U.S. patent application number 11/653296 was filed with the patent office on 2007-05-24 for cigarette filter and cigarette provided with the same.
This patent application is currently assigned to Japan Tobacco Inc.. Invention is credited to Takashi Hasegawa.
Application Number | 20070113863 11/653296 |
Document ID | / |
Family ID | 35786237 |
Filed Date | 2007-05-24 |
United States Patent
Application |
20070113863 |
Kind Code |
A1 |
Hasegawa; Takashi |
May 24, 2007 |
Cigarette filter and cigarette provided with the same
Abstract
A cigarette filter includes a cigarette filter material to which
2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl is
added.
Inventors: |
Hasegawa; Takashi; (Tokyo,
JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
Japan Tobacco Inc.
|
Family ID: |
35786237 |
Appl. No.: |
11/653296 |
Filed: |
January 16, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP05/13659 |
Jul 26, 2005 |
|
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11653296 |
Jan 16, 2007 |
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Current U.S.
Class: |
131/334 ;
131/331 |
Current CPC
Class: |
A24D 3/14 20130101; A24D
3/163 20130101 |
Class at
Publication: |
131/334 ;
131/331 |
International
Class: |
A24D 3/06 20060101
A24D003/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 27, 2004 |
JP |
2004-219103 |
Claims
1. A cigarette filter comprising a cigarette filter material to
which 2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl is
added.
2. The cigarette filter according to claim 1, wherein the filter
material comprises activated carbon particles.
3. The cigarette filter according to claim 1, wherein 3 to 10 parts
by weight of 2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl
is added based on 100 parts by weight of the filter material.
4. A cigarette provided with a cigarette filter according to claim
1.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a Continuation Application of PCT Application No.
PCT/JP2005/013659, filed Jul. 26, 2005, which was published under
PCT Article 21(2) in Japanese.
[0002] This application is based upon and claims the benefit of
priority from prior Japanese Patent Application No. 2004-219103,
filed Jul. 27, 2004, the entire contents of which are incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a cigarette filter and a
cigarette provided with the same, and more specifically, to a
cigarette filter excellent in efficiency of removing nitrogen
oxides (NOx) in the mainstream smoke and a cigarette provided with
the same.
[0005] 2. Description of the Related Art
[0006] Nowadays, various requirements are imposed on cigarettes,
one of which is to decrease the amount of NOx in the mainstream
smoke of cigarettes (Jpn. Pat. Appln. KOKAI Publication No.
2002-119270). Jpn. Pat. Appln. KOKAI Publication No. 2002-119270
discloses a tobacco filter in which a procyanidin is incorporated
in filaments that form the filter.
[0007] However, it has been found that the conventional tobacco
filters are not capable of removing NOx from the mainstream smoke
to a satisfactory degree.
BRIEF SUMMARY OF THE INVENTION
[0008] Thus, it is an object of the present invention to provide a
cigarette filter that can efficiently remove nitrogen oxides from
the tobacco mainstream smoke, and a cigarette provided with such
filter.
[0009] According to the present invention, there is provided a
cigarette filter comprising a cigarette filter material to which
2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl is
added.
[0010] Further, according to the present invention, there is
provided a cigarette provided with a cigarette filter according to
the present invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0011] FIG. 1 is a graph showing the reduction rate of NO in the
mainstream smoke of cigarettes manufactured in Example 1, which
will be described later in detail, together with that of a
comparative example;
[0012] FIG. 2 is a graph showing the reduction rate of NO in the
mainstream smoke of cigarettes manufactured in Example 2, which
will be described later in detail, together with that of a
comparative example;
[0013] FIG. 3 is a graph showing the reduction rate of NO in the
mainstream smoke of cigarettes manufactured in Example 3, which
will be described later in detail, together with that of a
comparative example; and
[0014] FIG. 4 is a graph showing the reduction rate of NO in the
mainstream smoke of cigarettes manufactured in Example 4, which
will be described later in detail, together with that of a
comparative example.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The present invention will be described in more detail
below.
[0016] A cigarette filter according to the present invention
comprises a cigarette filter material to which
2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl (PTIO) is
added.
[0017] In the cigarette filter of the present invention, PTIO, an
effective ingredient for removing nitrogen oxides, is a compound
known per se (see, for example, Jpn. Pat. Appln. KOKAI Publication
No. 9-43153).
[0018] In the cigarette filter of the present invention, use may be
made, as the filter material, of cellulose acetate fiber tow,
filter paper and porous particulate carrier such as activated
carbon. In the case where cellulose acetate fiber tow is used as
the filter material, PTIO can be added by spraying PTIO onto the
fiber tow. When filter paper is used, PTIO can be impregnated into
the filter paper. The filter material thus obtained can be wrapped
with a wrapper by an ordinary method, and connected to an end of a
cigarette.
[0019] In the case where a porous particulate carrier such as
activated carbon is used as the filter material, PTIO is
impregnated in the porous particulate carrier, and then the thus
obtained PTIO-carrying particles are filled in a cavity as is known
in the art or added to a tow. More specifically as to the cavity
filling, a plain filter is provided to either end of a filter
wrapper paper pipe. The PTIO-carrying particles are filled in the
cavity between these plain filters. On the other hand, the addition
to the tow is carried out by a method similar to that used for
charcoal filters of commercially available cigarettes, that is, the
PTIO-carrying particles are dispersed between the fibers of the
acetate filter.
[0020] PTIO is added preferably in an amount of 3 to 10 parts by
weight, particularly preferably, 5 to 7 parts by weight based on
100 parts by weight of the filter material. PTIO significantly
reduces the amount of NO and NOx contained in the cigarette
mainstream smoke even under wet conditions, which are equivalent to
the actual smoking conditions.
[0021] The present invention will be described by way of Examples,
but the present invention should not be limited to the
Examples.
EXAMPLE 1
[0022] <Preparation of PTIO-Impregnated Activated Carbon>
[0023] 10 mg, 30 mg, 50 mg and 100 mg of PTIO (available from Wako
Pure Chemical Industries, Ltd.; CAS: 18390-00-6) were completely
dissolved in 2490 mg, 2470 mg, 2450 mg and 2400 mg of ethanol,
respectively, thus preparing PTIO ethanol solutions having a
concentration of 0.4% by weight, 1.2% by weight, 2% by weight and
4% by weight, respectively. To each of the ethanol solutions, 1 g
of coconut shell activated carbon (available from Japan
Envirochemicals Ltd; a specific surface area: about 1200
m.sup.2/g), which was dried in advance by heating at 200.degree. C.
in vacuo, was added, and stirred for 60 minutes using a test tube
mixer. Thereafter, the solvent ethanol was removed in a water bath
of 50.degree. C. while blowing nitrogen gas into the solution, and
then the resultant material was dried by heating at 120.degree. C.
in vacuo. Thus, PTIO-impregnated activated carbon was obtained. It
was measured that the PTIO-impregnated activated carbon obtained
using the ethanol solution having a PTIO concentration of 0.4% by
weight was impregnated with PTIO in an amount corresponding to 1%
of the weight of activated carbon (PTIO-impregnated activated
carbon I), the PTIO-impregnated activated carbon obtained using the
ethanol solution having a PTIO concentration of 1.2% by weight was
impregnated with PTIO in an amount corresponding to 3% of the
weight of activated carbon (PTIO-impregnated activated carbon II),
the PTIO-impregnated activated carbon obtained using the ethanol
solution having a PTIO concentration of 2% by weight was
impregnated with PTIO in an amount corresponding to 5% of the
weight of activated carbon (PTIO-impregnated activated carbon III),
and the PTIO-impregnated activated carbon obtained using the
ethanol solution having a PTIO concentration of 4% by weight was
impregnated with PTIO in an amount corresponding to 10% of the
weight of activated carbon (PTIO-impregnated activated carbon
IV).
[0024] <Manufacture of Cigarette Samples>
[0025] Commercially available American blend tobacco rods were used
as tobacco rods. Filter plugs in which PTIO-impregnated activated
carbons obtained above were cavity-filled were attached to one-end
sides of the tobacco rods respectively. The filter plugs had a
plain filter (made of cellulose acetate fiber tow) having a length
of 5 mm provided on both ends of each plug and 0 mg, 50 mg, 100 mg
and 200 mg of PTIO-impregnated activated carbon particles were
filled at closest packing. The plugs had no ventilation holes.
[0026] <Measurements of Amount of NO and NOx>
[0027] The cigarette samples obtained above were set on a smoking
machine (RM 26 available from Borgwaldt GmbH), and were burnt under
the following conditions.
[0028] Smoke suction volume: 17.5 mL/puff
[0029] Puffing time: 2 seconds/puff
[0030] Puff interval: 58 seconds
[0031] Number of times of puffing: 7 times
[0032] For each of 7 times of puffing (smoke suction) and an idle
running puff (one time after completion of burning), smoke having
passed though the Cambridge filter was diluted 20-fold (by
collecting it with an aluminum bag in which 17.5 mL.times.19=332.5
mL of nitrogen gas was injected in advance). Then, the
concentrations of NO and NOx were measured by the chemiluminescent
method. The weights of NO and NOx were calculated from the
concentrations obtained above, and the calculated weight values of
all the puffs and idle-running puff were summed up to obtain a
delivery amount per cigarette. For comparison purpose, a similar
cigarette sample was manufactured with activated carbon not
impregnated with PTIO, and the delivery amount per cigarette was
obtained in a similar manner. The NO and NOx reduction rates were
calculated based on the NO and NOx delivery amounts per cigarette
obtained similarly for a plain cigarette without the filter
connected thereto. The NO reduction rate (%) of each sample was
illustrated in FIG. 1. In FIG. 1, a line indicates the results
obtained in the case where the PTIO-impregnated activated carbon I
was used, a line b indicates the results obtained in the case where
the PTIO-impregnated activated carbon II was used, a line c
indicates the results obtained in the case where the
PTIO-impregnated activated carbon III was used, a line d indicates
the results obtained in the case where the PTIO-impregnated
activated carbon IV was used, and a line e indicates the results
obtained in the case where the activated carbon with no PTIO
impregnated was used.
[0033] From the results shown in FIG. 1, it can be seen that the
filters that contain PTIO-impregnated activated carbon particles
significantly reduce the amount of NO as compared to the activated
carbon particles that do not contain PTIO. In particular, the
activated carbons carrying 3 to 10% by weight of PTIO have a
remarkably high NO reduction effect. It should be noted that the
NOx reduction rate exhibited a tendency similar to those of the
above-described NO reduction rates.
EXAMPLE 2
[0034] PTIO-impregnated activated carbon II prepared in Example 1
was subjected to moisture absorption until it reaches the
equilibrium at a temperature of 22.degree. C. and a relative
humidity of 60%, and thus moisture-absorbed PTIO-impregnated
activated carbon III was obtained. Cigarettes were manufactured as
in Example 1 except that the moisture-absorbed PTIO-impregnated
activated carbon III was used, and the NO reduction rate in the
mainstream smoke was obtained. The results were illustrated in FIG.
2. In FIG. 2, a line a indicates the results obtained in the case
where the moisture-absorbed PTIO-impregnated activated carbon III
was used, and a line b indicates the results obtained in the case
where activated carbon obtained by similar moisture absorption
except that PTIO was not impregnated. From the results shown in
FIG. 2, it can be seen that when the moisture absorption is carried
out, the NO reduction rate is slightly lowered as compared to the
case of the dry PTIO-impregnated activated carbon III (Example 1);
however the NO amount is significantly reduced as compared to the
case where simple activated carbon is used, indicating that PTIO
will sufficiently have an effect of reducing the NO amount, even
under actual smoking (corresponding to filter ventilation of 50%).
It should be noted also here that the NOx reduction rate exhibited
a tendency similar to that of the NO reduction rate described
above.
EXAMPLE 3
[0035] The cigarette samples manufactured in Example 1 were burnt
under the same conditions as in Example 1 except that the smoke
suction volume was changed to 35 mL/puff. Cigarette samples using
activated carbon not impregnated with PTIO were burnt also at a
smoke suction volume of 35 mL/puff. The NO reduction rate in the
mainstream smoke was calculated. The results are illustrated in
FIG. 3. In FIG. 3, a line a indicates the results obtained in the
case where the PTIO-impregnated activated carbon III was used, and
a line b indicates the results obtained in the case where the
activated carbon without PTIO was used. From the results shown in
FIG. 3, it can be seen that when the smoke suction volume is
increased, the NO reduction rate is lowered as compared to the case
of Example 1; however the samples using the PTIO-impregnated
activated carbon III exhibits a significantly higher NO reduction
rate than that of the cigarette samples using the activated carbon
without PTIO. It should be noted also here that the NOx reduction
rate exhibited a tendency similar to that of the NO reduction rate
described above.
EXAMPLE 4
[0036] Cigarette samples similar to those of Example 2 (which used
moisture-absorbed PTIO) were burnt under the same conditions as
those in Example 3, and the NO reduction rate in the mainstream
smoke was calculated. With regard to cigarette samples using
activated carbon not impregnated with PTIO, the NO reduction rate
in the mainstream smoke was calculated. The results were
illustrated in FIG. 4. In FIG. 4, a line a indicates the results
obtained in the case where the PTIO-impregnated activated carbon
was used, and a line b indicates the results obtained in the case
where the activated carbon without PTIO was used. From the results
shown in FIG. 4, it can be seen that when the smoke suction volume
is increased, the NO reduction rate is lowered as compared to the
case of Example 2; however the samples using the PTIO-impregnated
activated carbon exhibits a significantly higher NO reduction rate
than that of the cigarette samples using the activated carbon
without PTIO. It should be noted also here that the NOx reduction
rate exhibited a tendency similar to that of the NO reduction rate
described above.
[0037] As described above, the cigarette filter of the present
invention can efficiently remove nitrogen oxides from the tobacco
mainstream smoke.
* * * * *