A FORMULATION FOR USE IN AN AEROSOL-GENERATING SYSTEM

Abstract

A formulation for an aerosol-generating system is provided, the formulation including: one or more aerosol formers; and one or more polymers selected from the group consisting of: polyvinyl acetate, polyvinyl alcohol, polyethylene glycol, polyglycolic acid, polylactic acid, polydioxanone, polycaprolactone, polyethylene, polypropylene glycol, and starch, in which the formulation has a melting point of between 100 degrees Celsius and 300 degrees Celsius. An aerosol-generating article for the aerosol-generating system, and an aerosol-generating system, are also provided.

Claims

1.-15. (canceled)

16. A formulation for an aerosol-generating system, the formulation comprising: one or more aerosol formers; and one or more polymers selected from the group consisting of: polyvinyl acetate, polyvinyl alcohol, polyethylene glycol, polyglycolic acid, polylactic acid, polydioxanone, polycaprolactone, polyethylene, polypropylene glycol, and starch, wherein the formulation has a melting point of between 100 degrees Celsius and 300 degrees Celsius.

17. The formulation according to claim 16, wherein the formulation has a melting point of between 180 degrees Celsius and 270 degrees Celsius.

18. The formulation according to claim 16, wherein the formulation has an aerosol former content of between 20 percent by weight and 85 percent by weight.

19. The formulation according to claim 18, wherein the formulation has an aerosol former content of between 35 percent by weight and 55 percent by weight.

20. The formulation according to claim 17, wherein the one or more aerosol formers comprise one or more water-miscible polyhydric alcohols.

21. The formulation according to claim 20, wherein the one or more water-miscible polyhydric alcohols are selected from the group consisting of: vegetable glycerol, propylene glycol, and sorbitol.

22. The formulation according to claim 16, further comprising one or more organic acids.

23. The formulation according to claim 22, wherein the formulation has an organic acid content of less than 10 percent by weight.

24. The formulation according to claim 22, wherein the one or more organic acids are selected from the group consisting of: malonic acid, citric acid, 2-ethylbutyric acid, acetic acid, adipic acid, benzoic acid, butyric acid, cinnamic acid, cycloheptane-carboxylic acid, fumaric acid, glycolic acid, hexanoic acid, lactic acid, levulinic acid, malic acid, myristic acid, octanoic acid, oxalic acid, propanoic acid, pyruvic acid, succinic acid, and undecanoic acid.

25. The formulation according to claim 24, wherein the one or more organic acids are selected from the group consisting of: malonic acid, citric acid, lactic acid, benzoic acid, levulinic acid, fumaric acid, and acetic acid.

26. The formulation according to claim 16, wherein the formulation has a polymer content of greater than or equal to about 0.5 percent by weight.

27. The formulation according to claim 16, further comprising one or more metal salts.

28. The formulation according to claim 27, wherein the one or more metal salts are selected from the group consisting of: metal alginates, metal cinnamates, metal cycloheptanecarboxylates, metal levulinates, metal propanoates, metal stearates, and metal undecanoates.

29. The formulation according to claim 28, wherein the one or more metal salts are selected from the group consisting of: metal cinnamates, metal cycloheptanecarboxylates, metal stearates, and metal undecanoates.

30. An aerosol-generating article for an aerosol-generating system, the aerosol-generating article containing a formulation according to claim 16.

31. An aerosol-generating system, comprising: a formulation according to claim 16; and an atomiser configured to generate an aerosol from the formulation.

Description

[0155] Specific embodiments will now be described, by way of example only, with reference to the following examples and the accompanying drawings, in which:

[0156] FIG. 1 shows schematically a sectional side view of an aerosol-generating system comprising an aerosol-generating device and an aerosol-generating article comprising a formulation according to the invention;

[0157] FIG. 2 shows schematically a sectional view of the aerosol-generating system of FIG. 1, with the aerosol-generating article inserted into the aerosol-generating device;

[0158] FIG. 3 shows schematically a sectional view of an alternative aerosol-generating system comprising an aerosol-generating article comprising a formulation according to the invention;

[0159] FIG. 4 shows schematically a sectional view of an aerosol-generating article comprising a formulation according to the invention, before heating of the aerosol-forming substrate;

[0160] FIG. 5 shows schematically a sectional view of an aerosol-generating article comprising a formulation according to the invention, during heating of the aerosol-forming substrate;

[0161] FIG. 6 is a graph showing average aerosolised collected mass in mg per puff for a range of different aerosol former compositions;

[0162] FIG. 7 is a graph showing average nicotine in mg per puff for a range of different aerosol former compositions; and

[0163] FIG. 8 is a graph showing average nicotine percent for a range of different aerosol former compositions.

[0164] Aerosol-generating systems for delivering to a user typically comprise an atomiser configured to generate an inhalable aerosol from a formulation. Some known aerosol-generating systems comprise a thermal atomiser such as an electric heater that is configured to heat and vaporise the formulation to generate an aerosol. Typical formulations for use in aerosol-generating systems are nicotine formulations, which may be liquid nicotine formulations comprising an aerosol former such as glycerine and/or propylene glycol.

[0165] An aerosol generating system can comprise an aerosol-generating device and an aerosol-generating article containing a formulation. Typical aerosol-generating systems may suffer from a problem of unwanted leakage of the formulation out of the aerosol-generating article. Leakage of a formulation may occur in a number of different situations, such as: when there is too much of the formulation in a reservoir of the aerosol-generating article; when the material forming one or more parts of the aerosol-generating article or system fails to retain the formulation as designed; due to a change in pressure, for example when at a high altitude during transport by an aeroplane; or at a high temperature, for example due to hot weather.

[0166] It would be desirable to provide a formulation that provides a reduced risk of leakage from an aerosol-generating article or system compared to typical formulations.

[0167] FIGS. 1 and 2 show an aerosol-generating system including an aerosol-generating device 10 and an aerosol-generating article 20. In this example, the aerosol-generating article 20 is cartridge.

[0168] The aerosol-generating device 10 is configured to receive the aerosol-generating article 20 in a cavity 18. The aerosol-generating article 20 includes a housing 24. The housing 24 defines a reservoir 22. The reservoir 22 has a reservoir opening that can be covered by a removable cover 26. An aerosol-forming substrate is disposed in the reservoir 22. The aerosol-forming substrate in the reservoir 22 may be a formulation according to the invention.

[0169] In the example shown in FIGS. 1 and 2, the aerosol-generating article 20 includes an atomiser configured to generate an aerosol from the formulation in the reservoir 22. The atomiser may be a thermal atomiser. In the example shown in FIGS. 1 and 2 the atomiser is an electric heater 30. In other examples, the atomiser may be another type of atomiser, such as a non-thermal atomiser.

[0170] In the example of FIGS. 1 and 2, the aerosol-generating article 20 contains an aerosol-forming substrate and an atomiser and may therefore be referred to as a “cartomiser”.

[0171] The aerosol-generating article 20 is replaceable by a user when the aerosol-forming substrate provided in the reservoir 22 is depleted.

[0172] FIG. 1 shows the aerosol-generating article 20 just prior to insertion into the aerosol-generating device 10. The arrow 1 in FIG. 1 indicates the direction of insertion of the aerosol-generating article 20 in to the aerosol-generating device 10.

[0173] The aerosol-generating device 10 is portable and has a size comparable to a conventional cigar or cigarette. The aerosol-generating device 10 comprises a main body 11 and a mouthpiece portion 12. The main body 11 contains a battery 14, such as a lithium iron phosphate battery, control electronics 16 and a cavity 18.

[0174] The mouthpiece portion 12 is connected to the main body 11 by a hinged connection 21 and can move between an open position as shown in FIG. 1 and a closed position as shown in FIG. 2. The mouthpiece portion 12 is placed in the open position to allow for insertion and removal of an aerosol-generating article 20 and is placed in the closed position when the aerosol-generating system is to be used to generate aerosol.

[0175] The mouthpiece portion 12 comprises a plurality of air inlets 13 and an outlet 15. In use, a user sucks or puffs on the outlet 15 to draw air from the air inlets 13, through the mouthpiece portion to the outlet 15, and thereafter into the mouth or lungs of the user. Internal baffles 17 are provided to force the air flowing through the mouthpiece portion 12 past the aerosol-generating article 20.

[0176] The housing 24 includes a capillary material soaked in the aerosol-forming substrate. The capillary material in this example is positioned adjacent the electric heater 30.

[0177] The cavity 18 has a circular cross-section and is sized to receive a housing 24 of the aerosol-generating article 20. Electrical connectors 19 are provided at the sides of the cavity 18 to provide an electrical connection between the control electronics 16 and battery 14 and corresponding electrical contacts on the aerosol-generating article 20. This setup allows power to be supplied to the electric heater 30.

[0178] FIG. 2 shows the aerosol-generating article 20 inserted into the cavity 18 of the aerosol-generating device 10. In this position, the electrical connectors 19 rest against the corresponding electrical contacts on the aerosol-generating article 20. The cover 26 has been fully removed and the mouthpiece portion 12 has been moved to a closed position.

[0179] The mouthpiece portion 12 is retained in the closed position by a clasp mechanism (not illustrated). It will be apparent to a person of ordinary skill in the art that other suitable mechanisms for retaining the mouthpiece in a closed position may be used, such as a snap fitting or a magnetic closure.

[0180] The mouthpiece portion 12 in a closed position retains the aerosol-generating article 20 in electrical contact with the electrical connectors 19 so that a good electrical connection is maintained in use, whatever the orientation of the aerosol-generating system is.

[0181] In use, when the aerosol-generating device 10 is activated by a user, the electric heater 30 melts and aerosolises at least a portion of the aerosol-forming substrate in the reservoir 22. As a user sucks or puffs on the outlet 15, air flows through the air inlets 13 and over the electric heater 30 and the capillary material. The air flowing over the electric heater 30 and the capillary material entrains the volatized aerosol components from the vaporised aerosol-forming substrate. The air with entrained aerosol-forming substrate then flows out through the outlet 15 and to the user. This air flow regime is shown in FIG. 2.

[0182] FIG. 3 shows an alternative embodiment of an aerosol-generating system including an aerosol-generating article 200. In this example, the aerosol-generating article 200 is a “lip-stick” advance mechanism aerosol-generating article 200. The aerosol-generating article 200 includes a body 212. The body 212 defines a reservoir 210. The reservoir 210 has a reservoir opening 215. The aerosol-forming substrate 211 is disposed in the reservoir 210. A heater 222 is disposed proximate to the reservoir opening 215. In this example, the body 212 includes a ring or rotation element 251 that is coupled to the movable rigid base 213. The ring or rotation element 251 translates rotational movement into lateral movement via a spiral or helical groove 214. Pins (not shown) couple the rigid base 213 to the spiral or helical groove 214 to provide the lateral movement of the aerosol-forming substrate 211. The aerosol-forming substrate 211 is a formulation according to the invention that may flow into and through a mesh layer of the heater 222.

[0183] In alternative embodiments (not shown), the aerosol-generating system may comprise an automatic mechanism to move or advance the aerosol-forming substrate 211 toward the heater 222. In such alternative embodiments, the controller 253 of the aerosol-generating device 200 may activate an actuator or advancement mechanism to advance the aerosol-forming substrate 211 and rigid base 213 toward the heater 222 upon detecting that the heater 222 is not in contact the aerosol-forming substrate 211. The actuator or advancement mechanism may be provided on the aerosol-generating article 200.

[0184] FIGS. 4 and 5 are schematic sectional views of an alternative aerosol-generating article 300. FIG. 4 shows the aerosol-generating article 300 before it has been used by the user. The aerosol-generating article 300 includes a body 312 defining a reservoir 310 having a reservoir opening 315. Aerosol-forming substrate 311 is disposed in the reservoir 310. The aerosol-generating article 300 includes a heater 322 located across the reservoir opening 315. In this example, the heater 322 has a heating element in the form of a mesh layer 323. The aerosol-generating article 300 also includes a transfer element 324. The transfer element 324 is preferably formed from a porous material. In the example of FIG. 4, the transfer element 324 is formed from a layer of glass fibers. The transfer element 324 provides control of the flow of the aerosol-forming substrate 311 from the reservoir 310 to the mesh layer 313 of the heater 322. In this example, the aerosol-forming substrate 311 is a formulation according to the invention.

EXAMPLES

[0185] One formulation according to the invention (Example A) is prepared having the composition shown in Table 1. The formulation of Example A is a solid at standard temperature and pressure.

TABLE-US-00002 TABLE 2 Example A Glycerine (% by weight) aerosol former 15.9 Polypropylene Glycol (% by weight) aerosol former 14 Polyvinyl Alcohol (% by weight) polymer 7 Water (% by weight) 60 Nicotine (% by weight) 2 Lactic (% by weight) organic acid 1.1

[0186] The formulation of Example A is prepared by: [0187] (1) heating the one or more aerosol formers to a temperature of between about 100 degrees Celsius and about 120 degrees Celsius using a hotplate stirrer; [0188] (2) adding the one or more polymers to the one or more aerosol formers, while stirring constantly, and then continuing to heat the mixture to a temperature of between about 85° C. and about 95° C. until the mixture was clear; [0189] (3) adding water to the clear mixture; [0190] (4) decreasing the heating temperature of the mixture to about 50° C. and adding the organic acid and the nicotine to the mixture, while stirring constantly; and [0191] (5) pouring the heated mixture into a mould and then allowing the mixture to cool and congeal to form the formulation.

[0192] An example of use of a formulation according to the invention as an aerosol-forming substrate will now be described with reference to the formulation of Example A when used as an aerosol-forming substrate 311 in the aerosol-generating article 300 shown in FIGS. 4 and 5.

[0193] FIG. 4 shows the aerosol-forming substrate 311 at standard temperature and pressure. FIG. 5 shows the aerosol-forming substrate 311 at an elevated temperature when heated by the heater 322.

[0194] In the example of FIGS. 4 and 5, the aerosol-forming substrate 311 is a solid at standard temperature and pressure because the melting point of the aerosol-forming substrate 311 is between 60 degrees Celsius and 300 degrees Celsius. In another example, the aerosol-forming substrate 311 is a colloid at standard temperature and pressure. The colloid may have a solid continuous phase and a liquid dispersed phase.

[0195] Therefore, before the heater 322 has been activated, the aerosol-forming substrate 311 is in the solid phase.

[0196] The aerosol-generating article 300 is inserted into the aerosol-generating device 10 that is shown in FIG. 1

[0197] The aerosol-generating device 300 is then activated by a user. Activation of the aerosol-generating device 10 involves activation of the heater 322 of the aerosol-generating article 300. Activation of the heater 322 heats a portion of the aerosol-generating substrate 311 contained within the transfer element 324. In this example, the heater 322 is activated at a power of 0.8 Watts for a time of six minutes. In one example, the heater 322 may be activated at a different power level. In another example, the heater 322 may be activated for a different time period.

[0198] Activation of the heater 322 at a power of 0.8 Watts for six minutes increases the temperature of the mesh layer 323 to around 200 degrees Celsius.

[0199] Heating of aerosol-forming substrate 311 contained within the transfer element 324 increases the temperature of at least a portion of the aerosol-forming substrate 311, which causes the heated portion of the aerosol-generating substrate 311 to melt in to a liquid.

[0200] FIG. 5 shows an example in which the whole of the aerosol-forming substrate 311 has been transitioned into a liquid through heating of the aerosol-forming substrate 311 by the heater 322. In another example, at least a portion, or only a portion of the aerosol-forming substrate 311 is melted into a liquid when the heater 322 activates. For example, the portion of the aerosol-forming substrate 311 that is adjacent the heater 322 may melt into a liquid, but the remaining portion of the aerosol-forming substrate 311 may remain as a solid.

[0201] The temperature of the aerosol-forming substrate 311 increases until at least a portion of the melted aerosol-forming substrate 311 contained within the transfer element 324 vaporises into an aerosol.

[0202] The aerosol can then be inhaled by a user through the outlet 15.

[0203] After the first heating cycle of the heater 322 has finished, the aerosol-forming substrate 311 cools down. The aerosol-forming substrate 311 forms back into a solid, as is shown in FIG. 4.

[0204] The aerosol-generating article 300 may be used several times before the aerosol-generating substrate 311 contained within the reservoir 310 is fully consumed. Thus, the aerosol-generating article 300 may experience multiple heating cycles. Therefore, in use, the aerosol-forming substrate may experience multiple phase changes.

[0205] Advantageously, the aerosol-forming substrate 311 is stored as a solid or a substantially solid colloid within the reservoir 310. Since the aerosol-forming substrate 311 is stored as a solid, it is far less likely to leak or escape out of the reservoir 310 than a liquid aerosol-forming substrate 311. In view of this, an aerosol-generating article, aerosol-generating device or an aerosol-generating system that includes an aerosol-forming substrate 311 consisting of the formulation according to the invention has an improved shelf-life.

[0206] In addition, an aerosol-forming substrate 311 consisting of the formulation according to the invention melts into a liquid when it is heated during the normal heating cycle of an aerosol-generating article, aerosol-generating device or an aerosol-generating system. This means that the aerosol-forming substrate flows as a normal liquid aerosol-forming substrate and can be vaporised into an aerosol as normal. As discussed, depending on the specific design of the aerosol-generating article, aerosol generating device or aerosol generating system either a portion of the aerosol-forming substrate or the entire aerosol-forming substrate may melt during a heating cycle.

[0207] Furthermore, when an aerosol-forming substrate 311 consisting of the formulation according to the invention cools down after a heating cycle, it solidifies back into a solid and can therefore no longer flow out of the reservoir 310. This prevents leakage of the aerosol-forming substrate 311 between uses of the aerosol-generating article, aerosol-generating device or an aerosol-generating system.

[0208] FIG. 6 shows the average aerosolised collected mass in mg per puff for a range of different aerosol former compositions when the weight percent of propylene glycol (PG) is varied relative to the weight percent of vegetable glycerine (VG). For example, the data for “25% PGvsVG” is for a formulation comprising an aerosol former composition that contains 25 percent by weight propylene glycol and 75 percent by weight vegetable glycerine.

[0209] FIG. 7 is a graph showing average nicotine in mg per puff for a range of different aerosol former compositions when the weight percent of propylene glycol (PG) is varied relative to the weight percent of vegetable glycerine (VG). For example, the data for “25% PGvsVG” is for a formulation comprising an aerosol former composition that contains 25 percent by weight propylene glycol and 75 percent by weight vegetable glycerine.

[0210] FIG. 8 is a graph showing average nicotine percent for a range of different aerosol former compositions when the weight percent of propylene glycol (PG) is varied relative to the weight percent of vegetable glycerine (VG). For example, the data for “25% PGvsVG” is for a formulation comprising an aerosol former composition that contains 25 percent by weight propylene glycol and 75 percent by weight vegetable glycerine.

[0211] The data in the graphs shows that, as discussed above, by including propylene glycol as an aerosol former in a formulation that includes nicotine, there is an improvement in the nicotine content of the aerosol. For example, the highest weight percent of nicotine is when there is 5 weight percent of propylene glycol in the aerosol former. This improvement may be due to more efficient vaporisation of the nicotine because propylene glycol has a lower boiling point (188° C.) compared to glycerine (290° C.).

[0212] However, if there is high amount of propylene glycol in the formulation (for example 25 percent by weight propylene glycol) then the nicotine content of the aerosol decreases because the propylene glycol can be vaporised during a heating cycle. Therefore, it is advantageous to have a limited amount of propylene glycol in the nicotine formulation.

[0213] The exemplary embodiments described above are not intended to limit the scope of the claims. Other embodiments consistent with the exemplary embodiments described above will be apparent to those skilled in the art. Features described in relation to one embodiment may also be applicable to other embodiments.