U.S. patent application number 11/079042 was filed with the patent office on 2005-07-21 for disposable absorbent article employing odor reduction layer containing metalphthalocyanine material.
This patent application is currently assigned to The Procter & Gamble Company. Invention is credited to Kawakami, Yoshihisa, Rajagopalan, Vijay, Rezai, Ebrahim, Ueda, Kimio.
Application Number | 20050159719 11/079042 |
Document ID | / |
Family ID | 43706187 |
Filed Date | 2005-07-21 |
United States Patent
Application |
20050159719 |
Kind Code |
A1 |
Kawakami, Yoshihisa ; et
al. |
July 21, 2005 |
Disposable absorbent article employing odor reduction layer
containing metalphthalocyanine material
Abstract
The present invention is directed to a disposable absorbent
article. The disposable absorbent article of the present invention
includes a fluid storage layer disposed between the topsheet and
backsheet and having a body-facing surface and a garment-facing
surface opposing the body-facing surface. The fluid storage layer
contains a superabsorbent material. The disposable absorbent
article further includes an odor reduction layer disposed at either
the body-facing surface side or the body-facing surface side of the
fluid storage layer. The odor reduction layer contains a
metalphthalocyanine material. The disposable absorbent article
further includes an isolation means disposed between the
superabsorbent material and the odor reduction layer for isolating
the metalphthalocyanine material from contacting at least a part of
the superabsorbent material.
Inventors: |
Kawakami, Yoshihisa;
(Higashinada-ku, JP) ; Rajagopalan, Vijay;
(Higashinada-ku, JP) ; Ueda, Kimio;
(Higashinada-ku, JP) ; Rezai, Ebrahim;
(Higashinada-ku, JP) |
Correspondence
Address: |
THE PROCTER & GAMBLE COMPANY
INTELLECTUAL PROPERTY DIVISION
WINTON HILL TECHNICAL CENTER - BOX 161
6110 CENTER HILL AVENUE
CINCINNATI
OH
45224
US
|
Assignee: |
The Procter & Gamble
Company
|
Family ID: |
43706187 |
Appl. No.: |
11/079042 |
Filed: |
March 14, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11079042 |
Mar 14, 2005 |
|
|
|
10149273 |
Aug 23, 2002 |
|
|
|
Current U.S.
Class: |
604/360 |
Current CPC
Class: |
A61F 13/8405
20130101 |
Class at
Publication: |
604/360 |
International
Class: |
A61F 013/15; A61F
013/20 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 9, 1999 |
WO |
PCT/US99/29239 |
May 4, 2000 |
WO |
PCT/US00/12161 |
Claims
What is claimed is:
1. A disposable absorbent article, comprising: a topsheet, a
backsheet combined with the topsheet, a fluid storage layer
disposed between the topsheet and backsheet and having a
body-facing surface and a garment-facing surface opposing the
body-facing surface, the fluid storage layer containing a
superabsorbent material; an odor reduction layer disposed at the
body-facing surface side of the fluid storage layer, the odor
reduction layer containing a metalphthalocyanine material; and an
isolation means disposed between the superabsorbent material and
the odor reduction layer for isolating the metalphthalocyanine
material from contacting at least a part of the superabsorbent
material.
2. The disposable absorbent article of claim 1, wherein the
metalphthalocyanine material has the central metal selected from
the transition elements.
3. The disposable absorbent article of claim 2, wherein the central
metal is Ni(II), Fe(III), Co(II), Mn(II), Cu, or Zn(II).
4. The disposable absorbent article of claim 1, wherein the odor
reduction layer includes at least about from 0.001% to about 10%,
by weight, of the metalphthalocyanine material, and from about 90%
to about 99.999% of a carrier means.
5. The disposable absorbent article of claim 1, wherein the odor
reduction layer disposed adjacent to the body-facing surface of the
fluid storage layer.
6. The disposable absorbent article of claim 4, wherein the carrier
means is a nonwoven material.
7. The disposable absorbent article of claim 1, wherein the
isolation means is a tissue layer or a nonwoven layer disposed
between the fluid storage layer and the odor reduction layer.
8. The disposable absorbent article of claim 1, wherein the odor
reduction layer further comprises a viscosity control agent.
9. The disposable absorbent article of claim 1, wherein the
topsheet includes the odor reduction layer.
10. The disposable absorbent article of claim 1, further comprising
a barrier cuff having a proximal edge and a distal edge, the
proximal edge being joined to the topsheet and the distal edge
being away from the body-facing surface of the topsheet, wherein
the barrier cuff includes the odor reduction layer.
11. The disposable absorbent article of claim 1, further comprising
a waistband which includes the odor reduction layer.
12. The disposable absorbent article of claim 1, further comprising
a side panel which includes the odor reduction layer.
13. A disposable absorbent article, comprising: a topsheet, a
backsheet combined with the topsheet, a fluid storage layer
disposed between the topsheet and backsheet and having a
body-facing surface and a garment-facing surface opposing the
body-facing surface, the fluid storage layer containing a
superabsorbent material; an odor reduction layer disposed at the
body-facing surface side of the fluid storage layer which envelops
at least a part of the fluid storage layer, the odor reduction
layer containing a metalphthalocyanine material; and an isolation
means disposed between the superabsorbent material and the odor
reduction layer for isolating the metalphthalocyanine material from
contacting at least a part of the superabsorbent material.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser.
No. 10/149,273 filed Aug. 23, 2002, pending.
FIELD
[0002] The present invention relates to disposable absorbent
articles. More specifically, the present invention relates to
disposable absorbent articles which employ an odor reduction layer
containing a metalphthalocyanine material. Examples of such
disposable absorbent articles include disposable underwears,
disposable diapers (adult and baby) including pull-on diapers and
training pants, disposable panties for menstrual use, and
disposable absorbent pads including sanitary napkins.
BACKGROUND
[0003] A wide variety of disposable absorbent articles are designed
not only to be efficient in the absorption of body fluids such as
urine, blood, menses and the like, but also to be sanitary and
comfortable in-use, are known in literature. Disposable absorbent
products of this type generally comprise a fluid-permeable topsheet
material, an absorbent core (or a fluid storage layer), and a
fluid-impermeable backsheet material. Various shapes, sizes and
thicknesses of such articles have been explored in an attempt to
make their use more comfortable and convenient.
[0004] For some time now, studies for such disposable absorbent
articles have been primarily focused on the absorptive capacity of
the article. As a result, various absorbent polymers with high
absorptive power have been developed. Such known superabsorbent
materials (also known as hydrogel-forming absorbent polymers) are
capable of absorbing from about 30 to 60 grams of water per gram of
polymer.
[0005] More recently, research has been focused on the removal of
foul odors and the prevention of skin diseases such as dermatitis,
rash and redness caused by wearing a disposable absorbent article
for a relatively long time. Many body fluids have an unpleasant
odor (or an malodor), or develop such an odor when in contact with
air and/or bacteria for prolonged periods. Additionally, urine
and/or other exudates absorbed into the absorbent article are
converted to ammonia by urease produced by skin-flora, i.e., a
group of normal microorganisms on the skin. This ammonia, in turn,
may cause dermatitis, rash and/or other forms of skin irritation.
Such disease of the skin in infants can be a serious medical matter
which, in extreme cases, can result in death.
[0006] Antimicrobial materials and bactericides in general are
chemical compositions that are used to prevent microbiological
contamination and deterioration of products, materials, and
systems. Such antimicrobial materials and bactericides can also
effectively work for the removal or reduction of foul odors
developed from disposable absorbent articles which has already
absorbed body fluids. However, depending on the manner of the
application of antimicrobial materials or bactericides in
disposable absorbent articles, it is found that such antimicrobial
materials and bactericides tend to affect the absorptive capacity
of disposable absorbent articles.
[0007] For example, Japanese Patent (Kokoku) Publication No.
H4-17058 discloses a disposable diaper which includes an absorbent
layer containing a superabsorbent material and a antimicrobial
material included in the superabsorbent material. Similarly,
Japanese Patent (Kokai) Publication No. H5-277143 discloses a
disposable diaper which includes a superabsorbent material
containing an odor reduction material. Metalphthalocyanine
derivatives are disclosed in H5-277143 as examples of the odor
reduction material. Further, Japanese Patent (Kokai) Publication
No. S64-25856 discloses a sanitary napkin which includes an
absorbent sheet including a superabsorbent material and a
metalphthalocyanine derivative as an odor reduction material. In
those structures disclosed, the antimicrobial or odor reduction
material is in contact with the superabsorbent material, as a
result, the absorptive capacity of the superabsorbent material
tends to be decreased because of the existence of the antimicrobial
or odor reduction material.
[0008] Based on the foregoing, there is a need for disposable
absorbent articles whose absorptive capacity is not affected by the
use of a metalphthalocyanine or its derivatives as an odor
reduction material.
SUMMARY
[0009] The present invention is directed to a disposable absorbent
article. The disposable absorbent article of the present invention
includes a topsheet and a backsheet combined with the topsheet. The
disposable absorbent article further includes a fluid storage layer
disposed between the topsheet and backsheet and having a
body-facing surface and a garment-facing surface opposing the
body-facing surface. The fluid storage layer contains a
superabsorbent material. In one aspect of the invention, the
disposable absorbent article further includes an odor reduction
layer disposed at either the body-facing surface side or the
body-facing surface side of the fluid storage layer. The odor
reduction layer contains a metalphthalocyanine material. The
disposable absorbent article further includes an isolation means
disposed between the superabsorbent material and the odor reduction
layer for isolating the metalphthalocyanine material from
contacting at least a part of the superabsorbent material.
[0010] In another aspect of the invention, the disposable absorbent
article further includes an odor reduction layer which envelops at
least a part of the fluid storage layer. The odor reduction layer
contains a metalphthalocyanine material. The disposable absorbent
article further includes an isolation means disposed between the
superabsorbent material and the odor reduction layer for isolating
the metalphthalocyanine material from contacting at least a part of
the superabsorbent material.
[0011] The foregoing answers the need for disposable absorbent
articles whose absorptive capacity is not affected by the use of a
metalphthalocyanine or its derivatives as an odor reduction
material.
[0012] These and other features, aspects, and advantages of the
present invention will become evident to those skilled in the art
from reading of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWING
[0013] While the specification concludes with claims particularly
pointing out and distinctly claiming the invention, it is believed
that the invention will be better understood from the following
description of preferred embodiments which is taken in conjunction
with the accompanying a drawing and which like designations are
used to designate substantially identical elements, and in
which:
[0014] FIGURE is a simplified plan view of one preferred embodiment
of the disposable absorbent article of the present invention in its
flat uncontracted condition showing the body-facing side of the
garment.
DETAILED DESCRIPTION
[0015] All cited references are incorporated herein by reference in
their entireties. Citation of any reference is not an admission
regarding any determination as to its availability as prior art to
the claimed invention.
[0016] Herein, "comprise" and "include" mean that other element(s)
and step(s) which do not affect the end result can be added. These
terms encompass the terms "consisting of" and "consisting
essentially of".
[0017] Herein, "nonwoven" may include any material which has been
formed without the use of textile weaving processes which produce a
structure of individual fibers which are interwoven in an
identifiable manner. Methods of making suitable nonwovens includes
a carded nonwoven process, a spunbonded nonwoven process, a
meltblown nonwoven process, or the like.
[0018] Herein, "layer" does not necessarily limit the element to a
single strata of material in that a layer may actually comprise
laminates or combinations of sheets or webs of the requisite types
of materials.
[0019] Herein, "joined" or "joining" encompasses configurations
whereby an element is directly secured to another by affixing the
element directly to the other element, and configurations whereby
the element is indirectly secured to the other element by affixing
the element to intermediate member(s) which in turn are affixed to
the other element.
[0020] Herein, "metalphthalocyanine material" encompasses a
metalphthalocyanine, its derivatives, and any mixture materials
thereof.
[0021] The absorbent structures of the present invention can be
utilized in disposable absorbent articles which are capable of
absorbing significant quantities of body fluids, such as urine and
water in body wastes. Examples of such disposable absorbent
articles include disposable underwears, disposable diapers (adult
and baby) including pull-on diapers and training pants, disposable
panties for menstrual use, and disposable absorbent pads including
sanitary napkins.
[0022] The disposable absorbent article of the present invention
includes a topsheet and a backsheet combined with the topsheet. The
disposable absorbent article of the present invention generally
includes three basic structural components: (1) a fluid storage
layer disposed between the topsheet and backsheet, and containing a
superabsorbent material; (2) an odor reduction layer disposed at
either the body-facing surface side or the body-facing surface
side, and containing a metalphthalocyanine material; and (3) an
isolation means disposed between the superabsorbent material and
the odor reduction layer for isolating the metalphthalocyanine
material from contacting at least part of, preferably all of the
superabsorbent material. In a preferred embodiment, the odor
reduction layer is disposed adjacent to either the body-facing
surface or the garment-facing surface of the fluid storage
layer.
[0023] The odor reduction layer is preferably disposed between the
topsheet and the fluid storage layer. The odor reduction layer may
be disposed between the backsheet and the fluid storage layer. The
isolation means is preferably disposed between the fluid storage
layer and the odor reduction layer. More preferably, the odor
reduction layer is disposed adjacent to either the body-facing
surface or the garment-facing surface of the fluid storage layer
such that it can be in contact with of the fluid storage layer. The
topsheet can be either liquid pervious or liquid impervious. In a
preferred embodiment, the topsheet is liquid pervious. Similarly,
the backsheet can be either liquid pervious or liquid impervious.
In a preferred embodiment, the backsheet is liquid impervious. The
liquid pervious topsheet and backsheet can be formed by treating
them with a finishing oil or a surfactant well known in the art.
Further, the liquid impervious backsheet can be formed by employing
an impervious thin plastic film. In a preferred embodiment, the
disposable absorbent article further includes; a liquid pervious
topsheet, and a liquid impervious backsheet combined with the
topsheet.
[0024] In a preferred embodiment, the topsheet includes and works
as the odor reduction layer of the present invention. In this
embodiment, the isolation means is disposed between the fluid
storage layer and the topsheet.
[0025] In an yet preferred embodiment, the disposable absorbent
article further includes a barrier cuff having a proximal edge and
a distal edge. The proximal edge is joined to the topsheet, while
the distal edge is away from the body-facing surface of the
topsheet. In this embodiment, the barrier cuff includes the odor
reduction layer of the present invention. The topsheet functions as
the isolation means in such an embodiment.
[0026] In a still preferred embodiment, the disposable absorbent
article further includes a waistband which includes the odor
reduction layer of the present invention. In such an embodiment,
the odor reduction layer may be positioned above the topsheet or
below the topsheet.
[0027] In an yet preferred embodiment, the disposable absorbent
article further includes a side panel (or an ear panel) including
the odor reduction layer of the present invention.
[0028] The odor reduction layer of the present invention can
comprise a single layer of essentially 100% metalphthalocyanine
material, or can also include a carrier means. Preferably, the odor
reduction layer contains at least from about 0.001% to about 10%,
by weight, of the metalphthalocyanine material, and from about 90%
to about 99.999% of the carrier means. More preferably, the odor
reduction layer contains at least from about 0.002% to about 0.6%,
by weight, of the metalphthalocyanine material, and from about
99.998% to about 99.4% of the carrier means. In a preferred
embodiment, the odor reduction layer contains about 0.3% of the
metalphthalocyanine material, and about 99.7% of the carrier means.
The metalphthalocyanine material can be contained in the odor
reduction layer in any form which can be incorporated into the odor
reduction layer.
[0029] Many body fluids have an unpleasant odor (or an malodor), or
develop such an odor when in contact with air and/or bacteria for
prolonged periods. Additionally, urine and/or other exudates
absorbed into the fluid storage layer are converted to ammonia by
urease produced by skin-flora, i.e., a group of normal
microorganisms on the skin. This ammonia, in turn, may cause
dermatitis, rash and/or other forms of skin irritation. The
principal function of the odor reduction layer is to reduce such an
unpleasant odor which is contained in and/or may be developed from
the body fluid absorbed and retained in the fluid storage layer.
The metalphthalocyanine material, upon contact with a body fluid,
neutralizes the ammonia components contained in the absorbed body
fluid through the neutralization.
[0030] The odor reduction layer may have a number of shapes and
sizes. For example, the odor reduction layer is typically in the
form of rectangular, hourglass, or asymmetrical. The odor reduction
layer generally has a thickness or diameter between about 0.25 mm
and about 10.0 mm. Preferably for use in absorbent products, the
odor reduction layer are in the form of rectangular having a
thickness of greater than about 250 microns. The odor reduction
layer preferably has a thickness between about 0.5 mm and about 3
mm, typically about 1 mm.
[0031] As indicated hereinbefore, the odor reduction layer includes
a metalphthalocyanine material. A preferred metalphthalocyanine
material may have the following chemical structure: 1
[0032] The metalphthalocyanine material has the central metal
(indicated by "M" in the above chemical structure) selected from
the transition elements. In a preferred embodiment, the central
metal of the metalphthalocyanine material is Ni(II), Fe(III),
Co(II), Mn(II), Cu, or Zn(II).
[0033] In a more preferred embodiment for use of disposable
diapers, the central metal of the metalphthalocyanine material is
Fe(III) or Co(II).
[0034] Preferred metalphthalocyanine derivatives have --COOH as the
functional group. Such preferred metalphthalocyanine derivatives
can have either di, tetra or octa forms of --COOH. Alternatively,
the metalphthalocyanine derivatives can have any form selected from
the group consisting of from mono to octa forms of
--SO.sub.3Na.
[0035] In a preferred embodiment, the odor reduction layer includes
a carrier means which holds or keeps the metalphthalocyanine
material within the fluid storage layer through physical or
chemical bonds. Any materials known in the art can be used as the
carrier means as long as it can hold or keep the
metalphthalocyanine material therein. Preferred carrier means
includes fibrous materials such as nonwoven webs, tissue webs, and
fluffs of synthetic fibers or natural fibers such as cellulose
fibers; foams, apertured polymeric webs or films; and the like.
Preferably, at least 95%, more preferably at least 99% by weight of
the metalphthalocyanine material is physically bonded to the
component material of the carrier means, while the rest of the
metalphthalocyanine material may remain unbonded or chemically
bonded to some of the component material of the carrier means.
[0036] In a preferred embodiment, the carrier means is a nonwoven
material. More preferably, the nonwoven material is a resin bonded
nonwoven material formed by polyethylene terephthalate (PET)
fibers. A preferred resin bonded nonwoven material which can be
used as the carrier means is commercially available from PGI
Nonwovens, USA, under Code No. 68500.
[0037] In an alternative preferred embodiment, the carrier means is
formed by a natural fibrous material such as cellulose fibers in
the form of fluff, which is conventionally utilized and generally
referred to as "airfelt" in absorbent cores (or fluid storage
layers).
[0038] In a preferred embodiment, the metalphthalocyanine material
is dispersed uniformly throughout the carrier means. In an
alternative preferred embodiment, the metalphthalocyanine material
is dispersed non-uniformly in the carrier means, e.g., the basis
weight of the metalphthalocyanine material changes horizontally,
vertically or both within the odor reduction layer. For example,
the odor reduction layer can have a metalphthalocyanine material
gradient in the horizontal direction, such as with more
metalphthalocyanine material being present in regions of relatively
high fluid handling requirements (i.e., near the region of fluid
discharge) and less metalphthalocyanine material at lower demand
regions. In another example, the basis weight of the
metalphthalocyanine material may change in the vertical direction
(i.e., the thickness direction) of the odor reduction layer.
[0039] In one embodiment, the metalphthalocyanine material is in
the form of discrete particles. In a preferred embodiment, the
particles of the metalphthalocyanine material are distributed in a
fibrous material of the carrier means to form the odor reduction
layer. Such an odor reduction layer is typically made by airlaying,
wherein an airstream of the particles of the metalphthalocyanine
material is metered into an airstream of the fibrous materials of
the carrier means. Alternatively, the particles of the
metalphthalocyanine material can be laminated between two or more
webs of fibrous material such as nonwoven materials to form the
odor reduction layer.
[0040] In a preferred embodiment, the basis weight of the odor
reduction layer can range from about 0.002 to 0.012 g/cm.sup.2,
more preferably from about 0.003 to 0.008 g/cm.sup.2, and yet more
preferably from about 0.004 to 0.007 g/cm.sup.2.
[0041] The density and basis weight of the odor reduction layer
does not need to be uniform throughout the layer. The odor
reduction layer can contain regions of relatively higher and
relatively lower density and basis weight. The density values for
the odor reduction layer are calculated from basis weight and layer
caliper measured under a confining pressure of 0.2 psi (1.43
kPa).
[0042] Other materials or agents can be used with the
metalphthalocyanine material as an aid in producing the odor
reduction layer. In a preferred embodiment, water is used in
conjunction with the metalphthalocyanine material. The water
functions to promote uniform dispersion of the metalphthalocyanine
material on the surface of the carrier means and permeation of the
metalphthalocyanine material into the surface region of the carrier
means. The water is used in a proportion of less than about 20
parts by weight (i.e., 0 parts to about 20 parts by weight),
preferably in the range of from about 0.01 parts to about 20 parts
by weight, more preferably in the range of from about 0.1 parts to
about 10 parts by weight, per 100 parts by weight of the carrier
means. The actual amount of water to be used will vary depending
upon the kind of the component material and the carrier means.
[0043] In a more preferred embodiment, a viscosity control agent
and/or a binding agent is/are additionally used in conjunction with
the metalphthalocyanine material.
[0044] The viscosity control agent functions to further promote
uniform dispersion of the metalphthalocyanine material on the
surface of the carrier means and permeation of the
metalphthalocyanine material into the surface region of the carrier
means. A preferred viscosity control agent is a methlose.
[0045] The binding agent further promotes stronger and more
flexible physical bond between the metalphthalocyanine material and
the component material of the carrier means. A preferred binding
agent is selected from the group consisting of carboxy methyl
cellulose, polyurethane, polyfix, polyamine and a mixture
thereof.
[0046] In a preferred embodiment wherein the carrier means is a
resin bonded nonwoven material formed by polypropylene fibers, a
methlose and a carboxy methyl cellulose are used as the viscosity
control agent and the binding agent, respectively. The viscosity
control agent is used in a proportion of less than about 40 parts
by weight (i.e., 0 parts to about 40 parts by weight), preferably
in the range of from about 0.001 parts to about 40 parts by weight,
more preferably in the range of from about 0.01 parts to about 30
parts by weight, per 100 parts by weight of the carrier means. The
binding agent is used in a proportion of less than about 40 parts
by weight (i.e., 0 parts to about 40 parts by weight), preferably
in the range of from about 0.001 parts to about 30 parts by weight,
more preferably in the range of from about 0.1 parts to about 20
parts by weight, per 100 parts by weight of the carrier means. The
actual amounts and kinds of the viscosity control agent and the
binding agent to be used vary depending upon the kinds of the
metalphthalocyanine material and the component material of the
nonwoven material.
[0047] In an alternative preferred embodiment wherein the carrier
means is a resin bonded nonwoven material formed by polyethylene
terephthalate (PET) fibers, the metalphthalocyanine material is
contained in a mixture with water, a viscosity control agent (e.g.,
a methlose) and a binding agent (e.g., a carboxy methyl cellulose).
The use of the water can provide the preferred penetration of the
metalphthalocyanine material into the carrier means while also
providing a necessary uniformity of dispersion of the
metalphthalocyanine material. However, a mixture of all three
agents is more preferred in order to control the amount of the
penetration of the metalphthalocyanine material into the carrier
means.
[0048] In an yet alternative preferred embodiment wherein the
carrier means is a resin bonded nonwoven material formed by
polyethylene terephthalate (PET) fibers, the metalphthalocyanine
material is contained in a mixture with water, and two or more
binding agents.
[0049] In a preferred embodiment, such binding agents is a mixture
of a polyurethane and a polyamine. The polyurethane is used in a
proportion of less than about 40 parts by weight (i.e., 0 parts to
about 40 parts by weight), preferably in the range of from about
0.001 parts to about 40 parts by weight, more preferably in the
range of from about 0.01 parts to about 30 parts by weight, per 100
parts by weight of the carrier means. The polyamine is used in a
proportion of less than about 40 parts by weight (i.e., 0 parts to
about 40 parts by weight), preferably in the range of from about
0.001 parts to about 30 parts by weight, more preferably in the
range of from about 0.01 parts to about 20 parts by weight, per 100
parts by weight of the carrier means.
[0050] In an alternative preferred embodiment, such binding agents
is a mixture of a carboxy methyl cellulose, a polyurethane and a
polyfix. The carboxy methyl cellulose is used in a proportion of
less than about 40 parts by weight (i.e., 0 parts to about 40 parts
by weight), preferably in the range of from about 0.01 parts to
about 40 parts by weight, more preferably in the range of from
about 0.1 parts to about 30 parts by weight, per 100 parts by
weight of the carrier means. The polyurethane is used in a
proportion of less than about 40 parts by weight (i.e., 0 parts to
about 40 parts by weight), preferably in the range of from about
0.01 parts to about 30 parts by weight, more preferably in the
range of from about 0.1 parts to about 20 parts by weight, per 100
parts by weight of the carrier means. The polyfix is used in a
proportion of less than about 40 parts by weight (i.e., 0 parts to
about 40 parts by weight), preferably in the range of from about
0.01 parts to about 30 parts by weight, more preferably in the
range of from about 0.1 parts to about 20 parts by weight, per 100
parts by weight of the carrier means.
[0051] The pH of the metalphthalocyanine material solution needs to
be controlled (or chosen) depending on the type of the
metalphthalocyanine material and the functional group bonded
therein. For example, in a preferred embodiment wherein the
metalphthalocyanine material has a tetra --COOH or a mono-tetra
sulfonate as the functional group, the pH of the
metalphthalocyanine material solution is controlled between about 3
and 6, more preferably between about 4 and 5.
[0052] The metalphthalocyanine material solution may be applied to
the carrier means by any of various techniques and apparatus used
for applying solutions to materials including coating, dumping,
pouring, spraying, atomizing, or immersing the solution on the
carrier means. In a preferred embodiment, the metalphthalocyanine
material solution is applied onto at least a portion of the carrier
means. Preferably, the metalphthalocyanine material solution is
coated onto the entire surface of most, preferably all, of the
carrier means.
[0053] Alternatively, the metalphthalocyanine material solution can
be generally mixed with component fibers of the carrier means
before the formation of the carrier means. The method of mixing can
be done by any of a number of mixing techniques and mixing
apparatus known in the art as long as the component fibers of the
carrier means can be fully coated with the metalphthalocyanine
material solution. After the component fibers are thoroughly coated
with the metalphthalocyanine material solution, the formation for
the carrier means is carried out to form the odor reduction
layer.
[0054] The fluid storage layer can include a single layer of
essentially 100% superabsorbent material. Preferably, the fluid
storage layer includes a superabsorbent material and a carrier
means for the superabsorbent material. The carrier means may be
manufactured from a wide variety of liquid-absorbent materials
commonly used in disposable diapers and other absorbent articles
such as a comminuted wood pulp which is generally referred to as
airfelt. Examples of other carrier means include creped cellulose
wadding; meltblown polymers including coform; chemically stiffened,
modified or cross-linked cellulosic fibers; tissue including tissue
wraps and tissue laminates; absorbent foams; absorbent sponges; or
any equivalent material or combinations of materials.
[0055] The fluid storage layer includes at least 15%, by weight,
preferably at least 25%, of superabsorbent material (defined more
fully hereafter), and from 0% to about 85%, preferably less than
about 75%, of the carrier means. The principal function of the
fluid storage layer is to absorb discharged body fluid and retain
such fluid under the pressures encountered as a result of the
wearer's movements.
[0056] As indicated hereinbefore, the fluid storage layer includes
superabsorbent material such as, but not necessarily limited to,
discrete particles of absorbent gelling material and superabsorbent
fibrous material such as acrylate grafted fibers and superabsorbent
modified cellulosic fibers. The superabsorbent material can be in
any form which can be incorporated into the fibrous material of the
carrier means to form the fluid storage layer. Superabsorbent
materials are described in more detail below. The superabsorbent
material, upon contact with fluids such as water or body fluids,
absorb such fluids. The fluid discharged into the disposable
absorbent article and transported to the fluid storage layer can be
acquired and held by the superabsorbent material, thereby providing
the articles herein with enhanced absorbent capacity and/or
improved fluid retention performance.
[0057] The superabsorbent materials are those which are capable of
absorbing at least about 10 grams, preferably at least about 15 g,
more preferably at least about 20 g, of Synthetic Urine (1.0% NaCl
aqueous solution) per gram of superabsorbent material, as
determined according to the hereinafter described Absorbent
Capacity procedure.
[0058] The superabsorbent material utilized herein is typically in
the form of discrete particles of absorbent gelling material. These
particles are preferably distributed within a fibrous material of
the carrier means. The fluid storage layer which has particles of
the absorbent gelling material distributed in fibrous materials of
the carrier means is typically made by airlaying, wherein an
airstream of the particles of the absorbent gelling material is
metered into an airstream of the fibrous materials of the carrier
means. The superabsorbent fibrous material can include synthetic or
natural fibers. Suitable natural fibrous material for the carrier
means are cellulose fibers, in the form of fluff, such as is
conventionally utilized and generally referred to as "airfelt" in
absorbent cores (or fluid storage layers).
[0059] The average dry density of the fluid storage layer including
the carrier means is generally in the range of from about 0.06 to
about 0.5 g/cm.sup.3, more preferably within the range of from
about 0.10 to about 0.4 g/cm.sup.3, yet more preferably from about
0.15 to about 0.3 g/cm.sup.3, and still more preferably from about
0.15 to about 0.25 g/cm.sup.3. Typically the basis weight of the
fluid storage layer can range from about 0.02 to 0.12 g/cm.sup.2,
more preferably from about 0.04 to 0.08 g/cm.sup.2, and yet more
preferably from about 0.05 to 0.07 g/cm.sup.2.
[0060] The density and basis weight of the fluid storage layer does
not need to be uniform throughout the layer. The fluid storage
layer can contain regions of relatively higher and relatively lower
density and basis weight. The density values for the fluid storage
layer are calculated from basis weight and layer caliper measured
under a confining pressure of 0.2 psi (1.43 kPa). The density and
basis weight values include the weight of the superabsorbent
material. Additionally, the fluid storage layer can have a
superabsorbent material gradient, such as with more superabsorbent
material being present in regions of relatively high fluid handling
requirements (i.e., near the region of fluid discharge) and less
superabsorbent material at lower demand regions.
[0061] Preferably, the superabsorbent material which is employed in
the fluid storage layer is a substantially water-insoluble,
slightly cross-linked, partially neutralized, polymeric absorbent
gelling material. This material forms a hydrogel upon contact with
water. Such polymer materials can be prepared from polymerizable,
unsaturated, acid-containing monomers. Suitable unsaturated acidic
monomers for use in preparing the polymeric gelling material
include those disclosed in U.S. Pat. No. 4,654,039 issued to Brandt
et al. on Mar. 31, 1987 and reissued as U.S. Pat. No. RE 32,649 on
Apr. 19, 1988. Preferred monomers include acrylic acid, methacrylic
acid, and 2-acrylamido-2-methyl propane sulfonic acid. Acrylic acid
is especially preferred for preparation of the polymeric gelling
agent material.
[0062] The polymeric component formed from unsaturated,
acid-containing monomers may be grafted on to other types of
polymer moieties such as starch or cellulose. Polyacrylate grafted
starch materials of this type are also especially preferred.
[0063] Preferred polymeric absorbent gelling materials which can be
prepared from conventional types of monomers include hydrolyzed
acrylonitrile grafted starch, polyacrylate grafted starch,
polyacrylates, maleic anhydride-based copolymers and combinations
thereof. Especially preferred are the polyacrylates and
polyacrylate grafted starch.
[0064] Whatever the nature of the basic polymer components of the
hydrogel-forming polymeric absorbent gelling material particles,
such materials will in general be slightly cross-linked.
Cross-linking agents serves to render the hydrogel-forming polymer
gelling materials substantially water-insoluble, and cross-linking
thus in part determines the gel volume and extractable polymer
characteristics of the hydrogels formed from the polymeric gelling
agents employed. Suitable cross-linking agents are well known in
the art and include, for example, those described in greater detail
in U.S. Pat. No. 4,076,663 issued to Masuda et al. on Feb. 28,
1978. Preferred cross-linking agents are the di- or polyesters of
unsaturated mono- or polycarboxylic acids with polyols, the
bisacrylamides and the di- or triallyl amines. Other preferred
cross-linking agents are N,N'-methylenebisacrylamide, trimethylol
propane triacrylate and triallyl amine. The cross-linking agent can
generally constitute from about 0.001 mole percent to 5 mole
percent of the resulting hydrogel-forming polymer material. More
preferably, the cross-linking agent will constitute from about 0.01
mole percent to 3 mole percent of the hydrogel-forming polymeric
gelling material particles used herein.
[0065] The slightly cross-linked, hydrogel-forming polymeric
gelling material particles are generally employed in their
partially neutralized form. Such materials are considered partially
neutralized when at least 25 mole percent, and preferably at least
50 mole percent of monomers used to form the polymer are acid
group-containing monomers which have been neutralized with a
salt-forming cation. Suitable salt-forming cations include alkali
metal, ammonium, substituted ammonium and amines. This percentage
of the total monomers utilized which are neutralized acid
group-containing monomers is referred to herein as the "degree of
neutralization."
[0066] Alternatively, the particles of absorbent gelling material
can be laminated between two or more webs of fibrous material to
form the fluid storage layer, such as exemplified in U.S. Pat. No.
4,578,068 issued to Kramer et al. on Mar. 25, 1986.
[0067] The isolation means can be formed by any structure which can
work for the isolation of the metalphthalocyanine material from the
superabsorbent material. Such a structure for the isolation can be
any structure which spaces the metalphthalocyanine material in the
odor reduction layer away from contacting at least part of,
preferably all of the superabsorbent material. In a preferred
embodiment, the isolation means is an interposed material disposed
between the odor reduction layer and the superabsorbent material.
Preferred interposed materials for the isolation means include
fibrous materials such as nonwoven webs, tissue webs, and fluffs of
synthetic fibers or natural fibers such as cellulose fibers; foams,
apertured polymeric webs or films; and the like. In a preferred
embodiment, the isolation means is a tissue layer or a nonwoven
layer which is disposed between the fluid storage layer and the
odor reduction layer. In a more preferred embodiment, such a tissue
or nonwoven layer is also used for enveloping at least a part of,
more preferably the entire portion of the fluid storage layer.
[0068] In an alternative preferred embodiment, the odor reduction
layer envelops at least a part of, more preferably the entire
portion of a fluid storage layer which includes a superabsorbent
material and a carrier means for the superabsorbent material. In
this embodiment, the carrier means also works as the isolation
means. Preferably, the odor reduction layer is formed by a tissue
or a nonwoven layer. Preferred isolation means for this particular
embodiment may be formed by any material which are used for the
carrier means of the fluid storage layer. In a preferred
embodiment, the isolation means is a comminuted wood pulp (e.g.,
airfelt) which is contained in the fluid storage layer together
with the superabsorbent material.
[0069] The basis weight of the isolation means can range from about
0.001 to 0.008 g/cm.sup.2, more preferably from about 0.0012 to
0.006 g/cm.sup.2, and yet more preferably from about 0.0013 to
0.005 g/cm.sup.2. In a preferred embodiment wherein the interposed
material is a nonwoven material, the basis weight of the tissue
material is about 0.0049 g/cm.sup.2.
[0070] The density and basis weight of the interposed material does
not need to be uniform throughout the material. The interposed
material can contain regions of relatively higher and relatively
lower density and basis weight. The density values for the
interposed material are calculated from basis weight and material
caliper measured under a confining pressure of 0.2 psi (1.43 kPa).
A preferred tissue material to be used as the interposed material
is available from Fripa Co., Ltd., under Code No. 1110000.
[0071] Particularly preferred embodiments of the disposable
absorbent article are disclosed hereinafter by referring to the
drawing. Herein, "absorbent article" refers to devices which absorb
and contain body exudates, and, more specifically, refers to
devices which are placed against or in proximity to the body of the
wearer to absorb and contain the various exudates discharged from
the body. Herein, "disposable" is used herein to describe absorbent
articles which are not intended to be laundered or otherwise
restored or reused as an absorbent article (i.e., they are intended
to be discarded after a single use and, preferably, to be recycled,
composted or otherwise disposed of in an environmentally compatible
manner). A preferred embodiment of the disposable absorbent article
of the present invention is a unitary disposable diaper 20, shown
in FIGURE. Herein, "unitary" absorbent article refers to absorbent
articles which are formed of separate parts united together to form
a coordinated entity so that they do not require separate
manipulative parts like a separate holder and liner. Herein,
"diaper" refers to an absorbent article generally worn by infants
and incontinent persons that is worn about the lower torso of the
wearer. It should be understood, however, that the present
invention is also applicable to other disposable absorbent articles
such as disposable underwears, disposable diapers (adult and baby)
including pull-on diapers and training pants, disposable panties
for menstrual use, and disposable absorbent pads including sanitary
napkins.
[0072] FIGURE is a plan view of the disposable diaper 20 in its
flat-out, uncontracted state (i.e., with elastic induced
contraction pulled out) with portions of the structure being
cut-away to more clearly show the construction of the diaper 20 and
with the portion of the diaper 20 which faces the wearer, the
body-facing surface 40, facing the viewer. As shown in FIGURE, the
diaper 20 preferably comprises a chassis 22 comprising a liquid
pervious topsheet 24; a liquid impervious backsheet 26 joined to
the topsheet; and a fluid storage layer 28 positioned between the
topsheet 24 and the backsheet 26. The fluid storage layer 28 has a
pair of opposing longitudinal edges 60. The diaper preferably
further comprises side panels 30; elasticized leg cuffs 32;
elasticized waistbands 34; and a fastening system 36 preferably
comprising a pair of securement members 37 and a landing member
38.
[0073] The diaper 20 is shown in FIGURE to have a body-facing
surface 40 (facing the viewer in FIGURE), a garment-facing surface
42 opposed to the body-facing surface 40, a back region 44, a front
region 46 opposed to the back region 44, a crotch region 48
positioned between the back region 44 and the front region 46, and
a periphery which is defined by the outer perimeter or edges of the
diaper 20 in which the side edges are designated 50 and the end
edges are designated 52. The body-facing surface 40 of the diaper
20 comprises that portion of the diaper 20 which is positioned
adjacent to the wearer's body during use (i.e., the body-facing
surface 40 generally is formed by at least a portion of the
topsheet 24 and other components joined to the topsheet 24). The
garment-facing surface 42 comprises that portion of the diaper 20
which is positioned away from the wearer's body (i.e., the
garment-facing surface 42 is generally formed by at least a portion
of the backsheet 26 and other components joined to the backsheet
26). The back region 44 and the front region 46 extend from the end
edges 52 of the periphery to the crotch region 48.
[0074] The diaper 20 also has two centerlines, a longitudinal
centerline 100 and a transverse centerline 110. The term
"longitudinal", as used herein, refers to a line, axis, or
direction in the plane of the diaper 20 that is generally aligned
with (e.g. approximately parallel with) a vertical plane which
bisects a standing wearer into left and right halves when the
diaper 20 is worn. The terms "transverse" and "lateral", as used
herein, are interchangeable and refer to a line, axis or direction
which lies within the plane of the diaper that is generally
perpendicular to the longitudinal direction (which divides the
wearer into front and back body halves).
[0075] The chassis 22 comprises the topsheet 24, the backsheet 26
and the fluid storage layer 28 having the pair of opposing
longitudinal edges 60, the body-facing surface, and the
garment-facing surface. The body-facing surface generally faces the
body of the wearer while the garment-facing surface generally faces
away from the body of the wearer (and the garment of the wearer).
When the absorbent article comprises a separate holder and a liner,
the chassis 22 generally comprises the holder and the liner (i.e.,
the chassis 22 comprises one or more layers of material to define
the holder while the liner comprises an absorbent composite such as
a topsheet, a backsheet, and a fluid storage layer.) For unitary
absorbent articles, the chassis 22 preferably comprises the
topsheet 24, the backsheet 26 and the fluid storage layer 28 of the
diaper with other features added to form the composite diaper
structure.
[0076] In the embodiment shown in FIGURE, the topsheet 24 and the
backsheet 26 have length and width dimensions generally larger than
those of the fluid storage layer 28. The topsheet 24 and the
backsheet 26 extend beyond the edges of the fluid storage layer 28
to thereby form the periphery of the diaper 20. While the topsheet
24, the backsheet 26, and the fluid storage layer 28 may be
assembled in a variety of well known configurations, exemplary
chassis configurations are described generally in U.S. Pat. No.
3,860,003 entitled "Contractible Side Portions for Disposable
Diaper" which issued to Kenneth B. Buell on Jan. 14, 1975; and U.S.
Pat. No. 5,151,092 entitled "Absorbent Article With Dynamic Elastic
Waist Feature Having A Predisposed Resilient Flexural Hinge" which
issued to Kenneth B. Buell et al., on Sep. 29, 1992.
[0077] The fluid storage layer 28 may be any absorbent member which
is generally compressible, conformable, non-irritating to the
wearer's skin, and capable of absorbing and retaining liquids such
as urine and other certain body exudates. As shown in FIGURE, the
fluid storage layer 28 has a garment-facing side, a body-facing
side, a pair of side edges, and a pair of waist edges. The fluid
storage layer 28 may be manufactured in a wide variety of sizes and
shapes (e.g., rectangular, hourglass, "T"-shaped, asymmetric,
etc.). Preferably, the fluid storage layer 28 includes a
superabsorbent material and a carrier means for the superabsorbent
material. In this embodiment, the carrier means is preferably
formed from comminuted wood pulp which is generally referred to as
airfelt.
[0078] The configuration and construction of the fluid storage
layer 28 may vary (e.g., the fluid storage layer may have varying
caliper zones, a hydrophilic gradient, a superabsorbent gradient,
or lower average density and lower average basis weight acquisition
zones; or may comprise one or more layers or structures). Further,
the size and absorbent capacity of the fluid storage layer 28 may
also be varied to accommodate wearers ranging from infants through
adults. However, the total absorbent capacity of the fluid storage
layer 28 should be compatible with the design loading and the
intended use of the diaper 20.
[0079] One embodiment of the diaper 20 has an asymmetric, modified
T-shaped fluid storage layer 28 having ears in the front region but
a generally rectangular shape in the back region. Exemplary
absorbent structures for use as the fluid storage layer 28 that
have achieved wide acceptance and commercial success are described
in U.S. Pat. No. 4,610,678 entitled "High-Density Absorbent
Structures" issued to Weisman et al. on Sep. 9, 1986; U.S. Pat. No.
4,673,402 entitled "Absorbent Articles With Dual-Layered Cores"
issued to Weisman et al. on Jun. 16, 1987; U.S. Pat. No. 4,888,231
entitled "Absorbent Core Having A Dusting Layer" issued to Angstadt
on Dec. 19, 1989; and U.S. Pat. No. 4,834,735, entitled "High
Density Absorbent Members Having Lower Density and Lower Basis
Weight Acquisition Zones", issued to Alemany et al. on May 30,
1989. The fluid storage layer may further comprise the dual core
system containing an acquisition/distribution core of chemically
stiffened fibers positioned over a fluid storage layer as detailed
in U.S. Pat. No. 5,234,423, entitled "Absorbent Article With
Elastic Waist Feature and Enhanced Absorbency" issued to Alemany et
al., on Aug. 10, 1993; and in U.S. Pat. No. 5,147,345, entitled
"High Efficiency Absorbent Articles For Incontinence Management"
issued to Young, LaVon and Taylor on Sep. 15, 1992.
[0080] In a preferred embodiment, the diaper 20 further includes an
odor reduction layer (not shown in FIGURE) of the present invention
which is disposed between the topsheet 24 and the fluid storage
layer 28. Alternatively, the odor reduction layer may be disposed
between the backsheet 26 and the fluid storage layer 28.
[0081] In these embodiments, an isolation means (not shown in
FIGURE) is formed by a tissue or nonwoven material which envelops
at least a part of, preferably the entire portion of the material
of the carrier means. The portion of the isolation layer which
disposed between the fluid storage layer and the odor reduction
layer isolates the metalphthalocyanine material from contacting the
superabsorbent material contained in the fluid storage layer 28.
Preferably, the odor reduction layer is disposed on the either the
body-facing surface or the garment-facing surface of the fluid
storage layer 28 such that it can be in contact with of the fluid
storage layer.
[0082] In an alternative preferred embodiment, the isolation means
(not shown in FIGURE) is formed by a separate material from such a
fluid storage layer enveloping material (i.e., a tissue or nonwoven
material). Preferably, such a separate material (i.e., an isolation
means) is disposed between the odor reduction layer and the fluid
storage layer 28. A preferred separate material is a nonwoven
material.
[0083] The topsheet 24 is preferably positioned adjacent the
body-facing surface of the fluid storage layer 28 and is preferably
joined thereto and to the backsheet 26 by attachment means (not
shown) such as those well known in the art. Suitable attachment
means are described with respect to joining the backsheet 26 to the
fluid storage layer 28. In a preferred embodiment, the topsheet 24
and the backsheet 26 are joined directly to each other in the
diaper periphery and are indirectly joined together by directly
joining them to the fluid storage layer 28 by any suitable
attachment means.
[0084] The topsheet 24 is preferably compliant, soft feeling, and
non-irritating to the wearer's skin. Further, the topsheet 24 is
preferably liquid pervious permitting liquids (e.g., urine) to
readily penetrate through its thickness. A suitable topsheet 24 may
be manufactured from a wide range of materials such as woven and
nonwoven materials; polymeric materials such as apertured formed
thermoplastic films, apertured plastic films, and hydroformed
thermoplastic films; porous foams; reticulated foams; reticulated
thermoplastic films; and thermoplastic scrims. Suitable woven and
nonwoven materials can be comprised of natural fibers (e.g., wood
or cotton fibers), synthetic fibers (e.g., polymeric fibers such as
polyester, polypropylene, or polyethylene fibers) or from a
combination of natural and synthetic fibers. A preferred nonwoven
material for the topsheet 24 is a carded nonwoven material of
polypropylene which available from Amoco Fabrics, under Code No.
Soft P-10, 23 Stly 007.
[0085] The topsheet 24 is preferably made of a hydrophobic material
to isolate the wearer's skin from liquids which have passed through
the topsheet 24 and are contained in the fluid storage layer 28
(i.e. to prevent rewet). If the topsheet 24 is made of a
hydrophobic material, at least the body-facing surface of the
topsheet 24 is treated to be hydrophilic so that liquids will
transfer through the topsheet more rapidly. This diminishes the
likelihood that body exudates will flow off the topsheet 24 rather
than being drawn through the topsheet 24 and being absorbed by the
fluid storage layer 28. The topsheet 24 can be rendered hydrophilic
by treating it with a surfactant. Suitable methods for treating the
topsheet 24 with a surfactant include spraying the topsheet 24
material with the surfactant and immersing the material into the
surfactant. A more detailed discussion of such a treatment and
hydrophilicity is contained in U.S. Pat. No. 4,988,344 entitled
"Absorbent Articles with Multiple Layer Absorbent Layers" issued to
Reising, et al on Jan. 29, 1991 and U.S. Pat. No. 4,988,345
entitled "Absorbent Articles with Rapid Acquiring Absorbent Cores"
issued to Reising on Jan. 29, 1991.
[0086] An alternative preferred topsheet 24 comprises an apertured
formed film. Apertured formed films are preferred for the topsheet
because they are pervious to body exudates and yet non-absorbent
and have a reduced tendency to allow liquids to pass back through
and rewet the wearer's skin. Thus, the surface of the formed film
which is in contact with the body remains dry, thereby reducing
body soiling and creating a more comfortable feel for the wearer.
Suitable formed films are described in U.S. Pat. No. 3,929,135,
entitled "Absorptive Structures Having Tapered Capillaries", which
issued to Thompson on Dec. 30, 1975; U.S. Pat. No. 4,324,246
entitled "Disposable Absorbent Article Having A Stain Resistant
Topsheet", which issued to Mullane, et al. on Apr. 13, 1982; U.S.
Pat. No. 4,342,314 entitled "Resilient Plastic Web Exhibiting
Fiber-Like Properties", which issued to Radel. et al. on Aug. 3,
1982; U.S. Pat. No. 4,463,045 entitled "Macroscopically Expanded
Three-Dimensional Plastic Web Exhibiting Non-Glossy Visible Surface
and Cloth-Like Tactile Impression", which issued to Ahr et al. on
Jul. 31, 1984; and U.S. Pat. No. 5,006,394 "Multilayer Polymeric
Film" issued to Baird on Apr. 9, 1991.
[0087] In a preferred embodiment, the topsheet includes an odor
reduction layer (not shown in FIGURE) of the present invention.
More preferably, such a topsheet is formed by a nonwoven material
which is treated with the metalphthalocyanine material of the
present invention so that it can function as the odor reduction
layer of the present invention. A preferred nonwoven material for
such a topsheet 24 is a carded nonwoven material of polypropylene
which available from Amoco Fabrics, under Code No. Soft P-10, 23
Stly 007. In these embodiments, an isolation means can be either an
interposed material disposed between the topsheet 24 and the fluid
storage layer 28, or any structure that contributes the isolation
between the topsheet 24 and the fluid storage layer 28.
[0088] The backsheet 26 is that portion of the diaper 20 which is
generally positioned away from the wearer's skin and which prevents
the exudates absorbed and contained in the fluid storage layer 28
from wetting articles which contact the diaper 20 such as bedsheets
and undergarments. Thus, the backsheet 26 is preferably impervious
to liquids (e.g., urine) and is preferably manufactured from a thin
plastic film, although other flexible liquid impervious materials
may also be used. (As used herein, the term "flexible" refers to
materials which are compliant and will readily conform to the
general shape and contours of the human body.) However, the
backsheet 26 permits vapors to escape from the diaper 20. A
suitable material for the backsheet 26 is a thermoplastic film
having a thickness of from about 0.012 mm (0.5 mil) to about 0.051
mm (2.0 mils), preferably comprising polyethylene or
polypropylene.
[0089] The backsheet 26 is preferably positioned adjacent the
garment-facing surface of the fluid storage layer 28 and is
preferably joined thereto by any suitable attachment means known in
the art. For example, the backsheet 26 may be secured to the fluid
storage layer 28 by a uniform continuous layer of adhesive, a
patterned layer of adhesive, or an array of separate lines,
spirals, or spots of adhesive. Adhesives which have been found to
be satisfactory are manufactured by H. B. Fuller Company of St.
Paul, Minn. and marketed as HL-1258. An example of a suitable
attachment means comprising an open pattern network of filaments of
adhesive is disclosed in U.S. Pat. No. 4,573,986 entitled
"Disposable Waste-Containment Garment", which issued to Minetola et
al. on Mar. 4, 1986. Another suitable attachment means comprising
several lines of adhesive filaments swirled into a spiral pattern
is illustrated by the apparatus and methods shown in U.S. Pat. No.
3,911,173 issued to Sprague, Jr. on Oct. 7, 1975; U.S. Pat. No.
4,785,996 issued to Ziecker, et al. on Nov. 22, 1978; and U.S. Pat.
No. 4,842,666 issued to Werenicz on Jun. 27, 1989. Alternatively,
the attachment means may comprise heat bonds, pressure bonds,
ultrasonic bonds, dynamic mechanical bonds, or any other suitable
attachment means or combinations of these attachment means as are
known in the art.
[0090] Embodiments are also contemplated wherein the fluid storage
layer 28 is not joined to the backsheet 26, and/or the topsheet 24
in order to provide greater extensibility in the front region 46
and the back region 44. Alternative embodiments are contemplated
wherein an additional member, such as a liquid impervious barrier
material(s) (not shown), is positioned between the garment-facing
surface of the fluid storage layer 28 and the backsheet 28. Any
such barrier member may or may not be joined to the fluid storage
layer 28. Further, the backsheet 26 may or may not be joined to any
barrier material(s) that are positioned between the backsheet 26
and the fluid storage layer 28.
[0091] The diaper 20 preferably further comprises an outer cover
(not shown in FIGURE) joined with at least a portion of the
garment-facing surface of the backsheet 26 forming a laminate. The
outer cover preferably comprises a nonwoven material. (However,
embodiments are contemplated wherein the outer cover comprises
materials such as woven webs, foams, scrims, films, loose fibers,
or any other material or combination of materials known in the art
that will give the diaper a cloth-like look and/or feel and is at a
minimum air permeable.) The outer cover may cover all or
substantially all of the garment-facing surface of the backsheet
26, or may cover only discrete predetermined portions. In a
preferred embodiment, the nonwoven material of the outer cover
covers all or substantially all of the backsheet 26 in order to
provide the diaper with a cloth-like look and feel. Further, the
outer cover may provide the diaper with a low cost landing zone
capable of engaging the hooks of a hook and loop type fastener.
(Such a landing zone could be utilized as a portion of a primary
fastening system or as a means for disposing of a soiled diaper.)
Alternatively, the outer cover may cover only specific portions of
the backsheet 26, such as the garment-facing surface of the side
panels 30. In one such embodiment, the outer cover is comprised in
the breathable side panels 30. Thus, the outer cover may provide
extra strength, bulk, aesthetic appeal or other characteristics
desired in the breathable side panels 30.
[0092] The nonwoven material comprised in the outer cover is
preferably liquid and air pervious. The nonwoven material may
comprise natural fibers (e.g. cotton or wood fibers), or may
comprise fibers of polyethylene, polypropylene, polyester, or any
combination of such fibers. Further, the nonwoven may be carded,
spunmelt, meltblown or air-through bonded or have any other
characteristic or be manufactured in any manner known in the art.
Preferably, the nonwoven is comprised of sufficient thermoplastic
material to allow for thermal bonding of the material to other
components of the diaper.
[0093] The diaper 20 preferably further comprises elasticized leg
cuffs 32 for providing improved containment of liquids and other
body exudates. Each elasticized leg cuff 32 may comprise several
different embodiments for reducing the leakage of body exudates in
the leg regions. (The leg cuff can be and is sometimes also
referred to as leg bands, side flaps, barrier cuffs, or elastic
cuffs.) U.S. Pat. No. 3,860,003 describes a disposable diaper which
provides a contractible leg opening having a side flap and one or
more elastic members to provide an elasticized leg cuff (gasketing
cuff). U.S. Pat. No. 4,909,803 entitled "Disposable Absorbent
Article Having Elasticized Flaps" issued to Aziz et al. on Mar. 20,
1990, describes a disposable diaper having "stand-up" elasticized
flaps (barrier cuffs) to improve the containment of the leg
regions. U.S. Pat. No. 4,695,278 entitled "Absorbent Article Having
Dual Cuffs" issued to Lawson on Sep. 22, 1987; and U.S. Pat. No.
4,795,454 entitled "Absorbent Article Having Leakage-Resistant Dual
Cuffs" issued to Dragoo on Jan. 3, 1989, describe disposable
diapers having dual cuffs including a gasketing cuff and a barrier
cuff. U.S. Pat. No. 4,704,115 entitled "Disposable Waist
Containment Garment" issued to Buell on Nov. 3, 1987, discloses a
disposable diaper or incontinence garment having
side-edge-leakage-guard gutters configured to contain free liquids
within the garment.
[0094] It is preferred that each elasticized leg cuff 32 comprise
at least an inner barrier cuff 70 comprising a barrier flap 68 and
a spacing element 69 such as described in the above-referenced U.S.
Pat. No. 4,909,803. In a preferred embodiment, the elasticized leg
cuff 32 additionally comprises an elastic gasketing cuff 63 with
one or more elastic strands 65, positioned outboard of the barrier
cuff such as described in the above-referred U.S. Pat. No.
4,695,278. Further, the elasticized leg cuff 32 preferably has a
proximal edge 33 and a distal edge 35. The distal edge 35 of the
elasticized leg cuff 32 is that part of the elasticized leg cuff 32
which is spaced away from the chassis 22 of the diaper when the
diaper 20 is being worn. The proximal edge 33 is that part of the
elasticized leg cuff 32 which is joined to the chassis 22 of the
diaper 20. The proximal edge 33 is generally located laterally
inboard of the periphery of the diaper 20.
[0095] In a preferred embodiment, the barrier flap 68 includes an
odor reduction layer (not shown in FIGURE) of the present
invention. More preferably, such a barrier flap 68 is formed by a
nonwoven material which is treated with the metalphthalocyanine
material of the present invention so that it can function as the
odor reduction layer of the present invention. A preferred nonwoven
material for such a barrier flap 68 is a carded nonwoven material
of polypropylene which available from BBA Nonwovens, U.S.A, under
Code No. E-H. In these embodiments, an isolation means can be
formed by either the topsheet 24, or any structure that contributes
the isolation between the barrier flap 68 and the fluid storage
layer 28.
[0096] In a preferred embodiment, the side panel 30 includes a
laminate of a first nonwoven coverstock layer and a second nonwoven
coverstock layer. Preferably, at least one of the first and second
nonwoven coverstock layers is formed by the odor reduction layer of
the present invention. More preferably, at least one of the first
and second nonwoven coverstock layers is formed by a part of the
outer cover or the barrier flap 68 which includes the odor
reduction layer of the present invention. In an alternative
preferred embodiment, the odor reduction layer of the present
invention is disposed between the first and second nonwoven
coverstock layers of the side panel 30.
[0097] It may also be desirable to provide the diaper 20 with
extensibility or elasticity in all or a portion of the side panels
30. (Herein, "extensible" refers to materials that are capable of
extending in at least one direction to a certain degree without
undue rupture. Herein, "elasticity" and "elastically extensible"
refer to extensible materials that have the ability to return to
approximately their original dimensions after the force that
extended the material is removed. As used herein, any material or
element described as "extensible" may also be elastically
extensible unless otherwise provided.) Extensible side panels 30
provide a more comfortable and contouring fit by initially
conformably fitting the diaper to the wearer and sustaining this
fit throughout the time of wear well passed when the diaper has
been loaded with exudates since the side panels allow the sides of
the diaper to expand and contract. Extensible side panels 30
further provide more effective application of the diaper 20 since
even if the diaperer pulls one side panel 30 farther than the other
during the application (asymmetrically), the diaper 20 will
"self-adjust" during wear. While the extensible side panels 30 may
be constructed in a number of configurations, examples of diapers
with extensible side panels are disclosed in U.S. Pat. No.
4,857,067, entitled "Disposable Diaper Having Shirred Ears" issued
to Wood, et al. on Aug. 15, 1989; U.S. Pat. No. 4,381,781 issued to
Sciaraffa, et al. on May 3, 1983; U.S. Pat. No. 4,938,753 issued to
Van Gompel, et al. on Jul. 3, 1990; and in U.S. Pat. No. 5,151,092
issued to Buell et al. on Sep. 29, 1992.
[0098] The diaper 20 preferably further comprises an elasticized
waistband 34 that provides improved fit and containment. The
elasticized waistband 34 is that portion or zone of the diaper 20
which is intended to elastically expand and contract to dynamically
fit the wearer's waist. The elasticized waistband 34 preferably
extends longitudinally outwardly from at least one of the waist
edges of the fluid storage layer 28 and generally forms at least a
portion of the end edge of the diaper 20. Disposable diapers are
generally constructed so as to have two elasticized waistbands, one
positioned in the back region and one positioned in the front
region, although diapers can be constructed with a single
elasticized waistband. Further, while the elasticized waistband 34
or any of its constituent elements can comprise a separate element
affixed to the diaper 20, the elasticized waistband 34 may be
constructed as an extension of other elements of the diaper such as
the backsheet 26 or the topsheet 24, preferably both the backsheet
26 and the topsheet 24. The elasticized waistband 34 may be
constructed in a number of different configurations including those
described in U.S. Pat. No. 4,515,595 entitled "Disposable Diapers
With Elastically Contractible Waistbands" issued to Kievit &
Osterhage on May 7, 1985, and in U.S. Pat. No. 5,151,092 entitled
"Absorbent Article With Dynamic Elastic Waist Feature Having A
Predisposed Resilient Flexural Hinge" issued to Buell, Clear &
Falcone on Sep. 29, 1992; and elasticized waistbands made from a
structural elastic-like film (SELF) web as described in the
previously referenced WO 95/03765.
[0099] In a preferred embodiment, the elasticized waistband 34
includes a laminate of a first nonwoven coverstock layer, an
elastomeric layer, and more preferably a second nonwoven coverstock
layer. Preferably, at least one of the first and second nonwoven
coverstock layers is formed by the odor reduction layer of the
present invention. The elastomeric layer can be formed by any
elastomeric materials known in the art. The elasticized waistband
34 is preferably disposed on the body-facing surface or the
garment-facing surface of the topsheet 24 and operatively joined in
an elastically contractible condition with the topsheet 24 to
gather the elasticized waistband 34.
[0100] The diaper 20 also comprises a fastening system 36 which
forms a side closure which maintains the back region 44 and the
front region 46 in an overlapping configuration such that lateral
tensions are maintained around the circumference of the diaper to
maintain the diaper on the wearer. Exemplary fastening systems are
disclosed in U.S. Pat. No. 3,848,594 issued to Buell on Nov. 19,
1974; U.S. Pat. No. 4,662,875 issued to Hirotsu and Robertson on
May 5, 1987; U.S. Pat. No. 4,869,724 issued to Scripps on Sep. 26,
1989; U.S. Pat. No. 4,846,815 issued to Scripps on Jul. 11, 1989;
U.S. Pat. No. 4,894,060 issued to Nestegard on Jan. 16, 1990; U.S.
Pat. No. 4,946,527 issued to Battrell on Aug. 7, 1990; and U.S.
Pat. No. 5,326,612 entitled "Nonwoven Female Component For
Refastenable Fastening Device And Method of Making the Same" issued
to David J. K. Goulait on Jul. 5, 1994.
[0101] All documents cited in the Detailed Description of the
Invention are, in relevant part, incorporated herein by reference;
the citation of any document is not to be construed as an admission
that it is prior art with respect to the present invention.
[0102] While particular embodiments of the present invention have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
invention. It is therefore intended to cover in the appended claims
all such changes and modifications that are within the scope of
this invention.
* * * * *