WO2016024206A1

WO2016024206A1 - Moisturized activated carbon for smoking articles

Info

Publication number: WO2016024206A1
Application number: PCT/IB2015/056081
Authority: WO
Inventors: Yves Jordil
Original assignee: Philip Morris Products S.A.
Priority date: 2014-08-11
Filing date: 2015-08-10
Publication date: 2016-02-18
Also published as: RU2692843C2; RU2017102175A3; KR20170041667A; JP6944368B2; JP2017529829A; KR102570776B1; RU2017102175A

Abstract

Smoking articles include activated carbon with high initial moisture content and a breakable capsule situated where moisture can be transferred from the capsule to the activated carbon. Preferably, the activated carbon has a moisture content sufficient to prevent the activated carbon from decreasing the moisture content of the capsule by an amount that causes the capsule to leak or break under routine storage and handling conditions of the article.

Description

MOISTURIZED ACTIVATED CARBON FOR SMOKING ARTICLES

This disclosure relates to smoking articles that include activated carbon and a breakable capsule.

Combustible smoking articles, such as cigarettes, typically have shredded tobacco (usually in cut filler form) surrounded by a paper wrapper forming a tobacco rod. A cigarette is employed by a smoker by lighting one end of the cigarette and burning the tobacco rod. The smoker then receives mainstream smoke by drawing on the opposite end or mouth end of the cigarette, which typically contains a filter. The filter is positioned to entrap some constituents of mainstream smoke before the mainstream smoke is delivered to a smoker.

A number of smoking articles in which an aerosol generating substrate, such as tobacco, is heated rather than combusted have also been proposed in the art. In heated smoking articles, the aerosol is generated by heating the aerosol generating substrate. Known heated smoking articles include, for example, smoking articles in which an aerosol is generated by electrical heating or by the transfer of heat from a combustible fuel element or heat source to an aerosol generating substrate. During smoking, volatile compounds are released from the aerosol generating substrate by heat transfer from the heat source and entrained in air drawn through the smoking article. As the released compounds cool they condense to form an aerosol that is inhaled by the consumer. Also known are smoking articles in which a nicotine- containing aerosol is generated from a tobacco material, tobacco extract, or other nicotine source, without combustion, and in some cases without heating, for example through a chemical reaction. Such non-combustible smoking articles may also include a filter positioned to adsorb smoke constituents before the mainstream smoke is delivered to a user.

Filters in smoking articles, whether combustible or non-combustible, may contain activated carbon to remove selected constituents from smoke.

Combustible or non-combustible smoking articles may include breakable capsules to provide enhanced flavor or other sensory attributes during smoking of the article. The capsules may include one or more flavorants, cooling or freshening agents, or the like. The capsules may be broken by heat, mechanical forces, or other suitable mechanisms to release contents of the capsule for delivery to a smoker.

The capsules may be placed in proximity to activated carbon within a smoking article, which can result in premature rupture of the capsule. The inventors have found that activated carbon, typically having a moisture level of about 2%, can act as a desiccant and can adsorb moisture from the shell of capsules, which can cause the capsules to leak or rupture prematurely. For example, the activated carbon may adsorb moisture from its environment including the capsules to reach a level of about 10% to 15%, and as a result, the capsules may leak or rupture during storage or when the smoking article is being handled prior to the article being smoked.

One object of the present invention is to provide a smoking article that includes activated carbon and a breakable capsule where the breakable capsule is not prematurely ruptured due to desiccant activity of the activated carbon. Other objects of the present invention will be evident to those of skill in the art upon reading and understanding the present disclosure, which includes the claims that follow and accompanying drawings.

In various aspects of the present invention, smoking articles include activated carbon material with high initial moisture content and a breakable capsule in sufficiently close proximity to the activated carbon material to allow transfer of moisture between the breakable capsule and the activated carbon. Preferably, the activated carbon material has a moisture content sufficient to prevent the activated carbon material from decreasing the moisture content of the capsule by an amount that causes the capsule to break under routine storage conditions of the article. In some embodiments, the activated carbon material has a moisture content of about 5% or greater.

As used herein, "moisture content" means weight percent of moisture in a material. Moisture content can be measured by comparing the weight of a test material to the weight of the material when it is dried. The difference in weight is attributable to the moisture that is residing in the material. The moisture is primarily water. A material may be dried via any suitable technique, such as drying in an oven at an elevated temperature to remove moisture.

In some aspects a smoking article includes a filter portion comprising an upstream portion and a downstream portion. The upstream portion comprises activated carbon having a moisture content of about 5% or greater, and the downstream portion is free of activated carbon. The smoking article includes a single breakable capsule which is positioned between the upstream portion and the downstream portion or in the upstream portion. The breakable capsule is positioned within a distance from the activated carbon sufficient to allow transfer of moisture between the activated carbon material and the breakable capsule. The smoking article is free of breakable capsules other than the single breakable capsule.

Various aspects of the smoking articles of the present invention may have one or more advantages relative to currently available smoking articles that include breakable capsules and activated carbon. For example, because the activated carbon material of the smoking articles has high initial moisture content, the breakable capsules are less likely to become dry and to leak or break prematurely. Capsules that leak or break prematurely deliver less flavor when the user causes the capsule to break while the smoking article is smoked. Accordingly, a user is more likely to have the desired smoking experience due to full flavor delivery via the capsules with smoking articles according to various aspects of the present invention. In other words, it is less likely that a user will find a leaking or broken capsule in a smoking article. The incidence of leakage or broken capsule in smoking articles under storage or retail environments that are hot, dry or both hot and dry is expected to be lower with various aspects of smoking articles of the present invention. In addition, smoking articles according to various aspects of the present invention can be exposed to drier or hotter conditions than currently available articles during storage and handling. Additional advantages of one or more aspects of smoking articles described herein will be evident to those of skill in the art upon reading and understanding the present disclosure.

Any suitable breakable capsule may be employed in a smoking article as described herein. A breakable capsule includes a core containing a flavorant or other sensory-enhancing agent and includes a shell surrounding the core. Contents of the core can be released upon breaking the shell.

A breakable capsule may have any suitable shell. For example, the shell of a breakable capsule can be a polysaccharide based material, such as pectin or alginate; gelatin; a paraffin wax; a polyvinyl alcohol; vinyl acetate; algin; or any other suitable material or combinations thereof. It can be appreciated that a multitude of processes exist for manufacturing breakable capsules. Accordingly, the capsules can be of varying size and shape, differing resistance to kinetic or thermal forces to break or rupture the capsule, and can include alternative capsule compositions and capsule constituents.

Any suitable sensory-enhancing agent may be included in the core of a breakable capsule. Suitable flavorants include aromatic or fragrance molecule as conventionally used in the formulation of flavoring or fragrance compositions.

Preferably, the flavorant is an aromatic, terpenic or sesquiterpenic hydrocarbon. The flavorant may be an essential oil, alcohol, aldehyde, phenolic molecule, carboxylic acid in their various forms, aromatic acetal and ether, nitrogenous heterocycle, ketone, sulfide, disulfide and mercaptan which may be aromatic or non-aromatic. Examples of flavoring agents include natural or synthetic aromas or fragrances. Examples of suitable fragrances are fruity, confectionery, floral, sweet, woody fragrances. Examples of suitable aromas are coconut, vanilla, coffee, chocolate, cinnamon, mint, or roasted or toasted aromas.

The core may comprise one or more sensation agents, including freshening agents, cooling agents, or hot effect agents, which respectively provide a freshening or cooling effect or a hot effect in the mouth. Suitable freshening agents may be, but are not limited to, menthyl succinate and derivatives thereof. A suitable hot effect agent may be, but is not limited to, vanillyl ethyl ether.

The concentration of sensory-enhancing agent in a breakable capsule can be adjusted or modified to provide a desired amount of the sensory-enhancing agent.

Thus, the concentration of sensory-enhancing agent within each capsule can be the same or can vary depending on the desired sensory result.

The core or the shell may comprise one or more sweeteners, which may be provided in the form of a solution or suspension in ethanol. Examples of suitable sweeteners may be, but is not limited to, sorbitol, aspartame, saccharine, NHDC, sucralose, acesulfame, neotame, or the like.

The core may comprise one or more fillers as used in aromatic emulsions such as, for example, dammar gum, wood resins of the ester gum type, sucrose acetate isobutyrate (SAIB) or brominated vegetable oils. These agents may serve to adjust the density of the fluid core. Examples of breakable capsules that may be used in smoking articles of the present invention include mechanically breakable capsules, such as crushable capsules; heat rupturable capsules; microcapsules with diameters of 0.3mm to 1.0mm; or macrocapsules with diameters of 1.0 mm to 7.0 mm; and the like. Preferably, the breakable capsules are crushable capsules. As used herein, a crushable capsule is a capsule having a crush strength from about 0.01 kp to about 5 kp, preferably from about 0.5 kp to about 2.5 kp. The crush strength of the capsule can be measured by continuously applying a load vertically onto one capsule until rupture. The crush strength of the capsules can be measured by using a LLOYD - CHATILLON Digital Force Gauge, Model DFIS 50, having a capacity of 25Kg, a resolution of 0.02 Kg, and an accuracy of +/- 0, 15 %. The force gauge can be attached to a stand; the capsule can be positioned in the middle of a plate that is moved up with a manual thread screw device. Pressure can then be applied manually. The gauge records the maximum force applied at the very moment of the rupture of the capsule (measured in, for example, Kg or in Lb). Rupture of the capsule results in the release of contents of the core.

Additional methods for characterizing capsules include crush force which is the maximum compressive force measured in, for example, Newtons that a capsule can withstand before breakage; and distance at breakage which is the change in dimension of the capsule due to compression, i.e., deformation, at breakage. It can also be expressed for example by the ratio between a dimension of the capsule (e.g., the capsule diameter) and the dimension of the capsule, measured in the direction of the compression force, when it is compressed to the point of breakage. The compression is generally applied toward the floor by the compression plates of an automatic or manual compression testing machine. Such machines are well known in the art and commercially available.

In preferred embodiments, the capsule has a crush strength prior to introduction into a smoking article of from about 0.6 kp to about 2 kp, preferably from about 0.8 kp to about 1.2 kp. The capsule preferably has a crush strength after introduction into a smoking article and subjected to a smoking test from about 0.6 kp to about 2 kp, more preferably from about 0.8 kp to about 1.2 kp. Alternatively, the capsule has a crush force value prior to introduction into a smoking article of about 10.0 N to about 20.0 N, preferably from about 11 N to about 18 N, and more preferably in the range of about 12.0 N to about 16.0 N. The compression test machine can operate at a range of speed from 10 mm/min to 420 mm/min. For capsules of diameter in the range of about 4 mm to about 7 mm diameter, the capsule prior to introduction into a smoking article may exhibit a distance at breakage of about 0.60 mm to about 0.80 mm, preferably about 0.74 mm. The above crush force and distance at breakage is typically obtained when a universal tensile/compression testing machine equipped with 100 N tension load cell like, Instron or equivalent, is operating at about 30 mm/min and at 22°C under 60% relative humidity. An example of a manual test machine is the Alluris Type FMI - 220C2 - Digital Force Gauge 0-200N - Supplier : Alluris GmbH & Co.

In some embodiments, crushable capsules are capsules as described in published European patent application EP1906775A2, entitled "Smoking device incorporating a breakable capsule, breakable capsule and process for manufacturing said capsule," or as disclosed in US2004/0261807.

Preferably, a crushable capsule incorporates selected hydrocolloids in the outer shell of the capsule, in a coating of the outer shell by a moisture barrier layer or in both the outer shell and in the coating. For example, the shell, coating or shell and coating may independently include one or more hydrocolloid selected from gellan gum, agar, alginates, carrageenans, pectins, arabic gum, ghatti gum, pullulan gum, mannan gum or modified starch, alone or as a mixture thereof or in combination with gelatin.

The shell may contain any suitable amount of the one or more hydrocolloids, such as from about 1.5% w/w to about 95% w/w, preferably from about 4% w/w to about 75% w/w, and even more preferably from about 20% w/w to about 50% w/w of the total dry weight of the shell.

The shell may further include one or more fillers. As used herein a "filler" is any suitable material that can increase the percentage of dry material in the shell. Increasing the dry material amount in a shell can result in solidifying the shell, and in making the shell physically more resistant to deformation. Preferably, the filler is selected from the group comprising starch derivatives such as dextrin, maltodextrin, cyclodextrin (alpha, beta or gamma), or cellulose derivatives such as hydroxypropylmethylcellulose (HPMC), hydroxypropylcellulose (HPC) , methylcellulose (MC) , carboxymethylcellulose (CMC), polyvinyl alcohol, polyols or mixture thereof. Dextrin is a preferred filler. The amount of filler in the shell is generally 98.5% or less, preferably from about 25% to about 95%, more preferably from about 40% to about 80%, and even more preferably from about 50% to about 60% by weight of the total dry weight of the shell.

Preferably, the shell of the capsule comprises gelatin. The shell preferably includes 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more gelatin by weight, excluding the weight of any filler that may be present in the shell.

The shell of a crushable capsule may be of any suitable thickness. In some embodiments, the shell thickness of the capsule is from about 10 microns to about 500 microns, preferably from about 30 microns to about 150 microns, more preferably from about 50 microns to about 80 microns.

A capsule for incorporation into a smoking article in accordance with the teachings presented herein may have any suitable ratio of the weight of the shell to the weight of the capsule. For example, the ratio of the weight of the shell to the weight of the shell can be from about 8% to about 50%, preferably from about 8% to about 20%, more preferably from about 8% to about 15%, by weight/total weight of the capsule.

The core of the capsule included within the smoking article of the invention may include a mixture of materials or products which are lipophilic or partially soluble in ethanol, or of molecules formulated as oil/water/oil emulsions.

The core may represent any suitable weight percent of the capsule. For example, the core of a breakable capsule represents by weight from about 50% to about 92% of the capsule, preferably from about 80% to about 92% by weight, more preferably from about 85 % to about 92% by weight.

The core of the capsule may include one or more lipophilic solvents conventionally used in the food, pharmaceutical or cosmetic industries. In preferred embodiments, these lipophilic solvents may be triglycerides, especially medium chain triglycerides, and in particular triglycerides of caprylic and capric acid, or mixtures of triglycerides such as vegetable oil, olive oil, sunflower oil, corn oil, groundnut oil, grape seed oil, wheat germ oil, mineral oils and silicone oils. The core may contain any suitable amount of lipophilic solvent. For example, the amount of lipophilic solvent in the core of a capsule is of the order of 0.01 to 90%, preferably 25 to 75% by weight of the total weight of the capsule. The core may also comprise one or more sensory-enhancing agents, fillers, sweeteners, or combinations thereof as described above.

A capsule may have any suitable total weight. For example, the total weight of the capsule can be from about 5 mg to about 60 mg, preferably from about 10 mg to about 50 mg, more preferably from about 20 mg to about 40 mg.

A capsule for incorporation into a smoking article in accordance with the teachings presented herein may have any suitable outer diametric dimension. In some embodiments, the outer diameter of the capsule is in the range of about 0.5 mm to about 8 mm, preferably from about 1 mm to about 5 mm, more preferably from about 1.5 mm to about 4.5 mm, and even more preferably from about 2.5 mm to about 4 mm.

In some embodiments, a capsule for use in a smoking article of the invention is a seamless capsule obtained through a co-extrusion process. The co-extrusion process can be a synchronous extrusion of two liquids: an external and hydrophilic liquid phase, and an internal and lipophilic liquid phase. Preferably, the co-extrusion process includes three main stages: compound drop formation, shell solidification and capsule collection. The compound drop is a sphere of the liquid fill phase inside the shell phase. The liquid fill phase constitutes the core. The shell phase constitutes the shell. The capsules of the invention may be produced by any suitable co-extrusion process, such as described in EP1906775A2 or EP 513603.

One or more breakable capsules are incorporated into a smoking article in sufficiently close proximity to activated carbon to allow transfer of moisture between the activated carbon and the breakable capsule. It will be understood that, when the activated carbon is brought into proximity to the breakable capsule, there is a transfer of moisture between them, and that once equilibrium is established, transfer of moisture continues but there is no net change in the moisture content of the breakable capsule and the activated carbon.

Activated carbon is a generic term used to describe a family of carbonaceous adsorbents with an extensively developed internal pore structure. Activated carbon can be produced from a carbonaceous source material such as wood, lignite, coal, coconut husk or shells, peat, pitch, polymers, cellulose fibers, polymer fibers, or the like. Activated carbon may be produced by any suitable process such as physical activation or chemical activation. In physical activation, the source material is developed into activated carbon using hot gases by carbonization, activation/oxidization or carbonization and activation/oxidization. The process of carbonization includes pyrolyzing source material at high temperatures, typically in the range of about 600°C to about 900°C, in the absence of oxygen. Activation/oxidization includes exposing carbonized material to oxidizing atmospheres, such as steam, carbon dioxide or oxygen, at temperatures above 250°C. Temperatures for activation/oxidization typically range from about 600°C to about 1200°C.

Chemical activation includes impregnating raw source material with certain chemicals, such as an acid, base or salt, such as phosphoric acid, potassium hydroxide, sodium hydroxide, calcium chloride, or zinc chloride. The raw materials are then carbonized at temperatures that are typically lower than physical activation carbonization. For example, temperatures for chemical activation carbonization may be in the range of from about 450°C to about 900°C. Carbonization and activation may occur simultaneously.

For purposes of the present disclosure, carbonaceous source material may be activated via any suitable process. For example, the activation process can comprise chemical activation, which may include shorter activation times and lower temperatures relative to physical activation. Alternatively, physical activation may be employed.

Pore size and surface characteristics may be varied according to well-known techniques, which can affect the efficiency with which activated carbon can remove selected smoke constituents, such as 1 ,2-propadiene, 1 ,3-butadiene, isoprene, benzene, 1 ,2-pentadiene, 1 ,3-cyclopentadiene, 2,4-hexadiene, 1 ,3-cyclohexadiene, methyl-1 ,3-cyclopentadiene, benzene, toluene, p-xylene, m-xylene, o-xylene, styrene (vinylbenzene), 1-methylpyrrole, formaldehyde, acetaldehyde, acrolein, propionaldehyde, isobutyraldehyde, 2-methyl isovaleraldehyde, acetone, methyl vinyl ketone, diacetyl, methyl ethyl ketone, methyl propyl ketone, methyl 2-furyl ketone, hydrogen cyanide, acrylonitrile, and combinations thereof. The ability to control pore size distribution and surface characteristics, such as surface oxygen concentration, of activated carbon are well known in the art. See, for example, (i) WO 2010/103323 A1 , entitled METHODS FOR INCREASING MESOPORES INTO MICROPOROUS CARBON; (ii) Lillo-Rodenas et al. (2005), Behaviour of activated carbons with different pore size distributions and surface oxygen groups for benzene and toluene adsorption at low concentrations, Carbon 43: 1758-1767; and (iii) Romero-Anaya, et al. (2010), Spherical activated carbon for low concentration toluene adsorption, Carbon 48:2625- 2633. In general, the pore size distribution and surface characteristics can be readily modified by adjusting the activating atmosphere (e.g., 0₂, C0₂ or steam) and the activation time and temperature. Further treatment, e.g. in an inert atmosphere, may be performed to modify surface oxygen content without modifying porosity. One of skill in the art may readily adjust activation parameters to achieve activated carbon for use in filters and smoking articles of the present invention.

The activated carbon for used in filters or smoking articles of the present invention preferably has a specific surface area (BET) of about 1 100 m²/g or greater. Generally, the activated carbon will have a BET of about 2500 m²/g or less. Preferably, the activated carbon has a BET of about 1600 m²/g or greater.

Activated carbon for use in smoking articles typically has a moisture content of from about 2% to about 3%. However, as described above, the inventors have found that, at such relatively low moisture content, activated carbon can act as a desiccant to dry out breakable capsules in smoking articles in which the capsules are placed in proximity to the activated carbon. According to the present invention, smoking articles that include breakable capsules in proximity to activated carbon material have a higher initial moisture content than activated carbon typically employed in smoking articles. Preferably, the activated carbon has a moisture content that is sufficiently high to prevent the activated carbon from reducing the moisture content of the capsule by an amount that causes the capsule to prematurely break, such as breakage of the capsule under routine storage and handling of the smoking article. As used herein, "routine storage and handling" means typical storage and handling conditions to which a smoking article is exposed from the time of manufacture of the article to the time the article is smoked, including transportation and handling by a retailer and the consumer. Routine storage conditions can be simulated by storage at 22°C, at 60% relative humidity for three months.

In some embodiments, the activated carbon has a moisture content sufficiently high to prevent the activated carbon from reducing the moisture content of the capsule in the smoking article by an amount that causes the capsule to break under a crush strength or crush force substantially less than the initial crush strength or crush force of the capsule. The moisture content and mechanical properties of capsules can be characterized by measuring its crush strength, crush force or distance at breakage. For example, the activated carbon may have a moisture content sufficiently high to prevent the capsule from drying by an amount that decreases the crush strength, crush force or distance at breakage of the capsule by about 50% or more upon routine storage of the smoking article. In other words, the crush strength, crush force or distance at breakage of the capsule measured after routine storage is at least 50% of the crush strength, crush force or distance at breakage of the capsule measured at the time a smoking article containing the capsule is manufactured. Preferably, the activated carbon has a moisture content sufficiently high to prevent the capsule from drying by an amount that decreases the crush strength, crush force or distance at breakage of the capsule by about 30% or more upon routine storage of the smoking article. In other words, the crush strength, crush force or distance at breakage of the capsule measured after routine storage is preferably at least 70% of the crush strength, crush force or distance at breakage of the capsule measured at the time a smoking article containing the capsule is manufactured. More preferably, the activated carbon has a moisture content sufficiently high to prevent the capsule from drying by an amount that decreases the crush strength, crush force or distance at breakage of the capsule by about 20% or more upon routine storage of the smoking article. In other words, the crush strength, crush force or distance at breakage of the capsule measured after routine storage is more preferably at least 80% of the crush strength crush force or distance at breakage of the capsule measured at the time a smoking article containing the capsule is manufactured. Even more preferably, the activated carbon has a moisture content sufficiently high to prevent the capsule from drying by an amount that decreases the crush strength, crush force or distance at breakage of the capsule by about 10% or more upon routine storage of the smoking article. In other words, the crush strength, crush force or distance at breakage of the capsule measured after routine storage is even more preferably at least 90% of the crush strength, crush force or distance at breakage of the capsule measured at the time a smoking article containing the capsule is manufactured. Most preferably, the activated carbon has a moisture content sufficiently high to prevent the capsule from drying by an amount changes the crush strength of the capsule upon routine storage of the smoking article. Experiments have shown that storage of a smoking article having a gelatin capsule under extremely dry conditions can reduce the crush force of the capsule from about 14 N as measured at the time of manufacture to 7.9 N, which results in premature breakage of the capsule when it is handled under routine conditions. As used herein, extremely dry conditions can be simulated by exposing the smoking article to a temperature of 42°C, a relative humidity of 15% for 72 hours. It has been observed that under routine storage conditions, the currently employed activated carbon can dessicate a capsule in a smoking article resulting in premature breakage similar to those instances when a smoking article without activated carbon has been exposed to extremely dry conditions. Therefore, the crush strength, crush force or distance at breakage of a capsule that is measured after the smoking article (without activated carbon) has been exposed to extremely dry conditions exemplifies the crush strength, crush force or distance at breakage of a capsule that leaks or breaks prematurely. According to the present invention, a breakable capsule in a smoking article which also contains activated carbon after storage under routine storage conditions preferably has a crush strength of at least 8 N or greater; more preferably at least 9 N or greater; even more preferably at least 10 N or greater; and yet even more preferably at least 12 N or greater.

A method to determine the effect of moisture on a capsule is based on measuring the maximum compressive force that a capsule can withstand before breaking. The compression is applied toward the floor using a standard electromechanical compression tester (Instron, Massachusetts, USA) at a machine speed of 30 mm/minute. Distance at breakage is another parameter for measuring the performance of a capsule. For example, gelatin-based capsule kept under extremely dry conditions suffers a loss of 50% of its distance at breakage. The mean distance at breakage for gelatin-based capsules stored under standard conditions was 0.74 mm (SE = 0.012, SD = 0.114, CV = 15.4% and 90 samples). As used herein, standard conditions can be simulated by exposing the smoking article to a temperature of 22°C, a relative humidity of 60% for 72 hours. For comparisons, the mean distance at breakage for gelatin-based capsules stored under extremely dry conditions was 0.34mm (SE = 0.01 , SD = 0.12, CV = 35.1 % and 90 samples). Preferably, the distance of breakage of a breakable capsule, after storage of a smoking article containing the capsule and activated carbon according to the present invention under routine conditions, is greater than 0.35 mm; more preferably greater than 0.4 mm; more preferably greater than 0.5 mm; and even more preferably greater than 0.6 mm.

To test the crush strength of a capsule after incorporation into a smoking article, the capsule may be removed from the article and tested as described above.

In some embodiments, the activated carbon material has a moisture content sufficient to prevent the activated carbon material from adsorbing about 3% or more of the moisture content of the capsule. Preferably, the activated carbon material absorbs about 1.5% or less of the moisture content of the capsule during routine storage of the smoking article. More preferably, the activated carbon material absorbs about 1 % or less of the moisture content of the capsule during routine storage of the smoking article. Typically, capsule comprising gelatin has about 10% moisture at the time the smoking article is manufactured. When the capsule moisture falls below 6-7%, the capsule is liable to leakage or premature breakage.

In some embodiments, the activated carbon material, when placed in a smoking article, has a moisture content of about 5% or greater, preferably about 8% or greater, preferably about 10% or greater, preferably about 12% or greater, preferably about 20% or greater, and more preferably about 15% or greater. Generally, the activated carbon will have a moisture content of about 25% or less. Moisture content of activated carbon can be tested by any method that is based on heating a sample in air in an oven at constant temperature (e.g., 145°C to 155°C) to constant weight, such as ASTM D2867- 09, "Standard Test Method for Moisture in Activated Carbon." (Annual Book of ASTM Standards, ASTM, 1916 Race Street, Philadelphia, PA 19104, USA). Moisture content in percentage (%) is given by the formula:

100 x (weight of original sample - weight of dried sample) / weight of original sample.

The moisture content of activated carbon can be controlled by chemical activation using oxidation treatment with hydrochloric acid and nitric acid, or potassium hydroxide to increase the hydrophilic groups up to 30%. Many techniques are known in the art for manufacturing activated carbon with hydrophilic groups of 15% to 25% and most preferably from 18% to 22%. While the moisture content of the activated carbon material may decrease over time under routine storage conditions, the high initial moisture content should be sufficient to prevent substantial drying of the breakable capsule due to desiccant activity of the activated carbon material for three or more weeks under routine storage conditions.

Activated carbon may be placed in a filter for a smoking article in any suitable manner. For example, activated carbon can be intermingled with fibrous filter material, placed in a void space in the filter, or in a combination, i.e., intermingled with fibrous filter material and in a void space in the filter.

In embodiments, activated carbon is provided in a filter in a plug-space-plug configuration, where the activated carbon is present in a void space between two sections of filter plug material. Preferably, the plugs of filter sections in a plug-space- plug filter configuration are plugs of cellulose acetate tow. In embodiments, activated carbon is provided in a carbon on tow configuration. The amount of activated carbon that can be used in a smoking article of the invention can range from about 10 mg to about 80 mg, and preferably from 25 mg to 60 mg (especially in a double filter). In a filter comprising a cavity, such as a plug-space-plug filter configuration, the amount of activated carbon in the cavity ranges from about 50 mg to about 150 mg and preferably from about 70 mg to about 120 mg.

One or more breakable capsule as described above may be placed in the smoking article, preferably in a filter element. Preferably, the filter element also contains the activated carbon. One or more breakable capsule may be placed within a void or cavity in the filter. For example, the one or more capsule may be placed in one or more cavity in a plug-space-plug configuration. The filter may contain a plurality of filter elements into which one or more breakable capsule may be placed. The filter is configured such that pressure can be applied by a smoker to the outside region of the filter to break the capsule. In some preferred embodiments, the breakable capsule is placed in filter material, such as tow.

The breakable capsule is positioned in the filter in proximity to the activated carbon material. The capsule and the activated carbon material are in sufficiently close proximity such that, the activated carbon material would adsorb at least some moisture from the capsule if the activated carbon material had sufficiently low moisture content. In some embodiments, the breakable capsule is positioned within a distance of about 0.5 mm to about 15 mm, preferably about 2 mm to about 9 mm, and most preferably about 6.75 mm from at least a portion of the activated carbon. In some embodiments, the breakable capsule is intermingled with at least some of the activated carbon.

Any suitable smoking article may include a filter having activated carbon material and a breakable capsule as described in this disclosure, where the filter is disposed downstream of a smokable material. The term "downstream" refers to relative positions of elements of the smoking article described in relation to the direction of mainstream smoke as it is drawn from a smokable material and into a user's mouth. Preferably, a breakable capsule is positioned downstream of the activated carbon such that the activated carbon does not adsorb flavorant or other sensor-enhancing agents released by the capsule.

The term "smoking article" includes cigarettes, cigars, cigarillos and other articles in which a smokable material, such as a tobacco, is lit and combusted to produce smoke. The term "smoking article" also includes articles in which smokable material is not combusted, such as but not limited to smoking articles that heat a smoking composition directly or indirectly, or smoking articles that use air flow or a chemical reaction, with or without a heat source, to deliver nicotine or other materials from the smokable material.

As used herein, the term "smoke" is used to describe an aerosol produced by a smoking article. An aerosol produced by a smoking article may be, for example, smoke produced by combustible smoking articles, such as cigarettes, or aerosols produced by non-combustible smoking articles, such as heated smoking articles or non-heated smoking articles.

All scientific and technical terms used herein have meanings commonly used in the art unless otherwise specified. The definitions provided herein are to facilitate understanding of certain terms used frequently herein.

As used herein, the singular forms "a", "an", and "the" encompass embodiments having plural referents, unless the content clearly dictates otherwise.

As used herein, "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise. The term "and/or" means one or all of the listed elements or a combination of any two or more of the listed elements. As used herein, "have", "having", "include", "including", "comprise", "comprising" or the like are used in their open ended sense, and generally mean "including, but not limited to". It will be understood that "consisting essentially of, "consisting of, and the like are subsumed in "comprising," and the like.

The words "preferred" and "preferably" refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the disclosure, including the claims.

FIG. 1 is a schematic perspective view of an embodiment of a partially unrolled smoking article. FIGS. 2-4 are schematic longitudinal sectional views of embodiments of filters including activated carbon material and a breakable capsule. The smoking articles and filters depicted in FIGS. 1 -4 illustrate embodiments of smoking articles or components of smoking articles described above. The schematic drawings are not necessarily to scale and are presented for purposes of illustration and not limitation. The drawings depict one or more aspects described in this disclosure. However, it will be understood that other aspects not depicted in the drawings fall within the scope and spirit of this disclosure.

Referring now to FIG. 1, a smoking article 10, in this case a cigarette, is depicted.

The smoking article 10 includes a rod 20, such as a tobacco rod, and a mouth end filter 30. The filter segment 30 and rod 20 are shown as being separated for purposes of illustration, but may be abutting. The depicted smoking article 10 includes plug wrap 60, cigarette paper 40, and tipping paper 50. In the depicted embodiment, the plug wrap 60 circumscribes at least a portion of the filter 30. The cigarette paper 40 circumscribes at least a portion of the rod 20. Tipping paper 50 or other suitable wrapper circumscribes the plug wrap 60 and a portion of the cigarette paper 40 as is generally known in the art. The filter 30 includes activated carbon material and a breakable capsule, which may be oriented as depicted in, for example, FIGS. 2 - 4.

FIG. 2 illustrates an embodiment where filter 30 is in a plug 32-space 33-plug 34- space 35-plug 36 configuration. Downstream plug 32 is the mouth end plug and is preferably white cellulose acetate tow. Breakable capsule 80 is disposed in void space 33 between downstream plug 32 and upstream plug 34. Activated carbon (not shown) may occupy void space 35 between filter plug 34 and filter plug 36.

Alternatively, filter 30 can include middle plug 33 in which capsule 80 is disposed. Middle plug 33 can be a separate plug or a portion of upstream 34 or downstream 32 plug.

FIG. 3 illustrates an embodiment where filter 30 is in a plug 32-space 33-plug 34 configuration. Downstream plug 32 is the mouth end plug and is preferably white cellulose acetate tow. Breakable capsule 80 is disposed in void space 33 between downstream plug 32 and upstream plug 34. Activated carbon (not shown) may also occupy the void space 33 between filter plugs 32 and 34. Alternatively, filter 30 can include middle plug 33 in which capsule 80 is disposed. Middle plug 33 can be a separate plug or a portion of upstream 34 or downstream 32 plug.

FIG. 4 illustrates an embodiment where filter 30 is in a plug 32-space 33-plug 34 configuration. Downstream plug 32 is the mouth end plug and is preferably white cellulose acetate tow. Breakable capsule 80 is disposed in void space 33 between downstream plug 32 and upstream 34. Plug 34 is a carbon-on-tow plug. Alternatively, filter 30 can include middle plug 33 in which capsule 80 is disposed. Middle plug 33 can be a separate plug or a portion of upstream 34 or downstream 32 plug.

Claims

CLAIMS:

1. A smoking article comprising:

(i) a filter portion comprising an upstream portion and a downstream portion, wherein the upstream portion comprises activated carbon having a moisture content of about 5% or greater and wherein the downstream portion is free of activated carbon; and

(ii) a single breakable capsule which is positioned between the upstream portion and the downstream portion or in the upstream portion, wherein the breakable capsule is positioned within a distance from the activated carbon sufficient to allow transfer of moisture between the activated carbon material and the breakable capsule,

wherein the smoking article is free of breakable capsules other than the single breakable capsule .

2. A smoking article according to claim 1 , wherein the upstream portion of the filter segment comprises an upstream plug of cellulose acetate tow, wherein the downstream portion of the filter segment comprises an downstream plug of cellulose acetate tow, wherein a void space is defined between the upstream plug and the downstream plug, and wherein the single breakable capsule is disposed in the void space.

3. A smoking article according to claim 1 , wherein the filter portion further comprises a middle portion between the upstream portion and the downstream portion, wherein the middle portion comprises cellulose acetate tow, and wherein the single breakable capsule is disposed within the tow of the middle portion.

4. A smoking article according to claim 1 , wherein the upstream portion comprises cellulose acetate tow, and wherein the single breakable capsule is disposed within the tow of the upstream portion.

5. A smoking article according to any one of the preceding claims, wherein the activated carbon has a moisture content of about 8% or greater.

6. A smoking article according to any one of the preceding claims, wherein the activated carbon has a moisture content of about 15% or greater.

7 A smoking article according to any one of the preceding claims, wherein the capsule comprises gelatin.

8. A smoking article according to any one of the preceding claims, wherein the moisture content of the breakable capsule measured at the time of manufacture is not reduced by an amount that is 3% or more after the smoking article is stored at 22°C, 60% relative humidity for three months.

9. A smoking article according to any one of the preceding claims, wherein the crush force of the breakable capsule is greater than 8 N after the smoking article is stored at 22°C, 60% relative humidity for three months.

10. A smoking article according to any one of the preceding claims, wherein the crush force or distance at breakage of the breakable capsule after the smoking article is stored at 22°C, 60% relative humidity for three months is 90% or more of the crush force or distance at breakage of the capsule at the time of manufacture of the smoking article.

1 1. A smoking article according to any one of the preceding claims, wherein the distance at breakage of the breakable capsule is greater than 0.4 mm after the smoking article is stored at 22°C, 60% relative humidity for three months.

A smoking article according to any one of the preceding claims, wherein the breakable capsule is positioned at a distance of about 10 mm from the activated carbon.

13. A method for manufacturing a smoking article to prevent premature breaking of a breakable capsule in the smoking article, the method comprising:

incorporating an upstream filter comprising activated carbon having a moisture content of 5% or greater into the smoking article;

incorporating a downstream filter that is free of activated into the smoking article; and

positioning a single breakable capsule in the smoking article in the upstream filter or between the upstream filter and the downstream filter such that the single breakable capsule is positioned within a distance from the activated carbon which allows transfer of moisture between the activated carbon and the breakable capsule.

14. A method according to claim 13, wherein the activated carbon has a moisture content of about 15% or greater.

15. A method according to claim 13 or claim 14, wherein the breakable capsule is positioned at a distance of about 10 mm or less from the activated carbon.