U.S. patent application number 09/814551 was filed with the patent office on 2001-09-27 for article having a lotioned topsheet.
Invention is credited to Rijswijck, Laura Graves Spalding Van, Roe, Donald Carroll, Rule, Julie Charlene.
Application Number | 20010025162 09/814551 |
Document ID | / |
Family ID | 34197593 |
Filed Date | 2001-09-27 |
United States Patent
Application |
20010025162 |
Kind Code |
A1 |
Roe, Donald Carroll ; et
al. |
September 27, 2001 |
Article having a lotioned topsheet
Abstract
An article containing a liquid pervious topsheet coated with a
lotion composition is disclosed. The lotion composition provides a
skin benefit and/or reduces the adherence of BM to the skin of the
wearer, thereby improving the ease of BM clean up. The lotion
composition applied to the article in a nonuniform manner,
preferably such there are regions on the article's topsheet that
are not coated with lotion.
Inventors: |
Roe, Donald Carroll;
(Cincinnati, OH) ; Rijswijck, Laura Graves Spalding
Van; (Burlington, KY) ; Rule, Julie Charlene;
(Cincinnati, OH) |
Correspondence
Address: |
THE PROCTER & GAMBLE COMPANY
PATENT DIVISION
SHARON WOODS TECHNICAL CENTER- BOX B22
11450 GROOMS ROAD
CINCINNATI
OH
45242
US
|
Family ID: |
34197593 |
Appl. No.: |
09/814551 |
Filed: |
March 22, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09814551 |
Mar 22, 2001 |
|
|
|
08908852 |
Aug 8, 1997 |
|
|
|
08908852 |
Aug 8, 1997 |
|
|
|
08884069 |
Jun 27, 1997 |
|
|
|
6118041 |
|
|
|
|
08884069 |
Jun 27, 1997 |
|
|
|
08345159 |
Nov 28, 1994 |
|
|
|
5643588 |
|
|
|
|
Current U.S.
Class: |
604/364 ;
604/367 |
Current CPC
Class: |
A61F 13/15577 20130101;
A61F 13/51113 20130101; A61F 13/8405 20130101; A61Q 19/00 20130101;
A61L 15/48 20130101; A61F 2013/8461 20130101; A61F 2013/51117
20130101; A61F 2013/8455 20130101; A61K 8/0208 20130101; A61K
2800/31 20130101; A61F 13/512 20130101; A61F 13/4942 20130101; A61L
15/34 20130101 |
Class at
Publication: |
604/364 ;
604/367 |
International
Class: |
A61F 013/15; A61F
013/20 |
Claims
What is claimed is:
1. A disposable article 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 article and an outer surface oriented
toward the skin of the wearer when said article 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.degree. C. and which is partially transferable to the
wearer's skin; and C) an absorbent core positioned between said
topsheet and said backsheet; wherein the lotion is applied to the
liquid pervious topsheet nonuniformly.
2. The disposable article of claim 1 wherein the lotion is applied
to the outer surface of the liquid pervious topsheet such that
regions of the topsheet's outer surface are not coated with
lotion.
3. The disposable article of claim 1 wherein the percent open area
of the topsheet is from about 1% to about 99%.
4. The disposable article of claim 3 wherein the percent open area
of the topsheet is from about 5% to about 95%.
5. The disposable article of claim 4 wherein the percent open area
of the topsheet is from about 10% to about 90%.
6. The disposable article of claim 5 wherein the percent open area
of the topsheet is from about 20% to about 80%.
7. The disposable article of claim 6 wherein the percent open area
of the topsheet is from about 30% to about 70%.
8. The disposable article of claim 1 wherein the lotion is applied
to the topsheet in the form of a plurality of stripes that are
separated by a plurality of stripes having no lotion.
9. The disposable article of claim 1 wherein the lotion comprises a
petroleum based emollient selected from the group consisting of
mineral oil, petrolatum, and mixtures thereof.
10. The disposable article of claim 9 wherein said emollient is
petrolatum.
11. The disposable article of claim 9 wherein said emollient is
mineral oil.
12. The disposable article of claim 9 wherein said lotion coating
comprises an immobilizing agent, said immobilizing agent having a
melting point of at least about 40.degree. C.
13. A disposable article 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 article and an outer surface oriented
toward the skin of the wearer when said article 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.degree. C. and which is partially transferable to the
wearer's skin, said lotion coating comprising: (i) from about 10 to
about 95% of a substantially water free emollient having a plastic
or fluid consistency at 20.degree. C. and comprising a member
selected from the group consisting of petroleum-based emollients,
fatty acid ester emollients, alkyl ethoxylate emollients, and
mixtures thereof; (ii) from about 5 to about 90% of one or more
agents capable of immobilizing said emollient on said outer surface
of the topsheet, said one or more immobilizing agents having a
melting point of at least about 35.degree. C.; and C) an absorbent
core positioned between said topsheet and said backsheet; wherein
the lotion is applied to the liquid pervious topsheet
nonuniformly.
14. The disposable article of claim 13 wherein the lotion is
applied to the outer surface of the liquid pervious topsheet such
that certain areas of the topsheet are not coated with lotion.
15. The disposable article of claim 14 wherein the percent open
area of the topsheet is from about 1% to about 99%.
16. The disposable article of claim 15 wherein the percent open
area of the topsheet is from about 5% to about 95%.
17. The disposable article of claim 16 wherein the percent open
area of the topsheet is from about 10% to about 90%.
18. The disposable article of claim 13 wherein said emollient
contains about 5% or less water and comprises a petroleum based
emollient selected from the group consisting of mineral oil,
petrolatum, and mixtures thereof.
19. The disposable article of claim 18 wherein said emollient is
petrolatum.
20. The disposable article of claim 18 wherein said emollient is
mineral oil.
21. The disposable article of claim 13 wherein said lotion coating
comprises from about 5 to about 50% of said immobilizing agent,
said immobilizing agent having a melting point of at least about
40.degree. C.
22. The disposable article of claim 21 wherein said immobilizing
agent comprises a C.sub.14-C.sub.22 fatty alcohol.
23. The disposable article of claim 22 wherein said immobilizing
agent comprises a C.sub.16-C.sub.18 fatty alcohol selected from the
group consisting of cetyl alcohol, stearyl alcohol, and mixtures
thereof.
24. The disposable article of claim 21 wherein said immobilizing
agent comprises a polyhydroxy fatty acid ester having the formula:
5wherein R is a C.sub.5-C.sub.31 hydrocarbyl group; 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.
25. The disposable article of claim 21 wherein said immobilizing
agent comprises a polyhydroxy fatty acid amide having the formula:
6wherein R.sup.1 is H, C.sub.1-C.sub.4 hydrocarbyl, 2-hydroxyethyl,
2-hydroxypropyl, methoxyethyl, methoxypropyl or a mixture thereof;
R.sup.2 is a C.sub.5-C.sub.31 hydrocarbyl group; and Z is a
polyhydroxyhydrocarbyl moiety having a linear hydrocarbyl chain
with at least 3 hydroxyls directly connected to the chain.
26. The disposable article of claim 21 wherein said immobilizing
agent comprises a paraffin wax.
27. The disposable article of claim 14 wherein lotion is
transferred to the skin that is contacted by the article during
wear.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part application of
copending U.S. patent application Ser. No. __________, filed Jun.
27, 1997 by D. C. Roe et al., which is a continuation application
of U.S. patent application Ser. No. 08/345,159, filed Nov. 28, 1997
by D. C. Roe et al. (issued as U.S. Pat. No. 5,643,588 on Jul. 1,
1997).
TECHNICAL FIELD
[0002] 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 and/or 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
[0003] 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
referred 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.
[0004] 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 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.
[0005] One substance that has been applied as a lotion to absorbent
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.degree.-390.degree. C.) fractions in petroleum. Mineral
oil is liquid at ambient temperatures, e.g. 20.degree.-25.degree.
C. As a result, mineral oil is relatively fluid and mobile, even
when applied to article topsheets.
[0006] 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 products, but
other detrimental effects as well.
[0007] 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 article, 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.
[0008] 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 product. This
can create the need for barrier-type packaging or wrapper films to
avoid smearing or other leakage of mineral oil from the
product.
[0009] Accordingly, it would be desirable to provide lotioned
absorbent products that: (1) have desirable therapeutic or
protective coating 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
absorbent product; and (4) do not require special wrapping or
barrier materials for packaging.
[0010] U.S. Pat. No. 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
pressure-rupturable capsules is used in U.S. Pat. No. 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-care substance contained in the capsules is either not
delivered at all or is delivered non-uniformly leaving some areas
of skin uncoated.
[0011] U.S. Pat. No. 3,896,807 to Buchalter teaches an article
impregnated with a solid oil phase of cream formulation which forms
a cream upon addition of moisture thereto. A major disadvantage of
the article disclosed 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.
[0012] U.S. Pat. No. 3,489,148 to Duncan et al. 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 slow in promoting transfer of urine to the
underlying absorbent cores.
[0013] Therefore, it is an object of the present invention to
provide a disposable absorbent article having a hydrophilic
topsheet having superior fluid handling properties.
[0014] It is a further object of the present invention to provide a
hydrophilic absorbent article topsheet having a lotion coating on
the outer surface of the topsheet that is transferable to the
wearer's skin and is effective at producing desired skin benefits
and/or reducing the adherence of BM to the skin, thereby improving
the ease of BM cleanup.
[0015] It is yet a further object of the present invention
desirable to provide lotioned absorbent articles 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 article; and (4) do not require special wrapping
or barrier materials for packaging.
[0016] 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
[0017] The present invention relates to a disposable absorbent
article having a lotion coating on the outer surface of the
topsheet that is semisolid or solid at ambient temperatures (i.e.,
at 20.degree. C.) and is adapted to be transferred to the wearer's
skin, where it acts to reduce the adherence of BM to the skin of
the wearer, thereby improving the ease of BM clean up.
[0018] Briefly, the disposable articles of the present invention
comprise:
[0019] A) a liquid impervious backsheet;
[0020] B) a liquid pervious, hydrophilic topsheet joined to said
backsheet, said topsheet having an inner surface oriented toward
the interior of said article and an outer surface oriented toward
the skin of the wearer when said article 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.degree. C. and which is partially transferable to the
wearer's skin, said lotion coating comprising:
[0021] (i) from about 10 to about 95% of a substantially water free
emollient having a plastic or fluid consistency at 20.degree. 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;
[0022] (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.degree. C.; and
[0023] C) an absorbent core positioned between said topsheet and
said backsheet.
[0024] The quantity of lotion coating on a least a portion of the
article topsheets of the present invention preferably ranges from
about 0.1 mg/in.sup.2 to about 25 mg/in.sup.2, more preferably from
about 1 mg/in.sup.2 to about 10 mg/in.sup.2. Lotioned article
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 benefits. In addition, special barrier or
wrapping materials are unnecessary in packaging the lotioned
products of the present invention.
[0025] 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 article topsheet
at room temperature, are transferable to the wearer at body
temperature, and yet are not completely liquid under extreme
storage conditions.
[0026] 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a schematic representation illustrating a
preferred process for applying the lotion composition of the
present invention to article topsheets.
[0028] FIG. 2 is a schematic representation illustrating an
alternative process for applying the lotion composition of the
present invention to article topsheets.
[0029] FIG. 3 is an absorbent article in the form of a diaper
according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] 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."
[0031] All percentages, ratios and proportions used herein are by
weight unless otherwise specified.
[0032] A. Absorbent Article
[0033] 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.
[0034] 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 worn toward or
adjacent to the body of the wearer, while the "garment surface" is
on the opposite side and is intended to be worn toward or placed
adjacent to the wearer's body or undergarments when the disposable
absorbent article is worn.
[0035] 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 FIG. 3 and further described below, in
addition to those of other disposable absorbent articles which are
generally described herein.
[0036] 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,
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.
[0037] The configuration and construction of the absorbent core may
also be varied (e.g., the absorbent core may have varying caliper
zones and/or 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 overnight sanitary napkins, and to accommodate wearers ranging
from infants to adults.
[0038] 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.
[0039] 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.
[0040] The backsheet is impervious to liquids (e.g., menses and/or
urine) and is preferably manufactured from a thin plastic film,
although other flexible liquid impervious materials may also be
used. As used herein, the term "flexible" refers to materials which
are compliant and will readily conform to the general shape and
contours of the human body. 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 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,
Ind., 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.
[0041] 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 FIG. 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.
[0042] For example, the backsheet and/or 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, Minn. 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.
Pat. No. 4,573,986, issued to Minetola, et al. on Mar. 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. Pat. No.
3,911,173 issued to Sprague, Jr. on Oct. 7, 1975; U.S. Pat. No.
4,785,996 issued to Zwieker, et al. on Nov. 22, 1978; and U.S. Pat.
No. 4,842,666 issued to Werenicz on Jun. 27, 1989. Each of these
patents are incorporated herein by reference. 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.
[0043] A preferred disposable absorbent article in which the
lotioned 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 wearer. In other words, the term
"diaper" includes infant diapers, training pants, adult
incontinence devices, etc.
[0044] FIG. 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) 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
FIG. 3, the diaper 50 preferably comprises a liquid pervious
topsheet 520; a liquid impervious backsheet 530 joined with the
topsheet 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.
[0045] The diaper 50 is shown in FIG. 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 crotch
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 wearer's 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, respectively, from the end
edges 57 of the periphery 51 to the lateral centerline 53 of the
diaper 50. FIG. 3 also shows the longitudinal centerline 59.
[0046] FIG. 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.
The 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.
[0047] 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. Pat. No. 3,860,003 issued to Buell on
Jan. 14, 1975; U.S. Pat. No. 5,151,092 issued to Buell et al. on
Sep. 29, 1992; U.S. Pat. No. 5,221,274 issued to Buell et al. on
Jun. 22, 1993. Each of these patents is incorporated herein by
reference. Another diaper configuration to which the present
invention can be readily adapted are described in co-pending U.S.
patent application Ser. No. 08/203,456; filed on Feb. 28, 1994 and
incorporated herein by reference. 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.
[0048] A topsheet 520 which is particularly suitable for use in the
diaper 50, 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.
[0049] 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 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. Pat. No. 4,988,344 entitled "Absorbent Articles with Multiple
Layer Absorbent Layers" issued to Reising, et al on Jan. 29, 1991
and U.S. Pat. No. 4,988,345 entitled "Absorbent Articles with Rapid
Acquiring Absorbent Cores" issued to Reising on Jan. 29, 1991, each
of which is incorporated by reference herein.
[0050] 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.
[0051] The absorbent core 540 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 the present invention that have
achieved wide acceptance and commercial success are described in
U.S. Pat. No. 4,610,678 entitled "High-Density Absorbent
Structures" issued to Weisman et al. on Sep. 9, 1986; U.S. Pat. No.
4,673,402 entitled "Absorbent Articles With Dual-Layered Cores"
issued to Weisman et al. on Jun. 16, 1987; U.S. Pat. No. 4,888,231
entitled "Absorbent Core Having A Dusting Layer" issued to Angstadt
on Dec. 19, 1989; and U.S. Pat. No. 4,834,735, entitled "High
Density Absorbent Members Having Lower Density and Lower Basis
Weight Acquisition Zones", issued to Alemany et al. on May 30,
1989. The absorbent core may further comprise the dual core system
containing an acquisition/distribution core of chemically stiffened
fibers positioned over an absorbent storage core as detailed in
U.S. Pat. No. 5,234,423, entitled "Absorbent Article With Elastic
Waist Feature and Enhanced Absorbency" issued to Alemany et al., on
Aug. 10, 1993; and in U.S. Pat. No. 5,147,345, entitled "High
Efficiency Absorbent Articles For Incontinence Management" issued
to Young, LaVon and Taylor on Sep. 15, 1992. All of these patents
are incorporated herein by reference.
[0052] 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 are 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.
[0053] The elasticized leg cuffs 550 can be constructed in a number
of different configurations, including those described in U.S. Pat.
No. 3,860,003; U.S. Pat. No. 4,909,803, issued to Aziz et al. on
Mar. 20, 1990; U.S. Pat. No. 4,695,278, issued to Lawson on Sep.
22, 1987; and U.S. Pat. No. 4,795,454, issued to Dragoo on Jan. 3,
1989, each being incorporated herein by reference.
[0054] 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. Pat. No. 4,515,595 issued to Kievit et al. on May 7, 1985;
U.S. Pat. No. 5,026,364 issued to Robertson on Jun. 25, 1991; and
the above referenced U.S. Pat. No. 5,151,092 issued to Buell et al.
on Sep. 29, 1992, each of these references being incorporated
herein by reference.
[0055] 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. Pat. No. 4,857,067, issued to Wood, et al. on Aug. 15, 1989;
U.S. Pat. No. 4,381,781, issued to Sciaraffa, et al. on May 3,
1983; U.S. Pat. No. 4,938,753, issued to Van Gompel, et al. on Jul.
3, 1990; and U.S. Pat. No. 5,151,092, issued to Buell et al. on
Sep. 29, 1992; each of which are incorporated herein by
reference.
[0056] Exemplary fastening systems 570 are disclosed in U.S. Pat.
No. 4,846,815, issued to Scripps on Jul. 11, 1989; U.S. Pat. No.
4,894,060, issued to Nestegard on Jan. 16, 1990; U.S. Pat. No.
4,946,527, issued to Battrell on Aug. 7, 1990; U.S. Pat. No.
3,848,594, issued to Buell on Nov. 19, 1974; U.S. Pat. No. B1
4,662,875, issued to Hirotsu et al. on May 5, 1987; and U.S. Pat.
No. 5,151,092, issued to Buell et al. on Sep. 29, 1992; each of
which is incorporated herein by reference.
[0057] The diaper 50 is preferably applied to a wearer by
positioning one of the waist regions of the diaper, preferably the
second waist region 58, under the wearer'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.
[0058] The lotioned topsheets 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 the wearer by
inserting the wearer's legs into the leg openings and sliding the
training pant into position about the wearer's lower torso.
Suitable training pants are disclosed in U.S. Pat. No. 5,246,433,
issued to Hasse, et al. on Sep. 21, 1993.
[0059] 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), inserts for absorbent articles,
capacity boosters for absorbent articles, briefs, bed pads, and the
like regardless of whether they are worn by adults or other
incontinent persons. Suitable incontinence articles are disclosed
in U.S. Pat. No. 4,253,461 issued to Strickland, et al. on Mar. 3,
1981; U.S. Pat. Nos. 4,597,760 and 4,597,761 issued to Buell; the
above-mentioned U.S. Pat. No. 4,704,115; U.S. Pat. No. 4,909,802
issued to Ahr, et al.; U.S. Pat. No. 4,964,860 issued to Gipson, et
al. on Oct. 23, 1990; and in U.S. patent application Ser. No.
07/637,090 filed by Noel, et al. on Jan. 3, 1991 (PCT Publication
No. WO 92/11830 published on Jul. 23, 1992).
[0060] B. Lotion Composition.
[0061] The lotion compositions of the present invention are solid,
or more often semisolid, at 20.degree. C., i.e. at ambient
temperatures. By "semisolid" is meant that the lotion composition
has a rheology 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.
[0062] 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% liquid) above potential "stressful" storage
conditions that can be greater than 45.degree. C. (e.g., warehouse
in Arizona, car trunk in Florida, etc.). Specifically, the lotion
compositions of the present invention should have the following
melt profile:
1 Characteristic Preferred Range Most Preferred % liquid at 2-50
3-25 room temp. (20.degree. C.) % liquid at 25-95 30-90 body temp.
(37.degree. C.) final melting point (.degree. C.) .gtoreq.38
.gtoreq.45
[0063] 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 article topsheet to which they are applied.
This means less lotion composition is required for imparting
desirable therapeutic or protective coating lotion benefits.
[0064] When applied to outer surface of article 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.
[0065] The article 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 article
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.
[0066] The lotion compositions of the present invention comprise:
(1) an emollient(s); (2) an immobilizing agent(s) for the
emollient; (3) optionally a hydrophilic surfactant(s); and (4)
other optional components.
[0067] 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 article. 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 article 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.degree. C.
[0068] 1. Emollient
[0069] 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.degree.
C., i.e., at ambient temperatures. This particular emollient
consistency allows the lotion composition to impart a soft,
lubricious, lotion-like feel.
[0070] 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.
[0071] 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.
[0072] Suitable fatty acid ester type emollients include those
derived from C.sub.12-C.sub.28 fatty acids, preferably
C.sub.16-C.sub.22 saturated fatty acids, and short chain
(C.sub.1-C.sub.8, preferably C.sub.1-C.sub.3) 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 (C.sub.12-C.sub.28, preferably
C.sub.12-C16) and shorter chain fatty acids e.g., lactic acid, such
as lauryl lactate and cetyl lactate.
[0073] Suitable alkyl ethoxylate type emollients include
C.sub.12-C.sub.22 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 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 about 1:4.
[0074] Suitable fatty alcohol type emollients include
C.sub.12-C.sub.22 fatty alcohols, preferably C.sub.16-C.sub.18
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: I to about
1:2.
[0075] 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:
1
[0076] wherein, R.sub.1 and R.sub.2, 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.sub.1 and R.sub.2 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.sub.1 and R.sub.2 can
additionally independently be other silaceous functionalities such
as, but not limited to siloxanes, polysiloxanes, silanes, and
polysilanes. The radicals R.sub.1 and R.sub.2 may contain any of a
variety of organic functionalities including, for example, alcohol,
carboxylic acid, phenyl, and amine functionalities.
[0077] 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, diphenyl, naphthyl, and the like. Exemplary
alkaryl radicals are toyl, xylyl, ethylphenyl, and the like.
Exemplary aralkyl radicals are 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.
[0078] 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 article topsheet. This includes, but is not
limited to, viscosity as low as 5 centistokes (at 37.degree. C. as
measured by a glass viscometer) to about 20,000,000 centistokes.
Preferably the polysiloxanes have a viscosity at 37.degree. 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 article topsheets 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 article topsheets are discussed in more
detail hereinafter.
[0079] Preferred polysiloxanes compounds for use in the present
invention are disclosed in U.S. Pat. No. 5,059,282 (Ampulski et
al), issued Oct. 22, 1991, which is incorporated herein by
reference. 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 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, alkyl, carboxyl, and hydroxyl groups are more
preferred than the others; and phenyl-functional groups are most
preferred.
[0080] Besides petroleum-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% 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 atoms in their fatty chain, such as stearic acid,
propoxylated fatty alcohols; glycerides, acetoglycerides, and
ethoxylated glycerides of C.sub.12-C.sub.28 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.
[0081] 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 lotion composition comprises from
about 20 to about 80%, most preferably from about 40 to about 75%,
of the emollient.
[0082] 2. Immobilizing Agent
[0083] An especially key component of the lotion compositions of
the present invention is an agent capable of immobilizing the
emollient on the article topsheet to which the lotion composition
is applied. Because the emollient in the composition has a plastic
or fluid consistency at 20.degree. C., it tends to flow or migrate,
even when subjected to modest shear. When applied to a article
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 article.
[0084] This migration of the emollient into the interior of the
article can cause undesired effects on the absorbency of the
article 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 emollient has to be applied
to the article 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 article core.
[0085] The immobilizing agent counteracts this tendency of the
emollient to migrate or flow by keeping the emollient primarily
localized on the surface of the article 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 article
topsheet as well.
[0086] It is also advantageous to "lock" the immobilizing agent on
the surface of the article 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 article topsheet via blowers, fans, etc. can
speed up crystallization of the immobilizing agent.
[0087] 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.degree. 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.degree. C. Typically, the immobilizing agent will have a melting
point in the range of from about 50.degree. to about 150.degree.
C.
[0088] Suitable immobilizing agents for the present invention can
comprise a member selected from the group consisting of
C.sub.14-C.sub.22 fatty alcohols, C.sub.12-C.sub.22 fatty acids,
and C.sub.12-C.sub.22 fatty alcohol ethoxylates having an average
degree of ethoxylation ranging from 2 to about 30, and mixtures
thereof. Preferred immobilizing agents include C.sub.16-C.sub.18
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 C.sub.16-C.sub.18 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 C.sub.16-C.sub.18 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.
[0089] Importantly, these preferred immobilizing agents such as the
C.sub.16-C.sub.18 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 article
core.
[0090] 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 character.
Because of the possible skin sensitivity of those using article
topsheets to which the lotion composition is applied, these esters
and amides should also be relatively mild and non-irritating to the
skin.
[0091] Suitable polyhydroxy fatty acid esters for use in the
present invention will have the formula: 2
[0092] wherein R is a C.sub.5-C.sub.31 hydrocarbyl group,
preferably straight chain C.sub.7-C.sub.19 alkyl or alkenyl, more
preferably straight chain C.sub.9-C.sub.17 alkyl or alkenyl, most
preferably straight chain C.sub.11-C.sub.17 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 erythrose; sugar alcohols
such as erythritol, xylitol, malitol, mannitol and sorbitol; and
anhydrides of sugar alcohols such as sorbitan.
[0093] One class of suitable polyhydroxy fatty acid esters for use
in the present invention comprises certain sorbitan esters,
preferably the sorbitan esters of C.sub.16-C.sub.22 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 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 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.
[0094] Another class of suitable polyhydroxy fatty acid esters for
use in the present invention comprises certain glyceryl monoesters,
preferably glyceryl monoesters of C.sub.16-C.sub.22 saturated fatty
acids such as glyceryl monostearate, glyceryl monopalmitate, and
glyceryl monobehenate. Again, like the sorbitan 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.
[0095] Another class of suitable polyhydroxy fatty acid esters for
use in the present invention comprise certain sucrose fatty acid
esters, preferably the C.sub.12-C.sub.22 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.
[0096] Suitable polyhydroxy fatty acid amides for use in the
present invention will have the formula: 3
[0097] wherein R.sup.1 is H, C.sub.1-C.sub.4 hydrocarbyl,
2-hydroxyethyl, 2-hydroxypropyl, methoxyethyl, methoxypropyl or a
mixture thereof, preferably C.sub.1-C.sub.4 alkyl, methoxyethyl or
methoxypropyl, more preferably C.sub.1 or C.sub.2 alkyl or
methoxypropyl , most preferably C.sub.1 alkyl (i.e., methyl) or
methoxypropyl; and R.sup.2 is a C.sub.5-C.sub.31 hydrocarbyl group,
preferably straight chain C.sub.7-C.sub.19 alkyl or alkenyl, more
preferably straight chain C.sub.9-C.sub.17 alkyl or alkenyl, most
preferably straight chain C.sub.11-C.sub.17 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. Pat. No. 5,174, 927 (Honsa),
issued Dec. 29, 1992 (herein incorporated by reference) which
discloses these polyhydroxy fatty acid amides, as well as their
preparation.
[0098] The Z moiety preferably will be derived from a reducing
sugar in a reductive amination reaction; most preferably glycityl.
Suitable reducing sugars include glucose, fructose, maltose,
lactose, galactose, mannose, and xylose. High dextrose corn syrup,
high fructose corn syrup, and high maltose corn syrup can be
utilized, as well as the individual sugars listed above. These corn
syrups can yield mixtures of sugar components for the Z moiety.
[0099] The Z moiety preferably will be selected from the group
consisting of --CH.sub.2--(CHOH).sub.n--CH.sub.2OH,
--CH(CH.sub.2OH)--[(CHOH).sub.n-- 1]--CH.sub.2OH,
--CH.sub.2OH--CH.sub.2--(CHOH).sub.2(CHOR.sup.3)(CHOH)--CH-
.sub.2OH, where n is an integer from 3 to 5, and R.sup.3 is H or a
cyclic or aliphatic monosaccharide. Most preferred are the
glycityls where n is 4, particularly
--CH.sub.2--(CHOH).sub.4--CH.sub.2OH.
[0100] In the above formula, R.sup.1 can be, for example, N-methyl,
N-ethyl, N-propyl, N-isopropyl, N-butyl, N-2-hydroxyethyl,
N-methoxypropyl or N-2-hydroxypropyl. R.sup.2 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.
[0101] The most preferred polyhydroxy fatty acid amides have the
general formula: 4
[0102] wherein R.sup.1 is methyl or methoxypropyl; R.sup.2 is a
C.sub.11-C.sub.17 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.
[0103] As previously noted, some of the immobilizing agents require
an emulsifier 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
CH.sub.3(CH.sub.2).sub.17(OCH- .sub.2CH.sub.2).sub.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 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.
[0104] 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 carnauba, 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. P.O. Box 1098 West Babylon, N.Y. 11704.
[0105] 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%, most preferably from about 10 to about
40%, of the immobilizing agent.
[0106] 3. Optional Hydrophilic Surfactant
[0107] As mentioned above, it is highly desirable that the article
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 C.sub.16-C.sub.18 fatty alcohols having HLB
values below about 7 will require addition of hydrophilic
surfactant to improve weffability when the lotion composition is
applied to article topsheets. Similarly, a hydrophobic emollient
such as petrolatum will require the addition of a hydrophilic
surfactant.
[0108] 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.
[0109] Suitable nonionic surfactants may be substantially
nonmigratory after the lotion composition is applied to the article
topsheets 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 surfactants 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.degree. C. In this
regard, these nonionic surfactants will preferably have melting
points similar to those of the immobilizing agents previously
described.
[0110] Suitable nonionic surfactants for use in lotion compositions
of the present invention include alkylglycosides; alkylglycoside
ethers as described in U.S. Pat. No. 4,011,389 (Langdon, et at),
issued Mar. 8, 1977; alkylpolyethoxylated esters such as Pegosperse
1000MS (available from Lonza, Inc., Fair Lawn, N.J.), ethoxylated
sorbitan mono-, di- and/or tri-esters of C.sub.12-C.sub.18 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
C.sub.11-C.sub.15 linear alcohols with 9 moles of ethylene oxide),
marketed by Union Carbide Corporation; KYRO EOB (condensation
product of C.sub.13-C.sub.15 linear alcohols with 9 moles of
ethylene oxide), marketed by The Procter & Gamble Co., the
NEODOL brand name surfactants marketed by Shell Chemical Co., in
particular NEODOL 25-12 (condensation product of C.sub.12-C.sub.15
linear alcohols with 12 moles of ethylene oxide) and NEODOL 23-6.5T
(condensation product of C.sub.12-C.sub.13 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 C.sub.18 straight chain alcohol with 27
moles of ethylene oxide). (Certain of the hydrophilic surfactants,
in particular ethoxylated alcohols such as NEODOL 25-12, can also
function as alkyl ethoxylate emollients). Other examples of
preferred ethoxylated alcohol surfactants include ICI'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.
[0111] Another type of suitable surfactant for use in the present
invention includes Aerosol OT, a dioctyl ester of sodium
sulfosuccinic acid marketed by American Cyanamid Company.
[0112] 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%, by
weight of the lotion composition.
[0113] The amount of hydrophilic surfactant required to increase
the wettability of the lotion composition to a desired level will
depend upon the 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.
[0114] 4. Other Optional Components
[0115] 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.
[0116] C. Treating Article Topsheets With Lotion Composition
[0117] In preparing lotioncid products according to the present
invention, the lotion composition is applied to the outer surface
(i.e., body facing surface) of a article 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 article topsheet.
[0118] The manner of applying the lotion composition to the article
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 the
therapeutic and/or protective lotion benefits. Particularly
suitable application methods will apply the lotion composition
primarily to the outer surface of the article topsheet.
[0119] The minimum level of lotion to be applied to the article
topsheets is an amount effective for reducing the adherence of BM
to the skin and/or providing a skin benefit to the wearer. The
level of lotion applied will depend on various factors, including
the relative amount of surface area of the topsheet not treated
with lotion, the lotion composition and the like. In general, with
lotion compositions that are relatively hydrophobic and are to be
applied to essentially all of the topsheet, the lotion is
preferably applied to the article topsheet in an amount ranging
from about 0.1 mg/in.sup.2 to about 15 mg/in.sup.2. It will be
recognized that for lotions that are relatively hydrophilic, higher
add-on levels may be used without adversely impacting fluid
handling properties of the topsheet to an unacceptable degree.
Because the 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 and/or wettability properties.
[0120] The lotion composition may be applied to the entire surface
of the topsheet or portions thereof. In one embodiment, the lotion
composition is applied in a stripe aligned with and centered on the
longitudinal centerline of the disposable absorbent article. In
this embodiment, as described in the Examples hereinafter, the
lotion composition is preferably applied to a discrete version of
the topsheet, e.g., a 3.75 inch wide (article lateral direction)
and 7 inch long (article longitudinal direction) patch generally
disposed toward the second waist region.
[0121] As discussed, the lotion composition can also be applied
nonuniformly to the outer surface of the article topsheet. By
"nonuniform" it is meant that the amount, location, 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. In a preferred embodiment, the surface of
the topsheet will have regions where no lotion is applied,
particularly in areas of the topsheet that correspond to the crotch
region of the article. As used herein, the crotch region of the
article is the rectangle, defined below, that is centered
longitudinally and laterally about the article's crotch point. The
"crotch point" is determined by placing the article on a wearer in
a standing position and then placing an extensible filament around
the legs in a figure eight configuration. The point in the article
corresponding to the point of intersection of the filament is
deemed to be the crotch point of the article. It is understood that
the crotch point is determined by placing the absorbent article on
a wearer in the intended manner and determining where the crossed
filament would contact the article. The length of the crotch region
corresponds to 40% of the absorbent article's total length (i.e.,
in the y-dimension). The width of the crotch region is equivalent
to the width of the widest absorbent core component as measured at
the crotch point. (As used herein, "absorbent core" components are
those materials involved with acquiring, transporting, distributing
and/or storing body fluids. As such, the term absorbent core does
not include the topsheet or backsheet of the absorbent article.) By
way of illustration, for an article having a length of 20 in. and a
core width at the crotch point of 4 in., the crotch region is the
rectangle, centered on the crotch point, having a length of 8 in.
and a width of 4 in.
[0122] For certain lotion compositions (e.g., those that are
hydrophobic), these untreated regions further facilitate liquid
passage through the topsheet and into the absorbent core.
Surprisingly, while the topsheet is treated nonuniformly (e.g., the
topsheet has microscopic or macroscopic regions where no lotion is
applied), during wear of the article, lotion is transferred to the
wearer even in regions of the skin corresponding to non-lotion
regions of the topsheet. The amount and uniformity of lotion
transferred to the skin is believed to depend on several factors,
including, for example, contact of the wearer's skin to the
topsheet, friction created during wear time between the wearer's
skin and the treated topsheet, warmth generated from wearer to
enhance the transfer of the lotion, the lotion properties, lotion
composition, and the like.
[0123] Where the lotion is applied nonuniformly, any lotion pattern
may be utilized, including, for example, application of small
droplets (obtained via, e.g., spraying) discrete dots (obtained
via, e.g., gravure printing), stripes that run in the longitudinal
or lateral direction of the article, etc. In those embodiments
where the topsheet comprises discrete, untreated regions, the
percent open area of the region of the topsheet that corresponds to
the crotch region of the article can vary widely. (As referred to
herein, the "percent open area" of the topsheet is determined by
(i) measuring the surface area of the topsheet that overlies the
crotch region, (ii) measuring the total surface area of the
untreated region(s) in this portion of the topsheet and (iii)
dividing the measurement in (ii) by the measurement in (i). As used
herein, "untreated" means a region of the topsheet having less than
about 0.07 mg/in.sup.2. In this regard, the percent open area may
be from about 1% to about 99%, from about 5% to about 95%, from
about 10% to about 90%, from about 15% to about 85%, from about 20%
to about 80%, from about 25% to about 75%, from about 30% to about
70%, or from about 35% to about 65%. The percent open area required
to achieve the desired lotion effect and the desired fluid handling
properties of the topsheet will be dictated largely by the
characteristics of the lotion (in particular the lotion's
composition and its relative hydrophilicity/hydrophilicy
properties).
[0124] In general, with lotion compositions that are relatively
hydrophobic and are to be applied such that regions of the topsheet
are not coated with lotion, the lotion is preferably applied to the
article topsheet in an amount ranging from about 0.1 mg/in.sup.2 to
about 35 mg/in.sup.2. It will be recognized that for lotions that
are relatively hydrophilic, higher add-on levels may be used
without adversely impacting fluid handling properties of the
topsheet to an unacceptable degree. Of course, for articles having
relatively high percent open areas in the crotch, greater add-on
levels may be obtainable without adversely affecting fluid handling
by the topsheet.
[0125] In one preferred embodiment, the topsheet comprises stripes
of lotion that run in the article's longitudinal direction. These
longitudinal stripes of lotion are separated by longitudinal
stripes where little or no lotion is applied to the topsheet. In
these embodiments, each lotion stripe will typically have a width
of from about 0.1 in. to about 0.75 in., more typically from about
about 0.1 in. to about 0.5 in., and the width of the stripes
containing no lotion will typically be from about 0.1 in. to about
1 in., more typically from about 0.15 to about 0.5 in.
[0126] The lotion composition can be applied to the topsheet at any
point 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.
[0127] The lotion composition is typically applied from a melt
thereof to the article 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.degree. to about 100.degree. C., preferably from 40.degree. to
about 90.degree. C., prior to being applied to the article
topsheet. Once the melted lotion composition has been applied to
the article 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.
[0128] In applying lotion compositions of the present invention to
article topsheets, spraying, gravure coating and extrusion coating
methods are preferred. FIG. 1 illustrates one such preferred method
involving spraying of the coating on the article topsheet before
the topsheet is assembled with the other raw materials into a
finished product. Referring to FIG. 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.degree. 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).
[0129] FIG. 2 illustrates an alternative preferred method involving
continuous or intermittent spraying of the lotion composition on to
a article topsheet during the converting operation. Referring to
FIG. 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 article 5 to spray station 6
where topsheet patch 7 is sprayed with a hot, molten (e.g.,
65.degree. C.) lotion composition. After leaving spray station 6,
nonlotioned article 5 becomes lotioned article 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; and/or (2) the speed
at which conveyor belt 1 travels under spray station 6.
SPECIFIC ILLUSTRATIONS OF THE PREPARATION OF LOTIONED ARTICLE
TOPSHEETS ACCORDING TO THE PRESENT INVENTION
[0130] The following are specific illustrations of treating article
topsheets with lotion compositions in accordance with the present
invention:
EXAMPLE 1
[0131] A. Preparation of Lotion Compositions
[0132] 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 C.sub.16-C.sub.18 primary alcohol
made by the Procter & Gamble Company under the name TA-1618);
Steareth-2 (Brij 72, a C.sub.18 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:
2 TABLE I Component Weight % Mineral Oil 50 Cetearyl Alcohol 35
Steareth-2 15
[0133] B. Preparation of Lotioned Article Topsheet by Hot Melt
Spraying
[0134] Lotion Composition A is placed into a heated tank operating
at a temperature of 170.degree. F. The composition is subsequently
applied with a contact applicator (using, for example, a Meltex
EP45 hot melt adhesive applicator head having 5 slots and operating
at a temperature of 170.degree. F.) onto the topsheet of an article
in a striped pattern where the stripes run in the article's
longitudinal direction. Specifically, 5 stripes are applied, each
stripe measuring 0.25 in. wide (i.e., in the articles lateral
direction) and 11.75 in. long at an add-on level=0.0077 g/in.sup.2
(12 g/m.sup.2). The distance between the stripes is 0.31 in.
EXAMPLE 2
[0135] The lotion composition A (prepared in accordance with the
procedure in Example I) is subsequently sprayed onto the topsheet
of a article in a 3.75 inch wide (article lateral direction) stripe
centered on the longitudinal centerline and extending the entire
length of the product. Add-on level=0.006 g/in.sup.2 (9.3
g/m.sup.2).
EXAMPLE 3
[0136] The lotion composition A (prepared in accordance with the
procedure in Example I) is subsequently sprayed onto the topsheet
of a article in a 3.75 inch wide (article lateral direction) stripe
centered on the longitudinal centerline and 7 inch long (article
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 g/in.sup.2 (4.65 g/m.sup.2).
EXAMPLE 4
[0137] A. Preparation of Lotion Compositions
[0138] 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 C.sub.16-C.sub.18 primary alcohol
made by the Procter & Gamble Company under the name TA-1618).
The weight percentages of these components are shown in Table II
below:
3 TABLE II Component Weight % Mineral Oil 65 Cetearyl Alcohol
35
[0139] B. Preparation of Lotioned Tissue by Hot Melt Spraying
[0140] Lotion Composition B is placed into a heated tank operating
at a temperature of 125.degree. F. The composition is subsequently
sprayed (using a Dynatec E84B1758 spray head, operating at a
temperature of 165.degree. F. and an atomization pressure of 2.40
psig) onto the topsheet of a article in a 3.75 inch wide (article
lateral direction) and 7 inch long (article 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
g/in.sup.2 (9.3 g/m.sup.2).
EXAMPLE 5
[0141] A. Preparation of Lotion Composition
[0142] A water free lotion composition (Lotion C) is made by mixing
the following melted (i.e., liquid) components together: White
Protopet.RTM. 1S (white petrolatum made by Witco Corp.), Cetearyl
Alcohol (a mixed linear C.sub.16-C.sub.18 primary alcohol made by
the Procter & Gamble Company under the name TA-1618);
Steareth-2 (Brij 762, a C.sub.18 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:
[0143] 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:
4 TABLE III Component Weight % WhiteProtopet .RTM. 50 1S Cetearyl
Alcohol 35 Steareth-2 15
[0144] B. Preparation of Lotioned Tissue by Hot Melt Spraying
[0145] Lotion Composition C is placed into a heated tank operating
at a temperature of 125.degree. F. The composition is subsequently
sprayed (using a Dynatec E84B 1758 spray head, operating at a
temperature of 165.degree. F. and an atomization pressure of 2.40
psig) onto the topsheet of a article in a 3.75 inch wide (article
lateral direction) and 7 inch long (article 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
g/in.sup.2 (9.3 g/m.sup.2).
EXAMPLE 6
[0146] A. Preparation of Lotion Composition
[0147] A water free lotion composition (Lotion D) is made by mixing
the following melted (i.e., liquid) components together: White
Protopet.RTM. 1S (white petrolatum made by Witco Corp.); Dow
Corning 556 Cosmetic Grade Fluid(a polyphenylmethylsiloxane made by
the Dow Corning Corporation), An example of a particularly
preferred paraffin wax is Parrafin S.P. 434 (a paraffin wax made by
Strahl and Pitsch Inc.); Cetearyl Alcohol (a mixed linear
C.sub.16-C.sub.18 primary alcohol made by the Procter & 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:
5 TABLE IV Component Weight % WhiteProtopet .RTM. 52 1S
Polyphenylmethyl- 20 siloxane Paraffin Wax 15 Cetearyl Alcohol 10
PEG 2000 3
[0148] B. Preparation of Lotioned Tissue by Hot Melt Spraying
[0149] Lotion Composition D is placed into a heated tank operating
at a temperature of 150.degree. F. The composition is subsequently
sprayed (using a Dynatec E84B1758 spray head, operating at a
temperature of 170.degree. F. and an atomization pressure of 2.40
psig) onto the topsheet of a article in a 3.75 inch wide (article
lateral direction) and 7 inch long (article 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
g/in.sup.2 (9.3 g/m.sup.2).
* * * * *