U.S. patent application number 12/545203 was filed with the patent office on 2009-12-17 for heated volatile dispensing device with use-up indicator.
Invention is credited to Joel E. Adair, Gopal P. Ananth, Brian T. Davis, Padma Prabodh Varanasi.
Application Number | 20090311148 12/545203 |
Document ID | / |
Family ID | 38017001 |
Filed Date | 2009-12-17 |
United States Patent
Application |
20090311148 |
Kind Code |
A1 |
Adair; Joel E. ; et
al. |
December 17, 2009 |
Heated Volatile Dispensing Device With Use-Up Indicator
Abstract
Heated volatile dispensers are disclosed that are provided with
automated use-up indicators. The indicators are associated with a
porous substrate. A migrateable dye is covered by meltable material
adjacent the substrate. Heating of a substrate such as a slab
impregnated with an insect repellent both causes the insect
repellent to dispense and melts the covering. The dye then migrates
to a visible surface of the substrate to indicate a degree of use.
The extent of migration, and the patterns formed on the visible
surface by the migrating dye, indicate the extent to which the
volatile air treatment chemical has been dispensed.
Inventors: |
Adair; Joel E.; (Racine,
WI) ; Davis; Brian T.; (Burlington, WI) ;
Ananth; Gopal P.; (Racine, WI) ; Varanasi; Padma
Prabodh; (Racine, WI) |
Correspondence
Address: |
S.C. JOHNSON & SON, INC.
1525 HOWE STREET
RACINE
WI
53403-2236
US
|
Family ID: |
38017001 |
Appl. No.: |
12/545203 |
Filed: |
August 21, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11347614 |
Feb 3, 2006 |
|
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12545203 |
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Current U.S.
Class: |
422/173 |
Current CPC
Class: |
A01M 1/2077 20130101;
A61L 9/02 20130101; A01M 29/12 20130101; G04F 1/00 20130101; A61L
9/03 20130101; G01N 31/229 20130101 |
Class at
Publication: |
422/173 |
International
Class: |
F01N 3/10 20060101
F01N003/10 |
Claims
1. A device capable of dispensing a volatile air treatment chemical
upon heating of a portion of the device, the device comprising: a
dye positioned in a cavity of the device; a covering positioned
relative to the cavity to restrict migration of the dye from the
cavity prior to heating of the covering, wherein the covering
comprises a solid material that can be melted by heating; and a
substrate having air treatment chemical applied thereto, the
substrate being positioned on an opposite side of the covering than
the cavity is on; wherein the dye, covering and substrate comprise
a use indicator configured to automatically communicate an extent
to which the air treatment chemical has been dispensed from the
substrate as the substrate is heated; wherein the covering permits
migration of the dye through the substrate to a visible surface in
response to melting of the covering; and wherein the extent to
which the dye becomes visible at the visible surface is indicative
of the extent to which the air treatment chemical has been
dispensed from the substrate.
2. The device of claim 1, wherein the visible surface is on a
peripheral surface of the substrate.
3. The device of claim 1, wherein the covering comprises a wax.
4. The device of claim 3, wherein the covering further comprises a
polymer.
5. The device of claim 1, wherein: the substrate has at least two
viewing positions along visible surfaces of the substrate; the dye
can reach a first of said viewing positions before reaching a
second of said viewing positions; and the dye being visibly present
at the first of said viewing positions but not at the second of
said viewing positions will be indicative of a lesser degree of
use-up of the air treatment chemical than if the dye is visible at
both of said first and second viewing positions.
6. The device of claim 1, wherein the substrate has an array of
preformed pathways extending from adjacent the covering to adjacent
the visible surface for causing preferential migration of the dye
through the preformed pathways once migration of the dye
begins.
7. The device of claim 6, where the pre-formed pathways are not
uniformly spaced across the substrate.
8. The device of claim 1, wherein a peripheral surface of the
substrate is pre-marked with a symbolic or textual indication which
indicates a degree of use-up of the air treatment chemical once the
dye reaches adjacent that pre-marked indication.
9. The device of claim 1, wherein a peripheral surface of the
substrate is pre-marked with a symbolic or textual indication, and
the indication is such that it can be hidden by migrating dye to
indicate a degree of use-up of the air treatment chemical.
10. A device capable of dispensing a volatile air treatment
chemical upon heating of a portion of the device, the device
comprising: a substrate having an air treatment chemical applied
thereto and having a channel in which a dye is positioned, the
channel having a narrowed portion that restricts migration of the
dye from the channel prior to heating of the channel; wherein the
dye and substrate comprise a use indicator configured to
automatically communicate an extent to which the air treatment
chemical has been dispensed from the substrate as the substrate is
heated; wherein the channel permits migration of the dye to a
visible surface in response to heating of the substrate; wherein
the extent to which the dye becomes visible at the visible surface
is indicative of the extent to which the air treatment chemical has
been dispensed from the substrate; and wherein the narrowed portion
of the channel expands due to heating of the substrate and thereby
facilitates migration of the dye from the channel.
11. The device of claim 1, wherein the substrate has a stepped
construction, and after heating the covering the dye can reach an
exposed surface of a first step of the substrate stack before it
reaches an exposed surface of a second step of the substrate
stack.
12. The device of claim 1, wherein the substrate is a porous solid
material that has been impregnated with the air treatment
chemical.
13. The device of claim 1, wherein the air treatment chemical is
selected from the group consisting of insect control actives,
fragrances, sanitizers and deodorizers.
14. The device of claim 13, wherein the insect control actives are
selected from the group consisting of insect control repellents and
insecticides.
15. A device for dispensing an air treatment chemical into a
surrounding air environment in response to heating of a substrate,
the device comprising: a porous substrate to which has been applied
the air treatment chemical; a dye positioned in, against, or
adjacent the substrate; and means for controlling migration of the
dye such that migration of the dye prior to said heating is
restricted, and migration of the dye to a visible surface after
such heating is facilitated.
16. The device of claim 16, wherein a degree to which the dye
becomes visible along said visible surface constitutes an
indication of an extent to which the air treatment chemical has
been dispensed from the substrate.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a divisional application claiming priority on U.S.
Ser. No. 11/347,614 which was filed on Feb. 3, 2006.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] The present invention relates to indicators that provide
information to consumers about the extent of use of consumable
air-treatment products. More specifically it relates to air
treatment dispensing devices where a heater causes dispensing of an
air treatment chemical and also initiates a use-up cue system that
is in the form of a migrating indicator dye.
[0004] A variety of prior art devices are known that use heat to
dispense air treatment chemicals. For example, it is known that a
porous pad, wick, or other substrate can be impregnated or coated
with a volatizable air treatment chemical. When heat is applied to
the substrate, the air treatment chemical is dispensed into the
air.
[0005] In some of these devices a portion of the substrate is
dipped into an associated reservoir of the air treatment chemical
(typically a mix of solvent and volatile treatment chemical). The
porous substrate then acts as a wick that draws the chemical to the
heated region, as needed.
[0006] The level of the air treatment chemical/solvent mix in the
reservoir is typically visible to consumers. Thus, the emptying of
the reservoir provides a way for consumers to monitor when more air
treatment chemical is needed. However, for some applications it is
preferred not to have to use the somewhat bulky storage reservoir.
Further, that type of reservoir system may have certain other
disadvantages besides size (e.g. cost).
[0007] Hence, the art has developed a variety of porous materials
that are impregnated at a factory with air treatment chemicals.
They are then positioned adjacent or on a heater, and the heating
dispenses the air treatment chemical into the air from the slab (by
itself and/or with assistance of a fan or the like). However, the
heating of such a substrate does not typically significantly change
the appearance of the substrate, particularly when the substrate is
a solid rather than a gel.
[0008] Thus, producers of such products will often estimate average
useful life of such products under normal usage conditions, and
note that information on their packaging. However, these substrates
may be used with a variety of different types of heaters which heat
at different temperatures or in different ways. Even where only a
single type of heater is to be used with a particular type of
substrate, heater performance may be inconsistent over time from
model to model.
[0009] Thus, while estimated averaging of useful life can provide
rough guidance regarding useful life, that estimate will not be
exact in most cases. As a result, some companies prefer to provide
expected life information in a manner that encourages the product
to be thrown away somewhat earlier than the average statistical
life. This reduces the risk that there will be significant use of
the product after the product has become ineffective, albeit at the
cost of a somewhat higher level of waste due to disposing of some
product which still has some useful life.
[0010] Even where information is provided by the manufacturer
regarding expected useful life, some consumers will not learn of,
or alternatively not apply, that information. Rather, they will
assume what an appropriate useful life is or should be, and thus in
some cases prematurely throw away the product, and in others use it
after its effective life is over. Further, even where the consumer
is initially aware of the appropriate assumption for a usage life,
they may forget about the need to replace the product until well
after the product has become ineffective.
[0011] There are a number of automatic use-up cue systems which
have been developed and applied in varied contexts which rely on
some form of chemical reaction to cause an automatic color change
after use for a specified period. However, systems of this type are
difficult to reliably apply in a heated environment, particularly
where the exact heat conditions that the product will be exposed to
is not controllable or predictable. This is particularly important
because chemical reactions typically proceed at very different
speeds depending on the environmental temperature.
[0012] Some other known indicator devices rely on the migration of
a dye to a visible position as an indicator of the extent of use or
use-up. See e.g. U.S. Pat. Nos. 4,212,153, 4,903,254 and 6,701,864.
However, these devices typically require consumer intervention to
initiate the dye migration, and sometimes require complex
structures to control use of the dye. They thereby unnecessarily
increase the cost of the indicator and may also reduce the
likelihood of consumer acceptance, particularly where the manner of
using the product is not conceptually straightforward. See also
U.S. Pat. No. 4,987,849.
[0013] Thus, there is still a need in the art to have improved
use-up cue systems for heated volatile dispensers which do not rely
on viewing liquid levels in a reservoir and can adjust for varied
heating conditions.
BRIEF SUMMARY OF THE INVENTION
[0014] In one aspect the invention provides a substrate capable of
dispensing a volatile air treatment chemical upon heating of the
substrate. The substrate includes a use indicator associated with
the substrate and configured to automatically communicate an extent
to which the air treatment chemical has been dispensed from the
substrate as the substrate is heated. The indicator includes at
least one dye, and a covering configured to restrict migration of
the dye prior to heating of the covering, and to permit migration
of the dye to a visible surface in response to heating of the
covering.
[0015] Upon heating of the substrate, the dye can at least in part
migrate to the visible surface. The extent to which the dye becomes
visible at the visible surface is indicative of the extent to which
the air treatment chemical has been dispensed from the
substrate.
[0016] In preferred forms the visible surface is on a peripheral
top surface of the substrate, the covering is made of a material
that can be melted by heating such as a wax or polymer, and the
substrate has at least two viewing positions along visible surfaces
of the substrate. The migrating dye can reach a first of the
viewing positions before reaching a second of the viewing
positions, and the migrating dye being visibly present at the first
of said viewing positions but not at the second of said viewing
positions will be indicative of a lesser degree of use-up of the
air treatment chemical than if the migrating dye is visible at both
of said first and second viewing positions.
[0017] In other forms the substrate can have an array of pre-formed
"quick migration" pathways extending from the covering to adjacent
the visible surface for causing preferential migration of the dye
through the pathways once migration of the dye begins. These can be
uniformly or non-uniformly spaced across the substrate.
[0018] In some aspects a peripheral surface of the substrate is
pre-marked with symbolic or textual indications such that they
indicate a degree of use-up of the air treatment chemical once the
dye reaches adjacent that pre-marked indication. For example, the
markings 1/4, 1/2, 3/4, and "replace" can appear along a visible
surface of the substrate. As the die progressively reaches each,
information regarding the extent of use is communicated.
[0019] In another form a peripheral surface of the substrate is
pre-marked with a symbolic or textual indication (e.g. "New"), and
the subsequent hiding of that indication by migrating dye indicates
a degree of use-up of the air treatment chemical.
[0020] While the dye can be stored prior to use in a separate
cavity, it can also be pre-positioned in expandable channels of the
substrate prior to heating the substrate. For example, substrates
made of polyethylene terephthalate ("PET") or comparable polymers
are known to have their pore size expand in response to heating. By
using a migrateable dye with it, such a system can be achieved.
Examples of suitable dyes are Cartasol dyes, sold by the Clariant
Corporation.
[0021] In another form the substrate is a stepped construction of
substrate material. After heating the covering the migrating dye is
able to migrate to reach an exposed surface of a first step of the
substrate stack before it reaches an exposed surface of another
step of the substrate stack. This facilitates a patterned depiction
of dye in a specified order, thereby providing additional
informational.
[0022] In the most preferred forms the substrate is a porous solid
material that has been impregnated with the air treatment chemical
such as insect control actives, fragrances, sanitizers and
deodorizers. The invention is particularly well suited to dispense
insect control repellents and insecticides, and provide information
to the public as to when sufficient dispensing has occurred to
provide initial protection, and when sufficient dispensing has
occurred to render the substrate ineffectual thereafter.
[0023] One possible embodiment provides a single viewing position
along a top surface of the substrate where as more dye appears,
more use of the air treatment chemical is indicated. For example,
the darker the color at that viewing position, the more use that
has occurred. There could even be a color chart pre-printed and
attached adjacent the viewing position to provide a quick
comparison of colors to correlated usage levels.
[0024] Alternatively, the substrate could have multiple viewing
positions along visible surfaces of the substrate or device. The
substrate will be configured via thickness, preferential flow
passages, or other means such that the dye reaches some of the
viewing positions before others. There can be pre-marking on the
substrate indicating to a consumer that the dye reaching a certain
position first means initiation or partial use-up, and the dye
reaching another position indicates more complete or complete
use-up.
[0025] The markings on the surfaces can be textual or symbolic. The
use-up message can be communicated with reference to them, or with
reference to particular symbols. For example, the dye could be
configured to fill a quarter of a circle or a quarter of a
rectangle first, followed by completing a half or more.
Alternatively, the visible surface of the substrate could have
various bars that are sequentially filled in or covered or
connected.
[0026] Further, the device could be provided with an visible circle
that is pre-marked on the top surface. Its central portion is
colored first. The expansion of the coloration to an outer
surrounding circle could then indicate further use.
[0027] In another form the invention provides a device for
dispensing an air treatment chemical into a surrounding air
environment in response to heating of a substrate. The device has a
porous substrate to which has been applied the air treatment
chemical, a dye positioned in, against, or adjacent the substrate,
and means for controlling migration of the dye such that migration
of the dye prior to the heating is restricted, and migration of the
dye to a visible surface after such heating is facilitated. The
degree to which the dye becomes visible along the visible surface
constitutes an indication of the extent to which the air treatment
chemical has been dispensed from the substrate.
[0028] In the most preferred form the means for controlling the
initiation is a meltable covering or encasement, such as a meltable
coating made of a wax or a wax/polymer mix. It is preferable that
the wax won't melt at lower than about 50.degree. C, preferably not
lower than 60.degree. C. Microcrystaline paraffin waxes are
suitable for this purpose. An example of an especially preferred
wax/polymer mix is microcrystalline paraffin and high density
polyethylene.
[0029] In alternative embodiments, the means for controlling the
initiation can be a peel-off or intervening layer that is
physically removed by the consumer immediately prior to heating. In
yet another alternative, the means for controlling the initiation
could be that the porous material is of a nature that its pore size
increases upon heating. The dye could be selected to have a size
that would not fit through the pores (and thus be trapped) until
the pore sizes increase sufficiently under heating conditions.
[0030] In yet another form the invention provides a method of
producing an air treatment device having an automatic use-up
indicator. One covers a migrateable dye with a meltable substance,
and positions the covered dye proximate to a porous substrate to
which has been applied an air treatment chemical.
[0031] A wide variety of volatile air treatment chemicals can be
dispensed via heated volatile dispensers, as is well known in the
art. This may include, for example, insect control actives,
fragrances, sanitizers and deodorizers. Particularly preferred
insect control actives are insect control repellents and
insecticides such as pyrethroids such as transfluthrin or
metofluthrin, mixed, if used in a liquid form, with from 99 to 95
wt percent of a suitable, volatile solvent. Hydrocarbon solvents
such as Exxon Corporation's Isopar solvents are examples.
Alternatively, even solid or gel form air treatment chemicals could
be used provided that upon heating they will volatilize.
[0032] A preferred substrate is a porous heat stable slab-like
substrate, such as one of the porous substrates conventionally used
for dispensing insect repellents. Examples include, without
limitation, sintered ceramics, compressed cellulosic materials,
porous polymers, and silica or other particles bound into a mass by
a resin material.
[0033] The migrating dye may be of varied types. It is preferred
that the dye be heat stable. However, even where this is not the
case, the instability of the dye can provide an additional piece of
information. For example, the initial migration might provide one
form of information, and a further color change of the dye after it
first appears (due to further heating) could communicate additional
usage. In any event, one preferred migrating dye is guaiazulene
dye.
[0034] It should be appreciated that the principles of the present
invention can be applied to a wide variety of devices. For example,
the exact nature of the heater is not critical. While electrical
heaters are preferred, even flame heaters (e.g. insect control
lanterns) can have the principles of the present invention
effectively applied to them. In any event, one form of electrical
heater that may be used with insect repellent slabs is the insect
mat heater sold by S. C. Johnson & Son, Inc. under the
Raid.RTM. brand.
[0035] The present invention thus provides an automatic means of
indicating to a consumer the extent to which consumable portions of
air treatment devices have been used up. The substrates of the
present invention are inexpensive to produce, reliable, and
conceptually straightforward insofar as a consumer's ability to
readily understand how they operate. They help avoid waste due to
the premature disposal of such consumables even when they still
have considerable useful life, and they help reduce consumer
dissatisfaction which can be caused by use of a consumable after
its effective life is over.
[0036] The foregoing and other advantages of the present invention
will be apparent from the following description. In that
description reference is made to the accompanying drawings which
form a part thereof, and in which there is shown by way of
illustration, and not limitation, preferred embodiments of the
invention. Such embodiments do not necessarily represent the fall
scope of the invention, and reference should therefore be made to
the claims herein for interpreting the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 is a schematic cross-sectional view of an
air-treatment device in accordance with the present invention;
[0038] FIG. 2 depicts a set of cross-sectional, and corresponding
plan, views of the substrate of FIG. 1, at various stages after
heating, showing progressive filling of a semi-circle by a
migrateable dye;
[0039] FIG. 3 depicts another set of cross-sectional, and
corresponding plan, views of an alternative substrate which could
be used with the FIG. 1 heater, at various stages after heating,
showing how pre-formed expandable passageways can be used to direct
a migrateable dye first to a bar design and then to fill in a
semi-circle, where the migrateable dye (prior to heating) is
trapped in those passageways;
[0040] FIG. 4 depicts yet another set of cross-sectional, and
corresponding plan, views of an alternative substrate which could
be used with the FIG. 1 heater, at various stages after heating,
showing how another array of pre-formed expandable passageways can
be used to direct a migrateable dye first to a portion of a
semi-circle, and then to fill the rest of the semi-circle, where
the migrateable dye (prior to heating) is trapped in those
passageways;
[0041] FIG. 5 depicts a set of top plan views indicating how in
another alternative substrate (through use of clustered preferred
pathways or other means) shading could start at the center of a
circle and then fill out the rest of the circle;
[0042] FIG. 6 depicts another set of top plan views indicating how
in another alternative substrate (through use of clustered
preferred pathways or other means) the coloration could completely
fill a central circle, and then fill a surrounding larger circular
area;
[0043] FIG. 7 depicts a set of top plan views indicating how
another substrate could have its entire top surface gradually
change color upon heating, with the degree of color change
indicating the degree of use of the air treatment chemical; and
[0044] FIG. 8 is a view similar to FIG. 7, but of a slightly
different embodiment where a top surface of the substrate had
marked thereon a word that becomes hidden as the substrate becomes
more and more dyed on its top surface.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] Referring first to FIGS. 1 and 2, there is shown an air
treatment device 10 which has a substrate with a base 1, a cavity
filled with a migrateable dye 12, a wax layer covering 13, a first,
thin, porous substrate layer 14, and a second, somewhat thicker,
porous substrate layer 15. The base 11 is cup-shaped, heat
resistant, and impermeable to the dye.
[0046] The dye cavity is semi-circular and aligned with the
semi-circular viewing position 29 at the top of the substrate
layers 14/15. The substrate layer 14 is circular in top view. The
layer covering 13 is semi-circular in top view, and can also extend
down along an inner diameter side of the dye 12. The top substrate
layer 15 constitutes three-quarters of a circle.
[0047] The porous substrate layers 14/15 are preferably
pre-impregnated with an insect control repellent 17 which is
dispensed to the air as the substrate is heated. An electrical
heater 18 heats the substrate and is powered by a conventional
electrical connection 19.
[0048] When the heater 18 is turned on, one of the effects is to
melt the layer covering 13. This frees the dye 12 so that it begins
to migrate upwardly into substrate layer 14. Because of the
thinness of substrate layer 14, very shortly after heating begins a
first one-quarter 26 will become visibly dyed (s the middle drawing
of FIG. 2). However, it will take substantially longer for the dye
to also migrate through a quarter circle corresponding to where
substrate layer 15 overlies the dye 12.
[0049] Thus, the indicator will not appear as in the right drawing
of FIG. 2 until much later. Through appropriate selection of the
dye, the solvents, the pore structure, possibly thickeners mixed
with the dye or air treatment chemical, the substrate thickness,
and the heaters, the semi-circle can be caused to fill the
remaining one-half quite slowly, and preferably only at about the
time the air treatment chemical is used up.
[0050] If desired, the dye can be mixed with additional, or can
provide the only, air treatment chemical. However, in most cases we
prefer to have the air treatment chemical separately impregnate the
substrate outside of the dye cavity.
[0051] FIG. 2 confirms that the substrate layers 14 and 15 form a
stepped structure. Hence, the dye reaches the top exposed surface
of the first step 27 long before it reaches the top exposed surface
of the second step 28.
[0052] FIGS. 3 and 4 depict structures where the dye is stored
within aligned passageways 30 prior to heating. These passageways
may be narrowed at their upper end so that they do not permit
upward migration to visible surface 31 until heating occurs. Then,
after heating, those pores expand enough for the dye to migrate
first through some of the larger passageways corresponding in FIG.
3 to particular bars, and corresponding in FIG. 4 to bars and a
region. Further heating causes further expansion of pores, and thus
completion of the semi-circle 32. While a variety of substrates may
have this expansion capability, one possible material to achieve
this is polyethylene terephthalate.
[0053] FIG. 4 shows how some of the passageways with larger
diameters can be grouped at a side 40, while others 41 can be
spaced at other positions. Note that this results in a segment 42
being filled first. Note also the lined designations A, B, C, D and
E are permanent markings that provide information regarding the
degree of use.
[0054] As shown in FIGS. 5 and 6, by utilizing a high concentration
of easy flow passages near the center of a substrate it is possible
to cause the centers to shade or darken first, thereby providing
another indication of extent of use.
[0055] For the alternative designs of FIGS. 7 and 8, a bottom
rectangular dye cavity permits uniform upward migration of the dye
after heating, resulting in the top surface of the substrate
becoming progressively more colored as use continues. A color chart
of a permanent nature might be placed adjacent the substrate to
compare the color hue at any given time with a specified degree of
use-up.
[0056] The FIG. 8 embodiment could be very similar to the FIG. 7
embodiment except that there is a permanent marking of the word
"NEW" on the top surface of the substrate. It progressively becomes
more hidden as the dye migrates to that surface. For this purpose,
the dye could have a color identical to the color of the text.
[0057] As should be appreciated from the examples provided above,
the present invention can be applied in a wide variety of ways. For
example, the substrates could be square, spherical, or have many
other shapes. Thus, the claims should not be construed as being
limited to just the disclosed preferred embodiments.
INDUSTRIAL APPLICABILITY
[0058] The present invention provides automated migrating dye
use-up cues for use with devices that dispense volatile materials
in response to heating.
* * * * *