EA013588B1 - A cigarette component, a cigarette and a method of making thereof - Google Patents

Abstract

Encapsulated catalyst particles can be incorporated in tobacco cut filler and/or cigarette paper used to form a cigarette. The encapsulated catalyst particles, which can decrease carbon monoxide and/or nitric oxide in mainstream tobacco smoke, comprise catalyst particles that are encapsulated with a volatile coating. During the smoking of a cigarette comprising the encapsulated catalyst particles, the volatile coating is volatilized to expose an active surface of the catalyst particles.

Description

Cigarettes emit both mainstream smoke when puffed and sidestream smoke during static combustion. The components of both mainstream smoke and sidestream smoke are carbon monoxide (CO) and nitric oxide (N0). Reducing the content of carbon monoxide and / or nitric oxide in the smoke is desirable.

Cigarettes and components of cigarettes (e.g., a tobacco bag and cigarette paper) are disclosed, including encapsulated catalyst particles capable of reducing carbon monoxide and / or nitric oxide in the mainstream smoke, in which the encapsulated catalyst particles are at least catalyst particles partially coated with a volatile encapsulating substance. Preferably, the catalyst particles are completely coated with a volatile encapsulating substance.

The catalyst particles, which may include nanoparticles, preferably include elemental metal, alloy, oxide and / or oxyhydroxide of at least one element selected from the group consisting of Md, A1, δί, ίι, V, Cr, Mn, Te, Co, N1, Cu, Ζη, Ce, Υ, Ζτ, N6, Mo, Ki, Hell, δη, Ce, Pr, Ba, H, Ta, ED, Ke, 05.1g and Au.

Preferred catalyst particles can reduce the content of the tobacco smoke component, for example, catalyzing the conversion of carbon monoxide to carbon dioxide and / or nitric oxide to nitrogen, the oxidation of carbon monoxide to carbon dioxide and the reduction of nitric oxide to nitrogen.

The volatile encapsulating substance is preferably a wax, a water-soluble polymer or a water-insoluble polymer. The volatile encapsulating material may include a flavoring compound, for example menthol, a menthol derivative or a menthol precursor. Preferred volatile encapsulating substances have an evaporation temperature of from about 40 to about 350 ° C or are able to evaporate into the atmosphere with a relative humidity of more than about 5%.

In an embodiment, the volatile encapsulating material comprises a first layer (e.g., an aroma layer) in contact with the catalyst particles and a second layer formed over the first layer.

In a cigarette including encapsulated catalyst particles, the volatile encapsulating substance is capable of vaporizing (for example, due to thermal or chemical decomposition) during smoking of the cigarette to expose the active surface of the catalyst particles.

In one embodiment, the encapsulated catalyst particles may be distributed homogeneously or unevenly across the cigarette tobacco rod. In another embodiment, the encapsulated catalyst particles may be included in a paper wrapper or cigarette filter. For example, encapsulated catalyst particles may be included in a first (i.e., inner) layer of a multilayer wrapper.

The encapsulated catalyst particles can be dispersed throughout the paper wrapper or printed on the surface of the paper wrapper. The cigarette may include a mixture of different encapsulated catalyst particles.

A method for producing a cigarette comprises (1) including encapsulated catalyst particles in at least and / or on one of: a tobacco bag and a cigarette wrapper; (ίί) feeding the tobacco bags into a cigarette machine to produce a tobacco rod; (w) wrapping the cigarette wrapper around the tobacco rod to form a wrapped tobacco rod; and (ίν) optionally attaching the cigarette filter to the tobacco rod using cigarette paper. Encapsulated catalyst particles may be included by spraying, spraying or dipping. For example, encapsulated catalyst particles can be incorporated into cigarette paper by spraying or applying the encapsulated catalyst particles onto a wet base web, intermediate web, or finished web.

In FIG. 1A shows an optical microscope view of particles of the NANOCAΤ iron oxide catalyst immediately after preparation.

In FIG. 1B and 1C show optical microscope views of encapsulated iron oxide alginate NANOCAΤ in the form of particles and fibers, respectively.

The components of cigarettes, cigarettes, and methods for smoking cigarettes comprising encapsulated catalyst particles are disclosed. The encapsulated catalyst particles include a core of one or more catalyst particles and a vaporized encapsulating layer (i.e., a coating) formed around this core. The vaporizing encapsulating layer may be a protective layer for the catalyst particles at temperatures close to ambient (for example, during storage of cigarettes and below the combustion / pyrolysis zone in a lit cigarette), but when exposed to elevated temperature, humidity or a component of the gas phase of the cigarette smoke the material can be vaporized (for example, by thermal or chemical decomposition) to open the underlying catalyst particles.

Encapsulated catalyst particles may be included in one or more components of a cigarette, such as a tobacco bag, cigarette paper, and a cigarette filter cigarette. In cigarettes including encapsulated catalyst particles, the amount of carbon monoxide and / or nitric oxide in the mainstream smoke can be reduced. Methods for providing cigarettes including encaps

- 1 013588 promoted catalyst particles, include encapsulating the catalyst particles and incorporating the encapsulated catalyst particles into one or more components used to make the cigarette.

The inclusion of catalyst particles in one or more components of a cigarette is disclosed in US published applications of the same applicant, 2004/0131859; 2004/0040566 and 2004/0110633, the contents of which are incorporated herein by reference. Catalyst particles can be incorporated into a cigarette to reduce the concentration in the mainstream smoke and / or sidestream smoke of one or more components of the gas phase (e.g., CO or N0). However, during smoking of a cigarette comprising catalyst particles, semi-vaporizing or non-vaporizing combustion products such as resin may form on the catalyst particles. The early formation of semi-vaporizing and non-vaporizing deposits can effectively inactivate the catalyst particles (for example, by creating a barrier between the catalyst particles and the gas phase components and / or by chemical interaction with the catalyst particles). For example, a layer of semi-vaporizing or non-vaporizing material can be effectively impermeable to gas phase components in the mainstream smoke stream. In addition, at elevated temperatures, semi-vaporizing or non-vaporizing materials can react with catalyst particles and reduce their catalytic activity.

Encapsulated catalyst particles are disclosed, including an evaporative coating formed directly on an open surface (e.g., a catalytic surface) of catalyst particles. By evaporation coating is meant that the encapsulating layer preferably has an evaporation temperature lower than the evaporation temperature of the resin or other by-products of the solid combustion / pyrolysis of tobacco. Before smoking a cigarette comprising encapsulated catalyst particles, the volatile encapsulating substance preferably at least partially covers, more preferably completely covers the catalyst particles. Preferred vaporizing coatings evaporate while smoking a cigarette.

In a cigarette including encapsulated catalyst particles, when the encapsulated catalyst particles are exposed to a temperature lower than the vaporization temperature of the encapsulating substance, the volatile encapsulating substance forms a protective layer on which semi-vaporizing and non-vaporizing materials (e.g., resin) can deposit. Semi-vaporizing or non-vaporizing materials can form and precipitate on the vaporizing encapsulating material, and not on the catalyst particles. When the temperature reaches or exceeds the evaporation temperature of the encapsulating substance, the volatile encapsulating substance, like any material formed on it, can be removed to open the active surface of the catalyst particles. Thus, the active surface of the catalyst particles can be opened under smoking conditions (i.e., in front of the combustion zone) for catalysis and / or oxidation of the gas components of the mainstream smoke and / or sidestream smoke. Applicants have unexpectedly discovered that encapsulated catalyst particles incorporated into a cigarette have a higher catalytic efficiency during smoking of a cigarette than non-encapsulated catalyst particles.

In an embodiment, the cigarette comprises encapsulated catalyst particles in which, while smoking, the volatile encapsulating substance is volatilized at a distance of from about 0.1 to about 10 mm, preferably from about 0.5 to about 2 mm, to the carbonization line. As used herein, a charring line is a line created on a wrapper of cigarette paper from a side of a cigarette burning zone that occurs during smoking of a cigarette.

The encapsulating layer is made of a vaporizing material that can be thermally or chemically decomposed. In a first embodiment, the encapsulating substance can be thermally decomposed (for example, by melting, sublimation or pyrolysis) when exposed to a temperature higher than the temperature of the medium, but below about 350 ° C, preferably below about 200 ° C, to open the surface of the catalyst particles for the mainstream smoke, side smoke or both. Preferred encapsulating substances are thermally decomposed at a temperature of from about 40 to about 200 ° C. In another embodiment, the encapsulating substance may chemically decompose (for example, dissolve) when exposed to components of cigarette smoke that are formed during smoking. For example, moisture from the mainstream smoke can interact with the encapsulating layer to vaporize the encapsulating material and open the catalyst particles. Preferred layers of the encapsulating substance are chemically decomposed upon exposure to the mainstream smoke or sidestream smoke having a relative humidity of more than about 5%, more preferably more than about 20%.

By providing an evaporative encapsulating layer, the active catalytic surface of particles included in a cigarette (e.g., a tobacco bag) can be opened in front of the combustion zone of the cigarette. A vaporizing encapsulating layer can minimize physical interaction and chemical reaction between catalyst particles and non-vaporizing or semi-vaporizing products of combustion and / or pyrolysis (e.g., resin). For example, high temperature cracking of resin molecules through reaction with catalyst particles can be minimized.

Catalyst particles, which include a core of encapsulated catalyst particles, may

- 2 013588 include an elemental metal, alloy, oxide and / or oxyhydroxide of at least one element selected from the group consisting of Md, A1, δί, Τί, V, Cr, Mn, Fe, Co, N1, Cu, Ζη, Xie, Υ, Ζτ, N6. Mo, Ki, Hell, δη, Ce, Pr, Ba, Ηί, Ta, ED, Ke, Og, 1g and Au.

The catalyst particles preferably include nanoparticles. By nanoparticles is meant that the catalyst particles have an average diameter of less than a micron. Preferably, the nanoparticles have an average size of less than about 100 nm, more preferably less than about 50 nm, and most preferably less than about 10 nm.

Preferred catalyst particles include iron oxides and / or oxyhydroxides. For example, МАСН I, 1пс, К1пд οί Ртикяа, Pennsylvania, USA sells Fe ₂ О ₃ nanoparticles under the trademarks NANOSA® Fine Micron Oxide (δΡΙΟ) and NANOSA® Magnetic Iron Oxide. NANΟCAΤ® Fine Iron Oxide (δΡΙΟ) is an amorphous iron oxide in the form of a free-flowing powder with a particle size of about 3 nm, a specific surface area of about 250 m ² / g and bulk density of about 0.05 g / ml. NANΟCAΤ® Highly dispersed Iron Oxide (δΡΙΟ) is synthesized by a vapor-phase process, which brings it into a state substantially free of impurities that may be present in conventional catalysts and is suitable for use in food, medicine, and cosmetics. NANΟCAΤ® Magnetic Iron Oxide is a free-flowing powder with a particle size of about 25 nm and a surface area of about 40 m ² / g. Additionally preferred catalyst particles include oxides and / or oxyhydroxides of manganese, copper or cerium.

The encapsulating substance that forms the coating encapsulating the catalyst particles may include wax, a water-soluble polymer, a water-insoluble polymer or other material capable of vaporizing while smoking a cigarette to expose the catalyst particles beneath it. Preferred encapsulating substances are non-toxic, easily applied to the catalyst particles and stable (for example, thermally and chemically stable) under typical storage conditions for cigarettes. Preferably, the encapsulating substance comprises one or more flavoring compounds.

The encapsulating substance may include wax.

Preferred waxes include heat-melting materials having a melting point of about 40 to about 350 ° C. As examples, waxes include beeswax, coconut wax, candelilla wax, carnauba wax, montan wax, urikuri wax, paraffin wax, rice wax, or mixtures thereof.

The encapsulating substance may include a water-soluble polymer. As examples, water soluble polymers include polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxides, water soluble polyamides, water soluble polyesters, water soluble celluloses, acrylic acid polymers, or mixtures thereof. Natural and modified water-soluble polymers include starches, dextrin, resins, gelatins, pectin, alginates, gum arabic, or mixtures thereof.

Preferred encapsulating substances are alginates. Alginates are salts of the long chain carbohydrate biopolymer alginic acid and include sodium alginate, calcium alginate, potassium alginate and propylene glycol alginate. Although alginic acid is insoluble in water, salts are hydrocolloids (i.e., they bind or absorb water) and can be formed into a coating.

Alginates are generally resistant to acid and temperature. Regulation of the concentration of calcium ions that cause cross-linking controls the strength of the gel. Combining alginate with other resins such as pectin can increase viscosity.

Alginates can be dispersed in water at ambient temperature, although solubility tends to decrease with decreasing water temperature. Alginate concentrations above 2 wt.% Can be dispersed using intensive shear mixing to remove lumps. High-speed mixers combine intense flow with intense shear to increase mixing efficiency.

A preferred method for preparing encapsulated catalyst particles comprising a calcium alginate coating is discussed below.

The encapsulating substance may include a water-insoluble polymer. By way of example, water-insoluble polymers include polyethylene, polypropylene, polyacrylates, polymethacrylates, polymethyl methacrylates, polyvinyl chloride, polyvinylidene chloride, polysaccharides, or mixtures thereof.

The encapsulating substance may include a flavoring compound. Preferred flavoring compounds include menthol, derivatives of menthol compounds and menthol precursors. Other suitable flavoring compounds include synthetic and natural aromas, essential oils, alcohols, aldehydes, esters, esters, ketones, phenols, and mixtures thereof. The flavoring compound may be an aromatic compound or a non-aromatic compound.

The catalyst particles can be coated with one or more layers of the same or different vaporizing encapsulating substances. For example, multiple coating steps can be applied to achieve the desired thickness and / or degree of coverage of the desired encapsulation.

- 3 013588 substance. In a further example, the catalyst particles may be coated with a first vaporizing coating and then a second vaporizing coating. In a preferred embodiment, the first vaporizing coating comprises a flavoring compound.

Many methods can be applied to obtain encapsulated catalyst particles. Suitable methods include providing catalyst particles and forming at least one vaporizing encapsulating layer on the catalyst particles. Methods include gas phase techniques and liquid phase techniques.

In the gas-phase procedure described in the example, the catalyst particles can be mixed with an encapsulating substance in a liquid phase (for example, a solution or an undiluted liquid of an evaporating compound) to form a mixture. During mixing, the temperature and amount of shaking can be controlled. For example, the catalyst particles and the encapsulating substance solution can be mixed at room temperature and sonicated to form a homogeneous mixture.

The catalyst particle-encapsulating material mixture may be dried to obtain encapsulated catalyst particles. According to a preferred method, the mixture can be aspirated to form an aerosol comprising catalyst particles coated with an encapsulating material. The aerosolization temperature and propagation speed can be controlled to obtain encapsulated catalyst particles in the solid phase (i.e., in which the encapsulated layer dries to form a hard coating on the catalyst particles).

By way of example, encapsulated catalyst particles comprising 50% by weight of ΝΑΝΟΤΆΤ® iron oxide particles coated with gum arabic can be prepared by first mixing iron oxide particles (~ 1 g) with gum arabic (~ 1 g) in about 30 ml of deionized water with constant shaking to obtain a uniform suspension of particles of iron oxide. The suspension is sprayed using a 0.5 mm nozzle at about 170 ° C, whereby the water present in the mixture evaporates and particles of iron oxide coated with gum arabic are formed. Depending on the processing conditions, the encapsulated catalyst particles can be in the form of a powder, granulate or agglomerate, the encapsulated catalyst particles can be in the form of spheres, spheroids, threads, fibrils, etc.

In an exemplary liquid phase method, catalyst particles can be immersed in an encapsulating substance or an encapsulating substance precursor in a liquid phase (e.g., a solution or undiluted liquid of an evaporating compound) to form a mixture in which a coating is formed on the catalyst particles. The temperature during the dive can be controlled and the mixture can optionally be shaken (for example, mixed). The catalyst particles and the encapsulating substance can be mixed at room temperature to form a coating. After immersion, the coated catalyst particles can be dried and optionally processed further to obtain encapsulated catalyst particles. Additional processing may include crosslinking the encapsulating polymer, for example, by an ion exchange reaction.

A method for producing alginate-encapsulated catalyst particles involves immersing the catalyst particles in an alginate salt solution to obtain coated catalyst particles and then treating the coated catalyst particles to form a cross-linked polymer coating with alginate.

As an example, encapsulated catalyst particles comprising 50% by weight of NΑNΟCΑΤ® iron oxide particles coated with calcium and / or sodium alginate can be prepared by first mixing the particles of iron oxide (~ 1 g) with a solution of sodium alginate (1 g of sodium alginate in 100 ml of deionized water) with constant shaking to obtain particles of iron oxide coated with sodium alginate.

The mixture is preferably homogenized (for example, for 30-130 s), left in the air (for example, for 10-60 minutes) and then re-homogenized (for example, for 30-130 s).

The sodium alginate coating can be at least partially and preferably completely converted (e.g., polymerized) to the calcium alginate coating via an ion exchange reaction. A known volume of particles of iron oxide coated with sodium alginate is preferably brought into contact with a solution comprising a polyvalent cation. The solution may include an aqueous or non-aqueous (e.g., alcoholic) solution. In a preferred method, the solution includes calcium chloride (for example, a 0.1 M aqueous solution of calcium chloride), in which Ca ^{2+ is} exchanged for Να ¹ 'through an ion exchange reaction that forms a cross-linked calcium alginate coating around the iron oxide particles. Other solutions of polyvalent cations suitable for forming cross-linked encapsulating layers may include aluminum, manganese, iron, copper, zinc, strontium, silver and barium. The strength of the crosslinked polymer encapsulating material can be controlled by varying the degree of crosslinking. The number of cross-links is proportional to the duration of the reaction (i.e., solidification time) between the encapsulating

- 4 013588 substance and solution of a polyvalent cation. Other polymers that can be crosslinked by ion exchange include polysaccharides.

In a preferred method, a known volume of particles of iron oxide coated with sodium alginate is dispersed dropwise (for example, through a syringe, for example, with a 26.5 gauge needle) in a solution of calcium chloride. The height and speed of propagation can be adjusted to control the size of the encapsulated particles. Excess calcium chloride solution can be removed (for example, filtered or decanted) after a given period of exposure time (for example, up to about 2 hours), and the particles coated with calcium alginate can be washed and dried. Encapsulated catalyst particles may be prepared, comprising at least about 10, 20, 30, 40, 50, 60, 70, 80, or 90 ± 5 wt.% Catalyst particles (e.g., iron oxide particles).

Optical micrographs of iron oxide / calcium alginate samples are shown in Figure 1. FIG. 1A shows an optical micrograph of ΝΑΝΟί, ΆΤ® particles of iron oxide immediately after preparation. FIG. 1B shows an optical micrograph of iron oxide particles encapsulated with calcium alginate in the form of irregular and spherical particles. FIG. 1C shows an optical micrograph of iron oxide particles encapsulated with calcium alginate in the form of fibrils.

Additional methods for preparing encapsulated catalyst particles include polymer-polymer incompatibility (in which the catalyst particles are coated by selectively adsorbing one polymer from a solution of incompatible polymers that are dissolved in a common solvent); fluidized bed encapsulation and gas phase polymerization.

The encapsulated micron size catalyst particles may have an average particle size of from about 1 μm or less to about 1000 μm or more. Encapsulated catalyst particles can have an average particle size of 10, 20, 30, 40, 50, 60, 70, 80 or 90 μm ± 5 μm to about 100, 200, 300, 400, 500, 600, 700, 800 or 900 μm ± 50 μm, encapsulated catalyst particles may include individual particles or an agglomerate of coated catalyst particles. Preferred encapsulated catalyst particles have an average particle size of less than 1 μm. Submicron and nanoparticles of the catalyst can be encapsulated to obtain encapsulated catalyst particles having an average particle size of from 10, 20, 30, 40, 50, 60, 70, 80 or 90 nm ± 5 nm to about 100, 200, 300, 400, 500 , 600, 700, 800 or 900 nm ± 50 nm depending on the average coating thickness.

According to a preferred method, the encapsulated catalyst particles are included in at least one of: a tobacco bag, cigarette paper, and a cigarette filter used to make a cigarette. By incorporating the catalyst particles into one or more components of the cigarette, the amount of carbon monoxide and / or nitric oxide in the mainstream smoke stream during smoking can be reduced.

Preferably, the encapsulated catalyst particles are included in the tobacco bag, cigarette paper and / or cigarette filter in an amount effective to effectively reduce the concentration of carbon monoxide and / or nitric oxide in the mainstream smoke by at least 5% (e.g., at least 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90 or 95%). The preferred amount of catalyst particles per cigarette is up to about 200 mg (for example, from 1 to 200 mg, from 1 to 50 mg, or from 50 to 100 mg). Encapsulated catalyst particles can be included in a cigarette in an amount effective to convert at least 5%, more preferably at least 25% of carbon monoxide in the main stream of tobacco smoke to carbon dioxide at a temperature of less than about 200 ° C and / or conversion at least 5%, more preferably at least 25% of nitric oxide in the main stream of tobacco smoke into nitric oxide at a temperature of less than about 200 ° C.

A method for producing a cigarette is disclosed, comprising the steps of (1) including encapsulated catalyst particles in at least and / or one of: a tobacco bag, cigarette paper and a cigarette filter; (ίί) feeding the tobacco bags into a cigarette machine to produce a tobacco rod; (ίίί) wrapping the cigarette wrapper around the tobacco rod to form a wrapped tobacco rod; and (ίν) optionally attaching the cigarette filter to the tobacco rod using cigarette paper.

Without wishing to be limited by theory, it is believed that while smoking cigarettes, including encapsulated catalyst particles, CO and / or ΝΟ, can be catalyzed in the presence of oxygen to reduce the level of CO and / or ΝΟ in the main and / or sidestream smoke. It is also believed that following a catalytic reaction, the catalyst particles can oxidize CO in the presence or absence of oxygen and / or reduce ΝΟ to reduce the level of CO and / or ΝΟ in the main stream and / or sidestream smoke. Preferably, the encapsulated catalyst particles can be catalyzed as the conversion of CO to ί.'Ο ₂ . so and ΝΟ in Ν ₂ .

As used herein, a catalyst is capable of affecting the rate of a chemical reaction, for example, a catalyst can increase the rate of oxidation of carbon monoxide to carbon dioxide without participating in the reaction as a reactant or a reaction product. The oxidizing agent is capable of oxidizing the reactant, for example, by transferring oxygen to the reactant in such a way that the oxidizing agent itself is reduced. Sun

- 5 013588 the reducing agent is capable of reducing the reagent, for example, by obtaining oxygen from the reagent so that the reducing agent itself is oxidized.

Smoking a cigarette means heating or burning a cigarette to form smoke that can be drawn in through the cigarette. In general, smoking a cigarette involves setting fire to one end of a cigarette, and while the tobacco contained therein undergoes a combustion reaction, drawing smoke from the combustion through the mouthpiece of the cigarette. You can also smoke a cigarette in other ways. For example, a cigarette can be smoked by heating a cigarette and / or heating using electric heating means, as described in US Pat. Nos. 6,053,176; 5,934,289; 5591368 or 5322075.

The term "mainstream smoke" refers to a mixture of gases passing down the tobacco rod and exiting the end of the filter, i.e. smoke coming out or drawn in from the mouthpiece of a cigarette while smoking a cigarette. The main stream of smoke includes smoke that extends both through the lit portion and through the cigarette wrapper. The term "side smoke" refers to smoke emitted during static combustion.

Several factors contribute to the formation of carbon monoxide and nitric oxide in a cigarette. In addition to the components in tobacco, temperature and oxygen concentration in a cigarette during combustion can affect their formation. For example, the total amount of carbon monoxide generated during smoking is obtained from a combination of three main sources: thermal decomposition (about 30%), combustion (about 36%) and carbon dioxide reduction with carbonized tobacco (at least 23%). The formation of carbon monoxide from thermal decomposition, which is largely controlled by chemical kinetics, begins at a temperature of about 180 ° C and ends at about 1050 ° C. The formation of carbon monoxide and carbon dioxide during combustion is controlled to a large extent by the diffusion of oxygen to the surface (k _a ) and through the surface reaction (k _b ). At 250 ° C, k _a and k _{b are} approximately equal. At 400 ° C, the reaction becomes controlled by diffusion. Finally, the reduction of carbon dioxide with carbonized tobacco or charcoal occurs at temperatures around 390 ° C and above.

During combustion, nitric oxide is released in the mainstream smoke at a concentration of about 0.5 mg / cigarette. However, nitric oxide can be reduced with carbon monoxide according to the following reactions:

2ΝΟ + 0Ο -> \ C) -CO ₂

Ν ₂ Ο + 0Ο —Ν ₂ + 0Ο ₂ .

While smoking, there are three distinct areas in a cigarette: a combustion zone, a pyrolysis / distillation zone, and a condensation / filtration zone. The combustion zone is the burning zone of a cigarette that occurs during smoking of a cigarette, usually at the lit end of the cigarette. The temperature in the combustion zone varies from about 700 to about 950 ° C, and the heating rate can increase to 500 ° C / s. Oxygen is consumed in the combustion of tobacco to liberate carbon monoxide, carbon dioxide, nitric oxide, water vapor and other organic compounds (such as tar). The combustion zone is highly exothermic and the heat generated is transferred to the pyrolysis / distillation zone.

The pyrolysis zone is a site located beyond the combustion zone, where the temperature varies from about 200 to about 600 ° C. The pyrolysis zone is where the greatest amount of carbon monoxide is released. The main reaction is the pyrolysis (i.e. thermal decomposition) of tobacco, which leads to the formation of carbon monoxide, carbon dioxide, nitric oxide, charcoal and other smoke components (e.g. tar) using the heat generated in the combustion zone.

In the condensation / filtration zone, the temperature varies from ambient temperature to about 150 ° C. The main process in this area is the condensation / filtration of smoke components. A certain amount of carbon monoxide, carbon dioxide, nitric oxide and nitrogen diffuses from the cigarette and a small amount of oxygen (for example, air) diffuses into the cigarette.

While smoking a cigarette, the main stream of smoke flows to the filter at the end of the cigarette. When carbon monoxide and nitric oxide move through a cigarette, oxygen diffuses inward, and carbon monoxide and nitric oxide diffuse out of the cigarette through the wrapper. After, as a rule, 2-second puffs, the CO and сигар cigarettes are concentrated on the periphery of the cigarette, i.e. near the cigarette wrapper, in front of the burning zone. Due to diffusion of Ο ₂ into a cigarette, the oxygen concentration is also high in the peripheral region. The flow of air into the tobacco rod is greatest near the combustion zone in the periphery of the cigarette and is approximately proportional to the temperature gradient, i.e., a higher air flow is associated with large temperature gradients. In a typical cigarette, the highest temperature gradient is from the combustion zone (> 850 ° C-900 ° C) along the axis to the filter at the end of the cigarette. Within a few millimeters beyond the combustion zone, the temperature drops to close to ambient. Additional information regarding airflow patterns, component formation in cigarettes during smoking, and smoke formation and transport can be found in Kkbatb V. Wakeg, Mesbapsht ok 8tok Rogtaboy apb Iebuegu, K.eeep1 Abuapeez ίη Tobasso 8e1epee, νοΐ.6, pp. 184 -224, (1980) and K1sbatb K. Wakeg, Wapabop ίί 1Pe Sa5 Rothshabop Kedyupz χνίΐΐιίη and Odatebe SoshShshbop Coa1 bshtd 1Pe 8toksd Sus1e, Webgade / ig Tabak-6 013588

Gogee Nipd [p (sgpa (1op1. Νοΐ.11, 1, ρρ.1-17, (1981), the contents of both are incorporated herein by reference.

Non-volatile compounds, such as gum, formed during the combustion and / or pyrolysis of tobacco, can coat unencapsulated catalyst particles and reduce their catalytic efficiency. The non-volatile compounds formed on the surface of the encapsulated catalyst particles, however, can be removed by removing the vaporized encapsulating layer from the catalyst particles, thereby opening the catalyst particles to cigarette smoke.

Encapsulated catalyst particles may be provided as a dry powder, paste or dispersion in a liquid. For example, encapsulated catalyst particles may be sprayed onto, sprayed onto, or mixed with tobacco bag or cigarette paper. In a further example, a tobacco bag or cigarette paper material may be rinsed or coated by dipping in a liquid containing encapsulated catalyst particles.

Cigarette manufacturing techniques are known in the art. Any conventional or modified cigarette manufacturing technique can be used to incorporate encapsulated catalyst particles. In cigarette manufacturing, typically, the composition of the tobacco bag is possibly mixed with other cigarette additives and fed into a cigarette machine to produce a tobacco rod, which is then wrapped in cigarette paper to produce a wrapped tobacco rod which is cut into pieces and possibly attached filters. The resulting cigarettes can be made to desired specifications using standard or modified cigarette manufacturing techniques and equipment. Cigarettes can have a length of about 50 to about 120 mm. The circumference is about 15 to about 30 mm, and preferably about 25 mm. The packing density of the tobacco is usually in the range from about 100 to about 300 mg / cm ³ and preferably from 150 to about 275 mg / cm ³ .

One embodiment provides a method of creating encapsulated catalyst particles and then depositing the catalyst particles on and / or incorporating them into a tobacco bag, which is then used to make a cigarette. The tobacco bag is typically in the form of slices or pieces of breadth ranging from about 1/4 to about 1/8 cm (from about 1/10 to about 1/20 inch) or even 1/16 cm (1/40 inch). The length of the segments varies from about 0.65 to about 7.6 cm (about 0.25 to about 3.0 inches). Cigarettes may further include one or more flavorings or other additives (e.g., flammable additives, combustion modifiers, pigments, binding agents, etc.).

Any suitable tobacco blend may be used as a tobacco bag. Examples of suitable types of tobacco materials include smoke-dried tobacco, Barley, Bright, Maryland or Orient, rare or specialty tobacco, and mixtures thereof. Tobacco material may be provided in the form of tobacco leaf, processed tobacco materials, such as expanded or “expanded” tobacco, processed tobacco stems, such as cut-rolled or cut-expanded blooms, reconstituted tobacco materials or mixtures thereof. Tobacco may also include tobacco substitutes.

Encapsulated catalyst particles can be added to a raw tobacco bag (e.g., unpacked ground tobacco) supplied to a cigarette machine, or incorporated directly into a tobacco rod prior to wrapping a cigarette wrapper around this rod to form a wrapped tobacco rod. Preferably, the encapsulated catalyst particles are provided continuously along the tobacco rod, although the encapsulated catalyst particles can be located at discrete places along the tobacco rod. Thus, the encapsulated catalyst particles can be homogeneously or non-homogeneously distributed along the tobacco rod. For example, a tobacco rod may include a first charge of encapsulated catalyst particles at one location along the tobacco rod, and a second charge of encapsulated particles at a second location along the tobacco rod. A preferred tobacco rod comprising the encapsulated catalyst particles comprises a first loading of the encapsulated catalyst particles in a filter at the end of the tobacco rod and a second charge of the encapsulated catalyst particles at the far end of the tobacco rod, in which the first charge is larger than the second charge.

The encapsulated catalyst particles and the tobacco bag can be provided in any desired ratio, for example from 1 to 90 wt.% Encapsulated catalyst particles and from 99 to 10 wt.% Tobacco bags, more preferably from about 1 to about 50 wt.% Encapsulated catalyst particles most preferably from about 1 to about 20% by weight of the encapsulated catalyst particles.

In addition to or instead of incorporating the encapsulated catalyst into the tobacco rod, the encapsulated catalyst particles can be incorporated into the cigarette paper before or after the cigarette paper is incorporated into the cigarette, the encapsulated catalyst particles can be incorporated into the cellulosic paper web by depositing the particles directly on the cellulosic web or on the web-filler material that is included in the paper, the encapsulated catalyst particles may be included in the cigarette paper and / or in Raw materials used for the manufacture of cigarette paper (for example, included in paper raw materials for a cigarette paper machine).

- 7 013588

Encapsulated catalyst particles can be incorporated into cigarette paper by spraying or applying the particle to a wet base web (e.g., cellulosic), an intermediate web, or a finished web. According to one method, the encapsulated catalyst particles in the form of a dry powder are physically mixed with cigarette paper material during the papermaking process. In another method, a suspension (eg, an aqueous suspension) of encapsulated catalyst particles may be included in the headbox of a paper machine, and encapsulated catalyst particles may be included in cigarette paper during the papermaking process.

The encapsulated catalyst particles and cigarette paper can be provided in any desired ratio, for example from 1 to 90 wt.% Of the catalyst and from 99 to 10 wt.% Of cigarette paper. In a preferred embodiment, the amount of encapsulated catalyst particles comprises from about 1 to about 50 wt.%, More preferably from about 1 to about 20 wt.% Of cigarette paper.

The amount, location and distribution of the encapsulated catalyst particles in a cigarette can be selected as a function of temperature and airflow characteristics demonstrated during smoking in order to adapt, for example, to increase or maximize the rate of conversion of CO to CO ₂ and / or N0 to Ν ₂ . The amount of encapsulated catalyst particles included in the cigarette may be selected so that the amount of carbon monoxide and the amount of nitric oxide in the mainstream smoke is reduced during smoking of the cigarette.

Encapsulated catalyst particles can be applied and / or printed on at least one surface of the paper wrapper (e.g., the inner and / or outer surface) to create text or image on the cigarette wrapper. The amount of print and / or amount of catalyst can be changed to establish a reduction in the amount of CO and / or N0.

The vaporized encapsulating layer may be colored (e.g., food coloring) to control the appearance of the encapsulated catalyst particles. For example, the color of the encapsulated catalyst particles can be provided to match or contrast with the color of cigarette paper (or tobacco bags).

The cigarette may include a mixture of different encapsulated catalyst particles. An encapsulated catalyst particle composition (i.e., a composition and / or catalyst particle size and / or composition and / or coating thickness) can be selected to function in a given temperature range, and a catalytically effective amount of catalyst particles can be included in a cigarette component (e.g. , tobacco bag, cigarette filter and / or cigarette paper) for controlling the conversion efficiency and / or selectivity of the catalyst. For example, the first encapsulated catalyst particles may be included in a tobacco bag of a cigarette, and the second encapsulated catalyst particles may be included in a cigarette paper. Cigarette paper, including encapsulated catalyst particles, can be used as a paper wrapper, paper filter and / or paper filler in a cigarette.

A cigarette wrapper may be any wrapper suitable for wrapping a tobacco bag, including wrappers containing flax, hashish, kenaf, esparto cereal, rice straw, cellulose, etc. Optional filler materials, flavorings, and flammable additives may be included in the cigarette wrapper. The wrapper may have more than one layer in cross section, as in the two-layer wrapper disclosed in US patent 5143098 (applicant), the full contents of which are incorporated into this description by reference.

Encapsulated catalyst particles may be included in a cigarette wrapper. The paper wrapper, which includes a web of fibrous cellulosic material, may further include particles of filler material for the web, such as particles of calcium carbonate (CaCO ₃ ). In practice, the filler material for the web serves as a means to control the permeability of the wrapper. The permeability of a wrapper is typically measured in Sogsb units. which are defined as the volume of air, measured in cubic centimeters, passing through one square centimeter of material in one minute at a pressure drop of 1.0 kPa.

The paper wrapper may include one or more layers. A preferred cigarette includes a first wrapper, a second wrapper formed around the first wrapper, and encapsulated catalyst particles included in the first wrapper.

The encapsulated catalyst particles will preferably be distributed throughout the tobacco rod and / or parts of the cigarette wrapper. By providing an encapsulated catalyst throughout the at least one component of the cigarette, the amount of carbon monoxide drawn through the cigarette can be reduced, especially the combustion, pyrolysis, condensation and / or filter portions.

Another object of the invention relates to a method for processing tobacco smoke, which involves igniting a cigarette to generate tobacco smoke and drawing smoke through a cigarette in which a volatile encapsulating substance is at least partially volatilized to open the surface of the catalyst particles. In a preferred embodiment, the volatile encapsulating substance is volatilized at a distance of about 0.1 to 10 mm to the carbonization line.

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Although various embodiments have been described above, various changes and modifications are obvious to those skilled in the art. Such changes and modifications should be considered as included in the scope of the attached claims.

Claims (20)

CLAIM 1. Component cigarettes containing encapsulated catalyst particles capable of reducing the content of at least one of carbon monoxide and nitric oxide in the mainstream smoke, and these catalyst particles are at least partially covered with a volatile encapsulating substance, and this component is selected from the group consisting of a tobacco bag, cigarette paper and a cigarette filter. 2. A component according to claim 1, in which: (a) catalyst particles are completely coated with a volatile encapsulating agent; (b) catalyst particles include at least one of an elemental metal, alloy, oxide, and oxyhydroxide of at least one element selected from the group consisting of Md, Al, δί, Τί, V, Cr, Mn, Eu, Co, N1 , Si, Ζη, Ge, Υ, Ζτ, IL, Mo, Ki, Hell, δη, Ce, Pr, La, Ηί, Ta, ^, Pe, Ob, 1g and Au; (c) the catalyst particles include at least one of manganese, iron, copper or cerium oxide and oxyhydroxide; (b) the catalyst particles include nanoparticles; or (e) the catalyst particles have an average particle size of less than about 100 nm or less than about 50 nm. 3. Component according to claim 1, in which the volatile encapsulating substance includes at least one of: (a) a wax selected from the group consisting of beeswax, coconut wax, candelilla wax, carnauba wax, montan wax, urricuri wax, paraffin wax, rice wax, and mixtures thereof; (B) a water soluble polymer selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxides, water soluble polyamides, water soluble polyesters, water soluble celluloses, acrylic acid polymers, starches, dextrins, gums, gelatins, pectin, alginates, gum arabic and mixtures thereof; (c) a water-insoluble polymer selected from the group consisting of polyethylene, polypropylene, polyacrylates, polymethacrylates, polymethyl methacrylates, polyvinyl chloride, polyvinylidene chloride, polysaccharides, and mixtures thereof; (b) a first layer in contact with catalyst particles and a second layer formed over the first layer; and (e) a first layer comprising a flavoring compound and a second layer formed over the first layer. 4. Component according to claim 1, in which: (a) the volatile encapsulating substance has an evaporation temperature of from about 40 to about 350 ° C; (b) the volatile encapsulating substance is capable of evaporating into the atmosphere with a relative humidity of more than about 5% or (c) the volatile encapsulating substance has an evaporation temperature of from about 40 to about 350 ° C and is capable of evaporating into the atmosphere with a relative humidity of more than about 5 % 5. A component according to claim 1, in which the volatile encapsulating substance comprises a flavoring compound. 6. A component according to claim 5, in which the flavoring compound comprises menthol, a menthol derivative, menthol precursor, or a mixture thereof. 7. The component according to claim 5, in which the flavoring compound includes an artificial flavor, natural flavor, essential oil, aldehyde, alcohol, ester, ketone, phenol, or a mixture thereof. 8. Component according to claim 1, in which the catalyst particles are able to act as an oxidizing agent for converting carbon monoxide to carbon dioxide, a reducing agent for converting nitric oxide to nitrogen, as a catalyst for converting at least one of carbon monoxide to carbon dioxide and oxide nitrogen to nitrogen. 9. A cigarette comprising a tobacco rod, cigarette paper and possibly a filter in which at least one of the tobacco rod, cigarette paper and the filter includes encapsulated catalyst particles capable of reducing the content of at least one of carbon monoxide and nitric oxide mainly a stream of tobacco smoke in which the catalyst particles are at least partially coated with a volatile encapsulating substance. 10. A cigarette according to claim 9, in which: (a) the volatile encapsulating substance is able to evaporate while smoking a cigarette to open the active surface of the catalyst particles; (b) a volatile encapsulating substance is adapted for thermal or chemical decomposition. - 9 013588 when smoking a cigarette to open the surface of catalyst particles or (c) a volatile encapsulating substance is capable of evaporation and thermal or chemical decomposition during smoking of a cigarette to open the surface of catalyst particles. 11. A cigarette according to claim 9, wherein the catalyst particles are completely coated with a volatile encapsulating substance. 12. The cigarette according to claim 9, wherein the encapsulated catalyst particles are included in an amount effective to convert at least 5% of carbon monoxide in the mainstream smoke to carbon dioxide or at least 5% nitric oxide in the mainstream tobacco smoke nitrogen, or in an amount effective to convert at least 5% of carbon monoxide in the mainstream tobacco smoke to carbon dioxide and at least 5% nitric oxide in the mainstream tobacco smoke into nitrogen. 13. A cigarette according to claim 9, in which the encapsulated catalyst particles are included in a total amount of up to about 200 mg per cigarette. 14. A cigarette according to claim 9, in which the encapsulated catalyst particles are uniformly or non-uniformly distributed along the tobacco rod. 15. A cigarette according to claim 9, wherein the cigarette paper comprises at least one of: (a) a wrapper having a first layer and a second layer formed around the first layer, the encapsulated catalyst particles being included in the first layer; and (b) a wrapper in which the encapsulated catalyst particles are applied or printed or applied and printed on at least one surface of the wrapper. 16. A cigarette according to claim 9, comprising a mixture of different encapsulated catalyst particles. 17. A method for producing a cigarette, comprising: (ΐ) the inclusion of encapsulated catalyst particles at least in, on, or in and on one of the following: tobacco bags, cigarette filter and cigarette wrapper; (ΐΐ) feeding the tobacco bag into a cigarette machine to produce a tobacco rod; (ϊϊΐ) wrapping the cigarette wrapper around the tobacco rod to obtain a wrapped cigarette tobacco rod and (ΐν) it is possible to attach the cigarette filter to the tobacco rod using tipping paper. 18. The method according to 17, in which the inclusion includes spraying, spraying or dipping. 19. The method according to claim 17, wherein the encapsulated catalyst particles are incorporated into cigarette paper by spraying or applying the encapsulated catalyst particles onto a wet base web, intermediate web or finished web. 20. The method according to claim 17, wherein the step of incorporating comprises combining the encapsulated catalyst particles and at least one of the tobacco bags and the cigarette wrapper in the absence of liquid.