U.S. patent application number 10/946440 was filed with the patent office on 2005-08-04 for tobacco smoke filter.
Invention is credited to Lesser, Craig A., Von Borstel, Reid W..
Application Number | 20050166933 10/946440 |
Document ID | / |
Family ID | 22871662 |
Filed Date | 2005-08-04 |
United States Patent
Application |
20050166933 |
Kind Code |
A1 |
Lesser, Craig A. ; et
al. |
August 4, 2005 |
Tobacco smoke filter
Abstract
A tobacco smoke filter comprising a copper-containing porphyrin
or an iron analog of C.I. Reactive Blue 21 dye. A method of making
a first tobacco smoke filter segment, comprising the steps of
providing one or more than one substance; producing a mixture of
cellulose fiber, sodium sulfate, chlorine water and a substance;
heating the mixture for a sufficient time at one or more than one
temperature sufficient to covalently link the substance to the
cellulose fiber; and forming the cellulose fiber with covalently
bound substance into the first tobacco smoke filter segment. The
substance can be a copper-containing porphyrin or an iron analog of
C.I. Reactive Blue 21 dye.
Inventors: |
Lesser, Craig A.; (Malibu,
CA) ; Von Borstel, Reid W.; (Potomac, MD) |
Correspondence
Address: |
SHELDON & MAK, INC
225 SOUTH LAKE AVENUE
9TH FLOOR
PASADENA
CA
91101
US
|
Family ID: |
22871662 |
Appl. No.: |
10/946440 |
Filed: |
September 20, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10946440 |
Sep 20, 2004 |
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10380294 |
Mar 10, 2003 |
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6792953 |
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10380294 |
Mar 10, 2003 |
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PCT/US01/41997 |
Sep 4, 2001 |
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60232048 |
Sep 12, 2000 |
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Current U.S.
Class: |
131/334 ;
131/331; 131/332 |
Current CPC
Class: |
A24D 3/061 20130101;
A24D 3/16 20130101; A24D 3/14 20130101; A24B 15/282 20130101; A24D
3/10 20130101; B41J 2/17513 20130101 |
Class at
Publication: |
131/334 ;
131/331; 131/332 |
International
Class: |
A24D 003/06; A24B
015/18 |
Claims
What is claimed is:
1. A method of making a first tobacco smoke filter segment,
comprising the steps of: (a) providing one or more than one
copper-containing porphyrin; (b) producing a mixture of cellulose
fiber, sodium sulfate, chlorine water and the copper-containing
porphyrin; (c) heating the mixture for a sufficient time at one or
more than one temperature sufficient to covalently link the
copper-containing porphyrin to the cellulose fiber; and (d) forming
the cellulose fiber with covalently bound, copper-containing
porphyrin into the first tobacco smoke filter segment.
2. The method of claim 1, where the copper-containing porphyrin
provided is a copper phthalocyanine.
3. The method of claim 1, where the copper-containing porphyrin
provided is C.I. Reactive Blue 21 dye.
4. The method of claim 1, where the mixture of cellulose fiber and
the copper-containing porphyrin produced comprises a ratio of about
1.2:10 copper-containing porphyrin to cellulose fiber by
weight.
5. The method of claim 1, further comprising rinsing the mixture of
cellulose fiber with covalently bound, copper-containing porphyrin
after heating the mixture.
6. The method of claim 1, further comprising adding one or more
than one additional substance to the cellulose fiber with
covalently bound, copper-containing porphyrin.
7. The method of claim 6, where the one or more than one additional
substance is selected from the group consisting of activated
charcoal, chitin and lignin.
8. The method of claim 6, where the one or more than one additional
substance is selected from the group consisting of an antioxidant,
dry water, a humectant, microcapsules, a radical scavenger, a
surfactant and combinations of the preceding.
9. A method of making a smokable device comprising the steps of:
(a) providing a first tobacco smoke filter segment made according
to claim 1; and (b) affixing the first tobacco smoke filter segment
to a body of divided tobacco.
10. The method of claim 9, further comprising the step of affixing
a second tobacco smoke filter segment that is substantially free of
copper-containing porphyrin to the body of divided tobacco.
11. The method of claim 10, where the second tobacco smoke filter
segment affixed to the body of divided tobacco comprises cellulose
acetate fibers treated with triacetin.
12. A tobacco smoke filter comprising a first tobacco smoke filter
segment made according to claim 1.
13. A tobacco smoke filter comprising a first tobacco smoke filter
segment made according to claim 1, and further comprising a second
tobacco smoke filter segment that is substantially free of
copper-containing porphyrin.
14. A smokable device comprising the tobacco smoke filter according
to claim 12 affixed to a body of divided tobacco.
15. A smokable device comprising the tobacco smoke filter according
to claim 13 affixed to a body of divided tobacco.
16. A method of filtering tobacco smoke comprising the steps of:
(a) providing the smokable device of claim 14; (b) igniting the
body of divided tobacco such that smoke passes through the body of
divided tobacco and into the filter; and (c) allowing the smoke to
pass through the filter thereby filtering the smoke.
17. A method of filtering tobacco smoke comprising the steps of:
(a) providing the smokable device of claim 15; (b) igniting the
body of divided tobacco such that smoke passes through the body of
divided tobacco and into the filter; and (c) allowing the smoke to
pass through the filter thereby filtering the smoke.
18. A method of making a first tobacco smoke filter segment,
comprising the steps of: (a) providing one or more than one
copper-containing porphyrin; (b) producing a mixture of cellulose
fiber and the copper-containing porphyrin; (c) heating the mixture
for a sufficient time at one or more than one temperature
sufficient to covalently link the copper-containing porphyrin to
the cellulose fiber; (d) rinsing the mixture of cellulose fiber
with covalently bound, copper-containing porphyrin; and (e) forming
the cellulose fiber with covalently bound, copper-containing
porphyrin into the first tobacco smoke filter segment.
19. The method of claim 18, where the copper-containing porphyrin
provided is a copper phthalocyanine.
20. The method of claim 18, where the copper-containing porphyrin
provided is C.I. Reactive Blue 21 dye.
21. The method of claim 18, where the mixture of cellulose fiber
and the copper-containing porphyrin produced comprises a ratio of
about 1.2:10 copper-containing porphyrin to cellulose fiber by
weight.
22. The method of claim 18, where the mixture of cellulose fiber
and the copper-containing porphyrin further comprises sodium
sulfate and chlorine water.
23. The method of claim 18, further comprising adding one or more
than one additional substance to the cellulose fiber with
covalently bound, copper-containing porphyrin.
24. The method of claim 23, where the one or more than one
additional substance is selected from the group consisting of
activated charcoal, chitin and lignin.
25. The method of claim 23, where the one or more than one
additional substance is selected from the group consisting of an
antioxidant, dry water, a humectant, microcapsules, a radical
scavenger, a surfactant and combinations of the preceding.
26. A method of making a smokable device comprising the steps of:
(a) providing a first tobacco smoke filter segment made according
to claim 18; and (b) affixing the first tobacco smoke filter
segment to a body of divided tobacco.
27. The method of claim 26, further comprising the step of affixing
a second tobacco smoke filter segment that is substantially free of
copper-containing porphyrin to the body of divided tobacco.
28. The method of claim 27, where the second tobacco smoke filter
segment affixed to the body of divided tobacco comprises cellulose
acetate fibers treated with triacetin.
29. A tobacco smoke filter comprising a first tobacco smoke filter
segment made according to claim 18.
30. A tobacco smoke filter comprising a first tobacco smoke filter
segment made according to claim 18, and further comprising a second
tobacco smoke filter segment that is substantially free of
copper-containing porphyrin.
31. A smokable device comprising the tobacco smoke filter according
to claim 29 affixed to a body of divided tobacco.
32. A smokable device comprising the tobacco smoke filter according
to claim 30 affixed to a body of divided tobacco.
33. A method of filtering tobacco smoke comprising the steps of:
(a) providing the smokable device of claim 31; (b) igniting the
body of divided tobacco such that smoke passes through the body of
divided tobacco and into the filter; and (c) allowing the smoke to
pass through the filter thereby filtering the smoke.
34. A method of filtering tobacco smoke comprising the steps of:
(a) providing the smokable device of claim 32; (b) igniting the
body of divided tobacco such that smoke passes through the body of
divided tobacco and into the filter; and (c) allowing the smoke to
pass through the filter thereby filtering the smoke.
35. A method of making a smokable device comprising the steps of:
(a) providing a first tobacco smoke filter segment made by: (i)
providing one or more than one copper-containing porphyrin; (ii)
producing a mixture of cellulose fiber and the copper-containing
porphyrin; (ii) heating the mixture for a sufficient time at one or
more than one temperature sufficient to covalently link the
copper-containing porphyrin to the cellulose fiber; and (iv)
forming the cellulose fiber with covalently bound,
copper-containing porphyrin into the first tobacco smoke filter
segment; (b) affixing the first tobacco smoke filter segment to a
body of divided tobacco; and (c) affixing a second tobacco smoke
filter segment that is substantially free of copper-containing
porphyrin to the body of divided tobacco.
36. The method of claim 35, where the copper-containing porphyrin
provided is a copper phthalocyanine.
37. The method of claim 35, where the copper-containing porphyrin
provided is C.I. Reactive Blue 21 dye.
38. The method of claim 35, where the mixture of cellulose fiber
and the copper-containing porphyrin produced comprises a ratio of
about 1.2:10 copper-containing porphyrin to cellulose fiber by
weight.
39. The method of claim 35, where the mixture of cellulose fiber
and the copper-containing porphyrin further comprises sodium
sulfate and chlorine water.
40. The method of claim 35, further comprising rinsing the mixture
of cellulose fiber with covalently bound, copper-containing
porphyrin after heating the mixture.
41. The method of claim 35, further comprising adding one or more
than one additional substance to the cellulose fiber with
covalently bound, copper-containing porphyrin.
42. The method of claim 41, where the one or more than one
additional substance is selected from the group consisting of
activated charcoal, chitin and lignin.
43. The method of claim 41, where the one or more than one
additional substance is selected from the group consisting of an
antioxidant, dry water, a humectant, microcapsules, a radical
scavenger, a surfactant and combinations of the preceding.
44. The method of claim 35, where the second tobacco smoke filter
segment affixed to the body of divided tobacco comprises cellulose
acetate fibers treated with triacetin.
45. A smokable device made according to claim 35.
46. A method of filtering tobacco smoke comprising the steps of:
(a) providing the smokable device of claim 45; (b) igniting the
body of divided tobacco such that smoke passes through the body of
divided tobacco and into the filter; and (c) allowing the smoke to
pass through the filter thereby filtering the smoke.
47. A method of making a first tobacco smoke filter segment,
comprising the steps of: (a) providing an iron analog of C.I.
Reactive Blue 21 dye; (b) producing a mixture of cellulose fiber
and the iron analog of C.I. Reactive Blue 21 dye; (c) heating the
mixture for a sufficient time at one or more than one temperature
sufficient to covalently link the iron analog of C.I. Reactive Blue
21 dye to the cellulose fiber; and (d) forming the cellulose fiber
with covalently bound iron analog of C.I. Reactive Blue 21 dye into
the first tobacco smoke filter segment.
48. The method of claim 47, where the mixture of cellulose fiber
and the iron analog of C.I. Reactive Blue 21 dye further comprises
sodium sulfate and chlorine water.
49. The method of claim 47, further comprising rinsing the mixture
of cellulose fiber with covalently bound iron analog of C.I.
Reactive Blue 21 dye after heating the mixture.
50. The method of claim 47, further comprising adding one or more
than one additional substance to the cellulose fiber with
covalently bound, copper-containing porphyrin.
51. The method of claim 50, where the one or more than one
additional substance is selected from the group consisting of
activated charcoal, chitin and lignin.
52. The method of claim 50, where the one or more than one
additional substance is selected from the group consisting of an
antioxidant, dry water, a humectant, microcapsules, a radical
scavenger, a surfactant and combinations of the preceding.
53. A method of making a smokable device comprising the steps of:
(a) providing a first tobacco smoke filter segment made according
to claim 47; and (b) affixing the first tobacco smoke filter
segment to a body of divided tobacco.
54. The method of claim 53, further comprising the step of affixing
a second tobacco smoke filter segment that is substantially free of
iron analog of C.I. Reactive Blue 21 dye to the body of divided
tobacco.
55. The method of claim 54, where the second tobacco smoke filter
segment affixed to the body of divided tobacco comprises cellulose
acetate fibers treated with triacetin
56. A tobacco smoke filter comprising a first tobacco smoke filter
segment made according to claim 47.
57. A tobacco smoke filter comprising a first tobacco smoke filter
segment made according to claim 47, and further comprising a second
tobacco smoke filter segment that is substantially free of iron
analog of C.I. Reactive Blue 21 dye.
58. A smokable device comprising the tobacco smoke filter according
to claim 56 affixed to a body of divided tobacco.
59. A smokable device comprising the tobacco smoke filter according
to claim 57 affixed to a body of divided tobacco.
60. A method of filtering tobacco smoke comprising the steps of:
(a) providing the smokable device of claim 58; (b) igniting the
body of divided tobacco such that smoke passes through the body of
divided tobacco and into the filter; and (c) allowing the smoke to
pass through the filter thereby filtering the smoke.
61. A method of filtering tobacco smoke comprising the steps of:
(a) providing the smokable device of claim 59; (b) igniting the
body of divided tobacco such that smoke passes through the body of
divided tobacco and into the filter; and (c) allowing the smoke to
pass through the filter thereby filtering the smoke.
62. An iron analog of C.I. Reactive Blue 21 dye.
63. Paper impregnated with an iron analog of C.I. Reactive Blue 21
dye.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation of U.S. patent
application Ser. No. 10/380,294 entitled "Tobacco Smoke Filter,"
filed Mar. 10, 2003, now U.S. Pat. No. 6,792,953 issued Sep. 21,
2004 which claims priority from International Patent Application
PCT/US01/41997, entitled "Tobacco Smoke Filter," filed Sep. 4,
2001, which claims the benefit of U.S. Provisional Patent
Application 60/232,048, entitled "Cigarette Filter," filed Sep. 12,
2000; the contents of which are incorporated by reference herein in
its entirety.
BACKGROUND
[0002] It is widely known that tobacco smoke contains mutagenic and
carcinogenic compounds which cause substantial morbidity and
mortality to smokers. Examples of such substances include
polycyclic aromatic hydrocarbons (PAH) and nitrosamines.
[0003] Polycyclic aromatic hydrocarbons appear to cause toxicity by
intercalating within DNA molecules. Nitrosamines are electrophilic,
alkylating agents which are potent carcinogens. Nitrosamines are
not present in fresh or green tobaccos and are not formed during
combustion. They are instead formed by reactions involving free
nitrate during processing and storage of tobacco, or by the
post-inhalation, metabolic activation of secondary amines present
in tobacco smoke.
[0004] Attempts to reduce the amount of toxic and mutagenic
compounds that reach the smoker include tobacco smoke filters
positioned between the burning tobacco and the smoker. Conventional
filters are made of cellulose acetate, with or without activated
charcoal. These conventional filters, however, are only partially
effective in reducing the amount of toxic and mutagenic compounds
reaching the smoker. Further, conventional filters
disadvantageously remove flavor compounds, thereby decreasing
acceptance by the smoker.
[0005] There is, therefore, a need for an improved filter for a
smokable device that substantially removes toxic and mutagenic
compounds from tobacco smoke. Further, there is a need for an
improved filter which allows the passage of flavor compounds while
substantially removing toxic and mutagenic compounds from tobacco
smoke. Such an improved filter would preferably be simple and
inexpensive to manufacture, and convenient to use.
SUMMARY
[0006] The present invention is directed to a tobacco smoke filter
that meets these needs. In one embodiment, there is provided a
method of making a first tobacco smoke filter segment. The method
comprises the steps of, first, providing one or more than one
copper-containing porphyrin. Then, a mixture of cellulose fiber and
the copper-containing porphyrin is produced. Next, the mixture is
heated for a sufficient time at one or more than one temperature
sufficient to covalently link the copper-containing porphyrin to
the cellulose fiber. Then, the cellulose fiber with covalently
bound, copper-containing porphyrin is formed into the first tobacco
smoke filter segment.
[0007] In one embodiment, the copper-containing porphyrin provided
is a copper phthalocyanine. In a preferred embodiment, the
copper-containing porphyrin provided is C.I. Reactive Blue 21 dye.
In another embodiment, the mixture of cellulose fiber and the
copper-containing porphyrin produced comprises a ratio of about
1.2:10 copper-containing porphyrin to cellulose fiber by weight. In
a preferred embodiment, the mixture of cellulose fiber and the
copper-containing porphyrin further comprises sodium sulfate and
chlorine water.
[0008] In one embodiment, The method further comprises rinsing the
mixture of cellulose fiber with covalently bound, copper-containing
porphyrin after heating the mixture. In another embodiment, the
method further comprising adding one or more than one additional
substance to the cellulose fiber with covalently bound,
copper-containing porphyrin. In one embodiment, the one or more
than one additional substance is selected from the group consisting
of activated charcoal, chitin and lignin. In another embodiment,
the one or more than one additional substance is selected from the
group consisting of an antioxidant, dry water, a humectant,
microcapsules, a radical scavenger, a surfactant and combinations
of the preceding.
[0009] According to one embodiment, there is provided a method of
making a smokable device. The method comprises the steps of, first,
providing a first tobacco smoke filter segment made according to
the present invention, and then affixing the first tobacco smoke
filter segment to a body of divided tobacco. The method can further
comprise the step of affixing a second tobacco smoke filter segment
that is substantially free of copper-containing porphyrin to the
body of divided tobacco. In a preferred embodiment, the second
tobacco smoke filter segment affixed to the body of divided tobacco
comprises cellulose acetate fibers treated with triacetin.
[0010] According to one embodiment of the present invention, there
is provided a tobacco smoke filter comprising a first tobacco smoke
filter segment made according to the present invention. The tobacco
smoke filter can also comprise a second tobacco smoke filter
segment that is substantially free of copper-containing porphyrin.
According to another embodiment, there is provided a smokable
device comprising the tobacco smoke filter according to the present
invention affixed to a body of divided tobacco.
[0011] According to one embodiment of the present invention, there
is provided a method of filtering tobacco smoke. The method
comprises the steps of providing the smokable device of according
to the present invention, igniting the body of divided tobacco such
that smoke passes through the body of divided tobacco and into the
filter, and allowing the smoke to pass through the filter thereby
filtering the smoke.
[0012] The present invention further comprises an iron analog of
C.I. Reactive Blue 21 dye and methods, tobacco smoke filters and
smokable devices of the present invention, where the iron analog of
C.I. Reactive Blue 21 dye is substituted for the copper-containing
porphyrin. Additionally, there is provided.
DESCRIPTION
[0013] According to one embodiment of the present invention, there
is provided a filter for tobacco smoke. The filter can be provided
in combination with cigarettes or cigars or other smokable devices
containing divided tobacco. Preferably, the filter is secured to
one end of the smokable device, positioned such that smoke produced
from the tobacco passes into the filter before entering the smoker.
The filter can also be provided by itself, in a form suitable for
attachment to a cigarette, cigar, pipe, or other smokable
device.
[0014] The filter according to the present invention advantageously
removes a significant proportion of mutagens and carcinogens from
cigarette smoke. The filter further retains satisfactory or
improved smoke flavor, nicotine content, and draw characteristics.
The filter is designed to be acceptable to the user, being neither
cumbersome nor unattractive as are commercially made filters which
are designed to add onto the ends of premade cigarettes. Further,
filters according to the present invention can be made of
inexpensive, safe and effective components, and can be manufactured
with only minor modifications of standard cigarette manufacturing
machinery.
[0015] According to one embodiment of the present invention, the
filter comprises a porous substrate. The porous substrate can be
any nontoxic material suitable for use in filters for smokable
devices that are also suitable for incorporation with the other
substances according to embodiments of the present invention. Such
porous substrates include cellulosic fiber such as cellulose
acetate, cotton, wood pulp, and paper; and polyesters, polyolefins,
ion exchange materials and other materials as will be understood by
those with skill in the art with reference to this disclosure.
[0016] Filter Containing a Humectant
[0017] According to one embodiment of the present invention, the
filter comprises at least one humectant, with or without other
substances disclosed in this disclosure. The humectant is capable
of absorbing moisture from tobacco smoke and releasing it into the
porous substrate in order to wet-filter tobacco smoke that passes
through the filter. Among other advantages, wet-filtration systems
according to the present invention help remove particulate matter
from tobacco smoke and can be made integral with a tobacco
containing product.
[0018] The humectant can be any suitable humectant. For example,
the humectant can be selected from the group consisting of
glycerol, sorbitol, propylene glycol, sodium lactate, calcium
chloride, potassium phosphate, sodium pyrophosphate or sodium
polyphosphate, calcium citrate, calcium gluconate, potassium
citrate, potassium gluconate, sodium tartrate, sodium potassium
tartrate, and sodium glutamate.
[0019] In a preferred embodiment, the humectant incorporated into
the filter is sodium pyroglutamate (also known as sodium
2-pyrrolidone-5-carboxylate or NaPCA). Advantageously, sodium
pyroglutamate is nontoxic, effective at removing charged particles
from tobacco smoke and functions as a humectant in the temperature
range of tobacco smoke. Further, it is nonhazardous, stable, simple
to manufacture and convenient to use. Sodium pyroglutamate has the
following structure: 1
[0020] Filters according to the present invention are simple and
inexpensive to manufacture. In one method of manufacture, a
solution containing the humectant, such as sodium pyroglutamate, is
prepared. Then, the porous substrate is wetted with the solution.
The wetted substrate is then dried, leaving a residue of the
humectant dispersed on or in the porous substrate. In a preferred
embodiment, the humectant is present in an amount of from about 5%
to about 60% by dry weight of the filter.
[0021] The effectiveness of a tobacco smoke filter containing
sodium pyroglutamate according to the present invention was tested
as follows.
[0022] Three types of filters were tested for relative
effectiveness in removing tar from cigarette smoke:
[0023] 1) Conventional cellulose acetate filter ("Cell-Ac");
[0024] 2) Wet-filtration tobacco smoke filter containing cellulose
acetate with sodium pyroglutamate ("SoPyro") according to the
present invention; and
[0025] 3) Commercially available wet-filtration tobacco smoke
filter (Aquafilter.RTM., Aquafilter Corp.).
[0026] Cellulose acetate filters containing sodium pyroglutamate
were prepared by, first, removing cellulosic filters from
commercial cigarettes. The fibers weighed approximately 0.21 g.
Next, approximately 0.5 mL of a 10% by weight solution of sodium
pyroglutamate was applied to each filter, and the filter was dried
overnight at 60.degree. C.
[0027] The conventional cellulose acetate filter and the cellulose
acetate filters containing sodium pyroglutamate were weighed and
inserted into a 40 mm segment of polycarbonate tubing having an
inside diameter identical to the outside diameter of a standard
cigarette. A filterless cigarette having 0.85 g of tobacco was
inserted into one end of the polycarbonate tubing in proximity to
one end of the filter. The other end of the polycarbonate tubing
was attached to tubing connected to a suction pump. Duplicates of
each filter type were tested. Each Aquafilter.RTM. used in this
test was also attached to a filterless cigarette having 0.85 g of
tobacco and then attached to tubing connected to a suction
pump.
[0028] The filtered cigarettes were lit and intermittent suction,
simulating inhalation of cigarette smoke, was applied until the
cigarette had burned to within 12.5 mm of the unlit end. The
filters were removed from either the polycarbonate tube or were
removed from the Aquafilter.RTM., weighed, and placed in 10 mL of
methanol to elute tar and other substances from the smoke that were
retained in the filter. Light absorbance (at a wavelength of 350
nm) of the ethanolic filter eluates was used as an index of the
amount of smoke components retained on the filters. The weight
gained by the filters during smoke passage was also recorded. The
results of the test are presented in Table 1.
1TABLE 1 TEST FILTER ABSORBANCE at 350 nm Weight Gain 1 Cell-Ac
0.470 A.U. 35 mg 2 Cell-Ac 0.381 A.U. 30 mg 3 SoPyro 0.731 A.U. 71
mg 4 SoPyro 0.625 A.U. 60 mg 5 Aquafilter .RTM. 0.540 A.U. * 6
Aquafilter .RTM. 0.560 A.U. * * The weight gain due to absorbance
of smoke components on the Aquafilter could not be determined,
since the Aquafilter actually lost weight during passage of smoke,
presumably due to evaporation of water.
[0029] Based on the absorbance data, the filters according to one
embodiment of the present invention (Tests 3 and 4) are
significantly more effective than conventional cellulose acetate
filters without the humectant (Tests 1 and 2), and also more
effective than the Aquafilter.RTM. (Tests 5 and 6).
[0030] Filter Containing Dry Water
[0031] According to another embodiment of the present invention,
there is provided a filter for wet-filtering tobacco smoke
comprising "dry water," with or without other substances disclosed
in this disclosure. Dry water is a combination of methylated silica
and water. In one embodiment, the methylated silica is present in
an amount from about 5% to 40% and the water is present in an
amount from about 60% to 95% by weight. In a preferred embodiment,
the methylated silica is present in an amount of about 10% and the
water is present in an amount of about 90% by weight.
Advantageously, dry water has good stability when used in a filter
according to the present invention. Further, it is inexpensive,
nontoxic and not harmful to the environment.
[0032] In a preferred embodiment, dry water is present in an amount
of about 1% to about 20% by weight of the filter. In a particularly
preferred embodiment, dry water is present in an amount of about 5%
to about 10% by weight of the filter.
[0033] Dry water for use with the present invention can be made,
for example, by shaking excess water with methylated silica in a
closed container until an equilibrium emulsion is achieved. Excess
water is decanted, and a drying agent, such as non-derivatized
silica, is added in amounts equivalent to 10% of the amount of
methylated silica in the emulsion. The emulsion is further shaken
to disperse the drying agent.
[0034] One problem associated with the use of dry water in a
tobacco smoke filter is that, when present as a continuous layer
between the tobacco and the smoker, dry water tends to clog pores
in the filter, thereby increasing resistance to airflow and
decreasing smoking pleasure. In order to overcome this problem,
there is provided an embodiment of the present invention having dry
water admixed with a loose fibrous material. This additional
fibrous material provides scaffolding to reduce impaction of silica
particles into the filter material when suction is applied by the
smoker. Examples of such material include cellulose or cellulose
acetate having fiber lengths short enough such that the dry water
behaves as a flowable powder. In a preferred embodiment, the fiber
length is less than about 1 mm. In a preferred embodiment, the
tobacco smoke filter according to the present invention includes
both a porphyrin, as discussed in this disclosure, in addition to
the dry water. For example, a tobacco smoke filter according to the
present invention includes a section of between about 3 mm and 6 mm
filled with dry water, chlorophyllin and cellulose, within the
filter or at the distal end of the filter between the conventional
filter material and the tobacco. Tobacco smoke in such a filter
passes through the dry water and porphyrin which retain
carcinogenic smoke constituents within the dry water and
chlorophyllin layer.
[0035] Tobacco smoke filters according to this aspect of the
present invention can be made by adding a dry water and porphyrin
mixture during manufacture of the filter or can be made by
injecting the mixture into the filter or at the interface between
the tobacco and the conventional filter. The dry water and
porphyrin mixture can be injected either into the axial end of the
filter or through the side of the smokable device, such as through
a cannula attached to an injection device. Preferably, the
injection device meters the amount of material administered per
each injection.
[0036] Alternately, the dry water and porphyrin mixture can be
included in a filter extension for attachment to a conventional
smokable device such as a standard cigarette, or to a cigarette
filter by the smoker. The filter extension comprises a layer of dry
water and porphyrin and, preferably, a fibrous material as a
matrix. The filter extension further comprises a sleeve which
extends axially forward for fitting over the proximal end of the
smokable device. The sleeve is bounded by a porous retaining
element to maintain the dry water and porphyrin within the filter
extension. Preferably, the sleeve further comprises a length of
conventional filter material such that, upon connection to the
smokable device, the filter extension and smokable device appear to
substantially be a conventional smokable device.
[0037] Filters Containing a Copper-containing Porphyrin
[0038] According to another embodiment of the present invention,
there is provided a cigarette filter comprising at least one
porphyrin, such as chlorophyll, with or without other substances
disclosed in this disclosure. Preferably, the porphyrin is a
copper-containing porphyrin, such as chlorophyllin and copper
phthalocyanine trisulfonate (copper phthalocyanine, copper
phthalocyanate).
[0039] Porphyrins are planar compounds which inactivate several
classes of mutagens and carcinogens. Porphyrins inactivate planar
mutagens and carcinogens primarily by binding the carcinogen to the
planar porphyrin structure through hydrophobic interactions.
Therefore, porphyrins ideally need to be maintained in aqueous
environments to optimally adsorb these tobacco smoke carcinogens.
Porphyrins further inactivate carcinogens by binding polycyclic
aromatic hydrocarbons (PAH) through .pi.-.pi. (pi-pi) bonding. The
copper-containing porphyrins also inactivate many classes of
non-planar mutagens and carcinogens including some nitrosamines
through reaction with the copper ion. While known to inactivate
various carcinogens, it has not been known how to effectively
utilize porphyrins in tobacco smoke filters.
[0040] Chlorophyllin is a naturally occurring, copper-containing
porphyrin and is the stable form of chlorophyll in which the
magnesium present in chlorophyll has been replaced by copper.
Chlorophyllin has the following formula: 2
[0041] Chlorophyllin, however, is difficult to chemically link to
tobacco smoke filter components. Therefore, in a preferred
embodiment, the copper-containing porphyrin incorporated into the
tobacco smoke filter is copper phthalocyanine. Copper
phthalocyanine is a nontoxic, synthetic chlorophyllin analog which
can be more easily linked to tobacco smoke filter components than
chlorophyllin. Copper phthalocyanine has the following formula:
3
[0042] In one embodiment, the copper-containing porphyrin, such as
copper phthalocyanine, is incorporated into a tobacco smoke filter
by directly adding the copper-containing porphyrin to the tobacco
smoke filter. In a preferred embodiment, the copper phthalocyanine
can be incorporated into a tobacco smoke filter as a covalently
bound ligand to cotton, such as the textile dye "blue cotton," or
as a covalently bound ligand to rayon, such as "blue rayon," or as
a covalently bound ligand to other suitable material as will be
understood by those in the art with reference to this disclosure.
In another preferred embodiment, copper phthalocyanine can be
incorporated into a tobacco smoke filter in combination with other
tobacco smoke filter embodiments of the present invention.
[0043] Copper-containing porphyrin is preferably attached to
cellulosic fibers in the form of an activated reagent called C.I.
Reactive Blue 21 dye, a vinylsulfone derivative of copper
phthalocyanine trisulfonate, as described in Hayatsu, Journal of
Chromatography, 597: 37-56 (1992), incorporated in this disclosure
by reference in its entirety, which forms a stable ether linkage to
free hydroxyl groups on cellulosic fibers to form "blue cellulose"
or other materials under mild conditions (unlike
chlorophyllin).
[0044] Cellulose is the base material used to manufacture tobacco
smoke filters. The standard form of cellulose used for
manufacturing tobacco smoke filters is cellulose acetate fibers,
made by treating cellulose with acetic anhydride. This reaction
replaces the free hydroxyl groups present on natural cellulose with
more hydrophobic acetate groups. The cellulose acetate is then
treated with triacetin (glycerol triacetate), a solvent that joins
some of the cellulose acetate fibers together because cellulose
acetate, unlike cellulose is partially soluble in triacetin.
Disadvantageously, however, replacing the hydroxyl groups with
acetate groups and treating the cellulose with triacetin greatly
diminishes the number of potential attachment sites for
copper-containing porphyrin molecules and renders triacetin
treated-cellulose acetate less desirable as a base material for
tobacco smoke filters that untreated cellulose.
[0045] Therefore, according to one embodiment of the present
invention, there is provided a tobacco smoke filter comprising one
or more than one segment, that is, at least a first segment. The
first segment comprises copper-containing porphyrin and cellulose
that has not been treated with acetic anhydride or triacetin.
Preferably, the tobacco smoke filter further comprises a second
segment that comprises cellulose acetate treated with triacetin but
that is substantially free of copper-containing porphyrin.
[0046] In a preferred embodiment, the copper-containing porphyrin
in the first segment is present in an amount of from about 0.1% to
about 5% by dry weight of the filter covalently bound. In a
particularly preferred embodiment, the copper-containing porphyrin
in the first segment is present in an amount of from about 1% to
about 3% by dry weight of the filter.
[0047] In one embodiment of the present invention, there is
provided a smokable device comprising a body of divided tobacco
affixed to a tobacco smoke filter comprising the first segment.
Preferably, the smokable device comprises the first segment
adjacent the body of divided tobacco and a second segment adjacent
that is at the proximal end of the smokable device. This
configuration advantageously allows a user of the smokable device
to draw smoke directly through the second segment of the tobacco
smoke filter, thereby obtaining a convention feel while using the
smokable device.
[0048] In another embodiment of the present invention, there is
provided a method of making a tobacco smoke filter as disclosed in
this disclosure. The method produces a tobacco smoke filter
comprising copper-containing porphyrin, such as copper
phthalocyanine, that tends to stay uniformly dispersed in the
filter during the manufacturing process and as moisture accumulates
in the filter during the burning of the tobacco, and that tends not
to leach out of the filter during use.
[0049] The method comprises preparing the filter material from
cellulose or from other materials to which one or more than one
copper-containing porphyrin has been covalently bound. The filter
material is then made into tobacco smoke filters comprising at
least one segment of the material with covalently bound,
copper-containing porphyrin. The tobacco smoke filter can also
comprise one or more than one segment of material that is
substantially free of copper-containing porphyrin. The use of
filter material comprising covalently bound, copper-containing
porphyrin permits high speed, high-volume manufacturing of smokable
devices, such as cigarettes, incorporating a filter according to
the present invention using existing equipment.
[0050] The method comprises the steps of, first providing one or
more than one copper-containing porphyrin, such as copper
phthalocyanine. In a preferred embodiment, the copper-containing
porphyrin is a vinylsulfone derivative of copper phthalocyanine
trisulfonate, such as C.I. Reactive Blue 21 dye (ORCO.RTM. REACTIVE
Turquoise RP, available from Organic Dyestuffs Corporation, East
Providence, R.I. US).
[0051] The amounts of material given in the following steps are
relative amounts and are for example, only. The amounts would be
scaled upward for commercial production as will be understood by
those in the art with reference to this disclosure. After providing
the copper-containing porphyrin, a mixture is produced comprising a
ratio of about 1.2:10 copper-containing porphyrin to cellulose
fiber by weight, such as approximately 1.2 g of the
copper-containing porphyrin and approximately 10 g of cellulose
fiber of a grade suitable for use as paper-making pulp. The mixture
further comprises approximately 10 g of sodium sulfate in
approximately 200 mL of chlorine water. Then, the mixture is heated
to about 30.degree. C. for about 35 minutes, after which, the
temperature is raised to about 70.degree. C. for about 60 minutes
to complete the covalent binding of the copper-containing porphyrin
to the cellulose fiber. The mixture is then collected on a mesh and
rinsed thoroughly under running tap water, producing cellulose
fiber with covalently bound, copper-containing porphyrin. The
cellulose fiber with covalently bound, copper-containing porphyrin
is then formed into a segment of a tobacco smoke filter using
commercially available equipment. The filter is then attached to a
body of divided tobacco to produce a smokable device according to
the present invention. Additionally, the present invention
comprises copper-containing porphyrin impregnated paper made as
disclosed above, for use in making tobacco smoke filters or for
other uses.
[0052] The method of method of making a tobacco smoke filter can
further comprise adding one or more than one additional substance
to the tobacco smoke filter of the present invention in addition to
copper-containing porphyrin. In a preferred embodiment, the one or
more than one additional substance is chitin, a polysaccharide
derived from the shells of arthropods, because chitin particles
comprise a high density of free hydroxyl groups that can be
covalently attached to metal-porphyrin compounds, such as C.I.
Reactive Blue 21 dye. By dry weight, chitin can be covalently bound
to about four times as much C.I. Reactive Blue 21 dye as an
equivalent amount of cellulose. In a preferred embodiment, chitin
granules (available from Sigma Chemical Company, St. Louis, Mo. US)
are covalently bound to copper-containing porphyrin in method
equivalent to the reaction disclosed above in which the cellulose
is replaced with chitin. The amounts of material given in the
following steps are relative amounts and are for example, only. The
amounts would be scaled upward for commercial production as will be
understood by those in the art with reference to this disclosure.
This can be accomplished by, for example, dissolving 0.8 g C.I.
Reactive Blue 21 dye and 6.8 g sodium sulfate in 133 mL of
distilled water. Then, 2.0 g of chitin are added and the mixture is
stirred gently for 20 minutes at 30.degree. C. Next, 2.7 g of
sodium carbonate are added and the mixture is allowed to stand at
30.degree. C. for 15 minutes and is then heated from 30.degree. C.
to 70.degree. C. over the course of 20 minutes. The mixture is then
stirred while maintaining a temperature of 70.degree. C. for 60
minutes, to allow the linking reaction to go to completion. The
resulting copper phthalocyanine-derivatized chitin is collected in
a sintered glass filter and rinsed thoroughly with distilled water
to remove unreacted dye and the salts.
[0053] The copper-containing porphyrin covalently bound to chitin
can be incorporated into paper by mixing it with cellulose pulp in
a ratio of between about 1:20 and about 1:1 copper-containing
porphyrin covalently bound to chitin to cellulose by dry weight.
The cellulose can also comprise covalently bound copper-containing
porphyrin according to the present invention. The incorporation
comprises mixing the chitin with cellulose pulp in the initial step
of paper making, as the cellulose is being macerated in water
(before the pulp is laid out on a mesh, pressed and dried). The
chitin-impregnated cellulose can then be used for manufacture of
tobacco smoke filters according to the present invention.
[0054] In a preferred embodiment, the one or more than one
additional substance is activated charcoal or is lignin (a
constituent of wood produced as a byproduct of preparation of
cellulose paper pulp from wood). Either or both of these substances
can be added to cellulose covalently bound to copper-containing
porphyrin according to the present invention, especially for
fabrication of paper incorporating activated charcoal or lignin.
When present, activated charcoal or lignin is added to the
cellulose in the same manner and ratio as chitin disclosed
above.
[0055] Further, in a preferred embodiment the filter produced as
disclosed above is attached to a tobacco smoke filter made of
standard cellulose acetate fibers treated with triacetin to produce
a filter comprising at least two segments. Preferably, the segment
comprising cellulose acetate fibers treated with triacetin is
proximal, that is away from the lit end of the smokable device, to
the segment comprising copper-containing porphyrin impregnated
cellulose fibers, and the segment comprising copper-containing
porphyrin impregnated cellulose fibers is between the body of
divided tobacco and the segment comprising cellulose acetate fibers
treated with triacetin.
[0056] The effectiveness of a two segment filter made according to
the present invention was tested as follows. Tobacco smoke filter
were prepared comprising two segments. Each proximal segment
comprised cellulose acetate fibers treated with triacetin. The
distal segment of one filter comprised copper phthalocyanine
impregnated cellulose fibers as disclosed above, while the distal
segment of the other filter comprised cellulose fibers that were
not treated with triacetin and that were not impregnated with a
copper-containing porphyrin. The two segment filters were then
placed in plastic tubing leaving approximately 0.5 cm of the tube
without the filter, and a 3 cm long rod of tobacco from a
Marlboro.RTM. cigarette was fitted into the 0.5 cm empty end of the
tubing abutting the filter to create smokable devices. The tobacco
was lit and the smokable devices were subjected to ten 20 mL puffs
with a suction pump, until the tobacco was burned down flush with
the end of the plastic tube. The filters were removed from the
tubes and placed in 10 mL of methanol containing ammonia in a 50:1
dilution to elute the retained polycyclic aromatic hydrocarbons
from the filters. The 10 mL extracts were evaporated down to 1 mL
and subjected to thin layer chromatography on aluminum oxide with 5
mL hexane. Total polycyclic aromatic hydrocarbon content was
estimated spectrofluorimeterically. The results indicated that the
two segment filter comprising copper phthalocyanine according to
the present invention retained 80 ng of polycyclic aromatic
hydrocarbons while the two segment filter without copper
phthalocyanine retained 6 ng of polycyclic aromatic hydrocarbons.
This 13-fold increase is particularly significant in that the total
polycyclic aromatic hydrocarbons produced during combustion of the
tobacco rod is estimated to be between about 100 ng and 200 ng.
Therefore, the two segment filter according to the present
invention removed between about 40% and 80% of the total amount of
polycyclic aromatic hydrocarbons from the tobacco smoke.
[0057] In another embodiment, the tobacco smoke filter of the
present invention comprises an iron analog of the copper-containing
porphyrin rather than the copper-containing porphyrin. In a
preferred embodiment, the analog is an iron analog of C.I. Reactive
Blue 21 dye produced by acidification of the C.I. Reactive Blue 21
dye, addition of iron sulfate and then addition of a suitable base,
as will be understood by those in the art with reference to this
disclosure. Alternately, an iron salt, such as anhydrous iron
chloride, can be used instead of a copper salt during initial
synthesis of C.I. Reactive Blue 21 dye to produce an iron analog.
The iron analog of C.I. Reactive Blue 21 dye can also be used to
make paper impregnated with iron analog of C.I. Reactive Blue 21
dye, corresponding to the copper-containing porphyrin impregnated
paper as disclosed above, for use in making tobacco smoke filters
or for other uses.
[0058] Filter Containing Microcapsules
[0059] According to another embodiment of the present invention,
there is provided a filter for tobacco smoke comprising a porous
substrate having microcapsules dispersed in the porous substrate,
with or without other substances disclosed in this disclosure. The
microcapsules preferentially include an inner core with an outer
shell.
[0060] The cores of the microcapsules comprise at least one
vegetable oil. Suitable vegetable oils include at least one oil
selected from the group consisting of castor oil, cotton seed oil,
corn oil, sunflower oil, sesame oil, soybean oil, and rape oil. In
a preferred embodiment, the vegetable oil is safflower oil. Other
oils are also suitable, as will be understood by those with skill
in the art with reference to this disclosure. In a preferred
embodiment, the vegetable oil is present in an amount of from about
20% to about 80% by dry weight of the microcapsules, and more
preferably from about 30% to about 70% by dry weight of the
microcapsules.
[0061] In a preferred embodiment, the microcapsule cores also
contain a porphyrin, such as chlorophyllin, or another porphyrin
such copper phthalocyanine. When present, the chlorophyllin is
preferably present in an amount of from about 1% to about 10% by
dry weight of the microcapsules, and more preferably from about 2%
to about 5% by dry weight of the microcapsules.
[0062] In a preferred embodiment, the microcapsule shells comprise
a humectant. In a preferred embodiment, the humectant is sodium
pyroglutamate, though other humectants can be used as will be
understood by those with skill in the art with reference to this
disclosure. In a preferred embodiment, the humectant, such as
sodium pyroglutamate, is present in an amount of from about 10% to
about 90% by dry weight of the microcapsules, and more preferably
from about 20% to about 70% by dry weight of the microcapsules.
[0063] In another preferred embodiment, the microcapsule shells
also comprise methylcellulose. In a preferred embodiment, the
methylcellulose is present in an amount of from about 5% to about
30% by dry weight of the microcapsules, and more preferably from
about 10% to about 25% by dry weight of the microcapsules.
[0064] In another preferred embodiment, the microcapsule shells
comprises a polymeric agent such as polyvinylalcohol or polyvinyl
pyrrolidone, or can comprise both polyvinylalcohol and polyvinyl
pyrrolidone, in addition to methylcellulose or in place of
methylcellulose. In a preferred embodiment, the polymeric agent is
present in an amount of from about 2% to about 30% by dry weight of
the microcapsules, and more preferably from about 5% to about 20%
by dry weight of the microcapsules.
[0065] Compounds used in formulation of microcapsules according to
the present invention are available from a variety of sources known
to those with skill in the art, such as Sigma Chemical Co., St.
Louis, Mo. US.
[0066] Microcapsules suitable for use in the present invention can
be made according to a variety of methods known to those with skill
in the art. For example, microcapsules according to the present
invention can be produced by combining 200 g of vegetable oil with
500 g of an aqueous suspension comprising 25 g of low-viscosity
methylcellulose, 5 g of chlorophyllin, 50 g of sodium pyroglutamate
and 150 g of corn starch in water. The mixture is emulsified and
spray-dried to form microcapsules.
[0067] Microcapsules according to the present invention can be
formed by spray drying methods at the site of cigarette
manufacturing machinery by spraying onto sheets of cellulose
acetate filter tow before the tow is formed into cylindrical
filters. Alternatively, suitable microcapsules can be
premanufactured and added to sheets of cellulose acetate filter tow
by dropping the microcapsules onto the tow with a vibrating pan or
by other techniques as will be understood by those with skill in
the art with reference to this disclosure. Further, microcapsules
can be incorporated into prefabricated filters by sprinkling the
microcapsules into the filter tow before the tow is rolled and
shaped in rods of filter material.
[0068] As will be appreciated by those with skill in the art, the
manufacture of filters containing microcapsules according to the
present invention will require only minor modification of
conventional filter-cigarette manufacturing equipment. Further, the
manufacture of filters containing microcapsules according to the
present invention is only marginally more expensive than
conventional filters.
[0069] In use, the humectant portions of the microcapsules trap
moisture from tobacco smoke passing through the filter. Sodium
pyroglutamate is particularly preferred because it can be
incorporated into the filter in a dry form.
[0070] When present, the oil portions of the microcapsules trap
certain harmful volatile compounds like pyridine without impeding
the flow of flavor and aroma producing compounds. When present,
chlorophyllin is a potent inactivator of carcinogenic components of
tobacco smoke.
[0071] The methylcellulose portions of the microcapsules impart
structural stability to the microcapsules but disperse upon warming
and when exposed to moisture. Unlike most commonly used
viscosity-imparting substances, methylcellulose precipitates from
warm solutions. Further, it is soluble at lower temperatures than
most commonly used viscosity-imparting substances.
[0072] When tobacco smoke filters containing microcapsules
comprising a shell of sodium pyroglutamate and methylcellulose and
a core of vegetable oil and chlorophyllin, according to the present
invention, filter tobacco smoke, the microcapsules capture heat and
moisture from the tobacco smoke. The methylcellulose precipitates
into a fibrous material which increases the effective surface area
available for wet-filtration of the tobacco smoke. This allows the
moisture retained by the sodium pyroglutamate to rapidly disperse
into the filter material. The chlorophyllin partitions
approximately evenly between the aqueous and oil environments,
allowing increased inactivation of both particulate and vapor-phase
toxic and mutagenic compounds of tobacco smoke than if the
chlorophyllin was available in only one phase.
[0073] Filters Containing a Surfactant
[0074] In another preferred embodiment, the filters of the present
invention additionally comprise at least one surfactant to improve
the effectiveness of the tobacco smoke filter, with or without
other substances disclosed in this disclosure. In a particularly
preferred embodiment, the surfactant is present in an amount of
from about 0.1% to about 10%, and more preferably from about 0.1%
to about 2% by weight of the filter.
[0075] The surfactant is preferably nontoxic and can include one or
more of the following classes of compounds: (1) a polyoxyalkylene
derivative of a sorbitan fatty acid ester (i.e., polyoxyalkylene
sorbitan esters), (2) a fatty acid monoester of a
polyhydroxy-alcohol, or (3) a fatty acid diester of a polyhydroxy
alcohol, though other suitable surfactants will be understood by
those with skill in the art with reference to the disclosure in
this disclosure. Examples of suitable surfactants include
ethoxylates, carboxylic acid esters, glycerol esters,
polyoxyethylene esters, anhydrosorbitol esters, ethoxylated
anhydrosorbitol esters, ethoxylated natural fats, oils and waxes,
glycol esters of fatty acids, polyoxyethylene fatty acid amides,
polyalkylene oxide block copolymers, and poly(oxyethylene-consist
of-oxypropylene). Other suitable surfactants can also be used as
will be understood by those with skill in the art with reference to
the disclosure in this disclosure.
[0076] Filters Containing an Additional Substance
[0077] The filter can additionally include one or more other
substances which filter or inactivate toxic or mutagenic components
of tobacco smoke. Examples of such substances include antioxidant
and radical scavengers such as glutathione, cysteine,
N-acetylcysteine, mesna, ascorbate, and
N,N'-diphenyl-p-phenyldiamine; aldehyde inactivators such as
ene-diol compounds, amines, and aminothiols; nitrosamine traps and
carcinogen inactivators such as ion-exchange resins, chlorophyll;
and nicotine traps such as tannic acid and other organic acids. In
one preferred embodiment, the filter includes colloidal silica, a
compound which can scavenge secondary amines from tobacco smoke,
thereby preventing conversion of the secondary amines to
nitrosamines in the body. Other suitable substances can also be
used as will be understood by those with skill in the art with
reference to the disclosure in this disclosure. In a preferred
embodiment, the other substances are present in an amount of from
about 0.1 to about 10%, and more preferably from about 0.1 to about
2% by weight of the filter.
[0078] Filters Having Certain Combinations of Substances Disclosed
in this Disclosure
[0079] According to another embodiment of the present invention,
there is provided a tobacco smoke filter comprising combinations of
substances disclosed in this disclosure. In a preferred embodiment,
the filter comprises a humectant, such as sodium pyroglutamate, in
combination with dry water. This combination functions
synergistically to improve wet-filtration of tobacco smoke. In one
embodiment, the filter comprises sodium pyroglutamate in an amount
of between about 1% and 20% of the aqueous portion of the dry water
by weight. In a preferred embodiment, the filter comprises sodium
pyroglutamate in an amount of between about 5% and 10% of the
aqueous portion of the dry water by weight.
[0080] In another preferred embodiment, the filter comprises a
copper-containing porphyrin, such as copper phthalocyanine, in
combination with a humectant such as sodium pyroglutamate, dry
water or both. These combinations are particularly preferred
because copper-containing porphyrins scavenge carcinogens better in
aqueous environments. In one embodiment, the copper-containing
porphyrin comprises between about 0.5% to about 5% of the dry water
by weight.
[0081] In another preferred embodiment, the filter comprises
chlorophyllin, in combination with a humectant, dry water or both.
In one embodiment, the chlorophyllin comprises between about 0.5%
to about 5% of the dry water and the humectant is between about 1%
and 20% of the dry water by weight.
[0082] A specific example of such a combination would be blue rayon
(copper phthalocyanine impregnated rayon) combined with dry water.
When present in an amount between about 10 mg to 100 mg in the 3 mm
tobacco end of a standard cellulose acetate tobacco smoke filter,
the combination does not impair draw but reduces mutagenicity of
tobacco smoke 75-80% by the Ames test. Further, these components
are inexpensive, safe, and not harmful to the environment.
[0083] Combinations of dry water and porphyrin are produced, for
example, by adding dry porphyrin in amounts up to the amount of
methylated silica by weight to dry water, made according the
description in this disclosure. The porphyrin must be added after
the dry water has been stably emulsified. Dissolution of porphyrin
in water prior to emulsification in methylated silica results in an
unstable porphyrin/dry water compound. In a preferred embodiment,
the porphyrin is added in amounts of about 0.1 to 0.5 grams per
gram of methylated silica. A similar method is used to produce the
combination of dry water and porphyrin-derivatized fiber, such as
blue cotton or blue rayon. After combining the two substances, the
combination is shaken or stirred to homogeneity.
[0084] Filters Having a Circumferential Barrier
[0085] Filters according to the present invention are preferably
provided with an exterior, circumferential, moisture-impervious
barrier or casing to prevent wetting of the smoker's hands. Such a
barrier can be made from a polymeric material such as ethylvinyl
acetate copolymer, polypropylene, or nylon, as is understood by
those with skill in the art.
[0086] Position of Substances within Filters
[0087] The substances disclosed in this disclosure can be
incorporated into filters according to the present invention in a
variety of configurations. For example, the substance or substances
can be dispersed throughout the filter in a substantially uniform
manner. Alternately, the substance or substances can be dispersed
in only one segment of the filter such as in the proximal third
(the end nearest the smoker), in the middle third or in the distal
third (the end nearest the tobacco).
[0088] In another embodiment, at least one substance is dispersed
in one segment of the filter and at least one other substance is
dispersed in a different segment of the filter. The two segments
can have overlapping areas. For example, a filter according to the
present invention can have dry water dispersed in the distal third
of the filter and a copper-containing porphyrin dispersed in the
proximal third of the filter. Also for example, a filter according
to the present invention can have microcapsules dispersed in the
distal half of the filter and sodium pyroglutamate dispersed in the
proximal two-thirds of the filter, such that the two substances are
dispersed in an overlapping area of the filter as well as
nonoverlapping areas.
[0089] In another embodiment, the substance or substances can be
incorporated into a filter that is then affixed to an end of a
standard tobacco smoke filter. In a preferred embodiment, the
substance or substances are incorporated into a tobacco smoke
filter that resembles a shortened version of a standard tobacco
smoke filter, and the shortened filter is then affixed to an end of
a standard tobacco smoke filter. In this embodiment, the user will
not be overtly aware of the additional shortened filter because of
its resemblance in construction to a standard filter, unlike
commercially available filters which add onto the proximal end of a
smokable device.
[0090] Further, the substance or substances according to the
present invention can be incorporated into a layer of the filter
between the fibrous material making up the remainder of the filter,
and the body of divided tobacco.
[0091] Smokable Devices Incorporating Filters According to the
Present Invention
[0092] According to another embodiment of the present invention,
there is provided a smokable device comprising a tobacco smoke
filter as disclosed in this disclosure affixed to a body of divided
tobacco. For example, such a smokable device can be a cigarette
incorporating a filter containing microcapsules having sodium
pyroglutamate dispersed in the porous substrate.
[0093] Method of Filtering Tobacco
[0094] According to another embodiment of the present invention,
there is provided a method of filtering tobacco in a smokable
device. The method comprises the steps of, first, providing a
smokable device comprising the tobacco smoke filter according to
the present invention affixed to a body of divided tobacco. Next,
the body of divided tobacco is ignited such that smoke passes
through the body and into the filter. Then, the smoke is allowed to
pass through the filter thereby filtering the smoke.
[0095] Method of Making a Smokable Device
[0096] According to another embodiment of the present invention,
there is provided a method of making a smokable device. The method
comprises the steps of, first, providing a tobacco smoke filter
according to the present invention. Next, the filter is affixed to
a body of divided tobacco.
[0097] Although the present invention has been discussed in
considerable detail with reference to certain preferred embodiments
thereof, other embodiments are possible. Therefore, the spirit and
scope of the appended claims should not be limited to the
description of the preferred embodiments contained in this
disclosure.
* * * * *