U.S. patent application number 11/106402 was filed with the patent office on 2005-09-15 for absorbent article comprising an agent able to convey a perception to the wearer, without the need to create the external condition perceived.
This patent application is currently assigned to The Procter & Gamble Company. Invention is credited to Carlucci, Giovanni, Di Cintio, Achille, Meo, Daniela, Pesce, Antonella.
Application Number | 20050203473 11/106402 |
Document ID | / |
Family ID | 32109063 |
Filed Date | 2005-09-15 |
United States Patent
Application |
20050203473 |
Kind Code |
A1 |
Pesce, Antonella ; et
al. |
September 15, 2005 |
Absorbent article comprising an agent able to convey a perception
to the wearer, without the need to create the external condition
perceived
Abstract
The present invention relates to absorbent articles, such as
sanitary napkins, panty-liners, nursing pads, baby diapers and the
like. The absorbent articles include an agent able to convey a
perception to the wearer, without the need to create the external
condition perceived by the wearer. Such absorbent articles are able
to improve comfort, by, for example, conveying to the wearer
thereof a long lasting freshness sensation upon prolonged wearing
time of such articles.
Inventors: |
Pesce, Antonella; (Pescara,
IT) ; Meo, Daniela; (Salerno, IT) ; Carlucci,
Giovanni; (Chieti, IT) ; Di Cintio, Achille;
(Pescara, IT) |
Correspondence
Address: |
THE PROCTER & GAMBLE COMPANY
INTELLECTUAL PROPERTY DIVISION
WINTON HILL TECHNICAL CENTER - BOX 161
6110 CENTER HILL AVENUE
CINCINNATI
OH
45224
US
|
Assignee: |
The Procter & Gamble
Company
Cincinnati
OH
|
Family ID: |
32109063 |
Appl. No.: |
11/106402 |
Filed: |
April 14, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11106402 |
Apr 14, 2005 |
|
|
|
10687687 |
Oct 17, 2003 |
|
|
|
Current U.S.
Class: |
604/367 |
Current CPC
Class: |
A61L 2300/802 20130101;
A61L 2300/20 20130101; A61L 15/46 20130101; A61L 15/20 20130101;
A61L 2300/40 20130101 |
Class at
Publication: |
604/367 |
International
Class: |
A61F 013/15; A61F
013/20 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 17, 2001 |
EP |
01109350.7 |
Apr 16, 2002 |
WO |
PCT/US02/11910 |
Claims
What is claimed is:
1. An absorbent article comprising an agent able to convey a
perception to the wearer, without the need to create the external
condition perceived by the wearer, wherein said article is selected
from the group consisting of panty liners, sanitary napkins,
incontinent pads, interlabial pads, and breast pads.
2. The article according to claim 1, wherein the agent is a cooling
agent able to stimulate thermo-receptors of the skin and/or mucosal
surface of the wearer of the article, to convey a freshness
sensation to the wearer, without the need to change the temperature
on the skin and/or mucosal surface.
3. The article according to claim 2 wherein the cooling agent is
selected from the group consisting of ketals, carboxamides,
cyclohexyl derivatives, cyclohexanol derivatives, camphor, borneol,
eucalyptol, methyl salicylate, tea tree oil, eucalyptus oil,
peppermint oil and mixtures thereof.
4. The article according to claim 2, wherein the cooling agent is
selected from the group consisting of: ketal according to the
following formula: 16in which R.sup.1 represents a
C.sub.2-C.sub.6-alkylene radical having at least 1, but not more
than 3, hydroxyl group(s), preferably I hydroxyl group, and either
R.sup.2 and R.sup.3 independently of one another represent
C.sub.1-C.sub.10-alkyl which is optionally substituted by about 1
to about 3 radicals selected from the group comprising hydroxyl,
amino and halogen, C.sub.5-C.sub.7-cycloalkyl, preferably
cyclohexyl, C.sub.6-C.sub.12-aryl, preferably phenyl, with the
proviso that the total of the C atoms of R.sup.2 and R.sup.3 is not
less than 3, or R.sup.2 and R.sup.3 together represent an alkylene
radical which, together with the carbon atom which carries the
radicals R.sup.2 and R.sup.3, forms a 5-7-membered ring, it being
possible for this alkylene radical, in turn, to be substituted by
C.sub.1-C.sub.6-aklyl groups, or mixtures thereof; or a carboxamide
of the following formula: 17wherein R', when taken separately, is
hydrogen or an aliphatic radical containing up to about 25 carbon
atoms; R" when taken separately is hydroxy, or an aliphatic radical
containing up to about 25 carbon atoms, with the proviso that when
R' is hydrogen, R" may also be an aryl radical of up to about 10
carbon atoms and selected from the group consisting of substituted
phenyl, phenalkyl or substituted phenalkyl, naphthyl and
substituted naphthyl, pyridyl; and R' and R", when taken together
with the nitrogen atom to which they are attached, represent a
cyclic or heterocyclic group of up to about 25 carbon atoms,
18wherein R' and R", when taken separately, are each hydrogen,
C.sub.1-C.sub.5 alkyl or C.sub.1-C.sub.8 hydroxyalkyl and provide a
total of no more than about 8 carbon atoms, with the proviso that
when R' is hydrogen, R" may also be alkylcarboxyalkyl of up to
about 6 carbon atoms; R' and R", when taken together, represent an
alkylene group of up to 6 carbon atoms, the opposite ends of which
group are attached to the amide nitrogen atom thereby to form a
nitrogen heterocycle, the carbon chain of which may optionally be
interrupted by oxygen; R.sub.1 is hydrogen or C.sub.1-C.sub.5
alkyl; and R.sub.2 and R.sub.3 are each C.sub.1-C.sub.5 alkyl; with
the provisos that (i) R.sub.1, R.sub.2 and R.sub.3 together provide
a total of at least about 5 carbon atoms, preferably from about
5-10 carbon atoms; and (ii) when R.sub.1 is hydrogen, R.sub.2 is
C.sub.2-C.sub.5 alkyl and R.sub.3 is C.sub.3-C.sub.5 alkyl and at
least one of R.sub.2 and R.sub.3 is branched, preferably in an
alpha or beta position relative to the carbon atom marked (*) in
the formula, or a mixture thereof; or a cyclohexanol derivative
according to the following general formulae: 19wherein R represents
a linear or branched alkyl group having about 1 to about 5 carbon
atoms, 20wherein R.sup.1 and R.sup.2 are independently hydrogen, or
a linear or branched alkyl group having about 1 to about 5 carbon
atoms, or mixtures thereof; or a cyclohexyl derivative according to
the following general formula 21wherein R represents --H, a
C.sub.1-C.sub.5 linear or branched alkyl group, a C.sub.1-C.sub.5
alkenyl group, a C.sub.1-C.sub.5 alkoxy group or a C.sub.1-C.sub.5
acyloxy group, R.sub.1 represents --H, or a linear or branched
alkyl group having from 1 to 5 carbon atoms, or mixtures thereof,
or a mixture thereof.
5. The article according to claim 2, wherein the cooling agent is
menthyl lactate.
6. The article according to claim 2, which comprises menthol as a
first cooling agent in combination with a second cooling agent,
preferably selected from the group consisting of ketals,
carboxamides, cyclohexyl derivatives other than menthol,
cyclohexanol derivatives and mixtures thereof.
7. The article according to claim 2, which comprises on at least a
portion of the article from about 0.01 gm.sup.2 to about 300
gm.sup.2 of a cooling agent or a mixture thereof.
8. The article according to claim 1, comprising a delivery system
for containing and delivering the agent to at least a portion of
the skin and/or mucosal surface of mammal wearing the article.
9. The article according to claim 8, wherein the delivery system is
an emollient-containing composition comprising from about 0.1% to
about 99.9%, by weight of the agent or mixture thereof, and from
about 99.9% to about 0.1%, by weight of the emollient or mixture
thereof.
10. The article according to claim 9, wherein the delivery system
comprises an emollient typically selected from the group consisting
of petroleum-based; fatty acids, particularly those having from
about 8 to about 28 carbon atoms in their fatty chain; sucrose
ester fatty acids; polyethylene glycol and derivatives thereof;
fatty acid ester type; alkyl ethoxylate type; fatty acid ester
ethoxylates; fatty alcohol type; polysiloxane type; propylene
glycol and derivatives thereof; glycerine and derivatives thereof,
including glyceride, acetoglycerides, and ethoxylated glycerides of
C.sub.8-C.sub.28 fatty acids; spermaceti and other waxes; fatty
alcohol ethers, particularly those having from about 8 to about 28
carbon atoms in their fatty chain, propoxylated fatty alcohols;
other fatty esters of polyhydroxy alcohols; lanolin and its
derivatives; kaolin and its derivatives; sorbitol and its
derivative; trihydroxy stearin; ester derivatives and mixtures
thereof.
11. The article according to claim 8, wherein the delivery system
comprises triethyl citrate, acetyl tributyl citrate, triacetyl
citrate, O acetyl triethyl citrate, polyethylene glycol and/or
propylene glycol.
12. The article according to claim 1, wherein the article comprises
a wearer-facing surface, wherein at least a portion of the
wearer-facing surface comprises the agent.
13. The article according to claim 1, wherein said article is a
hygienic absorbent article comprising a topsheet as a wearer facing
surface, a backsheet as a garment facing surface and an absorbent
core sandwiched between the topsheet and backsheet.
14. The absorbent article according to claim 13, wherein said
backsheet comprises at least one layer selected from an apertured
polymeric film or a 2-dimensional planar apertured film.
15. The absorbent article according to claim 14, wherein said layer
is a 2-dimensional planar apertured layer, wherein said apertures
have an average diameter of from about 150 micrometers to about 1
micrometers.
16. The absorbent article according to claim 14, wherein said layer
is an apertured polymeric film, wherein said apertures have an
average diameter of from about 100 micrometers to about 500
micrometers.
17. The absorbent article according to claim 14, wherein said
breathable backsheet comprises at least two layers, a first layer
comprising an apertured layer and a second layer comprising a
fibrous layer.
18. The article according to claim 1, wherein at least a portion of
the article is provided in a color that further contributes to the
perception conveyed to the wearer of the article.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser.
No. 10/687,687 filed Oct. 17, 2003, pending.
FIELD OF THE INVENTION
[0002] The present invention relates to absorbent articles in
particular sanitary napkins and panty liners, which comprise an
agent able to convey a perception to the wearer of the articles,
without the need to create the external condition perceived.
[0003] Suitable agents to be used according to the present
invention are for example agents that are able to stimulate
thermo-receptors of human body (e.g., cold or heat receptors)
without the need to create a temperature change at the skin and/or
mucosal surface of the wearer of the article.
BACKGROUND OF THE INVENTION
[0004] A more and more important consumer need, which underlies
development in the absorbent article field, in particular
catamenials, is the provision of products with higher comfort level
during use.
[0005] One means for providing consumer comfort benefits in
absorbent articles is by the provision of breathable products.
Breathability has typically concentrated on the incorporation of so
called `breathable backsheets` in the absorbent articles. Commonly
utilized breathable backsheets are microporous films and apertured
formed films having directional fluid transfer as disclosed in for
example U.S. Pat. No. 4,591,523. Both these types of breathable
backsheets are vapour permeable allowing gaseous exchange with the
environment. This thereby allows for the evaporation of a portion
of the fluid stored in the core and increases the circulation of
air within the absorbent article. The latter is particularly
beneficial as it reduces the sticky feeling experienced by many
wearers during use.
[0006] Although absorbent articles, such as diapers for babies or
sanitary napkins or panty liners for women, have improved a lot the
last years with respect to various features like protection and
comfort in use, there is still a consumer need for further
improvements, namely making more pleasant the experience of wearing
absorbent articles, like feminine hygienic absorbent articles,
especially upon prolonged wearing periods.
[0007] It is thus an object of the present invention to provide
absorbent articles, preferably those for feminine protection, which
make the wearing experience more pleasant, thereby improving
comfort in use.
[0008] It has now been found that improved pleasantness to the
wearing experience can be achieved by providing absorbent articles,
like sanitary napkins and panty liners, comprising an agent able to
convey a perception to the wearer of the articles, without the need
to create the external condition perceived by the wearer.
Advantageously the present invention provides an absorbent article
that provides an useful function, namely conveying improved comfort
to the wearer of the article by simulating various sensations as
desired like cooling sensation or warming sensation, without
changing the environmental conditions at the surface of the
wearer's body to which the article is contacted.
[0009] The agent(s) used in an article of the present invention,
has(ve) the ability to cause a subjective perception/sensation to
the wearer without the need to create the external condition
perceived by the wearer of the article. This perception/sensation
is attributed to the direct stimulus on the receptors at the
sensory nerve endings, which in turn stimulate the central nervous
system. The receptors concerned are sensory receptors able to
convey warm, cold, tactile or pain sensation.
[0010] In a preferred embodiment the absorbent articles according
to the present invention like sanitary napkins and panty liners
comprise a cooling agent able to convey a cooling/freshness
sensation, without the need to create the corresponding external
condition perceived by the wearer, i.e., without the need to change
temperature at body surface of the wearer of the article. The
cooling agents suitable for use in the article herein are able to
directly stimulate the thermo-receptors of the skin and/or mucosal
membrane of the wearer of the article. It is further noticeable
that due to the persistence of the stimuli a long lasting
cooling/freshness sensation is delivered, this even after stopping
direct contact between the skin and/or mucosal surface and the
article, more precisely the cooling agent. Advantageously, these
freshness properties are delivered without that any wet feeling is
perceived on the contact of the article with skin and/or mucosal
surface, resulting thereby in outstanding freshness and dryness
sensation and hence cleanness sensation. Furthermore, the
perception of freshness and dryness sensation by the wearer of the
article is believed to reduce the tendency of the wearer to
perspire.
[0011] Suitable cooling agents for use herein to deliver above
mentioned benefits are typically selected from the group consisting
of peppermint oil, eucalyptol, eucalyptus oil, methyl salicylate,
camphor, tea tree oil, ketals, carboxamides, cyclohexanol
derivatives, cyclohexyl derivatives described herein after and
mixtures thereof.
[0012] Preferred cooling agents for use herein are ketals,
carboxamides, cyclohexanol derivatives, cyclohexyl derivatives
other than menthol, for example menthyl lactate. All these cooling
agents beside their long lasting cooling properties have the
advantage of being less irritating to skin than menthol,
substantially free of mint-type odor and physically stable at use
and room temperatures. Indeed, all these cooling agents do not have
the tendency to sublimate at usage (direct contact with body) or
room temperatures in contrast to menthol, thereby resulting in
improved stability in use conditions and during storage of the
article. Advantageously the whole activity potential of these
cooling agents is maintained up to the time it is needed, i.e., up
to the time the article is worn by for example a human and during
that wearing time.
[0013] The agent used herein may be present neat (powder, flakes,
particles, wax, liquid and the like) or may be in a carrier vehicle
as a solution, suspension, dispersion, emulsion and the like.
Moreover the agent may be releasably contained by a microcapsule,
an absorbent material, a cell, an adhesive, an emollient-containing
composition, a solid support, a nanophase particulate structure and
the like. Indeed, in a preferred embodiment herein the article
according to the present invention comprises a delivery system for
releasably containing and delivering the agent to at least a
portion of the skin and/or mucosal surface of the wearer of the
article. The delivery system may be of any configuration including,
but not limited to, one that contains the agent in powder, particle
or flake form, or in a solution, a dispersion, a suspension, an
emulsion or the like. The delivery system may comprise a structure
such as a microcapsule, an absorbent material, a nanophase
particulate structure, a cell, an adhesive, a solid support, or the
like or a composition such as an emollient-containing composition.
Preferably the delivery system is an emollient-containing
composition. In one particularly suitable embodiment herein the
emollient-containing composition consists essentially of the
emollient and the agent used herein without any additional
compound. Preferably the delivery system positions the agent in
proximity to the skin during wear of the article and, more
preferably, onto at least a portion of the skin and/or mucosal
surface of the wearer of the article.
[0014] The presence of a delivery system, preferably
emollient-containing composition, is desirable as it provides for
faster perception to the wearer of the article as well as sustained
perception upon prolonged wearing time. Indeed, without to be bound
by any theory, it is speculated that the delivery system, namely
emollient-containing composition (preferably ester derivatives as
described herein after--for example triethyl citrate), acts as a
carrier for the agent like the cooling agent as described herein,
to help it migrate from its location in the article to the body
surface of the wearer (skin and/or mucosal surface), penetrate the
outer layers of the skin (stratum corneum) and bring it into direct
and prolonged contact with the receptors (e.g., thermo-receptors)
of mammal skin and/or mucosal surface. In other words, the delivery
system, namely emollient-containing composition, like ester
derivatives described herein after, helps the agents like cooling
agents to reach their target, namely thermo-receptors, in faster
condition, thereby delivering a more immediate freshness sensation
and maintain it in prolonged contact with the thermo receptors,
thereby promoting long lasting freshness sensation as compared to
the same article comprising the cooling agents at same level but
neat. Advantageously, in the preferred embodiment herein the
presence of an emollient on top of the cooling agents delivers an
optimized freshness sensation (both more immediate and upon
prolonged wearing time of the article), while maintaining or even
improving skin health. Indeed, the presence of emollient
moisturizes/hydrates and softens the skin and tends to reduce
roughness, cracking and skin irritation.
[0015] Additionally the presence of such delivery system, namely
the emollient-containing composition as described herein after,
helps solubilisation of the agent like the cooling agent, thereby
facilitating homogeneous application (if desired) of the agent over
at least a portion of the article. In a preferred embodiment herein
the agent is applied on the wearing facing surface of the article
in a homogeneous way thereby further contributing to faster and
sustained perception during prolonged wearing time of the
article.
[0016] Yet a further advantage of the presence of such delivery
system, namely the emollient-containing composition as described
herein after, is its contribution to physical and chemical
stability of the agent during storage and use of the articles
herein.
[0017] In a preferred embodiment herein, wherein the agent is a
cooling agent, typically those described herein after, the article
according to the present invention is breathable, i.e., liquid
vapor permeable and preferably air permeable. Indeed, the
breathability of the article further contributes to the freshness
and dryness sensation, and especially to long lasting freshness and
dryness sensation. Without to be bound by theory, it is speculated
that the use of breathable article is able to maintain a more
comfortable skin surface temperature over the skin surface which it
covers, that is closer to the temperature of the skin surface when
the consumer is not wearing such an article in contrast to non
breathable article. This will provide a more ideal or `normal`
temperature perception in the genital region and hence contributes
to the freshness sensation provided by the presence of the cooling
agent in the article of the present invention. Also the
breathability of the article reduces humidity at the article/skin
interface and hence increases the dryness sensation. This increase
in freshness and dryness sensation to the wearer results in
outstanding cleanliness perception.
[0018] By using breathable absorbent articles, not only improved
comfort (i.e., improved freshness and dryness sensation) to the
wearer during use is provided but also reduction of malodour
perception. It is believed that the breathable environment does not
only contribute to the primary comfort benefit (freshness and
dryness sensation) but also provides effective reduction or even
prevention of malodor formation typically associated with body
discharge onto the article worn into contact with human body.
Indeed the breathability of the article, which reduces the hot,
humid and anaerobic environment between the skin of the wearer and
the surface of the article, contributes in an overall reduction of
growth of microorganisms, known as being responsible of malodor
formation. Furthermore, the reduction in the hot, humid and
occlusive environment between the vicinity of the skin of the
wearer and the article itself also reduces the tendency of the
wearer to perspire. Consequently, the amount of associated
perspiration related odour is reduced too.
[0019] In an embodiment herein the articles according to the
present invention might comprise on top of the agents, typically
cooling agents, any odor control agent (e.g., zeolite, silicate,
silica, chelating agents, oxidizing agents, antimicrobial agents
and the like). Such articles are particularly beneficial for
further improving comfort and discretion in use.
BACKGROUND ART OF THE INVENTION
[0020] In U.S. Pat. Nos. 5,649,914 and 5,797,892; a toilet training
aid is disclosed which generates a heating or cooling effect in the
presence of urine from the wearer within the article. The heating
or cooling effect is intended to cause the wearer discomfort in an
attempt to aid in the toilet training process. This heating or
cooling effect performs no useful function upon the article itself.
Instead, the toilet training aid acts upon the wearer to cause the
wearer to take some action (i.e., remove the wet article and apply
a new one). Further, the toilet training aid responds solely to
conditions within the article itself, not to conditions between the
article and the wearer. Further, the toilet training aid is only
functioning for a short period of time and is not designed to
provide a sustained reduction in relative humidity or temperature
for typical wear times. EP 704 195 discloses sanitary napkins to be
used as menstrual detector containing a temperature-sensitive
reactive chemical. Example of such temperature-sensitive reactive
chemical include sodium thiosulfate or sodium hyposulfite, which
can respond by turning cold upon coming into contact with and
dissolving in a hot liquid, such as a menstrual flow. This art on
hygienic disposable absorbent articles mentioned herein before in
no way teaches an effort to improve comfort of the wearer by
modifying perception by the nervous central system of the wearer
without modifying the external environmental conditions perceived
by the wearer.
[0021] Cooling agents that provide cooling sensation without
modifying temperature on skin and/or mucosal surfaces per se are
known as well as their application in edible compositions like
beverages and chewing-gum, in cosmetic products like shave lotions,
deodorants, face creams, shampoos, toilet soaps and dentifrices, in
tobacco preparations like cigars, cigarettes and chewing tabacco.
See for example U.S. Pat. No. 5,451,404, U.S. Pat. No. 5,266,592 or
DE 26 08 226. WO 96/14840 also discloses the use of menthyl lactate
as pain reliever.
[0022] None of these prior art references discloses nor suggests
absorbent articles, namely hygienic disposable articles like
sanitary napkins and/or panty liners, comprising an agent able to
convey a perception to the wearer (for example a warming or
freshness/cooling sensation) without the need to create the
external condition perceived by the wearer, for example without the
need to change environmental temperature conditions, whereby
improved comfort and discretion is delivered.
SUMMARY OF THE INVENTION
[0023] This invention encompasses an absorbent article comprising
an agent able to convey a perception to the wearer without the need
to create the external condition perceived by the wearer.
[0024] Highly preferred articles are feminine hygienic disposable
absorbent articles like sanitary napkins and/or panty liners.
[0025] Highly preferred agents according to the present invention
are cooling agents that are able to chemically stimulate the
thermo-receptors of human skin and/or mucosal surface, to convey a
freshness sensation to the wearer of the article, without the need
to modify the temperature at the skin/mucosal surface.
[0026] In a preferred embodiment the absorbent articles comprise a
delivery system for containing and delivering the agent, preferably
cooling agent, to at least a portion of the skin and/or mucosal
surface of a wearer of the article. Preferably the delivery system
is an emollient-containing composition comprising an emollient on
top of the agent. The emollient-containing composition allows
delivering more rapidly a perception/sensation to the wearer of the
article upon contact of the article to the skin and/or mucosal
surface while maintaining the perception/sensation upon prolonged
wearing time, typically during all the wearing time of the article,
this while maintaining or even improving skin health.
[0027] In a preferred embodiment the absorbent article according
the present invention is breathable. The breathability of the
article which reduces the hot, humid and occlusive environment
between the skin of wearer of the article and the article
contributes to the freshness and dryness sensation perceived by the
use due to the presence of the cooling agent as described herein,
this upon prolonged wearing time, thereby resulting in further
improved cleanness feeling.
DETAILED DESCRIPTION OF THE INVENTION
[0028] By "article" it is meant herein any tridimentional solid or
semi-solid substrate/material being able to comprise an agent as
described herein and being suitable to be worn in direct contact
with skin and/or mucosal surface of human body.
[0029] The term "disposable" is used herein to describe articles
that are not intended to be launched or otherwise restored or
reused as an article (i.e., they are intended to be discarded after
a single use and, preferably to be recycled, composted or otherwise
disposed of in an environmentally compatible manner).
[0030] As used herein, the term `hygienic article` refers to
various articles of comfort and/or medical use, for the use by
babies and adults or even animals.
[0031] The term "absorbent article" is used herein in a very broad
sense including any article able to receive and/or absorb and/or
contain and/or retain fluids and/or exudates, especially body
fluids/body exudates. "Absorbent articles" as referred to herein
include, without to be limited to, sanitary napkins, panty liners,
incontinence pads, interlabial pads, breast pads, sweat-absorbent
underarm pads, collar inserts, baby diapers, adult incontinence
diapers, and human waste management devices. Typically such human
urine or faecal management devices comprise a bag having an
aperture and a flange surrounding the aperture for preferably
adhesive attachment to the urogenital area and/or the perianal area
of a wearer. Any faecal or urine management device known in the art
is suitable for use herein. Such devices are described in for
example WO 99/00084 to WO 99/00092.
[0032] As used herein, the term `wearer-facing` surface refers to
the surface of the component of the article generally oriented to
face the wearer skin and/or mucosal surface during use of the
article. As used herein, the term `garment facing` surface refers
to the opposite outer surface of the article, typically the surface
directly facing the garment of a wearer, if worn in direct contact
with garment.
[0033] As used herein, the term `body fluids and/or body exudates`
refers to any fluids/exudates produced by human body occurring
naturally or accidentally like for instance in the case of skin
cutting, including for instance perspiration, urine, menstrual
fluids, faeces, vaginal secretions and the like.
[0034] As used herein the term, `maintain skin health` means to
preserve the natural state of healthy skin. The term `improve skin
health` refers to a reduction in the extent of adverse skin
effects. These terms describe skin health in the area covered by
the articles. It will be recognized that the articles of the
present invention maintain or even improve skin health in different
regions of an individual wearer.
Agent
[0035] According to the present invention the articles comprise as
an essential component an agent able to convey a perception to the
wearer without the need to create the external condition perceived
by the wearer.
[0036] By `external condition` it is meant environmental condition
at body surface, typically skin and/or mucosal surface of the
wearer of the article to which the article is applied to/contacted
to.
[0037] By `perception` it is meant the result perceived by the
nervous central system of a wearer, of a multistep process
initiated by the stimulation of one or more sensory receptors of
the skin and/or mucosal surface of said wearer.
[0038] Such perceptions typically include tactile sensation,
warming sensation, cooling/freshness sensation, pain-free sensation
and the like. Each of these perceptions/sensations is initiated by
the stimulation of one or more sensory receptors (e.g.,
thermo-receptors include warm and cold receptors, noci-receptors
and the like).
[0039] More details on such receptors are available in literature.
An example of reference on thermo-receptors is:"Thermal sensation
and thermo-receptors in man" by Herbert Hensel, M D, published by
Charles C. Thomas in 1982.
[0040] The articles of the present invention comprise an amount of
the agent sufficient to stimulate the receptors in the areas of the
skin and/or mucosal surfaces with which the articles come into
contact and thereby promote the desired perception/sensation. As
the type, degree and longevity of the sensation varies from agents
to agents, the amount of agents used in each article will vary
widely.
[0041] Highly preferred agents for use herein are warming or
cooling agents, which are typically able to stimulate
thermo-receptors (i.e., hot or cold sensory receptors), without the
need to create temperature change at the body surface of the wearer
of the article.
[0042] The cooling agents suitable for use herein include all
cooling agents being able to penetrate skin barrier and for which
the cooling effect (also called herein freshness effect) is a
physiological effect due to the direct action of these agents on
the nerve endings of the body responsible for the detection of cold
without any occurrence of temperature change on the surface of the
body. It is believed that these agents act as a direct chemical
stimulus on the cold receptors at the nerve endings, which in turn
stimulate the central nervous system. In this way a
freshness/cooling sensation is simulated even in absence of real
change in skin temperature. Due to the persistence of the stimuli a
long lasting freshness/cooling sensation is delivered even after
removal of the cooling agent.
[0043] It is to be understood herein that the freshness/cooling
sensation is personnel to a given individual. It must be admitted
that skin tests are somewhat subjective, some individuals
experiencing a greater or lesser freshness/cooling sensation than
others when subjected to the same test. This perception depends on
the density of thermo-receptors on skin and on the skin thickness.
Typically it is observed that the thinner the skin is the more
intense is the cooling sensation (also called herein freshness
sensation). Without to be bound by any theory, it is believed that
the thinner the skin is, the more rapid is the penetration of the
cooling agent through the skin and higher is the absorption level
thereof. Furthermore studies have demonstrated that geographic
factors and/or races further play a role in perception of freshness
sensation.
[0044] Studies performed on cooling agent activity have showed that
four features of the molecular structure of the cooling agents are
particularly important to deliver freshness/cooling sensation.
Reference is made to H. R. Watson et al., Journal of the Society of
Cosmetic Chemist, Vol. 29, p 185-200, 1978, incorporated herein per
reference.
[0045] Suitable cooling agents for use herein posses the following
properties:
[0046] a hydrogen binding function--The cooling agents apparently
need to have an atom or group able to bind hydrogen. The stronger
the molecule's hydrogen binding capacity, the stronger the cooling
effect. However, the presence of more than one hydrogen-binding
group in its molecule can reduce its cooling effect, as the
molecule would no longer have the correct lipophilic
characteristics;
[0047] a compact hydrocarbon skeleton such that the body's receptor
is able to `recognize` them;
[0048] a balance between their hydrophilic and hydrophobic parts
for both delivering cooling properties and able them to penetrate
the biological membrane such as outer skin layers--The most common
method of determining this balance is to use the Hansch log P
value--the coefficient of water and n-octanol distribution
according to Hansch. The log P value is acknowledged as being a
crucial factor in a substance's pharmacological
activity--especially as regards how it is transported through skin.
The log p values of preferred cooling agents for use herein
generally lies somewhere between 2.0 and 3.0;
[0049] typically a molecular weight of between 150 and 350.
[0050] Without to be bound by theory, it is speculated that
suitable cooling agents for use herein are those being able to
penetrate through the skin surface and depolarize (clear the
potential differential between the inside and outside nervous cell
membranes by blocking calcium ion exchange) the membrane of cold
receptors. The perception of freshness sensation is the result of
the depolarization. More particularly, it is believed that due to
binding calcium properties of the cooling agents, the equilibrium
between the concentration of calcium ion outside and inside the
nervous cell membrane is disturbed. In other words, by reducing the
calcium ion level outside the nervous cell membrane, the membrane
is depolarized, resulting thereby in increased discharge rate of
nerve fibers and hence transfer of electrical stimuli to central
nervous system. Without to be bound by any theory, it is believed
that the long lasting effect is linked to binding stability
properties of the cooling agent and calcium ion complex. The higher
is the stability of the complex cooling agent-calcium ion, the
longer the calcium is linked to the cooling agent, the longer is
the resulting freshness sensation.
[0051] Suitable cooling agents typically include menthol or
peppermint oil. Although such compounds are known to provide
freshness sensation, they suffer the disadvantage of having strong
mint odor, being irritant to skin at high concentration and
sublimating at room temperature. Thus highly preferred cooling
agents for use herein are those, which are less odorant than
menthol or peppermint oil. Actually mint odor-free cooling agents
are preferred herein to be used alone or in combination with
menthol (or sources thereof like peppermint oil or other plant
extracts containing them), thereby providing articles which have
improved odour profile and skin safety profile.
[0052] Particularly suitable cooling agents to be used herein
include ketals, carboxamides, cyclohexanol derivatives and/or
cyclohexyl derivatives.
[0053] Ketals:
[0054] Ketals suitable for use herein are according to the
following formula: 1
[0055] in which R.sup.1 represents a C.sub.2-C.sub.6-alkylene
radical having at least 1, but not more than 3, hydroxyl group(s),
preferably one hydroxyl group, and either R.sup.2 and R.sup.3
independently of one another represent C.sub.1-C.sub.10-alkyl which
is optionally substituted by 1 to 3 radicals selected from the
group comprising hydroxyl, amino and halogen (such as fluorine,
chlorine, bromine or iodine), C.sub.5-C.sub.7-cycloalkyl,
preferably cyclohexyl, C.sub.6-C.sub.12-aryl, preferably phenyl,
with the proviso that the total of the C atoms of R.sup.2 and
R.sup.3 is not less than 3, or R.sup.2 and R.sup.3 together
represent an alkylene radical which, together with the carbon atom
which carries the radicals R.sup.2 and R.sup.3, forms a
5-7-membered ring, it being possible for this alkylene radical, in
turn, to be substituted by C.sub.1-C.sub.6-aklyl groups.
[0056] Preferred radicals R.sup.2 and R.sup.3 comprise methyl,
isopropyl and tert-butyl.
[0057] The length of the radicals R.sup.2 and R.sup.3 influences
the effect of the compounds I: shorter radicals lead to an
immediate, short effect; longer radicals lead to a delayed, but
prolonged effect. When solubility of the compounds in water is
desired it is preferable to use the compounds with short radicals
R.sup.2 and R.sup.3.
[0058] Preferred radicals R.sup.1 embrace 1,2- and 1,3-alkylene
radicals, which, together with the two oxygen atoms and with the
carbon atom to which the two oxygen atoms are attached, form a
dioxolane or dioxane ring.
[0059] Preferred compounds I in which R.sup.2 and R.sup.3 together
represent an alkylene radical are those of the formula 2
[0060] in which R.sup.4 to R.sup.15 independently of one another
denote hydrogen or C.sub.1-C.sub.6-alkyl, preferably hydrogen or
C.sub.1-C.sub.4-alkyl, and m and n independently of one another
denote zero or 1.
[0061] Preferred compounds of the formula Ia are those in which the
total of m+n is 1, i.e. ketals of an optionally substituted
cyclohexanone.
[0062] Preferred substituents, of which there may be present, in
particular, 1 to 3, are methyl, isopropyl and tert.-butyl.
[0063] The ketals I can be prepared by known processes. For
example, ketal I will generally be prepared by acid-catalysed
reaction of the ketone on which ketal I is based and not less than
the equivalent amount of aliphatic C.sub.3-C.sub.6-alcohol having
not less than 3 and not more than 5, preferably 3, hydroxyl groups.
In general, the ketone on which ketal I is based and not less than
0.5 tool equivalents, but, as a rule, a 1.2- to 4-fold, preferably
1.5- to 3-fold excess of this amount of the C.sub.3-C.sub.6-alcohol
having 3 to 5 hydroxyl groups will be employed. Examples of acid
catalysts, which can be used, are p-toluenesulphonic acid,
phosphoric acid or potassium hydrogen sulphate in catalytically
effective amounts (for example 0.1 to 3 g of p-toluenesuphonic acid
per mole of ketone). The reaction will preferably be carried out
either in an organic solvent, which together with water forms an
azeotrope, so that the water, which is liberated during the
formation of the ketal, can be eliminated by azeotropic
entrainment, or water-consuming coreagents such as, for example,
trialkyl ortho esters are used. Examples of preferred organic
solvents comprise benzene, toluene, xylene, chloroform, methylene
chloride and trichloroethylene.
[0064] The reaction can be regarded as complete when water no
longer separates out or when an ester/alcohol mixture is no longer
separated out. It is recommended to wash the products subsequently
with dilute alkali and with water, to separate and dry the organic
phase, to strip off the solvent and, if appropriate, to purify the
residue, for example by distillation.
[0065] Particularly preferred ketals I are those of the formulae
3
[0066] in which R.sup.1 has the abovementioned meaning.
[0067] Particularly preferred ketals are the ketals II.
[0068] The ketals I to be employed herein can have asymmetric C
atoms; optical isomerism can therefore occur. Depending on the
starting material and the preparation methods used, they can exist
in the form of mixtures of the optical isomers or in the form of
pure isomers. The cooling effect of the isomers may differ, so that
one or the other isomer may be preferred.
[0069] These ketals are for example described and exemplified in
U.S. Pat. No. 5,266,592, incorporated herein by reference in its
entirety.
[0070] An example of ketal commercially available include a ketal
of formula (II) above, where R.sup.1 is ethyl--(2 hydroxymethyl),
namely menthone glycerol Ketal, available from Haarmann &
Reimer GmbH (Germany) under the name Frescolat MGA.RTM..
[0071] Carboxamides
[0072] The carboxamides found most useful to be used herein are
those described in U.S. Pat. No. 4,136,163, Jan. 23, 1979 to Wason
et al., and U.S. Pat. No. 4,230,688, Oct. 28, 1980 to Rawsell et
al. Both incorporated herein by reference in their entirety.
[0073] Particularly suitable carboxamides for use herein are
N-substituted-p-menthane3-carboxamides (U.S. Pat. No. 4,136,163).
These compounds are 3-substituted-p-menthanes of the formula: 4
[0074] where R', when taken separately, is hydrogen or an aliphatic
radical containing up to 25 carbon atoms; R" when taken separately
is hydroxy, or an aliphatic radical containing up to 25 carbon
atoms, with the proviso that when R' is hydrogen R" may also be an
aryl radical of up to 10 carbon atoms and selected from the group
consisting of substituted phenyl, phenalkyl or substituted
phenalkyl, naphthyl and substituted naphthyl, pyridyl; and R' and
R", when taken together with the nitrogen atom to which they are
attached, represent a cyclic or heterocyclic group of up to 25
carbon atoms, e.g. piperidino, morpholino etc.
[0075] In the above definitions "aliphatic" is intended to include
any straight-chained, branched-chained or cyclic radical free or
aromatic unsaturation, and thus embraces alkyl, cycloalkyl,
alkenyl, cycloalkenyl, alkynyl, hydroxyalkyl, acyloxyalkyl, alkoxy,
alkoxyalkyl, aminoalkyl, acylaminoalkyl, carboxyalkyl and similar
combinations.
[0076] Typical values for R' and R" when aliphatic are methyl,
ethyl, propyl, butyl, isobutyl, n-decyl, cyclopropyl, cyclohexyl,
cyclopentyl, cycloheptylmethyl, 2-hydroxyethyl, 3-hydroxy-n-propyl,
6-hydroxy-n-hexyl, 2-aminoethyl, 2-acetoxyethyl,
2-ethylcarboxyethyl, 4-hydroxy-2-butynyl, carboxymethyl etc. When
R" is aryl typical values are benzyl, naphthyl, 4-methoxyphenyl,
4-hydroxyphenyl, 4-methylphenyl, 3-hydroxy-4-methylpheny- l,
4-fluorophenyl, 4-nitrophenyl, 2-hydroxynaphthyl, pyridyl, etc.
[0077] Other suitable carboxamides for use herein are certain
acyclic tertiary and secondary carboxamides disclosed in U.S. Pat.
No. 4,230,688, incorporated herein by reference. These have the
structure 5
[0078] where R' and R", when taken separately, are each hydrogen,
C.sub.1-C.sub.5 alkyl or C.sub.1-C.sub.8 hydroxyalkyl and provide a
total of no more than 8 carbon atoms, with the proviso that when R'
is hydrogen R" may also be alkylcarboxyalkyl of up to 6 carbon
atoms;
[0079] R' and R", when taken together, represent an alkylene group
of up to 6 carbon atoms, the opposite ends of which group are
attached to the amide nitrogen atom thereby to form a nitrogen
heterocycle, the carbon chain of which may optionally be
interrupted by oxygen;
[0080] R.sub.1 is hydrogen or C.sub.1-C.sub.5 alkyl; and R.sub.2
and R.sub.3 are each C.sub.1-C.sub.5 alkyl; with the provisos that
(i) R.sub.1, R.sub.2 and R.sub.3 together provide a total of at
least 5 carbon atoms, preferably from 5-10 carbon atoms; and (ii)
when R.sub.1 is hydrogen, R.sub.2 is C.sub.2-C.sub.5 alkyl and
R.sub.3 is C.sub.3-C.sub.5 alkyl and at least one of R.sub.2 and
R.sub.3 is branched, preferably in an alpha or beta position
relative to the carbon atom marked (*) in the formula.
[0081] Where the compounds used have an asymmetric carbon atom
either optical isomer may be used in pure form but generally a
mixture of optical isomers will be used. In some cases the degree
of cooling produced by the compounds on the skin will differ as
between optical isomer, in which case one or other isomer may be
preferred.
[0082] The preferred carboxamides used herein are the tertiary
compounds, i.e., those wherein each of R.sub.1, R.sub.2 and R.sub.3
is C.sub.1-C.sub.5 alkyl, especially those where R.sub.1 is methyl,
ethyl or n-propyl and at least one of R.sub.2 and R.sub.3 is a
branched chain group having branching in an alpha or beta position
relative to the C atom marked (*) in the formula. Also preferred
are mono-substituted amides, i.e. where R' is H, and di-substituted
amides where R' and R" are methyl or ethyl. A further preferred
group consists of amides of the formula given where R.sub.1 is
hydrogen and at least one of R.sub.2 and R.sub.3 is branched in an
alpha position relative to the carbon atom marked * in the
formula.
[0083] The carboxamides may readily be prepared by conventional
techniques, for example, by reaction of an acid chloride of the
formula R.sub.1 R.sub.2, R.sub.3 COCl with an amine of the formula
HNR'R" in the presence of a hydrogen chloride acceptor. Such
reactions are entirely conventional and the procedures involved
will readily be understood by the persons skilled in the art.
[0084] Particularly suitable carboxamides for use herein are
mono-substituted tertiary amides of the formula: 6
[0085] wherein R.sub.1, R.sub.2 and R.sub.3 are each
C.sub.1-C.sub.5 alkyl and together provide a total of at least 5,
preferably 5-10 carbon atoms; and R' is C.sub.1-C.sub.5 alkyl,
C.sub.1-C.sub.8 hydroxyalkyl or alkylcarboxyalkyl of up to 8 carbon
atoms. In this group R.sub.1 is preferably methyl, ethyl or
n-propyl and one or both of R.sub.2 and R.sub.3 is branched in an
alpha or beta position relative to the carbon atom marked (*).
[0086] An example of such aliphatic carboxamides is methyl-(N,2,3
tri-methyl)-2-isopropyl butanamide commercially available from IFF
(International Flavors & Fragrances-US) under the name
WS-23.RTM.. An example of such cyclic carboxamides is ethyl
menthane carboxamide commercially available from Rhodia Chirex (UK)
under the name WS-3.RTM..
[0087] Cyclohexanol Derivatives
[0088] Suitable cyclohexanol derivatives for use herein are
represented by the following general formula: 7
[0089] wherein R represents a linear or branched alkyl group having
1 to 5 carbon atoms.
[0090] The formal nomenclature thereof is
2-(2-alkoxy-1-methylethyl)-5-met- hylcyclohexanol. The above
compound has a plurality of stereoisomers. Although any of them has
strong refrigerating activity and is practically odorless, a
cyclohexanol derivative represented by the following general
formula: 8
[0091] wherein R represents a linear or branched alkyl group having
1 to 5 carbon atoms, namely (1R, 2S, 5R,
8R)-2-(2-alkoxy-1-menthyflethyl)-5-meth- ylcyclohexanol is
preferred from the viewpoint of, for example, the continuity of
cooling sensation.
[0092] Suitable cyclohexanol derivatives for use herein also
include those of following general formula: 9
[0093] wherein R.sup.1 and R.sup.2 are independently hydrogen, or a
linear or branched alkyl group having 1 to 5 carbon atom.
[0094] Examples of the linear or branched alkyl groups each having
1 to 5 carbon atoms represented by R in the above general formulae
(1) and (1a) or by R.sup.1 and R.sup.2 in formulae (2), include
methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl,
tert-butyl, n-pentyl, isopentyl, sec-pentyl, tert-pentyl and
neopentyl groups. Of these, methyl, ethyl, isopropyl, tert-butyl
and n-pentyl groups are preferred, and a methyl group is especially
preferred.
[0095] These compounds are described in more details including
process of making them in U.S. Pat. No. 5,756,857, herein
incorporated as reference.
[0096] An example of commercially available cyclohexanol
derivatives of formulae (2) above is 5-methyl-2-(1-methylethenyl)
available from Takasago (Japan) under the name Coolact P.RTM..
[0097] Cyclohexyl Derivatives
[0098] Suitable cyclohexyl derivatives for use herein are
represented by the following general formula: 10
[0099] wherein R represents --H, a C.sub.1-C.sub.5 linear or
branched alkyl group, alkenyl group, alkoxy group or acyloxy group,
R.sub.1 represents --H, or a linear or branched alkyl group having
from 1 to 5 carbon atoms.
[0100] Highly preferred cyclohexyl derivatives for use herein alone
or in combination are those according to above formula with the
exception of the compound wherein both R and R.sub.1 are hydrogen
(menthol). Indeed these compounds are preferred, especially menthyl
lactate, as they are free of mint odor and have improved safety
profile to skin. Also these coumpounds have lower volatility
properties than menthol so that they do not have high tendency to
sublimate during use at body temperature (typically around
35.degree. C.-37.degree. C.), even less at room temperature
(20-25.degree. C.), thereby being particularly suitable for use in
the articles herein. These articles retain their whole cooling
properties up to the time of use thereof.
[0101] The above compound has a plurality of stereoisomers.
Although any of them has strong refrigerating activity and is
practically odorless, with the exception of those wherein both R
and R.sub.1 are hydrogen (i.e., menthol), cyclohexyl derivatives
represented by the following general formula are preferred for use
herein from the viewpoint of, for example, the continuity of
cooling sensation. 11
[0102] Highly preferred compounds are those of formula above
wherein R.sub.1=H and R is propanediol, carboxy-hydroxyethyl or
carboxy hydroxypropyl. An example of these compounds is
menthoxypropanediol available from Takasago under name
TK10.RTM..
[0103] Highly preferred cyclohexyl derivative is menthyl lactate.
Menthyl lactate is according to following formula 12
[0104] This compound is commercially available from Haarmann &
Reimer GmbH (Germany) under the name FRESCOLAT, Type ML. It can
also be readily made by processes known in the art by esterifying
the hydroxy group of menthol with lactic acid. Two thirds of its
molecular weight is attributable to the menthol moiety. Methyl
lactate is virtually odorless, not suffering from the `mint note`
that otherwise customary in the case of menthol or peppermint oil.
Advantageously this material has been found to be usefull as
topical pain reliever (see WO 96/14840 incorporated herein by
reference).
[0105] Other suitable cooling agents for use herein also include
peppermint oil, camphor, borneol, eucalyptol, methyl salicylate,
tea tree oil, or eucalyptus oil as well as plant extracts
containing one or more of these compounds.
[0106] The cooling agent might be use alone or in combination.
[0107] In one aspect of the present invention the cooling agents
used are the cyclohexyl derivative of above mentioned general
formulae wherein both R and R.sub.1 are hydrogen (i.e., menthol)
together with a second cooling agent. Menthol is preferably not
used alone herein as the cooling agent due to its strong mint odor
and its tendency to irritate skin when used alone.
[0108] The second cooling agent preferably is one of those listed
herein above namely ketals, carboxamides, cyclohexanol derivatives
and/or cyclohexyl derivatives with the exception of menthol. These
later class of compound is preferred, especially menthyl lactate,
as beside their longer lasting freshness properties, the absence of
mint odor and their excellent safety profile to skin, these
compounds are particularly stable for use in articles herein.
Menthyl lactate has been found to act as pain reliever.
[0109] In one aspect of the present invention menthol is used
together with a second cooling agent, preferably a cyclohexyl
derivative with the exception of the cyclohexyl derivatives of
above general formula mentioned herein wherein both R and R.sub.1
are hydrogen (preferably menthyl lactate), or a ketal or a
caboxamide, and/or cyclohexanol derivative. Advantageously such
combinations deliver optimized freshness sensation while keeping
the mint odor at a level that is sufficiently low. Preferably the
menthol and said second cooling agent are at a weight ratio of
menthol to the second cooling agent in the range of 1/1 to 1/100,
more preferably 1/1 to 1/10, such that the odor of the menthol is
barely perceptible and less irritating to skin and/or mucosal
surface. Such combinations also deliver more optimized freshness
properties due to the combined action of menthol which is able to
reach the thermo-receptors of the skin and/or mucosal surface
immediately upon contact with skin, thereby fastening the
perception of freshness, and due to the second agent like ketal,
carboxamide, cyclohexyl derivative or cyclohexyl derivative with
the exception of menthol, which all have a lower penetration rate
(amount per time) through skin to reach the thermo-receptors than
menthol, thereby resulting in longer lasting freshness
properties.
[0110] The articles of the present invention comprise an amount of
the cooling agent or a mixture thereof sufficient to stimulate the
thermo-receptors in the areas of the skin and/or mucosal surfaces
with which the articles come into contact and thereby convey the
desired freshness sensation. As the degree and longevity of the
freshness sensation varies from cooling agents to cooling agents
the amount of cooling agents used in each article will vary
widely.
[0111] Typically, the absorbent article of the present invention,
like feminine hygienic disposable absorbent article, comprise the
cooling agent or a mixture thereof on at least a portion of the
article at a level of from 0.01 gm.sup.2 to 300 gm.sup.2,
preferably from 0.05 to 200 gm.sup.2, more preferably from 1
gm.sup.2 to 100 gm.sup.2 and most preferably from 2 gm.sup.2 to 20
gm.sup.2.
[0112] Suitable warming agents for use herein include, but are not
limited to, vanilloid type compounds like vanillyl butyl ether
commercially available from Takasago under the name of
TK-1000.RTM.) and Capsaicin.RTM. available from Sabinsa Corporation
(US).
[0113] Delivery System
[0114] Preferably the agent, like the cooling agent, may be
releasable incorporated into any delivery system known to those
skilled in the art that directly or indirectly facilitates the
transfer of the agent to the skin of the wearer of the article. The
delivery system may contain the agent neat, as a powder, flake or
particulate form, wax, liquid or in a carrier vehicle as a
solution, suspension, dispersion, emulsion or composition. When
released from the delivery system the agent is free to migrate from
the location of the delivery system in the article to the skin
and/or mucosal surface of the wearer. The delivery system may be a
component of any portion or portions of the absorbent article
including, but not limited to, the topsheet, the backsheet, the
absorbent core, any secondary layer(s) intermediate the core and
sheet layers, the leg cuff, the side panel, the waist region, the
fastener, the wings, an insertable element such as an absorbent
material inserted into the absorbent article for use during wear of
the article, specialized structures such as those employed to
contain bowel movements (e.g., bowel movement "pockets"), and the
like. Preferably the delivery system is positioned in proximity to
the wearer's skin and, more preferably is a component of a
wearer-facing surface of portions of the article such as the
topsheet, side panels, leg cuffs, waist region, fasteners, wings
and the like.
[0115] When the agent is released by the delivery system it may be
in an active functional form such as in a solution, dispersion,
suspension, emulsion or the like, or it may be non-functional such
as in powder, wax, flake or particulate form and activated by
contact with moisture from urine and feces or other known
means.
[0116] The types of delivery systems that are useful in the
articles of the invention for facilitating automatic transfer of
the agent from any portion of the article to the skin and/or
mucosal surface of a wearer will be readily apparent to those
skilled in the art.
[0117] Exemplary delivery systems include, for example,
pressure-rupturable or dissolvable microcapsules that are induced
to express the agent upon dissolving due to contact with moisture
from bodily fluid, or rupturing due to pressure from the body or
manual rupturing by a user prior to applying the article to a
wearer. For example, a water-soluble film that encloses and
expresses a powder upon contact with moisture is described in U.S.
Pat. No. 4,790,836 and would be a suitable material for use in
microcapsules containing the agent in any form such as a powder,
particulate, liquid or semi-solid. Examples of pressure-rupturable
microcapsules suitable for containing the agent are described in
U.S. Pat. No. 3,585,998. Such microcapsules may be present in any
portion of the article, including the wearer-facing surface. U.S.
Pat. No. 4,623,339 describes an insertable layer that is removable
from an article prior to use and manually pressure activatable to
express a substance through slits in the layer. The disclosures of
each of the foregoing patents are hereby incorporated by
reference.
[0118] Other suitable delivery systems for containing the agent
include, but are not limited to, "cells" in the article that are
enclosed or partially enclosed voids, regularly or irregularly
shaped, that release the agent when in contact with moisture, heat
or pressure; and water-soluble adhesives and other such
compositions which release the agent upon contact with moisture,
and the like.
[0119] Regardless of the delivery system employed, the agent like
the cooling agent upon release may be migrable from its original
location, e.g., it may be moved by the flow of body fluid, by
motion of the wearer, by pressure and the like, or because of a
decrease in viscosity upon exposure to body heat, to other regions
in the article. Agents that are hydrophilic or are incorporated
into vehicles that are hydrophilic may migrate throughout
hydrophilic structures of the article, such as through hydrophilic
pores or other openings that allow body fluid to flow from the
topsheet to the core. Preferably, however, the delivery systems
containing the agents like the cooling agents are positioned in
proximity to the skin of the wearer.
[0120] Other delivery systems suitable herein also include a wide
variety of carrier vehicles. Carrier vehicles for the agent,
typically the cooling agent include compositions that are in the
form of lotions, creams, oils, ointments, powders, emulsions,
foams, or gels. Typical carrier vehicles for the agents like
cooling agents, include aqueous or alcoholic solutions, oils and
fats such as hydrocarbon oils, fatty acid esters, long chain
alcohols and silicone oils, finely divided solids such as starch or
talc and the like.
[0121] In a preferred embodiment, the agents, like cooling agents,
are dissolved, suspended or emulsified components of
emollient-containing compositions that can be positioned anywhere
in the articles, but preferably are incorporated into a
wearer-facing surface of the articles, such as the topsheet, wings,
leg cuff and the like of hygienic disposable absorbent
articles.
[0122] Suitable emollient-containing compositions for containing
and delivering the agent are described further below.
[0123] In such a preferred embodiment, the emollient-containing
composition comprises 0.1% to 99.9%, preferably from 3% to 90%,
more preferably from 5% to 60%, and most preferably from 10% to 40%
by weight of the agent or mixture thereof, and from 99.9% to 0.1%,
preferably from 97% to 10%, more preferably 95% to 40%, and most
preferably from 90% to 60% by weight of the emollient or mixture
thereof.
[0124] Highly preferred herein the emollient-containing composition
consists of the agent, preferably the cooling agent or a mixture
thereof together with an emollient or a mixture thereof.
[0125] In addition to its function as a vehicle for delivering an
effective concentration of an agent like cooling agent to a
wearer's skin, the emollient composition is particularly beneficial
to skin, it improves skin hydratation and softness, and hence
maintains or even improves skin health. Suitable emollients to be
used herein assure a film-forming capacity on the skin, which gives
emolliency and helps prevent skin dehydration when directly
contacting the skin, thereby reducing or even eliminating the
occurrence of skin itching or burning. Suitable emollients to be
used herein are also able to locate themselves between the layers
of the epiderm (thanks to their similarity with substances
naturally contained in the epiderm (stratum corneum)), enhancing
thereby the elastic properties of the skin.
[0126] The presence of an emollient, especially alcohol/ester
derivatives as described herein after, results in optimum
perception profile during wearing of the articles. For example the
freshness sensation is not only delivered more quickly upon wearing
of the article, but also is sustained/controlled over longer
periods of time, as compared to a similar article with same level
of agent like cooling agent but in absence of such an emollient
(typically ester derivatives like those of formulae (III) herein
after like triethyl citrate). Without to be bound by any theory, it
is believed that the presence of the emollient solubilises the
agent helping it to penetrate more quickly through the outer
layer(s) of the skin and/or mucosal surface to make it readily
available to the receptors. Furthermore the emollient due to its
high affinity to skin and/or mucosal surface, deposits on the skin
and remains into contact and within the skin/mucous for prolonged
periods of time, allowing thereby diffusion of the agent through
the skin upon prolonged periods of time, this results in further
long perception like long lasting freshness feeling if cooling
agent as described herein are used.
[0127] The emollient-containing composition may be in a variety of
forms, including, but not limited to, emulsions, dispersions,
suspensions, gels, and the like.
[0128] In order to deliver an effective concentration of the agent
to the skin via an article over time, an effective amount of the
emollient-containing composition containing the agent that is
applied to or migrated to one or more of the wearer-facing surfaces
of the article depends, to a large extent on the emollient
used.
[0129] The quantity of the emollient-containing composition on at
least a portion of the wearer-facing surface of the absorbent
article preferably ranges from 0.5 g/m.sup.2 to 250 g/m.sup.2, more
preferably from 4 g/m.sup.2 to 80 g/m.sup.2, still more preferably
from 8 to 40 g/m.sup.2.
[0130] As discussed further hereinafter, the emollient-containing
compositions useful for transferring the agents to the skin of the
wearer preferably, though not necessarily, have a melting profile
such that they are relatively immobile and localized on the
wearer-facing surface of the article at room temperature, are
readily transferable to the wearer at body temperature, and yet are
not completely liquid under extreme storage conditions. Preferably,
the compositions are easily transferable to the skin by way of
normal contact, wearer motion, and/or body heat. Because the
composition preferably is substantially immobilized on the
article's wearer-facing surface, relatively low levels of
composition are needed to impart the desired benefits.
[0131] In one embodiment, the emollient-containing compositions
useful herein are water-in-oil emulsions, wherein the agent is in
solution or suspension in either the aqueous phase or the oil
phase. However, the emollient-containing composition itself may be
solid or more often semi-solid, at 20.degree. C., i.e. at ambient
temperatures. By "semisolid" is meant that the composition has a
rheology typical of pseudoplastic or plastic liquids. When no shear
is applied, the compositions can have the appearance of a
semi-solid but can be made to flow as the shear rate is increased.
This is due to the fact that, while the composition contains
primarily solid components, it also includes a liquid
component.
[0132] Preferred compositions are at least semi-solid at room
temperature to minimize composition migration before wear of the
article. In addition, the compositions preferably have a final
melting point (100% liquid) above potential "stressful" storage
conditions that can be greater than 45.degree. C. (e.g., warehouse
in Arizona, car trunk in Florida, etc.). Specifically, preferred
compositions will have the following melt profile:
1 Characteristic Preferred Range Most Preferred % liquid at 2-50
3-25 room temp. (20.degree. C.) % liquid at 25-95 30-90 body temp.
(37.degree. C.) final melting point (.degree. C.) 38 45
[0133] By being solid or semisolid at ambient temperatures,
preferred emollient-containing compositions containing the agent do
not have a tendency to flow and migrate to a significant degree to
undesired locations of the article to which they are applied. This
means less composition is required for imparting desirable
sensorial perception and skin care benefits.
[0134] As used herein, the term "emollient" is a material that
protects against wetness or irritation, softens, soothes, supples,
coats, lubricates, moisturizes, protects and/or cleanses the skin.
(It will be recognized that several of the monographed actives
listed above are "emollients", as that term is used herein.) In a
preferred embodiment, these emollients will have either a plastic
or liquid consistency at ambient temperatures, i.e., 20.degree.
C.
[0135] Representative emollients useful in the present invention
include, but are not limited to, emollients that are
petroleum-based; sucrose ester fatty acids; polyethylene glycol and
derivatives thereof; humectants; fatty acids, particularly those
having from 8 to 28 carbon atoms in their fatty chain, (e.g.,
mirytol); fatty acid ester type; alkyl ethoxylate type; fatty acid
ester ethoxylates; fatty alcohol type; polysiloxane type; propylene
glycol and derivatives thereof, glycerine and derivatives thereof,
including glyceride, acetoglycerides, and ethoxylated glycerides of
C.sub.8-C.sub.28 fatty acids; triethylene glycol and derivatives
thereof; spermaceti or other waxes; fatty alcohol ethers,
particularly those having from 8 to 28 carbon atoms in their fatty
chain, such as cetiol, stearic acid; propoxylated fatty alcohols;
other fatty esters of polyhydroxy alcohols; lanolin and its
derivatives; kaolin and its derivatives; sorbitol and its
derivatives; trihydroxy stearin; or mixtures of these
emollients.
[0136] 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.
[0137] Suitable fatty acid ester type emollients include those
derived from C.sub.8-C.sub.28 fatty acids, preferably
C.sub.12-C.sub.22 saturated fatty acids, and short chain
(C.sub.1-C.sub.8, preferably C.sub.1-C.sub.3) monohydric alcohols.
Representative examples of such esters include methyl palmitate,
methyl stearate, isopropyl laurate, isopropyl myristate, isopropyl
palmitate, ethylhexyl palmitate and mixtures thereof. Suitable
fatty acid ester emollients can also be derived from esters of
longer chain fatty alcohols (C.sub.12-C.sub.28, preferably
C.sub.12-C.sub.16) and shorter chain fatty acids e.g., lactic acid,
such as lauryl lactate and cetyl lactate.
[0138] Suitable alkyl ethoxylate type emollients include
C.sub.8-C.sub.22 fatty alcohol ethoxylates having an average degree
of ethoxylation of from about 2 to about 30. Preferably, the fatty
alcohol ethoxylate emollient is selected from the group consisting
of lauryl, cetyl, and stearyl ethoxylates, and mixtures thereof,
having an average degree of ethoxylation ranging from about 2 to
about 23. Representative examples of such alkyl ethoxylates include
laureth-3 (a lauryl ethoxylate having an average degree of
ethoxylation of 3), laureth-23 (a lauryl ethoxylate having an
average degree of ethoxylation of 23), ceteth-10 (a cetyl alcohol
ethoxylate having an average degree of ethoxylation of 10) and
steareth-10 (a stearyl alcohol ethoxylate having an average degree
of ethoxylation of 10).
[0139] Suitable fatty alcohol type emollients include
C.sub.9-C.sub.22 fatty alcohols, preferably C.sub.12-C.sub.18 fatty
alcohols. Representative examples include cetyl alcohol and stearyl
alcohol, and mixtures thereof.
[0140] Other suitable types of emollients for use herein include
polysiloxane compounds. In general, suitable polysiloxane materials
for use in the present invention include those having monomeric
siloxane units of the following structure: 13
[0141] wherein, R.sup.1 and R.sup.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.sup.1 and R.sup.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.sup.1 and R.sup.2 can
additionally independently be other silaceous functionalities such
as, but not limited to siloxanes, polysiloxanes, silanes, and
polysilanes. The radicals R.sup.1 and R.sup.2 may contain any of a
variety of organic functionalities including, for example, alcohol,
carboxylic acid, phenyl, and amine functionalities. Exemplary alkyl
radicals are methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl,
decyl, octadecyl, and the like. Exemplary alkenyl radicals are
vinyl, allyl, and the like. Exemplary aryl radicals are phenyl,
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.
[0142] Suitable fatty ester type emollients also include
polyolpolyesters as described in U.S. Pat. No. 5,609,587, issued to
Roe on Mar. 11, 1997, the disclosure of which is incorporated
herein by reference. Exemplary polyols include, but are not limited
to, polyhydric compounds such as pentaerythritol; sugars such as
raffinose, maltodextrose, galactose, sucrose, glucose, xylose,
fructose, maltose, lactose, mannose and erythrose; and sugar
alcohols such as erythritol, xylitol, malitol, mannitol and
sorbitol. Such polyols are esterified with fatty acids and/or other
organic radicals having at least two carbon atoms and up to 30
carbon atoms. While it is not necessary that all of the hydroxyl
groups of the polyol be esterified, preferred polyolpolyester
emollients of the present invention have substantially all (e.g. at
least about 85%) of the hydroxyl groups esterified. Particularly
preferred are sucrose polyolpolyesters such as sucrose
polycottonate, sucrose polysoyate, and sucrose polybehenate.
Mixtures of such polyolpolyesters are also suitable emollients for
the present invention.
[0143] Highly preferred emollients for use herein are the
acid/ester derivatives of below formulae.
[0144] Advantageously, beside their emolliency properties, these
ester derivatives, especially those according to formulae (II) and
(m) below, can function as enzyme substrates, which, when acted
upon by a hydrolyzing enzyme typically present in body fluid, will
be hydrolyzed resulting in the release of free acids. The presence
of these acids will lower the pH of the area where the esters are
topically applied to. This will amount to inactivation of all or
most enzymes present in this area and resulting from contact of
this area with body fluids/exudates, such as the lipase enzymes,
protease enzymes and the like. This effect is relatively long
lasting. In other words, the presence of such esters not only
provides optimized perception profile (including delivery of not
only faster but also sustained/controlled perception like freshness
sensation in the event the agent is a cooling agent as described
herein, upon prolonged wearing time of the articles), but reduces
or even prevents the occurrence of skin irritation or skin rash as
well as the formation of malodor due to microbial activity. Indeed
the use of these esters in the absorbent articles of the present
invention able to provide the article with the additional benefit
of deodorancy effect on the skin/intimate area.
[0145] Accordingly in on aspect of the present invention, the
invention is based on the finding that the presence of ester
derivatives, especially those according to formulae (II) and (1H)
herein below, not only moisturizes/hydrates and softens the skin,
thereby reducing roughness, cracking and skin irritation that would
otherwise be typically associated with cooling agents like menthol
especially when used alone, but also deodorizes skin/mucosal
surface due to their antimicrobial activity, namely their enzyme
inhibitor activity (this later benefit is particularly noticeable
upon occurrence of body fluids/exudates). Without to be bound by
theory it is speculated that malodor control benefit is due to a
double mechanisms: competitive inhibition with the natural
substrates on the active side of the enzymes and enzymes inhibition
due to acidic pH created by ester hydrolysis of the ester
derivatives described herein.
[0146] Highly preferred emollients for use herein are the
alcohol/ester/acid derivatives according to the following formulae:
14
[0147] wherein R.sub.1 and each R.sub.2 independently are an acyl
group with from 2 to 22 carbon atoms, or an alkyl, alkenyl,
arylalkyl, hydroxyalkyl group with from 1 to 24 carbon atoms or
hydrogen, whereby at least one of R.sub.1 and R.sub.2 is such an
acyl group, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8,
and R.sub.9 are independently an alkyl, alkenyl, arylalkyl,
hydroxyalkyl, alkoxy groups of from 1 to 24 carbon atoms, hydroxy
group or hydrogen; R.sub.10 and R.sub.11 are independently an
alkyl, alkenyl, arylalkyl, hydroxyalkyl, alkoxy groups of from 2 to
24 carbon atoms, hydroxy group or hydrogen; A and B are
independently a C.sub.1-C.sub.6 linear or branched alkylene, alkyl,
alkenylene, alkoxylene, alkoxyl, hydroxyalkylene, hydroxyalkyl
groups; the values of x are independently from 0 to 15; the values
of y are independently 0 or 1, typically with the proviso that when
x=2 and y=0, at least one R.sub.2 is an alkyl, alkenyl, arylalkyl,
hydroxyalkyl group with from 1 to 24 carbon atoms or hydrogen.
[0148] Particular suitable alcohol derivatives for use herein are
those according to formulae (I) herein above, wherein the values of
x are independently from 0 to 15, y=0, R.sub.1 and R.sub.2 are
independently hydrogen, alkyl or alkenyl group of 1 to 24 carbon
atoms, with the proviso that at least R.sub.1 or R.sub.2 is
hydrogen, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are independently
an alkyl or alkenyl group of from 1 to 3 carbon atoms or hydrogen.
Highly preferred alcohol derivatives are propylene glycol or
polyethylene glycol.
[0149] Preferred for their antimicrobial activity are the ester
compounds as defined above, wherein the compound is of formula (I)
or (II) wherein x is 1 or 2, y is 0; R.sub.1 and one R.sub.2 are a
C.sub.2-C.sub.16 acyl group, R.sub.10 and one or more R.sub.11 are
a C.sub.2-C.sub.16 alkyl group; R.sub.3, R.sub.4, R.sub.5, R.sub.6,
R.sub.7 and R.sub.8 are hydrogen, R.sub.9 is independently H, or
hydroxy group.
[0150] It is even more preferred that the ester derivative is a
mono or diester of formula (II), most preferably a mono or diester
of citric acid or tartaric acid (or salts thereof), or a triester
of citric acid.
[0151] Another preferred ester derivatives for use herein is an
ester compound of the formula: 15
[0152] wherein R.sub.1, R.sub.2 and R.sub.3 are independently an
acyl, alkyl or alkenyl or hydroxyalkyl group with from 1 to 22
carbon atoms, and R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8
are independently selected from the group consisting of
C.sub.1-C.sub.10 linear or branched acyl, alkyl, alkenyl,
hydroxyalkyl or alkoxy groups, hydroxy, chloride, bromide, amine or
hydrogen.
[0153] Highly preferred are the compounds above wherein R.sub.4,
R.sub.5, R.sub.7 and R.sub.8 of said compound are hydrogen, R6 is
hydrogen, hydroxy, C1-C4 linear or branched alkyl, alkenyl,
hydroxyalkyl or alkoxy groups and preferably wherein R.sub.1,
R.sub.2 and R.sub.3 are independently an C.sub.1-C.sub.4 alkyl
group or hydrogen.
[0154] Such preferred compounds include triethyl citrate, acetyl
tributyl citrate, triacetyl citrate, or O acetyl triethyl citrate.
Highly preferred is triethyl citrate. Triethyl citrate is
commercially available from Aldrich.
[0155] Optional Agents
[0156] The absorbent articles according to the present invention
may further comprise other conventional agents or mixtures
thereof.
[0157] Optional Odour Control Agents
[0158] Odour control agent or combinations thereof, known in the
art for this purpose may be used herein. These agents can typically
be classified according to the type of odour the agent is intended
to combat. Odors may be chemically classified as being acidic,
basic or neutral.
[0159] Alternatively, the odor control agents may be categorized
with respect to the mechanism by which the malodor detection is
reduced or prevented. For example, odor control agents which
chemically react with malodorous compounds or with compounds which
produce malodorous degradation products thereby generating
compounds lacking odor or having an odor acceptable to consumers
may also be utilized herein.
[0160] Suitable odor control agents for use herein typically
include carboxylic acids such as citric acid, lauric acid, boric
acid, adipic acid and maleic acid, oxidizing agents, antimicrobial
agents, activated carbons, clays, zeolites, silicates, silica,
diatomaceous earth and starches. Such odor control agents and
systems are disclosed in more details in EP-A-348 978, EP-A-510
619, WO 91/12029, WO 91/11977, WO 91/12030, WO 81/01643 and WO
96/06589, which are all incorporated herein by reference. Highly
preferred odor control agents are zeolite together with silicate
and/or silica.
[0161] In a preferred embodiment herein the hygienic absorbent
article, further comprises, as the odor control agents, zeolite
together with silicate/silica in a weight ratio of silicate/silica
to zeolite of from 1:5 to 5:1, preferably from 3:1 to 1:3 and most
preferably about 1:1. This combination has been found to be
particularly effective in terms of odor control over a broad range
of malodorous compounds. Silicate/silica and zeolite have a
complementary odor control properties towards various malodorous
compounds, thereby resulting in outstanding overall odor control
reduction.
[0162] Alternative odor control agents are ion exchange resins such
as those described in U.S. Pat. No. 4,289,513 and U.S. Pat. No.
3,340,875.
[0163] Suitable odor control agents also include chelating agents
and may be selected from amino carboxylates such as for example
ethylenediamine-tetracetate, as described for example in U.S. Pat.
No. 4,356,190, amino phosphonates such as ethylenediaminetetrakis
(methylene-phosphonates), polyfunctionally-substituted aromatic
chelating agents as described in U.S. Pat. No. 3,812,044 and
mixtures thereof. Without intending to be bound by theory it is
believed that the benefit of these materials is in part due to
their exceptional ability to remove iron, copper, calcium,
magnesium and manganese ions present in the absorbed fluids and
their degradation products by the formation of chelates.
[0164] Another suitable odor control agent for use herein is an
acidic pH buffer system, such as citric acid and sodium
bicarbonate, sodium phosphate and sorbic acid buffer systems.
[0165] Typically, the articles herein may comprise the odor control
agent or a mixture thereof, on at least a portion thereof, at a
level of from 0 gm.sup.2 to 600 gm.sup.-2, preferably from 5 to 500
gm.sup.-2, more preferably from 10 gm.sup.-2 to 350 gm.sup.-2 and
most preferably from 20 gm.sup.-2 to 200 gm.sup.-2.
[0166] Further optional agents to be used herein also include
perfumes. In another aspect of the present invention the articles
herein are typically free of perfumes. Indeed, the addition of
perfume might not be desirable by some wearer of hygienic feminine
protection articles who might associate their presence to the
presence of odor perceived as a negative in intimate feminine care
and/or as causing potential skin irritation.
Incorporation of the Agent into the Articles
[0167] Vehicle
[0168] The agent like cooling agent for use in the article of the
invention may be water-soluble or lipid-soluble and may be
incorporated into the article neat, such as in dry powder or
particulate form or liquid or in the form of a solution,
suspension, dispersion, emulsion, wax or the like in a
dermatologically acceptable carrier vehicle that does not interfere
with the physiological properties of the agent. The agent may also
be incorporated in another structure that in turn is incorporated
into the article during manufacture or assembly. For example, the
agent may be coated onto or otherwise attached or bound to a
nanophase particulate structure or other solid support such as
glass, plastic or agarose beads, and the like, or contained in
pressure-rupturable or dissolvable microcapsules and the like, or
contained in an absorbent material. The use of other types of
incorporable elements for containing the agent and methods for
their incorporation will be readily apparent to one skilled in the
art.
[0169] Carrier vehicles for the agent like cooling agent include
compositions that are in the form of lotions, creams, oils,
ointments, powders, foams, or gels and the like and that may
contain any ingredients commonly used in the art for such
compositions. The ingredients of the compositions will depend on
the character of the composition; thus, for example, lotions will
generally comprise different ingredients than powders. It is
preferable that agent-containing compositions intended for transfer
to the skin have a pH of no less than about 4 and no greater than
about 7.5.
[0170] Incorporation
[0171] The agent employed in the articles of the invention is
incorporated into the article in a configuration that does not
itself interfere with the normal function of the various structures
of the article (e.g., the absorbency of the core, the liquid
perviousness of the topsheet, and the like for hygienic absorbent
articles). The agent may be incorporated into any portion or
portions of the article including, but not limited to, the
topsheet, the backsheet, the absorbent core, any secondary layer(s)
intermediate the core and sheet layers, a leg cuff, a side panel, a
waist region, wings, a fastener, an insertable element such as an
absorbent material inserted into the absorbent article for use
during wear of the article, specialized structures such as those
employed to contain bowel movements (e.g., bowel movement
"pockets"), and the like. The agent may be incorporated into the
article neat or, alternatively, the agent may be contained in a
delivery system described herein before that is incorporated into
any of the foregoing portions of the article and that delivers the
agent directly or indirectly to the skin of a wearer during normal
wear of the article.
[0172] Any number of different agent or mixtures of agents as
described herein before, whether or not they are incorporated into
a delivery system, may be uniformly or nonuniformly distributed
throughout the article and/or onto the surface of one layer or
several layers of the article.
[0173] Preferably the agent may be incorporated directly onto the
surface (typically wearer-facing surface) of or within the
structure of any type of topsheet, including woven, nonwoven and
apertured structured topsheets, the backsheet, and/or absorbent
core materials, or other components of the article during
manufacture or assembly by diverse methods which will be readily
apparent to those skilled in the art. For example the agent can be
applied, optionally after being dispersed in a liquid or semi-solid
carrier vehicle, to the topsheet, to the absorbent core, or to the
core side of the backsheet, by spraying, dipping, printing, soaking
or otherwise contacting the selected structural element with the
agent and optionally its carrier vehicle. Among the many other
techniques that can be employed are graft or radical
polymerization, or steam treating of the structural elements in
order to bind the agent by hydrogen bonding that is easily reversed
when such surfaces are wetted by body waste to release the agent.
Preferably the agent like the cooling agent as described herein, is
incorporated into at least a portion of a wearer-facing surface of
the article, in homogenous or non-homogeneous manner, i.e.,
following pattern that can be of any configuration including dotes,
lines and so on. Preferably the agent is applied in at least the
so-called central zone of the wearer facing surface of the topsheet
of a feminine protection absorbent article, i.e., the area of
discharge of body fluid. Typically the agent might be applied on
the whole surface of the wearer-facing surface of the article.
Preferably, the agent like the cooling agent as described herein,
is incorporated into at least a portion of a wearer-facing surface
of the article and is available for automatic transfer to the
wearer's skin and/or mucosal surface during normal contact, wearer
motion and/or body heat during wear of the article. Alternatively,
the article further comprises a delivery system that contains the
agent and, during wear of the article the delivery system
automatically delivers at least a portion of the agent to the skin
and/or mucosal surface of the wearer. In a more preferred
embodiment, the delivery system is an emollient-containing
composition containing the agent and various emollients, as
described hereinbefore, that is delivered directly from a
wearer-facing surface to the wearer's skin to perform an immediate
and sustained perception like freshness sensation in the event
where the agent is a cooling agent as described herein, while
maintaining or even improving skin health.
[0174] The Article
[0175] The absorbent articles according to the present invention
(e.g., sanitary napkins, pantiliners and the like) are typically
provided in color communicating a hygienic condition. This
conventionally results in white or predominantly white articles.
This did fit well with the historically predominant undergarment
color in which these articles are worn, namely white undergarments.
With recent trend in fashion the tendency is to wear undergarments
of colors matching the colors of the cloths, including black,
purple, red, yellow, green and the like. Actually any color is
suitable for the articles to be worn in contact with body,
including primary colors and combinations thereof in any tonality.
Advantageously by providing the articles, especially hygienic
articles in colors matching the colors of the undergarments,
enhanced discretion in use is obtained. The article might be
colored only on the wearer-facing surface and/or on the garment
facing surface or might be colored through its thickness. The
colored might be uniform or non-uniform, multicolor image might
also be used depending on end used of the articles. It is
understood herein that the colored articles might be opaque to
transparent, including all degree of transparency.
[0176] Furthermore it has been found that the choice of colors for
the hygienic articles (preferably feminine protection absorbent
articles) may further contribute to the perception conveyed to the
wearer of the article for example freshness sensation and hence
participates to improve the comfort and/or cleanness feeling.
Particular preferred colors are green and/or blue (including any
tonality thereof), which are believed to stimulate freshness
sensation. The choice of color might also be triggered by the
emotion/mood that is desired during wearing experience, the
influence of the color on mood is known from chromo-therapy and
might be selected as appropriate. For example the colors might be
selected so that melancholy can be dissipated during menstruation.
Particular preferred colors, green and/or blue (including any
tonality thereof), are believed to also convey relaxation
feeling.
[0177] The article typically comprises a substrate made of a
nonwoven material, or a woven material or a polymeric film, or a
gel. Such films and nonwovens or wovens materials can be made for
example from polymers such as polyethylene or polypropylene
compositions. Conventionally such polymers have been provided with
a coloring material such as titanium dioxide to provide a white
opacity. Simply using other coloring materials (e.g., dyes,
pigments and so on) namely coloring materials like black, navy
bleu, green, yellow, gray and the like, provides a colored film or
material of other color than white.
[0178] It is to be understood herein that any conventional method
known to those skilled in the art to provide colored substrates is
suitable for use herein. Colored substrates can typically be
provided by different methods well known to those skilled in the
art, including pigmenting the materials, dying the materials or
color printing the materials.
[0179] The articles according to the present invention are
preferably breathable and typically have a water vapour
permeability (as measured by the water vapour permeability test
method described herein after) higher than 100 (g) 1 (m.sup.2/24
hrs), preferably of more than 200 (g) 1 (m.sup.2/24 hrs), more
preferably higher than 300 (g) 1 (m.sup.2124 hrs), and most
preferably higher than 400 (g) 1 (m.sup.2/24 hrs).
[0180] Particularly preferred hygienic disposable absorbent
articles as those described as follows:
[0181] They typically comprise a tospheet directly facing the
wearer in use, and a backsheet directly facing the garment in use,
and an absorbent core sandwiched there between.
Absorbent Core
[0182] According to the present invention, the absorbent core can
include the following components: (a) an optional primary fluid
distribution layer preferably together with a secondary optional
fluid distribution layer; (b) a fluid storage layer; (c) an
optional fibrous ("dusting") layer underlying the storage layer;
and (d) other optional components. According to the present
invention the absorbent may have any thickness depending on the end
use envisioned.
a Primary/Secondary Fluid Distribution Layer
[0183] One optional component of the absorbent according to the
present invention is a primary fluid distribution layer and a
secondary fluid distribution layer. The primary distribution layer
typically underlies the topsheet and is in fluid communication
therewith. The topsheet transfers the acquired fluid to this
primary distribution layer for ultimate distribution to the storage
layer. This transfer of fluid through the primary distribution
layer occurs not only in the thickness, but also along the length
and width directions of the absorbent product. The also optional
but preferred secondary distribution layer typically underlies the
primary distribution layer and is in fluid communication therewith.
The purpose of this secondary distribution layer is to readily
acquire fluid from the primary distribution layer and transfer it
rapidly to the underlying storage layer. This helps the fluid
capacity of the underlying storage layer to be fully utilized. The
fluid distribution layers can be comprised of any material typical
for such distribution layers. In particular fibrous layers maintain
the capillaries between fibers even when wet are useful as
distribution layers.
b Fluid Storage Layer
[0184] Positioned in fluid communication with, and typically
underlying the primary or secondary distribution layers, is a fluid
storage layer. The fluid storage layer typically comprises any
usual absorbent gelling material. It preferably comprises such
materials in combination with suitable carriers.
[0185] Suitable carriers include materials, which are
conventionally utilized in absorbent structures such as natural,
modified or synthetic fibers, particularly modified or non-modified
cellulose fibers, in the form of fluff and/or tissues. Most
preferred are tissue or tissue laminates in the context of sanitary
napkins and panty liners.
[0186] An embodiment of the absorbent structure made according to
the present invention may comprise multiple layers comprises a
double layer tissue laminate typically formed by folding the tissue
onto itself. These layers can be joined to each other for example
by adhesive or by mechanical interlocking or by hydrogen bridge
bands. Absorbent gelling materials and/or other optional materials
can be comprised between the layers.
[0187] Modified cellulose fibers such as the stiffened cellulose
fibers can also be used. Synthetic fibers can also be used and
include those made of cellulose acetate, polyvinyl fluoride,
polyvinylidene chloride, acrylics (such as Orlon), polyvinyl
acetate, non-soluble polyvinyl alcohol, polyethylene,
polypropylene, polyamides (such as nylon), polyesters, bicomponent
fibers, tricomponent fibers, mixtures thereof and the like.
Preferably, the fiber surfaces are hydrophilic or are treated to be
hydrophilic. The storage layer can also include filler materials,
such as Perlite, diatomaceous earth, Vermiculite, etc., to improve
liquid retention.
[0188] If the absorbent gelling materials are dispersed
non-homogeneously in a carrier, the storage layer can nevertheless
be locally homogenous, i.e. have a distribution gradient in one or
several directions within the dimensions of the storage layer.
Non-homogeneous distribution can also refer to laminates of
carriers enclosing absorbent gelling materials partially or
fully.
c Optional Fibrous ("Dusting") Layer
[0189] An optional component for inclusion in the absorbent core
according to the present invention is a fibrous layer adjacent to,
and typically underlying the storage layer. This underlying fibrous
layer is typically referred to as a "dusting" layer since it
provides a substrate on which to deposit absorbent gelling material
in the storage layer during manufacture of the absorbent core.
Indeed, in those instances where the absorbent gelling material is
in the form of macro structures such as fibers, sheets or strips,
this fibrous "dusting" layer need not be included. However, this
"dusting" layer provides some additional fluid-handling
capabilities such as rapid wicking of fluid along the length of the
pad.
d Other Optional Components of the Absorbent Structure
[0190] The absorbent core according to the present invention can
include other optional components normally present in absorbent
webs. For example, a reinforcing scrim can be positioned within the
respective layers, or between the respective layers, of the
absorbent core. Such reinforcing scrims should be of such
configuration as to not form interfacial barriers to fluid
transfer. Given the structural integrity that usually occurs as a
result of thermal bonding, reinforcing scrims are usually not
required for thermally bonded absorbent structures.
The Topsheet
[0191] According to the present invention the absorbent article
comprises as an essential component a topsheet. The topsheet may
comprise a single layer or a multiplicity of layers. In a preferred
embodiment the topsheet comprises a first layer which provides the
user facing surface of the topsheet and a second layer (also called
secondary topsheet) between the first layer and the absorbent
structure/core.
[0192] The topsheet as a whole and hence each layer individually
needs to be compliant, soft feeling, and non-irritating to the
wearer's skin. It also can have elastic characteristics allowing it
to be stretched in one or two directions. According to the present
invention the topsheet may be formed from any of the materials
available for this purpose and known in the art, such as woven and
non woven fabrics and films. In a preferred embodiment of the
present invention at least one of the layers, preferably the upper
layer, of the topsheet comprises a liquid permeable apertured
polymeric film. Preferably, the upper layer is provided by a film
material having apertures which are provided to facilitate liquid
transport from the wearer facing surface towards the absorbent
structure. If present the lower layer preferably comprises a non
woven layer, an apertured formed film or an airlaid tissue.
[0193] Apertured topsheet comprises a plurality of apertures having
a pore size of 0.0001 mm to 5 mm. All apertures might have the same
dimensions or apertures of different dimensions might be present.
The open area of the apertured topsheet is typically from 1% to
50%, preferably from 5% to 45%, more preferably from 10% to 40% and
most preferably from 20% to 35%.
[0194] The apertured topsheet is typically an apertured polymeric
film. Suitable apertured polymeric film topsheets for use herein
include polymeric apertured formed films, apertured formed
thermoplastic films, apertured plastic films, and hydroformed
thermoplastic films; porous foams; reticulated foams; reticulated
thermoplastic films; and thermoplastic scrims.
[0195] Apertured formed films are particularly suitable for use
herein as the apertured topsheet because they are pervious to body
exudates and yet non-absorbent and have a reduced tendency to allow
fluids to pass back through and rewet the wearer's skin. Thus, the
surface of the formed film that 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 (Thompson), issued Dec. 30, 1975; U.S. Pat. No.
4,324,246 (Mullane, et al.), issued Apr. 13, 1982; U.S. Pat. No.
4,342,314 (Radel. et al.), issued Aug. 3, 1982; U.S. Pat. No.
4,463,045 (Ahr et al.), issued Jul. 31, 1984; and U.S. Pat. No.
5,006,394 (Baird), issued Apr. 9, 1991. Particularly preferred
microapertured formed film topsheets are disclosed in U.S. Pat. No.
4,609,518 (Curro et al), issue Sep. 2, 1986 and U.S. Pat. No.
4,629,643 (Curro et al), issued Dec. 16, 1986.
[0196] The body surface of the polymeric film topsheet can be
hydrophilic so as to help liquid to transfer through the topsheet
faster than if the body surface was not hydrophilic. In a preferred
embodiment, surfactant is incorporated into the polymeric materials
of the formed film topsheet such as is described in PCT Publication
No. WO 93/09741, "Absorbent Article Having A Nonwoven and Apertured
Film Coversheet" filed on Nov. 19, 1991 by Aziz, et al.
Alternatively, the body surface of the topsheet can be made
hydrophilic by treating it with a surfactant such as is described
in the above referenced U.S. Pat. No. 4,950,254.
[0197] Other suitable apertured topsheet for use herein are made of
woven or nonwoven materials or knit materials. Such materials might
be comprised of natural fibers (e.g., wood or cotton fibers),
synthetic fibers (e.g., polymeric fibers such as polyester,
polypropylene, or polyethylene fibers) or from a combination of
natural and synthetic fibers.
[0198] Particularly suitable apertured topsheet for use herein are
nonwoven topsheet. Suitable nonwoven materials/layers include
fibrous nonwoven materials/layers formed by a carding process or a
spunbond process or meltblown process whereby molten polymeric
material is extruded through a die, attenuated to lengthen the
extruded polymer into fibers and decrease the diameter thereof and
is subsequently deposited on a forming surface. Methods of forming
such nonwoven materials/layers are known to those skilled in the
art. Polymeric materials suitable for use in forming such fibrous
nonwoven materials/layers include polyolefins such as polyethylene
and polypropylene, polyesters, nylons, ethylene vinyl acetate,
ethylene methacrylate, copolymers of the above materials, block
copolymers such as A-B-A block copolymers of styrene and butadiene,
and the like.
[0199] Beside the conventional nonwoven materials described herein
before, the apertured topsheet for use herein can be made of
conventional nonwoven materials typically provided by any process
mentioned herein before like spunbond process, into which
additional apertures can be formed by any conventional method known
to those skilled in the art for this purpose after the nowoven
materials have been formed per se.
[0200] In yet a preferred embodiment herein the apertured topsheet
comprises an apertured polymeric film, preferably an apertured
formed film, together with a nonwoven outer layer (the nonwoven
layer being directed towards the wearer surface). Typically the
nonwoven layer is disposed onto the apertured polymeric film in a
discontinuous way so that at least the region where liquid is
expected to be discharged onto the absorbent article is free of the
nonwoven layer. Indeed, it is particularly preferred that the
topsheet be a so-called hybrid topsheet in which the wearer
contacting surface is provided in its longitudinal center by an
apertured polymeric film while a region not including the center is
provided with a non-woven such as e.g. the high loft non-woven or
other non-woven which does provide particularly skin friendliness.
Such topsheets have been disclosed in EPA-523 683, EP-A-523 719,
EP-A-612 233, or EP-A-766 953.
[0201] The Backsheet
[0202] The backsheet primarily prevents the extrudes absorbed and
contained in the absorbent structure from wetting articles that
contact the absorbent product such as underpants, pants, pyjamas
and undergarments. The backsheet is preferably impervious to
liquids (e.g. menses and/or urine) and is preferably manufactured
from a thin plastic film, although other flexible liquid impervious
materials can also be used. As used herein, the term "flexible"
refers to materials that are compliant and will readily conform to
the general shape and contours of the human body. The backsheet
also can have elastic characteristics allowing it to stretch in one
or two directions. In a preferred embodiment the backsheet
comprises a first layer which provides the garment facing surface
of the backsheet and a second layer (also called secondary
backsheet) between the first layer and the absorbent
structure/core.
[0203] The backsheet typically extends across the whole of the
absorbent structure and can extend into and form part of or all of
the preferred sideflaps, side wrapping elements or wings.
[0204] In addition to the prevention of liquid transport through
the backsheet, the backsheet is preferably breathable. Hence the
backsheet also permits the transfer of water vapour and preferably
both water vapour and air through it and thus allows reduction of
humid and occlusive environment on the skin contacted with the
article. Breathable is preferred herein as it contributes to
further improve the freshness sensation and dry feeling associated
with the cooling agents used according to the present invention.
Even more preferred herein the disposable absorbent articles have
both a breathable backsheet and an apertured polymeric film
topsheet for further improved freshness sensation of the articles
herein comprising cooling agents.
[0205] Suitable breathable backsheets for use herein include all
breathable backsheets known in the art. In principle there are two
types of breathable backsheets, single layer breathable backsheets
which are breathable and impervious to liquids and backsheets
having at least two layers, which in combination provide both
breathability and liquid imperviousness. Suitable single layer
breathable backsheets for use herein include those described for
example in GB A 2184 389, GB A 2184 390, GB A 2184 391, U.S. Pat.
No. 4,591,523, U.S. Pat. No. 3 989 867, U.S. Pat. No. 3,156,242 and
WO 97/24097.
[0206] Suitable dual or multi layer breathable backsheets for use
herein include those exemplified in U.S. Pat. No. 3,881,489, U.S.
Pat. No. 4,341,216, U.S. Pat. No. 4,713,068, U.S. Pat. No.
4,818,600, EP 203 821, EP 710 471, EP 710 472, WO 97/24095, WO
97/24096, WO 97/24097 and EP 793 952.
[0207] Particularly preferred are backsheets meeting the
requirements as defined in European Patent Application EP 813 849
and more preferably wherein the absorbent article also meets the
requirements as described therein.
[0208] The breathable backsheet may comprise at least one,
preferably at least two water vapour permeable layers. Suitable
water vapour permeable layers include 2-dimensional, planar micro
and macro-porous films, monolithic films, macroscopically expanded
films and formed apertured films. According to the present
invention the apertures in said layer may be of any configuration,
but are preferably spherical or oblong. The apertures may also be
of varying dimensions. In a preferred embodiment the apertures are
preferably evenly distributed across the entire surface of the
layer, however layers having only certain regions of the surface
having apertures is also envisioned.
[0209] 2 dimensional planar films as used herein have apertures
having an average diameter of from 1 micrometers to 200
micrometers. Typically, 2-dimensional planar micro porous films
suitable for use herein have apertures having average diameters of
from 150 micrometers to 1 micrometers, preferably from 120
micrometers to 10 micrometers, most preferably from 90 micrometers
to 15 micrometers. Typical 2-dimensional planar macroporous films
have apertures having average diameters of from 200 micrometers to
90 micrometers. Macroscopically expanded films and formed apertured
films suitable for use herein typically have apertures having
diameters from 100 micrometers to 500 micrometers. Embodiments
according to the present invention wherein the backsheet comprises
a macroscopically expanded film or an apertured formed film, the
backsheet will typically have an open area of more than 5%,
preferably from 10% to 35% of the total backsheet surface area.
[0210] Suitable 2 dimensional planar layers of the backsheet may be
made of any material known in the art, but are preferably
manufactured from commonly available polymeric materials. Suitable
materials are for example GORE-TEX (.TM.) or Sympatex (.TM.) type
materials well known in the art for their application in so-called
breathable clothing. Other suitable materials include XMP-1001 of
Minnesota Mining and Manufacturing Company, St. Paul, Minn., USA.
As used herein the term 2-dimensional planar layer refers to layers
having a depth of less than 1 mm, preferably less than 0.5 mm,
wherein the apertures have an average uniform diameter along their
length and which do not protrude out of the plane of the layer. The
apertured materials for use as a backsheet in the present invention
may be produced using any of the methods known in the art such as
described in EP 293 482 and the references therein. In addition,
the dimensions of the apertures produced by this method may be
increased by applying a force across the plane of the backsheet
layer (i.e. stretching the layer).
[0211] Suitable apertured formed films include films which have
discrete apertures which extend beyond the horizontal plane of the
garment facing surface of the layer towards the core thereby
forming protuberances. The protuberances have an orifice located at
their terminating ends. Preferably said protuberances are of a
funnel shape, similar to those described in U.S. Pat. No.
3,929,135. The apertures located within the plane and the orifices
located at the terminating end of protuberance themselves maybe
circular or non circular, provided the cross sectional dimension or
area of the orifice at the termination of the protuberance is
smaller than the cross sectional dimension or area of the aperture
located within the garment facing surface of the layer. Preferably
said apertured preformed films are uni directional such that they
have at least substantially, if not complete one directional fluid
transport towards the core. Suitable macroscopically expanded films
for use herein include films as described in for example in U.S.
Pat. No. 6,378,19 and U.S. Pat. No. 4,591,523.
[0212] Suitable macroscopically expanded films for use herein
include films as described in for example U.S. Pat. No. 4,637,819
and U.S. Pat. No. 4,591,523.
[0213] Suitable monolithic films include Hytrel.TM., available from
DuPont Corporation, USA, and other such materials as described in
Index 93 Congress, Session 7A "Adding value to Nonwovens", J-C.
Cardinal and Y. Trouilhet, DuPont de Nemours International S.A.,
Switzerland.
[0214] The backsheet may comprise in addition to said water vapour
permeable layer additional backsheet layers. Said additional layers
may be located on either side of said water vapour permeable layer
of the backsheet. The additional layers may be of any material,
such as fibrous layers or additional water vapour permeable layers
as described herein above.
[0215] In a particularly preferred embodiment herein a dual or
multiple layer breathable backsheet composite is used in the
absorbent article. Suitable breathable backsheets for use herein
comprise at least a first and a second layer. The first layer is
positioned between the garment facing surface of the absorbent core
and the wearer facing surface of the second layer. It is oriented
such that it retards or prevents liquid from passing from the
absorbent core towards the outside while allowing free air flow and
water vapor through it. The second layer provides water vapor and
air permeability so as to support breathability of the article. In
addition to water vapor permeability the air permeability is
desirable in order to further improve the comfort benefit from the
breathability of the article.
[0216] Such a first layer is preferably in direct contact with the
absorbent core. It provides air and water vapor permeability by
being apertured. Preferably this layer is made in accordance with
the aforementioned U.S. Pat. No. 5,591,510 or PCT WO 97/03818, WO
97/03795. In particular, this layer comprises a polymeric film
having capillaries. The capillaries extend away from the wearer
facing surface of film at an angle which is less then 90 degrees.
Preferably the capillaries are evenly distributed across the entire
surface of the layer, and are all identical. However, layers having
only certain regions of the surface provided with apertures, for
example only an area outside the region aligned with the central
loading zone of the absorbent core, maybe provided with such
capillaries.
[0217] Methods for making such three-dimensional polymeric films
with capillary apertures are identical or similar to those found in
the apertured film topsheet references, the apertured formed film
references and the micro-/macroscopically expended film references
cited above. Typically a polymeric film such as a polyethylene
(LDPE, LLDPE, MDPE, HDPE or laminates thereof) or preferably a
monolithic polymeric film is heated close to its melting point and
exposed through a forming screen to a suction force which pulls
those areas exposed to the force into the forming apertures which
are shaped such that the film is formed into that shape and, when
the suction force is high enough, the film breaks at its end
thereby forming an aperture through the film.
[0218] Especially using a monolithic polymer film as the material
for the first layer provides water vapor permeability even under
stress conditions. While the apertures provide air permeability
during "leakage safe" situations but close the capillaries under
stress conditions the monolithic material maintains water vapor
permeability in such a case. Preferred breathable monolithic film
materials for use herein are those having a high vapor exchange.
Suitable monolithic films include Hytrel (.TM.), available from
DuPont Corporation, USA, and other such materials as described in
Index 93 Congress, Session 7A "Adding value to Nonwovens", J-C.
Cardinal and Y. Trouilhet, DuPont de Nemours international S.A,
Switzerland.
[0219] Various forms, shapes, sizes and configurations of the
capillaries are disclosed in EP-A-934 735 and EP-A-934 736 both of
which are herein incorporated for reference. In particular the
apertures form capillaries, which have side walls. The capillaries
extend away from the wearer facing surface of the film for a length
which typically should be at least in the order of magnitude of the
largest diameter of the aperture while this distance can reach up
to several times the largest aperture diameter. The capillaries
have a first opening in the plane of the garment facing surface of
the film and a second opening which is the opening formed when the
suction force (such as a vacuum) in the above mentioned process
creates the aperture. Naturally the edge of the second opening may
be rugged or uneven, comprising loose elements extending from the
edge of the opening. However, it is preferred that the opening be
as smooth as possible so as not to create a liquid transport
entanglement between the extending elements at the end of the
second opening of the capillary with the absorbent core in the
absorbent article (in contrast this may be desirable for apertured
film topsheets where such loose elements provide the function of
sucker feet). The capillaries in the first layer of the breathable
backsheet allow air and water vapor permeability which is not
hindered by them being slanted at an angle or by the shape. At the
same time the slanting and shaping will allow the capillaries to
close under pressure excerpted from the wearer facing side on them
such that liquid transport through the capillaries towards the
outside of the article becomes nearly impossible. Hence these
three-dimensional formed film layers are highly preferable in the
context of breathable absorbent articles and in particular so with
the additional second outer layer which is provided as hereinafter
explained.
[0220] The second outer layer of the breathable backsheet according
to the present invention is a fibrous nonwoven web having a basis
weight of less than 40 g/m2, preferably of less than 28 g/m2. More
preferably, the second outer layer is a fibrous nonwoven web formed
by a layered composite of a meltblown nonwoven layer made from
synthetic fibers having a basis weight of less than 13 g/m2 and of
a spunbonded nonwoven layer also made from synthetic fibers.
[0221] In the most preferred embodiment herein the backsheet
comprises at least a first layer of a resilient, three dimensional
web which consists of a liquid impervious polymeric film having
apertures forming capillaries which are not perpendicular to the
plane of the film but are disposed at an angle of less than
90.degree. relative to the plane of the film, and at least a second
breathable layer of a porous web which is a fibrous nonwoven
composite web of a meltblown nonwoven layer made from synthetic
fibers having a basis weight of less than 13 g/m2 and of a
spunbonded nonwoven layer made from synthetic fibers.
[0222] Using as the breathable backsheet in the absorbent article
of the present invention, a backsheet comprising at least one
breathable layer of a resilient, three dimensional web which
consists of a liquid impervious polymeric film having apertures
forming capillaries which are not perpendicular to the plane of the
film but are disposed at an angle of less than 90.degree. relative
to the plane of the film, and at least another breathable layer of
a porous web which consists of a fibrous nonwoven web having a
basis weight of less than 40 g/m2 (particularly of about 28 g/m2),
further contributes to the outstanding benefit of the present
invention. Indeed these backsheet functions very well in term of
comfort, soiling prevention of the user panty, dryness, etc. while
providing additional comfort due to the reduced basis weight of the
non-woven layer. This reduction of basis weight also provides an
improved material consumption structure of the whole article.
[0223] According to the present invention the absorbent article may
find utility as sanitary napkins, panty liners, adult incontinence
products, nursing pads and baby diapers. The present invention
finds particular susceptibility as sanitary napkins and panty
liners. A new product design, which is a sub-form of a sanitary
napkin or panty liner form, namely thong shaped sanitary napkins or
panty liners, so called thong liners, are particularly susceptible
to the present invention. The thong liner design is such that it
provides the sanitary napkin or panty liner with a shape such that
it can be worn in thong slips, G-string undergarments or string
panties, hence the thong shape is fundamentally triangular or
trapezoidal.
[0224] Thus in addition to the components described herein above,
the absorbent article may also comprise all those features and
parts which are typical for products in the context of their
intended use such as wings and side flaps, undergarment adhesive
means, release paper, wrapping elements, fastening means and the
like. Optionally, the absorbent articles of the present invention
can comprise all those components typical for the intended product
use. For example absorbent articles can comprise components such as
wings in order to improve their positioning and soiling protection
performance especially towards the rear end of the article. Such
designs are shown for example in EP 130 848 or EP 134 086, Thong
liners with wings are shown in US design 394,503, UK designs
2,076,491 and 2,087,071 as well as internationally filed industrial
model DM 045544, filed under the Hague Agreement, registered on
Oct. 21, 1998.
[0225] Irrespective whether the wings are specially designed for
thong liners or for conventional absorbent articles they can be
provided as separate pieces and be attached to the thong liner or
conventional pantiliners or sanitary napkins, or they can be
integral with the materials of the absorbent articles, e.g. by
being integral extension of the topsheet, the backsheet or a
combination thereof. If the wings are attached then they can be
attached in a basic outward pointing position or already be
predisposed towards their in-use position, i.e. towards the
longitudinal centerline.
[0226] Most preferred absorbent articles will comprise a fastening
adhesive for attachment. In the case of sanitary napkins,
pantliners or thongliners a so-called panty fastening adhesive is
preferred to be present on the backsheet for attachment to an
undergarment. However, for sweat pads, e.g. underarm sweat pads,
either attachment to an adjacent garment or attachment to the skin
of the wearer directly can also be considered. Of course, such
direct skin attachment, which is conventionally provided by water
gel, hydrogel or oil gel based body adhesives, can also be used in
sanitary napkins or body liners (in contrast to pantiliners).
Moisture Vapour Permeability Test
[0227] The basic principle of the test is to quantify the extent of
water vapour transmission of a backsheet construction and/or an
article. The test method that is applied is based on a standardized
textile industry applied test method and commonly referred to as
the "cup test method". The test is performed in a stable
temperature/humidity laboratory maintained at a temperature of
23.degree. C. at 50% RH for a period of 24 hours.
[0228] Apparatus:
[0229] 1) Sample cup of open area=0.00059 m.sup.2
[0230] 2) Syringe to introduce the distilled water into the
completed sample cup.
[0231] 3) Wax to seal the cup once sample has been arranged.
[0232] 4) A circular punch to facilitate preparation circular
samples of diameter=30 mm.
[0233] 5) Laboratory of stable climatic conditions (23.degree.
C..+-.0.5.degree. C./50% RH.+-.1% RH)
[0234] 6) Laboratory balance accurate to 4 decimal places.
[0235] Sample Preparation/Measurements:
[0236] The test is to be performed on the article or the backsheet
construction. A representative article or backsheet is selected and
a sample is cut to size using the punch. The sample cut is
sufficiently large to adequately overlap the sample holder and to
ensure material that may have been damaged or undesirably stretched
due to the cutting operation lies outside of the measurement centre
when the measurement is performed. The sample is so arranged onto
of the sample cup so as to fully overlap the cup. The sample is
oriented so as to ensure that the surface exposed to the laboratory
environment is the same that would be found while wearing the
article.
[0237] The closure ring of the sample cup is then placed onto the
sample and pushed down. This ensures that the excess material is
held firmly in place and does not interfere with the measurement. A
wax is then applied to the entire surface of the closure ring to
ensure the whole upper part of the apparatus is closed to the
environment. Distilled water (5.+-.0.25 ml) is introduced with the
syringe into the sealed sample cup via the minute perforation.
Finally this perforation is sealed with silicone grease.
[0238] The entire cup (containing sample and water) is weighed and
the weight recorded to 4 decimal places. The cup is then placed in
a ventilation stream generated by a fan. The air flowing over the
top of the sample cup is 3.+-.0.3 m/sec and confirmed via a wind
velocity meter ("Anemo", supplied by Deuta SpA., Italy). The sample
cup remains in the ventilated test field for a period of 24 hrs and
is then re-weighted. During this period if the test sample is
sufficiently breathable the liquid in the sample holder is able to
diffuse out of the sample holder and into the laboratory
environment. This results in a reduction in the weight of water in
the sample holder that can be quantified on re-weighing the
complete sample cup following the 24 hr period. The vapour
permeability value is determined as the weight loss divided by the
open area of the sample holder and quoted per day.
[0239] i.e. Vapour Permeability=Weight Loss (g)/(0.00059 m.sup.2/24
hrs.)
[0240] The present invention is further illustrated by the
following examples.
EXAMPLES
Example 1
[0241] Pantiliners were prepared by modifying panty liners
commercially available, namely "Alldays".RTM. manufactured by
Procter & Gamble, Germany.
[0242] The topsheet is a film/non woven composite {film supplier
code 45105 BP Chemical Plastic Germany, non woven supplier code
T-27 AXC Corolind HDPE LINOTEC)
[0243] 30 g/m.sup.2 of an emollient-containing composition
consisting of 23% by weight of menthyl lactate available from
H&R (Germany) under the name Frescolat ML.RTM. and of 77% by
weight of triehyl citrate (available from Aldrich) was sprayed
homogenously over the whole surface of the wearer-facing surface of
the topsheet.
[0244] The core is an airlaid material containing an absorbing
gelling compound having a basis weight of 100 g/m.sup.2 and
available from Concert under the code GH 100.91209.
[0245] The backsheet comprises two layers a first layer and a
second layer. The first layer (also called secondary backsheet) is
in contact with the absorbent tissue and the second layer. The
second layer is in contact with the first layer and the
undergarment of the wearer. The first layer is a formed apertured
film (HEX) {supplied by Tredegar Film Products B.V. Holland under
the manufacturing code X-25368}. The second layer is composed of a
microporous layer {supplied by EXXON Company IL under the
manufacturing code EXXAIRE BF112 W}. Each backsheet layer is joined
over the full surface by an extensively overlapped spiral glue
application at a basis weight of approximately 8 g/m.sup.2. The
glue used for attachment of both backsheet layers was supplied by
SAVARE' SpA. Italy (under the material code PM17).
Example 2
[0246] This is an example of a pantiliner according to the present
invention. The pantiliner is based on a `Alldays`.RTM. pantiliner
available from Procter & Gamble Germany, which has been
modified.
[0247] The topsheet is a film/non woven composite {film supplier
code 45105 BP Chemical Plastic Germany, non woven supplier code
T-27 AXC Corolind HDPE LINOTEC) 30 g/m.sup.2 of an
emollient-containing composition consisting of 23% by weight of
menthyl lactate available from H&R (Germany) under the name
Frescolat ML.RTM. and of 77% by weight of triehyl citrate
(available from Aldrich) was sprayed homogenously over the whole
surface of the wearer-facing surface of the topsheet.
[0248] The core material is a tissue laminate (13.2 cm.times.4.0
cm) composed of a 2 layers of airlayed tissue of 55 g/m.sup.2 basis
weight {available from Unikay Italy under the supplier code Unikay
303 LF}. Between the two tissue layers the laminate contains an
absorbing gelling material, namely Agm Aqualic (available from
Shokubai under the code Aqualic L-74) and an odor control material
namely Zeolite A (available from Degussa under the code Zeolite
Wessalith CS)
[0249] The backsheet comprises two layers a first layer and a
second layer. The first layer (also called secondary backsheet) is
in contact with the absorbent tissue and the second layer. The
second layer is in contact with the first layer and the
undergarment of the wearer. The first layer is a formed apertured
film (HEX) {supplied by Tredegar Film Products B.V. Holland under
the manufacturing code X-25368}. The second layer is composed of a
microporous layer {supplied by EXXON Company IL under the
manufacturing code EXXAIRE BF112 W}. Each backsheet layer is joined
over the full surface by an extensively overlapped spiral glue
application at a basis weight of approximately 8 g/m.sup.2. The
glue used for attachment of both backsheet layers was supplied by
SAVARE' SpA. Italy (under the material code PM17).
Example 3
[0250] These are examples of sanitary napkins according to the
present invention. The sanitary napkins are based on an `Always
Ultra`.RTM. sanitary napkin available from Procter & Gamble
Germany, which has been modified.
[0251] The topsheet is a film/airlaid composite, with a first outer
topsheet layer made of an apertured film (S-RIS CPM material
available from Tredegar Holland under the code X-25602) and a
second topsheet layer, positioned between the first outer topsheet
layer and the core, made of air laid material (available from DUNI
Sweden under the code PTC X 077).
[0252] 30 g/m.sup.2 of an emollient-containing composition
consisting of 23% by weight of menthyl lactate available from
H&R (Germany) under the name Frescolat ML.RTM. and of 77% by
weight of triehyl citrate (available from Aldrich) was sprayed
homogenously over the whole surface of the wearer-facing surface of
the topsheet, i.e. the outer surface of the apertured film.
Alternatively only the wearer-facing surface of the airlaid second
topsheet layer was homogeneously sprayed with the
emollient-containing composition or both the airlaid second
topsheet layer and the first apertured topsheet layer.
[0253] The core material is an airlaid core containing Agm
available from Concert (Germany) under the name GH 150 1006.
[0254] The backsheet is a multi-layer breathable backsheet
comprising a formed apertured film backsheet layer and a second
microporous layer. The first layer is a PE film with a crush
resistant hexagonal hole configuration {supplied by Tredegar Film
Products B.V. Holland under the manufacturing code X 25368). The
second layer of backsheet has been replaced by a microporous layer
(manufactured by Tredegar Hungary under the name XBF 610W).
FURTHER EXAMPLES
[0255] Additional panty liners as the ones of Examples 1 or 2 as
well as additional sanitary napkins as the ones of Example 3 above
were prepared, except that instead of applying the
emollient-containing composition mentioned in examples 1 to 3, the
following compositions were sprayed homogenously over the whole
surface of the wearer-facing surface of the topsheet:
[0256] Either
[0257] 30 g/m.sup.2 of an emollient-containing composition
consisting of 20% by weight of menthoxypropanediol available from
Takasago under the name TK-10.RTM. and of 80% by weight of triethyl
citrate or triacetyl citrate (available from Aldrich). or
[0258] 20 g/m.sup.2 of an emollient-containing composition
consisting of 20% by weight of menthone glycerol ketal available
from H&R under the name Frescolat MGA.RTM. and of 80% by weight
of triethyl citrate or triacetyl citrate (available from Aldrich).
or
[0259] 20 g/m.sup.2 of an emollient-containing composition
consisting of 20% by weight of ethyl menthane carboxamide available
from Rhodia Chirex under the name WS-3.RTM. and of 80% by weight of
triethyl citrate or acetyl tributyl citrate (available from
Aldrich). or
[0260] 30 g/m.sup.2 of an emollient-containing composition
consisting of 30% by weight of ethyl menthane carboxamide available
from available from Rhodia Chirex under the name WS3.RTM. and of
70% by weight of propylene glycol (available from Aldrich). or
[0261] 40 g/m.sup.2 of an emollient-containing composition
consisting of 30% by weight of menthyl lactate available from
Haarman&Reimer (Germany) under the name Frescolat.RTM.ML and of
70% by weight of propylene glycol (available from Aldrich). or
[0262] 30 g/m.sup.2 of an emollient-containing composition
consisting of 25% by weight of menthyl lactate available from
Haarman&Reimer (Germany) under the name Frescolat.RTM.ML, 5% by
weight of 1-Menthol available from Takasago under the name Menthol
and of 70% by weight of propylene glycol (available from Aldrich).
or
[0263] 30 g/m.sup.2 of an emollient-containing composition
consisting of 25% by weight of menthyl lactate available from
Haarman&Reimer (Germany) under the name Frescolat.RTM.ML, 5% by
weight of 1-Menthol available from Takasago under the name Menthol
and of 70% by weight of triethyl citrate (available from Aldrich).
or
[0264] 30 g/m.sup.2 of an emollient-containing composition
consisting of 20% by weight of menthyl lactate available from
Haarman&Reimer (Germany) under the name Frescolat.RTM.ML, 10%
by weight of 1-Menthol available from Takasago under the name
Menthol and of 70% by weight of acetyl-tributyl citrate (available
from Aldrich). or
[0265] 30 g/m.sup.2 of an emollient-containing composition
consisting of 25% by weight of menthoxy propanediol available from
Takasago under the name TK10.RTM., 5% by weight of 1-Menthol
available from Takasago and of 70% by weight of propylene glycol
(available from Aldrich).
[0266] All sanitary napkins and panty liners illustrated herein
before were found to improve comfort to the wearer in use,
including quasi immediate (after only about 2 minutes of wearing
time) and long lasting freshness sensation (over more than 3 to 4
hours), while maintaining or even improving skin health.
[0267] All documents cited in the Detailed Description of the
Invention are, in relevant part, incorporated herein by reference;
the citation of any document is not to be construed as an admission
that it is prior art with respect to the present invention. To the
extent that. any meaning or definition of a term in this written
document conflicts with any meaning or definition of the term in a
document incorporated by reference, the meaning or definition
assigned to the term in this written document shall govern.
[0268] 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. It is therefore intended to cover in the appended claims
all such changes and modifications that are within the scope of
this invention.
* * * * *