Note: Descriptions are shown in the official language in which they were submitted.
CA 02285620 1999-10-14
WO 98147546 PCT/IB981a0618
ABSORBENT ARTICLES HAVING LOTIONED LEG CUFFS CONTAINING
A POLYSILOXANE EMOLLIENT
TECHNICAL FIELD
This application relates to absorbent articles such as diapers, training
pants, adult incontinence devices, and the like, having leg cuffs. More
particularly, the present invention relates to absorbent articles having a
lotion coating on the surface of the leg cuffs that is transferable to the
wearer's skin by normal contact and wearer motion andlor body heat. The
lotions disclosed in the present invention minimize the abrasion between the
cuffs and skin in the area where the cuffs contact the wearer's skin,
resulting
in less skin irritation.
BACKGROUND OF THE INVENTION
The major function of absorbent articles such as disposable diapers
and incontinent briefs or undergarments is to absorb and contain body
exudates. Such articles are thus intended to prevent body exudates from
soiling, wetting, or otherwise contaminating clothing or other articles, such
as bedding, that come in contact with the wearer. The most common mode
of failure for such products occurs when body exudates leak out of the gaps
between the article and the wearer's leg or waist to adjacent clothing
because they are not immediately absorbed within the article and the
absorbent article is not able to sustain a good fit on the wearer such that
gaps are created allowing the exudates to leak out of the chassis of the
absofbent article. For example, urine tends to be deposited into the
topsheet in gushes such that the urine migrates to the gaps in the chassis
where it can come in contact with clothing or other articles and be absorbed
by these articles. Additionally, loose fecal material that is not easily
absorbed by the absorbent article tends to 'Moat" on the liquid-receiving
surface and work its way past the gaps in the article in the legs or waist of
the wearer.
Contemporary disposable diapers have a topsheet, a backsheet, an
absorbent core, and elasticized leg flaps generally formed from an elastic
CA 02285620 1999-10-14
WO 98/47546 PCT/IB98/00618
2
member being enclosed in the continuous topsheet and backsheet which
extend beyond the edges of the absorbent core. These elasticized ieg flaps
prove effective generally to prevent wicking and overtlow from the fluid
laden diaper to clothing contacting the edges of the diaper in that the
elasticized ieg flaps present a fluid impervious barrier between the edge of
the diaper and the contacting clothing, and in addition, provide a gasketing
action about the legs of the wearer to maintain a seal about the leg and
minimize gapping. However leakage along the perimeter of the diaper may
still occur. As the diaper is wom for longer periods of time, forces tend to
act on the diaper to degrade the initial fit on the wearer. Large gaps and
sagging of the diaper in the legs and waist are formed by the degradation in
fit. Thus, as liquids are deposited onto the topsheet, some of the liquid is
not immediately absorbed through the topsheet and migrates toward the
edges of the diaper where it can leak through or past the gaps in the diaper
and come in contact with clothing or undergarments where it can be
absorbed by and wicked into such garments.
Disposable diapers may be provided with barrier cuffs which inhibit
loose fecal material or gushes of urine or liquids from soiling the wearer's
clothing. The barrier cuffs restrain the free flow of this material and
provide
a structure to hold such material within the diaper so that as such material
freely floats or flows on the topsheet of the diaper, it is contained within
the
diaper. Despite the effectiveness of such structures in containing such
material, it has been found that liquids can leak through the barrier cuffs
and
soil the wearers clothing. In addition, the barrier leg cuffs can cause skin
marking in the area where the leg cuff contacts the skin.
It has now been discovered that applying a lotion coating on the
surface of the leg cuffs that is transferable to the wearer's skin by normal
c~ and wearer motion and/or body heat can improve the containment
characteristics, reduce skin irritation, of the diaper as well as lead to
improved ease of BM clean up. As used herein, the term leg cuff includes
barrier leg cuffs, gasket cuffs and combinations and variations thereof. The
coating of the cuffs with the lotions disclosed herein can increase the
hydrophobicity of the cuffs, thereby improving the leakage performance.
The hydrophobic lotion coating allows for flexibility in cuff designs using
nonwoven materials by providing an alternate method to achieve the
desired hydrophobicity. This can lead to reduced material costs.
I T
CA 02285620 1999-10-14
WO 98/47546 PCT/IB98/00618
3
Irt~rtantly, the lotions disclosed in the present invention act to minimize
the
abrasion between the cuffs and skin in the area where the cuffs contact the
wearer's skin, resulting in less skin irritation. The lotions also provide a
protective coating on the wearer's skin that helps prevent the adherence of
BM to the skin, thereby improving the ease of BM cleanup.
One substance that has been applied as a lotion to diaper products
to impart a soothing, protective coating is mineral oil. Mineral oil (also
known as liquid petrolatum) is a mixture of various liquid hydrocarbons
obtained by distilling the high-boiling (i.e., 300°-390°C)
fractions in
petroleum. Mineral oil is liquid at ambient temperatures, e.g. 20°-
25°C. As
a result, mineral oil is relatively fluid and mobile when applied to diapers.
Because mineral oil is fluid and mobile at ambient temperatures, it tends not
to remain localized on the body contacting surface of the barrier leg cuffs,
but instead migrates through the leg cuffs into the interior of the diaper.
Accordingty, relatively high levels of mineral oil need to be applied to the
barrier leg cuffs to provide the desired therapeutic or protective coating
lotion benefits. This leads not only to increased costs for these lotioned
barrier leg cuff diaper products, but other detrimental effects as well,
including decreased absorbency of the underlying absorbent core.
Even without increasing its level, the tendency of mineral oil fo
migrate once applied has other detrimental effects. For example, the
applied mineral oil can , transfer to, into and through the packaging or
wrapper material for the lotioned diaper product. This can create the need
for barrier type packaging or wrapper films to avoid smearing or other
leakage of mineral oil from the diaper product.
Accordingly, it would be desirable to provide diaper products having
ked leg cuffs that: (1 ) have desirable therapeutic or protective coating
a
lotion benefits (2) do not require relatively high levels of coatings that are
liquid at room temperature (e.g., mineral oil) (3) do not adversely affect the
absorbency of the diaper product; and (4) do not require special wrapping or
barrier materials for packaging.
Therefore, it is an object of the present invention to provide a diaper
having lotioned leg cuffs wherein the lotion is transferable to the wearer's
skin and provides desirable therapeutic benefits, resulting in less skin
irritation.
CA 02285620 1999-10-14
WO 98/47546 PCT/IB98/00618
4
It is a further object of the present invention to provide a diaper
having iotioned leg cuffs wherein the lotion is transferable to the wearer's
skin and is effective at reducing the adherence of BM to the skin, thereby
improving the ease of BM cleanup.
It is a further object of the present invention to provide a disposable
diaper having leg cuffs having improved liquid containment properties.
It is yet a further object of the present invention desirable to provide
diapers having lotioned leg cuffs that do not require relatively high levels
of
mineral oil, and do not require special wrapping or barrier materials for
packaging.
These and other objects are obtained using the present invention, as
will become readily apparent from a reading of the following disclosure.
SUMMARY OF THE INVENTI N
The present invention relates to an absorbent article, such as a
disposable diaper, having a lotion coating on the surface of the leg cuffs
that is semisolid or solid at ambient temperatures (i.e., at 20°C) and
is
adapted to be transferred to the wearer's skin. Upon transfer to the skin, the
lotion provides desirable therapeutic and/or protective coating lotion
benefits resulting in less skin irritation and also reducing the adherence of
BM to the skin of the wearer, thereby improving the ease of BM clean up.
The coating of the cuffs with the lotions disclosed herein can also increase
the hydrophobicity of the cuffs, thereby improving their leakage
performance. The hydrophobic lotion coating allows for flexibility in cuff
designs using nonwoven materials by providing an alternate method to
achieve the desired hydrophobicity. This can lead to reduced material
cosh:
Briefly, the absorbent articles of the present invention comprise:
A) a backsheet;
B) a liquid pervious, topsheet joined to said backsheet;
C) an absorbent core positioned between said topsheet and said
backsheet; and
CA 02285620 1999-10-14
WO 98147546 PCT/IB98100618
D) a barrier leg cuff disposed adjacent each of the absorbent
article's two longitudinal side edges, wherein each of said barrier
leg cuffs has a proximal edge affixed adjacent to said longitudinal
side edge of said absorbent article and a distal edge unsecured
to at least a portion of said absorbent article, wherein each of
said barrier leg cuffs has an inner surtace oriented toward the
interior of said absorbent article and an outer surtace oriented
toward the skin of the wearer when said absorbent article is being
wom, wherein at least a portion of said barrier leg cuff outer
surface or inner surface has disposed thereon an effective
amount of a lotion coating which is semi-solid or solid at 20°C
and which is at least partially transferable to the wearer's skin,
said lotion coating comprising:
(i) from about 10 to about 95% of a polysiloxane emollient
having a plastic or fluid consistency at 20°C; and
(ii) from about 5 to about 90°~ of an agent capable of
immobilizing said polysiloxane emollient on said outer
surface or inner surface of the barrier leg cuff, said
immobilizing agent having a melting point of at least about
35°C.
The absorbent article can have two elastically contractible gasketing
cuffs in addition to or instead of the barrier leg cuffs. Each elastically
contractible gasketing cuff is disposed adjacent each of said two
longitudinal side edges of said absorbent article, said gasketing cuffs
extending laterally outward from said diaper longitudinal side edges,
wherein each of said gasketing cuffs has a front surface oriented
toward the skin of the wearer when said diaper is being wom and a
back surface opposed to said front surtace, wherein at Least a portion
of said gasketing cuff front surface or back surface has disposed
thereon an effective amount of a lotion coating which is semi-solid or
solid at 20°C and which is at least partially transferable to the
wearer's
skin, said lotion coating comprising:
(i) from about 5 to about 95°r6 of a polysitoxane emollient having
a plastic or fluid consistency at 20°C; and
CA 02285620 1999-10-14 -
WO 98/47546 PCT/IB98/00618
6
(ii) from about 5 to about 95% of an agent capable of
immobilizing said polysiloxane emollient on said front surface
or back surface of the gasketing leg cuff, said immobilizing
agent having a melting point of at least about 35°C.
The quantity of lotion coating on at least a portion of the body
contacting surface of the leg cuffs of the present invention (barrier and/or
gasketing cuffs) preferably ranges from about 0.1 mg/in2 to about 50
mg/in2, more preferably from about 1 mglin2 to about 25 mglin2. Lotioned
leg cuffs according to the present invention provide therapeutic andlor
protective lotion coating benefits, as well desirable BM cleaning benefits. In
addition, the hydrophobic lotions can improve the cuffs' hydrophobicity
and/or provide an alternate means to achieve the desired hydrophobicity.
Because the emollient is substantially immobilized on the surface of the leg
cuffs, less lotion composition is needed to impart the desired skin care
benefits. In addition, special barrier or wrapping materials are preferably
not necessary in packaging the lotioned diaper products of the present
invention.
As will be discussed hereinafter, the lotion compositions of the
present invention preferably have a melting profile such that they are
relatively immobile and localized on the diaper leg cuffs at room
temperature, are transferable to the wearer at body temperature, and yet
are not completely liquid under extreme storage conditions.
Importantly, the lotion compositions of the present invention are
easily transferable to the skin by way of normal contact, wearer motion,
andlcx body heat. Without being bound by theory, it is believed that the
loti~ o~nposition changes the surface energy of the skin, and/or forms a
"b' reducing the affinity of the skin for BM or urine. The BM or urine,
therefore, has a reduced tendency to stick to the skin, and is easier to
remove.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a plan view of a disposable diaper embodiment of the
present invention having portions cut away to reveal underlying structure.
t
CA 02285620 1999-10-14
WO 98/47546 PCT/IB98I00618
7
Figure 2 is a fragmentary sectional view taken along section line 2 - 2
of Figure 1.
Figure 3 is a fragmentary sectional view taken along section line 3 - 3
of Figure 1.
Figure 4 is a perspective view of an absorbent article in the form of a
disposable diaper according to the present invention
Figure 5 is a schematic representation illustrating a preferred process
for applying the lotion composition of the present invention to diaper barrier
leg cuffs.
Figure 6 is a schematic representation illustrating an alternative
process for applying the lotion composition of the present invention to
diaper barrier leg cuffs.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the term "comprising" means that the various
components, ingredients, or steps, can be conjointly employed in practicing
the present invention. Accordingly, the term "comprising" encompasses the
more restrictive terms "consisting essentially of and "consisting of."
All percentages, ratios and proportions used herein are by weight
unless otherwise specified.
A. Absorbent Article
As used herein, the term "absorbent article" refers to devices which
a4~b and contain body exudates, and more spec~cally, refers to devices
are placed against the skin of a wearer to absorb and contain the
various exudates discharged from the body. The term "disposable" is used
herein to destxibe absorbent articles which are not intended to be laundered
or othervvise restored or reused as an absorbent article after a single use.
Examples of disposable absorbent articles include feminine hygiene
garments such as sanitary napkins and panti-liners, diapers, incontinence
briefs, diaper holders, training pants, and the like.
Disposable absorbent articles typically comprise a liquid pervious
topsheet, a liquid impervious badcsheet joined to the topsheet and an
absorbent core positioned between the topsheet and the backsheet.
CA 02285620 1999-10-14
WO 98/47546 PCT/IB98/00618
8
Disposable absorbent articles and components thereof, including the
topsheet, backsheet, absorbent core, and any individual layers of these
components, have a body surface and a garment surface. As used herein,
"body surface" means that surface of the article or component which is
intended to be wom toward or adjacent to the body of the wearer, while the
"garment surface" is on the opposite side that faces away from the wearer
and is oriented toward the wearer's undergarments when the disposable
absorbent article is wom.
The following description generally discusses the absorbent core,
topsheet, and backsheet materials that are useful in disposable absorbent
articles. It is to be understood that this general description applies to
these
components of the specific absorbent articles shown in Figures 1-4 and
further described below, in addition to those of other disposable absorbent
articles which are generally described herein.
In general, the absorbent core is capable of absorbing or retaining
liquids (e.g., menses, urine, and/or other body exudates). The absorbent
core is preferably compressible, conformable, and non-irritating to the
wearer's skin. The absorbent core may be manufactured in a wide variety of
sizes and shapes (e.g., rectangular, oval, hourglass, 'T' shaped, dog bone,
symmetric, asymmetric, etc.). In addition to the absorbent composites of the
present invention, the absorbent core may include any of a wide variety of
liquid-absorbent materials commonly used in absorbent articles, such as
comminuted wood pulp, which is generally referred to as airfelt. Examples
of other suitable absorbent materials for use in the absorbent core include
creped cellulose wadding; meltblown polymers inGuding coform; chemically
sieffened, mod~ed or cross-linked cellulosic fibers; synthetic fibers such as
fed polyester fibers; peat moss; tissue including tissue wraps and
tissue laminates; absorbent foams; absorbent sponges; superabsorbent
polymers; absorbent gelling materials; or any equivalent material or
combinations of materials, or mixtures of these.
The configuration and construction of the absorbent core may also be
varied (e.g., the absorbent core may have varying caliper zones andlor have
a profile so as to be thicker in the center; hydrophilic gradients; gradients
of
the absorbent composite of the present invention, superabsorbent
gradients; or lower average density and lower average basis weight zones,
e.g., acquisition zones; or may comprise one or more layers or structures).
CA 02285620 1999-10-14
WO 98147546 PCT/IB98100618
9
The total absorbent capacity of the absorbent core should, however, be
compatible with the design loading and the intended use of the absorbent
article. Further, the size and absorbent capacity of the absorbent core may
be varied to accommodate different uses such as diapers, incontinence
pads, pantiliners, regular sanitary napkins, and overnight sanitary napkins,
and to accommodate wearers ranging from infants to adults.
The absorbent core can include other absorbent components that are
often used in absorbent articles, for example, a dusting layer, a wicking or
acquisition layer, or a secondary topsheet for increasing the wearer's
comfort.
The topsheet is preferably compliant, soft feeling, and non-irritating to
the wearers skin. Further, the topsheet is liquid pervious, permitting liquids
(e.g., menses and/or urine) to readily penetrate through its thickness. A
suitable topsheet may be manufactured from a wide range of materials such
as woven and nonwoven materials (e.g., a nonwoven web of fibers);
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. When the topsheet comprises a nonwoven
web, the web may be manufactured by a wide number of known techniques.
For example, the web may be spunbonded, carded, wet-laid, melt-blown,
hydroentangled, combinations of the above, or the like.
The badcsheet is preferably impervious to liquids (e.g., menses
andl~ urine), at least in the crotch region of the absorbent article, and is
prefi~ably 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. The backsheet
prevents the exudates absorbed and contained in the absorbent core from
wetting articles which contact the absorbent article such as bedsheets,
pants, pajamas and undergarments. The backsheet may thus comprise a
woven or nonwoven material, polymeric films such as thermoplastic films of
polyethylene or polypropylene, or composite materials such as a film-coated
CA 02285620 1999-10-14
WO 98/47546 PCT/IB98100618
nonwoven material. A suitable backsheet is a polyethylene film having a
thickness of from about 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mils).
Exemplary polyethylene films are manufactured by Clopay Corporation of
Cincinnati, Ohio, under the designation P18-1401 and by Tredegar Film
Products of Terre Haute, Indiana, under the designation XP-39385. The
backsheet is preferably embossed and/or matte finished to provide a more
clothlike appearance. Further, the backsheet may permit vapors to escape
from the absorbent core (i.e., the backsheet is breathable) while still
preventing exudates from passing through the backsheet. The size of the
backsheet is dictated by the size of the absorbent core and the exact
absorbent article design selected.
The backsheet and the topsheet are positioned adjacent the garment
surface and the body surface, respectively, of the absorbent core. The
absorbent core is preferably joined with the topsheet, the backsheet, or both
in any manner as is known by attachment means (not shown in Figure 3)
such as those well known in the art. However, embodiments of the present
invention are envisioned wherein portions of the entire absorbent core are
unattached to either the topsheet, the backsheet, or both.
For example, the backsheet andlor the topsheet may be secured to
the absorbent core or to each other 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,
Minnesota under the designation HL-1258 or H-2031. The attachment
means will preferably comprise an open pattern network of filaments of
adhesive as is disclosed in U.S. Patent 4,573,986, issued to Minetola, et al.
on March 4, 1986, and which is incorporated herein by reference. An
exemplary attachment means of an open pattern network of filaments
comprises several lines of adhesive filaments swirled into a spiral pattern
such as illustrated by the apparatus and method shown in U.S. Patent
3,911,173 issued to Sprague, Jr. on October 7, 1975; U.S. Patent 4,785,996
issued to Zwieker, et al. on November 22, 1978; and U.S. Patent 4,842,666
issued to Werenicz on June 27, 1989. Each of these patents are
incorporated herein by reference. Alternatively, the attachment means may
comprise heat bonds, pressure bonds, ultrasonic bonds, dynamic
r r
CA 02285620 1999-10-14
WO 98/47546 PCT/IB98~00618
11
mechanical bonds, or any other suitable attachment means or combinations
of these attachment means as are known in the art.
A preferred disposable absorbent article in which the lotioned leg
cuffs of the present invention may be used are diapers. As used herein, the
term "diaper" refers to an absorbent article generally wom by infants, and
incontinent persons that is wom about the lower torso of the wearer. In other
words, the term "diaper" includes infant diapers, training pants, adult
incontinence devices, etc. The present invention is also applicable to other
types of disposable products such as sanitary napkins and panty liners that
contain leg cuffs. -
Figure 1 is a plan view of a preferred embodiment of the diaper 20 of
the present invention in its flat-out, uncontracted state (i.e., with all
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 contacts the wearer facing the viewer. The diaper 20 is
shown in Figure 1 to have a front waist region 22, a back waist region 24, a
crotch region 26 and a periphery 28 which is defined by the outer edges of
the diaper in which the longitudinal edges are designated 30 and the end
edges are designated 32. The diaper 20 additionally has a lateral centerline
which is designated 34 and a longitudinal centerline which is designated 36.
The diaper 20 comprises a liquid pervious topsheet 38, the top surface of the
topsheet 38 being designated 40; a liquid impervious backsheet 42; an
absorbent core 44 having side edges 46 and comprising an absorbent layer
48 and first and second tissue layers 50 and 52, respectively; a pair of tape-
tab fasteners 54; gasketing cuffs 56 each comprising a side flap 58 and flap
elastic members 60; barrier cuffs 62 each having a proximal edge 64, a distal
edge 66, an inner surface 68, an outer surface 70, a first end 72 and a
second end 74; and spacing means 76 such as spacing elastic member 77
for spaang the distal edge 66 away from the topsheet top surface 40. The
diaper 20 additionally comprises adhesive means 78 such as a glue bead 79
for securing closed the first and second ends 72 and 74 of each barrier cuff
62. The areas in which the adhesive means 78 are disposed are designated
front closure zone 80 and back closure zone 82. While the topsheet 38, the
absorbent core 44, the backsheet 42, and the elastically contractible
gasketing cuffs 56 may be assembled in a variety of well known
configurations, a preferred diaper configuration is described generally in
U.S.
CA 02285620 1999-10-14
WO 98/47546 PCT/iB98/00618
12
Pat. No. 3,860,003 entitled "Contractable Side Portions for Disposable
Diaper", which issued to K B. Buell on January 14, 1975, and which patent is
incorporated herein by reference.
The diaper 20 is shown in Figure 1 to have an outer surface 86, and
an inner surface 84 opposed to the outer surface 86. The inner surface 84 of
the diaper 20 comprises that portion of the diaper 20 which is positioned
adjacent to the wearers body during use (i.e., the inner surface 84 generally
is formed by at least a portion of the topsheet 38 and other components that
may be joined to the topsheet 38). The outer surface 86 comprises that
portion of the diaper 20 which is positioned-~away from the wearer's body
(i.e., the outer surface 86 generally is formed by at least a portion of the
backsheet 42 and other components that may be joined to the backsheet 42).
As used herein, the portion of the diaper 20 or component thereof which
faces the wearer is also referred to as the body facing surface. Similarly,
the
portion facing away from the wearer is also referred to herein as the garment
facing surface.
Figure 1 shows a preferred embodiment of the diaper 20 in which the
topsheet 38 and the backsheet 42 are coextensive and have length and
width dimensions generally larger than those of the absorbent core 44. The
topsheet 38 is associated with and superposed on the backsheet ~ 42 to
thereby form the periphery 28 of the diaper 20.
The diaper 20 has front and back waist regions 22 and 24 extending,
respectively, from the end edges 32 of the diaper periphery 28 toward the
lateral centerline 34 of the diaper 20 a distance from about 114 to about 1I3
the length of the diaper 20. The waist regions comprise those portions of the
diaper 20 which, when wom, encircle the waist of the wearer. The crotch
reg~n 26 is that portion of the diaper 20 between the waist regions 22 and
24,~ and comprises that portion of the diaper 20 which, when wom, is
positioned between the legs of the wearer and covers the lower torso of the
wearer.
Figure 2 is a fragmentary sectional view taken along line 2-2 of
Figure 1 and depicts the diaper construction in the back waist region 24 of
the diaper 20. (It should be understood that the diaper construction in the
front waist region 22 is identical to the construction in the back waist
region
24.) The absorbent core comprises the absorbent layer 48 that is shown as
being completely enveloped by the first and second tissue layers 50 and 52.
T
CA 02285620 1999-10-14
WO 98147546 PCT/IB98100618
13
The absorbent core 44 is disposed between the topsheet 38 and the
backsheet 42; both the topsheet 38 and the backsheet 42 extend beyond the
side edge 46 of the absorbent core 44 to define the side flap 58. The
juxtaposed areas of the topsheet 38 and the backsheet 42 are adhesively
secured together by adhesive 88. In a preferred embodiment, the flap
elastic members 60 do not extend into the front waist region 22 so that the
gasketing cuff 56 is not formed in this region. The barrier cuff 62 is shown
as
being a separate element secured to the topsheet 38; the proximal edge 64
being formed by securing the element to the topsheet 38 by adhesive 92.
The inner surface 68 of the barrier cuff 62 (also referred to herein as the
barrier leg cuff's inboard surface) is secured to the topsheet top surface 40
by adhesive means 78 such as the glue bead 79. Therefore, the distal edge
66 is closed. (i.e., it is not spaced away from the topsheet top surface 40).
It
should be noted that the spacing elastic member 77 is not disposed in this
region because the distal edge 66 is not designed to be spaced away from
the topsheet top surface 40 in the waist regions. Therefore, the barrier cuff
62 is not open nor ready to constrain the flow of body exudates in this
region.
Figure 3 is a fragmentary sectional view taken along line 3-3 of
Figure 1 and depicts the diaper construction in the crotch region 26 of the
diaper 20 as it is shaped before being applied to the wearer (i.e., the diaper
20 is subjected to elastic contraction). The absorbent core 44 comprises the
absorbent layer 48 that is shown as being completely enveloped by the first
and second tissue layers 50 and 52. The absorbent core 44 is disposed
between the topsheet 38 and the backsheet 42; both the topsheet 38 and the
backsheet 42 extend beyond the side edge 46 of the absorbent core 44 to
define the side flap 58. The juxtaposed areas of the topsheet 38 and the
bsheet 42 are adhesively secured together by adhesive 88. The topsheet
38 ~rtd the badcsheet 42 also enclose the flap elastic members 60 adjacent
the longitudinal edge 30 in the periphery 28. The flap elastic members 60
are secured in the topsheet-backsheet formed side flap 58 by elastic
attachment means 90. The elastically contractible gasketing cuff 56 is
thereby fon~ned by the side flap 58 and the flap elastic members 60. The
gasketing cuff has. a front surface 57 orientated toward the skin of the
wearer
when the diaper is wom, and a back surface 59 opposed to the front surface.
The barrier cuff 62 is shown as being formed by securing an element to the
topsheet 38 between the flap elastic members 60 and the side edge 46 of the
absorbent core 44. The proximal edge 64 of the barrier cuff 62 is formed by
CA 02285620 1999-10-14
WO 98147546 PC"T/IB98100618
14
securing the barrier cuff element to the topsheet 38 by adhesive 92. The
spacing elastic members 77 are enclosed in a tunnel that is formed when an
end of the barrier cuff element is folded back upon itself; the spacing
elastic
members 77 being secured in the barrier cuff 62 by elastic attachments
means 94. The distal edge 66 of the barrier cuff is spaced away from the
topsheet top surface 40 by the elastic gathering action of the spacing elastic
members 77; a channel 96 thereby being formed by at least the proximal
edge 64, the distal edge 66 and the inboard surface 68 of the barrier cuff 62.
The channel 96 is shown as being ready to restrain, contain and hold body
exudates until the diaper 20 is removed from the wearer.
Diapers of the present invention can have a number of well known
configurations, with the absorbent cores thereof being adapted to the
present invention. Exemplary configurations are described generally in U.S.
Patent 3,860,003 issued to Buetl on January 14, 1975; U.S. Patent
5,151,092 issued to Buell et al. on September 29, 1992; U.S. Patent
5,221,274 issued to Buell et al. on June 22, 1993. Each of these patents is
incorporated herein by reference.
A topsheet 38 which is particularly suitable for use in the diaper 20, is
carded and thermally bonded by means well known to those skilled in the
fabrics art. A satisfactory topsheet for the present invention comprises
staple length polypropylene fibers having a denier of about 2.2 As used
herein, the term "staple length fibers" refers to those fibers having a length
of at least about 15.9 mm (0.625 inches). Preferably, the topsheet has a
basis weight from about 14 to about 25 grams per square meter. A suitable
topsheet is manufactured by Veratec, Inc., a Division of International Paper
Company, of Walpole, Mass. under the designation P-8.
The topsheet 38 of diaper 20 - is preferably made of a hydrophilic
material to promote fapid transfer of liquids (e.g., urine) through the
topsheet. tf the topsheet is made of a hydrophobic material, preferably at
least the upper surface of the topsheet 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 rather than being
drawn through the topsheet and being absorbed by the absorbent core.
The topsheet can be rendered hydrophilic by treating it with a surfactant.
Suitable methods for treating the topsheet with a surfactant include spraying
the topsheet material with the surfactant and immersing the material into the
CA 02285620 1999-10-14
WO 98/47546 PCT/IB98/00618
surfactant. A more detailed discussion of such a treatment and
hydrophilicity is contained in U.S. Patents 4,988,344 entitled "Absorbent
Articles with Multiple Layer Absorbent Layers" issued to Reining, et al on
January 29, 1991 and U.S. Patent 4,988,345 entitled "Absorbent Articles
with Rapid Acquiring Absorbent Cores" issued to Reising on January 29,
1991, each of which is incorporated by reference herein.
In a preferred embodiment of a diaper as described herein, the
backsheet 42 has a modified hourglass shape extending beyond the
absorbent core a minimum distance of about 1.3 cm to about 6.4 cm (about
0.5 to about 2.5 inch) around the entire diaper periphery.
The absorbent core 44 may take on any size or shape that is
compatible with the diaper 20. One preferred embodiment of the diaper 20
has an asymmetric, modified T-shaped absorbent core 44 having ears in the
first waist region but a generally rectangular shape in the second waist
region. Exemplary absorbent structures for use as the absorbent core of the
present invention that have achieved wide acceptance and commercial
success are described in U.S. Patent 4,610,678 entitled "High-Density
Absorbent Structures" issued to Weisman et al. on September 9, 1986; U.S.
Patent 4,673,402 entitled "Absorbent Articles With Dual-Layered Cores"
issued to Weisman et al. on June 16, 1987; U.S. Patent 4,888,231 entitled
"Absorbent Core Having A Dusting Layer" issued to Angstadt on December
19, 1989; and U.S. Patent 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 absorbent core may
further comprise the dual core system containing an acquisitioNdistribution
core of chemically stiffened fibers positioned over an absorbent storage
~ ag detailed in U.S. Patent 5,234,423, entitled "Absorbent Article With
Elastic Waist Feature aid Enhanced Absorbency" issued to Alemany et al.,
on August 10, 1993; and in U.S. Patent 5,147,345, entitled "High Efficiency
Absorbent Articles For Incontinence Management" issued to Young, LaVon
and Taylor on September 15, 1992. All of these patents are incorporated
herein by reference.
In a preferred embodiment, the diaper 20 comprises elasticized barrier
leg cuffs 62 and elasticized gasketing cuffs 56 for providing improved
containment of liquids and other body exudates; and a fastening system 54
which forms a side closure which maintains the front waist region 22 and the
CA 02285620 1999-10-14
WO 98/47546 PCT/IB98/00618
16
back waist region 24 in an overlapping configuration such that lateral
tensions are maintained around the circumference of the diaper to maintain
the diaper on the wearer. The diaper 20 may also comprise an elastic waist
feature (not shown) and/or elasticized side panels (not shown) in the waist
regions 22 and 24 to provide a more comfortable and contouring fit and more
effective application of the diaper 20.
The elasticized leg cuffs provide for improved containment of liquids
and other body exudates can be constructed in a number of different
configurations, including those described in U.S. Patent No. 3,860,003; U.S.
Patent No. 4,909,803, issued to Aziz et al. on Mar. 20, 1990; U.S. Patent
No. 4,695,278, issued to Lawson on Sept. 22, 1987; and U.S. Patent No.
4,795,454, issued to Dragoo on Jan. 3, 1989, each being incorporated
herein by reference. Each elasticized leg cuff 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. Patent 3,860,003,
incorporated herein by reference, 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.
Patent 4,909,803 entitled "Disposable Absorbent Article Having Elasticized
Flaps" issued to Aziz et al. on March 20, 1990, and incorporated herein by
reference, describes a disposable diaper having "stand-up" elasticized flaps
(barrier cuffs) to improve the containment of the leg regions. U.~.- P~ient
4,695,278 entitled "Absorbent Article Having Dual Cuffs" issue! va t.av~rsr~r~
on September 22, 1987, and incorporated herein by reference, ~sc~-it~s a
disposable diaper having dual cuffs including a gasketang a~#f arid a barrier
cu$: While each elasticized leg cuff may be coc~f~gurec~ so as to be similar
to~.~ny of the leg bands, side flaps, harrier cuVirfs, or elastic cuffs
described
aboys, it is praaf~sr~ed that the elasticized leg cuff comprise barrier leg
cuffs
62 and gasketing cuffs 56 as described in detail below.
Each barrier cuff 62 is a flexible member having a proximal edge 64, a
distal edge fib, an inner surface 68 (also referred to herein as the inboard
surface) and an outer surface 70 (also referred to herein as the outboard
surface). The inner surface is oriented toward the interior of the diaper, and
the outer surface is orientated toward the skin of the wearer when the diaper
is being wam. As used herein, the term flexible ref~e;rs to materials which
are
i r
CA 02285620 1999-10-14
WO 98/47546 PCTlIB98/00618
compliant and will readily conform to the general shape and contours of the
body. The barrier cuff 62 may be manufactured from a wide variety of
materials such as polypropylene, polyester, rayon, nylon, foams, plastic
films, formed films, and elastic foams. A number of manufacturing
techniques may be used to manufacture the barrier cuff. For example, the
barrier cuff 62 may be woven, non-woven, spunbonded, meltblown, carded,
coated, laminated, combinations of the above, or the like. A particularly
preferred barrier cuff 62 comprises a polypropylene material containing no
finish or surfactant to render it liquid impermeable. A particularly preferred
polypropylene material is manufactured by Crown Zellerbach Company as
Celestra. In addition, because of the hydrophobic lotion coating of the
present invention, the barrier cuff may be made from hydrophilic material.
As shown in Figures 1 and 3, the ban-ier cuff 62, and more particularly
the proximal edge 64, is disposed adjacent to the diaper longitudinal side
edge 30, inboard of and preferably adjacent to the gasketing cuff 56. The
term "inboard" is defined as the direction toward the centerline (34 or 36,
respectively) of the diaper that is parallel to the respective edge of the
diaper
20 along which the particular gasketing cuff 56 is disposed. The barrier cuff
62 is disposed inboard of the gasketing cuff 56 so that exudates, especially
loose fecal material which is not easily absorbed and tends to float along the
topsheet top surface 40, will contact the barrier cuff 62 before it can
contact
the gasketing cuff 56. The barrier cuff 62 is disposed adjacent the gasketing
cuff 56 to provide a more effective dual restraint against the flow of body
exudates. The barrier cuff 62 is preferably disposed between the flap elastic
member 60 of the gasketing cuff 56 and the longitudinal centerline 36 of the
diaper 20. Most preferably, the barrier cuff 62 is disposed between the flap
elasEic member 60 and the side edge 46 of the absorbent core 44 in the
cxo~Ch region 26 of the diaper 20.
The proximal edge 64 and the distal edge 66 are in spaced relation to
each other and define the width of the barrier cuff 62. The proximal and
distal edges 64 and 66, respectively, may be in a parallel, non parallel,
rectilinear or curvilinear relationship. In addition, the barrier cuff 62 may
have
a variety of different cross sectional areas including circular, square,
rectangular or any other shape such as shown in Figure 3. Preferably, the
proximal edge 64 is spaced from the distal edge 66 in a parallel and
rectilinear relationship to provide a barrier cuff 62 having uniform widths.
CA 02285620 1999-10-14
WO 98/47546 PCT/IB98/00618
18
Each barrier cuff 62 preferably has a width of at least about 5 mm, and
preferably from about 10 mm to about 25 mm.
A preferred embodiment of the diaper 20 shown in Figures 2 and 3 is
provided with the barrier cuff 62 joined to the topsheet 38. The term "joined"
includes any means for affixing the ban-ier cuff 62 to the diaper 20, and
includes embodiments wherein the barrier cuff 62 is a separate element
having the proximal edge 64 directly or indirectly attached to the topsheet 38
(i.e., integral) or embodiments wherein the barrier cuff 62 is made from the
same element or material as the topsheet 38 so that the proximal edge 64 is
a continuous and undivided element of the topsheet (i.e., unitary). The
barrier cuff 62 may alternatively be joined to the side flap 58, the backsheet
42, the absorbent core 44, the topsheet 38 or any combination of these or
other elements of the diaper 20. In a prefer-ed diaper 20, the barrier cuffs
62
are integral with the topsheet 38. The integral barrier cuff 62 is preferably
formed by a single strip of material which is secured to the topsheet by
adhesive 92, the distal edge 66 being formed by folding an end of the
material back upon itself.
The distal edge 66 is preferably disposed inboard of the proximal
edge 64 to present a more effective barrier against the flow of exudates. The
distal edges 66 are maintained inboard of the proximal edges 64 by the
adhesive means 78 so as to obviate their inversion. While the distal edges
66 may alternatively be disposed in other positions in relation to the
proximal
edges 64, such positions are not preferred.
The distal edge 66 is preferably not secured to any other element in at
least the crotch region 26 of the diaper 20 so that it may be spaced away
from the top surface 40 of the topsheet 38. The distal edge 66 is preferably
spaced away from the top surface 40 of the topsheet 38 so that the barrier
cuff 62 may form a channel 96 to enhance the containment of the article. As
used herein, "spaced" includes embodiment wherein the distal edges 66 may
assume one or more positions relative to the top surface 40 of the topsheet
38 including at some times assuming a position adjacent the top surface 40
of the topsheet 38. The distance between the distal edge 66 to the top
surface 40 of the topsheet 38 is measured along a line drawn from the distal
edge 66 to the closest part of the topsheet 38 when the distal edge 66 is
positioned so as to be spaced away from the topsheet~as far as possible.
(i.e., in the elastically contracted position). Preferably, the distal edge 66
is
CA 02285620 1999-10-14
WO 98/47546 PCT/IB98In0618
19
spaced away from the topsheet 38 by a height of at least about 2 mm, and
more preferably of from about 5 mm (about 1/4") to about 10 mm (3/8").
The channel 96 is formed at least along the proximal and distal edges
64 and 66 and the inboard surface 68 of the ban-ier cuff 62. The channel 96
forms a barrier to the flow of exudates as they tend to move or float acxoss
the topsheet 38. Thus the channel 96 holds and contains exudates until the
diaper 20 can be removed.
!n addition to barrier leg cuffs, the absorbent articles of the present
invention preferably comprise gasket cuffs 56. The elastically contractible
gasketing cuffs 56 are disposed adjacent the periphery 28 of the diaper 20,
preferably along each longitudinal edge 30 so that the gasketing cuffs 56
tend to draw and hold the diaper 20 against the legs of the wearer. While
the gasketing cuffs 56 may comprise any of several means as are well known
in the diaper art, a particularly preferred gasketing cxrff construction
comprises a flexible side flap 58 and a flap elastic member 60, as is
described in detail U.S. Pat. No. 3,860,003, issued to Buell on January 14,
1975 and incorporated herein by reference. In addition, a method and
apparatus suitable for manufacturing a disposable diaper having elastically
contractible gasketing cuffs 56 are described in U.S. Pat. No. 4,081,301
entitled "Method and Apparatus for Continuously Attaching Discrete,
Stretched Elastic Strands to Predetermined Isolated Portions of Disposable
Absorbent ArtiGes" which issued to K B. Buell on Mar. 28, 1978 and which
patent is incorporated herein by reference.
The side flap 58 should be highly flexible and thus contractible so that
the flap elastic members 60 may gather the side flap 58 to provide a
gss#ing cuff 56 about the legs or waist of the wearer. The side flaps 58
ac~~:tt~ portion of the diaper 20 between the periphery 28 and the edges of
they absorbent cxare 44. Thus in a preferred embodiment of the present
invention as shown in Figure 1, the side flaps 58 are formed from the
extension of the backsheet 42 and the topsheet 38 from and along the side
edges 46 of the absorbent core 44 of the diaper 20 in at least the crotch
region 26.
The flap elastic members 60 are secured to the side flaps 58 in an
elastically contractible condition so that in a normally unrestrained
configuration, the flap elastic members 60 effectively contract or gather the
side flaps 58. The flap elastic members 60 can be secured to the side flaps
CA 02285620 1999-10-14
WO 98147546 PCT/IB98100618
58 in an elastically contractible condition in at least two ways. For example,
the flap elastic members 60 may be stretched and secured to the side flaps
58 while the side flaps 58 are in an uncontracted condition. Alternatively,
the
side flaps 58 may be contracted, for example by pleating, and the flap elastic
members 60 secured to the contracted side flaps 58 while the flap elastic
members 60 are in their unrelaxed or unstretched condition.
In the embodiment illustrated in Figure 1, the flap elastic members 60
extend essentially the entire length of the side flaps 58 in the crotch region
26 of the diaper 20. Alternatively, the elastic members 60 may extend the
entire length of diaper 20, or any other length suitable to provide an
elastically contractible gasketing cuff. The length of the flap elastic
members
60 is dictated by the diapers design.
In the diaper 20 of Figure 3, the flap elastic members 60 are
associated with the side flaps 58 by securing them to the side flaps 58 with
elastic attachments means 90. The elastic attachment means 90 should be
flexible and of sufficient adhesiveness to hold the flap elastic member in its
stretched condition. The elastic attachment means 90 herein are preferably
glue beads made of hot melt adhesives such as marketed by Findley
Adhesives Incorporated, Elm Grove, Wis. as Findley Adhesives 581. A more
detailed description of the manner in which the flap elastic members 60 may
be positioned and secured to the diaper 20 can be found in U.S. Pat. No.
4,253,461 issued to Strickland and Visscher on Mar. 3, 1981, and U.S. Pat.
No. 4,081,301 issued to Buell on Mar. 28, 1978, both of which are
incorporated herein by reference.
One flap elastic member 60 which has been found to be suitable is an
elas~c strand having a cross section of 0.18 mm by 1.5 mm. and made from
nafut~l rubber as available from Easthampton Rubber Thread Company of
Stewert, Va., under the trademark L-1900 Rubber Compound. Other suitable
flap elastic members 60 can be made from natural rubber, such as elastic
tape sold under the trademark Fulflex 9211 by Fulflex Company of Scotland,
N.C. The flap elastic member 60 may also comprise any heat shrinkable
elastic material as is well known in the art. Other suitable flap elastic
members 60 may comprise a wide variety of materials as are well known in
the art including elastomeric films, polyurethane films, elastomeric foams,
and formed elastic scrim.
CA 02285620 1999-10-14
WO 98!47546 PCT/1898/00618
21
In addition, the flap elastic members 60 may take a multitude of
configurations. For example, the width of the flap elastic members 60 may
be varied from about 0.25 mm (0.01 inches) to about 25 mm (1.0 inch) or
more; the flap elastic members 60 may comprise a single strand of elastic
material or may comprise several parallel or non-parallel strands of elastic
material; or the flap elastic members 60 may be rectilinear or curvilinear.
Still further, the flap elastic members 60 may be affixed to the diaper 20 in
any of several ways which are well known in the art. For example, the flap
elastic members 60 may be ultrasonically bonded, heatlpressure sealed into
the diaper 20 using a variety of bonding patterns or the elastic members 60
may simply be glued to the diaper 20.
The elasticized waist feature preferably comprises an elasticized
waistband (not shown) that may be constructed in a number of different
configurations including those described in U.S. Patent No. 4,515,595 issued
to Kievit et al. on May 7, 1985; U.S. Patent No. 5,026,364 issued to
Robertson on Jun. 25, 1991; and the above referenced U.S. Patent No.
5,151,092 issued to Buell et al. on Sept. 29, 1992, each of these references
being incorporated herein by reference.
The elasticized side panels may be constructed in a number of
configurations. Examples of diapers with elasticized side panels positioned
in the ears (ear flaps) of the diaper are disclosed in U. S. Patent No.
4,857,067, issued to Wood, et al. on Aug. 15, 1989; U.S. Patent No.
4,381,781, issued to Sciaraffa, et al. on May 3, 1983; U.S. Patent No.
4,938,753, issued to Van Gompel, et al. on Jul. 3, 1990; and U.S. Patent No.
5,151,092, issued to Buell et aI. on Sept. 29, 1992; each of which are
incorporated herein by reference.
Exemplary fastening systems 54 are disclosed in U.S. Patent No.
4,846,815, issued to Scripps on July 11, 1989; U.S. Patent No. 4,894,060,
issued to Nestegard on Jan. 16, 1990; U.S. Patent No. 4,946,527, issued to
Battrell on Aug. 7, 1990; U.S. Patent No. 3,848,594, issued to Buell on Nov.
19, 1974; U.S. Patent No. B1 4,662,875, issued to Hirotsu et al. on May 5,
1987; and U.S. Patent No. 5,151,092, issued to Buell et al. on Sept. 29,
1992; each of which is incorporated herein by reference.
Figure 4 is a perspective view of the diaper 20 in its elastically
contracted position prior to being placed on the wearer. The topsheet 38 is
shown as the body contacting surface of the diaper 20, the backsheet 42
CA 02285620 1999-10-14
WO 98147546 PCT/IB98I00618
22
being disposed away from the body of the wearer. The gasketing cuffs 56 are
shown to be gathered or contracted by the flap elastic members (not shown
in Figure 4). The diaper 20 is shown as having two barrier cuffs 62
extending adjacent to and inboard of the gasketing cuffs 56. The distal
edges 66 are shown to be gathered and contracted by the spacing elastic
members (not shown) in the crotch region 26 so as to provide a longitudinally
extending channel 96 along the diaper 20. In addition, the ends 72 and 74 of
the barrier cuff 62 are secured closed in the front and back closure zones 80
and 82, respectively, so as to provide comfort for the wearer, to obviate
inversion of the barrier cuffs, and for ease of application of the diaper.
The diaper 20 is applied to a wearer, by positioning the back waist
region 24 under the wearer's back, and drawing the remainder of the diaper
20 between the wearer's leg so that the front waist region 22 is positioned
across the front of the person. The ends of the tape-tab fasteners 54 are
then secured preferably to outwardly facing areas of the diaper 20. !n this
manner, the barrier cuffs 62 should be disposed in the crotch region of the
wearer and should provide the dispositions and functions described
hereinbefore. Once applied, the distal edges 66 of the barrier cuffs 62
extend through the groin areas and diverge upwardly along both of the
buttocks of the wearer. Neither of the barrier cuffs 62 encircle the thighs of
the wearer. However, the gasketing cuffs 56 will encircle the thighs and
create a gasketing action against the thighs. The ends of the barrier cuff 62
are secured to the topsheet 38 to obviate the inversion of the barrier cuffs,
for comfort for the wearer during application and use, and for ease of
application.
The iotioned cuffs of the present invention are also useful in training
partt~: The teen "training pants", as used herein, refers to disposable
gartrts having fixed sides and leg openings. Training pants are placed in
position ort the wearer by inserting the wearers legs into the leg openings
and sliding the training pant into position about the wearer's tower torso.
Suitable training pants are disclosed in U.S. Patent No. 5,246,433, issued to
Hasse, et al. on September 21, 1993. The lotioned cuffs of the present
invention are also applicable to absorbent articles that are a combination or
"hybrid" of training pants and diapers.
Another disposable absorbent article for which the lotioned topsheets
of the present invention are useful are incontinence articles. The term
CA 02285620 1999-10-14
WO 98/47546 PCT/IB98/00618
23
"incontinence article" refers to pads, undergarments (pads held in place by
a suspension system of same type, such as a belt, or the like), inserts for
absorbent articles, capacity boosters for absorbent articles, briefs, bed
pads, and the like regardless of whether they are wom by adults or other
incontinent persons. Suitable incontinence articles are disclosed in U.S.
Patent No. 4,253,461 issued to Strickland, et al. on March 3, 1981; U.S.
Patent Nos. 4,597,760 and 4,597,761 issued to Buelt; the above-mentioned
U.S. Patent No. 4,704,115; U.S. Patent No. 4,909,802 issued to Ahr, et al.;
U.S. Patent No. 4,964,860 issued to Gipson, et al. on October 23, 1990; and
in U.S. Patent Application Serial No. 07/631,090 fated by Noel, et al. on
January 3, 1991 (PCT Publication No. WO 92/11830 published on July 23,
1992).
B. Lotion Composition
The lotion compositions of the present invention are solid, or more
often semisolid, at 20°C, i.e. at ambient temperatures. By "semisolid"
is
meant that the lotion composition has a Theology typical of pseudoplastic or
plastic fluids. When no shear is applied, the lotion compositions can have
the appearance of a semi-solid but can be made to flow as the shear.rate is
increased. This is due to the fact that, while the lotion composition contains
primarily solid components, it also includes some minor liquid components.
The lotion compositions of the present invention are at least semi-
solid at room temperature to minimize lotion migration. In addition, the
lotion compositions preferably have a final melting point (100°r6
liquid)
Fpotential "stressful" storage conditions that can be greater than
45°C
(e~; warehouse in Arizona, car trunk in Florida, etc.).
Specifically, the lotion compositions of the present invention should have
the following melt profile:
Characteristic Preferred Ranae Most Preferred
°~ liquid at ~ 2-50 3-25
room temp. (20 °C)
liquid at 25-95 30-90
body temp. (37 °C)
CA 02285620 1999-10-14
WO 98147546 PCTlIB98/00618
24
final melting point (°C) >_38 >_45
By being solid or semisolid at ambient temperatures, these lotion
compositions do not have a tendency to flow and migrate into the interior of
the diaper to which they are applied. This means less lotion composition is
required for imparting desirable therapeutic or protective coating lotion
benefits.
As used herein, the term "leg cuff' is inclusive of both barrier cuffs
62, gasketing cuffs 56, and combinations and_yariations thereof.
In preparing lotioned diaper products according to the present
invention, the lotion composition is preferably applied to the body contacting
surface (i.e., body facing surface) of a diaper leg cuff. As defined herein,
the body contacting surface of a barrier leg cuff is normally the outer
surface, and the body contacting surface of a gasketing leg cuff is normally
the front surface. However, lotion can penetrate through some of the cuff
materials, so applying lotion to the garment contacting surface of the leg
cuffs (i.e, barrier leg cuff inner surface andlor gasketing leg cuff back
surface) is also expressly within the scope of the present invention.
When applied to the above-described surfaces of the leg cuffs, the
lotion compositions of the present invention are transferable to the wearer's
skin by normal contact, wearer motion, andlor body heat. Importantly, the
lotions disclosed in the present invention minimize the abrasion between the
cuffs and skin in the area where the cuffs contact the wearer's skin,
resulting
in less skin irritation.
The diaper barrier leg cuffs of the present invention andlor the
gasketing leg cuffs contain an effective amount of the lotion composition.
As used herein, the term "effective amount of a lotion coating" refers to an
amount of a particular lotion composition which, when applied to a diaper
leg cuff will be effective in reducing the abrasion between the cuffs and skin
in the area where the cuffs contact the wearer's skin, resulting in less skin
irritation. The lotions are also effective in reducing the adherence of BM to
the skin of the wearer. Of course, the effective amount of a lotion coating
will depend, to a large extent, on the particular lotion composition used.
r
CA 02285620 1999-10-14
WO 98/47546 PCT/1B98/00618
The lotion compositions of the present invention comprise: (1 ) an
emollient(s); (2) an immobilizing agents) for the emollient; (3) optionally a
hydrophilic surfactant(s); and (4) other optional components.
The viscosity of the formulated lotion compositions, including
emollient, immobilizing agent, and optional components should be as high
as possible to keep the lotion from flowing into the interior of the diaper.
Unfortunately, high viscosities can also lead to lotion compositions that are
difficult to apply without processing problems. Therefore, a balance must be
achieved so the viscosities are high enough to keep the lotion compositions
localized on the body contacting surface of the diaper leg cuffs, but not so
high as to cause processing problems. Suitable viscosities for the lotion
compositions will typically range from about 1 to about 5000 centipoises,
preferably from about 5 to about 200 centipoises, more preferably from
about 10 to about 100 centipoises measured at 60°C.
1. Emollient
The key active ingredient in these lotion compositions is one or more
emollients. As used herein, an emollient is a material that softens, soothes,
supples, coats, lubricates, moisturizes, or cleanses the skin. An emollient'
typically accomplishes several of these objectives such as soothing,
moisturizing, and lubricating the skin. For the purposes of the present
invention, these emollients have either a plastic or fluid consistency at
20°C,
i.e., at ambient temperatures. This particular emollient consistency allows
the lotion composition to impart a soft, lubricious, lotion-like feel.
The emollients useful in the present invention are also substantially
free of water. By "substantially free of water' is meant that water is not
intentionally added to the emollient. Addition of water to the emollient is
not
necessary in preparing or using the lotion compositions of the present
invention and could require an additional drying step. However, minor or
trace quantities of water in the emollient that are picked up as a result of,
for
example, ambient humidity can be tolerated without adverse effect.
Typically, the emollients used in the present invention contain about
5°~ or
less water, preferably about 1 °~ or less water, most preferably about
0.5°~
or less water.
CA 02285620 1999-10-14
WO 98/47546 PCTI1898/00618
26
The preferred emollients for use in the lotion compositions of the
present invention are polysiloxane compounds. In general, suitable
polysiloxane materials for use in the present invention include those having
monomeric siloxane units of the following structure:
R~
Si-O
R
2
wherein, R~ and R2, for each independent siloxane monomeric unit can
each independently be hydrogen or any alkyl, aryl, alkenyl, alkaryl, arakyl,
cycloalkyl, halogenated hydrocarbon, or other radical. Any of such radicals
can be substituted or unsubstituted. R~ and R2 radicals of any particular
monomeric unit may differ from the corresponding functionalities of the next
adjoining monomeric unit. Additionally, the polysiloxane can be either a
straight chain, a branched chain or have a cyclic structure. The radicals R~
and R2 can additionally independently be other silaceous functionalities
such as, but not limited to siloxanes, polysiloxanes, silanes, and
polysilanes. The radicals R~ and R2 may contain any of a variety of organic
functionalities including, for example, alcohol, carboxylic acid, phenyl, and
amine functionalities.
Exemplary alkyl radicals are methyl, ethyl, propyl, butyl, pentyl, hexyl,
octyl, decyl, octadecyl, and the like. Exemplary alkenyl radicals are vinyl,
allyl, and the like. Exemplary aryl radicals are phenyl, Biphenyl, naphthyl,
and the like. Exemplary alkaryl radicals are toyl, xylyl, ethyiphenyl, and the
like. Exemplary aralkyl radicals are benzyl, alpha-phenylethyl, beta-
phenylethyl, alpha-phenylbutyt, and the like. Exemplary cycloalkyl radicals
are cyclobutyl, cyclopentyl, cyclohexyl, and the like. Exemplary
halogenated hydrocarbon radicals are chloromethyl, bromoethyl,
tetrafluorethyl, fluorethyl, trifluorethyl, trifluorotloyl, hexafluoroxylyl,
and the
like.
Viscosity of polysiloxanes useful may vary as widely as the viscosity of
polysiloxanes in general vary, so long as the polysiloxane is flowable or can
be made to be flowable for application to the diaper leg cuffs. This includes,
but is not limited to, viscosity as low as 5 centistokes (at 37°C as
measured
CA 02285620 1999-10-14
WO 98/4546 PCT/IB98/00618
27
by a glass viscometer) to about 20,000,000 centistokes. Preferably the
polysiloxanes have a viscosity at 37°C ranging from about 5 to about
5,000
centistokes, more preferably from about 5 to about 2,000 centistokes, most
preferably from about 100 to about 1000 centistokes. High viscosity
polysiloxanes which themselves are resistant to flowing can be effectively
deposited upon the diaper leg cuffs by such methods as, for example,
emulsifying the polysiloxane in surfactant or providing the polysiloxane in
solution with the aid of a solvent, such as hexane, listed for exemplary
purposes only. Particular methods for applying polysiloxane emollients to
diaper leg cuffs are discussed in more detail hereinafter.
Preferred polysiloxanes compounds for use in the present invention
are disclosed in U.S. Patent 5,059,282 (Ampulski et al), issued October 22,
1991, which is incorporated herein by reference. Particularly preferred
polysitoxane compounds for use as emollients in the lotion compositions of
the present invention include phenyl-functional polymethylsiloxane
compounds (e.g., Dow Coming 556 Cosmetic-Grade Fluid:
polyphenylmethylsiloxane), dimethicone compounds, and cetyl or stearyl
functionalized dimethicones such as Dow 2502 and Dow 2503 polysiloxane
fluids, respectively. In addition to such substitution with phenyl-functional
or
alkyl groups , effective substitution may be made with amino, carboxyl,
hydroxyl, ether, polyether, aldehyde, ketone, amide, ester, and thiol groups.
Of these effective substituent groups, the family of groups comprising
phenyl, amino, alkyl, carboxyl, and hydroxyl groups are more preferred than
the others; and phenyl-functional groups are most preferred.
Other types of suitable polysiloxane materials for use herein include,
quaterneuy amino potysiloxanes, carboxylated polysiioxanes, ethoxylated
poi~itoxanes, and the like. Representative of such materials are those
po~s~bxanes described in U.S. Patent No. 5,558,873, issued March 8, 1995
to Funk et al., and U.S. Patent No. 5,552,020, issued July 21, 1995 to Smith
et al., the disclosure of each of which is incorporated herein by reference.
It is to be understood, that the polysitoxanes materials described
above are also sometimes generically referred to in the art as "silicones
compounds". It is to be understood that silicone compounds having the
desired emollient properties are expressly within the scope of the present
invention.
CA 02285620 1999-10-14
WO 98147546 PCT/IB98/00618
28
Other types of emollients useful in the present invention include
petroleum-based, fatty acid ester type, alkyl ethoxylate type, fatty acid
ester
ethoxylates, fatty alcohol type, or mixtures of these emollients. Suitable
petroleum-based emollients include those hydrocarbons, or mixtures of
hydrocarbons, having chain lengths of from 16 to 32 carbon atoms.
Petroleum based hydrocarbons having these chain lengths include mineral
oil (also known as "liquid petrolatum") and petrolatum (also known as
"mineral wax," "petroleum jelly" and "mineral jelly"). Mineral oil usually
refers to less viscous mixtures of hydrocarbons having from 16 to 20 carbon
atoms. Petrolatum usually refers to more viscous mixtures of hydrocarbons
having from 16 to 32 carbon atoms. Petrolatum and mineral oil are
particularly preferred emollients for lotion compositions of the present
invention.
Suitable fatty acid ester type emollients include those derived from
C12-C2g fatty acids, preferably C16-C22 saturated fatty acids, and short
chain (C 1-Cg, preferably C ~ -C3) monohydric alcohols. Representative
examples of such esters include methyl palmitate, methyl stearate, isopropyl
laurate, isopropyl myristate, isopropyl paimitate, ethylhexyl palmitate and
mixtures thereof. Suitable fatty acid ester emollients can also be derived
from esters of longer chain fatty alcohols (C12-C28, preferably C12-Ct6)
and shorter chain fatty acids e.g., lactic acid, such as lauryl lactate and
cetyl
lactate.
Suitable alkyl ethoxylate type emollients include C12-C~ fatty
alcohol ethoxylates having an average degree of ethoxylation of from about
2 to about 30. Preferably, the fatty alcohol ethoxylate emollient is selected
from the group consisting of lauryl, cetyl, and stearyl ethoxylates, and
mix~tues thereof, having an average degree of ethoxylation ranging from
about 2 to about 23. Representative examples of such alkyl ethoxylates
include laureth-3 (a lauryl ethoxylate having an average degree of
ethoxylation of 3), laureth-23 (a lauryl ethoxylate having an average degree
of ethoxylation of 23), ceteth-10 (a cetyl alcohol ethoxylate having an
average degree of ethoxylation of 10) and steareth-10 (a stearyl alcohol
ethoxylate having an average degree of ethoxylation of 10). These alkyl
ethoxylate emoElients are typically used in combination with the petroleum-
based emollients, such as petrolatum, at a weight ratio- of alkyl ethoxylate
CA 02285620 1999-10-14
WO 98147546 PCT/IB98100618
29
emollient to petroleum-based emollient of from about 1:1 to about 1:5,
preferably from about 1:2 to about 1-4.
Suitable fatty alcohol type emollients include C12-C~ fatty alcohols,
preferably C1g-C1g fatty alcohols. Representative examples include cetyl
alcohol and stearyl alcohol, and mixtures thereof. These fatty alcohol
emollients are typically used in combination with the petroleum-based
emollients, such as petrolatum, at a weight ratio of fatty alcohol emollient
to
petroleum-based emollient of from about 1:1 to about 1:5, preferably from
about 1:1 to about 1:2.
Besides polysiioxane-based emollients, fatty acid ester emollients,
fatty acid ester ethoxylates, alkyl ethoxylate emollients fatty alcohol
emollients, and polysiloxanes, the emollients useful in the present invention
can include minor amounts (e.g., up to about 10°r6 of the total
emollient) of
other, conventional emollients. These other conventional emollients
include, but are not limited to propylene glycol, glycerine, triethylene
glycol,
spermaceti or other waxes, fatty acids, and fatty alcohol ethers having from
12 to 28 carbon atoms in their fatty chain, such as stearic acid, propoxylated
fatty alcohols; glycerides, acetoglycerides, and ethoxylated glycerides of
C12-C2g fatty acids; other fatty esters of polyhydroxy alcohols; lanolin and
its derivatives, and cod liver oil. These other emollients should be included
in a manner such that the solid or semisolid characteristics of the lotion
composition are maintained.
The amount of emollient that can be included in the lotion
composition will depend on a variety of factors, including the particular
emollient involved, the lotion-like benefits desired, the other components in
the Nation composition and like factors. The lotion composition can comprise
from about 5 to about 95°~ of the emollient. Preferably, the lotion
composition comprises from about 20 to about 80°~, most preferably from
about 40 to about 75°~, of the emollient.
2. Immobilizin4 Ayent
An especially key component of the lotion compositions of the
present invention is an agent capable of immobilizing the polysiloxane
emollient on the diaper leg cuff to which the lotion composition is applied.
Because the emollient in the composition has a plastic or fluid consistency
CA 02285620 1999-10-14
WO 98/47546 PCTIiB98/00618
at 20°C, it tends to flow or migrate, even when subjected to modest
shear.
When applied to a diaper leg cuff, especially in a melted or molten state, the
emollient will not remain primarily on the surface of the leg cuff. Instead,
the
emollient will tend to migrate and flow into the interior of the diaper.
This migration of the emollient into the interior of the diaper can
cause undesired effects on the absorbency of the diaper core due to the
hydrophobic characteristics of many of the emollients used in the lotion
compositions of the present invention. Also, migration of lotion through the
cuff can cause can have an adverse effect on the sustained elasticity of the
elastic gathers. It also means that much more emollient has to be applied to
the diaper leg cuff to get the desired therapeutic or protective lotion
benefits. Increasing the level of emollient not only increases the cost, but
also exacerbates the undesirable effect on the absorbency of the diaper
core, as well on the performance of the contracted or elastic gathers.
The immobilizing agent counteracts this tendency of the emollient to
migrate or flow by keeping the emollient primarily localized on the surface of
the diaper leg cuff to which the lotion composition is applied. This is
believed to be due, in part, to the fact that the immobilizing agent raises
the
melting point of the lotion composition above that of the emollient. Since the
immobilizing agent is also miscible with the emollient (or solubilized in the
emollient with the aid of an appropriate emulsifier), it entraps the emollient
on the surface of the diaper leg cuff as well.
It is also advantageous to "lock" the immobilizing agent on the
surface of the diaper leg cuff. This can be accomplished by using
immobilizing agents which quickly crystallize (i.e., solidify) at the surface
of
the t~ cuff. In addition, outside cooling of the treated diaper leg cuff via
blowers, fans, etc. can speed up crystallization of the immobilizing agent.
tn addition to being miscible with (or solubilized in) the emollient, the
immobilizing agent needs to have a melting point of at least about
35°C.
This is so the immobilizing agent itself will not have a tendency to migrate
or
flow. Preferred immobilizing agents will have melting points of at least
about 40°C. Typically, the immobilizing agent will have a melting point
in
the range of from about 50° to about 150°C.
Suitable immobilizing agents for the present invention can comprise a
member selected from the group consisting of C14-C~ fatty alcohots, C12-
CA 02285620 1999-10-14
WO 98/47546 PCT/IB98/00618
31
C~ fatty acids, and C12-C22 fatty alcohol ethoxylates having an average
degree of ethoxylation ranging from 2 to about 30, and mixtures thereof.
Preferred immobilizing agents include C1g-C1g fatty alcohols, most
preferably selected from the group consisting of cetyl alcohol, stearyl
alcohol, and mixtures thereof. Mixtures of cetyl alcohol and stearyl alcohol
are particularly preferred. Other preferred immobilizing agents include C1g-
C1g fatty acids, most preferably selected from the group consisting of
palmitic acid, stearic acid, and mixtures thereof. Mixtures of palmitic acid
and stearic acid are particularly preferred. Still other preferred
immobilizing
agents include C1g-C1g fatty alcohol ethoxylates having an average degree
of ethoxylation ranging from about 5 to about 20. Preferably, the fatty
alcohols, fatty acids and fatty alcohols are linear.
Importantly, these preferred immobilizing agents such as the C1g -
C1g fatty alcohols increase the rate of crystallization of the lotion causing
the lotion to crystallize rapidly onto the surface of the substrate. Lower
lotion levels can therefore be utilized or a superior lotion feel can be
delivered. Traditionally, greater amounts of lotion were needed to generate
softness because of the flow of these liquids into the diaper core.
Other types of immobilizing agents can be used either atone or in
combination with the fatty alcohols, fatty acids, and fatty alcohol
ethoxylates
described above. Examples of these other types of immobilizing agents
includes polyhydroxy fatty acid esters, polyhydroxy fatty acid amides, and
mixtures thereof. Preferred esters and amides will have three or more free
hydroxy groups on the polyhydroxy moiety and are typically nonionic in
character. Because of the possible skin sensitivity of those using diaper leg
cuffs to which the lotion composition is applied, these esters and amides
shodld also be relatively mild and non-irritating to the skin.
Suitable polyhydroxy fatty acid esters for use in the present invention
will have the formula:
O
II
R-C-O Y
n
CA 02285620 1999-10-14
WO 98147546 PCT/IB98/00618
32
wherein R is a C~-Cg~ hydrocarbyl group, preferably straight chain C7-Cog
alkyl or alkenyl, more preferably straight chain Cg-C~~ alkyl or alkenyl, most
preferably straight chain C ~ ~ -C ~ 7 alkyl or alkenyl, or mixture thereof; Y
is a
polyhydroxyhydrocarbyl moiety having a hydrocarbyl chain with at least 2
free hydroxyls directly connected to the chain; and n is at least 1. Suitable
Y groups can be derived from potyols such as glycerol, pentaerythritol;
sugars such as raffinose, maltodextrose, galactose, sucrose, glucose,
xylose, fructose, maltose, lactose, mannose and erythrose; sugar alcohols
such as erythritol, xylitol, malitol, mannitol and sorbitol; and anhydrides of
sugar alcohols such as sorbitan.
One class of suitable polyhydroxy fatty acid esters for use in the
present invention comprises certain sorbitan esters, preferably the sorbitan
esters of C~6-C~ saturated fatty acids. Because of the manner in which
they are typically manufactured, these sorbitan esters usually comprise
mixtures of mono-, di-, tri-, etc. esters. Representative examples of suitable
sorbitan esters include sorbitan palmitates (e.g., SPAN 40), sorbitan
stearates (e.g., SPAN 60), and sorbitan behenates, that comprise one or
more of the mono-, di- and tri-ester versions of these sorbitan esters, e.g.,
sorbitan mono-, di- and tri-patmitate, sorbitan mono-, di- and tri-stearate,
sorbitan mono-, di and tri-behenate, as well as mixed tallow fatty acid
sorbitan mono-, di- and tri-esters. Mixtures of different sorbitan esters can
also be used, such as sorbitan palmitates with sorbitan stearates.
Particularty preferred sorbitan esters are the sorbitan stearates, typically
as
a mixture of mono-, di- and tri-esters (plus some tetraester) such as SPAN
60, and sorbitan stearates sold under the trade name GLYCOMUL-S by
Lonte, Inc. Although these sorbitan esters typically contain mixtures of
mono-, di- and tri-esters, plus some tetraester, the mono- and di-esters are
usually the predominant species in these mixtures.
Another class of suitable polyhydroxy fatty acid esters for use in the
present invention comprises certain glyceryl monoesters, preferably glyceryl
monoesters of C~6-C~ saturated fatty acids such as glyceryl
monostearate, glyceryl monopafmitate, and gtyceryl monobehenate. Again,
tike the sorbitan esters, glyceryl monoester mixtures will typically contain
some di- and triester. However, such mixtures should contain
CA 02285620 1999-10-14
WO 98J47546 PCT/IB98/00618
33
predominantly the glyceryi monoester species to be useful in the present
invention.
Another class of suitable polyhydroxy fatty acid esters for use in the
present invention comprise certain sucrose fatty acid esters, preferably the
C12-C22 saturated fatty acid esters of sucrose. Sucrose monoesters and
diesters are particularly preferred and include sucrose mono- and di-
stearate and sucrose mono- and di- laurate.
Suitable polyhydroxy fatty acid amides for use in the present
invention will have the formula:
0 R'
II I
R2-C -N-Z
wherein R1 is H, C~-C4 hydrocarbyl, 2-hydroxyethyl, 2-hydroxypropyl,
methoxyethyl, methoxypropyl or a mixture thereof, preferably C1-C4 alkyl,
methoxyethyl or methoxypropyl, more preferably C1 or C2 alkyl or
methoxypropyl , most preferably C1 alkyl (i.e., methyl) or methoxypropyl;
and R2 is a C5-C31 hydrocarbyl group, preferably straight chain C7-C1g
alkyl or alkenyl, more preferably straight chain Cg-C17 alkyl or alkenyl, most
preferably straight chain C11-C17 alkyl or alkenyl, or mixture thereof; and Z
is a polyhydroxyhydrocarbyl moiety having a linear hydrocarbyl chain with at
least 3 hydroxyls directly connected to the chain. See U.S. patent 5,174,
927 (Honsa), issued December 29, 1992 (herein incorporated by reference)
which disGoses these polyhydroxy fatty acid amides, as well as their
presration.
-n., r,
T~ Z moiety preferably will be derived from a reducing sugar in a
reductive amination reaction; most preferably giycityl. Suitable reducing
sugars include glucose, fructose, maltose, lactose, galactose, mannose, and
xylose. High dextrose com syrup, high fructose com syrup, and high
maltose com syrup can be utilized, as well as the individual sugars listed
above. These com syrups can yield mixtures of sugar components for the Z
moiety.
The Z moiety preferably will be selected from the group consisting of
-CH2-(CHOH)n-CH20H, -CH(CH20H)-[(CHOH)n-1 j-CH20H, -CH20H-
CA 02285620 1999-10-14
WO 98147546 PCT/IB98/00618
34
CH2-(CHOH)2(CHOR3)(CHOH)-CH20H, where n is an integer from 3 to 5,
and R3 is H or a cyclic or aliphatic monosaccharide. Most preferred are the
glycityls where n is 4, particularly -CH2-(CHOH)4-CH20H.
In the above formula, R1 can be, for example, N-methyl, N-ethyl, N-
propyl, N-isopropyl, N-butyl, N-2-hydroxyethyl, N-methoxypropyl or N-2-
hydroxypropyl,. R2 -can be selected to provide, for example, cocamides,
stearamides, oleamides, lauramides, myristamides, capricamides,
palmitamides, tallowamides, etc. The Z moiety can be 1-deoxyglucityl, 2-
deoxyfructityl, 1-deoxymaltityl, 1-deoxylactityl, 1-deoxygalactityl, 1-
deoxymannityl, 1-deoxymaltotriotityl, etc.
The most preferred polyhydroxy fatty acid amides have the general
formula:
O R~ OH
R2-C-N-CH2 CH CH2-OH
4
wherein R1 is methyl or methoxypropyl; R2 is a C11-C17 straight-chain alkyl
or alkenyl group. These include N-lauryl-N-methyl glucamide, N-lauryl-N-
methoxypropyl glucamide, N-cocoyl-N-methyl glucamide, N-cocoyl-N-
methoxypropyl glucamide, N-palmityl-N-methoxypropyl glucamide, N-
tallowyl-N-methyl glucamide, or N-tallowyl-N-methoxypropyl glucamide.
As previously noted, some of the immobilizing agents require an
emulsfier for solubilization in the emollient. This is particularly the case
for
certain of the glucamides such as the N-alkyl-N-methoxypropyl glucamides
having HLB values of at least about 7. Suitable emulsifiers will typically
include those having HLB values below about 7. In this regard, the sorbitan
esters previously described, such as the sorbitan stearates, having HLB
values of about 4.9 or less have been found useful in solubilizing these
glucamide immobilizing agents in petrolatum. Other suitable emulsifiers
include steareth-2 (polyethylene glycol ethers of stearyl alcohol that conform
to the formula CH3(CH2)17(OCH2CH2)nOH, where n has an average value
of 2), sorbitan tristearate, isosorbide laurate, and glyceryl monostearate.
The emulsifier can be included in an amount sufficient to solubilize the
CA 02285620 1999-10-14
WO 98/49546 PCT/IB98/00618
immobilizing agent in the emollient such that a substantially homogeneous
mixture is obtained. For example, an approximately 1:1 mixture of N-cocoyl-
N-methyl glucamide and petrolatum that will normally not melt into a single
phase mixture, will melt into a single phase mixture upon the addition of
20% of a 1:1 mixture of Steareth-2 and sorbitan tristearate as the emulsifier.
Other types of ingredients that can be used as immobilizing agents,
either alone, or in combination with the above-mentioned immobilizing
agents, include waxes such as camauba, beeswax, candelilla, paraffin,
ceresin, esparto, ouricuri, rezowax, and other known waxes. Preferably the
wax is a paraffin wax. An example of a particularly prefen-ed paraffin wax is
Parrafin S. P. 434 from Strahl and Pitsch Inc. P.O. Box 1098 West Babylon,
NY 11704.
The amount of immobilizing agent that should be included in the
lotion compositions will depend on a variety of factors, including the
particular polysiloxane emollient involved, the particular immobilizing agent
involved, whether an emulsifier is required to solubilize the immobilizing
agent in the emollient, the other components in the lotion composition and
like factors. The lotion composition can comprise from about 5 to about
90°~ of the immobilizing agent. Preferably, the lotion composition
comprises
from about 5 to about 50%, most preferably from about 10 to about 40°~,
of
the immobilizing agent.
3. Q~tional Hvdroohilic Surfactant -
Depending upon the particular immobilizing agent used in the lotion
composition of the present invention, an additional hydrophilic surfactant (or
a rte of hydrophilic surfactants) may optionally be used to improve
prooessability andlor stability of the lotions.
Suitable hydrophilic surfactants will be miscible with the emollient
and the immobilizing agent so as to form homogeneous mixtures. Because
of possible skin sensitivity of those using disposable absorbent products to
which the lotion composition is applied, these surfactants should also be
relatively mild and non-irritating to the skin. Typically, these hydrophilic
surfactants are nonionic to be not only non-irritating to the skin, but also
to
avoid other undesirable effects on any underlying tissue laminate structure,
e.g., reductions in tensile strength.
CA 02285620 1999-10-14
WO 98/47546 PCT/IB98/00618
36
Suitable nonionic surfactants may be substantially nonmigratory after
the lotion composition is applied to the diaper leg cuffs and will typically
have HLB values in the range of from about 4 to about 20, preferably from
about 7 to about 20. To be nonmigratory, these nonionic surtactants will
typically have melt temperatures greater than the temperatures commonly
encountered during storage, shipping, merchandising, and use of
disposable absorbent products, e.g., at least about 30°C In this
regard,
these nonionic surfactants will preferably have melting points similar to
those of the immobilizing agents previously described.
Suitable nonionic surfactants for use-in lotion compositions of the
present invention include alkylglycosides; alkylglycoside ethers as
described in U.S. patent 4,011,389 (Langdon, et al), issued March 8, 1977;
alkylpolyethoxylated esters such as Pegosperse 1000MS (available from
Lonza, Inc., Fair Lawn, New Jersey), ethoxylated sorbitan mono-, di- and/or
tri-esters of C12-C18 fatty acids having an average degree of ethoxylation
of from about 2 to about 20, preferably from about 2 to about 10, such as
TWEEN 60 (sorbitan esters of stearic acid having an average degree of
ethoxylation of about 20) and TWEEN 61 (sorbitan esters of stearic acid
having an average degree of ethoxylation of about 4), and the condensation
products of aliphatic alcohols with from about 1 to about 54 moles of
ethylene oxide. The alkyl chain of the aliphatic alcohol is typically in a
straight chain (linear) configuration and contains from about 8 to about 22
carbon atoms. Particularly preferred are the condensation products of
alcohols having an alkyl group containing from about 11 to about 22 carbon
atoms with from about 2 to about 30 moles of ethylene oxide per mole of
alcohol. Examples of such ethoxylated alcohols include the condensation
products of myristyl alcohol with 7 moles of ethylene oxide per mole of
alcohol, the condensation products of coconut alcohol (a mixture of fatty
alcohols having alkyl chains varying in length from 10 to 14 carbon atoms)
with about 6 moles of ethylene oxide. A number of suitable ethoxylated
alcohols are commercially available, including TERGITOL 15-S-9 (the
condensation product of C11-C15 linear alcohols with 9 moles of ethylene
oxide), marketed by Union Carbide Corporation; KYRO EOB (condensation
product of C13-C15 linear alcohols with 9 moles of ethylene oxide),
marketed by The Procter 8 Gamble Co., the NEODOL brand name
surfactants marketed by Shelf Chemical Co., in particular NEODOL 25-12
(condensation product of C12-C15 linear aicohols with 12 moles of ethylene
j ~
CA 02285620 1999-10-14
WO 9814'1546 PCT/1898/00618
37
oxide) and NEODOL 23-6.5T (condensation product of C12-C1g linear
alcohols with 6.5 moles of ethylene oxide that has been distilled (topped) to
remove certain impurities), and especially the PLURAFAC brand name
surfactants marketed by BASF Corp., in particular PLURAFAC A-38 (a
condensation product of a C18 straight chain alcohol with 27 moles of
ethylene oxide). (Certain of the hydrophilic surfactants, in particular
ethoxytated alcohols such as NEODOL 25-12, can also function as alkyl
ethoxylate emollients). Other examples of preferred ethoxylated alcohol
surfactants include ICl's class of Brij surfactants and mixtures thereof, with
Brij 72 (i.e., Steareth-2) and Brij 76 (i.e., Steareth-10) being especially
preferred. Also, mixtures of cetyl alcohol and stearyl alcohol ethoxylated to
an average degree of ethoxylation of from about 10 to about 20 may also be
used as the hydrophilic surfactant.
Another type of suitable surfactant for use in the present invention
includes Aerosol OT, a diodyl ester of sodium sulfosuccinic acid marketed
by American Cyanamid Company.
Still another type of suitable surfactant for use in the present
invention includes silicone copolymers such as General Electric SF 1188 (a
copolymer of a polydimethylsiloxane and a polyoxyalkylene ether) and
General Electric SF 1228 (a silicone polyether copolymer). These silicone
surfactants can be used in combination with the other types of hydrophilic
surfactants discussed above, such as the ethoxylated alcohols. These
silicone surfactants have been found to be effective at concentrations as low
as 0.1 °~, more preferably from about 0.25 to about 1.0°r6, by
weight of the
lotion composition.
The amount of hydrophilic surfactant required to improve the
prooessability and/or stability of the lotion composition will depend upon the
type of emollient and immobilizing agent used, the HLB value of the
surfactant used and like factors. The lotion compositions of the present
invention can optionally comprise from about 1 to about 50°~ of the
hydrophilic surfactant, more preferably from about 1 to about 25°r6, by
weight of the hydrophilic surfactant.
4. Other Oational Components
Lotion compositions can comprise other optional components
typically present in emollient, creams, and lotions of this type. These
CA 02285620 1999-10-14
WO 98147546 PCT/IB98/00618
38
optional components include water, viscosity modifiers, perfumes,
disinfectant antibacterial actives, pharmaceutical actives, film formers,
vitamins (e.g., vitamin E), deodorants, opacifiers, astringents, solvents and
the like. Materials such as zinc oxide, calamine, and allantoin can also be
used to help protect the skin from irritation and diaper rash. In addition,
stabilizers can be added to enhance the shelf life of the lotion composition
such as cellulose derivatives, proteins and lecithin. All of these materials
are well known in the art as additives for such formulations and can be
employed in appropriate amounts in the lotion compositions of the present
invention. In addition, aloe extract in amounts from about 0.1 °~ to
about
20°~ by weight is a preferred optional component for the lotion
components
disclosed herein.
C. Treatin4 Diaaer Lea Cuffs With Lotion Composition
In preparing lotioned diaper products according to the present
invention, the lotion composition is preferably applied to the body contacting
surface (i.e., body facing surface) of a diaper leg cuff. As defined herein,
the body contacting surface of a barrier leg cuff is normally the outer
surface
and the body contacting surface of a gasketing leg cuff is normally the front
surface. However, lotion can penetrate through some of the cuff materials,
so applying lotion to the garment contacting surface of the leg cuffs (i.e,
barrier leg cuff inner surface andlor gasketing leg cuff back surface) is also
expressly within the scope of the present invention.
Any of a variety of application methods that evenly distribute
lubricious materials having a molten or liquid consistency can be used.
Suitlbte methods include spraying, printing (e.g., flexographic printing),
coming (e.g., gravure or slot coating), extrusion, or combinations of these
application techniques, e.g. spraying the lotion composition on a rotating
surface, such as a calender roll, that then transfers the composition to the
body contacting surface of the diaper leg cuffs. If desired, lotion can also
be
applied to both sides of the cuffs to improve the cuff s hydrophobicity.
The manner of applying the lotion composition to the diaper leg cuffs
should be such that the leg cuffs do not become saturated with the lotion
composition. If the leg cuffs becomes saturated with the.lotion composition,
there is a greater potential for the lotion to migrate into the interior of
the
T 1
CA 02285620 1999-10-14
WO 98/47546 PCT/IH98/00618
39
diaper where it can have a deterimental effect on the absorbency of the
underlying absorbent core. Also, saturation of the leg cuffs is not required
to obtain the . therapeutic and/or protective lotion benefits. Particularly
suitable application methods will apply the lotion composition primarily to
the body contacting surtace of the diaper leg cuff. However, lotion can
penetrate through some of the cuff materials, so applying lotion to the
garment contacting surface of the leg cuffs is also within the scope of the
present invention.
The minimum level of lotion to be applied to the diaper leg cuff is the
smallest amount effective in reducing the abrasion between the cuffs and
skin in the area where the cuffs contact the wearer's skin, thereby resulting
in less skin irritation. The lotions are also effective in reducing the
adherence of BM to the skin of the wearer. Of course, the effective amount
of a lotion coating will depend, to a large extent, on the particular lotion
composition used. The lotion composition is preferably applied to the diaper
leg cuffs of the present invention in an amount ranging from about 0.1
mg/in2 to about 50 mg/in2 more preferably from about 1 mglin2 to about 25
mg/in2 (mg of lotion per square inch of coated leg cuff). Because the
emollient is substantially immobilized on the surface of the leg cuff, less
lotion composition is needed to impart the desired skin care benefits. Such
relatively low levels of lotion composition are adequate to impart the desired
therapeutic and/or protective lotion benefits to the leg cuff.
The lotion composition may be applied evenly and uniformly onto
either or both surfaces of the leg cuff or portions thereof. The lotion
coating
may also be patterned (i.e., stripes, boxes, dots, spirals, etc.) Preferably,
the tofion composition is registered with the region of the leg cuff that
will, in
usa,. be most in contact with the wearer and is applied in a stripe aligned
with and centered on the longitudinal centerline of each cuff. Most
preferably, as described in the Examples hereinafter, the lotion composition
is applied in a stripe to a discrete portion of the barrier leg cuff , e.g., a
1.4
inch wide (diaper lateral direction) and 11.75 inch long (diaper longitudinal
direction) patch generally disposed in the crotch portion of the inner surface
of the barrier leg cuff.
The lotion composition can also be applied nonunifortnly to either or
both surfaces of the diaper leg cuff. By "nonuniform" is meant that the
amount, pattern of distribution, etc. of the lotion composition can vary over
CA 02285620 1999-10-14
WO 98/47546 PCT/IB98/00618
the leg cuff surface. For example, some portions of the treated surface of the
leg cuff can have greater or lesser amounts of lotion composition, including
portions of the surface that do not have any lotion composition on it.
The lotion composition can be applied to the leg cuff at any point
during assembly. For example, the lotion composition can be applied to the
leg cuff of the finished disposable absorbent product before it has been
packaged. The lotion composition can also be applied to the leg cuff before
it is combined with the other raw materials to form a finished disposable
absorbent product.
The lotion composition is typically applied from a melt thereof to the
diaper leg cuff. Since the lotion composition melts at significantly above
ambient temperatures, it is usually applied as a heated coating to the leg
cuff. Typically, the lotion composition is heated to a temperature in the
range from about 35° to about 100°C, preferably from 40°
to about 90°C,
prior to being applied to the diaper leg cuff. Once the melted lotion
composition has been applied to the diaper leg cuff, it is allowed to cool and
solidify to form solidified coating or film on the surface of the leg cuff.
Preferably, the application process is designed to aid in the cooling/set up
of the lotion.
In applying lotion compositions of the present invention to diaper leg
cuffs, slot coating, extrusion coating, gravure coating, and spraying methods
are preferred. Figure 5 illustrates a preferred method involving continuous
or intermittent contact slot coating of the lotion composition on to a diaper
barrier leg cuff during the converting operation. Referring to Figure 5,
conveyor belt 1 advances in the direction shown by the arrows on turning
rolls 3 and 4 and becomes returning conveyor belt 2. Conveyor belt 1
cartlas nonlotioned diaper 5 to contact slot coating station 6 where barrier
leg ~ patch 7 is coated with a hot, molten (e.g., fi5°C) lotion
composition.
After leaving slot coating station 6, nonlotioned diaper 5 becomes lotioned
diaper 8 having lotioned barrier leg cuffs. The amount of lotion composition
transferred to barrier leg cuff patch 7 is controlled by: (1 ) the rate at
which
the molten lotion composition is applied from contact slot coating station 6;
and/or (2) the speed at which conveyor belt 1 travels under slot coating
station 6.
Figure 6 illustrates an alternate preferred method involving contact
slot coating of the lotion composition on the diaper barrier leg cuffs before
CA 02285620 1999-10-14
WO 98!47546 PCT/1898/00618
41
the leg cuffs are assembled with the other raw materials into a finished
product. Referring to Figure 6, a nonwoven barrier leg cuff web 1 is
unwound from parent barrier leg cuff roll 2 (rotating in the direction
indicated
by arrow 2a) and advanced to the contact slot coating station 6 where one
side of the web is coated with a hot, molten (e.g., 65°C) lotion
composition.
After leaving slot coating station 6, nonwoven barrier leg cuff web 1
becomes a lotioned barrier leg cuff web indicated by 3. Lotioned barrier leg
cuff web 3 is then advanced around turning roll 4 and turning roll 8, and
then wound up on lotioned barrier leg cuff parent roll 10 (rotating in the
direction indicated by arrow 10a).
SPECIFIC ILLUSTRATIONS OF THE PREPARATION OF LOTIONED
DIAPER BARRIER LEG CUFFS ACCORDING TO THE PRESENT
INVENTION
The following are specific illustrations of treating diaper barrier leg
cuffs with lotion compositions in accordance with the present invention:
Example 1
A. Preparation of Lotion Composition
A water free lotion composition (Lotion A) is made by mixing the
following melted (i.e., liquid) components together: White Protopet~
1 S (white petrolatum made by Witco Corp. ); Dow Coming 556
Cosmetic Grade Fluid (a polyphenylmethylsiloxane made by the Dow
Coming Corporation), Parrafin S.P. 434 (a paraffin wax made by
Strahl and Pitsch Inc.); Cetearyl Alcohol (a mixed linear C16-C18
primary alcohol made by the Procter 8 Gamble Company under the
name TA-1618); PEG 2000 (a polyethylene glycol having a MW of
2000 made by Sigma-Aldrich Corp). The weight percentages of
these components are shown in Table I below:
Table I
Component Weight ~
WhiteProtopet~ 52
1S
Polyphenylmethyl-20
siloxane
CA 02285620 1999-10-14
WO 98147546 PCT/IB98100618
42
Paraffin Wax 15
Cetearyl Alcohol10
P E G 2000 3
B. Preparation of Lotioned Diaper Lea Cuff by Hot Melt Coating
Lotion Composition A is placed into a heated tank operating at a
temperature of 170°F. The composition is subsequently applied with
a contact applicator (i.e., a Meltex EP45 hot melt adhesive applicator
head operating at a temperature of 170°F) onto the outer surface of
the barrier leg cuffs of a diaper in a 1.4 inch wide (diaper lateral
direction) and 11.75 inch long (diaper longitudinal direction) area, the
patch centered in the contracted area of the leg cuff. Add-on level =
0.0116 glint ( 18.0 g/m2 ).
Example 2
The lotion composition A (prepared in accordance with the procedure in
Example 1 ) is subsequently applied onto the outer surface of the barrier
leg cuffs of a diaper in a 1.4 inch wide (diaper lateral direction) stripe
centered on the longitudinal centerline of each leg cuff and extending the
entire length of the leg cuff. Add-on level = 0.0116 grn2 (18 glm2).
Example 3
The lotion composition A (prepared in accordance with the procedure in
Example 1 ) is subsequently applied onto the outer surface of the barrier
leg cuffs of a diaper in a 1.4 inch wide (diaper lateral direction) stripe
Catered on the longitudinal centerline of each leg cuff and 11.75 inch
long (diaper longitudinal direction) area, the patch centered in the
contracted area of the leg cuff. Add-on level = 0.0077 glint (12.0 g/m2).
