Wrapper with pH indicator for aerosol generating articles

Abstract

The present invention relates to an aerosol generating article comprising a mouthpiece portion and an aerosol-forming substrate portion, and an outer wrapper configured to connect the mouthpiece portion and the aerosol-forming substrate portion to form an aerosol generating article, wherein at least a portion of the outer wrapper is provided with a halochromic portion. The present invention also relates to an aerosol generating system comprising an aerosol generating device and the aerosol generating article of the present invention. The present invention further relates to a method for manufacturing an aerosol generating article comprising an outer wrapper provided with a halochromic portion.

Description

Technical Field

[0001] The present invention relates to an aerosol-generating article comprising a moisture-absorbing wrapper. The present invention also relates to an aerosol-generating system comprising an aerosol-generating article, and a method of manufacturing an aerosol-generating article.

Background Art

[0002] One type of aerosol-generating system is an electrically operated aerosol-generating system. A well-known handheld electrically operated aerosol-generating system typically comprises a battery, control electronics, and an electric heater for heating an aerosol-generating article specially designed for use in an aerosol-generating device. The aerosol-generating article comprises an aerosol-forming substrate. In some embodiments, the aerosol-forming substrate is in the form of a plug, such as a tobacco plug, and the electric heater contained within the aerosol-generating device is inserted into the aerosol-forming substrate when the smoking article is inserted into the aerosol-generating device.

[0003] Typically, such aerosol-generating articles are made of a combination of a plurality of rod-shaped elements, which may also be referred to as plugs. Each plug may be wrapped by a plug wrapper. A stick wrapper may be used to connect the individual rod-shaped elements and form an elongated aerosol-generating article. The proximal end of the aerosol-generating article is intended to contact the user's lips. The distal end of the aerosol-generating article is intended to be inserted inside the aerosol-generating device and is intended to be heated to generate an inhalable aerosol. The aerosol-generating article may include a substrate plug that holds the aerosol-forming substrate at the distal end and a mouthpiece filter (MPF) at the proximal end. Other plugs may be provided between the substrate plug and the mouthpiece filter. Such plugs may be, for example, cardboard tubes, cooling elements made of polylactic acid (PLA), or hollow acetate tubes (HAT).

[0004] Electrically heated aerosol-generating articles are also called heated-and-burn (HnB) articles because they are heated during consumption but not burned. HnB articles may not necessarily change their appearance during consumption, and as a result, users may have difficulty distinguishing between used and unused HnB articles. This can be a problem when consumers return used aerosol-generating articles to their original packaging along with other new (unused) aerosol-generating articles, which can occur if there is no trash can nearby for disposing of used / consumed aerosol-generating articles.

[0005] It would be desirable to provide an aerosol generating article that allows used aerosol generating articles to be easily distinguished from unused aerosol generating articles.

[0006] Nevertheless, it would be particularly desirable to provide an aerosol generating article having a front plug and a covered stick wrap that allows used aerosol generating articles to be easily distinguished from unused aerosol generating articles.

[0007] It would be even more desirable to provide aerosol-generating articles that allow used articles to be permanently distinguished from unused articles, at least for several days. [Overview of the Initiative]

[0008] According to one embodiment of the present invention, an aerosol generating article is provided, comprising a mouthpiece portion, an aerosol-forming substrate portion, and an outer wrapper configured to connect the mouthpiece portion and the aerosol-forming substrate portion to form an aerosol generating article. A halochromic portion is provided in at least a portion of the outer wrapper.

[0009] As used herein, the term “heated aerosol generating article” refers to an aerosol generating article for aerosol generation that includes an aerosol generating substrate intended to be heated rather than burned in order to release volatile compounds capable of forming aerosols. Such articles are commonly referred to as “heated non-combustible” products.

[0010] As used herein, the term "aerosol-generating substrate" refers to a substrate capable of releasing volatile compounds that can form aerosols when heated. The aerosols generated from the aerosol-generating substrates of the aerosol-generating articles described herein may be visible or invisible and may include vapors (e.g., fine particles of a substance in a gaseous state, which is normally a liquid or solid at room temperature) as well as liquid droplets of gas and condensed vapors.

[0011] As used herein, the terms “rod” or “rod-shaped element” refer to a substantially cylindrical element having a substantially polygonal cross-section, and preferably a circular, oval, or elliptical cross-section. As used herein, the term “article” refers to an aerosol-generating article unless otherwise specified.

[0012] As used herein, the term "longitudinal axis" refers to the direction corresponding to the main longitudinal axis of the aerosol generating article, extending between the upstream and downstream ends of the article. During use, air is drawn through the aerosol generating article in the longitudinal direction. The term "transverse direction" refers to the direction perpendicular to the longitudinal axis.

[0013] As used herein, the terms “upstream” and “downstream” refer to the relative position of an element (or part of an element) of an aerosol-generating article with respect to the direction in which aerosols are transported through the article during use.

[0014] The aerosol generating article according to the present invention is suitable for use in an aerosol generating system comprising an electrically heated aerosol generating device having an internal heating element for heating an aerosol generating substrate. For example, the aerosol generating article according to the present invention has a particular application in an aerosol generating system comprising an electrically heated aerosol generating device having an internal heater blade adapted to be inserted into a rod of an aerosol generating substrate. This type of aerosol generating article is described in the prior art, for example, European Patent No. EP-A-0 822 670.

[0015] As used herein, the term "aerosol generator" refers to a device that includes a heating element that interacts with an aerosol-generating substrate of an aerosol-generating article to generate an aerosol.

[0016] As used herein, the terms “halochromic moiety” or “halochromic material” refer to a moiety or material that exhibits a visibly perceptible reaction under specific pH conditions and / or upon contact with an aqueous medium having a specific pH value. The visibly perceptible reaction of a halochromic moiety may include a change in color.

[0017] The halochromic portion of the outer wrapper may include a pH indicator. The halochromic portion may be configured to change its appearance depending on the pH value when in contact with an aqueous medium. In the Arrhenius model, the halochromic portion contains hydronium ions (H3O + ) or hydrogen ions (H + It can be configured to detect )

[0018] The halochromic portion may be configured to change its appearance upon contact with saliva. The typical pH value of saliva can range from 6.2 to approximately 7.6. However, due to the consumption of food or beverages, the pH value of saliva may range from 4 to 8.5. Therefore, contact between a halochromic material and saliva may cause a halochromic reaction, such as discoloration of the halochromic portion.

[0019] As will be discussed in more detail below, the halochromic portion of the outer wrapper article may be configured in various ways. Changes in visual appearance may be visually perceived by the user. The overall user experience can be enhanced by configuring the aerosol-generating article so that the halochromic portion of the outer wrapper changes its appearance in response to changes in pH. Changes in pH may be induced by saliva on the user's lips that come into contact with the halochromic portion. Contact between saliva and the halochromic portion may occur during the use of the aerosol-generating article. Therefore, changes in visual appearance may be attributed to the user who used that particular aerosol-generating article. Thus, the user can easily distinguish between a used aerosol-generating article and an unused one.

[0020] This can be particularly advantageous when consumers return used aerosol-generating articles to their original packaging, which also stores unused aerosol-generating articles. This situation may arise when there is no available trash can for disposing of used aerosol-generating articles. The aerosol-generating articles described herein allow users to easily distinguish between used and unused aerosol-generating articles, thereby avoiding an unpleasant and potentially harmful user experience.

[0021] Furthermore, because users can distinguish between used and unused items, they may be more inclined to retain unused aerosol-generating items rather than littering or improperly disposing of used items.

[0022] The halochromic portion may be provided so as to come into contact with the user's lips during normal use of the aerosol-generating article. The halochromic portion may also be provided so as to come into contact with the user's saliva during normal use of the aerosol-generating article.

[0023] The halochromic portion may be provided adjacent to the mouthpiece portion of the aerosol-generating article. The halochromic portion may be provided on the mouthpiece portion of the aerosol-generating article. The halochromic portion may be provided around the mouthpiece portion of the aerosol-generating article.

[0024] The halochromic portion may extend around the entire circumference of the mouthpiece of the aerosol-generating article. The halochromic portion may extend around a portion of the circumference of the mouthpiece of the aerosol-generating article.

[0025] The halochromic portion may extend over the entire length of the mouthpiece of the aerosol-generating article. The halochromic portion may extend over up to 70 percent of the entire length of the mouthpiece of the aerosol-generating article. The halochromic portion may extend over up to 50 percent of the entire length of the mouthpiece of the aerosol-generating article. The halochromic portion may extend over up to 30 percent of the entire length of the mouthpiece of the aerosol-generating article.

[0026] By providing a halochromic portion on the mouthpiece of the aerosol-generating article, the likelihood that the halochromic portion comes into contact with the user's lips and / or the user's saliva is increased. This is particularly applicable to embodiments in which the halochromic portion is configured to extend around a large distance from, or even around the entire circumference of, the mouthpiece of the aerosol-generating article.

[0027] The halochromic portion may also be configured to extend over the entire length of the aerosol-generating article. The halochromic portion may extend over up to 50 percent of the entire length of the aerosol-generating article. The halochromic portion may extend over up to 25 percent of the entire length of the aerosol-generating article. The halochromic portion may extend over up to 20 percent of the entire length of the aerosol-generating article. The halochromic portion may extend around the entire circumference of the aerosol-generating article. The halochromic portion may extend around a portion of the circumference of the aerosol-generating article.

[0028] The halochromic portion does not necessarily have to be provided in the mouthpiece of the aerosol-generating article. Even when the halochromic portion is not provided in the mouthpiece, the halochromic portion can come into contact with the user's saliva, for example, when the user licks the aerosol-generating article with the tongue.

[0029] The halochromic portion is selected from materials having an appropriate threshold pH, and it may be ensured that the halochromic portion changes visually only upon contact with a pH outside the threshold range. Selecting the halochromic portion to have an appropriate threshold pH can help avoid false activation of the halochromic portion. Such false activation can lead to mis-marking an unused article as a used article when the article is actually still unused.

[0030] The halochromic material may be provided as a chemical compound in the form of a solution or slurry of an organic acid, a sugar, or an amine combined with a sugar.

[0031] The halochromic portion of the outer wrapper may be made from a halochromic paint, ink, adhesive, pigment, wax, or solution that can be applied to the outer wrapper during manufacture. The halochromic portion may include one or more of nanoparticles, dyes, chemical agents, and combinations thereof. A wide variety of materials having various pH profiles that change visually upon contact with a solution such as saliva are known.

[0032] Exposure of the halochromic portion to saliva, which can be regarded as a solution having a pH value below a given threshold pH, can chemically react the pH indicator of the halochromic portion disposed on the outer surface of the article and cause a color change. Before contact with saliva, the indicator may be configured to remain invisible and thus not affect the appearance of the aerosol-generating article. Upon contact with saliva, the chemical reaction of the halochromic portion induces a color change. This color change can be recognized by the user. Thus, the user may identify each article as a used article.

[0033] A wide variety of halochromic materials with diverse pH profiles are known to those skilled in the art. These halochromic materials may undergo a visual change at a specific threshold pH value. The specific threshold pH value may depend on the specific halochromic material used. Different halochromic substances may exhibit different color changes. Different halochromic substances may exhibit different color changes and may change color at different threshold pH values.

[0034] The halochromic portion material may initially have any desired color. The initial color of the halochromic portion can be selected as needed for any given aerosol-generating article. Advantageously, the halochromic portion may initially be transparent or white. The halochromic portion may initially appear to be the same color as the outer wrapper of the article. By configuring the halochromic portion in this way, it may not be visually recognizable in an unused aerosol-generating article.

[0035] A halochromic portion material may undergo a color change upon contact with a pH value below or above a given threshold pH value. The halochromic portion may be configured to become colored, colorless, change its color, or display a marking or message in response to a change in pH. The halochromic portion may be configured to have a gradual color change, becoming darker or stronger as the pH value increases or decreases. In any case, the halochromic portion is configured to undergo a visible color change that is recognizable to the user. The color change of the halochromic portion may depend on the pH value of the solution received over it.

[0036] The markings on aerosol-generating elements may have any preferred form that is easily perceptible and understandable to the user. The markings may include words, graphic elements, or symbols that may be useful in conveying information to the user. The markings may be printed markings. The markings may include terms such as “In Use,” “Empty,” “Dispose,” or similar terms. Symbols may include “X” (initial X), “!” (exclamation mark), warning symbols, or any other symbols suitable for warning or alerting the user. The markings may include one or more lines or dots. The markings may include patterns of lines or dots.

[0037] The halochromic portion may be configured to undergo a reversible or irreversible color change in response to a change in pH value. The halochromic portion may also be configured to include a combination of reversible and irreversible halochromic materials, which results in both reversible and irreversible visual changes.

[0038] Halochromic portions configured to produce irreversible color changes may be advantageous. Irreversible visual changes in the halochromic portion can effectively communicate to the user that an aerosol-generating article has been used. Therefore, irreversible visual changes may be advantageous in ensuring that the user is notified of a used article after consuming it.

[0039] The color change of the halochromic portion of the outer wrapper may be irreversible, at least when considering the time scale over which a user can reasonably expect to carry a used aerosol-generating item. For a color change to be considered irreversible, it must last for at least 10 days, at least 5 days, or at least 3 days. The color change of the halochromic portion of the outer wrapper may last for at least 24 hours.

[0040] The halochromic portion may comprise a single halochromic material having a specific threshold pH and a corresponding visual change. The halochromic portion may comprise multiple different halochromic materials, each of which may have a different threshold pH and / or visual change. The halochromic portion may also comprise a color-forming agent that is blended with one or more halochromic materials to obtain any desired color change effect.

[0041] The halochromic portion may contain one or more of the following halochromic materials as a pH indicator (the approximate operating range in which each pH indicator changes from substantially colorless to colored, or from a first color to a second color, is given in parentheses; as shown, some halochromic materials have multiple operating ranges): Alizarin (5.6~7.2; 11.0~12.4), Alizarin Red S (4.3~6.3), Benzopurpurine 4B (2.2~4.2), 4,4'-Bis(2-amino-1-natyluazo)-2,2'- Stilbendisulfonic acid (3.0~4.0), 4,4'-bis(4-amino-1-natylazo)-2,2'-stilbendisulfonic acid (8.0~9.0), Brilliant Yellow (6.6~8.0), Bromocresol Green (3.8~5.4), Bromocresol Purple (5.4~6.8), Bromophenol Blue (3.0~4.6), Bromothymol Blue (6.0~7.0), Chlorophenol Red (5.2~8.8), Congo Red (3.0~5.2), o-Cresolphthalein (7.8~9.8), Cresol Red (0.0~1. 0;7.0~8.8), p-dimethylaminoazobenzene (2.8~4.4), 4-(4-dimethylamino-1-nylazo)-3-methoxybenzenesulfonic acid (3.5~4.8), 2-(p-dimethylaminophenylazo)pyridine (0.2~1.8;4.4~5.6), N,N-dimethyl-p-(m-tolylazo)analine (2.6~4.8), 2,4-dinitroenol (2.0~4.7), 2-(2,4-dinitroenylazo)-1-natol-3,6-disulfonic acid, disodium salt (6.0~7.0), 6,8-dinitro-2,4-(1H) Quinazoline dione (6.4~8.0), 4-(p-exoxyphenylazo)-m-phenylene-diamine monohydrochloride (2.2~5.8), ethylbis(2,4-dimethylphenyl) ethanolate (8.4~9.6), ethyl orange (3.2~4.8), ethyl red (4.0~5.8), metacresol purple (1.2~2.8; 7.4~9.0), methyl orange (3.2~4.4), methyl red (4.8~6.0), p-naphtholbenzene (8.2~10.0), neutral red (6.8~8.0), 1o-nitrophenol (5.4~6.6) m-nitrophenol (6.8-8.6), phenolphthalein (8.2-9.8), phenol red (6.6-8.0), 4-phenylazo-1-naphthylamine (4.0-5.6), propyl red (4.8-6.6), rezazurin (3.8-6.4), resorcinol blue (4.4-6.2), tetrabromophenolphthalein ethyl ester, potassium salt (3.0-4.2), and thymol blue (1.2-2.8, 8.0-9.6).

[0042] The halochromic portion may also contain one or more of the following halochromic materials as pH indicators, which change their color under basic conditions: phthalein-type pH dyes such as o-cresolphthalein, phenolphthalein, and thymolphthalein; phenol-type dyes such as m-nitrophenol and p-nitrophenol; cyanine; and bis-(2,4-dinitrophenyl)ethyl acetate.

[0043] The halochromic portion may also include one or more of the following halochromic materials as a pH indicator that changes color under acidic conditions: phthalide-type color-forming dyes such as diarylphthalide dyes and indolylphthalide dyes; fluoran dyes; leuco dyes such as acylleucorazine dyes and leucoauramine dyes; spiropyran dyes; rhodamine lactam dyes; triarylmethane dyes; and chromene dyes.

[0044] Suitable color-changing dyes that color under acidic conditions are commercially available under the trade names PERGASCRIPT® (Ciba-Geigy Corporation, Greensboro, NC) and COPIKEM® (Hilton Davis Company, Cincinnati, Ohio). Preferred color-changing dyes include crystalline violet lactone, malachite green lactone, PERGASCRIPT® Red I-6B (bis-indolylphthalide dye), PERGASCRIPT® Black I-2R (diaminofluorane dye), PERGASCRIPT® I-2G (xanthene dye), COPIKEM® 1 Black CVL, Vermilion-DCF (Hodogaya Chemical (USA) Inc.), Red-DCF (Hodogaya Chemical (USA) Inc.), and Orange-DCF (Hodogaya Chemical (USA) Inc.).

[0045] The halochromic portion may include multiple pH indicators that change color over different pH ranges. The halochromic portion may exhibit a variety of different colors depending on the detected pH value. For example, the halochromic portion may be configured to change color according to the pH value according to the following color scheme: Red, pH 2.0, very strong acid; Orange, pH 4.0, strong acid; Yellow, pH 6.0, weak acid; Green, pH 8.0, weak alkali; Blue, pH 10.0, strong alkali. In such a color change spectrum, when the halochromic portion comes into contact with saliva, a first color change from the first color to the second color may occur. When the halochromic portion is completely saturated, a further color change from the second color to the third color may occur.

[0046] The halochromic portion may include a single pH indicator material. The single pH indicator material may have one or more threshold pH values. A particularly suitable pH indicator material may be litmus. Litmus is a pH indicator material that turns red at any pH value below 5.0 and blue at any pH value above 8.0. Therefore, either color change can be perceived as an indication that the item has been used. Furthermore, this pH indicator material allows the user to determine whether their saliva is acidic or basic. The color change may also include, but is not required, a change in hue (i.e., a change from light blue to dark blue, or from pink to red) or a complete change in color (i.e., a change from red to blue).

[0047] Suitable color-forming or color-changing agents may include leuco dyes, liquid crystal-based inks, colorants, and melting materials. Color changes can be brought into contact with a color activator / colorant that induces proton transfer to the leuco dye, thereby allowing the leuco dye to take on its colored form; however, similar color changes from substantially colorless to colored can also result from electron transfer and / or proton transfer reactions. Leuco dyes are dyes that can switch between two chemical forms. In one of these chemical forms, the leuco dye may be colorless. In the other chemical form, the leuco dye may have a specific color.

[0048] Reversible conversions between different chemical forms of leuco dyes can be caused by changes in pH. Irreversible conversions may involve reduction or oxidation reactions. The colorless form of a leuco dye can be called the leuco form. From a structural standpoint, the change from substantially colorless to colored is often induced by cleaving the lactone ring to form a more conjugated species that absorbs in the visible range.

[0049] As described above, the aerosol-generating article may be provided with an outer wrapper, and at least a portion of the outer wrapper may be provided with a halochromic portion. The halochromic material of the halochromic portion may be applied to the surface of the outer wrapper by one or more of the following techniques: spray printing, microcapsule coating, stamping, printing, silkscreen printing, intaglio printing, letterpress printing, lithography, stencil printing, flexographic printing, and coater printing. The appropriate coating technique may be selected depending on the halochromic material and the wrapping material used. The halochromic material may be provided in the form of a halochromic ink. The halochromic ink can be deposited onto the wrapper material using conventional printing techniques.

[0050] Halochromic materials may be mixed with adhesives to obtain pH-sensitive adhesives. Such pH-sensitive adhesives may be used to form an adhesive seal on the outer wrapper of an aerosol-generating article.

[0051] The halochromic material may be provided in the form of a pH-sensitive wax. Such a pH-sensitive wax may be applied to any desired portion of the outer wrapper of the aerosol-generating article, as described above.

[0052] The outer wrapper may be a paper wrapper. The outer wrapper may be formed from conventional paper used in the manufacture of aerosol-generating articles. The outer wrapper may also be called chipping paper. The chipping paper is used to connect the mouthpiece portion to the rest of the aerosol-generating article.

[0053] The outer wrapper may be formed from a paper sheet material having a thickness of less than 100 micrometers. The outer wrapper may be formed from a paper sheet material having a thickness of less than 65 micrometers, less than 60 micrometers, less than 55 micrometers, less than 50 micrometers, less than 45 micrometers, less than 40 micrometers, or less than 35 micrometers.

[0054] The total basis weight of the paper sheet material on which the outer wrapper is formed may be less than 65 grams per square meter, less than 60 grams per square meter, less than 55 grams per square meter, less than 50 grams per square meter, less than 45 grams per square meter, less than 40 grams per square meter, less than 35 grams per square meter, less than 30 grams per square meter, less than 25 grams per square meter, or less than 20 grams per square meter.

[0055] The outer wrapper may be formed from a paper sheet material having an appropriate porosity.

[0056] The permeability of the paper sheet material used in the hydrochromic portion of the stick wrap may exceed 30 centrosta units (CU) at an applied pressure difference of 1 kilopascal (kPa). The uncracked outer wrapper may exhibit a filtronic pressure drop of approximately 14.1–24.2 millimeters of water column. In this context, the term “filtronic pressure drop” is defined as the number of millimeters of water passing through the layer of chipping paper in response to a flow rate of 17.5 cubic centimeters / second.

[0057] The paper material used to form the outer wrapper may itself be pH-sensitive paper that changes color in response to changes in pH value.

[0058] The chemical reactions that lead to the color change of halochromic materials are substantially independent of the paper wrapper material. However, the surface properties of the paper wrapper can influence the chemical reactions.

[0059] An aerosol-generating article may comprise multiple elements, including a rod of an aerosol-generating substrate.

[0060] The aerosol-generating article may generally include a hollow acetate tube directly adjacent to the aerosol-generating substrate. The rod of the aerosol-generating substrate is formed of an aerosol-forming material, which may include homogenized tobacco material.

[0061] As used herein, the term “homogenized tobacco material” encompasses any tobacco material formed by the aggregation of tobacco material particles. Sheets or webs of homogenized tobacco material are formed by aggregating particulate tobacco obtained by grinding one or both of the leaf blades and / or stems of tobacco leaves, or by other means of powdering. Furthermore, homogenized tobacco material may also contain one or more small amounts of tobacco dust, tobacco fines, and other particulate tobacco by-products formed during tobacco processing, handling, and shipping. Sheets of homogenized tobacco material may be produced by molding, extrusion, papermaking processes, or any other suitable process known in the art.

[0062] In a preferred embodiment, the rod comprises one or more sheets of homogenized tobacco material assembled to form a plug and surrounded by an outer wrapper. As used herein in relation to the present invention, the term “sheet” refers to a thin, layered element having a width and length considerably greater than its thickness. As used herein in relation to the present invention, the term “assembly” refers to a sheet that is spiraled, folded, or otherwise compressed or shrunk substantially transversely to the longitudinal axis of an aerosol-generating article.

[0063] The homogenized tobacco material sheet used in the present invention may have a tobacco content of at least about 40 weight percent on a dry weight basis, more preferably at least about 50 weight percent on a dry weight basis, more preferably at least about 70 weight percent on a dry weight basis, and most preferably at least about 90 weight percent on a dry weight basis.

[0064] The homogenized tobacco material sheet preferably contains an aerosol-forming agent. The homogenized tobacco material sheet may contain a single aerosol-forming agent, or it may contain a combination of two or more aerosol-forming agents.

[0065] Suitable aerosol-forming materials are well known in the industry and include, but are not limited to, monohydric alcohols (such as menthol), polyhydric alcohols (such as triethylene glycol, 1,3-butanediol, and glycerin), esters of polyhydric alcohols (such as glycerol monoacetate, glycerol diacetate, or glycerol triacetate), and aliphatic esters of monocarboxylic acids, dicarboxylic acids, or polycarboxylic acids (such as dimethyl dodecanediate, dimethyl tetradecanediate, erythritol, 1,3-butylene glycol, tetraethylene glycol, triethyl citrate, propylene carbonate, ethyl laurate, triacetin, meso-erythritol, diacetin mixtures, diethyl suberate, triethyl citrate, benzyl benzoate, benzyl phenylacetate, ethyl vanillate, tributyline, lauryl acetate, lauric acid, myristic acid, and propylene glycol).

[0066] The homogenized tobacco material sheet preferably has an aerosol-forming content of more than 5 percent by dry weight. The homogenized tobacco material sheet may have an aerosol-forming content of approximately 5 percent to approximately 30 percent by dry weight. In one preferred embodiment, the homogenized tobacco material sheet has an aerosol-forming content of approximately 20 percent by dry weight.

[0067] The homogenized tobacco material sheet used in the present invention may contain one or more endogenous binders which are endogenous tobacco binders, one or more exogenous tobacco binders which are exogenous tobacco binders, or a combination thereof, in order to assist in the aggregation of particulate tobacco. Alternatively, or additionally, the homogenized tobacco material sheet used as an aerosol generating substrate may contain other additives including, but not limited to, tobacco fibers and non-tobacco fibers, aerosol formers, wetting agents, plasticizers, flavoring agents, fillers, aqueous and non-aqueous solvents, and combinations thereof.

[0068] Suitable exogenous binders to be included in the homogenized tobacco material sheet used in the present invention are well known in the industry and include, but are not limited to, rubbers such as guar gum, xanthan gum, gum arabic, and locust bean gum; cellulose binders such as hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, and ethyl cellulose; polysaccharides such as starch, organic acids (such as alginic acid), conjugated base salts of organic acids (such as sodium alginate), agar, pectin, and combinations thereof.

[0069] Suitable non-tobacco fibers for inclusion in homogenized tobacco material sheets used in aerosol generating substrates are well known in the art and include, but are not limited to, cellulose fibers, coniferous fibers, hardwood fibers, jute fibers, and combinations thereof. Before inclusion in homogenized tobacco material sheets used in aerosol generating substrates, the non-tobacco fibers may be treated by suitable processes well known in the art, including, but are not limited to, mechanical pulping, purification, chemical pulping, bleaching, sulfate pulping, and combinations thereof.

[0070] The homogenized tobacco sheet used in this invention preferably has a width of about 70 mm to about 250 mm, for example, about 120 mm to about 160 mm. The thickness of the homogenized tobacco sheet is preferably about 50 micrometers to about 300 micrometers, and more preferably about 150 micrometers to about 250 micrometers.

[0071] The homogenized tobacco sheets used in the aerosol generating article of the present invention may be manufactured by methods well known in the art, for example, the method disclosed in International Patent Application No. WO-A-2012 / 164009A2.

[0072] In one preferred embodiment, a sheet of homogenized tobacco material used in an aerosol-generating article is formed by a molding process from a slurry containing particulate tobacco, guar gum, cellulose fibers, and glycerin.

[0073] As described above, as an alternative to using an aggregate of homogenized tobacco material sheets, the aerosol-generating substrate may be formed from multiple strips or fragments of homogenized tobacco material sheets. For example, the aerosol-generating substrate may be formed from multiple fragments of homogenized tobacco material that are aligned along their long axis, bundled together, and packaged to form a rod of aerosol-forming substrate.

[0074] The homogenized tobacco material fragments are preferably about 10 mm to about 20 mm in length, more preferably about 12 mm to about 18 mm in length, more preferably about 14 mm to about 16 mm in length, and more preferably about 15 mm in length. Alternatively, or additionally, the homogenized tobacco material fragments are preferably about 0.4 mm to about 0.8 mm in width.

[0075] The density of the homogenized tobacco material sheet, on which the fragments are formed, is preferably about 500 to about 1500 milligrams per cubic centimeter, more preferably about 800 to about 1200 milligrams per cubic centimeter, even more preferably about 900 to about 1100 milligrams per cubic centimeter, and most preferably about 900 to about 970 milligrams per cubic centimeter.

[0076] The bulk density of homogenized tobacco material fragments within the aerosol generating substrate is preferably about 0.4 grams to about 0.8 grams per cubic centimeter, preferably about 0.5 grams to about 0.7 grams per cubic centimeter, and most preferably about 0.65 grams to about 0.67 grams per cubic centimeter.

[0077] As described above, homogenized tobacco material can be formed by molding a slurry. Alternatively, homogenized tobacco material can be formed by another preferred method, such as extrusion.

[0078] The aerosol-generating substrate preferably comprises a rod of homogenized tobacco material surrounded by a wrapper, the wrapper being provided in contact with the homogenized tobacco material. The wrapper may be formed from any suitable sheet material having the ability to be wrapped around the homogenized tobacco material to form an aerosol-forming substrate. The wrapper may be porous or non-porous. The wrapper is preferably a paper wrapper, but alternatively, the wrapper may be made of a material other than paper.

[0079] The rod of the aerosol-forming substrate preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol-generating article.

[0080] The rod of the aerosol generating substrate preferably has an outer diameter of at least 5 mm. The rod of the aerosol generating substrate may have an outer diameter of about 5 mm to about 12 mm, for example, about 5 mm to about 10 mm, or about 6 mm to about 8 mm. In one preferred embodiment, the rod of the aerosol generating substrate has an outer diameter of within 7.2 mm ± 10 percent.

[0081] The rod of the aerosol generating substrate may have a length of about 7 mm to about 15 mm. In one embodiment, the rod of the aerosol generating substrate may have a length of about 10 mm. In a preferred embodiment, the rod of the aerosol forming substrate has a length of about 12 mm.

[0082] The rod of the aerosol generating substrate preferably has a substantially uniform cross-section along its length. It is particularly preferable that the rod of the aerosol generating substrate has a substantially circular cross-section.

[0083] The aerosol generating article according to the present invention preferably comprises one or more elements in addition to the rod of the aerosol forming substrate. For example, the aerosol generating article may further comprise at least one of a mouthpiece, an aerosol cooling element, and a support element (such as a hollow acetate tube). For example, in one preferred embodiment, the aerosol generating article comprises, in a linear and continuous arrangement, a rod of the aerosol generating substrate as described above, a support element located immediately downstream of the aerosol forming substrate, an aerosol cooling element located downstream of the support element, and a stick wrap surrounding the rod, the support element, and the aerosol cooling element.

[0084] The aerosol generating system according to the present invention comprises an aerosol generating article, as described in detail above, combined with an aerosol generating device adapted to receive the upstream end of the aerosol generating article during user experience. The aerosol generating device comprises a heating element configured to heat an aerosol generating substrate in order to generate an aerosol during use. When the aerosol generating article is inserted into the aerosol generating device, the heating element is preferably adapted to penetrate the aerosol generating substrate. For example, the heating element is preferably in the form of a heater blade.

[0085] The heating element may also be an external heating element that surrounds the aerosol-generating article during use.

[0086] The heating element may be a resistance heating element or an induction heating element.

[0087] The heating element is controlled to operate within a predetermined operating temperature range, below the maximum operating temperature, during use. The thermal indicator of the aerosol generating article is adapted so that it does not reach a threshold temperature during normal use of the aerosol generating article in an aerosol generator where the heating element operates below the maximum operating temperature. This ensures that the thermal indicator does not activate during normal use when the aerosol generating article and aerosol generator are used together.

[0088] The aerosol generator preferably further includes a housing, a power source connected to a heating element, and a control element configured to control the supply of power from the power source to the heating element.

[0089] A suitable aerosol generator for use in the aerosol generation system of the present invention is described in International Publication No. A2013 / 098405.

[0090] The present invention also relates to an aerosol generating system comprising an aerosol generating device and an aerosol generating article as described herein.

[0091] The aerosol-generating article may be configured as described above.

[0092] The present invention also relates to a method for manufacturing an aerosol-generating article. The method includes the steps of providing at least a mouthpiece portion and an aerosol-forming substrate portion, providing an outer wrapper, and wrapping and connecting the mouthpiece portion and the aerosol-forming substrate portion with the outer wrapper to form an aerosol-generating article. The outer wrapper is provided with a halochromic portion.

[0093] Providing a halochromic portion on the outer wrapper may be achieved in several ways. The halochromic portion may be obtained by applying a halochromic solution containing a pH indicator to the paper wrapper. The halochromic material may be applied or laminated onto the surface of the paper wrapper in the form of a paint, ink, dye, or another layer of material having the applied halochromic material. The halochromic solution may be applied using different methods such as spraying, microcapsule application, stamping, and printing. Suitable printing methods include screen printing, intaglio, letterpress printing, lithography, stencil printing, flexographic printing, and coater printing.

[0094] Halochromic materials may also be applied to paper wrappers by evaporation-drying, penetration-drying, emulsion, or oxidative polymerization methods. Halochromic materials may also be provided in the form of thermosetting resins, photocuring resins, or printing inks. Application of halochromic materials may also involve the use of molds.

[0095] Applying a halochromic solution to paper may involve applying a leuco dye by printing or stamping ink onto a paper wrapper. The halochromic material may be based on the concept of liquid crystal. In this case, the material may need to be encapsulated and then applied to the paper wrapper.

[0096] The wrapper material may be formed from pH-sensing sensor paper. The halochromic material may be integrated with the pH-sensing sensor paper. The halochromic material may further be integrated with at least any other component, layer, or portion of the outer wrapper. The halochromic material may be incorporated into the wrapper material during paper manufacturing. The halochromic material may be immersed in the paper structure during paper manufacturing. In this way, the halochromic material may form part of the paper material rather than being coated onto the surface of the paper wrapper after paper manufacturing. [Examples]

[0097] 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.

[0098] Example 1: An aerosol generating article comprising a mouthpiece portion and an aerosol-forming substrate portion, and an outer wrapper configured to connect the mouthpiece portion and the aerosol-forming substrate portion to form an aerosol generating article, wherein a halochromic portion is provided on at least a portion of the outer wrapper. Example 2: The aerosol generating article according to Example 1, wherein the halochromic portion includes a pH indicator. Example 3: The aerosol generating article according to Example 2, wherein the halochromic portion is configured to change its appearance depending on the pH value of the aqueous medium when it comes into contact with the aqueous medium. Example 4: An aerosol generating article according to any one of Examples 1 to 3, wherein the halochromic portion is configured to change its visual appearance upon contact with saliva. Example 5: An aerosol generating article according to any one of Examples 1 to 4, wherein the halochromic portion extends at least partially circumferentially around the aerosol generating article. Example 6: The aerosol generating article according to any one of Examples 1 to 5, wherein the halochromic material is located adjacent to and / or around the mouthpiece, and preferably the halochromic material extends around the entire circumference of the mouthpiece of the aerosol generating article. Example 7: An aerosol generating article according to any one of Examples 1 to 6, wherein the halochromic material is located around the mouthpiece and extends around the entire circumference of the mouthpiece of the aerosol generating article. Example 8: The halochromic portion, in the Arrhenius model, is the hydronium ion (H3O + ) or hydrogen ions (H + An aerosol-generating article according to any one of Examples 1 to 7, configured to detect ). Example 9: An aerosol-generating article according to any one of Examples 1 to 8, wherein the halochromic portion comprises one or more of the following: nanoparticles, dyes, chemical agents, and combinations thereof. Example 10: An aerosol-generating article according to any one of Examples 1 to 9, wherein the halochromic portion is made of a halochromic paint, ink, adhesive, pigment, wax, or solution that can be applied to an outer wrapper during manufacturing. Example 11: The aerosol-generating article according to Example 10, wherein the halochromic material comprises one or more of the following: leuco dyes, liquid crystal-based inks, colorants, and melting materials. Example 12: An aerosol-generating article according to any one of Examples 1 to 11, wherein a halochromic material is applied to the surface of an outer wrapper by one or more of the following methods: spraying, microcapsule coating, stamping, printing, silkscreen printing, intaglio, letterpress printing, lithography, stenciling, flexogray, and coater printing. Example 13: An aerosol generating article according to any one of Examples 1 to 12, wherein the halochromic portion of the outer wrapper is configured to be initially transparent or to have the same (or similar) color as the outer wrapper, and the halochromic portion of the outer wrapper is configured to change color in response to the detection of a change in pH value. Example 14: An aerosol generating article according to any one of Examples 1 to 13, wherein the color change of the halochromic portion depends on the pH value of the solution received by the halochromic portion. Example 15: An aerosol-generating article according to any one of Examples 1 to 14, wherein the halochromic portion comprises a single halochromic material having a specific threshold pH and a corresponding visual change. Example 16: The aerosol generating article according to Example 15, comprising a single pH indicator dye, such as litmus, in which the halochromic material exhibits a first color below a first pH threshold and a second color above a second pH threshold. Example 17: An aerosol-generating article according to any one of Examples 1 to 16, wherein the halochromic portion comprises multiple different halochromic materials, each of which has a different threshold pH and / or visual change from one another. Example 18: An aerosol generating article according to any one of Examples 1 to 17, wherein the halochromic portion comprises a leuco dye and a color activator / color developer, and is configured to induce the transfer of protons and / or electrons to the leuco dye in a manner dependent on the pH value of the aqueous medium upon contact with the aqueous medium. Example 19: An aerosol generating article according to any one of Examples 1 to 18, wherein the halochromic portion extends in the longitudinal direction along at least partially the length of the aerosol generating article. Example 20: The aerosol generating article according to any one of Examples 1 to 19, wherein the halochromic portion is the same length as the mouthpiece, or the length of the halochromic portion is at least 75% of the length of the mouthpiece, or the length of the halochromic portion is at least 50% of the length of the mouthpiece. Example 21: An aerosol-generating article according to any one of Examples 1 to 20, wherein the color change of the halochromic portion is irreversible. Example 22: An aerosol generating system comprising an aerosol generating device and an aerosol generating article described in any of Examples 1 to 21. Example 23: A method for manufacturing an aerosol-generating article, comprising: providing at least a mouthpiece portion and an aerosol-forming substrate portion; providing an outer wrapper; and wrapping and connecting the mouthpiece portion and the aerosol-forming substrate portion with the outer wrapper to form an aerosol-generating article, wherein the outer wrapper is provided with a halochromic portion.

[0099] Features described in relation to one embodiment may be equally applicable to other embodiments of the present invention.

[0100] The present invention will be further explained with reference to the following attached drawings, which are for illustrative purposes only. [Brief explanation of the drawing]

[0101] [Figure 1] Figure 1 shows a schematic diagram of an aerosol-generating object. [Figure 2] Figure 2 shows an aerosol-generating article with a halochromic portion before and after use. [Figure 3] Figure 3 shows an aerosol-generating article having a halochromic portion that includes a text portion. [Figure 4] Figure 4 shows an aerosol-generating article having a halochromic portion with graphic elements. [Modes for carrying out the invention]

[0102] Figure 1 shows a cross-sectional view of the aerosol generating article 10. The aerosol generating article 10 comprises a mouthpiece 12 located at the proximal end of the article 10. The article 10 further comprises a PLA (polylactic acid) plug 14, a hollow acetate tube 16, and an aerosol-forming substrate portion 18, which includes an aerosol-forming substrate, for example, an assembly of homogenized tobacco sheets. A front plug 20 is provided at the distal end of the article 10. The article is enclosed by an outer wrapper 22. A central axis 24 extends centrally along the long axis of the aerosol generating article 10.

[0103] The outside air drawn into the aerosol generating article 10 by the user enters primarily through the front plug 20 at the distal or upstream end of the aerosol generating article 10. The outside air is guided through the aerosol forming substrate and mixes with vapor and other volatile substances generated as the aerosol forming substrate is heated to form an aerosol. The heated air and aerosol are then guided forward through further elements of the aerosol generating article 10 and exit the aerosol generating article 10 at the proximal or downstream end through the mouthpiece 12. All elements form an internal airflow path through the aerosol generating article 10.

[0104] Figure 2 illustrates an aerosol generating article 10, for simplification, with a mouthpiece 12 at the proximal end and only the remaining portion of the aerosol generating article 10 at the distal end. The article 10 on the left is unused. The mouthpiece 12 is provided with a halochromic portion 30 that is not visually recognizable in the unused aerosol generating article 10. The halochromic portion includes a pH indicator. In this case, the pH indicator contains phenol red. The phenol red exhibits a stepwise transition from pale yellow to orange to red over a pH range of 6.8 to 8.2.

[0105] The item 10 on the right was used and came into contact with the user's lips during use. Upon contact with the user's lips, a certain amount of the user's saliva came into contact with the halochromic portion 30 provided on the mouthpiece 12 of the aerosol generating item 10. The pH value of the user's saliva was in the range of 6.5 to 7.0. For this reason, the pH indicator of the halochromic portion 30 changed its color from pale yellow to pale orange through a visual change. The halochromic portion 30 is provided in the form of two stripes on the outer wrapper 22 of the mouthpiece 12. Thus, two pale orange stripes appear on the mouthpiece 12 of the used aerosol generating item 10. In this way, the user can easily distinguish between a used aerosol generating item and an unused aerosol generating item 10.

[0106] Figure 3 also illustrates an aerosol generating article 10 similar to the aerosol generating article 10 in Figure 2. The mouthpiece 12 is provided with a halochromic portion 30 that is not visually recognizable on an unused aerosol generating article 10. During use, the article 10 comes into contact with the user's lips, and the halochromic portion 30 provided on the mouthpiece 12 of the aerosol generating article 10 becomes recognizable. In this case, the halochromic portion 30 includes two parts 32, 34. The text portion 32 is configured to form the word element "used". Thus, in this embodiment, the user can actually read from the article 10 that the article 10 has been used. Furthermore, in the embodiment of Figure 3, the halochromic portion 30 includes a progressive portion 34 that indicates how long the aerosol generating article 10 has been used. The length of use may indicate the level of depletion of the aerosol generating article 10. The progressive marking 34 is an arrow symbol containing four segments. The first and second segments are already visible. Further segments are not yet visible and are indicated only by dotted lines. Therefore, the user can deduce from this progressive marking 34 that the aerosol-generating item 10 has already been depleted by 50 percent.

[0107] Figure 4 shows an aerosol generating article 10 comprising a plurality of rod-shaped elements 12, 14, 16, 18, and 20 connected to one another by an outer wrapper 22. The outer wrapper 22 is made from conventional cigarette paper. The aerosol generating article 10 comprises five elements: a front plug 20, a sensing medium plug 18, a hollow acetate tube 16, a PLA filter 14, and a mouthpiece 12.

[0108] When article 10 is still unused, no specific marking is visible. However, after use, when the halochromic portion 30 of the outer wrapper 22 comes into contact with the user's saliva, the halochromic portion 30 changes color and the marking appears. In this case, the halochromic portion 30 is provided in the form of a graphic figure. The figure shows a red triangle with an exclamation mark. The appearance of the graphic figure informs the user that this article 10 has already been used. Thus, the user can clearly and easily distinguish between used and unused aerosol-generating articles 10.

Claims

1. Aerosol-generating article, The mouthpiece portion and the aerosol-forming substrate portion, The aerosol generating article comprises an outer wrapper configured to connect the mouthpiece portion and the aerosol forming substrate portion, An aerosol-generating article in which a halochromic portion is provided on at least a portion of the outer wrapper.

2. The aerosol generating article according to claim 1, wherein the halochromic portion includes a pH indicator.

3. The aerosol generating article according to claim 2, wherein the halochromic portion is configured to change its appearance depending on the pH value of the aqueous medium when it comes into contact with the aqueous medium.

4. The aerosol generating article according to any one of claims 1 to 3, wherein the halochromic portion is configured to change its appearance when it comes into contact with saliva.

5. The aerosol generating article according to any one of claims 1 to 4, wherein the halochromic material is located adjacent to and / or around the mouthpiece, preferably the halochromic material extends around the entire circumference of the mouthpiece of the aerosol generating article.

6. The aerosol generating article according to any one of claims 1 to 5, wherein the halochromic portion comprises one or more of nanoparticles, dyes, chemical agents, and combinations thereof.

7. The aerosol-generating article according to any one of claims 1 to 6, wherein the halochromic portion is made of a halochromic paint, ink, adhesive, pigment, wax, or solution that can be applied to the outer wrapper paper during manufacturing.

8. The aerosol generating article according to claim 7, wherein the halochromic material comprises one or more of leuco dyes, liquid crystal-based inks, colorants, and melting materials.

9. The aerosol generating article according to any one of claims 1 to 8, wherein the halochromic portion comprises a single halochromic material having a specific threshold pH and a corresponding visual change.

10. The aerosol generating article according to claim 9, wherein the halochromic material comprises a single pH indicator dye, such as litmus, which exhibits a first color below a first pH threshold and a second color above a second pH threshold.

11. The aerosol generating article according to any one of claims 1 to 10, wherein the halochromic portion comprises a plurality of different halochromic materials, each of the different halochromic materials comprising different threshold pH and / or visual changes.

12. The aerosol generating article according to any one of claims 1 to 11, wherein the halochromic portion comprises a leuco dye and a color activator / color developer, and is configured to induce the transfer of protons and / or electrons to the leuco dye in a manner dependent on the pH value of the aqueous medium when in contact with the aqueous medium.

13. The aerosol generating article according to any one of claims 1 to 12, wherein the color change of the halochromic portion is irreversible.

14. Aerosol generator and an aerosol generating system comprising an aerosol generating article according to any one of claims 1 to 13.

15. A method for manufacturing an aerosol-generating article, To provide at least a mouthpiece portion and an aerosol-forming substrate portion, To provide an outer wrapper, This includes wrapping and connecting the mouthpiece portion and the aerosol-forming substrate portion with the outer wrapper in order to form the aerosol-generating article, A method in which a halochromic portion is provided to the outer wrapper.

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