U.S. patent application number 10/868032 was filed with the patent office on 2004-11-18 for flavored carbon useful as filtering material of smoking article.
This patent application is currently assigned to PHILIP MORRIS INCORPORATED. Invention is credited to Nepomuceno, Jose G., Taylor, Barbara G., Yang, Zuyin.
Application Number | 20040226569 10/868032 |
Document ID | / |
Family ID | 27752778 |
Filed Date | 2004-11-18 |
United States Patent
Application |
20040226569 |
Kind Code |
A1 |
Yang, Zuyin ; et
al. |
November 18, 2004 |
Flavored carbon useful as filtering material of smoking article
Abstract
Flavored carbon useful as a filtering material of a smoking
article such as a cigarette is made by applying liquid flavorant to
activated carbon particles in a fluidized bed. The flavored carbon
can be used to impart desired taste to mainstream smoke while
removing one or more components from mainstream smoke.
Inventors: |
Yang, Zuyin; (Midlothian,
VA) ; Nepomuceno, Jose G.; (Beaverdam, VA) ;
Taylor, Barbara G.; (Midlothian, VA) |
Correspondence
Address: |
BURNS DOANE SWECKER & MATHIS L L P
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Assignee: |
PHILIP MORRIS INCORPORATED
|
Family ID: |
27752778 |
Appl. No.: |
10/868032 |
Filed: |
June 16, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10868032 |
Jun 16, 2004 |
|
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|
10079813 |
Feb 22, 2002 |
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Current U.S.
Class: |
131/207 ;
131/202; 131/360 |
Current CPC
Class: |
A24D 1/002 20130101;
A24D 3/0225 20130101 |
Class at
Publication: |
131/207 ;
131/202; 131/360 |
International
Class: |
A24D 001/04 |
Claims
1. A process for making flavored carbon particles, the process
comprising: (i) introducing activated carbon particles into a
vessel; (ii) introducing a fluidizing gas into the vessel so as to
fluidize the activated carbon particles; and (iii) introducing a
liquid flavorant into the vessel while the activated carbon
particles are in a fluidized state, the liquid flavorant being
absorbed and optionally adsorbed onto the activated carbon
particles such that pores of the flavored carbon particles can
preferentially remove at least one selected gaseous component from
mainstream tobacco smoke.
2. The process of claim 1, wherein the process is carried out in a
batch or continuous manner to provide 0.1 to 20% by weight of
flavorant on the activated carbon particles.
3. The process of claim 2, wherein the process is carried out in a
batch manner without heating the activated carbon particles while
in the fluidized state.
4. A process for making flavored carbon particles, the process
comprising: (i) introducing activated carbon particles into a
vessel containing a plurality of compartments; (ii) introducing a
fluidizing gas into the vessel so as to fluidize the activated
carbon particles such that the activated carbon particles pass
sequentially through the compartments while in the fluidized state;
and (iii) introducing a liquid flavorant into the vessel while the
activated carbon particles are in a fluidized state and at ambient
temperature, the liquid flavorant being dripped onto an upper
surface of the fluidized bed of the activated carbon particles in
at least two of the compartments such that the liquid flavorant is
absorbed and optionally adsorbed onto the activated carbon
particles.
5. The process of claim 1, wherein the activated carbon has an
average particle size from about 10 mesh to about 70 mesh.
6. The process of claim 1, wherein the activated carbon has an
average particle size from about 0.2 mm to about 1 mm.
7. The process of claim 1, wherein the fluidizing gas is
nitrogen.
8. The process of claim 1, wherein the vessel includes a gas
exhaust conduit separated from the interior of the vessel by a
filter, the process including periodic blowback of gas through the
filter to clean activated carbon particles from the filter.
9. The process of claim 1, wherein the process is carried out for
10 to 60 minutes.
10. The process of claim 1, further comprising placing the flavored
activated carbon particles in a cigarette filter.
11. The process of claim 1, further comprising placing the flavored
activated carbon particles in smoking material of a cigarette.
12. The process of claim 10, wherein the activated carbon comprises
at least about 80% micropores.
13. The process of claim 10, wherein the flavored carbon has an
average particle size from about 10 mesh to about 20 mesh.
14. The process of claim 10, wherein the flavored carbon has an
average particle size from about 0.2 mm to about 1 mm.
15. The process of claim 10, wherein the cigarette filter comprises
from about 10 mg to about 200 mg of the flavored carbon.
16. A method of making a cigarette filter, the method comprising:
(i) providing flavored carbon particles produced according to the
process of claim 1, and (ii) incorporating the flavored carbon
particles into a cigarette filter.
17. A method of making a cigarette, said method comprising: (i)
providing a cut filler to a cigarette making machine to form a
tobacco rod; (ii) placing a paper wrapper around the tobacco rod;
(iii) providing a cigarette filter made by the process according to
claim 16; and (iv) attaching the cigarette filter to the tobacco
rod to form the cigarette.
18. The method of claim 17, wherein the cigarette is for an
electrical smoking system.
19. The process of claim 1, wherein the activated carbon particles
are at a temperature of 40.degree. F. to 70.degree. F. while in the
fluidized state such that the liquid flavorant is impregnated into
pores of the activated carbon particles without evaporation of the
liquid flavorant.
20. The process of claim 19, wherein substantially all of the
liquid flavorant introduced into the vessel is impregnated in the
carbon particles.
21. The process of claim 4, wherein the activated carbon particles
are at a temperature of 40.degree. F. to 70.degree. F. while in the
fluidized state such that the liquid flavorant is impregnated into
pores of the activated carbon particles without evaporation of the
liquid flavorant.
22. The process of claim 21, wherein substantially all of the
liquid flavorant introduced into the vessel is impregnated in the
carbon particles.
23. The process of claim 1, wherein the at least one selected
gaseous component is selected from the group consisting of
1,3-butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile,
benzene, toluene, styrene, acetaldehyde and hydrogen cyanide.
24. The process of claim 16, wherein the flavored carbon particles
can preferentially remove at least one selected mainstream tobacco
smoke gaseous component selected from the group consisting of
1,3-butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile,
benzene, toluene, styrene, acetaldehyde and hydrogen cyanide from
mainstream tobacco smoke.
25. The process of claim 17, wherein the flavored carbon particles
can preferentially remove at least one selected mainstream tobacco
smoke gaseous component selected from the group consisting of
1,3-butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile,
benzene, toluene, styrene, acetaldehyde and hydrogen cyanide from
mainstream tobacco smoke.
26. The process of claim 4, wherein the flavored carbon particles
have a loading of 0.1 to 20% by weight of the flavorant.
27. The process of claim 26, wherein the flavored carbon particles
have a loading of 1 to 5% by weight of the flavorant.
28. The process of claim 1, wherein the flavored carbon particles
have a loading of 1 to 5% by weight of the flavorant.
29. The process of claim 1, wherein the liquid flavorant is applied
onto the activated carbon particles at a flow rate of at least 10
g/min.
30. The process of claim 1, wherein the liquid flavorant is applied
onto the activated carbon particles at a flow rate of 15 to 25
g/min.
31. The process of claim 1, wherein the liquid flavorant is
dissolved in a carrier selected from the group consisting of
propylene glycol, ethyl alcohol, water and glycerin.
32. The process of claim 4, wherein the liquid flavorant is
dissolved in a carrier selected from the group consisting of
propylene glycol, ethyl alcohol, water and glycerin.
33. The process of claim 1, wherein the fluidizing of the activated
carbon particles by the fluidizing gas is continued after the
liquid flavorant has been applied to the activated carbon particles
to promote distribution of the flavorant in the fluidized bed.
34. The process of claim 4, wherein the fluidizing of the activated
carbon particles by the fluidizing gas is continued after the
liquid flavorant has been applied to the activated carbon particles
to promote distribution of the flavorant in the fluidized bed.
35. The process of claim 4, wherein the compartments are separated
by partitions which include at least one opening, the openings in
adjacent partitions being offset from each other to prevent the
activated carbon particles from flowing directly from one
compartment to the next compartment.
36. The process of claim 4, wherein the residence time of the
activated carbon particles in the compartments is 5 to 60 minutes.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 10/079,813, filed on Feb. 22, 2002, the entire contents of
which are hereby incorporated by reference.
FIELD OF INVENTION
[0002] The invention relates generally to treatment of carbon
particles with a flavorant and use of flavored carbon as filtering
material in smoking article.
BACKGROUND
[0003] Cigarette filters, incorporating various materials that
mechanically, chemically and/or physically remove components of
mainstream cigarette smoke have the disadvantage of non-selectively
filtering components from mainstream smoke, even those components
that contribute to flavor. The result may be a cigarette with an
unsatisfactory taste. Efforts to improve taste of cigarettes by
incorporating a flavorant in the cigarette have been disclosed in
U.S. Pat. Nos. 3,236,244; 3,972,335; 4,281,671; 4,549,875;
4,567,850; 4,662,384; 4,715,390; 4,768,526; 5,012,829; 5,016,654;
5,144,967; 5,356,704; 5,588,446; and 5,598,868.
[0004] U.S. Pat. No. 3,236,244 discloses a cigarette filter in
which activated carbon is used to release a flavoring agent during
smoking of a cigarette. The '244 patent states that there is no
significant release of the adsorbed flavoring agent by
volatilization or otherwise during storage and that a filter
element containing adsorbed menthol does not evidence the
characteristic odor of the flavoring agent. In the sole example in
the '244 patent, activated carbon was added to a menthol-ethyl
alcohol and water solution, the mixture was agitated at room
temperature for two hours, the carbon was separated by filtration
and washed three times with water containing 20% alcohol, and the
washed carbon was dried for 20 minutes in an oven at 220.degree. F.
The carbon product was dispersed in a cellulosic carrier base and
formed into paper sheet weighing about 16 grams per square
meter.
[0005] U.S. Pat. No. 3,972,335 discloses a cigarette filter
containing menthol or other smoke flavoring agent wherein granular
activated carbon is impregnated with a pore-modifying agent such as
sucrose capable of blocking the most retentive portions of the
activated carbon and the less retentive portions of the activated
carbon are available for adsorption of the flavoring agent.
According to the '335 patent, the activated carbon includes 0.2 to
20, preferably 2 to 10% by weight of the menthol or other smoke
flavoring agent. The pore modifying agent is added in amounts of 1
to 40, preferably 5 to 30% by weight of the original weight of the
activated carbon, such amounts being less than the maximum amount
which could be impregnated in the carbon. The '335 patent states
that the pore modifying agent will occupy at least 50% of the pore
volume and at least 60% of the surface area. The pore modifying
agent materials are preferably organic compositions which are not
solvents for menthol or other smoke-flavoring agent. Likewise, the
pore modifying agent should not be soluble in the solvent system
used to incorporate the menthol or other smoke-flavoring agent when
it is later added to the activated carbon. The pore modifying agent
can be sprayed onto the activated carbon or the activated carbon
can be immersed in the solution after which the treated carbon is
dried at 80 to 110.degree. C. The menthol can be liquefied by
heating and sprayed on the carbon, a concentrated solution of
menthol in a solvent such as ethanol can be sprayed on the
activated carbon.
[0006] U.S. Pat. Nos. 4,163,452 and 4,363,333 disclose the use of
porous activated carbon particles as filter material in cigarette
filters. The '452 patent discloses that the porous activated carbon
is treated with 0.5 to 25% nitroxide and is used in a center
section of a triple filter. The '333 patent discloses that the
porous activated carbon is treated with 2 to 15% of a C-nitroso
compound and the treated carbon is used in the center cavity of a
triple filter having 5 mm long filter plugs of cellulose acetate at
each end.
[0007] Several modified forms of activated carbon are disclosed in
U.S. Pat. Nos. 3,091,550; 3,217,715; 3,652,461; 4,062,368;
5,344,626; 5,496,785; 5,538,929; 5,614,459; 5,705,269; 5,880,061;
and 6,117,810. The production of such modified activated carbon
typically requires additional process steps, such as coating the
activated carbon with solutions, filtration, drying and/or
crystallization. U.S. Pat. No. 5,792,720 discloses a method of
manufacturing TEDA-impregnated activated carbon in a fluidized bed
absorbing tower wherein heated air and TEDA vapor are supplied into
a lower portion of the tower.
[0008] U.S. Pat. No. 4,068,389 discloses a distributor plate of a
fluidized bed apparatus. Fluidized beds used for drying,
granulation, spray coating, agglomeration and the like are
disclosed in "Controlling particle size and release properties" by
David M. Jones (see Chapter 17 of Flavor Encapsulation, ACS
Symposium Series 370, 1988, pages 158-176). Despite various
developments in adsorbent and filtration materials, an economical
technique for production of flavor impregnated carbon would be
desirable.
SUMMARY OF THE INVENTION
[0009] In one embodiment, the invention relates to a process for
making a flavored carbon which can be used as a flavor release
component of a cigarette. The process comprises (i) introducing
activated carbon particles into a vessel; (ii) introducing a
fluidizing gas into the vessel so as to fluidize the activated
carbon particles; and (iii) introducing a liquid flavorant into the
vessel while the activated carbon particles are in a fluidized
state, the liquid flavorant being applied to the carbon particles
via adsorption and/or absorption. Another embodiment of the
invention relates to flavored carbon particles produced by this
process.
[0010] In another embodiment, the invention relates to a smoking
article comprising the flavored carbon particles described above. A
preferred smoking article is a cigarette. The flavored carbon
particles are dispersed in smoking material and/or located in a
filter. Preferably, the smoking article comprises from about 10 mg
to about 200 mg of the flavored carbon particles.
[0011] In another embodiment, the invention relates to a cigarette
filter comprising the flavored carbon particles described above.
Preferably, the cigarette filter comprises from about 10 mg to
about 200 mg of the flavored carbon particles. In yet another
embodiment, the invention relates to a cut filler composition
comprising the flavored carbon particles.
[0012] Preferably, the activated carbon comprises at least about
80% micropores, has an average particle size from about 10 mesh to
about 70 mesh, and/or has an average particle size from about 0.2
mm to about 1 mm. The micropore volume of the activated carbon is
preferably at least 0.2 cc/g, more preferably 0.2 to 0.4 cc/g.
[0013] An embodiment of the invention also relates to a method of
making a cigarette filter, said method comprising: (i) providing
flavored carbon particles as described above, and (ii)
incorporating the flavored carbon particles into a cigarette
filter.
[0014] Another embodiment of the invention relates to a method of
making a cigarette, said method comprising: (i) providing a cut
filler to a cigarette making machine to form a tobacco rod; (ii)
placing a paper wrapper around the tobacco rod; (iii) providing a
cigarette filter comprising flavored carbon particles as described
above; and (iv) attaching the cigarette filter to the tobacco rod
to form the cigarette. In yet another embodiment, the invention
relates to a method of making a cigarette, said method comprising:
(i) adding flavored carbon particles as described above to a cut
filler; (ii) providing the cut filler comprising the
surface-modified adsorbent to a cigarette making machine to form a
tobacco rod; and (iii) placing a paper wrapper around the tobacco
rod to form the cigarette.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Various features and advantages of the invention will become
apparent from the following detailed description of the preferred
embodiments thereof in connection with the accompanying drawings,
in which:
[0016] FIG. 1 is a diagram of a batch type fluidizing bed apparatus
which can be used to treat carbon particles with a flavoring
additive.
[0017] FIG. 2 is a diagram of a continuous type fluidizing bed
apparatus which can be used to treat carbon particles with a
flavoring additive.
[0018] FIG. 3 is a partially exploded perspective view of a
cigarette incorporating one embodiment of the present invention
wherein folded paper containing the surface-modified adsorbent is
inserted into a hollow portion of a tubular filter element of the
cigarette.
[0019] FIG. 4 is partially exploded perspective view of another
embodiment of the present invention wherein the surface-modified
adsorbent is incorporated in folded paper and inserted into a
hollow portion of a first free-flow sleeve of a tubular filter
element next to a second free-flow sleeve.
[0020] FIG. 5 is a partially exploded perspective view of another
embodiment of the present invention wherein the surface-modified
adsorbent is incorporated in a plug-space-plug filter element.
[0021] FIG. 6 is a partially exploded perspective view of another
embodiment of the present invention wherein the surface-modified
adsorbent is incorporated in a three-piece filter element having
three plugs.
[0022] FIG. 7 is a partially exploded perspective view of another
embodiment of the present invention wherein the surface-modified
adsorbent is incorporated in a four-piece filter element having a
plug-space-plug arrangement and a hollow sleeve.
[0023] FIG. 8 is a partially exploded perspective view of another
embodiment of the present invention wherein the surface-modified
adsorbent is incorporated in a three-part filter element having two
plugs and a hollow sleeve.
[0024] FIG. 9 is a partially exploded perspective view of another
embodiment of the present invention wherein the surface-modified
adsorbent is incorporated in a two-part filter element having two
plugs.
[0025] FIG. 10 is a partially exploded perspective view of another
embodiment of the present invention wherein the surface-modified
adsorbent is incorporated in a filter element which may be used in
a smoking article.
DETAILED DESCRIPTION
[0026] The invention provides a process for making flavored carbon
particles, wherein a flavorant comprising one or more flavor
ingredients is applied to activated carbon particles in a fluidized
state. The invention also relates to the flavored carbon particles
produced by this process, as well as smoking articles, cigarette
filters, and methods which incorporate the flavored carbon
particles.
[0027] The flavored carbon particles can be used as a flavor
release medium and a filtration agent. In particular, the flavored
carbon particles of the invention could be used to release flavor
while filtering one or more selected components from mainstream
smoke. The term "mainstream" smoke includes the mixture of gases
passing down the tobacco rod and issuing through the filter end,
i.e. the amount of smoke issuing or drawn from the mouth end of a
smoking article during smoking of the smoking article. The
mainstream smoke contains smoke that is drawn in through both the
lit region of the smoking article, as well as through the paper
wrapper.
[0028] Activated carbon is available in various particle form such
as granules, beads, powder, or the like and can be made from
various sources including bituminous coal, lignite, coconut shells,
wood, olive pits, peat, synthetic polymers, petroleum pitch,
petroleum coke, and coal tar pitch. Carbon can be activated by
steam treatment or chemically, e.g., thermally treating sawdust
with phosphoric acid as a catalyst. The activation treatment
develops the carbon porosity and activated carbon can be provided
with a wide range of pore sizes or the pore sizes can be controlled
to provide a desired pore size distribution. For example, U.S. Pat.
No. 5,880,061 describes a process to provide coal based carbon with
a pore size distribution of at least 0.25 ml/g of pore sizes below
15 angstroms representing at least 40% of the total pore volume of
pores up to 300 angstroms and at least 10% of the total pore volume
up to 300 angstroms having pore sizes of 100 to 300 angstroms. In
general, it is desirable for activated carbon to have a pore volume
of at least 0.2 cc/g and a BET specific surface area of at least
100 m.sup.2/g, preferably at least 250 m.sup.2/g and more
preferably at least 500 m.sup.2/g, e.g, 1000 to 2000 m.sup.2/g.
Activated carbon is available in various particle sizes such as
12.times.20 mesh or 16.times.35 mesh and U.S. Pat. Nos. 4,163,452
and 4,363,333 describe use of 100 g of activated carbon particles
in the cavity of a triple filter for purposes of reducing the level
of NO in mainstream smoke. According to the present invention, the
flavorant can be applied to commercially available activated carbon
or specially prepared activated carbon.
[0029] The flavored carbon particles can be made by the following
process, where a fluidizing bed is used to apply a flavorant onto
the activated carbon particles. In the process, activated carbon
particles are introduced into a vessel. In order to fluidize the
particles, a gas such as nitrogen is introduced into the bottom of
the vessel. A flavorant such as a conventional or proprietary
flavor solution containing one or more flavor ingredients is
introduced into the vessel while the particles are in a fluidized
state. Preferably, the liquid flavorant is sprayed or dripped onto
the fluidized particles while maintaining the particles at ambient
temperature, i.e., the process is carried out without heating the
particles. Although liquid flavorant is applied to the upper
surface of the fluidized bed, the agitation of the carbon particles
distributes the flavorant throughout the bed of carbon
particles.
[0030] A particularly preferred activated carbon is commercially
available from PICA USA, Inc., Truth or Consequences, N. Mex. The
activated carbon could also be manufactured by any suitable method
known in the art. Such methods include the carbonization of coconut
husk, coal, wood, pitch, cellulose fibers, or polymer fibers, for
example. Carbonization is usually carried out at high temperatures,
i.e. 200-800.degree. C. in an inert atmosphere, followed by
activation under reduced conditions. The activated carbon particles
produced could be in the form of beads, granules, fragments, powder
or fibers.
[0031] In a preferred embodiment, the activated carbon comprises
granulated carbon having particles ranging in size from 0.1 mm to
about 5 mm. For example, the carbon particles can be carbon pellets
having sizes of 0.5 to 5 mm. In a most preferred embodiment, the
activated carbon particles range in size from about 0.2 mm to about
1 mm. In terms of Tyler screen mesh size, the carbon particles are
preferably from about 6 mesh to about 70 mesh, preferably 10 mesh
to about 70 mesh, and more preferably from about 14 to 35 mesh.
[0032] The carbon particles can have any desired pore size
distribution such as micropores, mesopores and macropores. The term
"microporous" generally refers to such materials having pore sizes
of about 20 .ANG. or less while the term "mesoporous" generally
refers to such materials with pore sizes of about 20-500 .ANG.. In
a preferred embodiment, the proportion of micropores to mesopores
will be about 20 to 80% micropores to 80 to 20% mesopores. In a
most preferred embodiment, the pores of the activated carbon
comprise at least 80% micropores. The relative ratio of micropores,
mesopores and macropores can be provided such that selected gaseous
components can be removed from the tobacco smoke stream. Thus, the
pore sizes and pore distribution can be adjusted accordingly as
needed for a certain application.
[0033] The activated carbon can be selected to have a sufficient
surface area to preferentially adsorb selected components from
cigarette smoke. While surface area is inversely proportional to
particle size, when used as cigarette filter material, activated
carbon particles of small particle size may pack together too
densely to permit mainstream smoke to flow through the filter
during smoking. If particle size is too large, there may be
insufficient surface area to accomplish the desired degree of
filtration. Therefore, such factors can be taken into account in
selecting an activated carbon having a particular particle
size.
[0034] The flavorant used in making the flavored carbon particles
may be adsorbed and/or absorbed by the activated carbon, e.g., the
flavorant can be located on the exterior and/or interior surfaces
of the activated carbon. However, it is desirable to apply the
flavorant in a manner which does not block all of the pores to
thereby allow targeted removal of one or more gas components of the
tobacco smoke. For example, the flavorant can be applied in a
manner which allows the flavored carbon to reduce the content of
one or more gaseous components such as 1,3-butadiene, acrolein,
isoprene, propionaldehyde, acrylonitrile, benzene, toluene,
styrene, acetaldehyde and hydrogen cyanide. For example, the
activated carbon particles can be provided with a loading of 0.1 to
20% by weight of the flavorant. A preferred loading is 1 to 5% of
the flavorant. Due to volatility of the flavorant, it is preferred
to apply the flavorant without heating during the fluidized bed
treatment or subsequent thereto.
[0035] In the fluidizing treatment, an inert gas such as nitrogen
is used to fluidize the carbon particles. The flow rate of the
fluidizing gas will depend on the size of the fluidized bed. In a
preferred embodiment, the flow rate is at least 5 ft.sup.3/minute,
more preferably 10 to 20 ft.sup.3/minute. The flow rate of the
flavorant onto the carbon particles will depend on the amount of
carbon being treated and/or the duration of the fluidized bed
treatment. In a preferred embodiment, the flavorant is applied as a
liquid at a flow rate of at least 10 g/minute, e.g., 15 to 25
g/minute for a batch of 25 pounds of activated carbon. The
flavorant can be dissolved or suspended in a carrier such as
propylene glycol, ethyl alcohol, ethanol, water, glycerin or the
like, e.g., an aqueous solution containing flavorant and ethanol.
After the flavorant is applied to the carbon in the fluidized bed,
the fluidizing action can be continued to promote thorough
distribution of the flavorant in the fluidized bed. As an example,
the flavorant can be applied to the carbon particles for a period
of 15 minutes and the fluidizing action can be continued for an
additional 5 minutes thereafter. While not wishing to be bound by
theory, it is believed that the fluidizing gas is effective in
causing the flavorant to be distributed throughout the carbon
particles via mass transfer and/or particle collisions.
[0036] According to a preferred embodiment, the flavored carbon
according to the invention is prepared in a fluidizing bed
apparatus. Any suitable vessel that is capable of maintaining the
activated carbon particles in a fluidized state may be used. Such
vessels can be designed as batch or continuous processing
apparatus. An exemplary batch type fluidized bed arrangement is
shown in FIG. 1 and an exemplary continuous type fluidized bed
arrangement is shown in FIG. 2. A highly advantageous feature of
the fluidized bed technique of applying the flavorant to the carbon
is that the carbon can deliver flavor while performing an added
function of reducing the content of at least one gaseous component
in the tobacco smoke, the at least one gaseous component including
1,3-butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile,
benzene, toluene, styrene, acetaldehyde and hydrogen cyanide.
[0037] In the FIG. 1 arrangement, a vessel 200 is loaded with
activated carbon 212 and a fluidizing gas flows upwardly through
openings in a distribution plate 214. The gas preferably comprises
an inert gas such as nitrogen supplied through supply line 216.
After passing through the bed of carbon particles, the fluidizing
gas is removed from the vessel through exhaust line 218 after
passing through filters 220, 222. The carbon particles can be
supplied into the vessel 210 through feed port 224. To clean off
accumulated material such as fine carbon particles, a clearing gas
such as nitrogen can be blown back through the filters 220,222 via
supply line 226. A series of valves can be used to isolate the
exhaust line 218 from the supply line 226 whereby nitrogen is
prevented from flowing into supply line 226 when gasses are
withdrawn through exhaust line 218. Likewise, the valves can
isolate the exhaust line 218 from the blow back gas supplied by
supply line 226 during cleaning of the filters 220,222. The filter
cleaning can be conducted during treatment of the carbon, e.g.,
nitrogen blow back can be carried out periodically while the carbon
is in a fluidized state. As an example, if the carbon is treated
for 15 minutes, the nitrogen blow back can be carried out in 2
second pulses every 60 seconds during the carbon treatment. Liquid
flavorant in tank 228 can be removed by a pump 230 which sends the
liquid flavorant through supply line 232 and into the vessel after
passing through nozzles 234, 236. The treated carbon can be removed
from the vessel through a discharge line 238.
[0038] In the FIG. 2 arrangement, a compartmented vessel 240 is
loaded with activated carbon 242 and a fluidizing gas flows
upwardly through openings in a distribution plate (not shown). The
gas preferably comprises nitrogen supplied through supply line 246.
After passing through the bed of carbon particles, the fluidizing
gas is removed from the vessel through exhaust line 248 after
passing through filters 250, 251, 252, 253. The, carbon particles
can be supplied into the vessel 240 through feed line 254.
[0039] To clean off accumulated material such as fine carbon
particles, a clearing gas such as nitrogen can be blown back
through the filters 250, 252 via supply line 256. A series of
valves can be used to isolate the exhaust line 248 from the supply
line 256 whereby nitrogen is prevented from flowing into supply
line 256 when gasses are withdrawn through exhaust line 248.
Likewise, the valves can isolate the exhaust line 248 from the blow
back gas supplied by supply line 256 during cleaning of the filters
250-253. The filter cleaning can be conducted during treatment of
the carbon, e.g., nitrogen blow back can be carried out
periodically while the carbon is in a fluidized state. As an
example, if the carbon is treated for 15 minutes, the nitrogen blow
back can be carried out in 2 second pulses every 60 seconds during
the carbon treatment.
[0040] Liquid flavorant in tank 258 can be removed by a pump 260
which sends the liquid flavorant through supply line 262 and into
the vessel after passing through nozzles 264, 265, 266, 267. The
treated carbon can be removed from the vessel through a discharge
line 268. The vessel 240 can have any desired number of
compartments, e.g. in the embodiment shown the vessel includes 6
compartments 270, 272, 274, 276, 278, 280 separated by partitions
282, 284, 286, 288, 290. The liquid flavorant can be supplied only
to the middle compartments 272, 274, 276, 278 whereby the first
compartment 270 can be used as a loading compartment and the last
compartment 280 can be used as a discharge compartment.
[0041] Passage of carbon particles from one compartment to the next
is achieved by providing one or more openings in the partitions
282, 284, 286, 288, 290. For example, a single opening can be
provided at the bottom of each partition, e.g., a rectangular
opening of 1-2 inches by 2-4 inches. To prevent the carbon
particles from flowing directly from one compartment to the next,
it is advantageous to offset the openings, e.g., the first
partition 282 can have an opening near one side of the vessel and
the next partition 284 can have an opening near the opposite side
of the vessel and so on to provide a tortuous path of travel of the
carbon through the vessel.
[0042] The fluidized bed of carbon particles behaves like a liquid
with a portion of the fluidized particles being driven upwardly by
the fluidizing gas with some of the particles being transferred
from the first compartment 270 into the second compartment 272 by
flowing through an opening (e.g., 1 by 2 inch opening) between the
compartments 270, 272 at the bottom of the partition 282. In like
manner, the particles move from compartment to compartment until
they reach the discharge compartment. Thus, the particles move from
compartment to compartment while in a fluidized state and
ultimately are removed from the vessel after a predetermined
residence time. The residence time can vary depending on the size
of the vessel and number of compartments. In a preferred
embodiment, the residence time can range from 5 to 60 minutes, more
preferably 10 to 20 minutes.
[0043] The sizes of the compartments of the vessel are preferably
the same and the liquid flavorant can be distributed in the middle
compartments by 2 or more outlets in each compartment. The liquid
flavorant is preferably supplied to each compartment at a flow rate
which achieves uniform distribution of the flavorant on the carbon
particles. For example, the flavorant can be supplied at a flow
rate which results in a liquid drops, spray of liquid, or
continuous flow of liquid onto the bed of fluidized particles. If
sprayed, it is desirable that the flavorant not be atomized to such
an extent that volatile flavoring agent(s) is carried out of the
vessel rather than be applied to the carbon particles. While not
wishing to be bound by theory, it is believed that uniform
distribution of the flavorant is assisted by the fluidizing gas
which aids mass transfer of flavorant from particle to particle as
the particles travel in vertical and/or horizontal directions in
the fluidized bed. A preferred outlet arrangement provides one
outlet for distributing flavorant over an area of 20 to 60
in.sup.2, e.g., about 30 to 40 in.sup.2 at the upper surface of the
fluidized bed.
[0044] The flavorant can be applied to the fluidized particles at
any desired temperature. In a preferred embodiment, the bed is not
heated and the particles can be at a temperature in the range of 40
to 70.degree. F., preferably 45 to 65.degree. F. Heating of the
carbon particles during the treatment is not required because
adequate impregnation of the particles with the flavorant can be
achieved without heating. In fact, depending on the flavorant
composition, heating of the fluidized particles could result in
loss of flavorant through evaporation of the flavorant. In a
preferred embodiment, substantially all of the flavorant introduced
into the vessel is impregnated in the carbon particles. In terms of
added weight, the carbon particles can be treated to include 0.1 to
20% of the flavorant, preferably 1 to 5% flavorant. The flavorant
preferably masks the taste of the carbon particles and introduces
acceptable flavor and taste characteristics when used in a
cigarette filter. Further, it is desirable that the treated carbon
particles do not have an objectionable odor, i.e., the treated
carbon particles are essentially odorless. However, when
incorporated in a cigarette filter, the treated carbon particles
preferably release some of the flavorant (through displacement of
the molecules) while removing gaseous components of the tobacco
smoke stream passing through the filter.
[0045] The flavored carbon particles may be used in a variety of
applications, including smoking articles, cut filler compositions
and cigarette filters. Thus, in one embodiment, the invention
relates to a smoking article comprising flavored carbon particles.
The smoking article may be any article containing smokeable
material, such as a cigarette, a pipe, a cigar and a
non-traditional cigarette. Non-traditional cigarettes include, for
example, cigarettes for electrical smoking systems as described in
commonly-assigned U.S. Pat. Nos. 6,026,820; 5,988,176; 5,915,387;
5,692,526; 5,692,525; 5,666,976; and 5,499,636. The flavored carbon
particles may be located in a filter and/or dispersed in the
smoking material itself. Typical smoking articles will include from
about 10 mg to about 200 mg of the flavored carbon particles,
although the amount needed can also be determined easily by routine
experimentation and/or adjusted accordingly.
[0046] The invention further relates to cigarette filters
comprising the flavored carbon particles. Any conventional or
modified filter may incorporate the flavored carbon particles. In
one embodiment, the flavored carbon particles are incorporated into
or onto a support such as paper (e.g., tipping paper) that is
located along a filter portion of a cigarette. As will be
recognized by persons skilled in the art, such paper can be used,
for example, as a wrapper or a liner in the filter portion of the
cigarette. The flavored carbon particles can also be loaded onto a
support such as lightly or tightly folded paper inserted into a
hollow portion of the cigarette filter. The support is preferably
in the form of a sheet material such as crepe paper, filter paper,
or tipping paper. However, other suitable support materials such as
organic or inorganic cigarette compatible materials can also be
used.
[0047] FIG. 3 illustrates a cigarette 2 having a tobacco rod 4, a
filter portion 6, and a mouthpiece filter plug 8. As shown,
flavored carbon particles can be loaded onto folded paper 10
inserted into a hollow cavity such as the interior of a free-flow
sleeve 12 forming part of the filter portion 6.
[0048] FIG. 4 shows a cigarette 2 having a tobacco rod 4 and a
filter portion 6, wherein the folded paper 10 is located in the
hollow cavity of a first free-flow sleeve 13 located between the
mouthpiece filter 8 and a second free-flow sleeve 15. The paper 10
can be used in forms other than as a folded sheet. For instance,
the paper 10 can be deployed as one or more individual strips, a
wound roll, etc. In whichever form, a desired amount of flavored
carbon particles can be provided in the cigarette filter portion by
adjusting the amount of flavored carbon particles coated per unit
area of the paper and/or the total area of coated paper employed in
the filter (e.g., higher amounts of surface-modified adsorbent can
be provided simply by using larger pieces of coated paper). In the
cigarettes shown in FIGS. 1 and 2, the tobacco rod 4 and the filter
portion 6 are joined together with tipping paper 14. In both
cigarettes, the filter portion 6 may be held together by filter
overwrap 11.
[0049] The flavored carbon particles can be incorporated into the
filter paper in a number of ways. For example, the flavored carbon
particles can be mixed with water to form a slurry. The slurry can
then be coated onto pre-formed filter paper and allowed to dry. The
filter paper can then be incorporated into the filter portion of a
cigarette in the manner shown in FIGS. 3 and 4. Alternatively, the
dried paper can be wrapped into a plug shape and inserted into a
filter portion of the cigarette. For example, the paper can be
wrapped into a plug shape and inserted as a plug into the interior
of a free-flow filter element such as a polypropylene or cellulose
acetate sleeve. In another arrangement, the paper can comprise an
inner liner of such a free-flow filter element.
[0050] Alternatively, the flavored carbon particles are added to
the filter paper during the paper-making process. For example, the
flavored carbon particles can be mixed with bulk cellulose to form
a cellulose pulp mixture. The mixture can be then formed into
filter paper according to methods known in the art.
[0051] In another embodiment of the present invention, the flavored
carbon particles are incorporated into the fibrous material of the
cigarette filter portion itself. Such filter materials include, but
are not limited to, fibrous filter materials including paper,
cellulose acetate fibers, and polypropylene fibers. This embodiment
is illustrated in FIG. 5, which shows a cigarette 2 comprised of a
tobacco rod 4 and a filter portion 6 in the form of a
plug-space-plug filter having a mouthpiece filter 8, a plug 16, and
a space 18. The plug 16 can comprise a tube or solid piece of
material such as polypropylene or cellulose acetate fibers. The
tobacco rod 4 and the filter portion 6 are joined together with
tipping paper 14. The filter portion 6 may include a filter
overwrap 11. The filter overwrap 11 containing traditional fibrous
filter material and flavored carbon particles can be incorporated
in or on the filter overwrap 11 such as by being coated thereon.
Alternatively, the flavored carbon particles can be incorporated in
the mouthpiece filter 8, in the plug 16, and/or in the space 18.
Moreover, the flavored carbon particles can be incorporated in any
element of the filter portion of a cigarette. For example, the
filter portion may consist only of the mouthpiece filter 8 and the
flavored carbon particles can be incorporated in the mouthpiece
filter 8 and/or in the tipping paper 14.
[0052] FIG. 6 shows a cigarette 2 comprised of a tobacco rod 4 and
filter portion 6. This arrangement is similar to that of FIG. 3
except the space 18 is filled with flavored carbon particles or a
plug 15 made of material such as fibrous polypropylene or cellulose
acetate containing the flavored carbon particles. As in the
previous embodiment, the plug 16 can be hollow or solid and the
tobacco rod 4 and filter portion 6 are joined together with tipping
paper 14. There is also a filter overwrap 11.
[0053] FIG. 7 shows a cigarette 2 comprised of a tobacco rod 4 and
a filter portion 6 wherein the filter portion 6 includes a
mouthpiece filter 8, a filter overwrap 11, tipping paper 14 to join
the tobacco rod 4 and filter portion 6, a space 18, a plug 16, and
a hollow sleeve 20. The flavored carbon particles can be
incorporated into one or more elements of the filter portion 6. For
instance, the surface-modified adsorbent can be incorporated into
the sleeve 20 or the flavored carbon particles can be filled into
the space within the sleeve 20. If desired, the plug 16 and sleeve
20 can be made of material such as fibrous polypropylene or
cellulose acetate containing flavored carbon particles. As in the
previous embodiment, the plug 16 can be hollow or solid.
[0054] FIGS. 8 and 9 show further modifications of the filter
portion 6. In FIG. 6, cigarette 2 is comprised of a tobacco rod 4
and filter portion 6. The filter portion 6 includes a mouthpiece
filter 8, a filter overwrap 11, a plug 22, and a sleeve 20, and the
flavored carbon particles can be incorporated in one or more of
these filter elements. In FIG. 9, the filter portion 6 includes a
mouthpiece filter 8 and a plug 24, and the flavored carbon
particles can be incorporated in one or more of these filter
elements. Like the plug 16, the plugs 22 and 24 can be solid or
hollow. In the cigarettes shown in FIGS. 6 and 7, the tobacco rod 4
and filter portion 6 are joined together by tipping paper 14.
[0055] Various techniques can be used to apply the flavored carbon
particles to filter fibers or other substrate supports. For
example, the flavored carbon particles can be added to the filter
fibers before they are formed into a filter cartridge, e.g., a tip
for a cigarette. The flavored carbon particles can be added to the
filter fibers, for example, in the form of a dry powder or a slurry
by methods known in the art. If the flavored carbon particles are
applied in the form of a slurry, the fibers are allowed to dry
before they are formed into a filter cartridge.
[0056] In another preferred embodiment, the flavored carbon
particles are employed in a hollow portion of a cigarette filter.
For example, some cigarette filters have a plug/space/plug
configuration in which the plugs comprise a fibrous filter material
and the space is simply a void between the two filter plugs. That
void can be filled with the flavored carbon particles of the
present invention. An example of this embodiment is shown in FIG.
5. The flavored carbon particles can be used in granular form or
loaded onto a suitable support such as a fiber or thread.
[0057] In another embodiment of the present invention, the flavored
carbon particles are employed in a filter portion of a cigarette
for use with a smoking device as described in U.S. Pat. No.
5,692,525, the entire content of which is hereby incorporated by
reference. FIG. 10 illustrates one type of construction of a
cigarette 100 which can be used with an electrical smoking device.
As shown, the cigarette 100 includes a tobacco rod 60 and a filter
portion 62 joined by tipping paper 64. The filter portion 62
preferably contains a tubular free-flow filter element 102 and a
mouthpiece filter plug 104. The free-flow filter element 102 and
mouthpiece filter plug 104 may be joined together as a combined
plug 110 with plug wrap 112. The tobacco rod 60 can have various
forms incorporating one or more of the following items: an overwrap
71, another tubular free-flow filter element 74, a cylindrical
tobacco plug 80 preferably wrapped in a plug wrap 84, a tobacco web
66 comprising a base web 68 and tobacco flavor material 70, and a
void space 91. The free-flow filter element 74 provides structural
definition and support at the tipped end 72 of the tobacco rod 60.
At the free end 78 of the tobacco rod 60, the tobacco web 66
together with overwrap 71 are wrapped about cylindrical tobacco
plug 80. Various modifications can be made to a filter arrangement
for such a cigarette incorporating the flavored carbon particles of
the invention.
[0058] In such a cigarette, the flavored carbon particles can be
incorporated in various ways such as by being loaded onto paper or
other substrate material which is fitted into the passageway of the
tubular free-flow filter element 102 therein. The flavored carbon
particles may also be deployed as a liner or a plug in the interior
of the tubular free-flow filter element 102. Alternatively, the
flavored carbon particles can be incorporated into the fibrous wall
portions of the tubular free-flow filter element 102 itself. For
instance, the tubular free-flow filter element or sleeve 102 can be
made of suitable materials such as polypropylene or cellulose
acetate fibers and the flavored carbon particles can be mixed with
such fibers prior to or as part of the sleeve forming process.
[0059] In another embodiment, the flavored carbon particles can be
incorporated into the mouthpiece filter plug 104 instead of in the
element 102. However, as in the previously described embodiments,
according to the invention, flavored carbon particles may be
incorporated into more than one component of a filter portion such
as by being incorporated into the mouthpiece filter plug 104 and
into the tubular free-flow filter element 102.
[0060] The filter portion 62 of FIG. 10 can also be modified to
create a void space into which the flavored carbon particles can be
inserted.
[0061] As explained above, the flavored carbon particles can be
incorporated in various support materials. When the flavored carbon
particles are used in filter paper, the particles may have an
average particle diameter of 10 to 100 .mu.m, preferably 30 to 80
.mu.m. When the surface-modified adsorbent is used in filter fibers
or other mechanical supports, larger particles may be used. Such
particles preferably have a mesh size from 10 to 70, and more
preferably from 20 to 50 mesh.
[0062] The amount of flavored carbon particles employed in the
cigarette filter by way of incorporation on a suitable support such
as filter paper and/or filter fibers depends on the amount of
constituents in the tobacco smoke and the amount of constituents
desired to be removed. As an example, the filter paper and the
filter fibers may contain from 10% to 50% by weight of the flavored
carbon particles.
[0063] An embodiment of the invention relates to a method of making
a cigarette filter, said method comprising: (i) providing flavored
carbon particles as described above, and (ii) incorporating the
flavored carbon particles into a cigarette filter. Any conventional
or modified methods for making a filter may be used to incorporate
the flavored carbon particles.
[0064] Another embodiment of the invention relates to a method of
making a cigarette, said method comprising: (i) providing a cut
filler to a cigarette making machine to form a tobacco rod; (ii)
placing a paper wrapper around the tobacco rod; (iii) providing a
cigarette filter comprising flavored carbon particles as described
above; and (iv) attaching the cigarette filter to the tobacco rod
to form the cigarette. In yet another embodiment, the invention
relates to a method of making a cigarette, said method comprising:
(i) adding flavored carbon particles as described above to a cut
filler; (ii) providing the cut filler comprising the flavored
carbon particles to a cigarette making machine to form a tobacco
rod; and (iii) placing a paper wrapper around the tobacco rod to
form the cigarette.
[0065] Examples of suitable types of tobacco materials which may be
used include flue-cured, Burley, Maryland or Oriental tobaccos, the
rare or specialty tobaccos, and blends thereof. The tobacco
material can be provided in the form of tobacco lamina; processed
tobacco materials such as volume expanded or puffed tobacco,
processed tobacco stems such as cut-rolled or cut-puffed stems,
reconstituted tobacco materials; or blends thereof. The invention
may also be practiced with tobacco substitutes.
[0066] In cigarette manufacture, the tobacco is normally employed
in the form of cut filler, i.e. in the form of shreds or strands
cut into widths ranging from about {fraction (1/10)} inch to about
{fraction (1/20)} inch or even {fraction (1/40)} inch. The lengths
of the strands range from between about 0.25 inches to about 3.0
inches. The cigarettes may further comprise one or more flavorants
or other additives (e.g. burn additives, combustion modifying
agents, coloring agents, binders, etc.) known in the art.
[0067] Techniques for cigarette manufacture are known in the art,
and may be used to incorporate the surface-modified adsorbent. The
resulting cigarettes can be manufactured to any desired
specification using standard or modified cigarette making
techniques and equipment. The cigarettes of the invention may range
from about 50 mm to about 120 mm in length. Generally, a regular
cigarette is about 70 mm long, a "King Size" is about 85 mm long, a
"Super King Size" is about 100 mm long, and a "Long" is usually
about 120 mm in length. The circumference is from about 15 mm to
about 30 mm in circumference, and preferably around 25 mm. The
packing density is typically between the range of about 100
mg/cm.sup.3 to about 300 mg/cm.sup.3, and preferably 150
mg/cm.sup.3 to about 275 mg/cm.sup.3.
[0068] While the invention has been described with reference to
preferred embodiments, it is to be understood that variations and
modifications may be resorted to as will be apparent to those
skilled in the art. Such variations and modifications are to be
considered within the purview and scope of the invention as defined
by the claims appended hereto.
[0069] All of the above-mentioned references are herein
incorporated by reference in their entirety to the same extent as
if each individual reference was specifically and individually
indicated to be incorporated herein by reference in its
entirety.
* * * * *