U.S. patent application number 08/869897 was filed with the patent office on 2002-07-25 for emollient-treated absorbent interlabial application.
Invention is credited to KLOFTA, THOMAS JAMES, OSBORN III, THOMAS WARD.
Application Number | 20020099350 08/869897 |
Document ID | / |
Family ID | 27542110 |
Filed Date | 2002-07-25 |
United States Patent
Application |
20020099350 |
Kind Code |
A1 |
OSBORN III, THOMAS WARD ; et
al. |
July 25, 2002 |
EMOLLIENT-TREATED ABSORBENT INTERLABIAL APPLICATION
Abstract
Absorbent devices, and more particularly absorbent devices that
are worn interlabially by female wearers for catamenial purposes,
incontinence protection, or both, that have a emollient composition
on their body-contacting surface are disclosed. The interlabial
device has a body-contacting surface that is pre-moistened or
pre-treated with an emollient to prevent drying of the wearer's
labial tissue and to reduce friction of the structure against the
wearer's labial tissue. The absorbent device is preferably capable
of maintaining contact with the inside surfaces of the wearer's
labia majora when worn. The emollient composition comprises a
plastic or fluid emollient such as mineral oil, petrolatum and/or
polysiloxane, an immobilizing agent such as a fatty alcohol or wax
to immobilize the emollient on the body-contacting surface of the
device, and optionally a hydrophilic surfactant to improve
wettability of the coated surface. Because the emollient is
substantially immobilized on the surface of the absorbent device,
less emollient is required to impart the desired therapeutic or
protective emollient coating benefits.
Inventors: |
OSBORN III, THOMAS WARD;
(CINCINNATI, OH) ; KLOFTA, THOMAS JAMES;
(CINCINATTI, OH) |
Correspondence
Address: |
THE PROCTER & GAMBLE COMPANY
PATENT DIVISION
IVORYDALE TECHNICAL CENTER - BOX 474
5299 SPRING GROVE AVENUE
CINCINNATI
OH
45217
US
|
Family ID: |
27542110 |
Appl. No.: |
08/869897 |
Filed: |
June 5, 1997 |
Current U.S.
Class: |
604/385.17 ;
604/363 |
Current CPC
Class: |
A61F 13/47209 20130101;
A61F 13/82 20130101; A61L 15/34 20130101; A61L 15/20 20130101; A61L
15/48 20130101; A61F 13/15211 20130101; A61L 15/26 20130101 |
Class at
Publication: |
604/385.17 ;
604/363 |
International
Class: |
A61F 013/15; A61F
013/20 |
Claims
What is claimed is:
1. An absorbent interlabial device for wearing in the interlabial
space of a female wearer, said interlabial device having a
body-contacting surface at least a portion of which is capable of
maintaining contact with the inside surfaces of the wearer's labia
when the absorbent device is worn, and an absorbent portion,
wherein at least a portion of said body-contacting surface
comprises an emollient composition, said emollient composition
comprising a substantially water-free emollient, said emollient
composition being free of hydrocarbon components having a molecular
weight greater than or equal to 1,500, wherein at least a portion
of said emollient composition remains on said body-contacting
surface without being absorbed into said interlabial device.
2. The absorbent device of claim 1 wherein said emollient begins to
soften at or below human body temperature.
3. The absorbent interlabial device of claim 1 wherein said
emollient has a plastic or liquid consistency at 20.degree. C.
4. An absorbent interlabial device for wearing in the interlabial
space of a female wearer said interlabial device having a
body-contacting surface at least a portion of which is capable of
maintaining contact with the inside surfaces of the wearer's labia
when said device is worn, and an absorbent portion, wherein at
least a portion of said body-contacting surface comprises an
emollient composition which is liquid, semisolid, or solid at
20.degree. C., wherein said emollient composition comprises a
substantially water free emollient having a plastic or liquid
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
5. The absorbent device of claim 4 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
6. The absorbent device of claim 4 wherein said emollient
composition comprises: (i) from about 10 to about 95% of a
substantially water free emollient having a plastic or liquid
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, and (ii) from about 5 to about 90% of an agent capable of
immobilizing said emollient on said body-contacting surface, said
immobilizing agent having a melting point of at least about
35.degree. C.
7. The absorbent device of claim 6 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
8. The absorbent device of claim 7 wherein said emollient is
petrolatum.
9. The absorbent device of claim 7 wherein said emollient is
mineral oil.
10. The absorbent device of claim 6 wherein said immobilizing agent
is selected from the group consisting of polyhydroxy fatty acid
esters, polyhydroxy fatty acid amides, C.sub.14-C.sub.22 fatty
alcohols, C.sub.12-C.sub.22 fatty acids, C.sub.12-C.sub.22 fatty
alcohol ethoxylates, waxes, and mixtures thereof.
11. The absorbent device of claim 4 wherein the quantity of
emollient composition on said body contacting portion of said
absorbent device ranges from about 0.1 mg/cm.sup.2 to about 30
mg/cm.sup.2.
12. The absorbent device of claim 11 wherein the quantity of
emollient composition on said body contacting portion of said
absorbent device ranges from about 1 mg/cm.sup.2 to 15
mg/cm.sup.2.
13. The absorbent device of claim 6 wherein said emollient
composition 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.
14. The absorbent device of claim 13 wherein said immobilizing
agent comprises a C.sub.14-C.sub.22 fatty alcohol.
15. The absorbent device of claim 14 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.
16. The absorbent device of claim 6 wherein said immobilizing agent
comprises a paraffin or microcrystalline wax.
17. The absorbent device of claim 4 wherein said emollient
composition further comprises from about 1 to about 50% of a
hydrophilic surfactant, said hydrophilic surfactant having an HLB
value of at least about 4.
18. The absorbent device of claim 6 wherein said emollient
composition further comprises from about 1 to about 50% of a
hydrophilic surfactant, said hydrophilic surfactant having an HLB
value of at least about 4.
19. The absorbent device of claim 18 wherein said emollient
composition further comprises from about 1 to about 25% of said
hydrophilic surfactant, said hydrophilic surfactant being nonionic
and having an HLB value of from about 4 to about 20.
20. The absorbent device of claim 19 wherein said hydrophilic
surfactant comprises an ethoxylated alcohol having an alkyl chain
of from about 8 to about 22 carbon atoms and having an average
degree of ethoxylation ranging from about 1 to about 54.
21. The absorbent device of claim 20 wherein said ethoxylated
alcohol has an alkyl chain of from about 11 to about 22 carbon
atoms and having an average degree of ethoxylation ranging from
about 2 to about 30.
22. An absorbent interlabial device insertable into the interlabial
space of a female wearer said interlabial device having a
body-contacting surface at least a portion of which is capable of
maintaining contact with the inside surfaces of the wearer's labia
when the device is worn, said interlabial device comprising: a main
absorbent portion comprising an upper portion comprising part of
said body-contacting surface and a lower portion, said upper
portion facing toward the vestibule floor of said wearer during
insertion into said interlabial space and leading said lower
portion during insertion therein, said lower portion being opposed
to said upper portion and upon insertion of said absorbent device
into said interlabial space said lower portion facing away from the
floor of the vestibule of said wearer; and a pair of flexible
extensions joined to said upper portion of said main absorbent
portion and extending downwardly and outwardly therefrom, said
flexible extensions comprising part of said body-contacting
surface, wherein at least a portion of said body-contacting surface
comprises an effective amount of a emollient composition which is
semi-solid or solid at 20.degree. C. and which is partially
transferable to the wearer's skin, said emollient composition
comprising a substantially water free emollient having a plastic or
liquid 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
23. The absorbent device of claim 22 wherein said portion of said
body-contacting surface that comprises said emollient composition
is said upper portion of said main absorbent portion.
24. The absorbent device of claim 22 wherein said portion of said
body-contacting surface that comprises said flexible extensions is
said upper portion of said main absorbent portion.
25. The absorbent device of claim 22 wherein both said upper
portion of said main absorbent portion and said flexible extensions
comprise said emollient composition.
26. An absorbent interlabial device which fits at least partially
within a female wearer's labial vestibule, said interlabial device
having a body-contacting surface, wherein at least a portion of
said absorbent device is capable of maintaining contact with the
inside surfaces of the wearer's labia when said device is worn, and
an absorbent portion, wherein at least a portion of said
body-contacting surface comprises an effective amount of a
emollient composition which is semi-solid or solid at 20.degree.
C., said emollient composition comprising a substantially water
free emollient having a plastic or liquid 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 said absorbent interlabial device has a
capacity of greater than or equal to about 2.5 grams of saline when
said device is measured under 0.25 psi of pressure.
27. The absorbent device of claim 26 having a capacity greater than
or equal to about 4.0 grams of saline.
28. The absorbent device of claim 27 further comprising a non-ionic
surfactant thereon.
29. An absorbent interlabial device according to claim 1 that is
sufficiently flushable that it completely clears the bowl under the
Flushability Test at least about 70% of the time in two or fewer
flushes.
30. An absorbent interlabial device according to claim 1 that is
sufficiently flushable that it completely clears the bowl under the
Flushability Test at least about 95% of the time in one flush.
31. An absorbent interlabial device according to claim 1 which
disperses into at least two fragments as measured by the Water
Dispersion Test in less than or equal to about one hour.
32. An absorbent interlabial device according to claim I wherein
said emollient coating comprises a multi-component emollient
composition having at least one component with a peak heat
absorption of less than 37.degree. C.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an absorbent device that is
worn interlabially for catamenial purposes, incontinence
protection, or both. More particularly, the present invention
relates to an interlabial device that is pre-moistened or
pre-treated with an emollient for improved comfort.
BACKGROUND OF THE INVENTION
[0002] All manner and variety of absorbent articles configured for
the absorption of body fluids such as menses, urine and feces are,
of course, well known. With respect to feminine protection devices,
the art has offered two basic types; sanitary napkins have been
developed for external wear about the pudendal region while tampons
have been developed for internal wear within the vaginal cavity for
interruption of menstrual flow therefrom. Such tampon devices are
disclosed in U.S. Pat. No. 4,412,833, entitled "Tampon Applicator",
issued to Weigner, et al. on Nov. 1, 1983, and U.S. Pat. No.
4,413,986, entitled "Tampon Assembly With Means For Sterile
Insertion", issued to Jacobs on Nov. 8, 1983.
[0003] Hybrid devices which attempt to merge the structural
features of the sanitary napkins and the tampons into a single
device have also been proposed. Such hybrid devices are disclosed
in U.S. Pat. No. 2,092,346, entitled "Catamenial Pad", issued to
Arone on Sep. 7, 1937, and U.S. Pat. No. 3,905,372, entitled
"Feminine Hygiene Protective Shield", issued to Denkinger on Sep.
16, 1975. Other less intrusive hybrid devices are known as labial
or interlabial sanitary napkins and are characterized by having a
portion which at least partially resides within the wearer's
vestibule and a portion which at least partially resides external
of the wearer's vestibule. Such devices are disclosed in U.S. Pat.
No. 2,662,527, entitled "Sanitary Pad", issued to Jacks on Dec. 15,
1953, and U.S. Pat. No. 4,631,062, entitled "Labial Sanitary Pad",
issued to Lassen, et al. on Dec. 23, 1986.
[0004] Interlabial pads have the potential to provide even greater
freedom from inconvenience because of their small size and reduced
risk of leakage. Numerous attempts have been made in the past to
produce an interlabial pad which would combine the best features of
tampons and sanitary napkins while avoiding at least some of the
disadvantages associated with each of these types of devices.
Examples of such devices are described in U.S. Pat. No. 2,917,049
issued to Delaney on Dec. 15, 1959, U.S. Pat. No. 3,420,235 issued
to Harmon on Jan. 7, 1969, U.S. Pat. No. 4,595,392 issued to
Johnson, et al. on Jun. 17, 1986, and U.S. Pat. No. 5,484,429
issued to Vukos, et al. on Jan. 16, 1996. A commercially available
interlabial device is FRESH 'N FIT.RTM. PADETTE interlabial product
which is marketed by Athena Medical Corp. of Portland, Oreg. and
described in U.S. Pat. Nos. 3,983,873 and 4,175,561 issued to
Hirschman on Oct. 5, 1976 and Nov. 27, 1979, respectively.
[0005] However, many of these devices have not met with great
commercial success. There are drawbacks associated with all of the
above products. The devices described in these patents are believed
to potentially be uncomfortable to wear due to frictional
discomfort associated with rubbing of the product against the
labial walls and sticking of the surfaces of the device to the
labial walls. Furthermore, the frictional drag and sticking of the
body-contacting surface of such devices against the labia can
prevent these devices from being properly inserted, leading to
discomfort.
[0006] The problem of drying of a female wearer's labial vestibule
area has been discussed in the patent literature. For example, U.S.
Pat. No. 4,846,824 issued to Lassen, et al. on Jul. 11, 1989, is
directed to a labial sanitary pad that has a "physiologically
hydrous" cover (that is, a cover material supposedly designed to
"maintain a moist interface between the tissues of the vestibule
and the pad"). Types of cover materials specified in the Lassen, et
al. patent include a spunlaced polyester fiber nonwoven and a rayon
cover. The Lassen, et al. patent states that the covers can be
provided with various "coatings" to maintain the physiologically
hydrous feature, but no specific coatings appear to be
disclosed.
[0007] European Patent Application EP 0 692 263 A2, "Method of
reducing the coefficient of friction of absorbent products and wax
coated products produced thereby", is directed to lubricated
absorbent products having a coating of a small amount of high
molecular weight solid waxy substance which has a softening point
above body temperature. However, there are drawbacks associated
with the use of high molecular weight materials for this purpose.
High molecular weight materials will not be as soothing or
lotion-like to the wearer's skin as lower molecular weight
materials. In addition, high molecular weight materials will not be
capable of transferring to the wearer's skin to provide skin care
benefits. High molecular weight waxes can also become brittle and
tend to flake or chip off an absorbent article due to their lack of
flexibility if the absorbent article is of a type that is required
to flex and bend. Further, if the softening point of such materials
is higher than room temperature, application of such materials to
an absorbent article will be more difficult, and will require that
the material be heated in order to coat an absorbent article with
such a material.
[0008] A vaginal moisture balanced tampon and process is disclosed
in European Patent Application 0 685 215 A1. However, the
interlabial device of the present invention is not intended to be
worn inter-vaginally as a tampon.
[0009] Thus, a need exists for an interlabial device that is small
in size and that can be easily inserted and that provides
protection against incontinence, menstrual discharges, and
discharges of bodily exudates throughout a great range of wearer
motions. A need exists for an interlabial device which is
absorbent, has a reduction in frictional discomfort associated with
rubbing of the product against the labial walls and sticking of the
surfaces of the device to the labial walls. A need also exists for
an interlabial device that has a reduced tendency to dry the inside
surface of the wearer's labia.
[0010] Therefore, it is an object of the present invention to
provide an interlabial device that is small in size and that can be
easily inserted and that provides protection against incontinence,
menstrual discharges, and discharges of bodily exudates throughout
a great range of wearer motions.
[0011] It is another object of the present invention to provide an
interlabial device which is absorbent, but has a reduction in
frictional discomfort associated with rubbing of the product
against the labial walls and sticking of the surfaces of the device
to the labial walls.
[0012] It is another object of the present invention to provide an
interlabial device that has a reduced tendency to dry the inside
surface of the wearer's labia.
[0013] It is still another object of the present invention to
provide an interlabial device that can be inserted into the space
between the wearer's labia with less friction so that it will more
easily be fully inserted into the desired wearing position.
[0014] These and other objects of the present invention will become
more readily apparent when considered in reference to the following
description and when taken in conjunction with the accompanying
drawings.
SUMMARY OF THE INVENTION
[0015] This invention relates to absorbent devices, and more
particularly to an absorbent device that is insertable into the
interlabial space of a female wearer for catamenial purposes,
incontinence protection, or both. The interlabial device has a
body-contacting surface (in particular, a surface contacting the
labial vestibule) which is pre-treated with an emollient to prevent
drying of the wearer's labial tissue and to reduce friction of the
structure against the wearer's labial tissue.
[0016] The absorbent interlabial device of the present invention,
in one preferred embodiment, comprises a main absorbent portion and
a pair of flexible extensions joined to the main absorbent portion.
The main absorbent portion preferably comprises an upper portion
and a lower portion opposed to the lower portion. The upper portion
faces toward the vestibule floor of the wearer during insertion of
the absorbent device into the wearer's interlabial space and during
use. That is, the upper portion is positioned furthest inward into
the space between the wearer's labia thus leading the lower portion
of the absorbent device during insertion. Upon insertion, the lower
portion is less fully inserted into the wearer's interlabial space
than the upper portion and the lower portion faces away from the
floor of the vestibule of the wearer. The flexible extensions
preferably extend downwardly and outwardly from the upper portion
of the main absorbent portion and are joined to the same. The
flexible extensions are preferably capable of maintaining contact
with inside surfaces of the wearer's labia and covering a
substantial portion of the same.
[0017] At least a portion of said body-contacting surface of the
interlabial device comprises an effective amount of an emollient
coating which is preferably semisolid or solid at ambient
temperature, 68.degree. F. (or 20.degree. C.). The coating
preferably comprises 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/or polysiloxane emollients, and mixtures thereof In
a preferred embodiment, the 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
In an alternate preferred embodiment, the emollient emollient
contains about 5% or less water and comprises a polysiloxane
emollient.
[0018] The emollient-treated interlabial device provides a
reduction in frictional discomfort associated with rubbing of the
product against the labial walls and sticking of the surfaces of
the device to the labial walls. The emollient-treated interlabial
device also has a reduced tendency to dry the inside surface of the
wearer's labia. The interlabial device, because of the presence of
the emollient, can be inserted into the space between the wearer's
labia with less friction so that it will more easily be fully
inserted into the desired wearing position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] While the specification concludes with claims particularly
pointing out and distinctly claiming the subject matter which is
regarded as forming the present invention, it is believed that the
invention will be better understood from the following description
taken in conjunction with the accompanying drawings, in which:
[0020] FIG. 1 is a perspective view of a preferred embodiment of
the absorbent interlabial device of the present invention.
[0021] FIG. 2 is an end view of the absorbent device shown in FIG.
1.
[0022] FIG. 3 is an end view of a variation of the preferred
embodiment shown in FIG. 2.
[0023] FIG. 4 is an end view of an alternative preferred embodiment
of the present invention having a pleated main absorbent
portion.
[0024] FIG. 5 is an end view of an alternative preferred embodiment
of the present invention showing a main absorbent portion having a
multiple layer structure.
[0025] FIG. 6 is a cross-sectional view of a wearer's body
surrounding and including the wearer's labia majora and labia
minora showing how a prior art interlabial device might fit in the
space between the wearer's labia when the wearer is standing.
[0026] FIG. 7 is a cross-sectional view of the same region of the
wearer's body shown in FIG. 6 showing how the prior art device
might fit when the wearer squats.
[0027] FIG. 8 is a cross-sectional view of the same region of the
wearer's body shown in FIG. 7 showing the flexible extensions of
the present invention covering the wearer's fingertips as the
absorbent device of the present invention is inserted into the
wearer's interlabial space.
[0028] FIG. 9 is a cross-sectional view of the same region of the
wearer's body shown in FIG. 6 showing how the absorbent interlabial
device of the present invention fits when the wearer is
standing.
[0029] FIG. 10 is a cross-sectional view of the same region of the
wearer's body shown in FIG. 7 which shows how the absorbent
interlabial device of the present invention fits when the wearer
squats.
[0030] FIG. 11 is a sectional view of the wearer's body showing how
a hypothetical prior art interlabial device that is not treated
with an emollient may fit.
[0031] FIG. 12 is a sectional view of the wearer's body showing how
the emollient-treated interlabial device of the present invention
may fit.
[0032] FIG. 13 is a schematic perspective view of the Three Point
Bend Test apparatus.
[0033] FIG. 14 is a plan view of an apparatus suitable for
flushability determination according to the method described in the
TEST METHODS section below.
[0034] FIG. 15 is a cross-section of the flushability apparatus of
FIG. 14 taken along line 15-15 thereof
DETAILED DESCRIPTION OF THE INVENTION
[0035] A. The Absorbent Device.
[0036] The present invention is directed to an interlabial
absorbent article (or "absorbent interlabial structure" or
"absorbent interlabial device") which has a body-contacting surface
that is pre-lubricated to prevent drying of the wearer's labial
tissue and to reduce friction of the structure against the wearer's
labial tissue. FIGS. 1-3 show one preferred embodiment of the
interlabial absorbent structure of the present invention,
interlabial device 20. The present invention, however, can be in
many other forms, and is not limited to a structure having the
particular configuration shown in the drawings.
[0037] As used herein the term "absorbent interlabial device"
refers to a structure which has at least some absorbent components,
and is specifically configured to reside at least partially within
the interlabial space of a female wearer during use. Preferably,
more than one-third, more preferably more than half of the entire
absorbent interlabial device 20 of the present invention resides
within such interlabial space, more preferably still substantially
the entire absorbent interlabial device 20 resides within such
interlabial space, and most preferably the entire absorbent
interlabial device 20 resides within such interlabial space of a
female wearer during use.
[0038] As used herein, the term "interlabial space" refers to that
space in the pudendal region of the female anatomy which is located
between the inside surfaces of the labia majora extending into the
vestibule. Located within this interlabial space are the labia
minor, the vestibule and the principal urogenital members including
the clitoris, the orifice of the urethra, and the orifice of the
vagina. Standard medical authorities teach that the vestibule
refers to the space bounded laterally by the inside surfaces of the
labia minora and extending interiorly to the floor between the
clitoris and the orifice of the vagina. Therefore, it will be
recognized that the interlabial space as defined above may refer to
the space between the inside surfaces of the labia majora,
including the space between the inside surfaces of the labia minora
also known as the vestibule. The interlabial space for purposes of
the present description does not extend substantially beyond the
orifice of the vagina into the vaginal interior.
[0039] The term "labia" as used herein refers generally to both the
labia majora and labia minora. The labia terminate anteriorly and
posteriorly at the anterior commissure and the posterior
commissure, respectively. It will be recognized by those skilled in
the art that there is a wide range of variation among women with
respect to the relative size and shape of labia majora and labial
minora. For purposes of the present description, however, such
differences need not be specifically addressed. It will be
recognized that the disposition of the absorbent interlabial device
into the interlabial space of a wearer as defined above will
require placement between the inside surfaces of the labia majora
without regard to the precise location of the boundary between the
labia majora and the labia minora for a particular wearer. For a
more detailed description of this portion of the female anatomy,
attention is directed to Gray's Anatomy, Running Press 1901 Ed.
(1974), at 1025-1027.
[0040] The absorbent interlabial device 20 shown in FIG. 1 has a
longitudinal centerline L which runs along the "x" axis shown in
FIG. 1. The term "longitudinal", as used herein, refers to a line,
axis or direction in the plane of the interlabial device 20 that is
generally aligned with (e.g., approximately parallel to) a vertical
plane which bisects a standing wearer into left and right body
halves when the interlabial device 20 is worn. The terms
"transverse," "lateral," or "y direction" as used herein, are
interchangeable, and refer to a line axis or direction that is
generally perpendicular to the longitudinal direction. The lateral
direction is shown in FIG. 1 as the "y" direction. The "z"
direction, shown in FIG. 1, is a direction parallel to the vertical
plane described above. The term "upper" refers to an orientation in
the z-direction toward the wearer's head. "Lower" or downwardly is
toward the wearer's feet.
[0041] As shown in FIG. 1, the interlabial device 20 comprises a
main absorbent portion (or "central absorbent") 22, and a pair of
flexible extensions 24 joined to the main absorbent portion 22. The
main absorbent portion 22 should be at least partially absorbent.
The main absorbent portion 22 may comprise non-absorbent portions,
such as a liquid impervious barrier to prevent absorbed exudates
from leaking out of the main absorbent portion 22. The main
absorbent portion 22 comprises an upper portion 26 and a lower
portion 28 that is opposed to the upper portion. The flexible
extensions 24 are joined to the upper portion 26 of the main
absorbent portion. In use, the upper portion 26 is positioned
furthest inward into the wearer's interlabial space. The
interlabial device has a body-facing (or "body-contacting") surface
20A and a back surface 20B. The body-facing surface 20A can be
comprised of at least a portion of the absorbent portion 22, at
least a portion of the flexible extensions 24, or at least a
portion of both.
[0042] The interlabial device 20 should be of a suitable size and
shape that allows at least a portion thereof to fit comfortably
within the wearer's interlabial space and to cover the wearer's
vaginal orifice, and preferably also the wearer's urethra. The
interlabial device 20 at least partially blocks, and more
preferably completely blocks and intercepts the flow of menses,
urine, and other bodily exudates from the wearer's vaginal orifice
and urethra.
[0043] The size of the interlabial device 20 is also important to
the comfort associated with wearing the device. In the preferred
embodiment shown in FIG. 1, the main absorbent portion 22 of the
interlabial device 20 has a length as measured along the
longitudinal centerline, L, of between about 35 mm and about 100
mm. Preferably, the length of the interlabial device 20 is between
about 45 mm and about 55 mm, and more preferably, is about 49 mm.
The caliper (or width) of the main absorbent portion 22 of the
interlabial device as measured in the transverse direction (or
"y"-direction) is preferably less than or equal to about 8 mm, more
preferably the caliper is between about 3 mm and about 6 mm, most
preferably, the caliper is about 4.5 mm. Caliper measurements given
herein were measured using an AMES gage with a 0.25 psi (gauge)
load and a 0.96 inch diameter foot. Those skilled in the art will
recognize that if a 0.96 inch diameter foot is not appropriate for
a particular sample size, the foot size may be varied while the
load on the gauge is accordingly varied to maintain a confining
pressure of 0.25 psi (gauge). The height (or "z"-direction
dimension) of the main absorbent portion 22 is preferably between
about 8 mm and about 35 mm, and more preferably is about 20 mm.
[0044] The interlabial device 20 is preferably provided with
sufficient absorbency to absorb and retain the exudates discharged
from the wearer's body. The capacity of the product, however, is
dependent at least partially upon the physical volume of the
absorbent interlabial device 20, particularly the main absorbent
portion 22 thereof The main absorbent portion 22 preferably has a
capacity of at least about 1 g of 0.9% by weight saline solution,
and may have a capacity of up to about 30 g by using absorbent gels
or foams that expand when wet. Capacities may typically range from
about 2 to about 20 grams, for saline. In particularly preferred
embodiments, the interlabial device has a capacity of greater than
or equal to about 2.5 grams of saline, and more preferably greater
than or equal to about 4 grams of saline. Those skilled in the art
will recognize that the capacity for absorption of body exudates
such as menses will typically be smaller than the capacities given
above for absorption of saline. A method for measuring absorbent
capacity is described in the Test Methods section, below. Since the
interlabial space can expand, larger volumes can be stored in the
interlabial space, if the fluid is stored as a gel, which adjusts
to the body pressures. Additionally, if the absorbent interlabial
device 20 does not reside completely within the wearer's
interlabial space, some of the absorbed exudates may be stored
externally to the wearer's interlabial space.
[0045] The main absorbent portion 22 of the preferred embodiment
shown in FIGS. 1-3 may comprise any suitable type of absorbent
structure that is capable of absorbing and/or retaining liquids
(e.g. menses and/or urine). The main absorbent portion 22 may be
manufactured in a wide variety of shapes. Non-limiting examples
include ovoid, trapezoidal, rectangular, triangular, cylindrical,
hemispherical or any combination of the above. The main absorbent
portion 22 may, likewise, be manufactured and from 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 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. Preferred absorbent materials
comprise folded tissues, woven materials, nonwoven webs, needle
punched rayon, and layers or pieces of foam. The main absorbent
portion 22 may comprise a single material or a combination of
materials, such as a wrapping layer surrounding a central wadding
comprised of a different absorbent material.
[0046] In the preferred embodiment shown in FIG. 1, the main
absorbent portion 22 is formed of a soft absorbent material such as
rayon fibers or other suitable natural or synthetic fibers or
sheeting. The main absorbent portion 22 shown in FIG. 1 is
generally of an ovoid cross sectional shape as shown in FIG. 2. The
main absorbent portion 22 of the embodiment shown in FIGS. 1 and 2
comprises an upper portion 26 with a larger transverse sectional
dimension relative to that of the lower portion 28. The upper
portion 26 is preferably integral with the lower portion 28. In
less preferred embodiments, however, the upper portion 26 and lower
portion 28 may comprise separate elements joined together by any
suitable means know in the art. In the preferred embodiment shown
in FIGS. 1 and 2, the juncture of the upper portion 26 and lower
portion 28 of the main absorbent portion 22 comprises a
substantially abrupt change in the transverse dimension thereby
forming a shoulder-like configuration at such juncture. In the
preferred embodiment shown in FIGS. 1 and 2, the juncture of the
upper portion 26 and lower portion 28 of the main absorbent portion
22 is formed by stitching 34.
[0047] In a variation of the preferred embodiment described above
and shown in FIGS. 1 and 2, the upper portion 26 may have a smaller
transverse sectional dimension relative to the transverse sectional
dimension of the lower portion 28. An absorbent interlabial device
20 having such a configuration is shown in FIG. 3.
[0048] The main absorbent portion 22 can be made by any suitable
process. U.S. Pat. No. 4,995,150 issued to Gerstenberger et al. on
Feb. 26, 1991 and U.S. Pat. No. 4,095,542 issued to Hirschman on
Jun. 20, 1978 describe methods for making absorbent devices which
are suitable for use as the main absorbent portion 22 of the
absorbent interlabial device 20 shown in FIGS. 1-3.
[0049] As shown in FIGS. 1-3, a preferred embodiment of the
absorbent interlabial device 20 also comprises a pair of flexible
extensions 24 which are joined to the upper portion 26 of the main
absorbent portion 22 of the absorbent interlabial device 20. In the
preferred embodiment shown in FIGS. 1-3, the flexible extensions 24
are generally rectangular in shape. Other shapes are also possible
for the flexible extensions 24 such as semi-circular, trapezoidal,
or triangular. The flexible extensions 24 preferably are from about
30 mm to about 160 mm in length, more preferably from about 45 mm
to about 130 mm in length, and most preferably from about 50 mm to
about 115 mm in length. While the flexible extensions 24 can have a
length (measured in the x-direction) which is shorter than the main
absorbent portion 22, preferably they have a length which is the
same as or longer than the main absorbent portion 22 of the
absorbent interlabial device 20. The width of each flexible
extensions refers to the distance from the attachment of flexible
extension 24 to the main absorbent portion 22 (or the proximal end
24A of the flexible extension 24) to the distal end (or free end)
24B of the flexible extension 24. The width of the flexible
extensions 24 is preferably about equal to or greater than the
height of the main absorbent portion as described above. The
caliper of the flexible extensions is preferably less than or equal
to about 3 mm, more preferably less than or equal to about 2 mm,
and most preferably less than or equal to about 1 mm. Ideally, the
caliper of the flexible extensions 24 and the main absorbent
portion 22 are selected such that the caliper of the overall
absorbent interlabial structure 20 is less than or equal to about 8
mm.
[0050] The flexible extensions 24 may be constructed of a tissue
layer. A suitable tissue is an airlaid tissue available from Fort
Howard Tissue Company of Green Bay, Wis. and having a basis weight
of 35 lbs./3000 sq. ft. Another suitable airlaid tissue is
available from Merfin Hygenic Products, Ltd., of Delta, British
Columbia, Canada, having a basis weight of 61 g/m.sup.2 and having
the designation grade number 176. Still another suitable material
is an airlaid cotton batt such as that sold as cosmetic squares by
Revco Stores, Inc. of Twinsberg, Ohio. The flexible extensions 24
may optionally be backed with a layer of material which is
impervious or semi-pervious to body exudates such as, polyethylene,
polypropylene, or a polyvinylalchohol.
[0051] In the preferred embodiments shown in FIGS. 1-3 the pair of
flexible extensions 24 may comprise a single sheet of material
extending to either side of the longitudinal centerline L of the
main absorbent portion 22 of the absorbent interlabial device 20.
Alternatively, the pair of flexible extensions 24 may comprise
separate sheets of material independently joined to the upper
portion 26 of the main absorbent portion 22. Preferably, the
flexible extensions 24 are arranged symmetrically about the
longitudinal centerline L of the main absorbent portion 22. The
flexible extensions 24 are joined to the upper portion 26 of the
main absorbent portion 22 of the absorbent interlabial device 20.
Most preferably, the flexible extensions are joined to the top
surface of the upper portion 26 of the main absorbent portion 22,
or within about 3 mm of the top surface of the main absorbent
portion 22.
[0052] The term "joined", as used herein, encompasses
configurations in which an element is directly secured to another
element by affixing the element directly to the other element;
configurations in which the element is indirectly secured to the
other element by affixing the element to intermediate member(s)
which in turn are affixed to the other element; and configurations
in which one element is integral with another element; i.e., one
element is essentially part of the other element.
[0053] The flexible extensions 24 may be joined to the upper
portion 26 of the main absorbent portion 22 by any variety of
means. For example, in the preferred embodiments shown in FIGS. 1-3
the flexible extensions 24 may be joined to the upper portion 26
using any suitable adhesive 36 centered about the longitudinal
centerline L of the main absorbent portion 22 (i.e., on opposite
sides of the longitudinal centerline L). The adhesive 36 may extend
continuously along the length of the main absorbent portion 22 or
it may be applied in a "dotted" fashion at discrete intervals.
Alternatively, the flexible extensions 24 may be joined to the
upper portion 26 of the main absorbent portion 22 by stitching
(such as with cotton or rayon thread), thermally bonding, fusion
bonding, or any other suitable means known in the art for joining
such materials.
[0054] As shown in FIGS. 1-3, the flexible extensions 24 are
attached to the upper portion 26 of the main absorbent portion 28.
The flexible extensions 24 extend downwardly and outwardly from the
main absorbent portion 22 to a free end 24B which is unattached to
the main absorbent portion. The flexible extensions 24 may be
biased slightly outward from the main absorbent portion 22 so as to
tend to keep the extensions 24 in contact with the inner surfaces
of the labia when the absorbent interlabial device 20 is in place.
Additionally, the naturally moist surfaces of the labia will have a
tendency to adhere to the material comprising the flexible
extensions 24 further tending to keep them in contact with the
inner surfaces of the labia. Preferably the flexible extensions 24
should be capable of motion from a position where the free ends of
the flexible extensions 24 lie adjacent to the main absorbent
portion 22 (as shown in FIG. 9) to a position where the flexible
extensions 24 extend directly out from the main absorbent portion
22 in the transverse direction (as shown in FIG. 4).
[0055] The flexible extensions 24 should be of sufficient width and
flexibility to allow the flexible extensions to cover the wearer's
fingertips as the absorbent interlabial device 20 is inserted into
the wearer's interlabial space. FIG. 8 shows how a wearer may grasp
the main absorbent portion 22 of the absorbent interlabial device
20 while the flexible extensions 24 remain between the wearer's
fingers and her body as the device 20 is inserted. Additionally,
the flexible extensions 24 should be capable of moving with the
inner surfaces of the wearer's labia to maintain contact with the
same. The flexible extensions 24 help keep the main absorbent
portion 22 in place throughout a range of wearer motions such as
squatting.
[0056] The flexible extensions may be hydrophilic or hydrophobic.
The flexible extensions 24 may be treated to make them less
hydrophilic than the main absorbent portion 22. The hydrophilicity
of a material is generally expressed in terms of its contact angle.
Thus, the flexible extensions 24 may have an advancing contact
angle greater than the advancing contact angle of the main
absorbent portion 22, such that fluid is preferentially directed
toward and absorbed by the main absorbent portion 22. The flexible
extensions 24 may be either absorbent or non-absorbent. Preferably,
the flexible extensions 24 have at least some absorbency. However,
the majority of the fluid absorbed and retained by the absorbent
interlabial device 20 will preferably ultimately be retained in the
main absorbent portion 22. For a more detailed description of
hydrophilicity and contact angles see the following publications
which are incorporated by reference herein: The American Chemical
Society Publication entitled "Contact Angle, Wettability, and
Adhesion," edited by Robert F. Gould, and copyrighted in 1964; and
TRI/Princeton Publications, Publication Number 459, entitled "A
Microtechnique for Determining Surface Tension," published in April
1992, and Publication Number 468 entitled, "Determining Contact
Angles Within Porous Networks," published in January, 1993, both
edited by Dr. H. G. Heilweil.
[0057] The stiffness of both the main absorbent portion 22 and the
flexible extensions 24 is important for product comfort. If the
main absorbent portion 22 is too flexible, the device is not
conveniently or easily placed between the folds of the labia, if it
is too stiff, the device is uncomfortable and when the user is in a
sitting position, the product can be forced forward against the
clitoris causing discomfort. The main absorbent portion 22
preferably has a stiffness approximately equal to that of the
products described in U.S. Pat. Nos. 4,995,150 and 4,095,542.
[0058] The strength and stiffness of the flexible extensions 24 are
important characteristics of their design. If the flexible
extensions 24 have a wet burst strength of about less than or equal
to 15 grams, they will tend to shred and may leave pieces remaining
in the wearer's interlabial space. Similarly, if the flexible
extensions 24 are as stiff as a manila file folder, they do not
provide sufficient flexibility to dynamically adjust to the motion
of the labia. The stiffness of the flexible extensions is measured
as a bending resistance. Preferably, the flexible extensions 24
have a bending resistance of less than about 25 gm measured using
the Three Point Bend Test. More preferably, the flexible extensions
24 have a bending resistance of less than or equal to about 5 gm. A
description of the Three Point Bend Test is contained in the Test
Methods section, below. The flexible extensions 24 also have an
inherent strength, so that during application and wear they do not
tear. The wet strength for the flexible extensions should exceed 15
grams, and preferably exceeds 150 grams, and most preferably
exceeds 300 grams. The wet strengths given above are measured using
the Wet Burst Test which is described in greater detail in the Test
Methods section, below.
[0059] In an alternative preferred embodiment shown in FIG. 4, the
main absorbent portion 22 of the absorbent interlabial device 20
comprises a pleated structure. As shown in FIG. 4, the main
absorbent portion 22 comprises a folded tissue web. The folded
tissue web preferably has a strength greater than that of standard
non-wet strength toilet tissue. Preferably, the main absorbent
portion 22 comprises a tissue having a temporary wet strength of
greater than or equal to about 100 g. In a preferred design this
wet strength will decay to about 50% or less of the original
strength over about 30 minutes.
[0060] As shown in FIG. 4, the tissue web comprising the main
absorbent portion 22 is folded into a pleated structure comprising
a plurality of pleats 30 that are arranged in a laterally
side-by-side relationship. The tissue web can be folded so that it
has any suitable number of pleats. Preferably, the tissue web is
folded so that the overall caliper (i.e., the width) of the main
absorbent portion 22 of this embodiment is between about 2 mm and
less than or equal to about 7 mm.
[0061] The pleats in the folded tissue web are preferably connected
or joined (or retained) in some suitable manner so that the pleated
sections maintain their pleated configuration, and are not able to
fully open. The pleats can be connected by a variety of means
including the use of thread, adhesives, or heat sealing tissues
which contain a thermoplastic material, such as, polyethylene. A
preferred design uses stitching which joins all of the pleats in
the main absorbent portion 22 together. Preferably, the main
absorbent structure 22 is provided with five stitch locations (four
at the comers and one additional location approximately midway
between the two lower comers).
[0062] The pleated structure of the main absorbent portion 22
provides several advantages. One advantage provided by the pleated
structure is that exudates can penetrate into the pleats of the
structure which present a larger and more effective absorbent
surface for acquisition than a flat surface. This is particularly
important when dealing with potentially viscous fluids and
particulate material such as cellular debris and clots which can
plug the surface of the structure presented to the body. A second
advantage of this design is that the caliper (or width) of the
product can be easily and conveniently controlled by varying the
number of pleats. The structure shown in FIG. 4 also provides a
convenient central zone for grasping the product and inserting into
the labia, while the body/fingers on the inserting hand are
protected from contacting the wearer's body.
[0063] As noted above for the preferred embodiment shown in FIGS.
1-3, the flexural rigidity of the main absorbent portion 22 is also
important for product comfort with the pleated structure shown in
FIG. 4. An advantage of the pleated structure is that the number,
thickness, and tightness of the pleats control the stiffness of the
structure.
[0064] The preferred embodiment shown in FIG. 4, preferably has
main absorbent portion 22 and flexible extension 24 dimensions
similar to those described above for the embodiment shown in FIGS.
1-3. The width of the main absorbent portion 22 of the interlabial
device 20 as measured in the transverse direction (y-direction) is
preferably between about 2 mm and less than or equal to about 7 mm.
Preferably, in a preferred embodiment, the width of the main
absorbent portion of the interlabial device 20 is about 4.5 mm. As
shown in FIG. 4, where the main absorbent portion 22 is of a
uniform transverse dimension (i.e., there is no abrupt change in
transverse dimension defining the juncture between the upper
portion and lower portion) the division between the upper portion
26 and lower portion 28 is considered to be at a height equal to
about one-half of the total height of the main absorbent portion
22.
[0065] The pleated design shown in FIG. 4 has the additional
benefit of easily providing the flexible extensions 24. The
extensions 24 can comprise the same material as the main absorbent
portion 22, or they can comprise a different material. The
extensions 24 are joined to the upper portion 26 of the main
absorbent portion 22, and most preferably, for this embodiment, are
joined to the top surface of the main absorbent portion 22, or
within 2 millimeters of the top surface of the main absorbent
portion 22. Preferably, in the embodiment shown in FIG. 4, the
extensions 24 are integral portions of the main absorbent portion
22 (that is, the extensions 24 comprise integral extensions of the
absorbent tissue material that is folded to form the main absorbent
portion 22.
[0066] The main absorbent portion 22 and the flexible extensions 24
of the absorbent interlabial device 20 shown in FIG. 4 may be
constructed from any of the materials previously discussed for the
embodiments shown in FIGS. 1-3.
[0067] The embodiment shown in FIG. 4 can be provided with various
optional features. For example, there may be spacers or high loft
or void zones between the pleats to improve the ability of the
device 20 to move exudates downward. Additionally, the pleats on
the portion of the product contacting the pelvic floor do not need
to be of uniform height. For example, the pleated material in the
center might be higher and, therefore, easily collapsed under
pressure. Such an arrangement can provide better fit and/or
comfort.
[0068] In another variation of the pleated structure shown in FIG.
4, the main absorbent portion 22 may comprise a plurality of
individual layers 32 joined in a face-to-face relationship. Such a
device is shown in FIG. 5. The structure shown in FIG. 5 may have
all of the same characteristics described above for the pleated
structure. One benefit of the use of a plurality of individual
layers 32 is that the various layers may comprise different
materials with different properties or characteristics. Each of the
flexible extensions 24 may be integral with one of the individual
layers 32 or may be joined separately to the upper portion 26 of
the main absorbent portion 22. Preferably, the individual layers 32
are arranged in a side-by-side relationship so that the spaces
between the layers are oriented in the z-direction (as shown in
FIG. 5).
[0069] The interlabial device 20 in any of the embodiments shown in
the drawings may comprise other optional components. For example,
the interlabial device 20 may comprise a topsheet 42 positioned
over and joined to all or a portion of the body-facing surface of
the device 20 and/or a backsheet 38 positioned over and joined to
all or a portion of its back surface, including the flexible
extensions 24. Preferably, if a topsheet 42 and/or a backsheet 38
is used, these components are joined to at least a portion of the
main absorbent portion. In an alternative embodiment, the main
absorbent portion could be at least partially wrapped by a topsheet
42.
[0070] If a topsheet is used, the topsheet should be compliant,
soft feeling, and non-irritating to the wearer's skin. Further, the
topsheet should be 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; 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, rayon,
polypropylene, or polyethylene fibers) or from a combination of
natural and synthetic fibers.
[0071] The topsheet may comprise an apertured formed film.
Apertured formed films are pervious to body exudates and, if
properly apertured, have a reduced tendency to allow liquids to
pass back through and rewet the wearer's skin. Thus, the surface of
the formed film which is in contact with the body remains dry,
thereby reducing body soiling and creating a more comfortable feel
for the wearer. Suitable formed films are described in U.S. Pat.
No. 3,929,135, entitled "Absorptive Structures Having Tapered
Capillaries", which issued to Thompson on Dec. 30, 1975; U.S. Pat.
No. 4,324,246 entitled "Disposable Absorbent Article Having A Stain
Resistant Topsheet", which issued to Mullane, et al. on Apr. 13,
1982; U.S. Pat. No. 4,342,314 entitled "Resilient Plastic Web
Exhibiting Fiber-Like Properties", which issued to Radel, et al. on
Aug. 3, 1982; U.S. Pat. No. 4,463,045 entitled "Macroscopically
Expanded Three-Dimensional Plastic Web Exhibiting Non-Glossy
Visible Surface and Cloth-Like Tactile Impression", which issued to
Ahr, et al. on Jul. 31, 1984; and U.S. Pat. No. 5,006,394
"Multilayer Polymeric Film" issued to Baird on Apr. 9, 1991. The
preferred topsheet for the present invention is the formed film
described in one or more of the above patents and marketed on
sanitary napkins by The Procter & Gamble Company of Cincinnati,
Ohio as the "DRI-WEAVE" topsheet.
[0072] In a preferred embodiment of the present invention, the body
surface of the formed film topsheet is hydrophilic so as to help
liquid to transfer through the topsheet faster than if the body
surface was not hydrophilic so as to diminish the likelihood that
menstrual fluid will flow off the topsheet rather than flowing into
and being absorbed by the main absorbent portion 22. In a preferred
embodiment, surfactant is incorporated into the polymeric materials
of the formed film topsheet. Alternatively, the body surface of the
topsheet can be made hydrophilic by treating it with a surfactant
such as is described in U.S. Pat. No. 4,950,254 issued to
Osborn.
[0073] If a backsheet is used, the backsheet could be impervious or
semi-pervious to liquids (e.g., menses and/or urine) and is
preferably flexible. 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 main absorbent
portion 22 from wetting articles which contact the absorbent
interlabial device 20 such as the wearer's undergarments. The
backsheet also assists the main absorbent portion 22 in preventing
the wearer's body from being soiled by exudates. Additionally, use
of the backsheet may provide an improved surface for the wearer to
grasp between the fingers as the absorbent interlabial device 20 is
inserted, or as the device is optionally removed with the
fingers.
[0074] The backsheet may 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. Preferably, the 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). An exemplary polyethylene film is manufactured by
Clopay Corporation of Cincinnati, Ohio, under the designation
P18-0401. The backsheet may permit vapors to escape from the main
absorbent portion 22 (i.e., breathable) while still preventing
exudates from passing through the backsheet.
[0075] As previously discussed, the absorbent interlabial device 20
of the present invention is preferably designed to be placed
entirely within the interlabial space of a wearer. To use the
absorbent interlabial device 20 of the present invention, the
wearer holds the main absorbent portion 22 between her fingers. As
shown in FIG. 8, the flexible extensions 24 are spread apart so as
to cover the tips of the wearer's fingers during insertion. This
feature provides for a hygenic insertion of the absorbent
interlabial device 20 of the present invention. The upper portion
26 is inserted first and furthest into the interlabial space. The
wearer may assume a squatting position during insertion to assist
in spreading the labial surfaces. Once the absorbent interlabial
device 20 is inserted, the flexible extensions 24 tend to adhere to
the inside surfaces of the labia. When the wearer is standing, the
labial walls close more tightly around the absorbent interlabial
device 20 as shown in FIG. 9.
[0076] FIG. 12 shows the interlabial device 20 in place in a
wearer's body. The parts of the wearer's body, W, shown in FIG. 12
are designated as follows: bladder, B, clitoris, C, urethra, U,
labia minora, N, labia majora, J, vagina, V, vaginal introitus, VI,
anus, A, hymenal ring, H, and large intestine, I. The interlabial
device 20 is inserted so that it is worn between the wearer's labia
minora N and labia majora J and blocks the wearer's vaginal
introitus VI without entering the vagina past the hymenal ring H.
That is, the interlabial device 20 lies at least partially in the
vestibule bounded by the labia minora when such device is worn. The
interlabial device 20 may also cover, but does not necessarily
occlude, the wearer's urethra U. Preferably, the interlabial device
20 covers both the wearer's vaginal introitus VI and the wearer's
urethra U. Ideally, the interlabial device 20 is maintained in
contact with as large a portion of the inner surface area of the
wearer's labia minora N and labia majora J as possible. This will
ensure that the interlabial device 20 intercepts as much of the
wearer's body exudates as possible. Preferably, the entire
interlabial device 20 is intended to be worn below the wearer's
hymenal ring H.
[0077] The interlabial device 20 may also contain a portion that is
worn outside the wearer's labia majora J. This portion could, for
example, be used for storage of body exudates that are transferred
from the portion of the interlabial device 20 that is worn between
the wearer's labia minora and labia majora. The portion of the
interlabial device 20 that is worn between the wearer's labia
minora and labia majora will, as a result, will have exudates
drained therefrom, and be able to receive additional loadings of
body exudates.
[0078] The interlabial device 20 is preferably at least partially
retained in place by exerting a slight laterally outwardly-oriented
pressure on the inner surfaces of the wearer's labia minora, labia
majora, or both. Additionally, the product is also held by
attraction of naturally moist labial surfaces to the tissue
comprising the flexible extensions 24. Optionally, the flexible
extensions 24 may be provided with a bio-compatible adhesive to
assist the adhesion of the flexible extensions 24 to the inside
surfaces of the wearer's labia. The strength of such an adhesive
should be selected to assist the absorbent interlabial device 20 in
staying in place, while still allowing for reliable, and
comfortable removal of the device from the wearer's interlabial
space.
[0079] The absorbent interlabial device 20 is believed to differ
from the prior art in a number of respects. FIG. 6 shows a prior
art interlabial device positioned within the interlabial space when
the wearer is standing. When the wearer squats, however, the labia
tend to separate as shown in FIGS. 7 and 10. The prior art device
may tend to shift to one side or another in such a situation (as
shown in FIG. 7). If the wearer urinates when the prior art device
is in the position shown in FIG. 7, the stream of urine will
completely miss the device. The flexible extensions 24 of the
present invention, however, are adapted to maintain contact with
the inside surfaces of the labia in order to keep the absorbent
interlabial device 20 in proper position (as shown in FIG. 10).
This action of the flexible extensions 24 is believed to keep the
absorbent interlabial device 20 of the present invention in a
position which more consistently blocks the orifice of the urethra
than the prior art device. As a result, the absorbent interlabial
device 20 of the present invention is believed to be expelled by
urination more reliably than the prior art device. As noted
previously, the flexible extensions 24 also cover the wearer's
fingertips during insertion (as shown in FIG. 8) thereby providing
for a more hygienic insertion than is achieved with the prior art
device. Optionally, the absorbent interlabial device 20 may be
removed by grasping the lower portion 28 of the main absorbent
portion 22 with the fingers. Again, the flexible extensions 24
continue to cover the fingertips thereby allowing for a more
hygienic removal of the absorbent interlabial device 20 than is
achieved with the prior art device.
[0080] The absorbent interlabial device 20 can be worn as a "stand
alone" product. Alternatively, it can be worn as a back up to a
tampon, or in combination with a sanitary napkin, pantiliner, or
incontinence pad for menstrual or incontinence use. If the
absorbent interlabial device 20 is used with a sanitary napkin, the
sanitary napkin can be of any thickness. Use with a sanitary napkin
may be preferred at night to reduce rear soiling. The interlabial
device 20 can be worn in conventional panties, or it can be used
with menstrual shorts.
[0081] Numerous alternative embodiments of the absorbent
interlabial device of the present invention are possible. For
example, these products are designed to be removed by urination,
although an alternative extraction string or loop may be used.
These products may also be used with medicinal treatments. These
products may be constructed of materials which are biodegradable
and/or which will fragment in water with agitation (as in a
toilet).
[0082] Preferably, the absorbent interlabial device 20 is
flushable. As used herein the terms "flushable and flushability"
refer to a product's ability to pass through typical commercially
available household toilets and plumbing drainage systems without
causing clogging or similar problems that can be directly
associated with the physical structure of the product. It is
recognized, however, that there can be many differences between the
various types of toilets available. Therefore, for the purposes of
the appended claims, a test to determine the flushability of a
catamenial product, such as an interlabial device, is set out in
the TEST METHODS section of this specification.
[0083] The absorbent interlabial device 20 may also be constructed
with a plurality of slits in the main absorbent portion 22 so as to
permit bending of the product in multiple independent directions.
Such a structure allows the product to more easily respond to the
stresses associated with body movements. As shown in FIG. 12, in
preferred versions of any of the embodiments shown in the prior
drawing figures, the upper corner portions 26A and the lower corner
portions 28A of the interlabial device 20 may be rounded to reduce
the forces that the product transfers to the wearer's body when the
wearer sits down. The top surface of the structure may also have
one or more slits or have other regions of preferred bending so
that product may easily adjust to the vertical pressure against the
pelvic floor, to help accommodate the non-linear surface of the
pelvic floor between the clitoris and the perineum.
[0084] The flexible extensions 24 of the absorbent devices above
may also act as a spring in both wet and dry conditions such that
the sides of the product tend to expand outward pressing against
the lateral walls of the labial vestibule, thereby, holding the
product in place. In addition, it is preferred that the flexible
extensions 24 maintain the ability to act as a "spring" when wet,
such as when the product is saturated with liquid. Structures, such
as polyurethane foams can provide these properties.
[0085] B. The Emollient Composition.
[0086] The emollient compositions used on the interlabial device of
the present invention may be solid, liquid, or semisolid at
20.degree. C., i.e. at ambient temperatures. Preferably, the
emollient compositions have a semisolid consistency that can be
described as an unctuous jelly-like consistency at 20.degree. C. By
"semisolid" is meant that the emollient composition has a rheology
typical of pseudoplastic or plastic fluids. The term "fluid", as
used herein, means liquid (as opposed to gas).
[0087] The physical states of the emollient composition and the
components thereof described herein refer to their states at any
time after the product is manufactured and the emollient
composition is applied to the product. Thus, for the purpose of the
appended claims, the device will be considered to be in the claimed
state if it is in the state specified in storage, on store shelves,
or in use. When no shear is applied, the emollient compositions
described herein 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 emollient composition contains primarily solid
components, it also includes some minor liquid components.
[0088] If these emollient compositions are solid or semisolid at
ambient temperatures, they will have a reduced tendency to flow and
migrate into the interior of the absorbent interlabial device to
which they are applied. This also allows less emollient composition
to be used for imparting softness and smoothing benefits.
[0089] When an effective amount of the emollient compositions are
applied to the body-contacting surface of the interlabial device
20, the emollient compositions described herein impart a soft,
lubricious, smooth feeling to the user of the device. This
particular feel has also been characterized as "silky", "slick",
"smooth", etc.
[0090] The emollient compositions of the present invention
preferably comprise: (1) an emollient(s); (2) an immobilizing
agent(s) for the emollient; (3) optionally a hydrophilic
surfactant(s); and (4) other optional components.
[0091] 1. Emollient
[0092] The key active ingredient in these emollient compositions is
one or more emollients. As used herein, an emollient is a material
that smoothes, softens, soothes, supples, coats, lubricates,
moisturizes, or cleanses the skin and/or mucous membranes. 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
semisolid, a plastic, or a fluid consistency at 20.degree. C.,
i.e., at ambient temperatures. By "plastic consistency" is meant
that the emollient behaves as a non-Newtonian liquid which can be
made to flow when a sufficient shear rate is applied thereto. By
"fluid consistency" is meant that the emollient behaves as a
Newtonian liquid which flows immediately when stressed, with the
the rate of flow being proportional to the stress. The plastic or
fluid emollient consistency allows the emollient composition to
impart a soft, lubricious, smoothing feel.
[0093] The emollients will, therefore, preferably have a softening
point at body temperature, 98.6.degree. F. (37.degree. C.). (Body
temperature will be slightly less in the area of a female wearer's
labial vestibule.) Preferably, the emollient composition has at
least one component with a peak heat absorption of less than
99.degree. F. (37.degree. C.). This will ensure that at least part
of the components will melt below body temperature to provide a
more fluid feel and reduced friction against the body. Peak heat
absorption can be measured using a differential scanning
calorimeter. In addition, in preferred embodiments, the emollients
will soften over a span of temperatures, rather than having a sharp
transition at which it changes from a solid to a liquid. For
example, the emollients may begin to soften at about 20.degree. C.,
or less, and be approximately 80% melted ("melted", as used herein,
means completely liquid) at 38.degree. C. (about 100.degree. F.).
This will provide the emollient coated device with a lubricious
feel at body temperatures which will increase as it adjusts from
ambient temperature to body temperature.
[0094] The emollients used in the present invention preferably do
not contain any high molecular weight hydrocarbon components. If
the emollients used herein contain hydrocarbon components, the
molecular weights of such components are preferably less than
1,500, more preferably less than or equal to about 1,400, and most
preferably less than or equal to about 1,200. Such emollients will
provide more soothing or lotion-like benefits to the wearer's skin
than high molecular weight materials. They will also be capable of
transferring to the wearer's skin to provide skin care benefits
unlike high molecular weight materials. In addition, they will
remain flexible when the interlabial device flexes and bends, and
will not tend to flake or chip off the interlabial device.
[0095] The emollients useful in the present invention are also
substantially free of water. Preferably, the overall emollient
composition is also substantially free of water. By "substantially
free of water" it is meant that water is not intentionally added to
the emollient (or emollient composition). Addition of water to the
emollient (or emollient composition) is not necessary in preparing
or using the emollient compositions on the present invention and
could require an additional drying step. However, minor or trace
quantities of water in the emollient (or emollient composition)
that are picked up as a result of, for example, ambient humidity
can be tolerated without adverse effect. Typically, the emollients
(and emollient compositions) used in the present invention contain
about 10% or less water, preferably 5% or less water, more
preferably about 1% or less water, and most preferably about 0.5%
or less water.
[0096] 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, 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 is a particularly preferred emollient for emollient
compositions for use on the interlabial device of the present
invention. Petrolatum has a molecular weight of between about 600
and about 700.
[0097] 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, butyl
myristate, butyl stearate, octyl palmitate, isopropyl isostearate,
isopropyl palmitate, ethylhexyl palmitate and mixtures thereof
Suitable fatty acid ester emollients can also be derived from
monoesters and diesters of both short chain (C.sub.1 to C.sub.10)
and longer chain fatty alcohols (C.sub.12-C.sub.28, preferably
C.sub.12-C.sub.16) and shorter chain organic acids e.g., lactic
acid, such as lauryl lactate and cetyl lactate. Additional examples
include diisopropyl sebacate, dimethyl sebacate, dioctyl sebacate,
dibutyl sebacate, diisopropyl adipate, and dicapryl adipate. In
addition, mixtures of petroleum based emollients and fatty acid
ester emollients, if mixed in the right proportions, can sometimes
provide emollients systems that have a superior feel compared to
the pure components individually.
[0098] 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) steareth-10 (a stearyl alcohol ethoxylate
having an average degree of ethoxylation of 10), and ceteareth-10
(a mixture of cetyl and stearyl ethoxylates 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.
[0099] 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 1:1 to about 1:2.
[0100] 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
[0101] 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.
[0102] 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.
[0103] Viscosity of useful 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 body-contacting surface of the interlabial
device. 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
body-contacting surface 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 body-contacting surface are discussed in
more detail hereinafter.
[0104] 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 emollient compositions 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.
[0105] Preferably, emollient compositions containing a polysiloxane
will further comprise a petroleum based emollient selected from the
group consisting of mineral oil, petrolatum, and mixtures thereof.
However, the polysiloxanes emollients described above can also be
used alone.
[0106] Besides petroleum-based emollients, fatty acid ester
emollients, fatty acid ester ethoxylates, alkyl ethoxylate
emollients and fatty alcohol emollients, 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/solvents. These other, conventional emollients/solvents
include propylene glycol, polyethylene glycol, hexylene 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; silicone polyether
copolymers, and polysiloxanes having a viscosity at 20.degree. C.
of from about 5 to about 2,000 centistokes such as disclosed in
U.S. Pat. No. 5,059,282 (Ampulski et al), issued Oct. 22, 1991,
which is incorporated by reference. These other emollients should
be included in a manner such that the solid or semisolid
characteristics of the emollient composition are maintained.
[0107] The amount of emollient that can be included in the
emollient composition will depend on a variety of factors,
including the particular emollient involved, the emollient-like
benefits desired, the other components in the emollient composition
and like factors. The emollient composition can comprise from about
5 to about 95% of the emollient. Preferably, the emollient
composition comprises from about 10 to about 90% by weight, more
preferably from 20 to about 80%, most preferably from about 40 to
about 75%, of the emollient.
[0108] 2. Immobilizing Agent
[0109] An optional component of the emollient compositions useful
on the interlabial device of present invention is an agent capable
of immobilizing the emollient on the surface of the body-contacting
surface 20A of the device. 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 an absorbent interlabial device, especially in a melted or
molten state, the emollient will not remain primarily on the
body-contacting surface of the device. Instead, the emollient will
tend to migrate and flow into the interior of the device.
[0110] The need for an immobilizing agent is generally greater of
the body-contacting surface of the interlabial device comprises an
absorbent material, such as cellulose, than it is if the
body-contacting surface comprises an apertured plastic film since
the apertured film will not tend to absorb the emollient. The
immobilizing agent counteracts the tendency of the emollient to
migrate or flow by keeping the emollient primarily localized on the
body-contacting surface of the absorbent interlabial device. This
is believed to be due, in part, to the fact that the immobilizing
agent forms hydrogen bonds with any cellulose in the interlabial
device. Through this hydrogen bonding, the immobilizing agent
becomes localized on the surface of the interlabial device. 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
absorbent device as well.
[0111] It is also advantageous to "lock" the immobilizing agent on
the body-contacting surface of the interlabial device. This can be
accomplished by using immobilizing agents which quickly solidify
(e.g., crystallize) at the surface of the interlabial device.
Alternatively, outside cooling of the treated interlabial device by
the flow of air over the surface of the device when the device is
moving rapidly between stations on a manufacturing line may speed
up crystallization of the immobilizing agent. In addition, outside
cooling of the treated interlabial device via blowers, fans, etc.
can speed up crystallization of the immobilizing agent.
[0112] In addition to being miscible with (or solubilized in) the
emollient, the immobilizing agent preferably has 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.
[0113] The viscosity of the immobilizing agent should also be as
high as possible to keep the emollient from flowing into the
interior of the interlabial device. Unfortunately, high viscosities
can also lead to emollient compositions that are difficult to apply
without processing problems. Therefore, a balance must be achieved
so the viscosities are high enough to keep the immobilizing agent
localized on the surface of the interlabial device, but not so high
as to cause processing problems. Suitable viscosities for the
immobilizing agent will typically range from about 5 to about 200
centipoises, preferably from about 15 to about 100 centipoises,
measured at 60.degree. C.
[0114] 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 cetyl
acid, stearyl acid, and mixtures thereof Mixtures of cetyl acid and
stearyl 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.
[0115] Importantly, these preferred immobilizing agents such as the
C.sub.16-C.sub.18 fatty alcohols increase the rate of
crystallization of the emollient causing the emollient to
crystallize rapidly onto the surface of the interlabial device.
Lower emollient levels can therefore be utilized or a superior feel
can be delivered.
[0116] Optionally, other types of immobilizing agents can be used
in combination with the fatty alcohols, fatty acids, and fatty
alcohol ethoxylates described above. Typically, only minor amounts
of these other types of immobilizing agents would be used (i.e., up
to about 10% of the total immobilizing agent). Examples of these
other types of immobilizing agents includes polyhydroxy fatty acid
esters, polyhydroxy fatty acid amides, waxes (preferably waxes
having a molecular weight of less than 1,500, more preferably less
than or equal to 1,400, and most preferably less than or equal to
about 1,200), and mixtures thereof To be useful as immobilizing
agents, the polyhydroxy moiety of the ester or amide should have at
least one free hydroxy group. It is believed that these free
hydroxy group(s) are the ones that co-crosslink through hydrogen
bonds with any cellulosic fibers of the interlabial device to which
the emollient composition is applied and homo-crosslink, also
through hydrogen bonds, the hydroxy groups of the alcohol, acid,
ester or amide, thus entrapping and immobilizing the other
components in the emollient matrix. Suitable waxes include, but are
not limited to microcrystalline waxes, synthetic waxes, such as
polyethylene-type waxes, and silicone waxes.
[0117] It is also believed that molecules such as long chain fatty
alcohols can orient themselves and interact with one another to
form a lamellar structure. In this lamellar structure, the hydroxyl
groups and alkyl chains of neighboring alcohol molecules orient and
interact with one another to form an organized structure. In this
"packing arrangement," the hydroxyl groups of the alcohols form
hydrogen bonds with the cellulose polar functionalities (e.g.,
hydroxy or carbonyl) to "immobilize" the alcohols at the
body-contacting surface of the interlabial device. Since the
alcohols are miscible with the preferred emollients, anchoring
and/or immobilization of the emollient will occur.
[0118] 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 interlabial devices to which the emollient composition is
applied, these esters and amides should also be relatively mild and
non-irritating to the skin.
[0119] Suitable polyhydroxy fatty acid esters for use in the
present invention will have the formula: 2
[0120] 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.
[0121] 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.
[0122] 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.
[0123] 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 are particularly preferred
and include sucrose monostearate and sucrose monolaurate.
[0124] Suitable polyhydroxy fatty acid amides for use in the
present invention will have the formula: 3
[0125] 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.
[0126] 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.
[0127] The Z moiety preferably will be selected from the group
consisting of --CH.sub.2--(CHOH).sub.n--CH.sub.2OH,
--CH(CHOH)--[(CHOH).sub.n-1]--CH- .sub.2OH,
--CHOH-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.
[0128] 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.
[0129] The most preferred polyhydroxy fatty acid amides have the
general formula: 4
[0130] 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.
[0131] 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.
[0132] The amount of immobilizing agent that should be included in
the emollient 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 emollient composition and like factors. The
emollient composition can comprise from about 5 to about 80% of the
immobilizing agent. Preferably, the emollient composition comprises
from about 5 to about 50%, most preferably from about 10 to about
40%, of the immobilizing agent.
[0133] 3. Optional Hydrophilic Surfactant
[0134] The interlabial device of the present invention is
preferably disposed of by flushing the same down a conventional
toilet. In such cases, it may be desirable that the interlabial
device be sufficiently wettable so that it will not float.
Depending upon the particular immobilizing agent used in the
emollient composition, 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 BLB values below about 7
may require addition of hydrophilic surfactant to improve
wettability. Similarly, a hydrophobic emollient such as petrolatum
may require the addition of a hydrophilic surfactant.
[0135] Suitable hydrophilic surfactants are preferably miscible
with the emollient and the immobilizing agent so as to form
homogeneous mixtures. Because of possible skin sensitivity of those
using the interlabial device, these surfactants should also be
relatively mild and non-irritating to the skin. Typically, these
hydrophilic surfactants are nonionic to be non-irritating to the
skin.
[0136] Suitable nonionic surfactants are preferably substantially
nonmigratory after the emollient composition is applied to the
interlabial device 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
absorbent articles, 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.
[0137] Suitable nonionic surfactants for use in emollient
compositions include alkylglycosides; alkylglycoside ethers as
described in U.S. pat. No. 4,011,389 (Langdon, et al), 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 76 ( i.e.,
Steareth-10) and Brij 56 (i.e., Cetyl-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.
[0138] 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.
[0139] 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 emollient composition.
[0140] The amount of hydrophilic surfactant required to increase
the wettability of the emollient 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
emollient 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 emollient
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.
[0141] It is also possible that a surfactant can be used which is
separately applied to the interlabial device, and is not included
in the emollient composition. If a surfactant is separately applied
to the interlabial device, it is preferably applied to the back
surface 20B of the same so that it does not come in contact with
the wearer's body. In other embodiments, particularly where the
interlabial device is not provided with a liquid impervious
backsheet, the surfactant could be eliminated altogether. In such
cases, the interlabial device will be sufficiently wettable that it
is flushable. The back surface of such an interlabial device will
typically not have an emollient coating thereon, and will readily
wet and sink when placed in a toilet.
[0142] 4. Other Optional Components
[0143] Emollient compositions can comprise other optional
components typically present in emollient, creams, and emollients
of this type. These optional components include water, viscosity
modifiers, pH modifiers, buffers, perfumes, disinfectant
antibacterial actives, pharmaceutical actives, film formers,
deodorants, opacifiers, astringents, solvents, organic acids,
preservatives, anti-viral actives, drugs, vitamins, aloe vera,
panthenol, and the like. In addition, stabilizers can be added to
enhance the shelf life of the emollient 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
emollient compositions for use in the present invention.
[0144] C. Treating the Interlabial Structure With Emollient
Composition.
[0145] The body-contacting surface of the interlabial device 20 is
pre-treated. The body-contacting surface 20A is treated with a
substance or an emollient (such as a liquid) which is suitable for
contact with the wearer's skin and which will help or aid in
maintaining the hydration level of the labial tissue and reduce
friction therewith.
[0146] In preparing lotioned interlabial products of the present
invention, the emollient composition is applied to the
body-contacting surface 20A of the interlabial product. 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
emollient composition on a rotating surface, such as a calender
roll, that then transfers the composition to the body-contacting
surface of the interlabial device 20.
[0147] The manner of applying the emollient composition to the
interlabial device should be such that the body-contacting surface
20A does not become saturated with the emollient composition. If
the body-contacting surface 20A becomes saturated with the
emollient composition, there is a greater potential for the
emollient to block the pores or other openings in the
body-contacting surface, reducing the ability to transmit fluid
through the body-contacting surface to the absorbent portions of
the interlabial device. Also, saturation of the body-contacting
surface 20A is not required to obtain the benefits described
herein.
[0148] The emollient composition is preferably applied to the
body-contacting surface 20A of the interlabial device in an amount
ranging from about 0.1 mg/cm.sup.2 to about 30 mg/cm.sup.2 more
preferably from about 1 mg/cm.sup.2 to about 15 mg/cm.sup.2 (mg of
emollient per square centimeter of coated body-contacting surface).
Because the emollient is substantially immobilized on the surface
of the body-contacting surface, less emollient composition is
needed to impart the desired benefits. Such relatively low levels
of emollient composition are adequate to impart the desired
benefits to the interlabial device, yet do not saturate the
interlabial device's absorbency and/or wettability properties.
[0149] The emollient composition may be applied to the entire
body-contacting surface of the interlabial device, or portions
thereof For example, the emollient composition may be applied to
the body-contacting portion of the main absorbent portion, to the
body-contacting portion of the flexible extensions, or to the
body-contacting portion of both the main absorbent portion and the
flexible extensions. Preferably, the emollient composition is
applied to the body-contacting portion of both the main absorbent
portion and any flexible extensions.
[0150] The emollient composition can also be applied nonuniformly
to the body-contacting surface of the interlabial device. By
"nonuniform" is meant that the amount, pattern of distribution,
etc. of the emollient composition can vary over the body-contacting
surface. For example, some portions of the body-contacting surface
can have greater or lesser amounts of emollient composition,
including portions of the surface that do not have any emollient
composition on it. If the emollient is applied nonuniformly, the
levels of the emollient specified above are preferably averages of
the amount of coating applied to the entire surface.
[0151] The emollient composition can be applied to the interlabial
device at any point during assembly. For example, the emollient
composition can be applied to the body-contacting surface of the
finished interlabial device before it has been packaged. The
emollient composition can also be applied to components of the
interlabial device before they are combined with the other raw
materials to form the finished interlabial device.
[0152] The emollient composition may be applied from a melt thereof
to the body-contacting surface of the interlabial device. If the
emollient composition melts at a temperature above ambient
temperatures, it can be applied as a heated coating to the
body-contacting surface. Typically, the emollient 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 body-contacting surface of the
interlabial device. Once the melted emollient composition has been
applied to the body-contacting surface of the interlabial device,
it is allowed to cool and solidify to form solidified coating or
film on the body-contacting surface. Preferably, the application
process is designed to aid in the cooling/set up of the
emollient.
[0153] In applying the emollient composition to interlabial
devices, spraying, gravure coating and extrusion coating methods
are preferred. One preferred method, when the interlabial device is
provided with a topsheet, is spraying the emollient on the topsheet
before the topsheet is assembled with the other raw materials into
the finished product. In carrying out this method, a web of
topsheet material is unwound from parent topsheet roll and advanced
to a spray station where one side of the web is sprayed with a hot,
molten (e.g., 65.degree. C.) emollient composition. After leaving
spray station, the web of topsheet material becomes an
emollient-treated topsheet which is thereafter used in the assembly
of the finished product.
[0154] An alternative preferred method involves continuous or
intermittent spraying of the emollient composition on the
body-contacting surface of the assembled or partially assembled
interlabial device. When it is said that the emollient composition
can be applied to a partially assembled interlabial device, there
are a number of ways this can be accomplished. These include, but
are not limited to the following. If the interlabial device is
provided with flexible extensions, the web of material that is
converted into the flexible extensions can be treated before the
material is joined to the main absorbent portion to form the
interlabial device. The main absorbent portion could similarly be
treated separately before the flexible extensions are joined
thereto. In this regard, it is contemplated that the main absorbent
portion will initially be in the form of a continuous rope-like web
that will be intermittently cut into discrete lengths to form a
plurality of main absorbent portions. It will often be most
convenient to treat the main absorbent portion before it is cut
into discrete lengths.
[0155] In treating the interlabial device by spraying the emollient
onto the assembled or partially assembled device, the interlabial
device or desired portion or component thereof can be carried in
any suitable manner to a spray station where the body-contacting
surface of the interlabial device is sprayed with a hot, molten
(e.g., 65.degree. C.) emollient composition. After leaving the
spray station, the interlabial device has an emollient coated
body-contacting surface. The amount of emollient composition
transferred to body-contacting surface can be controlled by: (1)
the rate at which the molten emollient composition is sprayed from
spray station; and/or (2) the speed at which the interlabial device
travels under the spray station.
[0156] Providing the interlabial device with a coating of emollient
provides a number of advantages. The emollient-treated absorbent
device provides a reduction in frictional discomfort associated
with rubbing of the device against the labial walls and sticking of
the surfaces of the device to the labial walls. The interlabial
device also has less of a drying sensation to the inside surfaces
of the wearer's labia due to the presence of the emollient. In
addition, as shown by comparing FIGS. 11 and 12, the interlabial
device can be inserted into the space between the wearer's labia
with less friction so that it will more easily be fully inserted
into the desired wearing position.
[0157] FIG. 11 shows a hypothetical example of a prior art
interlabial device that is not treated with an emollient. FIG. 11
shows a prior art interlabial pad in place in a wearer's body. When
the user attempts to insert such the device, the friction between
the body-contacting surface of the device and the inside walls of
the wearer's labia may prevent the device from being fully inserted
as shown in FIG. 11. This may prevent the device from providing
maximum protection against leakage. It may also result in portions
of the lower portion of the device, such as lower corner portions
28A, remaining outside the labial vestibule. When the wearer sits,
these lower corner portions 28A may be pressed upward causing
discomfort to the wearer.
[0158] FIG. 12 shows how, on the other hand, the emollient-treated
interlabial device of the present invention will tend to be capable
of being more fully inserted into the labial vestibule so that the
lower corner portions reside completely inside the wearer's labial
vestibule.
[0159] Another advantage of the interlabial device of the present
invention is that the emollients described herein are substantially
free of water. Hydrous emollients are less preferred because such
materials can support bacterial growth during storage of the
product prior to shipment to the consumer.
[0160] In other embodiments, the emollients described herein could
be applied to other types of absorbent articles, particularly other
types of feminine hygiene articles, such as sanitary napkins, panty
liners, incontinence devices, and tampons. The relatively lower
molecular weight and melting temperature of the emollients
described herein make them particularly suitable for use with
absorbent articles that have an apertured film topsheet such as
those topsheet materials described above. Without wishing to be
bound to any particular theory this is believed to be so because
such topsheets will not have fibers which help maintain the coating
thereon by the emollient embedding into the spaces between the
same. Higher molecular weight and higher melting point temperature
materials will typically readily flake off apertured films, when
such films are flexed.
[0161] The disclosure of all patents, patent applications (and any
patents which issue thereon, as well as any corresponding published
foreign patent applications), and publications mentioned throughout
this description are hereby incorporated by reference herein. It is
expressly not admitted, however, that any of the documents
incorporated by reference herein teach or disclose the present
invention.
Test Methods
Absorbent Capacity
[0162] Absorbent capacity may be determined as follows. The test is
performed on samples that have been conditioned by leaving them in
a room at 50% relative humidity and at 73.degree. F. for a period
of two hours prior to the test. The test should be performed under
similar conditions.
[0163] The article is weighed to the nearest 0.1 gram. The article
is then submerged in a beaker of sterile 0.9% saline solution
(obtainable from the Baxter Travenol Company of Deerfield, Ill.),
such that the article is totally submerged and is not bent or
otherwise twisted or folded. The article is submerged for 10
minutes. The article is removed from the saline and laid
horizontally on a wire mesh screen having square openings 0.25
inches by 0.25 inches (0.64 cm by 0.64 cm) for five minutes to
allow the saline to drain out to the article. Both sides of the
article are then covered with absorbent blotters, such as the
filter paper #631 available from the Filtration Science Corp.,
Eaton-Dikeman Division of Mount Holly Springs, Pa. A uniform 17.6
grams per square centimeter load is placed over the article to
squeeze excess fluid out. The absorbent blotters are replaced every
30 seconds until the amount of fluid transferred to the absorbent
blotters is less than 0.5 grams in a 30 second period. Next, the
article is weighed to the nearest 0.1 gram and the dry weight of
the article is subtracted. The difference in grams is the absorbent
capacity of the article.
Three Point Bend Test
[0164] The Three Point Bend Test is performed on samples that have
been conditioned by leaving them in a room at 50% relative humidity
and at 73.degree. F. for a period of two hours prior to the test.
The test should be performed under similar conditions.
[0165] The three point bend test uses an INSTRON Model 4502 tensile
and compression testing machine, which is available from Instron
Corporation of Canton, Mass. The test also uses a special
displacement "T-rod" and a special test sample holder. As shown in
FIG. 13, the "T-rod" 1101 comprises a pair of 6.40 mm diameter
metal rods perpendicularly mounted together. The drive rod 1102 is
about 125 mm long and the push rod 1103 is about 75 mm long.
Preferably, the end of the drive rod 1102 is tapered to fit the
circumference of the push rod 1103 and the two are glued, welded
and/or screwed to each other. The opposite end of the drive rod
1102 is mounted to the crosshead unit of the INSTRON machine. The
test sample holder 1104 comprises a fixture base 1105 for
positioning and supporting a pair of supporting rods 1108. The
fixture base 1105 comprises a base 1105 and two rectangular
supports 1107 mounted in parallel on the base 1106. The base 1106
and the supports 1107 are each preferably made of LEXAN (plexiglas)
plate of about 10 mm to about 13 mm thickness. A supporting rod
1108 of the same materials as the "T-bar" and about 150 mm long is
mounted on each support 1107 of the fixture base 1105. The
supporting rods 1108 are mounted so as to leave 10 mm of open space
between them (measured at the point on each rod which is closest to
the other). As shown in FIG. 13, the "T-rod" 1101 is centered
between the supporting rods 1108.
[0166] The INSTRON machine is set for a crosshead speed of 2.0
in/min (50.8 mm/min). The INSTRON machine is set up so that the
crosshead unit will travel 10 mm down and back for each sample
tested.
[0167] Prior to testing of a sample, the T-rod 1101 is lowered
until it is resting directly on top on one of the supporting rods
1108. The vertical position of the T-rod 1101 is "zeroed" when the
load as it rests on supporting rod 1108 is about 1 gram.sub.f. The
T-rod 1101 is then raised 5 mm from this zero position and centered
between both supporting rods 1108.
[0168] The sample 1000 to be tested can be a piece of material
taken from one of the flexible extensions. The sample 1000 taken
from the flexible extensions should have a dimension of about 25 mm
in the longitudinal direction LD and a dimension in the transverse
direction of about 10 mm. If the flexible extensions on the product
to be tested are too small, a larger sample of the same material
should be used for the test. The sample is placed so that the push
rod 1103 is running parallel to a side of the sample that was
oriented in the transverse direction TD.
[0169] The T-rod 1101 is then allowed to travel through a complete
10 mm cycle (i.e., 10 mm down and 10 mm back up). Consequently, the
T-rod 1101 will make contact with the sample 1000 after about 5 mm
and bend the sample about an additional 5 mm. The bending
resistance is the peak force required to bend the sample as the
T-rod travels through a complete 10 mm cycle.
Burst Strength Test
Overview
[0170] A test specimen, held between annular clamps, is subjected
to increasing force that is applied by a 0.625 inch diameter,
polished stainless steel ball. The burst strength is that force
that causes the sample to fail. Burst strength may be measured on
wet or dry samples.
1 Apparatus Burst Tester Intelect-II-STD Tensile Test Instrument,
Cat. No. 1451- 24PGB or the Thwing-Albert Burst Tester are both
suitable. Both instruments are available from Thwing-Albert
Instrument Co., Philadelphia, PA. The instruments must be equipped
with a 2000 g load cell and, if wet burst measurements are to be
made, the instruments must be equipped with a load cell shield and
a front panel water shield. Conditioned Room Temperature and
humidity should be controlled to remain within the following
limits: Temperature: 73 .+-. 3.degree. F. (23.degree. C. .+-.
2.degree. C.) Humidity: 50 .+-. 2% Relative Humidity Paper Cutter
Scissors or other equivalent may be used Pan For soaking wet burst
samples, suitable to sample size Solution Water for soaking wet
burst samples should be equilibrated to the temperature of the
conditioned room. Timer Appropriate for measuring soak time
Sample preparation
[0171] 1) Cut the sample to a size appropriate for testing (minimum
sample size 4.5 in.times.4.5 in). If the sample to be tested is too
small (e.g., a flexible extension with overall dimensions less than
4.5 in.times.4.5 in) a larger sample of the same material should be
used to determine wet burst strength. Prepare a minimum of five
samples for each condition to be tested.
[0172] 2) If wet burst measurements are to be made, place an
appropriate number of cut samples into a pan filled with
temperature-equilibrated water.
Equipment Setup
[0173] 1) Set the burst tester up according to the manufacturer's
instructions. If an Intelect-II-STD Tensile Test Instrument is to
be used the following are appropriate:
[0174] Speed: 12.7 centimeters per minute
[0175] Break Sensitivity: 20 grams
[0176] Peak Load: 2000 grams
[0177] 2) Calibrate the load cell according to the expected burst
strength.
Measurement and Reporting
[0178] 1) Operate the burst tester according to the manufacturer's
instructions to obtain a burst strength measurement for each
sample.
[0179] 2) Record the burst strength for each sample and calculate
an average and a standard deviation for the burst strength for each
condition.
[0180] 3) Report the average and standard deviation for each
condition to the nearest gram.
[0181] Report the average and the standard deviation for each group
of four samples.
[0182] This concludes the test.
Water Dispersion Test
[0183]
2 Apparatus Stirrer Magnetic, Thermolyne type Model S7225 or 7200
(no substitutions). Permanently inscribe a circle 3.5 inches (8.9
centimeter) on the top surface of the stirrer. The center of the
circle must be coincident with the geometric center of the stirrer.
Stirring Bar 2.5 inch (6.2 centimeter) TEFLON coated with spinning
ring. Permanently mark one end of the bar with black ink for a
distance of 0.5 inch (1.2 centimeter) back from the tip.
Thermometer 30 to 120.degree. F. with 1 degree divisions Timer
Digital stopwatch Stroboscope Variable speed stroboscope, model 964
available from Strobette, Power Instrument, Inc. of Skokie, IL is
suitable Beaker Kimax brand 2000 milliliter with spout (no
substitution), Inscribe a fill mark at a height of 5.6 inches (14.3
centimeters) from the flat bottom of the beaker. Do not use any
beaker not having a flat bottom. Conditioned Room Temperature and
humidity should be controlled to remain within the following
limits: Temperature: 73 .+-. 3.degree. F. (23.degree. C. .+-.
2.degree. C.) Humidity: 50 .+-. 2% Relative Humidity
Test Setup
[0184] 1. Fill the beaker to the fill mark with 73.+-.3.degree. F.
tap water.
[0185] 2. Place the beaker on the magnetic stirrer centering it in
the inscribed circle.
[0186] 3. Add the stirring bar to the beaker.
[0187] 4. Turn the stroboscope on and set the speed to 1000 rpm
according to the manufacturer's directions.
[0188] 5. Turn the magnetic stirrer on with the on/off switch.
Adjust the speed of the magnetic stirrer until the stirring bar
appears to be stationary and both ends appear to be black. This
indicates that the magnetic stirrer is turning at 500 rpm (i.e.
half the setting on the stroboscope). Turn the magnetic stirrer off
with the on/off switch.
Procedure
[0189] 1. Hold a sample (e.g. an absorbent interlabial device 20) 3
to 4 inches (7.6 to 10.2 centimeters) above the surface of the
water. Gently drop the sample onto the water surface, starting the
timer when the sample touches the water surface.
[0190] 2. Wait 5 seconds.
[0191] 3. Start the magnetic stirrer with the on/off switch.
[0192] 4. Record the time required until the sample separates into
at least two pieces. If the motion of the stirring bar is disrupted
by the sample so it no longer rotates, turn off the magnetic
stirrer. Recenter the magnet without removing the sample and
restart the stirrer immediately. The time recorded is the total
time that the sample remains in the water, including the time
required to restart the stirrer.
[0193] 5. Repeat steps 1 through 4 with an additional 3
samples.
Calculation and Reporting
[0194] Calculate and report the mean and standard deviation of the
water dispersibility time for the four samples tested. However, if
at least one of the four samples separates into at least two
fragments during the time specified in the appended claims, the
sample will be considered to be water dispersible. The term
"fragments" as used herein, is not intended to include the
separation of merely a few loose fibers (that is, fibers which
constitute less than 5% of the total product mass) from the sample.
The interlabial devices described herein preferably disperse into
at least two fragments within about 1 hour, more preferably within
about 30 minutes.
[0195] This concludes the test.
Flushability
Overview
[0196] As noted above, the terms "flushable or flushability" refer
to a product's capacity to pass through typical commercially
available household toilets and plumbing drainage systems without
causing clogging or similar problems that can be directly
associated with the physical characteristics of the product. For
the purpose of the appended claims, catamenial products are
evaluated for flushability via relative ease of toilet bowl and
trap evacuation and subsequent transport through a simulated
plumbing system. The flushability of such a device should be
measured by the following test procedure.
[0197] The test procedure is designed to simulate two days of
normal toilet usage for a family of 4 (2 men, 2 women). The test
employs a flushing sequence to simulate the following conditions:
male urination visits, female urination visits (including post
urinary drying with tissue), disposal of catamenial product (that
is, the interlabial device or other device to be tested) with
cleaning using tissue, and bowel movement visits. The amount of
tissue to be used for each tissue flush is a normal loading of 2
strips of seven sheets. The normal loading is based on consumer
research regarding typical habits and practices. The test is
designed to simulate the conditions a product will encounter if it
is flushed through a conventional toilet and into a municipal sewer
or into a septic tank. Samples are evaluated for: 1) toilet bowl
and trap clearance, 2) drain line blockage, and 3) disintegration
during flushing.
Apparatus
[0198] An apparatus suitable for the flushability test is shown in
plan view in FIG. 14. The apparatus includes:
[0199] a 3.5 gallon (13.2 liter) water saver siphon vortex toilet
referred to as 210 (additional toilets can also be attached to the
piping layout shown in FIG. 14 to evaluate the behavior of test
samples using different flushing mechanisms such as commercial,
pressure toilets);
[0200] approximately 59 feet (18 meters) of 4 inch (10 cm) inside
diameter acrylic pipe (As can be seen from FIG. 14, the piping is
assembled in roughly a square configuration having linear runs 211,
213, 215, 217, 219, 221 approximately 10 feet (3 meters) long);
[0201] a cast iron tee 223 slightly downstream of the toilet 210
that is open to the atmosphere for venting;
[0202] five cast iron ninety degree elbows 212, 214, 216, 218, and
220;
[0203] a snag 222 positioned vertically (FIG. 15) approximately 15
feet from the pipe's terminal end and approximately 1 inch (2.5 cm)
long; and
[0204] a screen (No. 4 Tyler sieve) to capture solid effluent for
evaluation of disintegration.
[0205] The apparatus used for this method is set up to be
equivalent to ANSI Standard A112.19.2M-1990 for Vitreous China
fixtures. The piping is plumbed to provide a drop of 0.25 inch per
foot (2 centimeters/meter) of pipe length.
Materials
[0206] Tissue Product used in Test: standard CHARMIN.RTM. toilet
tissue manufactured by The Procter & Gamble Company of
Cincinnati, Ohio.
[0207] Synthetic Fecal Material Prepared according to the method
described below
Test Flushing Sequence
[0208] The test flushing sequence simulates 2 days of normal toilet
usage for a family of 4 (2 men, 2 women; based on consumer habits
and practices research). The sequence of 34 total flushes consists
of 14 flushes with an empty bowl, 8 flushes with tissue only, 6
flushes with tissue and a catamenial product and 6 flushes with
tissue and simulated fecal matter (SFM). When it is used, the SFM
is placed in the bowl just prior to the addition of tissue. The SFM
loading of 160 g.+-.5 g consists of two 1 inch (2.5
centimeter).times.4 inch (10 centimeter) pieces and one 1 inch (2.5
centimeter).times.2 inch (5 centimeter) piece. Folded tissue strips
(or the catamenial product) are placed in the bowl at 10 second
intervals. Ten seconds after the final strip or catamenial product
is placed into the bowl, the toilet is flushed. The flushing
sequence is described below as a series of two routines combined in
the following order:
[0209] Routine #1 (To be performed first 6 times for a total of 30
flushes)
[0210] 1) Flush With Tissue Only--Take a drain line blockage
reading 2 minutes after the water reaches the simulated
obstruction, wait 1 additional minute, and move to step 2.
[0211] 2) Flush With Empty Bowl. Take a drain line blockage reading
2 minutes after the water reaches the snag point and move to step
3.
[0212] 3) Flush With Tissue and Catamenial Product--Take a drain
line blockage reading 2 minutes after the water reaches the snag
point, wait 1 additional minute, and move to step 4.
[0213] 4) Flush With Empty Bowl. Take a drain line blockage reading
2 minutes after the water reaches the snag point and move to step
5.
[0214] 5) Flush With Tissue and Simulated Fecal Matter (SFM). Take
a drain line blockage reading 2 minutes after the water reaches the
snag point, wait 1 additional minute.
[0215] Routine #2 (To be performed 1 time)
[0216] 1) Flush With Tissue Only--Take a drain line blockage
reading 2 minutes after the water reaches the snag point, wait 1
additional minute, and move to step 2.
[0217] 2) Flush With Empty Bowl. Take a drain line blockage reading
2 minutes after the water reaches the snag point and move to step
3.
[0218] 3) Flush With Tissue Only--Take a drain line blockage
reading 2 minutes after the water reaches the snag point, wait 1
additional minute, and move to step 4.
[0219] 4) Flush With Empty Bowl. Take a drain line blockage reading
2 minutes after the water reaches the snag point.
[0220] Total number of flushes per sequence is 34.
[0221] If, after the second flush in the flushing sequence, the
product remains in the bowl or trap after flushing, the tissue and
or catamenial product is plunged into the drainage line manually
and the flushing sequence will continue. After completion of each
trial loading, the drainage pipe will be cleared prior to beginning
subsequent testing.
[0222] The above described flushing sequence is repeated three
times for each test product.
Data Reporting
[0223] The degree of drain line blockage is determined by measuring
the length of water dammed up behind the obstruction. Graduations
are marked every 12 inches (30 centimeters) on the drainpipe
upstream of the obstruction. Each one foot length that the water is
backed up corresponds to 0.25 inch (0.6 centimeter) or 6.25% of
blockage at the obstruction point. Test product residues which exit
the drainpipe are also collected.
[0224] The following data are recorded for each evaluation:
[0225] 1) Incidence of failure (%) of catamenial product to clear
bowl and trap in one flush
[0226] 2) Incidence of failure (%) of catamenial product to clear
bowl and trap in two flushes
[0227] 3) Incidence of product on simulated snag
[0228] 4) Maximum level (%) of drain line blockage
[0229] 5) Cumulative level (%) of drain line blockage over the 2
day simulated test period.
[0230] Preferably, the products described herein will completely
clear the bowl at least about 70% of the time in two or fewer
flushes, more preferably at least about 80% of the time in one
flush, and most preferably at least about 95% of the time in one
flush. The products described herein will preferably have a maximum
level of drain line blockage of less than or equal to about 80%.
The products described herein will preferably have a cumulative
level of drain line blockage over the 2 day simulated test period
of less than or equal to about 50%.
Preparation of Synthetic Fecal Material
[0231] I. Materials Needed:
[0232] Feclone synthetic fecal matter (900 grams); (Available from
Siliclone Studio, Valley Forge, Pa. as product BFPS-7 dry
concentrate )
[0233] Tap water at 100.degree. C. (6066 grams)
[0234] II. Equipment Needed:
[0235] Mixer (Available from Hobart Corp., Troy, Ohio as Model
A200)
[0236] Extruder (Available from Hobart Corp., Troy, Ohio. as Model
4812)
[0237] Disposable Centrifuge tubes with screw caps (50 ml)
(Available from VWR Scientific, Chicago, Ill. as Catalog No.
21-008-176)
[0238] Water Bath to control temperature to 37.degree. C.
[0239] III. Preparation:
[0240] 1. Pour the 100.degree. C. water into the mixing bowl of the
mixer and add the dry Feclone concentrate.
[0241] 2. Mix on low for 1 minute.
[0242] 3. Mix on medium speed for 2 minutes.
[0243] 4. After the material is well mixed, transfer to the
extruder.
[0244] 5. Using an ice pick, punch a small hole in the tip of each
centrifuge tube.
[0245] 6. Extrude the Feclone into the centrifuge tubes.
[0246] 7. Cap the centrifuge tubes and store in the
refrigerator.
[0247] 8. Before using, put the tubes in the water bath at
38.degree. C.
Specific Illustrations of the Preparation of Emollient-treated
Interlabial Devices
[0248] The following are specific illustrations of interlabial
devices with emollient compositions in accordance with the present
invention:
EXAMPLE 1
[0249] A. Preparation of Emollient Compositions
[0250] A water free emollient composition (Emollient 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:
3 TABLE I Component Weight % Mineral Oil 50 Cetearyl Alcohol 35
Steareth-2 15
[0251] B. Preparation of Emollient-Treated Interlabial Device by
Hot Melt Spraying
[0252] Emollient Composition A 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 body-contacting surface of the
interlabial device. Add-on level=2.3 mg/cm.sup.2).
EXAMPLE 2
[0253] A. Preparation of Emollient Compositions
[0254] A water free emollient composition (Emollient 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:
4 TABLE II Component Weight % Mineral Oil 65 Cetearyl Alcohol
35
[0255] B. Preparation of Emollient-Treated Interlabial Device by
Hot Melt Spraying
[0256] Emollient 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) body-contacting surface of the interlabial
device. Add-on level=0.006 g/in.sup.2 (2.3 mg/cm.sup.2).
EXAMPLE 3
[0257] A. Preparation of Emollient Composition
[0258] A water free emollient composition (Emollient 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);
Cetearth 10 (a blend or mixture of C.sub.16 and C.sub.18 alcohols
ethoxylated to an average of 10 ethoxylate units obtained from BASF
Corp. of Mount Olive, N.J.). The weight percentages of these
components are shown in Table I below:
[0259] A water free emollient composition (Emollient 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:
5 TABLE III Component Weight % WhiteProtopet .RTM. 50 1S Cetearyl
Alcohol 35 Cetearth-10 15
[0260] B. Preparation of Emollient-Treated Interlabial Device by
Hot Melt Spraying
[0261] mollient Composition C 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) body-contacting surface of the interlabial
device. Add-on level=0.004 g/in.sup.2 (1.5 mg/cm.sup.2).
EXAMPLE 4
[0262] A. Preparation of Emollient Composition
[0263] A water free emollient composition (Emollient 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:
6 TABLE IV Component Weight % WhiteProtopet .RTM. 52 1S
Polyphenylmethyl- 10 siloxane Paraffin Wax 15 Cetearyl Alcohol 20
PEG 2000 3
[0264] B. Preparation of Emollient-Treated Interlabial Device by
Hot Melt Spraying
[0265] Emollient 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) body-contacting surface of the interlabial
device. Add-on level=0.006 g/in.sup.2 (2.3 mg/cm.sup.2).
[0266] While particular embodiments of the present invention have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
invention.
* * * * *