Aerosol generating article containing carboxylic acid

Abstract

An aerosol generating article (10) is provided for generating an inhalable aerosol when heated. The aerosol generating article (10) comprises an aerosol generating element (12) containing a nicotine-containing aerosol generating substrate and a downstream section (17) located downstream of the aerosol generating element (12). The downstream section (17) contains a carboxylic acid selected from the group consisting of citric acid, benzoic acid, fumaric acid, lactic acid, and combinations thereof.

Description

Technical Field

[0001] The present invention relates to an aerosol-generating article comprising an aerosol-generating element and adapted to generate an inhalable aerosol upon heating. In particular, the present invention relates to an aerosol-generating article comprising an aerosol-generating element including a nicotine-containing aerosol-generating substrate. Aspects of the present disclosure further relate to an aerosol-generating system comprising an electrically-operated aerosol-generating device used to heat an aerosol-generating article of the above type.

Background Art

[0002] Aerosol-generating articles comprising an aerosol-generating substrate, such as a tobacco-containing substrate, that are heated rather than combusted are known in the art. Typically, in such heated smoking articles, an 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.

[0003] Several aerosol-generating devices for heating aerosol-generating articles have been disclosed in the art. Such devices include, for example, electrically heated aerosol-generating devices in which an aerosol is generated by heat transfer from one or more electrical heater elements of the aerosol-generating device to the aerosol-generating element of the aerosol-generating article. For example, electrically heated devices have been proposed that include an internal heater blade adapted to be inserted into a substrate. As an alternative, inductively heatable consumables containing a substrate and a susceptor disposed within the substrate have also been proposed. As another alternative, it may be an electrically heated device comprising an external heater that heats the substrate from the outside of the consumable, and the external heater may be resistive or inductive. For this purpose, the aerosol-generating article is partially received within the heating cavity of the aerosol-generating device such that the upstream end of the aerosol-generating article is inserted into the cavity while the downstream end of the aerosol-generating article protrudes outside the cavity.

[0004] Conventionally, substrates for heated tobacco products have generally been manufactured using randomly oriented tobacco material fragments, strands, or strips, or cut fillers. As an alternative, rods for heated tobacco products formed from aggregated nicotine containing aggregated sheets or films or gels of tobacco material (cast leaf) are proposed, for example, in WO-A-2012 / 164009. Alternative rods for heated tobacco products are known from WO-A-2011 / 101164. These rods are formed from strands of homogenized tobacco material and can be formed by casting, rolling, calendering, or extruding a mixture containing particulate tobacco and at least one aerosol-forming agent to form sheets of homogenized tobacco material. In alternative embodiments, rods may also be formed from strands of homogenized tobacco material obtained by extruding a mixture containing particulate tobacco and at least one aerosol-forming agent to form a continuous length of homogenized tobacco material. Solid, nicotine-containing, non-tobacco substrates are also known. For example, WO-A-2015 / 082652 describes an aerosol generating rod comprising an assembly of sheets of non-tobacco material enclosed in a wrapper. The sheets of non-tobacco material are textured or crimped and comprise an adsorbent substrate, a nicotine salt, and an aerosol-forming body.

[0005] During the use of an aerosol-generating article, volatile compounds are released from the aerosol-generating substrate by heat transfer from a heat source and are carried into the air drawn through the aerosol-generating article. When the released compounds cool, they condense to form aerosols.

[0006] In aerosol-generating articles where the aerosol-generating substrate contains tobacco or nicotine in other forms, the aerosol may induce a low to moderate irritation response in the throat of an adult smoker and a sensation of warmth or intensity in their chest. The irritation of the aerosol, as understood as the sensation experienced in the throat of an adult smoker, and the intensity of the aerosol, as typically understood as the sensation experienced in the chest of an adult smoker, can vary based on the properties and composition of the aerosol-generating substrate from which the aerosol is formed, including but not limited to the nicotine concentration in the aerosol. In some cases, higher levels of nicotine supply can increase the irritation and cause discomfort to the consumer's throat.

[0007] Therefore, it would be desirable to provide a novel and improved aerosol generating article that is adapted to suppress or at least reduce such unpleasant sensations without significantly affecting aerosol delivery levels or taste. [Overview of the project]

[0008] This disclosure relates to an aerosol generating article for generating an inhalable aerosol when heated.

[0009] Aerosol-generating articles may be equipped with aerosol-generating elements.

[0010] The aerosol generating element may include a nicotine-containing aerosol generating substrate.

[0011] The nicotine-containing aerosol generating substrate may be a solid nicotine-containing aerosol generating substrate. The aerosol generating element may include a downstream section located downstream of the aerosol generating element.

[0012] The downstream section of the aerosol-generating article may contain a carboxylic acid.

[0013] The carboxylic acid can be selected from the group consisting of citric acid, benzoic acid, fumaric acid, lactic acid, and combinations thereof.

[0014] For example, an aerosol generating article may have a mouthpiece in a downstream section of the aerosol generating article, such as a mouthpiece containing a segment of filter material, and the carboxylic acid may be provided at a position within the mouthpiece.

[0015] This disclosure also relates to an aerosol generating system comprising an electrically operated aerosol generating device and an aerosol generating article comprising an aerosol generating element including an aerosol generating substrate.

[0016] The aerosol generating apparatus may include means for heating the aerosol generating substrate to a temperature sufficient to generate aerosols from the aerosol generating substrate.

[0017] According to a first aspect of the present invention, an aerosol generating article is provided for generating an inhalable aerosol when heated, the aerosol generating article comprising: an aerosol generating element comprising a nicotine-containing aerosol generating substrate; and a downstream section located downstream of the aerosol generating element, comprising a carboxylic acid selected from the group consisting of citric acid, benzoic acid, fumaric acid, lactic acid and combinations thereof.

[0018] A second aspect of the present invention provides an aerosol generating system comprising an aerosol generating device and an aerosol generating article according to the first aspect of the present invention. The aerosol generating device includes means for heating the aerosol generating substrate to a temperature sufficient to generate an aerosol from the aerosol generating substrate.

[0019] As used herein in connection with the present invention, the term "aerosol-generating article" is used to describe an article comprising an aerosol-generating substrate that generates and delivers a heated, inhalable aerosol to a user.

[0020] Where used herein in connection with the present invention, the term “aerosol-generating substrate” is used to describe a substrate comprising an aerosol-forming material capable of releasing an aerosol in response to heating of a volatile compound capable of generating an aerosol. In particular, an aerosol-generating substrate is a solid aerosol-generating substrate. Solid nicotine-containing aerosol-generating substrates include both tobacco-containing and non-tobacco substrates. Tobacco-containing substrates include tobacco plant material (e.g., shredded tobacco leaf material, or homogenized tobacco material made from particles of tobacco leaf material, as described in more detail below). Non-tobacco substrates may include solid carrier material (e.g., plant material derived from plants other than tobacco, or cellulosic material such as paper) to which a nicotine-containing composition is applied as a coating, by impregnation, or by other means.

[0021] Conventional cigarettes are ignited when the user holds a flame to one end of the cigarette and draws air through the other end. Localized heat provided by the flame and the 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-producing substrate, such as tobacco, without combustion of the flavor-producing substrate. Known heated aerosol generating articles include, for example, electrically heated aerosol generating articles and aerosol generating articles in which the aerosol is generated by heat transfer from a heat source to a physically separated aerosol-forming material.

[0022] The aerosol generating article according to the present invention has a particular application in an aerosol generating system comprising an aerosol generating device having a heating chamber in which the aerosol generating article is received, such that heat can be supplied to the aerosol generating substrate. This may be achieved by providing one or more heating elements arranged around the periphery of the heating chamber, which are resistance-heated or induction-heated. Alternatively, this may also be achieved by resistance-heated blade-shaped components of the aerosol generating device that are inserted into the aerosol generating substrate when the aerosol generating article is inserted into the heating chamber.

[0023] According to yet another alternative, the susceptor element may be provided within an aerosol generating substrate, and the aerosol generator may have an inductor for generating an alternating electromagnetic field or a fluctuating electromagnetic field. When the aerosol generating article engages with the aerosol generator, the fluctuating electromagnetic field generated by the inductor induces a current in the susceptor element, thereby heating the susceptor element. The electrically operated aerosol generator is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of 1 to 5 kiloamperes / meter (kA / m), preferably 2 to 3 kA / m, for example, about 2.5 kA / m.

[0024] The aerosol generating article according to the present invention has a proximal end through which the aerosol exits the aerosol generating article for delivery to the user during use. The proximal end of the aerosol generating article may also be referred to as the downstream end or mouth end of the aerosol generating article. During use, the user directly or indirectly inhales the proximal end of the aerosol generating article in order to inhale the aerosol generated by the aerosol generating article.

[0025] The aerosol-generating article according to the present invention has a distal end. The distal end is the opposite side of the proximal end. The distal end of the aerosol-generating article is also sometimes referred to as the upstream end of the aerosol-generating article.

[0026] The components of the aerosol-generating article according to the present invention can be described as being upstream or downstream of each other based on their relative positions between the proximal end and the distal end of the aerosol-generating article.

[0027] As used herein in connection with this specification, the term "longitudinal direction" is used to describe the direction between the upstream end and the downstream end of the aerosol-generating article. During use, air is drawn longitudinally through the aerosol-generating article.

[0028] As used herein in connection with the present invention, the term "length" is used to describe the maximum dimension in the longitudinal direction of the aerosol-generating article or a component of the aerosol-generating article.

[0029] As used herein in connection with the present invention, the term "transverse direction" is used to describe a direction perpendicular to the longitudinal direction. Unless otherwise specified, the "cross-section" of the aerosol-generating article or a component of the aerosol-generating article refers to a cross-section.

[0030] As used herein in connection with the present invention, the term "width" refers to the maximum dimension in the transverse direction of the aerosol-generating article or a component of the aerosol-generating article. When the aerosol-generating article has a substantially circular cross-section, the width of the aerosol-generating article corresponds to the diameter of the aerosol-generating article. When a component of the aerosol-generating article has a substantially circular cross-section, the width of the component of the aerosol-generating article corresponds to the diameter of the component of the aerosol-generating article.

[0031] As used herein in connection with the present invention, the term “hollow tubular element” is used to describe a substantially cylindrical element having a tubular space along its longitudinal axis. The tubular portion may have a substantially circular, substantially oval, or substantially elliptical cross-section. The tubular space may have a substantially circular, substantially oval, or substantially elliptical cross-section. Specifically, the term “hollow tubular element” is used to describe an element that defines at least one airflow conduit establishing an uninterrupted fluid communication between the upstream end of the hollow tubular element and the downstream end of the hollow tubular element.

[0032] The term "carboxylic acid," as used herein, is used to define a classification of organic compounds containing a carboxyl group, in which a carbon atom is bonded to an oxygen atom by a double bond and to a hydroxyl group by a single bond.

[0033] As briefly described above, an aerosol generating article according to one aspect of the present invention comprises an aerosol generating element comprising an aerosol generating substrate. In contrast to known aerosol generating articles, the aerosol generating article further comprises a downstream section located downstream of the aerosol generating element, the downstream section comprising a carboxylic acid selected from the group consisting of citric acid, benzoic acid, fumaric acid, lactic acid, and combinations thereof.

[0034] The inventors have found that providing at least one of the above-mentioned carboxylic acids downstream of an aerosol-generating article can favorably attenuate, or even substantially prevent, the occurrence of the unpleasant throat sensation known to consumers to be associated with aerosol irritation, without significantly affecting the overall taste of the aerosol.

[0035] Nicotine in aerosols typically exists in the form of unprotonated nicotine (also called free base nicotine), which tends to be more volatile than protonated nicotine and is therefore delivered to consumers in amounts that can lead to increased perceived throat irritation. While we do not wish to be bound by theory, it is understood that in the carboxylic acids mentioned above, the acidity of the hydroxyl proton is enhanced by the presence of the carbonyl group, and therefore these acids exhibit high reactivity with weak bases such as volatile unprotonated nicotine present in aerosols.

[0036] Therefore, providing one or more of the carboxylic acids listed above at a position in the aerosol-generating article downstream of the aerosol-generating substrate has the beneficial effect that free base nicotine in the aerosol interacts and reacts with the acidic proton of the carboxylic acid before reaching the downstream end of the article. In this way, the free base nicotine is replaced, at least partially, with a less volatile protonated form before the aerosol reaches the consumer's mouth. The protonated form of nicotine tends to bind to the particulate phase of the aerosol provided to the consumer rather than the gaseous phase. As a result, perceived throat irritation is advantageously reduced.

[0037] Citric acid, benzoic acid, fumaric acid, and lactic acid are all widely present in nature and are generally biodegradable. Therefore, incorporating one or more of these carboxylic acids into aerosol-generating articles does not substantially increase the overall environmental impact.

[0038] The aforementioned carboxylic acids can be readily incorporated into one or more components of the downstream section of an aerosol-generating article before combining various components to form the article. As will be described in more detail below, this requires only minor modifications to existing manufacturing processes. Therefore, the aerosol-generating articles according to the present invention can be manufactured efficiently and quickly, advantageously without requiring extensive modifications to existing equipment.

[0039] As briefly described above, in the aerosol generating article according to the present invention, one or more of citric acid, benzoic acid, fumaric acid, and lactic acid may be provided in the downstream section. The downstream section of the aerosol generating article includes one or more components, each of which is arranged axially aligned with the aerosol generating element.

[0040] For example, the downstream section of an aerosol-generating article may include a mouthpiece filter element (MPF) at the downstream end of the aerosol-generating article.

[0041] In some embodiments, the MPF may be provided immediately downstream of the aerosol generating element. Preferably, the MPF is provided adjacent to the aerosol generating element, with the downstream end of the aerosol generating element in contact with the upstream end of the MPF.

[0042] In other embodiments, the downstream section may include one or more intermediate components provided between the aerosol generating element and the MPF. For example, as will be described in more detail below, the downstream section may comprise one or more of the following: support elements, aerosol cooling elements, etc.

[0043] In a preferred embodiment, the downstream section of the aerosol-generating article includes an MPF, and the carboxylic acid is provided at a location within the MPF.

[0044] The MPF can advantageously provide support for carboxylic acids so that they can rapidly interact with aerosol volatile species. For example, carboxylic acids can be dispersed within fibrous filter material forming the plug elements of the MPF. Providing the carboxylic acid at a location within the MPF is considered particularly advantageous from a manufacturing standpoint because it is easy to adapt existing processes for producing MPFs containing additives to the incorporation of carboxylic acids according to the present invention, as will be discussed in more detail below.

[0045] In another embodiment, the downstream section of the aerosol-generating article comprises a support element, and the carboxylic acid is provided at a position within the support element.

[0046] Typically, in an aerosol-generating article, the support element is provided immediately downstream of the aerosol-generating element. Preferably, the support element is provided adjacent to the aerosol-generating element, with the downstream end of the aerosol-generating element in contact with the upstream end of the support element.

[0047] Supplying carboxylic acids to supporting elements, particularly elements adjacent to aerosol-generating elements, has the advantage that aerosol volatile species can begin interacting with the hydroxyl protons of the carboxylic acid functional group immediately after being released from the aerosol-generating substrate. As a result, there is a greater likelihood that more protonated species will have time to accumulate in the particle phase before the aerosol reaches the downstream end of the article.

[0048] As briefly described above, in certain embodiments, the downstream section of the aerosol-generating article may include an aerosol cooling element. Typically, the aerosol cooling element is located at an intermediate position between the aerosol-generating element and the downstream end of the article, preferably upstream of the MPF.

[0049] In some cases, the aerosol cooling element may be provided immediately downstream of the aerosol generating element, preferably adjacent to it. Thus, the downstream end of the aerosol generating element abuts against the upstream end of the aerosol cooling element.

[0050] In other cases, the aerosol cooling element may be positioned immediately downstream of the support element, which in turn is located immediately downstream of the aerosol generating element. For example, the support element may be adjacent to the aerosol generating element, and the aerosol cooling element may be adjacent to the support element, so that the three components of such an aerosol generating article are in a continuous contact arrangement.

[0051] In one embodiment, the downstream section of the aerosol generating article comprises an aerosol cooling element adjacent to the aerosol generating element, and the carboxylic acid is provided at a position within the aerosol cooling element.

[0052] In a further embodiment, the downstream section comprises a support element downstream of the aerosol generating element and an aerosol cooling element downstream of the support element, wherein the carboxylic acid is provided at a position within the aerosol cooling element.

[0053] Providing a carboxylic acid at a specific location within an aerosol cooling element may have certain advantages.

[0054] In certain embodiments, aerosol cooling elements of an aerosol-generating article may generally be configured to provide a fairly large surface area for heat exchange within a relatively small volume, so that the temperature of the aerosol can be reduced as efficiently and rapidly as possible. For example, an aerosol cooling element comprising an aggregate of sheets of a polymer material such as polylactic acid has been described, the aggregate of sheets defining a plurality of elongated channels extending along the long axis of the article. Providing a carboxylic acid at one location of such an aerosol cooling element has the advantage that the carboxylic acid can be applied to a fairly large surface that is exposed to the aerosol flowing through the aerosol cooling element during use, for example. As a result, the large surface area of ​​the aerosol cooling element may also be advantageous for the occurrence of effective interactions between aerosol volatile species and carboxylic acid molecules.

[0055] In other embodiments, the aerosol cooling element may be configured to rely on the introduction of air from outside the aerosol-generating article into a cavity defined within the aerosol cooling element in order to lower the temperature of the aerosol. This can result in relatively rapid cooling of the aerosol, which may be associated with the rapid formation of new nuclei of aerosol particles. Providing a carboxylic acid at a location within one such aerosol cooling element may have the advantage that the carboxylic acid may be available to react with the aerosol volatile species just before it condenses to form new nuclei or binds to already formed aerosol particles, thus enhancing the irritation reduction function.

[0056] In some embodiments, the aerosol-generating article further includes an upstream section located upstream of the aerosol-generating element. Providing an upstream section may have several advantages, which will be discussed in more detail below. In one preferred embodiment, the upstream section does not contain a carboxylic acid.

[0057] As is evident from the above description, the present invention provides several different possible arrangements with respect to the precise location of the carboxylic acid within the aerosol-generating article. Generally, providing the carboxylic acid closer to or further from the downstream end of the aerosol-generating article can affect the amount of interaction between nicotine and the carboxylic acid in the aerosol. Providing the carboxylic acid further downstream from the aerosol-generating element is advantageous in that the carboxylic acid may interact with residual free base nicotine still remaining in the aerosol as it approaches the mouth end of the article, which can maximize the proportion of free base nicotine that responds to its protonated form. As a result, it is advantageous that the aerosol irritation perceived by adult smokers can be minimized.

[0058] In the aerosol-generating article according to the present invention, the carboxylic acid may be provided in an amount of at least 0.05 milligrams in the downstream section of the aerosol-generating article. Preferably, the carboxylic acid is provided in an amount of at least 0.1 milligrams in the downstream section of the aerosol-generating article. More preferably, the carboxylic acid is provided in an amount of at least 0.5 milligrams in the downstream section of the aerosol-generating article.

[0059] In a preferred embodiment, the carboxylic acid is supplied to the downstream section of the aerosol generating article in an amount of at least 1 milligram. Preferably, the carboxylic acid is supplied to the downstream section of the aerosol generating article in an amount of at least 5 milligrams. More preferably, the carboxylic acid is supplied to the downstream section of the aerosol generating article in an amount of at least 15 milligrams. Even more preferably, the carboxylic acid is supplied to the downstream section of the aerosol generating article in an amount of at least 25 milligrams. Most preferably, the carboxylic acid is supplied to the downstream section of the aerosol generating article in an amount of at least 50 milligrams.

[0060] In a preferred embodiment, the carboxylic acid is supplied to the downstream section of the aerosol-generating article in an amount of at least 75 milligrams. Preferably, the carboxylic acid is supplied to the downstream section of the aerosol-generating article in an amount of at least 100 milligrams.

[0061] In the aerosol generating article according to the present invention, the carboxylic acid may be provided in an amount of 400 milligrams or less in the downstream section of the aerosol generating article. Preferably, the carboxylic acid may be provided in an amount of at least 350 milligrams or less in the downstream section of the aerosol generating article. Preferably, the carboxylic acid may be provided in an amount of at least 250 milligrams or less in the downstream section of the aerosol generating article. More preferably, the carboxylic acid may be provided in an amount of at least 200 milligrams or less in the downstream section of the aerosol generating article. Even more preferably, the carboxylic acid may be provided in an amount of at least 150 milligrams or less in the downstream section of the aerosol generating article.

[0062] In some embodiments, the carboxylic acid may be supplied in an amount of 0.05 to 200 milligrams to the downstream section of the aerosol generating article. Preferably, the carboxylic acid may be supplied in an amount of 0.1 to 200 milligrams to the downstream section of the aerosol generating article. Preferably, the carboxylic acid may be supplied in an amount of 0.5 to 200 milligrams to the downstream section of the aerosol generating article. More preferably, the carboxylic acid may be supplied in an amount of 1 to 200 milligrams to the downstream section of the aerosol generating article. More preferably, the carboxylic acid may be supplied in an amount of 5 to 200 milligrams to the downstream section of the aerosol generating article. Even more preferably, the carboxylic acid may be supplied in an amount of 15 to 200 milligrams to the downstream section of the aerosol generating article. Even more preferably, the carboxylic acid may be supplied in an amount of 25 to 200 milligrams to the downstream section of the aerosol generating article. Most preferably, the carboxylic acid may be supplied in an amount of 50 to 200 milligrams to the downstream section of the aerosol generating article.

[0063] In some embodiments, the carboxylic acid may be supplied in an amount of 0.05 to 150 milligrams to the downstream section of the aerosol generating article. Preferably, the carboxylic acid may be supplied in an amount of 0.1 to 150 milligrams to the downstream section of the aerosol generating article. Preferably, the carboxylic acid may be supplied in an amount of 0.5 to 150 milligrams to the downstream section of the aerosol generating article. More preferably, the carboxylic acid may be supplied in an amount of 1 to 150 milligrams to the downstream section of the aerosol generating article. More preferably, the carboxylic acid may be supplied in an amount of 5 to 150 milligrams to the downstream section of the aerosol generating article. Even more preferably, the carboxylic acid may be supplied in an amount of 15 to 150 milligrams to the downstream section of the aerosol generating article. Even more preferably, the carboxylic acid may be supplied in an amount of 25 to 150 milligrams to the downstream section of the aerosol generating article. Most preferably, the carboxylic acid may be supplied in an amount of 50 to 150 milligrams to the downstream section of the aerosol generating article.

[0064] In the aerosol-generating article according to the present invention, the total amount of carboxylic acid may be at least 2.6 micromoles. Preferably, the total amount of carboxylic acid is at least 5 micromoles. More preferably, the total amount of carboxylic acid is at least 40 micromoles. Even more preferably, the total amount of carboxylic acid is at least 122 micromoles. In a more preferred embodiment, the total amount of carboxylic acid is at least 215 micromoles. In a particular preferred embodiment, the total amount of carboxylic acid is at least 520 micromoles.

[0065] In the aerosol-generating article according to the present invention, the total amount of carboxylic acid may be 2700 micromoles or less. Preferably, the total amount of carboxylic acid is 1700 micromoles or less. More preferably, the total amount of carboxylic acid is 1220 micromoles or less. In a particular preferred embodiment, the total amount of carboxylic acid is 555 micromoles or less.

[0066] In some embodiments, the total amount of carboxylic acid in the downstream section of the aerosol-generating article is 2.6 micromoles to 2700 micromoles, preferably 5 micromoles to 2700 micromoles, more preferably 40 micromoles to 2700 micromoles, even more preferably 122 micromoles to 2700 micromoles, particularly preferably 215 micromoles to 2700 micromoles, or 520 micromoles to 2700 micromoles.

[0067] In other embodiments, the total amount of carboxylic acid in the downstream section of the aerosol-generating article is 2.6 micromoles to 1700 micromoles, preferably 5 micromoles to 1700 micromoles, more preferably 40 micromoles to 1700 micromoles, even more preferably 122 micromoles to 1700 micromoles, particularly preferably 215 micromoles to 1700 micromoles, or 520 micromoles to 1700 micromoles.

[0068] In further embodiments, the total amount of carboxylic acid in the downstream section of the aerosol-generating article is 2.6 micromoles to 1220 micromoles, preferably 5 micromoles to 1220 micromoles, more preferably 40 micromoles to 1220 micromoles, even more preferably 122 micromoles to 1220 micromoles, particularly preferably 215 micromoles to 1220 micromoles, or 520 micromoles to 1220 micromoles.

[0069] In further embodiments, the total amount of carboxylic acid in the downstream section of the aerosol generating article is 2.6 micromoles to 555 micromoles, preferably 5 micromoles to 555 micromoles, more preferably 40 micromoles to 555 micromoles, even more preferably 122 micromoles to 555 micromoles, particularly preferably 215 micromoles to 555 micromoles, or 520 micromoles to 555 micromoles.

[0070] As described above, in certain embodiments, the downstream section comprises a mouthpiece filter (MPF), and the carboxylic acid is supplied to a position within the MPF.

[0071] In some preferred embodiments, the carboxylic acid is provided in an amount of at least 0.05 milligrams in the MPF. Preferably, the carboxylic acid is provided in an amount of at least 0.1 milligrams in the MPF. More preferably, the carboxylic acid is provided in an amount of at least 0.5 milligrams in the MPF.

[0072] In a preferred embodiment, the carboxylic acid is provided in an amount of at least 1 milligram in the MPF. Preferably, the carboxylic acid is provided in an amount of at least 5 milligrams in the MPF. More preferably, the carboxylic acid is provided in an amount of at least 15 milligrams in the MPF. Even more preferably, the carboxylic acid is provided in an amount of at least 25 milligrams in the MPF. Most preferably, the carboxylic acid is provided in an amount of at least 50 milligrams in the MPF.

[0073] In a preferred embodiment, the carboxylic acid is provided in an amount of at least 75 milligrams in the MPF. Preferably, the carboxylic acid is provided in an amount of at least 100 milligrams in the MPF.

[0074] In some embodiments, the carboxylic acid may be provided in an amount of 400 milligrams or less in the MPF. Preferably, the carboxylic acid is provided in an amount of 350 milligrams or less in the MPF. Preferably, the carboxylic acid is provided in an amount of 250 milligrams or less in the MPF. More preferably, the carboxylic acid is provided in an amount of 200 milligrams or less in the MPF. Even more preferably, the carboxylic acid is provided in an amount of 150 milligrams or less in the MPF.

[0075] In some embodiments, the carboxylic acid may be provided in an amount of 0.05 to 200 milligrams per MPF, preferably 0.1 to 200 milligrams per MPF, more preferably 0.5 to 200 milligrams per MPF, and even more preferably 1 to 200 milligrams per MPF. In certain preferred embodiments, the carboxylic acid may be provided in an amount of 5 to 200 milligrams per MPF, preferably 15 to 200 milligrams per MPF, more preferably 25 to 200 milligrams per MPF, and even more preferably 50 to 200 milligrams per MPF.

[0076] In some embodiments, the carboxylic acid may be provided in an amount of 0.05 to 150 milligrams per MPF, preferably 0.1 to 150 milligrams per MPF, more preferably 0.5 to 150 milligrams per MPF, and even more preferably 1 to 150 milligrams per MPF. In certain preferred embodiments, the carboxylic acid may be provided in an amount of 5 to 150 milligrams per MPF, preferably 15 to 150 milligrams per MPF, more preferably 25 to 150 milligrams per MPF, and even more preferably 50 to 150 milligrams per MPF.

[0077] In some embodiments, the total amount of carboxylic acid may be at least 2.6 micromoles in the MPF. Preferably, the total amount of carboxylic acid is at least 5 micromoles in the MPF. More preferably, the total amount of carboxylic acid is at least 40 micromoles in the MPF. Even more preferably, the total amount of carboxylic acid is at least 122 micromoles in the MPF. In a more preferred embodiment, the total amount of carboxylic acid is at least 215 micromoles in the MPF. In a particular preferred embodiment, the total amount of carboxylic acid is at least 520 micromoles in the MPF.

[0078] In some embodiments, the total amount of carboxylic acid may be 2700 micromoles or less in the MPF. Preferably, the total amount of carboxylic acid is 1700 micromoles or less in the MPF. More preferably, the total amount of carboxylic acid is 1220 micromoles or less in the MPF. In a particular preferred embodiment, the total amount of carboxylic acid is 555 micromoles or less in the MPF.

[0079] In some embodiments, the total amount of carboxylic acid in the MPF is 2.6 micromoles to 2700 micromoles, preferably 5 micromoles to 2700 micromoles, more preferably 40 micromoles to 2700 micromoles, even more preferably 122 micromoles to 2700 micromoles, particularly preferably 215 micromoles to 2700 micromoles, or 520 micromoles to 2700 micromoles.

[0080] In other embodiments, the total amount of carboxylic acid in the MPF is 2.6 micromoles to 1700 micromoles, preferably 5 micromoles to 1700 micromoles, more preferably 40 micromoles to 1700 micromoles, even more preferably 122 micromoles to 1700 micromoles, particularly preferably 215 micromoles to 1700 micromoles, or 520 micromoles to 1700 micromoles.

[0081] In further embodiments, the total amount of carboxylic acid in the MPF is 2.6 micromoles to 1220 micromoles, preferably 5 micromoles to 1220 micromoles, more preferably 40 micromoles to 1220 micromoles, even more preferably 122 micromoles to 1220 micromoles, particularly preferably 215 micromoles to 1220 micromoles, or 520 micromoles to 1220 micromoles.

[0082] In further embodiments, the total amount of carboxylic acid in the MPF is 2.6 micromoles to 555 micromoles, preferably 5 micromoles to 555 micromoles, more preferably 40 micromoles to 555 micromoles, even more preferably 122 micromoles to 555 micromoles, particularly preferably 215 micromoles to 555 micromoles, or 520 micromoles to 555 micromoles.

[0083] In some embodiments, the total amount of carboxylic acid is at least 0.5 micromoles per millimeter of MPF. Preferably, the total amount of carboxylic acid is at least 1 micromoles per millimeter of MPF. Preferably, the total amount of carboxylic acid is at least 6 micromoles per millimeter of MPF. More preferably, the total amount of carboxylic acid is at least 18 micromoles per millimeter of MPF. In a preferred embodiment, the total amount of carboxylic acid is at least 31 micromoles per millimeter of MPF. In a particular preferred embodiment, the total amount of carboxylic acid is at least 80 micromoles per millimeter of MPF.

[0084] In some embodiments, the total amount of carboxylic acid is 390 micromoles or less per millimeter of MPF. Preferably, the total amount of carboxylic acid is 250 micromoles or less per millimeter of MPF. More preferably, the total amount of carboxylic acid is 185 micromoles or less per millimeter of MPF. In preferred embodiments, the total amount of carboxylic acid is 120 micromoles or less per millimeter of MPF.

[0085] In some embodiments, the total amount of carboxylic acid is 0.5 micromoles to 390 micromoles per millimeter of MPF, preferably 1 micromoles to 390 micromoles per millimeter of MPF, more preferably 6 micromoles to 390 micromoles per millimeter of MPF, even more preferably 31 micromoles to 390 micromoles per millimeter of MPF, and particularly preferably 80 micromoles to 390 micromoles per millimeter of MPF.

[0086] In some embodiments, the total amount of carboxylic acid is 0.5 micromoles to 250 micromoles per millimeter of MPF, preferably 1 micromoles to 250 micromoles per millimeter of MPF, more preferably 6 micromoles to 250 micromoles per millimeter of MPF, even more preferably 31 micromoles to 250 micromoles per millimeter of MPF, and particularly preferably 80 micromoles to 250 micromoles per millimeter of MPF.

[0087] In some embodiments, the total amount of carboxylic acid is 0.5 to 185 micromoles per millimeter of MPF, preferably 1 to 185 micromoles per millimeter of MPF, more preferably 6 to 185 micromoles per millimeter of MPF, even more preferably 31 to 185 micromoles per millimeter of MPF, and particularly preferably 80 to 185 micromoles per millimeter of MPF.

[0088] In some embodiments, the total amount of carboxylic acid is 0.5 to 120 micromoles per millimeter of MPF, preferably 1 to 120 micromoles per millimeter of MPF, more preferably 6 to 120 micromoles per millimeter of MPF, even more preferably 31 to 120 micromoles per millimeter of MPF, and particularly preferably 80 to 120 micromoles per millimeter of MPF.

[0089] In certain preferred embodiments, the carboxylic acid is citric acid.

[0090] In some embodiments, citric acid is supplied to the downstream section of the aerosol-generating article in an amount of at least 0.05 milligrams. Preferably, citric acid is supplied to the downstream section of the aerosol-generating article in an amount of at least 0.1 milligrams. More preferably, citric acid is supplied to the downstream section of the aerosol-generating article in an amount of at least 0.5 milligrams.

[0091] In a preferred embodiment, citric acid is provided in an amount of at least 1 milligram to the downstream section of the aerosol generating article. Preferably, citric acid is provided in an amount of at least 5 milligrams to the downstream section of the aerosol generating article. More preferably, citric acid is provided in an amount of at least 15 milligrams to the downstream section of the aerosol generating article. Even more preferably, citric acid is provided in an amount of at least 25 milligrams to the downstream section of the aerosol generating article. In a particular preferred embodiment, citric acid is provided in an amount of at least 50 milligrams to the downstream section of the aerosol generating article.

[0092] In certain embodiments, citric acid is supplied to the downstream section of the aerosol-generating article in an amount of at least 75 milligrams. Preferably, citric acid is supplied to the downstream section of the aerosol-generating article in an amount of at least 100 milligrams.

[0093] In the aerosol generating article according to the present invention, citric acid may be provided in an amount of 400 milligrams or less in the downstream section of the aerosol generating article. Preferably, citric acid may be provided in an amount of at least 350 milligrams or less in the downstream section of the aerosol generating article. Preferably, citric acid may be provided in an amount of at least 250 milligrams or less in the downstream section of the aerosol generating article. More preferably, citric acid may be provided in an amount of at least 200 milligrams or less in the downstream section of the aerosol generating article. Even more preferably, citric acid may be provided in an amount of at least 150 milligrams or less in the downstream section of the aerosol generating article.

[0094] In some embodiments, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 0.05 to 200 milligrams. Preferably, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 0.1 to 200 milligrams. More preferably, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 0.5 to 200 milligrams. Even more preferably, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 1 to 200 milligrams. In certain preferred embodiments, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 5 to 200 milligrams. Preferably, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 15 to 200 milligrams. More preferably, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 25 to 200 milligrams. Even more preferably, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 50 to 200 milligrams.

[0095] In some embodiments, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 0.05 to 150 milligrams. Preferably, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 0.1 to 150 milligrams. More preferably, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 0.5 to 150 milligrams. Even more preferably, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 1 to 150 milligrams. In certain preferred embodiments, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 5 to 150 milligrams. Preferably, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 15 to 150 milligrams. More preferably, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 25 to 150 milligrams. Even more preferably, citric acid is supplied to the downstream section of the aerosol generating article in an amount of 50 to 150 milligrams.

[0096] In certain embodiments, the total amount of citric acid is at least 3 micromoles in the downstream section. Preferably, the total amount of citric acid is at least 5 micromoles in the downstream section. More preferably, the total amount of citric acid is at least 25 micromoles in the downstream section. Even more preferably, the total amount of citric acid is at least 80 micromoles in the downstream section. In a more preferred embodiment, the total amount of citric acid is at least 140 micromoles in the downstream section. In a particular preferred embodiment, the total amount of citric acid is at least 260 micromoles in the downstream section.

[0097] In some embodiments, the total amount of citric acid is 1300 micromoles or less in the downstream section. Preferably, the total amount of citric acid is 1040 micromoles or less in the downstream section. More preferably, the total amount of citric acid is 780 micromoles or less in the downstream section. In a particular preferred embodiment, the total amount of citric acid is 520 micromoles or less in the downstream section.

[0098] In some embodiments, the total amount of citric acid in the downstream section of the aerosol-generating article is 3 micromoles to 1300 micromoles, preferably 5 micromoles to 1300 micromoles, more preferably 25 micromoles to 1300 micromoles, even more preferably 80 micromoles to 1300 micromoles, particularly preferably 140 micromoles to 1300 micromoles, or 260 micromoles to 1300 micromoles, or 520 micromoles to 1300 micromoles.

[0099] In other embodiments, the total amount of citric acid in the downstream section of the aerosol-generating article is 3 micromoles to 1040 micromoles, preferably 5 micromoles to 1040 micromoles, more preferably 25 micromoles to 1040 micromoles, even more preferably 80 micromoles to 1040 micromoles, particularly preferably 130 micromoles to 1040 micromoles, or 260 micromoles to 1040 micromoles, or 520 micromoles to 1040 micromoles.

[0100] In further embodiments, the total amount of citric acid in the downstream section of the aerosol-generating article is 3 micromoles to 780 micromoles, preferably 5 micromoles to 780 micromoles, more preferably 25 micromoles to 780 micromoles, even more preferably 80 micromoles to 780 micromoles, particularly preferably 130 micromoles to 780 micromoles, or 260 micromoles to 780 micromoles, or 520 micromoles to 780 micromoles.

[0101] In certain embodiments, citric acid is provided in an amount of at least 0.05 milligrams in the MPF. Preferably, citric acid is provided in an amount of at least 0.1 milligrams in the MPF. More preferably, citric acid is provided in an amount of at least 0.5 milligrams in the MPF.

[0102] In a preferred embodiment, citric acid is provided in an amount of at least 1 milligram in the MPF. Preferably, citric acid is provided in an amount of at least 5 milligrams in the MPF. More preferably, citric acid is provided in an amount of at least 15 milligrams in the MPF. Even more preferably, citric acid is provided in an amount of at least 25 milligrams in the MPF. In a particular preferred embodiment, citric acid is provided in an amount of at least 50 milligrams in the MPF.

[0103] In some embodiments, citric acid is provided in an amount of at least 75 milligrams in the MPF. Preferably, citric acid is provided in an amount of at least 100 milligrams in the MPF.

[0104] In certain embodiments, citric acid is provided in an amount of 400 milligrams or less in the MPF. Preferably, citric acid is provided in an amount of 350 milligrams or less in the MPF. More preferably, citric acid is provided in an amount of 250 milligrams or less in the MPF. Even more preferably, citric acid is provided in an amount of 200 milligrams or less in the MPF. In certain preferred embodiments, citric acid is provided in an amount of 150 milligrams or less in the MPF.

[0105] In some embodiments, citric acid is provided in an amount of 0.05 to 200 milligrams in the MPF. Preferably, citric acid is provided in an amount of 0.1 to 200 milligrams in the MPF. More preferably, citric acid is provided in an amount of 0.5 to 200 milligrams in the MPF. Even more preferably, citric acid is provided in an amount of 1 to 200 milligrams in the MPF. In certain preferred embodiments, citric acid is provided in an amount of 5 to 200 milligrams in the MPF. Preferably, citric acid is provided in an amount of 15 to 200 milligrams in the MPF. More preferably, citric acid is provided in an amount of 25 to 200 milligrams in the MPF. Even more preferably, citric acid is provided in an amount of 50 to 200 milligrams in the MPF.

[0106] In some embodiments, citric acid is provided in an amount of 0.05 to 150 milligrams in the MPF. Preferably, citric acid is provided in an amount of 0.1 to 150 milligrams in the MPF. More preferably, citric acid is provided in an amount of 0.5 to 150 milligrams in the MPF. Even more preferably, citric acid is provided in an amount of 1 to 150 milligrams in the MPF. In certain preferred embodiments, citric acid is provided in an amount of 5 to 150 milligrams in the MPF. Preferably, citric acid is provided in an amount of 15 to 150 milligrams in the MPF. More preferably, citric acid is provided in an amount of 25 to 150 milligrams in the MPF. Even more preferably, citric acid is provided in an amount of 50 to 150 milligrams in the MPF.

[0107] In some embodiments, the total amount of citric acid is at least 0.4 micromoles per millimeter of MPF. Preferably, the total amount of citric acid is at least 1 micromoles per millimeter of MPF. More preferably, the total amount of citric acid is at least 5 micromoles per millimeter of MPF. Even more preferably, the total amount of citric acid is at least 11 micromoles per millimeter of MPF. In a more preferred embodiment, the total amount of citric acid is at least 20 micromoles per millimeter of MPF. In a particular preferred embodiment, the total amount of citric acid is at least 40 micromoles per millimeter of MPF.

[0108] In certain embodiments, the total amount of citric acid is 185 micromoles or less per millimeter of MPF. Preferably, the total amount of citric acid is 150 micromoles or less per millimeter of MPF. More preferably, the total amount of citric acid is 111 micromoles or less per millimeter of MPF. In certain preferred embodiments, the total amount of citric acid is 75 micromoles or less per millimeter of MPF.

[0109] In some embodiments, the total amount of citric acid is 0.4 micromoles to 185 micromoles per millimeter of MPF, preferably 1 micromoles to 185 micromoles per millimeter of MPF, more preferably 5 micromoles to 185 micromoles per millimeter of MPF, even more preferably 11 micromoles to 185 micromoles per millimeter of MPF, particularly preferably 20 micromoles to 185 micromoles per millimeter of MPF, or 40 micromoles to 185 micromoles per millimeter of MPF.

[0110] In some embodiments, the total amount of citric acid is 0.4 micromoles to 150 micromoles per millimeter of MPF, preferably 1 micromoles to 150 micromoles per millimeter of MPF, more preferably 5 micromoles to 150 micromoles per millimeter of MPF, even more preferably 11 micromoles to 150 micromoles per millimeter of MPF, particularly preferably 20 micromoles to 150 micromoles per millimeter of MPF, or 40 micromoles to 150 micromoles per millimeter of MPF.

[0111] In some embodiments, the total amount of citric acid is 0.4 micromoles to 111 micromoles per millimeter of MPF, preferably 1 micromoles to 111 micromoles per millimeter of MPF, more preferably 5 micromoles to 111 micromoles per millimeter of MPF, even more preferably 11 micromoles to 111 micromoles per millimeter of MPF, particularly preferably 20 micromoles to 111 micromoles per millimeter of MPF, or 40 micromoles to 111 micromoles per millimeter of MPF.

[0112] In some embodiments, the total amount of citric acid is 0.4 to 75 micromoles per millimeter of MPF, preferably 1 to 75 micromoles per millimeter of MPF, more preferably 5 to 75 micromoles per millimeter of MPF, even more preferably 11 to 75 micromoles per millimeter of MPF, particularly preferably 20 to 75 micromoles per millimeter of MPF, or 40 to 75 micromoles per millimeter of MPF.

[0113] As briefly discussed above, the downstream section may include one or more components provided axially aligned with the aerosol generating substrate. For example, the downstream section may comprise one or more of a support element, an aerosol cooling element, and a mouthpiece element.

[0114] In one embodiment, the downstream section is formed from a support element, an aerosol cooling element, and mouthpiece elements arranged in a continuous and contact relationship with each other. In another embodiment, the downstream section is formed from an aerosol cooling element and mouthpiece elements arranged in a continuous and contact relationship with each other.

[0115] Support elements may be provided immediately downstream of the aerosol generating substrate, preferably adjacent to it. One such support element is adapted to provide structural strength to the aerosol generating article. Advantageously, the support element is configured to resist the downstream movement of the aerosol generating substrate during insertion of the heating element of the aerosol generating device into the aerosol generation.

[0116] Aerosol cooling elements may be provided to facilitate the cooling of aerosols generated during use of an aerosol-generating article before they reach the downstream end of the article.

[0117] The aerosol cooling element preferably has low draw resistance. That is, the aerosol cooling element preferably provides low resistance to the air passage through the aerosol generating article. It is preferable that the aerosol cooling element does not substantially affect the draw resistance of the aerosol generating article.

[0118] The aerosol cooling element may comprise multiple channels extending along its longitudinal axis. These multiple longitudinal channels may be defined by a paper material that has undergone one or more of the following processes: crimping, pleating, gathering, and folding, to form the channels. Alternatively, the multiple longitudinal channels may be defined by a single sheet that has undergone one or more of the following processes: crimping, pleating, gathering, and folding, to form the multiple channels. Alternatively, the multiple longitudinal paths may be defined by multiple sheets that have undergone one or more of the following processes: crimping, pleating, gathering, and folding, to form the multiple paths.

[0119] For example, an aerosol cooling element may be formed from an aggregate of material sheets having a specific surface area of ​​approximately 10 square millimeters to approximately 100 square millimeters per milligram. In some embodiments, an aerosol cooling element may be formed from an aggregate of paper material sheets having a specific surface area of ​​approximately 35 square millimeters per milligram. For example, an aerosol cooling element may be formed from an aggregate of polylactic acid (PLA) sheets.

[0120] At least one of the support element and the aerosol cooling element may be in the form of a hollow tubular element. In some embodiments, both the support element and the aerosol cooling element are in the form of a hollow tubular element, which may differ in length, inner diameter, or both.

[0121] In the aerosol-generating articles according to the present invention, such hollow tubular elements provide an unrestricted flow channel. This means that the hollow tubular elements provide a negligible level of RTD. As used herein in relation to the present invention, the term “negligible level of RTD” is used to describe an RTD of less than 1 mmH2O per 10 mm of length of the hollow tubular substrate element, less than 0.4 mmH2O per 10 mm of length of the hollow tubular substrate element, or less than 0.1 mmH2O per 10 mm of length of the hollow tubular substrate element. Therefore, the flow channel should not contain any components that would obstruct the airflow in the longitudinal direction. Preferably, the flow channel is substantially empty.

[0122] The hollow tubular element may have an overall length of at least about 10 millimeters, at least about 12 millimeters, or at least about 15 millimeters.

[0123] The hollow tubular element may have a total length of approximately 30 mm or less, 25 mm or less, or approximately 23 mm or less.

[0124] Hollow tubular elements may have total lengths of approximately 10 mm to 30 mm, 10 mm to 25 mm, or 10 mm to 23 mm. Hollow tubular elements may have total lengths of approximately 12 mm to 30 mm, 12 mm to 25 mm, or 12 mm to 23 mm. Hollow tubular elements may have total lengths of approximately 12 mm to 30 mm, 12 mm to 25 mm, or 12 mm to 23 mm.

[0125] The overall length of the hollow tubular element can be selected based on the desired overall length of the aerosol-generating article.

[0126] In some embodiments, the ventilation zone may be provided downstream of the aerosol generating substrate.

[0127] For example, cooling of the smoke flow generated during the combustion of an aerosol-generating substrate can be achieved by providing a ventilation zone along the mouthpiece of the aerosol-generating article.

[0128] As another example, sufficient cooling of the aerosol flow generated as the aerosol generating substrate heats up and drawn out through the hollow tubular element as described above can be achieved by providing a ventilation zone along the hollow tubular element itself. While we do not wish to be bound by theory, the temperature reduction resulting from introducing cooler outside air into the aerosol generating article downstream of the aerosol generating element through the ventilation zone may have a favorable effect on the nucleation and growth of aerosol particles.

[0129] The ventilation zone may include, for example, a plurality of perforations provided through the tubular wall of a hollow tubular element. The ventilation zone may include at least one row of circumferential perforations. The ventilation zone may include two rows of circumferential perforations. For example, the perforations may be formed online during the manufacture of the aerosol-generating article. Each circumferential row of perforations may contain 8 to 30 perforations.

[0130] In some embodiments, the downstream section of the aerosol generating article may include, in a continuous order, a support element, an aerosol cooling element, and a mouthpiece. Preferably, one or more of the support element, aerosol cooling element, and mouthpiece are in the form of the plug element described above.

[0131] As described above, the downstream section of the aerosol generating article is located downstream of the aerosol generating substrate and may include a mouthpiece element located at the downstream end, oral end, or proximal end of the aerosol generating article.

[0132] The mouthpiece element may be a mouthpiece filter element, and the carboxylic acid is provided within the mouthpiece filter. The mouthpiece element may comprise at least one filter segment, and the carboxylic acid is provided within the filter segment. For example, the mouthpiece element may comprise one or more segments of a fibrous filter material. Suitable fibrous filter materials are known in the art. For example, at least one mouthpiece filter segment may comprise a cellulose acetate filter segment formed from cellulose acetate tow.

[0133] The aerosol-generating articles according to the present invention can be manufactured using existing equipment, and the process can be essentially modified only to the extent necessary to incorporate the carboxylic acid into its position in the downstream section. Generally, the process of incorporating a carboxylic acid into the components of the downstream section will be known to those skilled in the art. One such component can then be combined with the remaining components to form an aerosol-generating article according to a process conventional in the art.

[0134] For example, known processes for manufacturing mouthpiece filter segments from fibrous filter materials can be easily adapted to incorporate carboxylic acids into mouthpiece filters. This applies not only to the most commonly used fibrous materials such as cellulose acetate, but also to alternative fibrous materials such as wood pulp fibers, natural fibers (e.g., cotton, flax), regenerated cellulose (e.g., rayon), and other synthetic fibers (e.g., acrylic fibers, polyester fibers).

[0135] More specifically, fibrous material, typically supplied in bale form, can be drawn out into bundles or "tows" of 10,000 to 30,000 filaments. The tows are then spread out, fluffed, or "boomed" and usually placed under tension, and passed through an air jet. The boomed tows are passed through a funnel or other converging device, and then through a formed opening to form a filter rod. The filter rod is provided with an outer layer to maintain its shape, either by being wrapped with a plug wrapping of paper or other sheet material, or by heating to fuse the outermost filaments together to form a self-supporting layer.

[0136] Plasticizers or binders may be added to the tow during or after boom processing to improve the hardness of the filter rods manufactured according to the procedure described above. These additives bond the filaments together at the points where they intersect when the tows are bundled, thereby strengthening the rod's rigidity. The filter segments thus processed must be cured by either short-term heating or air curing.

[0137] As has been done conventionally with other additives such as flavoring agents and humectants, carboxylic acids may be incorporated into the filter segments by applying them to the tows during or after boom processing by spraying them with liquid, mist, or aerosol form.

[0138] Subsequently, additives can be applied to the mouthpiece filter segment, for example, a carboxylic acid in this invention. Furthermore, additives such as flavoring agents (which form aerosols upon contact with hot tobacco smoke and flow into the smoker's mouth with the smoke) and humectants can also be added. It is known that these additives can be applied to the tow by spraying them onto the tow in the form of liquid, mist, or aerosol during or after boom processing.

[0139] A mouthpiece filter may consist of a single filter segment. A mouthpiece filter may include two or more filter segments that are in contact with each other at their ends and aligned axially.

[0140] The parameters or characteristics described herein for the mouthpiece filter as a whole may be equally applicable to the filter segments of the mouthpiece filter.

[0141] Mouthpiece filters may have low particulate filtration efficiency.

[0142] Mouthpiece filters may have RTDs with approximately 25 mmH2O or less, approximately 20 mmH2O or less, or approximately 15 mmH2O or less.

[0143] The mouthpiece filter may have at least approximately 10 milliliters of H2O in its RTD.

[0144] Mouthpiece filters may have RTDs with approximately 10 mmH2O to 25 mmH2O, approximately 10 mmH2O to 20 mmH2O, or approximately 10 mmH2O to 15 mmH2O.

[0145] Providing carboxylic acid within the mouthpiece filter does not substantially affect the overall RTD of the mouthpiece filter.

[0146] Preferably, the mouthpiece filter has a substantially circular cross-section.

[0147] Preferably, the mouthpiece filter has an outer diameter substantially the same as the outer diameter of the aerosol-generating article.

[0148] The mouthpiece filter may have a length of at least approximately 5 millimeters.

[0149] The length of the mouthpiece filter may be approximately 14 millimeters or less, preferably 12 millimeters or less, 10 millimeters or less, or approximately 9 millimeters or less.

[0150] The length of the mouthpiece filter can be approximately 5 mm to 12 mm, or approximately 5 mm to 9 mm.

[0151] The length of the mouthpiece filter can be approximately 5 mm to 11 mm, or approximately 5 mm to 9 mm.

[0152] For example, the length of the mouthpiece filter may preferably be about 7 millimeters.

[0153] The length of the mouthpiece filter can be selected based on the desired overall length of the aerosol-generating article.

[0154] The mouthpiece filter may be enclosed by a plug wrap.

[0155] The mouthpiece filter may not be breathable to prevent air from entering the aerosol-generating object along the mouthpiece filter.

[0156] The mouthpiece filter may be connected by a chipping wrapper to one or more adjacent components of the aerosol-generating article.

[0157] An aerosol-generating article may have an end cavity defined at its downstream end. For example, a mouthpiece filter may itself be in the form of a hollow tubular element. Alternatively, a mouthpiece filter may include a non-hollow segment immediately upstream of a hollow tubular segment provided at the downstream end of the mouthpiece filter. As a further alternative, the end cavity may be defined by an outer wrapper of the mouthpiece filter that extends beyond the downstream end of the filtration material segment of the mouthpiece filter.

[0158] In some embodiments, the aerosol-generating article comprises an upstream section located upstream of the aerosol-generating substrate. The upstream section is preferably located immediately upstream of the aerosol-generating substrate. The upstream section preferably extends from the upstream end of the aerosol-generating article to the upstream end of the aerosol-generating substrate. The upstream section preferably includes an upstream element located immediately upstream of the rod of the aerosol-generating substrate.

[0159] If the aerosol-generating substrate contains shredded tobacco, such as tobacco cut filler, the upstream section or its components may additionally help prevent the loss of loose tobacco particles from the upstream end of the article.

[0160] The upstream section or its upstream element may also provide some degree of additional protection to the aerosol-generating substrate during storage, by covering at least to some extent the upstream end of the aerosol-generating substrate which may otherwise be exposed. In the case of an aerosol-generating article intended to be inserted into a cavity in an aerosol generator so that the aerosol-generating substrate can be externally heated within the cavity, the upstream section or its upstream element may advantageously facilitate the insertion of the upstream end of the article into the cavity.

[0161] The upstream elements of the upstream section may be made of any material suitable for use in an aerosol generating article. The upstream elements may be made of the same material used for one of the other components of the aerosol generating article, such as a mouthpiece, aerosol cooling element, or support element, the geometric shapes and functions of which are described above. Preferred materials for the upstream elements include filter materials, ceramics, polymer materials, cellulose acetate, cardboard, zeolites, or aerosol generating substrates.

[0162] Preferably, the upstream section or its upstream element has an outer diameter approximately equal to the outer diameter of the aerosol-generating article. Preferably, the outer diameter of the upstream section or its upstream element is about 6 mm to about 8 mm, more preferably about 7 mm to about 7.5 mm. Preferably, the upstream section or its upstream element has an outer diameter of about 7.1 mm.

[0163] Preferably, the upstream section or upstream element has a length of about 2 mm to about 8 mm, more preferably about 3 mm to about 7 mm, and more preferably about 4 mm to about 6 mm. In a particularly preferred embodiment, the upstream section or upstream element has a length of about 5 mm. The length of the upstream section or upstream element may be advantageously varied to provide the desired total length of the aerosol-generating article.

[0164] The upstream section is preferably surrounded by a wrapper such as a plug wrap. The wrapper surrounding the upstream section is preferably a rigid plug wrap, for example, a plug wrap having a basis weight of at least about 80 grams / square meter (gsm), or at least about 100 gsm, or at least about 110 gsm. This provides increased structural rigidity to the upstream section.

[0165] The upstream section is preferably connected by an outer wrapper to the rods of the aerosol generating substrate and, optionally, to at least a portion of the downstream section.

[0166] In a preferred embodiment of the present invention, the upstream section of the aerosol-generating article does not contain a carboxylic acid.

[0167] The aerosol-generating article preferably has an overall length of 40 mm to 80 mm, or 40 mm to about 70 mm, or 40 mm to about 60 mm, or 45 mm to about 80 mm, or about 45 mm to about 70 mm, or 45 mm to 60 mm, or 50 mm to 80 mm, or 50 mm to about 70 mm, or about 50 mm to about 60 mm. In one exemplary embodiment, the overall length of the aerosol-generating article is about 45 mm.

[0168] Preferably, the aerosol-generating article has a substantially circular cross-section.

[0169] The aerosol-generating article preferably has an outer diameter of about 5 mm to about 12 mm, or about 6 mm to about 12 mm, or about 7 mm to about 12 mm, or about 5 mm to about 10 mm, or about 6 mm to about 10 mm, or about 7 mm to about 10 mm, or about 5 mm to about 8 mm, or about 6 mm to about 8 mm, or about 7 mm to about 8 mm. In other embodiments, the aerosol-generating article has an outer diameter of less than 7 mm.

[0170] The overall RTD of the aerosol-generating article is preferably at least 10 mmH2O, more preferably at least 15 mmH2O, more preferably at least 20 mmH2O, more preferably at least 25 mmH2O, and more preferably at least 30 mmH2O.

[0171] The overall RTD of the aerosol-generating article is preferably 70 mmH2O or less, more preferably 60 mmH2O or less, more preferably 55 mmH2O or less, more preferably 50 mmH2O or less, and more preferably 45 mmH2O or less.

[0172] For example, the overall RTD of an aerosol-generating article could be 10 mmH2O to 70 mmH2O, or 15 mmH2O to 60 mmH2O, or 20 mmH2O to 55 mmH2O, or 25 mmH2O to 45 mmH2O, or 30 mmH2O to 45 mmH2O.

[0173] As described above, the aerosol generating article according to the present invention comprises an aerosol generating substrate. In some embodiments, the aerosol generating article comprises a rod of the aerosol generating substrate surrounded by a rod plug wrap.

[0174] Preferably, the rod of the aerosol generating substrate has a length of at least 8 millimeters, more preferably at least 9 millimeters, and more preferably at least 10 millimeters. Preferably, the length of the rod of the aerosol generating substrate is less than 16 millimeters, more preferably less than 15 millimeters, and more preferably less than 14 millimeters. For example, the rod of the aerosol generating substrate may have a length of 8 to 16 millimeters, or 9 to 15 millimeters, or 10 to 14 millimeters. In a particularly preferred embodiment, the rod of the aerosol generating substrate has a length of about 12 millimeters.

[0175] The ratio of the length of the rod of the aerosol generating substrate to the total length of the aerosol generating article is preferably at least 0.10, more preferably at least 0.15, more preferably at least 0.20, and more preferably at least 0.25. Preferably, the ratio of the length of the rod of the aerosol generating substrate to the total length of the aerosol generating article is less than 0.50, more preferably less than 0.45, more preferably less than 0.40, and more preferably less than 0.35. For example, the ratio of the length of the rod of the aerosol generating substrate to the total length of the aerosol generating article may be 0.1 to 0.5, or 0.15 to 0.45, or 0.2 to 0.4, or 0.25 to 0.35.

[0176] The rod of the aerosol generating substrate preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol generating article.

[0177] Preferably, the rod of the aerosol generating substrate has an outer diameter of at least 5 mm, more preferably at least 6 mm, and more preferably at least 7 mm. Preferably, the rod of the aerosol generating substrate has an outer diameter of less than 12 mm, more preferably less than 10 mm, and more preferably less than 8 mm. For example, the outer diameter may be 5 mm to 12 mm, or 6 mm to 10 mm, or 7 mm to 8 mm. In a particularly preferred embodiment, the rod of the aerosol generating substrate has an outer diameter of about 7.1 mm.

[0178] Preferably, the rod of the aerosol generating substrate has a substantially uniform cross-section along its length. Particularly preferably, the rod of the aerosol generating substrate has a substantially circular cross-section.

[0179] The aerosol-generating substrate may have a density of at least about 150 milligrams / cubic centimeter, at least about 175 milligrams / cubic centimeter, at least about 200 milligrams / cubic centimeter, or at least or about 250 milligrams / cubic centimeter.

[0180] The aerosol-generating substrate may have a density of approximately 500 milligrams / cubic centimeter or less, approximately 450 milligrams / cubic centimeter or less, approximately 400 milligrams / cubic centimeter or less, or approximately 350 milligrams / cubic centimeter or less.

[0181] The RTD of the aerosol-generating substrate rod may be at least about 4 mmH2O, at least about 5 mmH2O, or at least about 6 mmH2O.

[0182] The RTD of the aerosol generating substrate rod may be approximately 10 mmH2O or less, approximately 9 mmH2O or less, or approximately 8 mmH2O or less.

[0183] The aerosol generating substrate may be a solid aerosol generating substrate. Suitable types of materials for use in the aerosol generating substrate are described below and include, for example, homogenized tobacco materials such as tobacco cut filler and cast leaf, aerosol generating films, and gel compositions.

[0184] The aerosol generating substrate preferably includes an aerosol-forming agent. Suitable aerosol-forming agents include, for example, polyhydric alcohols (e.g., triethylene glycol, 1,3-butanediol, propylene glycol, glycerin, etc.), esters of polyhydric alcohols (e.g., glycerol mono-, di-, or triacetate, etc.), aliphatic esters of mono-, di-, or polycarboxylic acids (e.g., dimethyl dodecanediate, dimethyl tetradecanediate, etc.), and combinations thereof.

[0185] Preferably, the aerosol-forming body comprises one or more of glycerin and propylene glycol. The aerosol-forming body may consist of glycerin, or propylene glycol, or a combination of glycerin and propylene glycol.

[0186] In certain embodiments, the aerosol generating substrate preferably contains at least 5 weight percent of aerosol-forming material on a dry weight basis of the aerosol generating substrate, more preferably at least 10 weight percent on a dry weight basis, and even more preferably at least 15 weight percent on a dry weight basis. In such embodiments, the aerosol generating substrate preferably contains 30 weight percent or less of aerosol-forming material on a dry weight basis of the aerosol generating substrate, more preferably 25 weight percent or less on a dry weight basis, and more preferably 20 weight percent or less on a dry weight basis. For example, the aerosol-forming material content of the aerosol generating substrate may be 5 weight percent to 30 weight percent, or 10 weight percent to 25 weight percent, or about 15 weight percent to about 20 weight percent on a dry weight basis. Therefore, in such embodiments, the aerosol-forming material content is relatively low.

[0187] In other embodiments, the aerosol generating substrate preferably contains at least 40 weight percent of aerosol forming material on a dry weight basis of the aerosol generating substrate, more preferably at least 45 weight percent on a dry weight basis, and more preferably at least 50 weight percent on a dry weight basis. In such embodiments, the aerosol generating substrate preferably contains 80 weight percent or less of aerosol forming material on a dry weight basis of the aerosol generating substrate, more preferably 75 weight percent or less on a dry weight basis, and more preferably 70 weight percent or less on a dry weight basis. For example, the aerosol forming material content of the aerosol generating substrate may be 40 weight percent to 80 weight percent, or 45 weight percent to 75 weight percent, or 50 weight percent to 70 weight percent on a dry weight basis. Therefore, in such embodiments, the aerosol forming material content is relatively high.

[0188] In some preferred embodiments, the aerosol generating substrate includes tobacco material. For example, the aerosol generating substrate may include shredded tobacco material. For example, the shredded tobacco material may be in the form of cut fillers, as will be described in more detail below. Alternatively, the shredded tobacco material may be in the form of shredded sheets of homogenized tobacco material. Preferred homogenized tobacco materials for use in the present invention are described below.

[0189] In the context of this specification, the term “cut filler” is used to refer to a blend of shredded plant material, such as tobacco plant material comprising one or more of the following: leaf laminas, processed stems and veins, and homogenized plant material.

[0190] The cut filler suitable for use in the present invention may generally be similar to the cut filler used in conventional smoking articles. The cutting width of the cut filler may preferably be 0.3 mm to 2.0 mm, or 0.5 mm to 1.2 mm, or 0.6 mm to 0.9 mm.

[0191] Preferably, the strands have a length of about 10 mm to about 40 mm, and the strands are then arranged to form a rod of aerosol generating substrate.

[0192] Preferably, the cut filler is immersed in an aerosol-forming body. Immersion of the cut filler can be carried out by spraying or by other suitable application methods. Preferably, the aerosol-forming body in the cut filler comprises one or more glycerol and propylene glycol. The aerosol-forming body may consist of glycerol, or propylene glycol, or a combination of glycerol and propylene glycol.

[0193] In other preferred embodiments, the aerosol generating substrate comprises homogenized plant material, preferably homogenized tobacco material.

[0194] As used herein, the term “homogenized plant material” encompasses any plant material formed by the aggregation of plant particles. For example, a sheet or web made of homogenized tobacco material for an aerosol generating substrate of the present invention may be formed by aggregating particles of tobacco material obtained by crushing, grinding, or pulverizing a plant material and optionally one or more thin layers of tobacco leaves and / or tobacco leaf stems. Homogenized plant material may be produced by molding, extrusion, papermaking processes, or any other suitable process known in the art.

[0195] Homogenized plant material can be provided in any preferred form.

[0196] In some embodiments, the homogenized plant material may be in the form of one or more sheets. As used herein in relation to the present invention, the term “sheet” refers to a layered element having a width and length substantially greater than its thickness.

[0197] The homogenized plant material may be in the form of multiple pellets or granules.

[0198] Homogenized plant material may be in the form of multiple strands, strips, or fragments. As used herein, the term “strand” refers to an elongated element of the material having a length substantially greater than its width and thickness.

[0199] The aerosol-forming content of the homogenized tobacco material is preferably within the range defined above for aerosol-generating substrates having a relatively low aerosol-forming content.

[0200] In other preferred embodiments, the aerosol-generating substrate is in the form of an aerosol-generating film comprising a cellulosic film-forming agent, nicotine, and an aerosol-forming agent. The aerosol-generating film may further contain a cellulosic reinforcing agent. The aerosol-generating film may further contain water, preferably less than 30 percent by weight.

[0201] As used herein, the term “film” is used to describe a solid layered element having a thickness less than its width or length. A film may be self-supporting.

[0202] In the context of the present invention, the term "cellulose-based film-forming agent" is used to refer to a cellulose polymer having the ability to form a continuous film, either by itself or in the presence of an auxiliary thickener. Preferably, the cellulose-based film-forming agent is selected from the group consisting of hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), hydroxyethyl methylcellulose (HEMC), hydroxyethylcellulose (HEC), hydroxypropylcellulose (HPC), and combinations thereof. In certain preferred embodiments, the cellulose-based film-forming agent is HPMC.

[0203] The aerosol-forming material content of the aerosol-generating film is within the range defined above for aerosol-generating substrates having a relatively high aerosol-forming material content.

[0204] Aerosol-generating films suitable for use as an aerosol-generating substrate in an aerosol-generating article according to the present invention are described in WO-A-2020 / 207733 and WO-A-2022 / 074157.

[0205] Preferably, the aerosol generating film contains 0.5% to 10% by weight of nicotine, or 1% to about 8% by weight of nicotine, or about 2% to about 6% by weight of nicotine, on a dry weight basis.

[0206] The aerosol-generating film may be a substantially tobacco-free aerosol-generating film.

[0207] In alternative embodiments of the present invention, the aerosol generating substrate may comprise a gel composition containing nicotine, at least one gelling agent, and an aerosol forming body. The gel composition is preferably substantially free of tobacco.

[0208] The preferred weight range of nicotine in the gel composition is the same as that defined above in relation to the aerosol generating film.

[0209] A suitable gel composition for use as an aerosol generating substrate in an aerosol generating article according to the present invention is described in WO-A-2021 / 170642.

[0210] The gel composition preferably contains at least 50 weight percent of aerosol-forming material, more preferably at least 60 weight percent, and more preferably at least 70 weight percent, on a dry weight basis. The gel composition may contain up to 80 weight percent of aerosol-forming material. The aerosol-forming material in the gel composition is preferably glycerol.

[0211] In certain embodiments of the present invention, the aerosol generating article further includes one or more elongated susceptor elements within a rod of the aerosol generating substrate. For example, one or more elongated susceptor elements may be arranged substantially along their longitudinal axis within the aerosol generating rod and may be in thermal contact with the aerosol generating substrate.

[0212] As used herein in relation to the present invention, the term "susceptor element" refers to a material capable of converting electromagnetic energy into heat.

[0213] Suitable susceptor elements for use in the aerosol generating substrate of the aerosol generating article according to the present invention are described in WO-A-2021 / 170673.

[0214] Preferably, the rod of the aerosol generating substrate is surrounded by a wrapper. The wrapper may be a paper wrapper or a non-paper wrapper.

[0215] Suitable paper wrappers for use in specific embodiments of the present invention are known in the art and include, but are not limited to, cigarette papers and filter plug wrappers. Suitable non-paper wrappers for use in specific embodiments of the present invention are known in the art and include, but are not limited to, sheets of homogenized tobacco material.

[0216] As described above, the aerosol generating articles described above are used in an aerosol generating system that includes an electrically operated aerosol generating device and the aerosol generating articles. The aerosol generating device includes means for heating the aerosol generating substrate of the aerosol generating article to a temperature sufficient to generate aerosols from the aerosol generating substrate.

[0217] Preferably, the aerosol generating device comprises a housing that defines a cavity configured to receive an aerosol generating article, and means for heating the aerosol generating substrate to a temperature sufficient to generate an aerosol from the aerosol generating substrate when the aerosol generating article is received in the cavity.

[0218] The aerosol generator could be a handheld aerosol generator.

[0219] An aerosol generator can be an electrically operated aerosol generator.

[0220] The aerosol generator may include a power supply and control electronics.

[0221] The aerosol generator may include a battery and control electronics.

[0222] The aerosol generator may be configured to internally heat the aerosol generating substrate. That is, the aerosol generator may be configured to supply heat to the aerosol generating substrate from a position inside the aerosol generating article.

[0223] For example, in some embodiments, the aerosol generator includes a heater element configured to be inserted into the aerosol generating element when an aerosol generating article is received in the cavity of the aerosol generator.

[0224] In other embodiments, the aerosol generating article comprises a susceptor element provided at a position within the aerosol generating element, and the aerosol generating device comprises an inductor coil located on or within the housing, and the power supply of the aerosol generating device is connected to the inductor coil and configured to supply a high-frequency oscillating current to the inductor coil. This generates an alternating magnetic field that induces a voltage within the susceptor element. The induced voltage causes a current to flow within the susceptor element, and this current causes Joule heating of the susceptor element, which then heats the aerosol generating substrate. The aerosol generating device may have the ability to generate a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of 1 to 5 kiloamperes / meter (kA m), preferably 2 to 3 kA / m, for example, about 2.5 kA / m.

[0225] The aerosol generator may be configured to externally heat the aerosol generating substrate. That is, the aerosol generator may be configured to supply heat to the aerosol generating substrate from a location outside the aerosol generating article. For example, in some embodiments, the aerosol generator includes a heater element located around the periphery of a cavity and configured to heat the aerosol generating substrate of the aerosol generating article from outside the aerosol generating element of the aerosol generating article. [Examples]

[0226] The present invention is defined in the claims. However, a non-exclusive list of non-limiting embodiments is provided below. One or more features of these embodiments may be combined with any one or more features of other embodiments, forms, or aspects described herein.

[0227] Example 1: An aerosol generating article comprising: an aerosol generating element containing a nicotine-containing aerosol generating substrate; and a downstream section located downstream of the aerosol generating element, the downstream section containing a carboxylic acid selected from the group consisting of citric acid, benzoic acid, fumaric acid, lactic acid, and combinations thereof. Example 2: The aerosol generating article according to Example 1, wherein the downstream section comprises a mouthpiece filter, and a carboxylic acid is provided at a position within the mouthpiece filter. Example 3: The aerosol generating article according to Example 1, wherein the downstream section comprises a support element adjacent to the aerosol generating element, and the carboxylic acid is provided at a position within the support element. Example 4: The aerosol generating substrate according to Example 1, wherein the downstream section comprises an aerosol cooling element adjacent to the aerosol generating element, and the carboxylic acid is provided at a position within the aerosol cooling element. Example 5: The aerosol generating substrate according to Example 3, wherein the downstream section comprises an aerosol cooling element downstream of the support element, and a carboxylic acid is provided at a position within the aerosol cooling element. Example 6: An aerosol-generating article according to any one of Examples 1 to 5, further comprising an upstream section located upstream of an aerosol-generating element. Example 7: The aerosol-generating article according to Example 7, wherein the upstream section does not contain a carboxylic acid. Example 8: An aerosol generating article according to any one of Examples 1 to 7, wherein the aerosol generating substrate comprises at least 10 weight percent of an aerosol forming material. Example 9: An aerosol generating article according to any one of Examples 1 to 8, wherein the aerosol generating substrate contains multiple fragments of tobacco material. Example 10: An aerosol generating article according to any one of Examples 1 to 8, wherein the aerosol generating substrate includes one or more sheets of homogenized tobacco material. Example 11: An aerosol generating article according to any one of Examples 1 to 8, wherein the aerosol generating substrate comprises a gel composition containing nicotine, at least one gelling agent, and an aerosol forming body. Example 12: An aerosol generating article according to any one of Examples 1 to 8, wherein the aerosol generating substrate comprises hydroxypropyl methylcellulose and one or more cellulosic reinforcing agents. Example 13: An aerosol-generating article according to any one of Examples 1 to 12, wherein the downstream section contains at least 2.6 micromoles of carboxylic acid. Example 14: An aerosol-generating article according to any one of Examples 1 to 13, wherein the downstream section contains 1700 micromoles or less of carboxylic acid. Example 15: An aerosol-generating article according to any one of Examples 1 to 14, wherein the downstream section contains at least 0.5 milligrams of carboxylic acid. Example 16: An aerosol-generating article according to any one of Examples 1 to 15, wherein the downstream section contains 150 milligrams or less of a carboxylic acid. Example 17: The aerosol-generating articles according to Examples 11 and 12, wherein the carboxylic acid is citric acid. Example 18: An aerosol-generating article according to any one of Examples 1 to 17, wherein the downstream section contains at least 1.22 milligrams of benzoic acid. Example 19: An aerosol-generating article according to any one of Examples 1 to 18, wherein the downstream section contains 98 milligrams or less of benzoic acid. Example 20: An aerosol-generating article according to any one of Examples 1 to 19, wherein the downstream section contains at least 0.9 milligrams of lactic acid. Example 21: An aerosol-generating article according to any one of Examples 1 to 20, wherein the downstream section contains 72 milligrams or less of lactic acid. Example 22: An aerosol-generating article according to any one of Examples 1 to 21, wherein the downstream section contains at least 1.16 milligrams of fumaric acid. Example 23: An aerosol-generating article according to any one of Examples 1 to 22, wherein the downstream section contains 93 milligrams or less of fumaric acid. Example 24: The aerosol-generating article according to Example 2, wherein the mouthpiece filter contains at least 0.5 milligrams of carboxylic acid. Example 25: The aerosol generating article according to Example 2, wherein the mouthpiece filter contains 150 milligrams or less of carboxylic acid. Example 26: The aerosol-generating article according to Example 2, wherein the mouthpiece filter contains at least 2.6 micromoles of carboxylic acid. Example 27: The aerosol generating article according to Example 2, wherein the mouthpiece filter contains 1700 micromoles or less of carboxylic acid. Example 28: The aerosol-generating article according to Example 2, wherein the mouthpiece filter contains at least 0.5 micromoles of carboxylic acid per millimeter of the mouthpiece filter. Example 29: The aerosol generating article according to Example 2, wherein the mouthpiece filter contains 390 micromoles or less of carboxylic acid per millimeter of the mouthpiece filter. Example 30: The aerosol-generating article according to Example 2, wherein the mouthpiece filter contains at least 0.024 milligrams of carboxylic acid per cubic millimeter of the mouthpiece filter. Example 31: The aerosol-generating article according to Example 2, wherein the mouthpiece filter contains 0.29 milligrams or less of carboxylic acid per cubic millimeter of the mouthpiece filter. Example 32: An aerosol-generating article according to any one of Examples 1 to 31, wherein the downstream section contains at least 0.5 milligrams of citric acid. Example 33: An aerosol-generating article according to any one of Examples 1 to 32, wherein the downstream section contains 150 milligrams or less of citric acid. Example 34: An aerosol-generating article according to any one of Examples 1 to 33, wherein the downstream section contains at least 3 micromoles of citric acid. Example 35: An aerosol-generating article according to any one of Examples 1 to 34, wherein the downstream section contains 1300 micromoles or less of citric acid. Example 36: The aerosol-generating article according to Example 2, wherein the mouthpiece filter contains at least 0.5 milligrams of citric acid. Example 37: The aerosol generating article according to Example 2, wherein the mouthpiece filter contains 150 milligrams or less of citric acid. Example 38: The aerosol-generating article according to Example 2, wherein the mouthpiece filter contains at least 0.4 micromoles of citric acid per millimeter of the mouthpiece filter. Example 39: The aerosol generating article according to Example 2, wherein the mouthpiece filter contains 185 micromoles or less of citric acid per millimeter of the mouthpiece filter. Example 40: An aerosol-generating article according to any one of Examples 1 to 39, comprising a ventilation zone located along the downstream section. Example 41: An aerosol-generating article according to any one of Examples 1 to 40, wherein the total length of the article is 60 millimeters or less. Example 42: An aerosol generating article according to any one of Examples 1 to 41, wherein the total length of the aerosol generating article is at least 50 millimeters. Example 43: An aerosol generating article according to any of Examples 1 to 42, wherein the diameter of the aerosol generating article is at least 5 millimeters. Example 44: An aerosol generating article according to any one of Examples 1 to 43, wherein the diameter of the aerosol generating article is 7.3 millimeters or less. Example 45: The aerosol-generating article according to Example 2, wherein the length of the mouthpiece filter is at least 5 millimeters. Example 46: The aerosol-generating article according to Example 2, wherein the length of the mouthpiece filter is 12 millimeters or less.

[0228] Herein, the present invention will be further explained with reference to the attached drawings, although this is purely illustrative. [Brief explanation of the drawing]

[0229] [Figure 1] Figure 1 is a cross-sectional view of an aerosol-generating article according to a first embodiment of the present disclosure. [Figure 2] Figure 2 is a cross-sectional view of an aerosol generating system equipped with the aerosol generating article shown in Figure 1. [Modes for carrying out the invention]

[0230] Figure 1 shows a schematic cross-sectional view of an aerosol generating article 10 according to the present invention. The aerosol generating article 10 has a substantially cylindrical shape. The aerosol generating article 10 comprises a rod 12 of an aerosol generating substrate 12. The rod 12 of the aerosol generating substrate has a substantially cylindrical shape and contains an assembly of homogenized tobacco sheets. The article further comprises a downstream section 17 located downstream of the rod 12 of the aerosol generating substrate. The downstream section 17 includes a first hollow tubular element 14, a second hollow tubular element 15, and a mouthpiece filter 18. The mouthpiece filter 18 is located at the proximal (downstream) end of the article 10.

[0231] The downstream section 17 includes an intermediate section 17a located between the aerosol generating substrate rod 12 and the mouthpiece filter 18. The intermediate section 17a comprises a first hollow tubular element 14 and a second hollow tubular element 15.

[0232] The aerosol generating article 10 further comprises an upstream element 11 at the distal (upstream) end of the article 10. The upstream element 11 is a solid cylindrical plug element having a filled cross-section. The upstream element 11 contains cellulose acetate. The RTD of the upstream element is 5.5 mmH2O.

[0233] The longitudinal axis 7 extends centrally along the longitudinal axis of the aerosol generating article 10. In this embodiment, the length of the upstream element 11 is 5 millimeters. The upstream element 11, the rod 12 of the aerosol generating substrate, the first hollow tubular element 14, the second hollow tubular element 15, and the mouthpiece filter 18 are arranged end-to-end along the longitudinal axis 7.

[0234] The upstream element 11, the aerosol generating substrate rod 12, the first hollow tubular element 14, the second hollow tubular element 15, and the mouthpiece filter 18 are surrounded by a wrapper 16.

[0235] It will be understood that, in addition to the wrapper 16, one or more components of the aerosol generating article 10, namely the upstream element 11, the rod 12 of the aerosol generating substrate, and the mouthpiece filter 18, may each be surrounded by individual wrappers (not shown) located beneath the wrapper 16.

[0236] The rod 12 of the aerosol generating substrate has a rod length parallel to the longitudinal axis 7 of the aerosol generating article 10 and a rod width perpendicular to the longitudinal axis 7 of the aerosol generating article 10. The rod width is substantially uniform along the rod length. In this embodiment, the rod width is 7 millimeters. In this embodiment, the rod length is 11 millimeters. The draw-out resistance (RTD) of the rod 12 of the aerosol generating substrate is 13.6 milliH2O. The length of the aerosol generating article 10 is 45 millimeters. The draw-out resistance (RTD) of the aerosol generating article 10 is 46 milliH2O.

[0237] The aerosol generating article 10 shown in Figure 1 further comprises a susceptor element 12a disposed within the rod 12 of the aerosol generating substrate. The susceptor element 12a is configured to be heated when penetrated by a changing magnetic field. The length of the susceptor element 12a is approximately equal to the length of the rod; that is, the length of the susceptor element 12a is 11 millimeters. The width of the susceptor element 12a is 4 millimeters, and the thickness of the susceptor element 12a is 60 micrometers.

[0238] As described above, the downstream section 17 includes a mouthpiece filter 18, a second hollow tubular element 15, and a first hollow tubular element 14. The downstream section 17 extends between the rod 12 of the aerosol generating substrate and the downstream end of the aerosol generating article 10. The downstream section 17 has a length of 29 millimeters. The second hollow tubular element 15 is downstream of the first hollow tubular element 14. The first hollow tubular element 14 is in the form of a hollow acetate tube. The second hollow tubular element 15 is in the form of a hollow acetate tube. The first hollow tubular element 14 abuts against the downstream end of the rod 12 of the aerosol generating substrate. The length of the first hollow tubular element 14 is 8 millimeters. The length of the second hollow tubular element 15 is 9 millimeters.

[0239] The first hollow tubular element 14 contains a lumen. The lumen of the first hollow tubular element 14 has a substantially circular cross-sectional shape. The second hollow tubular element 15 contains a lumen. The lumen of the second hollow tubular element 15 has a substantially circular cross-sectional shape. The width (internal width) of the lumen of the second hollow tubular element 15 is greater than the width (internal width) of the lumen of the first hollow tubular element 14. The wall thickness of the second hollow tubular element 15 is less than the wall thickness of the first hollow tubular element 14. The wall thickness of the second hollow tubular element 15 is 1.05 millimeters. The wall thickness of the second hollow tubular element 14 is 1.9 millimeters. The width of each of the first hollow tubular element 14 and the second hollow tubular element 15 is 7.1 millimeters. The combined RTD of the first hollow tubular element 14 and the second hollow tubular element 15 is approximately 0 millimeters of H2O.

[0240] The second hollow tubular element 15 includes a ventilation zone located along the second hollow tubular element 15. It will be understood that the ventilation zone may be provided alternatively or additionally along the first hollow tubular element 14. The ventilation zone includes one or more rows of ventilation holes 13 arranged circumferentially around the second hollow tubular element 15 in a cross section substantially perpendicular to the longitudinal axis 7 of the aerosol-generating article 10. The ventilation holes 13 are perforations through the wall of the second hollow tubular element 15. The ventilation level of the aerosol-generating article 10 is approximately 50 percent. Each circumferential row of ventilation holes 13 contains 11 holes. The ventilation holes 13 extend through both the first wrapper 16 and the second wrapper 19 in a direction perpendicular to the longitudinal axis 7. The distance of the ventilation holes 13 from the downstream end of the article 10 is 18 millimeters.

[0241] The mouthpiece filter 18 is located at the downstream end of the aerosol generating article 10 and contains 1.5 milligrams of citric acid. The mouthpiece filter 18 abuts against the downstream end of the second hollow tubular element 15. The mouthpiece filter 18 contains a low-density acetate filter segment. The citric acid is added to the cellulose acetate tow in the form of an aqueous solution (e.g., a 0.5 mol / liter aqueous solution of citric acid) during manufacturing.

[0242] The RTD of mouthpiece filter 18 is approximately 18 mm of H2O. The length of mouthpiece filter 18 is 12 mm. The width of mouthpiece filter 18 is 7.3 mm.

[0243] Figure 2 shows a schematic cross-sectional view of a portion of an aerosol generating system 1000, which includes the aerosol generating article 10 and the aerosol generating device 100 shown in Figure 1.

[0244] In this embodiment, the aerosol generating article 10 includes a susceptor element 12a disposed within the rod 12 of the aerosol generating substrate. The susceptor element 12a is configured to be heated when penetrated by a changing magnetic field.

[0245] The aerosol generator 100 further comprises an inductor coil 126 that surrounds the device cavity 121 and the susceptor element 12a. The inductor coil 126 is arranged to generate a changing magnetic field within the device cavity 121 that penetrates the susceptor element 12a and inductively heats the susceptor element 12a.

[0246] The device cavity 121 is configured to receive at least a portion of the aerosol-generating article 10. The distal end of the device cavity 121 has a closed end. The proximal end of the device cavity 121 has an open end. The aerosol-generating article 10 can be inserted into the device cavity 121 through the open end of the device cavity 221.

[0247] When in use, the user inserts the aerosol generating article 10 into the device cavity 121 of the aerosol generating device 100.

[0248] The aerosol generator 100 further comprises a power supply (not shown) and electronic equipment (not shown) arranged to supply power to an inductor coil 226 to generate a changing magnetic field within the device cavity 121, thereby inductively heating the susceptor element 12a.

[0249] The susceptor element 12a heats the rod 12 of the aerosol generating substrate when the aerosol generating article 10 is received into the device cavity 121. The operation of these inductor coils 126 may be performed manually, or it may occur automatically in response to the user inhaling the aerosol generating article 10 when the aerosol generating article 10 is inserted into the device cavity 121.

[0250] The entire length of the rod 12 of the aerosol generating substrate is received within the device cavity 121. The device cavity 121 has a substantially circular cross-sectional shape. The device cavity 121 has substantially the same cross-sectional shape as the rod 12 of the aerosol generating substrate. The ventilation holes 13 of the second hollow tubular element 15 are not received within the device cavity 121.

[0251] During use, the inductor coil 126 is controlled to heat the susceptor element 12a within a defined operating temperature range below the maximum operating temperature.

[0252] The tests were conducted on an aerosol-generating article (sample article) according to the present invention, with the aim of evaluating the effect of carboxylic acids provided within the mouthpiece filter on the composition of the aerosol delivered at the downstream end of the mouthpiece filter.

[0253] More specifically, the aerosol generating article as described above is provided with reference to the drawing in Figure 1. As described above, a sample article was prepared containing a mouthpiece filter containing 1.5 milligrams of citric acid.

[0254] To evaluate the effect of citric acid on aerosol composition, a comparative article was prepared and subjected to the same test, as will be discussed in more detail below. The comparative article was substantially identical to the sample article but did not contain citric acid.

[0255] Both sample and control articles were subjected to smoking tests under Health Canada's Intense (HCI) Act, which specifies a smoke duration of 2 seconds, a 30-second interval between consecutive smokes, a smoke volume of 55 milliliters, and a sinusoidal smoke shape with a complete ventilation block. For each article subjected to the smoking test, the smoking cycle consisted of 9 smokes.

[0256] Nicotine delivery was measured for both the sample and control items. Nicotine delivery measured for the sample items was consistently found to be higher than that measured for the control items. In particular, an increase in nicotine delivery ranging from 12 to 22 percent was detected.

Claims

1. An aerosol generating article for generating an inhalable aerosol when heated, wherein the aerosol generating article is an aerosol generating element containing a nicotine-containing aerosol generating substrate, An aerosol generating article comprising: a downstream section located downstream of the aerosol generating element, the downstream section comprising a carboxylic acid selected from the group consisting of citric acid, benzoic acid, fumaric acid, lactic acid, and combinations thereof.

2. The aerosol generating article according to claim 1, wherein the downstream section comprises a mouthpiece filter, and the carboxylic acid is provided at a position within the mouthpiece filter.

3. The aerosol generating article according to claim 1, wherein the downstream section comprises a support element adjacent to the aerosol generating element, and the carboxylic acid is provided at a position within the support element.

4. The aerosol generating substrate according to claim 1, wherein the downstream section comprises an aerosol cooling element adjacent to the aerosol generating element, and the carboxylic acid is provided at a position within the aerosol cooling element.

5. The aerosol generating article according to any one of claims 1 to 4, wherein the article further comprises an upstream section located upstream of the aerosol generating element.

6. The aerosol generating article according to claim 6, wherein the upstream section does not contain a carboxylic acid.

7. The aerosol generating article according to any one of claims 1 to 6, wherein the downstream section contains at least 0.5 milligrams of carboxylic acid.

8. The aerosol generating article according to claim 8, wherein the carboxylic acid is citric acid.

9. The aerosol generating article according to any one of claims 1 to 8, further comprising a ventilation zone located along the downstream section.

10. The aerosol generating article according to any one of claims 1 to 9, wherein the aerosol generating substrate comprises at least about 10 weight percent of an aerosol forming body.

11. The aerosol generating article according to any one of claims 1 to 10, wherein the aerosol generating substrate comprises at least one of a plurality of tobacco material fragments, one or more homogenized tobacco material sheets, and a gel composition comprising nicotine, at least one gelling agent, and an aerosol forming body.

12. The aerosol generating article according to any one of claims 1 to 11, wherein the total length of the aerosol generating article is at least 50 millimeters.

13. The aerosol generating article according to any one of claims 1 to 12, wherein the diameter of the aerosol generating article is 5 mm to 7.3 mm.

14. The aerosol generating article according to claim 2, wherein the length of the mouthpiece filter is 5 mm to 12 mm.

15. An aerosol generating system comprising an electrically operated aerosol generating device and an aerosol generating article according to any one of claims 1 to 14, wherein the aerosol generating device includes means for heating the aerosol generating substrate to a temperature sufficient to generate aerosols from the aerosol generating substrate.

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