Aerosol-generating article

Abstract

An aerosol generating article (10) for an aerosol generating device (18). The aerosol generating article (10) comprises an aerosol generating substrate (12) and a filter (14) surrounded by a wrapper (16). The filter (14) contains a thermochromic material and a flavorant, and only the tip (62) of the filter contains the thermochromic material. The thermochromic material undergoes a temperature-dependent irreversible color change at a threshold temperature or higher and has the ability to cause a color change at the tip (62) of the filter (14).

Description

Technical Field

[0001] The present disclosure generally relates to aerosol-generating articles, and more particularly to aerosol-generating articles for aerosol-generating devices.

Background Art

[0002] In recent years, the popularity and use of risk reduction devices or risk modification devices (also known as vaporizers) have grown rapidly as an alternative to the use of conventional tobacco products. Various devices and systems are available that heat or warm an aerosol-generating substrate rather than burning it to generate an aerosol that the user inhales.

[0003] Commercially available risk reduction devices or risk modification devices are generally aerosol-generating devices, i.e., so-called heat-not-burn devices. This type of device generates an aerosol or vapor by heating an aerosol-generating substrate contained in an aerosol-generating article, such as a heated tobacco stick, in a heating section to a temperature typically in the range of 150°C to 300°C. Heating the aerosol-generating substrate to a temperature within this range without burning or combusting it generates vapor, which typically cools and condenses to form an aerosol for the user of the device to inhale.

[0004] Typically, used aerosol generating articles for disposal are stored by the user together with new unused aerosol generating articles until an opportunity for disposal arises. Thus, the user must distinguish between new and used aerosol generating articles. With prior art mechanisms, this can be difficult due to the similarity in appearance of new and used aerosol generating articles. If a user attempts to smoke a used aerosol generating article by mistake, the user will have an unpleasant sensory experience and, in some cases, will be subject to an increased health risk. Further, battery power will be wasted, and as a result, the device may need to be recharged before the next smoking session. Accordingly, there is a need to provide an aerosol generating article that mitigates this drawback.

Summary of the Invention

Means for Solving the Problems

[0005] According to a first aspect of the present disclosure, there is provided an aerosol generating article for an aerosol generating device, the aerosol generating article comprising an aerosol generating substrate surrounded by a wrapper and a filter, at least a portion of the filter comprising a thermochromic material and a flavorant, the thermochromic material having the ability to cause a temperature-dependent irreversible color change at a threshold temperature or higher and to cause a color change in at least a portion of the filter. The filter preferably includes a tip, and the thermochromic material is preferably included within the tip of the filter, and most preferably only within the tip of the filter.

[0006] The user can easily distinguish between a new aerosol generating article and a used aerosol generating article based on the color change of at least a portion of the filter. Thus, the user is much less likely to accidentally select a used aerosol generating article for smoking when, for example, new aerosol generating articles 10 are stored together, and thus to suffer the associated unpleasant sensory experiences, health risks, and wasted battery use. The used aerosol generating article also has an aesthetically pleasing appearance based on the color change. When a thermochromic material is included within the tip of the filter, if the aerosol generating article is stored upright in a box, the color change, or lack thereof, may be readily visible to the user, helping the user to distinguish between a new and a used aerosol generating article without having to first remove the article from the box. Providing the thermochromic material only within the tip of the filter can reduce the amount of material used and also provide an aesthetically pleasing surprise to the user after use of the aerosol generating article.

[0007] Below a threshold temperature, the color of at least a portion of the filter can be determined by the thermochromic material. Below the threshold temperature, the color of at least a portion of the filter can indicate the identification of the flavorant. This provides a clear visual indication of the flavorant present.

[0008] The thermochromic material and / or flavorant can be impregnated within the material of at least a portion of the filter 14, for example, within the material of the tip of the filter. The thermochromic material and / or flavorant can be uniformly dispersed throughout at least a portion of the filter. Alternatively, the concentration of the thermochromic material and / or flavorant included within at least a portion of the filter can vary at different sites. The thermochromic material and / or flavorant can be included within at least a portion of the filter only at selected isolated sites.

[0009] The thermochromic material and / or flavorant can be included only within a portion of the filter, for example, only within the tip of the filter. This can reduce the materials used and thus the cost. Alternatively, the thermochromic material and / or flavorant can be included throughout the filter. This can provide a stronger visual impression.

[0010] In some cases, the threshold temperature is from 50°C to 250°C, or from 100°C to 250°C.

[0011] The thermochromic material can include any of copper(I) iodide (CuI), 2Cu(CNS) 2 .2 pyridine, or ammonium metavanadate (NH 4 VO 3 ).

[0012] In some cases, the thermochromic material and flavorant are included in a solution, and at least a portion of the filter contains the solution.

[0013] According to a second aspect of the present disclosure, a method of manufacturing an aerosol-generating article for an aerosol-generating device, the aerosol-generating article comprising an aerosol-generating substrate surrounded by a wrapper and a filter, the method comprising incorporating a thermochromic material and a flavorant into at least a portion of the filter, the thermochromic material having the ability to undergo a temperature-dependent irreversible color change above a threshold temperature and cause a color change in at least a portion of the filter, is provided.

[0014] Preferably, the filter includes a tip, and the thermochromic material is incorporated only within the tip of the filter.

[0015] In some cases, the thermochromic material and flavorant are included in a solution, and the method comprises applying the solution to at least a portion of the filter, for example, to the tip of the filter.

[0016] In some cases, the thermochromic material and flavorant are included in a solution, and the method comprises It includes dipping the tip of the filter into the solution.

[0017] In some cases, the solution contains a carrier solvent, and the method includes evaporating at least a part of the carrier solvent during the production of the aerosol-generating article.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0019] Here, by way of mere example and with reference to the accompanying drawings, embodiments of the present disclosure will be described.

[0020] Referring to FIG. 1, an aerosol-generating article 10 according to the present disclosure is schematically shown. The aerosol-generating article 10 is configured to be used with an aerosol-generating device 18, for example, as schematically shown in FIG. 2. Together, the aerosol-generating article 10 and the aerosol-generating device 18 form an aerosol-generating system 100.

[0021] The aerosol-generating device 18 can be equally referred to as a "heated tobacco device", a "heat-not-burn tobacco device", a "device for vaporizing tobacco products", etc., and is interpreted as a device suitable for realizing these effects. The features disclosed herein are equally applicable to devices designed to vaporize any aerosol-generating substrate.

[0022] The aerosol generating device 18 is a handheld portable device, which means that the user can hold and support the device with one hand without assistance. The aerosol generating device 18 has a first (or proximal) end 20 and a second (or distal) end 22 and includes a device housing 24.

[0023] The aerosol generating device 18 includes a controller 26. The aerosol generating device 18 may include a user interface for controlling the operation of the aerosol generating device 18 via the controller 26.

[0024] The controller 26 is configured to detect the start of use of the aerosol generating device 18 in response to a user input, such as pressing a button to activate the aerosol generating device 18, or in response to a detected air flow through the aerosol generating device 18. As will be understood by those skilled in the art, the air flow through the aerosol generating device 18 indicates inhalation or a "puff" by the user. The aerosol generating device 18 may include a puff detector, such as an air flow sensor (not shown), to detect the air flow through the aerosol generating device 18.

[0025] The controller 26 may include an electronic circuit. The aerosol generating device 18 includes a power source 28, such as a battery. The power source 28 and the electronic circuit may be configured to operate at a high frequency in the case of an inductive heating type vapor generating device 18. For example, the power source 28 and the electronic circuit may be configured to operate at a frequency of about 80 kHz to 500 kHz, optionally about 150 kHz to 250 kHz, and optionally about 200 kHz. The power source 28 and the electronic circuit could also be configured to operate at a higher frequency, such as in the MHz band, if desired.

[0026] The aerosol generating device 18 comprises a heating assembly 30. The heating assembly 30 further comprises a heating section 32. The heating section 32 is configured to receive the aerosol generating article 10 according to an example of the present disclosure. In some examples, the heating section 32 has a substantially cylindrical cross-section. The heating section 32 defines a cavity.

[0027] The heating section 32 has a first end 34 and a second end 36. The heating section 32 is provided with an opening 38 at the first end 34 for receiving the aerosol generating article 10. In the illustrated example, the heating section 32 includes a substantially cylindrical side wall 40, that is, a side wall 40 having a substantially circular cross-section.

[0028] The aerosol generating article 10 according to an example of the present disclosure comprises an aerosol generating substrate 12. The aerosol generating substrate 12 can be any kind of solid or semi-solid material. Exemplary types of aerosol generating solids include powders, granules, pellets, shreds, strands, particles, gels, strips, loose leaf, cut leaf, cut filler, porous materials, foamed materials, or sheets. The aerosol generating substrate 12 can include plant-derived materials, particularly tobacco. Advantageously, it can include reclaimed tobacco. The aerosol generating substrate 12 can be a tobacco plug.

[0029] The aerosol generating substrate 12 can include an aerosol forming agent. Examples of aerosol forming agents include polyhydric alcohols such as glycerin or propylene glycol and mixtures thereof. Typically, the aerosol generating substrate 12 can include an aerosol forming agent content of about 5% to about 50% on a dry weight basis. In some examples, the aerosol generating substrate 12 can include an aerosol forming agent content of about 10% to about 20%, optionally about 15% on a dry weight basis.

[0030] When heated, the aerosol generating substrate 12 can release volatile compounds. The volatile compounds can include nicotine or flavor compounds such as tobacco flavorants.

[0031] Typically, the shape of the aerosol generating article 10 corresponds to the shape of the heating section 32. The aerosol generating article 10 can generally be cylindrical or rod-shaped. The aerosol generating article 10 may be substantially formed in the shape of a stick and may generally be similar to a cigarette having a tubular region with an aerosol generating substrate 12 disposed in a suitable form. The aerosol generating article 10 is a disposable and replaceable article and can accommodate, for example, tobacco as an aerosol generating substrate. The aerosol generating article 10 may be a heated tobacco stick. The aerosol generating article 10 is a consumable.

[0032] The aerosol generating article 10 has a first end 42 (or mouth end) and a second end 44, and a filter 14 is provided at the first end 42. The filter 14 functions as a mouthpiece and may include, for example, a breathable plug containing cellulose acetate fibers.

[0033] In the illustrated example, the aerosol generating article 10 includes a first section 46, a second section 48, and a third section 49. The first section 46 includes the aerosol generating substrate 12, i.e., a tobacco plug. In the illustrated example, the entire extent of the first section 46 is not shown. The second section 48 includes a vapor outlet channel 50. The vapor outlet channel 50 includes a hollow tube 52, for example, an acetate tube. The third section 49 includes the filter 14.

[0034] In the illustrated example, the filter 14 includes a mouthpiece filter 54 and a polymer film filter 56. The aerosol generating substrate 12 and the filter 14 are surrounded by a wrapper 16, which is the paper wrapper 16 in the examples of the present disclosure, and are thus embodied as the aerosol generating article 10. In the illustrated example, a secondary paper wrapper 58, i.e., a mouth end paper, is provided at the first end 42. The wrapper 16 may be breathable. The wrapper 16 is an outer wrapper. Depending on the design, one or more vapor collection regions, cooling regions, and other structures may also be included.

[0035] To use the aerosol generating device 18, the user inserts the aerosol generating article 10 through the opening 38 into the heating section 32, such that the second end 44 of the aerosol generating article 10 is disposed at the second end 36 of the heating section 32, and the filter 14 at the first end 42 of the aerosol generating article 10 protrudes from the first end 34 of the heating section 32 so that the user can grip it with their lips.

[0036] The heating assembly 30 includes a heater 60, i.e., a heating element, arranged to heat the aerosol generating substrate 12 of the aerosol generating article 10 received in the heating section 32.

[0037] The heating assembly 30 may be an induction heating assembly (not shown). The induction heating assembly further comprises an induction coil (not shown). The induction coil is configured to be energized to generate an alternating electromagnetic field for inductively heating an inductively heatable susceptor (not shown). Thus, in such an example, the heater 60 is the inductively heatable susceptor.

[0038] The inductively heatable susceptor may be arranged around the heating section 32. Alternatively, the inductively heatable susceptor may be arranged to protrude into the heating section 32 from the second end 36 (e.g., as a heating blade or pin) through the aerosol generating substrate 12 when the aerosol generating article 10 is inserted into the aerosol generating device 18. In other examples, the inductively heatable susceptor may instead be provided within the aerosol generating substrate 12 during the manufacture of the aerosol generating article 10. In such an example, the aerosol generating article 10 comprises the inductively heatable susceptor.

[0039] The induction coil may be energized by the power supply 28 and the controller 26. The induction coil may comprise a litz wire or a litz cable. However, it should be understood that other materials may also be used.

[0040] The induction coil can extend around the heating section 32. Thus, the induction coil may be annular. The induction coil may have a substantially helical shape. In some examples, the circular cross-section of the helical induction coil can facilitate the insertion of the aerosol-generating article 10 and optionally one or more induction-heatable susceptors into the heating section 32 and ensure uniform heating of the aerosol-generating substrate 12.

[0041] The induction-heatable susceptor includes a conductive material. The induction-heatable susceptor can include, but is not limited to, one or more of graphite, molybdenum, silicon carbide, niobium, aluminum, iron, nickel, nickel-containing compounds, titanium, mild steel, stainless steel, low-carbon steel, and alloys thereof, such as nickel-chrome or nickel-copper, and composite materials of metallic materials. In some examples, the induction-heatable susceptor includes a metal selected from the group consisting of mild steel, stainless steel, and low-carbon stainless steel.

[0042] During use, when an electromagnetic field is applied in the vicinity of the induction-heatable susceptor, the induction-heatable susceptor generates heat due to the energy conversion from electromagnetic to thermal energy caused by eddy currents and magnetic hysteresis losses.

[0043] The induction coil can be arranged to operate with a varying electromagnetic field having a magnetic flux density of about 20 mT to about 2.0 T (highest density point) during use.

[0044] An alternative approach is to utilize a resistive heating assembly (not shown). In such a case, the heater 60 is a resistive heater (not shown). The resistive heater may surround the aerosol-generating substrate 12 and transfer heat to the outer surface of the aerosol-generating substrate 12. For example, the resistive heater may be arranged around the heating section 32. Alternatively, the resistive heater may be arranged to protrude into the heating section 32 from the second end 36 (e.g., as a heating blade or pin) to penetrate the aerosol-generating substrate 12 when the aerosol-generating article 10 is inserted into the aerosol-generating device 18. During use, the current from the power source 28 is supplied directly to the resistive heater to generate heat.

[0045] In an example of the present disclosure, at least a portion of the filter 14 of the aerosol generating article 10 includes a thermochromic material and a flavorant. The thermochromic material has the ability to cause a temperature-dependent irreversible color change above a threshold temperature and cause a color change in at least a portion of the filter 14. Thus, the color change in at least a portion of the filter 14 is permanent. The color change is a visual change. That is, it results in a change in the appearance of at least a portion of the filter 14.

[0046] Based on the color change of at least a portion of the filter 14, a user can easily distinguish between a new aerosol generating article 10 and a used aerosol generating article 10. Thus, the user is much less likely to accidentally select a used aerosol generating article 10 for smoking when, for example, new aerosol generating articles 10 are stored together, and thus suffer the associated unpleasant sensory experiences, health risks, and wasted battery usage. The used aerosol generating article also has an aesthetically pleasing appearance based on the color change.

[0047] In some examples, the threshold temperature is between 50°C and 250°C. The threshold temperature can be between 50°C and 200°C. The threshold temperature can be between 50°C and 300°C. The threshold temperature can be between 150°C and 300°C. The threshold temperature can be between 150°C and 250°C, or between 100°C and 250°C. The threshold temperature can be between 60°C and 220°C. The threshold temperature can be less than 300°C, less than 250°C, or less than 200°C. The threshold temperature can be at least 50°C or at least 100°C. The threshold temperature may be greater than the maximum storage temperature of the aerosol generating article 10 and lower than the minimum smoking temperature. In an example of the present disclosure, when vapor above the threshold temperature passes through the filter 14 and encounters, i.e., traverses, the thermochromic material, the thermochromic material undergoes a temperature-dependent irreversible color change. Thus, it is the vapor temperature that determines whether the threshold temperature is met.

[0048] The thermochromic material is, for example, copper(I) iodide (CuI), 2Cu(CNS) 2.2 pyridine, or ammonium metavanadate (NH 4 VO 3 ). Above the transition temperature of 60 °C to 62 °C, copper(I) iodide causes a color change from grayish-tan to orange. Above the transition temperature of 135 °C, 2Cu(CNS) 2 .2 pyridine causes a color change from green to yellow. Above the transition temperature of 220 °C, 2Cu(CNS) 2 .2 pyridine causes a color change from yellow to black. Above the transition temperature of 150 °C, ammonium metavanadate causes a color change from white to brown. Above the transition temperature of 170 °C, ammonium metavanadate causes a color change from brown to black.

[0049] In some cases, the thermochromic material may contain two or more different distinct compounds, such as copper(I) iodide (CuI), 2Cu(CNS) 2 .2 pyridine, or ammonium metavanadate (NH 4 VO 3 ).

[0050] The thermochromic material can be a dye or can be included in a dye formulation. The thermochromic material can be an ink or can be included in an ink formulation.

[0051] A flavoring, also known as a flavour, flavouring agent, or flavourant, is any substance that imparts the flavor of another substance. The flavoring can be a volatile flavor-generating component. The flavoring can be provided in solid or liquid form. The flavoring can include, but is not limited to, the following: menthol or menthol-like substances, licorice, chocolate, fruit flavors or essences (e.g., citrus, cherry, etc.), vanilla, spices (e.g., ginger, cinnamon), and tobacco flavors. In some cases, the flavoring also provides a fragrance.

[0052] In some examples, the thermochromic material and / or flavorant is included only within a portion of the filter 14. In such examples, the thermochromic material causes a color change only in the portion of the filter 14. This can reduce the materials used and thus the cost. By way of example, the portion of the filter 14 alone can be a small portion of the filter 14, for example, less than half of the filter 14. For example, in some examples, the portion of the filter alone can be the tip 62 of the filter. In other examples, the portion of the filter 14 alone can be most of the filter 14, that is, a majority of the filter 14.

[0053] Alternatively, the thermochromic material and / or flavorant can be included throughout the filter 14. In such examples, the thermochromic material causes a color change throughout the filter 14. This can provide a stronger visual impression.

[0054] In some examples, the thermochromic material and flavorant are included within the same location within at least a portion of the filter 14. In other examples, the thermochromic material and flavorant are included within different locations within at least a portion of the filter 14.

[0055] In an example where the filter 14 includes the mouthpiece filter 54 and the polymer film filter 56, the thermochromic material and flavorant can be included within the mouthpiece filter 54 and / or the polymer film filter 56. In other examples, the thermochromic material can be included within one of the mouthpiece filter 54 or the polymer film filter 56, and the flavorant can be included within the other of the mouthpiece filter 54 or the polymer film filter 56. The thermochromic material and / or flavorant can be included only within a portion of, or throughout, the mouthpiece filter 54 and / or the polymer film filter 56.

[0056] Below the threshold temperature, the thermochromic material can impart a color different from the natural color of the filter material onto at least a portion of the filter 14. Thus, the color of at least a portion of the filter 14 can be determined by the thermochromic material. In such an example, the color imparted onto at least a portion of the filter 14 by the thermochromic material above the threshold temperature can be the same as, or substantially the same as, the natural color of the filter material. Alternatively, the color imparted onto at least a portion of the filter 14 by the thermochromic material above the threshold temperature can be different from the natural color of the filter material, but also different from the color imparted onto at least a portion of the filter 14 by the thermochromic material below the threshold temperature.

[0057] In other examples, below the threshold temperature, the thermochromic material can impart a color that is the same as, or substantially the same as, the natural color of the filter material onto at least a portion of the filter 14. In such an example, the color imparted onto at least a portion of the filter 14 by the thermochromic material above the threshold temperature is different from the natural color of the filter material.

[0058] In some examples, below the threshold temperature, the thermochromic material does not impart any color onto at least a portion of the filter 14. Therefore, the thermochromic material is colorless. Thus, below the threshold temperature, the filter including the thermochromic material retains the natural color of the filter material.

[0059] In some examples, below the threshold temperature, the color of at least a portion of the filter 14 indicates the identification of a flavorant, for example, green for menthol and red for berry. This provides a clear visual indication of the flavorant present. As described above, the color of at least a portion of the filter 14 below the threshold temperature can be determined by the thermochromic material or can be the natural color of the filter material. Alternatively, the color of at least a portion of the filter 14 below the threshold temperature can be determined, for example, by the presence of a dye.

[0060] In other examples, at temperatures above the threshold temperature, the color of at least a portion of the filter 14 may indicate the identification of the flavorant, for example, green for menthol and red for berries. As described above, the color of at least a portion of the filter 14 at temperatures above the threshold temperature is caused by the temperature-dependent irreversible color change of the thermochromic material.

[0061] In some examples, the thermochromic material and / or the flavorant is impregnated within the material of at least a portion of the filter 14. Thus, the thermochromic material and / or the flavorant is integral with at least a portion of the filter 14. The thermochromic material and / or the flavorant is integrated within the material of at least a portion of the filter 14. The thermochromic material and / or the flavorant is bonded to the material of at least a portion of the filter 14. The thermochromic material and / or the flavorant is incorporated within the material of at least a portion of the filter 14.

[0062] The thermochromic material and / or the flavorant can be uniformly dispersed throughout at least a portion of the filter 14. Alternatively, in some examples, the concentration of the thermochromic material and / or the flavorant contained within at least a portion of the filter 14 is different at different sites. For example, the thermochromic material and / or the flavorant can be concentrated on or around the visible front portion of the filter 14, i.e., the filter tip 62. The thermochromic material and / or the flavorant can be contained within at least a portion of the filter 14 only at selected isolated sites.

[0063] The thermochromic material and the flavorant can be contained within a solution. Thus, in such examples, the thermochromic material is mixed with the flavorant. At least a portion of the filter 14 can contain the solution. In some examples, the solution is impregnated within the material of at least a portion of the filter 14. Thus, the solution is integral with at least a portion of the filter 14. The solution is integrated within the material of at least a portion of the filter 14. The solution is bonded to the material of at least a portion of the filter 14. The solution is incorporated within the material of at least a portion of the filter 14.

[0064] The solution may contain one or more additional components, i.e., ingredients, that, for example, increase or improve the flavor / aroma. Such additional components include, but are not limited to, the following substances: sugar or sugar-like substances, oils, alcohols, or fragrances.

[0065] During use of the aerosol generation system 100, heat from the heater 60 (i.e., an inductively heatable susceptor or a resistive heater) is transferred to the aerosol generation substrate 12 of the aerosol generation article 10 disposed in the heating compartment 32, for example, by conduction, radiation, and convection, to generate vapor by heating the aerosol generation substrate 12 (without burning the aerosol generation substrate 12), and the vapor is cooled and condensed to form an aerosol for inhalation by the user of the aerosol generation device 18 through the filter 14. When the vapor / aerosol above the threshold temperature passes through the filter 14, the thermochromic material undergoes a temperature-dependent irreversible color change, causing a color change in at least a portion of the filter 14 containing the thermochromic material. The flavorant present within at least a portion of the filter 14 imparts flavor to the vapor / aerosol as the vapor / aerosol passes through the filter 14. Evaporation of the aerosol generation substrate 12 is promoted, for example, by adding air from the ambient environment through an air inlet (not shown).

[0066] Generally speaking, a vapor is a substance that is in the gaseous phase at a temperature lower than its critical temperature, which means that the vapor can be condensed into a liquid by increasing the pressure without lowering the temperature. On the other hand, an aerosol is one in which fine solid particles or droplets are suspended in air or another gas. However, it should be noted that in this specification, the terms "aerosol" and "vapor" can be used interchangeably, particularly with respect to the form of the inhalable medium generated for the user to inhale.

[0067] Examples of the present disclosure also provide a method of manufacturing an aerosol generation article 10 according to the examples of the present disclosure. The method includes incorporating a thermochromic material and a flavorant within at least a portion of the filter 14.

[0068] As described above, in some examples, the thermochromic material and the flavorant are included in a solution. In such examples, the thermochromic material is mixed with the flavorant. The solution can be in the form of a liquid, an oil, or a wax. In such examples, the method includes applying the solution to at least a portion of the filter 14. The solution can be impregnated into the material of at least a portion of the filter 14. The solution can be applied by taking advantage of the capillary forces of the filter 14, for example, by dipping or applying the solution onto the tip 62 of the filter 14. Alternatively, the solution can be dispersed within the material of the filter 14 (i.e., the filter material), for example, by spraying the solution onto the filter material before forming the cylindrical shape of the filter 14.

[0069] The solution can include a carrier solvent. In such examples, the method can include evaporating at least a portion of the carrier solvent during the manufacture of the aerosol-generating article 10. The carrier solvent can be partially or fully evaporated during manufacture, i.e., before use. In the case of a liquid solution, the carrier solvent can be aqueous or non-aqueous.

[0070] In some examples, if it is desired to reduce the evaporation of the carrier solvent, a humectant can be added to the carrier solvent or used as the carrier solvent. Suitable humectants include, but are not limited to, the following: polyhydric alcohols (e.g., propylene glycol (PG), triethylene glycol, 1,2-butanediol, and vegetable glycerin (VG)) and their esters (e.g., glycerol mono-, di-, or tri-acetate).

[0071] Before evaporation of the carrier solvent, the typical solution volume is in the range of 0.1 ml to 1.0 ml, and in particular, the solution volume can be 0.3 ml. Typically, the thermochromic material can be less than 10% of the liquid volume, and the dry volume of the solution can typically be less than 50% of the liquid volume.

[0072] The figure also illustrates a method of manufacturing the aerosol generating device 10 according to an example of the present disclosure. The figure also illustrates a method of providing the aerosol generating system 100 according to an example of the present disclosure.

[0073] Although the exemplary embodiments have been described in the previous paragraphs, it should be understood that various modifications to those embodiments can be made without departing from the scope of the appended claims. Therefore, the breadth and scope of the claims should not be limited to the exemplary embodiments described above.

[0074] Unless otherwise stated herein or clearly inconsistent with the context, any combination of any possible variations of the above features is encompassed by the present disclosure.

[0075] Throughout this specification and the claims, unless the context clearly requires otherwise, words such as "comprise", "comprising", etc. should be construed in an inclusive sense, i.e., in the sense of "including, but not limited to", rather than in an exclusive or exhaustive sense.

Claims

1. Aerosol generating article (10) for an aerosol generating device (18), the aerosol generating article (10) comprising an aerosol generating substrate (12) and a filter (14) surrounded by a wrapper (16), wherein the filter (14) includes a tip (62), the filter (14) includes a thermochromic material and a flavoring agent, the thermochromic material is contained only within the tip (62) of the filter, and the thermochromic material undergoes a temperature-dependent irreversible color change above a threshold temperature, and has the ability to cause a color change at the tip (62) of the filter (14).

2. The aerosol generating article (10) according to claim 1, wherein, below the threshold temperature, the thermochromic material imparts a color different from the natural color of the filter material to the tip (62) of the filter (14).

3. The aerosol generating article (10) according to claim 1 or 2, wherein, below the threshold temperature, the color of the tip (62) of the filter (14) indicates the identification of the flavoring agent.

4. The aerosol generating article (10) according to claim 1 or 2, wherein the thermochromic material and / or flavoring is impregnated into the material at the tip (62) of the filter 14.

5. The aerosol generating article (10) according to claim 1 or 2, wherein the thermochromic material and / or flavoring is uniformly dispersed over the entire tip (62) of the filter (14).

6. The aerosol generating article (10) according to claim 1 or 2, wherein the concentrations of the thermochromic material and / or flavoring contained within the tip (62) of the filter (14) are different and contained only within at least a portion of the filter (14) in different parts or selected isolated parts.

7. The aerosol generating article (10) according to claim 1 or 2, wherein the flavoring is contained only within a portion of the filter (14), and the portion is preferably the tip (62) of the filter.

8. The aerosol generating article (10) according to claim 1 or 2, wherein the flavoring is contained throughout the filter (14).

9. The aerosol generating article (10) according to claim 1 or 2, wherein the threshold temperature is 50°C to 250°C.

10. The aforementioned thermochromic material is copper(I) iodide (CuI), 2Cu(CNS) ２ 2. Pyridine, or ammonium metavanadate (NH ４ VO ３ An aerosol generating article (10) according to claim 1 or 2, comprising any of the following:

11. The aerosol generating article (10) according to claim 1 or 2, wherein the thermochromic material and the flavoring agent are contained in a solution, and the tip (62) of the filter (14) contains the solution.

12. A method for manufacturing an aerosol generating article (10) for an aerosol generating device (18), wherein the aerosol generating article (10) is surrounded by a wrapper (16) The aerosol generating substrate (12) and filter (14) are provided, and the filter (14) includes a tip (62), and the method is A method comprising incorporating a thermochromic material and a flavoring agent into the filter (14), wherein the thermochromic material is incorporated only into the tip (62) of the filter, and the thermochromic material has the ability to undergo a temperature-dependent irreversible color change above a threshold temperature, causing a color change at the tip (62) of the filter (14).

13. The aforementioned heat-changeable material and flavoring agent are contained in the solution, and the method is The method according to claim 12, comprising applying the solution to the tip (62) of the filter (14).

14. The aforementioned heat-changeable material and flavoring agent are contained in the solution, and the method is The method according to claim 12 or 13, comprising immersing the tip (62) of the filter in the solution.

15. The solution contains a carrier solvent, and the method is The method according to claim 13, comprising evaporating at least a portion of the carrier solvent during the manufacture of the aerosol generating article (10).

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