AU2003284199B2 - Electrically heated cigarette including controlled-release flavoring - Google Patents

Electrically heated cigarette including controlled-release flavoring Download PDF

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Publication number
AU2003284199B2
AU2003284199B2 AU2003284199A AU2003284199A AU2003284199B2 AU 2003284199 B2 AU2003284199 B2 AU 2003284199B2 AU 2003284199 A AU2003284199 A AU 2003284199A AU 2003284199 A AU2003284199 A AU 2003284199A AU 2003284199 B2 AU2003284199 B2 AU 2003284199B2
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Australia
Prior art keywords
flavoring
electrically heated
cigarette
heated cigarette
release
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AU2003284199A
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AU2003284199A1 (en
Inventor
Deborah J. Newman
Beverley C. Woodson
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Philip Morris Products SA
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Philip Morris Products SA
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Priority to US42249702P priority Critical
Priority to US60/422,497 priority
Application filed by Philip Morris Products SA filed Critical Philip Morris Products SA
Priority to PCT/US2003/034290 priority patent/WO2004041007A2/en
Publication of AU2003284199A1 publication Critical patent/AU2003284199A1/en
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Classifications

    • AHUMAN NECESSITIES
    • A24TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24BMANUFACTURE OR PREPARATION OF TOBACCO FOR SMOKING OR CHEWING; TOBACCO; SNUFF
    • A24B15/00Chemical features or treatment of tobacco; Tobacco substitutes, e.g. in liquid form
    • A24B15/18Treatment of tobacco products or tobacco substitutes
    • A24B15/28Treatment of tobacco products or tobacco substitutes by chemical substances
    • A24B15/281Treatment of tobacco products or tobacco substitutes by chemical substances the action of the chemical substances being delayed
    • A24B15/282Treatment of tobacco products or tobacco substitutes by chemical substances the action of the chemical substances being delayed by indirect addition of the chemical substances, e.g. in the wrapper, in the case
    • AHUMAN NECESSITIES
    • A24TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24FSMOKERS' REQUISITES; MATCH BOXES; SIMULATED SMOKING DEVICES
    • A24F47/00Smokers' requisites not otherwise provided for
    • A24F47/002Simulated smoking devices, e.g. imitation cigarettes
    • A24F47/004Simulated smoking devices, e.g. imitation cigarettes with heating means, e.g. carbon fuel
    • A24F47/008Simulated smoking devices, e.g. imitation cigarettes with heating means, e.g. carbon fuel with electrical heating means
    • AHUMAN NECESSITIES
    • A24TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24BMANUFACTURE OR PREPARATION OF TOBACCO FOR SMOKING OR CHEWING; TOBACCO; SNUFF
    • A24B15/00Chemical features or treatment of tobacco; Tobacco substitutes, e.g. in liquid form
    • A24B15/18Treatment of tobacco products or tobacco substitutes
    • A24B15/28Treatment of tobacco products or tobacco substitutes by chemical substances
    • A24B15/281Treatment of tobacco products or tobacco substitutes by chemical substances the action of the chemical substances being delayed
    • A24B15/283Treatment of tobacco products or tobacco substitutes by chemical substances the action of the chemical substances being delayed by encapsulation of the chemical substances
    • AHUMAN NECESSITIES
    • A24TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24BMANUFACTURE OR PREPARATION OF TOBACCO FOR SMOKING OR CHEWING; TOBACCO; SNUFF
    • A24B15/00Chemical features or treatment of tobacco; Tobacco substitutes, e.g. in liquid form
    • A24B15/18Treatment of tobacco products or tobacco substitutes
    • A24B15/28Treatment of tobacco products or tobacco substitutes by chemical substances
    • A24B15/281Treatment of tobacco products or tobacco substitutes by chemical substances the action of the chemical substances being delayed
    • A24B15/283Treatment of tobacco products or tobacco substitutes by chemical substances the action of the chemical substances being delayed by encapsulation of the chemical substances
    • A24B15/284Treatment of tobacco products or tobacco substitutes by chemical substances the action of the chemical substances being delayed by encapsulation of the chemical substances the additive being bound to a host by chemical, electrical or like forces, e.g. use of precursors, inclusion complexes

Description

WO 2004/041007 PCT/US2003/034290 -1 ELECTRICALLY HEATED CIGARETTE INCLUDING CONTROLLED-RELEASE FLAVORING BACKGROUND 5 [0001] Traditional cigarettes are smoked by lighting an end of a wrapped tobacco rod and drawing air predominately through the lit end by suction at a mouthpiece end of the cigarette. Traditional cigarettes deliver smoke as a result of combustion, during which tobacco is combusted at temperatures that typically exceed 800'C during a puff. The heat of combustion releases various gaseous 10 combustion products and distillates from the tobacco. As these gaseous products are drawn through the cigarette, they cool and condense to form an aerosol, which provides the flavors and aromas associated with smoking. [0002] Traditional cigarettes produce sidestream smoke during smoldering between puffs. Once lit, they normally are fully consumed or discarded. 15 Relighting a traditional cigarette is possible, but is not desirable for subjunctive reasons including flavor, taste and odor. [0003] An alternative to the more traditional cigarette is the electrically heated cigarette used in electrical smoking systems. As compared to traditional cigarettes, electrical smoking systems significantly reduce sidestream smoke, and 20 also permit smokers to suspend and reinitiate smoking as desired. Exemplary electrical smoking systems are disclosed in commonly-assigned U.S. Patents Nos. 6,026,820; 5,988,176; 5,915,387; 5,692,526; 5,692,525; 5,666,976; 5,499,636; and 5,388,594, each of which is hereby incorporated by reference in its entirety. Electrical smoking systems include an electrically powered lighter and an 25 electrically heated cigarette, which is constructed to cooperate with the lighter. It is desirable that electrical smoking systems be capable of delivering smoke in a WO 2004/041007 PCT/US2003/034290 -2 manner similar to the smoker's experiences with traditional cigarettes, such as by providing an immediacy response (smoke delivery occurring immediately upon draw), a desired level of delivery (that correlates with FTC tar level), a desired resistance to draw (RTD), as well as puff-to-puff and cigarette-to-cigarette 5 consistency. [0004] Volatile flavorings have been incorporated in traditional cigarettes to add flavors and aromas to mainstream and sidestream tobacco smoke. See, for example, U.S. Patents Nos. 3,006,347; 3,236,244; 3,344,796; 3,426,011; 3,972,335; 4,715,390; 5,137,034; 5,144,964; and 6,325,859, and commonly 10 owned International Publication No. WO 01/80671. The added flavorings are desirably volatilized when the cigarette is smoked. However, volatile flavorings tend to migrate in the cigarette to other components and possibly through the entire cigarette. Volatile flavorings can be lost from cigarettes during storage and distribution at ordinary conditions prior to smoking of the cigarettes. The degree 15 of migration of volatile flavorings in cigarettes depends on different factors, including the flavoring's vapor pressure, the solubility of the flavoring in other components of the cigarette, and temperature and humidity conditions. In addition, a large portion of the added flavoring can be lost to the side stream smoke in traditional cigarettes. 20 [0005] Flavorings that have been incorporated in traditional cigarettes also can chemically and/or physically deteriorate by contacting and/or reacting with other components of the cigarette, as well as with the environment. For example, activated carbon has been incorporated in traditional cigarettes to remove gas phase constituents from mainstream smoke. However, flavorings that have been 25 incorporated in the cigarettes along with the activated carbon have been adsorbed by the activated carbon, clogging pores of the activated carbon and consequently WO 2004/041007 PCT/US2003/034290 -3 deactivating the activated carbon, thereby diminishing its ability to filter tobacco smoke. [0006] For the foregoing reasons, flavorings that have been incorporated in traditional cigarettes have not been totally satisfactorily delivered to the smoker. 5 Consequently, the flavorings incorporated in some traditional cigarettes have not satisfactorily provided the desired taste effect to the smoker and the flavorings' desired value to the subjective quality of the cigarette has been less than desired. Due to the flavoring loss, the uniformity of flavored cigarettes has not been totally satisfactory. In addition, the sorption of flavorings by sorbents in the cigarettes has 10 deactivated the sorbents and thereby reduced their ability to remove gas phase constituents from tobacco smoke. SUMMARY [0007] In view of the above-described problems that have been encountered in 15 some traditional cigarettes including flavorings and those also including sorbents, an electrically heated cigarette is provided, which includes a sorbent and a controlled-release flavoring. In a preferred embodiment, the electrically heated cigarette comprises a sorbent and a flavoring incorporated in the cigarette in a form that preferably minimizes release and migration of the flavoring in the 20 cigarette prior to smoking, for example, at ambient conditions, and thus preferably minimizes deactivation of the sorbent by the flavoring. In addition, the flavoring preferably is released in the cigarette in a controlled manner during smoking. Consequently, the flavoring preferably enhances subjective characteristics of the cigarette while the sorbent maintains its ability to remove gas-phase constituents 25 from mainstream smoke. [0008] A preferred embodiment of the electrically heated cigarette comprises at least one sorbent and a flavoring-release additive including one or more flavorings.

WO 2004/041007 PCT/US2003/034290 -4 The flavoring is releasable in the cigarette upon the flavoring-release additive being heated to at least a minimum temperature, which occurs during smoking of the cigarette. [0009] The flavoring-release additive can be incorporated in various forms in the 5 electrically heated cigarette. In one preferred embodiment, the flavoring-release additive comprises beads. In another preferred embodiment, the flavoring-release additive is a film. In yet another preferred embodiment, the flavoring-release additive is an inclusion complex including a selected host molecule, and the flavoring as a guest molecule in the inclusion complex. 10 [0010] In another preferred embodiment, two or more different flavoring-release additives having different flavoring release temperatures are located at different locations in an electrically heated cigarette that reach different temperatures from each other. The flavoring-release additives can be located at locations in the electrically heated cigarette that reach the flavoring release temperature for those 15 flavoring-release additives. Accordingly, the flavoring-release additive can provide efficient, controlled release of the flavoring during smoking. [0011] The electrically heated cigarette can comprise various sorbents. By providing the flavoring in the flavoring-release additive, which preferably minimizes release and/or migration of the flavoring until the flavoring-release 20 additive reaches the flavoring release temperature, the flavoring is preferably substantially prevented from being sorbed by, and thus deactivating, the sorbent, thereby not adversely affecting the sorbent's ability to remove selected gas-phase constituents from mainstream tobacco smoke. In addition, because the flavoring is temperature released in the cigarette, it can be effectively delivered to a smoker in 25 a controlled manner during puff cycles of the cigarette.

WO 2004/041007 PCT/US2003/034290 -5 [0012] A preferred embodiment of an electrical smoking system comprises a lighter and at least one electrically heated cigarette including at least one sorbent and a flavoring-release additive. [0013] A preferred embodiment of a method of making an electrically heated 5 cigarette comprises incorporating a sorbent and a flavoring-release additive into an electrically heated cigarette. BRIEF DESCRIPTION OF THE DRAWINGS [0014] FIG. 1 illustrates a preferred embodiment of an electrically heated 10 cigarette for use in an electrical smoking system with the cigarette in a partially unassembled condition. [0015] FIG. 2 illustrates the electrically heated cigarette shown in FIG. 1 in the assembled condition with one end of the cigarette contacting a stop piece of an electrically operated lighter of the electrical smoking system. 15 [0016] FIG. 3 illustrates another preferred embodiment of an electrically heated cigarette for use in an electrical smoking system with the cigarette in a partially unassembled condition. [0017] FIG. 4 illustrates a preferred embodiment of an electrical smoking system with an electrically heated cigarette inserted into the electrically operated 20 lighter. [0018] FIG. 5 illustrates the electrical smoking system shown in FIG. 4 with the cigarette withdrawn from the lighter. [0019] FIG. 6 illustrates a heater fixture of the electrical smoking system.

WO 2004/041007 PCT/US2003/034290 -6 DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0020] An electrically heated cigarette includes one or more sorbents and at least one flavoring for affecting flavor, taste, and/or aroma of tobacco smoke. In a preferred embodiment, the flavoring is incorporated in the cigarette in a flavoring 5 release additive, which preferably minimizes the release and/or migration of the flavoring in the cigarette prior to smoking. Preferably, the flavoring is released from the flavoring-release additive in a controlled manner during smoking of the cigarette. The flavoring-release additive enables the flavoring to enhance subjective characteristics of the cigarette while avoiding an adverse impact on the 10 effectiveness of the sorbent in removing selected gas-phase constituents from mainstream smoke. [0021] In a preferred embodiment of the electrically heated cigarette, the flavoring is released in the cigarette upon the flavoring-release additive being heated to at least a minimum temperature (flavoring release temperature), which 15 occurs when a smoker draws mainstream smoke through the cigarette. [0022] It has been determined that different regions of the electrically heated cigarette reach different temperatures when a smoker draws on the cigarette. In a preferred embodiment, different flavoring-release additives are selectively disposed at two or more locations in the electrically heated cigarette that 20 respectively reach at least the minimum temperature at which the flavoring is released from the flavoring-release additive disposed at that location. By selectively locating one or more flavoring-release additives in the cigarette, the cigarette can provide efficient, controlled release of the flavoring during smoking. [0023] The flavoring-release additive can have various constructions and 25 compositions and can be located at one or more locations, and/or incorporated in one or more components of the electrically heated cigarette. The flavoring-release additives can be designed to have different associated flavoring release WO 2004/041007 PCT/US2003/034290 -7 temperatures. Accordingly, the flavoring-release additives can be incorporated in the electrically heated cigarette at locations that are most suitable for providing efficient release of the flavoring from the particular flavoring-release additive. [0024] The electrically heated cigarette can comprise one or more sorbents 5 capable of removing selected gas-phase constituents from mainstream smoke. By providing the flavoring in the flavoring-release additive that preferably minimizes the release and/or migration of the flavoring in the cigarette until the flavoring release additive reaches at least the minimum temperature, the flavoring is preferably substantially prevented from deactivating the sorbent. Thus, the ability 10 of the sorbent to remove selected gas-phase constituents from mainstream tobacco smoke can be maintained. Preferably, the flavoring-release additive enables the flavoring to be effectively delivered to a smoker in a controlled manner. [0025] As used herein, the term "sorption" denotes filtration by adsorption and/or absorption. Sorption is intended to encompass interactions on the outer 15 surface of the sorbent, as well as interactions within the pores and channels of the sorbent. In other words, a "sorbent" is a substance that has the ability to condense or hold molecules of other substances on its surface, and/or the ability to take up other substances, i.e., through penetration of the other substances into its inner structure, or into its pores. The term "sorbent" as used herein refers to either an 20 adsorbent, an absorbent, or a substance that can function as both an adsorbent and an absorbent. [0026] As used herein, the term "remove" refers to adsorption and/or absorption of at least some portion of a component of mainstream tobacco smoke. [0027] The term "mainstream smoke" includes the mixture of gases passing 25 down the tobacco rod and issuing through the filter end, i.e., the amount of smoke issuing or drawn from the mouth end of a cigarette during smoking of the WO 2004/041007 PCT/US2003/034290 -8 cigarette. The mainstream smoke contains air that is drawn in through the heated region of the cigarette and through the paper wrapper. [0028] The term "molecular sieve" as used herein refers to a porous structure comprised of an inorganic material and/or organic material. Molecular sieves 5 include natural and synthetic materials. Molecular sieves can sorb molecules of certain dimensions, while rejecting molecules having larger dimensions. [0029] FIGS. 1 and 2 illustrate a preferred embodiment of the electrically heated cigarette 23. However, it should be understood that the electrically heated cigarette can have other configurations suitable for smoking in an electrically 10 powered lighter. The electrically heated cigarette 23 comprises a tobacco rod 60 and a filter tipping 62 joined together by tipping paper 64. The tobacco rod 60 preferably includes a tobacco web or "mat" 66 folded into a tubular form about a free-flow filter 74 at one end and a tobacco plug 80 at the other end. [0030] An over wrap 71 surrounds the tobacco-containing mat 66 and is held 15 together along a longitudinal seam. The over wrap 71 retains the mat 66 in a wrapped condition about the free-flow filter 74 and tobacco plug 80. [0031] The mat 66 preferably comprises a base web 68 and a layer of tobacco material 70. The tobacco material 70 can be located along the inside surface or the outside surface of the base web 68. At the tipped end of the tobacco rod 60, the 20 mat 66 and the over wrap 71 are wrapped about the free-flow filter plug 74. Preferably, the tobacco plug 80 comprises a relatively short tobacco column 82 of cut filler tobacco, which is retained by a surrounding inner wrap 84. [0032] A void 90 is between the free-flow filter 74 and the tobacco plug 80. The void 90 is an unfilled portion of the tobacco rod 60 and is in fluid 25 communication with the tipping 62 through the free flow filter 74. [0033] The tipping 62 preferably comprises a free-flow filter 92 located adjacent the tobacco rod 60 and a mouthpiece filter plug 94 at the distal end of the tipping WO 2004/041007 PCT/US2003/034290 -9 62 from the tobacco rod 60. Preferably, the free-flow filter 92 is tubular and transmits air with very low pressure drop. The mouthpiece filter plug 94 closes off the free end of the tipping 62. [0034] The cigarette 23 optionally includes at least one row of perforations 12 5 adjacent the free end 15 of the cigarette 23. The perforations can be formed as slits 17, which preferably extend through the over wrap 71, the mat 66 and the inner wrap 84. [0035] To further improve delivery, at least one additional row of perforations 14 comprising slits 17 can optionally be formed at a location along the tobacco 10 plug 80. The perforations 12 or 14 may comprise a single row or a dual row of slits 17. The number and extent of the slits 17 can be selected to control the resistance to draw (RTD) along the side walls of the cigarettes 23 and the delivery. [0036] Optional holes 16 provided in the mat 66 are covered by the over wrap 71. The perforations 12, 14 can be used to approximate desired delivery levels for 15 the cigarette 23, with the holes 16 being used to adjust delivery with a lesser effect on the RTD. [0037] The cigarette 23 preferably has a substantially constant diameter along its length. The diameter of the cigarette 23, like more traditional cigarettes, is preferably between about 7.5 mm to 8.5 mm so that the electrical smoking system 20 21 provides a smoker with a familiar "mouth feel" during smoking. [0038] The tobacco column 82 preferably comprises cut filler of a typical blend of tobaccos, such as blends comprising bright, Burley, and Oriental tobaccos together with, optionally, reconstituted tobaccos and other blend components, including traditional cigarette flavors. 25 [0039] The free-flow filter 92 and the mouthpiece filter plug 94 are preferably joined together as a combined plug with a plug wrap 101. The plug wrap 101 is WO 2004/041007 PCT/US2003/034290 -10 preferably a porous, low-weight plug wrap. The combined plug is attached to the tobacco rod 60 by the tipping paper 64. [0040] As described above, the electrically heated cigarette 23 can comprise one or more sorbents that remove gas-phase constituents of tobacco smoke. The 5 sorbent can comprise one or more porous materials through which tobacco smoke can flow. In a preferred embodiment, the sorbent is activated carbon. For example, the sorbent can comprise activated carbon granules located in a void in the filter, or activated carbon particles loaded on fibrous material or paper. The activated carbon can be in various forms including particles, fibers, beads, and the 10 like. The activated carbon can have different porosity characteristics, such as a selected pore size and total pore volume. [0041] In another preferred embodiment, the sorbent is one or more suitable molecular sieve sorbent materials. Molecular sieve sorbents that may be used in the electrically heated cigarette 23 include, but are not limited to, one or more of 15 the zeolites, mesoporous silicates, alumino phosphates, mesoporous aluminosilicates, and other related porous materials, such as mixed oxide gels, which may optionally further comprise inorganic or organic ions and/or metals. See, for example, commonly-owned International Publication No. WO 01/80973, which is incorporated herein by reference in its entirety. 20 [0042] In a preferred embodiment, the sorbent is one or more zeolites. Zeolites include crystalline aluminosilicates having pores, such as channels and/or cavities of uniform, molecular sized dimensions. There are many known unique zeolite structures having different sized and shaped pores, which can significantly affect the properties of these materials with regard to sorption and separation processes. 25 Molecules can be separated by zeolites by size and shape effects related to the possible orientation of the molecules in the pores, and/or by differences in strength of sorption. One or more zeolites having pores larger than one or more selected WO 2004/041007 PCT/US2003/034290 -11 gas phase components of a gas that is desired to be filtered can be used in the electrically heated cigarette 23, such that only selected molecules that are small enough to pass through the pores of the molecular sieve material are able to enter the cavities and be sorbed on the zeolite. 5 [0043] The zeolite can be, but is not limited to, one or more of zeolite A; zeolite X; zeolite Y; zeolite K-G; zeolite ZK-5; zeolite BETA; zeolite ZK-4 and zeolite ZSM-5. In a preferred embodiment, zeolite ZSM-5 and/or zeolite BETA is used. ZSM-5 is in the MFI structural classification family and represented by the crystal chemical data [Nak(A1Si 9 60

,O

192 ) 16H 2 0, with n < 27, orthorhombic, Pnma], 10 while zeolite BETA is in the BEA structural classification family and represented by the crystal chemical data [Na 7

(A

7

S

5 70 12 8 ) tetragonal, P4 1 22]. These two zeolites are thermally stable at temperatures up to about 800 C, allowing them to be incorporated in cigarette filters and/or the tobacco rod of the electrically heated cigarette 23. 15 [0044] In another preferred embodiment, the sorbent incorporated in the electrically heated cigarette 23 has a composite composition. In such embodiment, the sorbent comprises, for example, activated carbon and one or more molecular sieve materials, such as those described above. For example, sorbent fibers can be impregnated with at least one sorbent. 20 [0045] Microporous, mesoporous, and/or macroporous molecular sieves may be used in the electrically heated cigarette 23, depending on the selected component(s) desired to be removed from mainstream tobacco smoke. [0046] The sorbent can be incorporated in one or more locations of the electrically heated cigarette 23. For example, the sorbent can placed in the 25 passageway of the tubular free-flow filter 74, in the free-flow filter 92, and/or in the void space 90. The sorbent can additionally or alternatively be incorporated in the tobacco plug 80.

WO 2004/041007 PCT/US2003/034290 -12 [0047] FIG. 3 shows another preferred embodiment of an electrically heated cigarette 23 including a filter 150. The filter 150 comprises a sorbent in the form of oriented fibers 152 and a sleeve 154, such as paper, surrounding the fibers. The sorbent can be, for example, one or more of activated carbon, silica gel, 5 zeolite, and other molecular sieves in fibrous forms. The sorbents can be surface modified materials, for example, surface modified silica gel, such as amino propyl silyl (APS) silica gel. Sorbent mixtures can provide different filtration characteristics to achieve a targeted filtered mainstream smoke composition. [0048] Alternatively, the fibers 152 can comprise one or more sorbent materials, 10 such as carbon, silica, zeolite and the like, impregnated in microcavity fibers, such as TRIAD T M micro-cavity fiber, as disclosed in commonly-owned International Publication No. WO 01/80973. In a preferred embodiment, the fibers are shaped microcavity fibers impregnated with particles of one or more sorbent materials, or alternatively continuous activated carbon fibers. The fibers preferably have a 15 diameter of from about 10 microns to about 100 microns. The fibers can have a length of from about 10 microns to about 200 microns, for example. [0049] In another preferred embodiment, the fibers are bundles of non continuous fibers, which are preferably oriented parallel to the direction of mainstream smoke flow through the electrically heated cigarette. 20