252c of the second sheet
252 and the front end 253b of the third sheet 253 as viewed in
the front-back direction A of the innermost sheet member 220,
a non-elastic region 273 which is not elastically contractible
in the transverse direction B is formed. A pair of regions 257
each comprising a plurality of dots gathered together on the
inner surface of the first sheet 251 corresponds to the joints
CA 02719287 2010-09-22
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237 in Fig. 8 located symmetrically about the transverse center
line Q-Q.
[0054]
In the bodily fluid-absorbent structure 222, the inner
sheet 223 and the outer sheet 224 sandwiching therebetween the
core 226 extend outward from the periphery of the core 226 and
bonded to each other outboard of the periphery of the core 226
by hot melt adhesive 258 to form the side flaps 222a and the
end flaps 222b. Along the crotch region's side edges 227 in
the flatly developed diaper 201a, the leg elastic members 228
are sandwiched between the inner sheet 223 and the outer sheet
224 and extend under tension in the front-back direction A.
Portions of the inner sheet 223 are bonded to the outer surface
221b of the innermost sheet member 220 by hot melt adhesive 259.
The outer sheet 224 is preferably the same as the inner sheet
223 in shape as well as in size or dimensioned to slightly larger
than the inner sheet 223. When the outer sheet 224 is
dimensioned to be slightly larger than the inner sheet 223, a
portion of the outer sheet 224 extending outward from the
periphery of the inner sheet 223 is more preferably bonded to
the outer surface 221b of the innermost sheet member 220.
[0055]
To obtain the diaper 201 from the flatly developed diaper
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201a of Fig. 9, the flatly developed diaper 201a is folded along
the transverse center line Q-Q with the innermost sheet member
220 inside, then respective halves of the first sheet 251 are
joined to each other by joining the two regions 257 to each other
and simultaneously the side edges 207a, 207a of the front waist
region 207 defined by the innermost sheet member 220 are joined
to the side edges 208a, 208a of the rear waist region 208 defined
also by the innermost sheet member 220 at the joints 209 (See
Fig. 7) .
[0056]
With the diaper 201 obtained in this manner being put on
the wearer's body, the innermost sheet member 220 in the crotch
region 206 is spaced upward from the portion of the inner sheet
223 surrounded by the side flaps 222a and the end flaps 222b
of the bodily fluid-absorbent structure 222 and thereby forms
the body waste retaining space 231 adapted to prevent urine and
feces from coming in contact with the wearer's skin. At the
same time, the innermost sheet member 220 in the crotch region
206 functions as a barrier adapted to prevent the inner sheet
223 soiled and/or wetted with feces and/or urine from coming
in contact with the wearer's skin. Furthermore, the portion
of the innermost sheet member 220 defining the tuck 220a
cooperates with the portions of the innermost sheet member 220
CA 02719287 2010-09-22
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extending outward from both sides of the tuck 220a in the
transverse direction B to form a partition serving as a
separator adapted to prevent urine and feces from being mixed
with each other. Asa consequence, in this diaper 201, fluidity
of body waste would not be enhanced due to intermixture of feces
and urine and the wearer's skin would not be soiled with body
waste over a wide range. Furthermore, a length dimension of
the innermost sheet member 220 extending along the center line
P-P extending in the front-back direction A as viewed in Fig.
9 is shortened by the dimension used to form the tuck 220a as
seen in Figs. 7 and 8 and therefore the innermost sheet member
220 would not be formed with remarkable gathers. The second
and third sheets 252, 253 of the innermost sheet member 220
formed with the front elastic region 271 and the rear elastic
region 272, respectively, are present in the front and rear
waist regions 207, 208, respectively, and thereby assure high
fitness of these two waist regions 207, 208 to the wearer's skin.
Portions of the second and third sheets 252, 253 forming parts
of the crotch region 206 form at least parts of the respective
peripheries 276, 277 of the front and rear openings 233, 234
of the first sheet 251 serve to assure elastic fitness of these
peripheries to the wearer's skin around the wearer's external
genital and anus and reliable flow or movement of urine or feces
CA 02719287 2010-09-22
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into the body waste retaining space 231.
[0057]
As will be apparent from the plan view of the flatly
developed diaper 201a, the leg elastic members 228 extending
along the side edges of the bodily fluid-absorbent structure
222 in the front-back direction A respectively intersect with
the front elastic region 271 and the rear elastic region 272
provided in the innermost sheet member 220 to be contractible
in the transverse direction B. In addition, as will be apparent
from Fig. 7, both the front elastic region 271 and the rear
elastic region 272 are substantially continuous in the
circumferential direction between the respective side edges
207a, 207a and 208a, 208a of the front and rear waist regions
207, 208 joined together at the joints 209. Consequently, the
front and rear elastic regions 271, 272 in the vicinity of the
respective side edges 207a, 207a and 208a, 208a cooperate with
the elastic members 228, 228 intersecting with the front and
rear elastic regions 271, 272 to define elastic regions adapted
to surround the wearer's legs.
[0058]
It should be noticed here that the innermost sheet member
220 is non-elastic in a bottom 275 of the crotch region 206 and
therefore the width of this bottom 275, i.e., the dimension of
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the bottom 275 in the transverse direction B is never reduced
due to the innermost sheet member 220. With the diaper 201
having such crotch region 206 put on the wearer's body, the side
edges 227 of the crotch region 206 kept in tight contact with
the wearer's inguinal region is not subject to a force in the
transverse direction B functioning to move these side edges 227
of the crotch region 206 inward from the inguinal region.
Consequently, the preventive effect of the diaper 201 against
sideways leakage of bodily fluids is further improved.
[0059]
Fig. 10 is a view similar to Fig. 9, illustrating one
preferred embodiment of the present invention. In the flatly
developed diaper 201a shown by Fig. 10, the rear end 252c of
the second sheet 252 adapted to be contractible in the
transverse direction B lies between front opening 233 and one
of the paired regions 257 and the front end 253b of the third
sheet 253 lies between the rear opening 234 and the other of
the paired regions 257. With the diaper 201 obtained from such
flatly developed diaper 201a put on the wearer's body, the
respective portions of the front elastic region 271 and the rear
elastic region 272 defining the front and rear waist regions
207, 208 are stretched in the waist-surrounding direction and
the respective portions partially defining the crotch region
CA 02719287 2010-09-22
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206 are stretched circumferentially of the respective legs.
The respective peripheral edges 276, 277 of the front opening
233 and the rear opening 234 lie over all in the front elastic
region 271 and the rear elastic region 272 and, with the diaper
201 put on the wearer's body, these peripheral edges 276, 277
closely fit over all to the wearer's skin. In the flatly
developed diaper 201a, the non-elastic region 273 is defined
between the paired regions 257 of the innermost sheet member
220. With the diaper 201 put on the wearer's body, the bottom
275 of the crotch region 206 having the side edges 227, 227
tightly retained by the wearer's inguinal region would not
contract in the transverse direction B and the side edges 227,
227 would not be disengaged from the inguinal region.
[0060]
As will be apparent from Figs. 9 and 10, in the second
and third sheets 252, 253, the rear end 252c extends in the
transverse direction B between the front opening 233 and one
of the paired joints 237 (See Fig. 8), i.e., one of the paired
regions 257 or across the front opening 233 and the front end
253b extends in the transverse direction B between the rear
opening 234 and the other of the paired joints 237 or across
the rear opening 234. In other words, the rear end 252c extends
in the transverse direction B between a top 231t of the front
CA 02719287 2010-09-22
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opening 233 as viewed in the vertical direction C and one of
the paired joints 237 and the front end 253b extends in the
transverse direction B between a top 232t of the rear opening
234 and the other of the paired joints 237.
[0061]
In the flatly developed diaper 201a of Fig. 10, in order
to enhance contractile force of the second sheet 252 and the
third sheet 253 along the peripheral edge of the waist-opening
211 when the diaper 201 is put on the wearer's body, a plurality
of thread-like elastic members 278, 279 are attached under
tension to the first sheet 251. In the flatly developed diaper
201a according to this embodiment, adhesive 241 used to bond
the innermost sheet member 220 to the inner sheet 223 extends
across the crotch region 206 to the both side edges 227, 227.
In this case, the front body waste retaining sub-space 231a and
the rear body waste retaining sub-space 231b are sealed to each
other over all in the transverse direction B.
[0062]
While the innermost sheet member 220 has the same planar
shape as that of the first sheet 251 according to the illustrated
embodiments, such innermost sheet member 220 may be replaced
by an alternately formed innermost sheet member 220 comprising
a first sheet 251 defining the crotch region 206 or a part of
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the crotch region 206 and a second sheet 252 defining the front
waist region 207 or the front waist region 207 and a part of
the crotch region 206.
[0063]
While, in the diaper 201, the innermost sheet member 220
is preferably liquid-impervious and more preferably
air-permeable and liquid-impervious, sheets having properties
different one from another may be combined one with another to
obtain the innermost sheet member 220 which is liquid-pervious
in the crotch region 206 or in a part of the crotch region 206
and liquid-impervious in the front and rear waist regions 207,
208. For example, the first sheet 251 constituting the
innermost sheet member 220 may be formed of a nonwoven fabric
of thermoplastic synthetic fibers or a thermoplastic synthetic
resin film. Alternatively, a laminated sheet of nonwoven
fabric layers or a laminated sheet of nonwoven fabrics and films
may be used as the first sheet 251. The second and third sheets
252, 253 may be formed, for example, of an elastically
stretchable and contractible nonwoven fabric containing
elastic threads such as urethane threads or an elastically
stretchable and contractible film of natural or synthetic
rubber. The inner sheet 223 may be formed, for example, of a
liquid-pervious nonwoven fabric, a thermoplastic synthetic
CA 02719287 2010-09-22
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resin film or a composite sheet consisting of a nonwoven fabric
and a film laminated one on another. The outer sheet 224 may
be formed, for example, of a liquid-impervious nonwoven fabric,
a thermoplastic synthetic resin film or a composite sheet
consisting of a nonwoven fabric and a film laminated one on
another.
[0064]
Details of one or more embodiments of the disposable
pants-type diaper according to the present invention will be
more fully understood from the description given hereunder with
reference to Figs. 11-17.
[0065]
Fig. 11 is a partially cutaway perspective view showing
the disposable pants-type diaper 301 as put on the wearer's body
wherein a front-back direction, a transverse direction and a
vertical direction of the diaper 301 are respectively indicated
by the double-headed arrows A, B and C which are orthogonal one
to another. The diaper 301 includes a pants-shaped chassis 310
comprising a liquid-pervious inner sheet 302, a
liquid-impervious outer sheet 303 and a bodily f luid-absorbent
core 304. The chassis 310 has a crotch region 306, a front waist
region 307 extending forward from the crotch region 306 and a
rear waist region 308 extending rearward from the crotch region
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306. The front and rear waist regions 307, 308 are put flat
and sealed together along respective pairs of side edges 307a,
307a and 308a, 308a of these waist regions 307, 308, more
specifically, at joints 309 arranged intermittently in the
vertical direction as viewed in Fig. 11 along these side edges
307a, 307a and 308a, 308a and thereupon a waist-opening 311 and
a pair of leg-openings 312 are formed. Along a periphery 311a
of the waist-opening 311, a plurality of waist elastic members
314a extending in a circumferential direction is sandwiched
between the inner and outer sheets 302, 303 and bonded under
tension to at least one of the inner and outer sheets 302, 303.
Along a periphery of each of the leg-openings 312, a plurality
of leg elastic members 314b extending in the circumferential
direction is sandwiched between the inner and outer sheets 302,
303 and bonded under tension to at least one of these inner and
outer sheets 302, 303. Three components, i.e., the leg elastic
members 314b and the inner and outer sheets 302, 303 cooperate
together to define respective elastic regions 341 surrounding
the wearer's legs. Of the diaper 301, at least the crotch region
306 includes a bodily fluid absorbent structure 345 comprising
the inner and outer sheets 302, 303 and the absorbent core 304
sandwiched therebetween. The bodily fluid absorbent structure
345 extends in the front-back direction A and curves convexly
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downward to define a bottom portion 306a of the crotch region
306.
[0066]
Fig. 12 is a partially cutaway perspective view showing
the diaper 301a as after the front and rear waist regions 307,
308 of the diaper 301 have been unsealed at the joints 309 and
flatly developed as a whole in the front-back direction A as
well as in the transverse direction B wherein such developed
diaper 301a is shown as viewed from its inner side. In the state
of such developed diaper 301a, the chassis 310 in Fig. 11 appears
as a concave shaped flattened chassis 310a. The periphery 311a
of the waist-opening 311 in Fig. 11 appears herein as a front
end 307b and a rear end 308b of the flattened chassis 310a and
the peripheries 313 of the respective leg-openings 312 appear
herein as the crotch region's side edges 313b of the flattened
chassis 310a. While the crotch region's side edges 313b
convexly curve toward the center line P-P extending in the
front-back direction A to bisect a dimension of the flattened
chassis 310a in the transverse direction X, the respective pairs
of side edges 307a, 307a and 308a, 308a of the front and rear
waist regions 307, 308 extend substantially in parallel to this
center line P-P. The absorbent core 304 also is concave shaped
and is formed of a mixture 304a of fluff pulp fibers and
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super-absorbent polymer particles wrapped with a bodily
fluid-absorbent and highly dispersant wrapping sheet 304b such
as a tissue paper. In the flattened chassis 310a, the innermost
sheet member 320 made of, for example, a hydrophobic nonwoven
fabric, a plastic film or a composite sheet thereof, more
preferably, a hydrophobic and liquid-impervious nonwoven
fabric, a plastic film or a composite sheet thereof is attached
to the inner sheet 302 defining the inner surface of the
flattened chassis 310a in the crotch region 306 so that the
innermost sheet member 320 may define a separator 320a (See Fig.
13) . Such flatly developed diaper 301a is formed symmetrically
about the center line P-P extending in the front-back direction
A. The lowermost portion 306a of the crotch region 306 lies
on the transverse center line Q-Q bisecting a dimension of the
flatly developed diaper 301a in the front-back direction A.
[0067)
The innermost sheet member 320 is attached to the
flattened chassis 310a so that the innermost sheet member 320
may be interposed between the inner sheet 302 and the diaper
wearer's skin (not shown) when the diaper 301 is put on the
wearer's body. The innermost sheet member 320 has side edges
323 respectively fixed to the crotch region's side edges 313b
by hot melt adhesive 324, a front edge 321 lying before the
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lowermost portion 306a of the crotch region 306 and extending
in the transverse direction B between the side edges 323, 323
and a rear edge 322 lying behind the lowermost portion 306a of
the crotch region 306 and extending in the transverse direction
B between the side edges 323, 323. The innermost sheet member
320 in the illustrated embodiment is not bonded to the inner
sheet 302 and adapted to be spaced from the inner sheet 302 except
the side edges 323 so that a tunnel- or pocket-like body waste
retaining space 331 extending from the front edge 321 to the
rear edge 322 may be defined between the innermost sheet member
320 and the inner sheet 302. Along the front edge 321 and the
rear edge 322, the innermost sheet member 320 is folded to form
a sleeve 321a and a sleeve 322a, respectively. These sleeves
321a, 322a contain therein a front elastic member 321b and a
rear elastic member 322a attached under extension thereto,
respectively, to define front elastic region 342 and a rear
elastic region 343 both extending between the crotch region's
side edges 313b. These elastic regions 342, 343 intersect with
the elastic regions 341 of the flattened chassis 310a. A
distance Hf from the transverse center line Q-Q to the front
edge 321 is substantially equal to a distance Hr from the
transverse center line to the rear edge 322.
[0068]
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The innermost sheet member 320 is provided on the front
edge 321 with a deformation restricting sheet member 381 on the
center line P-P extending in the front-back direction A. The
deformation restricting sheet member 381 may be provided in the
form of a block made of a sponge, a foamed polyurethane, a foamed
polystyrene, a foamed polyethylene, a felt or a nonwoven fabric
having a flexibility sufficient to be easily deformed under a
body weight of the wearer of the diaper 301 and, more preferably,
having an elastic recovery properties also sufficient for a
rapid recovery after deformation. The innermost sheet member
320 is provided on the rear edge 322 with a region 382 indicated
by an imaginary line. The deformation restricting sheet member
381 is bonded to this region 382 when the side edges 307a, 307a
and 308a, 308a of the flattened chassis 301a are joined together
to obtain the diaper 301 (See Figs. 13 and 14).
[0069]
Fig. 13 is a sectional view taken along the line XIII-XIII
in Fig. 11 and the line XIII-XIII corresponds to the center line
P-P extending in the front-back direction A in Fig. 12. In the
pant-shaped chassis 310, the front and rear waist regions 307,
308 are joined together along the respective side edges 307a,
307a and 308a, 308a thereof. The crotch region 306 curves in
U-shape as viewed in the front-back direction A and the
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lowermost portion 306a of the crotch region 306 defines a bottom
of this U-shaped curve. The crotch region's side edges 313b
appear in Fig. 13 as the peripheral edges 313 defining the
leg-openings 312. The innermost sheet member 320 has the front
edge 321 and the rear edge 322 thereof bonded to each other by
the deformation restricting sheet member 381 and the portion
336 shown in Fig. 12 to extend in the front-back direction A
between the front edge 321 and the rear edge 322 sags toward
the lowermost portion 306a to form the separator 320a
partitioning the crotch region 306 into a front half and a rear
half. The deformation restricting sheet member 381 has a
thickness N in the front-back direction A and a height L in the
vertical direction and is attached to the innermost sheet member
320 by adhesion or sealing. The region in which the deformation
restricting sheet member 381 is joined to the rear edge 322 is
designated by a reference numeral 382. The separator 320a has
its lower end 335 bonded to the lowermost portion 306a of the
crotch region 306 by adhesive (not shown) and has height K
corresponding to a dimension from the deformation restricting
sheet member 381 to the inner sheet 302 in the lowermost portion
306a of the crotch region 306. In the body waste retaining space
331 formed by cooperation of the innermost sheet member 320 with
the inner sheet 302, the front edge 321 of the innermost sheet
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member 320 is adapted to be spaced from the inner sheet 302 and
thereby to define a front opening 333 and the rear edge 322 is
adapted to be spaced from the inner sheet 302 and thereby to
define a rear opening 334.
[0070]
Fig. 14 is an overhead view of the diaper 301 of Fig. 11
as viewed from above the waist-opening 311 in a direction
indicated by the arrows XIV-XIV in Fig. 13. The deformation
restricting sheet member 381 has a width M in the transverse
direction B and each of the front and rear ends 321, 322 is
bisected in the transverse direction B by the deformation
restricting sheet member 381 divided in two, i.e., right
segments 321R, 322R adapted to be put in contact with a right
leg of the diaper wearer (not shown) and left segments 321L,
322L adapted to be put in contact with a left leg of the diaper
wearer. The right segments 321R, 322R cooperate with each other
to define a laterally facing V-shaped space so that the wearer's
right leg may be guided through this laterally facing V-shaped
space. In a similar manner, the left segments 321L, 322L
cooperate with each other to define a laterally facing V-shaped
space so that the wearer's left leg may be guided through this
laterally facing V-shaped space. As illustrated, the
respective leg-openings 312 of the chassis 310 have a right leg
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peripheral edge 313R and a left leg peripheral edge 313L. The
respective peripheral edges 3138, 313L comprise upper segments
315a not overlapping the side edges 323 of the innermost sheet
member 320 and lower segments 315b overlapping the side edges
323 and bonded thereto (See Fig. 13 also) In Fig. 14,
respective ranges of these upper segments 315a and lower
segments 315b are indicated by double-headed arrows G and H.
[0071]
Sequence in which the diaper 301 maybe put on the wearer' s
body will be described below together with behavior of the
diaper 301. First, the front and rear waist regions 307, 308
of the chassis 310 may be spaced from each other in the front-back
direction A and then the waist-opening 311 may be sufficiently
broadened as seen in Figs. 11 and 14. Thereby the front edge
321 of the separator 320a formed of the innermost sheet member
320 is deformed so that the right segment 321R and the left
segment 321L are curved in V-shape facing forward in the
front-back direction A around the deformation restricting sheet
member 381. In a similar manner, the rear edge 322 is deformed
so that the right segment 322R and the left segment 322L are
curved in V-shape facing rearward in the front-back direction
A (See Fig. 14) . Consequently, the front opening 333 and the
rear opening 334 for the body waste retaining space 331 are
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automatically broadened (See Fig. 13) . The left segments 321L,
322L are spaced from each other in the front-back direction A
at the same moment that the right segments 321R, 322R are spaced
from each other in the front-back direction A. Now the diaper
wearer (not shown) may guide his or her right leg into an opening
341R for the right leg defined by the upper segment 315a of the
right leg peripheral edge 3138, the right segment 321R of the
front edge 321 and the right segment 322R of the rear edge 322.
Then the wearer may guide his or her right leg into the
leg-opening 312 for the right leg defined by the upper segment
315a and the lower segment 315b of the right leg peripheral edge
3138. Without interruption, the wearer may guide his or her
left leg into an opening 341L for the left leg defined by the
upper segment 315a of the left leg peripheral edge 313L, the
left segment 321L of the front edge 321 and the left-hand segment
322L of the rear edge 322. Then the wearer may guide his or
her right leg into the leg-opening 312 for the left leg defined
by the upper segment 315a and the lower segment 315b of the left
leg peripheral edge 313L-
[0072]
In the diaper 301 after it has been put on the wearer's
body, the peripheral edges 313 of the respective leg-openings
312, i . e . , the right leg peripheral edge 313R and the left leg
CA 02719287 2010-09-22
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peripheral edge 313L are elastically contractible in a
circumferential direction thereof, on one hand, and the front
edge 321 and the rear edge 322 of the separator 320a are
elastically contractible in the transverse direction B, on the
other hand. With such arrangement, the upper segment 315a of
the peripheral edge 313R for the right leg and the right segments
321R, 322R of the separator 320a are elastically put in close
contact around the right leg in the vicinity of the right leg' s
inguinal region to forma primary seal 3518 (See Fig. 14) serving
to prevent leakage of bodily fluids. Below the primary seal
3518, the lower segment 315b and the upper segment 315a of the
peripheral edge 313R for the right leg are integrated to form
a secondary seal 352R (See Fig. 14) serving to prevent leakage
of bodily fluids. Function of this secondary seal 352R is
similar to that of the leg seal in the conventional pants-type
diaper. The arrangement and function as have been described
just above are true with respect to the left leg. Specifically,
the upper segment 315a of the peripheral edge 313L for the left
leg and the left segments 321L, 322L of the separator 320a are
elastically put in close contact around the left leg in the
vicinity of the left leg's inguinal region to form a primary
seal 351L serving to prevent leakage of bodily fluids. Below
the primary seal 351L, the lower segment 315b and the upper
CA 02719287 2010-09-22
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segment 315a of the peripheral edge 313L for the left leg are
integrated to form a secondary seal 352L serving to prevent
leakage of bodily fluids. The diaper 301 having been put on
the wearer's body may be sufficiently pulled up along the body
to assure that a central segment of the separator 320a as viewed
in the transverse direction B along which the deformation
restricting sheet member 381 is attached thereto comes in
contact with the wearer's skin between the wearer's external
genital and anus.
[0073]
With the diaper 301 put on the wearer's body in the state
as has been described above, the portion 336 of the separator
320a is positioned to divide the wearer's crotch region into
a front half and a rear half. In the front half of the wearer's
crotch region, the wearer's external genital lying before the
front edge 321 is exposed in the front opening 333 and, in the
rear half of the wearer's crotch region, the wearer's anus lying
behind the rear edge 322 is exposed in the rear opening 334.
Consequentially, it is assure that urine discharged by the
wearer flows through the front opening 333 into the pocket-like
body waste retaining space 331 and feces excreted by the wearer
moves through the rear opening 334 into the body waste retaining
space 331. In this way, it is possible for the diaper 301 to
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prevent urine and/or feces from coming in contact with the
wearer's skin by the presence of the separator 320a. In
addition, the deformation restricting sheet member 381 attached
to the separator 320a functions to restrict the bodily
fluid-absorbent structure from being crooked along the center
line P-P in the front-back direction and thereby pressed against
the diaper wearer' skin as the diaper wearer moves his or her
legs tobe closed up. Thereby the deformation restricting sheet
member 381 prevents the internal volume of the body waste
retaining space 331 from being unacceptably reduced. The
deformation restricting sheet member 381 further prevents the
bodily fluid-absorbent structure 345 from moving close to the
front opening 333 and/or the rear opening 334 and thereby
closing these openings 333, 334.
[00741
The shape of the bodily fluid-absorbent structure 345
behaving to be crooked in this manner is indicated by imaginary
lines in Fig. 11 and Fig. 15. The bodily fluid-absorbent
structure 345 in Fig. 11 as well as the bodily fluid-absorbent
structure 345 in Fig. 15 corresponding to the bodily
fluid-absorbent structure 345 potentially behaves to move in
opposite directions of the arrows E and F to be crooked and
pressed in the direction of the arrow G against the wearer's
CA 02719287 2010-09-22
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skin. However, the deformation restricting sheet member 381
is able to restrict such movement.
(0075]
In response to change of the diaper wearer's posture from
sitting posture to standing posture, the deformation
restricting sheet member 381 accelerates the separator 320a to
return from its state collapsing on the inner sheet 302 during
sitting posture of the diaper wearer to the initial state in
which the separator 320a extends downward from the region
defined between the front and rear openings 333, 334 toward the
inner sheet 302 as shown in Fig. 13 and thereby allows the
separator 320a to fulfill its primary function. In the case
of the separator 320a extending downward as seen in Fig. 13
having its lower end 335 bonded to the lowermost portion 306a
of the crotch region 306, the separator 320a extending between
the front edge 321 and the lower end 335, i . e . , between the rear
edge 322 and the lower end 335 can quickly recover its normal
state as seen in Fig. 13 even if the separator 320a has collapsed
onto the inner sheet 302. Specifically, the deformation
restricting sheet member 381 having stiffness higher than the
innermost sheet member 320 is attached to the separator 320a
and therefore the separator 320a can easily recover its primary
state merely as the front edge 321 is pulled forward and the
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rear edge 322 is pulled rearward.
[0076]
The deformation restricting sheet member 381 functioning
in the manner as has been described above has the width M
preferably in a range of 10 to 70mm, more preferably in a range
of 30 to 60mm, the thickness N preferably in a range of 1 to
10mm, more preferably in a range of 3 to 7mm and the height L
preferably in a range of 30 to 100%, more preferably in a range
of 50 to 80% of the height K of the separator 320a. If any one
or more of these dimensions of the deformation restricting sheet
member 381 is or are out of the ranges as have been described,
feeling to wear the diaper 301 will be deteriorated and/or
deformation restricting function of the deformation
restricting sheet member 381 in the separator 320a and the
bodily f luid-absorbent structure 345 will be insufficient. In
order that the deformation restricting sheet member 381 can
fulfill its primary function of enhancing the stiffness of the
separator 320a in the central segment thereof as viewed in the
transverse direction B, the deformation restricting sheet
member 381 is formed of a material preferably having stiffness
in a range of 40 to 130N, more preferably in a range of 60 to
90N based on Procedure D of Stiffness Measuring Method specified
by Section 6 of JIS K 6400-2. If the stiffness is less than
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40N, the deformation restricting sheet member 381 will be too
flexible to fulfill its function and if the stiffness exceeds
130N, the deformation restricting sheet member 381 will make
the separator 320a locally stiff beyond an allowable limit. In
addition to the requirements as have been described above, the
deformation restricting sheet member 381 preferably has an
elastically restoring force.
[0077]
In the diaper 301, the front edge 321 of the innermost
sheet member 320 defining the separator 320a partially defines
the peripheral edge of the front opening 333. As viewed in the
front-back direction A, the front edge 321 lies behind the
wearer's external genital and positioned so that the external
genital can be reliably exposed in the front opening 333. While
the front edge 321 is exemplarily illustrated to extend linearly
in the transverse direction B, it is also possible to form the
front edge 321 to curve convexly toward the transverse center
line Q-Q. The rear edge 322 of the innermost sheet member 320
partially defines the peripheral edge of the rear opening 334.
As viewed in the front-back direction A, the rear edge 322 lies
before the wearer's anus and positioned so that the anus can
reliably face the rear opening 334. While such rear edge 322
is exemplarily illustrated to extend linearly in the transverse
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direction B, it is possible to form the rear edge 322 to curve
convexly toward the transverse center line Q-Q.
[0078]
In the crotch region 306 of the flattened chassis 310a
shown by Fig. 12, the inner and outer sheets 302, 303 put flat
together define side flaps 325 outside the liquid-absorbent
core 304. When the crotch region 306 is curved in U-shape under
contraction of the elastic regions 341 and thereupon the diaper
301 is put into the state as illustrated by Fig. 11, the side
flaps 325 behave to raise themselves along side edges 304c of
the core 304 in the vicinity of the transverse center line Q-Q,
i . e . , in the vicinity of the lowermost portion 306a of the crotch
region 306. The innermost sheet member 320 having the side
edges 323 bonded to the inner surface of the elastic regions
341 pulls the side flaps 325 inward in the transverse direction
of the diaper 301, i.e., toward the center line P-P extending
in the front-back direction as the waist-opening 311 is
broadened. In consequence, the behavior of the side flaps 325
to raise themselves is further enhanced. Such behavior of the
side flaps 325 becomes further significant as the front edge
321 and the rear edge 322 elastically contract. The side flaps
325 having such behavior come in close contact with the wearer's
thighs from below with respect to the diaper 301 and thereby
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effectively prevent bodily fluids from leaking out along the
wearer's thighs.
[0079]
To implement the present invention, a liquid-pervious
sheet material such as a nonwoven fabric or a perforated plastic
film may be used as the inner sheet 302. A liquid-impervious
sheet material such as a plastic film or a composite sheet
consisting of a plastic film and a nonwoven fabric may be used
as the outer sheet 303. Fluff pulp fibers or a mixture of fluff
pulp fibers and super-absorbent polymer particles wrapped with
an appropriate sheet material such as a tissue paper may be used
as the liquid-absorbent core 304. A hydrophobic sheet material
such as a nonwoven fabric or a plastic film, more preferably,
a hydrophobic and liquid-impervious sheet material may be used
as the innermost sheet member 320. While the innermost sheet
member 320 are preferably provided along the front edge 321 and
the rear edge 322 with the elastic members 321b, 322b attached
under tension thereto so that the innermost sheet member 320
may be elastically contracted, it is possible to eliminate use
of the elastic members 321b, 322b by using an elastic sheet
material adapted to be elastically and contracted in the
transverse direction B as the innermost sheet member 320. It
should be appreciated that the present invention includes an
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embodiment according to which both the front edge 321 and the
rear edge 322 are not elastically contractible in the transverse
direction B.
[0080]
Fig. 15 is a partially cutaway perspective view of one
preferred embodiment of the diaper 301 according to the present
invention. Regions and members of this embodiment similar to
those in the diaper 301 of Fig. 11 are designated with similar
reference numerals. Specifically, the diaper 301 of Fig. 15
also has the crotch region 306, the front waist region 307 and
the rear waist region 308 wherein the side edges 307a, 307a and
308a, 308a of the front and rear waist regions 307, 308 are put
flat and sealed together at the joints 309 arranged
intermittently in the vertical direction to form the
waist-opening 311 and a pair of the leg-openings 312. The
diaper 301 according to this embodiment also includes the
innermost sheet member 320 facing the wearer' skin (not shown)
and a bodily fluid absorbent member 345 attached to the outer
surface 320b of the innermost sheet member 320 wherein these
innermost sheet member 120 and the bodily fluid absorbent member
122 are integrated with each other to form the pant-shaped
chassis 310. The innermost sheet member 320 is preferably
hydrophobic, more preferably hydrophobic and
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liquid-impervious. Elastic sheet pieces 352 are bonded under
tension to the inner surface of the innermost sheet member 320
in the front waist region 307 and the rear waist region 308,
respectively, so that the innermost sheet member 320 may be
elastically contracted in the circumferential direction. The
innermost sheet member 320 is formed in the crotch region 306
with the front opening 333 and the rear opening 334. The front
opening 333 has the peripheral edge 333b and is positioned in
front of the transverse center line Q-Q so that the wearer's
external genital can be exposed in this front opening 333. The
rear opening 334 has the peripheral edge 334b and is positioned
behind the transverse center line Q-Q so that the wearer's anus
can be exposed in this rear opening 334. Referring to Fig. 15,
the deformation restricting sheet member 381 interposed between
the lower segment 334b of the peripheral edge 334b and the lower
segments 334c of the peripheral edge 334b both of the innermost
sheet member 320 to join these two segments 333c, 334c is shown
(See Fig. 16 also) . The imaginary lines J indicate the
potential behavior of the bodily fluid-absorbent structure 122
in the crotch region 306 moving inward in opposite directions
of the arrows E and F and thereby being crooked so as to be pressed
in a direction of the arrow G against the diaper wearer's skin.
The deformation restricting sheet member 381 is effective to
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restrict such potential behavior.
[0081]
The bodily fluid absorbent member 122 has the bodily fluid
absorbent structure 345 comprising the liquid-pervious inner
sheet 302, the liquid-impervious outer sheet 303 and the bodily
fluid absorbent core 304 sandwiched the inner and outer sheets
302, 303. These inner and outer sheets 302, 303 extend outward
beyond the periphery of the core 304 and put flat and bonded
together outside the periphery of the core 304 wherein at least
one of these inner and outer sheets 302, 303 is bonded to the
innermost sheet member 320 so that the front opening 333 and
the rear opening 334 may be covered with said one of the inner
and outer sheets 302, 303 from outside of the innermost sheet
member 320. Along the side edges 313 of the crotch region 306,
the inner sheet 302, the outer sheet 303 and the innermost sheet
member 320 are placed one on another and bonded together. Also
along the side edges 313, the leg elastic members 314b
sandwiched between the inner sheet 302 and the outer sheet 303
is bonded under tension to at least one of these two sheets 302,
303. Between the side edges 313, the inner sheet 302 and the
innermost sheet member 320 are not bonded to each other so that
the innermost sheet member 320 may be spaced from the inner sheet
302 in the thickness direction of the core 304 to form the body
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waste retaining space 331 into which urine flows through the
front opening 303 and feces moves through the rear opening 334.
[0082]
Fig. 16 is a sectional view taken along the line XVI-XVI
in Fig. 11 wherein the line XVI-XVI corresponds to the center
line P-P extending in the front-back direction. The innermost
sheet member 320 is indirectly bonded to itself along the lower
segment 333c of the peripheral edge 333b defining the front
opening 333 and the lower segment 334c of the peripheral edge
334b defining the rear opening 334 via the deformation
restricting sheet member 381 having the thickness N and the
height K. The portion 336 of the innermost sheet member 320
defined in the front-back directionAbetween the lower segments
333c, 334c sags down toward the lowermost portion 306a of the
crotch region 306. The portion 336 of the innermost sheet
member 320 extending between the lower segments 333c, 334c in
the front-back direction A extends downward toward the lower
most portion 306a of the crotch region 306 and the lower end
335 of the innermost sheet member 320 is joined to the inner
sheet 302.
[0083]
Fig. 17 is a view similar to Fig. 16, showing another
preferred embodiment of the present invention. In the diaper
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301 shown by Fig. 17, the innermost sheet member 320 is directly
bonded to itself to form the separator 320a. The deformation
restricting sheet member 381 is attached to the rear surface
383 of the separator 320a. With this alternative arrangement,
there is possibility that loose passage flowing into the body
waste retaining space comes in direct contact with the
deformation restricting sheet member 381. Considering such
possibility, it will be advantageous to form the deformation
restricting sheet member 381 by a sponge having interconnected
cells or a sheet material having many voids such as a nonwoven
fabric of crimped conjugate fibers since loose passage can be
trapped by these voids. By trapping loose passage of high
fluidity in the voids, loose passage would be prevented from
flowing out of the rear opening and soiling the wearer's skin.
It should be appreciated here that the deformation restricting
sheet member 381 may be attached not to the rear surface 383
but to the front surface 382 of the separator 320a without
departing from the scope of the present invention.
