U.S. patent application number 15/575679 was filed with the patent office on 2018-10-04 for aerosol generating material and devices including the same.
The applicant listed for this patent is BRITISH AMERICAN TOBACCO (INVESTMENTS) LIMITED. Invention is credited to Bryan ALLBUTT, Walid Abi AOUN, Edward Dennis JOHN.
Application Number | 20180279666 15/575679 |
Document ID | / |
Family ID | 53506082 |
Filed Date | 2018-10-04 |
United States Patent
Application |
20180279666 |
Kind Code |
A1 |
AOUN; Walid Abi ; et
al. |
October 4, 2018 |
AEROSOL GENERATING MATERIAL AND DEVICES INCLUDING THE SAME
Abstract
There is provided a solid aerosol generating material including
about 5-35 wt % tobacco extract; about 50-80 wt % filler; about
10-35 wt % aerosol generating agent; and about 2.5-10 wt % binder;
wherein weight percentage is calculated on a dry weight basis.
Inventors: |
AOUN; Walid Abi; (London,
GB) ; ALLBUTT; Bryan; (London, GB) ; JOHN;
Edward Dennis; (London, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BRITISH AMERICAN TOBACCO (INVESTMENTS) LIMITED |
LONDON |
|
GB |
|
|
Family ID: |
53506082 |
Appl. No.: |
15/575679 |
Filed: |
May 19, 2016 |
PCT Filed: |
May 19, 2016 |
PCT NO: |
PCT/EP2016/061313 |
371 Date: |
November 20, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A24F 47/008 20130101;
A24B 15/32 20130101; A24F 40/20 20200101; A24B 15/167 20161101;
A24B 15/14 20130101; A24B 15/24 20130101; A24F 40/46 20200101; A24B
15/403 20130101; A24B 3/14 20130101 |
International
Class: |
A24B 15/14 20060101
A24B015/14; A24B 15/32 20060101 A24B015/32; A24B 15/40 20060101
A24B015/40; A24B 15/24 20060101 A24B015/24; A24B 3/14 20060101
A24B003/14; A24F 47/00 20060101 A24F047/00; A24B 15/16 20060101
A24B015/16 |
Foreign Application Data
Date |
Code |
Application Number |
May 20, 2015 |
GB |
1508671.3 |
Claims
1. A solid aerosol generating material comprising; about 5-35 wt %
tobacco extract; about 50-80 wt % filler; about 10-35 wt % aerosol
generating agent; and about 2.5-10 wt % binder, wherein weight
percentage is calculated on a dry weight basis.
2. The aerosol generating material according to claim 1 in the form
of a sheet.
3. The aerosol generating material according to claim 1, wherein
the filler is an organic material comprising at least one of wood
pulp, cellulose or cellulose derivatives.
4. The aerosol generating material according to claim 3, wherein
the filler comprises chalk.
5. The aerosol generating material according to claim 1, wherein
the aerosol generating agent comprises at least one of: a polyol, a
monohydric alcohol, a non-polyol high boiling point hydrocarbon, an
acid, a glycerol derivative, an ester, or a mixture thereof.
6. The aerosol generating material according to claim 5, wherein
the aerosol generating agent comprises glycerol or propylene
glycol.
7. The aerosol generating material according to claim 1, wherein
the binder comprises at least one of an alginate, a polysaccharide,
a cellulose, a modified cellulose, a starch, a a modified starch,
or a natural gum.
8. The aerosol generating material according to claim 7, wherein
the binder comprises an alginate, and wherein the alginate is at
least one of sodium alginate, calcium alginate, potassium alginate
or ammonium alginate.
9. The aerosol generating material according to claim 1, wherein
the aerosol generating material is a cast material.
10. A component for aerosol generation by electrical heating, the
component comprising an aerosol generating material according to
claim 1 and an electrically resistive heating element, wherein the
electrically resistive heating element is at least partially
embedded in the aerosol generating material.
11. A device for generating an inhalable aerosol or gas, the device
comprising an aerosol generating material according to claim 1 and
a heating means which volatilises components in use to form an
aerosol or gas.
12. The device according to claim 11, wherein the heating means is
an electrical heating means.
13. The device according to claim 12, wherein the electrical
heating means is an electrically resistive heating element.
14. The device according to claim 11, wherein the heating means is
at least partially embedded in the aerosol generating material.
15. The device according to claim 11, wherein the device is a
tobacco heating product.
16. A method of making an aerosol generating material comprising
components including about 5-35 wt % tobacco extract, about 50-80
wt % filler, about 10-35 wt % aerosol generating agent, and about
2.5-10 wt % binder, wherein weight percentage is calculated on a
dry weight basis, the method comprising: providing a slurry
comprising the components of the aerosol generating material and
water; casting, extruding or spraying the slurry; and drying the
slurry to form the solid aerosol generating material.
17. The method of making an aerosol generating material according
to claim 16 further comprising initially preparing the tobacco
extract with a pH that exceeds about 6.
18. The aerosol generating material according to claim 1, wherein
the filler is an inorganic material comprising at least one of
calcium carbonate, perlite, vermiculite, diatomaceous earth,
colloidal silica, magnesium oxide, magnesium sulphate or magnesium
carbonate.
19. The aerosol generating material according to claim 5, wherein
the aerosol generating agent comprises one or more of sorbitol,
glycerol, propylene glycol, triethylene glycol, lactic acid,
diacetin, triacetin, triethylene glycol diacetate, triethyl
citrate, ethyl myristate, isopropyl myristate, methyl stearate,
dimethyl dodecanedioate, dimethyl tetradecanedioate, or mixtures
thereof.
20. The aerosol generating material according to claim 5, wherein
the aerosol generating agent comprises: sorbitol, glycerol,
propylene glycol, triethylene glycol, or another polyol, or
diacetin, triacetin, triethylene glycol diacetate, triethyl
citrate, ethyl myristate, isopropyl myristate, methyl stearate,
dimethyl dodecanedioate, dimethyl tetradecanedioate, or another
ester, or a mixture thereof.
Description
PRIORITY CLAIM
[0001] The present application is a National Phase entry of PCT
Application No. PCT/EP2016/061313, filed May 19, 2016, which claims
priority from GB Patent Application No. 1508671.3, filed May 20,
2015, each of which is hereby fully incorporated herein by
reference.
TECHNICAL FIELD
[0002] The present disclosure relates to aerosol generating
material which emits an aerosol and/or gas on heating.
BACKGROUND
[0003] Tobacco material is heated in smoking articles for the
purpose of releasing substances contained in the material and
delivering these as an aerosol.
[0004] In many smoking articles, combustion of tobacco material
releases thermal energy which in turn releases a smoke aerosol from
the tobacco material. Combustion causes various physico-chemical
degradation processes, which may be a combination of oxidative
degradation, pyrolysis, pyrosynthesis, and distillation. The
thermal energy generated by combustion tends to be high, however,
and the amount of heat released is often difficult to control.
[0005] In other smoking articles, the heat providing the thermal
energy needed to release an aerosol is provided by electrical
heating.
[0006] Heat not burn devices (also known as tobacco heating devices
or tobacco heating products) are non-combustion type smoking
articles, developed as an alternative to conventional, combustible
cigarettes. These devices volatilize components of tobacco by
heating the tobacco material, suitably by electrical heating
(although other means of heating could be used); pyrolysis or
combustion of the tobacco or volatiles is avoided. The volatilized
components condense to form an inhalable aerosol.
SUMMARY
[0007] According to a first aspect of the disclosure, there is
provided a solid aerosol generating material comprising about 5-35
wt % tobacco extract, about 50-80 wt % filler, about 10-35 wt %
aerosol generating agent and about 2.5-10 wt % binder.
[0008] In use, the aerosol generating material is heated to
generate at least one delivery of an inhalable aerosol and/or gas.
In some cases, the aerosol generating material may be heated to
generate multiple deliveries of an inhalable aerosol and/or
gas.
[0009] All percentages by weight described herein (denoted wt %)
are calculated on a dry weight basis, unless explicitly stated
otherwise. All weight ratios are also calculated on a dry weight
basis. A weight quoted on a dry weight basis refers to the whole of
the extract or slurry or material, other than the water, and may
include components which by themselves are liquid at room
temperature and pressure, such as glycerol. Conversely, a wet
weight refers to all components, including water.
[0010] In some embodiments, the aerosol generating material is in
the form of a sheet.
[0011] In some embodiments, the filler comprises an inorganic
material such as calcium carbonate, perlite, vermiculite,
diatomaceous earth, colloidal silica, magnesium oxide, magnesium
sulphate and magnesium carbonate. In some embodiments, the filler
comprises chalk. In some cases, the filler comprises an organic
material such as wood pulp, cellulose and cellulose
derivatives.
[0012] In some embodiments, the aerosol generating agent comprises
a polyol such as sorbitol, glycerol, and glycols like propylene
glycol or triethylene glycol; a non-polyol such as monohydric
alcohols, high boiling point hydrocarbons, acids such as lactic
acid, glycerol derivatives, esters such as diacetin, triacetin,
triethylene glycol diacetate, triethyl citrate or myristates
including ethyl myristate and isopropyl myristate and aliphatic
carboxylic acid esters such as methyl stearate, dimethyl
dodecanedioate and dimethyl tetradecanedioate. In some embodiments,
the aerosol generating agent comprises glycerol or propylene
glycol.
[0013] In some embodiments, the binder comprises alginate,
celluloses or modified celluloses, starches or modified starches,
or natural gums. In some embodiments, the binder comprises an
alginate such as sodium alginate, calcium alginate, potassium
alginate or ammonium alginate.
[0014] In some embodiments, the aerosol generating material is a
cast material.
[0015] According to a second aspect of the present disclosure,
there is provided a component for aerosol generation by electrical
heating, the component comprising an aerosol generating material as
described herein and an electrically resistive heating element,
wherein the electrically resistive heating element is at least
partially embedded in the aerosol generating material.
[0016] According to a third aspect of the present disclosure, there
is provided a device for generating an inhalable aerosol and/or
gas, the device comprising an aerosol generating material as
described herein and a heating means which volatilizes components
in use to form an aerosol and/or gas.
[0017] In some embodiments, the heating means is an electrical
heating means. In some embodiments, the electrical heating means is
an electrically resistive heating element.
[0018] In some embodiments, the heating means is at least partially
embedded in the aerosol generating material.
[0019] In some embodiments, the device for generating an inhalable
aerosol and/or gas comprises a component for aerosol generation by
electrical heating as described herein.
[0020] In some embodiments, the device is a tobacco heating product
(also known as a heat not burn device or a tobacco heating
device).
[0021] According to a fourth aspect of the present disclosure,
there is provided a slurry for forming an aerosol generating
material as described herein, comprising water, about 5-35 wt %
tobacco extract, about 50-80 wt % filler, about 10-35 wt % aerosol
generating agent and about 2.5-10 wt % binder.
[0022] According to a fifth aspect of the disclosure, there is
provided a method of making an aerosol generating material as
described herein. The method comprises (a) providing a slurry
comprising the components of the aerosol generating material and
water, (b) casting, extruding or spraying the slurry, and (c)
drying the slurry to form the solid aerosol generating
material.
[0023] According to a sixth aspect of the disclosure, there is
provided the use of an aerosol generating material as described
herein, a component as described herein or a device as described
herein, to generate an aerosol and/or gas.
[0024] To the extent that they are compatible, optional or
preferable features of each aspect of the disclosure may be
combined with other aspects of the disclosure defined herein.
Specifically, features of the aerosol generating material described
herein may be applicable to the component for aerosol generation,
the device for generating an inhalable aerosol and/or gas, the
slurry for making the aerosol generating material and methods of
making the aerosol generating material, and vice versa.
[0025] Further features and advantages will become apparent from
the following description of embodiments of the disclosure, given
by way of example only.
DETAILED DESCRIPTION
[0026] The present disclosure relates to an aerosol generating
material that may be heated to emit an inhalable aerosol and to
devices incorporating the same.
[0027] More specifically, the present disclosure provides a solid
aerosol generating material comprising about 5-35 wt % tobacco
extract, about 50-80 wt % filler, about 10-35 wt % aerosol
generating agent and about 2.5-10 wt % binder.
[0028] The disclosure also provides a component for aerosol
generation by electrical heating comprising an aerosol generating
material as described herein and an electrically resistive heating
element, wherein the electrically resistive heating element is at
least partially embedded in the aerosol generating material.
[0029] The disclosure also provides a device for generating an
inhalable aerosol and/or gas, the device comprising an aerosol
generating material as described herein. In some embodiments, the
device comprises a component for aerosol generation as described
herein.
[0030] The inventors have found that specific amounts of the
various components must be included in the aerosol generating
material. As set out in detail below, the aerosol generating
material is generally a cast or extruded material, suitably formed
from a slurry of the constituent components. If the relative
proportions of the constituents are incorrect, the binder may gel,
the slurry solids content may be too high and/or the slurry may be
too viscous (or conversely, not viscous enough), thereby preventing
casting or extrusion. Additionally, the aerosol generating
materials defined herein produce an aerosol with acceptable
characteristics such as taste and density, whilst forming the
aerosol efficiently and effectively.
Tobacco Extract
[0031] The aerosol generating material comprises a tobacco extract.
A tobacco extract is a composition of tobacco that is obtained by a
method comprising the treatment of tobacco with a solvent, and may
further comprise other treatment steps (such as concentration). The
extract may be formed by the treatment of any suitable tobacco,
such as single grades or blends, cut rag or whole leaf, including
Virginia and/or Burley and/or Oriental tobacco.
[0032] The solid aerosol generating material comprises about 5-35
wt % tobacco extract. In some embodiments, the aerosol generating
material comprises 5-25 wt %, 5-20 wt %, 10-20 wt % or 10-15 wt %
tobacco extract. In some embodiments, it may comprise at least
about 5%, 7%, 10% or 12% by weight of tobacco extract. In some
embodiments, it may comprises less than about 35%, 25%, 20%, 18% or
15% by weight of tobacco extract. In some embodiments, the solid
aerosol generating material comprises about 12 wt % tobacco
extract.
[0033] In some embodiments, the tobacco extract may be obtained by
a method comprising the treatment of tobacco with water. In some
embodiments, the treatment of tobacco with water may comprise
adding water to tobacco, separating the resulting water-based
liquid extract from the insoluble portion of tobacco feedstock, and
optionally removing excess water to form a tobacco extract. Any
suitable filtration methods may be used, such as centrifugal solids
filtration or vacuum fluidized bed filtration. Any suitable
evaporative concentration methods may be used, such as vacuum
spinning disk, vacuum falling, or rising film evaporation.
Techniques including spray-drying or freeze-drying may also be
utilized to reduce/remove water content. Such processes would be
known to those skilled in the art of filtration and evaporative
concentration.
[0034] In some embodiments, tobacco extract may be obtained by a
method comprising altering the pH of the solution. In some
embodiments, the pH of the tobacco extract may be greater than or
equal to about 6, 6.5, 7, 7.5, 8 or 9. In some cases, the pH of the
tobacco extract is less than or equal to about 10.5, 10 or 9.5. In
some embodiments, the pH of the tobacco extract is greater than or
equal to about 7. In some embodiments, the pH of the tobacco
extract is about 7. Altering the pH of the solution may comprise
the addition of an alkaline material, suitably a carbonate such as
lithium, sodium, potassium or calcium carbonate, to the solution to
increase the pH. In some embodiments, the water extract solution is
acidic (pH around 5.2) and, on addition of a metal carbonate, the
pH is adjusted to give a tobacco extract solution with pH of
greater than or equal to about 7. The inventors have found that a
tobacco extract with a pH in the claimed range reduces excessive
gelling on addition to a slurry, giving a mixable slurry that is
easily processable into a homogenous aerosol generating material.
The slurry viscosity is such that the slurry can be easily cast or
extruded. If the pH of the tobacco extract is too acidic, the pH of
the slurry may drop causing solvation of metal ions (such as
calcium ions from chalk), which in turn cause excessive
gelation.
[0035] In some embodiments, tobacco extract may be obtained by a
method comprising extraction using a supercritical fluid, e.g.
supercritical carbon dioxide. In some other embodiments, tobacco
extract may be obtained by a method comprising extraction with a
solvent which may comprise a polyol or other suitable higher
boiling liquids. In some cases, the extraction solvent may comprise
glycerol and/or propylene glycol (and optionally water).
[0036] In some embodiments, the tobacco extract may be prepared by
a method comprising steps for removing or reducing the
concentration of certain substances. For example, the tobacco
extract may be treated with bentonite to reduce protein content,
and/or polyvinylpolypyrrolidone to reduce polyphenol content.
[0037] In some embodiments, the tobacco extract may be prepared by
a method comprising adding or increasing the concentration of one
or more substances. In some of these embodiments, aerosol
generating agents and/or flavorants may be added, for example.
[0038] A tobacco extract included in the aerosol generating
material in the devices of the invention may have any suitable
chemical composition. The solid content of the tobacco extract may
be at least about 2%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%
50%, 60%, 75%, 80%, 85%, 90% or 95% on a wet weight basis (total
weight including water). The tobacco extract may have a pH in the
range of 5 to 9, suitably 6 to 8, 6.5 to 7.5 or about 7.
Filler
[0039] The aerosol generating material comprises a filler. Suitably
the filler may comprise one or more inorganic filler materials,
which include, but are not limited to: calcium carbonate, perlite,
vermiculite, diatomaceous earth, colloidal silica, magnesium oxide,
magnesium sulphate, magnesium carbonate, and suitable inorganic
sorbents, such as molecular sieves. Chalk is particularly suitable.
In some cases, the filler may comprises one or more organic filler
materials, which include, but are not limited to: wood pulp,
cellulose and cellulose derivatives.
[0040] The filler material may be selected to have one or more
purposes. In some embodiments, it may act as a sorbent and/or
support for other substances in the aerosol generating material. In
some embodiments, it may act as a structure for adsorbing other
substances before releasing them on heating. In some embodiments,
it may act as a sorbent and/or support for an aerosol generating
agent, such as glycerol, and/or any other substances that influence
the sensory characteristics of the aerosol generated on
heating.
[0041] In some embodiments, an inorganic filler material may be
included in the aerosol generating material to provide additional
strength. In some embodiments, it may be included to help retain
the tobacco extract within the aerosol generating material and to
provide an aerosol generating material with suitable strength for
subsequent processing/utilization.
[0042] The aerosol generating material comprises about 50-80 wt %
filler, suitably an inorganic filler material. In some embodiments,
the aerosol generating material comprises 60-80 wt % or 65-75 wt %
filler. In some embodiments, it may comprise at least about 50%,
55%, 60%, 65% or 67% by weight of filler. In some embodiments, it
may comprise less than about 80%, 78%, 75% or 70% by weight of
filler. In some embodiments, the solid aerosol generating material
comprises about 67 wt % filler. In these embodiments, the filler
may comprise, substantially consist of or consist of chalk.
[0043] A filler material is necessary to give the solid aerosol
generating material a dry consistency which means that the material
can be processed down-stream (shredded, blended, rolled, crimped,
shaped etc.). If the filler content is too low, the aerosol
generating material is not processable; the material is typically
tacky or sticky. Additionally, the inventors believe that the
filler material, and in particular chalk, increases the strength of
the aerosol generating material, prevents migration of the aerosol
generating agent (i.e. ensures a uniform composition) and minimizes
unwanted water uptake (i.e. the material is then less
hygroscopic).
[0044] However, the inventors have also established that, if the
filler content is too high, the aerosol generating material is
difficult to form. In some embodiments, the aerosol generating
material is formed from a slurry (as discussed in detail herein)
and, if the filler content is high, the slurry is difficult to
process because the solid content is too high. A high filler
content makes it difficult to cast the slurry (although extrusion
may be possible). Additionally, if the filler content is too high
it may insulate the volatilizable components of the aerosol
generating material, thereby necessitating the use of more energy
to form an aerosol and to consume all of the material. The
inventors have established that the filler content defined herein
provides a good balance of these properties.
Aerosol Generating Agent
[0045] The aerosol generating material comprises an aerosol
generating agent. In this context, an "aerosol generating agent" is
an agent that promotes the generation of an aerosol. An aerosol
generating agent may promote the generation of an aerosol by
promoting an initial vaporization and/or the condensation of a gas
to an inhalable solid and/or liquid aerosol. In some embodiments,
an aerosol generating agent may improve the delivery of flavor from
the aerosol generating material.
[0046] Any suitable aerosol generating agent or agents may be
included in the aerosol generating material of the disclosure.
Suitable aerosol generating agents include, but are not limited to:
a polyol such as sorbitol, glycerol, and glycols like propylene
glycol or triethylene glycol; a non-polyol such as monohydric
alcohols, high boiling point hydrocarbons, acids such as lactic
acid, glycerol derivatives, esters such as diacetin, triacetin,
triethylene glycol diacetate, triethyl citrate or myristates
including ethyl myristate and isopropyl myristate and aliphatic
carboxylic acid esters such as methyl stearate, dimethyl
dodecanedioate and dimethyl tetradecanedioate. Suitably, the
aerosol generating agent may comprise, substantially consist of, or
consist of glycerol, propylene glycol, triacetin and/or ethyl
myristate. In some cases, the aerosol generating agent may
comprise, substantially consist of, or consist of glycerol and/or
propylene glycol.
[0047] The solid aerosol generating material comprises about 10-35
wt % aerosol generating agent. In some embodiments, the aerosol
generating material comprises 10-30 wt %, 15-25 wt % or 15-20 wt %
aerosol generating agent. In some embodiments, it may comprise at
least about 10%, 12% or 15% by weight of aerosol generating agent.
In some embodiments, it may comprise less than about 35%, 30%, 25%
or 20% by weight of aerosol generating agent.
[0048] A minimum amount of aerosol generating agent is required to
efficiently and effectively generate an aerosol. However, the
inventors have found if the amount of aerosol generating agent is
too high, the aerosol generating material is difficult to form. In
some embodiments, the aerosol generating material is formed from a
slurry (as discussed in detail herein) and, if the aerosol
generating agent content is high, the resulting aerosol generating
material is too tacky/sticky/hygroscopic to allow processing into a
consumable product. The inventors have established that the aerosol
generating agent content defined herein provides a good balance of
these properties.
Binder
[0049] The aerosol generating material comprises 2.5-10 wt %
binder. In some embodiments, the binder comprises one or more of an
alginate, celluloses or modified celluloses, starches or modified
starches, and natural gums.
[0050] Suitable binders include, but are not limited to: alginate
salts comprising any suitable cation; celluloses or modified
celluloses, such as hydroxypropyl cellulose and
carboxymethylcellulose; starches or modified starches;
polysaccharides such as pectin salts comprising any suitable
cation, such as sodium, potassium, calcium or magnesium pectate;
xanthan gum, guar gum, and any other suitable natural gums; and
mixtures thereof. In some embodiments, the binder comprises,
substantially consists of or consists of one or more alginate salts
selected from sodium alginate, calcium alginate, potassium alginate
or ammonium alginate.
[0051] In some embodiments, the aerosol generating material
comprises 5-10 wt %, 6-9 wt %, 6-8 wt % or 6-7 wt % binder. In some
embodiments, it may comprise at least about 2.5%, 3%, 4%, 5% or 6%
by weight of binder. In some embodiments, it may comprise less than
about 10%, 9%, 8% or 7% by weight of binder. In some embodiments,
the aerosol generating material comprises 6.2-6.8 wt % binder. In
some embodiments, the aerosol generating material contains more
tobacco extract (dry weight) than binder.
[0052] The binder increases the toughness or strength of the
aerosol generating material. It also increases the viscosity of the
slurry used to form the aerosol generating material, allowing it to
be cast or extruded (for example) and to retain the desired shape.
However, higher binder contents are undesirable because the
slurries used to form the aerosol generating material may become
too viscous to allow casting. Additionally, the cost of such
aerosol generating materials increases with the binder content
level.
[0053] The inventors have also found that the weight ratio of
tobacco extract to binder (such as alginate) is important because
ions present in the tobacco extract can cause the binder to gel
excessively and cause syneresis; at the weight ratios claimed,
excessive gelation and syneresis are minimized. Thus, the inventors
have determined suitable maximum binder contents.
[0054] Alginate salts are derivatives of alginic acid and are
typically high molecular weight polymers (10-600 kDa). Alginic acid
is a copolymer of .beta.-D-mannuronic (M) and .alpha.-L-guluronic
acid (G) units (blocks) linked together with (1,4)-glycosidic bonds
to form a polysaccharide. The inventors have determined that
alginate salts with a high M monomer content are less susceptible
to undesired gelling on contact with tobacco extract and
accordingly, syneresis is reduced when using an alginate with a
high M monomer content. The binder may therefore comprise an
alginate salt in which at least about 40%, 45%, 50%, 55%, 60% or
70% of the monomer units in the alginate copolymer are
0-D-mannuronic units.
Further Optional Components
[0055] In some embodiments, one or more further components may be
included in the aerosol generating material.
[0056] In some embodiments, additional ingredients may be included
in the aerosol generating material for amelioration of sensory
characteristics of the aerosols generated. In some cases, water,
flavorings, casings, or substances which may be acidic or basic in
character may alter the taste, flavor, and sensory impact of the
aerosol. In some embodiments, these additional ingredients may lead
to a milder or mellow effect. In some embodiments, they may lead to
more pronounced sensory effects.
[0057] In some embodiments, the aerosol generating material may
comprise water. Water may be included for any suitable purpose, and
may be included having been purified using any suitable method of
purification, such as reverse osmosis, distillation, and/or ion
exchange. In some embodiments, it may be included to moisten the
material. Alternatively or in addition, it may be included to
modify the sensory characteristics of the aerosol and/or gas
generated from the material on heating.
[0058] Any suitable quantity of water may be included in the
aerosol generating material. For example, in some embodiments, the
aerosol generating material may comprise about 1-25%, 1-15%, 3-15%,
3-10%, 7-10% or about 3-7% water by weight on a wet weight basis
(i.e. by weight of the total composition including water).
[0059] In some embodiments, the aerosol generating material may
comprise one or more compounds for the purpose of lowering the
boiling point of one or more other substances in the aerosol
generating material. In some of these embodiments, the aerosol
generating material may comprise one or more compounds for the
purpose of forming an azeotrope with one or more other substances
in the aerosol generating material.
[0060] In some embodiments, the aerosol generating material may
comprise one or more flavorants. As used herein, the terms "flavor"
and "flavorant" refer to materials which, where local regulations
permit, may be used to create a desired taste or aroma in a product
for adult consumers.
[0061] The terms "flavor" and "flavorant" may 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,
cardamom, 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), flavor enhancers, bitterness receptor
site blockers, sensorial receptor site activators or stimulators,
sugars and/or sugar substitutes (e.g., sucralose, acesulfame
potassium, aspartame, saccharine, cyclamates, lactose, sucrose,
glucose, fructose, sorbitol, or mannitol), and other additives such
as charcoal, chlorophyll, minerals, botanicals, or breath
freshening agents. They may be imitation, synthetic or natural
ingredients or blends thereof. They may be in any suitable form,
for example, oil, liquid, or powder.
[0062] In some embodiments, the aerosol generating material may
comprise one or more colorants. In some embodiments, the aerosol
generating material may be colored such that it resembles
components of a conventional, combustible cigarette. In some
embodiments a caramel colorant may be included in the aerosol
generating material.
[0063] In some embodiments, the aerosol generating material may
comprise heat-conducting particles. These may improve the rate of
heat transfer in use through the aerosol generating material.
[0064] In some embodiments, the aerosol generating material may
additionally comprise a further tobacco material in addition to
tobacco extract, such as ground tobacco, tobacco fiber, cut
tobacco, extruded tobacco, tobacco stem and/or reconstituted
tobacco.
Component for Aerosol Generation
[0065] The component for aerosol generation by electrical heating
comprises the aerosol generating material described herein and an
electrically resistive heating element, wherein the heating element
is at least partially embedded in the aerosol generating
material.
[0066] By "electrically resistive heating element", it is meant
that on application of a current to the element, resistance in the
element transduces electrical energy into thermal energy which
heats the aerosol generating material.
[0067] The heating element may be in the form of a mesh, coil or a
plurality of wires.
[0068] The heating element may comprise a metal or metal alloy.
Metals are excellent conductors of electricity and thermal energy.
Suitable metals include but are not limited to: copper, aluminum,
platinum, tungsten, gold, silver, and titanium. Suitable metal
alloys include but are not limited to: nichrome and stainless
steel.
[0069] The component for aerosol generation may be formed by
casting, extruding or spraying a slurry onto the heating element,
the slurry comprising the components of the aerosol generating
material and water. The component may be in sheet form.
Device for Generating an Inhalable Aerosol and/or Gas
[0070] The device comprises an aerosol generating material as
described herein and a heating means which volatilizes components
in use to form an aerosol and/or gas.
[0071] In some embodiments, the heating means is an electrical
heating means. In some embodiments, the heating means is at least
partially embedded in the aerosol generating material. In some
embodiments, the electrical heating means is an electrically
resistive heating element.
[0072] In some embodiments, the device comprises a component for
aerosol generation as described herein.
[0073] In some embodiments, the heating of the aerosol generating
material does not result in any significant combustion of the
material. In some embodiments, the heating results in no combustion
or essentially no combustion of the aerosol generating material. In
some embodiments, the device is a heat not burn device, also known
as a tobacco heating device or a tobacco heating product. Such
devices are non-combustion type smoking articles, developed as an
alternative to conventional, combustible cigarettes. These devices
volatilize components of tobacco by heating the tobacco material;
pyrolysis or combustion of the tobacco or volatiles is avoided. The
volatized components condense to form an inhalable aerosol. The
aerosol often comprises water, a humectant, nicotine and optionally
other tobacco components such as flavors and aromas. Thus, in some
embodiments, the device is one in which tobacco is heated to
volatilize components without pyrolysis or combustion of the
tobacco.
[0074] Using electricity to heat aerosol generating material in a
smoking article has many advantages. In particular, it has many
advantages over using combustion. Combustion is a complex process
that generates aerosols by a combination of interactive
physico-chemical processes which may include oxidative degradation,
pyrolysis, pyrosynthesis, and distillation. It generally leads to
the generation of complex aerosols. For example, smoke arising from
a combustible smoking article comprising tobacco is a complex,
dynamic mixture of more than 5000 identified constituents. The
exothermic processes of combustion may be self-sustaining, and may
result in heat generation rates, and heat output quantities,
sufficient for degradation of the combustible matrix. In some
cases, the matrix may be completely degraded to an ash residue
which may comprise inorganic, non-combustible materials. Very high
temperatures can be reached in burning cigarettes due to the
exothermic reaction of combustion. In between taking puffs of a
cigarette (the inter-puff smoldering period), the center of the
burning zone in the tobacco rod of the cigarette can reach
temperatures as high as 800.degree. C. During taking a puff of a
cigarette, the periphery of the burning zone in the tobacco rod of
the cigarette can reach temperatures as high as 910.degree. C.
[0075] Using electrical resistance heating systems (such as some
heat not burn devices, also known as tobacco heating products or
tobacco heating devices) is advantageous because the rate of heat
generation is easier to control, and lower levels of heat are
easier to generate, compared with using combustion for heat
generation. In some embodiments, the device includes an actuator,
which allows the user to initiate electrical heating.
[0076] The use of electrical heating systems therefore allows
greater control over the generation of an aerosol and/or gas from
aerosol generating materials. Furthermore, it allows for aerosol
and/or gas to be generated without combustion taking place, rather
than through combustive degradation. Electrical heating systems can
also facilitate the generation of an aerosol and/or gas from
inherently non-combustible materials, such as inorganic sorbents
with ingredients that generate an aerosol and/or gas when
heated.
[0077] In some embodiments, the devices of the disclosure are able
to provide multiple deliveries or doses of aerosol and/or gas. This
means that the aerosol generating material may be heated to produce
sufficient aerosol and/or gas to allow multiple puffs. This may be
achieved by heating the aerosol generating material for a period of
time sufficient to produce a volume of aerosol and/or gas suitable
for multiple deliveries. In some embodiments, this may involve
heating the aerosol generating material constantly. Alternatively,
this may involve successive, shorter periods of heating the aerosol
generating material, optionally with each period producing a single
delivery or dose of aerosol and/or gas.
[0078] In some embodiments, the device is capable of heating the
aerosol generating material to a temperature sufficient to
significantly increase the rate of evaporation and/or sublimation
of a substance in the aerosol generating material, but insufficient
to initiate combustion. This may be the case when the device is a
heat not burn device. In some other embodiments, the device is
capable of heating the aerosol generating material to a temperature
sufficient to initiate combustion. This may be the case when the
device is a combustible device.
[0079] In some embodiments, the device may be configured to heat
the aerosol generating material to a temperature of between about
50-400.degree. C., 100-350.degree. C., 150-350.degree. C.,
150-330.degree. C., or 180-300.degree. C.
[0080] In some embodiments, the aerosol generating material may be
provided in a cartridge, and the cartridge may be insertable into
the device. In some of these embodiments, this cartridge may be
replaceable. In some embodiments, the cartridge may be combined
with other parts of the aerosol generating device in any suitable
way. In some embodiments, it may be attached to other parts of the
device by a friction fit and/or a screw fit and/or a press fit.
Method of Making the Aerosol Generating Material
[0081] In some embodiments, the aerosol generating material is made
from a slurry, the slurry comprising the components of the aerosol
generating material and water. In some embodiments, the slurry is
extruded or cast and then dried to form the aerosol generating
material. In alternative embodiments, the slurry may be sprayed and
then dried to form the aerosol generating material. In some
embodiments, the method of making the aerosol generating material
further comprises the initial step of making the slurry.
[0082] To form the slurry, the components of the aerosol generating
material may be added in any suitable order. In some embodiments,
the slurry may undergo mixing during and/or after the addition of
its components and, in these embodiments, may undergo mixing for
any suitable length of time. The length of time over which the
slurry undergoes mixing will depend on its composition and volume,
and may be varied accordingly. In some embodiments, the slurry may
undergo mixing as necessary to make the composition of the slurry
substantially homogeneous and to ensure that the slurry has the
required flow and viscosity characteristics for casting.
[0083] Phase separation of slurries used to from the aerosol
generating material defined herein is minimal at the weight ratios
of tobacco extract to binder defined herein. At low binder
concentrations, the inventors have observed separation of water
from the slurry. Thus, the inventors have established that a
minimum binder quantity is necessary as defined herein. The
inventors have also established that the binder to water weight
ratio is important in reducing/minimizing or preventing
syneresis.
[0084] The wet weight ratio of tobacco extract to binder in the
slurry may be in the range of about 10:1 to about 2:1, suitably
about 6:1 to about 3:1. The weight ratio of water (including water
present in other components, such as water used as a solvent in the
tobacco extract) to binder may be in the range of about 100:1, 80:1
or 75:1 to about 50:1, 30:1 or 25:1.
[0085] In some embodiments, the method of the invention comprises
obtaining a tobacco extract, as set out above. The resulting
tobacco extract may be added to the slurry.
[0086] In some embodiments, the method of making a slurry may
comprise (1) mixing the glycerol and binder, (2) adding water and
mixing, (3) adding filler and mixing, (4) adding tobacco extract
and mixing to form a smooth slurry. The mixing after addition of
tobacco extract will typically be a high shear mixing. In
embodiments in which the binder is a solid, (1) creates a
dispersion/suspension of the binder in the aerosol generating
agent.
[0087] In some embodiments, the method of making a slurry may
comprise (1) adding the binder to the water and mixing, (2) adding
the aerosol generating agent and mixing (3) adding filler and
mixing, and (4) adding tobacco extract and mixing thoroughly to
form a smooth slurry.
[0088] In some embodiments, the slurry of aerosol generating
material may be formed by a process comprising adding one or more
additives, such as flavorants or colorants.
[0089] The slurry may be cast into a sheet on a casting plate or
the band of a bandcasting machine. In some embodiments, the slurry
may be cast so that the sheet has approximately even thickness or
depth; a casting knife may be used to ensure even thickness. In
some embodiments, the cast sheet may have a thickness or depth of
about 0.5-6 mm, 0.6-5 mm, 0.7-4 mm, 0.8-3 mm, 0.9-2.5 mm or 1-2 mm.
In some embodiments, the slurry may be cast to have a thickness or
depth of about 2 mm or of about 1 mm.
[0090] After being shaped, for example by casting or extruding, the
slurry may be dried using any suitable method of drying. In some
embodiments, the slurry may be dried at room temperature (i.e.
about 20-25.degree. C.). In some embodiments, the slurry may be
warmed to effect drying. In some embodiments, the slurry may be
dried in warm air (i.e. an oven). In some embodiments, plate or
band on which the wet slurry is resting may be warmed to effect
drying. In embodiments where the slurry is warmed, the slurry may
be dried at any suitable temperature for any suitable length of
time. In some embodiments, the slurry may be dried at a temperature
of about 30-120.degree. C., 70-110.degree. C., 60-100.degree. C.,
40-75.degree. C., 45-60.degree. C. or 45-55.degree. C.
[0091] The cast sheet may be removed from the casting plate or band
of the bandcasting machine by any suitable method. In some cases,
the sheet and plate/band simply separate on application of a force.
In some cases, the sheet may be removed using an item for accessing
the space between structure and the plate, such as a knife or blade
(a "doctoring knife"). Alternatively or in addition, the structure
may be removed by increasing the temperature of the contact point
between the structure and the plate. In some such embodiments, the
structure may be removed from the plate using steam which, in
addition to increasing the temperature of the contact point between
the structure and the plate, causes sorption of water by the
aerosol generating material which aids its removal.
[0092] In some embodiments, the sheet may be conditioned after
being removed from the plate. In some embodiments, the sheet may be
conditioned at a temperature of about 20-25.degree. C., such as
about 22.degree. C. Alternatively or in addition, the component may
be conditioned in air with a relative humidity of about 50-80%,
such as about 60%. Commonly, conditioning is carried out at
22.degree. C. and a relative humidity of 60% for an appropriate
time period, e.g. 48 hours.
[0093] In some embodiments, the component may then be stored (e.g.
in a sealed container) at a temperature below room temperature
(e.g. 4-20.degree. C.) and at any suitable humidity for any
suitable length of time, before being incorporated into the device
of the disclosure.
[0094] In some embodiments, the slurry may be cast, extruded or
sprayed onto an electrically resistive heating element so that, on
drying of the slurry, the electrically resistive heating element is
at least partially embedded in the aerosol generating material.
[0095] The formed aerosol generating material may be rolled, cut,
shredded, blended or subject to other processes before being formed
into suitable consumables and, optionally, incorporated into
devices of the present disclosure.
[0096] The invention will now be illustrated with reference to
examples. These examples are for illustrative purposes only and do
not limit the scope of the invention in any way.
EXAMPLES
[0097] "Solids" and "Solid(s) Content" refer to the whole of the
extract or slurry other than the water, and may include components
which by themselves are liquid at room temperature and pressure,
such as glycerol.
[0098] The term "Wet Weight Basis" (WWB) refers to constituent
concentration data calculated for material weights including water;
"Dry Weight Basis" (DWB) refers to constituent concentration data
for material weights corrected for water content. A weight quoted
on a dry weight basis may include components which by themselves
are liquid at room temperature and pressure, such as glycerol.
[0099] In the Examples, Reverse Osmosis [RO] quality water refers
to softened water which is additionally purified by reverse
osmosis.
Example 1: Tobacco Extraction and Extract Composition
[0100] Seven batches of whole leaf Burley tobacco (4.5 kg per
batch) were extracted with 80 kg water (RO quality) at 60.degree.
C. for 25-30 minutes with gentle agitation. The resulting mixture
was filtered and centrifuged and the combined resulting extracts
(480 l) were concentrated utilizing an evaporative concentration
process to 41.1% solids content (in this context, `solids content`
refers to the non-aqueous portion of the water extract). Table 1
shows the composition of the resulting tobacco extract.
TABLE-US-00001 TABLE 1 Composition of tobacco extract. Ingredient %
weight/weight Solid(s) Content 41.1 Nicotine 3.37
[0101] The nicotine value refers to the absolute nicotine content
of the aqueous tobacco extract (including water). [In other words,
it is quoted on a wet weight basis.]
[0102] The density of the concentrated extract was 1.21
g/cm.sup.3.
[0103] After the process 9.12 kg of concentrated extract was
obtained and stored at -18.degree. C. until required.
Example 2: Aerosol Generating Material--Manufacturing Procedure and
Composition
[0104] Water (756 g--reverse osmosis purified) was placed in a high
shear mixer. Whilst mixing, sodium alginate powder (15.01 g) was
slowly added, ensuring even mixing and full hydration to a smooth,
viscous fluid. Glycerol (24.99 g) was added to the high shear mixer
with continuous mixing. Chalk (156.99 g) was then added in a slow
powder stream with continuous high shear mixing. Finally, tobacco
extract (61.26 g, prepared according to Example 1) was added with
continuous high shear mixing until a smooth, free flowing slurry
was formed.
[0105] After a smooth, free flowing slurry had been formed, the
material was ready for casting into sheet.
[0106] The slurry was then cast onto a stainless steel casting
plate at 2 mm thickness using a casting knife. This provided a
constant thickness of the slurry which was then dried. Drying can
be effected by air drying at ambient conditions for approximately
24 hours or in an oven at about 45-55.degree. C. for 0.5-5 hours
(minimum time used to reduce loss of volatiles). The dried sheet
was then removed from the plate and conditioned by exposure at
22.degree. C. and 60% relative humidity (RH), for 48 hours. In some
cases, the dried sheet was cut off the casting plate using a
"doctoring" knife.
[0107] The resulting aerosol generating material was analyzed for
water, nicotine and glycerol content and the results are shown in
Table 2.
TABLE-US-00002 TABLE 2 Analysis of the aerosol generating material.
Nicotine (mg/g) Glycerol (mg/g) Water (%) 6.7 (WWB) 90.3 (WWB) 6.3
7.15 (DWB) 96.4 (DWB)
[0108] Note: WWB: Wet Weight Basis (data calculated for material
weights including water content); DWB: Dry Weight Basis (corrected
for water content).
Example 3: Aerosol Generation
[0109] Three samples of aerosol generating material, prepared
according to Example 2, were heated in contact with an electrically
resistive heating element. The resulting aerosol was analyzed.
[0110] Table 3 indicates the aerosol composition that resulted in
some of the experiments.
TABLE-US-00003 TABLE 3 Resulting aerosol compositions. Weight of
Analyte in Aerosol Collected (Blank Corrected) Sample Aerosol
Generating Glycerol Number Material Weight (g) Nicotine (mg) (mg) 1
1.4054 9.4 92.8 2 1.4132 9.4 87.4 3 1.3929 9.0 79.0
[0111] Table 4 below indicates the percentage transfer of nicotine
and glycerol from the aerosol generating material to the aerosol
following heating.
TABLE-US-00004 TABLE 4 Percentage transfer of selected substances
to form aerosol. Percentage Transfer of Aerosol Analytes from
Aerosol Generating Generating Material to Sample Material Weight
Aerosol (%) Number (g) Nicotine Glycerol 1 1.4054 99.8 73.1 2
1.4132 99.3 68.5 3 1.3929 96.4 62.8
Example 4: Tobacco Extraction and Extract Composition
[0112] Seven batches of whole leaf Virginia tobacco (4.5 kg per
batch) were extracted with 80 kg water (RO quality) at 60.degree.
C. for 25-30 minutes with gentle agitation. The resulting mixture
was filtered and centrifuged and the combined resulting extracts
(500 l) were concentrated utilizing an evaporative concentration
process to 49.6% solids content (in this context, "solids content"
refers to the non-aqueous portion of the water extract). Table 5
shows the composition of the resulting tobacco extract.
TABLE-US-00005 TABLE 5 Composition of tobacco extract. Ingredient %
weight/weight Solid(s) Content 49.6 Nicotine 3.63
The nicotine value refers to the absolute nicotine content of the
aqueous tobacco extract (including water). [In other words, it is
quoted on a wet weight basis.]
[0113] The density of the concentrated extract was 1.25
g/cm.sup.3.
[0114] After the process 11.68 kg of concentrated extract was
obtained and stored at -18.degree. C. until required.
Examples 5-17
[0115] The aerosol generating materials of these examples were
prepared by:
1. The alginate powder was mixed with glycerol. 2. The
alginate-glycerol mixture was then added to water using a Silverson
homogeniser at a high speed for .about.8 minutes; the beaker was
kept in an ice-box which was filled with ice chips (in order to
keep the mixtures cool, which would have heated up due to high
energy mixing). 3. Chalk was added into the alginate-glycerol-water
mixture and mixed for .about.10 minutes, using a Silverson
homogeniser at the same high speed. 4. Tobacco extract, prepared
according to Example 4, was then added and the homogenisation
carried out for .about.8-10 minutes, depending on the alginate type
and concentration; the homogenisation speed was the same as in
steps 2 and 3. Overall, the total preparatory time was between 20
to 25 minutes.
[0116] The slurry compositions are shown below in Table 6.
TABLE-US-00006 TABLE 6 Slurry compositions. *Tobacco Alginate Chalk
Extract Example Weight Weight Glycerol Weight Number (g) (g) Weight
(g) (g) 5 15.00 157.00 35.00 61.32 6 15.00 157.00 35.00 61.32 7
10.00 162.00 35.00 61.32 8 10.00 162.00 35.00 61.32 9 15.00 157.00
35.00 61.32 10 10.00 162.00 35.00 61.32 11 20.00 151.00 35.00 61.32
12 15.00 117.00 35.00 61.32 13 15.00 77.00 35.00 61.32 14 15.00
37.00 35.00 61.32 15 20.00 117.00 35.00 61.32 16 20.00 77.00 35.00
61.32 17 20.00 37.00 35.00 61.32 *Tobacco extract weight is quoted
on a wet weight basis (i.e. includes water content)
[0117] The slurries were cast onto metal plates to form 1 mm thick
sheets. The casted slurries were placed into an oven (Thermo
Scientific Heraeus Oven) which was pre-set at 45.degree. C. The
slurries were dried into films, and when these were seen to be
self-peeling off the plates, these were taken out of the oven and
allowed to cool to room temperature. The sheets were then
equilibrated in an oven (Binder unit) which was pre-set at
20.degree. C. and 60% relative humidity for 48 hours.
Sheet Constituent Analysis
[0118] The water content of the equilibrated sheets was measured
using the Karl Fischer technique. Approximately 5 g of a sample was
accurately weighed into a dried 50 ml volumetric flask and filled
to the mark with methanol. The sample and extraction solvent were
mixed for 30 minutes and 5 ml of extraction solvent was then
injected into the Karl Fischer equipment. Single extracts of the
samples were taken with 3 measurements per extract carried out.
[0119] The equilibrated sheets were analyzed for nicotine,
propylene glycol and glycerol by GC-FID. For each sample, small
pieces of the sheet were cut off for sample extraction.
Approximately 1 g of sample was accurately weighed into a
centrifuge tube and 20 ml HPLC grade water added. The sample was
macerated in the water for 2 minutes at 5000 rpm and subsequently
filtered through a PTFE 0.45 .mu.m filter into a GC vial for GC-FID
analysis. Each sample was prepared and analyzed in duplicate.
[0120] The results are shown in Table 7 below.
TABLE-US-00007 TABLE 7 Water, nicotine and glycerol content of
formed sheets. Dry Glycerol Nicotine Water Matter mg/g mg/g Example
Repetition (g/100 g) (g/100 g) (DWB) (DWB) 5 1 8.37 91.63 153 8.0 2
149 7.8 6 1 8.62 91.38 155 6.6 2 157 6.3 7 1 7.94 92.06 147 6.7 2
150 5.6 8 1 8.37 91.63 157 7.0 2 154 7.3 9 1 8.33 91.67 149 7.4 2
146 7.4 10 1 7.47 92.53 158 7.1 2 148 7.0 11 1 8.50 91.50 142 6.9 2
147 6.6
[0121] The various embodiments described herein are presented only
to assist in understanding and teaching the claimed features. These
embodiments are provided as a representative sample of embodiments
only, and are not exhaustive and/or exclusive. It is to be
understood that advantages, embodiments, examples, functions,
features, structures, and/or other aspects described herein are not
to be considered limitations on the scope of the invention as
defined by the claims or limitations on equivalents to the claims,
and that other embodiments may be utilized and modifications may be
made without departing from the scope of the claimed invention.
Various embodiments of the invention may suitably comprise, consist
of, or consist essentially of, appropriate combinations of the
disclosed elements, components, features, parts, steps, means,
etc., other than those specifically described herein. In addition,
this disclosure may include other inventions not presently claimed,
but which may be claimed in future.
* * * * *