U.S. patent application number 12/000864 was filed with the patent office on 2008-09-11 for banded cigarette paper with reduced ignition propensity.
This patent application is currently assigned to Philip Morris USA Inc.. Invention is credited to Shalva Gedevanishvili, Ping Li, Peter J. Lipowicz, Yousef Mohajer, Firooz Rasouli, Weijun Zhang.
Application Number | 20080216852 12/000864 |
Document ID | / |
Family ID | 39589064 |
Filed Date | 2008-09-11 |
United States Patent
Application |
20080216852 |
Kind Code |
A1 |
Rasouli; Firooz ; et
al. |
September 11, 2008 |
Banded cigarette paper with reduced ignition propensity
Abstract
A cigarette made from cigarette paper comprising a base web and
at least one banded region comprising iron oxide nanoparticles. The
at least one banded region has a porosity less than a porosity of
the base web such that the at least one banded region exhibits a
slower burn rate compared to adjacent non-banded regions.
Inventors: |
Rasouli; Firooz;
(Midlothian, VA) ; Li; Ping; (Glen Allen, VA)
; Mohajer; Yousef; (Midlothian, VA) ; Lipowicz;
Peter J.; (Midlothian, VA) ; Gedevanishvili;
Shalva; (Richmond, VA) ; Zhang; Weijun;
(Richmond, VA) |
Correspondence
Address: |
BUCHANAN, INGERSOLL & ROONEY PC
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Assignee: |
Philip Morris USA Inc.
Richmond
VA
|
Family ID: |
39589064 |
Appl. No.: |
12/000864 |
Filed: |
December 18, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60877640 |
Dec 29, 2006 |
|
|
|
Current U.S.
Class: |
131/281 ;
131/365; 162/139 |
Current CPC
Class: |
A24D 1/025 20130101 |
Class at
Publication: |
131/281 ;
131/365; 162/139 |
International
Class: |
A24C 1/36 20060101
A24C001/36; A24D 1/02 20060101 A24D001/02; D21H 23/00 20060101
D21H023/00 |
Claims
1. Cigarette paper comprising: a base web; and at least one banded
region comprising an add-on material and a burn promoter, wherein
the burn promoter comprises iron oxide nanoparticles in sufficient
quantity to reduce statistical occurrence of self-extinguishment;
and wherein the at least one banded region has a porosity less than
a porosity of the base web such that the at least one banded region
exhibits a slower burn rate compared to adjacent non-banded
regions.
2. The cigarette paper of claim 1, wherein non-banded regions
adjacent the at least one banded region comprise iron oxide
nanoparticles.
3. The cigarette paper of claim 1, wherein iron oxide nanoparticles
are only present in the at least one banded region.
4. The cigarette paper of claim 1, wherein the add-on material
comprises cellulose.
5. The cigarette paper of claim 1, wherein the add-on material
comprises starch.
6. The cigarette paper of claim 5, wherein a ratio of iron oxide
nanoparticles to starch is in the range of 0.35-0.55.
7. A cigarette comprising: tobacco material; and a cigarette paper
wrapped around said tobacco material, said cigarette paper
comprising: a base web; and at least one banded region comprising
an add-on material and a burn promoter, wherein the burn promoter
comprises iron oxide nanoparticles in sufficient quantity to reduce
statistical occurrence of self-extinguishment; and wherein the at
least one banded region has a porosity less than a porosity of the
base web such that the at least one banded region exhibits a slower
burn rate compared to adjacent non-banded regions.
8. The cigarette of claim 7, wherein the cigarette does not
self-extinguish in free burn conditions.
9. The cigarette of claim 7, wherein the cigarette
self-extinguishes in the at least one banded region when in contact
with a combustible substrate.
10. A method of making a cigarette comprising: wrapping the
cigarette paper of claim 1 around tobacco cut filler to make a
tobacco rod; slicing the tobacco rod into segments; and optionally
attaching a filter to one of the segments.
11. A method of making cigarette paper comprising forming at least
one banded region comprising iron oxide nanoparticles on a base
web, wherein the at least one banded region has a porosity less
than a porosity of the base web such that the at least one banded
region exhibits a slower burn rate compared to adjacent non-banded
regions.
12. The method of claim 11, wherein the at least one banded region
comprises cellulose.
13. The method of claim 12, wherein the at least one banded region
is formed by discharging a slurry comprising iron oxide
nanoparticles and cellulose on the base web.
14. The method of claim 12, wherein the base web comprises iron
oxide nanoparticles.
15. The method of claim 14, wherein the at least one banded region
is formed by discharging a slurry comprising cellulose on the base
web.
16. The method of claim 11, wherein the at least one banded region
comprises starch.
17. The method of claim 16, wherein a ratio of iron oxide
nanoparticles to starch is in the range of 0.35-0.55.
18. The method of claim 16, wherein the at least one banded region
is formed by printing a composition comprising iron oxide
nanoparticles and starch on the base web or by printing a
composition comprising starch on the base web.
19. The method of claim 16, wherein the base web comprises iron
oxide nanoparticles.
20. A method of making a cigarette comprising: making cigarette
paper according to claim 11; wrapping the cigarette paper around
tobacco cut filler to make a tobacco rod; slicing the tobacco rod
into segments; and optionally attaching a filter to one of the
segments.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority under 35 U.S.C.
.sctn.119(e) to U.S. provisional Application No. 60/877,640, filed
Dec. 29, 2006, the entire content of which is incorporated herein
by reference.
SUMMARY
[0002] Provided is cigarette paper comprising a base web and at
least one banded region comprising a burn promoter in the form of
iron oxide nanoparticles. The at least one banded region has a
porosity less than a porosity of the base web such that the at
least one banded region exhibits a slower burn rate compared to the
burn rate of adjacent non-banded regions.
[0003] The at least one banded region may comprise a material
selected from the group consisting of cellulose, starch, alginate,
and polyvinyl acetate. Non-banded regions adjacent the at least one
banded region may comprise iron oxide nanoparticles or iron oxide
nanoparticles may only present in the at least one banded
region.
[0004] Also provided is a cigarette comprising the cigarette paper.
The cigarette preferably does not self-extinguish in free burn
conditions, but does self-extinguish in the at least one banded
region upon contacting a combustible substrate. Additionally
provided is a method of making a cigarette comprising wrapping the
cigarette paper around tobacco cut filler to make a tobacco rod,
slicing the tobacco rod into tobacco rod segments and optionally
attaching filters to the tobacco rod segments.
[0005] Further provided is a method of making cigarette paper
comprising forming at least one banded region comprising a burn
promoter in the form of iron oxide nanoparticles on a base web. The
at least one banded region has a porosity less than a porosity of
the base web such that the at least one banded region exhibits a
slower burn rate compared to adjacent non-banded regions.
[0006] In an embodiment, the at least one banded region comprises
cellulose. The at least one banded region may be formed by
discharging a slurry comprising iron oxide nanoparticles and
cellulose on the base web or the base web may comprise iron oxide
nanoparticles and the at least one banded region may be formed by
discharging a slurry comprising cellulose on the base web.
[0007] In an embodiment, the at least one banded region comprises
starch. The at least one banded region may be formed by printing a
composition comprising iron oxide nanoparticles and starch on the
base web or the base web may comprise iron oxide nanoparticles and
the at least one banded region may be formed by printing a
composition comprising starch on the base web.
[0008] In addition, provided is a method of making a cigarette
comprising making cigarette paper, wrapping the cigarette paper
around tobacco cut filler to make a tobacco rod, slicing the
tobacco rod into tobacco rod segments and optionally attaching
filters to the tobacco rod segments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an illustration of a partially unwrapped cigarette
including a base web and banded cigarette paper where the paper
width is exaggerated.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0010] It has been surprisingly discovered that cigarettes made
from cigarette paper having banded regions comprising iron oxide
nanoparticles as a burn promoter have statistically fewer
occurrences of self-extinguishment in free burn conditions, but
will pass American Society of Testing and Materials (ASTM) Standard
E2187-02b (i.e., self-extinguish upon contacting a combustible
substrate), which is incorporated herein in its entirety by this
reference thereto.
Banded Cigarette Paper
[0011] The presently disclosed banded cigarette paper may be
manufactured by a method and using an apparatus, such as that
disclosed in commonly owned U.S. Pat. No. 6,596,125, hereby
incorporated by referenced in its entirety, which relates to method
and apparatus for applying a predetermined pattern of add-on
material to a base web, preferably in the form of bands, and more
particularly, to a method and apparatus for producing cigarette
papers having banded regions of additional material. As disclosed
therein, the banded regions may exhibit a slower burn rate in
comparison to those regions of the base sheet between the banded
regions. Further disclosures related to banded cigarette paper
include commonly owned U.S. Pat. Nos. 5,417,228, 5,474,095, and
5,534,114, each hereby incorporated by reference in its
entirety.
[0012] Referring now to FIG. 1, the banded cigarette paper 12 is
wrapped about a column of tobacco to form the tobacco rod 20 of a
cigarette 10, which will at the banded regions 14 exhibit a slower
burn rate in comparison to those regions of the base web 16 between
the banded regions 14.
[0013] Accordingly, the banded regions 14 may be formed by
discharging or spraying a slurry containing an add-on material on
the base web 16. The base web 16 of the presently disclosed banded
cigarette paper 12 is preferably comprised of cellulosic pulp, such
as, for example, flax pulp or wood pulp. The add-on material in the
slurry may comprise, for example, additional pulp, starch,
alginate, cellulose, or polyvinyl acetate. The add-on material
preferably comprises cellulose.
[0014] Alternatively, the banded regions 14 may be formed by
printing, preferably gravure printing, an aqueous film-forming
composition on the base web. The film-forming composition may
include an add-on material in the form of a film-forming compound,
such as, for example, starch, preferably an oxidized starch,
alginate, carrageenan, guar gum, or pectin. The film-forming
compound preferably comprises starch. Optionally, the film-forming
compound may comprise one or more filler materials such as, for
example, calcium carbonate or citrate.
[0015] The permeability of the banded regions 14 of the presently
disclosed banded cigarette paper 12 is lower than the permeability
of adjacent non-banded regions. Thus, the static burn rate of a
cigarette comprising the presently disclosed banded cigarette paper
12 is substantially decreased in the banded regions 14, which have
decreased porosity. The rate of oxygen diffusion through the paper
in these regions is thereby decreased, retarding combustion of the
cigarette.
Burn Promoter
[0016] Incorporation of burn promoter into banded regions of the
cigarette paper lessens the statistical occurrences of
self-extinguishment in free burn conditions. The effectiveness of
the burn promoter is sensitive to oxygen level. Accordingly, as
oxygen is abundant in free burn conditions, the effectiveness of
the burn promoter is sufficient to overcome the self-extinguishing
characteristic of the banded regions of the cigarette paper.
Conversely, as oxygen is not abundant in the conditions of ASTM
E2187-02b, the effectiveness of the burn promoter is not sufficient
to overcome the self-extinguishing characteristic of the banded
regions of the cigarette paper.
[0017] Thus, the burn promoter may be incorporated into the add-on
material of the banded regions of the cigarette paper or added to
the banded regions of the cigarette paper separately from the
add-on material of the banded regions, either before or after
addition of the add-on material. Alternatively, it is contemplated
that the base web of the presently disclosed banded cigarette paper
may comprise the burn promoter and the add-on material of the
banded regions not comprise additional burn promoter.
[0018] The term "burn promoter" as used herein refers to any
substance known to increase the rate at which the smolder process
of such materials as paper, cloth and plastic takes place. Such a
substance may contribute to the free burn of a cigarette.
Preferably, a reduced ignition propensity cigarette
self-extinguishes when placed onto a surface, but continues to
smolder when the cigarette is freely suspended, such as within the
holder of an ashtray or held between puffs. This latter attribute
is known as "free burn." To that end, a burn promoter works to
maintain the balance between self-extinguishment and free burn.
[0019] The burn promoter comprises iron oxide nanoparticles, such
as, for example, NANOCAT.RTM. Superfine Iron Oxide (SFIO) by MACH
I, Inc. (King of Prussia, Pa.). By "nanoparticles" is meant that
the particles have an average particle size of less than a micron.
The preferred average particle size is less than about 100 nm, with
a preferred surface area of from about 20 m.sup.2/g to about 400
m.sup.2/g, more preferably from about 200 m.sup.2/g to about 300
m.sup.2/g.
Tobacco
[0020] Examples of suitable types of tobacco materials that may be
used include, but are not limited to, flue-cured tobacco, Burley
tobacco, Maryland tobacco, Oriental tobacco, rare tobacco,
specialty tobacco, genetically modified tobacco, blends thereof and
the like. The tobacco material may be provided in any suitable
form, including, but not limited to, 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, blends thereof, and the like.
Tobacco substitutes may also be used.
[0021] In traditional cigarette manufacture, the tobacco is
normally used in the form of cut filler, i.e., in the form of
shreds or strands cut into widths ranging from about 1/10 inch to
about 1/20 inch or even about 1/40 inch. The lengths of the strands
range from between about 0.25 inch to about 3.0 inches. The
cigarettes may further comprise one or more flavors, or other
suitable additives (e.g., burn additives, combustion modifying
agents, coloring agents, binders, etc.).
Cigarette Production
[0022] During cigarette production or fabrication, tobacco is
placed along strips of cigarette paper reaching up to 6,000 meters
in length. The paper is closed over the tobacco, making one long
article known as a "rod," ready to be sliced into individual
cigarette portions and these portions can be attached to filter rod
segments, which are cut into filtered cigarettes. For instance, a
continuous rod can be cut into segments, which are attached to
double length filter segments. A slicer then slits the lengths in
two, dividing the double length filter equally in half to form two
cigarettes.
EXAMPLES
[0023] In a free burn test, a cigarette having two banded regions
comprising cellulose, formed according to the process of spraying
add-on slurry discussed above and which exhibited a slower burn
rate compared to adjacent non-banded regions, self-extinguished at
the first banded region in horizontal free burn conditions. In
contrast, three cigarettes having two banded regions comprising
cellulose, also formed according to the process of spraying add-on
slurry discussed above and which exhibited a slower burn rate
compared to adjacent non-banded regions, but which further
comprised NANOCAT.RTM. SFIO, did not self-extinguish at the first
banded region in horizontal free burn conditions. The NANOCAT.RTM.
SFIO was added to the banded regions by applying a slurry
comprising 2.5 g of NANOCAT.RTM. SFIO, 20 mL water, and 20 mL
methanol on the banded regions using a cotton swab. After the first
banded region was burned through in horizontal free burn
conditions, each cigarette was placed on 10 sheets of Whatman No. 1
(150 mm) filter paper. Each cigarette self-extinguished at the
second banded region.
[0024] Five cigarettes having iron oxide painted on slurry banded
regions tested according to ASTM E2187-02b yielded 1 total burn and
4 self-extinguishments. Of the three cigarettes having two iron
oxide painted on slurry banded regions tested for
self-extinguishment in free burn conditions at 90 degrees from
horizontal, two cigarettes extinguished at the first banded region
and one cigarette burned through the first banded region and
extinguished at the second banded region. The two cigarettes that
extinguished at the first banded region were relit and tested for
self-extinguishment in free burn conditions at 45 degrees from
horizontal, resulting in total burns. Two additional cigarettes
having iron oxide painted on slurry banded regions tested for
self-extinguishment in free burn conditions at 45 degrees from
horizontal also resulted in total burns.
[0025] In Tables 1-3 an ASTM E2187-02b designation of "pass"
corresponds to a cigarette self-extinguishing before the filter
line, while an ASTM E2187-02b designation of "fail" corresponds to
cigarette burning all the way to the filter line. In Tables 1-3
"self-extinguishment" refers to testing for self-extinguishment in
free burn conditions, with a self-extinguishment designation of
"pass" corresponds to a cigarette burning all the way to the filter
line and a self-extinguishment designation of "fail" corresponds to
a cigarette self-extinguishing before the filter line.
[0026] Hand-made cigarettes having banded regions comprising
various NANOCAT.RTM. SFIO weight percentages were tested according
to ASTM E2187-02b and "self-extinguishment" in a horizontal
position, at 45 degrees from horizontal, and at 90 degrees from
horizontal (vertical). Each test was run on five cigarettes for
each NANOCAT.RTM. SFIO weight percentage. Thus, in Table 1, a
passage percentage of 100% refers to 5 out of 5, a passage
percentage of 80% refers to 4 out of 5, and a passage percentage of
0% refers to 0 out of 5. The NANOCAT.RTM. SFIO was applied to the
cigarettes according to the spraying process discussed above, with
the slurry comprising 1.5 weight % flax plus NANOCAT.RTM. SFIO, and
the balance being water with or without small amounts of
additives.
TABLE-US-00001 TABLE 1 Self- Extinguishment (Passage %) Iron Oxide
Iron Oxide/ ASTM E2187-02b 45 degrees from 90 degrees from (Weight
%) Flax (Passage %) Horizontal Horizontal Horizontal 0.23 0.156 100
100 100 100 0.45 0.300 100 80 100 80 0.67 0.448 0 100 100 100
[0027] Table 1 shows that increasing the ratio of iron oxide to
flax in the banded regions beyond an optimal level may lead to
increased self-extinguishment failure, and eventually to ASTM
E2187-02b failure.
[0028] Tables 2 and 3 relate to embodiments wherein the banded
regions are formed from film-forming compositions comprising
starch, as discussed above with different amounts of iron oxide.
Specifically, Table 2 provides results for testing of cigarettes
having banded regions comprising 18% FLOKOTE 64 (18 grams of
FLOKOTE 64/100 grams of water), an oxidized corn starch from
National Starch & Chemical Company (Bridgewater, N.J.), plus
NANOCAT.RTM. SFIO. While the banded regions were applied by
hand-brushing, in commercial production such banded regions would
preferably be applied by printing.
TABLE-US-00002 TABLE 2 18% FLOKOTE 64 with NANOCAT .RTM. SFIO Self-
Horizontal Extinguishment Iron Iron ASTM Self- at 90 degrees Oxide
Oxide/ E2187-02b Extinguishment from Horizontal (Grams) Starch Pass
Fail Pass Fail Pass Fail 0.9 0.05 3 0 0 3 0 3 1.8 0.10 3 0 0 3 0 3
2.7 0.15 3 0 0 3 0 3 3.6 0.20 3 0 1 2 0 3 5.4 0.30 3 0 1 2 0 3 7.2
0.40 2 1 3 0 1 2 8.1 0.45 3 0 3 0 0 3 9.0 0.50 2 1 3 0 2 1 9.9 0.55
2 1 3 0 3 0
[0029] According to Table 2, ratios of NANOCAT.RTM. SFIO to dry
starch of 0.05, 0.10, and 0.15 yielded passage rates of 100% (3 out
of 3) for ASTM E2187-02b, but only 0% (0 out of 3) for
self-extinguishment both at horizontal and at 90 degrees from
horizontal. Ratios of NANOCAT.RTM. SFIO to dry starch of 0.20 and
0.30 yielded passage rates of 100% (3 out of 3) for ASTM E2187-02b,
but only 33% (1 out of 3) for self-extinguishment at horizontal and
0% (0 out of 3) for self-extinguishment at 90 degrees from
horizontal. Thus, with 18% FLOKOTE 64, a ratio of NANOCAT.RTM. SFIO
to dry starch of 0.40-0.55 is preferable.
[0030] Table 3 provides results for testing of cigarettes having
banded regions comprising 30% FLO-MAX 8 (30 grams of FLO-MAX 8/100
grams of water), an oxidized tapioca starch from National Starch
& Chemical Company (Bridgewater, N.J.), plus NANOCAT.RTM. SFIO.
Although in this test the banded regions were applied by
hand-brushing, in commercial production such banded regions would
preferably be applied by printing.
TABLE-US-00003 TABLE 3 30% FLO-MAX 8 with NANOCAT .RTM. SFIO Self-
Horizontal Extinguishment Iron Iron ASTM Self- at 90 degrees Oxide
Oxide/ E2187-02b Extinguishment from Horizontal (Grams) Starch Pass
Fail Pass Fail Pass Fail 6.0 0.20 3 0 0 3 0 3 9.0 0.30 3 0 0 3 0 3
10.5 0.35 3 0 2 1 0 3 12.0 0.40 3 0 3 0 3 0 13.5 0.45 0 3 3 0 3
0
[0031] According to Table 3, ratios of NANOCAT.RTM. SFIO to dry
starch of 0.20 and 0.30 yielded passage rates of 100% (3 out of 3)
for ASTM E2187-02b, but only 0% (0 out of 3) for
self-extinguishment both at horizontal and at 90 degrees from
horizontal. Thus, with 30% FLO-MAX 8, a ratio of NANOCAT.RTM. SFIO
content to dry starch of 0.35-0.45 is preferable.
[0032] While various embodiments have been described, 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 claims appended hereto.
* * * * *