Note: Descriptions are shown in the official language in which they were submitted.
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DIAPER HAVING A LOTIONED TOPSHEET CONTAINING A
POLYSILOXANE EMOLLIENT
TECHNICAL FIELD
This application relates to absorbent articles such as diapers,
training pants, adult incontinence devices, and the like. More particularly,
the present invention relates to absorbent articles having a lotion coating on
the outer surface of the topsheet that is transferable to the wearer's skin by
normal contact and wearer motion andlor body heat. The lotions disclosed
in the present invention reduce the adherence of BM to the skin of the
wearer, thereby improving the ease of BM clean up.
BACKGROUND OF THE INVENTION
Many types of disposable absorbent products, such as diapers, are
available that have a high capacity for absorbing urine. Disposable
products of this type generally comprise some sort of fluid-permeable
topsheet material, an absorbent core, and a fluid-impermeable backsheet
material. Although these types of absorbent structures may be highly
efficient for the absorption of fluids, they cannot absorb bowel movements
i.e., hereinafter refer-ed to as "BM"). Typically, the BM is trapped between
the outer surface of the fluid-permeable topsheet and the skin of the
wearer, much of it adhering to the wearer's skin.
To prevent BM from adhering to the wearer's skin, the caregiver
often applies protective or "repellent" products such as vaseline or mineral
oil to the buttocks and anal region before placing the absorbent article on
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the wearer. This procedure usually involves the caregiver's pouring of the
oil or lotion, for example, in one of their hands, rubbing both hands together
to distribute the substance thereon and then wiping the same on the skin of
the infant. To eliminate the need 'for this wasteful, messy, and easily
forgotten procedure, there have been numerous previous attempts to
prepare absorbent articles which contain a protective or therapeutic skin
care substance on the topsheet.
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, even when applied to
diaper topsheets.
Because mineral oil is fluid and mobile at ambient temperatures, it
tends not to remain localized on the surface of the topsheet, but instead
migrates through the topsheet into the interior of the diaper. Accordingly,
relatively high levels of mineral oil need to be applied to the topsheet to
provide the desired therapeutic or protective coating lotion benefits. This
leads not only to increased costs for these lotioned diaper products, but
other detrimental effects as well.
One of these detrimental effects is a decrease in the fluid handling
properties as high levels of mineral oil tend to block the topsheet openings.
Also, as mineral oil migrates to the interior of the diaper, it tends to act
as a
hydrophobic additive, thus decreasing the absorbency of the underlying
absorbent core, if one is used. This decrease in absorbency becomes more
pronounced as the level of mineral oil applied is increased.
Even without increasing its level, the tendency of mineral oil to
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 lotioned diaper products
that: (1 ) have desirable therapeutic or protective coating lotion benefits
(2)
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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.
U.S. Patent 3,585;998 to Hayford et al. teaches a disposable baby
diaper, an interior liner of which carries an array of pressure-rupturable
capsules containing baby oil. The patent teaches that it is desirable to
break the capsules prior to using the diaper by applying pressure with such
household items as a rolling pin, hand iron, etc. The same principle of
t0 pressure-rupturable capsules is used in U.S. Patent 3,464,413 to Goldfarb
et al. for making bandages capable of delivering a medicinal material to an
injury. Articles disclosed by both patents have a serious drawback.
Namely; unless the capsules are ruptured by applying pressure prior to
using the diaper or the bandage, the skin-Bare substance contained in the
capsules is either not delivered at aU or is delivered non-uniformly leaving
some areas of skin uncoated.
U.S. Patent 3,896,807 to Buchalter teaches an article impregnated
with a solid oil phase of dream formulation which fortes a cream upon
addition of moisture thereto. A major disadvantage of the article disclosed
ZO by the reference is that transfer of a beneficial substance from the
absorbent substrate to skin is delayed and is only realized when body fluids
are released.
U.S. Patent 3,489,748 to Duncan et ai. teaches a baby diaper
comprising a hydrophobic and oleophobic topsheet wherein a portion of the
topsheet is coated with a discontinuous film of oleaginous material. A major
disadvantage of the diapers disclosed in the Duncan et al. reference is that
the hydrophobic and oleophobic topsheets are stow in promoting transfer of
pine to the underlying absorbent cores.
Therefore, it is an object of an aspect of the present invention to provide
a disposable diaper having a hydrophilic topsheet having superior fluid
handling properties.
It is a further object of an aspect of the present invention to provide a
hydrophilic diaper topsheet having a lotion coating on the outer surface of
the
topsheet that 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.
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It is yet a further object of an aspect of the present invention desirable to
provide lotioned diaper products that: ( 1 ) have desirable BM release,
cleaning,
therapeutic or protective lotion coating benefits (2) do not require
relatively
high levels of mineral oil; (3) do not adversely affect the fluid handling
properties of the diaper, and (4) do not require special wrapping or barrier
materials fog 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 INVENTION
The present invention relates to a disposable diaper having a lotion
coating on the outer surface of the topsheet that is semisolid or solid at
ambient temperatures (i.e., at 20°C) and is adapted to be transfer-ed
to the
wearer's skin, where it acts to reduce the adherence of 8M to the skin of the
wearer, thereby improving the ease of BM clean up.
Briefly, the disposable diapers of an aspect of the present invention
comprise:
A) a liquid impervious backsheet;
B) a liquid pervious; hydrophilic topsheet joined to said
backsheet, said topsheet having an inner surface oriented
toward the interior of said diaper and an outer surface oriented
toward the skin of the wearer when said diaper is being wom,
wherein at least a portion of said topsheet outer surface
comprises an effective amount of a lotion coating which is
semi-solid or solid at 20°C and which is partially transferable
to the~wearers skin, said lotion coating comprising:
(t) from about 10 to about 95°~ of a substantiaNy water fre~
emollient having a plastic or fluid consistency at 20°C
and comprising a member selected from the group
consisting of petroleum-based emollients, fatty acid
ester emollients, alkyl ethoxylate emollients,
polysiloxane emollients, and mixtures thereof,
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(ii) from about 5 to about 90% of an agent capable of
immobilizing said emollient on said outer surface of the
topsheet, said immobilizing agent having a melting point
of at least about 35°C; and
5 C) an absorbent core positioned between said topsheet and said
backsheet.
The quantity of lotion coating on a least a portion of the diaper topsheets
of the present invention preferably ranges from about 0.1 mg/in2 to about 25
mg/in2, more preferably from about I mglinz to about 10 mglin2. Lotioned
diaper topsheets according to the present invention provide desirable BM
cleaning, therapeutic or protective lotion coating benefits. Because the
emollient is substantially immobilized on the surface of the topsheet, less
lotion
composition is needed to impart the desired skin care benef ts. In addition,
special barrier or wrapping materials are unnecessary 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 topsheet 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, and/or body-
heat. Without being bound by theory, it is believed that the lotion
composition
changes the surface energy of the skin, and/or forms a 'barrier" reducing the
affinity of the skin for BM. The BM, therefore, has a reduced tendency to
stick
to the skin, and is easier to remove.
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Sa
In accordance with another aspect of the present invention, there is
provided a disposable diaper comprising:
A) a liquid impervious backsheet;
B) a liquid pervious, hydrophilic topsheet joined to said backsheet, said
topsheet having an inner surface oriented toward the interior of said
diaper and an outer surface oriented toward the skin of the wearer when
said diaper is being worn, wherein at least a portion of said topsheet
outer surface comprises an effective amount of a lotion coating which is
semi-solid or solid at 20°C and which is 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, wherein said
polysiloxane emollient contains about 5% or less water and
comprises a polysiloxane compound having a viscosity at 37°C
of from about 5 to about 2,000 centistokes;
(ii) from about 5 to about 90% of an agent capable of
immobilizing said emollient on said outer surface of the topsheet,
said immobilizing agent being miscible with said polysiloxane
emollient, said immobilizing agent having a melting point of at
least about 35°C, wherein said immobilizing agent is selected
from the group consisting of polyhydroxy fatty acid esters,
polyhydroxy fatty acid amides, C,a-Czz fatty alcohols, C~z-Czz
fatty acids, Clz-Czz fatty alcohol ethoxylates, and mixtures
thereof; and
C) an absorbent core positioned between said topsheet and said
backsheet.
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Sb
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic representation illustrating a preferred process for
applying the lotion composition of the present invention to diaper topsheets.
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Figure 2 is a schematic representation illustrating an alternative
process for applying the lotion composition of the present invention to
diaper topsheets.
Figure 3 is an absorbent article in the form of a diaper according to
the present invention.
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
1o 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
absorb and contain body exudates, and more specifically, refers to devices
which 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 describe absorbent articles which are not intended to be
laundered or otherwise 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 backsheet joined to the topsheet and an
absorbent core positioned between the topsheet and the backsheet.
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 and is intended to be wom toward
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or placed adjacent to the wearer's body or undergarments when the
disposable absorbent article is worn.
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 Figure 3 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, dQg
bone, 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 including coform; chemically
stiffened, modified or cross-linked cellulosic fibers; synthetic fibers such
as
crimped 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). 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
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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 wearer's 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 backsheet is impervious to liquids (e.g., menses andlor urine)
and is preferably manufactured from a thin plastic film, although other
flexible liquid impervious materials may also be used. As used herein, the
tens '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 artiGes 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 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
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desigrsation XP-39385. The baclcsheet is preferably embossed andlor
matte finished to provide a more clothlike appearance. Further; the
badcsheet 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 surtace, respectively, of the absorbent core. The
absorbent core is preferably joined with the topsheet, the backsheet, or
1o 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. 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
3,91 ~i ,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 3une 27, 1989. Alternatively, the attachment
means may comprise heat bonds, pressure bonds, ultrasonic bonds, dynamic
mechanical bonds, or any other suitable attachment means or combinations of
these attachment means as are known in the art.
A preferred disposable absorbent article in which the totioned
topsheets of the present invention may be used are diapers. As used
herein, the term "diaper' refers to an absorbent article generally worn by
infants, and incontinent persons that is worn about the lower torso of the
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wearer. In other words, the term "diaper" includes infant diapers, training
pants, adult incontinence devices, etc.
Figure 3 is a plan view of the diaper 50 of the present invention in its
flat-out, uncontracted state (i.e., with elastic induced contraction pulled
out)
5 with portions of the structure being cut-away to more clearly show the
construction of the diaper 50 and with the portion of the diaper 50 which
faces away from the wearer, the outer surface, oriented towards the viewer.
As shown in Figure 3, the diaper 50 preferably comprises a liquid pervious
topsheet 520; a liquid impervious backsheet 530 joined with the topsheet
10 520; an absorbent core 540 positioned between the topsheet 520 and the
backsheet 530, the absorbent core 540 having a garment facing surface
542, a body facing surface 544, side edges 546, waist edges 548, and ears
549. The diaper 50 preferably further comprises elasticized leg cuffs 550;
an elastic waist feature multiply designated as 560; and a fastening system
generally multiply designated as 570.
The diaper 50 is shown in Figure 3 to have an outer surface 52, an
inner surface 54 opposed to the outer surface 52, a first waist region 56, a
second waist region 58, and a periphery 51 which is defined by the outer
edges of the diaper 50 in which the longitudinal edges are designated 55
and the end edges are designated 57. (While the skilled artisan will
recognize that a diaper is usually described in terms of having a pair of
waist
regions and a crotch region between the waist regions, in this application,
for simplicity of terminology, the diaper 50 is described as having only waist
regions including a portion of the diaper which would typically be designated
as part of the cxotch region). The inner surface 54 of the diaper 50
comprises that portion of the diaper 50 which is positioned adjacent to the
wearer's body during use (i.e., the inner surface 54 generally is formed by at
least a portion of the topsheet 520 and other components that may be joined
to the topsheet 520). The outer surface 52 comprises that portion of the
diaper 50 which is positioned away from the wearers body (i.e., the outer
surface 52 generally is formed by at least a portion of the backsheet 530 and
other components that may be joined to the backsheet 530). (As used
herein, the portion of the diaper 50 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.) The first waist region 56 and the second waist region 58 extend,
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respectively, from the end edges 57 of the periphery 51 to the lateral
centerline 53 of the diaper 50. Figure 3 also shows the longitudinal
centerline 59.
Figure 3 shows a preferred embodiment of the diaper 50 in which the
topsheet 520 and the backsheet 530 have length and width dimensions
generally larger than those of the absorbent core 540. Th~ elasticized leg
cuffs 550 and the backsheet 530 extend beyond the edges of the absorbent
core 540 to thereby form,~,the periphery 51 of the diaper 50.
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 Buell on January 14, 1975; U.S. Patent
5,151,Q92 issued to Buell et al. on September 29, 1992; U.S. PateAt
5,221,274 issued to Buell et al. on June 22, 1993. Another diaper
configuration
to which, the present invention can be readily adapted is described in U.S.
Patent No. 5,554,145, issued on September 10, 1996. The absorbent cores of
diapers described in these patents can be adapted in light of the teachings
herein to include the absorbent composite of the present invention as an
absorbent gelling material described therein.
A topsheet 520 which is particularly suitable for use in the diaper 50,
is carded and thermally bonded by means well known to those killed in the
fabrics art. A satisfactory topsheet for the present invention comprises
28 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 520 of diaper 50 is preferably made of a hydrophilic
material to promote rapid transfer of liquids (e.g., urine) through the
topsheet. If the topsheet is made of a hydrophobic material, 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
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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 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
Raising, et at on January 29; 1991 and U.S. Patent 4,988,345 entitled
"Absorbent Articles with Rapid Acquiring Absorbent Cores" issued to
Raising on January 29, 1991,
In a preferred embodiment of a diaper as described herein, the
backsheet 530 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 5~0 may take on any size or shape that is
compatible with the diaper 50. One preferred embodiment of the diaper 50
has an asymmetric, modified T-shaped absorbent core 540 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
lhe.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 Duai-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
acquisitionldistribution core of chemically stiffened fibers positioned over
an
absorbent storage core as detailed in U.S. Patent 5,234,423, entitled
"Absorbent Article With Elastic Waist Feature and 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"
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issued to Young, LaVon and Taylor on September 15, 1992.
In a preferred embodiment, the diaper 50 further comprises
elasticized leg cuffs 550 for providing improved containment of liquids and
other body exudates; an elastic waist feature 560 that provides improved fit
and containment; and a fastening system 570 which forms a side closure
which maintains the first waist region 56 and the second waist region 58 in
an overlapping configuration such that lateral tensions ace maintained
around the circumference of the diaper to maintain the diaper on the wearer.
The diaper 50 may also comprise elasticized side panels (not shown) in the
waist regions 56 and 58 to provide an elastically extensible feature that
provides a more comfortable and contouring fit and more effective
application of the diaper 50.
The elasticized leg cuffs 550 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 Mac. 20, 1990;
U.S. Patent No. 4,695,278, issued to Lawson on Sep. 22; 1987; and U.S.
Patent No. 4,795,454, issued to Dragoo on Jan. 3, 1989. '
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 fGevit 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 8ueff et al. on Sep. 29, 1992.
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 alon 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 Gompef, et at. on Jul. 3, 1990; and U.S. Patent No.
5,151,092, issued to Buell et al. on Sep. 29, 1992.
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Exemplary fastening systems 570 are disclosed in U.S: Patent No.
4,846,8'15, issued to Scripps on Jul. 11, 1989; U.S. Patent No. 4,894,060,
issued to Nestegard on Jan. 161990; U.S. Patent No. 4,946,527, issued to
Battrell on Aug. 7, 1990; U.S. Patent No. 38848,594, issued to 8uell on Nov.
19, 1974; U.S. Patent No. 81 4662;875, issued to Hirotsu et al. on May 5,
1987; and U.S. Patent No. 5,151,092; issued to BueU et al. on Sep. 29,
1 ssz
The diaper 50 is preferably applied to a wearer by positioning one of
the waist regions of the diaper, preferably th~ second waist region 58, under
the v~earer's back and drawing the remainder of the diaper between the
wearer's legs so that the other waist region, preferably the first waist
region
56, is positioned across the front of the wearer. The fastening system is
then applied to effect a side closure.
The lotioned topsheefis of the present invention are also useful in
training pants: The term '"training pants", as used herein, refers to
disposable garments having fixed sides and leg openings. Training pants
are placed in position on thd wearer by inserting the wearers legs into the
leg openings and sliding the training pant into position about the wearers
tower torso. Suitable training pants are disclosed in U.S: Patent No.
5,246,433, issued to Hasse; et al. on September 21, 1993:
Another disposable absorbent article for which the lotioned
topsheets of the present invention are useful are incontinence articles. The
term "incontinence article" refers to pads, undergarments (pads held in
place by a suspension system of same type, such as a belt, or the like),
inserks 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 Striddand, et at. on March 3, 7 981;
U.S. Patent Nos. 4,597,760 and 4,597;761 issued to 8ue11; 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. 071637,090 filed by
Noel, et al. on January 3; 1991- (PCT Publication No. WO 92111830
published on July 23, .1992j.
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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 rheology typical of pseudoplastic or
5 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-
10 solid at room temperature to minimize lotion migration. In addition, the
lotion compositions preferably have a final melting point (100°~
liquid)
above potential "stressful" storage conditions that can be greater than
45°C
(e.g., warehouse in Arizona, car trunk in Florida, etc.).
Specifically, the lotion compositions of the present invention should have
15 the following melt profile:
Characteristic Preferred Ran4e Most Preferred
°r6 liquid at 2-50 3-25
room temp. (20 °C)
°~ liquid at 25-95 30-90
body temp. (37 °C)
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 topsheet to which they are applied. This means less lotion
composition is required for imparting desirable therapeutic or protective
coating lotion benefits.
When applied to outer surface of diaper topsheets, the lotion
compositions of the present invention are transferable to the wearer's skin
by normal contact, wearer motion, and/or body heat. Importantly, the
lotions disclosed in the present invention reduce the adherence of BM to
the skin of the wearer, thereby improving the ease of BM clean up.
CA 02205036 1997-OS-09
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16
The diaper topsheets of the present invention 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 topsheet, will be 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 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, immobolizing 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 surface of the diaper topsheet, but not so
high as to cause processing problems. Suitable viscosities for the lotion
compositions will typically range from about 5 to about 200 centipoises,
preferably from about 15 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,
CA 02205036 1997-OS-09
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17
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.
Emollients useful in the present invention can be petroleum-based,
fatty acid ester type, alkyl ethoxylate type, fatty acid ester ethoxylates,
fatty
alcohol type, polysiloxane 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 (C1-Cg, preferably C1-C3) monohydric alcohols. Representative
examples of such esters include methyl palmitate, methyl stearate,
isopropyl laurate, isopropyl myristate, isopropyl palmitate, ethylhexyl
palmitate and mixtures thereof. Suitable fatty acid ester emollients can also
be derived from esters of longer chain fatty alcohols (C12-C2g, preferably
C12-C16) 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
mixtures 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
CA 02205036 2002-12-11
18
ethoxylate having an average degree of ethoxylation of 10). These alkyl
ethoxylate emollients are typically used in combination with the petroleum-
based emollients, such as petrolatum, at a weight ratio of alkyl ethoxylate
emollient to petroleum-based emollient of from about 1:1 to about 1:5,
preferably from about 1:2 to abaut 1:4.
Suitable fatty alcohol type emallients in~;lude C,2-C22 fatty alcohols,
preferably C~6-C~$ fatty alcohals. 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.
Other suitable types of emollients for use in the present invention
include polysiloxane compounds. In general suitable polysiloxane materials
for use in the present invention include those having monomeric siloxane
units of the following structure:
R~
(1) -Si-G-
R2
:25
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 Additianally, the poiysiloxane can be either a
straight chain, a branched chain ar have a cyclic structure. The radicals R~
and R2 can additionally independently be other siliceous 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.
CA 02205036 2003-03-03
19
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, ethylphenyl, and the
like. Exemplary aralkyl radicals ate benzyl, alpha-phenylethyl, beta
phenylethyl, alpha-phenylbutyl, 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 topsheet. This
inGudes, but is not limited to, viscosity as low as 5 centistokes (at 37'C as
meas~rred 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
'0 be effectively deposited upon the diaper topsheets by such methods as, for
example, emulsifying the polysilaxane in surfactant or providing the
polysiloxane in solution with the aid of a solvent, such as hexane, listed for
exemplary purposes only. Particular methods far applying polysiloxane
emollients to diaper topsheets ars 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. Particularly preferred polysiloxane compounds for use as
emollients in the lotion compositions of the present invention include
phenyl-functional polymethylsiloxane compounds (e.g., Dow Corning 556
3o Cosmetic-Grade Fluid: polyphenylmethylsiloxane) 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,
CA 02205036 1997-OS-09
WO 96/16681 PCT/US95/13808
alkyl, carboxyl, and hydroxyl groups are more preferred than the others;
and phenyl-functional groups are most preferred.
Besides petroleum-based emollients, fatty acid ester emollients, fatty
acid ester ethoxylates, alkyl ethoxylate emollients fatty alcohol emollients,
5 and polysiloxanes, the emollients useful in the present invention can
include minor amounts (e.g., up to about 10°h of the total emollient)
of
other, conventional emollients. These other, conventional emollients
include propylene glycol, glycerine, triethylene glycol, spermaceti or other
waxes, fatty acids, and fatty alcohol ethers having from 12 to 28 carbon
10 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.
These other emollients should be included in a manner such that the solid
or semisolid characteristics of the lotion composition are maintained.
15 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 lotion composition and like factors. The lotion composition can
comprise from about 10 to about 95°~ of the emollient. Preferably, the
20 lotion composition comprises from about 20 to about 80%, most preferably
from about 40 to about 75°~, of the emollient.
2. Immobilizin4 Acrent
An especially key component of the lotion compositions of the
present invention is an agent capable of immobilizing the emollient on the
diaper topsheet to which the lotion composition is applied. Because the
emollient in the composition has a plastic or fluid consistency at
20°C, it
tends to flow or migrate, even when subjected to modest shear. When
applied to a diaper topsheet, especially in a melted or molten state, the
emollient will not remain primarily on the surface of the topsheet. 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. It also means that much more
CA 02205036 1997-OS-09
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21
emollient has to be applied to the diaper topsheet 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.
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 topsheet 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 topsheet as well.
It is also advantageous to "lock" the immobilizing agent on the
surface of the diaper topsheet. This can be accomplished by using
immobilizing agents which quickly crystallize (i.e., solidify) at the surface
of
the topsheet. In addition, outside cooling of the treated diaper topsheet via
blowers, fans, etc. can speed up crystallization of the immobilizing agent.
In 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-C22 fatty alcohols,
C12-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
CA 02205036 1997-05-09
WO 96116681 PCT/US95/13808
22
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 C16 -
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 alone 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
Giaracter. Because of the possible skin sensitivity of those using diaper
topsheets to which the lotion composition is applied, these esters and
amides should 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-0 Y
n
wherein R 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 C1 ~-C17 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 polyols such as glycerol,
pentaerythritol; sugars such as raffinose, maltodextrose, galactose,
sucrose, glucose, xylose, fructose, maltose, lactose, mannose and
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23
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 C16-C22 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-palmitate, 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.
Particularly prefer-ed 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
Lonza, 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 C16-C~ saturated fatty acids such as glyceryl
monostearate, glyceryl monopalmitate, and glyceryl monobehenate. Again,
like the socbitan esters, glyceryl monoester mixtures will typically contain
some di- and triester. However, such mixtures should contain
predominantly the glyceryl 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-C~ 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:
CA 02205036 2003-12-18
24
R2-~-N-Z
. wherein R~ is H, C~-C4 hydrocarbyl, 2-hydroxyethyl, ' 2-hydroxypropyl,
methoxyethyt, methoxypropyl or a mixture thereof, preferably C~-C4 alkyl,
methoxyethyl or methoxypropyl, more preferably C~ or C2 alkyl or
methoxypropyl , most preferably C~ alkyl (i.e., methyl) or methoxypropyl;
and R2 is a C5-C3~ hydrocarbyl group, preferably straight chain C7-Cog
alkyl or alkenyl, more preferably straight chain Cg-C~7 alkyl or alkenyl,
most preferably straight chain C ~ ~ -C ~ 7 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 which discloses these
polyhydroxy fatty acid amides, as well as their preparation.
The Z moiety preferably will be derived from a reducing sugar in a
reductive amination reaction; most preferably glycityl. Suitable reduung
sugars include glucose, fnrctose, maltose, lactose, galactose, mannose,
and xylose. High dextrose com syrup, high fructose com syrup, and high
maltose com synrp 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 insisting of
-CHZ-(CHOH)n-CHZOH, -CH(CH20H~((CHOH)n-~j-CH20H, -CH20H-
CHZ-(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, R~ 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, oiearnides, lauramides, myristamides, capricamides,
palmitamides, tallowamides, etc. The Z moiety can be 1-deoxyglucityl, 2-
CA 02205036 1997-OS-09
WO 96/16681 PCT/US95/13808
deoxyfructityl, 1-deoxymaltityl, 1-deoxylactityl, 1-deoxygalactityl, 1-
deoxymannityl, 1-deoxymaltotriotityl, etc.
The most preferred polyhydroxy fatty acid amides have the general
formula:
5
0 R~ OH
R2-C-N-C H2 C H C H2-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-
10 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
emulsifier for solubilization in the emollient. This is particularly the case
for
15 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
20 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
25 solubilize the 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
CA 02205036 1997-OS-09
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26
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 preferred paraffin wax is
Parrafin S. P. 434 from Strahl and Pitsch Inc. PØ Box 1098 West Babylon,
NY 11704.
The amount of immobilizing agent that should be included in the
lotion composition will depend on a variety of factors, including the
particular 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°r6, most preferably from about 10 to about
40°r6, of the
immobilizing agent.
3. Optional Hvdroahilic Surfactant
As mentioned above, it is highly desirable that the diaper topsheet is
made of a hydrophilic material to promote rapid transfer of liquids (e.g.,
urine) through the topsheet. Similarly, it is important that the lotion
composition also be sufficiently wettable to ensure that liquids will transfer
through the topsheet more rapidly. This diminishes the likelihood that body
exudates will flow off the lotion coating rather than being drawn through the
topsheet and being absorbed by the absorbent core. Depending upon the
particular immobilizing agent used in the lotion composition of the present
invention, an additional hydrophilic surfactant (or a mixture of hydrophilic
surfactants) may, or may not, be required to improve wettability. For
example, some immobilizing agents, such as N-cocoyl-N-methoxypropyl
glucamide have HLB values of at least about 7 and are sufficiently wettable
without the addition of hydrophilic surfactant. Other immobilizing agents
such as the C16 - C1g fatty alcohols having HLB values below about 7 will
require addition of hydrophilic surfactant to improve wettability when the
lotion composition is applied to diaper topsheets. Similarly, a hydrophobic
emollient such as petrolatum will require the addition of a hydrophilic
surfactant.
i, ~ ~ rri i i ~ i~ i~,. ~W. ~,~
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Suitable hydrophilic surtactants 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.
Suitable nonionic surfactants may be substantially nonmigratory after
1o the lotion composition is applied to the diaper topsheets and will
typically
have HL8 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 surtactants 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- andlor
tri~sters of C12-C1g fatty acids having an average degree of ethoxylation
of from about 2 to about 20, preferably from about 2 to about 10; such as
TWEE~60 (sorbitan esters of stearic acid having an average degree of
ethoxylation of about 20) and TWEEI~~1 (socbitan 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 typit;ally in a
straight chain (linear) configuration and contains from about 8 to about 22
carbon atoms. Partiartarly 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
CA 02205036 2005-06-21
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alcohols having alkyl chains varying in length from 10 to 14 carbon atoms)
with about 6 moles of ethylene oxide. A number of suitabl Methoxylated
alcohols are commercially available, including TERGITOL 15-S-9 (the
condensation product of C11-C15 linear alcohols with 9 molof ethylene
oxide), marketed by Union Carbide Corporation; KYRO EOB (condensation
product of~ C1g-C15 linear alcohols with 9 moles of ethylene oxide),
marketed by The Procter ~ Gamble Co., the NEODO~Mbrand name
surfactants marketed by Shell Chemical Co., in particular NEOOO~M25-12
(condensation product of C12-C15 linear alcohols with 12 moles of ethylene
oxide) 'and NEODOLT~3-6.5T (condensation product of C12-C13 linear
alcohol with 6.5 moles of ethylene oxide that has been distilled (topped) to
remove certain impurities), and especially the PLURAFACT~rand name
surfactants marketed by BASF Corp., in particular PLURAFACT~-38 (a
condensation product of a C1 g straight chain alcohol with 27 moles of
ethylene oxide). (Certain of the hydrophilic surfactants, in particular
ethoxylated alcohols such as NEODOLT~lS-12, can also function as alkyl
ethoxylate emollients). Other exam~Mes of preferred ethoxylated alcohol
surfactants include ICt's class of. Brij surfactants and mixtures thereof,
with
BrijT~2 (i:e., Steareth-2) and BnjT~ ( i:e., Steareth-10) being especially
preferred. Also, mixtures of cetyl alcohol and stearyl alcohol ethoxylated to
an average degree of ethoxytation 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 sutfosuccinic 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 polydimethytsiloxane and a polyoxyalkylene ether) and
General Electric SF 1228 (a silicone polyether copolymer). These silicone
3o 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%, by weight of
the lotion composition.
The amount of hydrophilic surfactant required to increase the
wettability of the lotion composition to a desired level will depend upon the
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HLB value and level of immobilizing agent used, the HLB value of the
surfactant used and like factors. The lotion composition can comprise from
about 1 to about 50°~ of the hydrophilic surfactant when needed to
increase
the wettability properties of the composition. Preferably, the lotion
composition comprises from about 1 to about 25%, most preferably from
about 10 to about 20%, of the hydrophilic surfactant when needed to
increase wettability.
4. Other Optional Components
Lotion compositions can comprise other optional components
typically present in emollient, creams, and lotions of this type. These
optional components include water, viscosity modifiers, perfumes,
disinfectant antibacterial actives, pharmaceutical actives, film formers,
deodorants, opacifiers, astringents, solvents and the like. 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.
C. Treatino Diaaer Topsheets With Lotion Composition
In preparing lotioned diaper products according to the present
invention, the lotion composition is applied to the outer surface (i.e., body
facing surface) of a diaper topsheet. Any of a variety of application
methods that evenly distribute lubricious materials having a molten or liquid
consistency can be used. Suitable methods include spraying, printing (e.g.,
flexographic printing), coating (e.g., gravure 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 outer surface of the diaper topsheet.
The manner of applying the lotion composition to the diaper topsheet
should be such that the topsheet does not become saturated with the lotion
composition. If the topsheet becomes saturated with the lotion composition,
there is a greater potential for the lotion to block the topsheet openings,
reducing the ability of the topsheet to transmit fluid to the underlying
absorbent core. Also, saturation of the topsheet is not required to obtain
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the therapeutic and/or protective lotion benefits. Particularly suitable
application methods will apply the lotion composition primarily to the outer
surface of the diaper topsheet.
The minimum level of lotion to be applied to the diaper topsheets is
5 an amount effective for reducing the adherence of BM to the skin of the
wearer. The lotion composition is preferably applied to the diaper
topsheets of the present invention in an amount ranging from about 0.1
mglin2 to about 25 mg/in2 more preferably from about 1 mg/in2 to about 10
mg/in2 (mg of lotion per square inch of coated topsheet). Because the
10 emollient is substantially immobilized on the surface of the topsheet, 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 topsheet, yet do not
saturate the topsheet's absorbency andlor wettability properties.
15 The lotion composition may be applied to the entire surface of the
topsheet or portions thereof. Preferably, the lotion composition is applied in
a stripe aligned with and centered on the longitudinal centerline of the
disposable absorbent article. Most preferably, as described in the
Examples hereinafter, the lotion composition is applied to a discrete version
20 of the topsheet, e.g., a 3.75 inch wide (diaper lateral direction) and 7
inch
long (diaper longitudinal direction) patch generally disposed toward the
second waist region.
The lotion composition can also be applied nonuniformly to the outer
surface of the diaper topsheet. By "nonunifonn" is meant that the amount,
25 pattern of distribution, etc. of the lotion composition can vary over the
topsheet surface. For example, some portions of the treated surface of the
topsheet 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 topsheet at any point
30 during assembly. For example, the lotion composition,can be applied to the
topsheet of the finished disposable absorbent product before it has been
packaged. The lotion composition can also be applied to the topsheet
before it is combined with the other raw materials to form a finished
disposable absorbent product.
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The lotion composition is typically applied from a melt thereof to the
diaper topsheet. Since the lotion composition melts at significantly above
ambient temperatures, it is usually applied as a heated coating to the
topsheet. 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 topsheet. Once the melted lotion
composition has been applied to the diaper topsheet, it is allowed to cool
and solidify to form solidified coating or film on the surface of the
topsheet..
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
topsheets, spraying, gravure coating and extrusion coating methods are
preferred. Figure 1 illustrates one such preferred method involving
spraying of the coating on the diaper topsheet before the topsheet is
assembled with the other raw materials into a finished product. Referring to
Figure 1, a nonwoven topsheet web 1 is unwound from parent topsheet roll
2 (rotating in the direction indicated by arrow 2a) and advanced to spray
station 6 where one side of the web is sprayed with a hot, molten (e.g.,
65°C) lotion composition. After leaving spray station 6, nonwoven
topsheet
web 1 becomes a lotioned topsheet web indicated by 3. Lotioned topsheet
web 3 is then advanced around turning roll 4 and turning roll 8, and then
wound up on lotioned topsheet parent roll 10 (rotating in the direction
indicated by arrow 10a).
Figure 2 illustrates an alternative preferred method involving
continuous or intermittent spraying of the lotion composition on to a diaper
topsheet during the converting operation. Referring to Figure 2, 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 carries
nonlotioned diaper 5 to spray station 6 where topsheet patch 7 is sprayed
with a hot, molten (e.g., 65°C) lotion composition. After leaving spray
station 6, nonlotioned diaper 5 becomes lotioned diaper 8 having a lotioned
topsheet. The amount of lotion composition transferred to topsheet patch 7
is controlled by: (1 ) the rate at which the molten lotion composition is
sprayed from spray station 6; andlor (2) the speed at which conveyor belt 1
travels under spray station 6.
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SPECIFIC ILLUSTRATIONS OF THE PREPARATION OF LOTIONED
DIAPER TOPSHEETS ACCORDING TO THE PRESENT INVENTION
The following are specific illustrations of treating diaper topsheets
with lotion compositions in accordance with the present invention:
Example 1
A. Preaaration of Lotion Compositions
A water free lotion composition (Lotion A) is made by mixing the
following melted (i.e., liquid) components together: Mineral Oil
(Carnation White Mineral Oil, USP made by Witco Corp.), Cetearyl
Alcohol (a mixed linear C16-C1g primary alcohol made by the
Procter & Gamble Company under the name TA-1618); Steareth=2
(Brij 72, a C1 g linear alcohol ethoxylate having an average degree of
ethoxylation of 2, made by ICI America). The weight percentages of
these components are shown in Table I below:
Table I
Component Weight ~
Mineral Oil 50
Cetearyl Alcohol35
Steareth-2 15
B. Preparation of Lotioned Diaaer Topsheet by Hot Melt Spraying
Lotion Composition A is placed into a ' heated tank operating at a
temperature of 125°F. The composition is subsequently sprayed
(using a Dynatec E84B1758 spray head, operating at a temperature
of 165°F and an atomization pressure of 2.40 psig) onto the topsheet
of a diaper in a 3.75 inch wide (diaper lateral direction) and 7 inch
long (diaper longitudinal direction) area, the patch beginning 1 inch
forward of the lateral centerline and extending toward the rear of the
product. Add-on level = 0.006 glint (9.3 glm2).
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33
Example 2
The lotion composition A (prepared in accordance with the procedure in
Example I) is subsequently sprayed onto the topsheet of a diaper in a
3.75 inch wide (diaper lateral direction) stripe centered on the
longitudinal centerline and extending the entire length of the product.
Add-on level = 0.006 glint (9.3 glm2).
Example 3
The lotion composition A (prepared in accordance with the procedure in
Example I) is subsequently sprayed onto the topsheet of a diaper in a
3.75 inch wide (diaper lateral direction) stripe centered on the
longitudinal centerline and 7 inch long (diaper longitudinal direction)
area, the patch beginning 1 inch forward of the lateral centerline and
extending toward the rear of the product. Add-on level = 0.003 glint
(4.65 glm2).
Examale 4
A. Preparation of Lotion Comaositions
A water free lotion composition (Lotion B) is made by mixing the
following melted (i.e., liquid) components together: Mineral Oil
(Carnation White Mineral Oil, USP made by Witco Corp.), and
Cetearyl Alcohol (a mixed linear C16-C1g primary alcohol made by
the Procter 8~ Gamble Company under the name TA-1618). The
weight percentages of these components are shown in Table II
below:
Table II
Component Weight ~
Mineral Oil 65
Cetearyl Alcohol35
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B. Preparation of Lotioned Tissue by Hot Melt SarayinQ
Lotion Composition B is placed into a heated tank operating at a
temperature of 125°F. The composition is subsequently sprayed
(using a Dynatec E84B1758 spray head, operating at a temperature
of 165°F and an atomization pressure of 2.40 psig) onto the topsheet
of a diaper in a 3.75 inch wide (diaper lateral direction) and 7 inch
long (diaper longitudinal direction) area, the patch beginning 1 inch
forward of the lateral centerline and extending toward the rear of the
product. Add-on level = 0.006 glint (9.3 g/m2).
Example 5
A. Preparation of Lotion Composition
A water free lotion composition (Lotion C) is made by mixing ttie
following melted (i.e., liquid) components together: White Protopet~
1S (white petrolatum made by Witco Corp.), Cetearyl Alcohol (a
mixed linear C16-C1g primary alcohol made by the Procter 8~ Gamble
Company under the name TA-1618); Steareth-2 (Brij 762, a C1g
linear alcohol ethoxylate having an average degree of ethoxylation of
2 made by ICI America). The weight percentages of these
components are shown in Table I below:
A water free lotion composition (Lotion C) is made by mixing together
the following melted (i.e., liquid) components in the weight
percentages shown in the Table III below according to the procedure
of Example 2:
Table III
Component Weight h
WhiteProtopet~ 50
1S
Cetearyl Alcohol35
Steareth-2 15
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B. Preaaration of Lotioned Tissue by Hot Melt Spravina
Lotion Composition C is placed into a heated tank operating at a
temperature of 125°F. The composition is subsequently sprayed
(using a Dynatec E84B1758 spray head, operating at a temperature
5 of 165°F and an atomization pressure of 2.40 psig) onto the topsheet
of a diaper in a 3.75 inch wide (diaper lateral direction) and 7 inch
long (diaper longitudinal direction) area, the patch beginning 1 inch
forvvard of the lateral centerline and extending toward the rear of the
product. Add-on level = 0.006 g/in2 (9.3 g/m2).
Example 6
A. Preparation of Lotion Composition
A water free lotion composition (Lotion D) is made by mixing the
following melted (i.e., liquid) components together: White Protopet~
1S (white petrolatum made by Witco Corp.); Dow Coming 556
Cosmetic Grade Fluid(a polyphenylmethylsiloxane made by the Dow
Coming Corporation), An example of a particularly preferred paraffin
wax is Parrafin S.P. 434 (a para~n wax made by Strahl and Pitsch
Inc.); Cetearyl Alcohol (a mixed linear C16-C1g 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 IV below:
Table IV
Component Weight r6
WhiteProtopet~ 52
1S
Polyphenylmethyl- 20
siloxane
Para~n Wax 15
Cetearyl Alcohol 10
PEG 2000
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36
B. Preparation of Lotioned Tissue by Hot Melt Spravina
Lotion Composition D is placed into a heated tank operating at a
temperature of 150°F. The composition is subsequently sprayed
(using a Dynatec E84B1758 spray head, operating at a temperature
of 170°F and an atomization pressure of 2.40 psig) onto the topsheet
of a diaper in a 3.75 inch wide (diaper lateral direction) and 7 inch
long (diaper longitudinal direction) area, the patch beginning 1 inch
forvvard of the lateral centerline and extending toward the rear of the
product. Add-on level = 0.006 glint (9.3 g/m2).
