Aerosol-generating film

Abstract

To provide an alternative aerosol-generating film that has improved geometrical stability.SOLUTION: The present invention provides an aerosol-generating film comprising: a cellulose-based film forming agent; a non-cellulose-based thickening agent; water; and a polyhydric alcohol. The content of water is less than about 30 wt.% and the content of polyhydric alcohol is at least about 25 wt.%.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an aerosol-generating film. The aerosol-generating film according to the present invention may find use as an aerosol-generating substrate for producing an inhalable aerosol upon heating, and may therefore be used as a component of an aerosol-generating article. [Background technology]

[0002] Aerosol-generating articles in which an aerosol-generating substrate, such as a nicotine- or tobacco-containing substrate, is heated rather than combusted therein, are known in the art. Typically, in such heated smoking articles, the aerosol is generated by transferring heat from a heat source to a physically separated aerosol-generating substrate or material, which may be located in contact with, within, around, or downstream of the heat source. During use of the aerosol-generating article, volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source and are entrained in the air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol.

[0003] Numerous prior art documents disclose aerosol generating devices for consuming aerosol-generating articles, including, for example, electrically heated aerosol generating devices in which the aerosol is generated by the transfer of heat from one or more electric heater elements of the aerosol generating device to an aerosol-generating substrate of a heated aerosol-generating article.

[0004] Substrates for heated aerosol generating articles have often been produced in the past using randomly oriented pieces, strands, or strips of tobacco material. Alternatively, rods for heated aerosol generating articles formed from an assembly of sheets of tobacco material are disclosed, by way of example, in International Patent Application No. WO 2012 / 164009.

[0005] WO 2011 / 101164 discloses an alternative rod for a heated aerosol generating article formed from strands of homogenized tobacco material, which may be formed by casting, rolling, calendering or extrusion of a mixture comprising particulate tobacco and at least one aerosol former to form a sheet of homogenized tobacco material. In an alternative embodiment, the rod of WO 2011 / 101164 may be formed from strands of homogenized tobacco material obtained by extruding a mixture comprising particulate tobacco and at least one aerosol former to form a continuous length of homogenized tobacco material.

[0006] Alternative forms of nicotine-containing substrates have also been disclosed. As an example, liquid nicotine compositions, often referred to as e-liquids, have been proposed. These liquid compositions may be heated, for example, by a coiled electrically resistive filament in an aerosol generating device.

[0007] This type of substrate may require particular attention in the manufacture of the container holding the liquid composition to prevent undesired leakage. To address this issue and simplify the overall manufacturing process, it has also been proposed to provide a gel composition containing nicotine that generates a nicotine-containing aerosol upon heating. As an example, WO 2018 / 019543 discloses a thermoreversible gel composition, i.e. a gel that becomes fluid when heated to a melting temperature and solidifies again into a gel at a gelling temperature. The gel is provided in a cartridge housing, and the cartridge may be discarded and replaced when the gel is consumed.

[0008] In order for a gel composition to generate a satisfactory amount of aerosol during use, it is desirable for the gel composition to include a significant amount of an aerosol former, such as glycerol. However, due to the plasticizing nature of glycerol, it can be difficult to provide a gel composition that provides good aerosol delivery during use, and which at the same time is geometrically stable, i.e., does not shrink significantly as the gel composition solidifies and settles into a film form.

[0009] Therefore, it would be desirable to provide alternative aerosol-generating films with improved geometric stability. It would also be desirable to provide alternative aerosol-generating films that are simple to prepare and are provided in a variety of forms, such as supported and unsupported. In addition, it would be desirable to provide aerosol-generating films that have a high aerosol former content so that they can be successfully used as an aerosol-generating substrate in an aerosol-generating article and are easier to dispose of after use or have reduced environmental impact. It would also be desirable to provide alternative aerosol-generating films that allow for easier adjustment of aerosol delivery. Summary of the Invention

[0010] Therefore, the present invention relates to an aerosol-generating film. The aerosol-generating film may include a cellulosic film former. The aerosol-generating film may further include a non-cellulosic thickener. The aerosol-generating film may also include water. The aerosol-generating film may include a polyhydric alcohol. The water content may be about 30 weight percent or less. The polyhydric alcohol content may be at least about 25 weight percent.

[0011] According to an embodiment of the present invention, there is provided an aerosol-generating film comprising a cellulosic film former, a non-cellulosic thickener, water, and a polyhydric alcohol, the water content being about 30 weight percent or less and the polyhydric alcohol content being at least about 25 weight percent.

[0012] According to another aspect of the invention there is provided the use of a film as set out above in an article for generating an inhalable aerosol upon heating.

[0013] According to a further aspect of the present invention there is provided an aerosol-generating article for generating an inhalable aerosol upon heating, the article comprising an aerosol-generating substrate comprising a film as set out above.

[0014] In this regard, the present invention also relates to a system including an aerosol generating device comprising one such aerosol-generating article, and an aerosol generating device comprising a power supply and control circuitry. By way of example, the aerosol generating device may be an electrically heated aerosol generating device having an internal heater element for heating an aerosol-generating substrate, including a film.

[0015] The aerosol generating system may advantageously comprise a consumable aerosol generating article comprising an aerosol-generating film, and a reusable aerosol generating device comprising a power source and control circuitry.The aerosol generating system may comprise an aerosol generating article comprising an aerosol-generating film, and an aerosol generating device comprising a heater assembly, a power source and control circuitry.The aerosol generating system may comprise an aerosol generating article comprising an aerosol-generating film and a heater assembly, and an aerosol generating device comprising a power source and control circuitry.

[0016] It will be appreciated that any feature described with respect to one aspect of the invention is equally applicable to any other aspect of the invention.

[0017] As used herein, the term "film" is used to describe a solid, layered element that has a thickness that is less than its width or length.

[0018] The film may be self-supporting, in other words, it may have cohesive and mechanical properties such that it can be separated from a supporting surface, even when obtained by casting a film-forming formulation onto the supporting surface.

[0019] Alternatively, the film may be placed on a support or sandwiched between other materials, which may enhance the mechanical stability of the film.

[0020] In the context of the present invention, the term "cellulosic film former" is used to describe a cellulosic polymer that has the ability to form a continuous film by itself, or in the presence of an auxiliary thickener.

[0021] As used herein in connection with the present invention, the term "non-cellulosic thickener" is used to describe a non-cellulosic material that, when added to an aqueous or non-aqueous liquid composition, increases the viscosity of the liquid composition without substantially altering other properties of the liquid composition. Thickeners may increase the stability and improve the suspension of ingredients in the liquid composition. Thickeners may also be referred to as "thickeners" or "rheology modifiers."

[0022] The term "aerosol-generating article" is used herein to mean an article in which an aerosol-generating substrate is heated to generate an aerosol and deliver it to a consumer. As used herein, the term "aerosol-generating substrate" means a substrate capable of releasing a volatile compound upon heating to generate an aerosol.

[0023] A conventional cigarette is lit when a user applies a flame to one end of the cigarette and draws air through the other end. Localized heat provided by the flame and oxygen in the air drawn through the cigarette ignites the end of the cigarette, and the resulting combustion produces inhalable smoke. In contrast, in heated aerosol-generating articles, the aerosol is generated by heating a flavor-generating substrate, such as a tobacco-derived substrate or a substrate containing an aerosol former and flavorants.

[0024] Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles that generate an aerosol by the transfer of heat from a combustible fuel element or heat source to a physically separated aerosol-forming material. For example, the aerosol-generating article according to the present invention may find particular use in an aerosol generating system that includes an electrically heated aerosol generator having an internal heater blade adapted to supply heat to a film.

[0025] As used herein, the term "aerosol-generating device" refers to a device that includes a heater element that interacts with the aerosol-generating film according to the present invention to generate an aerosol. During use, volatile compounds are released from the aerosol-generating film by heat transfer and are entrained in the air that is drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol, which is inhaled by the consumer.

[0026] Substrates for heated aerosol-generating articles typically include an "aerosol former," i.e., a compound or mixture of compounds that facilitates the formation of an aerosol during use and that is preferably substantially resistant to thermal decomposition at the use temperature of the aerosol-generating article. Examples of suitable aerosol formers include polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3-butanediol, glycerin, etc.), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.).

[0027] The polyhydric alcohols in the aerosol-generating films of the present invention are also aerosol formers within the meaning given above.

[0028] As used herein, the term "exposed surface area of ​​the film" is used to mean the cumulative surface area of ​​the various surfaces of an aerosol-generating film according to the present invention that may be exposed to gaseous airflow during use through an aerosol-generating article containing the film.

[0029] The term "film thickness" is used herein to mean the smallest distance measured between opposing substantially parallel surfaces of a film.

[0030] The thickness of the aerosol-generating film may correspond substantially to the thickness to which the corresponding film-forming composition was cast or extruded, because the cast or extruded film-forming composition does not substantially shrink during drying, despite loss of water.

[0031] The "weight of the film" according to the present invention generally corresponds to the weight of the components of the corresponding film-forming composition minus the weight of the water evaporated during the drying process. If the film is self-supporting, it can be weighed by itself. If the film is placed on a support, the film and support are weighed, and the weight of the support measured before deposition of the film is subtracted from the combined weight of the film and support.

[0032] Unless otherwise indicated, the percentages by weight (identified herein by the expression "weight percent") of the components of the aerosol-generating films listed herein are based on the total weight of the aerosol-generating film.

[0033] In contrast to existing aerosol-generating films and known orally soluble nicotine-containing films, in the film of the present invention, a cellulose-based film former (preferably HPMC) is combined with a non-cellulose-based thickener and a polyhydric alcohol (preferably glycerin). It has been observed that a significant amount of polyhydric alcohol (such as glycerin), often included in a film-forming composition as a plasticizer, can adversely affect the geometric stability of the composition when cast on a support surface and dried to form a film. The inventors have surprisingly found that using a cellulose-based film former in combination with a non-cellulose-based thickener can counteract this effect, making it easier to form a film with a predetermined geometric parameter (e.g., thickness, surface area, etc.) with high accuracy and reproducibility.

[0034] In particular, as described in more detail below, the inventors have surprisingly found that aerosol-generating films comprising 6 weight percent or more of a cellulosic film former, and preferably HPMC, are particularly stable. Thus, they substantially maintain their shape and mass when exposed to various environmental conditions, such as changes in relative humidity from 10% to 60%. As a result, such aerosol-generating films advantageously do not release a liquid phase during storage or shipping.

[0035] Furthermore, when heated in an aerosol generating device, the aerosol-generating films according to the present invention may emit an aerosol containing polyhydric alcohol and, if present, alkaloid compounds such as nicotine, without substantially releasing a liquid phase.

[0036] The present invention therefore advantageously provides films having significant polyhydric alcohol content that can be easily cast or extruded and solidified, starting from a composition having a gel-like texture. Because a significant proportion of polyhydric alcohol, particularly glycerin, can be provided in film form while at the same time providing fine control over the geometry of the film, the present invention advantageously provides films that may find use as aerosol-generating substrates in aerosol-generating articles designed to be heated to release an aerosol.

[0037] Upon heating, most of the film's components essentially evaporate. In fact, it is typically observed that only some residue of the cellulosic film former is left behind after use. Therefore, aerosol-generating articles incorporating substrates that include the film according to the present invention may be easier to dispose of and have improved environmental impact.

[0038] In addition, the inventors have surprisingly found that films according to the present invention can exhibit tensile strength values ​​that make them suitable for use as self-supporting substrates within aerosol-generating articles, making the films versatile and advantageously adaptable to be provided within aerosol-generating articles in a variety of shapes and arrangements.

[0039] By adjusting parameters such as the thickness of the film, the exposed surface area, or the content of species such as nicotine or other alkaloids or compounds, or plant materials or plant extracts or flavorants within the film, it is possible to finely control the delivery of the species in aerosol form to the consumer.

[0040] Furthermore, films according to the present invention can be manufactured in a continuous process that can be run quickly and efficiently, and can be conveniently integrated into existing production lines for the manufacture of heated aerosol-generating articles.

[0041] As briefly described above, the aerosol-generating films of the present invention include a cellulosic film-forming agent, a non-cellulosic thickener, water comprising up to about 30 percent by weight of the film, and a polyhydric alcohol comprising at least about 25 percent by weight of the film.

[0042] One such film can be formed from a film-forming composition containing the above components in predetermined weighed amounts. As an example, in a method of making a film according to the present invention, a film-forming composition may be provided that includes a cellulosic film former, a non-cellulosic thickener, at least about 30 weight percent water, and at least about 10 weight percent polyhydric alcohol.

[0043] In the first step, the cellulosic film-forming agent and the thickener are dissolved in water. To facilitate the achievement of complete dissolution, heat is preferably provided to the aqueous mixture or the aqueous mixture is stirred, or both. In the second step, the polyhydric alcohol is added, optionally with other ingredients as described in more detail below. In the third step, the film-forming composition thus obtained is applied onto a support surface, for example by casting or extrusion, and is preferably left to solidify at room temperature. In the fourth step, the water is evaporated by providing heat to the applied film-forming composition. This is essentially a drying step, and may preferably be carried out by heating the applied film-forming composition at a temperature of at least about 50 degrees Celsius. During the drying step, the water content of the applied film-forming composition is reduced until the film contains 30 weight percent water or less, in order to obtain an aerosol-generating film. The film may then be removed from the support surface.

[0044] In the aerosol-generating films according to the present invention, the cellulosic film former is preferably selected from the group consisting of hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), hydroxyethyl methylcellulose (HEMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), and combinations thereof.

[0045] More preferably, in the aerosol-generating films according to the present invention, the cellulosic film-forming agent is selected from the group consisting of hydroxypropylmethylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), and combinations thereof.

[0046] In a particularly preferred embodiment, the cellulosic film former is HPMC.

[0047] The aerosol-generating films according to the present invention may comprise at least about 3 weight percent of the cellulosic film-forming agent. The aerosol-generating films according to the present invention may comprise up to about 70 weight percent of the cellulosic film-forming agent. The aerosol-generating films according to the present invention may comprise from about 3 weight percent to about 70 weight percent of the cellulosic film-forming agent.

[0048] In a preferred embodiment, an aerosol-generating film according to the present invention comprises at least about 5 weight percent of a cellulosic film-forming agent.

[0049] More preferably, the aerosol-generating films according to the present invention comprise at least about 6 weight percent of the cellulosic film-forming agent. Even more preferably, the aerosol-generating films according to the present invention comprise at least about 10 weight percent of the cellulosic film-forming agent.

[0050] Preferably, the aerosol-generating film comprises at least about 14 weight percent of the cellulosic film-forming agent. More preferably, the aerosol-generating film comprises at least about 16 weight percent of the cellulosic film-forming agent. Even more preferably, the aerosol-generating film comprises at least about 18 weight percent of the cellulosic film-forming agent.

[0051] Additionally or alternatively, the aerosol-generating film preferably comprises about 26 weight percent or less of a cellulosic film former. More preferably, the aerosol-generating film comprises about 24 weight percent or less of a cellulosic film former. Even more preferably, the aerosol-generating film comprises about 22 weight percent or less of a cellulosic film former.

[0052] In particularly preferred embodiments, the aerosol-generating film comprises at least about 3 weight percent HPMC. Aerosol-generating films according to the present invention may comprise up to about 70 weight percent HPMC. Aerosol-generating films according to the present invention may comprise from about 3 weight percent to about 70 weight percent HPMC.

[0053] More preferably, aerosol-generating films according to the present invention comprise at least about 5 weight percent HPMC, even more preferably at least about 6 weight percent HPMC, and most preferably at least 10 weight percent HPMC.

[0054] In a preferred embodiment, the aerosol-generating film comprises at least about 14 weight percent HPMC. More preferably, the aerosol-generating film comprises at least about 16 weight percent HPMC. Even more preferably, the aerosol-generating film comprises at least about 18 weight percent HPMC. Additionally or alternatively, the aerosol-generating film preferably comprises no more than about 26 weight percent HPMC. More preferably, the aerosol-generating film comprises no more than about 24 weight percent HPMC. Even more preferably, the aerosol-generating film comprises no more than about 22 weight percent HPMC.

[0055] In some preferred embodiments, the aerosol-generating film comprises from about 14 weight percent to about 26 weight percent HPMC. More preferably, the aerosol-generating film comprises from about 16 weight percent to about 24 weight percent HPMC. Even more preferably, the aerosol-generating film comprises from about 18 weight percent to about 22 weight percent HPMC.

[0056] In the aerosol-generating films according to the present invention, the non-cellulosic thickener may be selected from the group consisting of agar, xanthan gum, alginate, gellan gum, carrageenan, guar gum, gum arabic, locust bean gum, pectin, starch, and combinations thereof.

[0057] In the aerosol-generating films according to the present invention, the non-cellulosic thickener is preferably selected from the group consisting of agar, xanthan gum, alginates, and combinations thereof. In a preferred embodiment, the non-cellulosic thickener is agar.

[0058] Aerosol-generating films according to the present invention may comprise up to about 50 percent by weight of a non-cellulosic thickener. In a preferred embodiment, aerosol-generating films according to the present invention may comprise up to about 50 percent by weight of agar.

[0059] Preferably, the aerosol-generating film comprises at least about 1 weight percent of the non-cellulosic thickener. More preferably, the aerosol-generating film comprises at least about 2 weight percent of the non-cellulosic thickener. Even more preferably, the aerosol-generating film comprises at least about 3 weight percent of the non-cellulosic thickener. Additionally or alternatively, the aerosol-generating film preferably comprises no more than about 10 weight percent of the non-cellulosic thickener. More preferably, the aerosol-generating film comprises no more than about 8 weight percent of the non-cellulosic thickener. Even more preferably, the aerosol-generating film comprises no more than about 6 weight percent of the non-cellulosic thickener.

[0060] In some preferred embodiments, the aerosol-generating film comprises from about 1 weight percent to about 10 weight percent of the non-cellulosic thickener. More preferably, the aerosol-generating film comprises from about 2 weight percent to about 8 weight percent of the non-cellulosic thickener. Even more preferably, the aerosol-generating film comprises from about 3 weight percent to about 6 weight percent of the non-cellulosic thickener.

[0061] In a preferred embodiment, the aerosol-generating film comprises at least about 1 weight percent agar. More preferably, the aerosol-generating film comprises at least about 2 weight percent agar. Even more preferably, the aerosol-generating film comprises at least about 3 weight percent agar. Additionally or alternatively, the aerosol-generating film preferably comprises no more than about 10 weight percent agar. More preferably, the aerosol-generating film comprises no more than about 8 weight percent agar. Even more preferably, the aerosol-generating film comprises no more than about 6 weight percent agar.

[0062] In some preferred embodiments, the aerosol-generating film comprises from about 1 weight percent to about 10 weight percent agar. More preferably, the aerosol-generating film comprises from about 2 weight percent to about 8 weight percent agar. Even more preferably, the aerosol-generating film comprises from about 3 weight percent to about 6 weight percent agar.

[0063] Suitable polyhydric alcohols as aerosol formers include, but are not limited to, propylene glycol, triethylene glycol, 1,3-butanediol, and glycerin. In the aerosol-generating films according to the present invention, the polyhydric alcohol is preferably selected from the group consisting of glycerin, propylene glycol, and combinations thereof. In a particularly preferred embodiment, the polyhydric alcohol is glycerin.

[0064] As briefly set forth above, the aerosol-generating films according to the present invention contain at least about 25 weight percent polyhydric alcohol. More preferably, the aerosol-generating films contain at least about 30 weight percent polyhydric alcohol, and even more preferably, at least about 35 weight percent polyhydric alcohol.

[0065] In particularly preferred embodiments, the aerosol-generating film comprises at least about 40 weight percent polyhydric alcohol, even more preferably at least about 42 weight percent polyhydric alcohol, and most preferably at least about 44 weight percent polyhydric alcohol.

[0066] Additionally or alternatively, the aerosol-generating film preferably comprises less than about 90 weight percent polyhydric alcohol. More preferably, the aerosol-generating film comprises less than about 85 weight percent polyhydric alcohol. Even more preferably, the aerosol-generating film comprises less than about 80 weight percent polyhydric alcohol. In some preferred embodiments, the aerosol-generating film preferably comprises less than about 75 weight percent polyhydric alcohol, more preferably less than 70 weight percent polyhydric alcohol, and even more preferably less than 65 weight percent polyhydric alcohol. In some particularly preferred embodiments, the aerosol-generating film comprises less than 60 weight percent polyhydric alcohol.

[0067] In a preferred embodiment, the aerosol-generating film according to the present invention contains at least about 25 weight percent glycerin, more preferably at least about 30 weight percent glycerin, and even more preferably at least about 35 weight percent glycerin.

[0068] In a particularly preferred embodiment, the aerosol-generating film comprises at least about 40 weight percent glycerin, even more preferably at least about 42 weight percent glycerin, and most preferably at least about 44 weight percent glycerin.

[0069] Additionally or alternatively, the aerosol-generating film preferably comprises less than about 90 weight percent glycerin. More preferably, the aerosol-generating film preferably comprises less than about 85 weight percent glycerin. Even more preferably, the aerosol-generating film comprises less than about 80 weight percent glycerin. In some preferred embodiments, the aerosol-generating film preferably comprises less than about 75 weight percent glycerin, more preferably less than 70 weight percent glycerin, and even more preferably less than 65 weight percent glycerin. In some particularly preferred embodiments, the aerosol-generating film comprises less than 60 weight percent glycerin.

[0070] In the aerosol-generating film, the ratio between the weight of the cellulosic film former and the weight of the polyhydric alcohol is preferably at least about 0.1, more preferably at least about 0.2, and even more preferably at least about 0.3. Additionally or alternatively, in the aerosol-generating film, the ratio between the weight of the cellulosic film former and the weight of the polyhydric alcohol is preferably about 1 or less.

[0071] In a preferred embodiment, the aerosol-generating film has a ratio between the weight of the cellulosic film-forming agent and the weight of the polyhydric alcohol of from about 0.1 to about 1.

[0072] In a preferred embodiment, the aerosol-generating film has a ratio between the weight of HPMC and the weight of glycerin of at least about 0.1, more preferably at least about 0.2, and even more preferably at least about 0.3. Additionally or alternatively, the aerosol-generating film has a ratio between the weight of HPMC and the weight of glycerin of no more than about 1.

[0073] In a preferred embodiment, the aerosol-generating film has a ratio between the weight of HPMC and the weight of glycerin of about 0.1 to about 1.

[0074] In some particularly preferred embodiments, the aerosol-generating film contains from about 1 to about 10 grams of HPMC per 10 grams of glycerin.

[0075] In the aerosol-generating film, the ratio between the weight of the non-cellulosic thickener and the weight of the polyhydric alcohol is preferably at least about 0.05, more preferably at least 0.1, and even more preferably at least 0.2. Additionally or alternatively, in the aerosol-generating film, the ratio between the weight of the non-cellulosic thickener and the weight of the polyhydric alcohol is preferably no greater than about 0.5.

[0076] In a preferred embodiment, in the aerosol-generating film, the ratio between the weight of the non-cellulosic thickener and the weight of the polyhydric alcohol is from about 0.1 to about 0.5.

[0077] In the aerosol-generating film, the ratio between the weight of the agar and the weight of the glycerin is preferably at least about 0.05, more preferably at least 0.1, and even more preferably at least 0.2. Additionally or alternatively, in the aerosol-generating film, the ratio between the weight of the agar and the weight of the glycerin is preferably no greater than about 0.5.

[0078] In a preferred embodiment, in the aerosol-generating film, the ratio between the weight of agar and the weight of glycerin is from about 0.1 to about 0.5.

[0079] In some particularly preferred embodiments, the aerosol-generating film contains from 0.5 to about 5 grams of agar per 10 grams of glycerin.

[0080] In some embodiments, the aerosol-generating film comprises an alkaloid compound, a cannabinoid compound, or both.

[0081] As used herein in connection with the present invention, the term "alkaloid compound" is used to describe any one of a class of naturally occurring organic compounds that contain one or more basic nitrogen atoms. Generally, alkaloids contain at least one nitrogen atom in an amine-type structure. This nitrogen atom or another nitrogen atom in the molecule of the alkaloid compound may be active as a base in an acid-base reaction. Most alkaloid compounds have one or more of their nitrogen atoms as part of a ring system, such as a heterocyclic ring. In nature, alkaloid compounds are found primarily in plants, especially common in certain families of flowering plants. However, some alkaloid compounds are found in animal species and fungi. In the context of the present invention, the term "alkaloid compound" is used to describe both naturally occurring and synthetically produced alkaloid compounds.

[0082] Suitable alkaloid compounds for use in the aerosol-generating films according to the present invention include nicotine and anatabine.

[0083] As used herein in connection with the present invention, the term "cannabinoid compound" is used to describe any one of a class of naturally occurring compounds found in parts of the cannabis plant, namely hemp (Cannabis sativa species), Indian hemp (Cannabis indica species), and Cannabis ruderalis species. Cannabinoid compounds are particularly concentrated in the female flower heads. Naturally occurring cannabinoid compounds in the cannabis plant include tetrahydrocannabinol (THC) and cannabidiol (CBD). In the context of the present invention, the term "cannabinoid compound" is used to describe both naturally occurring and synthetically produced cannabinoid compounds.

[0084] Cannabinoid compounds suitable for use in the aerosol-generating films according to the present invention include tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiol (CBD), cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), cannabigerol monomethyl ether (CBGM), cannabivarin (CBV), cannabidivarin (CBDV), tetrahydrocannabivarin (THCV), cannabichromene (CBC), cannabicyclol (CBL), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabiersoin (CBE), cannabicitran (CBT).

[0085] In general, the aerosol-generating film may contain up to about 10 weight percent of alkaloid compounds or cannabinoid compounds, or both. Considering the application of the aerosol-generating film of the present invention as a substrate in an aerosol-generating article, this is advantageous because the content of alkaloid compounds or cannabinoid compounds, or both, in the film can be increased and adjusted to optimize the delivery of alkaloid compounds or cannabinoid compounds, or both, in aerosol form to consumers. Compared to existing aerosol-generating substrates based on the use of plant materials, this may advantageously allow a higher content of alkaloid compounds or cannabinoid compounds, or both, per volume of substrate (film) or per weight of substrate (film), which may be desirable from a manufacturing point of view.

[0086] Preferably, the aerosol-generating film comprises at least about 0.5 weight percent of an alkaloid compound or a cannabinoid compound, or both.Thus, it is preferred that the aerosol-generating film comprises at least about 0.5 weight percent of an alkaloid compound, or at least 0.5 weight percent of a cannabinoid compound, or at least about 0.5 weight percent of a combination of an alkaloid compound and a cannabinoid compound.

[0087] More preferably, the aerosol-generating film comprises at least about 1 weight percent of an alkaloid compound or cannabinoid compound, or both. Even more preferably, the aerosol-generating film comprises at least about 2 weight percent of an alkaloid compound or cannabinoid compound, or both. Additionally or alternatively, the aerosol-generating film preferably comprises less than about 6 weight percent of an alkaloid compound or cannabinoid compound, or both. More preferably, the aerosol-generating film comprises less than about 5 weight percent of an alkaloid compound or cannabinoid compound, or both. Even more preferably, the aerosol-generating film comprises less than about 4 weight percent of an alkaloid compound or cannabinoid compound, or both.

[0088] In a preferred embodiment, the aerosol-generating film contains from about 0.5 weight percent to about 10 weight percent of an alkaloid compound or a cannabinoid compound, or both, more preferably from about 1 weight percent to about 6 weight percent of an alkaloid compound or a cannabinoid compound, or both, and even more preferably from about 2 weight percent to about 5 weight percent of an alkaloid compound or a cannabinoid compound, or both.

[0089] In some embodiments, the aerosol-generating film comprises one or more of a cannabinoid and an alkaloid compound, including nicotine or anatabine, hi some preferred embodiments, the aerosol-generating film comprises nicotine.

[0090] As used herein in connection with the present invention, the term "nicotine" is used to describe nicotine, nicotine base, or nicotine salts. In embodiments where the aerosol-generating film comprises nicotine base or nicotine salts, the amounts of nicotine recited herein are the amounts of free base nicotine or the amounts of protonated nicotine, respectively.

[0091] The aerosol-generating film may contain natural or synthetic nicotine.

[0092] The aerosol-generating film may include one or more monobasic nicotine salts.

[0093] As used herein in connection with the present invention, the term "monobasic nicotine salt" is used to describe nicotine salts of monobasic acids.

[0094] Generally, aerosol-generating film may contain up to about 10 weight percent nicotine.Considering the application of the aerosol-generating film of the present invention as a substrate in an aerosol-generating article, this is advantageous because the nicotine content in the film can be increased and adjusted to optimize the delivery of nicotine in aerosol form to consumers.Compared to existing aerosol-generating substrates based on the use of tobacco plants, this may advantageously allow a higher nicotine content per volume of substrate (film) or per weight of substrate (film), which may be desirable from the viewpoint of manufacturing.

[0095] Preferably, the aerosol-generating film comprises at least about 0.5 weight percent nicotine. More preferably, the aerosol-generating film comprises at least about 1 weight percent nicotine. Even more preferably, the aerosol-generating film comprises at least about 2 weight percent nicotine. Additionally or alternatively, the aerosol-generating film preferably comprises less than about 6 weight percent nicotine. More preferably, the aerosol-generating film comprises less than about 5 weight percent nicotine. Even more preferably, the aerosol-generating film comprises less than about 4 weight percent nicotine.

[0096] In preferred embodiments, the aerosol-generating film comprises from about 0.5 weight percent to about 10 weight percent nicotine, more preferably from about 1 weight percent to about 6 weight percent nicotine, and even more preferably from about 2 weight percent to about 5 weight percent nicotine.

[0097] In some preferred embodiments, the aerosol-generating film comprises a cannabinoid compound. Preferably, the cannabinoid compound is selected from CBD and THC. More preferably, the cannabinoid compound is CBD.

[0098] The aerosol-generating film may contain up to about 10 weight percent CBD. Preferably, the aerosol-generating film contains at least about 0.5 weight percent CBD. More preferably, the aerosol-generating film contains at least about 1 weight percent CBD. Even more preferably, the aerosol-generating film contains at least about 2 weight percent CBD. Additionally or alternatively, the aerosol-generating film preferably contains less than about 6 weight percent CBD. More preferably, the aerosol-generating film contains less than about 5 weight percent CBD. Even more preferably, the aerosol-generating film contains less than about 4 weight percent CBD.

[0099] In a preferred embodiment, the aerosol-generating film comprises from about 0.5 weight percent to about 10 weight percent CBD, more preferably from about 1 weight percent to about 6 weight percent CBD, and even more preferably from about 2 weight percent to about 5 weight percent CBD.

[0100] The aerosol-generating film may be a substantially tobacco-free aerosol-generating film.

[0101] As used herein in connection with the present invention, the term "substantially tobacco-free aerosol-generating film" describes an aerosol-generating film having a tobacco content of less than 1 weight percent. For example, the aerosol-generating film may have a tobacco content of less than about 0.75 weight percent, less than about 0.5 weight percent, or less than about 0.25 weight percent.

[0102] The aerosol-generating film may be a tobacco-free aerosol-generating film.

[0103] As used herein in connection with the present invention, the term "tobacco-free aerosol-generating film" describes an aerosol-generating film that has zero percent tobacco content by weight.

[0104] In some embodiments, the aerosol-generating film comprises tobacco material or non-tobacco plant material or plant extracts. By way of example, the aerosol-generating film may include tobacco particles, such as tobacco lamina particles, as well as particles of other plants, such as cloves and eucalyptus.

[0105] In a preferred embodiment, the aerosol-generating film comprises an acid. More preferably, the aerosol-generating film comprises one or more organic acids. Even more preferably, the aerosol-generating film comprises one or more carboxylic acids. In a particularly preferred embodiment, the acid is lactic acid or levulinic acid.

[0106] The inclusion of an acid is particularly preferred in the embodiment of the aerosol-generating film that includes nicotine. This is because it has been observed that the presence of an acid can stabilize species dissolved in the film-forming composition, such as nicotine and other plant extracts. Without wishing to be bound by theory, it is understood that when nicotine is provided in a salt form, the acid can interact with the nicotine molecule, which substantially prevents nicotine from evaporating during the drying operation. Therefore, the loss of nicotine during the production of the film can be minimized, and advantageously, a higher and more controlled nicotine delivery to the consumer can be ensured.

[0107] Preferably, the aerosol-generating film comprises at least about 0.25 weight percent acid. More preferably, the aerosol-generating film comprises at least about 0.5 weight percent acid. Even more preferably, the aerosol-generating film comprises at least about 1 weight percent acid. Additionally or alternatively, the aerosol-generating film preferably comprises less than about 3.5 weight percent acid. More preferably, the aerosol-generating film comprises less than about 3 weight percent acid. Even more preferably, the aerosol-generating film comprises less than about 2.5 weight percent acid.

[0108] In a preferred embodiment, the aerosol-generating film comprises from about 0.25 weight percent to about 3.5 weight percent acid. More preferably, the aerosol-generating film comprises from about 0.5 weight percent to about 3 weight percent acid. Even more preferably, the aerosol-generating film comprises from about 1 weight percent to about 2.5 weight percent acid.

[0109] In a preferred embodiment, the aerosol-generating film comprises at least about 0.25 weight percent levulinic acid. More preferably, the aerosol-generating film comprises at least about 0.5 weight percent levulinic acid. Even more preferably, the aerosol-generating film comprises at least about 1 weight percent levulinic acid. Additionally or alternatively, the aerosol-generating film preferably comprises less than about 3.5 weight percent levulinic acid. More preferably, the aerosol-generating film comprises less than about 3 weight percent levulinic acid. Even more preferably, the aerosol-generating film comprises less than about 2.5 weight percent levulinic acid.

[0110] In a preferred embodiment, the aerosol-generating film comprises from about 0.25 weight percent to about 3.5 weight percent levulinic acid. More preferably, the aerosol-generating film comprises from about 0.5 weight percent to about 3 weight percent levulinic acid. Even more preferably, the aerosol-generating film comprises from about 1 weight percent to about 2.5 weight percent levulinic acid.

[0111] In a preferred embodiment, the aerosol-generating film comprises at least about 0.25 weight percent lactic acid. More preferably, the aerosol-generating film comprises at least about 0.5 weight percent lactic acid. Even more preferably, the aerosol-generating film comprises at least about 1 weight percent lactic acid. Additionally or alternatively, the aerosol-generating film preferably comprises less than about 3.5 weight percent lactic acid. More preferably, the aerosol-generating film comprises less than about 3 weight percent lactic acid. Even more preferably, the aerosol-generating film comprises less than about 2.5 weight percent lactic acid.

[0112] In a preferred embodiment, the aerosol-generating film comprises from about 0.25 weight percent to about 3.5 weight percent lactic acid. More preferably, the aerosol-generating film comprises from about 0.5 weight percent to about 3 weight percent lactic acid. Even more preferably, the aerosol-generating film comprises from about 1 weight percent to about 2.5 weight percent lactic acid.

[0113] The aerosol-generating film may optionally include a flavoring agent. In some embodiments, the aerosol-generating film may include up to about 2 weight percent flavoring agent. As an example, the aerosol-generating film may include menthol. Other suitable flavoring agents may include one or more of terpenes, terpenoids, eugenol, and eucalyptol.

[0114] In a particularly preferred embodiment, the aerosol-generating film consists of about 14 weight percent to about 26 weight percent HPMC, about 3 weight percent to about 6 weight percent agar, about 0.5 weight percent to about 4 weight percent nicotine, about 0.25 weight percent to about 3 weight percent acid, about 44 weight percent to about 60 weight percent glycerin, 0 weight percent to about 2 weight percent flavorant, and the balance water.

[0115] Aerosol-generating films having the above-described compositions have been found to be particularly easy to form with good reproducibility, and have been found to provide a satisfactory delivery of nicotine to the consumer when heated to generate an aerosol.Furthermore, it has been found that the tendency of nicotine to evaporate during manufacture (particularly during the drying step leading to the formation of the film itself from the corresponding gel-like film-forming composition) is substantially countered by the inclusion of an acid.

[0116] Aerosol-generating films according to the present invention preferably have a thickness of less than about 1 millimeter. More preferably, the aerosol-generating films have a thickness of less than about 0.75 millimeters. Even more preferably, the aerosol-generating films have a thickness of less than about 0.5 millimeters.

[0117] In particularly preferred embodiments, a layer of the film-forming composition is formed having a thickness of about 400 micrometers or less, more preferably about 300 micrometers or less, and even more preferably about 200 micrometers or less.

[0118] Additionally, or alternatively, the aerosol-generating film has a thickness of at least about 0.1 millimeters.

[0119] In preferred embodiments, the aerosol-generating film has a thickness of about 0.1 millimeter to about 1 millimeter, more preferably about 0.1 millimeter to about 0.75 millimeter, and even more preferably about 0.1 millimeter to about 0.5 millimeter. In particularly preferred embodiments, a layer of the film-forming composition is formed having a thickness of about 50 micrometers to 400 micrometers, and more preferably about 100 micrometers to 200 micrometers.

[0120] This is advantageous because the aerosol-generating film obtained under these circumstances has a thickness comparable to that of the cast leaf, or reconstituted tobacco, or other homogenized tobacco material used to form the substrate in the aerosol-generating article. Moreover, aerosol-generating films having a thickness falling within the above-mentioned ranges have been found to have sufficient strength while at the same time having a low weight, which helps to reduce the thermal inertia of the aerosol-generating substrate during use of the aerosol-generating article that includes the film as a substrate.

[0121] The thickness of the aerosol-generating film may be effectively controlled by controlling the thickness of the layer of the film-forming composition applied on the flat surface during production. This may be done, for example, by casting. Casting may be a simple way of processing the film-forming composition to obtain a film. This is a batch procedure that is typically used on a small scale, but continuous casting methods (e.g., based on knife coating or tape casting) may be used on an industrial scale, since the film-forming composition may be prepared on a continuous carrier tape, which allows for effective control of the layer thickness. Alternatively, the film-forming composition may be formed into a layer having a predetermined thickness by extrusion.

[0122] Preferably, the film according to the invention has a basis weight of at least about 100 grams per square meter. More preferably, the film according to the invention has a basis weight of at least about 120 grams per square meter. Even more preferably, the film according to the invention has a basis weight of at least about 140 grams per square meter.

[0123] Preferably, the film according to the invention has a basis weight of 300 grams per square meter or less. More preferably, the film according to the invention has a basis weight of 280 grams per square meter or less. Even more preferably, the film according to the invention has a basis weight of 260 grams per square meter or less.

[0124] In a preferred embodiment, the film according to the present invention has a basis weight of about 100 g / m2 to about 300 g / m2, more preferably about 120 g / m2 to about 280 g / m2, and even more preferably about 140 g / m2 to about 260 g / m2.In a particularly preferred embodiment, the film according to the present invention has a basis weight of about 200 g / m2.

[0125] Films such as those described above may find use as aerosol-generating substrates for aerosol-generating articles of the type in which the substrate is heated to release an inhalable aerosol, as opposed to articles in which the substrate is combusted to produce inhalable smoke.

[0126] Because the films according to the invention are simple to manufacture and because a finely controlled amount of the corresponding film-forming composition may be applied onto a supporting surface to form the film, and because the composition of the film, in particular the content of polyhydric alcohol and, if present, nicotine or plant material (including both tobacco and non-tobacco plant materials), may be finely tuned and finely controlled, the aerosol-generating films according to the invention are versatile and may be used as substrates in numerous forms. For example, the films according to the invention may be used as aerosol-generating substrates in supported as well as self-supporting forms. Furthermore, the films according to the invention may be used in different shapes and sizes, whereby the exposed surface area of ​​the film may be adjusted and tailored to specific uses and needs.

[0127] As an example, an aerosol-generating film according to the invention may be provided on the inner surface of a tubular carrier element such that the outer surface of the aerosol-generating film is exposed inside the longitudinal internal channel defined by the tubular carrier element. Upon heating, aerosol may be generated from the aerosol-generating film, which is then released into the internal channel and may be drawn through the aerosol-generating article into the mouth of a consumer.

[0128] Alternatively, an aerosol-generating film according to the invention may be configured to form a self-supporting rod and not require additional support structures within the aerosol-generating substrate. As an example, one or more aerosol-generating films according to the invention may be assembled to form a rod of aerosol-generating substrate. Alternatively, multiple films according to the invention may be stacked into a rod of aerosol-generating substrate. In a further alternative arrangement, multiple strips or pieces of an aerosol-generating film according to the invention may be aligned, assembled and rolled to form a rod of aerosol-generating substrate. Alternatively, the strips or pieces of the aerosol-generating film may be randomly oriented within the rod.

[0129] The invention will now be further described with reference to the following. EXAMPLES

[0130] Table 1 below sets forth the composition of the aerosol-generating film, along with the formulation of the film-forming composition from which the aerosol-generating film is obtained. [Table 1]

[0131] The aerosol-generating film is manufactured based on the composition in Table 1. For this purpose, HPMC and agar are mixed in glycerin using stirring until dissolved. Then, water, nicotine, and levulinic acid are added under stirring until dissolved. A layer of the film-forming composition thus obtained is formed on a flat surface and left to solidify. The layer of the film-forming composition is formed with a thickness of about 210 micrometers. The layer of the film-forming composition thus formed is heated to about 140 degrees Celsius for about 8 minutes.

[0132] The aerosol-generating film obtained after drying is solid. In other words, the aerosol-generating film has a stable size and shape and does not flow. The term "stable" is used herein to indicate that the aerosol-generating film according to the present invention substantially maintains its shape and mass when exposed to various environmental conditions. As such, it does not substantially release or absorb water when exposed to standard temperatures and pressures with varying relative humidities from about 10 percent to about 60 percent.

[0133] This is particularly advantageous as it ensures that the films according to the present invention do not release the liquid phase during storage or transportation (eg from the manufacturing facility to the point of sale).

[0134] The aerosol-generating film prepared as described above is heated to a temperature of about 180 degrees Celsius to about 250 degrees Celsius to simulate the conditions of use in an aerosol generating device. The nicotine, glycerin, and water contained within the film evaporate. The nicotine and glycerin condense to form an inhalable aerosol. The aerosol-generating film shrinks slightly and its volume decreases. However, the film remains solid and maintains its film form. It appears to harden slightly and take on a darker, brownish color.

[0135] 1. A substantially tobacco-free aerosol-generating film, comprising: A cellulosic film former; and A non-cellulosic thickener; Water, Nicotine and and a polyhydric alcohol, an aerosol-generating film having a water content of less than about 30 weight percent and a polyhydric alcohol content of at least about 25 weight percent; 2. The aerosol-generating film of 1, wherein the polyhydric alcohol content is at least about 40 weight percent. 3. The aerosol-generating film of 1 or 2, wherein the cellulose-based film-forming agent is selected from the group consisting of hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), and combinations thereof. 4. An aerosol-generating film as described in any one of claims 1 to 3, comprising at least 10 percent by weight of the cellulosic film-forming agent. 5. An aerosol-generating film described in any one of claims 1 to 4, wherein the non-cellulosic thickening agent is selected from the group consisting of agar, xanthan gum, alginate, and combinations thereof. 6. An aerosol-generating film as described in any one of claims 1 to 5, comprising at least 3 weight percent of the non-cellulosic thickener. 7. The aerosol-generating film of any one of claims 1 to 6, wherein the polyhydric alcohol is selected from the group consisting of glycerin, propylene glycol, and combinations thereof. 8. An aerosol-generating film according to any one of claims 1 to 7, further comprising an alkaloid compound, a cannabinoid compound, or both. 9. An aerosol-generating film according to any one of 1 to 8, further comprising a non-tobacco plant material or plant extract. 10. The aerosol-generating film of any one of claims 1 to 9, further comprising an acid. 11. The aerosol-generating film of claim 11, wherein the acid is lactic acid or levulinic acid. 12. An aerosol-generating film according to any one of claims 1 to 11, comprising a flavouring agent. 13. About 14 weight percent to about 26 weight percent HPMC; About 3 weight percent to about 6 weight percent agar; About 0.5 weight percent to about 4 weight percent nicotine; about 0.25 weight percent to about 3 weight percent acid; About 44 weight percent to about 60 weight percent glycerin; 0 weight percent to about 2 weight percent flavoring; 13. The aerosol-generating film according to any one of claims 1 to 12, wherein the remainder is water. 14. An aerosol-generating film according to any one of claims 1 to 13, wherein the film has a thickness of less than about 1 millimeter. 15. An aerosol-generating film as described in any one of claims 1 to 14, wherein the film has a thickness of at least about 0.1 millimeters. 16. Use of a film according to any one of 1 to 16 as an aerosol-generating substrate in an article for generating an inhalable aerosol upon heating. 17. An aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article comprising an aerosol-generating substrate comprising the film according to any one of 1 to 16.

Claims

1. 1. An aerosol-generating film having a tobacco content of less than 1 weight percent, comprising: A cellulosic film former; and A non-cellulosic thickener; Water, Nicotine and and a polyhydric alcohol, the cellulosic film former content is at least 14 weight percent and not more than 26 weight percent; an aerosol-generating film having a water content of less than 30 weight percent and a polyhydric alcohol content of at least 30 weight percent;

2. 2. The aerosol-generating film of claim 1, wherein the polyhydric alcohol content is at least 40 percent by weight.

3. 3. The aerosol-generating film of claim 1 or 2, wherein the cellulosic film-forming agent is selected from the group consisting of hydroxypropylmethylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), and combinations thereof.

4. 4. The aerosol-generating film of claim 1, wherein the non-cellulosic thickener is present in an amount of from 1 percent by weight to 10 percent by weight.

5. 5. The aerosol-generating film of claim 1, wherein the non-cellulosic thickening agent is selected from the group consisting of agar, xanthan gum, alginate, and combinations thereof.

6. 6. The aerosol-generating film of claim 1, comprising at least 3 percent by weight of the non-cellulosic thickener.

7. 7. The aerosol-generating film of claim 1, wherein the polyhydric alcohol is selected from the group consisting of glycerin, propylene glycol, and combinations thereof.

8. 8. An aerosol-generating film according to any preceding claim, further comprising a cannabinoid compound.

9. 9. The aerosol-generating film of any one of claims 1 to 8, further comprising a non-tobacco plant material or plant extract.

10. 10. The aerosol-generating film of claim 1, further comprising an acid.

11. 11. The aerosol-generating film of claim 10, wherein the acid is lactic acid or levulinic acid.

12. 12. The aerosol-generating film of any one of claims 1 to 11, comprising a flavourant.

13. 14 weight percent to 26 weight percent HPMC; 3 weight percent to 6 weight percent agar; 0.5 weight percent to 4 weight percent nicotine; 0.25 weight percent to 3 weight percent acid; 44 to 60 percent by weight of glycerin; 0 to 2 weight percent flavoring agent; The aerosol-generating film of any one of claims 1 to 12, wherein the remainder is water.

14. 14. An aerosol-generating film according to any one of the preceding claims, wherein the aerosol-generating film has a thickness of less than 1 millimetre.

15. An aerosol-generating film according to any one of the preceding claims, wherein the aerosol-generating film has a thickness of at least 0.1 millimetres.

16. Use of an aerosol-generating film according to any one of claims 1 to 15 as an aerosol-generating substrate in an article for generating an inhalable aerosol upon heating.

17. 16. An aerosol-generating article for generating an inhalable aerosol on heating, the aerosol-generating article comprising an aerosol-generating substrate comprising the aerosol-generating film according to any one of claims 1 to 15.

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