U.S. patent application number 12/813947 was filed with the patent office on 2010-09-30 for cigarette filter and filter-tipped cigarette.
Invention is credited to Masafumi TARORA, Atsusi TORII, Toru TSUJIMOTO.
Application Number | 20100242977 12/813947 |
Document ID | / |
Family ID | 40795404 |
Filed Date | 2010-09-30 |
United States Patent
Application |
20100242977 |
Kind Code |
A1 |
TARORA; Masafumi ; et
al. |
September 30, 2010 |
CIGARETTE FILTER AND FILTER-TIPPED CIGARETTE
Abstract
A single-segment filter having a filter plug uses a
high-rigidity and high-permeability paper longitudinal rigidity of
which is 30 or higher as measured in accordance with JIS P8143 and
air permeability of which is 1000 CORESTA units or greater as a
filter plug wrapper wrapping a filter material, and a multisegment
filter having a plurality of filter plugs uses the high-rigidity
and high-permeability paper as a filter plug wrapper wrapping a
filter material and/or a shaping paper joining plurality of filter
plugs. A cigarette comprises the particular filter.
Inventors: |
TARORA; Masafumi; (Tokyo,
JP) ; TORII; Atsusi; (Tokyo, JP) ; TSUJIMOTO;
Toru; (Tokyo, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
40795404 |
Appl. No.: |
12/813947 |
Filed: |
June 11, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2008/072074 |
Dec 4, 2008 |
|
|
|
12813947 |
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Current U.S.
Class: |
131/275 ;
131/202 |
Current CPC
Class: |
A24D 1/02 20130101; A24D
3/163 20130101; A24D 3/14 20130101; A24D 1/04 20130101; D21H 27/16
20130101 |
Class at
Publication: |
131/275 ;
131/202 |
International
Class: |
A24B 15/30 20060101
A24B015/30; A24F 1/20 20060101 A24F001/20 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 14, 2007 |
JP |
2007-323802 |
Claims
1. A cigarette filter comprising: a filter plug comprising a
cylindrical body of a filter plug wrapper which is cylindrically
shaped and a filter material disposed in the cylindrical body,
wherein the filter plug wrapper is formed of a high-rigidity and
high-permeability paper longitudinal rigidity of which is 30 or
higher as measured in accordance with JIS P8143 and air
permeability of which is 1000 CORESTA units or greater.
2. The cigarette filter according to claim 1, wherein the filter
plug contains activated charcoal particles.
3. A cigarette filter comprising: a plurality of filter plugs
comprising a most upstream filter plug and a most downstream filter
plug, each comprising a cylindrical body of a filter plug wrapper
which is cylindrically shaped and a filter material disposed in the
cylindrical body; and a shaping paper configured to wrap the
circumference of the plurality of filter plugs and join the
plurality of filter plugs to each other, wherein the filter plug
wrapper of at least one of the plurality of filter plugs is formed
of a high-rigidity and high-permeability paper longitudinal
rigidity of which is 30 or higher as measured in accordance with
JIS P8143 and air permeability of which is 1000 CORESTA units or
greater.
4. The cigarette filter according to claim 3, wherein the shaping
paper is formed of the high-rigidity and high-permeability
paper.
5. A cigarette filter comprising: a plurality of filter plugs
comprising a most upstream filter plug and a most downstream filter
plug, each comprising a cylindrical body of filter plug wrapper
which is cylindrically shaped and a filter material disposed in the
cylindrical body; and a shaping paper configured to wrap the
circumference of the plurality of filter plugs and join the
plurality of filter plugs to each other, wherein the shaping paper
is formed of a high-rigidity and high-permeability paper
longitudinal rigidity of which is 30 or higher as measured in
accordance with JIS P8143 and air permeability of which is 1000
CORESTA units or greater.
6. The cigarette filter according to claim 3, wherein a filter plug
disposed upstream of the most downstream filter plug contains
activated charcoal particles.
7. The cigarette filter according to claim 1, wherein the
longitudinal rigidity of the high-rigidity and high-permeability
paper is in the range of 30 to 400 and the air permeability of the
paper is in the range of 1000 to 30,000 CORESTA units.
8. The cigarette filter according to claim 1, wherein the filter
material of the filter plug having the high-rigidity and
high-permeability paper is formed of cellulose acetate fiber tow in
which a plasticizer is mixed in a ratio of 0% to less than 5% based
on the weight of the fiber tow.
9. The cigarette filter according to claim 1, wherein the filter
material of the filter plug having the high-rigidity and
high-permeability paper is formed of cellulose acetate fiber tow in
which a plasticizer is mixed in a ratio of 5 to 10% based on the
weight of the fiber tow.
10. The cigarette filter according to claim 1, wherein the filter
material of the filter plug having the high-rigidity and
high-permeability paper is formed of cellulose acetate fiber tow in
which a plasticizer is mixed in a ratio of more than 10% but 12% or
less based on the weight of the fiber tow.
11. The cigarette filter according to claim 1, wherein the filter
material does not contain any hardness increasing agent.
12. The cigarette filter according to claim 11, wherein the filter
material contains a paper.
13. The cigarette filter according to claim 1, further comprising a
flavor.
14. The cigarette filter according to claim 13, wherein the flavor
contains menthol.
15. The cigarette filter according to claim 1, wherein the
cylindrical body is extended out of the downstream end face of the
filter material so as to provide a recess portion.
16. The cigarette filter according to claim 3, wherein the shaping
paper is extended out of the downstream end face of the most
downstream filter plug so as to provide a recess portion.
17. A filter-tipped cigarette comprising: a cigarette main body
comprising a tobacco rod wrapped with a cigarette paper; and a
cigarette filter fitted to one end of the cigarette main body,
wherein the cigarette filter is formed of the cigarette filter of
claim 1.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a Continuation application of PCT Application No.
PCT/JP2008/072074, filed Dec. 4, 2008, 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. 2007-323802,
filed Dec. 14, 2007, 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
filter-tipped cigarette.
[0005] 2. Description of the Related Art
[0006] Filter-tipped cigarettes are developed and marketed to, for
example, milden the smoking taste. The filter-tipped cigarette
comprise a cigarette main body formed of a tobacco filler rod, such
as one comprising cut tobacco having the circumference thereof
wrapped with a cigarette paper, and a filter fitted to one end of
the cigarette main body. The filter has at least one filter plug.
In the filter plug, a filter material is disposed in a cylindrical
body formed of a wrapper (filter plug wrapper) shaped into a
cylindrical configuration (generally the configuration of a
circular cylinder). The filter is fitted to one end of the
cigarette main body by means of a tipping paper.
[0007] The filter hardness of the filter-tipped cigarette is a
parameter for the choice of cigarette by smokers. Most of now
commercially available filter-tipped cigarettes use a cellulose
acetate fiber bundle (tow) as a filter material (hereinafter also
referred to as cellulose acetate filter). As satisfactory filter
hardness cannot be obtained by the cellulose acetate fiber alone, a
plasticizer (for example, triacetin) is mixed therein so as to
impart hardness to the filter. It is known that the amount of
triacetin added to the cellulose acetate filter of now commercially
available filter-tipped cigarettes is in the range of 5 to 10% by
weight based on the amount of cellulose acetate.
[0008] Some smokers are satisfied with the current filter hardness
imparted by the addition of the above amount of triacetin, but some
smokers like harder filters.
[0009] It is known that with respect to the cellulose acetate
filter, the hardness thereof can be increased by increasing the
amount of plasticizer added. However, when the amount of triacetin
added is increased to a certain extent or over, the triacetin is
hydrolyzed to thereby generate acetic acid. Thus, there would occur
the problem that the interior of the cigarette package is filled
with the odor of acetic acid. Further, when a charcoal filter is
employed, there would occur the problem that triacetin is adsorbed
on the charcoal with the result that the function of the charcoal
(adsorption of smoke components) cannot be fully exerted.
[0010] With respect to the filter-tipped cigarettes, it is desired
for the ventilation ratio thereof to be high in order to permit the
inflow of ambient air for higher dilution of mainstream smoke.
[0011] A cigarette filter of high ventilation ratio, known as a
recessed cigarette filter, is disclosed in the pamphlet of
International Publication WO 00/00047. This cigarette filter
comprises, for example, two filter plugs both wrapped with a porous
or nonporous filter plug wrapper, the two filter plugs joined to
each other by means of a nonporous shaping paper. This filter is
fitted to a tobacco rod by means of a tipping paper. In order to
achieve a high ventilation ratio, the filter plug wrapper and the
shaping paper are provided with mechanically perforated relatively
large ventilation holes, and the tipping paper is provided with a
relatively small ventilation hole perforated by laser. The
ventilation holes would cause such problems that the cigarette
manufacturing cost is increased, the versatility to a variety of
cigarette products, including a low-tar cigarette or the like, is
lowered, and the stability of product quality is poor. These
problems are also pointed out for Jpn. PCT National Publication No.
2004-516814 disclosing a similar recessed filter.
[0012] In the pamphlet of International Publication WO 00/00047 and
Jpn. PCT National Publication No. 2004-516814, there is no direct
mention of the filter hardness.
BRIEF SUMMARY OF THE INVENTION
[0013] It is an object of the present invention to provide a
cigarette filter that can achieve satisfactory hardness and
ventilation ratio even when the filter plug wrapper and shaping
paper are not furnished with any ventilation hole and even when any
hardness increasing agent is not used therein, and to provide a
cigarette comprising such a cigarette filter.
[0014] According to a first aspect of the present invention, there
is provided a cigarette filter comprising: a filter plug comprising
a cylindrical body of a filter plug wrapper which is cylindrically
shaped and a filter material disposed in the cylindrical body,
wherein the filter plug wrapper is formed of a high-rigidity and
high-permeability paper longitudinal rigidity of which is 30 or
higher as measured in accordance with JIS P8143 and air
permeability of which is 1000 CORESTA units or greater.
[0015] According to a second aspect of the present invention, there
is provided a cigarette filter comprising: a plurality of filter
plugs comprising a most upstream filter plug and a most downstream
filter plug, each comprising a cylindrical body of a filter plug
wrapper which is cylindrically shaped and a filter material
disposed in the cylindrical body, and a shaping paper configured to
wrap the circumference of the plurality of filter plugs and join
the plurality of filter plugs to each other, wherein the filter
plug wrapper of at least one of the plurality of filter plugs is
formed of a high-rigidity and high-permeability paper longitudinal
rigidity of which is 30 or higher as measured in accordance with
JIS P8143 and air permeability of which is 1000 CORESTA units or
greater.
[0016] According to a third aspect of the present invention, there
is provided a cigarette filter comprising a plurality of filter
plugs comprising a most upstream filter plug and a most downstream
filter plug, each comprising a cylindrical body of filter plug
wrapper which is cylindrically shaped, a filter material disposed
in the cylindrical body, and a shaping paper configured to wrap the
circumference of the plurality of filter plugs and join the
plurality of filter plugs to each other, wherein the shaping paper
is formed of a high-rigidity and high-permeability paper
longitudinal rigidity of which is 30 or higher as measured in
accordance with JIS P8143 and air permeability of which is 1000
CORESTA units or greater.
[0017] Further, according to a fourth aspect of the present
invention, there is provided a filter-tipped cigarette comprising a
cigarette main body comprising a tobacco rod wrapped with a
cigarette paper and a cigarette filter fitted to one end of the
cigarette main body, wherein the cigarette filter is formed of the
cigarette filter of the present invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0018] FIG. 1 is a partially developed schematic perspective view
of a filter-tipped cigarette provided with a single-segment filter
according to an embodiment of the present invention.
[0019] FIG. 2 is a partially developed schematic perspective view
of a filter-tipped cigarette provided with a multisegment filter
according to an embodiment of the present invention.
[0020] FIG. 3 is a partially developed schematic perspective view
of a filter-tipped cigarette provided with a recessed
single-segment filter according to an embodiment of the present
invention.
[0021] FIG. 4 is a graph showing the hardness of each of cellulose
acetate filter plugs according to embodiments of the present
invention together with that of the conventional cellulose acetate
filter plug.
[0022] FIG. 5 is a graph showing changes of the hardness of a
cellulose acetate filter plug according to an embodiment of the
present invention together with that of the conventional cellulose
acetate filter plug brought about by changing the amount of
triacetin added.
[0023] FIG. 6 is a graph showing the hardness of each of paper
filter plugs according to embodiments of the present invention
together with that of the conventional paper filter plug.
[0024] FIG. 7 is a graph showing changes with time of the menthol
existence ratios in the cut tobacco and filter material with
respect to a cellulose acetate filter.
[0025] FIG. 8 is a graph showing changes with time of the menthol
existence ratios in the cut tobacco and filter material with
respect to a paper filter.
[0026] FIG. 9 is a graph showing changes with time of menthol
delivery into cigarette mainstream smoke with respect to each of a
cigarette with a cellulose acetate filter and a cigarette with a
paper filter.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The cigarette filter of the present invention encompasses a
so-called single-segment filter formed of a single filter plug and
a so-called multisegment filter comprising a plurality of filter
plugs including a most upstream filter plug and a most downstream
filter plug. In either case, each of the filter plugs includes a
cylindrical body, generally in the form of a circular cylinder, of
filter plug wrapper which is cylindrically shaped and a filter
material disposed in the cylindrical body. Illustratively, the
filter plug includes a filter material rolled up (wrapped) with a
filter plug wrapper. In the multisegment filter, the plurality of
filter plugs are wrapped with a shaping paper so as to be joined to
each other. In the present invention, the expressions "upstream"
and "downstream" are based on the direction of flow of tobacco
mainstream smoke passing through the interior of a cigarette.
[0028] In the present invention, the filter plug wrapper of the
single-segment filter is formed of a specified high-rigidity and
high-permeability paper. Also, in the multisegment filter of the
present invention, the filter plug wrapper of at least one filter
plug and/or the shaping paper is formed of a specified
high-rigidity and high-permeability paper.
[0029] The high-rigidity and high-permeability paper for use in the
present invention has a longitudinal rigidity (stiffness in the
longitudinal direction) of paper of 30 or higher as measured in
accordance with JIS P8143 (method of testing the stiffness of paper
by self-weight bending) and an air permeability of 1000 CORESTA
units or greater. Preferably, the high-rigidity and
high-permeability paper has a longitudinal rigidity of 30 to 400
and an air permeability of 1000 to 30,000 CORESTA units.
[0030] Examples of high-rigidity and high-permeability papers for
use in the present invention (represented by symbols S1 to S4) are
given in Table 1. Table 1 also includes a now generally employed
porous filter plug wrapper of high air permeability (conventional
filter plug wrapper, represented by symbol P).
TABLE-US-00001 TABLE 1 Type of Paper Conventional filter
High-rigidity and plug wrapper high-permeability paper Paper symbol
P S1 S2 S3 S4 Longitudinal rigidity 12.6-14.4 350 108 64 60
(L.sup.3/100) Air permeability 10000 2140 4080 7040 12670 (CORESTA
unit) Basis wt. (g/m.sup.2) 26.5 116 68 51 48 Thickness (.mu.m) 65
222 140 115 113
[0031] The case where cellulose acetate fiber tow is used as a
filter material will be described. As aforementioned, it is of
common practice to add a plasticizer, such as triacetin, to a
filter in an amount corresponding to 5 to 10% by weight based on
the weight of cellulose acetate fiber in order to impart a given
hardness to the filter. However, when the high-rigidity and
high-permeability paper according to the present invention is
employed, the same filter hardness as heretofore can be achieved
even by the addition of plasticizer in an amount corresponding to
less than 5% (including 0%) based on the weight of cellulose
acetate fiber. Needless to state, when the plasticizer is added to
the cellulose acetate fiber in the same amount corresponding to 5
to 10% based on the weight thereof as heretofore, the hardness over
the conventional filter can be achieved.
[0032] From the finding to now, it is understood that the addition
of triacetin in an amount of over 12% by weight will dissolve the
cellulose acetate fiber and will invite the problem of the
occurrence of acetic acid odor attributed to the decomposition of
triacetin. Accordingly, the upper-limit value of the conventional
filter hardness achieved without the occurrence of these problems
is the hardness corresponding to the addition of 12% by weight
triacetin. However, when the high-rigidity and high-permeability
paper according to the present invention is employed, the addition
of 12% by weight triacetin can achieve hardness over the
conventional upper-limit value. That is, the present invention can
be applied to the cellulose acetate filter having triacetin added
in an amount of over 10% by weight but not exceeding 12% by
weight.
[0033] The filter material of the cigarette filter of the present
invention is not limited to a cellulose acetate fiber. For example,
it is known in the art to use a filter obtained by shaping a
nonwoven fabric and a filter (paper filter) obtained by shaping a
paper (having undergone creping treatment) which are free of
hardness increasing agents (agents leading to an increase of filter
hardness), for example, a hardener inclusive of a plasticizer, such
as triacetin, and binders added to bind the filter material
together (for example, polyvinyl alcohol, polyvinyl acetate,
polyethylene glycol, dimethyl phthalate, diethyl phthalate and the
like). These filter materials can also be used in the present
invention.
[0034] It has been difficult for the filter material free of any
hardness increasing agent to achieve the filter hardness equivalent
to that of the cellulose acetate filter having triacetin mixed
therein. However, the filter hardness equivalent to or higher than
that of the cellulose acetate filter having triacetin mixed therein
can be achieved by the employment of the high-rigidity and
high-permeability paper according to the present invention.
[0035] The filter including the filter material free of any
hardness increasing agent exerts an additional advantage when it is
used in a filter-tipped cigarette having any of flavors (for
example, menthol, limonene, peppermint oil or spearmint oil; an
ester such as ethyl acetate, ethyl butyrate or ethyl benzoate; an
alcohol such as linalool, nerol or geraniol; a phenol such as
anethole; an aldehydes such as cinnamaldehyde or vanillin; a
lactone and a pyrazine), together with triacetin, sorbed in the
cellulose acetate fiber.
[0036] For example, in the current menthol cigarette, menthol is
mixed in cut tobacco, and a cellulose acetate filter containing
triacetin is fitted thereto. However, in the current cellulose
acetate filter, the menthol contained in the cigarette together
with triacetin is sorbed in the cellulose acetate fiber with time.
The menthol sorbed in the cellulose acetate fiber does not migrate
into the mainstream smoke during smoking. Accordingly, it is known
that even when menthol is present in the cigarette, the menthol
delivery into the mainstream smoke is decreased with time in
accordance with the sorption of menthol in the filter. In contrast,
in the filter material, such as a paper filter, free of any
plasticizer, hardener or binder, the sorption of menthol in the
filter with time does not occur as different from the cellulose
acetate filter containing a plasticizer, and menthol remains in the
cut tobacco. Therefore, even when the amount of menthol in the
cigarette is the same, the amount of menthol delivered from the cut
tobacco during smoking is greater to thereby ensure a menthol
delivery higher than in the use of the cellulose acetate filter
containing triacetin. In addition, as the sorption of menthol in
the filter is avoided, the menthol delivery into the mainstream
smoke during smoking is stable with time. Similar effects can be
exerted when a flavor, such as menthol, is added to the filter per
se, or when it is added to an aluminum-laminated paper within a
cigarette package. Moreover, these effects can be exerted when even
in the use of a cellulose acetate fiber, the addition amount of
triacetin causing the sorption is decreased, or when a substance
less likely to invite the sorption than triacetin (for example,
polyvinyl alcohol, polyvinyl acetate, polyethylene glycol, an epoxy
resin or the like) is used as the hardness increasing agent.
[0037] Needless to state, in the multisegment filter, a filter plug
formed of a filter material not containing any hardness increasing
agent can be combined with a filter plug formed of a cellulose
acetate fiber.
[0038] Further, the filter of the present invention can include a
filter plug having activated charcoal particles (charcoal) added
thereto. In the single-segment filter, activated charcoal particles
can be mixed in a single filter plug. In the multisegment filter,
generally, activated charcoal particles are added to a filter plug
upstream of the most downstream filter plug.
[0039] Still further, the filter of the present invention can have
the structure of a recessed filter as described in the pamphlet of
International Publication WO 00/00047 and Jpn. PCT National
Publication No. 2004-516814. Illustratively, in that case, when use
is formed of a single-segment filter, the cylindrical body of the
single filter plug is extended out of the downstream end face of
the filter material so as to provide a recess portion. When use is
formed of a multisegment filter, the shaping paper is extended out
of the downstream end face of the most downstream filter plug so as
to provide a recess portion.
[0040] The present invention will be described below with reference
to the drawings. Like elements are identified by like reference
numerals through all the drawings.
[0041] FIG. 1 is a partially developed schematic perspective view
of a filter-tipped cigarette 100 provided with a single-segment
filter.
[0042] The filter-tipped cigarette 100 includes a cigarette main
body 110 and a filter plug 120 provided at one end of the cigarette
main body 110. The cigarette main body 110 is identical to
conventional cigarettes and includes a tobacco rod and a cigarette
paper with which the circumference of the tobacco rod is wrapped,
both not shown. The tobacco rod is formed of a tobacco filler, such
as cut tobacco. The filter plug 120 includes a cylindrical body 122
of filter plug wrapper which is cylindrically shaped 121 and a
filter material 123 disposed in the cylindrical body 122. The
cigarette main body 110 and the filter plug 120 are joined to each
other by means of a tipping paper 130 so that the end faces thereof
unite with each other in the same fashion as in conventional
filter-tipped cigarettes. The tipping paper 130 can be provided
with ventilation holes 131.
[0043] In the filter-tipped cigarette shown in FIG. 1, the
high-rigidity and high-permeability paper according to the present
invention is used as the filter plug wrapper 121.
[0044] FIG. 2 is a partially developed schematic perspective view
of a filter-tipped cigarette 200 provided with a two-segment filter
as an example of the multisegment filter.
[0045] In the filter-tipped cigarette 200, a two-segment filter 210
is fitted to one end of a cigarette main body 110. The two-segment
filter 210 includes two filter plugs 220 and 230. The upstream
filter plug 220 includes a cylindrical body 222 of filter plug
wrapper which is cylindrically shaped 221 and a filter material 223
disposed in the cylindrical body 222. Likewise, the downstream
filter plug 230 includes a cylindrical body 232 of filter plug
wrapper which is cylindrically shaped 231 and a filter material 233
disposed in the cylindrical body 232. The two filter plugs 220 and
230 are joined to each other by means of a shaping paper 240 so
that the end faces thereof unite with each other. The cigarette
main body 110 and the two-segment filter 210 are joined to each
other by means of a tipping paper 130 so that the end faces thereof
unite with each other in the same fashion as in conventional
filter-tipped cigarettes.
[0046] In the filter-tipped cigarette shown in FIG. 2, either or
both of the filter plug wrappers 221 and 231 can be formed of the
high-rigidity and high-permeability paper according to the present
invention.
[0047] As most smokers generally put the downstream filter plug 230
in the mouth, the filter hardness is often felt by the lips.
Therefore, when the filter plug wrapper 231 of the downstream
filter plug 230 is formed of the high-rigidity and
high-permeability paper according to the present invention, even if
the filter plug wrappers of other filter plugs are not formed of
the high-rigidity and high-permeability paper, the smokers can feel
the retention or increase of the filter hardness. Further, the
smokers hold the cigarette with their fingers during smoking, so
that the filter hardness may be felt by the fingers. In that case,
it is desirable to use the high-rigidity and high-permeability
paper according to the present invention in the filter plug wrapper
221 of the upstream filter plug 220 near the cut tobacco. Needless
to state, when the high-rigidity and high-permeability paper
according to the present invention is used in both the filter plug
wrappers 221 and 231, the filter hardness can be simultaneously
felt by the lips and fingers. Moreover, when it is intended to
retain or increase the hardness of the whole of the filter with
respect to the cigarette provided with the multisegment filter, the
intention can be achieved by using the high-rigidity and
high-permeability paper according to the present invention in the
filter shaping paper 240 of the multisegment filter. In that case,
both the filter plug wrappers 221 and 231 may be formed of any of
conventional filter plug wrappers (rigidity (stiffness): 10 to 15,
air permeability: 70 to 30,000 CORESTA units, thickness: 30 to 80
.mu.m, and basis weight: 15 to 27 g/m.sup.2). When it is intended
to further increase the filter hardness, the intention can be
achieved by not only using the high-rigidity and high-permeability
paper in the filter plug wrapper 221 and/or 231 but also using the
high-rigidity and high-permeability paper according to the present
invention in the shaping paper 240 as well, namely, implementing
the double application of the high-rigidity and high-permeability
paper.
[0048] FIG. 3 is a partially developed schematic perspective view
of a filter-tipped cigarette 300 provided with a recessed
single-segment filter.
[0049] The cigarette 300 provided with a recessed filter includes a
cigarette main body 110 and a filter plug 320 provided at one end
of the cigarette main body 110. The filter plug 320 includes a
cylindrical body 322 of filter plug wrapper which is cylindrically
shaped 321 and a filter material 323 disposed in the cylindrical
body 322. The cylindrical body 122 is extended out of the
downstream end face of the filter material 323 so as to provide a
recess portion 324. The cigarette main body 110 and the filter plug
320 are joined to each other by means of a tipping paper 130 so
that the end faces thereof unite with each other in the same
fashion as in conventional filter-tipped cigarettes. The tipping
paper 130 can be provided with ventilation holes 131.
[0050] In the filter-tipped cigarette shown in FIG. 3, the
high-rigidity and high-permeability paper according to the present
invention is used as the filter plug wrapper 321.
EXAMPLE
[0051] The present invention will be described below with reference
to the following Examples.
Example 1
[0052] Filter plugs were produced in accordance with the routine
procedure using the papers indicated in Table 1 above as filter
plug wrappers. The employed filter material consisted of a
conventional cellulose acetate fiber tow having triacetin added
thereto in an amount corresponding to 6% by weight based on the
weight of the cellulose acetate fiber tow. Each of the filter plugs
had a circumference of 24.5 mm and a length of 25 mm. Each of the
filter plug wrappers covered the circumference of the filter
material in just proportion. The hardness of each of the obtained
filters was measured.
[0053] In nature, the hardness of each of the filters should be
measured in the condition of the filter fitted to the cigarette.
However, due to problems relating to measuring instruments, it is
difficult to measure the hardness of each of the filters in the
condition of the filter fitted to the cigarette. Therefore, the
hardness of each of the filters was measured in the form of a
filter plug before being fitted to the cigarette (hereinafter, the
filter hardness was measured by the same measuring method).
[0054] The filter hardness was measured using NFQA (filter quality
measuring instrument) manufactured by JT TOSHI. The results are
shown in FIG. 4. The filter hardness was calculated from a strain
occurring on the filter upon the application of a given load.
Accordingly, the less the strain, the greater the filter hardness
is. Thus, in FIG. 4, the less the value of filter hardness, the
harder the filter is.
[0055] It is apparent from FIG. 4 that the filter hardness of each
of the filter plugs provided with the high-rigidity and
high-permeability papers S1 to S4 according to the present
invention is increased over that of the filter plug provided with
the now usually employed filter plug wrapper P. All the filter
plugs provided with the high-rigidity and high-permeability papers
S1 to S4 according to the present invention exhibited an air
permeability of 1000 CORESTA units or higher. Further, the
high-rigidity paper S4 exhibiting an air permeability equivalent to
that of the now usually employed filter plug wrapper P could be
available.
[0056] Therefore, using the high-rigidity and high-permeability
paper according to the present invention makes it feasible to not
only achieve the retention or increase of the filter hardness but
also avoid the problems of the prior art of making ventilation
holes, namely, an increase of cigarette manufacturing cost, a low
versatility to a variety of cigarette products including a low-tar
cigarette or the like and a poor stability of product quality.
Example 2
[0057] Filter plugs with the same size as in Example 1 were
produced using the conventional filter plug wrapper P and
high-rigidity and high-permeability paper S4 indicated in Table 1.
The filter material was the same conventional cellulose acetate
fiber tow as in Example 1, but the amount of triacetin added to the
tow was changed (amounts equivalent to 0 to 12% by weight based on
the weight of cellulose acetate fiber). The hardness of each of the
obtained filter plugs was measured in the same manner as in Example
1. The results are shown in FIG. 5. In FIG. 5, the line a indicates
the results of the use of the filter plug wrapper P, and the line b
indicates the results of the use of the high-rigidity and
high-permeability paper S4.
[0058] It is apparent from FIG. 5 that when the high-rigidity and
high-permeability paper S4 is used, regardless of the amount of
triacetin added, the filter hardness is increased over that of the
filter plug using the conventional filter plug wrapper P.
[0059] As aforementioned, in the current cigarettes, triacetin is
added to the filter in an amount of 5 to 10% by weight based on the
weight of the filter material. However, it is seen that when the
high-rigidity and high-permeability paper S4 is used, the filter
hardness can be increased without the need to increase the amount
of triacetin.
[0060] In the instances where the amount of triacetin is less, it
is found that the filter hardness exhibited when the conventional
filter plug wrapper P is used and the amount of triacetin is about
6% by weight can be achieved by the use of triacetin in an amount
of about 3% by weight when the high-rigidity and high-permeability
paper S4 is used. Therefore, even when the amount of triacetin is
less, the hardness equivalent to that of the current filter can be
achieved by the use of the high-rigidity and high-permeability
paper S4.
Example 3
[0061] So-called paper filter plugs were produced using the papers
indicated in Table 1. The filter material used was a creped pulp
paper. The configuration of each of the obtained filter plugs was
the same as in Example 1. All the filter plugs exhibited an
air-flow resistance of 350 mm H.sub.2O/120 mm. The hardness of each
of the obtained filter plugs was measured in the same manner as in
Example 1. The results are shown in FIG. 6.
[0062] It is apparent from FIG. 6 that the paper filter plugs
wrapped with the high-rigidity and high-permeability papers
according to the present invention exhibit the same satisfactorily
increased hardness values as those of the cellulose acetate filter
plugs of Example 1 wrapped with the high-rigidity and
high-permeability papers according to the present invention.
Further, an increase of filter hardness up to the level equivalent
to the filter hardness exhibited by the cellulose acetate filter
having triacetin added in an amount of 6% by weight can be achieved
by the application of the present invention.
Example 4
[0063] Filter-tipped cigarettes were produced by fitting each of
the cellulose acetate filter plug produced using the conventional
filter plug wrapper P in Example 1 and the paper filter plug
produced using the high-rigidity and high-permeability paper S4 in
Example 3 to a cigarette main body by means of a tipping paper.
Menthol was added in an amount of 3.0 mg per cigarette to the cut
tobacco of the cigarette main body. The obtained filter-tipped
cigarettes were stored in an atmosphere conditioned at 22.degree.
C. and a relative humidity of 60% from immediately after the
completion of the production up to 12 weeks. The existence ratio of
menthol in the cut tobacco and filter material during the storage
period was measured by the method to be described below. The
results are shown in FIG. 7 and FIG. 8. FIG. 7 shows the results
with respect to the cellulose acetate filter plug. FIG. 8 shows the
results with respect to the paper filter plug. In FIG. 7 and FIG.
8, each of the shaded portions indicates the ratio of menthol in
the filter material, and each of the blank portions indicates the
ratio of menthol in the cut tobacco.
[0064] With respect to both the filter-tipped cigarettes during the
above storage period, the menthol delivery into mainstream smoke
(menthol/tar ratio (M/T ratio)) was measured by the method to be
described below. The results are shown in FIG. 9. In FIG. 9, the
line a indicates the results with respect to the cigarette with
paper filter, and the line b indicates the results with respect to
the cigarette with cellulose acetate filter.
<Method of Measuring the Amount of Menthol in Cut Tobacco and
Filter Material>
[0065] Each of the cigarettes was divided into a cut tobacco
portion (including the cigarette paper) and a filter portion.
[0066] Thereafter, the cut tobacco portion was put in methanol,
shaken at room temperature for 40 minutes and allowed to stand
still for 24 hours. The mixture was shaken once more for 40
minutes, and the supernatant was separated as a menthol
extract.
[0067] On the other hand, the filter portion was put in methanol,
shaken at room temperature for 40 minutes and allowed to stand
still for 24 hours. The supernatant was separated as a menthol
extract.
[0068] The thus obtained menthol extracts were analyzed by a gas
chromatograph equipped with a hydrogen flame ionization detector
(FID) as a detector. The quantity of menthol was determined by an
internal standard method. As the internal standard, 1,3-butanediol
was used.
[0069] <Method of Measuring menthol/tar Ratio>
[0070] The tar contained in tobacco mainstream smoke was measured
in accordance with ISO 3308 and 4387.
[0071] With respect to the menthol contained in tobacco mainstream
smoke, in accordance with ISO 4387, the mainstream smoke was
trapped in a Cambridge filter, and the Cambridge filter was put in
methanol and shaken at room temperature for 40 minutes. The
supernatant was separated as a menthol extract. The thus obtained
menthol extract was analyzed by a gas chromatograph equipped with
FID as a detector. The quantity of menthol was determined by an
internal standard method. As the internal standard, 1,3-butanediol
was used.
[0072] The menthol/tar ratio (M/T ratio) was calculated from the
values of the amounts of tar and menthol in mainstream smoke
determined by the above methods.
[0073] The obtained results attest to the migration of menthol from
the cut tobacco portion to the filter portion when the cellulose
acetate filter is used. Consequently, it is apparent that the
menthol delivery is lowered with time. In contrast, when the paper
filter is used, menthol does not migrate into the filter and
remains in the cut tobacco. As a result, as compared with the use
of the cellulose acetate filter, not only is the menthol delivery
stabilized with time but also a high menthol delivery can be
achieved.
[0074] As apparent from the above, the application of the present
invention makes it feasible to achieve a menthol cigarette that
while retaining its filter hardness, exhibits a high M/T ratio,
namely, a high menthol delivery even when a paper containing no
hardness increasing agent is used as the filter material.
* * * * *