U.S. patent application number 11/682518 was filed with the patent office on 2007-06-28 for absorbent article including a temperature change member.
This patent application is currently assigned to KIMBERLY-CLARK WORLDWIDE, INC.. Invention is credited to Andrew M. Long, Christopher P. Olson, Shirlee A. Weber.
Application Number | 20070149936 11/682518 |
Document ID | / |
Family ID | 35266848 |
Filed Date | 2007-06-28 |
United States Patent
Application |
20070149936 |
Kind Code |
A1 |
Weber; Shirlee A. ; et
al. |
June 28, 2007 |
ABSORBENT ARTICLE INCLUDING A TEMPERATURE CHANGE MEMBER
Abstract
An absorbent article has a liquid impermeable outercover, a
liquid permeable bodyside liner, and an absorbent assembly. The
absorbent assembly has a front portion, a rear portion, and a
central portion extending longitudinally between and
interconnecting the front portion and rear portion. The central
portion has an opening therein to define a gap between the front
portion and the rear portion. The absorbent assembly front portion
is disposed intermediate the outercover and the liner in a front
region of the article. The absorbent assembly rear portion is
disposed intermediate the outercover and the liner in a rear region
of the article. A temperature change member containing a
temperature change substance is disposed in the opening of the
central portion of the assembly.
Inventors: |
Weber; Shirlee A.; (Neenah,
WI) ; Olson; Christopher P.; (Neenah, WI) ;
Long; Andrew M.; (Appleton, WI) |
Correspondence
Address: |
SENNIGER POWERS (KCC)
ONE METROPOLITAN SQUARE
16TH FLOOR
ST LOUIS
MO
63102
US
|
Assignee: |
KIMBERLY-CLARK WORLDWIDE,
INC.
Neenah
WI
54957-0349
|
Family ID: |
35266848 |
Appl. No.: |
11/682518 |
Filed: |
March 6, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10955534 |
Sep 29, 2004 |
|
|
|
11682518 |
Mar 6, 2007 |
|
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|
Current U.S.
Class: |
604/361 |
Current CPC
Class: |
A61F 13/42 20130101;
A61F 2013/425 20130101; A61F 13/15203 20130101 |
Class at
Publication: |
604/361 |
International
Class: |
A61F 13/15 20060101
A61F013/15 |
Claims
1. An absorbent article having a front region, a rear region, and a
crotch region extending longitudinally between and interconnecting
the front and rear regions, the absorbent article comprising: a
liquid impermeable outercover; a liquid permeable bodyside liner;
an absorbent assembly having a front portion, a rear portion, and a
central portion extending longitudinally between and
interconnecting the front portion and rear portion, the central
portion having an opening therein to define a gap between the front
portion and the rear portion; the absorbent assembly front portion
being disposed intermediate the outercover and the liner in the
front region of the article; the absorbent assembly rear portion
being disposed intermediate the outercover and the liner in the
rear region of the article; and a temperature change member
containing a temperature change substance, said temperature change
substance being disposed in the opening of the central portion of
the assembly.
2. The absorbent article of claim 1, further comprising a front
waist edge and a rear waist edge, the absorbent assembly front
portion being spaced from the front waist edge by a second gap, and
the absorbent assembly rear portion being spaced from the rear
waist edge by a third gap.
3. The absorbent article of claim 1, further defining a front waist
edge and a rear waist edge and wherein the length of the absorbent
assembly front portion is the same as the length of the absorbent
assembly rear portion, and the length of the first gap between the
absorbent assembly front portion and the absorbent assembly rear
portion is the same as the sum of: (a) the length of a second gap
between the absorbent assembly front portion and the front waist
edge; and (b) the length of a third gap between the absorbent
assembly rear portion and the rear waist edge.
4. The absorbent article of claim 1, wherein the temperature change
member is spaced from the absorbent assembly front portion and the
absorbent assembly rear portion.
5. The absorbent article of claim 1, wherein the temperature change
member provides the article with a temperature change of at least
about 5.degree. C.
6. The absorbent article of claim 5, wherein the temperature change
member provides the article with a temperature change of at least
about 10.degree. C.
7. The absorbent article of claim 1, wherein the temperature change
substance is an endothermic material.
8. The absorbent article of claim 7, wherein the endothermic
material is Xylitol.
9. The absorbent article of claim 1, wherein the temperature change
substance is an exothermic material.
10. The absorbent article of claim 1, wherein the temperature
change substance is contained within a holder that is formed from a
liquid permeable material in at least a portion thereof.
11. The absorbent article of claim 10, wherein the holder is formed
from a wettable, non-woven material.
12. The absorbent article of claim 11, wherein the wettable
non-woven material is a co-form.
13. The absorbent article of claim 1, further comprising a pair of
containment flaps.
14. The absorbent article of claim 1, wherein the article is a
disposable training pant.
15. The absorbent article of claim 1, wherein the temperature
change member is free from contact with the absorbent assembly
front portion and the absorbent assembly rear portion, said
temperature change member being spaced longitudinally from each of
the absorbent assembly front portion and the absorbent assembly
rear portion.
Description
REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 10/955,534, filed Sep. 29, 2004, the entirety
of which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to absorbent articles that
include a temperature change member. More specifically, the
invention relates to an absorbent article such as training pants
that provides the wearer with a noticeable temperature change
sensation upon urination. Such articles can facilitate the toilet
training process.
BACKGROUND
[0003] Absorbent articles such as disposable diapers and training
pants are useful to absorb and contain body wastes. These products
have developed to the extent that urine is quickly drawn and
retained away from the wearer's skin so that the wearer remains
relatively dry and comfortable. Although improved performance of
disposable absorbent products enhances wearer dryness and comfort,
it can reduce the wearer's ability to notice or recognize when
urination occurs, especially if the wearer's attention is
distracted by an activity. This is not conducive to toilet training
because an important step in the early stages of toilet training is
the ability to recognize when urination occurs.
[0004] In an attempt to enhance a child's recognition of when
urination occurs, training pants have been designed with
temperature change members that provide a temperature change
sensation upon urination. For example, a temperature change
substance, such as endothermic particles, may be contained within a
liquid permeable cover that is strategically located on the
absorbent article. Upon urination, urine flows through the liquid
permeable cover, contacts the temperature change substance and
cools down.
[0005] Unfortunately, in certain circumstances where the
temperature change substance generally is located above the main
absorbent assembly, the temperature change substance may not be
fully effective as the urine can rinse through the temperature
change member and be quickly absorbed into the absorbent assembly.
As such, in those instances there may not be a distinct indication
of urination.
[0006] Further, in configurations where the temperature change
member is disposed above the absorbent assembly it can render the
article relatively bulky.
[0007] Thus, there is a need or desire for an absorbent article
with a temperature change member that is arranged to contact urine
effectively during urination so as to provide a wearer with a
distinct temperature change sensation, and hence a distinct signal
that urination has occurred.
[0008] It is also desirable for such an absorbent article to be
relatively thin so as to enhance the underwear-like perception of
the garment.
SUMMARY
[0009] In one aspect, an absorbent article has a front region, a
rear region, and a crotch region extending longitudinally between
and interconnecting the front and rear regions. The absorbent
article comprises a liquid impermeable outercover, a liquid
permeable bodyside liner, and an absorbent assembly. The absorbent
assembly has a front portion, a rear portion, and a central portion
extending longitudinally between and interconnecting the front
portion and rear portion. The central portion has an opening
therein to define a gap between the front portion and the rear
portion. The absorbent assembly front portion is disposed
intermediate the outercover and the liner in the front region of
the article. The absorbent assembly rear portion is disposed
intermediate the outercover and the liner in the rear region of the
article. A temperature change member containing a temperature
change substance is disposed in the opening of the central portion
of the assembly.
[0010] Other objects and features will be in part apparent and in
part pointed out hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 representatively illustrates a perspective view of an
absorbent article according to aspects of the present invention,
with portions cut away to show underlying features.
[0012] FIG. 2 representatively illustrates a top view of an
absorbent article according to aspects of the present invention at
an intermediate stage of assembly and in a flat and stretched
condition, with certain components omitted for clarity.
[0013] FIG. 3 representatively illustrates a top view of a portion
of a web for forming absorbent articles according to the present
invention.
[0014] FIG. 4 representatively illustrates a top view similar to
that of FIG. 3 with the web at a further stage in the
production.
[0015] FIG. 5 representatively illustrates a top view of an example
of a temperature change member for an absorbent article according
to the present invention.
[0016] FIG. 6 representatively illustrates a cross-sectional view
along the line 6-6 in FIG. 5.
[0017] FIG. 7 representatively illustrates a top view of an
absorbent article according to an alternative aspect of the present
invention at an intermediate stage of assembly and in a flat and
stretched condition, with certain components omitted for
clarity.
[0018] Corresponding reference characters indicate corresponding
parts throughout the drawings.
DEFINITIONS
[0019] As used herein, the term "attached" refers to the joining,
adhering, bonding, connecting, or the like, of two elements. Two
elements will be considered to be attached together when they are
integral with one another, or attached directly to one another or
indirectly to one another, such as when each is directly bonded to
intermediate elements.
[0020] As used herein, the term "bonded" refers to the joining,
adhering, connecting, attaching or the like, of two elements. Two
elements will be considered to be bonded together when they are
bonded directly to one another or indirectly to one another, such
as when each is directly bonded to intermediate elements.
[0021] As used herein, the term "comprising" is intended to be
inclusive or open-ended, and is not intended to exclude additional
elements that do not prevent operation of the invention.
[0022] As used herein, the term "disposable", when used to describe
articles such as garments, means an article that is designed to be
discarded after a limited use rather than being laundered or
otherwise restored for use.
[0023] As used herein, the term "disposed" and variations thereof
is intended to mean that one element can be integral with another
element, or that one element can be a separate structure attached
to or placed with another element or placed near another
element.
[0024] As used herein, the term "liquid impermeable", when used to
describe a layer or multi-layer laminate, means that a liquid, such
as urine, will not pass through the layer or laminate, under
ordinary use conditions, in a direction generally perpendicular to
the plane of the layer or laminate at the point of liquid contact,
and "liquid permeable" means a layer or laminate that is not liquid
impermeable.
[0025] As used herein, the term "member" when used in the singular
can have the dual meaning of a single element or a plurality of
elements.
[0026] As used herein, the term "non-woven material" means a
material that is formed without the aid of a textile weaving or
knitting process.
[0027] As used herein, the term "superabsorbent" refers to a
water-swellable, water-insoluble organic or inorganic material
capable, under the most favorable conditions, of absorbing at least
about fifteen times its weight and, more suitably, at least about
thirty times its weight in an aqueous solution containing 0.9
weight percent sodium chloride. The superabsorbent materials can be
natural, synthetic or modified natural polymers and materials, or a
combination of such materials. In addition, the superabsorbent
materials can be inorganic materials, such as silica gels, or
organic compounds such as cross-linked polymers.
[0028] These terms may be defined with additional language in the
remaining portions of the specification.
DESCRIPTION OF THE DRAWINGS
[0029] With reference to FIGS. 1, 2 and 7, an absorbent article 10
is shown for purposes of illustration as disposable training pants
for use by a child. The training pants 10 are illustrated in an
operative, fastened condition in FIG. 1, and in FIG. 2 and 7 the
training pants are shown in an intermediate stage of assembly, in a
flat and stretched condition, with certain components omitted for
clarity. The training pants 10 include a temperature change member
12 that is positioned and adapted to create a distinct temperature
change sensation upon urination, thereby to enhance the wearer's
ability to recognize when urination is occurring. The invention may
also be embodied in other types of absorbent articles such as, for
example, diapers or adult incontinence products.
[0030] By way of illustration only, various materials and methods
for constructing training pants such as the pants 10 of the various
aspects of the present invention are disclosed in PCT Patent
Application WO 00/37009 published on Jun. 29, 2000 in the name of
A. Fletcher et al.; U.S. Pat. No. 4,940,464 issued on Jul. 10, 1990
to Van Gompel et al.; U.S. Pat. No. 5,766,389 issued on Jun. 16,
1998 to Brandon et al.; and U.S. Pat. No. 6,645,190 issued on Nov.
11, 2003 to Olson et al., the contents of which are incorporated
herein by reference.
[0031] The training pants 10 include a chassis 14, and define first
and second end regions, e.g., a front region 16, and a rear region
18. The pants 10 also define an intermediate region, e.g., a crotch
region 20, intermediate and interconnecting the front and rear
regions 16 and 18. The chassis 14 includes a liquid permeable
bodyside liner 22 for contacting a wearer's body, and a liquid
impermeable outer cover 24 for contacting the wearer's clothing. An
absorbent assembly 25, which can include an absorbent assembly
front portion 26 and an absorbent assembly rear portion 28, can be
disposed on the chassis 14 intermediate the bodyside liner 22 and
the outer cover 24. The various components of the pants 10
described herein may be attached to one another in a variety of
ways as are known to those skilled in the art and include
adhesives, ultrasonic bonding, thermal bonding, pressure bonding or
other suitable attachment means, or combinations thereof.
[0032] In the various aspects of the present invention, the
absorbent assembly 25 and the temperature change member 12 may be
arranged to maximize the performance of the temperature change
member. For example, the absorbent assembly front portion 26 may be
at least partially spaced from the absorbent assembly rear portion
28 to provide a first gap C and the temperature change member 12
may be disposed between the front and rear absorbent assemblies 26
and 28, as representatively illustrated in FIG. 2 and 7.
[0033] The training pants 10 can have transversely opposed, front
side panel portions 30 attached to the chassis 14 in the front
region 16 of the pants 10, and transversely opposed, rear side
panel portions 32 attached to the chassis 14 in the rear region 18
of the pants 10. The front and rear side panel portions 30 may be
refastenably attachable to one another by a fastening system 33.
The absorbent chassis 14, side panels 30 and 32, and the fastening
system 33 together define refastenable pants having a waist opening
34, and a pair of leg openings 36 and 38. Alternatively, the front
side panel portions 30 may be permanently bonded to the rear side
panel portions 32 by non-refastenable seams, which may be formed by
any suitable means such as, for example, ultrasonic sealing,
adhesive bonding, heat sealing, adhesive coated tapes, or the like.
As mentioned above, the side panels 30 and 32 may be separate
members that are attached to the chassis 14 or alternatively they
may be formed integrally with the chassis 14, for example as
integral parts of the outer cover 24 and/or liner 22.
[0034] Suitable elastic materials for forming the front side panels
30 and the rear side panels 32, as well as processes for
incorporating elastic side panels into training pants, are
described in U.S. Pat. No. 4,940,464 issued on Jul. 10, 1990 to Van
Gompel et al.; U.S. Pat. No. 5,224,405 issued on Jul. 6, 1993 to
Pohjola; U.S. Pat. No. 5,104,116 issued on Apr. 14, 1992 to
Pohjola; and U.S. Pat. No. 5,046,272 issued on Sep. 10, 1991 to
Vogt et al., the contents of which are incorporated herein by
reference. In particular aspects, the elastic material may include
a stretch-thermal laminate (STL), a neck-bonded laminate (NBL), a
reversibly necked laminate, or a stretch-bonded laminate (SBL)
material. Methods of making such materials are well known to those
skilled in the art and described in U.S. Pat. No. 4,663,220 issued
on May 5, 1987 to Wisneski et al.; U.S. Pat. No. 5,226,992 issued
on Jul. 13, 1993 to Morman; European Patent Application EP 0 217
032 published on Apr. 8, 1987 in the name of Taylor et al.; and PCT
Patent Application WO 01/88245 in the name of Welch et al., the
contents of which are incorporated herein by reference. As is known
in the art, the side panels 30 and 32 may include elastic material
or stretchable but inelastic material.
[0035] The fastening system 33 may include any refastenable
fasteners suitable for absorbent articles, such as adhesive
fasteners, cohesive fasteners, mechanical fasteners, or the like.
In one aspect of the invention, the fastening system includes
mechanical fastening elements for improved performance. Suitable
mechanical fastening elements can be provided by interlocking
geometric-shaped materials, such as hooks, loops, bulbs, mushrooms,
arrowheads, balls on stems, male and female mating components,
buckles, snaps, or the like.
[0036] Leg elastics 40 may extend around the leg openings 36 and 38
of the training pants 10, as representatively illustrated in FIG.
1, so as to provide gaskets for reducing or preventing leakage
around the leg openings, between the training pants 10 and the legs
of the wearer. Likewise, the training pants 10 may also include
waist elastics 55. The waist elastics and the leg elastics 55 and
40 may be formed of any suitable elastic material that is well
known to those skilled in the art. For example, suitable elastic
materials include sheets, strands or ribbons of natural rubber,
synthetic rubber, or thermoplastic elastomeric polymers. In one
aspect of the invention, the waist elastics and/or the leg elastics
may include a plurality of dry-spun coalesced multi-filament
spandex elastomeric threads sold under the trade name LYCRA and
available from Invista of Wilmington, Del., U.S.A.
[0037] The training pants 10 may also include containment flaps 42
adjacent the elasticized leg cuffs 40 for improved containment of
liquid body exudates. Suitable constructions and arrangements for
the containment flaps 42 are generally well known to those skilled
in the art and are described, for example, in U.S. Pat. No.
4,704,116 issued on Nov. 3, 1987 to Enloe, the contents of which
are incorporated herein by reference.
[0038] The outer cover 24 suitably includes a material that is
substantially liquid impermeable. The outer cover 24 can be a
single layer of liquid impermeable material, but more suitably
includes a multi-layered laminate structure in which at least one
of the layers is liquid impermeable. For instance, the outer cover
24 can include a liquid permeable outer layer and a liquid
impermeable inner layer that are suitably joined together by a
laminate adhesive, ultrasonic bonds, thermal bonds, or the like.
The liquid permeable outer layer can be any suitable material and
desirably is one that provides a generally cloth-like texture, for
example a 20 grams per square meter (gsm) spunbond polypropylene
nonwoven web. The inner layer of the outer cover 24 can be both
liquid and vapor impermeable, or it may be liquid impermeable and
vapor permeable. The inner layer can be manufactured from a thin
plastic film, although other flexible liquid impermeable materials
may also be used. The inner layer, or the liquid impermeable outer
cover 24 when a single layer, prevents waste material from wetting
articles, such as bed sheets and clothing, as well as the wearer
and caregiver. One example of a liquid impermeable film for use as
a liquid impermeable inner layer, or a single layer liquid
impermeable outer cover 24, is a 0.02 millimeter polyethylene film
commercially available from Pliant Corporation of Schaumburg, Ill.,
U.S.A.
[0039] More suitably, the outer cover 24 is stretchable, and even
more suitably the outer cover is elastic. For example, the outer
cover 24 may be constructed of a single layer, multiple layers,
laminates, films, nonwoven fabrics, elastic netting, microporous
webs, bonded carded webs or foams comprised of elastomeric or
polymeric materials. The materials may be extensible or stretchable
in one direction or they may be biaxially extensible or
stretchable. Elastomeric non-woven laminate webs can include a
non-woven material joined to one or more gatherable non-woven webs,
films, or foams. Stretch Bonded Laminates (SBL) and Neck Bonded
Laminates (NBL) are examples of elastomeric composites. A non-woven
fabric is any web of material that has been formed without the use
of a textile weaving process that produces a structure of
individual fibers that are interwoven in an identifiable repeating
manner.
[0040] Examples of suitable materials are spunbond-meltblown
fabrics, spunbond-meltblown-spunbond fabrics, spunbond fabrics, or
laminates of such fabrics with scrims, films, foams, or other
non-woven webs. Elastomeric materials may include cast or blown
films, foams, or meltblown fabrics composed of polyethylene,
polypropylene, or polyolefin copolymers, as well as combinations
thereof. The elastomeric materials may include PEBAX elastomer
(available from AtoChem located in Philadelphia, Pa., U.S.A.),
HYTREL elastomeric polyester (available from E. I. DuPont de
Nemours of Wilmington, Del., U.S.A.), KRATON elastomer (available
from Kraton Polymers of Houston, Tex., U.S.A.), or strands of LYCRA
elastomer (available from Invista of Wilmington, Del., U.S.A.), or
the like, as well as combinations thereof. The outer cover 24 may
include materials that have elastomeric properties through a
mechanical process, printing process, heating process, or chemical
treatment. For example, such materials may be apertured, creped,
neck-stretched, heat activated, embossed, and/or micro-strained;
and may be in the form of films, webs, and/or laminates.
[0041] In one aspect of the invention, the outer cover 24 may
include a 13.6 gsm basis weight layer of G2760 KRATON elastomer
strands adhesively laminated with a 0.3 gsm layer of adhesive to at
least one facing. The facing can be composed of a thermal point
bonded bicomponent spunbond non-woven fibrous web having a 23.7 gsm
basis weight.
[0042] The bodyside liner 22 is suitably compliant, soft-feeling,
and non-irritating to the wearer's skin. The bodyside liner 22 is
also sufficiently liquid permeable to permit liquid body exudates
such as urine to readily penetrate through its thickness to the
temperature change member 12. A suitable bodyside liner 22 may be
manufactured from a wide selection of web materials, such as porous
foams, reticulated foams, apertured plastic films, woven and
non-woven webs, or a combination of any such materials. For
example, the bodyside liner 22 may include a meltblown web, a
spunbonded web, or a bonded-carded-web composed of natural fibers,
synthetic fibers or combinations thereof. The bodyside liner 22 may
be composed of a substantially hydrophobic material, and the
hydrophobic material may optionally be treated with a surfactant or
otherwise processed to impart a desired level of wettability and
hydrophilicity.
[0043] The bodyside liner 22 may also be stretchable, and more
suitably it may be elastic. Elastomeric materials suitable for
constructing the bodyside liner 22 include elastic strands, LYCRA
elastics, cast or blown elastic films, nonwoven elastic webs,
meltblown or spunbond elastomeric fibrous webs, as well as
combinations thereof. Examples of suitable elastomers include
KRATON elastomers, HYTREL elastomers, ESTANE elastomeric
polyurethanes (available from B.F. Goodrich and Company of
Cleveland, Ohio, U.S.A.), or PEBAX elastomers.
[0044] The bodyside liner 22 and the outer cover 24 may be attached
to one another along at least a portion of their periphery by
adhesive, ultrasonic bonding, thermal bonding or other suitable
attachment means known in the art.
[0045] The absorbent assembly 25 is suitably compressible,
conformable and capable of absorbing and retaining liquid body
exudates released by the wearer. For example, the absorbent
assembly can include a matrix of hydrophilic fibers, and more
suitably cellulosic fluff, such as wood pulp fluff, and
superabsorbent particles. One suitable pulp fluff is identified
with the trade designation CR1654, commercially available from U.S.
Alliance, Childersburg, Ala., U.S.A., and is a bleached, highly
absorbent sulfate wood pulp containing primarily soft wood fibers
and about 16% hardwood fibers. As an alternative to wood pulp
fluff, synthetic fibers, polymeric fibers, meltblown fibers, short
cut homofil bicomponent synthetic fibers, or other natural fibers
may be used. Suitable superabsorbent materials can be selected from
natural, synthetic, and modified natural polymers and materials.
The superabsorbent materials can be inorganic materials, such as
silica gels, or organic compounds, such as crosslinked polymers,
for example, sodium neutralized polyacrylic acid. Suitable
superabsorbent materials are available from various commercial
vendors, such as Dow Chemical Company of Midland, Michigan, U.S.A.,
and Stockhausen Inc., Greensboro, N.C., U.S.A.
[0046] The absorbent assembly 25 can have a density within the
range of about 0.10 to about 0.5 grams per cubic centimeter and may
be wrapped or encompassed by a suitable tissue or nonwoven wrap for
maintaining the integrity and/or the shape of the absorbent
assembly.
[0047] In some aspects, a surge management layer (not shown) may be
located adjacent the absorbent assembly 25, for example between the
absorbent assembly 25 and the bodyside liner 22, and attached to
one or more components of the chassis 14 by methods known in the
art, such as by adhesive, ultrasonic or thermal bonding. A surge
management layer helps to decelerate and diffuse surges or gushes
of liquid that may be rapidly introduced into the absorbent
assembly 25. Desirably, the surge management layer can rapidly
accept and temporarily hold the liquid prior to releasing the
liquid into the storage or retention portions of the absorbent
assembly 25. Examples of suitable surge management layers are
described in U.S. Pat. No. 5,486,166 and U.S. Pat. No. 5,490,846,
the contents of which are incorporated herein by reference.
[0048] The absorbent assembly 25 may have a variety of shapes and
configurations that may assist with the performance of the
temperature change member 12. For example, as representatively
illustrated in FIGS. 2 and 7, the absorbent assembly 25 may include
an absorbent assembly front portion 26 and an absorbent assembly
rear portion 26 disposed intermediate the outercover 22 and the
bodyside liner 24. The absorbent assembly front portion 26 may be
at least partially spaced from the absorbent assembly rear portion
28 to define a first gap indicated by the arrow marked C. That is,
the first gap C may be provided by the spacing between the inner
edge of the absorbent assembly front portion 26 and the inner edge
of the absorbent assembly rear portion 28. In a particular aspect,
the absorbent assembly front portion 26 may be completely spaced
from the absorbent assembly rear portion 28, as representatively
illustrated in FIG. 2. For example and as will be described in
greater detail below, such a configuration may be accomplished by
disposing the absorbent assembly 25 in a spaced manner between the
liner 22 and the outercover 24.
[0049] Alternatively, as representatively illustrated in FIG. 7,
the absorbent assembly front portion 26 may only be partially
spaced from the absorbent assembly rear portion 28. That is, the
first gap C need not extend across the entire width of the
absorbent assembly 25 in the crotch region 20 of the pants 10. For
example, the absorbent assembly 25 may include an absorbent
assembly central portion 70 in the crotch region 20 of the pants 10
located between the absorbent assembly front portion 26 and the
absorbent assembly rear portion 28. In particular, a portion of the
absorbent assembly 25, such as one or more strips 80 may extend
through the crotch region 20 and connect the absorbent assembly
front portion 26 to the absorbent assembly rear portion 28 to
provide the absorbent assembly central portion 70 (FIG. 7). As
such, the first gap C may be provided by an opening within the
absorbent assembly central portion 70. Such a configuration may be
accomplished by forming an absorbent assembly 25 with first gap C
in the central portion 70, or first gap C may be provided
subsequent to the formation of absorbent assembly 25, such as by
cutting out and removing a portion of the absorbent assembly
central portion 70. In one aspect, a water cutter may be used to
cut out and remove a portion of the absorbent assembly central
portion 70.
[0050] As can be appreciated by one of ordinary skill in the art,
the first gap C may be a variety of shapes and sizes. For example,
in the illustrated aspects, the first gap C may be generally
rectangular in shape. Alternatively, the first gap C may be oval,
circular, triangular, and the like or combinations thereof.
Further, in the various aspects of the present invention the first
gap C is generally free of highly absorbent material such as
cellulose fluff and superabsorbent material, but may include a
tissue layer or a nonwoven wrapsheet layer.
[0051] Turning now to FIG. 2, the absorbent assembly front portion
26 may be disposed in the front region 16 of the training pants 10,
intermediate the outercover 22 and the liner 24. For example, the
absorbent assembly front portion may be attached to the outer cover
24 or the liner 22. Similarly, the absorbent assembly rear portion
may be disposed in the rear region 18 of the training pants 10,
intermediate the outercover 24 and the liner 22. For example, the
absorbent assembly rear portion 28 may be attached to the outer
cover 24 or the liner 22. The temperature change member 12 may then
be disposed in the crotch region 20 of the training pants 10,
between the absorbent assembly front portion 26 and the absorbent
assembly rear portion 28. As such, upon insult, the urine may more
effectively interact with the temperature change member 12 thereby
resulting in a more noticeable temperature change for the wearer.
For example, the temperature change member 12 may be attached to
the outercover 24 or the liner 22.
[0052] In one aspect of the invention, the absorbent assembly front
portion 26 is the same size as the absorbent assembly rear portion
28, and hence the length A of the absorbent assembly rear portion
28 is the same as the length B of the absorbent assembly front
portion 26. Suitably, the absorbent assembly front portion and rear
portion 26 and 28 are disposed on the chassis 14 such that the
length of the first gap C can be equal to the sum of a second gap
and a third gap. The second gap is provided by the spacing between
the outer edge of the absorbent assembly front portion 26 and a
front waist edge 44 and is indicated by the arrow marked D; the
third gap is the distance between the outer edge of the absorbent
assembly rear portion 28 and a rear waist edge 46 and is indicated
by the arrow marked E. This configuration of the absorbent assembly
first portion and second portion 26 and 28 provides advantages in
the production of training pants according to the present
invention. For example, with this configuration, the absorbent
assemblies 26 and 28 may be cut from the same roll of absorbent
material and may be applied continuously to a web for forming
training pants according to aspects of the present invention.
[0053] FIG. 3 illustrates a portion of a web 48 of outer cover
material for forming training pants according to aspects of the
present invention in an automated process. The absorbent assembly
front portion and rear portion 26 and 28 may be formed by unwinding
absorbent material from a supply roll (not illustrated), cutting
the absorbent material at regular intervals, and applying the
absorbent material to the web 48 at regular intervals to form
alternating absorbent assembly front and rear portions 26 and 28,
which are spaced from one another by first gap C and a fourth gap,
which is indicated by the arrow marked F. Suitably, the length of
the fourth gap F is the substantially the same as the first gap C.
Accordingly, the web 48 may be cut along the broken lines 50,
thereby traversing the fourth gap F and forming individual training
pants 10. Thus, the fourth gap F can be divided into the second gap
and the third gap D and E, which together may be the same length as
the first gap C.
[0054] The supply roll may be driven by a variable speed drive (not
shown), that may be adjusted to effect suitable unwinding of the
absorbent material. Any suitable cutting device may be used to cut
the absorbent material. For example, the absorbent material may be
cut by a mechanical pinch-type cut-off knife, a shear-type cut-off
knife, a hot knife, or other cutting means well known in the art.
As mentioned above, the absorbent assembly 25 may optionally be
attached to the web 48 by any suitable means such as, for example,
adhesive bonding. Suitable adhesives include spray adhesives,
hot-melt adhesives, self-adhering elastomeric materials and the
like, which may be obtained from Bostik Findley Adhesives, Inc., of
Wauwatosa, Wisconsin, U.S.A., or from National Starch and Chemical
Company, of Bridgewater, N.J., U.S.A.
[0055] FIG. 4 representatively illustrates a subsequent stage in
the production of training pants according to one aspect of the
invention in which temperature change members 12 have been disposed
on the web 48 in alternate gaps (i.e., the first gap C) between the
front and rear absorbent assemblies 26 and 28. Accordingly, when
the web 48 is cut along the broken lines 50 to form separate
training pants 10, each pants can include an absorbent assembly
front portion 26, an absorbent assembly rear portion 28 and a
temperature change member 12 disposed in the first gap C between
the absorbent assembly front and rear portion 26 and 28.
[0056] The temperature change member 12 is adapted to create a
distinct temperature change sensation upon urination. With
reference to FIGS. 5 and 6, this temperature change sensation
results from a temperature change substance 52 that may include
particles captured within a holder 54. In one aspect of the
invention, the holder 54 may include a containment pouch formed
from a sheet of material that is folded over the temperature change
substance 52 along a fold line 56 and bonded along edges 58, 60 and
62 to enclose the temperature change substance within the pouch.
The edges of the material sheet may be bonded together by any
suitable means such as, for example, sonic bonds, thermal bonds,
adhesive bonds, and the like. Alternatively, the temperature change
substance 52 may be contained between two layers of material that
are joined together along all of the side edges thereof, or within
various other types of suitable holders.
[0057] The holder 54 may be formed from a highly wettable non-woven
material such as a co-form. In one aspect of the invention, the
sheet of co-form may include a sheet of NSP 130 gsm, 2.4 mm bulk,
65:35 fluff/polypropylene ratio co-form. Various co-form materials
are known to those skilled in the art. For instance, examples of
co-form materials are described in U.S. Pat. No. 4,100,324, issued
Jul. 11, 1978, to Anderson, et al., the contents of which are
hereby incorporated herein by reference.
[0058] Alternatively, the holder 54 may include a porous film or
fibrous layer. The fibrous layer may include a fibrous tissue, a
woven or non-woven fabric, a cellulosic fibrous web, or the like.
Suitable holders may be formed, for example, from a
liquid-permeable web material, such as a liquid-permeable film,
tissue, fabric, or the like. The fabric may be composed of a
hydrophilic material or composed of a hydrophobic material that has
been suitably treated to render it sufficiently hydrophilic.
[0059] The temperature change substance 52 can include a material
that provides a temperature change when placed near the wearer and
contacted with urine. The temperature change can be either an
absorption or release of heat that is noticeable to the wearer.
Absorption of heat by the temperature change substance 52 will
provide the wearer with a cool sensation, while a release of heat
by the substance will provide the wearer with a warm sensation.
Reference is made to aforementioned U.S. patent application Ser.
No. 10/462,166, in the name of Olson, et al., incorporated by
reference herein, for additional information regarding the
mechanism by which the temperature change sensation is
accomplished.
[0060] The temperature change substance 52 is responsive to contact
with an aqueous solution such as urine to either absorb or release
heat. The mechanism by which this is accomplished is dissolution of
the substance in the aqueous solution, swelling of the substance in
the aqueous solution, or reaction of the substance in the aqueous
solution. For example, the temperature change substance may include
particles that have a substantial energy difference between a
dissolved state and a crystalline state so that energy in the form
of heat is absorbed or released to the environment upon contact
with urine, or the temperature change substance may release or
absorb energy during swelling or reacting in an aqueous
solution.
[0061] While a wide variety of substances may result in a
temperature change when contacted with an aqueous solution, the
selection of a particular temperature change substance 52, the
determination of the amount to be used and the location of the
substance should be based in part on the desired temperature
change. Specifically, the temperature change member 12 may suitably
provide the training pants 10 with a temperature change of at least
about 5.degree. C., more suitably about 10.degree. C., still more
suitably about 15.degree. C., and still yet more suitably about
20.degree. C. when wet. As a result, in aspects where the
temperature change substance is endothermic, a drop in the
temperature of the product when insulted can be from about
37.degree. C. to about 25.degree. C., and further to about
20.degree. C., and still further to about 16.degree. C. The
temperature change can suitably last for at least 10 minutes, and
more suitably for approximately 15 minutes. Further, in the case of
an endothermic temperature change substance 52, the temperature
change can suitably lower (at least temporarily) the temperature of
the training pants 10 to less than about 25.degree. C. for improved
effectiveness, particularly with a preoccupied wearer (i.e., a
playing child).
[0062] By way of example, Xylitol particles may be selected to
provide a cooling sensation because Xylitol particles absorb heat
when dissolved in an aqueous solution. Other suitable temperature
change substances that absorb heat during dissolution include salt
hydrates, such as sodium acetate (H.sub.2O), sodium carbonate
(10H.sub.2O), sodium sulfate (10H.sub.2O), sodium thiosulfate
(5H.sub.2O), and sodium phosphate (10H.sub.2O); anhydrous salts
such as ammonium nitrate, potassium nitrate, ammonium chloride,
potassium chloride, and sodium nitrate; organic compounds such as
urea or the like. Temperature change substances that release heat
during dissolution include aluminum chloride, aluminum sulfate,
potassium aluminum sulfate, or the like.
[0063] The temperature change substance 52 may also include those
substances that absorb or release heat during swelling. By way of
illustration, one suitable temperature change substance that
releases heat during swelling is a lightly cross-linked partially
neutralized polyacrylic acid.
[0064] Alternatively, the temperature change substance may include
those substances that absorb or release heat upon reaction with an
aqueous solution. Examples include ortho esters or ketals such as
menthone ketals that result from reacting menthone with alcohols
containing 1 to 8 carbons or polyols containing 2 to 8 carbons, and
all structural and optical isomers thereof. Particular menthone
ketals that may be suitable include menthone-glycerol ketal and
menthone-propylene glycol ketal. Particular ketals are disclosed in
U.S. Pat. No. 5,348,750 issued to Greenberg, and U.S. Pat. No.
5,266,592 issued to Grub et al.
[0065] Thus, as described above, the holder 54 may be formed from a
co-form material, and the temperature change substance 52 may
include Xylitol particles contained within the co-form holder. Once
wet by urination, the Xylitol dissolves, creating an endothermic
response, and the high re-wet co-form holder 54 remains wet, cold
and soggy, thereby signaling to the wearer that urination has
occurred.
[0066] The temperature change member 12 is disposed within the
training pants 10 so that, upon urination, liquid makes contact
with the temperature change substance 52. More specifically, the
temperature change member 12 may be disposed in the first gap C.
For example, the temperature change member 12 can be disposed
intermediate the outercover 24 and liner 22 in the first gap C
between the absorbent assembly front portion 26 and the absorbent
assembly rear portion 28. Accordingly, liquid passing through the
bodyside liner 22 can collect between the absorbent assemblies 26
and 28, interact with the temperature change substance 52 and cool
down, before the urine is absorbed by the absorbent assembly 25. In
one aspect, the temperature change member disposed in the first gap
C may further be spaced from the absorbent assembly front portion
26 and the absorbent assembly rear portion 28. In addition, the
containment flaps 42 can serve to improve the gathering of liquid
in the crotch region 20 of the training pants 10. Thus, the
collection of liquid allows for a relatively high temperature
change, for example a drop in temperature of urine from about
37.degree. C. to about 25.degree. C., and further to about
20.degree. C., and still further to about 16.degree. C., for
signaling urination to the wearer. In practice, urine collecting
between the front and rear absorbent assemblies will gradually be
absorbed into the absorbent assemblies with body movements of the
wearer.
[0067] As can be readily appreciated, the temperature change member
12 can be of various shapes and sizes. For example, the temperature
change member 12 may be rectangular and may measure about 8 cm by
about 10 cm. Alternatively, the temperature change member 12 can be
oval in shape, circular, triangular, or the like. Further, the
temperature change member 12 can suitably contain various amounts
of the temperature change substance 52. For example, in the case of
Xylitol, the temperature change member 12 can contain between about
5 grams and about 30 grams, and particularly between about 10 grams
and about 25 grams, for example about 17 grams. Further, it will be
understood by those of skill in the art that the training pants 10
of the present invention could include more than one temperature
change member 12 between the absorbent assembly front portion and
rear portion 26 and 28.
[0068] By configuring the temperature change member 12 and the
absorbent assembly 25 in accordance with the present invention,
training pants 10 can be produced with enhanced temperature change
capability. Since the liquid contacting the temperature change
member 12 is allowed to collect between the absorbent assembly
front portion and rear portion 26 and 28, it may more readily
interact with the temperature change material 52 before it is
absorbed by the absorbent assembly 25. Thus, a greater degree of
temperature change sensation and a greater signal of urination, can
be achieved. In addition, the configuration of the temperature
change member 12 and the absorbent assembly 25 allows for a
relatively thin garment, which enhances the underwear-like
perception of the training pants 10. Finally, the configuration of
the various components in accordance with the present invention can
facilitate the automated production of the training pants 10.
[0069] A suitable procedure for determining the temperature change
when wet of a product containing a temperature change substance is
described below in the temperature change test as follows. The test
should be conducted in an environment having a stable temperature
of 21.degree. C. to 22.degree. C. and a stable humidity of about 50
percent. The product to be tested is prepared by removing any
elastic side panels and cutting all other elastics to permit the
product to lay as flat as possible. The product is positioned in a
Plexiglas cradle to simulate the configuration of the product in
actual use. The center of the product is placed in the deepest
portion of the cradle.
[0070] A liquid dispensing nozzle operatively connected to a liquid
dispensing pump is positioned to dispense saline onto the inner
surface of the product. The tip of the nozzle should be located 1
cm away from the inner surface and 10 cm forward of the center of
the product, along the product's longitudinal axis. The pump is
activated to dispense 90 ml of a stabilized isotonic 0.9% saline at
a rate of 15 ml/sec. The saline is certified blood bank saline
available from The Baxter Healthcare Corporation, Scientific
Products Division, McGraw Park, Ill., and is at a temperature of
37.degree. C.
[0071] The surface temperature of the product at the location of
the temperature change substance is measured using a standard
thermometer or temperature sensing thermistors connected to a
digital display or recording device. The surface temperature 30
seconds after the saline is dispensed is recorded as the test
temperature. A reference temperature is obtained by performing this
test on a portion of the product not including the temperature
change substance or on a similar product without the temperature
change substance. The surface temperature change when wet for the
product is the difference between the test temperature and the
reference temperature.
[0072] While the invention has been described in detail with
respect to specific embodiments thereof, it will be appreciated
that those skilled in the art, upon attaining an understanding of
the foregoing, may readily conceive of alterations to, variations
of and equivalents to these embodiments. Accordingly, the scope of
the present invention should be assessed as that of the appended
claims and any equivalents thereto.
* * * * *