U.S. patent application number 11/795999 was filed with the patent office on 2008-04-17 for cigarette filter material and cigarette filter.
Invention is credited to Takashi Hibi, Hiroki Taniguchi.
Application Number | 20080087290 11/795999 |
Document ID | / |
Family ID | 36777136 |
Filed Date | 2008-04-17 |
United States Patent
Application |
20080087290 |
Kind Code |
A1 |
Taniguchi; Hiroki ; et
al. |
April 17, 2008 |
Cigarette Filter Material and Cigarette Filter
Abstract
A cigarette filter material useful for selectively and
efficiently reducing formaldehyde while maintaining a palatable
component such as nicotine or tar is provided. A cigarette filter
material is obtained by adhesively treating a substrate (such as a
cellulose acetate fiber) with a dispersion comprising a particulate
polysaccharide having an amino group (e.g., chitosan) and a medium.
The medium may be a polar solvent (e.g., water, and an alcohol),
and a plasticizer for the substrate. A cigarette filter comprising
such cigarette filter material can efficiently and selectively
reduce formaldehyde. For example, the cigarette filter ensures a
retention of formaldehyde of not more than 65% while maintaining
retentions of nicotine and tar of not less than 75%,
respectively.
Inventors: |
Taniguchi; Hiroki; (Hyogo,
JP) ; Hibi; Takashi; (Hyogo, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
36777136 |
Appl. No.: |
11/795999 |
Filed: |
January 26, 2006 |
PCT Filed: |
January 26, 2006 |
PCT NO: |
PCT/JP06/01251 |
371 Date: |
July 25, 2007 |
Current U.S.
Class: |
131/332 ;
131/361; 493/39 |
Current CPC
Class: |
A24D 3/14 20130101 |
Class at
Publication: |
131/332 ;
131/361; 493/039 |
International
Class: |
A24D 1/04 20060101
A24D001/04; A24D 3/02 20060101 A24D003/02; A24D 3/06 20060101
A24D003/06 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 2, 2005 |
JP |
2005-027011 |
Claims
1. A cigarette filter material comprising a substrate and a
polysaccharide having an amino group, wherein the polysaccharide is
adhered to the substrate, wherein the substrate is treated with a
dispersion comprising the polysaccharide and a medium, and the
polysaccharide is dispersed in the form of a particle.
2. A cigarette filter material according to claim 1, wherein the
material has a filter rod structure and the polysaccharide is a
chitosan.
3. A cigarette filter material according to claim 2, wherein, the
dispersion comprises the polysaccharide having an average particle
size of 0.5 to 50 .mu.m, and the medium comprises at least one
member selected from the group consisting of a hydroxyl
group-containing solvent and a plasticizer for the substrate.
4. A cigarette filter material according to claim 3, wherein the
hydroxyl group-containing solvent is at least one member selected
from the group consisting of water and an alcohol, and the
plasticizer for the substrate is a lower fatty acid ester of a
polyol.
5. A cigarette filter material according to claim 1, wherein the
medium contains a polyol as a humectant.
6. A cigarette filter material according to claim 5, wherein the
polyol comprises at least one member selected from the group
consisting of a C.sub.2-6alkanediol, a di- to
tetraC.sub.2-4alkylene glycol, and a C.sub.3-10alkanetriol.
7. A cigarette filter material according to claim 6, wherein the
dispersion at least comprises a chitosan having a degree of
deacetylation of not less than 70% and an average particle size of
1 to 20 .mu.m, and a C.sub.3-6alkanetriol.
8. A cigarette filter material according to claim 7, wherein the
adhering amount of the polysaccharide is 1 to 100 parts by weight
relative to 100 parts by weight of the substrate.
9. A cigarette filter material according to claim 8, wherein the
medium resides in the substrate.
10. A cigarette filter material according to claim 9, wherein the
residual amount of the medium is 0.5 to 100 parts by weight
relative to 100 parts by weight of the substrate.
11. A cigarette filter material according to claim 9, wherein the
adhering amount of the polysaccharide is 1 to 80 parts by weight
relative to 100 parts by weight of the substrate, and the residual
amount of the medium is 5 to 400 parts by weight relative to 100
parts by weight of the polysaccharide.
12. A cigarette filter material according to claim 9, wherein the
medium residing in the substrate at least comprises a polyol as a
humectant, and the content of the polyol is 3 to 200 parts by
weight relative to 100 parts by weight of the polysaccharide.
13. A process for producing a cigarette filter material recited in
claim 1, which comprises treating a substrate with a dispersion,
wherein the dispersion comprises a particulate polysaccharide
having an amino group, and a medium.
14. A cigarette filter which is made of a cigarette filter material
recited in claim 1.
15. (canceled)
16. A cigarette which comprises a cigarette filter recited in claim
14.
Description
TECHNICAL FIELD
[0001] The present invention relates to a cigarette filter material
useful for selectively and efficiently removing an aldehyde (in
particular formaldehyde) while maintaining a palatable component
such as nicotine or tar, a process for producing the same, a
cigarette filter formed from the cigarette filter material, and a
cigarette comprising the cigarette filter.
BACKGROUND ART
[0002] A variety of components has been proposed as an adsorbent
for filtrating ingredients in smoke. As such components, in view of
adsorbing an acidic component, formaldehyde, or others, components
containing a basic component (such as an amine component) has been
enough reported. For example, Japanese Patent Application Laid-Open
Nos. 88078/1984 (JP-59-88078A) (Document 1), 1519882/1984
(JP-59-1519882A) (Document 2) and 54669/1985 (JP-60-54669A)
(Document 3) disclose an adsorbent for cigarette filter, in which a
polyethyleneimine, or an aliphatic amine having a low vapor
pressure is impregnated to an active carbon. Japanese Patent
Application Laid-Open Nos. 528105/2002 (JP-2002-528105A) (Document
4) and 528106/2002 (JP-2002-528106A) (Document 5) disclose a
cigarette filter having 3-aminopropylsilyl covalently bonded to a
related atomic group. Moreover, Japanese Patent Application
Laid-Open No. 505618/2003 (JP-2003-505618A) (Document 6) discloses
a filler containing an ammonium salt, and Japanese Patent
Application Laid-Open No. 71388/1982 (JP-57-71388A) (Document 7)
discloses addition of an amino acid for improving flavor of
cigarette.
[0003] However, most of the basic components as described above, in
particular, synthetic polymeric amines, often have a smell of a
specific amine odor due to decomposition of the amines or remain of
low molecular weight components. Moreover, the basic component
itself or a volatile substance contained therein vaporizes and
shows toxicity to the human body in many cases. Incidentally, the
volatilization of the basic component can be inhibited by
acidifying a solution thereof in the impregnation step. The basic
component, however, has a potential for liberation for some reason,
e.g., contact with other basic substances or hydrolysis. Further,
although a component such as an amino acid is often crystallized
and has a low volatile, enough adsorption effects in smoke cannot
be expected because the amino acid has a low adsorption activity in
such a crystal state. Thus, it has been considered that an
adsorbent containing a conventional basic component has some
effects on removal of the acidic substance or the aldehyde, however
such an adsorbent has been impractical for the adsorbent for
cigarette filter in terms of safety or effects thereof.
[0004] On the other hand, among such basic substances, a chitosan
derivative such as a chitin or a chitosan does not crystallize or
volatilize. Moreover, it is known that the chitosan derivative is
harmless to the human body and has an antibacterial activity. For
example, Japanese Patent Application Laid-Open No. 100713/1999
(JP-11-100713A) (Document 8) discloses a chitosan-containing
cellulose acetate fiber which contains a chitosan and has an
antibacterial rate of not lower than 26%. This document mentions
that dispersion and inclusion of a chitosan in a spin dope, for
example, by a manner such as a method of adding or mixing a
chitosan-dispersed liquid to a dope for cellulose acetate, wherein
the dispersion contains a chitosan pulverized to a size smaller
than a predetermined size (a maximum particle size of not larger
than 3 .mu.m), or a method of adding or mixing a chitosan to the
solvent directly and preparing the size of the chitosan by a
certain dispersion condition.
[0005] Moreover, cigarette filters made of such a chitin or
chitosan derivative have been also proposed. For example, Japanese
Patent Application Laid-Open No. 142600/1978 (JP-53-142600A)
(Document 9) discloses a cigarette filter containing a chitin or
chitin derivative in a proportion of not less than 3 wt % relative
to the cigarette filter. This document mentions that the chitin is
poly-N-acetyl-D-glucosamine, and that a method for involving the
chitin in the filter may include a method comprising directly
blending a powder obtained from the chitin with a cigarette filter
material, or a method comprising dissolving the chitin in a polar
solvent, then extruding the solution in a coagulant such as
isopropyl ether to give a fiber or film, and blending the fiber or
film with a cigarette filter material. For example, Example 1 of
the document mentions that after a cellulose acetate fiber bundle
is enough opened with air, 6% by weight of triacetin is sprayed
uniformly on the fiber bundle, and a chitin powder is attached with
the fiber bundle in a proportion of 3 to 70% by weight relative to
the bundle while the surface of the filament is sticky.
Incidentally, the document describes that, in the case of
particularly blending the chitin and chitin derivative with an
acetate filter, the chitin and chitin derivative imparts a
distinctive light aroma and palatability to a cigarette due to a
synergistic effect between an acetyl group in the derivative and an
acetyl group in the acetate. To be concrete, the document mentions
that the reducing (or removing) rate of tar is 34 to 41% and that
of nicotine is 28 to 29% in Examples so that the characteristics
are equivalent or more on conventional article.
[0006] Japanese Patent Application Laid-Open No. 168373/1985
(JP-60-168373A) (Document 10) discloses a cigarette filter
comprising, as a material, a fiber consisting of a chitin or a
derivative thereof (e.g., a chitosan obtained by deacetylation of
part or all of acetylamino groups in the chitin, and a compound
which is obtained by etherifying, esterifying, hydroxyethylifying
or O-methylifying OH groups or CH.sub.2OH groups in a chitin). This
document mentions that a production process for the fiber
preferably includes a process comprising dissolving a chitin or a
derivative thereof in a solvent to form a dope, and forming the
dope into a fiber by a wet spinning process. The cigarette filter
described in this document tends to adsorb tar or nicotine in use
compared with a filter containing triacetylcellulose or a rayon as
a material, and has an adsorption and adhesion performance
one-and-a half times to twice or more as high as a conventional
filter.
[0007] Japanese Patent Application Laid-Open No. 111679/1987
(JP-62-111679A) (Document 11) discloses a cigarette filter material
containing a polysaccharide ion exchanger or a powdery
polysaccharide (e.g., a cellulose, an agarose, an amylose, a
chitin, and a chitosan) for removing a mutagenic compound in smoke
during smoking. This document mentions that the polysaccharide ion
exchanger or the powdery polysaccharide can be used as a filter of
a cigarette body, or in the form dispersed or inserted in a space
of an acetate filter.
[0008] Japanese Patent Application Laid-Open No. 31452/1995
(JP-7-31452A) (Document 12) discloses a cigarette filter containing
a chitin or a chitosan in a proportion of 5 to 100% by weight. This
document mentions that the chitin or chitosan may be used singly or
in combination with a powder of fiber of silica, alumina,
aluminosilicate, zirconia, a rayon, a cellulose, a protein or a
synthetic resin. Moreover, this document mentions that the chitin
or chitosan may be used by impregnating a substrate comprising a
powder or a fiber of, for example, silica, alumina,
aluminosilicate, zirconia, activated carbon, or a cellulose (such
as rayon, cotton or wood pulp), a starch, a protein (such as a
gelatin or a casein), or a synthetic resin (such as cellulose
acetate, a polyethylene, a polyester or a nylon) with the chitin or
chitosan solution, and then drying the resulting matter. According
to the filter described in this document, a harmful component such
as nicotine, tar or an aldehyde in smoke can be effectively
adsorbed and collected. Incidentally, as a concrete method using
the chitin or chitosan solution, Example 3 has mentioned that a
filter was obtained by filling 80 mg of a powdery chitin or
chitosan in a paper tube, covering each side of the paper tube with
each 10 mg of a cotton nonwoven fabric to form a filter chip, and
connecting a cigarette part of a commercially available HIGH LIGHT
to the filter chip, where the filter had collecting rates of
nicotine, tar, and an acrolein of 70%, 75%, and 96%,
respectively.
[0009] Incidentally, it is conventionally considered that nicotine
or tar is a main harmful component in smoke, and there is growing
interest in delivery of nicotine or tar. Many countries obligate
indication of nicotine and tar. However, it appears that nicotine
itself is a taste component of a cigarette and directly takes part
in contentment of smoking. Moreover, regarding tar, removal of a
tar component in smoke at a relatively high level is not preferred
because aroma and palatability are deteriorated. That is,
indiscriminate reduction of low-volatile smoke components
containing tar or nicotine brings about insufficient taste and
feeling of unsatisfaction. On the other hand, an aldehyde, in
particular formaldehyde, not only has a pungent odor but also
effects on health adversely, and has attracted attention as one of
allergens recently. Accordingly, it is consequently preferred to
remove the aldehyde as much as possible.
[0010] It is therefore required to selectively remove an aldehyde
component (particularly formaldehyde) in smoke while maintaining
the amount of tar or nicotine in the smoke at a relatively high
level.
[0011] However, although the cigarette filter containing the
above-mentioned chitin or chitosan derivative have relatively safe
on the human body, the filter highly removes not only the aldehyde
such as formaldehyde but also a component such as nicotine or tar.
As a result, the cigarette deteriorates taste and palatability (or
aroma and palatability).
[0012] More specifically, in the case of directly using a particle
or a fiber of the chitin, the chitosan derivative, or the like for
a cigarette filter, the cigarette filter has non-selective
adsorbality to formaldehyde, and highly adsorbs not only
formaldehyde but also tar or nicotine as is the case with an
activated carbon or others. As a result, the amount of tar or
nicotine falls away, and the taste and palatability is not entirely
satisfactory for smokers. Accordingly, smokers often
unintentionally inhale smoke deeply or frequently during
smoking.
[0013] Further, since the chitosan or the like is hard and fragile
in its own, there is a possibility that, in a filter consisting of
a fiber of the chitosan, the chitosan fiber dropped out from the
filter is aspirated into the human body and causes injury to
respiratory organs.
[0014] Moreover, as described in the above-mentioned Document 12,
even in the case of adding a chitosan particle to cellulose acetate
filter which is used habitually as a cigarette filter, there is the
possibility that the particle damages respiratory organs due to
dropout.
[0015] Therefore, a cigarette filter enabling a small adsorption of
tar or nicotine while maintaining selective adsorbability to
formaldehyde has been required.
[0016] Patent Document 1: Japanese Patent Application Laid-Open No.
88078/1984 (JP-59-88078A) (Claims)
[0017] Patent Document 2: Japanese Patent Application Laid-Open No.
1519882/1984 (JP-59-1519882A) (Claims)
[0018] Patent Document 3: Japanese Patent Application Laid-Open No.
54669/1985 (JP-60-54669A) (Claims)
[0019] Patent Document 4: Japanese Patent Application Laid-Open
[0020] No. 528105/2002 (JP-2002-528105A) (Claims)
[0021] Patent Document 5: Japanese Patent Application Laid-Open No.
528106/2002 (JP-2002-528106A) (Claims)
[0022] Patent Document 6: Japanese Patent Application Laid-Open No.
505618/2003 (JP-2003-505618A) (Claims)
[0023] Patent Document 7: Japanese Patent Application Laid-Open No.
71388/1982 (JP-57-71388A) (Claims)
[0024] Patent Document 8: Japanese Patent Application Laid-Open No.
100713/1999 (JP-11-100713A) (Claims, Paragraph number [0012])
[0025] Patent Document 9: Japanese Patent Application Laid-Open No.
142600/1978 (JP-53-142600A) (Claims; page 2, the upper left column,
line 1 to the upper right column, line 2; and Examples)
[0026] Patent Document 10: Japanese Patent Application Laid-Open
No. 168373/1985 (JP-60-168373A) (Claims; and page 1, the right
column line 16 to page 2, the upper right column line 15)
[0027] Patent Document 11: Japanese Patent Application Laid-Open
No. 111679/1987 (JP-62-111679A) (Claims; and page 2, the upper left
column, lines 1 to 17)
[0028] Patent Document 12: Japanese Patent Application Laid-Open
No. 31452/1995 (JP-7-31452A) (Claims; Paragraph numbers [0004],
[0006]; and Examples)
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0029] It is therefore an object of the present invention to
provide a cigarette filter material capable of reducing (or
removing) efficiently an aldehyde (in particular, formaldehyde)
while maintaining a taste and palatability (or aroma and
palatability) component such as tar or nicotine at a high
level.
[0030] Another object of the present invention is to provide an
odorless cigarette filter material which has safety in oral intake
and which is useful for selectively reducing an aldehyde (in
particular, formaldehyde).
[0031] A further object of the present invention is to provide a
process for conveniently and efficiently producing a cigarette
filter material capable of selectively reducing an aldehyde (in
particular, formaldehyde).
[0032] It is a still another object of the present invention to
provide a cigarette filter capable of selectively reducing an
aldehyde (in particular, formaldehyde) without deterioration of
taste and palatability, and a cigarette comprising the cigarette
filter.
Means to Solve the Problems
[0033] The inventors of the present invention made intensive
studies to achieve the above objects. The inventors finally found
that a cigarette filter material comprising a substrate (e.g., a
substrate having a filter rod structure) treated with a dispersion
that comprises a particulate polysaccharide having an amino group
(e.g., a chitosan) and a medium (e.g., a hydroxyl group-containing
solvent such as water or an alcohol, and a plasticizer such as
triacetin) can selectively adsorb an aldehyde (in particular,
formaldehyde) compared with palatable components such as tar and
nicotine, probably because the filter exerts chemical adsorption
performance due to the amino group in the polysaccharide. The
present invention was accomplished based on the above findings.
[0034] That is, the cigarette filter material of the present
invention comprises a substrate and a polysaccharide particle
having an amino group, and the polysaccharide is adhered to the
substrate, wherein the substrate is treated with a dispersion
comprising the polysaccharide and a medium (or a dispersion medium
for the polysaccharide). The polysaccharide is dispersed in the
form of a particle in the dispersion. The substrate may have a
filter rod structure (for example, may be a filter rod having a
filter rod structure). In other words, the filter material may have
a filter rod structure (specifically, the filter material may
comprise a filament and have a filter rod structure). The
polysaccharide having an amino group may be a chitosan.
Incidentally, the filter rod structure means a structure (a filter
structure) formed by arranging a given amount of mono-filaments
(for example, about 3000 to 100000 mono-filaments) in the flow
direction of a mainstream smoke. In the dispersion, the average
particle size of the particulate polysaccharide may be about 0.1 to
100 .mu.m (for example, about 0.5 to 50 .mu.m). Moreover, in the
dispersion, the medium may comprise at least one member selected
from the group consisting of a polar solvent (particularly, a
hydroxyl group-containing solvent), and a plasticizer for the
substrate (e.g., triacetin, the plasticizer for the substrate is
sometimes simply referred to as "plasticizer"). The hydroxyl
group-containing solvent may be at least one member selected from
the group consisting of water and an alcohol. The plasticizer may
be an ester of a lower fatty acid (e.g., a
C.sub.1-4alkanecarboxylic acid such as acetic acid) with a polyol
(e.g., glycerin, and a polyglycerin). The medium may contain a
humectant capable of remaining in or adhering to the substrate even
after the treatment. For example, the medium may contain a polyol
as the humectant [for example, at least one member selected from
the group consisting of a C.sub.2-6alkanediol, a di- to
tetraC.sub.2-4alkylene glycol, and a C.sub.3-10alkanetriol (e.g.,
glycerin)].
[0035] The representative dispersion may contain, for example, a
chitosan having a degree of deacetylation of not less than 70% and
an average particle size of 1 to 20 .mu.m, and a medium such as a
C.sub.3-6alkanetriol (particularly, glycerin). Such a medium may
contain water, an alkanol, the plasticizer, and others.
[0036] The cigarette filter material of the present invention
comprises the substrate adhered the polysaccharide thereto (or
contained the polysaccharide therein). In such a cigarette filter
material, the adhering amount of the polysaccharide may be, for
example, about 1 to 100 parts by weight relative to 100 parts by
weight of the substrate.
[0037] Moreover, in the cigarette filter material of the present
invention, the medium may reside (or remain) in the substrate. Such
a remaining medium (or medium residing in the substrate) may
constitute a part or all of the medium in the dispersion. The
medium is allowed to contain or reside (or remain) in the
substrate. Therefore, the selectively reducing (or removing)
performance on an aldehyde (in particular formaldehyde) can be
further improved. The content of such a medium may be, for example,
about 0.5 to 100 parts by weight relative to 100 parts by weight of
the substrate. Further, the adhering amount of the polysaccharide
having an amino group may be about 1 to 80 parts by weight relative
to 100 parts by weight of the substrate. The residual amount of the
medium may be about 5 to 400 parts by weight relative to 100 parts
by weight of the polysaccharide having an amino group. In
particular, in the case of using the humectant as a medium, the
medium can efficiently be allowed to remain or contain in (or
adhere to) the substrate even after the adhesive treatment. For
example, in the cigarette filter material, the remaining medium may
at least comprise a polyol as a humectant, and the residual amount
of the polyol may be about 3 to 200 parts by weight relative to 100
parts by weight of the polysaccharide having an amino group.
[0038] The cigarette filter material of the present invention may
be produced by treating (or adhesively treating or allowing to
adhere) a substrate with a dispersion comprising a particulate
polysaccharide having an amino group and a medium that disperses
the polysaccharide, as mentioned above.
[0039] Moreover, the present invention includes a cigarette filter
made of the cigarette filter material. Since such a cigarette
filter can efficiently and selectively reduce (or remove) an
aldehyde (in particular formaldehyde), the present invention also
includes a method for reducing an amount of an aldehyde (in
particular formaldehyde) in main stream smoke, which comprises
forming the cigarette filter from the filter tow. In such a method,
taste and palatability (or aroma and palatability) components (such
as nicotine and tar) may be maintained at a high level. For
example, the retention of formaldehyde may be not more than 65%
while maintaining each retention of nicotine and tar of not less
than 75%.
[0040] Further, the present invention includes a cigarette
comprising said cigarette filter.
[0041] Incidentally, throughout this specification, the term
"chitosan" means a deacetylated compound obtainable by heating
chitin [.beta.-1,4-poly-N-acetyl-D-glucosamine,
(C.sub.8H.sub.13NO.sub.5).sub.n] with a concentrated alkali
solution, or other means, and the chitosan at least has a polymer
structure, .beta.-1,4-poly-D-glucosamine.
EFFECTS OF THE INVENTION
[0042] According to the present invention, the substrate (e.g., a
substrate having a filter rod structure of a cellulose ester fiber)
is adhesively treated with a dispersion comprising a particulate
polysaccharide having an amino group and a medium in combination.
And the effect is that an aldehyde (in particular, formaldehyde)
can be efficiently reduced (or removed) while maintaining a taste
and palatability (or aroma and palatability) component such as tar
or nicotine at a high level. Moreover, the cigarette filter
material of the present invention is odorless and safe even in the
case of oral intake because of using a polysaccharide (such as a
chitosan). In addition, the cigarette filter material is useful for
selective reduction (or removal) of an aldehyde (in particular,
formaldehyde). The cigarette filter of the present invention can
therefore selectively reduce (or remove) an aldehyde (in
particular, formaldehyde) without deterioration of taste and
palatability.
DETAILED DESCRIPTION OF THE INVENTION
[0043] In the cigarette filter material of the present invention
(hereinafter, may be simply referred to as "filter material" or
"material"), a substrate contained in the filter material is
treated (or adhesively treated) with a dispersion comprising a
particulate polysaccharide having an amino group and a medium (or a
dispersion medium for the polysaccharide), and at least the
polysaccharide (and the medium) are attached to the substrate.
[0044] That is, the polysaccharide having an amino group (e.g., a
chitosan) plays an important role in removal of an aldehyde (in
particular, formaldehyde) and usually forms a hydrogen bond. And,
the ability of adsorbing to the aldehyde (in particular
formaldehyde) is poor even in the case of being directly used as a
cigarette filter material or a cigarette filter because of the lack
of basic or nucleopetal property of the polysaccharide.
[0045] Accordingly, in the present invention, a particulate
polysaccharide having an amino group is added to a medium (or a
dispersion medium for the polysaccharide), and a reducing (or
removing) performance of the polysaccharide (or a selectively
reducing (or removing) performance) on an aldehyde can be improved.
Although it is not known exactly why such a selective reduction (or
removal) performance on the aldehyde is improved, in the cigarette
filter material of the present invention it is considered that the
adhesive treatment of the substrate with the dispersion containing
the polysaccharide and the medium contributes to, for example, (a)
efficient adhesion of the polysaccharide to the substrate while
maintaining the particulate form of the polysaccharide, (b)
effective action of the amino group on the selective reduction of
the aldehyde by inhibiting or weakening formation of a hydrogen
bond due to the amino group of the polysaccharide under the action
of the medium (and the medium residing in the substrate after the
adhesive treatment), (c) extension of the surface area of the
polysaccharide adhered to the substrate, (d) enhancement of the
adherence of the polysaccharide adhered to the substrate, (e)
combination of these effects (a) to (d). Thus, such a material
efficiently exerts the selectively reducing performance of the
polysaccharide on the aldehyde.
[0046] [Substrate]
[0047] The substrate may be treated with a dispersion containing a
polysaccharide having an amino group and a medium (or a dispersion
medium), and may comprise, depending on the shape (or structure) of
the substrate, for example, a fiber (or fibrous material) such as a
natural or synthetic fiber {for example, a cellulose ester fiber
(e.g., a cellulose acetate fiber), a cellulose fiber [for example,
a wood fiber (e.g., a wood pulp fiber made from a softwood,
hardwood, or others), a species fiber (e.g., a cotton fiber such as
a linter), a bast fiber, and a leaf fiber or a leafstalk (e.g.,
Manila hemp, and New Zealand flax)], a regenerated fiber (e.g., a
viscose rayon, a cupra (cuprammonium rayon), and an artificial silk
treated with nitric acid), a polyester fiber, a polyurethane fiber,
a polyamide fiber, and a polyolefin fiber (e.g., a polyethylene
fiber, and a polypropylene fiber)}, a particulate material [for
example, an inorganic particle (such as an activated carbon, a
diatomaceous earth, a silica gel, an alumina, a titanium oxide, a
zirconia or a zeolite), a chip of wood, and a particle comprising
other natural or synthetic polymer], and a protein (e.g., a
gelatin, and a casein). These components of the substrate may be
used singly or in combination.
[0048] Among them, the preferred component of the substrate may
include a fiber (a fibrous material), for example, a cellulose
ester fiber. In the cellulose ester fiber, examples of the
cellulose ester may include an organic acid ester such as cellulose
acetate, cellulose propionate or cellulose butyrate, or a mixed
fatty acid ester (e.g., cellulose acetate propionate, cellulose
acetate butyrate, and cellulose acetate phthalate); an inorganic
acid ester such as cellulose nitrate, cellulose sulfate or
cellulose phosphate; a mixed acid ester such as cellulose nitrate
acetate; and a cellulose ester derivative such as a
polycaprolactone-grafted cellulose acetate. These cellulose esters
may be used singly or in combination. Among them, the preferred
cellulose ester may include an organic acid ester (for example, an
ester of a cellulose with an organic acid having a carbon number of
about 2 to 4), for example, cellulose acetate, cellulose
propionate, cellulose butyrate, cellulose acetate propionate,
cellulose acetate butyrate, and others. In particular, cellulose
acetate (particularly cellulose diacetate) is preferred.
[0049] The degree of polymerization of the cellulose ester may be
usually about 10 to 1000 (for example, about 50 to 1000),
preferably about 50 to 900 (for example, about 100 to 800), and
more preferably about 200 to 800.
[0050] Moreover, the degree of substitution of the cellulose ester
(particularly cellulose acetate) may be, for example, selected from
the range of about 1 to 3 (for example, about 1 to 2.9), preferably
may be about 1.5 to 2.7, and more preferably about 1.7 to 2.6.
[0051] As for the fiber (for example, the cellulose ester fiber)
constituting the substrate, the average fiber length may be
selected from the range of about 0.1 mm to 5 cm, for example, may
be about 0.5 to 30 mm (for example, about 1 to 25 mm), preferably
about 2 to 20 mm, and more preferably about 3 to 15 mm (for
example, about 5 to 10 mm). Moreover, the average fiber diameter
may be, for example, about 0.01 to 100 .mu.m, preferably about 0.5
to 80 .mu.m, and more preferably about 1 to 50 .mu.m.
[0052] Incidentally, the filament in the filter tow (for example,
the cellulose ester filament) may have a crimping structure. And,
the filament can have a non-crimping structure.
[0053] Further, in the particle material (or the particulate
material), the average particle size may be, for example, about 0.1
to 2000 .mu.m, preferably about 10 to 1500 .mu.m, and more
preferably about 100 to 1000 .mu.m.
[0054] The shape of the substrate (or the structure) may be
suitably selected depending on the constitutive component form
(e.g., the fiber, and the particle), and may be a shape of the
constitutive component itself, such as a fibrous form or a particle
form (or a particulate) or may be any form such as a capillaceous
form, a woven fabric form, a nonwoven fabric form, a filter rod
structure (or a filter rod-like form, for example, a filter rod
structure having a crimped structure), a paper form (or a paper or
a paper structure), a sheet form and granules. Incidentally, the
substrate having the paper structure may be obtained by making a
staple from the fiber and forming the staple into a sheet through a
dry or wet nonwoven fabric process, or by mixing the staple with a
beat pulp to give a slurry and forming the slurry into a paper.
[0055] Moreover, the substrate may be a pre-formed filter (for
example, a filter rod formed from a cellulose ester (such as
cellulose acetate) having a crimped structure). Such a pre-formed
filter (or filter-like) substrate can be directly used as a
cigarette filter after coating treatment (and drying).
[0056] The preferred substrate may be in the form of a filter rod
formed from a fiber [or a filter (a filter substrate) having a rod
formed from a fiber]. A deal of particle matter such as nicotine
and tar exist in smoke or aerosol, especially in mainstream smoke.
In the case where the substrate comprises a fiber having a fibril,
such a particle matter tends to collide with the fibril part. In
the substrate having a fibril structure, therefore, the
transmittance of nicotine or tar is decreased, and there is the
possibility that the substrate is inappropriate for the object of
the present invention. On the contrary, the later-mentioned filter
rod (or filter having a filter rod structure) having a small amount
of the fibril comprises a mono-filament in a broad sense (a
multifilament having a substantially infinite continuous length)
defined by the polymer engineering. Accordingly, such a filter rod
(or filter) ensures to give an excellent delivery (or permeability)
to nicotine or tar without collision with any particle matter.
[0057] From such a viewpoint, therefore, the substrate comprises
the rod (or the filter rod) formed from a mono-filament rather than
the rod that has a sheet formed from a natural fiber having a
fibril, e.g., a natural fiber such as a cotton lint or an absorbent
cotton and a beat pulp (e.g., see Example 3 described in the
above-mentioned Japanese Patent Application Laid-Open No.
31452/0995 (JP-7-31452A)).
[0058] (Substrate Having Rod Structure or Filter Substrate Having
Filter Rod Structure)
[0059] As mentioned above, in the present invention, the most
preferred substrate is a substrate having a filter rod (in
particular, a filter substrate having a filter rod structure (or a
filter rod substrate)). The filter rod (the filter having a rod
structure) may comprise a mono-filament, that is a conventional
filter material (fiber), and may be made by spinning (dry, melt or
wet spinning). Examples of the fiber constituting the filter rod
substrate (that is, a compact of a mono-filament) may include, for
example, the cellulose fiber, the regenerated fiber (e.g., the
viscose rayon fiber, and the cupra (cuprammonium rayon) fiber), the
synthetic fiber such as the cellulose derivative fiber (e.g., the
cellulose ester fiber), the polyester fiber, the polyurethane
fiber, the polyamide fiber, the polyolefin fiber (e.g., the
polyethylene fiber, and the polypropylene fiber), and the others.
These fibers may be used singly or in combination.
[0060] Examples of the preferred fiber may include the cellulose
fiber, the cellulose ester fiber, and the like. In particular, the
fiber comprising at least the cellulose ester fiber is preferred.
As the cellulose ester fiber, there may be mentioned a fiber
similar to the above-mentioned one, for example, a fiber of an
organic acid ester such as cellulose acetate fiber, cellulose
propionate fiber or cellulose butyrate fiber (for example, a fiber
of an organic acid ester having a carbon number of about 2 to 4); a
mixed fatty acid ester fiber such as a cellulose acetate propionate
fiber or a cellulose acetate butyrate fiber; and a cellulose ester
derivative such as a polycaprolactone-grafted cellulose ester
fiber. The preferred cellulose ester fiber may include, for
example, a cellulose acetate fiber, a cellulose propionate fiber, a
cellulose butyrate fiber, a cellulose acetate propionate fiber, a
cellulose acetate butyrate fiber, and the like. In particular, the
cellulose acetate fiber is preferred. These cellulose ester fibers
may be also used singly or in combination.
[0061] In the filter rod (or the substrate having a filter rod
structure), the degree of polymerization of the cellulose ester may
be, for example, about 50 to 900, and preferably about 200 to 800.
Moreover, the degree of substitution of the cellulose ester may be
selected from the range of, for example, about 1.5 to 3.0.
[0062] The shape at cross section in the filament is not
particularly limited to a specific one, and for example, may be any
form such as a circular form, an elliptical form, an irregular form
(for example, Y-shaped form, X-shaped form, I-shaped form, R-shaped
form, and H-shaped form) or a shape at cross section of hollow
fiber. The shape at cross section is preferably a polygonal
irregular form such as Y-shaped form, X-shaped form, I-shaped form,
R-shaped form or H-shaped form. The filament diameter and the
filament length may be selected depending on the species of the
fiber. For example, the filament diameter may be about 0.01 to 100
.mu.m, and preferably 0.1 to 50 .mu.m, and the filament length may
be selected from the range of about 50 .mu.m to 5 cm, and
preferably about 100 .mu.m to 3 cm in many cases. In particular, in
the case where the substrate is the filter rod, the filament length
preferably corresponds to the length of the filter rod or a part of
the filter rod (e.g., about 3 to 30 mm, for example, about 10 mm,
and about 25 mm).
[0063] The fineness of the fiber (e.g., the cellulose ester fiber)
may be selected from the range of, for example, about 1 to 16
denier, and preferably 1 to 10 denier. The fiber such as the
cellulose ester fiber may have either of a non-crimped structure or
a crimped structure. The mono-filament that has a crimped structure
is more preferred.
[0064] The filter rod substrate is in the form of a rod (a fiber
bundle) formed by uniting (sheaving) filaments, for example, 3,000
to 1,000,000 mono-filaments (for example, 3,000 to 100,000
mono-filaments), preferably 5,000 to 100,000 mono-filaments
(particularly comprising cellulose ester filaments).
[0065] In the case of the filter rod substrate, the substrate may
be formed by mixing and uniting a filament treated with an amino
group-containing polysaccharide (for example, a chitosan) and an
untreated (or raw) filament. The use of a cellulose ester
(preferably cellulose acetate) as a material of such an untreated
filament is advantageous to taste and palatability, and ensures to
adjust the reducing rate of a formaldehyde and the residual rate of
tar or nicotine.
[0066] [Dispersion]
[0067] (Polysaccharide Having Amino Group)
[0068] The polysaccharide having an amino group (or amino
group-containing polysaccharide) is not particularly limited to a
specific one as far as the polysaccharide is a glucan derivative
and has an amino group as a substituent. Representative examples of
such a polysaccharide may include a chitosan.
[0069] The chitosan may be derived from a chitin whose the acetyl
group is at least deacetylated, as mentioned above. The degree of
deacetylation of the chitosan may be, for example, not lower than
20% (for example, about 30 to 100%), preferably not lower than 40%
(for example, about 50 to 99%), and more preferably not lower than
60% (for example, about 65 to 98%).
[0070] The chitosan used in the present invention usually has a
relatively high degree of deacetylation (namely, has many amino
groups), in order to enhance a selective reducing (or removing)
rate against an aldehyde (particularly, formaldehyde), in many
cases. That is, the chitosan having a high degree of deacetylation
has more amino groups compared with the chitin or the like, and is
excellent in a selective reducing effect on an aldehyde (in
particular, formaldehyde).
[0071] The degree of deacetylation of the chitosan may be
therefore, for example, not less than 60% (for example, about 65 to
100%), preferably not less than 70% (for example, about 75 to 99%),
and more preferably not less than 80% (for example, about 85 to
98%). Incidentally, in the chitosan, the "degree of deacetylation"
is represented by the following formula, wherein the acetyl group
of the chitosan is Al mol and the deacetyl group (i.e., amino
group) of the chitosan is A2 mol. Such an acetylation degree may
be, for example, analyzed by H-NMR, C-NMR, or other means.
A2/(A1+A2).times.100(%)
[0072] Moreover, the base dissociation constant "pK.sub.b" of the
chitosan at 25.degree. C. may be, for example, not less than 5.5
(for example, about 6 to 12), preferably not less than 6 (for
example, about 6.3 to 10), and more preferably not less than 6.5
(for example, about 6.8 to 9). In order to ensure higher reducing
rate to the aldehyde (in particular, formaldehyde), the base
dissociation constant may be usually not less than 7 (for example,
about 7.3 to 11), preferably not less than 7.5 (for example, about
7.8 to 10), and more preferably not less than 8 (for example, 8.5
to 9.5).
[0073] Incidentally, the chitosan may be a chitosan derivative
produced by derivatization. Such a chitosan derivative may include,
for example, a chitosan salt (for example, a carboxylate such as a
pyrrolidone carboxylate, a lactate or an alginate), a hydroxylated
chitosan [for example, a chitosan protected (or substituted) by a
hydroxyalkyl group (e.g., hydroxyethyl group, and hydroxypropyl
group), such as hydroxypropylchitosan, and a glycerylated
chitosan], and a cationated chitosan. Moreover, the chitosan
derivative may include a chitosan in which the OH group or
CH.sub.2OH group constituting the chitosan skeleton is protected
(or substituted) by a protecting group (or a substituent), for
example, an alkyl group (e.g., a C.sub.1-4alkyl group such as
methyl group), an ester group (or acyl group, for example, acetyl
group).
[0074] The degree of polymerization of the polysaccharide having an
amino group (in particular, the chitosan) may be selected from the
range of about 10 to 5000 (for example, about 50 to 4000), and for
example, may be about 20 to 3000, preferably about 300 to 2000 and
more preferably about 50 to 1000 (for example, about 100 to
500).
[0075] The polysaccharide is dispersed in the form of a particulate
(or a powder) in the dispersion. The polysaccharide may be in the
form of a particulate (e.g., a particle form, a fine particle form,
a pellet form), and may be a spherical form, a elliptical form, a
columnar form (e.g., a prismatic form), an amorphous form, or other
form.
[0076] The average particle size of the particulate polysaccharide
may be selected from the range of about 0.05 to 500 .mu.m (e.g.,
about 0.08 to 300 .mu.m), and may be, for example, about 0.1 to 100
.mu.m, preferably about 0.5 to 50 .mu.m, and more preferably about
1 to 20 .mu.m. Moreover, in the dispersion, the particulate
polysaccharide may be, depending on the species of the medium or
others, a primary particle or a secondary particle. By adjusting
the particle size of the polysaccharide in the dispersion, the
selectively reducing (or removing) performance on the aldehyde (in
particular, formaldehyde) can be enhanced.
[0077] In the dispersion, the content (dispersing amount) of the
polysaccharide may be selected from the range of about 0.01 to 200
parts by weight relative to 100 parts by weight of the medium (the
whole medium) depending on the species of the medium, and may be,
for example, about 0.05 to 150 parts by weight (e.g., about 0.1 to
100 parts by weight), preferably about 0.2 to 100 parts by weight
(e.g., about 0.5 to 90 parts by weight), and more preferably about
1 to 80 parts by weight (e.g., about 1 to 70 parts by weight).
[0078] (Medium)
[0079] The medium (or the dispersion medium) is not particularly
limited to a specific one as far as the medium is a solvent (or a
poor solvent to the polysaccharide) capable of dispersing the
particulate polysaccharide. Such a medium may be selected depending
on the species of the polysaccharide (e.g., the polymerization
degree, and the degree of deacetylation), and may be a conventional
solvent (a polar solvent, a nonpolar solvent) or may be a medium (a
solvent) capable of dissolving (or plasticizing) the substrate.
Moreover, the medium also includes a solid humectant as described
later. The media may be used singly or in combination.
[0080] The solvent may be a nonpolar solvent [for example, a
solvent having a relatively low dielectric or non-dielectric
constant (e.g., a solvent having a dielectric constant of less than
15), e.g., a hydrocarbon (e.g., an aliphatic or alicyclic
hydrocarbon, an aromatic hydrocarbon, and a halogenated
hydrocarbon), and a chain carboxylic acid ester (for example, an
acetic acid ester such as ethyl acetate or butyl acetate)], and
usually may comprise at least a polar solvent (or a polar liquid).
Incidentally, the polar solvent does not usually melt (or fuse) the
substrate.
[0081] The polar solvent may include, for example, water, an
alcohol, a ketone (e.g., a dialkyl ketone such as acetone, methyl
ethyl ketone or methyl isobutyl ketone), and an ether (for example,
a cyclic ether (e.g., tetrahydrofuran), a dialkylene glycol alkyl
ether (e.g., diethylene glycol dimethyl ether), and a glycol ether
ester (e.g., ethylene glycol monomethyl ether acetate, and
propylene glycol monomethyl ether acetate)].
[0082] The preferred polar solvent may include, from the viewpoint
of efficient releasing a hydrogen bond due to the amino group of
the polysaccharide, a hydroxyl group-containing solvent such as
water or the alcohol. Examples of the alcohol may include a monool
[for example, an alkanol such as a C.sub.1-10alkanol (e.g.,
methanol, ethanol, 1-propanol, isopropanol, n-butanol, 2-butanol or
isobutanol, preferably a C.sub.1-8alkanol, more preferably a
C.sub.1-6alkanol, and particularly a C.sub.1-4alkanol), a
cycloalkanol (e.g., a C.sub.4-10cycloalkanol such as cyclohexanol),
an alkylene glycol monoalkyl ether (e.g., a methyl cellosolve, an
ethyl cellosolve, a butyl cellosolve, and a propylene glycol
monomethyl ether), a dialkylene glycol monoalkyl ether (e.g.,
methylcarbitol, and ethylcarbitol), and a (poly)alkylene-glycol
monoacylate (e.g., ethylene glycol mono acetate)], and a polyol {a
diol [for example, an alkanediol (e.g., a C.sub.2-10alkanediol such
as ethylene glycol, propylene glycol, trimethylene glycol,
1,3-butanediol, 1,4-butanediol, 1,5-pentanediol or hexylene glycol,
preferably a C.sub.2-8alkanediol, more preferably a
C.sub.2-6alkanediol, and particularly a C.sub.2-4alkanediol), a
polyalkylene glycol (e.g., a di-to tetraC.sub.2-4alkylene glycol
such as diethylene glycol, dipropylene glycol, triethylene glycol
or tripropylene glycol)], a triol [for example, an alkanetriol (a
C.sub.3-10alkanetriol such as glycerin or 1,2,6-hexanetriol,
preferably a C.sub.3-6alkanetriol, and more preferably a
C.sub.3-4alkanetriol)], a tetra- or more hydric polyol [for
example, a multimer of a tri- or more polyol (e.g., the
alkanetriol) (for example, a polyglycerin such as diglycerin or
triglycerin)]}.
[0083] The polar solvents may be used singly or in combination.
[0084] In particular, the polar solvent may comprise at least a
polar solvent as a humectant (a polar solvent acting as a
humectant, hereinafter, may be referred to as a wetting polar
solvent). Such a polar solvent may include, among the
above-exemplified polar solvents, the dialkylene glycol monoalkyl
ether, the (poly)alkylene glycol monoacylate, and the polyol [for
example, the alkanediol, the alkanetriol (e.g., glycerin)]. The
most preferred wetting polar solvent includes the polyol, in light
of having a plurality of hydroxyl groups and being excellent in a
capacity for releasing the hydrogen bond due to the amino group of
the polysaccharide.
[0085] That is, the polyol resides (or remains) in or adheres to
the cigarette filter material (substrate) even after the adhesive
treatment (and drying) because of a relatively high boiling point
thereof, and therefore acts as a humectant (or a moisture
component). More specifically, the wetting polar solvent (e.g., the
polyol) is not volatile in the substrate after the adhesive
treatment, and remains in the cigarette filter material (or the
substrate). In addition, the polar solvent is excellent in release
of the hydrogen bond due to the amino group of the polysaccharide,
and is useful for improving the performance for selective reduction
(or removal) of the aldehyde. Furthermore, such a humectant
remaining in the cigarette filter material or the substrate ensures
to stably maintain the performance for selective reduction of the
aldehyde for a long period. Moreover, the wetting polar solvent
seems to have a function to inhibiting volatilization of water or
the monool (e.g., the alkanol) after the adhesive treatment. Thus,
the hydrogen bond due to the amino group of the polysaccharide can
be effectively released (or loosed) by allowing such a polar
solvent to remain in the substrate.
[0086] The wetting polar solvent may be used singly or in
combination. Moreover, a volatile medium [in particular, a volatile
polar solvent or non-wetting polar solvent, for example, at least
one solvent selected from the group consisting of water and a
monool (for example, an alkanol such as a C.sub.1-4alkanol)] and a
wetting polar solvent may be used in combination.
[0087] The boiling point of the wetting polar solvent
(particularly, a polyol) may be, for example, not lower than
150.degree. C. (e.g., about 180 to 500.degree. C.), preferably not
lower than 200.degree. C. (e.g., about 210 to 400.degree. C.), more
preferably not lower than 220.degree. C. (e.g., about 230 to
350.degree. C.), and particularly not lower than 250.degree. C.
(e.g., about 260 to 320.degree. C.).
[0088] Incidentally, the boiling point of the volatile medium
(e.g., a volatile polar solvent such as water or the alkanol) may
be, for example, lower than 150.degree. C. (e.g., about 35 to
145.degree. C.), preferably about 40 to 130.degree. C., and more
preferably about 50 to 120.degree. C.
[0089] The medium capable of plasticizing the substrate may include
a general plasticizer for the substrate. Such a medium capable of
plasticizing the substrate can efficiently enhance an adherence
between the substance and the substrate by plasticizing the
substrate. Examples of the plasticizer may include a phosphoric
acid ester {for example, an aliphatic phosphoric acid ester (e.g.,
a triC.sub.1-12alkyl ester of a phosphoric acid such as triethyl
phosphate), an aromatic phosphoric acid ester (e.g., a
C.sub.1-20alkyldiC.sub.6-15aryl ester of a phosphoric acid such as
octyldiphenyl phosphate, and a triC.sub.6-15aryl ester of a
phosphoric acid such as tricresyl phosphate), and a condensed
phosphoric acid ester [e.g., a dihydroxyarene-bis(diaryl phosphate)
such as resorcinol bis(diphenyl phosphate)]}, a carboxylic acid
ester {for example, an aromatic carboxylic acid ester [e.g., an
aromatic polycarboxylic acid ester such as an aromatic dicarboxylic
acid ester (for example, a phthalic acid ester, e.g., a
diC.sub.1-12alkyl ester of phthalic acid such as dimethyl
phthalate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate
or dioctyl phthalate, and a C.sub.1-6alkoxyC.sub.1-12alkyl ester of
phthalic acid such as dimethoxyethyl phthalate)], an aliphatic
carboxylic acid ester [for example, an aliphatic dicarboxylic acid
ester (e.g., a C.sub.1-12alkyl ester of a C.sub.6-12dicarboxylic
acid such as an adipic acid ester (such as dibutyl adipate, dioctyl
adipate or dibutoxyethoxyethyl adipate), an azelaic acid ester
corresponding to such an adipic acid ester, or a sebacic acid ester
corresponding to such an adipic acid ester), a citric acid ester
(e.g., acetyltributyl citrate), an unsaturated fatty acid ester
(e.g., a C.sub.1-12alkyl ester of a C.sub.8-30alkenecarboxylic acid
such as butyl oleate or methylacetyl recinoleate), a fatty acid
ester of a polyol or polyhydric alcohol (e.g., the
above-exemplified polyol, for example, a tri- to hexahyrdic alkanol
such as glycerin, trimethylolpropane, pentaerythritol or
sorbitol)}, and an ester oligomer (e.g., a caprolactone
oligomer).
[0090] The fatty acid ester of the polyol may include an ester of a
lower fatty acid (e.g., a C.sub.1-4alkanecarboxylic acid such as
acetic acid) with a polyol [for example, an alkanetriol mono- to
triacylate (e.g., a C.sub.3-6alkanetriol mono- to
triC.sub.1-4acylate such as monoacetin, diacetin, or triacetin,
preferably a glycerin mono- to triC.sub.2-3acylate)], a lower fatty
acid ester of a polyol oligomer [for example, a lower fatty acid
ester of a polyol dimer or trimer such as a mono- to tetracylate of
an alkanetriol dimmer (e.g., a diC.sub.3-6alkanetriol mono- to
tetraC.sub.1-4acylate such as diglycerin tetracetate)], and
others.
[0091] Among these plasticizers, as a plasticizer used in
combination with a substrate comprising a cellulose ester
(particularly, a cellulose acetate), a lower fatty acid ester of a
polyol, for example, an acetin (e.g., a glycerin di- to triacetate
such as diacetin or triacetin), is preferably used from the
viewpoint of excellent swelling capacity to the substrate. In
particular, among the lower fatty acid esters of the polyols, a
polyol di- or triC.sub.1-4acylate (particularly, a
C.sub.3-6alkanetriol di- or triC.sub.1-4acylate such as diacetin)
is excellent in a function improving adsorption performance to an
aldehyde of the polysaccharide containing an amino group, and may
be most preferably used. Therefore, as the plasticizer used in
combination with the substrate comprising a cellulose ester, a
plasticizer comprising at least polyol di- or triacylate
(particularly, diacetin, triacetin, and the like), particularly, an
acetin, may be preferably used.
[0092] In particular, the plasticizer may comprise at least a
polyol diacylate (particularly, a C.sub.3-6alkanetriol
diC.sub.1-4acylate such as diacetin). For example, the plasticizer
may comprise diacetin and triacetin.
[0093] Triacetin sometimes contains diacetin and/or monoacetin. In
usual, industrial triacetin contains diacetin and/or monoacetin as
impurities. In a plasticizer at least containing a polyol
diC.sub.1-4acylate (particularly, diacetin), the content of the
polyol diC.sub.1-4acylate (particularly, diacetin) may be not less
than 1% by weight (e.g., about 2 to 100% by weight), preferably
about 3 to 80% by weight, and more preferably about 5 to 60% by
weight (e.g., about 8 to 40% by weight) relative to the total
amount of the plasticizer (particularly, an acetin). The
combination of diacetin and other acetin (particularly, triacetin)
ensures to moderately enhance the viscosity of the dispersion with
improving the performance for adsorbing an aldehyde. Such a lower
fatty acid ester of a polyol (particularly, diacetin, triacetin,
and a mixture thereof) is excellent in capability of plasticizing a
cellulose ester, as well as has capability of releasing the
hydrogen bond due to the amino group of the polysaccharide,
Therefore, such a lower fatty acid ester of a polyol can enhance
selective reduction of an aldehyde (particularly, formaldehyde),
and further, can be preferably used because of high safety.
[0094] The plasticizers may be used singly or in combination.
[0095] Incidentally, the medium capable of plasticizing the
substrate may be usually in the form of a liquid (liquid form at a
room temperature). Moreover, the medium capable of plasticizing the
substrate usually has a relatively high boiling point [for example,
a boiling point of about 150 to 500.degree. C., preferably about
200 to 450.degree. C., and more preferably about 220 to 400.degree.
C. (e.g., about 250 to 380.degree. C.)], and the medium after the
adhesive treatment often remains (or resides) in the substrate or
the cigarette filter material without volatilization or drying.
Therefore, the medium capable of plasticizing the substrate may be
nonvolatile.
[0096] The preferred medium may include, depending on the species
of the substrate, a ester of a lower fatty acid with a polyol (for
example, a glycerin triC.sub.2-3acylate such as triacetin) in the
light of oral safety for human health. These media capable of
plasticizing the substrate may be used singly or in
combination.
[0097] Incidentally, throughout this specification, the medium also
includes a solid medium (solid at a room temperature) as long as
the solid medium can dissolve in the liquid medium (e.g., the polar
solvent, and the plasticizer). That is, the medium may comprise a
solid medium and a medium capable of dissolving the solid medium.
Such a solid medium may act as a humectant similar to the wetting
polar solvent, by remaining in the substrate even after adhesive
treatment (and drying).
[0098] The solid medium may include, for example, a synthetic
polymer having a hydroxyl group or an ether bond (an ether group)
[for example, a polyvinyl alcohol, and a polyalkylene glycol (e.g.,
a polyethylene oxide, a polypropylene oxide, and a polyethylene
oxide-polypropylene oxide)], a natural polymer (e.g., a gelatin, a
dextrin, and a starch), a cellulose derivative [for example, a
cellulose derivative having a hydroxyl group (e.g., a hydroxyalkyl
cellulose such as hydroxyethyl cellulose or hydroxypropyl
cellulose, and an alkyl-hydroxyalkyl cellulose such as
ethylhydroxyethyl cellulose), and a cellulose ether (e.g., a
carboxyalkyl cellulose such as carboxymethyl cellulose, and an
alkyl cellulose such as ethyl cellulose)], a carbohydrate (or a
saccharide) [for example, a monosaccharide (e.g., xylose, and
glucose), a disaccharide (e.g., cellobiose, and trehalose), and a
sugar alcohol (e.g., an inositol compound such as inositol or
bornesitol, and xylitol)]. These solid media may be used singly or
in combination.
[0099] Typical Examples of the medium may include (1) a medium (or
a dispersion medium) comprising water and/or a monool (e.g., an
alkanol including the polyol) (which may comprise the
above-mentioned solid humectant or others), (2) a medium (or a
dispersion medium) comprising the plasticizer (e.g., a lower fatty
acid ester of a polyol) (which may comprise the above-mentioned
solid humectant or others), and others.
[0100] The preferred medium may include a medium containing the
wetting polar solvent, for example, (1a) a medium comprising water
and/or a monool and the wetting polar solvent (for example, a
polyol such as glycerin), (2a) a medium comprising the plasticizer
and the wetting polar solvent, and the like.
[0101] Incidentally, in the case of the medium containing the
wetting polar solvent, the proportion of the wetting polar solvent
may be selected from the range of 0.01 to 100% by weight (e.g.,
0.05 to 50% by weight) relative to the medium in the dispersion.
For example, the proportion may be about 0.1 to 30% by weight,
preferably about 0.3 to 20% by weight, and more preferably about
0.5 to 15% by weight (e.g., about 1 to 10% by weight).
[0102] In particular, in the dispersion of the above embodiment
(1a), the proportion of the wetting polar solvent may be, for
example, about 0.05 to 30 parts by weight (e.g., about 0.1 to 20
parts by weight), preferably about 0.3 to 15 parts by weight, and
more preferably about 0.5 to 10 parts by weight (e.g., about 1 to 8
parts by weight) relative to 100 parts by weight of water and/or
the monool.
[0103] Incidentally, depending on the species of the medium to be
used and the combination thereof, various performances or
properties are sometimes imparted to the resulting cigarette filter
material. For example, the medium containing a kind of the polar
solvent such as an alkanol (e.g., a C.sub.1-4alkanol) seems to
efficiently increase the surface area of the polysaccharide adhered
to the substrate probably because the medium can efficiently
prevent or inhibit swelling or aggregation of the polysaccharide.
In the case where the medium containing a kind of the polar solvent
such as water or a polyol is used, agglutination of the
polysaccharide is caused in the medium. Then the surface area of
the polysaccharide adhered to the substrate is reduced, while such
a medium efficiently tends to inhibit or reduce an influence on a
hydrogen bond in a hydroxyl group in the polysaccharide. At last,
the ability of selective reduction on formaldehyde is
increasing.
[0104] [Cigarette Filter Material]
[0105] In the cigarette filter material of the present invention,
the polysaccharide having an amino group is adhered to the
substrate. The shape of the polysaccharide adhered to the substrate
usually corresponds to that of the polysaccharide in the
dispersion, and is often a particulate form. Moreover, the
particulate polysaccharide adhered to the substrate may be
aggregated.
[0106] In the cigarette filter material of the present invention,
the adhering amount (or the content or impregnating amount) of the
polysaccharide may be selected from the range of not more than 100
parts by weight (for example, about 1 to 100 parts by weight)
relative to 100 parts by weight of the substrate depending on the
species of the medium. For example, the adhering amount may be
about 1 to 80 parts by weight, preferably not more than 60 parts by
weight (e.g., about 2 to 60 parts by weight), preferably not more
than 40 parts by weight (e.g., about 3 to 40 parts by weight),
particularly not more than 30 parts by weight (e.g., about 4 to 30
parts by weight), and usually not more than 20 parts by weight
(e.g., about 5 to 20 parts by weight). In the case where the
content of the polysaccharide is too large, there is a possibility
that the adsorption amount of tar or nicotine is increased.
[0107] Moreover, in the cigarette filter material, the surface area
(the specific surface area) of the polysaccharide adhered to the
substrate may be, for example, not larger than 50 m.sup.2 (e.g.,
about 0.01 to 40 m.sup.2), preferably about 0.1 to 30 m.sup.2 and
more preferably about 0.5 to 20 m.sup.2 per gram of the
polysaccharide, in response to the species of the medium or the
particle size of the polysaccharide.
[0108] In particular, in the case of using the alkanol, the
plasticizer or others as a medium, the surface area (the specific
surface area) of the polysaccharide adhered to the substrate is
relatively large, and may be, for example, about 1 to 50 m.sup.2,
preferably about 3 to 30 m.sup.2 and more preferably about 5 to 20
m.sup.2 (e.g., about 6 to 15 m.sup.2) per gram of the
polysaccharide.
[0109] Incidentally, as described above, the surface area of the
polysaccharide varies depending on the species of the medium. If
unifying the condition such as the species of the medium or the
particle size of the polysaccharide, the larger the surface area of
the polysaccharide indicates the higher the performance for
selective reduction of the aldehyde (particularly formaldehyde). On
the other hand, if using the medium containing a component such as
water or the polyol, the surface area (the specific surface area)
of the polysaccharide has a tendency to become small, as described
above. However, such the medium (particularly containing the
polyol) is excellent in a performance for releasing the hydrogen
bond due to the amino group. Therefore, using said medium and
residing of the medium on the substrate ensures to enhance the
performance for selectively reducing (or removing) the aldehyde of
the polysaccharide even when the specific surface area of the
polysaccharide is small.
[0110] Moreover, in the cigarette filter material, the medium may
be completely removed from the material by drying (including
volatilization or air drying), or may partly or wholly reside in
the substrate. In particular, the wetting polar solvent (such as
the polyol), the plasticizer, and the medium (such as the solid
medium) reside in the cigarette filter material or substrate even
after drying in many cases. Incidentally, the volatile medium
(e.g., water, and the alkanol) may be allowed to reside in the
substrate or cigarette filter material by adjusting the drying
condition, or others. For example, in a fiber (such as a fiber
comprised of cellulose acetate filaments) having a relatively large
surface area, the fiber can hold adsorbed water by going through a
usual production process. However, such an absorbed water content
is few milligrams (for example, about 1 to 3 mg) per 100 mg of the
substrate at most. In particular, in the case of carrying out
vacuum drying or others, the fiber becomes an absolute dry state
(the absorbed water content is almost zero).
[0111] In the cigarette filter material, the residual amount (the
adhering amount, the content) of the medium may be selected from
the range of 0 to 100 parts by weight relative to 100 parts by
weight of the substrate, depending on the amount or concentration
of the dispersion, and for example, may be about 0.5 to 100 parts
by weight (e.g., about 0.8 to 90 parts by weight), preferably about
1 to 80 parts by weight (e.g., about 1.5 to 80 parts by weight),
more preferably about 2 to 70 parts by weight (e.g., about 3 to 60
parts by weight), particularly about 4 to 50 parts by weight (e.g.,
about 5 to 30 parts by weight), and usually about 5 to 20 parts by
weight (e.g., about 5 to 15 parts by weight).
[0112] In particular, in the case of using the medium containing
the wetting polar solvent, the remaining medium comprises the
wetting polar solvent (particularly, a polyol as a humectant), and
the residual amount (the adhering amount, the content) of the
wetting polar solvent (particularly, the polyol) may be selected
from the range of 0.1 to 100 parts by weight relative to 100 parts
by weight of the substrate, and may be, for example, about 1 to 100
parts by weight, preferably about 2 to 60 parts by weight, more
preferably about 3 to 40 parts by weight, and particularly about 5
to 20 parts by weight (e.g., about 5 to 15 parts by weight).
Incidentally, the residing proportion (the adhesion proportion, the
content proportion) of at least one member (selected from the group
consisting of water, the monool (e.g., a C.sub.1-4alkanol) and the
plasticizer) relative to the wetting polar solvent [the former/the
latter (weight ratio)] may be about 99/1 to 0/100, preferably about
95/5 to 5/95, and more preferably about 90/10 to 10/90 (e.g., about
85/15 to 15/85).
[0113] Moreover, the residual amount (the adhering amount, the
content) of the medium may be about 0 to 500 parts by weight,
preferably about 5 to 400 parts by weight, and more preferably
about 10 to 300 parts by weight (e.g., about 20 to 200 parts by
weight) relative to 100 parts by weight of the polysaccharide.
Further, in the case of using the medium containing the wetting
polar solvent, the residing medium comprises the wetting polar
solvent (particularly, the polyol as a humectant), and the residual
amount (the adhering amount, the content) of the wetting polar
solvent (particularly, the polyol as a humectant) may be, for
example, about 1 to 300 parts by weight, preferably about 3 to 200
parts by weight, more preferably about 5 to 180 parts by weight
(e.g., about 8 to 150 parts by weight), and particularly about 10
to 120 parts by weight relative to 100 parts by weight of the
polysaccharide.
[0114] In particular, in the case where the medium containing the
hydroxyl group-containing polar solvent [e.g., water, and an
alcohol (a monool, the polyol)] is used, the residual amount (the
adhering amount, the content) of the medium may be, in terms of
hydroxyl group of the medium (or in the total amount of the
hydroxyl group in the whole medium), not less than 0.1 mol (e.g.,
about 0.3 to 500 mol), for example, not less than 0.5 mol (e.g.,
about 0.8 to 300 mol), preferably not less than 1 mol (e.g., about
1.2 to 150 mol), more preferably not less than 1.5 mol (e.g., about
1.6 to 100 mol), and particularly about 1.8 to 80 mol (e.g., about
2 to 50 mol) relative to 1 mol of the glycose (or monosaccharide)
unit of the polysaccharide.
[0115] Incidentally, in the cigarette filter material of the
present invention, the amount of the polysaccharide or the medium
may be adjusted depending on the length of the material or filter.
For example, in the case of a short filter, since the delivery of
nicotine and tar becomes higher, the amount of the polysaccharide
can be increased. Moreover, based on this, the amount of the medium
may be increased.
[0116] Incidentally, the cigarette filter material may further
contain other component(s), for example, an inorganic fine powder
(e.g., kaolin, talc, diatomaceous earth, quartz, calcium carbonate,
barium sulfate, titanium oxide, and alumina), a heat stabilizer
(e.g., a salt of an alkali or alkaline earth metal), a coloring
agent, a whitening agent, an oil, a retention aid for paper, a
sizing agent, an adsorbent (e.g., an activated carbon), a
biodegradation or photodecomposition accelerator (e.g., an
anatase-type titanium oxide), and a natural polymer or a derivative
thereof (e.g., a cellulose powder). These other components may be
used singly or in combination.
[0117] The form of the cigarette filter material of the present
invention is not particularly limited to a specific one, and may
be, for example, any of a fibrous form, a capillaceous form, a
woven fabric form, a nonwoven fabric form, a tow-like form, a sheet
form and a particle form (or a particulate), depending on the form
of the substrate. Moreover, the form of the cigarette filter
material may be a filter rod form. Incidentally, the substrate
(that is, a substrate before an adhesive treatment) may have such a
form in advance, or such a form may be given by molding or shaping
an adhesively treated substrate (for example, a fibrous substrate,
and a particulate substrate) by a conventional method (for example,
a paper-making method). In particular, the cigarette filter
material is preferably a filter-rod form (particularly a fiber
bundle having a rod structure), as mentioned above.
[0118] [Production Process of Cigarette Filter Material]
[0119] The cigarette filter material of the present invention may
be obtained by adhesively treating a substrate with the dispersion
(a dispersion comprising a particulate polysaccharide having an
amino group and a medium (or a dispersion medium for the
polysaccharide)). That is, the cigarette filter material of the
present invention may be usually obtained by adhesively treating a
substrate with the dispersion to the substrate adhere (or contain)
at least the polysaccharide having an amino group [and if necessary
the medium (e.g., the wetting polar solvent)].
[0120] The adhesive treatment method (treating method) may be
appropriately selected depending on the shape of the substrate
(e.g., a fibrous form, and a filter rod form), the material
thereof, and is not particularly limited to a specific one as far
as the substrate and the dispersion can be contacted with each
other. For example, such a method may include (i) a method of
dipping (or impregnating or immersing) the substrate in the
dispersion, (ii) a method of spraying or sparging (or spreading)
the substrate with the dispersion, (iii) a method of coating the
substrate with the solution of the dispersion, and others. These
treatment methods may be used singly or in combination.
[0121] Such a treatment method of the present invention may be
introduced into the existing manufacturing apparatus for cigarette
filter, in particular an apparatus for producing a cigarette filter
having a filter rod made from a cellulose acetate filament. For
example, the polysaccharide (and the dispersion) may be adhered to
the substrate by bringing the dispersion into contact with the
substrate through the above method (e.g., coating, and dipping)
during the spinning step of a filter tow. Further, the adhesive
treatment may be carried out through a manner (such as spraying,
coating, or dipping) in a step for forming a filter rod (a rolling
up step) by winding off a tow band from a bale of filter tow band
to adhere the polysaccharide (and the dispersion) to the substrate.
Moreover, the polysaccharide (and the dispersion) may be adhered to
the substrate by dipping thus manufactured plug (tow bundle (or
rod)) in polysaccharide (and the dispersion).
[0122] Among these methods, the method (ii) of spraying or sparging
the substrate with the dispersion is preferred. In such a method,
particularly, in the case where the substrate is a fibrous material
(for example, a substrate having a filter rod structure), the
polysaccharide (and the medium) can be conveniently and efficiently
contained in the substrate (or in a dipping part of the
substrate).
[0123] The treatment with the dispersion may be conducted against a
part or all of the substrate. In particular, a substrate having a
filter rod shape ensures adhesion of the polysaccharide to the
bloomed filter rod by disposing or setting the dispersion as a part
of an apparatus for adding a common plasticizer and an activated
carbon for filter rod (e.g., the plasticizer such as triacetin) in
the filter rod maker. In this case, it is not necessary to wholly
coat the rod with the dispersion. Moreover, in the dipping method
(i), at least the whole surface of the substrate (or the dipping
part of the substrate) (preferably the whole surface and inside of
the dipping part of the substrate) may be adhesively treated with
the solution of the polysaccharide.
[0124] In the dipping method (i), the dipping time (or treatment
time) may be selected depending on the embodiment of the
polysaccharide or the content thereof, and may be, for example, not
shorter than 0.001 second (for example, about 0.001 second to 24
hours), preferably about 0.005 second to 1 hour, and more
preferably about 0.01 second to 30 minutes. Industrially, the
dipping time may be, for example, not shorter than 0.001 second
(for example, not shorter than 0.003 second), preferably about
0.003 to 30 seconds, and more preferably about 0.005 to 15
seconds.
[0125] Incidentally, the substrate adhesively treated with the
medium is usually dried. By such drying, volatile components such
as the volatile medium (e.g., water, and an alkanol) may be
completely removed from the substrate, or may partly or wholly
reside in the substrate. By suitably adjusting such drying
condition, the content of the medium to be left in the substrate
can be adjusted.
[0126] The drying manner may be selected depending on the species
of the medium (e.g., the volatile polar solvent, and the wetting
polar solvent), the amount of the medium to be left, or others, and
may be sun drying or air drying, and may be usually carried out by
a dryer (e.g., a dryer which can reduce pressure (such as a vacuum
dryer), and a hot air dryer).
[0127] The drying may be carried out under a room temperature (for
example, about 15 to 25.degree. C.), or under a warming temperature
(for example, about 40 to 200.degree. C., preferably about 45 to
180.degree. C., and more preferably about 50 to 150.degree. C.).
Moreover, the drying may be conducted under an atmospheric pressure
or a reduced pressure. The drying time may be, depending on the
drying temperature, the drying pressure, the species of the medium,
or other conditions. For example, the drying time may be not
shorter than 1 minute (e.g., about 3 minutes to 24 hours),
preferably about 5 minutes to 18 hours (e.g., 10 minutes to 12
hours), more preferably about 20 minutes to 10 hours (e.g., about
30 minutes to 8 hours).
[0128] [Cigarette Filter and Cigarette]
[0129] The cigarette filter material of the present invention is
useful for constituting a cigarette filter. In the cigarette
filter, the cigarette filter material of the present invention may
be used singly or in combination depending on the shape thereof.
The cigarette filter may comprise the cigarette filter material of
the present invention and other cigarette filter material [for
example, a graniferous cigarette filter material coating-treated
and the fibrous material (e.g., a fibrous material which is not
coating-treated)]. For example, the cigarette filter of the present
invention may constitute at least one part of a cigarette filter
divided into a plurality of parts (e.g., a dual, or a triple), for
example, one part of the dual, or both end parts of the triple.
Other cigarette filter material may constitute the remaining parts
(for example, the other part of the dual, or the intermediate part
of the triple). Examples of other cigarette filter material may
include a filter material composed of a part having a dalmatian
containing a particulate substance (such as an activated carbon)
and the other part having a natural.
[0130] The cigarette filter may be formed by a conventional method
depending on the structure of the substrate or the filter. For
example, the filter having a filter rod may be bloomed, then the
bloomed filter may be applied with a conventional plasticizer (such
as triacetin), and then the filter rod may be compacted at a given
diameter and wrapped by paper using a filter rod maker. Moreover,
the filter not having a filter rod may be produced by a
conventional method, for example, (a) a method of filling a
fibrous, powdery or other filter material directly in a metal mold
for forming filter rod to give a filter plug, (b) a method of
filling the filter material in a space of a pre-formed filter plug,
and other methods.
[0131] The cigarette filter of the present invention comprising the
cigarette filter material can efficiently reduce (or remove) an
aldehyde (e.g., formaldehyde) while maintaining a palatable
component (such as nicotine or tar or both) at a high level.
Therefore, the present invention also includes a method for
reducing an amount of an aldehyde (particularly, formaldehyde) in
main stream smoke, wherein the method comprises forming the filter
from the cigarette filter material [more specifically, a method for
reducing the amount of the aldehyde (particularly, formaldehyde)
while maintaining the amounts of nicotine and tar in main stream
smoke].
[0132] For example, the retention or retention rate of formaldehyde
(or formaldehyde retention) of the cigarette filter (in terms of
weight) may be selected from the range of not more than 90% (e.g.,
about 0 to 88%), and may be for example, not more than 85% (e.g.,
about 3 to 80%), preferably not more than 70% (e.g., about 5 to
65%), more preferably not more than 65% (e.g., about 10 to 60%),
and particularly not more than 50% (e.g., about 15 to 45%). Such a
cigarette filter can reduce formaldehyde at a high level.
[0133] Moreover, the nicotine retention (in terms of weight) of the
cigarette filter and the tar retention (in terms of weight) thereof
may be selected from the range of not less than 50% (e.g., about 55
to 100%), and are not less than 60% (e.g., about 65 to 100%),
preferably not less than 70% (e.g., about 75 to 99%), more
preferably not less than 75% (e.g., about 80 to 98%), and
particularly not less than 80% (e.g., about 85 to 97%).
[0134] In particular, the nicotine retention (in terms of weight)
of the cigarette filter may be selected from the range of not less
than 60% (e.g., about 65 to 100%), and may be, for example, not
less than 70% (e.g., about 75 to 99%), preferably not less than 80%
(e.g., about 82 to 98%), and more preferably not less than 85%
(e.g., about 88 to 95%). Moreover, the tar retention (in terms of
weight) of the cigarette filter may be selected from the range of
not less than 50% (e.g., about 55 to 100%), and may be, for
example, not less than 55% (e.g., about 60 to 100%), preferably not
less than 65% (e.g., about 70 to 99.9%), more preferably not less
than 70% (e.g., about 75 to 99.5%), and particularly not less than
75% (e.g., about 80 to 99%).
[0135] Incidentally, the retention (formaldehyde retention,
nicotine retention, tar retention) may be measured as the basis for
the amount of component (formaldehyde, nicotine, or tar) in smoke
passing through a cigarette filter comprising a cigarette filter
material before coating treatment. That is, the "retention" is
expressed by the following formula when "X" represents an amount of
formaldehyde (or nicotine or tar) in smoke passing through a
cigarette filter comprising the untreated cigarette filter material
(or the cigarette filter material before coating treatment) under
given conditions (e.g., flow volume, time period, and number of
times) and "Y" represents an amount of formaldehyde (or nicotine or
tar) in smoke passing through a treated cigarette filter in the
same conditions as the case of the measurement of the amount "X".
Retention(%)=(Y/X).times.100
[0136] Moreover, in the present invention, since the substrate
treated with the dispersion containing the polysaccharide and the
medium is employed, the substrate can be incorporated into the
cigarette filter without increase of the pressure drop of the
cigarette filter. The cigarette filter of the present invention
therefore has draw resistance suitable to smoke. The pressure drop
of the cigarette filter may be selected from the range of 150 to
600 mmWG (water gage) on the basis that air is passed at a flow
volume of 17.5 ml/sec. through a cigarette filter having a length
of 120 mm and a circumference of 24.5.+-.0.2 mm, and may be, for
example, about 180 to 500 mmWG, preferably about 200 to 450 mmWG
(e.g., about 220 to 400 mmWG), and more preferably about 250 to 350
mmWG.
[0137] Moreover, the cigarette of the present invention comprises
the cigarette filter (or the cigarette filter material). The site
to be disposed of the cigarette filter material is not particularly
limited to a specific one. In a cigarette shaped in the form of a
rod by a wrapper, the cigarette filter is often disposed in the
mouthpieth or between the mouthpieth and paper-wrapped cigarette.
Incidentally, the periphery of the cross section of the cigarette
corresponds to that of the cross section of the filter in many
cases, and may be usually about 15 to 30 mm, preferably about 17 to
27 mm.
INDUSTRIAL APPLICABILITY
[0138] The cigarette filter material of the present invention is
useful for constituting a cigarette filter (and a cigarette). In
smoking, such a cigarette filter (and the cigarette) of the present
invention can maintain the appropriate pressure drop (or draw
resistance) while holding a palatable component such as nicotine or
tar, and therefore ensures to selectively reduce (or remove) an
aldehyde (e.g., formaldehyde), which a harmful substance on the
human body, without deterioration of taste and palatability (aroma
and palatability) and of a sense of satisfaction in smoking.
EXAMPLES
[0139] The following examples are intended to describe this
invention in further detail and should by no means be interpreted
as defining the scope of the invention. Incidentally, in the
following Examples and Comparative Examples, each properties (a
draw resistance, an amount of nicotine, an amount of tar, and an
amount of formaldehyde) were measured by using a commercially
available cigarette [Peace Light Box (Registered Trademark No.
2122839) manufactured by Japan Tobacco, Inc.] in accordance with
the following methods.
[0140] [Draw Resistance]
[0141] The draw resistance of the above-mentioned cigarette [Peace
Light Box (Registered Trademark No. 2122839) manufactured by Japan
Tobacco, Inc.)] was directly measured by using a cigarette filter
sample containing the leaf part of the cigarette. In the sample,
the length of the filter was 25 mm and the periphery thereof was
about 25 mm. The draw resistance was determined as a pressure drop
measured by using an automatic pressure drop-measuring apparatus
(manufactured by Filtrona Instruments & Automation Ltd.,
FTS300) when the flow volume of air was 17.5 ml/second.
[0142] [Amount of Nicotine and Amount of Tar]
[0143] The smoking was conduced by using a cigarette filter sample
with the use of a piston-type automatic smoking instrument having
constant volume (manufactured by Heinr. Borgwaldt GmbH, RM20/CS) at
a flow rate of 17.5 ml/second for a smoking period of 2 second/time
with a smoking frequency of once per minute. Nicotine and tar in
smoke passed through the filter were collected by a glass fiber
filter (Cambridge filter), the amount of nicotine was measured by
using a gas chromatograph (manufactured by Hitachi, Ltd.,
G-3000).
[0144] The amount of tar was determined based on a gravimetric
technique.
[0145] The reducing (or removing) rate of nicotine and that of tar
were calculated based on the following formula. In the formula, Tn
and Tt represent amounts of nicotine and tar, respectively, adhered
to a Cambridge filter in control, and Cn and Ct represent amounts
of nicotine and tar, respectively, adhered to a Cambridge filter in
Comparative Examples and Examples. Reducing rate of
nicotine(%)=100.times.(1-Cn/Tn) Reducing rate of
tar(%)=100.times.(1-Ct/Tt)
[0146] [Reducing Rate of Formaldehyde]
[0147] The smoking was conduced by using a cigarette filter sample
with the use of a piston-type automatic smoking instrument having
constant volume (manufactured by Heinr. Borgwaldt GmbH, RM20/CS) at
a flow rate of 17.5 ml/second for a smoking period of 2 second/time
with a smoking frequency of once per minute. Formaldehyde in smoke
passed through the filter was collected in a DNPH
(dinitrophenylhydrazine) solution to derivatize the formaldehyde
with DNPH. The ultraviolet ray (UV) absorbance of the derivatized
formaldehyde was measured by using a gas chromatograph
(manufactured by Hitachi, Ltd., G-3000).
[0148] The reducing (or removing) rate of formaldehyde was
calculated in accordance with the following formula. In the
formula, Tf represents an amount of formaldehyde collected in the
control sample, and Cf represents an amount of formaldehyde
collected in each sample of Comparative Examples and Examples
mentioned below. Reducing rate of
formaldehyde(%)=100.times.(1-Cf/Tf)
Comparative Example 1
[0149] In Comparative Example 1, a chitosan particle was used. The
chitosan particle was prepared by pulverizing "Daichitosan M"
(manufactured by Dainichiseika Color & Chemicals Mfg. Co.,
Ltd.) by means of a pulverizer. The chitosah particle was passed
through a sieve to collect a particle passing through a 28 mesh
sieve and not passing through a 60 mesh sieve.
[0150] In a filter body (25 mm) of a cellulose diacetate crimped
fiber tow of a commercially available cigarette [Peace Light Box
(Registered Trademark No. 2122839) manufactured by Japan Tobacco,
Inc.)], a part of the filter body (14 mm from the end) was cut with
a razor. To the obtained longer piece (that is, a piece containing
a tobacco leaf-filled part), was inserted a glass tube having a
length of 20 mm and an internal diameter of 8 mm in order that the
remaining filter (11 mm) was promptly covered with the glass tube.
Then, the cigarette and glass tube were united with a sealing
tape.
[0151] The chitosan powder (20 mg) was filled in the empty space (9
mm) of the glass tube. Then, the cut shorter piece (that is, the
filter part (110 mg) having a length of 14 mm) was used to plug the
glass tube. Thereafter, the connect part of the glass tube to the
filter was also sealed up by wrapping a sealing tape around the
connect part.
[0152] Accordingly, the length of the filter comprising the
cellulose diacetate crimped fiber tow was 25 mm. Moreover, the
chitosan particle was filled in the extended part (9 mm) between
the filters. The filling amount of the chitosan particle was 20 mg
per cigarette.
[0153] Concerning this cigarette filter sample, the draw
resistance, the amount of nicotine, the amount of tar, and the
amount of formaldehyde were measured. Then, the reducing rate of
nicotine, that of tar and that of formaldehyde were calculated.
These results are shown in Table 1.
[0154] Incidentally, for evaluating the reducing rate of nicotine,
that of tar and that of formaldehyde, a control sample was made in
the same manner as the above-mentioned method except that the
chitosan particle was not filled.
Comparative Example 2
[0155] In Comparative Example 2, an activated carbon commonly used
for a cigarette filter was employed. As the activated carbon, a
crushed carbon "CW350SZ" was used manufactured by Futamura Chemical
Co., Ltd. The crushed carbon was passed through a sieve to collect
a particle passing through a 30 mesh sieve and not passing through
a 50 mesh sieve. In the same manner as Comparative Example 1, the
activated carbon was filled in the extended part between the
filters. The filling amount of the activated carbon was 20 mg per
cigarette.
[0156] Concerning this cigarette filter sample, the draw
resistance, the amount of nicotine, the amount of tar, and the
amount of formaldehyde were measured. Then, the reducing rate of
nicotine, that of tar and that of formaldehyde were calculated.
These results are shown in Table 1.
[0157] Incidentally, for evaluating the reducing rate of nicotine,
that of tar and that of formaldehyde, a control sample was made in
the same manner as the above-mentioned method except that the
activated carbon was not filled.
Example 1
[0158] In the same manner as Comparative Example 1, in a filter
body (25 mm) of a cellulose diacetate crimped fiber tow, a part of
the filter body (14 mm from the end) was cut with a razor. To the
obtained longer piece (that is, a piece containing a tobacco
leaf-filled part), was inserted a glass tube having a length of 20
mm and an internal diameter of 8 mm in order that the remaining
filter (11 mm) was promptly covered with the glass tube. Then, the
cigarette and glass tube were united with a sealing tape.
[0159] The cut shorter piece (that is, the filter part having a
length of 14 mm) was dipped (or immersed) in a chitosan-water
dispersion for 10 minutes, where the chitosan-water dispersion was
a dispersion containing 2% by weight of chitosan (having a degree
of deacetylation of 95%) (that is, a solution obtained by diluting
"Daichitosan FP-slurry" (manufactured by Dainichiseika Color &
Chemicals Mfg. Co., Ltd.) to three-fold in volume with water).
After dipping, the filter part was put in a vacuum dryer, and dried
for 8 hours and 30 minutes at a temperature of 22.degree. C. and
under a pressure of 80 mmHg. The amounts of chitosan and water
adhered to the resulting filter part were 13 mg and 0 mg,
respectively. The specific surface area of chitosan adhered to the
substrate was not more than 1 m.sup.2 (the minimum limit of
measurement: not more than 0.92 m.sup.2) per gram of chitosan.
[0160] The dried filter part having a length of 14 mm was used to
plug the glass tube so that the empty space (9 mm) of the glass
tube remained. Then, the connect part of the glass tube to the
dried filter was also sealed up by wrapping a sealing tape around
the part. Accordingly, the length of the filter comprising the
cellulose diacetate crimped fiber tow was 25 mm.
[0161] Concerning this cigarette filter sample, the draw
resistance, the amount of nicotine, the amount of tar, and the
amount of formaldehyde were measured. The retention of nicotine was
98%, that of tar was 100%, the reducing rate of formaldehyde was
19% (that is, the retention was 81%), and the draw resistance was
162 mmWG.
[0162] Incidentally, for evaluating the reducing rate of nicotine,
that of tar and that of formaldehyde, a control sample was made in
the same manner as the above-mentioned method except that the cut
filter piece (14 mm) was not treated.
Example 2
[0163] In the same manner as Comparative Example 1, in a filter
body (25 mm) of a cellulose diacetate crimped fiber tow, a part of
the filter body (14 mm from the end) was cut with a razor. To the
obtained longer piece (that is, apiece containing a tobacco
leaf-filled part), was inserted a glass tube having a length of 20
mm and an internal diameter of 8 mm in order that the remaining
filter (11 mm) was promptly covered with the glass tube. Then, the
cigarette and glass tube were united with a sealing tape.
[0164] The cut shorter piece (that is, the filter part having a
length of 14 mm) was dipped in a chitosan-water dispersion for 10
minutes, where the chitosan-water dispersion was a dispersion
containing 2% by weight of chitosan (having a degree of
deacetylation of 95%) (that is, a solution obtained by diluting
"Daichitosan FP-slurry" (manufactured by Dainichiseika Color &
Chemicals Mfg. Co., Ltd.) to three-fold in volume with water).
After dipping, the filter part was put in a vacuum dryer, and dried
for 5 hours at a temperature of 22.degree. C. and under a pressure
of 80 mmHg. The amounts of chitosan and water adhered to the
resulting filter part were 13 mg and 71 mg, respectively. The
specific surface area of chitosan adhered to the substrate was not
more than 1 m.sup.2 (the minimum limit of measurement: not more
than 0.92 m.sup.2) per gram of chitosan.
[0165] The dried filter part having a length of 14 mm was used to
plug the glass tube so that the empty space (9 mm) of the glass
tube remained. Then, the connect part of the glass tube to the
dried filter was also sealed up by wrapping a sealing tape around
the part. Accordingly, the length of the filter comprising the
cellulose diacetate crimped fiber tow was 25 mm.
[0166] Concerning this cigarette filter sample, the draw
resistance, the amount of nicotine, the amount of tar, and the
amount of formaldehyde were measured. The retention of nicotine was
83%, that of tar was 100%, the reducing rate of formaldehyde was
45% (that is, the retention was 55%), and the draw resistance was
179 mmWG.
[0167] Incidentally, for evaluating the reducing rate of nicotine,
that of tar and that of formaldehyde, a control sample was made in
the same manner as the above-mentioned method except that the cut
filter piece (14 mm) was not treated.
Example 3
[0168] In the same manner as Comparative Example 1, in a filter
body (25 mm) of a cellulose diacetate crimped fiber tow, a part of
the filter body (14 mm from the end) was cut with a razor. To the
obtained longer piece (that is, a piece containing a tobacco
leaf-filled part), was inserted a glass tube having a length of 20
mm and an internal diameter of 8 mm in order that the remaining
filter (11 mm) was promptly covered with the glass tube. Then, the
cigarette and glass tube were united with a sealing tape.
[0169] The cut shorter piece (that is, the filter part having a
length of 14 mm) was dipped in a chitosan-water dispersion for 10
minutes, where the chitosan-water dispersion was a dispersion
containing 2% by weight of chitosan (having a degree of
deacetylation of 95%) (that is, a solution obtained by diluting
"Daichitosan FP-slurry" (manufactured by Dainichiseika Color &
Chemicals Mfg. Co., Ltd.) to three-fold in volume with water).
After dipping, the filter part was put in a vacuum dryer, and dried
for 6 hours and 15 minutes at a temperature of 22.degree. C. and
under a pressure of 80 mmHg. The amounts of chitosan and water
adhered to the resulting filter part were 13 mg and 19 mg,
respectively. The specific surface area of chitosan adhered to the
substrate was not more than 1 m.sup.2 (the minimum limit of
measurement: not more than 0.92 m.sup.2) per gram of chitosan.
[0170] The dried filter part having a length of 14 mm was used to
plug the glass tube so that the empty space (9 mm) of the glass
tube remained. Then, the connect part of the glass tube to the
dried filter was also sealed up by wrapping a sealing tape around
the part. Accordingly, the length of the filter comprising the
cellulose diacetate crimped fiber tow was 25 mm.
[0171] Concerning this cigarette filter sample, the draw
resistance, the amount of nicotine, the amount of tar, and the
amount of formaldehyde were measured. The retention of nicotine was
89%, that of tar was 97%, the reducing rate of formaldehyde was 64%
(that is, the retention was 36%), and the draw resistance was 168
mmWG.
[0172] Incidentally, for evaluating the reducing rate of nicotine,
that of tar and that of formaldehyde, a control sample was made in
the same manner as the above-mentioned method except that the cut
filter piece (14 mm) was not treated.
Example 4
[0173] In the same manner as Comparative Example 1, in a filter
body (25 mm) of a cellulose diacetate crimped fiber tow, a part of
the filter body (14 mm from the end) was cut with a razor. To the
obtained longer piece (that is, a piece containing a tobacco
leaf-filled part), was inserted a glass tube having a length of 20
mm and an internal diameter of 8 mm in order that the remaining
filter (11 mm) was promptly covered with the glass tube. Then, the
cigarette and glass tube were united with a sealing tape.
[0174] The cut shorter piece (that is, the filter part having a
length of 14 mm) was dipped in a dispersion for 10 minutes, where
the dispersion comprised a chitosan-water dispersion containing 2%
by weight of chitosan (having a degree of deacetylation of 95%)
(that is, a solution obtained by diluting "Daichitosan FP-slurry"
(manufactured by Dainichiseika Color & Chemicals Mfg. Co.,
Ltd.) to three-fold in volume with water) and 1% by weight of
glycerin. After dipping, the filter part was put in a vacuum dryer,
and dried for 8 hours and 30 minutes at a temperature of 22.degree.
C. and under a pressure of 80 mmHg. The amounts of chitosan and
glycerin adhered to the resulting filter part were 13 mg and 7 mg,
respectively. The specific surface area of chitosan adhered to the
substrate was not more than 1 m.sup.2 (the minimum limit of
measurement: not more than 0.92 m.sup.2) per gram of chitosan.
[0175] The dried filter part having a length of 14 mm was used to
plug the glass tube so that the empty space (9 mm) of the glass
tube remained. Then, the connect part of the glass tube to the
dried filter was also sealed up by wrapping a sealing tape around
the part. Accordingly, the length of the filter comprising the
cellulose diacetate crimped fiber tow was 25 mm.
[0176] Concerning this cigarette filter sample, the draw
resistance, the amount of nicotine, the amount of tar, and the
amount of formaldehyde were measured. The retention of nicotine was
99%, that of tar was 86%, the reducing rate of formaldehyde was 51%
(that is, the retention was 49%), and the draw resistance was 158
mmWG.
[0177] Incidentally, for evaluating the reducing rate of nicotine,
that of tar and that of formaldehyde, a control sample was made in
the same manner as the above-mentioned method except that the cut
filter piece (14 mm) was not treated.
Example 5
[0178] In the same manner as Comparative Example 1, in a filter
body (25 mm) of a cellulose diacetate crimped fiber tow, a part of
the filter body (14 mm from the end) was cut with a razor. To the
obtained longer piece (that is, a piece containing a tobacco
leaf-filled part), was inserted a glass tube having a length of 20
mm and an internal diameter of 8 mm in order that the remaining
filter (11 mm) was promptly covered with the glass tube. Then, the
cigarette and glass tube were united with a sealing tape.
[0179] The cut shorter piece (that is, the filter part having a
length of 14 mm) was dipped in a dispersion for 10 minutes, where
the dispersion comprised a chitosan-water dispersion containing 2%
by weight of chitosan (having a degree of deacetylation of 95%)
(that is, a solution obtained by diluting "Daichitosan FP-slurry"
(manufactured by Dainichiseika Color & Chemicals Mfg. Co.,
Ltd.) to three-fold in volume with water) and 4% by weight of
glycerin. After dipping, the filter part was put in a vacuum dryer,
and dried for 8 hours and 30 minutes at a temperature of 22.degree.
C. and under a pressure of 80 mmHg. The amounts of chitosan and
glycerin adhered to the resulting filter part were 14 mg and 27 mg,
respectively. The specific surface area of chitosan adhered to the
substrate was not more than 1 m.sup.2 (the minimum limit of
measurement: not more than 0.92 m.sup.2) per gram of chitosan.
[0180] The dried filter part having a length of 14 mm was used to
plug the glass tube so that the empty space (9 mm) of the glass
tube remained. Then, the connect part of the glass tube to the
dried filter was also sealed up by wrapping a sealing tape around
the part. Accordingly, the length of the filter comprising the
cellulose diacetate crimped fiber tow was 25 mm.
[0181] Concerning this cigarette filter sample, the draw
resistance, the amount of nicotine, the amount of tar, and the
amount of formaldehyde were measured. The retention of nicotine was
94%, that of tar was 93%, the reducing rate of formaldehyde was 72%
(that is, the retention was 28%), and the draw resistance was 162
mmWG.
[0182] Incidentally, for evaluating the reducing rate of nicotine,
that of tar and that of formaldehyde, a control sample was made in
the same manner as the above-mentioned method except that the cut
filter piece (14 mm) was not treated.
Example 6
[0183] In the same manner as Comparative Example 1, in a filter
body (25 mm) of a cellulose diacetate crimped fiber tow, a part of
the filter body (14 mm from the end) was cut with a razor. To the
obtained longer piece (that is, apiece containing a tobacco
leaf-filled part), was inserted a glass tube having a length of 20
mm and an internal diameter of 8 mm in order that the remaining
filter (11 mm) was promptly covered with the glass tube. Then, the
cigarette and glass tube were united with a sealing tape.
[0184] The cut shorter piece (that is, the filter part having a
length of 14 mm) was dipped in a chitosan-ethanol dispersion for 10
minutes, where the chitosan-ethanol dispersion (manufactured by
Dainichiseika Color & Chemicals Mfg. Co., Ltd.) contained 6% by
weight of chitosan (having a degree of deacetylation of 90%). After
dipping, the filter part was put in a vacuum dryer, and dried for 5
hours at a temperature of 22.degree. C. and under a pressure of 80
mmHg. The amount of chitosan adhered to the resulting filter part
was 30 mg. The specific surface area of chitosan adhered to the
substrate was 9.8 m.sup.2 per gram of chitosan.
[0185] The dried filter part having a length of 14 mm was used to
plug the glass tube so that the empty space (9 mm) of the glass
tube remained. Then, the connect part of the glass tube to the
dried filter was also sealed up by wrapping a sealing tape around
the part. Accordingly, the length of the filter comprising the
cellulose diacetate crimped fiber tow was 25 mm.
[0186] Concerning this cigarette filter sample, the draw
resistance, the amount of nicotine, the amount of tar, and the
amount of formaldehyde were measured. The retention of nicotine was
96%, that of tar was 87%, the reducing rate of formaldehyde was 66%
(that is, the retention was 34%), and the draw resistance was 186
mmWG.
[0187] Incidentally, for evaluating the reducing rate of nicotine,
that of tar and that of formaldehyde, a control sample was made in
the same manner as the above-mentioned method except that the cut
filter piece (14 mm) was not treated.
Example 7
[0188] In the same manner as Comparative Example 1, in a filter
body (25 mm) of a cellulose diacetate crimped fiber tow, a part of
the filter body (14 mm from the end) was cut with a razor. To the
obtained longer piece (that is, a piece containing a tobacco
leaf-filled part), was inserted a glass tube having a length of 20
mm and an internal diameter of 8 mm in order that the remaining
filter (11 mm) was promptly covered with the glass tube. Then, the
cigarette and glass tube were united with a sealing tape.
[0189] The cut shorter piece (that is, the filter part having a
length of 14 mm) was dipped in a dispersion for 10 minutes, where
the dispersion comprised a chitosan-ethanol dispersion
(manufactured by Dainichiseika Color & Chemicals Mfg. Co.,
Ltd.) containing 6% by weight of chitosan (having a degree of
deacetylation of 90%), and 3% by weight of glycerin. After dipping,
the filter part was put in a vacuum dryer, and dried for 5 hours at
a temperature of 22.degree. C. and under a pressure of 80 mmHg. The
amounts of chitosan and glycerin adhered to the resulting filter
part were 30 mg and 15 mg, respectively. The specific surface area
of chitosan adhered to the substrate was 7.5 m.sup.2 per gram of
chitosan.
[0190] The dried filter part having a length of 14 mm was used to
plug the glass tube so that the empty space (9 mm) of the glass
tube remained. Then, the connect part of the glass tube to the
dried filter was also sealed up by wrapping a sealing tape around
the part. Accordingly, the length of the filter comprising the
cellulose diacetate crimped fiber tow was 25 mm.
[0191] Concerning this cigarette filter sample, the draw
resistance, the amount of nicotine, the amount of tar, and the
amount of formaldehyde were measured. The retention of nicotine was
88%, that of tar was 76%, the reducing rate of formaldehyde was 77%
(that is, the retention was 23%), and the draw resistance was 182
mmWG.
[0192] Incidentally, for evaluating the reducing rate of nicotine,
that of tar and that of formaldehyde, a control sample was made in
the same manner as the above-mentioned method except that the cut
filter piece (14 mm) was not treated.
Example 8
[0193] A chitosan-triacetin dispersion as a plasticizer (containing
40% by weight of chitosan having a degree of deacetylation of 90%)
(manufactured by Dainichiseika Color & Chemicals Mfg. Co.,
Ltd.) was impregnated to a cellulose diacetate crimped fiber tow
having a filament denier of 2.2 and a total denier of 40,000
(manufactured by Daicel Chemical Industries, Ltd.), and the tow was
bundled. The bundled tow was rolled up by an automatic rolling up
apparatus to give a cigarette filter rod having a length of 100 mm
and an outer diameter of 8 mm. The resulting rod was cut into
quarters in the direction of the long direction to obtain filter
chips each having a length of 25 mm. The amounts of chitosan and
triacetin adhered to the 25 mm filter chip were 16 mg and 23.8 mg,
respectively. The specific surface area of chitosan adhered to the
substrate was 6.8 m.sup.2 per gram of chitosan.
[0194] A filter body (25 mm) of a cellulose diacetate crimped fiber
tow of a commercially available cigarette [Peace Light Box
(Registered Trademark No. 2122839) manufactured by Japan Tobacco,
Inc.)] was cut with a razor. To the obtained longer piece (that is,
a tobacco leaf-filled part), was inserted a glass tube having a
length of 20 mm and an internal diameter of 8 mm in order that the
inserted part was 11 mm. Then, the cigarette and glass tube were
united with a sealing tape. The empty space (9 mm) of the glass
tube was stoppled with the filter chip made by using the
chitosan-triacetin dispersion as a plasticizer. Then, the connect
part of the glass tube to the filter was also sealed up by wrapping
a sealing tape around the part. Accordingly, the length of the
filter of the cellulose diacetate crimped fiber tow was 25 mm.
[0195] Concerning this cigarette filter sample, the draw
resistance, the amount of nicotine, the amount of tar, and the
amount of formaldehyde were measured. The retention of nicotine was
93%, that of tar was 97%, the reducing rate of formaldehyde was 38%
(that is, the retention was 62%), and the draw resistance was 164
mmWG.
[0196] Incidentally, for evaluating the reducing rate of nicotine,
that of tar and that of formaldehyde, a control sample was made in
the same manner as the above-mentioned method except that triacetin
was used as a plasticizer.
Example 9
[0197] A mixture of 100 parts by weight of a chitosan-triacetin
dispersion as a plasticizer (containing 40% by weight of chitosan
having a degree of deacetylation of 90%) (manufactured by
Dainichiseika Color & Chemicals Mfg. Co., Ltd.) and 10% by
weight of glycerin was impregnated to a cellulose diacetate crimped
fiber tow having a filament denier of 2.2 and a total denier of
40,000 (manufactured by Daicel Chemical Industries, Ltd.), and the
tow was bundled. The bundled tow was rolled up by an automatic
rolling up apparatus to give a cigarette filter rod having a length
of 100 mm and an outer diameter of 8 mm. The resulting rod was cut
into quarters in the direction of the long direction to obtain
filter chips each having a length of 25 mm. The amounts of
chitosan, triacetin and glycerin adhered to the 25 mm filter chip
were 15 mg, 22.5 mg and 2 mg, respectively. The specific surface
area of chitosan adhered to the substrate was 3.4 m.sup.2 per gram
of chitosan.
[0198] A filter body (25 mm) of a cellulose diacetate crimped fiber
tow of a commercially available cigarette [Peace Light Box
(Registered Trademark No. 2122839) manufactured by Japan Tobacco,
Inc.)] was cut with a razor. To the obtained longer piece (that is,
a tobacco leaf-filled part), was inserted a glass tube having a
length of 20 mm and an internal diameter of 8 mm in order that the
inserted part was 11 mm. Then, the cigarette and glass tube were
united with a sealing tape. The empty space (9 mm) of the glass
tube was stoppled with the filter chip made by using the
chitosan-triacetin dispersion as a plasticizer. Then, the connect
part of the glass tube to the filter was also sealed up by wrapping
a sealing tape around the part. Accordingly, the length of the
filter of the cellulose diacetate crimped fiber tow was 25 mm.
[0199] Concerning this cigarette filter sample, the draw
resistance, the amount of nicotine, the amount of tar, and the
amount of formaldehyde were measured. The retention of nicotine was
93%, that of tar was 97%, the reducing rate of formaldehyde was 38%
(that is, the retention was 62%), and the draw resistance was 168
mmWG.
[0200] Incidentally, for evaluating the reducing rate of nicotine,
that of tar and that of formaldehyde, a control sample was made in
the same manner as the above-mentioned method except that triacetin
was used as a plasticizer.
Example 10
[0201] A mixture of 100 parts by weight of a chitosan-triacetin
dispersion as a plasticizer (containing 40% by weight of chitosan
having a degree of deacetylation of 90%) (manufactured by
Dainichiseika Color & Chemicals Mfg. Co., Ltd.) and 10% by
weight of diacetin was impregnated to a cellulose diacetate crimped
fiber tow having a filament denier of 2.2 and a total denier of
40,000 (manufactured by Daicel Chemical Industries, Ltd.), and the
tow was bundled. The bundled tow was rolled up by an automatic
rolling up apparatus to give a cigarette filter rod having a length
of 100 mm and an outer diameter of 8 mm. The resulting rod was cut
into quarters in the direction of the long direction to obtain
filter chips each having a length of 25 mm. The amounts of
chitosan, triacetin and diacetin adhered to the 25 mm filter chip
were 15.5 mg, 23.3 mg and 2.1 mg, respectively. The specific
surface area of chitosan adhered to the substrate was 3.2 m.sup.2
per gram of chitosan.
[0202] A filter body (25 mm) of a cellulose diacetate crimped fiber
tow of a commercially available cigarette [Peace Light Box
(Registered Trademark No. 2122839) manufactured by Japan Tobacco,
Inc.)] was cut with a razor. To the obtained longer piece (that is,
a tobacco leaf-filled part), was inserted a glass tube having a
length of 20 mm and an internal diameter of 8 mm in order that the
inserted part was 11 mm. Then, the cigarette and glass tube were
united with a sealing tape. The empty space (9 mm) of the glass
tube was stoppled with the filter chip made by using the
chitosan-triacetin dispersion as a plasticizer. Then, the connect
part of the glass tube to the filter was also sealed up by wrapping
a sealing tape around the part. Accordingly, the length of the
filter of the cellulose diacetate crimped fiber tow was 25 mm.
[0203] Concerning this cigarette filter sample, the draw
resistance, the amount of nicotine, the amount of tar, and the
amount of formaldehyde were measured. The reducing rate of nicotine
was 5%, that of tar was 2%, that of formaldehyde was 68%, and the
draw resistance was 172 mmWG.
[0204] For evaluating the reducing rate of nicotine, that of tar
and that of formaldehyde, a control sample was made in the same
manner as the above-mentioned method except that triacetin and
dicetin were used as a plasticizer.
[0205] The results are shown in Table 1.
[0206] [Table 1] TABLE-US-00001 TABLE 1 Amount of hydroxyl Specific
group in medium to Reducing Reducing Reducing surface Content of 1
mol of glycose unit Draw rate of rate of rate of Chitosan area
medium of chitosan resistance nicotine tar formaldehyde (mg)
(m.sup.2/g) (mg) (mol) (mmWG) (%) (%) (%) Control -- -- -- -- 147
-- -- -- Com. Ex. 1 20 -- -- -- 172 18 5 10 Com. Ex. 2 -- -- -- --
163 37 1 24 Ex. 1 13 less than 1 -- -- 162 2 0 19 Ex. 2 13 less
than 1 water: 71 48.9 179 17 0 45 Ex. 3 14 less than 1 water: 19
12.1 168 11 3 36 Ex. 4 13 less than 1 glycerin: 7 2.82 158 1 14 51
Ex. 5 14 less than 1 glycerin: 27 10.1 162 6 7 72 Ex. 6 30 9.8 --
-- 186 4 13 66 Ex. 7 30 7.5 glycerin: 15 5.60 182 12 24 77 Ex. 8 16
6.8 triacetin: 23.8 -- 164 7 3 38 Ex. 9 15 3.4 glycerin: 2 0.81 168
10 9 52 triacetin: 22.5 Ex. 10 15.5 3.2 triacetin: 23.3 -- 172 5 2
68 diacetin: 2.1
* * * * *