GB2516104A

GB2516104A - Material for inclusion in a smoking article

Info

Publication number: GB2516104A
Application number: GB1312502.6A
Authority: GB
Inventors: Jocelyn Benning; Steven Coburn; Edward Dennis John; Kevin Mcadam; Biniam Fessehaye Tesfatsion
Original assignee: British American Tobacco Investments Ltd; British American Tobacco Co Ltd
Current assignee: British American Tobacco Investments Ltd
Priority date: 2013-07-12
Filing date: 2013-07-12
Publication date: 2015-01-14
Also published as: GB201312502D0

Abstract

A smokeable material for inclusion in a smoking article, comprises particles or fragments comprising chalk. Preferably, the particles or fragments are between 0.07m and 2000m in size, and the smokeable material further comprises tobacco. The chalk may be pure calcium carbonate, and may be essentially calcite, or a combination of calcium carbonate polymorphs including aragonite.

Description

Material for Inclusion in a Smoking Article

Technical Field

The invention r&ates to a smokeable material for inclusion in a smoking artide, the material comprising particles or fragments comprising chalk.

Background

The use of chalk in combustible products is known, for purposes such as increasing the opacity of the paper wrapper of a smoking article, or inclusion, as pare of a paiticulate io ceramic materia', in the wrapper of a smoking artide.

Summary

In accordance with a first aspect of the present invention there is provided a smokeabe material for inclusion in a smoking arUcle, the material comprising particles or fragments comprising chaTh.

In some embodiments, the partides or fragments substantiafly comprise, or consist of essentially pure calcium carbonate.

In some embodiments, the particles or fragments substantially comprise, or consist of calcite, or a combination of polymorphs of calcium carbonate including aragonite.

In some embodiments, the partides or fragments are between 0.07 hi and 2000 jim in size; between 1 jim and 500 jim in size; between 1 pm and 250 pm in size; between 1 and 100 jim in size; or between 1 pm and o im in size.

In some embodiments, around 99% of the particles or fragments have a size ofless than Jim.

In some embodiments, around 90%, 95%, 98% or 99% of the particles or fragments have a particle size distribution of less than 30 jim.

In some embodiments, the smokeable material further comprises tobacco.

In some embodiments, the particles or fragments are not incorporated or embedded within the tobacco and/or do not form part of a reconstituted tobacco sheet.

In some embodiments, the smokeable material further comprises one or more of tobacco substitutes, filler material, diluents, binders, humectants, flavour or flavourants or aerosol generating material.

In some embodiments, the particles or fragments comprising chalk are applied to the smokeable material in an amount between 10 mg and 300 mg per 550 mg smokeable io material; between 30 mg and 200 mg per 550 mg smokeable material; between 50 mg and 150 mg per omg smokeable material; or around 60, 70, 80, 90, 100, 110, 120 or mg per 550 mg smokeable material.

According to a second aspect of the present invention, there is provided a smoking artide comprising a smokeable material according to the first aspect of the invention.

According to a third aspect of the present invention, there is provided the use of chalk in a smoking article to reduce the level of one or more constituents of mainstream smoke generated upon use of the smoking article.

In some embodiments according to the third aspect of the invention, the chalk is essentially pure calcium carbonate, and may be essentially calcite, or a combination of polymorphs of calcium carbonate including aragonite.

In some embodiments according to the third aspect of the invention, the chalk is in the form of particles or fragments.

In some embodiments according to the third aspect of the invention, the chalk is ocated within the tobacco rod, and may be applied to the smokeable material within thetobacco rod.

Brief Description of the Drawings

Embodiments of the invention will now be described, by way of exampk only, with reference to the accompanying drawings, in which: Figure 1 is a representation of a smoking article in accordance with a second aspect of the present invention.

Figure 2 is a table showing the result of physica' an&ysis of test cigarettes comprising chalk, and control cigarettes.

Figure 3 provides detafis of smoking regime 1.

Figure 4 is a graph demonstrating the reduction of certain analytes achieved by Jo incorporating chaW into a smoking article. Details of the smoking regime used are shown in Figure 3.

Figure 5 shows the tabulated data for Figure 4.

is Detailed Description

Smoke arising from a smoking article which comprises tobacco is a complex, dynamic mixture of more than 5000 identified constituents. The constituents are present in the mainstream smoke (MS), which exits the mouth end of the cigarette, and are also released between puffs as constituents of sidestream smoke (SS).

It can be a research objective to decrease levels of at least some of the constituents of mainstream smoke, such as one or more of aromatic amines; phenols; carbonyls; polycyclic aromatic hydrocarbons; acrylonitrile; volatile hydrocarbons such as toluene, isoprene, styrene and benzene; nitrogen heterocyclics such as pyridine; TSNAS such as N'-nitrosoanabasine (NAB), N'-nitrosoanatabine (NAT), 4-(methylnitrosamrno)-1- (3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN); and inorganic compounds such as ammonia, hydrogen cyanide, nitric oxide and carbon monoxide.

Methods for selectively reducing mainstream smoke and/or sidcstream smoke constituents may include reducing the levels of certain compounds from the starting material by, for example, using biotechnological methods; blending of different types of tobacco, or treating the tobacco prior to incorporation into the smoking article; reducing the amount of tobacco in the smoking artide by inchiding diluents or ifilers; ventilation of the smoking article, where ambient air is drawn into the smoking article to dilute the MS; and use of a filter, which enhances the removal of MS constituents. In addition, attempts have been made to selectively remove or reduce constituents from cigarette smoke by incorporating sorbents into the smoking article.

The term chalk' generally refers to a naturally occurring, white, porous, sedimentary rock which is a form of limestone composed primarily of calcium carbonate.

Particulate material made from this type of chalk is typically referred to as ground calcium carbonate (GCC). The term chalk' also refers to precipitated calcium carbonate (PCC; otherwise known as purified, refined or synthetic calcium carbonate).

PCC and GCC have the same chemical composition, however, the shape and particTh io distribution are different: the shape of PCC crystals depends on the product, but the particles are typicafly uniform and regular in shape. In contrast, GCC is typically irregularly rhombohedral in shape, and the distribution of particle sizes is much broader than for a PCC of the same nominal median particle size.

The most common crystal arrangement for both ground and precipitated calcium carbonate is calcite, which is considered to be the most stable polymorph of cakium carbonate.

Chalk has a variety of uses. It is used to make lime mortar for building purposes. In agriculture chalk is used to raise the pH of soils with high acidity. Toothpaste typically comprises small amounts of chalk, to serve as an abrasive. Chalk can also be taken orally in small doses, to act as an antacid.

Chalk has also been used to improve opacity of the paper wrapper of a smoking article, and in the wrapper of a smoking article, when incorporated into a particulate ceramic material.

It has now been discovered that incorporation of chalk into smokeable material for incorporation into a smoking article selectively decreases the level of one or more constituents in the mainstream smoke generated from such artides in use.

Furthermore, the observed reductions for several of these constituents were greater than expected by the reduction observed for nicotine-free dry particulate matter (NFDPM).

The term chalk' as used herein includes chalk in all its known forms, including limestone; ground calcium carbonate; precipitated calcium carbonate; pure calcium carbonate (CaCO3) or essentially or substantially pure CaCO3; and calcite; as well as other polymorphs of calcium carbonate, such as aragonite and vaterite. The term chalk' may also include any of the abovementioned forms in combination, for example, chalk' can mean limestone comprising calcite and/or aragonite.

The term "NFDPM" is a term of the art, determined utilising a test methodology as would be understood by a skilled person. It is defined as the weight of mainstream smoke particulate matter trapped on a high efficiency particulate filter, minus the weight of nicotine and water on the filter. It is usually expressed in weight units of io milligrams per cigarette.

Accordingly, in a first aspect of the present invention there is provided a smokeable material for inclusion in a smoking article, the material comprising particles or fragments comprising chalk.

In some embodiments, the particles or fragments substantially comprise, or consist of chalk.

In some embodiments, the particles or fragments substantially comprise, or consist of essentially or substantially pure calcium carbonate (CaCO3), or pure CaCO3, In some embodiments, the particles or fragments substantially comprise, or consist of calcite or a combination of polymorphs of calcium carbonate including aragonite.

In some embodiments, the particles or fragments comprising chalk may not comprise a ceramic filler such as a metal oxide or a metal salt, and more particularly, alumina, silica, alumino-silicate, silicon carbide, stabilised or un-stabilised zirconium oxide, zircon, garnet or feldspar.

The partides or fragments comprising chalk may have one or more distinct shapes.

Typically, for example, these may include rhombohedral, scalanohedral or prismatic forms, as well as discrete or chistered orthorhombic crystal structures (such as aragonite, an orthorhombic acicuar system).

The chalk may be obtained from a supplier, such as Mineraria Sacilese s.p.a., Italy or Speciality Minerals®. The obtained chalk may be ground and/or precipitated calcium carbonate. It maybe obtained in the form of particulate or fragmented material, with particles or fragments within the desired size range, or with a particular particle size distribution. Akematively, the chath may be processed after purchasing, for example to break down agglomerates and/or reduce particle size to give partides in the desired size range. In either case, the chalk particles may be classified by size, for example by sieving, and the desired particle size fraction selected.

Alternatively, any method suitable for the preparation of granular material can be used to form chalk particles or fragments. For example, a desired particle size range(s) may io be created by mechanical disruption or grinding (either wet or dry grinding) a source material, such as a natural calcium carbonate ore. Such ores are typicafly high in chemical and mineralogical purity.

Precipitated calcium carbonate can be made by precipitation technologies. A typical manufacturing process involves producing milk of Bme (calcium hydroxide) which is subsequently treated with carbon dioxide or sodium carbonate to form precipitated calcium carbonate. Akemativdy, milk of lime is treated with ammonium chloride to produce a calcium chloride solution. After purification, this is treated with sodium carbonate to form a calcium carbonate precipitate.

Depending on the manufacturing technique, the control of process variables can determine the particle size and shape, surface area and other features such as compressibility, or whether the product is isomorphous calcite or acicular aragonite.

The resultant particles or fragments may then be classified into specific size ranges, by, for example, sequential sieving, or other suitable size classification methods.

In some embodiments, the particles or fragments may be between 0.07 jim and 2000 jim in size; between 1 jim and 500 jim in size; between 1 jim and 250 jim in size; between 1 jim and 100 jim in size; or between 1 jim and 50 jim in size.

In some embodiments, around 99% of the chalk particles have a size of less than 50 jim.

In some embodiments, around 90%, 95%, 98% or 99% of the chalk particles have a particle size distribution of less than 30 jim.

Particles or fragments of chalk maybe applied to other components of the smokeable material of a smoking artide prior to or during assembly or manufacture of the article.

For example, chalk partides or fragments may be sprinkled or sprayed onto tobacco prior to its incorporation into a smoking article.

Any suitable method may be used to achieve this aim. For example, application of particles or fragments of chalk to tobacco may be achieved using apparatus that allows objects such as granulate, particulate or powdered material to be added to smokeable io material prior to or during assembly of a smoking article. For example, chalk particles may be dropped using a gravimetric feeder set at an appropriate feed rate and, optionally, a funnel, onto a conveyor of tobacco.

Mternatively, suitable apparatus is disclosed in WO 2011/033121. In WO 2011/033121 granulate material is introduced to a hopper, which is connected to a hopper exit tube.

The granulate material drops, under gravity, from the hopper into the hopper exit tube from where it becomes entrained by either a venturi device or a vacuum pump, and is inserted into the tobacco rod or tobacco stream. Optionally, a vibratory conveyor may be utilised to convey the granulate material from the hopper exit tube to the venturi device or vacuum pump system.

In alternative embodiments, chalk particles or fragments may be applied to one or more components of a smoking article using a focussed stream driven by a compressed gas jet, by drawing the particles or fragments across one or more components of a smoking article by the action of vacuum and/or other methods known by a person skilled in the art.

Fragments or particles comprising or consisting of chalk may be distributed through the othcr components of the smokeable material if required by, for example, mixing.

The smokeable material to which particles or fragments of chalk are applied or with which partides or fragments of chalk are incorporated may comprise tobacco.

In some embodiments, the smokeable material further comprises one or more of the components typically found in the tobacco rod of a combustible product such as a smoking article. For example, tobacco substitutes, filler materials, diluents, binders, humectants, flavours or flavourants, and aerosol generating means.

In some embodiments, the particles or fragments of chalk are not incorporated or embedded within any other components of the smokeable material.

In some embodiments, the particles or fragments of chalk are not incorporated or embedded within the tobacco, and/or do not form part of a reconstituted tobacco sheet.

io Instead, the chalk partides or fragments are appBed to other components of the smokeabk material, such as the tobacco, which is pre-prepared in that it is, prior to the application of the chalk particles or fragments, suitable for direct incorporation into a smoking article.

Accordingly, following application to the smokeahle material, the chalk particles or fragments remain essentiafly separate from the other components of the smokeable material, so that they are either loose within the material, or loosely bound to the smokeable material.

In some embodiments, the particles or fragments comprising chalk are applied to the smokeable material in an amount between 10 mg and 300 mg per 550 mg smokeable material; between 30 mg and 200 mg per 550 mg smokeable material; between 50 mg and 150 mg per 550mg smokeable material; or around 60, 70, 80, 90, 100, 110, 120 or mg per 550 mg smokeable material.

In some embodiments, smokeable material according to the first aspect, may, when used in a smoking article, give rise to reduced levels of one or more constituents of mainstream smoke. In some embodiments, the smokeable material may give rise to reduccd levels of one or more of one or morc of: ammonia, benzo(a)pyrcnc, formaldehyde, hydrogen cyanide, catechol, hydroqtunone, m-cres&, o-cresol, p-cresol, phenol, resorcin&, NAB, NAT, NNK, and NNN.

Smokeabk material comprising chalk may be incorporated into a smoking article, such as a cigarette. Accordingly, in a second aspect, there is provided a smoking article comprising a smokeable material according to the first aspect of the invention.

Smoking articles according to the present invention may conform to any size or dimensions known for smoking articles.

Aiternativ&y, smoking artides according to the invention may comprise a coaxial core, comprising an inner core and outer annulus of smokeable materials, and wherein particles or fragments of chalk maybe incorporated into either or both of the inner core or outer annulus. In such embodiments, the smoking article may comprise the same or different wrapper materials for the inner core and outer annulus.

io Smoking articles typically comprise a filter at the mouth end, a rod which comprises smokeabk material, and paper wrapped around the rod.

Smoking articles according to the present invention may comprise any filter configuration known in the art. Filters for smoking articles typically comprise one or more of fibrous cellulose acetate, polypropylene material, polyethy'ene material, or gathered paper materiaL Referring to Figure 1, a smoking article, 1, is illustrated comprising a filter, 2 and a substantially cylindrical tobacco rod, 3, aligned with the filter, 2, such that one end of the tobacco rod, 3, abuts the end of the filter. The tobacco rod, 3, has a cut away area to demonstrate the location of particles of chalk, 4. The tobacco rod, 3 is joined to the filter, 2, by tipping paper in a conventional manner.

According to a third aspect, there is provided the use of chalk in a smoking article to reduce the level of one or more of the constituents of mainstream smoke generated upon use of the smoking article. In some embodiments, reductions in mainstream smoke constituents may include, but are not restricted to, one or more of those substances known as Hoffmann analytes. The chalk may be in the form of particles or fragmcnts.

In some embodiments, the use of chalk in a smoking article reduces the evel of one or more of: ammonia, benzo(a)pyrene, formaldehyde, hydrogen cyanide, catech&, hydroquinone, m-crescil, o-cresol, p-cresol, phenol, resorcincil, NAB, NAT, NNK, and NNN. -10-

In some embodiments, the use of chalk in a smoking article reduces the level of one or more of ammonia, benzo(a)pyrene, formaldehyde, hydrogen cyanide, catechol, hydroquinone, m-crescil, o-cresol, p-cresol, phenol, resorcincil, NAT and NNK.

The term Hoffmann analytes' is a term of art. It relates to a group of constituents of mainstream smoke generated from a smoking article, and includes aromatic amines; phenols; carbonyls; polycyclic aromatic hydrocarbons; acrylonitrile; volatile hydrocarbons such as isoprene, styrene and benzene; nitrogen heterocyclics such as pyridine; and TSNAS such N'-nitrosoanabasine (NAB), N'-nitrosoanatabine (NAT), io 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN); and inorganic compounds such as ammonia, hydrogen cyanide, nitric oxide and carbon monoxide.

In some embodiments according to the third aspect, the chalk is located within the tobacco rod, and may be appbed to the other components of the smokeable material, as discussed in relation to the second aspect, above.

Without wishing to be bound by any theory, it is suggested that the effects resulting from incorporation of chalk into a smoking article arise from a change in the combustion and/or pyrolysis profile of the smokeable material as a result of the presence of the chalk. This may be as a result of the physical presence of the chalk within the smokeable material, which exerts physicochemical effects on thermal processes within the combustion and/or pyrolysis zones of the smokeable material, resulting in reductions of analytes which include several nitrogen containing substances and phenolic substances. The observation that the reductions were greater than expected by reduction of NFDPM for some of the substances in mainstream smoke may indicate that synergistic effects could be occurring within the complex, dynamic combustion and/or pyrolysis processes occurring within the smoking article.

The foflowing examples are provided to illustrate the present invention and shoud not be construed as Bmiting thereof.

Example 1

Chalk particles (Calcitec V4o/S) having a particle size distribution wherein 99% of the s particles have a particle size distribution ofless than 30 tm were obtained from Mineraria Sacilese s.p.a.

-11 -Test cigarettes having smokeable material consisting of tobacco and chalk particles, and comparative (control) cigarettes, having smokeable materia' consisting of tobacco on'y were manufactured.

Test and control cigarettes were made using the specifications and materials set out in

Table A, below.

Table A

Cigarette Dimensions Length 83 mm, Circumference 21.2 mm Paper 50 Coresta Filter Cellulose acetate mono format mm p.d.

92.5 mm W.G.

Blend US style Blend (USB) Tipping Paper mm Control and test cigarettes contained the same weight of tobacco.

Following manufacture of the control cigarettes, test cigarettes were manufactured by adding chalk particles to the tobacco rod using apparatus as disclosed in WO Is 2011/033121 to give a particle loading in the range 80-100 mg/cigarette (as tested by weight). As the loading of chalk particles was approximately omg per cigarette, the resultant weight of the smokeable material for the test cigarettes was about 90 mg greater than the weight of smokeable material for the control cigarettes.

A physical analysis of test and contr& cigarettes was carried out. Results are shown in Figure 2.

Test and contr& cigarettes were then smoked using smoking regime 1, details of which are provided in Figure 3, and the mainstream smoke from each cigarette was analysed.

Results for smoking regime 1 are shown in Figure 4 with the corresponding data provided in Figure.

-12 -Cigarettes containing chalk particles reduced levels of certain components of mainstream smoke in comparison to control cigarettes. In particular, levels of ammonia, benzo(a)pyrene, formaldehyde, hydrogen cyanide, catech&, hydroquinone, m-cres&, o-cresol, p-cresol, phenol, resorcinol, NAB, NAT, NNK, and NNN were reduced in comparison to control cigarettes, with quinoline, acrylonitrile, isoprene, and 1,3-butadiene showing the lowest reductions.

Furthermore, the observed reductions for several of these substances were greater than expected by reduction of NFDPM. For example, ammonia, benzo(a)pyrene, io formaldehyde, hydrogen cyanide, catechol, hydroqtunone, m-cres&, o-cresol, p-cresol, phenol, resorcin&, NAT and NNK showed reductions in excess of that observed for NFDPM.

In order to address various issues and advance the art, the entirety of this disclosure shows, byway of illustration, various embodiments in which the claimed invention may be practiced and provide for a superior process for preparing material for inclusion in the smokeahle material of a smoking artide comprising particle or fragments comprising chalk. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are presented only to assist in understanding and teaching the claimed features. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope and/or spirit of the disclosure. Various embodiments may suitably comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. In addition, the disclosure includes other inventions not presently claimed, but which may be claimed in future.

Claims

-13 -Claims 1. A smokeahie material for inclusion in a smoking article, the material comprising particles or fragments comprising chalk.
2. A smokeable material as claimed in claim 1, wherein the particles or fragments substantially comprise, or consist of essentially pure calcium carbonate.
3. A smokeable material as claimed in claim 1 or 2, wherein the particles or io fragments substantiafly comprise, or consist of calcite, or a combination of p&ymorphs of calcium carbonate including aragonite.
4. A smokeable material as claimed in any of claims 1-3, wherein the particles or fragments are between 0.07 pm and 2000 pm in size; between 1 pm and 500 pm in i size; between 1 pm and 250 pm in size; between 1 pm and 100 pm in size; or between 1 pm and 50 pm in size.
5. A smokeahie material as daimed in any of claims 1-3, wherein around 99% of the particles have a size of less than 50 pm, or wherein around 90%, 95%, 98% or 99% of the particles have a particle size distribution of less than 30 p.m.
6. A smokeahie material as daimed in any of claims 1-5, wherein the smokeable material further comprises tobacco.
7. A smokeahie material as daimed in claim 6, wherein the partides or fragments are not incorporated or embedded within the tobacco; and/or do not form part of a
8. A smokeable material as claimed in claim 6 or 7, wherein the smokeable material further comprises one or more of tobacco substitutes, filler material, diluents, binders, humectants, flavour or flavourants or aerosol generating material.
9. A smokeable material as claimed in any of claims 1-8, wherein the particles or fragments comprising chalk are applied to the smokeable material in an amount between 10 mg and 300 mg per 550 mg smokeable material; between mg and 200 mg per 550 mg smokeable material; or between 50 mg and 150 mg per 550mg smokeable material, or in amount of around 60, 70, 80, 90, 100, 110, 120 or iomg per mg smokeable materiaL
10. A smoking article comprising a smokeable material according to any of claims 1-9.

ii. Use of chalk in a smoking article to reduce the level of one or more of the constituents of mainstream smoke generated upon use of the smoking article. I012. Use of chalk as daimed in daim ii, wherein the chalk is essentially pure cakium carbonate; and may be essentially calcite, or a combination of calcium carbonate polymorphs including aragonite.13. Use of chalk as daimed in daim 11 or daim 12, wherein the chalk is in the form of partides or fragments.14. Use of chalk as claimed in any of claims 11-13, wherein the chalk is located within the tobacco rod of the smoking article.15. Use of chalk as claimed in claim 14, wherein the chalk is applied to the smokeable material within the tobacco rod.