U.S. patent application number 13/518352 was filed with the patent office on 2013-02-28 for enhancing the disintegration and/or degradation of a smoking article.
This patent application is currently assigned to BRITISH AMERICAN TOBACCO (INVESTMENTS) LIMITED. The applicant listed for this patent is David Rushforth. Invention is credited to David Rushforth.
Application Number | 20130047999 13/518352 |
Document ID | / |
Family ID | 41717266 |
Filed Date | 2013-02-28 |
United States Patent
Application |
20130047999 |
Kind Code |
A1 |
Rushforth; David |
February 28, 2013 |
Enhancing the Disintegration and/or Degradation of a Smoking
Article
Abstract
A filter (2) for a smoking article (1) is provided by the
present invention, the filter comprising a vehicle containing a
liquid capable of enhancing the disintegration and/or
dispersibility of the smoking article. A method of enhancing the
disintegration and/or degradation of a smoking article is also
provided, wherein the smoking article comprises a vehicle
containing a liquid capable of enhancing the disintegration and/or
degradation of the smoking article.
Inventors: |
Rushforth; David; (London,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rushforth; David |
London |
|
GB |
|
|
Assignee: |
BRITISH AMERICAN TOBACCO
(INVESTMENTS) LIMITED
London
GB
|
Family ID: |
41717266 |
Appl. No.: |
13/518352 |
Filed: |
December 21, 2010 |
PCT Filed: |
December 21, 2010 |
PCT NO: |
PCT/GB10/52177 |
371 Date: |
October 3, 2012 |
Current U.S.
Class: |
131/332 ;
131/331 |
Current CPC
Class: |
A24D 3/061 20130101;
A24D 3/068 20130101 |
Class at
Publication: |
131/332 ;
131/331 |
International
Class: |
A24D 3/06 20060101
A24D003/06; A24D 1/04 20060101 A24D001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 21, 2009 |
GB |
0922254.8 |
Claims
1. A filter for a smoking article comprising a vehicle containing a
liquid capable of enhancing at least one of disintegration and
degradation of the smoking article, and wherein the filter
comprises filter material which is soluble, swellable or
dispersible in water.
2. The filter according to claim 1, wherein the liquid is capable
of enhancing dispersion of the smoking article.
3. The filter according to claim 1, wherein the vehicle comprises a
capsule.
4. The filter according to claim 1, wherein the vehicle is arranged
to be actuated to release the liquid after the smoking article has
been smoked.
5. The filter according to claim .sub.4, wherein the vehicle is
arranged to be actuated by a longitudinal or bending force acting
on the filter.
6. The filter according to claim 4, wherein actuating the vehicle
to release the liquid substantially deforms the filter.
7. The filter according to claim 1, wherein the liquid enhances
dissociation of components of the filter.
8. The filter according to claim 1, wherein the liquid is an
aqueous solution.
9. The filter according to claim 8, wherein the liquid is
water.
10. The filter according to claim 1, wherein the filter material is
polyvinyl alcohol.
11. The filter according to claim 1, wherein the filter comprises a
plugwrap, tipping paper and adhesive, and wherein one or more of
these is soluble, swellable or dispersible in water.
12. The filter according to claim 1, wherein the vehicle comprises
a biodegradable material.
13. The filter according to claim 1, wherein the vehicle comprises
a capsule having a crush strength of greater than 1.7 kp.
14. The filter according to claim 1, wherein the vehicle comprises
a capsule having a volume of no more than about 50% of the total
volume of the filter.
15. (canceled)
16. A smoking article comprising a filter, said filter comprising a
vehicle containing a liquid capable of enhancing at least one of
disintegration and degradation of the smoking article, and wherein
the filter comprises filter material which is soluble, swellable or
dispersible in water.
17. (canceled)
18. A method of enhancing at least one of disintegration and
degradation of a smoking article wherein the smoking article
comprises a filter and a vehicle containing a liquid capable of
enhancing at least one of the disintegration and degradation of the
smoking article, and wherein the filter comprises filter material
which is soluble, swellable or dispersible in water.
Description
[0001] The invention relates to enhancing the disintegration and/or
degradation of used smoking articles, and particularly, but not
exclusively, to enhancing the disintegration and/or degradation of
the filter of such smoking articles.
[0002] A problem with currently available tobacco smoke filters,
particularly cigarette filters, is that they can be difficult to
dispose of after use.
[0003] During smoking most of the tobacco rod and its
circumscribing paper wrapper are converted to gases and ash in an
incineration process. The remaining components of the spent smoking
article include a small portion of ash, part of the original
tobacco rod and wrapper, and the filter which is made up of the
filter plug, plugwrap, and tipping paper wrapped about the tobacco
rod and filter. There are also adhesives present that secure these
components together. Spent smoking articles are generally
completely dissociated into their individual constituent parts
within a relatively short period of time when exposed to moisture,
and/or mechanical abrasion. The individual components of the spent
smoking articles are thus subsequently able to disperse and
degrade.
[0004] The plug of filter material, however, typically does not
readily disperse or degrade. With limited exceptions, filters are
presently formed from highly crimped cellulose acetate fibres
bonded at their contact points using plasticizers to provide a
significant volume of interstitial space for the passage of smoke.
The bonded contact points of such filter elements degrade very
slowly under normal environmental conditions. The cellulose acetate
fibres are themselves generally poorly biodegradable.
[0005] Despite the developments to date towards improving the
biodegradability of filter plugs, there is interest in improved
techniques for producing filters having an enhanced biodegradation
rate. At the same time, there is also a need to retain the
filtration chemistry, smoke characteristics and consumer
acceptability provided by currently available smoking article
filters.
[0006] In order to produce smoking articles, including filter
cigarettes, which are more easily disintegrated or dispersed and
are more biodegradable, it is desirable to provide a smoking
article displaying a relatively rapid dissociation of the
individual components of the spent smoking article followed by a
good rate of dispersion and biodegradation of the individual
components. In other words, increasing the rate of dissociation of
a spent smoking article enhances the rate of degradation by
increasing the exposure of the individual components to natural
elements such as moisture, sunlight, mechanical abrasion, and
aerobic biodegradation.
[0007] One approach that has previously been used to improve the
dissociation of spent smoking article filters involves the
incorporation of water expandable gels in the filter material to
swell the filter upon contact with moisture and thereby break open
the filter tipping paper to expose the filter material to the
elements.
[0008] It has also been suggested to manufacture the components of
a smoking article filter, including the filtration material, the
filter plugwrap, and the tipping paper, from a moisture
disintegrative paper. The use of water soluble adhesives for
securing the filter plug and tipping paper wrappings is also
known.
[0009] All of these approaches to improving the degradation of
smoking article filters require the presence of water, such as
moisture from rain, snow, dew, or residual moisture from those
elements, for example, moist soil. However, in arid countries with
little rainfall, such approaches are unlikely to be effective.
[0010] A further problem is that the cellulose acetate tow commonly
used as filter material is not readily degradable or biodegradable.
Thus, despite efforts to promote the dissociation of the spent
smoking article, the filter material itself will not subsequently
degrade. Therefore, much of the effort expended to reduce the
environmental burden of spent smoking articles or to make such
spent smoking articles more environmentally compatible has been
directed to improving the biodegradability of the cellulose acetate
fibres. Water soluble polymers have been used instead of triacetin
which solvent bonds the cellulose acetate fibres typically used to
make filters. Alternatively, soluble polymeric materials such as
polyvinyl alcohol and ethylene vinyl alcohol copolymers may be used
in place of cellulose acetate. Meanwhile, a tobacco smoke filter
made of a creped paper manufactured from a wood pulp sheet and a
tobacco filter made from a regenerated cellulose fibre bundle are
also known. Compared with a filter comprising a cellulose acetate
fibre bundle, these filters disintegrate slightly more readily when
exposed to moisture.
[0011] While there are clearly environmentally preferable
alternatives to cellulose acetate, degradability again generally
depends on the presence of moisture, which as mentioned previously,
may be scarce in some areas.
[0012] In light of the above, at least one embodiment of the
invention provides a smoking article having enhanced
disintegration, dispersion and/or degradation. In particular, at
least one embodiment of the invention provides a filter for a
smoking article which is capable of degrading in the absence of
environmental water.
SUMMARY OF THE INVENTION
[0013] According to a first aspect of the invention, a filter for a
smoking article is provided which comprises a vehicle containing a
liquid capable of enhancing the disintegration and/or degradation
of the smoking article.
[0014] The vehicle, which can be a capsule, may be broken or
otherwise actuated to release the liquid immediately prior to
disposal of the smoking article, or may be broken or otherwise
actuated at a later time following disposal. Generally the vehicle
is arranged to be actuated to release the liquid after the smoking
article has been smoked.
[0015] The vehicle can be arranged to be actuated by a longitudinal
or bending force acting on the filter, such that, for instance, the
action of `stubbing out` the smoking article acts to release the
liquid. The process of actuation of the vehicle to release the
liquid may substantially deform the filter.
[0016] The liquid may enhance the degradation of the smoking
article in one or more of the following ways. Firstly, the various
components of the smoking article may be induced by the liquid to
dissociate, resulting in their increased exposure to the
environment and accelerated dispersion and biodegradation.
Secondly, the degradation of one or more of the components of the
smoking article may be directly enhanced by the liquid. For
example, the filter may comprise a filter material which may be
degraded by the liquid carried in the vehicle. Thus, for instance,
when a capsule containing the liquid is broken, the liquid is
released, and the degradation of the filter material is
enhanced.
[0017] According to a second aspect of the present invention, a
smoking article comprising a filter as described herein is
provided.
[0018] According to a third aspect of the present invention, the
use of a capsule containing a liquid for enhancing the
disintegration and/or degradation of a smoking article is
provided.
[0019] According to a fourth aspect of the present invention, a
method of enhancing the disintegration and/or degradation of a
smoking article is provided wherein the smoking article comprises a
capsule containing a liquid capable of enhancing the disintegration
and/or degradation of the smoking article.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] For a fuller understanding of the invention, reference is
made to the accompanying schematic drawings which each illustrate a
longitudinal cross-section of an individual filter cigarette
comprising a filter according to embodiments of the invention (not
to scale).
[0021] FIG. 1 shows a filter according to one embodiment of the
present invention.
[0022] FIG. 2 shows a filter according to an alternative embodiment
of the present invention.
DETAILED DESCRIPTION
[0023] The present invention provides a filter for use in a smoking
article, comprising a vehicle containing a liquid capable of
enhancing the disintegration, dispersion and/or degradation of the
smoking article. The vehicle is preferably resistant to
manipulation during use of the smoking article, and is intended to
be actuated upon disposal of the smoking article to release the
liquid contents into the filter. The disintegration and degradation
of the filter may occur directly, for example, by the dissolution
or dispersion of one or more of the components of the filter, such
as the filter material, in the liquid. Alternatively, the
enhancement of degradation may be indirect, for example, as a
result of increased environmental exposure resulting from the
accelerated dissociation of the filter by the liquid.
[0024] FIG. 1 shows a smoking article 1 comprising a filter 2. The
filter 2 comprises two sections of substantially cylindrical filter
plug 3, separated by a cavity 6. The filter plug and cavity are
wrapped in a plugwrap 4. A capsule 5 comprising a liquid is
situated within the cavity 6 of the filter 2. The smoking article
further comprises a cylindrical rod of smokeable material 7 aligned
with the filter 2 such that the end of the smokeable material rod 7
abuts the end of the filter 2. The rod is wrapped in a paper
wrapper 8, and is joined to the filter 2 by tipping paper 9 in a
conventional manner.
[0025] FIG. 2 shows an alternative embodiment in which
corresponding features have the same reference numerals. This
embodiment differs from that shown in FIG. 1 in that the capsule 15
is elongate in shape. In addition, rather than being positioned
with a cavity within the filter 2, the capsule 15 is embedded
within the material of the filter plug 13.
[0026] The liquid held within the capsule is capable of enhancing
the degradation of the smoking article. Consequently, the selection
of the liquid is dependent upon the composition of the materials
comprising the remainder of the smoking article and vice-versa. In
a preferred embodiment of the invention, the liquid is water and
various components of the smoking article are water-dispersible or
wet-degradable to some extent as outlined below. In this way, the
degradation of the smoking article is enhanced relative to an
identical smoking article lacking a water-containing capsule.
[0027] In the embodiment shown in the FIG. 2, the capsule 15 is
enclosed within the filter material 13. In some embodiments, the
filter may be a composite filter comprising multiple filter
segments. For example, the filter shown in FIG. 1 comprises two
sections of filter material 3 separated by a cavity 6, which
contains the capsule. In further embodiments, the capsule may be
located in a cavity formed between the filter material and the rod
of smokeable material, or the filter may comprise more than two
filter sections, and may even include multiple cavities.
[0028] In the embodiments shown in the figures, the smoking article
comprises a single capsule. In alternative embodiments, however,
more than one capsule may be used, and in such embodiments, the
capsules will generally be held within a cavity section formed in a
multi-section filter.
[0029] The capsule may be inserted into the filter using any
suitable method, and various methods of capsule insertion will be
known to the skilled person. Suitable apparatus may, for example,
include a means for supplying a continuous stream of filter
material from a source of such material (e.g., a bale, bobbin, or
the like). The apparatus may further include a capsule insertion
unit for inserting or depositing the individual capsules at
predetermined intervals within the filter material. The filter
material having capsules deposited therein may then be received
into a rod-making means for providing a continuous rod which may
subsequently be subdivided into the desired length at predetermined
intervals to form the individual filters of the invention.
[0030] Generally, prior art disclosures of capsules for use in
smoking article filters are concerned with providing encapsulation
methods aimed at releasing the encapsulated material before smoking
occurs. The capsules are designed to resist breakage only during
transport and storage, when the filter is not generally subject to
significant external pressure. The capsule is subsequently intended
to be ruptured immediately prior to use of the smoking article, and
since this is the first exposure of the smoking article to
significant manipulation and external pressure, the capsule is not
necessarily required to be particularly robust.
[0031] In contrast, capsules for use in the invention are intended
to be broken after the smoking article has been smoked, and thus
are preferably capable of tolerating a significant degree of
manipulation as the smoking article is smoked. Consequently, the
capsule of the present invention should be more robust than those
generally described in the prior art. It is important that the
capsule is not accidentally ruptured before the smoking article is
ready to be discarded. Such premature rupture could lead to the
filtration characteristics of the smoking article being changed and
deliveries being thereby altered compared to what is expected.
[0032] On the other hand, it is important that the capsule is not
overly robust as it should be easily breakable after smoking
ceases, during the manual extinguishing process or `stubbing out`.
The capsule for use in the present invention may, for example, have
a crush strength of between 1.5 and 2.5 kp, preferably between 1.7
and 2 kp.
[0033] The capsule may be designed and inserted into the filter in
such a way that the capacity to rupture is dependent upon the
nature of the pressure exerted. Pressure exerted by the user during
smoking will predominantly be exerted by the fingers and mouth to
the circumferential surface of the smoking article ("transverse"
pressure). In some embodiments of the invention, the capsule is to
be relatively resistant to transverse pressure to prevent premature
rupture. On the other hand, the stubbing out process is likely to
involve the application of "longitudinal" pressure along the length
of the smoking article, and consequently the capsule should
demonstrate a relatively reduced resistance to breakage in response
to longitudinal pressure.
[0034] This directional capsule resilience may be achieved in a
number of ways. For example, the capsule may be elliptical or ovoid
and consequently demonstrate an increased resistance to rupture
when pressure is exerted in one direction versus another.
Alternatively, directional resilience may be achieved using a
capsule which has been specifically strengthened in certain areas.
Such a capsule may be produced, for example, having an increased
shell thickness in selected areas. Naturally, a similar effect may
be achieved by weakening the capsule wall in certain areas, to
facilitate breakage or rupture in response to force being applied
in a particular manner or direction.
[0035] The stubbing out process can also involve bending of the
filter. Therefore, in some embodiments the capsule is designed to
demonstrate increased susceptibility to rupture when the filter is
bent or buckled. For example, a long cylindrical capsule may be
used which may be ruptured by being snapped. Such elongate capsules
will be positioned longitudinally within the filter, so that they
are easily bent and ruptured when the filter of the smoking article
is stubbed out and bent.
[0036] Various means of encapsulating substances, particularly
liquids, for release in smoking article filters are known, and are
generally suitable for use in the invention. Clearly, one of the
primary considerations is that the capsule should generally be
resistant to the degrading action of the intended contents. The
capsule should also comprise material which has a melting point
above the temperature of the smoke within the filter.
[0037] The capsule may exhibit brittleness under stress and/or may
comprise a line of weakness, such as a scored line, a brittle
point, or a weak section. Alternatively, a piercing means may be
incorporated within the filter.
[0038] In preferred embodiments, the capsule is constructed from a
frangible material. In one embodiment the capsule is composed of a
low solubility, high molecular weight polyvinyl alcohol. A number
of suitable alternative materials are known, and by way of example,
capsules typically utilized in the pharmaceutical industry may be
used. Such capsules may be gelatin based, for example, or may be
formed from a polymeric material, such as modified cellulose. One
type of modified cellulose which may be used is hydroxypropylmethyl
cellulose. Many biodegradable materials are known which may be
suitable for use in the production of capsules and these include
high molecular weight polyethylene glycols, polylactic acid,
plastarch material, polycaprolactone, polyglycolide, a
polyhydroxyalkanoate such as poly-3-hydroxybutytate, and
zein-derived bioplastics.
[0039] Alternatively, the capsule may comprise a length of
thin-walled glass tubing, the ends of which may be sealed by
heating or with a material capable of withstanding manual handling
prior to and during smoking, yet which can be fractured after
smoking. Other suitable materials include thin-walled aluminium
tubing or hollow foodstuff material, such as, for example, pasta,
or extruded hollow tubing of reconstituted tobacco material. The
inner walls of the capsule material may advantageously be coated
with a varnish or waterproof material, such as silicone, to
preserve the rigidity of the capsule material by preventing
absorption of, or degradation by, the liquid contents over a
prolonged period.
[0040] The capsule may alternatively be comprised of a wax, resin,
natural or synthetic gum, latex or plastic material which retains
its shape and strength at room temperature and at smoking
temperature but which fractures to release the liquid contents upon
pressure applied to extinguish the smoking article. Examples of
suitable waxes include beeswax, candelilla, carnauba, Shellac wax,
caranday, sugarcane wax, myrtle wax and petroleum wax.
[0041] Suitable resins include epoxy resins, terpene resins,
petroleum resins, ester gum, phenolic resins and rosin based
resins. Preferred gums include gum arabic, locust bean, guar,
alginates, carrageenan and pectin.
[0042] Preferably the substances comprising the capsule have no
effect on the taste of the mainstream smoke as smoking occurs.
[0043] The capsule may be formed in a variety of physical
formations including singular part or multipart capsules, large
capsules, small capsules, microcapsules, etc. A number of different
capsule configurations are suitable for use in the invention; for
example, the capsule may be generally spherical (as shown in FIG.
1), ovoid, ellipsoidal (as shown in FIG. 2), cylindrical, or may
approximate to a polygonal prism in shape.
[0044] The capsule may be coloured. For example, the capsule may
comprise a colouring agent. The colouring agent may be used to
render more easily the location of the capsule within the filter
during the manufacturing process. Alternatively or additionally,
the colouring agent may provide an interesting and attractive
appearance to the smoking article, particularly if the capsule or
capsules are intended to be only partially enclosed within the
filter material, or if the tipping paper is intended to have a
transparent window portion.
[0045] Alternatively or in addition, the liquid held in the capsule
may be coloured. This would give the user an additional, visual
indication that the liquid has been successfully released and that
degradation of the spent smoking article will be enhanced. A
coloured liquid also has the added benefit that it could act as an
indicator when the capsule is accidentally ruptured before smoking.
The colour would be a warning to the smoker that the smoking
article has been damaged and should not be smoked.
[0046] The size of the capsule is clearly dependent on the volume
of liquid required, but consideration should be given to the fact
that the presence of the capsule in the filter should not have an
adverse effect on the filtration or draw characteristics of the
filter.
[0047] In one preferred embodiment, the capsule is 5 mm in
diameter. Generally, the diameter of the capsule may be up to 80%
of the diameter of the smoking article. Preferably the capsule
diameter is up to 70%, up to 60%, or up to 50% of the diameter of
the smoking article. For example, the diameter of the capsule may
be between 2 and 7 mm, and preferably the diameter is between 4 and
6 mm.
[0048] The capsule should be large enough to accommodate sufficient
contents to enhance the degradation of the smoking article. The
volume required will vary according to the nature of the liquid
held within the capsule, the composition of the remainder of the
smoking article and the associated capacity of the liquid to
enhance the degradation of the smoking article. The volume of the
capsule may be up to 60%, up to 50%, up to 40%, or up to 30% of the
total volume of the filter. The requirement for a large volume of
liquid should be balanced, however, with the need to retain
sufficient filter material within the filter to provide the
required degree of filtration.
[0049] While it is preferable for the volume of the capsule to be
as large as possible, as the size of the capsule is increased, the
risk of premature breakage of the capsule is also increased.
Furthermore, the larger the capsule, the greater is the obstruction
to the smoke flow path. Consequently, to accommodate the required
amount of liquid, it may be preferable for the filter to comprise
two, three, four or more capsules. Multiple capsules may be
positioned, for example, at regularly spaced intervals along the
length of the filter. Alternatively, multiple capsules may be
situated as a cluster within the filter, for example within a
cavity formed between two sections of filter material.
[0050] Alternatively, long cylindrical or ellipsoidal capsules (or
tubes) may be used, having a length equal to a significant
proportion of the length of the filter, or even equal to the entire
length of the filter. Such capsules may be up to 5 mm in
diameter.
[0051] Multiple capsules may be used comprising different
liquids.
[0052] In some embodiments, the capsule or capsules may be further
encapsulated in a second capsule, or a sheath, or the like. This
may allow greater protection from accidental or premature breakage,
or incidental leakage. In this way, single wall or multi-wall
capsules may be used to tailor capsule stability, strength, rupture
resistance, processing ease in filter making, etc.
[0053] The capsule may be manufactured using any suitable method,
the method of manufacture of the capsule clearly being dependent on
the precise composition and make-up required. Various methods of
capsule manufacture will be known to the skilled person, including
techniques such as co-extrusion, spin coating, coacervation,
interfacial polymerization, solvent evaporation, and annular jet
forming.
[0054] In some embodiments in which the capsule is a seamless
capsule, the capsule may be produced using a co-extrusion process.
The co-extrusion process is a synchronous extrusion of the two
liquids that will subsequently form the shell and the capsule
contents (or "core"). The first (co-extrusion) step involves
forming a droplet having the liquid core material inside the liquid
shell material. After the co-extrusion step, the "capsule" is
solidified by cooling or by immersion in a curing agent, for
example. The capsules may then be subjected to various treatments,
such as washing, removal of surplus liquid, colouring, application
of additional coatings, etc.
[0055] Alternatively, an annular jet forming technique may be used.
This method utilises two concentric jets to eject an inner jet of
liquid core material and an outer jet of liquid shell material. The
fluid stream breaks into droplets and the liquid shell material
solidifies by phase transition induced by the presence of
cross-linking ions, pH differences, temperature changes, etc.
[0056] In some embodiments in which the capsule comprises a wax
capsule, the capsule may be formed, for example, by a method
comprising freezing a solution of the liquid core material until
small crystals are formed. According to this method, the crystals
are then dropped into molten wax and removed by spatula after a wax
coat has formed around the cold crystals. The frozen core material
gradually becomes liquid as the coated capsule reaches room
temperature.
[0057] In alternative embodiments, the capsule may be manufactured
in situ. For example, in embodiments in which the capsule comprises
a long cylindrical capsule extending the entire length of the
filter, the capsule may be constructed by crimping a continuous
tube into filter-length fragments as part of the filter
manufacturing process.
[0058] The liquid held within the capsule may be any liquid capable
of enhancing the degradation of one or more of the materials
comprising the remainder of the smoking article. Clearly the nature
of the liquid is dependent upon the composition of the materials of
the smoking article and vice-versa.
[0059] The disintegration and/or degradation of the smoking article
may be enhanced in one or more of the following ways. Firstly, the
dissociation of the smoking article may be enhanced, resulting in
the individual components having greatly increased exposure to the
environment and thus being susceptible to accelerated degradation.
Secondly, the degradation of one or more of the individual
components may be directly enhanced, for example one or more of the
components may be soluble or otherwise reactive with the liquid
held within the capsule.
[0060] Smoking articles generally comprise a number of different
papers (tipping paper, plugwrap, and tobacco wrapping paper) which
bind the various components of the smoking article and hold them
together. In some embodiments, the dispersion of the adhesive which
binds these papers, and/or the papers themselves is enhanced by the
action of the liquid in the capsule. In one preferred embodiment
the liquid is water, the adhesive is a water-soluble or a
water-dispersible adhesive, and the plugwrap and tipping papers
comprise moisture disintegrative papers. Thus, when the capsule is
ruptured, the water acts on the adhesive, the plugwrap, and the
tipping paper, enhancing the dissociation of the smoking article
and accelerating the environmental degradation of the various
components of the smoking article.
[0061] There are a number of means by which the liquid may enhance
the degradation of the smoking article. When the capsule is
ruptured, the liquid is released and is able to migrate throughout
the smoking article. In some embodiments, the liquid held within
the capsule is an aqueous solution, and one or more of the
remaining components of the smoking article are in some way
water-degradable, for example, composed of water-soluble or
water-dispersible material. In one embodiment, the liquid within
the capsule is water, and the filter material is a water-soluble or
water-dispersible material, such as polyvinyl alcohol.
[0062] In alternative embodiments, other liquids may be used in the
capsule, and clearly the selection of liquid to be used is
dependent on the composition of the other components of the smoking
article.
[0063] Generally the preferred liquids for use in the capsule are
aqueous solutions, and the most preferred liquid is water. Weak
acidic or basic solutions may be used. In general, any liquid may
be used that is not potentially toxic or harmful to the user. In
case of the accidental premature breakage of the capsule, it is
also important that none of the other components of the smoking
article degrade to yield products which are potentially toxic or
harmful to the user.
[0064] The liquid may be coloured. This may serve as a visible
indication that the capsule has been ruptured, which may be
important for two reasons. Firstly, this will inform the user if
the capsule is prematurely broken, thus alerting the user that the
smoking article should not be smoked. Secondly, when the user is
attempting to break the capsule, this will serve as confirmation to
the user that the capsule has indeed been satisfactorily ruptured.
The interesting possibility of observing a coloured liquid may also
serve as an incentive to encourage users to break the capsule upon
disposal of the smoking article.
[0065] In some embodiments, the degradation of the smoking article
is enhanced by means of a chemical reaction between the liquid and
one or more of the remaining components of the smoking article,
such as the filter material. The chemical contained within the
capsule may be selected to react specifically with the particular
component of the smoking article. Alternatively, the chemical may
show a less selective capacity to chemically react with and degrade
the smoking article, for example the chemical may be a weakly
acidic solution.
[0066] The filter may comprise two or more capsules containing
different liquids. The different liquids may react together or
otherwise combine to form a liquid capable of enhancing the
degradation of the smoking article. Alternatively, different
components of the smoking article may be subject to degradation by
different liquids.
[0067] In some embodiments, the capsule contains a solution which
acts as an attractant to microorganisms, insects, or other
organisms. Thus, the rate of degradation of the smoking article is
effectively enhanced by the action of the living organisms.
[0068] According to these embodiments, the capsule may contain an
environmentally acceptable aqueous solution of, for example,
glucose (or other sugar solution), salt (as a saline solution), or
starch (as a thin corn starch syrup). The skilled person will be
aware that in all of these embodiments the selection of the
materials comprising the reminder of the smoking article is
important to promote the action of the microorganisms.
[0069] The capsule is intended to be ruptured upon disposal of the
smoking article, and frequently, spent smoking articles are
associated with undesired odours. Therefore, in addition to the
degrading action, the liquid may additionally possess deodorising
qualities. Alternatively, individual degrading and deodorising
liquids may be incorporated into the filter in separate capsules,
to be ruptured simultaneously.
[0070] The deodorising agent may be a neutralising agent or a
masking agent, or be a combination of neutralising and masking
agents.
[0071] Preferred deodorisers include
2-trans-3,7-dimethyl-2,6-octadien-8-ol (often known as geraniol),
1-carvone, 1-carveol, terpinyl acetate, geranyl propionate,
citronellyl butyrate, citral, cis-3-hexenol, triacetin, benzyl
benzoate, acetone, safrole, terpinyl propionate, methyl salicylate,
hexyl cinnamic aldehyde, isopropyl alcohol, triethylglycol
diacetate (TEGDA), OdorGone.TM., methyl cinnamaldehyde, linalyl
propionate, acetic acid, citronellal, citronellyl formate, geranyl
formate and linalool. Mixtures of these compounds are also
suitable. Many other masking agents, such as perfumes, e.g.
essential oils used in pot pourri, are also suitable compounds for
use in the present invention.
[0072] The filter material used in the filters of the vast majority
of currently available smoking articles is composed of cellulose
acetate fibres and does not readily disintegrate or biodegrade.
[0073] The filter material of one embodiment of the invention is
composed of polyvinyl alcohol. Polyvinyl alcohol is commercially
available as a thermoplastic, water soluble, solid polymer that is
relatively inexpensive and non-toxic. Polyvinyl alcohol is unique
in being the only biodegradable, carbon-carbon backbone polymer
capable of complete biodegradation under environmental conditions.
Thus, in the embodiment shown, when the spent smoking article is
discarded, the user ruptures the capsule, for example by squeezing
the filter, or by stepping on the spent smoking article. This
releases the water contained within the capsule, which migrates
throughout the filter, and promotes the degradation of the
polyvinyl alcohol filter material.
[0074] In alternative embodiments, other water-degradable
substances may be used, such as starch, ethylene vinyl alcohol
copolymers, polylactic acid, creped paper manufactured from a wood
pulp sheet, or a regenerated cellulose fibre bundle.
[0075] As described above, the liquid may not act to dissolve the
filter material, but may enhance the degradation of the smoking
article via some other mechanism. For example, in some embodiments,
the filter material may be cellulose acetate which has been
manufactured using a water-soluble plasticizer to bind the
cellulose acetate fibres. According to these embodiments, the
liquid may be water, and other components, such as the plugwrap,
tipping paper, and/or adhesive, may also preferably be
water-soluble or water-dispersible. Consequently, rupture of the
capsule results in dissociation of the components of the filter,
including dispersion or dissolution of the plasticizer. As a
result, the cellulose acetate fibres are no longer bound to one
another and the filter material disintegrates and the individual
cellulose acetate fibres are able to disperse. As an alternative to
the use of a water-soluble plasticizer, non-woven or loose
processed cellulose acetate fibres may be used.
[0076] In embodiments in which the liquid promotes the dissociation
of the components of the smoking article, the filter may further
comprise a material or powder which is capable of expansion upon
the action of the liquid. In this way, rupture of the capsule
results in expansion of this substance and consequent rupture of
the filter. Suitable materials capable of expansion will be known
to the skilled person. For example, materials which will swell upon
contact with water include carboxymethyl cellulose,
water-dispersible starch, chemically modified starch, and super
absorbent polymers such as a cross-linked copolymer of acrylic acid
and sodium acrylate or a cross-linked copolymer of acrylamide and
potassium acrylate. These materials may be incorporated into the
filter, for example in powder form, and will swell when exposed to
water, for example water from the capsule of the invention. The
swelling action physically separates the components of the filter,
enhancing disintegration of the structure and dispersion of the
components.
[0077] In other embodiments, the liquid may be an aqueous solution
comprising biological agents capable of degrading the cellulose,
such as cellulase enzymes.
[0078] In some embodiments, the filter material may comprise paper.
The liquid may be water, which will not dissolve paper but will
nevertheless enhance its disintegration and degradation.
[0079] Filter materials may be used which are not biodegradable per
se but may be disintegrated or converted into a biodegradable form
by the action of a particular chemical held within the capsule.
[0080] Many smoking articles are configured to entrain a flavourant
within the smoke that is drawn along the smoking article by the
user. This is frequently achieved by the incorporation of
flavourant-containing capsules within the smoking article filter.
In such smoking articles, encapsulation prevents the volatile
flavourant from evaporating prematurely, with the capsule being
ruptured to release the flavourant prior to use of the smoking
article. This method of flavouring smoking articles is not
obviously compatible with the degradable smoking articles described
herein, however. This is due to the abundance of capsules that
would be required in the filter, and the fact that the flavourant
capsules should be ruptured prior to smoking, whereas the capsules
of degrading liquid should be broken upon disposal of the spent
smoking article.
[0081] Consequently, in some embodiments of the present invention,
the filter may comprise a thread passing along a longitudinal axis
of the filter from the tobacco rod end to the mouth end. According
to these embodiments, the threads are loaded with aromatic or
flavourant material. Thus, as smoke is drawn along the smoking
article, flavourant held within the thread becomes entrained in the
smoke. The use of a flavourant-enriched thread also provides a
simple means of incorporating flavourant into the smoking article
filter, requiring minimal modification of the manufacturing
process.
[0082] As used herein, the term "flavour", "flavouring", and
"flavourant" refer to materials which may be used to create a
desired taste or aroma. Preferred flavourants include extracts
(e.g., licorice, hydrangea, Japanese white bark magnolia leaf,
chamomile, fenugreek, clove, menthol, Japanese mint, aniseed,
cinnamon, herb, wintergreen, cherry, berry, peach, apple, Drambuie,
bourbon, scotch, whiskey, spearmint, peppermint, lavender,
cardamon, celery, cascarilla, nutmeg, sandalwood, bergamot,
geranium, honey essence, rose oil, vanilla, lemon oil, orange oil,
cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel,
piment, ginger, anise, coriander, coffee, or a mint oil from any
species of the genus Mentha), flavour masking agents, bitterness
receptor site blockers, receptor site enhancers, sweeteners (e.g.,
sucralose, acesulfame potassium, aspartame, saccharine, cyclamates,
lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and
other additives such as chlorophyll, minerals, botanicals, or
breath freshening agents. They may be imitation, synthetic or
natural ingredients or blends thereof.
[0083] The preferred material for the manufacture of the thread is
cotton, although other materials such as cellulose acetate and
rayon, or natural materials such as plant fibres, may also be used.
According to these embodiments, the liquid held within the capsule
may be capable of degrading the flavourant-enriched thread.
[0084] In some preferred embodiments of the present invention,
moisture disintegrative papers are used as the plugwrap, tobacco
wrapping paper and tipping paper. Thus when the capsule is
ruptured, water is released, and the degradation of the paper
wrappers is enhanced, promoting the dissociation of the smoking
article.
[0085] In alternative embodiments, one or more of the papers used
in the smoking article may not be disintegrated by water, but may
be otherwise biodegradable. In other embodiments, one or more of
the papers are not biodegradable per se but may be disintegrated by
the action of a particular chemical held within the capsule, such
as a weakly acidic solution, for example.
[0086] In order to produce an unusual visual effect, in some
embodiments, the filter comprises a transparent window which allows
visualisation of the filter material and/or capsule within the
filter. In some such embodiments, the capsule is held in a cavity
formed between two pieces of filter material and the transparent
window is aligned with the cavity section of the filter material.
In this way the user is provided with the unusual effect of being
able to visualise the capsule within the filter, and this may serve
as a reminder to break the capsule once the smoking article has
been smoked. To produce the effect of a transparent window, the
tipping paper may comprise a single piece of transparent material,
which can be, but is not limited to, one of polypropylene,
polyvinyl chloride (PVC), cellulose acetate film, polyethylene
terephthalate (PET), polyethylene oxide (PEOX), polyethylene,
cellophane, Natureflex.TM., polylactic acid, plastarch material,
polycaprolactone, polyglycolide, a polyhydroxyalkanoate such as
poly-3-hydroxybutyrate, and zein-derived bioplastics. The tipping
paper has an opaque coating on certain portions to leave a
transparent uncoated section which defines the window. Since the
material will be in contact with moisture from the user's mouth and
fingers, the transparent material used is either insoluble, or is
treated with a water-resistant external coating. According to these
embodiments comprising a transparent material, the liquid held
within the capsule may be capable of degrading the transparent
material.
[0087] Adhesive is generally used to bond the seams of the
plugwrap, tipping paper, and cigarette paper of a smoking article.
In preferred embodiments of the invention, water-soluble or
water-dispersible adhesives are used. Water released from the
capsule when it is ruptured causes loss of the bonding between the
various components of the smoking article, resulting in the
individual components having greatly increased exposure to the
environment, and thus being susceptible to accelerated
disintegration and biodegradation.
[0088] The preferred water soluble adhesives for the seam adhesives
are liquid starch adhesives. Hot melt adhesives, or EVA and PVA
adhesives may also be used.
[0089] In some embodiments, one or more of the adhesives used are
not water soluble. In this case, a solvent is held within the
capsule which acts to soften or solubilise the adhesive, promoting
disintegration of the smoking article.
[0090] Although the vehicle containing the liquid capable of
enhancing the disintegration and/or dispersion of the smoking
article has been generally described above as being a capsule,
other fluid-containing vehicles can be used. For instance, pockets
or pouches formed directly within a filter material or from a
separate material such as polyethylene could be used, to be
ruptured once the smoking article has been smoked. Also, a
sponge-like porous material such as a foamed plastic polymer could
be used to contain the fluid, which could be released via a
squeezing or twisting action once the smoking article has been
smoked. Other suitable fluid-containing arrangements would be
evident to those skilled in the art.
[0091] Above is described what is believed to be the preferred
embodiment of the invention. However, those skilled in the art will
recognise that changes and modifications may be made without
departing from the scope of the invention a defined in the
claims.
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