U.S. patent application number 12/430174 was filed with the patent office on 2009-08-20 for absorbent article.
This patent application is currently assigned to Uni-Cham Corporation. Invention is credited to Yukihiro Ito, Masataka Kinoshita, Makoto Suekane.
Application Number | 20090209928 12/430174 |
Document ID | / |
Family ID | 37235422 |
Filed Date | 2009-08-20 |
United States Patent
Application |
20090209928 |
Kind Code |
A1 |
Ito; Yukihiro ; et
al. |
August 20, 2009 |
ABSORBENT ARTICLE
Abstract
An absorbent article in which a plurality of absorbent
components is layered, and the absorbent component on top is peeled
off after use. The article is configured to inhibit twisting or
wrinkling during use. In the absorbent article, the upper absorbent
component is layered on the skin-facing surface of the bottom
absorbent component and peelably bonded by the temporal adhesive
member. The bottom absorbent component has higher flexural rigidity
than the upper absorbent component, and the compression recovery
rate of the bottom absorbent component is also set so as to be
higher than that of the upper absorbent component. It is thereby
possible to prevent the bottom absorbent component from twisting
and wrinkling when the upper absorbent component is placed against
the discharge area, and after the upper absorbent component is
peeled off, the volume of the bottom absorbent component is
restored, and comfort during contact thereof with the discharge
area is improved.
Inventors: |
Ito; Yukihiro; (Kanonji-shi,
JP) ; Suekane; Makoto; (Kanonji-shi, JP) ;
Kinoshita; Masataka; (Kanonji-shi, JP) |
Correspondence
Address: |
DARBY & DARBY P.C.
P.O. BOX 770, Church Street Station
New York
NY
10008-0770
US
|
Assignee: |
Uni-Cham Corporation
Shikokuchuo-shi
JP
|
Family ID: |
37235422 |
Appl. No.: |
12/430174 |
Filed: |
April 27, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11380780 |
Apr 28, 2006 |
|
|
|
12430174 |
|
|
|
|
Current U.S.
Class: |
604/359 ;
604/360; 604/365; 604/379; 604/385.05 |
Current CPC
Class: |
A61F 2013/8497 20130101;
A61F 2013/8414 20130101; A61F 13/8405 20130101; A61F 13/474
20130101; A61F 2013/15406 20130101; A61F 2013/15357 20130101 |
Class at
Publication: |
604/359 ;
604/365; 604/379; 604/360; 604/385.05 |
International
Class: |
A61F 13/84 20060101
A61F013/84; A61F 13/15 20060101 A61F013/15; A61F 13/53 20060101
A61F013/53; A61F 13/56 20060101 A61F013/56 |
Foreign Application Data
Date |
Code |
Application Number |
May 2, 2005 |
JP |
2005-134648 |
Claims
1. An absorbent article comprising: a bottom absorbent component
which is one of a plurality of layered absorbent components having
a liquid-absorbent layer, and which is positioned in a bottom stage
having a clothing-facing surface provided with positioning-fixing
means fixed to a piece of clothing, and having a skin-facing
surface on the opposite side from the clothing-facing surface; and
an upper absorbent component which is one of the plurality of
layered absorbent components, and which is peelably bonded to the
skin-facing surface of the bottom absorbent component; wherein the
bottom absorbent component has higher flexural rigidity than the
upper absorbent component when flexed in the longitudinal
direction, which is the anteroposterior direction between the legs
during fitting to the body, wherein an embossed pattern is formed
in at least one surface selected from the skin-facing surface of
the bottom absorbent component and a skin-facing surface of the
upper absorbent component, and mutually different patterns are
provided on the skin-facing surfaces.
2. The absorbent article according to claim 1, wherein a plurality
of the upper absorbent components is provided, each upper absorbent
component is peelably layered, and the flexural rigidity is higher
in the bottom absorbent component than in the upper absorbent
component disposed at the top.
3. The absorbent article according to claim 1, wherein a plurality
of the upper absorbent components is provided, each upper absorbent
component is peelably layered, and the flexural rigidity is higher
in any of the plurality of upper absorbent components that is
positioned closer to the clothing than in any of the plurality of
upper absorbent components that is positioned closer to the
skin.
4. The absorbent article according to claim 1, wherein the flexural
rigidity of the bottom absorbent component is increased by making
the weight of the material constituting the bottom absorbent
component greater than that of the upper absorbent component.
5. The absorbent article according to claim 1, wherein the flexural
rigidity of the bottom absorbent component is increased by making
the thickness of the bottom absorbent component greater than that
of the upper absorbent component.
6. The absorbent article according to claim 5, wherein the bottom
absorbent component comprises nonwoven cloth, and the nonwoven
cloth is heat-treated and increased in thickness.
7. The absorbent article according to claim 5, wherein the
thickness is increased by forming irregularities in the surface
layer of the bottom absorbent component.
8. An absorbent article comprising: a bottom absorbent component
which is one of a plurality of layered absorbent components having
a liquid-absorbent layer, and which is positioned in a bottom stage
having a clothing-facing surface provided with positioning-fixing
means fixed to a piece of clothing, and having a skin-facing
surface on the opposite side from the clothing-facing surface; and
an upper absorbent component which is one of the plurality of
layered absorbent components, and which is peelably bonded to the
skin-facing surface of the bottom absorbent component; wherein the
compression recovery rate (RC value) of the bottom absorbent
component is higher than that of the upper absorbent component.
9. The absorbent article according to claim 8, wherein a plurality
of the upper absorbent components is provided, each upper absorbent
component is peelably layered, and the bottom absorbent component
has a higher compression recovery rate (RC value) than does the
uppermost of the plurality of the upper absorbent components.
10. The absorbent article according to claim 8, wherein a plurality
of the upper absorbent components is provided, each upper absorbent
component is peelably layered, and any of the plurality of upper
absorbent components that is positioned closer to the clothing has
a higher compression recovery rate (RC value) than any of the upper
absorbent components that is positioned closer to the skin.
11. The absorbent article according to claim 8, wherein the
compression recovery rate (RC value) of at least one of the
materials constituting the bottom absorbent component is 40% or
higher.
12. An absorbent article comprising: a bottom absorbent component
which is one of a plurality of layered absorbent components having
a liquid-absorbent layer, and which is positioned in a bottom stage
having a clothing-facing surface provided with positioning-fixing
means fixed to a piece of clothing, and having a skin-facing
surface on the opposite side from the clothing-facing surface; an
upper absorbent component which is one of the plurality of layered
absorbent components, and which is layered on the skin-facing
surface of the bottom absorbent component; and a temporal adhesive
member which temporarily fixes the bottom absorbent component and
the upper absorbent component layered and fixed together in a
plurality of layers, and which is provided in the area in which the
plurality of layers are layered and fixed; wherein the adhesive
strength of the temporal adhesive member between the absorbent
components is lower than the fixing strength between each of the
plurality of layers constituting the bottom absorbent component and
than the fixing strength between each of the plurality of layers
constituting the upper absorbent component.
13. The absorbent article according to claim 12, wherein the
temporal adhesive member is formed in a position towards the inside
from the edge of the absorbent component.
14. The absorbent article according to claim 12, wherein the
temporal adhesive member is formed so as to have an excluded
portion.
15. The absorbent article according to claim 14, wherein the bottom
absorbent component and the upper absorbent component each have
four corners, and the plane pattern of the temporal adhesive member
is curved at the tip of each of the four corners.
16. The absorbent article according to claim 14, wherein the upper
absorbent component is partially compressed in the excluded
portion.
17. The absorbent article according to claim 12, wherein
non-fusible fibers are included in at least one surface selected
from the skin-facing surface of the bottom absorbent component and
the clothing-facing surface of the upper absorbent component, and
the temporal adhesive member is pressed in the thickness direction,
heated, and formed in a state in which the skin-facing surface and
the clothing-facing surface are placed opposite each other.
18. The absorbent article according to claim 1, wherein the
skin-facing surface of the bottom absorbent component and the
skin-facing surface of the upper absorbent component differ in
color from each other.
19. The absorbent article according to claim 1, wherein at least
one functional agent selected from the group consisting of an
antimicrobial agent, a deodorant, and a fragrance is included in at
least the bottom absorbent component.
20. The absorbent article according to claim 1, wherein at least
the bottom absorbent component has at least one functional agent
selected from the group consisting of an antimicrobial agent, a
deodorant, and a fragrance; and a tea-leaf extract is included as
the functional agent.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a Divisional application of U.S. patent application
Ser. No. 11/380,780, filed Apr. 28, 2006 which claims priority
under 35 U.S.C. .sctn.119 to Japanese Patent Application No.
2005-134648, filed May 2, 2005. The contents of each of these
applications are hereby incorporated by reference in their
entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an absorbent article which
is fixed to an undergarment and which absorbs vaginal discharge,
menstrual bleeding, urine, or the like, and particularly relates to
an absorbent article in which a plurality of absorbent components
can be layered and bonded together, the absorbent component on top
can be peeled off after use, and the absorbent component under the
top component can be used.
[0004] 2. Related Art
[0005] A composite menstrual sanitary product in which a plurality
of composite absorbent sheets is layered so as to be able to peel
apart is known as a menstrual sanitary product for absorbing blood
that is discharged from a woman's vagina. When this composite
menstrual sanitary product is used, the composite absorbent sheet
that is the bottom layer is fixed to the inside surface of an
undergarment, and the composite absorbent sheet that is the top
layer is placed against the area of discharge. After the blood flow
has been absorbed for a prescribed period of time by the top-layer
composite absorbent sheet, the top-layer composite absorbent sheet
is peeled off and discarded, and the composite absorbent sheet that
is disposed under the discarded layer is placed against the area of
discharge. The number of times that the absorbent product must be
changed can thereby be reduced.
[0006] For example, in the composite absorbent sheets described in
Japanese Laid-open Patent Application No. 2001-187084, the
bottom-layer composite absorbent sheet and the top-layer composite
absorbent sheet are each composed of a lining sheet, a surface
film, and a liquid-absorbent sheet sandwiched between the lining
sheet and the surface film. In each composite absorbent sheet, the
aforementioned lining sheet is formed so as to be larger than the
surface film, and the lining sheets of the top-layer composite
absorbent sheet and bottom-layer composite absorbent sheet are
bonded together by heat sealing or a pressure-sensitive adhesive
layer.
[0007] The aforementioned lining sheets are bonded together along
the periphery of the composite absorbent sheet, and an area is
formed in a portion thereof in which there is no bonding. The
top-layer composite absorbent sheet can easily be peeled from the
bottom-layer composite absorbent sheet by inserting a finger into
this area.
[0008] The conventional composite menstrual sanitary products
described in Japanese Patent Application No. 2005-134648 and other
publications use a stack of composite absorbent sheets having the
same structure. Therefore, when the top-layer composite absorbent
sheet is used after being placed against the discharge area, there
is a tendency for kinks or wrinkles to form in the bottom-layer
composite absorbent sheet as a result of body or undergarment
movement. When the top-layer composite absorbent sheet is peeled
off, the bottom-layer composite absorbent sheet adheres to the
discharge area instead of the top-layer composite absorbent sheet.
When the bottom-layer composite absorbent sheet is kinked or
wrinkled at this time, the adhesion of the bottom-layer composite
absorbent sheet to the discharge area is easily compromised. As a
result, the article becomes uncomfortable to wear when the
bottom-layer composite absorbent sheet is fitted, and there is also
a risk of leakage of blood and the like.
[0009] When the top-layer composite absorbent sheet is used after
being placed against the discharge area, the bottom-layer composite
absorbent sheet is in a compressed state for a long period of time
due to bodily pressure exerted on the top-layer composite absorbent
sheet. The bottom-layer composite absorbent sheet is therefore
likely to be in a crushed state due to the contamination of the
top-layer composite absorbent sheet when this top-layer composite
absorbent sheet is peeled off. As a result, the bottom-layer
composite absorbent sheet becomes uncomfortable to touch when it is
placed against the discharge area of the body, and the ability of
the bottom-layer composite absorbent sheet to absorb liquids is
diminished.
[0010] In the conventional composite menstrual sanitary products
described in Japanese Laid-open Patent Application No. 2001-187084
and other publications, the top-layer composite absorbent sheet and
the lining sheet of the bottom-layer composite absorbent sheet are
bonded together. The top-layer composite absorbent sheet is
therefore difficult to peel off when the bottom-layer composite
absorbent sheet is fixed to the undergarment. As a result, there is
a risk of the bottom-layer composite absorbent sheet being
separated from the undergarment when the top-layer composite
absorbent sheet is peeled off.
[0011] Since the bonding portion of the lining sheet is located at
the edge of the composite menstrual sanitary product, this bonding
portion can easily cause skin discomfort when it comes in contact
with the skin during fitting.
[0012] The bottom-layer composite absorbent sheet and the top-layer
composite absorbent sheet also have the same appearance, and are
difficult to distinguish from each other. Therefore, with this type
of composite menstrual sanitary product, when the user observes
during fitting that the product has absorbed blood or the like and
become contaminated, the user may be unable to correctly
distinguish whether the top-layer composite absorbent sheet or the
bottom-layer composite absorbent sheet has been used. This is
likely to cause inconvenience in the sense that the user may peel
off from the undergarment and discard both the top-layer composite
absorbent sheet and the bottom-layer composite absorbent sheet
regardless of the fact that the bottom-layer composite absorbent
sheet has not been used, or may peel the product from the
undergarment without preparing a replacement menstrual sanitary
product, even though the bottom-layer composite absorbent sheet is
being used.
SUMMARY OF THE INVENTION
[0013] An object of the present invention is to overcome the
abovementioned drawbacks of the prior art and to provide an
absorbent article whereby excessive twisting or wrinkling can be
prevented, or the occurrence of a crushed state can be minimized in
a bottom absorbent component such as a bottom-layer composite
absorbent sheet, and the bottom absorbent component can be used in
an optimal state when an upper absorbent component such as a
top-layer composite absorbent sheet is in use.
[0014] Another object of the present invention is to provide an
absorbent article whereby the upper absorbent component is easily
separated from the bottom absorbent component.
[0015] Yet another object of the present invention is to provide an
absorbent article that can be configured so that it is easy to
visually distinguish the difference between the upper absorbent
component and the bottom absorbent component.
[0016] A first aspect of the present invention is an absorbent
article in which a plurality of absorbent components having a
liquid-absorbent layer is layered together, wherein
positioning-fixing means fixed to clothing is provided on the
clothing-facing surface of a bottom absorbent component positioned
in a bottom stage, at least one upper absorbent component is
peelably bonded to the skin-facing surface of the bottom absorbent
component, and the bottom absorbent component has higher flexural
rigidity than the upper absorbent component when flexed in the
longitudinal direction.
[0017] In the absorbent article of the present invention, the
bottom absorbent component can easily be prevented from undergoing
the same twisting or wrinkling as the upper absorbent component
even with the body or undergarment moving when the upper absorbent
component is used after being placed against the discharge area. It
is therefore easy to cause the bottom absorbent component to adhere
to the discharge area when the spent upper absorbent component is
peeled off, and the fit comfort of the bottom absorbent component
is improved.
[0018] Furthermore, in the present invention, a plurality of the
upper absorbent components is provided, each upper absorbent
component is peelably layered, and the flexural rigidity is higher
in the bottom absorbent component than in the upper absorbent
component disposed at the top.
[0019] When a plurality of upper absorbent components is provided,
the bottom absorbent component is given a higher flexural rigidity
than the absorbent component on top. This configuration makes it
easier to minimize the occurrence of twisting or wrinkling in the
bottom absorbent component that is used last.
[0020] When a plurality of upper absorbent components is provided,
the absorbent component positioned between the top absorbent
component and the bottom absorbent component may have a lower
flexural rigidity than the top absorbent component. However, it is
preferred in the present invention that the flexural rigidity be
higher in any of the upper absorbent components that is positioned
closer to the clothing than in any of the upper absorbent
components that are positioned closer to the skin.
[0021] In the present invention, the flexural rigidity of the
bottom absorbent component is increased by making the weight of the
material constituting the bottom absorbent component greater than
that of the upper absorbent component, or the flexural rigidity of
the bottom absorbent component is increased by making the thickness
of the bottom absorbent component greater than that of the upper
absorbent component, for example.
[0022] In the present invention, the nonwoven cloth constituting
the bottom absorbent component is heat treated and increased in
thickness, and/or the thickness is increased by forming
irregularities in the surface layer of the bottom absorbent
component. The flexural rigidity of the bottom absorbent component
can thereby be increased.
[0023] A second aspect of the present invention is an absorbent
article in which a plurality of absorbent components having a
liquid-absorbent layer is layered together, wherein
positioning-fixing means fixed to a piece of clothing is provided
on the clothing-facing surface of a bottom absorbent component
positioned in a bottom stage, at least one upper absorbent
component is peelably bonded to the skin-facing surface of the
bottom absorbent component, and the compression recovery rate (RC
value) of the bottom absorbent component is higher than that of the
upper absorbent component.
[0024] A plurality of the upper absorbent components is also
provided in this case, each upper absorbent component is peelably
layered, and the compression recovery rate (RC value) is preferably
higher in the bottom absorbent component than in the upper
absorbent component disposed at the top. When a plurality of the
upper absorbent components is provided, any of the upper absorbent
components that is positioned closer to the clothing preferably has
a higher compression recovery rate (RC value) than any of the upper
absorbent components that is positioned closer to the skin.
[0025] In the present invention, the compression recovery rate (RC
value) of at least one of the materials constituting the bottom
absorbent component is preferably 40% or higher.
[0026] In the aspects of the present invention described above,
when the upper absorbent component is peeled off, the thickness of
the bottom absorbent component increases. When the compression
recovery rate (RC value) thereof is within the aforementioned
range, the overall thickness of the absorbent article during use of
the upper absorbent component can be made as small as possible, and
when only the bottom absorbent component is used, the thickness of
the bottom absorbent component is restored, and the fit comfort of
the bottom absorbent component against the vaginal opening or other
discharge area can be improved.
[0027] A third aspect of the present invention is an absorbent
article in which a plurality of absorbent components having a
liquid-absorbent layer is layered together, wherein
positioning-fixing means fixed to a piece of clothing is provided
on the clothing-facing surface of a bottom absorbent component
positioned in a bottom stage, at least one upper absorbent
component is layered on the skin-facing surface of the bottom
absorbent component, a plurality of layers is layered and fixed
together in both the bottom absorbent component and the upper
absorbent component, and a temporal adhesive member for temporarily
fixing the bottom absorbent component and the upper absorbent
component is formed in the area in which the plurality of layers of
absorbent components are layered; wherein the adhesive strength of
the temporal adhesive member between the absorbent components is
weaker than the fixing strength between the layers constituting the
bottom absorbent component and than the fixing strength between the
layers constituting the upper absorbent component.
[0028] In the present invention described above, the absorbent
components are composed of a plurality of layers layered together,
and a temporal adhesive member is formed in the area in which the
plurality of layers is layered together. Therefore, since the upper
absorbent component, which is an aggregate of a plurality of
layers, has a prescribed thickness when peeled from the bottom
absorbent component, it becomes easy to separate the upper
absorbent component from the bottom absorbent component. Since the
upper absorbent component is also temporarily fixed to the bottom
absorbent component in the area in which the plurality of layers is
layered, it is less likely for the bottom absorbent component to
bend and wrinkle when the upper absorbent component is peeled
off.
[0029] In the present invention, the temporal adhesive member is
preferably formed in a position towards the inside from the edge of
the absorbent component. By not placing the temporal adhesive
member at the edge, it becomes easy to prevent the temporal
adhesive member portion from causing discomfort to the skin of the
body.
[0030] The temporal adhesive member in the present invention is
also preferably formed so as to have an excluded portion.
[0031] When the temporal adhesive member is formed so as to have an
excluded portion, it becomes possible to reliably peel the upper
absorbent component from the bottom absorbent component.
[0032] It is preferred in the present invention that the bottom
absorbent component and the upper absorbent component each have
four corners, and that the plane pattern of the temporal adhesive
member be curved at the tip of each of the four corners.
[0033] When the temporal adhesive member formed at the corners has
a curved pattern, the temporal adhesive member is difficult to peel
off in the corners even when the excluded portion is used to apply
peeling force in the longitudinal direction with respect to the
upper absorbent component during wear. However, when a finger is
inserted into the excluded portion, and the upper absorbent
component is peeled upwards, since the peeling force is propagated
along the curved pattern, it becomes possible to separate the
temporary fixing at the corners without experiencing significant
resistance.
[0034] It is also preferred that the upper absorbent component be
partially compressed in the excluded portion. The compressed
portion of the upper absorbent component makes it easy to insert a
finger between the bottom absorbent component and the upper
absorbent component, and makes it possible to firmly grasp the
upper absorbent component in the excluded portion and peel the
upper absorbent component off.
[0035] A configuration may be adopted in the present invention
whereby non-fusible fibers are included in at least one surface
selected from the skin-facing surface of the bottom absorbent
component and the clothing-facing surface of the upper absorbent
component, and the temporal adhesive member is pressed in the
thickness direction, heated, and formed in a state in which the
skin-facing surface and the clothing-facing surface are placed
opposite each other.
[0036] When non-fusible fibers are positioned in the portion in
which the bottom absorbent component and the upper absorbent
component face each other, and the temporal adhesive member is
formed in this portion, it becomes easy to peel the bottom
absorbent component and upper absorbent component apart without an
excessive bonding force being created by the temporal adhesive
member.
[0037] It is also preferred in the present invention that the
skin-facing surface of the bottom absorbent component and the
skin-facing surface of the upper absorbent component differ in
color from each other. An embossed pattern is also preferably
formed in at least one surface selected from the skin-facing
surface of the bottom absorbent component and the skin-facing
surface of the upper absorbent component, and mutually different
patterns are preferably provided on the skin-facing surfaces. This
visually recognizable difference between the bottom absorbent
component and the upper absorbent component may be evident in both
color and pattern.
[0038] By adopting this type of configuration, it can be
immediately determined visually which layer of absorbent components
is being used even when the absorbent component is contaminated
with discharge. The user is also less likely to be inconvenienced
by mistakenly discarding an unused bottom absorbent component,
forgetting to bring a replacement absorbent article to the
washroom, or experiencing other inconveniences.
[0039] The present invention may also be configured so that at
least one functional agent selected from the group consisting of an
antimicrobial agent, a deodorant, and a fragrance is included in at
least the bottom absorbent component.
[0040] When an antimicrobial agent, a deodorant, a fragrance, or
other functional agent is included in the bottom absorbent
component as well as in the upper absorbent component, it becomes
easy to keep microorganisms from proliferating and creating an odor
during use. Including the aforementioned functional agent can be
effective for minimizing proliferation of microorganisms or odors
particularly in the bottom absorbent component that is worn for the
longest period of time. A tea leaf extract is included as an
example of this type of functional agent.
[0041] It becomes easy to suppress the occurrence of twisting or
wrinkling in the bottom absorbent component when the upper
absorbent component is peeled off in an absorbent article in which
a plurality of absorbent components is layered together. Comfort is
thereby improved when the bottom absorbent component is fitted to
the discharge area.
[0042] According to the present invention, when the upper absorbent
component is peeled off, the volume of the bottom absorbent
component is restored, the comfort of the bottom absorbent
component when placed against the discharge area can be improved,
and a high degree of liquid absorption can be demonstrated in the
bottom absorbent component.
[0043] Furthermore, according to the present invention, the upper
absorbent component can easily be peeled from the bottom absorbent
component, and the bottom absorbent component is less prone to
wrinkle or undergo other adverse effects when the upper absorbent
component is peeled off.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] FIG. 1 is a plan view showing the absorbent article
according to a first embodiment of the present invention as viewed
from the skin-facing surface;
[0045] FIG. 2A is a sectional view along line II-II of the
absorbent article shown in FIG. 1;
[0046] FIG. 2B is a separated sectional view of the separate
absorbent components;
[0047] FIG. 3 is a separated sectional view showing each absorbent
component of the absorbent article according to a second embodiment
of the present invention;
[0048] FIG. 4 is an enlarged plan view showing details of a pattern
in a compressed portion of the temporal adhesive member;
[0049] FIG. 5 is a plan view for describing the positional
relationship between a round seal and the temporal adhesive
member;
[0050] FIG. 6 shows the absorbent article according to a third
embodiment of the present invention, wherein FIG. 6A is a plan view
of the upper absorbent component as viewed from the skin-facing
surface;
[0051] FIG. 6B is a plan view of only the bottom absorbent
component as viewed from the skin-facing surface;
[0052] FIG. 7A is a plan view of the absorbent article according to
a fourth embodiment of the present invention;
[0053] FIG. 7B is a plan view of a state in which the upper
absorbent component is removed;
[0054] FIG. 8 is a partial sectional view along line VIII-VIII of
FIG. 7A;
[0055] FIG. 9 is a partial plan view of the temporal adhesive
member;
[0056] FIG. 10 is a plan view of the absorbent article according to
a fifth embodiment of the present invention; and
[0057] FIG. 11 is a diagram showing the compression recovery
rate.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0058] FIG. 1 is a plan view showing the absorbent article 1
according to a first embodiment of the present invention as viewed
from the skin-facing surface; FIG. 2A is a sectional view along
line II-II of the absorbent article shown in FIG. 1; and FIG. 2B is
a separated sectional view of the separate absorbent components of
the absorbent article 1.
[0059] The absorbent article 1 described hereinafter is used after
being fixed as a panty liner to the inside surface of the crotch
portion of an undergarment, and is used for the purpose of
absorbing vaginal discharge, small amounts of blood, and the like.
However, the absorbent article of the present invention may also be
configured for use as a menstrual sanitary product for absorbing a
relatively large quantity of blood, or as a urine-absorbent pad
used for the purpose of absorbing urine.
[0060] The absorbent article 1 shown in FIG. 1 and FIG. 2A is
bilaterally symmetrical about the boundary established by the
vertical center line Oy. The absorbent article is also symmetrical
about the boundary established by the horizontal center line Ox.
FIG. 2A is a sectional view of the absorbent article 1 along the
horizontal center line Ox. This absorbent article 1 has an
elongated shape in which the longitudinal dimension, which is the
dimension of the portion passed through by the vertical center line
Oy, is greater than the transverse dimension, which is the
dimension of the portion passed through by the horizontal center
line Ox. The article is fitted so that the longitudinal direction
is oriented in the anteroposterior direction between the legs of
the body.
[0061] As shown in FIG. 1, the absorbent article 1 has a front edge
2 outward-curved towards the front; a back edge 3 outward-curved
towards the back; and a right-side edge 4 and left-side edge 5
formed with a shape that curves inward so that the transverse
dimension decreases towards the vertical center line. The side of
this absorbent article 1 that faces the skin when fitted is the
skin-facing surface 6, and the side that faces the undergarment or
another piece of clothing is the clothing-facing surface 7. The
sheets constituting the absorbent article 1 are referred to as
"skin-facing" on the side towards the skin-facing surface 6, and as
"clothing-facing" on the side towards the clothing-facing surface
7.
[0062] As shown in FIGS. 2A and 2B, this absorbent article 1 has a
bottom absorbent component 10 and an upper absorbent component 20
that is layered on the skin side of the bottom absorbent component
10. The bottom absorbent component 10 is composed of a surface
sheet 11, a middle sheet 12, and an article backing sheet 13
layered together. The upper absorbent component 20 is composed of a
surface sheet 21, a middle sheet 22, and a back surface sheet 23
layered together.
[0063] The planar shape of the bottom absorbent component 10 is the
same as the planar shape of the entire absorbent article 1 shown in
FIG. 1, and the peripheral edge of the surface sheet 11, middle
sheet 12, and article backing sheet 13 constituting the bottom
absorbent component 10 has the same shape as the front edge 2, back
edge 3, right-side edge 4, and left-side edge 5 of the absorbent
article 1. The planar shape of the upper absorbent component 20 is
the same as the planar shape of the entire absorbent article 1
shown in FIG. 1, and the peripheral edge of the surface sheet 21,
middle sheet 22, and back surface sheet 23 constituting the upper
absorbent component 20 has the same shape as the front edge 2, back
edge 3, right-side edge 4, and left-side edge 5 of the absorbent
article 1.
[0064] In the bottom absorbent component 10, the surface sheet 11
and the middle sheet 12 are bonded together by a rubber-based
hot-melt adhesive applied in a spiral pattern or the like in an
amount (10 g/m.sup.2, for example) that does not inhibit the
transmission of liquid, and the surface sheet 11 and middle sheet
12 are also integrally fixed in a round seal 14. In the round seal
14, the surface sheet 11 and middle sheet 12 are heated and pressed
together, the thermofusible fibers included in at least one sheet
selected from the surface sheet 11 and the middle sheet 12 are
melted, and the surface sheet 11 and middle sheet 12 are securely
fixed to each other.
[0065] In the same manner, in the upper absorbent component 20, the
surface sheet 21 and the middle sheet 22 are bonded together by a
hot-melt adhesive applied in an amount that does not inhibit the
transmission of liquid, and the middle sheet 22 and back surface
sheet 23 are bonded together by a hot-melt adhesive. Furthermore,
the surface sheet 21, middle sheet 22, and back surface sheet 23
are integrally fixed in a round seal 24. In the round seal 24, the
surface sheet 21, middle sheet 22, and back surface sheet 23 are
heated and pressed together, the back surface sheet 23 and the
thermofusible fibers included in at least one sheet selected from
the middle sheet 22 and the surface sheet 21 are melted, and the
surface sheet 21, middle sheet 22, and back surface sheet 23 are
securely fixed to each other.
[0066] In FIG. 1, the round seal 24 formed on the upper absorbent
component 20 is indicated by a solid line. This round seal 24 is
formed along the entire length of the external periphery of the
upper absorbent component 20, and the round seal 24 is formed in a
position that is at a distance inward from the front edge 2, back
edge 3, right-side edge 4, and left-side edge 5 in the upper
absorbent component 20. In the same manner, the round seal 14 is
formed all the way around the bottom absorbent component 10, and
this round seal 14 is formed in a position that coincides with that
of the round seal 24 of the upper absorbent component 20, and is
formed with the same width dimension as the round seal 24.
[0067] Furthermore, the upper absorbent component 20 is layered on
the skin side of the surface sheet 11 of the bottom absorbent
component 10, and the pre-integrated surface sheet 11 and middle
sheet 12, as well as the pre-integrated upper absorbent component
20 are temporarily fixed to each other by a temporal adhesive
member 8 so as to be able to separate. The temporal adhesive member
8 is formed by layering the upper absorbent component 20 on the
surface sheet 11, and heating and pressing all of the layers except
the article backing sheet 13. The temporal adhesive member 8 is
indicated by a dashed line in FIG. 1. However, as shown in FIG. 2A,
the area in which the temporal adhesive member 8 is formed is
recessed in concave fashion in the skin-facing surface 6 of the
absorbent article 1.
[0068] As shown in FIG. 1, the temporal adhesive member 8 is formed
along the right-side edge 4 and left-side edge 5 of the absorbent
article 1, but in the front edge 2 and back edge 3, the temporal
adhesive member 8 is not formed in an area that extends laterally
over a distance W1 about the vertical center line Oy, and the area
W1 is the excluded portion of the temporal adhesive member 8.
[0069] In FIG. 2B, the width dimension of the round seal 14 formed
in the bottom absorbent component 10, and the width dimension of
the round seal 24 formed in the upper absorbent component 20 are
each indicated by the reference symbol Wa, and the width dimension
of the temporal adhesive member 8 is indicated by the reference
symbol Wb. FIG. 5 is a partial plan view showing an enlarged view
of the round seals 14 and 24 and the temporal adhesive member 8.
Also in FIG. 5, the width dimensions of the round seals 14 and 24
are indicated by the reference symbol Wa, and the width dimension
of the temporal adhesive member 8 is indicated by the reference
symbol Wb.
[0070] The area in which the round seals 14 and 24 are formed and
the area in which the temporal adhesive member 8 is formed coincide
with each other, and the width dimension Wb of the temporal
adhesive member 8 is greater than the width dimension Wa of the
round seals 14 and 24. The width dimension Wa of the round seals 14
and 24 is about 2 mm, for example, and the width dimension Wb of
the temporal adhesive member 8 is about 3 mm, for example.
[0071] The bonding strength between the bottom absorbent component
10 and the upper absorbent component 20 in the temporal adhesive
member 8 is set so as to be less than the bonding strength of the
round seal 14 between the surface sheet 11 and the middle sheet 12
of the bottom absorbent component 10. The bonding strength of the
temporal adhesive member 8 is also set so as to be less than the
bonding strength of the round seal 24 between the layers that
include the surface sheet 21, the middle sheet 22, and the back
surface sheet 23 of the upper absorbent component 20.
[0072] FIG. 4 shows the details of the pressed pattern on the
temporal adhesive member 8. The seal pattern is not shown in FIG. 5
and other drawings. In the temporal adhesive member 8 as shown in
FIG. 4, square pressure portions 8a are formed at a 45-degree angle
with respect to the longitudinal direction of the absorbent article
1, and the pressure portions 8a are spaced apart from each other
and arranged to form rows at a 45-degree angle. In the temporal
adhesive member 8, the surface sheet 11, the middle sheet 12, and
the upper absorbent component 20 are heated and pressed together in
the pressure portions 8a, the pressure portions 8a are concavely
shaped in the skin-facing surface, and the pressure portions 8a
function as joints between the surface sheet 11 and the upper
absorbent component 20.
[0073] As shown in FIG. 5, the pattern of the pressure portions 14a
and 24a of the round seal 14 that joins together the surface sheet
11 and middle sheet 12 of the bottom absorbent component 10, and
the pattern of the round seal 24 that fixes the layers in the upper
absorbent component 20, although not shown in detail in the
drawing, are the same as the pattern of the pressure portions 8a
shown in FIG. 4. The dimensions and arrangement pitch of the
pressure portions 8a of the temporal adhesive member 8 may be the
same as or different from the dimensions and arrangement pitch of
the pressure portions 14a and 24a of the round seals 14 and 24. For
example, the length of one side of the pressure portions 8a and the
pressure portions 14a and 24a is about 0.2 to 1 mm, and the
interval between the edges of adjacent pressure portions is about
0.2 to 1 mm.
[0074] The round seal 14 is formed by hot-pressing the surface
sheet 11 and middle sheet 12 sandwiched between a roll having a
smooth external periphery and a roll on which protrusions are
formed that correspond to the pattern of the pressure portions 14a.
The round seal 24 is formed by hot-pressing the upper absorbent
component 20 sandwiched between a roll having a smooth external
periphery and a roll on which protrusions are formed that
correspond to the pattern of the pressure portions 24a. In the same
manner, the temporal adhesive member 8 is formed by hot-pressing
the surface sheet 11, middle sheet 12, and upper absorbent
component 20 sandwiched between a roll having a smooth external
periphery and a roll on which protrusions are formed that
correspond to the pattern of the pressure portions 8a.
[0075] The two layers that include the surface sheet 11 and the
middle sheet 12 are the only materials that are sandwiched between
the rolls when the round seal 14 is formed, and the three layers
that constitute the upper absorbent component 20 are the only
materials that are sandwiched between the rolls when the round seal
24 is formed. In contrast, a total of five layers are sandwiched
between the rolls when the temporal adhesive member 8 is formed.
Furthermore, as previously mentioned, the width dimension Wa of the
round seals 14 and 24 is less than the width dimension Wb of the
temporal adhesive member 8. Accordingly, the compression force
applied to the pressure portions 8a of the temporal adhesive member
8 is less than the compression force applied to the pressure
portions 14a and 24a of the round seals 14 and 24 if the size and
pitch of the pressure portions 14a and 24a of the round seals 14
and 24, and the size and pitch of the pressure portions 8a of the
temporal adhesive member 8 are the same, and the pressing force and
heating temperature between the rolls during processing are also
the same.
[0076] It therefore becomes possible to set the strength of the
bond between the surface sheet 11 and the middle sheet 12 created
by the round seal 14, as well as the strength of the bond between
the layers of the upper absorbent component 20 created by the round
seal 24, to be sufficiently greater than the strength of the bond
between the surface sheet 11 and the back surface sheet 23 created
by the temporal adhesive member 8 even when the round seals 14 and
24 and the temporal adhesive member 8 are processed under the same
conditions.
[0077] It is preferred that at least one sheet selected from the
surface sheet 11 positioned on the skin side of the bottom
absorbent component 10, and the back surface sheet 23 positioned on
the clothing side of the upper absorbent component 20 have a
thermal-adhesive material, and that at least one of these
components include a non-fusible material.
[0078] The surface sheet 11 and the back surface sheet 23 are
adhesively bonded to each other by the adhesive force of the
thermal-adhesive material that is demonstrated when the temporal
adhesive member 8 is formed. However, when non-fusible fibers are
included in this adhesion surface, the surface sheet 11 and back
surface sheet 23 can be prevented from being fused together too
strongly by the temporal adhesive member 8, and it becomes easy to
peel the upper absorbent component 20 from the bottom absorbent
component 10. For example, the back surface sheet 23 is formed from
a polyethylene resin film or other thermal-adhesive resin; the
surface sheet 11 is formed from cotton, wood pulp, or other natural
fibers, or is formed solely from non-fusible fibers such as rayon
or other regenerated cellulose fibers; or the surface sheet 11 is
formed by mixing the non-fusible fibers with thermofusible fibers.
It is preferred in this case that the non-fusible fibers be
included in an amount of 50% mass or higher in the surface sheet
11, and that the remainder be composed of fusible fibers.
[0079] As shown in FIG. 2A, the temporal adhesive member 8 is
formed in a position at a distance Wc inward from the right-side
edge 4 and the left-side edge 5. Specifically, any of the round
seals 14 and 24 and the temporal adhesive member 8 may be formed in
an area that extends over the distance Wc. The distance Wc is
preferably 1 mm or greater, and more preferably 2 mm or
greater.
[0080] As shown in FIG. 5, the temporal adhesive member 8 is
preferably formed so as to protrude more towards the edge (the
right-side edge 4, for example) of the absorbent article 1 than the
round seals 14 and 24. In this case, none of the seal is disposed
in the area that extends over a width dimension Wc towards the
inside from the edge (the right-side edge 4, for example) of the
absorbent article 1, only the temporal adhesive member 8 is
disposed in the area that extends over the width dimension Wd
towards the inside, and the round seals 14 and 24 and the temporal
adhesive member 8 overlap further towards the inside. Therefore,
since the area that extends from the edge over the width dimension
Wc is flexible, and the rigidity increases in stages towards the
inside, skin discomfort is less likely to occur when the edge
touches the skin of the body.
[0081] The width dimension W1 of the excluded portion of the
temporal adhesive member 8 shown in FIG. 1 is set to 5 to 30 mm so
that a finger can be inserted into the excluded portion between the
surface sheet 11 of the bottom absorbent component 10 and the back
surface sheet 23 of the upper absorbent component 20.
[0082] After the upper absorbent component 20 and the surface sheet
11 and middle sheet 12 constituting the bottom absorbent component
10 are temporarily fixed by the temporal adhesive member 8, the
article backing sheet 13 is fixed by a hot-melt adhesive to the
clothing-facing surface of the middle sheet 12 of the bottom
absorbent component 10. The bonding strength of the hot-melt
adhesive between the middle sheet 12 and the article backing sheet
13 is set so as to be higher than the bonding strength of the
temporal adhesive member 8 between the bottom absorbent component
10 and the upper absorbent component 20.
[0083] A pressure-sensitive adhesive layer as a positioning-fixing
means is provided on the clothing-facing surface of the article
backing sheet 13, and a release sheet is provided for protecting
the pressure-sensitive adhesive layer before the absorbent article
1 is used. The strength with which the article backing sheet 13 and
the undergarment are adhesively fixed together by the
pressure-sensitive adhesive is set so as to be higher than the
strength with which the bottom absorbent component 10 and the upper
absorbent component 20 are bonded to each other by the temporal
adhesive member 8.
[0084] The strength with which the article backing sheet 13 and the
undergarment are adhesively fixed together is set so as to be less
than the bonding strength between the surface sheet 11 and the
middle sheet 12 in the bottom absorbent component 10, as well as
the bonding strength between the middle sheet 12 and the article
backing sheet 13.
[0085] The pressure-sensitive adhesive provided as the
positioning-fixing means on the clothing-facing surface of the
article backing sheet 13 is a hot-melt-type adhesive, and any one
type or combination of two or more types selected from a
styrene-isoprene-styrene copolymer, a styrene-butadiene-styrene
copolymer, a styrene-ethylene-butadiene-styrene copolymer, and a
styrene-butadiene copolymer can be used. The adhesive may be
applied in any pattern such as a striped or dotted pattern, and the
amount applied is in the range of 10 to 100 g/m.sup.2. The fixing
strength with respect to the undergarment is preferably 1
N/cm.sup.2 or higher.
[0086] The aforementioned fixing strength is a value measured after
affixing the article backing sheet 13 to the measuring unit of a
"PICMA tack tester IMC-1567" manufactured by Imoto Machinery Co.,
Ltd., and applying pressure for two seconds.
[0087] At least one sheet selected from the surface sheet 11 and
the middle sheet 12 of the bottom absorbent component 10 is
hydrophilic and is capable of absorbing and retaining liquid. In
the same manner, at least one sheet selected from the surface sheet
21 and the middle sheet 22 of the upper absorbent component 20 is
hydrophilic and is capable of absorbing and retaining liquid.
[0088] For example, the middle sheet 12 and the middle sheet 22
demonstrate liquid absorption capability; are nonwoven cloths
formed from cotton, wool, wood pulp, or other hydrophilic natural
fibers; and are, for example, spunlace nonwoven cloths.
Alternatively, the abovementioned sheets are spunlace nonwoven
cloths that include hydrophilized synthetic resin fibers, rayon
fibers, or other hydrophilic regenerated cellulose fibers. A
through-air nonwoven cloth may also be used that is formed from
hydrophilized synthetic resin fibers. A hydrophilic air-laid
nonwoven cloth may be used in which pulp fibers are layered by an
air-laying method and bonded together by a binder, or an air-laid
nonwoven cloth may be used that includes regenerated cellulose
fibers or synthetic resin fibers besides pulp fibers as the middle
sheet 12 and middle sheet 22. A super-absorbent polymer (SAP) may
also be added to the middle sheet 12 and middle sheet 22.
[0089] The surface sheets 11 and 21 are preferably capable of
transmitting liquid to the middle sheets 12 and 22, and a spunlace
nonwoven cloth or through-air nonwoven cloth may be used therein as
a hydrophilic nonwoven cloth. These sheets may also be formed from
a resin film that has numerous liquid-permeable pores.
[0090] A configuration may also be adopted in which the surface
sheet 11 constituting the bottom absorbent component 10 and the
surface sheet 21 constituting the upper absorbent component 20 are
omitted, the bottom absorbent component 10 is formed only by the
middle sheet 12 and article backing sheet 13, and the upper
absorbent component 20 is composed solely of the middle sheet 22
and back surface sheet 23.
[0091] The article backing sheet 13 and the back surface sheet 23
are impermeable to liquid and are formed from a polyethylene resin
film, a polypropylene resin film, a cellophane resin film, or the
like. The article backing sheet 13 and the back surface sheet 23
are preferably formed from an air-permeable, liquid-impermeable
resin film in which minute air pores are formed for transmitting
air. The film is obtained by mixing in numerous minute fillers and
stretching the product.
[0092] An SMS composite nonwoven cloth, in which a tri-layer
nonwoven cloth composed of spunbonded nonwoven cloth, melt-blown
nonwoven cloth, and spunbonded nonwoven cloth formed from
polypropylene resin fibers is bonded by a heat tool, may be used as
the article backing sheet 13 or the back surface sheet 23.
Alternatively, a composite nonwoven cloth may be used in which an
SMS composite nonwoven cloth, a melt-blown nonwoven cloth, and an
SMS composite nonwoven cloth are layered and heat-tooled. These
nonwoven cloths preferably have a weight of 15 to 40 g/m.sup.2.
Furthermore, the article backing sheet 13 or back surface sheet 23
may be formed from a laminate of the aforementioned nonwoven cloths
with a resin film.
[0093] Particularly since the bottom absorbent component 10 is
layered under the upper absorbent component 20, air permeability
with the outside of the undergarment is easily inhibited, and
moldering is a concern when the article is worn for a long period
of time during summer or in another hot and humid environment. The
aforementioned air-permeable nonwoven cloth is therefore preferred
for use as the back surface sheet 23 used in the upper absorbent
component 20. Since the aforementioned nonwoven cloth is flexible
in comparison with a resin film, the absorbent article 1 as a whole
is unlikely to acquire a rigid feel even when a back surface sheet
23 that is a nonwoven cloth is positioned in the middle of the
absorbent article 1.
[0094] The bottom absorbent component 10 composed of the surface
sheet 11, middle sheet 12, and article backing sheet 13, and the
upper absorbent component 20 composed of the surface sheet 21,
middle sheet 22, and back surface sheet 23 have different
characteristics from each other. First, the flexural rigidity in
the longitudinal direction is higher in the bottom absorbent
component 10 than in the upper absorbent component 20 when measured
independently in the bottom absorbent component 10 and the upper
absorbent component 20. Second, in addition to the aforementioned
rigidity difference, or irrespective of rigidity, the compression
recovery rate when compressed in the thickness direction is higher
in the bottom absorbent component 10 than in the upper absorbent
component 20 when measured independently in the bottom absorbent
component 10 and the upper absorbent component 20.
[0095] The abovementioned flexural rigidity may be measured using a
No. 311 Gurley-type stiffness tester manufactured by Yasuda Seiki
Seisakusho (Ltd.). A sample is created in which the bottom
absorbent component 10 and upper absorbent component 20 are cut so
that the width dimension in the direction along the horizontal
center line 0x is 25 mm and the length dimension in the direction
along the vertical center line Oy is 38 mm in the area in which the
round seals 14 and 24 are not formed, and measurement is performed
using the aforementioned tester so that the longitudinal direction
is the flexing direction. The Gurley flexural rigidity of the
bottom absorbent component 10 is preferably higher by at least 0.05
N per 25 mm of width than the Gurley flexural rigidity of the upper
absorbent component 20.
[0096] The flexural rigidity of the bottom absorbent component 10
can be made higher than the flexural rigidity of the upper
absorbent component 20 by making the weight (basis weight) of the
material constituting the bottom absorbent component 10 greater
than that of the upper absorbent component 20. Alternatively, even
when the materials constituting the bottom absorbent component 10
and the upper absorbent component 20 have the same weight, the
flexural resistance when flexed in the longitudinal direction can
be increased by making the thickness of the bottom absorbent
component 10 greater than the thickness of the upper absorbent
component 20, and the flexural rigidity of the bottom absorbent
component 10 can be made higher than the flexural rigidity of the
upper absorbent component 20.
[0097] A difference in thickness can be provided by bringing the
nonwoven cloth constituting the bottom absorbent component 10 into
contact with a hot roller and heat-treating the nonwoven cloth, or
by heat-treating with hot air and restoring the volume when at
least one sheet selected from the surface sheet 11 and the middle
sheet 12 of the bottom absorbent component 10 is a nonwoven cloth
that includes synthetic resin fibers. Alternatively, the thickness
of the bottom absorbent component 10 can be made greater than the
thickness of the upper absorbent component 20 by creating
corrugation so that at least one (the surface sheet 11 in FIG. 2A)
of the sheets selected from the surface sheet 11 and middle sheet
12 of the bottom absorbent component 10 has a rippled shape as
viewed in lateral cross-section, and is filled so that the tops and
bottoms of the waves extend parallel to the longitudinal direction,
as shown in FIG. 2B. As a result, the flexural rigidity of the
bottom absorbent component 10 can be increased.
[0098] The corrugation can be applied by providing a pair of gear
rolls in which a repeating pattern of depressions and protrusions
is formed along the peripheral surface, and passing the nonwoven
cloth between the gear rolls.
[0099] In the absorbent article 1 of the first embodiment shown in
FIG. 1 and FIGS. 2A and 2B, the middle sheet 12 of the bottom
absorbent component 10 and the middle sheet 22 of the upper
absorbent component 20 are formed from nonwoven cloths having the
same weight and fiber composition, and only the middle sheet 12 of
the bottom absorbent component 10 is heat treated and allowed to
restore its volume. As a result, the flexural rigidity of the
bottom absorbent component 10 is made higher than the flexural
rigidity of the upper absorbent component 20. The surface sheet 11
of the bottom absorbent component 10 and the surface sheet 21 of
the upper absorbent component 20 are also nonwoven cloths having
the same weight and fiber composition, and both sheets are
corrugated.
[0100] As a method for making the flexural rigidity of the bottom
absorbent component 10 greater than the flexural rigidity of the
upper absorbent component 20, the article backing sheet 13 of the
bottom absorbent component 10 may be formed from a material that
has higher rigidity than the back surface sheet 23 of the upper
absorbent component 20. For example, the back surface sheet 23 is
formed from a resin film or nonwoven cloth, and the article backing
sheet 13 is formed from a laminate of a nonwoven cloth and a resin
film.
[0101] As previously mentioned, by heat-treating and restoring the
volume of the nonwoven cloth constituting the bottom absorbent
component 10, and/or applying corrugation to the nonwoven cloth
constituting the bottom absorbent component 10, the compression
recovery rate when the bottom absorbent component 10 is compressed
in the thickness direction can be made higher than the compression
recovery rate of the upper absorbent component 20.
[0102] The compression recovery rate can be measured using a "KES
FB3-AUTO-A" automatic compression tester manufactured by Kato Tech
Co. (Ltd.). A summary of the graph obtained in this measurement is
shown in FIG. 11.
[0103] The bottom absorbent component 10 composed of the surface
sheet 11, middle sheet 12, and article backing sheet 13, or the
upper absorbent component 20 composed of the surface sheet 21,
middle sheet 22, and back surface sheet 23 is separately placed in
the automatic compression tester. An initial pressure P0 of 49 Pa
(0.5 g/cm.sup.2) is applied in the direction perpendicular to the
sample by a circular pressing plate having a surface area of 2
cm.sup.2, and the measured thickness at this time is designated as
the initial thickness dimension T0. The compression pressure is
linearly increased to Pm=4900 Pa (50 g/cm.sup.2) at a compression
rate of 50 seconds/1 mm with the initial pressure P0 as the
starting point, and the pressed thickness of the measurement sample
when the compression pressure Pm is applied is designated as
Tm.
[0104] The work of compression WC (Nm/m.sup.2) is the value
obtained by integrating the equation WC=.intg.PdT (wherein P is
pressure and T is thickness) from T0 to Tm with respect to curve
(i) in FIG. 11 obtained when the sample is compressed as described
above. The work of compression recovery WC' is the value
(Nm/m.sup.2) obtained when integration is performed in the same
manner as described above with respect to curve (ii) when the
compression pressure is returned from Pm to P0. The compression
recovery rate (RC value) is found by the equation
WC'/WC.times.100(%).
[0105] The compression recovery rate (RC value) of the upper
absorbent component 20 is preferably 40% or higher, and more
preferably 50% or higher. The maximum is 100%.
[0106] Heat treatment need not necessarily be performed as
described above when a plurality of sheets of bulky material having
cushioning properties, such as through-air nonwoven cloth, are
layered and used for the upper absorbent component 20 in order to
give the upper absorbent component 20 a higher compression recovery
rate than the bottom absorbent component 10.
[0107] When this absorbent article 1 is used, the release sheet
provided on the clothing-facing surface of the article backing
sheet 13 is peeled off, the article backing sheet 13 is adhesively
fixed to the crotch portion of the undergarment via the
pressure-sensitive adhesive layer, and the upper absorbent
component 20 is placed against the vaginal opening or other
discharge area. The upper absorbent component 20 absorbs vaginal
discharge, blood, or other discharged liquid, and when the upper
absorbent component 20 is contaminated, a finger is inserted
between the surface sheet 11 of the bottom absorbent component 10
and the back surface sheet 23 of the upper absorbent component 20
in the excluded portion of the temporal adhesive member 8 having
width dimension W1 shown in FIG. 1. The upper absorbent component
20 is then lifted up, the bond of the temporal adhesive member 8 is
released, and the upper absorbent component 20 is separated from
the bottom absorbent component 10. The surface sheet 11 of the
bottom absorbent component 10 is then used after being placed
against the discharge area.
[0108] As described above, by making the flexural rigidity of the
bottom absorbent component 10 higher than the flexural rigidity of
the upper absorbent component 20, deformation of the bottom
absorbent component 10 can be reduced in comparison with the amount
of deformation of the upper absorbent component 20 even when the
upper absorbent component 20 is twisted or wrinkled by body
movement or undergarment movement during use of the upper absorbent
component 20 against the discharge area. It thereby becomes easy
for the bottom absorbent component 10 to maintain a flat state when
the upper absorbent component 20 is peeled off after absorbing and
becoming contaminated with discharged material.
[0109] The bottom absorbent component 10 is heat treated and
allowed to restore its volume. In addition to or in lieu of this
treatment, corrugation is applied to the surface sheet 11 and other
components, and a compression recovery rate of 40% or higher, more
preferably 50% or higher, is obtained. The compression recovery
rate of the bottom absorbent component 10 is higher than the
compression recovery rate of the upper absorbent component 20.
Therefore, the bottom absorbent component 10 is pressed into the
upper absorbent component 20, and the overall thickness of the
absorbent article 1 is not significantly increased when the bottom
absorbent component 10 and the upper absorbent component 20 are
layered together. When the contaminated upper absorbent component
20 is peeled off, the thickness of the bottom absorbent component
10 is restored, and when the bottom absorbent component 10 is used
alone, the component feels soft against the discharge area.
Adequate liquid-absorption capability can also be demonstrated by
the bottom absorbent component 10 whose thickness is restored.
[0110] The temporal adhesive member 8 is formed in the area in
which the surface sheet 11 and the middle sheet 12 are layered in
the bottom absorbent component 10, and also in the area in which
the surface sheet 21, middle sheet 22, and back surface sheet 23
are layered in the upper absorbent component 20. Therefore, when
the upper absorbent component 20 is peeled off, the surface sheet
21, middle sheet 22, and back surface sheet 23 are lifted up
together and separated from the bottom absorbent component 10, and
the upper absorbent component 20 is easily peeled off. In the
bottom absorbent component 10, the force with which the upper
absorbent component 20 is peeled off in the area of the temporal
adhesive member 8 can be compensated for by the triple-layer
laminate composed of the surface sheet 11, middle sheet 12, and
article backing sheet 13. Therefore, wrinkling and other adverse
effects are unlikely to occur in the bottom absorbent component 10
even when the bottom absorbent component 10 is acted upon by this
peeling force.
[0111] FIG. 3 shows the absorbent article 101 according to a second
embodiment of the present invention. The drawing is a separated
sectional view showing a state in which each absorbent component is
separated.
[0112] In this absorbent article 101, a bottom absorbent component
110 is provided on the clothing-facing surface 7, an upper
absorbent component 120 is layered on the bottom absorbent
component 110, and a top absorbent component 130 is furthermore
provided on the skin-facing surface 6.
[0113] In the bottom absorbent component 110, a surface sheet 111
and a middle sheet 112 are layered and bonded together by a
hot-melt adhesive applied in an amount that does not inhibit the
transmission of liquid, and the surface sheet 111 and middle sheet
112 are also fixed in a round seal 114. In the upper absorbent
component 120, a surface sheet is not provided, and a middle sheet
122 and a back surface sheet 123 are laminated together, bonded by
a hot-melt adhesive, and fixed to each other by a round seal 124.
In the top absorbent component 130, a middle sheet 132 and a back
surface sheet 133 are bonded together by a hot-melt adhesive and
fixed by a round seal 134.
[0114] In this embodiment, the upper absorbent component 120 has a
two-layer structure that includes the middle sheet 122 and the back
surface sheet 123. Therefore, the round seal 124 of the upper
absorbent component 120 is not necessarily needed when the two
layers are securely fixed with a hot-melt adhesive. This applies in
the same manner to the top absorbent component 130, and the round
seal 134 of the top absorbent component 130 is not necessarily
needed.
[0115] The surface sheet 111 and middle sheet 112 of the bottom
absorbent component 110, the upper absorbent component 120, and the
top absorbent component 130 are layered together, and the bottom
absorbent component 110, upper absorbent component 120, and top
absorbent component 130 are temporarily fixed together in a
separable manner by a temporal adhesive member 8 having the same
pattern as the one shown in FIG. 1. After this temporary fixing, an
article backing sheet 113 is bonded to the middle sheet 112 of the
bottom absorbent component 110 by a hot-melt adhesive.
[0116] The pattern shape of the pressure portions in each of the
round seals 114, 124, and 134 and the temporal adhesive member 8 is
the same as in the first embodiment. The preferred ranges of the
width dimension Wa of the round seals 114, 124, and 134, the width
dimension Wb of the temporal adhesive member 8, the distance Wc
from the edge to the temporal adhesive member 8 and round seal, and
other dimensions are also the same as in the first embodiment.
[0117] The absorbent article 101 of this embodiment is used with
the top absorbent component 130 placed against the discharge area.
When the top absorbent component 130 is contaminated, the top
absorbent component 130 is peeled off, and the upper absorbent
component 120 is used after being placed against the discharge
area. When the upper absorbent component 120 has also become
contaminated, this upper absorbent component 120 is peeled off, and
the bottom absorbent component 110 is used after being placed
against the discharge area.
[0118] The flexural rigidity of the absorbent components in the
longitudinal direction is higher in the bottom absorbent component
110 than in the top absorbent component 130. The flexural rigidity
of the upper absorbent component 120 is higher than in the top
absorbent component 130 and lower than in the bottom absorbent
component 110. The compression recovery rate of the bottom
absorbent component 110 when compressed in the thickness direction
is higher than in the top absorbent component 130, and the
compression recovery rate of the upper absorbent component 120 is
higher than that of the top absorbent component 130 and lower than
that of the bottom absorbent component 110.
[0119] In the embodiment shown in FIG. 3, the middle sheet 132 of
the top absorbent component 130 and the middle sheet 122 of the
upper absorbent component 120 are nonwoven cloths having the same
weight and fiber composition. However, corrugation is applied to
the middle sheet 122 of the upper absorbent component 120, the
thickness of the upper absorbent component 120 is increased beyond
the thickness of the top absorbent component 130, and flexural
rigidity and compression recovery rate of the upper absorbent
component 120 are both higher than in the top absorbent component
130. In the bottom absorbent component 110, the middle sheet 112 is
heat-treated and allowed to restore its volume, the corrugation is
applied to the surface sheet 111, the bottom absorbent component
110 is provided with the greatest thickness and weight, and the
flexural rigidity and compression recovery rate are both set higher
in the bottom absorbent component 110 than in the upper absorbent
component 120 and top absorbent component 130.
[0120] It is preferred in the absorbent article 1 of the first
embodiment that the bottom absorbent component 10 and the upper
absorbent component 20 be visually distinguishable from each other.
A configuration is also preferably adopted in the absorbent article
101 of the second embodiment wherein at least the bottom absorbent
component 110 can be visually distinguished from the upper
absorbent component 120 and the top absorbent component 130.
Furthermore, it is preferred that the bottom absorbent component
110, the upper absorbent component 120, and the top absorbent
component 130 be visually distinguishable from each other.
[0121] Causing each absorbent component to be a different color
makes it possible to visually distinguish the absorbent components.
For example, a configuration may be adopted whereby any of the
absorbent components is formed from white fibers, and the
skin-facing surface is made white, whereas another absorbent
component is formed from colored fibers, and the skin-facing
surface is a color other than white. For example, when a catechin
as a functional agent that demonstrates deodorant capability is
added to the middle sheets 12 and 112 and/or the surface sheets 11
and 111 constituting the bottom absorbent component 10 or 110, a
green colorant is also preferably used that suggests the presence
of the catechin. The skin-facing surface of the bottom absorbent
components 10 and 110 thereby shows a pale green color. When the
upper absorbent component or top absorbent component is composed of
white fibers in this instance, it is easy to visually distinguish
during use whether the bottom absorbent components 10 and 110 are
in use. When a catechin has been added, antimicrobial effects and
deodorant effects can be demonstrated by the bottom absorbent
components 10 and 110 that are worn for the longest time, and
unpleasant odor can be prevented even when the article is worn for
a long period of time. It is also possible to add the catechin to
the upper absorbent components 20 and 120 or the top absorbent
component 130.
[0122] FIGS. 6A and 6B are plan views showing a third embodiment in
which the absorbent components are visually distinguishable from
each other. FIG. 6A is a plan view of the upper absorbent component
220 as viewed from the skin-facing surface. FIG. 6B is a plan view
of only the bottom absorbent component 210 as viewed from the
skin-facing surface.
[0123] In the upper absorbent component 220 shown in FIG. 6A, a
round seal 224 is formed in the periphery, and corrugation is
applied to the surface sheet 221. This corrugation gives the
cross-section of the surface sheet 221 a rippled shape, and the
tops and bottoms of the waves extend linearly and in parallel
fashion in the longitudinal direction. In the bottom absorbent
component 210 shown in FIG. 6B, the same corrugation as previously
described is applied to the surface sheet 211, and embossed
portions 215 in a leaf design are furthermore formed in the surface
sheet 211. Providing mutually different embossed patterns to the
skin-facing surfaces of the bottom absorbent component 210 and the
upper absorbent component 220 thereby makes it possible to easily
distinguish visually between the bottom absorbent component 210 and
the upper absorbent component 220.
[0124] When a configuration is adopted in which corrugation is
applied to the surface sheet of the bottom absorbent component, and
corrugation is not applied to the surface sheet of the upper
absorbent component, the bottom absorbent component can easily be
distinguished visually from the upper absorbent component by
visually determining whether corrugation is present. By applying
corrugation to the surface sheet of the bottom absorbent component
as described above, the bottom absorbent component can be endowed
with a higher flexural rigidity and compression recovery rate than
the upper absorbent component.
[0125] As described above, visual distinction of the absorbent
components is made possible by using different material in the
surface sheets of the bottom absorbent component and the upper
absorbent component, or by varying the structure of the surface
sheets.
[0126] By making it possible to distinguish between the bottom
absorbent component and the upper absorbent component as viewed
from the skin-facing surfaces thereof, the absorbent component that
is currently in contact with the discharge area can be identified,
the user can be prevented from being inconvenienced by mistakenly
discarding the entire absorbent article when the upper absorbent
component is in use, mistakenly removing the absorbent article from
the undergarment without having a replacement absorbent article
ready when the bottom absorbent component is in use, or
experiencing other inconveniences.
[0127] FIG. 7A is a plan view of the absorbent article 301
according to a fourth embodiment of the present invention as viewed
from the skin-facing surface 6. FIG. 7B is a plan view of a state
in which the upper absorbent component 320 is removed from the
absorbent article 301, and specifically shows the bottom absorbent
component 310 from the skin side. FIG. 8 is a partial sectional
view along line VIII-VIII in FIG. 7A. FIG. 9 is a partial enlarged
plan view showing the shape of the temporal adhesive member 8.
[0128] As shown in the partial sectional view in FIG. 8, this
absorbent article 301 is formed from two layers that include the
bottom absorbent component 310 and the upper absorbent component
320.
[0129] The bottom absorbent component 310 is formed from a surface
sheet 311, a first middle sheet 312, a second middle sheet 313, and
an article backing sheet 314. The surface sheet 311 is
liquid-permeable, and the first middle sheet 312 and second middle
sheet 313 are capable of absorbing and retaining liquid. In an
alternative configuration, one of the first middle sheet 312 and
second middle sheet 313 is liquid-absorbent, and the other sheet
may have high bulk and low density and demonstrate cushioning
ability. The article backing sheet 314 is air-permeable and
liquid-impermeable.
[0130] A round seal is not formed in the bottom absorbent component
310, and the layers are bonded by a hot-melt adhesive. A
rubber-based hot-melt adhesive is applied in a spiral pattern an
amount of about 10 g/m.sup.2 between the surface sheet 311 and the
first middle sheet 312, and between the first middle sheet 312 and
the second middle sheet 313 so that the layers can be securely
bonded together without inhibiting the transmission of liquid. The
second middle sheet 313 and the article backing sheet 314 are also
securely fixed together by a hot-melt adhesive.
[0131] The abovementioned absorbent component 320 has a surface
sheet 321, a middle sheet 322, and a back surface sheet 323. The
surface sheet 321 is liquid-permeable, the middle sheet 322 is
capable of absorbing and retaining liquid, and the back surface
sheet 323 is air-permeable and liquid-impermeable.
[0132] A round seal is also not formed in the upper absorbent
component 320, the surface sheet 321 and middle sheet 322 are
securely fixed together by a hot-melt adhesive applied in an amount
that does not inhibit the transmission of liquid, and the middle
sheet 322 and back surface sheet 323 are also securely fixed
together by a hot-melt adhesive.
[0133] As shown in FIG. 7A, the bottom absorbent component 310 and
the upper absorbent component 320 are temporarily fixed together by
the temporal adhesive member 8 so as to be able to separate. The
pattern of the temporal adhesive member 8 is the same as in the
first embodiment shown in FIG. 1, and the pattern of the pressure
portions 8a of the temporal adhesive member 8, the preferred range
of the width dimensions Wb of the temporal adhesive member 8, and
other characteristics are the same as in the first embodiment. The
strength of the bond between the bottom absorbent component 310 and
the upper absorbent component 320 created by the temporal adhesive
member 8 is set so as to be lower than the adhesion strength
between the layers in the bottom absorbent component 310 and the
adhesion strength between the layers of the upper absorbent
component 320.
[0134] As shown in FIG. 7A, the temporal adhesive member 8 extends
along the entire length of the edges that include the right-side
edge 4 and left-side edge 5 of the absorbent article 301, and the
ends 8b of the temporal adhesive member 8 are positioned inside the
front edge 2 and the back edge 3. The space between the
aforementioned ends 8b is an excluded portion in which the temporal
adhesive member 8 is cut out towards the insides of the front edge
2 and back edge 3. The width dimension of this excluded portion is
W1, and the preferred range thereof is the same as in the
aforementioned first embodiment.
[0135] As shown in FIG. 7A, in the front edge 2 and the back edge
3, a compressed portion 325 in which the upper absorbent component
320 is partially compressed is formed in the area (a) that includes
the excluded portion of the temporal adhesive member 8 and part of
the temporal adhesive member 8. As shown in FIG. 8, the surface
sheet 321, middle sheet 322, and back surface sheet 323 are all
compressed at the compressed portion 325, and part of the upper
absorbent component 320 is made thin. The compressed portion 325 is
formed in an area that extends over a length L in the longitudinal
direction from the front edge 2 and back edge 3. Length L is not
particularly limited and may be about 5 mm to 30 mm, for example.
The sum (2.times.L) of the lengths L of the compressed portions 325
formed in the front edge 2 and back edge 3 is preferably 1/4 or
less of the length dimension in the longitudinal direction of the
absorbent article 301, and more preferably 1/5 or less thereof.
Specifically, the compressed portions 325 do not extend to the
central region of the absorbent article 301.
[0136] The compressed portion 325 is formed after the surface sheet
321, middle sheet 322, and back surface sheet 323 constituting the
upper absorbent component 320 are bonded by the hot-melt adhesive,
in a step that precedes the temporary fixing of the bottom
absorbent component 310 and the upper absorbent component 320 by
the temporal adhesive member 8. The compressed portion 325 is
formed by pressing the upper absorbent component 320 at a normal or
elevated temperature using a roll having a smooth surface or a roll
on which a fine embossed pattern is formed on the surface.
[0137] When the compressed portion 325 is formed in the excluded
portion, the surface sheet 321, middle sheet 322, and back surface
sheet 323 constituting the upper absorbent component 320 become
difficult to separate even when the temporal adhesive member 8 is
not present, and it becomes possible to prevent layer separation
from occurring in the upper absorbent component 320 in the excluded
portion in which the temporal adhesive member 8 is not formed.
[0138] As shown in FIG. 8, a gap is easily formed in the excluded
portion of the temporal adhesive member 8 between the bottom
surface of the compressed portion 325 of the upper absorbent
component 320 and the surface sheet 311 of the bottom absorbent
component 310. It therefore becomes easy to grasp and peel off the
upper absorbent component 320 by the fingers and in the excluded
portion of the temporal adhesive member 8 when the upper absorbent
component 320 has become contaminated.
[0139] As shown in FIG. 7A, the ends 8b of the temporal adhesive
member 8 are positioned towards the inside with respect to the
front edge 2 and back edge 3. As a result, a portion of the
temporal adhesive member 8 is disposed at the corners 9 of the
absorbent article 301; specifically, at the boundary between the
right-side edge 4 and the front edge 2, the boundary between the
right-side edge 4 and the back edge 3, the boundary between the
left-side edge 5 and the front edge 2, and the boundary between the
left-side edge 5 and the back edge 3. By having a portion of the
temporal adhesive member 8 present at each corner 9, it becomes
easy to prevent the upper absorbent component 320 from improperly
separating from the bottom absorbent component 310 in the corners 9
when the absorbent article 301 is in use.
[0140] Inside the corners 9 of the absorbent article 301, portions
of the temporal adhesive member 8 form outwardly convex curves 8c
that follow the shape of the corners 9. The temporal adhesive
member 8 has the curves 8c, and the ends 8b are disposed inside the
front edge 2 and back edge 3. Therefore, the temporal adhesive
member 8 is disposed in an area that extends over a width dimension
W2 in the transverse direction in the front edge 2 and back edge 3,
as shown in FIG. 9. The aforementioned W2 is preferably at least
twice the width dimension Wb of the temporal adhesive member 8, and
is more preferably at least three times the width dimension Wb.
[0141] When this absorbent article 301 is worn while fixed to the
inside surface of an undergarment, and a longitudinally directed
peeling force F1 shown in FIG. 9 is applied to the front edge 2 or
back edge 3 in the excluded portion of the temporal adhesive member
8, the peeling force F1 can be received in the area that extends
over the width dimension W2 because the temporal adhesive member 8
is present in the area that extends over the width dimension W2 in
the front edge 2 and back edge 3. It is therefore easy to prevent
the upper absorbent component 320 from being improperly separated
from the bottom absorbent component 310 by the aforementioned
peeling force F1.
[0142] When the upper absorbent component 320 is contaminated with
vaginal discharge, blood, or the like, a lifting force acts in the
forward direction with respect to the plane of paper in FIG. 9 on
the upper absorbent component 320 at the front edge 2 or back edge
3 when the upper absorbent component 320 is grasped in the fingers
and peeled off at the excluded portion of the temporal adhesive
member 8 in the front edge 2 or back edge 3. As a result, a force
F2 can be applied in the direction of the pattern of the temporal
adhesive member 8 to the ends 8b of the temporal adhesive member 8,
as shown in FIG. 9. The peeling force is thus propagated from the
ends 8b along the curves 8c with respect to the temporal adhesive
member 8, and it becomes possible to peel the upper absorbent
component 320 from the bottom absorbent component 310 without
imparting excessive resistance to the fingers.
[0143] The compressed portion 325 may also be applied in the other
embodiments described previously, and the advantage of having
curves 8c formed in the temporal adhesive member 8 is the same in
the other embodiments.
[0144] As shown in FIG. 8, the surface sheet 311 of the bottom
absorbent component 310 and the surface sheet 321 of the upper
absorbent component 320 are both corrugated and have a rippled
pattern formed therein. In this absorbent article 301, the bottom
absorbent component 310 has a four-layer structure, and the upper
absorbent component 320 has a three-layer structure. Therefore, the
compression recovery rate and the flexural rigidity in the
longitudinal direction can be made higher in the bottom absorbent
component 310 than in the upper absorbent component 320.
[0145] As shown in FIG. 7B, embossed portions 315 formed in a leaf
design are interspersed in the surface sheet 311 of the bottom
absorbent component 310, and the bottom absorbent component 310 and
upper absorbent component 320 are easy to visually distinguish from
each other.
[0146] FIG. 10 is a plan view of the absorbent article 401
according to a fifth embodiment of the present invention as viewed
from the skin-facing surface 6.
[0147] In this absorbent article 401, at least one upper absorbent
component is layered on the bottom absorbent component in the same
manner as in the embodiments described above. A plurality of layers
is layered in each of the bottom absorbent component and the upper
absorbent component, the layers are bonded together by a hot-melt
adhesive in each of the absorbent components, and round seals are
formed as needed in the absorbent components.
[0148] The bottom absorbent component and the upper absorbent
component are temporarily fixed together by a temporal adhesive
member 8. In the absorbent article 401 shown in FIG. 10, the
temporal adhesive member 8 is formed along the entire length
towards the inside of the front edge 2 and back edge 3, and
excluded portions in which the temporal adhesive member 8 is
interrupted are formed towards the inside of the right-side edge 4
and the inside of the left-side edge 5.
[0149] In the aforementioned embodiments, the catechin or other
deodorant functional agent described above, or an antimicrobial
agent, a fragrance, or the like is preferably included in at least
the bottom absorbent components 10, 110, 210, and 310. However, the
functional agent may also be included in each of the upper
absorbent components 20, 120, 220, and 320, or the top absorbent
component 130.
[0150] One or more types selected from phenols extracted from
plants, such as catechins and the like, or active carbon, copper
ions, silver ions, and the like may be used as the functional
agent. As previously mentioned, a colorant is preferably used to
impart a green color to the skin-facing surface of the absorbent
component when a catechin is included, and when active carbon is
used, a colorant that gives the skin-facing surface a black color
is preferably used. The bottom absorbent component can easily be
distinguished from the upper absorbent component by combining a
colored absorbent component that includes these functional agents
and colorants with a white-colored absorbent component, the bottom
absorbent component can easily be distinguished visually from the
upper absorbent component, as described above. By forming the
embossed portions 215 and 315 in the leaf pattern shown in FIG. 6B
or FIG. 7B in the skin-facing surface of the absorbent component to
which a catechin is added, the absorbent component can be visually
recognized as having antimicrobial and deodorant effects, and a
fresh feeling can be imparted to the user.
[0151] Catechins are tea-leaf extracts extracted from tea leaves
with water or hot water, and are included among the fibers of the
middle sheet or surface sheet in the form of microparticles,
attached to a microparticulate porous substance, or sealed inside
microcapsules.
[0152] Catechins included in tea-leaf extracts include epicatechin,
epicatechin gallate, epigallocatechin, epigallocatechin gallate,
catechin gallate, and gallocatechin gallate. When a tea-leaf
extract is used, 10% mass or more, and more preferably 30% mass or
more, of epigallocatechin gallate is preferably included in the
tea-leaf extract.
[0153] Copper phthalocyanine green and other phthalocyanine-based
colorants can be used. It is also possible to use a copper
chlorophyll-based colorant, which is a natural food colorant. The
hue of the colorant preferably demonstrates concealing effects with
respect to vaginal discharge (colorless to light brown) and urine
(light yellow) among bodily fluids. In order to enhance the
impression of a catechin as a naturally occurring tea extract, a
hue between 10 YR and 10 G according to the Munsell color system is
desired for this coloration with consideration for the green color
of tea leaves. A hue from 10 Y to 10 G is preferred.
[0154] Tea-leaf extract is included in the middle sheet, for
example, and is added in a range of 0.1 to 1.0% mass with respect
to the mass of the middle sheet. The aforementioned colorant is
added in the range of 10 to 30 mass parts with respect to 100 mass
parts of the tea-leaf extract. When the tea-leaf extract is used in
the form of microparticles, the size of the microparticles is
preferably 5 micrometers or less, and more preferably 2 micrometers
or less.
(1) Example 1
[0155] An absorbent article 1 having a two-layer structure that
included a bottom absorbent component 10 and an upper absorbent
component 20 was created as shown in FIGS. 2A and 2B.
[0156] The surface sheet 11 of the bottom absorbent component 10
and the surface sheet 21 of the upper absorbent component 20 were
both formed from spunlace nonwoven cloth composed of 60% mass of
rayon fibers and 40% mass of polyethylene terephthalate fibers. The
weight thereof was 35 g/m.sup.2. Corrugation was applied to the
surface sheet 11 and the surface sheet 21.
[0157] The middle sheet 12 of the bottom absorbent component 10 and
the middle sheet 22 of the upper absorbent component 20 were both
formed from through-air nonwoven cloth composed of 50% mass of
polyethylene fibers and 50% mass of polypropylene fibers. The
polyethylene fibers and polypropylene fibers used both had a
fineness of 2.2 dtex and a fiber length of 40 mm, and the weight
thereof was 25 g/m.sup.2. The through-air nonwoven cloth
constituting the middle sheet 12 of the bottom absorbent component
10 was brought into contact with two hot rollers in an S-shape at
120 degrees C., heat-treated, and allowed to restore its
volume.
[0158] The thickness of the heat-treated middle sheet 12 was 1.4
mm, and the thickness of the non-heat-treated middle sheet 22 of
the upper absorbent component 20 was 0.5 mm. The compression
recovery rate (RC value) of the heat-treated middle sheet 12 when
measured alone was 53.83%.
[0159] The article backing sheet 13 of the bottom absorbent
component 10 and the back surface sheet 23 of the upper absorbent
component 20 were both formed from air-permeable polyethylene film
having a basis weight of 35 g/m.sup.2.
[0160] As shown in FIG. 1 and FIGS. 2A and 2B, a round seal 14 was
formed in the bottom absorbent component 10, a round seal 24 was
formed in the upper absorbent component 20, and a temporal adhesive
member 8 was formed for the temporary fixing of the bottom
absorbent component 10 to the upper absorbent component 20.
[0161] The bottom absorbent component 10 and the upper absorbent
component 20 were formed from the same material, but by
heat-treating and restoring the volume of the middle sheet 12 of
the bottom absorbent component 10, the thickness of the bottom
absorbent component 10 was made greater than that of the upper
absorbent component 20, and it became possible to make the flexural
rigidity and compression recovery rate greater in the bottom
absorbent component 10 than in the upper absorbent component
20.
(2) Example 2
[0162] An absorbent article having a two-layer structure was
created in the same manner as in Example 1.
[0163] The surface sheet 11, middle sheet 12, and article backing
sheet 13 of the bottom absorbent component 10 were the same as
those used in Example 1.
[0164] The surface sheet 21 of the upper absorbent component 20 was
formed from through-air nonwoven cloth composed of 50% mass of
polyethylene fibers and 50% mass or polypropylene fibers. The
polyethylene fibers and polypropylene fibers that were used both
had a fineness of 2.2 dtex and a fiber length of 40 mm, and the
weight thereof was 25 g/m.sup.2. The nonwoven cloth that was used
was neither heat-treated for volume recovery nor corrugated.
[0165] An air-laid nonwoven cloth in which pulp was laminated by an
air-laying method and the fibers were bonded together by a binder
was used as the middle sheet 22 of the upper absorbent component
20. The weight thereof was 35 g/m.sup.2. The back surface sheet 23
of the upper absorbent component 20 was an SMS composite nonwoven
cloth having a weight of 20 g/m.sup.2.
[0166] As shown in FIG. 1 and FIGS. 2A and 2B, a round seal 14 was
formed in the bottom absorbent component 10, a round seal 24 was
formed in the upper absorbent component 20, and a temporal adhesive
member 8 was formed for temporarily fixing the bottom absorbent
component 10 to the upper absorbent component 20.
[0167] By making the total weight (basis weight) of the materials
constituting the bottom absorbent component 10 greater than that of
the upper absorbent component 20, the flexural rigidity of the
bottom absorbent component 10 was set higher than that of the upper
absorbent component 20. The middle sheet 12 used in the bottom
absorbent component 10 had its volume restored by heat treatment,
and the bottom absorbent component 10 had a higher compression
recovery rate than the upper absorbent component 20.
(3) Example 3
[0168] An absorbent article 101 having the three-layer structure
shown in FIG. 3 was created as in Example 3.
[0169] The surface sheet 111 and middle sheet 112 of the bottom
absorbent component 110 were the same as the surface sheet 11 and
middle sheet 12 used in Example 1. A laminate of SMS composite
nonwoven cloth having a weight of 20 g/m.sup.2 and an air-permeable
polyethylene film having a basis weight of 20 g/m.sup.2 were used
as the article backing sheet 113.
[0170] A corrugated spunlace nonwoven cloth composed of 60% mass of
cotton fibers and 40% mass of polyethylene terephthalate fibers was
used as the middle sheet 122 of the upper absorbent component 120.
An air-permeable polyethylene film having a basis weight of 35
g/m.sup.2 was used as the back surface sheet 123.
[0171] A non-corrugated spunlace nonwoven cloth having a weight of
35 g/m.sup.2 composed solely of cotton fibers was used as the
middle sheet 132 of the top absorbent component 130. An
air-permeable polyethylene film having a basis weight of 23
g/m.sup.2 was used as the back surface sheet 133.
[0172] As shown in FIG. 3, a round seal 114 was formed in the
bottom absorbent component 110, and a round seal 124 was formed in
the upper absorbent component 120. A round seal 134 was formed in
the top absorbent component 130. A temporal adhesive member 8 was
formed for temporarily fixing together the bottom absorbent
component 110, upper absorbent component 120, and top absorbent
component 130.
[0173] By setting the weight and basis weight so as to increase in
sequence from the top absorbent component 130 to the upper
absorbent component 120 to the bottom absorbent component 110, the
flexural rigidity was also set so as to increase in the same
sequence. The middle sheet 122 of the upper absorbent component 120
was also corrugated, and the thickness thereof was increased,
whereby the flexural rigidity and compression recovery rate were
increased. In the bottom absorbent component 110, the middle sheet
112 was heat-treated and allowed to recover its volume, and the
surface sheet 111 was corrugated and increased in thickness,
whereby the flexural rigidity was increased, and the compression
recovery rate was also increased.
(4) Example 4
[0174] As shown in FIGS. 7 through 9, an absorbent article was
created without round seals formed in the absorbent components.
[0175] The bottom absorbent component 310 had a four-layer
structure, the same as shown in FIG. 8. The surface sheet 311 was a
spunlace nonwoven cloth composed of 60% mass of rayon fibers and
40% mass of polyethylene terephthalate fibers, and the weight
thereof was 35 g/m.sup.2. A corrugated sheet was used as the
surface sheet 311. The first middle sheet 312 was a spunlace
nonwoven cloth composed of 90% mass of rayon fibers and 10% mass of
hydrophilized polypropylene fibers, and the weight thereof was 30
g/m.sup.2. The second middle sheet 313 was a through-air nonwoven
cloth composed of 50% mass of hydrophilized polyethylene fibers and
50% mass of hydrophilized polypropylene fibers, and the weight
thereof was 30 g/m.sup.2. The article backing sheet 314 was formed
from an air-permeable polyethylene film having a basis weight of 35
g/m.sup.2.
[0176] The upper absorbent component 320 had a three-layer
structure that included a surface sheet 321, a middle sheet 322,
and a back surface sheet 323; the surface sheet 321 was the same as
the surface sheet 311 of the bottom absorbent component 310; and
the middle sheet 322 and back surface sheet 323 were the same as
the first middle sheet 312 and article backing sheet 314 of the
bottom absorbent component 310. Specifically, the upper absorbent
component 320 had the same structure as the bottom absorbent
component 310 without the second middle sheet 313. In the bottom
absorbent component 310, the surface sheet 311 was layered with the
first middle sheet 312, and embossed portions 315 were formed in
the leaf design shown in FIG. 7B.
[0177] The bottom absorbent component 310 and upper absorbent
component 320 were layered together, and a temporal adhesive member
8 was formed.
[0178] In Example 4, the bottom absorbent component 310 had a
four-layer structure, and the upper absorbent component 320 had a
three-layer structure. Therefore, the flexural rigidity of the
bottom absorbent component 310 could be set higher than that of the
upper absorbent component 320. The compression recovery rate could
also be set higher in the bottom absorbent component 310 than in
the upper absorbent component 320.
[0179] Tea-leaf extract and green colorant were added to the first
middle sheet 312 of the bottom absorbent component 310 and the
middle sheet 322 of the upper absorbent component 320, the green
color was visible through the surface sheet 311 in the bottom
absorbent component 310, and the green color was visible through
the surface sheet 321 in the upper absorbent component 320.
[0180] The component ratios of catechins included in the tea-leaf
extract were 31.5% mass of epigallocatechin gallate, 17.2% mass of
epigallocatechin, 17.2% mass of gallocatechin, 5.9% mass of
epicatechin, 5.0% mass of epicatechin gallate, 2.8% mass of
catechin gallate, and 1.9% mass of gallocatechin gallate. The tea
leaf powder including these catechins was used in the form of
microparticles having a diameter of less than 2 micrometers. The
tea leaf powder was added in the amount of 0.38% mass with respect
to the masses of the first middle sheet 312 and the middle sheet
322.
[0181] Copper phthalocyanine green having a green color was used as
the colorant. The colorant was added in the amount of 15% mass per
100% mass of the tea-leaf extract included in each of the first
middle sheet 312 and the middle sheet 322.
[0182] The first middle sheet 312 and middle sheet 322 were
manufactured according to a method whereby rayon fibers and
polypropylene fibers were mixed in a mass ratio of 90:10,
respectively; a spunlace nonwoven cloth having a weight of 30
g/m.sup.2 was formed; this spunlace nonwoven cloth was placed in a
drum-type dyeing machine; a nonionic/anionic surfactant as a
dispersing agent was added and the product was stirred; tea-leaf
extract and copper phthalocyanine green were added; the tea-leaf
extract was fixed to the fibers; and the fibers were colored
green.
(5) Example 5
[0183] An absorbent article was manufactured in which the bottom
absorbent component had a three-layer structure, the upper
absorbent component had a two-layer structure, the skin-facing
surface of the upper absorbent component was white, and the
skin-facing surface of the bottom absorbent component was
green.
[0184] In the bottom absorbent component, the surface sheet was the
same as the first middle sheet 312 of Example 4; specifically, the
surface sheet was formed from a spunlace nonwoven cloth that
included tea-leaf extract and a green colorant. A non-corrugated
sheet was used. The middle sheet and article backing sheet used in
the bottom absorbent component were the same as the heat-treated
and re-voluminized middle sheet 12 and article back surface sheet
13 used in the bottom absorbent component of Example 1.
[0185] The surface sheet of the upper absorbent component was a
through-air nonwoven cloth having a weight of 25 g/m.sup.2 formed
from 50% mass of hydrophilized polyethylene fibers and 50% mass of
hydrophilized polypropylene fibers, and the back surface sheet was
an SMS composite nonwoven cloth having a weight of 20
g/m.sup.2.
[0186] The bottom absorbent component and upper absorbent component
used were not provided with round seals, and the layers thereof
were bonded together. The bottom absorbent component and the upper
absorbent component were layered together, and a temporal adhesive
member 8 was formed.
[0187] It was possible to set a higher flexural rigidity and
compression recovery rate in the bottom absorbent component than in
the upper absorbent component.
[0188] While preferred embodiments of the present invention have
been described and illustrated above, it is to be understood that
they are exemplary of the invention and are not to be considered to
be limiting. Additions, omissions, substitutions, and other
modifications can be made thereto without departing from the spirit
or scope of the present invention. Accordingly, the invention is
not to be considered to be limited by the foregoing description and
is only limited by the scope of the appended claims.
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