EP2130444A1

EP2130444A1 - Smokable material and smokable articles

Info

Publication number: EP2130444A1
Application number: EP08015461A
Authority: EP
Inventors: Xavier Wertz
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-06-06
Filing date: 2008-09-02
Publication date: 2009-12-09
Also published as: WO2009147515A1

Abstract

The present invention relates to a smokable material comprising at least a reagent capable of interacting with CO₂ physically and/or chemically, leading to a CO₂ removing from the mainstream of smoke during the smoking of the smokable material. The present invention also relates to a smokable article comprising a smokable material (1), to a filter, for example a solid filter or a liquid filter, and to a sealed casing.

Description

Field of the Invention

The invention relates to smoking materials, smoking articles, filters, methods for making cigarettes, methods for smoking, methods for making filters and methods for making smoking articles which involve the use of an additive and/or device capable of lowering the amount of carbon dioxide in the mainstream of a smokable article during smoking.
In the following specification, references between brackets ([ref. x]) refer to the listing of references presented after Examples.

Background of the Invention

Smoking in general has been known for decades for its harmful effect, usually causing a chronic bronchitis, often leading to cancer.
Many and many solutions have previously been proposed to reduce the harmful effect of smoking. Most of the proposed solutions have the aim of eliminating from the smoke the molecules their inventors supposed being harmful such as tar, CO, NO and so on.
For example, US Patent No. 4,033,359 discloses the substitution of a part of the tobacco by inert mineral salts (mainly CaCO₃). This substitution reduces the amount of tobacco for one cigarette and thus, it intends to reduce the amount of any harmful molecules found in tobacco smoke. In this substitution, CaCO₃ only replaces tobacco and is chemically inert. Nevertheless, this substitution leads to produce the same amount of CO₂ and of any other molecule for a given amount of nicotine.
An other example is US Patent No. 6,782,892 which focuses on two particular molecules: CO and NO. This patent discloses an additive for tobacco which comprises a catalyst for converting CO and NO into CO₂ and N₂. This catalyst comprises a little amount of MnO and a little amount of Fe₂O₃. However, this US patent does not disclose any mean for decreasing the CO₂ partial pressure in the mainstream smoke. On the contrary, in this patent, the CO₂ partial pressure is increased.
In an other example, the US Patent No. 6,408,856 discloses the use of organic fibres with tobacco, for example, pure cellulose. Tobacco taste and nicotine are added to these cellulose fibres in order to produce the effect that smokers expect from tobacco smoking. Nevertheless, in this US patent, numerous molecules comprised in tobacco smoke are removed but the whole CO₂ remains, produced by the cellulose combustion.
An other example is disclosed in the British Patent No. 973,854 in which gaseous by-products, such as hydrogen cyanide and hydrogen sulphide, are removed. It is said to be achieved by making reacting hydrogen cyanide and hydrogen sulphide with iron oxide and zinc oxide. Nevertheless, the small amount of these additives can only react with the most reactive molecules such as hydrogen cyanide and hydrogen sulphide and leads to an unchanged CO₂ partial pressure in the mainstream smoke.
Almost all cancers in tissues follow a chronic inflammatory state of these tissues as disclosed by Shacter et al., Chronic inflammation and cancer, Oncology (Williston Park), 2002 Feb; 16(2): 217-230 [ref. 1]. According to that, some other proposed solutions try to reduce directly the inflammation. For example, the European Patent EP0591048 discloses a special cigarette filter designed for administrating pharmaceutical antiinflammatory molecules (taurine) by inhalation. Nevertheless, this solution only prevents the visible inflammation caused by smoking and does not act on any other smoking side effect. This solution is also difficult to use (as the smoker is supposed to break microspheres comprised in the cigarette filter before the ignition of the cigarette). Such a cigarette has a bad taste and is very expensive.
Until now, none of previously proposed solutions have been a clear success. More precisely, there is no solution to decrease the amount of CO₂ from mainstream smoke. Indeed, Martinet et al. Le tabagisme, Masson ed., Paris 2004 [ref. 2] lists on page 42 the cigarette smoke composition, including CO₂ and lists on page 43 the components of the cigarette smoke they think suitable to be removed from the cigarette smoke, not even noticing CO₂ as being harmful.
There is thus a need for solutions that overcome the problems and disadvantages of the prior art, and in particular, there is a need to have additives, smoking materials and smoking articles producing smoke with reduced composition in CO₂, less harmful for inhalation. There is a need in additives, smoking materials and smoking articles that improve smoke comfort and lower side effects of smoking.

Description of certain preferred embodiment of the Invention

The present invention allows to overcome these problems by providing a smokable material or a smoke filter comprising a compound or a device capable of interacting with CO₂ physically and/or chemically, leading to a CO₂ removing from the mainstream of smoke generated during the smoking of the smokable material.
In particular, the present invention relates to a smokable material comprising at least a reagent capable of reacting with carbon dioxide.
The term "smoking" as used herein is used generically and is understood as the production of smoke from burnout and/or combustion of a smokable material, such as for example dried or cured leaves of the tobacco plant. The produced smoke is intended to be inhaled.
The term "mainstream" smoke refers to a mixture of gases which is directly inhaled by the smoker from the smoking article.
The term "reagent" as used herein is used generically and is understood as any compound capable of reacting chemically with carbon dioxide. It can be added in a smokable material and/or a smoke filter and/or in a smokable device, for example during its manufacturing process or after. The reagent preferably lasts at least till the end of the smoking of the material and/or of the article. Examples of such reagents include metals, metal oxides, metal hydroxides, doped metal oxides (for example, ZrO₂ doped with Y₂O₃), organic molecules, organo-metallic molecules, metal peroxides and/or mixtures thereof.
The term "smokable material" as used herein is used generically and is understood as any material that can be lit and burned leading to a smoke intended to be inhaled. Examples of such smokable materials include tobacco cut-filler, for example for pipe smoking or cigarette making and other smokable materials without tobacco, such as, for example, cocoa substitutes, eucalyptus, cellulose or inorganic burnable material. The smokable material can further comprise other compounds and/or additives, for example flavour agents, binders.
The term "smokable article" as used herein is used generically and is understood as any object or device set at the time of the beginning of its smoking and/or during its smoking. Examples of such smokable articles include cigarettes, cigarettes with an added removable filter, pipes loaded with cut-filler, water-pipes loaded with any smokable material.
The terms "interacting with CO₂ physically" as used through this specification is used generically and is understood as any CO₂ interaction which does not involve any chemical reaction. It can be for example CO₂ capture by condensation, adsorption, absorption, etc. For example, the CO₂ could be captured by a cooling of the smoke at -57°C (condensation temperature for the CO₂ at atmospheric pressure) followed by the elimination of the liquid CO₂ and the re-heating of the remaining components of the smoke. In an other example, the CO₂ could be captured by an absorbent, such as, for example, plain water or an adsorbent, such as, for example, zeolites.
The terms "interacting with CO₂ chemically" as used through this specification is used generically and is understood as any CO₂ interaction which involves any chemical reaction. For example, the CO₂ can be removed by the mean of a reaction that may lead to a new chemical product, such as, for example, the following chemical reaction: Ca(OH)₂ + CO₂ → CaCO₃ + H₂O.
The terms "particle", "particles" as used herein are used generically and are understood as a material in discrete units. The particles can include granules, pulverulents, powders, spheres or flakes. Thus, the particles can have any desired shape such as, for example, cubic, rod-like, polyhedral, spherical or semi-spherical, rounded or semi-rounded, angular, irregular, flat or plate-like, etc. Shapes having a large greatest dimension/smallest dimension ratio, like needles, flakes and fibers, are also contemplated for use herein. The use of "particle" or "particulate" may also describe an agglomeration including more than one particle, particulate, or the like.
Nevertheless, using a smoking machine according to ISO 3308 and a CO₂ sensor (Testo 350XL), the inventor has measured that, firstly a smoker inhales 6.3x10^-5 m³ CO₂ for one cigarette, secondly the CO₂ partial pressure comprised in the cigarette smoke may range from 10 to 15% (about 63ml CO₂ at 20°C and 1 atmosphere pressure). The partial pressure of CO₂ may usually range around 6% in alveolar air, far lower than that which may be found in the smoke of a cigarette.
Experiments have just been done on mice and human cancer cells (HT-29 and A549 cancerous cell lines), randomly submitted to atmospheres containing 0%, 5%, 10%, 15% and 20% CO₂ partial pressure (Fig. 3). These experiments showed that an inhaled CO₂ partial pressure concentration over 5% causes an inflammatory reaction. Inflammatory cytokines II-6 and RANTES were measured in mice lungs with an ELISA assay and the transcriptions of inflammatory cytokines RANTES, MIP-1β, MIP-1α, MIP1, IP-10, MCP-1, TCA-3 and eotaxin were measured in mice lungs by RNase Protection Assay. In human cancer cells, the RNase Protection Assay has been used to measure RANTES, MIP-1β, MIP-1α, MCP-1 and IL-8, which are characteristic molecules of inflammation. All these results confirmed that a CO₂ concentration over 5% in volume causes an inflammation syndrome. The results of these experimentations are given in Fig. 4 to 8.
Figure 3 represents the CO₂ (scheme A) and O₂ (scheme B) variations in the atmosphere breathed by different mice groups. These measurements were made in the atmosphere within the whole-body plethysmograph (Buxco Electronics Inc., Troy, NY) in which mice where submitted to breathing various CO₂ concentration. Each line with its particular dots shape represents a particular mice group and the same group is represented with the same dots shape on both schemes A and B.
Figure 4 shows pro-inflammatory cytokines transcription in HT-29 after exposure to CO₂. It represents the RNAse Protection Assay performed on RNA from HT-29 cells after a 48 hours exposure to various CO₂ concentrations (in columns). It shows that an increased level of CO₂ increases the transcription level of RANTES, MIP-1β, MIP-1α, MCP-1 and IL-8.
Figure 5 shows pro-inflammatory cytokines secretion levels in HT-29 cells and in A549 cells after CO₂ exposure. It represents the precise measurements of pro-inflammatory cytokines secretions by cells, after 48 hours exposure to various CO₂ concentrations, using a Cytokine ELISPOT Assay, one particular dot for each of all successive experiments. Scheme A is for IL-8 secretion by HT-29 cells measurements, scheme B is for IL-8 secretion by A549 cells measurements, scheme C is for MCP-1 secretion by HT-29 cells measurements, scheme D is for MCP-1 secretion by A549 cells measurements, scheme E is for IL-6 secretion by HT-29 cells measurements and scheme F is for IL-6 secretion by A549 cells measurements.
Figure 6 shows pro-inflammatory cytokines transcription in mouse lung cells after CO₂ exposure. It represents the RNAse Protection Assay performed on RNA from mouse lung cells after an exposure to various CO₂ concentrations (in columns). It shows that an increased level of CO₂ increases the transcription level of RANTES, MIP-1β, MIP-1α, IP-10, MCP-1, TCA-3 and eotaxin. Non-pro-inflammatory proteins L32 and GAPDH secretion levels do not change.
Figure 7 shows pro-inflammatory cytokines secretion in mouse lung cells after CO₂ exposure. It represents the precise measurements of pro-inflammatory cytokines secretions by mouse lung cells, after an exposure to various CO₂ concentrations, using a Cytokine ELISPOT Assay, one particular dot for each of all successive experiments. Scheme A is for RANTES secretion measurements, scheme B is for IL-6 secretion measurements and scheme C is for MIP-2 secretion measurements.
Figure 8 shows the induction of Mucin-5AC production in mice, revealed by a Western-Blot analysis. β-actin is used for control.
The CO₂ may cause this inflammation through the local hyperosmolarity it generates. A possible mechanism for this hyperosmolarity creation contains 4 major elements, the 3 first ones being simultaneous:

1. CO₂ itself, as a solute in the aqueous substances found in a healthy lung. It then forms carbonic acid: CO₂ + H₂O → HCO₃ ^- + H⁺.
2. CO₂ high partial pressure (hypercapnia) shifts cells citric acid cycle to anaerobic metabolism. This causes lactic acid secretion which increases the osmolarity.
3. O₂ low partial pressure (hypoxia, less than 15% in volume in cigarette smoke) causes the same shift in metabolism as point 2 above.
4. A later phenomenon enhances the inflammation and irritation by making the smoker cough. This causes micro-damages to the tissues and particularly to capillaries. These capillaries damages spread oncotic proteins from capillaries to the extracellular matrix. The main purpose of these oncotic proteins is to increase the intra-capillaries osmolarity, their spread in the extracellular matrix also increases the extracellular matrix osmolarity.

This phenomenon is maintained by a regular smoking so that the biological inflammation removing process cannot be achieved.
The present invention presents the advantage of actively reducing the amount of CO₂ in smoke.
Generally, the reagent present in the smoking material of the present invention can be selected from the group comprising metals, salts, metal oxides, metal hydroxides, doped metal oxides, organic molecules, organo-metallic molecules, metal peroxides and/or mixtures thereof. Examples of preferred of such metals include Cu, Fe, Co, Ni, Ti, Pb, Cd. Examples of preferred of such metal oxides include MnO, MnO₂, ZnO₂, CaO₂, Fe₂O₃, Sr₂TiO₄, ZrO₂. Examples of preferred of such metal hydroxides include NaOH, KOH, LiOH, Ca(OH)₂, Mn(OH)₂, Sr(OH)₂, Cu(OH)₂, Mg(OH)₂, Pb(OH)₂, Ba(OH)₂, Fe(OH)₃. Examples of preferred of such doped metal oxide include ZrO₂ doped with Y₂O₃. Examples of preferred of such organic molecules include haemoglobin and plasma proteins. Examples for preferred of such organo-metallic molecules include zinc acetate, lead acetate and calcium acetate.
In a preferred embodiment, the reagent used as an additive to the smokable material is preferably capable of reacting with carbon dioxide to form inert molecules and, in particular, preferably capable of forming products that are physically and chemically stable at the burning temperature of the smokable material. A N-type thermocouple indicates a maximum burning temperature of a cigarette around 850°C. Then, the reagent is preferably capable of reacting with carbon dioxide to form products stable at temperatures higher than 850°C. Otherwise, the leading product could release the captured CO₂.
According to the present invention, the reagent is preferably selected within the group comprising CaO, ZnO₂, NaOH, KOH, LiOH, Ca(OH)₂, Mn(OH)₂, Sr(OH)₂, Mg(OH)₂, Pb(OH)₂, Cu(OH)₂, Ba(OH)₂ or Fe(OH)₃ or a combination thereof. The reagent is more preferably MnO, Mn(OH)₂, CaO, Ca(OH)₂, NaOH or KOH or a combination thereof. Indeed, these compounds present the advantage of forming stable products at 850°C by reacting with carbon dioxide.
According to the present invention, the reagent is preferably a metal hydroxide of formula M(OH)_x, where M is a cation metal selected from the group consisting of K⁺, Na⁺, K⁺, Ca²⁺, Cu²⁺, Mn²⁺, Sr²⁺, Mg²⁺, Pb²⁺, Ba²⁺ or Fe³⁺, and x is such that M(OH)_x is neutral. According to the present invention, the reagent is preferably NaOH, KOH, LiOH, Ca(OH)₂, Mn(OH)₂, Sr(OH)₂, Mg(OH)₂, Pb(OH)₂, Cu(OH)₂, Ba(OH)₂ or Fe(OH)₃, or a combination thereof. The reagent is more preferably MnO, Mn(OH)₂, CaO, Ca(OH)₂, NaOH or KOH or a combination thereof.
In an other embodiment, the reagent is preferably in the form of particles having an average particle size of from 10^-9 m to 1 cm, preferably from 5x10^-9m to 10^-3 m, more preferably from 5x10^-9 m to 1x10^-5 m, and more preferably from 1x10^-9m to 1x10^-7m. These small size present the advantage to maximize the particles surface area and then to maximize the surface in contact with the mainstream of smoke, for a better efficiency.
In an other embodiment, the reagent present in the smoking material of the present invention can be present in an amount effective to capture at least 0.1% (mol), preferably at least 68% (mol), preferably at least 100% (mol), and more preferably between 100% (mol) and 150% (mol) of the carbon dioxide comprised in the mainstream of smoke generated during the smoking of the smokable material.
The value of 68% of the carbon dioxide generated in the mainstream during smoking correspond to 5% of the residual CO₂ present in the smoke. This is the threshold the experimentations have shown non causing inflammation. Using more than the stoichiometric need is preferred in order to be sure to optimize the CO₂ smoke lowering until the end of the smoking and also to be sure that the present invention is efficient regardless the various ways smokers are smoking, as smokers usually do not smoke exactly according to ISO 3308.
In an other embodiment, the reagent is preferably added to the smokable material in an amount of 0.001 g to 10 g per g of smokable material, preferably 0.2 to 0.8 g, preferably 0.3 to 0.5 g, and more preferably 0.4 g per g of smokable material.
In an other embodiment, the preferred reagent is MnO and is added to the smokable material in an amount of 0.1 g to 10 g per g of smokable material, preferably 0.2 to 0.8 g per g of smokable material, preferably 0.3 to 0.5 g, and more preferably 0.4 g per g of smokable material.
The present invention also relates to a smoke filter, for example a solid smoke filter, said smoke filter comprising a reagent capable of reacting with carbon dioxide, in particular carbon dioxide that is comprised in the mainstream of smoke generated during the smoking of the smokable material. For example, the reagent can be homogeneously embedded among the filter or be present in a particular place, for example in a appropriate compartment. The reagent is as defined above.
The reagent present in the solid filter, for example a solid smoke filter, of the present invention is preferably present in an amount effective to capture at least 1% (mol), preferably at least 68% (mol), preferably at least 100% (mol) and preferably at least 200% (mol) of the carbon dioxide comprised in the mainstream of smoke generated during the smoking of the smokable material. It is preferable to use a higher amount of reagent than the amount required for stoichiometry. Indeed, the smoke repartition inside the filter intends not to be homogeneous, especially due to the air-streams coming through the papers porosities.
The present invention also relates to a liquid smoke filter comprising at least a reagent capable of reacting with carbon dioxide. Said carbon dioxide is for example the one comprised in the mainstream of smoke generated during the smoking of the smokable material. Said filter is for example the liquid filter in a water pipe. Examples for water pipes comprise hookas. The reagent is as defined above.
The reagent present in the liquid smoke filter of the present invention can be present in an amount effective to capture at least 1% (mol), preferably at least 68% (mol), preferably at least 100% (mol), preferably at least 200% (mol) and more preferably at least 1000% (mol) of the carbon dioxide comprised in the mainstream of smoke generated during the smoking of the smokable material. It is preferable to use a higher amount of reagent than the amount required for stoichiometry. Indeed, the smoke repartition inside the filter intends not to be homogeneous and the liquid filter intends not to be homogeneously stirred by the smoke stream.
The present invention also relates to a smokable article containing a smokable material according to the present invention and/or a smoke filter, for example a solid smoke filter, according to the invention and/or a liquid smoke filter according to the invention.
If the smokable article of the present invention comprises no filter, the use of the smokable material of the present invention allows to reduce the CO₂ content in the smoke as follows: while inhaled through the smokable article, the CO₂ (and in particular, CO₂ comprised in the smoke produced by the combustion) goes through the smokable material and reacts with the reagent it contains. The CO₂ is then removed from the mainstream smoke.
In an other embodiment, the present invention is used in the filter or in any device. An example for an external device added to a smokable device in order to obtain a smokable article is an additional pluggable filter, according to the present invention. For example, the present invention is preferably comprised in a removable cartridge which both ends are porous and the cartridge is placed inside a smoking device. For example, such a cartridge can be used in a Denhill Denicotea cigarette holder or in a Denhill Denicotea pipe.
The invention also relates to a sealed casing which opening is hermetically closed by a gum gasket used for long-term storage of a smokable material according to the invention and/or a smoke filter according to the invention and/or a smokable article according to the invention and/or an external device according to the invention. A long-term storage in the atmosphere would lead to have the present invention reacting with the atmospheric CO₂, thus loosing its efficiency at the smoking time.
In the case of a solid smokable material (without any liquid part), the use, within the present invention, of a highly moisturisable reagent or a reagent producing highly moisturisable ashes may not be preferred. Then, the use of KOH as a reagent in a smokable material or in a solid filter is not preferred.
In the case of a liquid smoke filter, the use of a reagent selected from the group comprising KOH and/or NaOH is preferred, such as for example in the case of a water pipe.
In the case of a cigarette rod wrapped in a porous cigarette paper, the mainstream of the smoke generated during the smoke of the smokable material is concentrated towards the cigarette axis. This makes preferable to insure a distribution of the present invention, inside the smokable material rod around its axis rather than an uniform distribution in its hole volume.

In the following table, there are some examples of possible reagents capable of reacting with carbon dioxide to form stable products (CO₂ in reagents and H₂O in products are not mentioned in this table).

Table 1

Reagent	Product	Product decomposition temperature (°C)	Miscellaneous	Molar mass of reactant (g)
ZnO₂	ZnCO₃	1100	-	99.39
Ca(OH)₂	CaCO₃	900	-	74.093
Mn(OH)₂	MnCO₃	1100	-	88.953
NaOH	Na₂CO₃	851 (melting)	moisturises and glowproofs	39.997
KOH	K₂CO₃	891 (melting)	moisturises and glowproofs	56.105
Fe(OH)₃	FeCO₃	745	-	89.86
Sr(OH)₂	SrCO₃	1100	-	121.634
CaO	CaCO₃	900	-	56.077
MnO	MnCO₃	1100	-	70.937
Mg(OH)₂	MgCO₃	350	Reagent must be retained	58.33
Pb(OH)₂	PbCO₂	350	Reagent and product must be retained	241.214
Pb(C₂H₃O₂)₂	PbCO₃+ 2 C₂H₄O₂	350	Reagent and products must be retained	325.288
Zn(C₂H₃O₂)₂	ZnCO₃ + 2 C₂H₄O₂	1100	Product must be retained	183.469
LiOH	Li₂CO₃	723 (melting)	Reagent and product must be retained	23.95
Ba(OH)₂	BaCO₃	811 (melting)	Reagent and product must be retained	171.342

According to the measurements done as described before, there are 63x10^-5m³ CO₂ in the mainstream of one cigarette. This is an equivalent for 2.75x10^-3mol CO₂ at 20°C and 1 atm. 2.75x10^-3mol MnO weights 0.19 g. Thus, the stoichiometric quantity of MnO is 0.19 g for the hole CO₂ contained in the mainstream of an usual 1.2 g cigarette. The CO₂ contained in other streams than the main stream have been diluted when inhaled and thus is not as harmful as that of the mainstream and removing this CO₂ is not preferred in this invention.
Other substances can be added to the present invention that are able to release O₂, in order to release O₂ and thus increase the O₂ partial pressure of the smoke but as this might lead to an explosive smokable material, this solution is not preferred in this invention when it is added to the smokable material. Nevertheless, such a principle could be used for a later adding O₂ to the smoke, for example by an injection into the filter.
For improving this anti-osmolar effect of CO₂ removing of the present invention, smokable materials and/or articles according to the present invention would preferably contain as less as possible reagents for molecules soluble in water and conveyable by the smoke to the lung (Tars are not soluble in water). For example, NH₃ is usually added for increasing the pH and thus facilitating the nicotine absorption.

Brief Description of the Drawings

Figure 1 represents a cigarette comprising (1) a tobacco rod wrapped in (2) a porous cigarette paper. The tobacco rod have two coaxial layers : (3) a centre of tobacco cut-filler comprising the smokable material of the present invention and round the former centre, a cylinder of tobacco cut-filler which does not comprise the present invention within its reagents.
Figure 2 represents a cigarette with (4) a tobacco rod and a filter rod wrapped in (3) a paper. The filter rod is composed of (1) two usual fibre filters (cellulose acetate) and the gap between these fibre filters is filled with (2) a foam and/or a powder comprising the reagent.
Figure 3 represents the diagram of the CO₂ (scheme A) and O₂ (scheme B) variations in the different groups.
Figure 4 represents gel to evaluate the pro-inflammatory cytokines transcriptions in HT-29 after exposure to CO₂.
Figure 5 represents the precise measurements of pro-inflammatory cytokines secretions by cells, after 48 hours exposure to various CO₂ concentrations, using a Cytokine ELISPOT Assay.
Figure 6 represents the RNAse Protection Assay performed on RNA from mouse lung cells after an exposure to various CO₂ concentrations (in columns).
Figure 7 represents the precise measurements of pro-inflammatory cytokines secretions by mouse lung cells, after an exposure to various CO₂ concentrations, using a Cytokine ELISPOT Assay.
Figure 8 represents the induction of Mucin-5AC production in mice, revealed by a Western-Blot analysis.

EXAMPLES

The following examples are provided to illustrate embodiments of the present invention, and should not be considered to limit the scope of the invention or the claims appended hereto.
Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing description; and it will be apparent to those skilled in the art that variations and modifications of the present invention can be made without departing from the scope or spirit of the invention. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
Unless otherwise noted, all parts and percentages are by weight. Those of the examples which are cigarette shaped smokable devices so described in the examples can be handmade or manufactured by machine using, for example, a Pilot Cigarette Maker from Hauni-Werk Korber & Co. KG.

Example 1: Preparation of a smokable material of the present invention comprising the additif MnO

27g MnO in nanopowder which scale is 5x10^-8m - 100x10^-8m and specific surface area is in the 25-50m².g^-1 (ref MN-OX-01-NP from American Elements, 23 Rue des Ardennes, 75019 Paris, France) and 81g flue-cured Virginia tobacco (supplied by Sree Ramakrishna Impex Ltd., 507, Saptagiri Towers, Begumpet HYDERABAD-500016, AP India 500 016) is suspended in 500g distilled water with 0.01g methyl cellulose (available as Methocel A4M from The Dow Chemical Co.). This mixture is agitated using a nine speed Hamilton Beach Stand Mixer, Model No. 53, set at Speed 1, for one hour.
The mixture is cast as a sheet of about 0.45 mm thickness onto a polyethylene sheet. The resulting cast sheet is dried at ambient temperature for about 24 hours and then cut into a cut-filler.

Example 2: Preparation of a smokable article of the present invention: a cigarette

The smoking material of example 1 is processed in an usual cigarette making machinery and the tobacco rod is wrapped in a non porous cigarette paper (cigarette paper ref. P-2831-60-1 from Kimberly-Clark Corp.) and a cellulose acetate filter (from Eastman Chemical Products, Inc.) is added.

Example 3: Preparation of a smokable article containing two different tobacco cut-fillers wrapped in a porous paper

First tobacco cut-filler: A smokable material is processed the same way as in example 1 with a doubled MnO powder quantity (54g).
Second tobacco cut-filler: 81g flue-cured Virginia tobacco (supplied by Sree Ramakrishna Impex Ltd., 507, Saptagiri Towers, Begumpet HYDERABAD-500016, AP India 500 016) is suspended in 500g distilled water with 0.01g methyl cellulose (available as Methocel A4M from The Dow Chemical Co.). This mixture is agitated using a nine speed Hamilton Beach Stand Mixer, Model No. 53, set at Speed 1, for one hour. The mixture is cast as a sheet of about 0.45 mm thickness onto a polyethylene sheet. The resulting cast sheet is dried at ambient temperature for about 24 hours and then cut into a cut-filler.
The tobacco rod comprises two different concentric cut-fillers, coaxially positioned, the outer being the second cut-filler of this example and the inner being the first cut-filler of this example. During the cigarette making process, a porous cigarette paper is used which is the perforated ECUSTA 01788 from Ecusta Corp.
This is then processed as an usual cigarette making process.
This article is shown in Fig 1: the cigarette comprises (1) a tobacco rod wrapped in (2) a porous cigarette paper. The tobacco rod have two concentric layers : (3) a centre of tobacco cut-filler comprising the present invention within its additives and round the former centre, a cylinder of tobacco cut-filler which does not comprise the present invention within its additives.

Example 4: Preparation of a smoke filter and a smokable article of the present invention

A cigarette filter is prepared as follows: preparing 2 filter materials (plain filters) in cellulose acetate (1) (from Eastman Chemical Products, Inc.); forming two filter sections by wrapping plug wrap paper (3) around each of the filter materials; loading 0.2g of 10-50 microns MnO powder (ref. MN-OX-02-P from American Elements, 23 Rue des Ardennes, 75019 Paris, France) in the space on the cut tobacco side and in the space on the mouth side between the two filter sections; and wrapping forming paper around the two filter sections. The outer wrap is a non-porous paper plug wrap, such as Ref. No. 646 available from Kimberly-Clark Corp. MnO is loaded in the space on the cut tobacco side. The cigarette is then proceeded as an usual cigarette making process. The filter rod is produced in a plug combiner machine. A variety of different types of plug combiner machines can be used, including the Hauni MULFI combiner (produced by Hauni-Werke Korber & Co. KG of Hamburg, Germany), the Molins DR25 (produced by Molins PLC, Milton Keynes, United Kingdom), the Molins DAPTC, etc.
This article is shown in Fig. 2: the cigarette comprises (4) a tobacco rod and a filter rod wrapped in (3) a paper. The filter rod is composed of (1) two usual fibres filters (cellulose acetate) and the gap between these fibres filters is filled with (2) a foam and/or a powder comprising the present invention.

Example 5: Preparation of a liquid filter and a water-pipe of the present invention.

10^-3 m³ water is put in a hookah.
100g KOH is added into the water and this aqueous solution mixed using a flexible plastic stick moved by hand until the hole KOH is dissolved (visual check by the operator).
The hookah is then used as usually.

Example 6: Preparation for a cartridge, a cigarette with a cigarette holder and a pipe of the present invention.

A Dunhill Denicotea cartridge is open by carefully removing its red top. The silica gel content is removed and replaced by 1-2 mm MnO granules (ref. MN-M-02-GR from American Elements, 23 Rue des Ardennes, 75019 Paris, France). The red top is glued back and the cartridge of the present invention is used as an usual Denicotea cartridge, in a cigarette holder or in a pipe.

Example 7: Preparation of a smoke filter and a smokable article of the present invention.

A smoke filter is prepared according to the method disclosed by the 1974 US Patent 3802441 , where the embedded mineral additive is replaced by the MnO powder of example 1 in the amount of 0.3g MnO for one cigarette filter. The cigarette is then proceeded as an usual cigarette making process.

Example 8: Preparation of a smokable material of the present invention comprising the additif CaO.

The same material as in example 1 is prepared, where the MnO powder is substituted with 22g CaO in nanopowder which scale is 50x10⁸m - 80x10^-8m and specific surface area is in the 15-50m².g^-1 (ref. CA-OX-01-NP from American Elements, 23 Rue des Ardennes, 75019 Paris, France).

Example 9: Preparation of a smokable article of the present invention: a cigarette

A smokable article is manufactured as in example 2 with the smokable material prepared in example 8.

Example 10: Preparation of a smokable article containing two different tobacco cut-fillers wrapped in a porous paper

First tobacco cut-filler: A smokable material is processed the same way as in example 8 with a doubled CaO powder quantity (44g). The CaO powder is the same as in example 8.
Second tobacco cut-filler: A smokable material is proceeded as the second tobacco cut-filler of example 3.
The smokable article is then proceeded as in example 3.
This article is shown in Fig 1: the cigarette comprises (1) a tobacco rod wrapped in (2) a porous cigarette paper. The tobacco rod have two concentric layers : (3) a centre of tobacco cut-filler comprising the present invention within its additives and round the former centre, a cylinder of tobacco cut-filler which does not comprise the present invention within its additives.

Example 11: Preparation of a smoke filter and a smokable article of the present invention

A filter and the smokable article are prepared as in example 4, where the MnO granules are replaced with 0.3g CaO granules (ref. Rhenogran CaO-80 from Rhein Chemie).
This article is shown in Fig. 2: the cigarette comprises (4) a tobacco rod and a filter rod wrapped in (3) a paper. The filter rod is composed of (1) two usual fibres filters (cellulose acetate) and the gap between these fibres filters is filled with (2) a foam and/or a powder comprising the present invention.

Example 12: Preparation of a liquid filter and a water-pipe of the present invention.

10^-3m³water is put in a hookah.
100g NaOH is added into the water and this aqueous solution mixed using a flexible plastic stick moved by hand until the hole KOH is dissolved (visual check by the operator).
The hookah is then used as usually.

Example 13: Preparation of a cartridge and a smokable article of the present invention.

A Dunhill Denicotea cartridge is open by carefully removing its red top. The silica gel content is removed and replaced by the same volume of CaO granules (ref. Rhenogran CaO-80 from Rhein Chemie). The red top is glued back and the cartridge is used as an usual Denicotea cartridge, in a cigarette holder or in a pipe.

Example 14: Preparation of a smoke filter and a smokable article of the present invention.

A smoke filter is prepared according to the 1966 British patent GB1037435 where the embedded additive is the CaO powder of example 8 in the amount of 0.3 g for one cigarette filter. The cigarette is then proceeded as an usual cigarette making process.

Example 15: Preparation of a smokable material of the present invention comprising the additif Ca(OH) ₂ .

The same material as in example 1 is prepared, where the MnO powder is substituted with 28.2g Ca(OH)₂ in nanopowder (ref. CA-HD-01 from American Elements 23 Rue des Ardennes, 75019 Paris, France, particle size on demand).

Example 16: Preparation of a smokable article of the present invention: a cigarette

A smokable article is manufactured as in example 2 with the smokable material prepared in example 15.

Example 17: Preparation of a smokable article containing two different tobacco cut-fillers wrapped in a porous paper

First tobacco cut-filler: A smokable material is processed the same way as in example 15 with a doubled Ca(OH)₂ powder quantity (56.4g). The Ca(OH)₂ powder is the same as in example 15.
Second tobacco cut-filler: A smokable material is proceeded as the second tobacco cut-filler of example 3.
The smokable article is then proceeded as in example 3.
This article is shown in Fig 1: the cigarette comprises (1) a tobacco rod wrapped in (2) a porous cigarette paper. The tobacco rod have two concentric layers : (3) a centre of tobacco cut-filler comprising the present invention within its additives and round the former centre, a cylinder of tobacco cut-filler which does not comprise the present invention within its additives.

Example 18: Preparation of a smoke filter and a smokable article of the present invention

A filter and the smokable article are prepared as in example 4, where the MnO granules are replaced with 0.3g Ca(OH)₂ 10-50 micron granules (ref. CA-HD-01 from American Elements 23 Rue des Ardennes, 75019 Paris, France, particle size on demand).
This article is shown in Fig. 2: the cigarette comprises (4) a tobacco rod and a filter rod wrapped in (3) a paper. The filter rod is composed of (1) two usual fibres filters (cellulose acetate) and the gap between these fibres filters is filled with (2) a foam and/or a powder comprising the present invention.

Example 19: Preparation of a cartridge and a smokable article of the present invention.

A Dunhill Denicotea cartridge is open by carefully removing its red top. The silica gel content is removed and replaced by the same volume of Ca(OH)₂ 1-2 mm granules (ref. CA-HD-01 from American Elements, 23 Rue des Ardennes, 75019 Paris, France, particle size on demand). The red top is glued back and the cartridge is used as an usual Denicotea cartridge, in a cigarette holder or in a pipe.

Example 20: Preparation of a smoke filter and a smokable article of the present invention.

A smoke filter is prepared according to the 1966 British patent GB1037435 where the embedded additive is the Ca(OH)₂ powder of example 15 in the amount of 0.3g for one cigarette filter. The cigarette is then proceeded as an usual cigarette making process.

Listing of references

[ref. 1]: Shacter E, Weitzman SA., Chronic inflammation and cancer., Oncology (Williston Park). 2002 Feb;16(2):217-26, 229; discussion 230-2.
[ref. 2]: Yves Martinet, Abraham Bohadana, Dominique Andolfatto, Lucette Barthélémy, Emmanuelle Béguinot, Le tabagisme, Masson ed., Paris 2004.

Claims

A smokable material comprising at least a reagent capable of reacting with carbon dioxide.
A smokable material according to claim 1, wherein said reagent is present in an amount effective to capture at least 0.1 % (mol) of the carbon dioxide comprised in the mainstream of smoke generated during the smoking of the smokable material.
A smokable material according to claim 1 or 2, wherein said reagent is in the form of particles having an average particle size of from 10^-9 m to 1 cm.
A smokable material according to any one of claims 1 to 3, wherein said reagent is present in an amount of 0.001 g to 10 g per g of smokable material.
A smokable material according to any one of claims 1 to 4, wherein the reagent is selected from the group comprising CaO, ZnO₂, MnO, NaOH, KOH, LiOH, Ca(OH)₂, Mn(OH)₂, Sr(OH)₂, Mg(OH)₂, Pb(OH)₂, Cu(OH)₂, Ba(OH)₂ or Fe(OH)₃, or a combination thereof.
A smokable material according to any one of claims 1 to 4, wherein the reagent is Ca(OH)₂, CaO, Mn(OH)₂ or MnO or a combination thereof.
A smoke filter comprising at least a reagent capable of reacting with carbon dioxide.
A smoke filter according to claim 7, wherein said reagent is present in an amount effective to capture at least 1% (mol) of the carbon dioxide comprised in the mainstream of smoke generated during the smoking of the smokable material.
A smoke filter according to any one of claims 7 to 8, wherein the reagent is selected from the group comprising CaO, ZnO₂, MnO, NaOH, KOH, LiOH, Ca(OH)₂, Mn(OH)₂, Sr(OH)₂, Mg(OH)₂, Pb(OH)₂, Cu(OH)₂, Ba(OH)₂ or Fe(OH)₃, or a combination thereof.
A solid smoke filter according to any one of claims 7 to 8, wherein the reagent is Ca(OH)₂, CaO, Mn(OH)₂ or MnO or a combination thereof.
A smoke filter according to claim 7 or 10, wherein said smoke filter is a solid smoke filter and wherein said reagent is in the form of particles having an average particle size of from 10^-9 m to 1 cm.
A smoke filter according to claim 7 or 10, wherein said smoke filter is a liquid smoke filter and wherein the reagent is NaOH or KOH or a combination thereof.
A smokable article containing a smokable material according to any one of claims 1-6 and/or a smoke filter according to any one of claims 7 to 12.