Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
1328987
, This invention relates to an absorbent article, such as a
diaper, feminine pad, panty liner, incontinent garment, underarm
shield, or bedpad which contains an anhydrous deodorant mixture
including acidic, basic and pH neutral odor absorbing particles.
More specifically, the mixture is a non-buffer.
This is a division of copending Canadian Patent Application
Serial No. 604,455, filed June 29, 198g.
Absorbent articles which are designed to be worn by humans to
absorb a quantity of urine, menstrual fluid, perspiration, etc.,
are known to acquire a variety of malodorous compounds including
amines and fatty acids. The emanation of odors from these absorbent
articles can cause the user to feel self conscious. Furthermore,
an absorbent article may emit an odor immediately after receiving
the initial flow of body fluid, which is well before the absorbent
article has retained a significant amount of fluid for which it has
capacity. In such a situation, the user may not prefer to change
the product due to its cost, time of occurrence or other
consideration, yet would like to eliminate the malodor.
A number of prior art devices have attempted to mask the
malodor or to camouflage it with an artificial scent, such as
perfume. U.S. patents 4,547,195, 4,545,080, 4,186,743 and 3,939,838
are examples of such prior art. In addition, there are patents which
teach specific deodorant compositions for controlling malodors in
feminine napkins and wound dressings. U.S. patents 2,024,145,
3,871,993 and 3,995,636 and Australia patent 109,904 are examples
of different types of deodorants.
For absorbent articles designed for absorbing urine and
menstrual fluid, it is known that such body fluids contain acidic,
basic and pH neutral odors which can best be controlled by providing
a deodorant which has an acidic, basic and pH neutral odor absorbing
~.. .
, .
- , -, .. : . :
,' ': ' :
~3289~7
properties. However, until now, manufacturerS have
concentrated on formulating deodorants with acid and
base buffers which arë activated when wetted by body
fluid. World patent 81/01643 is one such patent which
S teaches the use of ion exchange materials for the
deodorant~ Other references, such as U.S. patents
4,372,309, 4,583,980, 4,055,184 and 3,340,875, describe
controlling volatile nitrogen compounds, using citric
acid or acetyl citric acid to control basic odors, and
using hydrolyzed starch polyacrylonitrile graft
copolymers in acidic form. However, in the above
references the deodorant has to be wetted before the
buffer compound starts to control the malodor.
While the above-identified teachings attempt to
alleviate malodors emanating from absorbent articles,
there is still a need for a deodorant which can handle
various types of malodors while in the dry state.
Briefly, the present invention relates to an
absorbent article, such as a diaper, a feminine pad, a
panty liner, an incontinent garment, an underarm shield,
a bedpad, etc., which contains an anhydrous deodorant.
The general structure of one form of the invention
includes an absorbent with a first surface and second
surface aligned approximately opposite to the first
surface, a liquid-impermeable baffle positioned adjacent
to at least the second surface of the absorbent and a
fluid permeable cover positioned adjacent to at least
thc first surface of the absorbent.
~,., ,, - . .... .
... .
'"
. ' .
1328987
According to one aspect of the invention, there is
provided deodorizing means for absorbing malodors
emanating from the absorbent, the deodorizing means
being an anhydrous mixture of at least basic and pH
neutral odors absorbing particles positioned between the
baffle and the absorbent pad and wherein a substantial
portion of the mixture is located in the outer 50% of
the total surface area of the article.
According to a specific feature of the invention,
there is provided deodorizing means for absorbing
malodors emanating from the absorbent, the deodorizing
means being an anhydrous mixture of odors absorbing
particles, the mixture presenting from about 5 to 50% of
the total weight of the article and wherein a
substantial portion of the mixture is positioned to the
periphery of the article.
According to yet another feature of the invention,
there may be provided deodorizing means which is an
anhydrous mixture of at least basic and pH neutral odor
absorbent particles positioned between the baffle and
the respective side surfaces of the absorbent.
Alternatively, the particles may be incorporated into
the baffle.
Another general form of the invention is an
absorbent article having a C-shaped cross-section with a
first surface and a second surface aligned approximately
opposite to the first surface and including a
liquid-impermeable baffle positioned adjacent to at
, ~ . .
~; ` ' ' ,.
1328987
least a second surface of the absorbent and a fluid
permeable cover positioned adjacent to at least the
first surface of the absorbent. The fluid permeable
cover may surround the absorbent with the
liquid-impermeable baffle positioned adjacent to the
second surface may be attached to an exterior surface of
the cover.
According to an aspect of this form of the
invention, there is provided deordorizing means for
absorbing malodors emanating from the absorbent, the
deordorizing means being an anhydrous mixture of at
least basic and pH neutral odor absorbing particles in
the form of a non-woven web positioned within the folded
absorbent.
Alternatively, the deordorizing means in the form
of at least basic and pH neutral odor absorbing
particles may be positioned between the exterior surface
of the cover and the baffle.
Other objects and advantages of the present
invention will become more apparent to those skilled in
the art in view of the following description and the
accompanying drawings.
:
Brief Description of the Drawings
Figure 1 is a top view of an absorbent article,
such as a feminine pad, containing a deodorant mixture
for absorbing odors.
Figure 2 is a side view of the absorbent article
shown in Figure 1.
Figure 3 is an end view of the absorbent article
shown in Figure 1.
Figure 4 is an enlarged cross-sectional view of the
absorbent article shown in Figure 1 taken along line
4--4.
Figure 5 is a perspective view of an absorbent
article showing a majority of the deodorant mixture
positioned adjacent to the
~,
~ 3a
:,
`.t' .
. ......... .
' . .
"'I '
"',''~ '
.
` '
1328987
outer periphery of the article between the absorbent and the liquid-
impermeable baffle.
Figure 6 is a schematic of a rectangular sheet showing the
concentration of a deodorant mixture positioned thereon with "A"
being a minimum quantity, "B" being an intermediate quantity and
"C" being the greater quantity.
Figure 7 is a cross-sectional view of an absorbent article
having a deodorant mixture positioned between a vapor permeable
layer and a liquid-impermeable baffle.
Figure 8 is a cross-sectional view of an absorbent article
showing a deodorant mixture positioned between a vapor permeable
layer and a liquid-impermeable baffle wherein both the vapor
permeable layer and the liquid-impermeable baffle have approximately
equal surface areas.
Figure 9 is a cross-sectional view of an absorbent article
having a non-uniform layer of a deodorant mixture positioned within
the absorbent such that a greater quantity of the deodorant mixture
is adjacent to the outer periphery of the article and a lesser
amount of the mixture is positioned in the center of the article.
Figure 10 is a cross-sectional view of an alternative embodiment
showing a C-folded layer of deodorant positioned within the
absorbent.
Figure 11 is another embodiment of an absorbent article having
a liquid-impermeable baffle extending upwards about the sides of
the absorbent and a deodorant mixture is positioned between the
sides of the absorbent and the interior surface of the liquid-
impermeable baffle.
Figure 12 is a cross-sectional view of another embodiment
showing a deodorant mixture incorporated into the outer peripheral
surface of the absorbent article.
Figure 13 is a cross-sectional view of another embodiment
showing a deodorant mixture incorporated into the liquid permeable
baffle.
,
, .
1328987
Figure 14 is an enlarged view of the circled area shown in
Figure 13 depicting the deodorant particles dispersed between
fibers of the liquid-impermeable baffle.
Detailed Description of the Preferred Embodiment
Referring to Figures 1-4, an absorbent article 10 is shown.
The article 10 can be a diaper, a feminine pad, a panty liner, an
incontinent garment, an underarm shield, a bedpad, etc. For purposes
of discussion, the absorbent article 10 is depicted as a feminine
pad. The absorbent article 10 contains an absorbent 12, best shown
in Figure 4, which can be constructed of cellulose, wood fluff,
coform, meltblown or carded material, sphagnum moss, or other
conventional material. Coform is an air-form mixture of meltblown
and staple fibers such as wood fluff. The absorbent 12 is shown C-
folded having abutting ends 14 and 16. The absorbent 12 contains a
first surface 18, which faces the body of a user, and a second
surface 20 aligned approximately opposite to the first surface 18.
The absorbent article 10 also contains a liquid-impermeable
baffle 22, which is positioned adjacent to at least the second
surface 20 of the absorbent 12. It is possible that the baffle 22
can extend upwards around a portion of the sides of the absorbent
12 and even overlap a portion of the first surface 18 in certain
embodiments. The liquid-impermeable baffle 22 can be constructed
of polypropylene, polyethylene or other suitable material. A fluid
permeable cover 24 is positioned adjacent to at least the first
surface 18 of the absorbent 12. The cover 24 can extend completely
around the absorbent 12, as is shown in Figure 4. Alternatively,
it can partially cover the absorbent 12 and be attached directly to
the baffle 22 or an intermediate member, see Figures 7 and 8, so
that both the cover 24 and the baffle 22 sandwich the absorbent 12
therebetween. The cover 24 can be a nonwoven, spunbonded or film
material, or be made from a material having a netting type texture.
The cover 24 can be porous, embossed, perforated or exhibit a
smooth surface. The cover 24 is designed to come in contact the
body of the user and present a soft and comfortable feel while
,',. : ' '
'.~:` .
".,~
1328987
exhibiting the ability to allow human exudate in a form of blood,
menstrual, intramenstrual, urine or other types of body fluid to
readily pass through into the absorbent 12.
When the cover 24 completely surrounds the absorbent 12, as is
shown in Figure 4, opposite ends 26 and 28 of the cover 24 can be
bonded together. Furthermore, the baffle 22 can be bonded to the
outside surface of the cover 24 by construction adhesive 30. In
Figure 4, four distally spaced longitudinal strips of construction
adhesive 30 secure the baffle 22 to the cover 24. It is possible
to use only a single strip of adhesive if one desires. As with
most conventional pads, a garment adhesive 32, which can be pressure
sensitive, is applied to an outside surface of the baffle 22 and a
removable peel strip 34 is attached thereto. The peel strip 34 is
designed to be removed just prior to use of the product by the
ultimate consumer. In use, the consumer removes the peel strip 34
and attaches the product to the inside surface of an undergarment so
that the product will remain in position relative to the perineum
of the body.
The absorbent article 10 also contains a deodorizing mixture
36 for absorbing malodors which may emanate therefrom during use.
The odors are introduced into the absorbent article 10 when the
absorbent 12 absorbs body fluid. The body fluid can contain highly
malodorous compound such as amines and fatty acids. The following
odors are commonly known to exist in feminine pads: triethyl amine,
pyridine, furaldehyde, and n-propyl sulfide. The particular
malodorous compounds which will be absorbed by various absorbtion
articles will vary depending upon the person who is wearing the
absorption article and the type of fluid absorbed, i.e., urine,
menstrual fluid, per iration, etc. For feminine pads in particular,
the length of time that the article is worn, the quantity of fluid
which is absorbed and the exposure of the pad to different body
fluids will all determine the different odors which can be emitted
~' by the absorbent ~rticle.
The deodorizing mixture 36 is an anhydrous mixture of acidic,
basic and pH neutral odor absorbing particles. The mixture is a
.,
.
,, .
,::
,
', ' : , ,
,: :
1328987
non-buffer which neutralizes odors emanating from the article 10.
The particles are mixed together but each particle maintains its
distinct identity. Each particle is anhydrous and does not contain
water either absorbed on its surface or combined as water of
crystallization. All the particles are dry during the assembly
process and are designed to remove odors in the dry state and are
not normally designed to be wetted. Because of this, the particles
do not act as a buffer and do not require contact by urine or
menstrual fluid before they start to take effect. The particles
are dry blended and mixed without the use of solvent or water and
are retained in the dry state throughout the manufacturing process.
The particles themselves do not emit an unpleasant odor. The
deodorizing mixture 36 is blended without the addition of a solvent
or water and this is contrary to most buffers which are blended
with the addition of a solvent or with water.
As mentioned above, the deodorizing mixture 36 contains acidic,
basic and pH neutral odor absorbing particles. The acidic particles,
those having a pH of less than 7, may be any suitable dry acid
material which will provide control of basic odoriferous compounds.
Typical of such materials are ascorbic acid, stearic acid, boric
acid, maleic acid polymers, malonic acid, maleic acid, polyacrylic
acid and monopotassium phosphate. A preferred material is citric
acid for it is low in cost, safe to use, and has a low equivalent
weight. Low equivalent weight means that a large amount of the
acid is present per unit of weight. The amount of acid present
will vary depending upon the type of product that it is incorporated
into, and the particular odors that it is designed to control. For
feminine products, it has been found that a suitable amount of acid
is between about 20 and 50 percent of the total weight of the
deodorizing mixture. A preferred amount is between about 30 and 45
percent of the total weight of the deodorizing mixture. The amount
of acid should be in approximate stoichiometric balance with the
basic compound. This is advantageous in certain conditions.
Stoichiometric balance is desirable as the effectiveness of the
acid and base should be exhausted at approximately the same time.
.. . .
1328987
The basic odor controlling particles of the deodor;zing mixture
36, those having a pH of greater than 7, are designed to primarily
control acidic odoriferous compounds. Typical of such basic odor
control particles are inorganic salts of carbonates, bicarbonate,
phosphate, biphosphate, sulfate, bisulfate and mixtures thereof. A
preferred baslc odor absorbing material is sodium bicarbonate
because it is low in cost, safe to use and its effectiveness has
been established over a number of years by previous use in consumer
products. The amount of the basic odor absorbing particles used in
the blend can be between about 25 and 75 percent of the total
weight of the deodorizing mixture. A preferred range is between
about 40 and 65 percent of the total weight of the deodorizing
mixture. These percentages will give adequate odor control and
will also provide the stoichiometric balance as discussed above.
The pH neutral odor absorbing particles of the deodorizing
mixture 36, those having a pH of approximately 7, are designed to
absorb odoriferous compounds which are not acidic or basic. Typical
of such pH neutral odor absorbing materials are activated carbon,
clays, silicas, diatomaceous earth, polystyrene derivatives,
zeolites, molecular sieves and starches. A preferred material is a
synthetic molecular sieve, such as synthetic sodium aluminum silicate
with a zeolite structure that has been treated to be absorptive of
odoriferous compounds but not absorptive of water. Such material
is commercially available from UOP as ABSCENTSX and SMELLRITE0. It
should be noted that in the presence of water vapor, conventional
molecular sieves tend to loose most of their capacity to absorb
odors. In contrast, ABSCENTS and SMELLRITE0 appear to retain most
of their absorbent capacity in moist conditions and are therefor
preferred.
As stated above, the deodorizing mixture 36 is a non-buffer
mixture which can be inserted into an absorbent article in a variety
of ways. Preferably, the deodorizing mixture 36 will be positioned
such that it will not. be immediately contacted by body fluids
discharged by the user. The non-buffered mixture is most effective
when dry, although it will work in the wet condition. The
. : . :
.
1~28987
deodorizing mixture 36 should be positioned within the absorbent
article so as to intersect vapors emanating from the article and
thereby absorb the malodors. In this regard, the deodorizing
mixture 36 appears to be very useful when located around the
peripheral edge near the lateral sides of the article or on the
second surface 20 of the absorbent 12. In all of these positions,
the deodorizing mixture 36 will remain dry until the absorbent
article has absorbed a significant amount of fluid relative to its
ultimate capacity. It is also possible to position the deodorizing
mixture 36 in a central portion of the product, but shield it by
hydrophobic fibers in order to minimize its contact by body fluid
while still allowing it to absorb malodorous. The deodorizing
mixture 36 can further be placed within a fibrous material that is
hydrophobic in order to discourage passage of fluid there through.
It should be noted that the deodorizing mixture 36 absorbs the
malodors emanating from the article 10 and this contrasted to
fragrances which are designed to conceal or mask odors. If one
wished to add a perfume or a scent to the deodorizing mixture 36,
one must carefully select the perfume or scent to avoid detracting
from the functional ability of the mixture itself. The present
deodorizing mixture 36, being anhydrous, exhibits good shelf life
and stability and does not require any special type of packaging or
handling. However, to maintain maximum effectiveness, it is
advantageous to avoid close contact with strongly scented materials
; 25 during extended storage.
Referring to Figure 5, an absorbent article 38 is shown having
an absorbent 40 and a liquid-impermeable baffle 42 surrounded by a
fluid permeable cover 44. The baffle 42 has an upper surface 46
which is in contact with a lower surface of the absorbent 40.
; 30 Positioned on the upper surface 46 is a deodorizing mixture 48
containing acidic, basic and pH neutral odor absorbing particles, as
explained above. The deodorizing mixture 48 is applied to the
~, surface 46, such that a greater quantity or amount of the mixture
is present about the outer periphery of the baffle 42 than is
present in the central portion thereof. The greater number of
.,. ~ . .
". :
, ,~
.,,' ' ,
.... .
1328987
particles, designated 50, are shown being more compact and located
closer together. The lesser number of the particles, designated 52,
are located in the central portion and are spaced a greater distance
apart. The novel feature of utilizing a greater quantity of the
particles around the outer periphery of the absorbent article 38
presents the deodorizing mixture 48 to remain drier for a longer
period of time and therefore will facilitate better absorption of
malodors.
It has been found that the particle size of the deodorizing
mixture is important, especially when one attempts to form a blend
or mixture. If any one of the three ingredients is overly large or
particularly small, it is possible that during normal shipping cr
stacking of the product that the particles will shift and separate.
This can cause a substantial amount of one of the particles to end
up on the bottom, while other particles will be located at the top
of the mixture. In order to provide effective odor control, it is
important that the mixture retain blended and the particles have a
size which will allow them to stay blended. Experimentation has
shown that when the components of the deodorizing mixture are
citric acid, sodium bicarbonate and zeolite, that the citric acid
particles have a size of between about 40 and 400 micrometers, that
the sodium bicarbonate particles have a size of between about 25 and
250 micrometers and that the zeolite particles have a size of less
than about 20 micrometers. It should be noted that in these ranges
a substantial amount of the particles should be within these specific
ranges. If one were to use a sieve measurement to establish size,
then the following U.S. standard sieve sizes would correspond to
the above-mentioned micrometers. The citric acid should have a
size such that more than 90% passes through a number 40 sieve and
more than 90/O is retained on a number 400 sieve. The sodium
bicarbonate should have a size such that more than 90% passes
through a number 70 sieve and more than 70% is retained in a number
400 sieve. The zeolite should have a size such that more than 70%
passes through a number 400 sieve. Because many zeolites tend to
agglomerate, to obtain an accurate measure of the zeolite particle
;~ , .
~,. .
., ' , ,' ' ', ' .
1328987
particle size may require the use of a free flowing, fine particle
size material as an aid in driving the zeolite through the sieve.
Another measurement of the amount of the deodorizing mixture
which should be present in the absorbent article will depend upon
the given purpose that the article is designed to serve. It has
been found that from about 5 to 50 percent and preferably about 10
to 25 percent of the total weight of the article should be made up
of the mixture. It has also been found that the mixture works
satisfactorily when a substantial portion of the mixture is
positioned in the outer S0 percent of the total surface area of the
article. For products having a weight of at least 2 grams, the
amount of the deodorizing mixture 36 can be between .15 to 2.5 grams,
preferably .2 to 2.0 grams, and most preferably between about .4
and 1.0 grams. A preferred amount has been found to be about 1
gram for providing adequate odor protection without substantially
adding to cost. For a 1 gram mixture, one can have about 39 percent
by weight of citric acid, about 51 percent by weight of sodium
bicarbonate and about 10 percent by weight of a molecular sieve
zeolite.
Referring to Figure 6, a schematic is shown of a rectangular
sheet 54, having a quantity of a deodorizing mixture 56 positioned
thereon. The rectangular sheet 54 has a length denoted "L" and a
width denoted "W". The sheet 54 is representative of the surface
of a liquid-impermeable baffle which would receive the deodorizing
mixture. The sheet 54 contains three areas designated "A", "B" and
"C" with the central portion labeled "A", the intermediate portion
labeled "B", and the extreme outer portion labeled "C". The amount
of the deodorizing mixture 56 present in each portion varies. The
minimum amount of the mixture 56 is positioned in area "A", an
intermediate amount is positioned in area "B" and the maximum
amount is positioned in area "C".
¦ Experimentation has shown that at least 50 percent and
/! preferably 75 percent of the deodorizing mixture 56 should be located
in the outer 50 percent of the total surface area of the absorbent
article. More preferably, at least the outer 75 percent of the
i: 11
-
,.,. ~
.~ .
.... ..
. ~ -
.
. . ..
:
.. . .
1328987
deodorizing mixture 56 should be located in the outer 75 percent of
the total surface area of the absorbent article. Optimumly, at
least 90 percent of the deodorizing mixture 56 should be located in
the outer 75 percent of the total surface area of the article. The
purpose for positioning a greater quantity of the deodorizing
mixture 56 adjacent to the perimeter of the sheet 54 is to allow it
to maintain its dryness for a longer period of time and to be in a
position to intercept the odors emanating from the product along the
sides and bottom surfaces. By positioning the deodorizing mixture
between the absorbent and the liquid-impermeable baffle, as is
shown in Figure 5, the deodorizing mixture will be spaced away from
the porous fluid permeable cover. This distant relationship will
assist in preventing the mixture from migrating up and out through
the cover and into contact with the body of the user. Although the
mixture 56 is not known to be harmful to the skin, it would be
preferable to keep the mixture away from the skin. One reason for
this is that consumers have expressed their dislike with having a
residue of powder left on their body after using an absorbent
article.
Referring to Figure 7, an absorbent article 58 is shown having
an absorbent 60 sandwiched between a liquid-impermeable baffle 62
and a fluid permeable cover 64. The baffle 62 and cover 64 are
bonded together, such as by an adhesive or ultrasonic sealing to
form a peripheral seal 66. The absorbent article 58 also contains
a vapor permeable member or layer 68 which is positioned between the
absorbent 60 and the liquid-impermeable baffle 62. The vapor
permeable member 68 can be a nonwoven, fibrous web which is
preferably liquid-impermeable. The vapor permeable member 68 can be
bonded to the absorbent 60, the baffle 62 or both, such as by a
construction adhesive or by heat. Preferably, the vapor permeable
member 68 is located adjacent to the surface of the absorbent 60
which is away from the body of the user. Alternatively, the vapor
` permeable member 68 can be simply positioned adjacent to the
absorbent 60 without actually being bonding to it. The vapor
permeable member 68 can optionally be liquid permeable but should
12 -
. , `. ~ .' i
.. ~ : , ' '
... . .
1328987
contain some of hydrophob;c fibers so as to reduce the amount of
liquids which will permeate there through. It should also be noted
that the vapor permeable member 68 can have a smaller surface area
than that of the liquid-impermeable baffle 62 such that less material
has to be used. This may be important if the vapor permeable
material 68 is very costly.
Positioned between the vapor permeable member 68 and the
liquid-impermeable baffle 62 is a deodorizing mixture 70 as taught
above. The vapor permeable member 68 will allow the malodors from
the absorbent 60 to emanate there through and be absorbed by the
deodorizing mixture 70 while providing a barrier which will prolong
the amount of time it takes before the deodorizing mixture 70 is
wetted. As mentioned above, the deodorizing mixture 70 is a non-
buffer and therefore is not designed to be wetted in order to
activate it. The absorbent article 58 also contains a garment
adhesive 72 and a peel strip 74, the purpose of which was explained
above.
Referring to Figure 8, an alternative absorbent article 76 is
shown which is similar to the absorbent article 58. All of the
structural features which are identical to those discussed above
for Figure 7 bears the same reference numerical. The only difference
is that in Figure 8, a vapor permeable member or layer 78 is
coterminous with the baffle 62 and the cover 64 and is joined with
both to form a peripheral seal 80. It should be noted that the
deodorizing mixture can be deposited onto the baffle, by gravity,
be sprinkled on, be blown on, be air-formed, or be mixed with a
nonaqueous binder to form a layer and the layer is then interwoven
or meltblown onto a substrate. The particular method of introducing
the deodorizing mixture into the product will depend upon the
equipment available, the amount of mixture to be applied, the
l location where the mixture lS to be applied, the type of product,
! etc.
Referring to Figure 9, another embodiment of an absorbent
¦ article 82 is shown having an absorbent 84 completely surrounded by
a fluid permeable cover 86. A liquid-impermeable baffle 88 is
13
i
..
. , ~ , .
,
1328987
bonded by several strips of construction adhesive 90 to the exterior
of the cover 86 on the side away from the body of the user. The
absorbent art;cle 82 also contains a garment adhes;ve 92 covered by
a removable peel strip 94, the purpose of which was explained
above. The unique feature of the absorbent article 82 is that the
absorbent 84 is C-folded and has a cavity or opening 96 located
within the horizontal center portion of the C-fold. Positioned
within the cavity 96 is a nonwoven web 98 made up of a deodorizing
mixture of acidic, basic and pH neutral odor absorbing particles.
The nonwoven web 98 has a reduced diameter in the center such that
the outer periphery of the web 98 is thicker than the central
portion. The web 98 can be formed by dry mixing and blending the
three different components and then adding a nonaqueous binder to
hold the particles together. The web 98 can be compressed to a
desired cross-sectional configuration. The web 98 is then simply
laid onto the absorbent 84 before it is C-folded into the final
product. The web 98 can also contain hydrophobic fibers if desired,
to add strength and integrity as well as to repel fluid or moisture -
from contacting the odor absorbing particles.
Referring to Figure 10, an absorbent article 100 is shown
having a C-folded absorbent 102 completely surrounded by a fluid
permeable cover 104. A liquid-impermeable baffle 106 is bonded to
an exterior surface of the cover which is spaced away from the body
of the user. A garment adhesive 108 is bonded to an exterior
~ 25 surface of the baffle 106 and is covered by a peel strip 110. A
J web 112, constructed of a deodorizing mixture of acidic, basic and
pH neutral odor absorbing particles is C-folded within the center
portion of the absorbent 102. The web 112 is shown having a constant
thickness and again may contain hydrophobic fibers if desired.
- 30 Referring to Figure 11, another embodiment of an absorbent
~, article 114 is depicted having an absorbent 116 which is completely
, surrounded by a fluid permeable cover 118. The absorbent 116
contains a pair of opposed side surfaces 120 and 122. A liquid-
impermeable baffle 124 having a pair of upwardly extending side
portions 126 and 128 is positioned between the absorbent 116 and
14
- .
,
,,
, ,, , ~
. . .
13289~7
the cover 118. The side portions 126 and 12B extend upward and
substantially cover a greater portion of the side surfaces 120 and
122. Positioned in the cavities or spaces between the surfaces 120
and 126, and the surfaces 122 and 128, respectively, is a deodorizing
mixture 130. The absorbent article 114 also contains one or more
garment adhesive strips 132 which are bonded to an exterior surface
of the cover 118 and which hold a removable peel strip 134 in
place.
The deodorizing mixture 130 is composed of acidic, basic and pH
neutral odor absorbing particles as described above. By positioning
the deodorizing mixture 130 on the sides or peripheral portions of
the absorbent article 114, one can be assured that the deodorizing
mixture 130 will absorb any malodors emanating from the side or
periphery while remaining dry for a greater portion of the life of
the product. The reason for this is that in most absorbent articles
the fluid is dispersed along the central longitudinal top portion
of the cover and is drawn down into the absorbent along the central
vertical "Y" axis. As the absorbent 116 absorbs and retains
additional fluid, the fluid slowly progresses outward along the "X"
and "Z" axes wetting more of the absorbent 116. The absorbent
article 114 can absorb roughly 75 percent of the total fluid which
it is designed to absorb before the outer periphery or side edges
will be contacted by the fluid.
Referring to Figure 12, another embodiment of an absorbent
article 136 is shown containing an absorbent 138 having a first
surface 140 facing the body of a user and a second surface 142
positioned away from the body of the user. A liquid-impermeable
baffle 144 is positioned adjacent to the second surface 142 and
wraps around the sides of the absorbent 138 and partially covers a
portion of the first surface 140. Bonded to the baffle 144 and
positioned adjacent to the first surface 140 of the absorbent 138
is a fluid permeable cover 146. A garment adhesive 148 is applied
to the exterior surface of the baffle 144 and is covered by a
removable peel strip 150. A deodorizing mixture 152 is incorporated
into the absorbent 138 and extends about the entire periphery
-
.
1328987
thereof. The deodorizing mixture 152 can extend inward from the
lateral side edges of the absorbent 138 approximately 10 to 25
percent of its total width. By incorporating the deodorizing
mixture 152 into the side edges or periphery of the absorbent 138,
one may be able to speed up the manufacturing process and provide a
location for the deodorizing mixture 152 which will maintain its
dryness for essentially the entire life of the product.
Referring to Figures 13 and 14, another embodiment of an
absorbent article 154 is shown having an absorbent 156 sandwiched
between a liquid-impermeable baffle 158 and a fluid permeable cover
160. The baffle 158 and the cover 160 are joined together about
their periphery by construction adhesive 162 to form a peripheral
seal 164. The absorbent article 154 also contains a garment adhesive
166 applied to an exterior surface of the baffle 158 which is
covered by a removable peel strip 168. The novel feature of the
absorbent article 154 is that deodorizing particles 170 are
incorporated and dispersed within the baffle 158. The baffle 158
can also contain fibrous materials 172 which can provide integrity
as well as acting as a carrier for the deodorizing particles 170.
The deodorizing particles 170 are individual acidic, basic and pH
neutral odor absorbing particles blended or mixed together. Since
the deodorizing particles 170 are dispersed and incorporated directly
into the baffle 158, the baffle 158 should be vapor permeable. By
being vapor permeable, yet liquid-impermeable, the baffle 158 will
allow odors to emanate there through while preventing liquid from
exiting the article 154.
Referring once again to Figure 13, it should be noted that a
construction adhesive 174 is applied between the lower surface of
the absorbent 156 and the inner~surface of the baffle 158. The
adhesive 174 will bond the baffle 158 and provide integrity to the
product. The presence of the adhesive 174 is optional and can be
eliminated if not needed.
An illustrated laboratory test was conducted which although
not totally reflected of real world conditions, does offer evidence
supporting the contention that the deodorizing mixture described
16
. .. -
:
., . , . . . , :
: .. ,, :
.
. '~ ' , '~ .
1328987
herein is more effective than the presence of a single absorbing
substance, such as only an acid absorbent or a base absorbent. The
odoriferous compounds given off by absorbent articles, particularly
menstrual pads and panty liners, vary with the particular person
utilizing the pad, as well as the time of menstrual cycle and the
length of time the product is worn. Therefore, exact comparison in
real world situations are difficult to document except by numerically
calculated preferences in large groups of wearers. However, the
effectiveness of the deodorant ingredient against the odoriferous
compounds given off from menstrual products is demonstrated.
Example 1
In this example, about 97.5 milligrams (mg) of citric acid,
about 127 mg of sodium bicarbonate and about 25 mg of SMELLRITE~
molecular sieve material were tested individually and in combination.
The particles were exposed to the common types of odors found in
feminine pads containing menstrual fluids. These odors contained
triethyl amine, pyridine, furaldehyde, and n-propyl sulfide. There
may have been other odors emanating from the pad which were not
tested for. A mixture of odors was injected into a sealed vial
containing the particles. A sample of the air above the particles
j~ was taken five hours later and analyzed. The data from the analyses
is represented in Table 1. The data indicated that a large percent
j~ reduction of odors occurred after five hours and that the deodorizing
;~ 25 mixture did not interfere with the individual performance of the
three components. The results also confirmed that the deodorizing
mixture delivered a broader spectrum of performance than any
individual ingredient.
i
J
; 35
1328987
Table 1
Percent (%~ Reduction of Odor Level ~fter 5 rours
Acidic ~asic pH Neutral Deodori~ing
Absorbent Absorbent ~bsorbent Mixture Control
Citric Sodium SMELLRITE Mixture of No acidic,
Acid ~icarbonate these three basic or
substances pH neutral
absorbent.
t97.5 mg) (127.5 mg)~25 mg) ~250 mg)
Odorous ComPound
Triethyl amine 98 9 41 97 NR
Pyridine 94 NR 33 76 NR
Furaldehyde NR 1956 68 NR
N-propyl sulfide NR NR33 35 NR
Note: "NR~ indicates no reduction in odor level ~as observed.
The effectiveness of the deodorizing mixture was demonstrated
in a clinical study. New Freedom Anyday~ pantil;ner pads having a
construction similar to that shown in Figure 4 was tested with a
deodorizing mixture in the amount of 1 gram per product. The
mixture was evaluated to determine odor reducing ability. Four
trained judges evaluated the odor of the products using a 0 to 10
scale.
Thirty-three (33) subjects wore both unscented control products
and deodorized test products on alternate days. The judges observed
that for twenty of the subjects the deodorized test products had
less odor, while for ten subjects the control product had less
odor. For three subjects no difference was observed in the odor
level between the two products. Table 2 indicates the recorded
data.
18 -
. ,
.. ,, ~ . .. , . ~ ,.
.
1328987
Table 2
Clinical StudY
Difference in Number
mean odor of
ratinqs* Sub.iects Observations
102.00 1 Deodorized test
1.75 1 product had less
1.50 4 odor than the
.! 1. 25 4 control product.
:, 1.00
-' 150.75 5
0.50 2
0.~5
-0.25 8 Control product had less
20-0.50 1 odor than deodorized
-0.75 1 test product.
1 0.00 3 Control product and
j deodorized test product
j~ 25 exhibited equal odor.
¦~ 0.55 = mean difference
0.75 = standard deviation
0.13 = standard error
* Odor rating for deodorized test product minus the odor
rating for control product.
While the invention has been described in conjunction with
.~
~}~ several specific embodiments, it is to be understood that many
~ alternatives, modifications and variations will be apparent to
1 those skilled in the art in light of the aforegoing description.
Accordingly, this invention is intended to embrace all such
alternatives, modifications and variations which fall within the
spirit and scope of the appended claims.
,~j
:~ The above described absorbent article, which includes
deodorizing means for absorbing malodors in the form of an
anhydrous mixture of basic and pH neutral odor absorbing
j particles, or such a mixture also including acidic absorbic
partlcles, i~ also described and claimed in above-identified
copending Canadian Application Serial No. 604,455.
.,
.. ,. : ,~
:: :
"",. : .
:, ;. :
,. : - , ...
~ . . ;.
1328987
_UPPLEMENTARY DISCLOSURE
In addition to prior art devices described above,
still other U.S. patents, such as 4,304,675; 4,534,962 and
4,826,497, teach deodorizing compositions for rugs and
catamenial devices. The compositions vary, but the use of
sodium or potassium bicarbonate and natural and synthetic
zeolites is disclosed.
As described above, bodily fluids contain various
malodorous chemical compounds. These have been found to
include acyclic and cyclic amines, aldehydes, fatty acids,
and sulfur-containing compounds such as sulfides. Vaginal
secretions and used menstrual pads may contain many
malodorous chemical compounds: for example, trimethyl
amine, pyridine, furaldehye, isovaleric acid, and methyl
mercaptan. The boiling points of these compounds are 3C,
115-C, 162C, 179 C, and 37-C, respectively. To facilitate
laboratory evaluations, five compounds with boiling points
significantly above room temperature were chosen as models
to represent five types of chemical compounds. Triethyl
amine (boiling point 89 C), pyridine, furaldehyde,
isovaleric acid, and n-propyl sulfide (boiling point 142C)
were chosen as representatives of the types of odoriferous
chemical compounds to which an absorbent article might be
exposed.
It has been found that the deodorizing mixture 36
should be an anhydrous mixture of basic and pH neutral odor
absorbing particles, and may also include acidic odor
absorbing particles.
As previously indicated, the acidic particles, those
having a pH of less than 7, may be any suitable dry acid
material which will provide control of basic odoriferous
compounds. Typical of such materials are ascorbic acid,
; stearic acid, boric acid, maleic acid polymers, malonic
acid, maleic acid, polyacrylic acid and monopotassium
phosphate. A preferred material is citric acid, for it is
low in cost, safe to use, and has a low equivalent weight.
Low equivalent weight means that a large amount of the acid
is present per unit of weight. It has been found that the
amount of acid present will vary depending upon the type of
., .
'
"~ ......................................... . .
1328987
product that it is incorporated into ~nd the particular
odors that it is designed to control. For feminine
products, it has been found that very small amounts of
acid, less than about 10 percent, preferably less than
about 5 percent, and most preferably less than about 1
percent of the total weight of the deodorizing mixture is
desirous. It should be noted that the acid component can
be eliminated if desired. The amount of acid should be
less than, or approximately equal to, the stoichiometric
balance of the basic compound. A value equal to the
stoichiometric balance is desirable, as the effectiveness
of the acid and base should be exhausted at approximately
the same time.
The amount of the p~ neutral odor absorbing particles
used in the blend can be between about 1 to 25 percent of
the total weight of the deodorizing mixture. A preferred
ran~e is between about 10 to 20 percent, and a most
preferred range is between 15 to 20 percent of the total
weight of the deodorizing mixture.
The following example, Example la, further
demonstrates the effectiveness of the mixture ingredient
against the types of odoriferous compounds given off from
menstrual products.
xamPle la
In this example, about 97.5 milligrams (mg) of citric
acid, about 127 mg of sodium bicarbonate and about 25 mg of
SMELLRITE ~ molecular sieve material were tested
individually and in combination. The particles were
exposed to triethyl amine, isovaleric acid, pyridine,
furaldehyde, and n-propyl sulfide which were chosen as
representative of the types of odoriferous chemical
compounds to which an absorbent article might be exposed.
A mixture of these compounds was injected onto the
particles contained in a sealed vial. A sample of the air
above the particles was taken four (~) hours later and
analyzed using gas chromatography. The data indicated that
the three component mixture was a more effective absorbent
overall than any one of the individual components.
21
.,
1328987
, . . .
o . .
. ~ . . ooooo . o
C ~ C~ ~ .
o . ~
>
.
o
~, ,,, , , ~
C a~
O ~ ~ ~ a ~ ' ~
o x x <u ~ ~ ~ ~
C ~ >
g ,~
V i ~ E j ~
~1~ , c
, ~ I
J c ~ a ,~
~ ~ C I ~ ca ~ ' '
;`~ = O
C
~ ~ ~ ,
~ ~ D ~ ~ ~ ~ ' )
C~ ~ C~ O
,,;,~
` <I) ~
C L
K~ ~o C j , ~' ~ ~ V¦
o ~, ' . ~ C,_ ~ -- C Z
~ ' .
~',j
:
~" 22
~:.
.` .
,
:; :
. .. .
.,, . :,
