DD298202A5 - SMOKE PRODUCTS WITH IMPROVED MEANS FOR THE ADMINISTRATION OF AROMAS - Google Patents

Abstract

The invention relates generally to a smoking article comprising a fuel element, a physically separate aerosol generating means, a mouthpiece and improved means for delivering one or more flavoring agents to the user comprising a carbonaceous material in a non-burning portion of the smoking article carrying one or more flavoring agents or otherwise contains. More particularly, the invention relates to a carbonaceous tobacco leaf which is used as at least a portion of the mouthpiece of such articles and contains flavoring agents, in particular high-volatility flavoring agents such as menthol. Fig. 1 {smoking article; Fuel element; aerosol; Mouthpiece; carbonaceous layer material; Flavorings; Menthol}

Description

For this 3 pages drawings

The invention relates to smoking articles generally having a fuel element, a physically separate aerosol generating means and a separate mouthpiece and having an improved means for delivering one or more volatile flavoring agents to the user, comprising a carbonaceous material in a non-burning portion of the user Smoke article that carries one or more flavorings or otherwise contains. As used herein, the term "Rauehnrti" includes cigarettes, cigars, pipes, and other smoking articles which produce an aerosol such as smoke, More particularly, the invention relates to a carbonaceous sheet material which preferably contains tobacco, the sheet material being at least one Part of the mouthpiece of such articles is applied and flavorings, in particular hocl.iüchtige flavoring ") such as menthol, carries.

Cigarettes, cigars and pipes are the most popular forms of smoking articles. Over the years, many smoking products and smoking articles have been suggested as improvements or as alternatives to these popular forms of smoking articles, particularly cigarettes.

Many have suggested tobacco substitutes, for example. See, for example, U.S. Patent No. 4,079,742 to Rainer et al.

Two such substances, Cytrel and NSM, were introduced as partial substitutes for tobacco in Europe in the 1970s, but have not been commercially successful in the long term. Many others have suggested smoking articles, particularly cigarette smoking articles, based on the production of an aerosol or vapor. See, for example, in U.S. Patent 4,714,082 to Banerjee et al. cited background technique.

As far as the inventors are aware, none of the aforementioned smoking articles has ever been of considerable commercial success and none has ever been widely commercialized. The lack of such smoking products in the marketplace is attributed to a variety of reasons, including insufficient aerosol production both at the beginning and over the life of the product, bad taste, off-flavor due to thermal degradation of the smoke generator and / or flavoring agents, the presence of significant Amounts pyrolysis products and side stream smoke and a unsightly appearance include.

Thus, despite decades of interest and effort, there is still no smoking article on the market that offers the benefits and pleasurable aspects of smoking without emitting substantial amounts of incomplete combustion and pyrolysis products.

Recently, however, European Patent Application Nos. 0174645 and 0212234 and US Patent No. 4,714,082 assigned to RJ Reynolds Tobacco Co. have described smoking articles, particularly cigarette smoking articles, which offer the benefits and enjoyment of smoking without incinerating tobacco or giving off considerable amounts of incomplete combustion or pyrolysis products. The improved flavor delivery agent of this invention is particularly suitable for use with such articles.

Mentholated smoking articles account for a sizable share of the total market. In fact, nearly a third of all manufactured cigarettes are mentholated to a certain degree. However, one of the major problems with menthol and other fugitive and semi-volatile flavors used in smoking articles is that the flavors tend to migrate to other components of the article. This hiking is well documented in the literature. See, for example, Brozinski, M., et al., Beiträge zur Tabakforschung International 6,124-130 (1972); Curran, J. G., Tobacco Science 16, 40-42 (1972); and ReihLT.F. et al., Tobacco Science 17, 10-11 (1973).

In cigarettes it comes to the migration, whether the flavorings now in the tobacco, in the filter, in the wrapping material or on the packaging material (eg, mentholated film) built sino. The end result is similar in all these applications.

During storage, a balance of the flavor results, with the aroma migrating through the entire smoking article and associated packaging. The degree of migration depends, among other things, on the vapor pressure of the flavor, its solubility in the various components of the article, environmental conditions including temperature and relative humidity, resistance to migration of the various substances (eg tobacco, wrapper, filter material , Glue, etc.).

A number of attempts have been made to solve migration-related problems, but have had limited success. For example, various chemicals such as chemically-bonded non-volatile substances (eg, beta-cyclodextrin-menthol complexes, glucosides of menthol, mentholamides, esters, etc.) have been used to reduce migration.

See, for example, U.S. Patents 3,426,011 to Parmerter et al. and 3,344,796 to Yamaji et al. All of these compounds are generally of limited use due to the cost and poor taste of the smoke emitted.

Others have studied the use of so-called microencapsulated flavorants at various sites in the smoking article. See, for example, U.S. Patents 3,550,598 and 3,540,456 to McGlumphy et al., Swiss Patent 475,418 to Baumgartner Papiers SA, and Dutch Patent 8201585 to Dowve Egberts Koninklijke. Still others have included volatile flavorants in polymer systems such as linear low density polyethylene and inorganic filters such as CaCO ₃ , clays, etc., and have used these materials in the form of beads or filaments or particles in the filter systems or packaging systems. The problems with this method are that migration still occurs (though in a controlled manner), the levels of flavor required for such materials are often very high and the cost prohibitive, and that total deliveries of flavors are low, usually between 1-18 Ma .-% based on the dosages applied.

The use of coal in various cigarette components has also been suggested. Charcoal is used in particular in cover systems, as a filler and in filter systems for reducing the gas phase smoke constituents and for introducing flavoring substances into the cigarette. See, for example, U.S. Patents 2,063,014 to Allen, 3,744,496 to McCarty et al., 3,902,504 to Owens et al., 4,505,202 to Cogbill et al., 4,225,636 to Cline et al. However, coal, and especially activated carbon, has not found significant commercial use as a carrier of flavorings such as menthol since, among other reasons, activated carbon adsorbs the greater portion of menthol before it can be routed to the smoker. To compensate for this phenomenon, coal is generally saturated with flavor. However, as mentioned above, this leads to the undesirable migration of the flavoring to other components of the smoking article. See, for example, US Pat. No. 3,236,244 to Irby et al., Which describes the use of activated carbon both to remove unwanted constituents from the reactor and to introduce flavors therein.

U.S. Patent 3,972,335 to Tigglebeck et al. confirms this problem. Tigglebeck describes blocking the small pores of activated carbon with a pore-modifying agent such as sucrose. The pore-modifying agent is described as being used in amounts which will not block the less dense portions of the activated carbon but remain available for the adsorption of the flavor. Thereby, the shelf life of the smoking article is expediently increased by reducing the migration of the flavoring agent while permitting effective release of the flavoring agent during smoking. However, there appears to be a significant migration of more than about 40%. See example I in columns 5-6. As a result, carbon filters or cabbage sheets are generally not recommended for mentholated smoking articles.

The invention relates generally to a smoking article comprising a fuel element, a discrete aerosol generating means, a separate mouthpiece, and an improved means for delivering menthol and other volatile flavorants together with the aerosol without substantial migration of the flavor to the fuel element or other parts of the aerosol smoking article. The improved flavor delivery agent comprises a carbonaceous sheet material contained in a non-burning portion of the smoking article, e.g. B. in each longitudinally behind and at a distance from the fuel element arranged part of the article. However, it preferably has the shape of a cylindrical segment or plug and is located between the aerosol generating means and the mouthpiece of the smoking article. The smoking articles employing the improved flavor delivery agent are preferably cigarettes containing a short, e.g. H. use less than 30mm long, preferably carbonaceous fuel element. The aerosol generating means is preferably disposed longitudinally behind the fuel element and is in a conductive heat exchange relationship with the fuel element. The mouthpiece preferably comprises a filter segment, preferably of relatively low efficiency, to avoid adversely affecting the delivery of the aerosol generated by the aerosol generating means. The aroma delivery agent of the present invention comprises a carbonaceous sheet material which is present in any of the non-burning portions of the smoking article, i. in any of the longitudinally behind the fuel element or otherwise spaced apart therefrom, can be used. Preferably, it is located between the filter segment and the aerosol generating means. In certain preferred embodiments, the flavor delivery means consists of a segment of rolled, folded or aggregated carbonaceous sheet of tobacco paper about 5-15 mm in length.

It has been found that the improved aroma delivery agent of the present invention helps to reduce the migration of flavorings, particularly menthol and other volatile flavorants, to other parts of the smoking article or the equipment used to make these articles. The reduction of migration to the fuel source is particularly important because of the undesirable off-taste that can result from the thermal degradation and pyrolysis of the flavorants present in the burning fuel element. This reduction in migration also contributes to increasing the shelf life of smoking articles containing volatile flavorants such as menthol. It has also been found that the flavorings are readily and evenly released from the carbonaceous coating material during smoking as aerosol and hot gases pass from the aerosol generating agent over and through the coating material. It is believed that something temperatures of about 15O ⁰ C lying üb6r the normal aerosol contribute immediately behind the aerosol generating means that uniform amounts of flavoring agent over the life of the smoking article to be delivered of time. Moreover, smoking articles employing the carbonaceous coating material as part of the mouthpiece provide such reduced migration and uniform delivery of flavorings without substantially reducing the delivery of other aerosol components, e.g. As glycerol, water and the like. In other words, the filter performance of the carbonaceous sheet material is significantly lower than that of other cigarette fibers such as cellulose acetate tow. This is important in maintaining the desired delivery of the aerosol produced by the inventive smoking article.

The preferred carbonaceous layer material of the present invention acts as a heat sink, thereby helping to reduce the temperature of the aerosol perceived by smoker and preventing undesirable degradation or melting of the filter material.

Preferred smoking articles employing the improved flavor delivery agent of the present invention may exhibit at least 0.6 mg / jrosol in the first three puffs of smoking under FTC smoking conditions consisting of 35 ml strong 2 second streaks with 58 seconds of smoldering therebetween. measured as total wet particles (WTPM). Embodiments of the invention may even better 1.5mg aerosol or more in the first three moves

deliver. Most preferably, embodiments of the invention when smoked under FTC smoking conditions in the first three puffs can provide 3 mg aerosol or more. In addition, preferred embodiments of the invention provide, under FFC smoking conditions, at least six puffs, preferably at least about ten puffs, averaging at least about

0.8mg of total moisture particles per turn.

In addition to the above advantages, preferred smoking articles of the present invention can provide an aerosol that is chemically simple, consisting essentially of air, carbon oxides, water, the aerosol generator, desired flavorants or other desired volatiles, as well as trace amounts of other substances. The aerosol also preferably has no significant mutagenic potency measured by the Arnes test. In addition, preferred articles can be made virtually ash-free, so that the user does not have to remove ashes during use.

As used herein, and solely for the purpose of this application, "aerosol" is defined to include vapors, gases, particulates, and the like, both visible and invisible, and especially those components perceived by the user as "smoke-like." which are generated by the action of the heat from the burning brine element to substances contained in the aerosol generating means or elsewhere in the article.

As used herein, the term "conductive heat exchange ratio" means a physical arrangement of the aerosol generating means and the fuel element whereby heat is transferred from the burning fuel element to the aerosol generating means substantially throughout the firing period of the fuel element by thermal conduction Ratios of conductive heat exchanges may be achieved by placing the aerosol generating means in contact with the fuel element and so in close proximity to the burning portion of the fuel element and / or a conductive portion to transfer the heat from the burning fuel to the aerosol Preferably, both methods are used to provide conductive heat transfer.

As used herein, the term "carbonaceous" is primarily coal.

As used herein, the term "insulating part" applies to all substances that act primarily as insulators.

Preferably, these substances do not burn during use, but they may be slow burning coal and similar substances and substances that melt during use, for. As low temperature glass fibers. Suitable insulators have a thermal conductivity of less than about 0.05, preferably less than about 0.02, most preferably less than about 100,000 caHsec) (cm ² ) (° C / cm). See Hackh's Chemical Dictionary 672 (4th ed., 1969) and Lange's Handbook of Chemistry 10, 272-274 (11th ed., 1973).

Smoking articles employing the improved flavor delivery agent of the present invention are described in detail in the accompanying drawings and the following detailed description of the invention.

Fig. 1: is a longitudinal section of a preferred cigarette employing the improved aroma delivery agent of the present invention.

Fig. 1A: illustrates a preferred arrangement of the fuel element passage seen from the ignition end. Figure 2: illustrates the results of a study of migration of preferred cigarettes with and without them

Carbonaceous layer material according to the invention

 Fig. 3: schematically illustrates a method of forming the carbonaceous sheet material into one

cylindrical segment in the form of a filter plug

 Fig. 3A illustrates a bicone system that is used to agglomerate or fold the material into the shape of a filter plug.

According to the invention, an improved flavoring agent in smoking articles is provided. The flavor delivery agent is particularly suitable for smoking articles having a small combustible fuel element, a physically separate aerosol generating means and a separate mouthpiece as described in EPO Publication Nos. 174,645 and 212,234.

The improved flavor delivery agent is generally comprised of a carbonaceous sheet material, typically by the addition of coal (activated, non-activated coal or mixtures thereof) to ordinary pulp, such as pulp-stirred wood or flax fiber and / or pulp-stirred tobacco stalks is formed. This material is then formed into a sheet material using conventional papermaking techniques. Although the porosity of the carbonaceous sheet material may be within a wide range, it preferably has an internal porosity of between about 100 and 250 CORESTA units and a net porosity of greater than about 150 CORESTA units, preferably 300 and 30,000 CORESTA units. The net porosity is achieved by providing holes through mechanical, electrostatic or laser means and / or slits of the sheet material. Layered material having a porosity in this range is particularly advantageous because it allows the addition of larger amounts of flavoring to the carbonaceous layered material by adsorptive and / or absorptive mechanisms, and because the total effective surface area of the aroma delivery agent can be increased significantly without Filter performance of the carbonaceous layer material must be increased. The carbon content of the sheet material may vary over a wide range depending on a number of factors including the type and amount of carbon and / or flavor used, the location of the carbonaceous sheet material in the smoking article, and the shape or configuration of the sheet material. Generally, the carbon content may be between about 5 and 75 mass% of the layer material, preferably between about 10 and 40%, most preferably between about 15 and 30%. Although higher amounts of coal may be used, sheet material containing more than about 75 mass% of coal will impose limitations on papermaking as well as limitations on paper properties, e.g. Tensile strength, excessive dusting, and related problems. Although both activated and non-activated carbon can be used as the coal component of the coating material, activated carbon is preferred. As will be understood by those skilled in the art, there are a variety of activated carbons that are commercially available and can be used in accordance with the description of this invention. For example, there are coal-based, wood-based, and coconut shell base activated carbons available from a variety of sources. A

-6- Π98 202

Particularly preferred activated carbon, a coconut shell based coal, is PCB manufactured by Calgon Carbon Corporation, Pittsburgh, Pennsylvania. This special coal can be pulverized into many sizes. Although particles of any size could be used in the laminate according to the invention, the preferred sizes are between about 250-600 U.S. mesh size.

As will be appreciated by those skilled in the art, other adsorptive / absorptive materials may also be incorporated into the sheet material in place of or together with the carbon component of the sheet material. Such materials are charcoal, silica gel, zeolites, perlite, sepiolite, active clay, magnesium silicates and the like.

As mentioned above, the carbonaceous sheet material can be prepared using ordinary paper pulp. Preferably, it is prepared from a mixture of wood-masonry and a pulp made from tobacco stems. The carbon component of the sheet material is generally added to a pulp from the fiber pulps, and the resulting mixture is formed into a sheet using conventional papermaking machines. The preferred sheet material is a carbonaceous tobacco paper obtained by incorporating the desired amount of coal into the tobacco paper pulp used to make a Kimberly-Clark tobacco paper named P144-185-GAPF. Unmodified P144-185 GAPF contains approximately 60% tobacco mainly in the form of tobacco-treated tobacco stemggin and 35% soft wood pulp (reference dry matter mass). The moisture content of the non-modified layered material is preferably between about 11 and 14%. The material has a tear strength in the dry state of about 1600 to about 3 300g / inch and a dry matter mass of about 38 to about 44g / m ² . The material is made using a conventional papermaking process including the addition of about 2% glycerin or other humectant, about 1.8% potassium carbonate, about 0.1% flavor and about 1% commercial size. The sizing agent is commercially available as Aquapel 360XC Reactive Size from Hercules Corp., Wilmington, Delaware. In or on the carbonaceous layer material can in many ways such. B. by spraying, dipping, printing, vapor deposition u. Ä. Aromas are incorporated. The flavoring agent is preferably applied to the layer by a vapor deposition process. Vapor deposition is a process in which typically the flavor is heated to a point where it is highly volatile and the carbonaceous material is contacted or passed through with the vapors for the desired amount of flavor to the carbonaceous A preferred deposition method, referred to as "inner sheet transfer," involves contacting the carbonaceous sheet material with an inner sheet material. The inner sheet material may be any of a variety of materials, such as thick plug wrap, provided that its Another preferred method of flavoring the coating material is to print the flavor on the coating material ommel, which turns through a bath containing the respective Aiomastoffe.

Those skilled in the art will readily find other methods of applying flavoring agents to the carbon before or after their incorporation into the sheet material.

In the practice of this invention, any number of flavoring agents such as menthol, vanillin, coffees, tobacco extracts, nicotine, nicotine salts, caffeine, alcoholic beverages, cocoa butter and other substances which flavor the aerosol produced by the smoking article may be employed. Other flavorants which can be used are those listed in Leffingwell et al., Tobacco Flavorings for Smoking Products, RJ Reynolds Tobacco Company, Winston-Salem, North Carolina (1972).

The amount of flavoring agent impregnated or otherwise supported by the layered material may vary depending on the type of flavoring, the flavoring level, the carbon content of the layered material, the activity of the carbon, the location of the layered material in the smoking article, etc. the carbonaceous sheet material in the smoking article is curled, folded, aggregated or otherwise arranged, and similar factors are within a wide range. For example, if a strong flavoring agent such as alpha-ion is used, it may be desirable to have as little as 0.00001% by weight of the coating material. If menthol is the flavoring, the amount can be from 0.001 to saturation. In preferred smoking articles such as those described in Example I, the amount of menthol incorporated into the carbonaceous layer material is between about 3 and 6%, most preferably between about 4 and 5%.

As noted above, in certain preferred embodiments, the carbonaceous sheet material is located between the aerosol generating means and a mouthpiece filter, and is preferably in the form of a cylindrical filter plug. The sheet material may be formed into a cylindrical or other suitable form by conventional methods of making filter plugs, such as a conventional plug maker, to produce cellulose acetate tow. Figure 3 illustrates a means for forming the carbonaceous layered material in the form of a filter plug. As shown schematically in Figure 3, a roll 53 of flavored carbonaceous sheet material 50 is unwound and drawn into a preforming cone 54 which gathers or folds the sheet material 50 into a cylindrical shape suitable for passage into a cylindrical plug-drier. Two or more carbonaceous layers with different properties, e.g. With different carbon content, various flavorings, etc., may be processed separately or simultaneously to produce a multi-segment or multi-layer flavorant delivery agent. This shaped cylinder 55 receives a Papierumwicklung 56, and the combination is cut with the knife 58 in desired lengths 57. Prior to entering the accessory device, a continuous adhesive layer is applied to an edge of the wrapping paper 56 via an applicator. As these parts pass through the accessory device, the shaped cylinder 55 is further compressed to a rod having a cylindrical cross-section while being enveloped with the paper 56 at the same time. When the adhesive edge touches the overlapped portion of the wrapped rod, it is sealed by means of a sealing bar. This endless cylindrical rod is then cut into lengths 57 by means of the cutting device 58.

However, it is also possible to use the double-cone system shown in FIG. 3A instead of the Einkegelsystems 54. This system includes a cone within a cone as the preforming apparatus. The carbonaceous sheet material is introduced in a substantially stress-free state into the annular space between the cones so that the sheet material at the entrance winds around the radial portion of the inner cone. The cones can be moved relative to one another to achieve the desired uniformity and strength of the cylindrical segment.

Although not essential for the preparation of acceptable cylindrical segments of flavored carbonaceous sheet material, the sheet material is suitable for the addition of flavorants prior to forming into a cylindrical segment. Two such treatments, shown in Figure 3, may include a pair of grooved rollers for folding 59 and a liquid applicator 60 for surface treating the layered material with, for example, menthol, glycerin or other flavorants or net agents.

In preferred embodiments, where the carbonaceous sheet material is disposed between the aerosol generating means and the mouthpiece filter in the form of a cylindrical segment or plug, the length of the flavored carbonaceous layer segment will generally vary with the type and amount of flavoring agent used. For cigarettes employing the preferred mouthpiece described in Example I, the length of the carbonaceous sheet material segment is generally between about 5 and 30 mm, preferably between about 5 and 15 mm, and most preferably about 10 mm. From the standpoint of performance and / or aesthetics, the strength of the flavored carbonaceous layered segment employed in accordance with the present invention can vary widely without significantly affecting the delivery of aerosol to the user. However, it is desirable for the segment to feel and have the strength of a cigarette using conventional cellulose acetate filters.

The total pressure drop of smoking articles employing the improved flavor delivery agent of the present invention is preferably similar or equal to that of other cigarettes. The pressure drop of the carbonaceous layer material and de filter material in the mouthpiece itself varies according to the pressure drop of the front piece of the smoking article. In preferred smoking articles as described in Example I, the pressure drop is generally lower than that of conventional filter plugs; it is usually in the range of about 0.1 to 6.0 cm water / cm filter length, preferably in the range of about 0.5 to ei. 4,5cm What? r / cm filter length and best in the range of about 0.7 to about 1.5cm water / cm filter length. The filter pressure drop is the pressure drop in centimeters of water when 1050cm ³ Luft'pro minute are passed through c'nen filter plugs. This pressure drop can be normalized by dividing by the actual filter length to single-length filter plug.

Preferred smoking articles employing the improved aroma delivery agent of the present invention are described in the following patent applications:

applicant: Ser. Number: Joined: Sensabaughetal. 650604 September 14, 1984 Shannon et 3l. 684537 21.Dezember1984 Farrier et al. 769532 August 26, 1985 Banerjeeetal. 939203 8th December 198d Sensabaughetal. EPO 85111467.8 September 11, 1985 (published 3/19/86) Banerjeeotal. EPO 86109589.1 September 14, 1985 (published 3/4/87),

the descriptions of which are incorporated herein by reference.

Such a preferred smoking article is illustrated in Figure 1 accompanying this specification. In Figure 1, a cigarette is shown having a woes carbonaceous fuel element 10 having a plurality of passages 11, preferably about thirteen passages, which are arranged as shown in Figure 1A. Another preferred embodiment uses a fuel element with eleven holes similar to the arrangement in Figure 1A but with only five central passages arranged in the form of an "X." This fuel element is made from an extruded mixture of carbon (preferably carbon paper) sodium carboxymethylcellulose binder (SCMC binder), K ₂ CO ₃ and water, as described in the above cited patent applications and EPO applications.

The periphery 8 of fuel element 10 is surrounded by an elastic sheath of insulating fibers 16 such as glass fibers.

A metal capsule 12 overlaps a portion of the mouth end of fuel element 10 and encloses the physically separate aerosol generating means which contains a carrier substance 14 carrying one or more aerosol forming substances. The carrier substance may be in particulate form, in the form of a rod or in other forms, as described in detail in the abovementioned patent applications.

The capsule 12 is surrounded by a roll of tobacco filler 18. Two slot-shaped passages 20 are provided at the mouth end of the capsule in the center of the beaded tube.

At the mouth end of tobacco roll 18 is a mouthpiece 22, which preferably comprises a cylindrical segment of an aromatized carbonaceous sheet material 24 of this invention and a segment of non-woven thermoplastic fibers 26, whereby the aerosol reaches the user. The article or parts thereof is wrapped with one or more layers of cigarette paper 30-36.

As noted above, the carbonaceous sheet material may reside in one or more of the other non-combustible constituents of the smoking article. For example, the carbonaceous sheet material could be defibered and be the sole or part of the tobacco roll, or it could be used as one or more of the non-burning sheaths used to join the various components of the smoking article.

Upon ignition of the aforementioned cigarette, the fuel element burns to generate the heat utilized to volatilize the tobacco flavor and any additional aerosol forming substance or substances in the aerosol generating means and tobacco roll. Since the preferred fuel element is relatively short, the hot, burning, flame cone is always close to the aerosol generating means, thus maximizing heat transfer to the aerosol generating means and the tobacco roll and the resulting generation of aerosol and tobacco flavorings, particularly when using the aerosol preferred heat-conducting part. The hot gases, aerosol and flavoring agents from the aerosol generating means and the tobacco roll heat the flavored carbonaceous sheet material of the present invention which releases the flavor.

Due to the small size and the burning properties of the Bronnstoffelements this usually begins to burn within a few strokes substantially over its entire exposed length. The portion of the fuel element adjacent to the aerosol generator thus rapidly warms up, thereby substantially increasing heat transfer to the aerosol generator and the tobacco roll, particularly during the first and middle courses. Because the preferred fuel element is so short, there is never a long length of non-combusting fuel that could act as a heat sink, as was common in previous thermal aerosol articles. This in turn increases the temperature to which the flavored carbonaceous material is exposed, which is believed to increase the release of the flavor from the carbon component of the coating. However, because the aerosol forming substance and the tobacco flavor substance as well as the flavor on the carbonaceous sheet material are physically separated from the fuel element, they are exposed to substantially lower temperatures than generated by the burning fuel, thereby providing the potential for thermal degradation of flavorants and aerosol Materials is minimized.

In preferred embodiments, the short carbonaceous fuel element, thermally conductive member and insulating member with dom aerosol generators and the abac roll function together to form a system capable of producing substantial quantities of aerosol, tobacco flavorings and flavorings from the carbonaceous sheet material with virtually any draw. The immediate proximity of the fire cone to the aerosol generator and the roll of tobacco after a few moves together with the insulating part leads to a high heat output both during smoking and in the relatively long glow times between the individual trains.

In general, the combustible fuel elements that may be employed in the preferred embodiments have a diameter no greater than that of a cigarette (ie, less than or equal to 8 mm) and are generally less than about 30 mm long prior to smoking. Advantageously, the fuel element is about 15 mm or less in length, preferably only about 10 mm or even less. Advantageously, the diameter of the fuel element is between about 2 and 8 mm, preferably between about 4 and 6 mm. The density of the fuel elements employed here may generally be between about 0.7 and 1.5 g / cm ³ . The density is preferably greater than about 0.85 g / cm 2. The preferred material used to form fuel elements is carbon. The carbon content of these fuel elements is preferably 60 to 70 mA. %, preferably about 80Ma .-% or more. High carbon fuel elements are preferred because they produce little pyrolysis products and incomplete combustion products, little or no visible sidestream smoke and minimal ash and high heat capacity. But it can also fuel elements with lower carbon content, eg. B. about 50 to 60 wt .-%, can be used, especially where a small amount of tobacco, tobacco extract or a non-combustible inert filler W W used. Preferred fuel elements are described in detail in the aforementioned patent applications and EPO publications. The aerosol generating agent used in the present invention is physically separated from the fuel. By "physically separate," it is meant that the substrate, container, or chamber that constitutes the aerosol does not mix with or be part of the fuel element. This arrangement contributes to the thermal degradation of the aerosol forming substance and the Although not part of the fuel element, the aerosol generating means preferably abuts, is connected or otherwise adjacent to the fuel element so that the fuel and aerosol generating means are in proportion Preferably, the ratio of the conductive heat exchanges is achieved by providing a thermally conductive member such as a metal foil recessed from the firing end of the fuel element which effectively transfers heat from the burning fuel element to the aerosol generating means 1 converts or transmits.

The aerosol generating means is preferably arranged no more than 15mm from the firing end of the fuel element. The aerosol generating means may be between about 2 mm to about 60 mm in length, preferably from about 5 mm to 40 mm, and most preferably from about 20 mm to 35 mm in length. The diameter de? Aerosol generating agent may be between about 2 mm and about 8mm, preferably between about 3mm and 6mm.

The aerosol generating means preferably contains one or more thermally stable substances which carry one or more aerosol forming substances. In the applied herein, a "thermally stable" material is a material, the high, albeit controlled temperatures, eg., From about 400 ° C to about 600 ⁰ C, which finally come near the fuel voi, It is believed that the use of such material will maintain the simple "smoke chemistry" of the aerosol, as evidenced by lack of activity following the Arnes test in the preferred embodiments. Although not preferred, other aerosol generating means such as heat-expandable microcapsules or solid aerosol forming substances are within the scope of this invention provided they are capable of releasing sufficient aerosol-forming vapors.

Thermally stable substances that can be used as a carrier or substrate for the aerosol forming substance are well known to those skilled in the art. Suitable carriers should be porous and must be capable of retaining an aerosol forming compound and releasing potential aerosol forming vapor upon heating by the fuel. Suitable thermally stable materials are adsorbent carbons such as porous carbon, graphite, activated carbon or non-activated carbon and the like such as PC-25 and PG-60 available from Union Carbide Corp. SGL coal available from Calgon Carbon, Corp. is available. Other suitable substances are inorganic solids such as ceramics, glass, alumina, vermiculite, clay such as bentonite or mixtures thereof. Carbon and alumina substrates are preferred.

A particularly suitable alumina substrate is a high effective surface area clay (about 28 microVg) such as that available from the Davison Chemical Division of WR & Co. under the designation SMR-14-1896. This alumina (-14 to +20 U.S. mesh) is preferably sintered for about one hour at an elevated temperature, for example over 1000 ⁰ C, preferably from about 1400 to 155o C ^0, the corresponding washing and drying, prior to use consequences. The aerosol forming substance or substance used in the articles of the invention must be capable of aerosolizing the aerosol generating means when heated by the burning fuel element. Such substances are preferably tobacco-free, anhydrous aerosol-forming substances and consist of carbon, hydrogen and oxygen, but may also include other substances. Such substances may be in solid, semi-solid or liquid form. The boiling or sublimation point of the substance and / or the mixture of

Substances can be up to about 500 ⁰ C. Substances having such a property Jn include polyhydric alcohols such as glycerol, tri-butylene glycol and propylene glycol, and aliphatic esters of mono-, di- or polycarboxylic acids such as methyl stearate, dimethyl dodecanedioate, dimethyl tetradecanedioate and others.

The preferred aerosol forming substances are polyalcohols or mixtures of polyalcohols. Still bevu.-ugtore aerosol formers are selected from glycerol, triethylene glycol and propylene glycol.

When a substrate is used as a carrier, the aerosol forming substance may be dispersed on or into the substrate by any known method in a concentration sufficient to penetrate or coat the substrate. For example, the aerosol forming substance may be highly concentrated or applied in dilute solution by dipping, spraying, vapor deposition or the like. Solid aerosol forming ingredients may be mixed into the substrate material and at the same time dispersed therein, before the final substrate is formed.

While the charge of aerosol-forming substance is different from carrier to carrier and from aerosol-forming substance to aerosol-forming substance, the amount of liquid aerosol-forming substances may generally be between about 20 mg and about 140 mg, preferably between about 40 mg and ca. 110mg. As much of the aerosol former carried on the substrate should be delivered to the user as much as possible. Preferably, more than about 2% by weight, better still more than about 15% by weight and most preferably more than about 20% by weight of the aerosol former carried on the substrate is delivered to the user as total wetness particles.

The aerosol generating agent may also contain one or more volatile flavoring agents such as menthol, vanillin, artificial coffee, tobacco extracts, nicotine, caffeine, alcohol, and other aerosolizing flavoring agents. It may also be any other desired volatile, solid or liquid matter desired, as described in Leffingwell et al. is described included. These optional substances may be incorporated in the mouthpiece or in the preferred tobacco filling.

A particularly preferred aerosol generating means comprises the above-mentioned toner of the substrate containing spray-dried tobacco extract, levulinic acid or glucose pentaacetate, one or more flavorants and an aerosol generator such as clycerol.

A tobacco filling can be used after the fuel element. In such cases, hot vapors are passed through the tobacco to extract and distill the volatiles from the tobacco without incineration or substantial pyrolysis. The user thus obtains an aerosol containing the flavor and aroma of natural tobacco without the numerous combustion products produced by a conventional cigarette.

The thermally conductive material used in preferred embodiments as a container for the aerosol generating means is typically a metal foil, such as an aluminum foil, that is less than about 0.01 mm to about 0.1 mm or more in thickness. The thickness and / or type of conductive material may be varied to achieve the desired level of heat transfer (e.g., Grafoil from Union Carbide).

As shown in the embodiment shown in Figure 1, the rear portion of the fuel element is preferably taped or overlapped by the heat-conducting portion, the heat-conducting portion forming the container or capsule enclosing the aerosol-producing substrate of the invention. The heat-conducting part preferably extends over not more than the approximate half of the length of the fuel element. It is even better if the heat-conducting part does not overlap or otherwise touch the rear 5 mm, preferably 2-4 mm, of the bronfill element. Preferred recessed parts of this type do not affect the ignition or burning properties of the fuel element. Such parts help to extinguish the fuel element when it is consumed to the point of contact with the conductive part by acting as a heat sink. These parts also do not protrude from the firing end of the article, even after the fuel element has been consumed.

The insulating members used in the preferred smoking articles are preferably molded into an elastic sheath of one or more layers of insulating material. Advantageously, this shell is at least about 0.5 mm thick, preferably at least about 1 mm. The sheath preferably extends over more than about half, if not the entire length of the fuel element. It better still extends over substantially the entire outer periphery of the fuel element and the capsule for the aerosol generating means. As shown in the embodiment in Figure 1, various materials can be used to insulate these two parts of the article.

The presently preferred insulating materials, especially for the fuel element, are ceramic fibers such as glass fibers. Preferred glass fibers include trial fabrics made by Owens-Corning of Toledo, Ohio, under the names C GLASS S-158,6432 and 6437. Other suitable insulating materials, preferably non-combustible inorganic substances, may also be used.

To maximize aerosol delivery, which could otherwise be diluted by radial (i.e., external) air infiltration through the article, a nonporous paper can be used from the aerosol generating agent to the mouthpiece. Papers of this type are known in the cigarette and / or paper art, and blends of such papers can be used for various functional effects. Preferred papers used in the articles of the invention include RJR Archer's 88-17234 paper, RJR Archer's 8-0560-36 filter paper, Ecusta's 646 Plug Wrap, and ECUSTA 30637-801-12001, available from Ecusta of Pisgah Forest, NC. and paper grades of Kimberly-Clark Corporation P1768-182, P780-63-5, P850-186-2, P1487-184-2 and P850-1487-125. The filter is preferably provided with a series of holes spaced about 23mm from the mouth end of the article to give about 22% air dilution.

The aerosol produced by the preferred smoking article of the invention is chemically simple; It consists essentially of air, carbon oxides, aerosol forming agents including desired flavorings or other desired volatiles, water and trace amounts of other substances. The total wet particles produced by the preferred articles of the invention have no mutagenic activity as measured by the Arnes test, i. there is no significant dose-response relationship between the total wetness particles (WTPM) produced by the preferred smoking article of the present invention and the number of revertants encountered in standard test micro-organisms exposed to such products. According to the advocates of the Arnos test, a significant dose-dependent effect indicates the presence of mutagenic substances in the tested products. See Arnes et al., Courage. Res., 31: 347-3645 (1975); Nagao et al., Courage. Res., 42: 335 (1977).

Another advantage of the preferred embodiments of the invention is the relative lack of ash produced during use compared to the ash of other cigarettes. When the preferred coal fuel element burns, it is essentially converted to carbon oxides with relatively little ash production, so that no ash needs to be removed when the article of the invention is used.

The use of the improved flavoring agent in cigarettes in accordance with the present invention will be further illustrated by reference to the following examples, which are intended to aid a better understanding of the invention but are not to be construed as a limitation thereto. All percentages given here are in% by weight unless otherwise specified. All temperatures are expressed in degrees Celsius and are uncorrected.

example 1

A cigarette of the type shown in Fig. 1 was prepared in the following manner.

A. Preparation of the fuel source

The fuel element (10 mm long, 4.5 mm Außandurchmesser) having an apparent density of about 0.86 g / cm ³ was prepared from carbon (90%), SCMC binder (10%) and K ₂ CO ₃ (1%) was prepared.

The carbon was prepared by carbonizing Einei talk free grade of Grand Prairie Canadian force hardwood paper under a nitrogen blanket at a gradual increase in the temperature of about 10 ^c C per hour up to a Endverkohlungstemperatur of 750 ° C.

After cooling to less than about 35 ^° C. under nitrogen, the coal was ground to a mesh size of minus 200 (US). The pulverized coal was then heated to a temperature of up to about 850 ° C to remove the volatiles.

After re-cooling under nitrogen to less than about 35 ° C, the coal was ground to a fine powder, i. H.

a powder having an average particle size) of about 0.1 to 50 micrometers.

This fine powder was mixed with Hercules 7 HF SCMC binder (9 parts carbon: 1 part binder), 1% K 2 CO 3 and enough water to make a stiff, doughy slurry.

From this slurry, fuel elements were extruded with seven central holes each 0.021 inch diameter (about 0.5 mm) and six peripheral holes each about 0.01 inch (0.25 mm) in diameter. The fabric thickness or the distance between the central holes was about 0.08 inches (about 0.2 mm), and the average outer fabric thickness (the distance between the periphery and the peripheral holes) was 0.019 inches (0.48 mm), as shown in Figure 1A.

These fuel elements were then cured under a nitrogen atmosphere for three Stundon long after formation at 900 ⁰ C.

B. Spray dried cextract

A mixture of smoking-treated tobaccos was ground to a mirtelfine dust and extracted with water in a stainless steel container at a concentration of about 1 to 1.5 pounds of tobacco per gallon of water. The extraction was carried out at ambient temperature with mechanical stirring for about 1 to about 3 hours. The mixture was centrifuged to remove alluvial solids and the aqueous extract was spray dried by the aqueous solution continuously to a conventional spray dryer, an Anhydro size 1, was pumped at an inlet temperature of about 215-23O ⁰ C and the dried powder Material was collected at the exit of the dryer. The starting temperature was between about 82 and 9O ⁰ C.

C. Preparation of Sintered Alumina

High effective surface area clay (about 280 mVg) from WR Grace & Co. having a mesh size of -14 to +20 (US) was sintered for about one hour at a softening temperature of about 1400 to 155O ⁰ C, with Washed water and dried. This sintered alumina was bonded in a two-stage process with the ingredients listed in Table I in the proportions indicated:

Table I 68.11% aluminum oxide 19.50% glycerin 8.19% spray dried extract 3.60% HFCS (lnvertose) 0.60% cocoa extract Total: 100.0%

In the first step, the spray-dried tobacco extract was mixed with sufficient water to form a thin slurry. This thin slurry was then applied to the above-described alumina carrier by mixing until the thin slurry was uniformly absorbed by the clay soil. The clad alumina was then dried to reduce the moisture content to about 1%. In the second stage, the alumina so mixed was mixed with a combination of the other ingredients of the above table until the liquid was substantially absorbed in the aluminum support.

D. Assembly

The capsule used to construct the cigarette of Figure 1 was made from deep-drawn aluminum. The capsule had an average wall thickness of about 0.004 inches (0.1 mm) and was about 30 mm long, the outside diameter was about 4.5 mm. The back of the container was closed except for two slit-shaped openings (each about 0.65 mm x 3.45 mm in size and 1.14 mm from the other) to allow passage of the aerosol former to the user. About 330 mg of the aerosol generating substrate described above was filled into the capsule. A fuel element made as above was inserted into the open end of the filled capsule to a depth of about 3 mm.

E. Isoller cover

The combination of fuel element and capsule was wrapped at the end of the fuel element with a 10 mm long glass fiber envelope of Owens-Corning C GLASS S-158 with 3% Pektlnblndemittal up to a diameter of about 7.5 mm. The fiberglass wrap was then wrapped with an innerleaf material, a Kimberly-Clark test paper called P 780-63-5.

F. Tobacco roll

A tobacco rod measuring 7.5mm in diameter and 28mm in length, wrapped in Kimberly-Clark paper P1487-125, was modified to have a longitudinal passage of about 4.5mm in diameter by inserting a probe.

G. Assembly

The wrapped combination of fuel element and capsule was pushed into the passage of the tobacco rod until the fiberglass sheath encountered the tobacco. The fiberglass and Tobakabschnitte were connected by an outer sheet material, which encompassed both the combination of fuel element, insulating sheath and inner leaf and the wrapped tobacco rod. The outer sheet was a Kimberly Clark paper named P1768-182.

A mouthpiece of the type shown in Figure 1 was made by joining two sections: (1) a 10mm long and 7.5mm diameter carbonaceous tobacco sheet material adjacent to the capsule wrapped with Kimberly-Clark's paper P850-184-2, and ( 2) a 30 mm long and 7.5 mm in diameter cylindrical segment of a nonwoven, meltblown thermoplastic polypropylene nonwoven from Kimberly-Clark Corporation, designated PP-100-F, wrapped in Kimberly-Clark Corporation's paper P1487-184-2.

The carbonaceous tobacco sheet material was prepared by incorporating about 17% PCB-G activated carbon from Calgon Carbon Corporation into a stock used to produce a sheet material, obtained from Kimberly-Clark Corporation under the designation P144-185-GAPF becomes. This material was filled with about 4.5% menthol flavor by an inner leaf delivery method. Both sections of the mouthpiece are made by passing the tobacco paper and nonwoven web of thermoplastic fibers through the double cone forming system described above. These two sections were joined to a connecting outer panel from Kimberly-Clark-Corporation's paper P850-186-2. The connected mouthpiece section was joined to the section of wrapped fuel element and capsule through a final outer panel of Ecusta's filter paper 30637-801-12001.

Cigarettes so produced produced a mentholized aerosol without any undesirable off-flavor due to burning or thermal degradation of the menthol or other aerosol forming material. Organoleptic tests comparing such articles with commercially available low tar, mentholated cigarettes showed similar results for taste perception and feeding.

Example Il

Cigarettes similar to those described in Example I were assembled to examine the migration of menthol from its source to the fuel source over a 10-day period under 75/40 humidity conditions (75 ° F and 45% relative humidity). All prototypes were filled with approximately the same amount of menthol. In prototypes A and B, menthol was added directly to both the tobacco shell and the aerosol carrying substrate. In prototypes C and D, menthol was present in the segment of Kimberly-Clark tobacco paper P144-185-GAPF (the sheet material made without any carbon content) located between the aerosol-producing agent and the filter. In prototype E, the menthol was filled on plastic like beads purchased from Narrden Flavor House, Germany, under the name NFM. The beads were placed in a cavity made in the filter piece of the article. In the prototype F, the menthol was loaded onto a trial sponge material from Advanced Prolymer Systems, designated CH-43-16, and incorporated into the tobacco paper sheet P144-185-GAPF (the sheet material made without any carbon content) which is between the aerosol generating means and the filter section of the article. In prototype G made according to the invention, menthol was filled to a 10 mm segment of the carbonaceous tobacco layer material of the present invention which was located between the aerosol generating means and the filter.

As can be seen from Figure 2, the migration of menthol to the fuel source of such articles is substantially reduced when the menthol is filled onto the carbonaceous sheet material of the present invention and used in place of the normal tobacco paper plug.

Claims (47)

1. smoking article, characterized in that it (a) from a fuel element, (b) a physically separate aerosol generating agent with at least one aerosol forming agent and (c) separate means for supplying the aerosol generated by the aerosol generating means to the smoker, the delivery means containing a carbonaceous sheet material carrying at least one flavoring agent. 2. A smoking article according to claim 1, characterized in that the means for the aerosol supply consists of a mouthpiece with a filter plug and a segment of the carbonaceous layer material, which is located between the aerosol generating means and the filter plug. 3. Smoking article according to claim 2, characterized in that the carbonaceous layer material is in the form of a cylinder. 4. Smoking article according to claim 2, characterized in that the carbonaceous layer material is defibrated. 5. A smoking article according to claim 1, 2, 3 or 4, characterized in that the carbon content of the layer material is between about 5 and 75% by mass. 6. A smoking article according to claim 5, characterized in that the carbon content of the layer material is between about 10 and 40 wt .-%. 7. Smoking article according to claim 5, characterized in that the carbon content of the layer material between about 15 and 30Ma .-% is. 8. A smoking article according to claim 3, characterized in that the flavoring agent is menthol in an amount of about 0.001% by mass to saturation. 9. smoking article according to claim 8, characterized in that the amount of menthol is between about 3 and 6Ma .-%. 10. smoking article according to claim 8, characterized in that the amount of menthol is between about 4 and 5 wt .-%. 11. A smoking article according to claim 1,2,3,4,8, 9 or 10, characterized in that the carbonaceous layer material is a tobacco-containing paper. 12. A smoking article according to claim 11, characterized in that the tobacco content of the layer material is about 65Ma .-%. 13. A smoking article according to claim 3, characterized in that the cylinder of carbonaceous layer material between about 5 and 30 mm long. 14. A smoking article according to claim 13, characterized in that the cylinder of carbonaceous layer material between about 5 and 15 mm long. 15. Smoking article according to claim 1,2,3,4 or 6, characterized in that the fuel element before smoking is less than 30mm long. 16. A smoking article according to claim 1, characterized in that the fuel element and the aerosol generating means are in a ratio of the conductive heat exchanges. 17. A smoking article according to claim 16, characterized in that the ratio of the conductive heat exchanges is provided by a heat conducting part which contacts the fuel element and the aerosol generating means. 18. Article according to claim 17, characterized in that the heat-conducting part defines at least a portion of the fuel element. A smoking article according to claim 17, characterized in that the heat-conducting part includes at least a portion of the aerosol-forming substance. 20. A smoking article according to claim 1, characterized in that the fuel element includes coal. 21. A smoking article according to claim 20, characterized in that the fuel element before smoking is less than 30mm long and has a density of at least about 0.85g / c ^r i ³ . 22. A smoking article according to claim 1, characterized in that it further comprises an insulating member surrounding at least a portion of the fuel element. 23. A smoking article according to claim 22, characterized in that the insulating part is an elastic, non-burning part of at least 0.5 mm thickness. 24. A smoking article according to claim 1, characterized in that it further comprises an elastic insulating part surrounding at least a part of the aerosol generating means. 25. Article according to claim 24, characterized in that the insulating part includes a tobacco-containing substance. 26. smoking article, characterized in that it is made (a) a carbonaceous fuel element of less than about 30 mm in length prior to smoking, (b) a physically separate aerosol generating agent with at least one aerosol forming agent and (c) separate means for supplying the aerosol generated by the aerosol generating means to the smoker, the delivery means containing a carbonaceous sheet material carrying at least one flavoring agent. 27. A smoking article according to claim 26, characterized in that the means for the aerosol supply consists of a mouthpiece with a 10 to 40mm long filter plug and a 5 to 30mm long segment of a carbonaceous, tobacco-containing layer material extending between the aerosol generating means and the filter plug located. 28. smoking article, characterized in that it is made (a) a fuel element, (b) a physically separate aerosol generating agent with at least one aerosol forming agent and (C) is a carbonaceous layer material carrying at least one flavor, wherein the carbonaceous layer material is arranged longitudinally behind the fuel element and in spatial distance therefrom. 29. smoking article, characterized in that it is made (a) a fuel element, (b) a physically separate aerosol generating agent with at least one aerosol forming agent and (c) there is a tobacco-containing mass which is physically separated from the fuel element and which contains a carbonaceous layer material which carries at least one flavoring agent. 30. A smoking article according to claim 28, characterized in that the carbonaceous layer material is a shell for one or more components of the smoking article with the exception of the fuel element. 31. A smoking article according to claim 20, characterized in that at least a part of the aerosol-generating agent is bounded by a tobacco-containing mass containing the carbonaceous layer material. 32. A smoking article according to claim 26,28 or 29, characterized in that the carbon content of the layer material between about 5 and 75Ma .-% is. 33. A smoking article according to claim 32, characterized in that the carbon content of the layer material between about 10 and 40Ma .-% is. 34. A smoking article according to claim 32, characterized in that the carbon content of the layer material cd. 15 to 30 mass%. 35. A smoking article according to claim 26,28 or 29, characterized in that the flavoring agent is Meruhol in an amount of about 0.001% by mass to saturation. 36. A smoking article according to claim 35, characterized in that the amount of menthol is between about 3 and 6 wt .-%. 37. A smoking article according to claim 35, characterized in that the amount of menthol is between about 4 and 5 wt .-%. 38. A smoking article according to claim 26,28 or 29, characterized in that the carbonaceous Schichtmateria 'is a tobacco-containing paper. 39. A smoking article according to claim 38, characterized in that the tobacco content of the layer material is about 65Ma .-%. 40. A smoking article according to claim 26, 28 or 29, characterized in that the fuel element and the aerosol generating means are in a ratio of the conductive heat exchange. 41. A smoking article according to claim 40, characterized in that the ratio of the conductive heat exchange is provided by a thermally conductive part which contacts both the fuel element and the aerosol generating means. 42. A smoking article according to claim 41, characterized in that the heat-conducting part defines at least a portion of the fuel element. 43. A smoking article according to claim 41, characterized in that the heat-conducting part includes at least a portion of the aerosol-forming substance. 44. A smoking article according to claim 26,28 or 29, characterized in that the fuel element includes coal. 45. A smoking article according to claim 44, characterized in that the fuel element is less than about 30mm long and has a density of at least about 0.85g / cm ³ . 46. A smoking article according to claim 26,28 or 29, characterized in that it further comprises an insulating part, which surrounds at least a part of the fuel element. 47. A smoking article according to claim 46, characterized in that the insulating part is an elastic, non-burning part of at least 0.5mm thickness.