Note: Descriptions are shown in the official language in which they were submitted.
CA 02662806 2009-04-16
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APPARATUS FOR DELIVERING A VOLATILE MATERIAL
FIELD OF THE INVENTION
The present invention relates to an apparatus having a breathable membrane for
delivering a volatile material to the atmosphere in a continuous manner.
BACKGROUND OF THE INVENTION
It is generally known to use a device to evaporate a volatile material into a
space,
particularly a domestic space, in order to deliver a variety of benefits, such
as air freshening or
perfuming of the air. Non-energized systems, for example, systems that are not
powered by
electrical energy, are a popular way for the delivery of volatile materials
into the atmosphere.
These systems can be classified into those that require human actuation, such
as aerosols, and
those which do not required human actuation, such as wick based systems and
gels. The first
type delivers the volatile materials on demand and the second type in a more
continuous manner.
One type of apparatus for delivering a volatile material is disclosed in U.S.
Patent No.
4,161,283. It discloses an article for delivering a volatile material
comprising a reservoir,
polymeric sheet or membrane, and a barrier layer releasably bonded to the
outer wall of the
reservoir. One drawback with this type of article is its susceptibility to de-
lamination and
leakage because the volatile materials are in contact with the membrane during
storage or non-
use. Another drawback may be that volatile materials build up in the membrane
during storage,
resulting in a spike in intensity immediately after the barrier layer is
removed. Another
drawback may be that the peel force makes it is difficult to remove the
barrier layer without
damaging the polymeric sheet or membrane. Yet another drawback may be the
selectivity of the
membrane in that it does not easily allow low vapor pressure volatile
materials to diffuse through
the polymer.
Another apparatus for delivering a volatile material is disclosed in U.S.
Patent No.
4,824,707. It discloses a decorative air freshener unit having a capsule
containing a supply of
volatile fragrance. The capsule is trapped between a microporous sheet and a
backing sheet.
The capsule is ruptured by applied force and the released fragrance is
absorbed into the
microporous sheet which gradually exudes the fragrance. This approach may
limit the longevity
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of a scent since liquid is released all at once to the microporous sheet, and
there is little control
over the manner in which the liquid will wet the microporous sheet.
As such, there exists a need for an apparatus for delivering, over a period of
time, a
consistent release of volatile materials having a broad range of molecular
weights and vapor
pressures.
SUMMARY OF THE INVENTION
According to one embodiment of the invention, there is provided an apparatus
for
delivering a volatile material comprising a delivery engine having a reservoir
for containing a
volatile material; a rupturable substrate secured to the reservoir; a rupture
element positioned
adjacent to the rupturable substrate; and a microporous membrane enclosing the
reservoir,
rupturable substrate, and rupture element. The apparatus may deliver a
volatile material in a
continuous manner. In one aspect of the invention, the apparatus comprises a
housing for the
delivery engine. The housing may have vents for facilitating the diffusion of
volatile materials
from the delivery engine.
According to another embodiment of the invention, there is provided an
apparatus for
delivering a volatile material comprising a delivery engine having a liquid
reservoir for
containing a volatile material; a rupturable substrate secured to the
reservoir; a compressible
flange positioned adjacent to the rupturable substrate for rupturing the
rupturable substrate; a
collection basin in fluid communication with the liquid reservoir upon
rupturing the rupturable
substrate; and a breathable membrane enclosing the liquid reservoir,
rupturable substrate, rupture
element, and collection basin.
According to yet another embodiment of the invention, there is provided an
apparatus for
delivering a volatile material comprising a delivery engine having a liquid
reservoir for
containing a volatile material comprising a single opening; a rupturable
substrate enclosing the
single opening; a rupture element; a collection basin in fluid communication
with the liquid
reservoir upon rupturing the rupturable substrate; and a breathable membrane
enclosing the
liquid reservoir, rupturable substrate, rupture element, and collection basin.
The breathable
membrane has an evaporative surface area of about 15 cm2 to about 35 emz and
has an average
pore size of about 0.02 microns. The apparatus also comprises a housing for
receiving and
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releasably engaging the delivery system. The housing has a rib for guiding the
delivery engine
and a notch for compressing the rupture element upon insertion of the delivery
engine into the
housing.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with the claims particularly pointing out
and distinctly
claiming the invention, it is believed that the present invention will be
better understood from the
following description taken in conjunction with the accompanying drawings in
which:
Fig. 1 shows a perspective view of one embodiment of an apparatus in
accordance with
the present invention.
Fig. 2 shows an exploded, perspective view of one embodiment of a delivery
engine in
accordance with the present invention.
Fig. 3 shows a cross-sectional view of another embodiment of a rupture element
in
accordance with the present invention.
Fig. 4 shows a cross-sectional view of another embodiment of a rupture element
in
accordance with the present invention.
Fig. 5 shows a side elevational view of the delivery engine in Fig. 2 in
accordance with
the present invention.
Fig. 6 shows a front elevational view of one embodiment of a housing in
accordance with
the present invention.
Fig. 7 shows a top plan view of the housing in Fig. 6.
Fig. 8 shows a cross-sectional view along lines 8-8 of the apparatus in Fig.
1.
Fig. 9 shows the cross-sectional view in Fig. 8 where the delivery engine is
being
received by the housing.
Fig. 10 is a graph showing evaporation profiles of volatile materials having
varying vapor
pressure ranges evaporated from a breathable membrane in accordance with the
present
invention
Fig. 11 is a graph showing evaporation profiles of volatile materials
evaporated from a
polyethylene membrane and from a breathable membrane in accordance with the
present
invention.
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DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a non-energized apparatus for the delivery of
a volatile
material to the atmosphere in a continuous, non-energized manner. "Non-
energized" means that
the apparatus is passive does not require to be powered by a source of
external energy. In
particular, the apparatus does not need to be powered by a source of heat,
gas, or electrical
current, and the volatile material is not delivered by aerosol means. Further,
as used in this
specification and the appended claims, the singular forms "a", "an", and "the"
include plural
references unless the content clearly dictates otherwise. Thus, for example,
"a volatile material"
may include more than one volatile material
The apparatus of the present invention delivers a volatile material in a
substantially
continuous manner when the apparatus is in a resting position (i.e. the
apparatus is not being
moved). The emission level of volatile materials may exhibit a uniform
intensity until
substantially all the volatile materials are exhausted. The continuous
emission of the volatile
materials can be of any suitable length, including but not limited to, up to:
20 days, 30 days, 60
days, 90 days, shorter or longer periods, or any period between 30 to 90 days.
The apparatus of the present invention is suitable for purposes of providing
fragrances,
air fresheners, deodorizers, odor eliminators, malodor counteractants,
insecticides, insect
repellants, medicinal substances, disinfectants, sanitizers, mood enhancers,
and aromatherapy
aids, or for any other purpose using a volatile material that acts to
condition, modify, or
otherwise change the atmosphere or the environment. For purposes of
illustrating the present
invention in detail, but without intending to limit the scope of the
invention, the invention will be
described in an air freshening system for delivering liquid containing perfume
raw materials.
Refen-ing to Fig. 1, an apparatus 10 in accordance with the present invention
is shown.
The apparatus 10 includes a delivery engine 100 and a housing 200.
DELIVERY ENGINE
Referring to Fig. 2, the delivery engine 100 comprises a width, length and
depth along an
x-axis, y-axis, and z-axis, respectively. The width, length, and depth may be
such that the
delivery engine 100 is considered compact and/or portable. By "compact" or
"portable", it is
meant that the delivery engine 100 can be conveniently and comfortably carried
in a pocket,
CA 02662806 2009-04-16
purse, or the like. The delivery engine 100 can be constructed as a
disposable, single-use item or
one that it is replenished with a volatile material.
The delivery engine 100 may include a lip 102 that defines the outer perimeter
of the
delivery engine 100 and may circumference a reservoir 110 for containi.ng a
volatile material as
well as a collection basin 112. The delivery engine 100 may also include a
rupturable substrate
120 secured to the reservoir 110; a rupture element 130 positioned adjacent to
the rupturable
substrate 120; and a breathable membrane 140 secured to the lip 102 and
enclosing the
rupturable substrate 120, reservoir 110, and collection basin 112.
The body 104 of the delivery engine 100 can be thermoformed, injection molded,
or blow
molded with any known material. In some embodiments, the body 104 includes all
structural
aspects of the delivery engine 100 minus the rupturable substrate 120, the
rupture element 130,
and breathable membrane 140. In other embodiments, the body 104 includes the
rupture element
130. The body 104 may be made of a multi layer material which may include a
barrier layer to
prevent evaporation of a volatile component and at least one outer layer that
allows a rupturable
substrate 120 to be heat-sealed to the body 104. A suitable sealant layer
would include a layer of
polyethylene or polypropylene or any suitable polyolefin sealant that allows
for a leak proof seal
of the reservoir 110. Suitable materials to form the body 104 of the delivery
engine 100 include
plastics, such as Pentaplast Pentaform 2101 available from Klockner. In some
embodiments,
the material is colored or non-colored see-through plastic. The see-through
material permits
observation of the liquid and end-of life.
Reservoir
The delivery engine 100 may comprise a reservoir 110 for holding a volatile
material.
The reservoir 110 includes a width, length, and depth along the x-axis, y-
axis, and z-axis,
respectively. The reservoir 110 may be elongate in that its width to length
ratio is about 2:1 to
about 4:1, alternatively about 1.5:1 to about 2.5:1. The reservoir 110 may
have a width of about
45 mm to about 55 mm, alternatively about 51 mm; a length of about 15 mm to
about 30 mm to
about, alternatively about 23 mm; a depth of about 5 mm to about 15 mm,
alternatively about 11
mm. The dimensions of the reservoir 110 may be such that it holds about 2 ml
to about 50 ml of
liquid containing a volatile material. Alternatively, the reservoir 110 may
hold about 2 ml to
about 30 ml, alternatively about 2 ml to about 10 ml, alternatively about 2 ml
to about 8 ml,
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alternatively about 4 ml to about 6 ml, alternatively about 2 ml,
alternatively about 6 ml of liquid
containing a volatile material.
The reservoir 110 may include a bottom 114 and a single opening 116. The
reservoir
110 may also have a ridge 122 circumferencing the single opening 116 or the
upper edge of the
reservoir 110. This ridge 122 may provide a generally flat surface upon which
a rupturable
substrate 120 may be secured. The ridge 122 allows the secured area of the
rupturable
substrate 120 to be located away from the inner walls of the reservoir 110
where the volatile
material would be held.
It is contemplated that the delivery engine 100 of the present invention may
comprise two
or more reservoirs (not shown) which can be filled with the same or different
volatile materials.
The reservoirs may have any configuration that contacts the breathable
membrane 140 upon
rupture. For example, the reservoirs may be opposedly connected for use in a
flippable device.
In such a device, the breathable membrane 140 is fluidly connected between the
reservoirs.
Rupturable Substrate
Still referring to Fig. 2, the delivery engine 100 includes a rupturable
substrate 120. The
rupturable substrate 120 may be configured in any manner that prevents the
volatile material in
the reservoir 110 from contacting the breathable membrane 140 prior to
activating or rupturing
the delivery engine 100. In one embodiment, the rupturable substrate 120 may
enclose the
reservoir, prior to activation, by extending across the single opening 116
securing to the ridge
122 of the reservoir 110. The rupturable substrate 120 may be secured by a
layer of adhesives,
heat and/or pressure sealing, ultrasonic bonding, crimping, and the like or a
combination thereof.
The rupturable substrate 120 can be made of any material that ruptures with
applied
force, with or without the presence of an element to aid in such rupture.
Because the rupturable
substrate 120 is intended to contain a volatile material while in storage, it
may be made from a
layer of barrier material that prevents evaporation of the volatile material
prior to its intended use
and a layer of heat-sealable layer. Such materials may be impermeable to
vapors and liquids.
Suitable barrier materials for the rupturable substrate 120 include a flexible
film, such as a
polymeric film, a flexible foil, or a composite material such as
foil/polymeric film laminate.
Suitable flexible foils include a metal foil such as a foil comprised of a
nitrocellulose protective
lacquer, a 20 micron aluminum foil, a polyurethane primer, and 15 g/m2
polyethylene coating
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(Lidfoil 118-0092), available from Alcan Packaging. Suitable polymeric films
include
polyethylene terephtalate (PET) films, acrylonitrile copolymer barrier films
such as those sold
under the tradename Barex(V by INOES, ethylene vinyl alcohol, and combinations
thereof. It is
also contemplated that coated barrier films may be utilized as a rupturable
substrate 120. Such
coated barrier films include metalized PET, metalized polypropylene, silica or
alumina coated
film may be used. Any barrier material, whether coated or uncoated, may be
used alone and or
in combination with other barrier materials.
Rupture Element
The rupturable substrate 120 may be breached to release a volatile material by
actuating a
rupture element 130. The rupture element 130 can be injection, compression, or
pressure molded
using a polyolef n, such as polyethylene or polypropylene; polyester; or other
plastics as known
to be suitable for molding. The rupture element 130 could also be made by
thermoforming with
a discrete cutting step to remove parts not wanted.
The rupture element 130 may be positioned in a space 132 formed in the
delivery engine
body 104 that is adjacent to the rupturable substrate 120 and subjacent a
breathable membrane
140. The space 132 may be configured such that the rupture element 132 is
nested within the
space 132 and enclosed by a breathable membrane 140, thus requiring no other
means to hold the
rupture element 132 in the delivery engine 100. In one embodiment, the rupture
element 130 is
positioned between and in contact with said rupturable substrate 120 and said
breathable
membrane 140. A rupture element 130 that is directly adjacent to the
breathable membrane 140
may facilitate wetting of the breathable membrane 140. More specifically,
liquid may wick
between rupture element 130 and the breathable membrane 140 allowing for
maintenance of a
larger wetted surface area of the breathable membrane 1.40.
The rupture element 130 may be configured in any manner such that a user can
manually
actuate the rupture element 130 and breach the rupturable substrate 120 with
relative ease. In
one embodiment, a user may actuate the rupture element 130 by manually
compressing it. In
other embodiments, the rupture element 130 may breach the rupturable substrate
120 through
contact with an element provided in a delivery engine housing that engages and
compresses the
rupture element 130. Suitable compression forces to breach the rupturable
substrate 120 with a
rupture element 130 may be less than about 25N, alternatively, less than about
20N,
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alternatively less than about 15N, alternatively less than about ION,
alternatively less than
about 5N, alternatively from about IN to about 15N, alternatively, from about
IN, to about
ION, alternatively, from about 1N to about 5N.
The compression force can be measured using an electromechanical testing
system,
QTest Elite 10, available from MTS, along with a modified UL 283 finger probe
made of
polyamide. The UL 283 finger probe is described in Standard for Air Fresheners
and
Deodorizers, UL Standard 283, Fig. 10.1 (UL March 31, 2004). As described in
UL 283,
Fig. 10.1, the radius of the finger tip is 3.5 mm; height of the finger tip is
5 mm; depth of the
finger tip is 5.8 mm. However, unlike the fmger probe described in the
aforementioned text,
the modified UL 283 finger probe does not include any articulating joints.
Instead, it is in a
fixed position that is perpendicular to the rupture element 130 when testing
is conducted. The
testing occurs at ambient temperatures (23 2 C). The perimeter of a delivery
engine 100 is
rested on a support fixture, without directly contacting or directly securing
the rupture element
130 to the support fixture. The crosshead speed of the electromechanical
testing system is set
at 30 mm/min. The modified UL 283 finger probe is moved towards the rupture
element 130
to contact a region where displacement is desired for rupturing a rupturable
substrate 120.
Where a flange 134 such as the one described herein is utilized, the desired
region of
displacement is the mid-point of the flange 134. The mid-point is the point
that is half way
between the proximal end and distal end 136. For example, where a flange 134
is 2 cm from
proximal end to distal end 136, the mid-point is located at 1 cm. The machine
is run until the
rupture element 130 is displaced by 6 mm. Zero displacement is defined as the
point at which
0.1N of force (i.e. preload) is applied. The load at the first peak where the
rupturable substrate
120 is broken is recorded as the force to rupture. Those of ordinary skill in
the art will
appreciate that compression forces will vary depending on the physical
properties and
placement of the breathable membrane 140, rupture element 130, and rupturable
substrate 120
in a delivery engine 100.
There are numerous embodiments of the rupture element 130 described herein,
all of
which are intended to be non-limiting examples. Fig. 2 shows one non-limiting
embodiment of
the rupture element 130. In this embodiment, the rupture element 130 includes
a flange 134
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hinged to the rupture element 130. The flange 134 may be injection molded and
may include a
distal end 136. The distal end 136 may include one or more piercing elements
138 located in the
z-direction or towards the rupturable substrate 120. In one embodiment, the
distal end 136 may
include two spaced apart piercing elements 138 in the z-direction. In an
alternate embodiment,
the distal end 136 may form a single point (not shown) along the x-y plane. A
user may
manually compress or press downward in the z-direction on the flange 134 such
that the
rupturable substrate 120 is breached and a volatile material is released to
the breathable
membrane 140.
It is contemplated that the rupture element 130 may include more than one
flange 134
where additional points of rupture are desired. For example, the rupture
element 130 may
include a first compressible flange and a second compressible flange opposedly
hinged to said
rupture element (not shown).
Fig. 3 shows another embodiment of a rupture element 330 which includes one or
more
piercing elements 332 supported on a corresponding spring-like part 334. The
spring-like part
334 may be a metal coil, polyolefin or poIyurethane foam, injection molded
bristles, injection
molded plastic spring or hinge parts, or the like. Upon pressing the rupture
element 330 towards
the rupturable substrate 320, one or more piercing elements 332 will puncture
the rupturable
substrate 320 and then return to its original position.
Fig. 4 shows another embodiment of a rupture element 430 where it is
integrally
formed with the reservoir 410. This can be accomplished by thermoforming,
pressure
forming, injection molding or any known means of forming plastic parts. The
rupture element
430 in this embodiment, is a sharp piercing structure extending opposite from
the interior
bottom 414 of the reservoir. A user may compress the bottom 414 of the
reservoir 410 to
pierce the rupturable substrate 420 with the rupture element 430. This
embodiment eliminates
having to manufacture a separate rupture element 430, yet it performs the same
function.
Collection Basin
Now referring to Fig. 5, the delivery engine 100 may optionally include a
collection basin
112 to collect volatile materials from the reservoir 110 after the rupturable
substrate 120 is
compromised. The collection basin 112 may be any size, shape or configuration,
and may be
made of any suitable material, so long as it is in fluid communication with
the reservoir 110 and
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the breathable membrane 140 upon rupturing the rupturable substrate 120. It
may be sized to
collect any suitable volume of a volatile material to provide a controlled
volume of the volatile
material to the breathable membrane 140. In one embodiment, the collection
basin 112 may be
sized to collect about 1 ml to about 4 ml of volatile materials, alternatively
about I ml to about 3
ml, alternatively about I ml to about 2.5 ml, alternatively about 1.5 ml to
about 1.8 ml.
In one embodiment, the collection basin 112 may include a bottom 118 in the z-
direction
and a top that opens towards a breathable membrane 140. The breathable
membrane 140 may lie
across the open top, enclosing the collection basin 112 so liquid cannot flow
freely out through
the breathable membrane 140 . The collection basin 112 may be integrally
constructed with the
body 104 of the delivery engine 100 in a thermofonn part.
As shown in Fig. 5, in one embodiment, the collection basin 112 is positioned
downwardly or opposite the y-direction from the reservoir 110. When the
delivery engine 100 is
placed upright, a volatile material naturally flows down the reservoir 110
into the collection
basin 112 ensuring a controlled, continual dosing of the breathable membrane
140. Further, the
collection basin 112 has depth along the z-axis which is smaller in depth than
the reservoir 110.
The bottom 118 of the collection basin lies closer to the breathable membrane
140 than the
reservoir bottom 114, thus forming a step in the delivery engine 100. The
proximity of the
collection basin bottom 118 with the breathable membrane 140 helps to ensure a
continual
supply of volatile material and wet more surface area of the breathable
membrane 140, even
when very little volatile material remains in the delivery engine 100. When
the liquid contact
area of the breathable membrane 140 is greater, the evaporation rate of
volatile materials is
higher and fragrance intensity can be maintained over longer periods.
Membrane
The delivery engine 100 may include a breathable membrane 140. The breathable
membrane 140 is vapor permeable and prevents free flow of liquid out of the
membrane 140,
thus addressing leakage problems.
The breathable membrane 140 may be secured to the lip 102 of the delivery
engine 100 in
the same manner as the rupturable substrate 120 is secured to the ridge 122 of
the reservoir 110.
The breathable membrane 140 encloses the reservoir 110, rupturable substrate
120, rupture
element 130, and collection basin 112. In this way, the rupturable substrate
120 may be
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breached by compressing the breathable membrane 140 and the rupture element
130. Once
breached, the volatile material flows out of the reservoir 110, contacts the
breathable membrane
140, and is delivered to the atmosphere. Because the breathable membrane 140
is shielded from
the volatile material until the rupturable substrate 120 is breached, the
fragrance intensity may
build slowly from zero to its equilibrium rate of release when the breathable
membrane 140 is
fully wetted.
While not wishing to be bound by theory, the physical characteristics of a
membrane
may affect the diffusion rate of volatile materials through the membrane. Such
characteristics
may include materials used, pore size, thickness, and evaporative surface
area.
The breathable membrane 140 may be filled with any suitable filler and
plasticizer
known in the art. Fillers may include finely divided silica, clays, zeolites,
carbonates,
charcoals, and mixtures thereof. In one embodiment, the breathable membrane
140 may be
filled with about 50% to about 80%, by total weight, of silica, alternatively
about 60% to
about 80 %, alternatively about 70 % to about 80 %, alternatively about 70 %
to about 75 %.
In one embodiment, the breathable membrane 140 may include a microporous
membrane. The microporous mecnbrane is vapor permeable and capable of wicking
liquid, yet
prevents free flow of liquid out of the membrane. The microporous membrane may
have limited
selectivity leaving behind fewer perfume materials. Membranes that are
selective, such as
traditional polyethylenes, may inhibit high molecular weight volatile
materials and materials
with low solubility in polyethylene from diffusing through. This may limit
perfume
formulations, for example in the field of air fresheners where it is typically
desired to use
formulations having a wide variety of volatile materials having different
volatilities. For
example, some membranes may preclude the diffusion of alcohols, such as
linalool and
dihydromyrcenol which are widely used in perfume applications. The microporous
membrane
may have an average pore size of about 0.01 to about 0.06 microns,
alternatively from about
0.01 to about 0.05 microns, alternatively about 0.01 to about 0.04,
alternatively about 0.01 to
about 0.03, alternatively about 0.02 to about 0.04 micron, alternatively about
0.02 microns.
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The breathable membrane 140 may have a thickness in the z-direction, of about
0.01
mm to about 1 mm, alternatively between about 0.1 mm to 0.4 mm, alternatively
about 0.15
mm to about 0.35 mm, alternatively about 0.25 mm.
Those of ordinary skill in the art will appreciate that the surface area of
the breathable
membrane 140 can vary depending on the user preferred size of the delivery
engine 100. In
some embodiments, the evaporative surface area of the breathable membrane 140
may be about
2 cm2 to about 100 cm~, alternatively about 10 cm2 to about 50 cm2,
alternatively about 10
cm2 to about 45 cmz, alternatively about 10 cmz to about 35 cm2, alternatively
about 15 cm2
to about 40 cm2, alternatively about 15 cm2 to about 35 cm2, alternatively
about 20 cmz to
about 35 cm2, alternat ively about 30 cm2 to about 35 cm2, alternatively about
35 cmz .
Suitable breathable membranes 140 for the present invention include a
microporous,
ultra-high molecular weight polyethylene (UHMWPE) optionally filled with
silica as described
in US 7,498,369. Such UHMWPE membranes include DaramicTM V5, available from
Daramic, Solupor , available from DSM (Netherlands), and Teslin'' , available
from PPG
Industries, and combinations thereof. It is believed that these membranes
allow a volatile
material to freely dissipate, while containing liquid within the delivery
engine 100.
Other suitable breathable membranes 140 include any permeable polymeric,
thermoplastic, or thermoset material, including acetal, acrylic, cellulosic,
fluoroplastic,
polyamide, polyester, polyvinyl, polyolefin, styrenic, etc, alone, co-
extruded, woven or non-
woven, mixed or in combination with elastomers, rubber, solids, silicas, or
combinations thereof.
Also suitable are Hytrel' available from Dupont or Lotryll available from
Arkema.
In one aspect of the invention, the breathable membrane 140 may include a dye
that is
sensitive to the amount of volatile material it is in contact with to indicate
end-of-life.
Alt.ernatively, the breathable membrane 140 may change to transparent when in
contact with a
fragrance or volatile niaterial to indicate diffusion is occurring. Other
means for indicating
end-of-life that are known in the art are contemplated for the present
invention.
HOUSING
Now referring to Figs. 6 to 9, the apparatus 10 of the present invention may
include a
housing 200 for releasably engaging the delivery engine 100. The housing 200
may comprise a
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width, length and depth along an x-axis, y-axis, and z-axis, respectively (as
shown in Fig. 1).
The housing 200 can be made of any suitable material such as glass, ceramic,
wood, plastic,
composite material, etc, and can have any size, shape and configuration
suitable for encasing the
delivery engine 100. The housing 200 can be rigid or flexible and can be made
of material
which allows the transfer of volatile materials to the surrounding
environment. The housing 200
may include a base 210, a hollowed core 240 supported on the base 210 and
nested internally
within a shell 220. The housing 200 may also include a notch 270 and vents
260.
Shell and Hollowed Core
As seen in Figs. 8 and 9, the housing 100 may include a hollowed core 240
supported on
a base 210 and nested internally within a shell 220. The shell 220 may have a
front wall 222 and
a rear wall 224, both of which may be generally coextensive with a front wall
242 and a rear wall
244 of the hollowed core 240. The hollowed core 240 and shell 220 may be
elliptically
cylindrical and include a receiving end 230 for receiving the delivery engine
100. The receiving
end 230 may be disposed remotely from the base 210 of the housing 200.
Ribs and Notches
The inner face of the rear wall 244 of the hollowed core 240 may include one
or more
retaining ribs 246 for guiding the delivery engine 100 downward into its final
in-use position as
seen in Fig. 9. In one embodiment, the retaining ribs 246 may include a first
retaining rib and a
second retaining rib positioned on the inner face of the rear wall 244 and
which both extend
longitudinally along the y-axis. The first and second retaining ribs may be
positioned at the
intersection of the front 242 and rear walls 244 of the hollowed core 240 to
receive the lip 102 of
the delivery engine 100.
The housing 200 may also include a notch 270, or a plurality of notches, to
engage or
compress the rupture element 130 as the delivery engine 100 is being received
in the housing
200. In this way, a user is not required to manually activate the delivery
engine 100 prior to its
insertion into the housing 200. The notch 270 may be configured in any manner
such that the
delivery engine 100 can be inserted into the housing 200 with relative ease
while the notch 270
compresses the rupture element 130 and breaches the rupturable substrate 120.
Suitable insertion forces to insert the delivery engine 100 which compresses
the rupture
element 130 and breaches the rupturable substrate 120 include less than about
25N, alternatively
CA 02662806 2009-04-16
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less than about 20N, alternatively less than about 15N, alternatively less
than about 5N,
alterna.tively from about 1N to about 25N, alternatively from about 1N to
about 15N,
alternatively from about 5N to about 20N, alternatively from about 5N to about
15N,
alternatively about 8 to 15 N.
The insertion force can be measured using an electromechanical testing system,
QTest
Elite 10 available from MTS. The delivery engine 100 is clamped to the testing
system and
placed in the receiving end of the housing without any force against any notch
270 or elements
that breach or help breach the rupturable substrate 120. The crosshead speed
of the
electromechanical testing system is set at 50 mm/min. The room temperature is
23 2 C .
The machine is run until the rupturable substrate 120 is breached. Zero
displacement is defined
as the point at which 0.1N of force (i.e. preload) is applied. The load at the
first peak where the
rupture substrate 120 is broken is recorded as the force to rupture. Those of
ordinary skill in the
art will appreciate that insertion forces will vary depending on the physical
properties and
placement of the notch 270, breathable membrane 140, rupture element 130, and
rupturable
substrate 120.
In one embodiment, the notch 270 may be laterally off-set from the center of
the front
wall 242 of the hollowed core 240, so that less projection of the notch 270 in
the z-direction is
required when manufacturing. Thus, the breathable membrane 140 does not need
to be stretched
as far, resulting in less likelihood of damage.
The notch 270 and ribs 246 are configured such that the delivery engine 100
does not
need to bend when inserting, resulting in lower insertion force. As the
delivery engine 100 is
inserted into the housing 200, the notch 270 compresses the breathable
membrane 140 and the
rupture element 130 in the direction of the reservoir 110 to breach the
rupturable substrate 120
and release volatile materials to the breathable membrane 140. During
insertion of the delivery
engine 100, the ribs 246 guide the delivery engine 100 into contact and
against the notch 270,
maintaining the lateral position of the delivery engine 100 so the notch 270
fully engages the
rupture element 130.
Vents
CA 02662806 2009-04-16
The housing 200 may have a plurality of vents 260 or apertures which align in
a first,
open position to facilitate delivery of the volatile material from the
breathable membrane 140 to
the atmosphere of the room or rooms that require treatment. Increasing the
effective size of the
vents 260, may increase the delivery of volatile material. Conversely,
decreasing the effective
size of the vents 260, may decrease the delivery of volatile material.
The vents 260 may be disposed anywhere on the housing 200. In the embodiment
shown
in Figs. 6 to 9, the vents 260 are disposed on the front walls 222, 242 of
shell 220 and hollowed
core 240. The number and/or size of the vents 260 are not fixed. The size of
the vents 260 can
be controlled by the user through a variety of means. A user may open,
partially open, partially
close, or close the one or more vents 260 by sliding the shell 220 downwardly
along the y-axis
towards the base 210 such that the desired amount of emission is delivered to
the location
needing treatment. The housing 200 may also be constructed to enable open and
closing of the
vents 260 by rotation of the shell 240 around the x-axis (not shown). In
addition to the vents
260, the housing 200 may have other means for visual inspection of the
delivery engine 100.
The housing 200 may also include a clicking mechanism (not shown) to signal to
the user
that the housing 200 is in the desired open or closed position. Such clicking
mechanism may
include a first mating part (not shown) disposed along the outer face of the
hollowed core 240
and a second mating part (not shown) disposed along the inner face of the
shell 220. The mating
parts may frictionally engage the walls of the shell 220 and hollowed core 240
as they slide
against one another. When the desired open or closed position is reached the
mating parts may
releasably lock into place and may provide a clicking sound.
VOLATILE MATERIAL
The apparatus 10 and/or the delivery engine 100 of the present invention
deliver a
volatile material to the atmosphere in a continuous manner. The term "volatile
material" as used
herein, refers to a material that is vaporizable at room temperature and
atmospheric pressure
without the need of an energy source. The volatile material may be a
composition comprised
entirely of a single volatile material. The volatile material may also be a
composition comprised
entirely of a volatile material mixture (i.e. the mixture has more than one
volatile component).
Further, it is not necessary for all of the component materials of the
composition to be volatile.
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Any suitable volatile material in any amount or form, including a liquid or
emulsion, may be
used.
Liquid suitable for use herein may, thus, also have non-volatile components,
such as
carrier materials (e.g., water, solvents, etc). It should also be understood
that when the liquid is
described herein as being "delivered", "ernitted", or "released," this refers
to the volatiiization of
the volatile component thereof, and does not require that the non-volatile
components thereof be
emitted.
The volatile material can be in the form of perfume oil. Most conventional
fragrance
materials are volatile essential oils. The volatile material can be a volatile
organic compound
commonly available from perfumery suppliers. Furthermore, the volatile
material can be
synthetically or naturally formed materials. Examples include, but are not
limited to: oil of
bergamot, bitter orange, lemon, mandarin, caraway, cedar leaf, clove leaf,
cedar wood, geranium,
lavender, orange, origanum, petitgrain, white cedar, patchouli, neroili, rose
absolute, and the like.
In the case of air freshener or fragrances, the different volatile materials
can be similar, related,
complementary, or contrasting.
The volatile material may also originate in the form of a crystalline solid,
which has the
ability to sublime into the vapor phase at ambient temperatures or be used to
fragrance a liquid.
Any suitable crystalline solid in any suitable amount or form may be used. For
example, suitable
crystalline solids include but are not limited to: vanillin, ethyl vanillin,
coumarin, tonalid, calone,
heliotropene, musk xylol, cedrol, musk ketone benzohenone, raspberry ketone,
methyl naphthyl
ketone beta, phenyl ethyl salicylate, veltol, maltol, maple lactone,
proeugenol acetate, evemyl,
and the like.
It may not be desirable, however, for volatile materials to be closely similar
if different
volatile materials are being used in an attempt to avoid the problem of
emission habituation.
Otherwise, the people experiencing the emissions may not notice that a
different material is
being emitted. The different emissions can be provided using a plurality of
delivery systems
each providing a different volatile material (such as, musk, floral, fruit
emissions, etc). The
different emissions can be related to each other by a common theme, or in some
other manner.
An example of emissions that are different, but complementary might be a
cinnamon emission
and an apple emission.
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In addition to the volatile material of the present invention, the delivery
engine 100 may
include any known malodor composition to neutralize odors. Suitable malodor
compositions
include cyclodextrin, reactive aldehydes and ionones.
While not wishing to be bound by theory, the continuous delivery of a volatile
material
may be a function of various factors including membrane pore size; membrane
surface area; the
physical properties of a volatile material, such as molecular weight and
saturation vapor pressure
("VP"); and the viscosity and/or surface tension of the composition containing
the volatile
material.
The composition may be formulated such that the composition comprises a
volatile
material mixture comprising about 10% to about 100%, by total weight, of
volatile materials that
each having a VP at 25 C of less than about 0.01 torr; alternatively about 40%
to about 100%, by
total weight, of volatile materials each having a VP at 25 C of less than
about 0.1 torr;
alternatively about 50% to about 100%, by total weight, of volatile materials
each having a VP at
25 C of less than about 0.1 torr; alternatively about 90% to about 100%, by
total weight, of
volatile materials each having a VP at 25 C of less than about 0.3 torr. In
one embodiment, the
volatile material mixture may include 0% to about 15%, by total weight, of
volatile materials
each having a VP at 25 C of about 0.004 torr to about 0.035 torr; and 0% to
about 25%, by total
weight, of volatile materials each having a VP at 25 C of about 0. 1 torr to
about 0.325 torr; and
about 65% to about 100%, by total weight, of volatile materials each having a
VP at 25 C of
about 0.035 torr to about 0.1 torr. One source for obtaining the saturation
vapor pressure of a
volatile material is EPI SuiteTM, version 4.0, available from U.S.
Environmental Protection
Agency.
Two exemplary compositions comprising a volatile material mixture having
volatile
materials of varying VPs are set forth below in Tables 1 and 2. These
compositions are shown
by way of illustration and are not intended to be in any way limiting of the
invention.
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Table 1
Wt% Low VP (torr) VP (torr)
27.71 0.175 0.325
20.78 0.0875 0.1125
13.86 0.0625 0.0875
8.66 0.0375 0.0625
8.66 0.0175 0.0325
6.93 0.00875 0.01125
6.93 0.00625 0.00875
3.18 0.00375 0.00625
1.27 0.00175 0.00325
0.95 0.000875 0.001125
0.64 0.000625 0.000875
0.32 0.000375 0.000625
0.09 0.000175 0.000325
Table 2
Wt% Low VP (torr) Hi VP (torr)
= 33.38 0.175 0.325
25.75 0.0875 0.1126
19.07 0.0625 0.0875
13.86 0.0375 0.0625
4.00 0.0175 0.0325
1.50 0.00875 0.01125
0.50 0.00625 0.00875
0.72 0.00375 0.00625
0.55 0.00175 0.00325
0.27 0.000875 0.001125
0.20 0.000625 0.000875
0.13 0.000375 0.000625
0.07 0.000175 0.000325
The viscosity of a volatile material may control how and when a volatile
material is
delivered to the breathable membrane 140. For example, less viscous
compositions may flow
faster than the more viscous volatile materials. Thus, the membrane may be
first wetted with the
less viscous materials. The more viscous volatile material, being slightly
less or of similar
density with the less viscous phase, may remain in the collection basin 112
via gravity. Thus, the
CA 02662806 2009-04-16
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less viscous volatile material may be delivered to the breathable membrane 140
and emitted to
the atmosphere more quickly. To help prevent liquid from seeping through the
breathable
membrane 140, volatile materials may have viscosities less than about 23 cP
and surface tension
less than about 33mN/m.
In one embodiment, the composition containing a volatile material may have a
viscosity
of about 1.0 cP to less than about 25 cP, alternatively about 1.0 cP to less
than about 23,
alternatively about 1.0 cP to less than about 15 cP.
The composition containing a volatile material may be designed such that the
composition may include a surface tension of about 19 mN/m to less than about
33 mN/m,
alternatively about 19 mN/m to less than about 30 mN/m, alternatively about 19
mN/m to less
than about 27 mN/m.
EXAMPLES
The following examples are not to be construed as limitations of the present
invention
since many variations thereof are possible without departing from its spirit
and scope.
Example 1
In this example, two identical air freshening delivery engines are designed
utilizing a
Daramic V5 membrane with an evaporative surface area of approximately 34cm2.
Two perfume
compositions, RJJ-577 and RJJ-573-8, each having a volatile material mixture
with volatile
materials of different VP ranges are tested in the air freshening delivery
engines for evaporation
rates. The VP ranges of the volatile materials are shown in Tables 3 and 4.
Table 3
RJJ-577
VP VP Wt%
25 C 25 C
Low High
0 0.001 0.2
0.001 0.01 0.0
0.01 0.1 3.4
0.1 0.3 28.6
0.3 10 64.8
CA 02662806 2009-04-16
Table 4
RJJ-573-8
VP VP Wt%
C 25 C
Low High
0 0.001 1.9
0.001 0.01 8.5
0.01 0.1 32.6
0.1 0.3 49.8
0.3 10 6.8
One delivery engine is loaded with 6000 mg of perfume composition RJJ-577; the
other
with 6000 mg of perfume composition RJJ-573-8. RJJ-577 includes relatively
higher VP
components than RJJ-573-8. Each filled delivery engine is weighed; weight is
recorded. Both
delivery engines are placed into housings and held in a room at 21 C. At the
times indicated on
Fig. 10, the delivery engine is weighed; weight recorded. Fig. 10 shows that
after about two
weeks, the evaporation rate of RJJ-577 has almost flattened which would then
require another
delivery engine. This would be costly and may be viewed as burdensome by
consumers. On the
other hand, perfume RJJ-573-8 with a microporous membrane delivers consistent
linear intensity
over a longer period of time.
Example 2
In this exarnple, two air freshening delivery engines are constructed
utilizing different
membranes. Each is tested for evaporation rates using RJJ-573-8, which was
utilized in Example
1. 6000 mg of RJJ-573-8 is loaded into a delivery engine with a low density
polyethylene
membrane (LDPE) having an average pore size of about 40 microns. 6000 mg of
RJJ-573-8 is
loaded into a delivery engine having a Daramic V5 microporous membrane. As can
be seen
from Fig. 11, the microporous membrane is much more efficient in releasing the
relatively low
vapor pressure perfinne than the LDPE membrane. Thus, utilizing a microporous
membrane in
accordance with the present invention delivers higher intensities of lower
vapor pressure (i.e.
more pleasing "base note" perfume raw materials can be delivered).
Every numerical range given throughout this specification will include every
narrower
numerical range that falls within such broader numerical range, as if such
narrower numerical
CA 02662806 2009-07-08
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range were all expressly written herein. Further, the dimensions and values
disclosed herein are
not to be understood as being strictly limited to the exact numerical values
recited. Instead,
unless otherwise specified, each such dimension is intended to mean both the
recited value and a
functionally equivalent range surrounding that value. For example, a dimension
disclosed as "40
mm" is intended to mean "about 40 mm."
Every document cited herein is not an admission that it is prior art with
respect to any
invention disclosed or claimed herein or that it alone, or in any combination
with any other
reference or references, teaches, suggests or discloses any such invention.
Further, to the extent
that any meaning or definition of a term in this document conflicts with any
meaning or
definition of the same term in a document cited herein, the meaning or
definition assigned to that
term in this document shall govern.
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.
