BRPI0706603A2 - cigarette components having encapsulated catalyst particles and production methods and their use - 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

Patent Descriptive Report for "CIGARETTE COMPOUNDS HAVING EN-CAPSULATED CATALYST PARTICULARS AND METHODS OF PRODUCTION AND THEIR USE".

Background

Cigarettes produce both mainstream smoke during a puff and sidestream smoke during static burning.

Constituents of both mainstream and sidestream smoke are carbon monoxide (CO) and nitric oxide (NO). Reduction of carbon monoxide and / or nitric oxide in smoke is desirable.

summary

Cigarettes and cigarette components (e.g., cut tobacco filler and cigarette paper) are described comprising encapsulated catalyst particles capable of decreasing decarbon monoxide and / or nitric oxide in maintaining tobacco smoke, wherein the particulate Encapsulated catalysts comprise catalyst particles that are at least partially coated with a volatile encapsulant. Preferably the catalyst particles are fully coated with the volatile encapsulant.

Catalyst particles, which may comprise nanoscale particles, preferably comprise an elemental metal, alloy, oxide and / or oxydroxide of at least one element selected from the group consisting of Mg, Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu1 Zn, Ge, Y, Zr, Nb, Mo, Ru, Ag, Sn, Ce, Pr, La, Hf, Ta, W, Re, Os, Ir and Au.

Preferred catalyst particles may lower tobacco smoke constituents, for example, catalyze the conversion of carbon monoxide to carbon dioxide and / or nitric oxide to nitrogen, oxidize carbon monoxide to carbon dioxide and reduce nitric oxide to carbon dioxide. Trogen.

The volatile encasulant is preferably a wax, a water-soluble polymer or a water-insoluble polymer. The volatile encasulant may comprise a taste-bearing compound such as menthol, a menthol derivative or a menthol precursor. Preferred volatile encapsulants have a volatilization temperature of between about 40 ° C and about 350 ° C or volatilize on exposure to an atmosphere having a relative humidity of more than about 5%.

In one embodiment, the volatile encasulant comprises a first layer (e.g., a taste carrier layer) contacting the catalyst particles and a second layer formed above the first layer.

In a cigarette comprising the encapsulated catalyst particles, the volatile encasulant is adapted to volatilize (e.g. thermal or chemical degradation) during smoking of a cigarette to expose an active surface of the catalyst particles.

In one embodiment, the encapsulated catalyst particles may be incorporated homogeneously or not homogeneously along the tobacco rod of a cigarette. In another embodiment, encapsulated catalyst particles may be incorporated into a cigarette filter or paper wrapper. For example, encapsulated catalyst particles may be incorporated into the first (e.g. internal) layer of a multilayer paper wrapper. Encapsulated catalyst particles may be distributed throughout the paper wrapper or printed on a paper wrapper surface. A cylinder may comprise a mixture of different encapsulated catalyst particles.

A method of producing a cigarette comprises (i) incorporating catalyst particles encapsulated in and / or at least one of tobacco cut filler material and a cigarette wrapping paper; (ii) providing the cut tobacco filler material to a cigarette producing machine to form a tobacco column; and (iii) placing the cigarette paper wrap around the tobacco column to form a tobacco rod of a cigarette; and (iv) optionally attaching the cigarette filler to the tobacco column using lining paper. Encapsulated catalyst particles may be incorporated by spraying, dusting or dipping. For example, encapsulated catalyst particles may be incorporated into the cigarette paper by buffing or coating the encapsulated catalyst particles onto a wetted continuous sheet, an intermediate continuous sheet or a finished continuous sheet.

Brief Description of the Drawings

Figure 1 (a) shows an optical microscopic image of NANOCAT iron oxide catalyst particles as received. Figures 1 (bj and 1 (c) show optical microscopic images of particulate and fiber encapsulated NANO-CAT iron oxide, respectively.

Detailed Description of Preferred Embodiments

Cigarette components, cigarettes and methods for cigarette smoke having incorporated encapsulated catalyst particles therein are described. Encapsulated catalyst particles comprise a core of one or more catalyst particles and a volatile encapsulation layer (i.e. coating) formed around the core. A volatile encapsulation layer may be a protective layer for catalyst particles at ambient temperatures (eg during cigarette storage and downstream of the combustion / pyrolysis zone in a lit cigarette), but on exposure to a high temperature, humidified Gaseous phase or cigarette smoke constituents of the volatile material may volatilize (eg thermal or chemical degradation).

Encapsulated catalyst particles may be incorporated into one or more components of a cigarette such as cut tobacco filler material, cigarette paper and cigarette cigarette filter. In cigarettes comprising the encapsulated catalyst particles, the amount of carbon monoxide and / or nitric oxide in mainstream smoke may be reduced. Methods for providing cigarettes comprising encapsulated catalyst particles include encapsulating the catalyst particles and incorporating the encapsulated catalyst particles into one or more components used to form a cigarette.

The incorporation of the catalyst particles into one or more components of a cigarette has been described in U.S. Pat. 2004/0131859; 2004/0040566 and 2004/0110633, the contents of which are incorporated herein by reference. Catalyst particles may be incorporated into a cigarette to reduce the concentration in mainstream smoke and / or side-stream smoke of one or more gas phase constituents (eg, CO or NO). However, during smoking of a cigarette comprising catalyst particles, semi-volatile or non-volatile combustion products such as tar may form in the catalyst particles. Early deposition of semi-volatile and non-volatile deposits can effectively deactivate the catalyst particles (for example, by forming a barrier between decatalyst particles and non-gaseous constituents and / or by chemical interaction with catalyst particles). For example, a layer of semi-volatile or non-volatile material may be effectively impenetrable to gaseous phase constituents found in mainstream smoke. Moreover, at high temperatures, semi-volatile or nonvolatile materials may react with catalyst particles and decrease their catalytic activity.

Described are encapsulated catalyst particles comprising a volatile coating that is formed directly on an exposed surface (e.g., a catalytic surface) of the decatalyst particles. By volatile is meant that the preferred encapsulation layer has a volatilization temperature that is lower than the tar volatilization temperature or other solid phase decolusting / pyrolysis by-products of tobacco. Before cigarette smoke from a cigarillo comprising the encapsulated catalyst particles, the volatile coating is preferably at least partially encapsulated, more preferably fully encapsulated catalyst particles. Preferred volatile coatings are volatilized during smoking of a cigarette.

In a cigarette comprising the encapsulated catalyst particles, when the encapsulated catalyst particles are exposed to a temperature that is below the coating volatilization temperature, the volatile coating forms a protective layer on semi-volatile and non-volatile (e.g. tar) may deposit. Semi-volatile and nonvolatile materials may form and deposit on volatile coating and are not the catalyst particles. When the temperature reaches or exceeds the volatilization temperature of the encapsulant, volatile coating - as well as any materials formed upon it - may be removed to expose an active surface of the catalyst particles. Thus, an active surface of the catalyst particles may be exposed under smoke conditions (i.e., ahead of the combustion zone) to catalyze and / or oxidize gaseous constituents of mainstream and / or side stream smoke. Applicants have unexpectedly found that encapsulated catalyst particles that are incorporated into a cigarette have a higher catalytic effectiveness during cigarette smoking than unencapsulated catalyst particles.

In one embodiment, a cigarette comprises encapsulated catalyst particles wherein during cigarette smoking the volatile en-capsulant is volatilized at a distance of from about 0.1 mm to about 10 mm, preferably about 0 mm. .5 mm to about 2 mm ahead of the firing line. As used herein, the "firing line" is the line created in a cigarette paper wrapper at the end of the cigarette combustion zone produced during cigarette smoking.

The encapsulation layer is formed from a volatile material that can thermally or chemically degrade. In a first embodiment, the encapsulating material may thermally degrade (eg melt, sublimate or pyrolyze) upon exposure to a temperature above room temperature, but below about 350 ° C, preferably below about 200 ° C. ° C to expose a surface of the catalyst particles to mainstream smoke, sidestream smoke or both. Preferred thermally encapsulating materials degrade at a temperature between about 40 ° C and about 200 ° C. In another embodiment, the encapsulating material may chemically degrade (e.g. dissolve) upon exposure to cigarette smoke components generated during smoking. For example, moisture in the main resulting smoke may interact with the encapsulation layer to volatilize the encapsulating material and expose the catalyst particles. Preferred encapsulation layers chemically degrade on exposure to mainstream smoke or side stream smoke having a relative humidity of more than about 5%, more preferably more than about 20%.

By providing a volatile encapsulation layer, an active catalytic surface of particles that are incorporated into a cigarette (e.g., in cut tobacco filler material) can be exposed in front of the combustion region of a cigarette. The volatile encapsulation layer can minimize physical interaction and chemical reaction between particles and nonvolatile or semivoluble combustion and / or pyrolysis products (eg tar). For example, high temperature cracking of tar particles via reaction with the catalyst particles can be minimized.

Catalyst particles, which comprise the nucleus of encapsulated catalyst particles, may comprise an elemental metal, alloy, oxide and / or an oxyhydroxide of at least one element selected from the group consisting of Mg, Al, Si, Ti V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, Y, Zr, Nb, Mo, Ru, Ag, Sn, Ce, Pr, La, Hf, Ta, W, Re, Os and Au.

Catalyst particles preferably comprise nanoscale particles. By "nanoscale" is meant that the catalyst particles have an average particle diameter of less than one micron. Preferably, the nanoscale particles have an average particle size of less than about 100 nm. more preferably less than about 50 nm, and more preferably less than about 10 nm.

Preferred catalyst particles comprise iron oxides and / or oxohydroxides. For example, MACH I, Inc., King of Prussia, Pennsyl-vania, U.S. markets Fe2 O3 nanoscale particles under the trademarks NANOCAT® Superfine Iron Oxide (SFIO) and NANOCAT® Magnetic Iron Oxide. NANOCAT® Superfine Iron Oxide (SFIO) is amorphous ferric oxide in the form of a free-flowing powder with a particle size of about 3 nm, a specific surface area of about 250m2 / g, and an apparent density of about 0.05 g / ml. NANOCAT® Iron-Superfine Oxide (SFIO) is synthesized by a vapor phase process, which makes it substantially free of impurities that may be present in conventional catalysts, and is suitable for use in food, pharmaceuticals and cosmetics. . NANOCAT® Magnetic Iron Oxide is a free-flowing powder with a particle size of about 25 nm and a surface area of about 40 m2 / g. Other preferred catalyst particles comprise manganese, copper or cerium oxides and / or oxyhydroxides.

The encapsulant, which forms a coating that encapsulates the catalyst particles, may comprise a wax, a water-soluble polymer, a water-insoluble polymer or other material capable of volatilizing during smoking of a cigarette exposing the catalyst particles. underlying pain. Preferred encapsulation materials are non-toxic, easily coated on catalyst particles, and stable (e.g., thermally and chemically stable) under typical decigarette storage conditions. A preferred encapsulant comprises one or more flavoring compounds.

The encapsulant may comprise a wax. Preferred waxes include thermostable materials having a melt temperature of from about 40 ° C to about 350 ° C. Exemplary waxes include beeswax, coconut wax, candelilla wax, carnauba wax, mountain wax, cerade ouricuri, paraffin wax, rice wax or mixtures thereof.

The encapsulant may comprise a water soluble polymer. Exemplary water soluble polymers include polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxides, water soluble polyamides, water soluble polyesters, water soluble cellulose, acrylic acid polymers, or mixtures thereof. Naturally modified water-soluble polymers include starches, dextrins, gums, gelatines, pectin, alginates, gum arabic or mixtures thereof.

Preferred encapsulants are alginates. Alginates are long chain carbohydrate biopolymer alginic acid salts and include sodium algynate, calcium alginate, potassium alginate and propylene glycol alginate. Although alginic acid is water insoluble, the salts are hydro-colloids (ie, they bind or absorb water) and can be made into a coating.

Alginates are generally heat resistant and stable. Concentration adjustment of calcium ions, which cause crosslinking, gel concentration controls. Combination of alginate with other gums such as pectin may increase viscosity.

Alginates may be dispersed in ambient temperature water, through solubility is typically less when the water temperature decreases. Alginate concentrations above 2% by weight may be dispersed using high shear mixing to eliminate lumps. High speed mixers combine high flow with high shear to increase mixing efficiency. A preferred method of forming encapsulated catalyst departments comprising a calcium dealginate coating is discussed below.

The encapsulant may comprise a water insoluble polymer. Exemplary water-insoluble polymers include polyethylene, polypropylene, polyacrylates, polymethacrylates, polymethylmethoerylates, polyvinyl chloride, polyvinylidene chloride, polysaccharides, or mixtures thereof.

The encapsulant may comprise a defective carrier compound. Preferred flavor compounds include menthol, menthol derivatives menthol precursors. Other suitable flavor compounds include synthetic or natural fragrances, essential oils, alcohols, aldehydes, esters, ethers, ketones, phenols, and mixtures thereof. The flavor compound may be aromatic compound or a non-aromatic compound.

Catalyst particles may be coated with one or more layers of the same or different volatile encapsulants. For example, multiple coating steps may be used to achieve the desired thickness and / or coverage of a desired encapsulant. In another example, catalyst particles may be coated with a first volatile coating, and then with a second volatile coating. In a preferred embodiment, the first volatile coating comprises a flavor carrier compound.

A variety of methods may be used to form encapsulated catalyst particles. Suitable methods include providing the catalyst particles and forming at least one volatile encapsulating layer on the catalyst particles. Methods include liquid phase techniques and gas phase techniques.

In an exemplary gas phase technique, catalyst particles may be mixed with a liquid phase encapsulant (e.g., solution or pure liquid of a volatile compound) to form a mixture. During mixing, the temperature and the amount of stirring can be controlled. For example, catalyst particles and an encapsulant solution may be mixed at room temperature and sonicated to form a homogeneous mixture.

An encapsulant-catalyst particle mixture may be dried to form the encapsulated catalyst particles. According to a preferred method, the mixture may be aspirated to form an aerosol comprising catalyst particles coated with the encapsulant. Aerosolization temperature and dispersion rate can be controlled to form solid phase encapsulated catalyst particles (i.e., where the encapsulating layer dries to form a solid coating on the catalyst particles).

By way of example, encapsulated catalyst particles comprising 50% by weight of NANOCAT® iron oxide coated with gum arabic may be prepared first by mixing iron oxide particles (~ 1 g) with arabic gum (~ 1 g ) in about 30 ml of deionized water under constant agitation to form a uniform suspension of the iron oxide particles. The suspension is aerosolized using a 0.5 mm nozzle at about 170 ° C thereby water present in the mixture is evaporated and gum arabic-coated particles of iron oxide are formed. Depending on the processing conditions, the encapsulated catalyst particles may be in the form of a powder, granulate or agglomerate. The encapsulated catalyst particles may be in the form of spheres, spheroids, strands, fibrils and the like.

In an exemplary liquid phase technique, catalyst particles may be immersed in an encapsulant or liquid phase encapsulant precursor (e.g., pure liquid solution of a volatile compound) to form a mixture in which a coating is formed on the particles. catalyst cells. The temperature during immersion may be controlled and the mixture may optionally be stirred (e.g., stirred). Catalyst particles and an encapsulant may be mixed at room temperature to form the coating. After immersion, the coated catalyst particles may be dried and optionally further processed to form encapsulated catalyst particles. Another processing may comprise crosslinking of the encapsulation polymer, such as through an ion exchange reaction.

One method of forming alginate encapsulated catalyst particles comprises dipping catalyst particles in a solution of an alginate salt to form coated catalyst particles, and then treating the coated catalyst particles to form a crosslinked polymeric alginate coating. .

By way of example, encapsulated catalyst particles comprising 50% by weight of NANOCAT® iron oxide particles coated with calcium and / or sodium alginate may be prepared first by mixing iron oxide particles (~ 1 g) with a sodium alginate solution (1 g of sodium alginate in 100 ml of deionized water) under constant stirring to form sodium alginate-coated iron oxide particles. The mixture is preferably homogenised (e.g. for 30-130 seconds), allowed to adjust in air (e.g. for 10-60 minutes), and then rehomogenized (e.g. 30-130 seconds) .

The sodium alginate coating may be at least partially and preferably fully converted (e.g. polymerized) into a calcium alginate coating by an ion exchange reaction. A known volume of the comalginate coated iron oxide particles is preferably contacted with a solution comprising a multivalent cation. The solution may comprise an aqueous or non-aqueous (e.g. alcoholic) solution. In a preferred method, the solution comprises calcium chloride (e.g., 0.1 M aqueous calcium chloride solution) whereby Ca2 + is exchanged for Na1 + via an ion exchange reaction which forms a coating of volatile calcium alginate cross-linked around the iron oxide particles. Other multivalent cation solutions suitable for forming a cross-linked encapsulation layer may comprise aluminum, manganese, iron, copper, zinc, strontium, silver and barium. The hardness of a crosslinked polymer encapsulant can be encapsulant can be controlled by varying the degree of crosslinking. The amount of crosslinking is proportional to the reaction time (ie cure time) between the encapsulant and the multivalent cation solution. Other polymers that can be cross-linked via ion exchange include polysaccharides.

In a preferred method, a known volume of sodium alginate-coated iron oxide particles is dispersed dropwise (e.g., through a syringe such as a 26.5 gauge needle) into a calcium chloride solution. Height and dispersion rate can be controlled to control the size of encapsulated particles. Excess calcium chloride solution may be removed (eg filtered or decanted) after a preset cure time (eg up to about 2 h) and calcium alginate coated particles may be removed. washed and dried. Encapsulated catalyst particles comprising at least about 10, 20, 30, 40, 50, 60, 70, 80 or 90% by weight of catalyst particles (eg iron oxide particles) may be prepared .

Optical micrographs of iron oxide / calcium alginate samples are shown in Figure 1. Figure 1 (a) shows an optical micrograph of received NANOCAT® iron oxide departments. Figure 1 (b) shows an optical micrograph of calcium oxide encapsulated iron oxide particles in the form of irregular and spherical particles. Figure 1 (c) shows an optical micrograph of fibril-encapsulated calcium oxide-encapsulated iron oxide particles.

Additional methods for the formation of encapsulated catalyst particles include polymer-polymer incompatibility (wherein catalyst particles are coated via preferential adsorption of a polymer from a solution of incompatible polymers which are dissolved in a common solvent); fluidized bed encapsulation and fasegasosa polymerization.

Encapsulated micron size catalyst particles may have an average particle size of from about 1 micron or less to about 1000 microns or more. The encapsulated catalyst particles may have an average particle size of 10, 20, 30, 40, 50, 60.70, 80 or 90 microns ± 5 microns to about 100, 200, 300, 400, 500, 600,700 800 or 900 microns ± 50 microns. The encapsulated catalyst particles may comprise individual particles or an agglomerated coated catalyst departments. Preferred encapsulated catalyst particles have an average particle size of less than 1 micron. Nanoscale and submicron catalyst particles may be encapsulated to form encapsulated catalyst particles having an average particle size of 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 encapsulant thickness.

According to a preferred method, the encapsulated catalyst particles are incorporated in at least one of cut tobacco filler material, cigarette paper and cigarette filter which are used to form a cigarette. By incorporation of the catalyst particles into one or more components in mainstream smoke during smoking can be reduced.

Preferably, the encapsulated catalyst particles are incorporated in cut tobacco filler material, cigarette paper and / or cigarette filter in an amount effective to reduce the concentration of carbon monoxide and / or nitric oxide 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%). A preferred amount of catalyst particles per cigarette is up to about 200 mg (e.g., from 1 mg to 200 mg, from 1 mg to 50 mg, or from 50 mg to 100 mg). The encapsulated catalyst particles may be incorporated into a cigarette in an amount effective to convert at least 5%, more preferably at least 25% of mainstream tobacco smoke carbonone monoxide to carbon dioxide at a temperature of less than about 200 ° C. ° C and / or convert at least 5%, more preferably at least 25% of the nitric oxide in mainstream smoke to nitric oxide at a temperature of less than about 200 ° C.

Described is a method of producing a cigarette comprising the steps of (1) incorporating encapsulated catalyst particles in and / or at least one cut-off filler material into a cigarette making machine. (iii) placing the cigarette paper wrap around the tobacco column to form a tobacco rod of a cigarette; and (iv) optional attachment of the filler material to the tobacco column using cover paper.

While not wishing to be bound by theory, it is believed that when smoking a cigarette having encapsulated catalyst particles incorporated therein, CO and / or NO may be catalyzed in the presence of oxygen to reduce the level of CO and / or NO in the cigarette. primary current smoke / or side current. It is believed that subsequent to the catalytic reaction, catalyst particles may oxidize CO in the presence or absence of oxygen and / or reduce NO to decrease the level of CO and / or NO in mainstream smoke and / or side current. Preferably, the encapsulated catalyst particles may catalyze both CO to CO2 conversion and NO to N2.

As used herein, a catalyst is capable of affecting the rate of a chemical reaction, for example, a catalyst may increase the oxidation rate of carbon monoxide to carbon dioxide without participating as an oxidation reagent of a reactant, for example by oxygen donation. to the reagent such that the oxidant itself is reduced. A reducing agent is capable of reducing a reagent, for example by receiving oxygen from the reagent, such that the reducing agent itself is oxidized.

"Smoke" from a cigarette means the heating or combustion of the cigarette to form smoke which can be pulled through the cigarette. In general, smoke from a cigarette involves lighting one end of the cigarette and while the tobacco contained therein undergoes a combustion reaction, pulling smoke from the combustion through the end of the cigarette through the mouth. Cigar can also be smoked by other means. For example, the cigarette can be smoked by heating the cigarette and / or heating using an electric heater device as described in U.S. Patents assigned herein. 6,053,176; 5,934,289; 5,591,368 or 5,322,075.

The term "mainstream" smoke refers to the mixture of steps that transmit the tobacco rod and exit through the filter end, that is, the smoke that comes out or pulls from the end of a cigarillo through the mouth during smoking . Mainstream smoke contains smoke that is drawn both through the lit region and through the cigarette wrapper. The term "side stream" smoke refers to smoke produced during static burning.

Several factors contribute to the formation of carbon monoxide and nitric oxide in a cigarette. In addition to the constituents in tobacco, temperature and oxygen concentration in a cigarette during combustion may affect its formation. For example the total amount of carbon monoxide formed during smoking comes 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 monoxide transformation of 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 largely controlled by the diffusion of oxygen to the surface (ka) and via a surface reaction (kb). At 250 ° C, ka and kb are about the same. At 400 ° C, the reaction becomes controlled diffusion. Finally, carbon dioxide reduction with carbonized tobacco or charcoal occurs at temperatures around 390 ° C and above.

During combustion, nitric oxide is produced in the mainstream smoke at a concentration of about 0.5 mg / cigarette. However, nitric oxide may be reduced by carbon monoxide according to the following reactions. 2NO + GO -> N2O + CO2N2O + CO -> N2 + CO2

During smoking there are three distinct regions in a cigarette: the combustion zone, the pyrolysis / distillation zone, and the condensation / filtration zone. The combustion zone is the burning zone of the cigarette producing during smoking, usually at the lit end of the cigarette. The temperature in the combustion zone ranges from about 700 ° C to about 950 ° C, and the heating rate can be as high as 500 ° C / second.

Oxygen consumed in the combustion of tobacco to produce carbon monoxide, carbon dioxide, nitric oxide, water vapor and other organic compounds (eg tar). The combustion zone is highly exothermic and the heat generated is transported to the pyrolysis / distillation zone.

The pyrolysis zone is the region behind the combustion zone, where the temperature ranges from about 200 ° C to about 600 ° C. The pyrolysis zone is where most carbon monoxide is produced. The main reaction is pyrolysis (ie thermal degradation) of tobacco to produce carbon monoxide, carbon dioxide, nitric oxide, charcoal and other smoke components (eg tar) using heat generated in the combustion zone. .

In the condensation / filtration zone the temperature ranges from room temperature to about 150 ° C. The main process in this zone is the condensation / filtration of smoke components. Some amount of carbon monoxide, carbon dioxide, nitric oxide and nitrogen diffuse into the cigarette and some oxygen (eg air) diffuses into the cigarette.

During smoking a cigarette, mainstream smoke flows toward the end of the cigarette filter. Since carbon monoxide and nitric acid travel inside the cigarette, oxygen diffuses into the cigarette and carbon monoxide and nitric oxide diffuse out of the cigarette through the paper wrapper. After a 2-second puff of a cigarette, CO and NO are concentrated on the periphery of the cigarette, that is, near the cigarette wrapper, in front of the combustion zone. Due to the diffusion of O2 into the cigarette, oxygen concentration is also high in the peripheral region. The air flow within the tobacco rod is closest to the combustion region on the periphery of the cigarette and is approximately adequate with the temperature gradient, ie higher air flow is associated with higher temperature gradients. In a typical cigarette, the highest temperature gradient is from the combustion zone (> 850 ° C - 900 ° C) axially toward the end of the cigarette filter.

Within a few millimeter range behind the combustion zone the temperature drops to near room temperature. Further information on airflow patterns, cigarette constituent formation during smoking, and smoking and supply can be found at Richard R. Baker, "Mechanism of Smoke Formation and Delivery", Re-cent Advances in Tobacco Science, vol. 6, p. 184-224, (1980) and Ri-chard R. Baker, "Variation of the Gas Formation Regions within a Cigarette Coalition during the Smoking Cycle", Beitrage zur TabakforschungInternational, vol. 11, no. 1, p. 1-17, (1981), the contents of which are incorporated herein by reference.

Nonvolatile compounds such as tar produced from tobacco combustion and / or pyrolysis may coat non-encapsulated catalyst particles and decrease their catalytic effectiveness. Nonvolatile compounds that form on the surface of the encapsulated catalyst particles, however, may be removed by removing the volatile encapsulation layer from the catalyst particles, thereby exposing 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 sprinkled, sprayed or combined with cigarette paper or tobacco from the cut filler material. In another example, the cut tobacco filler material or cigarette paper material may be rinsed or coated with a liquid containing the encapsulated catalyst particles.

Techniques for cigarette manufacturing are known in the art.

Any conventional or modified cigarette making technique may be used to incorporate the encapsulated catalyst particles. In the manufacture of a cigarette, typically the cut filler composition is optionally combined with other cigarette additives, and is provided with a cigarette making machine to produce a cigarette column, which is then wrapped in cigarette paper to form a rod. detabaco that is cut into sections, and optionally coated with filters. The resulting cigarettes can be manufactured to desired specifications using standard or modified cigarette production equipment and techniques. Cigarettes can range from about 50 mm to about 120 mm in length. The circumference is about 15 mm to about 30 mm in circumference, and preferably about 25 mm. The tobacco packing density is typically in the range from about 100 mg / cm3 to about 300 mg / cm3, and preferably from 150 mg / cm3 to about 275mg / cm3.

One embodiment provides a method for forming the encapsulated catalyst particles and then depositing the catalyst particles onto and / or incorporating them into the cut tobacco filler material, which is then used to form a cigarette. Tobacco cut filler material is usually in the form of strips or strands cut to widths ranging from about 4 cm to about 1/8 cm (about 1/10 inch to about 1/20 inch). ) or 1/16 cm (1/40 inch). Bead lengths range from about 0.65 cm to about 7.6 cm (about 0.25 inch to about 3 inches). Cigarettes may further comprise one or more flavorings or other additives (e.g., burning additives, combustion modifying agents, coloring agents, binders, etc.).

Any suitable tobacco blend may be used for the cut filler material. Examples of suitable types of tobacco materials include flue-cure tobacco, Burley Bright, Maryland or Oriental, rare or particular tobacco products, and combinations thereof. Tobacco material may be provided in the form of a tobacco leaf, processed tobacco materials such as volume expanded or swollen tobacco, processed tobacco trunks such as cut or unfilled rolled trunks, reconstituted tobacco materials or combinations thereof.

Tobacco may also include tobacco substituents.

The encapsulated catalyst particles may be added to cut into the tobacco stock of cut filler material (e.g., loose cut filler material) supplied to a cigarette making machine or incorporated directly into a tobacco rod prior to winding. wrap a cigarette paper wrap around the cigarette rod to form a tobacco column. Preferably, the encapsulated catalyst particles are provided continuously throughout the length of a tobacco rod, although the encapsulated catalyst particles may be provided at discrete locations along the length of a tobacco rod. Thus, the encapsulated catalyst particles may be homogeneously or non-homogeneously distributed along the length of a tobacco rod. For example, a tobacco rod may comprise a first loading of encapsulated catalyst particles at a location along the tobacco rod and a second loading of encapsulated particles at a second location along the tobacco rod. A preferred tobacco rod comprising encapsulated catalyst particles has a first loading of encapsulated catalyst particles at the filter end of the tobacco rod and a second loading of encapsulated catalyst particles at the distal end of the tobacco rod, wherein the first loading is larger than the second load.

Encapsulated catalyst particles and tobacco cut filler may be provided in any desired ratio, for example, 1 wt% to 90 wt% encapsulated catalyst particles and 99 wt% to 10 wt% cut filler. tobacco, more preferably from about 1 wt% to about 50 wt% encapsulated decatalyst particles, more preferably about 1 wt% about 20 wt% encapsulated catalyst particles.

In addition to or instead of incorporating the encapsulated catalysts into the tobacco rod, the encapsulated catalyst particles may be incorporated into the cigarette paper before or after the cigarette paper is incorporated into a cigarette. Encapsulated catalyst particles may be incorporated into the cellulosic web of the paper by depositing the particles directly onto the cellulosic web or the web-filled filler material that is incorporated into the paper. Encapsulated catalyst particles may be incorporated into cigarette paper and / or into the raw materials used to produce cigarette paper (e.g., incorporated into the paper stock of a cigarette paper machine).

Encapsulated catalyst particles may be incorporated into cigarette paper by spraying or covering the particles over a wet (e.g. cellulosic) continuous sheet, an intermediate continuous sheet or a finished continuous sheet. According to one method, encapsulated catalyst particles in the form of a dry powder are physically mixed with the cigarette paper material during the papermaking process. In another method, pulp (e.g., aqueous paste) of the encapsulated catalyst particles may be incorporated into the top box of a papermaking machine and the encapsulated catalyst particles may be incorporated into the cigarette paper during the processing process. encapsulated catalyst particles and cigarette paper may be provided in any desired ratio, for example, 1 wt.% to 90 wt.% of catalyst and 99 wt.% to 10 wt.% carbon paper. Garro. In a preferred embodiment, amounts of encapsulated catalyst particles comprise from about 1 wt% to about 50 wt%, more preferably from about 1 wt% to about 20 wt% of the cigarette paper.

The amount, location and distribution in a cigarette of the encapsulated catalyst particles may be selected as a function of the temperature and air flow characteristics exhibited during smoking to adjust, for example, to increase or maximize the CO conversion rate. in CO2 and / or NO in N2. The amount of encapsulated catalyst particles incorporated in a cigarette may be selected such that the amount of carbon monoxide and the amount of nitric oxide in mainstream smoke is reduced during smoking of a cigarette.

Encapsulated catalyst particles may be coated and / or printed on at least one surface of a paper wrapper (e.g., an outer and / or inner surface) to form text or images on the cigarette wrapper paper. The amount of printing and / or the amount of catalyst may be varied to adjust the amount of CO and / or NO reduction.

The volatile encapsulating layer may be dried (e.g. with a food coloring) to control the appearance of the encapsulated decatalyst particles. For example, the color of the encapsulated catalyst particles may be provided to match or contrast with the color of the cigarette paper (or cut tobacco filler material).

A cigarette may comprise a mixture of different encapsulated catalyst particles. The composition of the encapsulated catalyst particles (i.e. the composition and / or size of the decatalyst particles and / or the composition and / or thickness of the encapsulant) may be selected to operate within a given temperature range and a The catalytically effective quality of the catalyst particles may be incorporated into a component of a cigarette (e.g., tobacco cut fill material, cigarette filter and / or cigarette paper) to control catalyst conversion efficiency and / or selectivity. . For example, the first encapsulated catalyst particles may be incorporated into the cut tobacco filler material of a cigarette and the second encapsulated catalyst particles may be incorporated into the cigarette paper. Cigarette paper having encapsulated catalyst particles incorporated therein may be used as a paper wrapper, filter paper and / or paper filler material within a cigarette.

Paper wrapper can be any suitable wrapper for wrapping the cut filler material, including wrapper wrappers, hemp, jute, esparto grass, rice straw, cellulose and so on. Optional filler materials, flavor additives, and burning additives may be included in the paper wrapper of the cigarette. The paper wrapper may have more than one layer in cross-section, such as a bilayer paper wrapper as described in U.S. Patent No. 5,243,098, the entire contents of which are incorporated herein by reference.

Encapsulated catalyst particles may be incorporated into a cigarette paper wrapper. The cigarette paper wrapper, which comprises a continuous sheet of fibrous cellulosic material, may further comprise particles of continuous filler material such as calcium carbonate (CaCOe). In practice, the web filler material serves as an agent for controlling the permeability of the paper wrapper. The permeability of the paper wrapper is typically measured in Coresta units, which is defined as the volume of air, is measured in cubic centimeters, which crosses a centimeter squared of material in one minute at a pressure drop of 1.0 kilopascals.

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

The encapsulated catalyst particles will preferably be distributed throughout the tobacco rod and / or the cigarette wrapping portions of a cigarette. By providing the encapsulated catalyst through all one or more components of a cigarette, it is possible to reduce the amount of carbon monoxide withdrawn through the cigarette, particularly in the combustion, pyrolysis, condensation and / or filler regions.

Another embodiment provides a method of treating cigarette smoke comprising lighting a cigarette to form tobacco smoke and passing smoke through the cigarette, wherein the volatile encapsulant at least partially volatilises to expose a surface of the catalyst particles. In a preferred embodiment, the volatile encapsulant is volatilized at a distance of from about 0.1 mm to 10 mm in front of the burning line.

While various embodiments have been described, it should be understood that variations and modifications may be resorted to as will be apparent to those skilled in the art. Such variations and modifications should be considered within the scope and scope of the claims appended hereto.

Claims (18)

1. A cigarette component comprising encapsulated catalyst particles capable of decreasing at least one of carbon monoxide and nitric oxide in mainstream tobacco smoke, wherein catalyst particles are at least partially coated with a volatile encapsulant, and wherein The component is selected from the group which consists of cut tobacco filler material, cigarette paper and cigarette filter. A component according to claim 1, wherein: (a) the catalyst particles are fully coated with the volatile encapsulant, (b) the catalyst particles comprise at least one of an oxide, oxide, alloy and elemental metal at least one element selected from the group consisting of Mg, Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, Y, Zr, Nb, Mo, Ru, Ag, Sn, Ce, Pr, La, Hf, Ta, W, Re, Os, Ir and Au (c) the catalyst particles comprise at least one of a manganese, iron, copper or cerium oxide hydroxide; catalyst particles comprise nanoscale particles; or (e) the catalyst particles have an average particle size of less than about 100 nm or less than about 50 nm. The component of claim 11, wherein the volatile encapsulant comprises at least one of: (a) a wax, a water-soluble polymer or a water-insoluble polymer, (b) a wax selected from the group consisting of beeswax, coconut wax, candelilla wax, carnauba wax, mountain wax, ouricuri wax, paraffin wax, rice wax and mixtures thereof (c) a water-soluble polymer selected from the group containing - consists of polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxides, water soluble polyamides, water soluble polyesters, water soluble celluloses, acrylic acid polymers, starches, dextrins, gums, gelatin, pectin, gum arabic and mixtures thereof; (d) a water-insoluble polymer selected from the group consisting of empolyethylene, polypropylene, polyacrylates, polymethacrylates, polymethyl methacrylates, polyvinyl chloride, polyvinylidene chloride, polysaccharides and mixtures thereof. (e) a first layer in contact with the catalyst particles and a second layer formed on the first layer; and (f) a first layer comprising a flavor carrier compound and a second layer formed on the first layer. The component of claim 1, wherein: (a) the volatile encapsulant has a volatilization temperature of between about 40 ° C and about 350 ° C (b) the volatile encapsulant is adapted to volatilize in an atmosphere having a relative humidity of more than about 5%; or (c) the volatile encapsulant has a volatilization temperature of from about 40 ° C to about 350 ° C and is adapted to volatilize in an atmosphere having a relative humidity of more than about 5%. The component of claim 1, wherein the volatile encapsulant comprises a taste carrier compound. The component of claim 5, wherein the taste-bearing compound comprises menthol, a menthol derivative, a menthol precursor, or a mixture thereof. The component of claim 5, wherein the taste-bearing compound comprises a synthetic fragrance, a natural fragrance, an essential oil, an aldehyde, an alcohol, an ester, a ketone, a phenol or a mixture thereof. A component according to claim 1, wherein the catalyst particles are capable of acting as an oxidant for the conversion of carbon monoxide to carbon dioxide, a reduction agent for the conversion of nitric oxide to nitrogen and as a catalyst for the conversion of at least one carbon monoxide to carbon dioxide and nitric oxide to nitrogen. A cigarette comprising a tobacco rod, cigarette paper and an optional filter, wherein at least one of the tobacco rod, cigarette paper and filter comprise encapsulated catalyst particles capable of decreasing at least one carbon monoxide. and nitric oxide in mainstream tobacco smoke, wherein the catalyst particles are at least partially coated with a volatile encapsulant. A cigarette according to claim 9, wherein: (a) the volatile encapsulant is adapted to volatilize during smoking of a cigarette to expose an active surface of the decatalyst particles, (b) the volatile encapsulant is thermally adapted or chemically degrade during cigarette smoking to expose the surface of the catalyst particles, or (c) the volatile encapsulant is adapted to volatilize and thermally or chemically degrade during cigarette smoking to expose a surface of the catalyst particles. The cigarette of claim 9, wherein the catalyst particles are fully coated with the volatile encapsulant. A cigarette according to claim 9, wherein the encapsulated catalyst particles are at least one of: (a) incorporated in an amount effective to convert at least 5% of carbon monoxide into mainstream tobacco smoke. carbon dioxide or at least 5% of nitric oxide in mainstream smoke in nitrogen or in an effective amount to convert at least 5% of carbon monoxide in mainstream smoke into carbon dioxide and at least 5% less nitric oxide in nitrogen mainstream tobacco smoke (b) incorporated in a total amount of up to about 200 mg per cigarette; and (c) homogeneously or not homogeneously distributed along the length of a tobacco rod. A cigarette according to claim 9, wherein the cigarette-clearing paper comprises at least one of: (a) a paper wrapper having a first layer and a second layer formed around the first layer, and wherein the particles of encapsulated catalysts are incorporated into the first layer, and (b) a paper wrapper and the encapsulated catalyst particles are coated, printed or coated and printed on at least one surface of the paper wrapper. A cigarette according to claim 9, wherein the cigarillo comprises a mixture of different encapsulated catalyst particles. A method of producing a cigarette comprising: (i) incorporating the encapsulated catalyst particles in, over, and at least one of cut tobacco filler material, cigarette filter and a cigarette paper wrapper, - ( ii) providing the cut tobacco filler material to a cigarette producing machine to form a tobacco column, (iii) placing the cigarette paper wrap around the tobacco column to form a tobacco rod of a cigarette; and (iv) optionally attaching the cigarette filter to the tobacco column using a wrapping paper. The method of claim 15, wherein the embodiment comprises spraying, dusting or dipping. A method according to claim 15, wherein the encapsulated catalyst particles are incorporated into the cigarette paper by sputtering or coating the encapsulated catalyst particles over a wetted continuous sheet, intermediate continuous sheet or finished continuous sheet. The method of claim 15, wherein the incorporation step comprises combining the encapsulated catalyst particles and at least one of the cut tobacco filler material and cigarette paper wrapper in the absence of a liquid.