JP2020521441A - Aerosol generating article with adiabatic heat source - Google Patents

Abstract

An aerosol-generating article (2) comprising an aerosol-forming substrate (4), a combustible heat source (3), and at least one layer (5) of ceramic paper surrounding at least a portion of the length of the combustible heat source (3). .. At least one layer (5) of ceramic paper comprises a cellulosic binder. [Selection diagram] Figure 1

Description

The present invention relates to aerosol-generating articles that include an aerosol-forming substrate and a combustible heat source, and methods for forming such aerosol-generating articles.

Many aerosol generating articles in which tobacco is heated rather than burned have also been proposed in the art. One purpose of such "heated" aerosol generating articles is to reduce known harmful smoke constituents of the type produced by the combustion and pyrolysis of tobacco in combustible cigarettes. In one known type of heated aerosol-generating article, the transfer of heat from a combustible heat source to an aerosol-forming substrate located adjacent to the combustible heat source produces an aerosol. During aerosol generation, volatile compounds are released from the aerosol-forming substrate by heat transfer from a combustible heat source and become entrained in the air drawn through the aerosol-generating article. As the emitted compounds cool, they condense to form an aerosol that is inhaled by the user.

The combustion temperature of the combustible heat source for use in the heated aerosol generating article should not be so high as to result in combustion or thermal decomposition of the aerosol-forming substrate during use of the heated aerosol generating article. However, the combustion temperature of the combustible heat source is sufficiently high to release sufficient volatile compounds from the aerosol-forming substrate to produce sufficient heat to produce an acceptable aerosol, especially at the beginning of inhalation. Should be

Various combustible heat sources have been proposed in the art for use in heated aerosol generating articles. The combustion temperature of a combustible heat source for use in heated aerosol generating articles is generally about 600°C to 800°C.

In order to reduce the surface temperature of the heated aerosol generating article, it is known to wrap the surrounding area of the combustible heat source of the heated aerosol generating article with a heat insulating member. However, it has been found that such insulating members can reduce the temperature of the combustible heat source during combustion of the combustible heat source, potentially reducing the effectiveness of the heat source in heating the aerosol-forming substrate to generate the aerosol. There is. This effect is particularly pronounced when the insulating member extends substantially the length of the combustible heat source. Such an insulating member may also impede the sustained combustion of the combustible heat source, thus reducing the duration of combustion of the combustible heat source.

It is desirable to provide an aerosol-generating article that has a low surface temperature in the vicinity of the heat source, has an acceptable appearance, and can be assembled in a simple and reliable manner. It is also desirable to provide an aerosol-generating article that produces an acceptable aerosol both at the beginning and end of inhalation.

According to a first aspect of the invention, there is provided an aerosol generating article comprising an aerosol forming substrate, a combustible heat source and at least one layer of ceramic paper surrounding at least a portion of the length of the combustible heat source. .. At least one layer of ceramic paper comprises a cellulose derivative.

In use, the flammable heat source may be ignited by an external heat source such as a lighter and combustion may be initiated. The flammable heat source may heat the aerosol-forming substrate such that the volatile compounds of the aerosol-forming substrate are vaporized. When a user inhales with an aerosol-generating article, air can be drawn into the aerosol-generating article and mixed with vapor from the heated aerosol-forming substrate to form an aerosol. The aerosol can be drawn out of the aerosol generating article and delivered to the user for inhalation by the user.

At least one layer of ceramic paper surrounding at least a portion of the length of the combustible heat source may insulate the combustible heat source. This may reduce the surface temperature of the aerosol-generating article at the flammable heat source. The at least one layer of ceramic paper may also allow sufficient air to pass through the layer such that combustion of the combustible heat source is not substantially impeded.

As used herein, the term "paper" is used to describe a sheet of thin mat or fiber. Generally, the papers described herein are made from fiber pulp pressed into thin sheets or mats. The paper of the present invention may include woven fibers. However, the papers of the present invention generally include non-woven fibers. The fibers of the paper of the present invention can be randomly woven. The paper described herein is generally thin. Stated another way, the thickness or depth of the sheet of mat or fiber is substantially less than other dimensions of the mat or sheet, such as the length and width of the mat or sheet. The paper described herein is generally flexible. In other words, the papers described herein can be bent or formed to wrap around a combustible heat source such that the paper surrounds at least a portion of the combustible heat source.

As used herein, the term "ceramic paper" is used to describe a paper that comprises a ceramic material. Stated another way, the term "ceramic paper" is used to describe a thin mat or sheet of fibers containing a ceramic material. As used herein, the terms "ceramic paper" and "ceramic fiber paper" are used interchangeably.

The ceramic paper of the present invention comprises fibers of ceramic material. The ceramic paper may include woven fibers of ceramic material. The ceramic paper may include non-woven fibers of ceramic material. The ceramic paper may include a fibrous ceramic material including at least one of a ceramic fiber raw cotton, a ceramic fiber cot, and a ceramic fiber fluff. In some embodiments, the ceramic paper may include only fibers of ceramic material. Stated another way, in some embodiments, the ceramic paper may be free of fibers of non-ceramic material.

The ceramic paper may include other forms of ceramic material, including particulate ceramic material. The ceramic paper may include more than one form of ceramic material, such as fibrous ceramic material and particulate ceramic material.

The ceramic material may include any suitable ceramic material. The ceramic material may include a crystalline ceramic material. The ceramic material may include a semi-crystalline ceramic material. The ceramic material may include an amorphous ceramic material. The ceramic material may be amorphous. The ceramic material may be semi-crystalline. The ceramic material may be crystalline.

As used herein, the term "ceramic material" includes glass. As used herein, the term "glass" is used to describe materials that exhibit a glass transition at the glass transition temperature. Generally, the term "glass" is used herein to describe an amorphous or amorphous solid material. However, the term "glass" also includes materials that include crystalline and amorphous components. A glass material that includes both crystalline and amorphous components may be referred to as a "glass ceramic" material.

The attributes of the glass material of the present invention can be defined by the method of forming the glass. As used herein, the term "glass" includes glass formed by any suitable method. Suitable methods of forming glass include melt quenching, physical vapor deposition, solid state reactions including thermochemical and mechanical chemical reactions, liquid state reactions such as sol-gel methods, radiation of crystalline solids such as radiative amorphization, and pressure. Amorphization (ie formation due to the action of high pressure) is included.

In some embodiments, the ceramic material may include glass. The ceramic material may be glass. The glass may be a glass ceramic material. The ceramic paper may include glass fibers. The ceramic paper may include glass ceramic fibers.

In some embodiments, the ceramic material may not include glass. Stated differently, the ceramic material may include any ceramic material other than glass. The ceramic material need not be a glass material. The ceramic material may be free of glass fibers. In those embodiments, the ceramic material generally comprises a crystalline ceramic material.

The ceramic material may include at least one of oxides, carbides, borides, nitrides and suicides. For example, the ceramic material can include metal oxides. The ceramic paper may include at least one of silica (SiO ₂ ), calcium oxide (CaO), magnesium oxide (MgO), alumina (Al ₂ O ₃ ), and zirconium dioxide (ZrO ₂ ). All are understood to be ceramic materials. For example, the ceramic paper may include at least one of alkaline earth silicate wool, alumina silicate wool, or polycrystalline wool. The ceramic paper may include at least one of iron oxide (Fe ₂ O ₃ ), potassium oxide (K ₂ O), and sodium oxide (Na ₂ O), all of which are ceramic materials. To be understood.

The ceramic paper may include any suitable amount of fibrous material. The ceramic paper may include at least about 40 weight percent ceramic material, at least about 50 weight percent ceramic material, or at least about 60 weight percent ceramic material. The ceramic paper may include less than about 99.99 weight percent ceramic paper material, or less than about 95 weight percent ceramic material. For example, the ceramic paper may include about 50 weight percent ceramic material to about 99.99 weight percent ceramic material.

Ceramic paper may include non-fibrous materials. The non-fibrous material may include water.

At least one layer of ceramic material according to the present invention comprises a cellulosic binder. Binders are used in some ceramic papers to hold the ceramic materials together. Providing a binder may also improve the mechanical properties of the ceramic paper. For example, the binder may make the ceramic paper less fragile and more flexible. This may advantageously allow at least a portion of the combustible heat source to be wrapped with at least one layer of ceramic paper.

As used herein, the term "cellulose derivative binder" is used to describe a binder that comprises a cellulose derivative. In particular, the cellulose derivative binder may include a cellulose derivative formed by the addition of specific side groups to cellulose.

Suitable cellulose derivatives include, but are not limited to, carboxymethyl cellulose (CMC), hydroxypropyl methyl cellulose (HPMC), hydroxyethyl methyl cellulose (HEC), hydroxyethyl cellulose, cellulose acetate, cellulose ester, and cellulose ether. The cellulose derivative binder preferably comprises carboxymethyl cellulose.

The cellulosic binder may be dispersed in a liquid, such as water, at a concentration of about 0.01 weight percent to about 20 weight percent.

It has been found that the use of a ceramic paper containing a cellulosic binder advantageously holds the ceramic fibers together and provides the advantageous mechanical attributes described above. Furthermore, the use of ceramic papers containing cellulosic binders has been found not to produce an offensive odor when a flammable heat source is ignited and burned.

At least one layer of ceramic paper may include any amount of cellulosic binder. At least one layer of ceramic paper comprises at least about 0.01 weight percent cellulose derivative binder, at least about 1 weight percent cellulose derivative binder, at least about 5 weight percent cellulose derivative binder, or at least about 10 weight percent. It may include a percentage of cellulose derivative binder. In some embodiments, at least one layer of ceramic paper comprises about 40 weight percent or less cellulosic binder, about 30 weight percent or less, or about 15 weight percent or less. May be included. At least one layer of ceramic paper may include from about 0.01 weight percent to about 40 weight percent cellulosic binder. Ceramic paper may include non-ceramic materials. Non-ceramic materials may include polymeric materials. Non-ceramic materials can include organic materials. Non-ceramic materials can include inorganic materials.

The ceramic paper may be further reinforced by additional means such as particulate reinforcement. For example, ceramic paper may be reinforced with particles of carbon black. The ceramic paper may further include titanium dioxide, which may include iron and manganese, aluminum trihydrate, and any other suitable component, including but not limited to pigments.

The ceramic paper may include any suitable amount of non-ceramic material. In some embodiments, the ceramic paper may include only ceramic material. Stated another way, in some embodiments, the ceramic paper may be free of any non-ceramic material. The ceramic paper may include about 0 weight percent non-ceramic material. The ceramic paper may include 0 weight percent non-ceramic material to about 25 weight percent non-ceramic material. The ceramic paper comprises at least about 0.5 weight percent non-ceramic material, at least about 2 weight percent non-ceramic material, at least about 10 weight percent non-ceramic material, at least about 20 weight percent non-ceramic material, at least about 30 weight percent. It may comprise a percent non-ceramic material, at least about 40 weight percent non-ceramic material, or at least about 50 weight percent non-ceramic material. The ceramic paper may include less than about 40 weight percent non-ceramic material, less than about 30 weight percent non-ceramic paper material, or less than about 15 weight percent non-ceramic material.

In some embodiments, the ceramic paper may include low in vivo sustained fiber. In some particular embodiments, the fibrous material of the ceramic paper may consist of low in vivo sustained fibers.

As used herein, the term "in vivo durability" refers to the length of time that intact fibers remain in the lungs and pleura (thorax) of the human respiratory system.

Suitable short-term tests for measuring in vivo durability include short-term inhalation experiments. An exemplary short-term inhalation experiment involves exposing rodents to known concentrations of a given type of fiber daily for 6 hours, 5 days, and then sacrificing to determine lung fiber damage. Such procedures are described in Bernstein, D.; M. , C.I. Morscheidt, H.; -G. Grimm, P.G. Thevenaz, and U. Teichert (1996) Evaluation of soluble fibers using the inhalation biopersistence model, a nine-fiber comparison. Inhalation Toxicol. 8(4):345-385. A suitable short-term test to measure alternative in vivo durability is to administer rodents by intratracheal instillation with a known amount of fiber in saline and periodically sacrifice to lung lung. Included are endotracheal infusion experiments involving determining fibrotic disorders.

Findings from both the short-term inhalation method and the intratracheal infusion method can be expressed as a weighted clearance half-life (WT1/2) or as the time required to eliminate 90% of the fibers from the lungs (T90).

Short-term in vivo sustainability studies by inhalation, as described in European Commission Directive 97/69/EC Note Q of 5 December 1997, indicate that fibers longer than 20 micrometers are weighted for 10 days or less. A fiber is "low" if it has been shown to have a half-life, or if a short-term in vivo durability test by endotracheal infusion has shown that fibers longer than 20 micrometers have a weighted half-life of 40 days or less. It can be considered to have "in vivo persistence" or "low in vivo durability". Also, as described in Note Q2 of the European Commission Directive 1999/836/EC of 26 October 1999 in the International Regulation on Mineral Wool notified by the German exception from Directive 97/69/EC, 5 μm With a length of less than 3 μm and a length-to-diameter ratio (WHO fibers) greater than 3:1 with a half-life of less than 40 days after intratracheal instillation of 2 mg of a fine suspension. In some cases, a fiber may be considered to have "low biopersistence" or "low biopersistence."

Materials with low in vivo durability can be removed or eliminated from the human respiratory system by a mechanism. One exemplary mechanism for removal of material from the respiratory system is physical migration, such as by mucociliary transport. Another exemplary mechanism for the removal of materials from the respiratory system is chemical dissolution. A material may be considered "biosoluble" if the material has a sufficiently high solubility in the solvent of the respiratory system.

In some embodiments, the ceramic paper may include biosoluble fibers. In some particular embodiments, the fibrous material of the ceramic paper may consist of biosoluble fibers.

As used herein, the term "biosoluble" is used to describe materials that are soluble in biological systems, and particularly those materials that are soluble in the human respiratory system. Used to describe. The biosolubility of materials in the human respiratory system can differ significantly from the solubility of materials in water. As used herein, biosoluble fibers are considered to be low in vivo sustained fibers.

As used herein, a substance is biodissolved if an in vitro static solubility test indicates that at least 0.1 g of the substance is dissolved in 100 ml of human respiratory system solvent. Can be considered sex. Similarly, a substance may be considered bioinsoluble if a static solubility test shows that less than 0.1 g of material is dissolved in 100 ml of human respiratory system solvent. ..

A suitable in vitro static solubility test involves exposing a sample of the substance to be tested to a suitable solvent at a temperature of 37° C. for 24 hours. After 24 hours, dissolution can be measured by determining the weight of the lysate composition or remaining sample. For example, elemental analysis using inductively coupled plasma spectroscopy of the lysing fluid may be used to calculate the total mass of the lysed sample in the lysing fluid.

Suitable solvents for use as human respiratory system solvents in in vitro static solubility tests include saline solutions and surrogates of human respiratory system solvents such as known simulated lung fluid (SLF). included. Known suitable SLFs include artificial lysosomal fluid (ALF), which has a pH of about 4.5, similar to the fluid that inhaled particles come into contact with after ingestion by alveoli and interstitial macrophages in the lung, and a pH of about. At 7.4, it contains a gambling solution that resembles deep interstitial macrophages in the lung.

Also, as used herein, in vitro kinetic solubility studies show that a substance has a dissolution rate constant of at least 150 square centimeters/hour/hour (ng/cm 2 ·hour) in a solvent of the human respiratory system. In some cases it may be considered "biosoluble".

A suitable in vitro dynamic solubility test involves slowly flowing a suitable solvent over a sample of the test substance and measuring the dissolution of the fiber over time. The test is run for an extended period, such as at least 3 weeks, to determine if the sample is uniform over an extended period. More specifically, the appropriate solvent is gradually pumped across a sample of fibers normalized to its surface area so that fresh solution is always provided to the sample. A particular suitable in vitro kinetic solubility test involves flowing the appropriate solvent for 1000 hours at a temperature of 37° C. over the sample to be tested at a rate of 5 ml per hour. The solution is collected and analyzed for the concentration of elements leached from the fiber sample. The solution is collected over the duration of the test, such as twice a week, to determine if the dissolution of the sample is uniform or constant over time.

Dissolution can be measured by determining the weight of the dissolution fluid composition or the remaining sample. For example, elemental analysis using inductively coupled plasma spectroscopy of the lysing fluid may be used to calculate the total mass of the lysed sample in the lysing fluid at specific time intervals. Since the sample surface area and solvent flow rate are known and the leachant concentration is determined from dissolution measurements, these values can be used to determine the dissolution rate by known methods. The dissolution rate may be expressed in nanogram/square centimeter/hour (ng/cm ² hours).

Suitable solvents for use as human respiratory system solvents in the in vitro dynamic solubility test include saline solutions and SLF, as described above for the in vitro static solubility test.

Certain suitable in vitro kinetic solubility tests are described in B. D. Law, W.W. B. Bunn & T. W. Hesterberg (2008) Solubility of Polymeric Organic Fibers and Manmade Vitreous Fibers in Gambles Solution, Inhalation Toxicology, 2:58, 159, 329-339, DOI, 329-339, DOI.

The biosoluble material can be any suitable biosoluble material. Suitable biosoluble materials include alkaline earth silicate materials and high alumina low silica materials.

In some preferred embodiments, the fibrous material comprises alkaline earth silicate fibers. In some particularly preferred embodiments, the fibrous material consists essentially of alkaline earth silicate fibers. In some particularly preferred embodiments, the fibrous material comprises alkaline earth silicate fibers.

In some embodiments of the present invention, the ceramic paper may include about 99.99 weight percent alkaline earth silicate material, such as alkaline earth silicate wool.

In some embodiments of the present invention, the ceramic paper may include about 50 weight percent fibrous alkaline earth silicate material to about 99.99 weight percent fibrous alkaline earth silicate material.

In some embodiments of the present invention, the ceramic paper comprises about 60 weight percent silicon dioxide to about 70 weight percent silicon dioxide, about 15 weight percent calcium oxide to about 35 weight percent calcium oxide, and about 4 weight percent. % Magnesium oxide to about 20 weight percent magnesium oxide.

In some embodiments of the present invention, the ceramic paper may include less than about 40 weight percent alumina, less than about 10 weight percent organic material, and less than about 1 weight percent moisture.

The above composition represents the weight percent of the various components after the ceramic paper has burned.

Examples of commercially available ceramic papers containing biosoluble ceramic fibers include: All of these are available from Morgan Advanced Materials, plc, Superwool® Fiber Paper, Superwool® Fiber Flex Wrap, Superwool® SuperFur®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®, Superwool®. (Registered trademark) Plus 332-E. Ceramic papers such as Final Advanced Materials Rescor 300 BL, or bio-soluble fiber paper without the DL-Thermal binder may also be suitable. Some binder-free ceramic paper comprising at least one of biosoluble fibers, low biopersistence fibers and fibers comprising at least one of silicon dioxide, calcium oxide and magnesium oxide May be appropriate. Some binder-free ceramic papers containing alkaline earth silicate fibers may be suitable.

In some embodiments, the ceramic paper may include one or more of biosustainable fibers and low biosustainable fibers. Examples of suitable materials that are at least one of biosoluble and low in vivo persistence include, but are not limited to, silicon dioxide, calcium oxide, and magnesium oxide. Particularly suitable materials that are at least one of biosoluble and low in vivo persistence include alkaline earth silicates.

Ceramic paper may have a low thermal conductivity. Stated another way, ceramic paper can be a good thermal insulator. For example, ceramic paper can have a thermal conductivity of about 0.5-2 W/mK at a temperature of about 23°C. This low thermal conductivity is especially observed when the ceramic paper comprises a woven or non-woven fibrous ceramic material. This may be due to the relatively open and highly porous structure of the ceramic paper, which is composed of a fibrous ceramic material that reduces heat transfer by conduction.

The ceramic paper may have a high permeability to air. This may be due to the relatively open and highly porous structure. At least one layer of ceramic paper may be sufficiently permeable that it allows air to not substantially interfere with the combustion of a combustible heat source. For example, at least one layer of ceramic paper may have an air permeability of greater than about 4000 (cm ³ /(min*cm ² ).

At least one layer of ceramic paper surrounds at least a portion of the length of the combustible heat source. At least one layer of the ceramic paper of the present invention may surround substantially the entire length of the combustible heat source. This allows aerosol-generating articles to benefit from the thermal insulating properties of ceramic paper, thereby reducing the surface temperature proximate to the heat source in use and also benefiting from the permeability of ceramic paper to air. , It may allow sufficient ambient air to reach the combustible heat source without substantially interfering with the ignition and combustion of the combustible heat source.

The ceramic paper may advantageously have mechanical properties. For example, ceramic paper may be flexible and suitable for machining due to the reinforcing effect of the ceramic material (particularly the ceramic fibers, if present). The ceramic paper may be machinable, which facilitates the formation of a layer of ceramic paper surrounding at least a portion of the length of the heat source.

As used herein, the term "layer" is used to describe a body of material that generally conforms to the shape of a combustible heat source. At least one layer of ceramic paper can be any suitable type of layer arranged to surround the heat source. Suitable types of layers include, among others, wrappers and coatings. As used herein, the term "application" is used to describe a layer of material that covers and adheres to a heat source.

At least one layer of ceramic paper may be in direct contact with the combustible heat source. At least one layer of ceramic paper may be spaced from the combustible heat source.

At least one layer of ceramic paper surrounds at least a portion of the length of the combustible heat source. For example, at least one layer of ceramic paper may surround approximately half the length of the combustible heat source. At least one layer of ceramic paper may surround more than half the length of the combustible heat source. At least one layer of ceramic paper may surround about 60 percent to about 100 percent of the length of the combustible heat source. At least one layer of ceramic paper may surround at least about 70 percent of the length of the combustible heat source. At least one layer of ceramic paper may surround at least about 80 percent of the length of the combustible heat source. At least one layer of ceramic paper may surround at least about 90 percent of the length of the combustible heat source. At least one layer of ceramic paper may substantially surround the length of the combustible heat source.

At least one layer of ceramic paper may surround the entire length of the combustible heat source. As used herein, the term "length" is used to describe the dimensions of a component or portion of an aerosol-generating article in the longitudinal direction of the aerosol-generating article.

At least one layer of ceramic paper may surround approximately half the length of the aerosol-forming substrate. Advantageously, the at least one layer of ceramic paper surrounding the aerosol-forming substrate may be below the surface temperature of the aerosol-generating article on the aerosol-forming substrate.

At least one layer of ceramic paper may surround the combustible heat source at the downstream end of the combustible heat source. This may advantageously reduce the surface temperature of the aerosol-generating article at the portion of the combustible heat source that is closer to the user during normal operation of the aerosol-generating article.

At least one layer of ceramic paper may surround the combustible heat source at the upstream end of the combustible heat source.

At least one layer of ceramic paper may surround the combustible heat source at the upstream and downstream ends.

The uncoated portion of the combustible heat source may be referred to herein as the "exposed" portion. At least one layer of the ceramic paper of the present invention may be provided to cover or surround the "exposed" or uncoated portion of the combustible heat source.

In some embodiments, a portion of the combustible heat source may be surrounded at the upstream end by at least one additional layer. The at least one additional layer can be a layer of cigarette paper. In those embodiments, the upstream portion of the combustible heat source is the exposed portion. In other words, the upstream portion of the combustible heat source is not covered by at least one additional layer. In those embodiments, at least one layer of ceramic paper may surround the upstream portion of the combustible heat source. At least one layer of ceramic paper surrounds the combustible heat source from the upstream end of the at least one additional layer surrounding the upstream portion of the combustible heat source to the downstream end of the combustible heat source or around its downstream end. sell. As such, in those embodiments, the combustible heat source may be surrounded substantially along its length by a combination of at least one additional layer at the downstream end and at least one layer of ceramic paper at the upstream end. .. In some embodiments, at least one layer of ceramic paper and at least one additional layer can partially overlap along the length of the combustible heat source.

The at least one layer of the combustible heat source, the aerosol-forming substrate, and the ceramic paper is configured to substantially prevent or prevent the temperature of the aerosol-forming substrate from exceeding about 375° C. during combustion of the combustible heat source. Can be done. For example, the at least one layer of a combustible heat source, an aerosol-forming substrate, and ceramic paper may substantially prevent or prevent the temperature of the aerosol-forming substrate from exceeding about 375° C. during combustion of the combustible heat source. Can be formed, dimensioned, and positioned. This can preserve the integrity of the aerosol-forming substrate. For example, if the aerosol-forming substrate comprises one or more aerosol-forming bodies, the aerosol-forming bodies may undergo thermal decomposition above a temperature of about 375°C. At higher temperatures, the tobacco may burn, for example, if the aerosol-forming substrate comprises tobacco.

The at least one layer of flammable heat source, aerosol-forming substrate, and ceramic paper has a temperature of the aerosol-forming substrate at 2 mm from the proximal surface of the aerosol-forming substrate during combustion of the flammable heat source of at least about 100 minutes for at least about 6 minutes. C may be configured to be.

At least one layer of ceramic paper can have any suitable thickness. Generally, at least one layer of ceramic paper is a thin layer. The thickness of the at least one layer of ceramic paper can be at least about 0.25 millimeters or at least about 0.5 millimeters. The thickness of at least one layer of ceramic paper can be less than about 10 millimeters or less than about 5 millimeters. At least one layer of ceramic paper may have a thickness of about 0.25 millimeters to about 10 millimeters, or about 0.5 millimeters to about 5 millimeters.

At least one layer of ceramic paper may further include one or more air inlets such as one or more perforations. The one or more air inlets may further increase the air permeability of the at least one layer of ceramic paper.

In some embodiments of the invention, the aerosol-generating article further comprises one or more airflow pathways along which air can be drawn through the aerosol-generating article for user inhalation. When a user inhales with an aerosol generating article, air is drawn into the aerosol generating article along one or more airflow paths.

At least one layer of ceramic paper may be separated from one or more airflow paths such that, in use, the air drawn through the aerosol-generating article along the one or more airflow paths is at least one of the ceramic papers. Do not directly contact the layers.

In some embodiments, at least one layer of ceramic paper comprises one or more layers such that air drawn through the aerosol-generating article along the one or more airflow paths does not directly contact the at least one layer of ceramic paper. May be arranged at a distance from the airflow path.

In some embodiments, one or more portions of the at least one layer of ceramic paper may be covered, coated, or trapped within a material that is substantially impermeable to fibers and particles. Good. One or more portions of the at least one layer of ceramic paper covered, coated, or confined within a material that is substantially impermeable to fibers and particles, along one or more airflow paths. It may be located proximate to the air drawn through the aerosol-generating article. The covering, coating, or confinement may separate air drawn through the aerosol-generating article along one or more airflow paths from fibers and particles of at least one layer of ceramic paper.

In some embodiments, one or more portions of the at least one layer of ceramic paper are encased within the layer of paper, thereby separating at least one layer of ceramic paper from one or more airflow paths. It The paper layer may be provided on at least one of the inner surface of at least one layer of ceramic paper and the outer surface of at least one layer of ceramic paper. A layer of paper may be provided on both the inner and outer surfaces of at least one layer of ceramic paper. The paper layer may include laminated paper. The paper layer may be co-laminated with at least one layer of ceramic paper. The paper layer may be provided only on a portion of at least one layer of ceramic paper adjacent the airflow path.

At least one layer of ceramic paper may be substantially flame resistant. As used herein, the term "combustion resistant" means a material that remains substantially intact during ignition and combustion of a combustible heat source. Providing at least one layer of fire resistant ceramic paper surrounding at least a portion of the length of the combustible heat source may advantageously prevent flames or smoke emitted from the layer. This may substantially prevent or inhibit unwanted emissions or odors emitted from the bed during combustion of the flammable heat source.

In some embodiments of the invention, the aerosol-generating article may further comprise one or more non-combustible, substantially impermeable barriers between the combustible heat source and the aerosol-forming substrate. One or more non-combustible substantially air-impermeable barriers between the combustible heat source and the aerosol-forming substrate separates the combustible heat source from one or more airflow pathways, and thus, in use, an aerosol-generating article. Air drawn through one or more air flow paths therethrough does not come into direct contact with the combustible heat source.

The aerosol-generating article according to the present invention comprises an aerosol-forming substrate. As used herein, the term "aerosol-forming substrate" is used to describe a substrate with the ability to release volatile compounds upon heating which can form an aerosol. The aerosol produced from the aerosol-forming substrate of an aerosol-generating article according to the present invention may or may not be visible, and vapors (e.g. fines of a substance that is gaseous are usually liquid or solid at room temperature). ), and liquid droplets of gas and condensed vapor.

The aerosol-forming substrate may be solid. The aerosol-forming substrate may be solid at room temperature.

The aerosol-forming substrate may include at least one aerosol former and at least one material capable of emitting a volatile compound in response to heating.

The at least one aerosol former is any suitable known compound or mixture of compounds that, in use, promotes the formation of a dense and stable aerosol and is substantially resistant to thermal degradation at the temperature of use of the aerosol-generating article. sell. Suitable aerosol formers are well known in the art and include, for example, polyhydric alcohols, esters of polyhydric alcohols such as glycerol monoacetate, diacetate or triacetate, and monocarboxylic acids, dicarboxylic acids or polycarboxylic acids. Includes aliphatic esters such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Exemplary aerosol formers for use in aerosol-generating articles according to the present invention are polyhydric alcohols such as triethylene glycol, 1,3-butanediol, and glycerin, or mixtures thereof.

The material capable of releasing a volatile compound in response to heating may be a plant-derived material charge (eg, a homogenized plant-derived material charge). For example, the aerosol-forming substrate may include one or more materials of plant origin including, but not limited to, tobacco, tea (eg, green tea), peppermint, bay, eucalyptus, basil, sage, bijozakura, and tarragon. .. The plant-based material may include additives including, but not limited to, wetting agents, flavoring agents, binders and mixtures thereof. The plant-derived material may consist essentially of tobacco material, optionally homogenized tobacco material.

The aerosol-generating article according to the present invention may include an aerosol-forming substrate that includes nicotine. For example, an aerosol-generating article according to the present invention comprises an aerosol-forming substrate that includes tobacco.

The aerosol-forming substrate can be surrounded by a filter plug wrap.

An aerosol-generating article according to the present invention comprises a combustible heat source arranged to heat an aerosol-forming substrate and separated from one or more airflow paths.

The combustible heat source may include a body of combustible material. The body of combustible material can have a substantially constant diameter. The body of combustible material may have a constant diameter along its length. This may advantageously simplify the processes involved in producing combustible heat sources and aerosol generating articles. In some embodiments, the body of combustible material may form a substantially annular cylindrical body having a substantially constant diameter along its length.

The combustible heat source may be a carbonaceous heat source. As used herein, the term "carbonaceous" is used to describe a combustible heat source containing carbon. The carbon content of the combustible carbonaceous heat source for use in an aerosol-generating article according to the present invention is preferably at least about 35 percent, more preferably at least about 40 percent, more preferably at least about 40 percent by dry weight of 30 combustible heat sources. Most preferred is about 45 percent.

The combustible heat source according to the present invention may be a combustible carbon-based heat source. As used herein, the term "carbon-based heat source" is used to describe a heat source that consists primarily of carbon.

The carbon content of the combustible carbon-based heat source for use in an aerosol-generating article according to the present invention is at least about 50 percent, preferably at least about 60 percent, by dry weight of the combustible carbon-based heat source, More preferably at least about 70 percent, and most preferably at least about 80 percent.

The combustible heat source of the present invention is separated from one or more airflow paths through the aerosol-generating article. As used herein, the term "air flow path" is used to describe the path of air along which the aerosol-generating article may be drawn for inhalation by a user. The terms "upstream" and "downstream" as used herein, when the user inhales with the aerosol-generating article, are relative to the components of the aerosol-generating article with respect to the direction in which air flows through one or more airflow paths. Used to describe direction and position.

Separation of the combustible heat source from one or more airflow paths of the aerosol-generating article may substantially prevent or inhibit activation of combustion of the combustible heat source while a user smokes. This may substantially prevent or prevent spikes in the temperature of the aerosol-forming substrate while the user smokes. This may substantially prevent or inhibit combustion or pyrolysis of the aerosol-forming substrate under conditions of heavy smoke absorption. This may substantially prevent or inhibit changes in the composition of the aerosol generated by the aerosol generating article depending on the user's smoke absorption situation.

Separation of the combustible heat source from the one or more airflow paths also results in combustion and decomposition products and other materials formed during ignition and combustion of the combustible heat source being an aerosol along one or more airflow paths. It may substantially prevent or inhibit entry into the air drawn through the generating article.

The separated combustible heat source of the present invention may include a blind heat source. As used herein, the term "blind" describes a flammable heat source in which air drawn through an aerosol-generating article for inhalation by a user does not pass through any airflow channels along the flammable heat source. Used for. As such, heat transfer between the blind combustible heat source and the aerosol-forming substrate occurs predominantly by conductive heat transfer.

Since no air flow channels are provided through the combustible heat source, conductive heat transfer between the combustible heat source and the aerosol-forming substrate is reduced or minimized. Reducing the conductive heat transfer between the combustible heat source and the aerosol-forming substrate can substantially prevent or inhibit spikes in the temperature of the aerosol-forming substrate while the user smokes. This may substantially prevent or inhibit combustion or pyrolysis of the aerosol-forming substrate under conditions of heavy smoke absorption. This may substantially prevent or inhibit changes in the composition of the aerosol generated by the aerosol generating article depending on the user's smoke absorption situation. It also substantially causes the combustion and decomposition products and other materials formed during ignition and combustion of the combustible heat source to enter the air drawn through the aerosol-generating article along one or more airflow paths. May be prevented or inhibited.

The separated combustible heat source of the present invention may include a non-blind heat source. As used herein, the term "non-blind" is a heat source in which air for inhalation by a user drawn through an aerosol-generating article passes through one or more airflow channels along the heat source. Used to describe. As such, heat transfer between the non-blind combustible heat source and the aerosol-forming substrate can occur by both conductive and convective heat transfer along one or more airflow channels.

As used herein, the term "airflow channel" is used to describe a flow path that extends along the length of a combustible heat source through which air may be drawn downstream for inhalation by a user. used. As such, the aerosol-generating articles of the present invention need not include one or more airflow channels.

One or more non-combustible, substantially impermeable barriers between the combustible heat source and the aerosol-forming substrate contact one or both of the proximal end of the combustible heat source and the distal end of the aerosol-forming substrate. It may include a first barrier in contact. The first barrier may facilitate separation of the combustible heat source from one or more airflow paths of the aerosol-generating article. The first barrier can reduce the maximum temperature to which the aerosol-forming substrate is exposed during ignition and combustion of the combustible heat source, and substantially prevent thermal decomposition or combustion of the aerosol-forming substrate during use of the aerosol-generating article or May hinder.

The term "non-combustible" as used herein is used to describe a material that is substantially non-combustible at the temperatures reached by a combustible heat source during its combustion or ignition.

As used herein, the term "impermeable" is used to describe a material that substantially prevents or blocks the passage of air therethrough.

The first barrier may abut one or both of the proximal end of the combustible heat source and the distal end of the aerosol-forming substrate. The first barrier may be adhered or otherwise affixed to one or both of the proximal end of the combustible heat source and the distal end of the aerosol-forming substrate.

The first barrier may include a first barrier coating provided on the proximal surface of the combustible heat source. In such an embodiment, the first barrier may include a first barrier coating that is provided over at least substantially the entire proximal surface of the combustible heat source. The first barrier may include a first barrier coating provided over the proximal surface of the combustible heat source. The first barrier coating may be formed and applied to the proximal surface of the combustible heat source by any suitable method, such as the method described in WO-A1-201320855.

Depending on the desired characteristics and performance of the aerosol generating article, the first barrier may have a low thermal conductivity or a high thermal conductivity. In certain embodiments, the first barrier is about 0.1 W/m. K to about 200 W/m. It may have a thermal conductivity of K.

The thickness of the first barrier may be appropriately adjusted to achieve good aerosol generating performance. In certain embodiments, the first barrier can have a thickness of about 10 microns to about 500 microns.

The first barrier may be formed from one or more suitable materials that are substantially heat stable and non-flammable at the temperatures achieved by the combustible heat source during ignition and combustion. Suitable materials are known in the art and include, but are not limited to, clays (such as bentonite and kaolinite), glasses, minerals, ceramic materials, resins, metals, and combinations thereof.

Materials in which the first barrier can be formed include clay and glass. Other materials with which the first barrier can be formed include copper, aluminum, stainless steel, alloys, alumina (Al ₂ O ₃ ), resins and mineral adhesives.

When the first barrier comprises a metal or alloy such as copper, aluminum, stainless steel, the first barrier coating advantageously serves as a heat link between the combustible heat source and the aerosol-forming substrate. sell. This may improve conductive heat transfer from the combustible heat source to the aerosol-forming substrate.

The aerosol-generating article may further include one or more air inlets downstream from the proximal end of the combustible heat source. In some embodiments, the one or more air inlets are between the proximal end of the combustible heat source and the proximal end of the aerosol-generating article. The one or more air inlets may be arranged such that air can be drawn through the one or more air inlets into one or more airflow paths of the aerosol-generating article without being drawn through the combustible heat source. This may substantially prevent or inhibit the temperature rise of the aerosol-forming substrate during smoke absorption by the user.

The one or more air inlets may include any suitable air inlet through which air may be drawn into the aerosol-generating article. For example, suitable air inlets include holes, slits, slots or other openings. The number, shape, size and placement of the air inlets may be adjusted appropriately to achieve good aerosol generating performance.

One or more air inlets can be located in the aerosol-forming substrate. One or more air inlets may be located between the distal end of the aerosol-forming substrate and the proximal end of the aerosol-forming substrate. Where one or more air inlets are located in the aerosol-forming substrate, and the aerosol-forming substrate includes a filter plug wrap, the filter plug wrap is provided with one or more openings that allow air into the aerosol-forming substrate. Can be done. The one or more openings can be slits, slots or other suitable openings through which air can be drawn into the aerosol-forming substrate. The number, shape, size and placement of the openings may be adjusted appropriately to achieve good aerosol generating performance.

The combustible heat source may include one or more airflow channels. In other words, the combustible heat source may be a non-blind heat source. The one or more airflow channels may extend along the length of the combustible heat source. The one or more airflow channels may form part of one or more airflow paths of the aerosol-generating article.

Where the combustible heat source comprises one or more airflow channels in the aerosol-generating article, the one or more non-combustible substantially impermeable barrier between the combustible heat source and the aerosol-forming substrate is A second barrier may also be included between the combustible heat source and one or more airflow channels.

The second barrier may facilitate separation of the combustible heat source from one or more airflow paths of the aerosol-generating article. The second barrier can reduce the maximum temperature to which the aerosol-forming substrate is exposed during ignition and combustion of the combustible heat source, thus avoiding or reducing thermal decomposition or combustion of the aerosol-forming substrate during use of the aerosol-generating article. To help.

The second barrier may be adhered to the combustible heat source or otherwise attached.

The second barrier may include a second barrier coating provided on the inner surface of the one or more airflow channels. The second barrier may include a second barrier coating provided over at least substantially the entire inner surface of the one or more airflow channels. The second barrier may include a second barrier coating provided over the inner surface of one or more airflow channels.

The second barrier coating may be provided by the insertion of a liner into one or more airflow channels. For example, a non-combustible, substantially air-impermeable hollow tube may include one or more airflow paths if the one or more airflow paths include one or more airflow channels extending through the interior of the combustible heat source. It may be inserted in each of the channels.

The second barrier is the ignition of the combustible heat source of the aerosol-generating article according to the invention and the entry of combustion or decomposition products formed during combustion into the air drawn downstream along one or more airflow channels. Can be advantageously substantially prevented or inhibited.

The second barrier may have a low thermal conductivity or a high thermal conductivity, depending on the desired characteristics and performance of the aerosol-generating article. The second barrier may have a low thermal conductivity.

The thickness of the second barrier may be appropriately adjusted to achieve good aerosol generating performance. In certain embodiments, the second barrier may have a thickness of about 30 microns to about 200 microns. In one embodiment, the second barrier has a thickness of about 30 microns to about 100 microns.

The second barrier may be formed from one or more suitable materials that are substantially heat stable and non-flammable at the temperatures achieved by the combustible heat source during ignition and combustion. Suitable materials are known in the art, such as clays, metal oxides (such as iron oxide, alumina, titania, silicon dioxide, silica-alumina, zirconia and ceria), zeolites, zirconium phosphates, and other ceramic materials. Or including, but not limited to, combinations thereof.

Materials in which the second barrier can be formed include clay, glass, aluminum, iron oxide and combinations thereof. If desired, catalyst raw material components, such as raw material components that promote the oxidation of carbon monoxide to carbon dioxide, may be incorporated into the second barrier. Suitable catalyst feedstock components include, but are not limited to, for example, platinum, palladium, transition metals and their oxides.

An aerosol-generating article according to the invention comprises a first barrier between a downstream end of a combustible heat source and an upstream end of an aerosol-forming substrate, and a combustible heat source and one or more airflow channels along the combustible heat source. The second barrier may be formed of the same or different material as the first barrier, if it includes a second barrier between and.

Where the second barrier comprises a second barrier coating provided on the inner surface of one or more airflow channels, such as the methods described in US-A-5,040,551 and WO-A1-2013131855. The second barrier coating may be applied to the inner surface of one or more airflow channels by any suitable method of.

The aerosol-generating article may further include one or more additional layers surrounding at least the proximal portion of the combustible heat source and the distal portion of the aerosol-forming substrate. The one or more additional layers may include at least one of a thermally conductive element that transfers heat from a combustible heat source to the aerosol-forming substrate, and a layer of cigarette paper.

The thermally conductive element may surround only the distal portion of the aerosol-forming substrate. The length of the aerosol-forming substrate may be substantially surrounded by the thermally conductive element. The thermally conductive element may be in direct contact with at least one of the combustible heat source and the aerosol forming substrate. The thermally conductive element need not be in direct contact with both the flammable heat source and the aerosol-forming substrate.

The thermally conductive element may provide a thermal link between the combustible heat source and the aerosol-forming substrate. The heat conductive element can be substantially flame resistant.

Suitable thermally conductive elements may include metal foil wrappers or alloy foil wrappers. Metal foil wrappers may include aluminum foil wrappers, steel foil wrappers, iron foil wrappers and copper foil wrappers. The heat conductive element may include a tube of aluminum.

The proximal portion of the combustible heat source surrounded by the thermally conductive element can be about 2 millimeters to about 8 millimeters in length, or about 3 millimeters to about 5 millimeters in length.

The distal portion of the flammable heat source that is not surrounded by the thermally conductive element can be about 4 millimeters to about 15 millimeters in length, or about 4 millimeters to about 8 millimeters in length.

The layer of cigarette paper may surround at least the proximal portion of the combustible heat source, the length of the aerosol-forming substrate, and some other components of the aerosol-generating article that are located proximally of the aerosol-forming substrate. The layer of cigarette paper can substantially surround the length of the combustible heat source. Where the layer of cigarette paper substantially surrounds the length of the combustible heat source, the layer of cigarette paper may be provided with ventilation, such as perforations, holes or slits, in the combustible heat source, whereby air Through a layer of cigarette paper to a flammable heat source. The number, shape, size and position of the openings may be appropriately adjusted to achieve good aerosol generating performance. The layer of cigarette paper is wrapped tightly around the flammable heat source and the aerosol-forming substrate so that the layer of cigarette paper grips and fixes the flammable heat source and the aerosol-forming substrate when the aerosol-generating article is assembled. Can be done.

At least one layer of ceramic paper can be a radially outer layer. If the aerosol-generating article comprises one or more additional layers, the radially outer layer of ceramic paper may cover at least a portion of the one or more additional layers. Stated another way, one or more additional layers may be disposed between the combustible heat source and at least one layer of ceramic paper. For example, if the aerosol-generating article comprises an additional layer comprising a thermally conductive element, the thermally conductive element may be a radially inner layer and at least one layer of ceramic paper is the thermally conductive element. May be an outer layer along a radius that surrounds at least a portion of the.

As used herein, the terms "radially outer" and "radially inner" are used to indicate the relative distance of the components of the aerosol-generating article from the longitudinal axis of the aerosol-generating article. It As used herein, the term "radial" is perpendicular to the longitudinal axis of the aerosol-generating article, which extends in the direction between the proximal and distal ends of the aerosol-generating article. Used to describe direction.

The one or more additional layers can be radial outer layers. The one or more additional layers may cover at least a portion of the at least one layer of ceramic paper.

At least one layer of ceramic paper may be secured or attached to one or more other components or parts of the aerosol-generating article. At least one layer of ceramic paper can be secured to any suitable component of the aerosol-generating article. For example, at least one layer of ceramic paper can be affixed to at least one of a combustible heat source, an aerosol-forming substrate, and one or more additional layers. At least one layer of ceramic paper may be secured to one or more components of the aerosol-generating article by any suitable means. At least one layer of ceramic paper can be fixed with an adhesive. Suitable adhesives may exhibit high temperature resistance such as silicate adhesives. Where the one or more additional layers are radial outer layers, the one or more additional layers can be tightly wrapped around at least a portion of the at least one layer of ceramic paper.

In some embodiments, at least one layer of ceramic paper may form part of a combustible heat source. As used herein, the term "integral" is in direct contact with the combustible heat source and adheres to the combustible heat source without the aid of exogenous adhesive or other intermediate bonding material. Used to describe a layer.

In some embodiments, at least one layer of ceramic paper may be formed from strips of ceramic paper having opposite ends. The strip of ceramic paper may be wrapped around a flammable heat source such that the opposite ends of the strip partially overlap. The overlapping opposite ends of the strips can be secured together using an adhesive or any other suitable means. This may fix at least one layer of ceramic paper on the combustible heat source.

In some embodiments, an intermediate layer can be provided between at least one layer of ceramic paper and at least one of a combustible heat source, an aerosol-forming substrate, and one or more additional layers. The intermediate layer may be adjacent to at least one layer of ceramic paper. The intermediate layer may be in contact with at least one layer of ceramic paper. The intermediate layer may be arranged radially inward of at least one layer of ceramic paper.

The intermediate layer may be an adhesive layer. The adhesive layer may include any suitable adhesive. Suitable adhesives may exhibit high temperature resistance such as silicate adhesives. The adhesive layer may be disposed between at least one layer of ceramic paper and the combustible heat source, and the at least one layer of ceramic paper may be attached to the combustible heat source. The adhesive layer may be disposed between at least one layer of ceramic paper and one or more additional layers, and at least one layer of ceramic paper may be attached to the one or more additional layers. The adhesive layer may be disposed between at least one layer of ceramic paper and the aerosol-forming substrate, and at least one layer of ceramic paper may be attached to the aerosol-forming substrate.

In some embodiments, at least one layer of ceramic paper may be formed from strips of ceramic paper having opposite ends. The strips of ceramic paper may be wrapped around a flammable heat source such that opposite ends of the strips abut and do not partially overlap. An adhesive layer may be provided on at least the opposite ends of the strip on the side of the strip facing the combustible heat source. The adhesive layer may secure the strip of ceramic paper to a flammable heat source, at least at opposite ends of the strip.

The aerosol-generating article can include a thermally conductive member disposed between the combustible heat source and the aerosol-forming substrate. The heat conductive member may be the above-mentioned first barrier. The aerosol-generating article can include a thermally conductive member and a first barrier. The heat conductive member may include a material similar to the heat conductive element. The aerosol generating article may include a heat conductive member and a heat conductive element. Providing at least one of a heat conductive element and a heat conductive member may facilitate conductive heat transfer between the combustible heat source and the aerosol-forming substrate.

The aerosol-generating article may further include any other suitable component. For example, the aerosol-generating article may comprise at least one of a transfer element, an aerosol cooling element, a spacer element and a mouthpiece. The one or more additional components may be in coaxial arrangement with the combustible heat source and the aerosol-forming substrate. One or more additional components can be located proximal to the aerosol-forming substrate. The one or more additional components can be arranged in any suitable order. The aerosol-generating article comprises a transfer element adjacent the proximal end of the aerosol-forming substrate, an aerosol cooling element adjacent the proximal end of the transfer element, a spacer element adjacent the proximal end of the aerosol cooling element, and a spacer element. And a mouthpiece adjacent the proximal end.

As used herein, the terms "proximal" and "distal" are used to describe the relative position of a component or part of a component of an aerosol-generating article according to the present invention. The proximal end of a component of an aerosol-generating article is the end of that component near the mouth-side end of the aerosol-generating article, and the distal end of the component of the aerosol-generating article is the mouth-side of the aerosol-generating article. Is the edge of that component, which is far from the edge of. Generally, the combustible heat source is located at the distal end of the aerosol-generating article.

According to a second aspect of the invention there is provided a method of forming an aerosol generating article according to the first aspect of the invention. The method comprises placing a combustible heat source to heat an aerosol-forming substrate, and surrounding at least a portion of the length of the combustible heat source with at least one layer of ceramic paper containing a cellulosic binder. ..

In some embodiments, the step of surrounding at least a portion of the length of the combustible heat source with at least one layer of ceramic paper comprises strips of ceramic paper having cellulosic binder with opposite ends. Providing, wrapping the flammable heat source with strips such that the flammable heat source is surrounded by at least one layer of ceramic paper, overlapping opposite ends of the strips, and overlapping edges together. Fixing and fixing at least one layer of ceramic paper to a combustible heat source.

The overlapping ends of the strips of ceramic paper can be secured together using any suitable means. For example, the overlapping ends of a strip of ceramic paper can be secured together with an adhesive. Suitable adhesives should have high temperature resistance and should include silica adhesives.

In some embodiments, the step of surrounding at least a portion of the length of the combustible heat source with at least one layer of ceramic paper comprises strips of ceramic paper having cellulosic binder with opposite ends. Providing, applying an adhesive layer to one side of the strip at at least each of the opposite ends, locating the strip such that the adhesive layer faces the combustible heat source, and Wrapping strips around a flammable heat source such that at least a portion of the length is surrounded by at least one layer of ceramic paper and abutting the opposing ends of the strips without overlapping the opposing ends. And securing the strip to the combustible heat source with an adhesive layer.

In some embodiments, at least one layer of ceramic paper may be laminated with additional layers, such as layers of cigarette paper. At least one layer of ceramic paper may be laminated with additional layers before the at least one layer of ceramic paper is attached to the combustible heat source. Co-laminated paper strips comprising at least one layer of ceramic paper and additional layers can be wrapped around a flammable heat source in a manner similar to ceramic paper strips. In some embodiments, the co-laminated paper may be arranged such that at least one layer of ceramic paper faces the combustible heat source. Stated another way, at least one layer of ceramic paper may be located radially inward of the additional layer. In some embodiments, the co-laminated paper may be arranged such that the additional layer faces the combustible heat source.

Although the present invention relates to ceramic paper, cellulosic binders can be used as binders in other layers used to surround at least a portion of the length of a combustible heat source in an aerosol-generating article. The cellulosic binder may be used in any layer of fibrous material. Cellulosic binders may be used in layers of fibrous material including ceramic fibers.

Cellulose derivative binders can be used in layers of fiber reinforced airgel.

As used herein, the term "airgel" is used to describe an open cell foam. The airgel may be mesoporous. The term "mesoporous" means a material that contains pores with diameters ranging from about 2 nanometers to about 50 nanometers. The airgel may include a network of interconnected structures, and the network of interconnected structures may be nanostructured. Aerogels can exhibit a porosity of greater than or equal to about 50 percent. Aerogels can exhibit a porosity of greater than or equal to about 90 percent. Aerogels can be formed by removing liquid components from conventional gels. It will be appreciated that conventional gel means the solids of a semi-solid colloidal suspension that is dispersed in a liquid.

Aerogels generally have a very low thermal conductivity. Without wishing to be bound by theory, conductive heat transfer is hindered in aerogels by their high porosity, while conductive heat transfer is hindered in aerogels by small pores. The small diameter pores limit the movement of air through the airgel.

As used herein, the term "fiber reinforced airgel" means a composite material that includes an airgel matrix that is reinforced with a fibrous material.
The present invention will be further described, by way of example only, with reference to the accompanying drawings.

FIG. 1 shows a schematic diagram of a first embodiment of an aerosol-generating article according to the invention, comprising a blind combustible heat source. 2 shows a temperature profile of an aerosol-generating article similar to that shown in FIG. 1 in a first position within the article. FIG. 3 shows a temperature profile for an aerosol-generating article similar to that shown in FIG. 1 in a second position within the article. FIG. 4 shows a temperature profile of an aerosol-generating article similar to that shown in FIG. 1 in a third position within the article. FIG. 5 shows a temperature profile of a further aerosol generating article similar to that shown in FIG. 1 in a third position within the article, one of the aerosol generating articles containing biosoluble alkaline earth silicate fibers. Including ceramic paper having. FIG. 6 shows a schematic diagram of a second embodiment of an aerosol generating article according to the present invention comprising a non-blind combustible heat source.

FIG. 1 shows a schematic diagram of an aerosol-generating article 2. The aerosol-generating article 2 includes a combustible heat source 3. The combustible heat source 3 comprises a substantially annular cylindrical body of carbonaceous material having a length of about 10 millimeters. The combustible heat source 3 is a blind heat source. In other words, the combustible heat source 3 does not include any air channels extending through it.

The aerosol-generating article 2 further comprises an aerosol-forming substrate 4. The aerosol-forming substrate 4 is located at the proximal end of the flammable heat source 3. The aerosol-forming substrate 4 comprises a substantially annular cylindrical plug 18 of tobacco material surrounded by a filter plug wrap 19.

A non-flammable, substantially impermeable first barrier 6 is located between the proximal end of the combustible heat source 3 and the distal end of the aerosol-forming substrate 4. The first barrier 6 comprises an aluminum foil disc. The first barrier 6 is also a heat conductive member between the combustible heat source 3 and the aerosol forming substrate 4 for conducting heat from the proximal surface of the combustible heat source 3 to the distal surface of the aerosol forming substrate 4. To form.

The thermally conductive element 9 surrounds the proximal portion of the combustible heat source 3 and the distal portion of the aerosol-forming substrate 4. The thermally conductive element 9 comprises a tube of aluminum foil. The thermally conductive element 9 is in direct contact with the proximal portion of the combustible heat source 3 and the filter plug wrap 19 of the aerosol-forming substrate 4.

The aerosol-generating article 2 is arranged at a moving element 11 arranged at the proximal end of the aerosol-forming substrate 4, an aerosol cooling element 12 arranged at the proximal end of the moving element 11, and a proximal end of the aerosol cooling element 11. Further provided are various other components located proximal to the aerosol-forming substrate 4, including the spacer element 13 and the mouthpiece 10 located at the proximal end of the spacer element 13.

The components of the aerosol-generating article 2 are packaged in a layer 7 of cigarette paper. A layer 7 of cigarette paper surrounds the heat-conducting element 9, but does not extend beyond the distal end of the heat-conducting element 9 nor over the distal portion of the combustible heat source 3.

According to the invention, the aerosol-generating article 2 further comprises a layer 5 of ceramic paper. The layer of ceramic paper 5 substantially surrounds the length of the combustible heat source 3, as well as the layer of cigarette paper 7, the thermally conductive element 9 and the distal portion of the aerosol-forming substrate 4. Stated another way, the layer of ceramic paper 5 is the radially outer layer at the distal end of the aerosol-generating article 2.

Layer 5 of ceramic paper comprises from about 60 weight percent silicon dioxide to about 70 weight percent silicon dioxide, about 16 weight percent calcium oxide to about 22 weight percent calcium oxide, and about 12 weight percent magnesium oxide to about 19 weight percent. Contains weight percent magnesium oxide. The layer 5 of ceramic paper also comprises aluminum oxide. Layer 5 of ceramic paper also contains a cellulosic binder. The cellulosic binder comprises CMC dispersed in water at a concentration of 8 weight percent.

A plurality of air inlets 8 are arranged in the aerosol-forming substrate 4, which allow ambient air to be drawn into the aerosol-generating article 2. The air inlet 8 comprises a plurality of perforations surrounding the aerosol-forming substrate 4 through the layer 7 of cigarette paper and the sublayer of the plug wrap 19. The air inlet 8 is arranged between the distal surface and the proximal surface of the aerosol-forming substrate 4.

When the user inhales with the mouthpiece 10 of the aerosol-generating article 2, ambient air can be drawn into the aerosol-generating article 2 through the air inlet 8. The air drawn into the aerosol-generating article 2 passes along the airflow path of the aerosol-generating article 2 from the air suction port 8 through the aerosol-forming substrate 4, the moving element 11, the cooling element 12, and the spacer element 13, and then the mouse. It can flow to the piece 10 and out of the mouthpiece 10 for further inhalation to the user. The general direction of the air flow through the aerosol generating article 2 is indicated by the arrows.

In use, a user may ignite flammable heat source 3 by exposing it to an external heat source such as a lighter. The combustible heat source 3 may be ignited and combusted, and heat may be carried from the combustible heat source 3 to the aerosol-forming substrate 4 via conduction through the thermally conductive member 6 and the thermally conductive element 9. The volatile components of the heated aerosol-forming substrate 4 may be evaporated. When the user inhales with the mouthpiece 10 of the aerosol-generating article 2, ambient air can be drawn into the airflow path of the aerosol-generating article 2 through the air inlet 8. The vapor from the heated aerosol forming substrate 4 may be mixed with the air drawn through the aerosol forming substrate 4 and may be drawn with the air towards the mouthpiece 10. As the vapor is drawn towards the mouthpiece 10, the vapor may cool and form an aerosol. The aerosol can be drawn out of the mouthpiece 10 and delivered to the user for inhalation.

Of course, the substantially impermeable first barrier 6 prevents air from being drawn through the combustible heat source 3 into the aerosol-forming substrate 4. Therefore, the first barrier 6 substantially separates the air flow path of the aerosol-generating article 2 from the combustible heat source 3.

In this embodiment, the layer of ceramic paper 5 extends over a small portion of the distal end of the aerosol-forming substrate 4. Therefore, the layer 5 of ceramic paper is arranged at a distance from the air inlet 8. This spacing substantially separates the layer of ceramic paper 5 from the air inlet 8, so that air drawn through the airflow path of the aerosol-generating article 2 does not contact the layer of ceramic paper 5.

Of course, in some embodiments, the layer of ceramic paper may be proximate the air inlet. In those embodiments, the portion of the layer of ceramic paper proximate the air inlet may be coated with a material that is substantially impermeable to fibers and particles. This substantially separates the portion of the layer of ceramic paper proximate the air inlet so that the air drawn through the airflow path of the aerosol-generating article does not contact the layer of ceramic paper.

Empirical data was collected to determine the temperature of the flammable heat source and the aerosol-forming substrate of various aerosol-generating articles similar to the aerosol-generating article 2 shown in FIG. 1, over the burn time of the combustible heat source. Each measured aerosol generating article contained a different layer of material that substantially surrounded the length of the combustible heat source. In the experiment, 2 mm deep holes were formed in the aerosol generating article, but two of the holes were formed in the flammable heat source at positions T ₁ and T ₂ in FIG. One is formed in the aerosol-forming substrate at position T ₃ in FIG. A thermocouple was inserted in each hole so that the temperature at each position could be measured. In particular, empirical data for aerosol-generating articles that include a layer of ceramic paper that substantially surrounds the length of the combustible heat source, but not a layer of material that substantially surrounds the length of the combustible heat source. Was collected in. 2-4 show graphs of experimental measurements of temperature over time at three different locations for various aerosol-generating articles.

FIG. 2 shows the temperature measured at 2 millimeters from the distal end of the combustible heat source, which corresponds to the position T ₁ shown in FIG. In other words, FIG. 2 shows the temperature at the distal end of the combustible heat source.

FIG. 3 shows the temperature measured at 5 millimeters from the distal end of the combustible heat source, which corresponds to the position T ₂ shown in FIG. In other words, FIG. 3 shows the temperature at approximately the midpoint along the length of the combustible heat source.

FIG. 4 shows the temperature measured at 11 mm from the distal end of the combustible heat source, which corresponds to the position T ₃ shown in FIG. In other words, FIG. 4 shows the temperature at the distal end of the aerosol-forming substrate.

All temperature profiles were measured using an electronic temperature probe inserted to a depth of approximately 2 millimeters within the relevant components of the aerosol generating article.

In Figures 2, 3 and 4, the "SMAR" line, labeled as 20, shows the temperature profile of an aerosol-generating article having an "exposed" combustible heat source. Stated another way, the "SMAR" line 22 shows the temperature profile of an aerosol-generating article without a layer of material that substantially surrounds the length of the combustible heat source.

2, 3 and 4, the "ceramic paper 1" line, labeled as 21, shows the temperature profile of an aerosol-generating article having a layer of ceramic paper substantially surrounding the length of the combustible heat source. .. The ceramic paper substantially surrounding the length of the flammable heat source in the "Ceramic Paper 1" measurement was Superwool® Plus Fiber available from Morgan Advanced Materials, plc.

2, 3 and 4, the "ceramic paper 2" line labeled as 22 shows the temperature profile of an aerosol-generating article having a layer of ceramic paper substantially surrounding the length of the combustible heat source. .. The ceramic paper that substantially surrounds the length of the flammable heat source in the “Ceramic Paper 2” measurement is Ningbo Firewheel Thermal Insulation & Sealing Co. , CFP Ceramic Fiber Paper available from Co., Ltd.

In FIGS. 2, 3 and 4, the “glass paper” line, labeled as 23, shows the temperature profile of an aerosol-generating article with a layer of ceramic paper substantially surrounding the length of the combustible heat source. The ceramic paper that substantially surrounded the length of the flammable heat source in the "glass paper" measurement was a ceramic paper containing glass fibers.

The aerosol-generating article has a temperature substantially similar to or above the temperature profile 20 of an aerosol-generating article having an exposed combustible heat source but no layer of material that substantially surrounds the length of the combustible heat source. It is desirable to have a layer of material that substantially surrounds the length of the aerosol-generating article to show the profile. If the combustible heat source exhibits a temperature similar to or higher than the exposed combustible heat source, this means that the layer of material that substantially encloses the length of the combustible heat source causes the combustible heat source to burn substantially. It means that it is not blocked.

Surprisingly, as shown in FIGS. 2, 3 and 4, the temperature profile 21, 22, 23 of an aerosol generating article having a layer of ceramic paper substantially surrounding the length of the combustible heat source is And a temperature profile 20 of the aerosol-generating article that does not have a layer of material that substantially surrounds the length of the combustible heat source at all three measurement locations of the aerosol-generating article during most of the burning time of The same is true. In addition, the temperature profile 21 and 22 of an aerosol-generating article having a layer of ceramic paper that substantially surrounds the length of the combustible heat source is substantially the same as the length of the combustible heat source for some period of time while in the aerosol-generating state. Substantially exceeds the temperature profile 20 of the aerosol-generating article without a layer of surrounding material.

This surprising result shows that providing at least one layer of ceramic paper that substantially surrounds the length of the combustible heat source advantageously does not substantially prevent combustion of the combustible heat source. In effect, providing a layer of ceramic paper may increase the temperature of the combustible heat source during the period between combustion of the combustible heat source.

FIG. 5 shows a graph of additional experimental data collected as described above for three particular aerosol generating articles. Similar to FIG. 4, FIG. 5 shows the temperature at the distal end of the aerosol-forming substrate, measured 11 mm from the distal end of the combustible heat source, corresponding to position T ₃ in FIG. The temperature profile was measured using an electronic temperature probe inserted to a depth of approximately 2 millimeters within the aerosol-forming substrate of the aerosol-generating article.

In Figure 5, the "SMAR" line, labeled as 30, shows the temperature profile of an aerosol-generating article having an "exposed" combustible heat source. Stated another way, the "SMAR" line 22 shows the temperature profile of an aerosol-generating article without a layer of material that substantially surrounds the length of the combustible heat source.

In FIG. 5, the "glass paper" line labeled as 31 shows the temperature profile of an aerosol-generating article with a layer of ceramic paper substantially surrounding the length of the combustible heat source. The ceramic paper that substantially surrounded the length of the flammable heat source in the "glass paper" measurement was a ceramic paper containing glass fibers. Ceramic paper containing glass fibers has a thickness of about 1 millimeter and a length of about 5.5 millimeters and extends from the distal end of the combustible heat source to the entire length of the combustible heat source to the distal end of the aerosol-forming substrate. Extend.

In Figure 5, the "biosoluble fiber" line, labeled as 32, shows the temperature profile of an aerosol-generating article with a layer of ceramic paper substantially surrounding the length of the combustible heat source. The ceramic paper that substantially surrounded the length of the flammable heat source in the "biosoluble fiber" measurement was Superwool® Plus Fiber available from Morgan Advanced Materials, plc. Superwool® Plus fibers contain biosoluble alkaline earth silicates. The ceramic paper containing biosoluble fibers has a thickness of about 0.5 millimeters and a length of about 5.5 millimeters and is an aerosol-forming substrate over the length of the combustible heat source from the distal end of the combustible heat source. Extending to the distal end of.

Surprisingly, as shown in FIG. 5, the temperature profile 32 of an aerosol-generating article having a layer of ceramic paper containing biosoluble alkaline earth silicate fibers shows a substantial length of combustible heat source after 200 seconds. It has been found to exhibit a higher temperature after about 200 seconds than both the temperature profile 30 of an aerosol generating article without a layer of surrounding material and the temperature profile 31 of an aerosol generating article with a layer of ceramic paper containing glass fibers. It was

This surprising result is that bio-soluble alkaline earth materials that substantially surround the length of the combustible heat source are compared to articles that have a layer of ceramic paper that includes glass fibers that substantially surround the length of the combustible heat source. It is shown that smoking time can be increased by providing an aerosol-forming article with a layer of ceramic paper containing silicate fibers.

The aerosol-generating articles according to the invention were measured by observing their effect by placing them on Whatman paper after ignition of the heat source. For example, aerosol-generating articles were inspected for 24 hours at about 23°C ± 3°C and 55% ± 5% relative humidity. The aerosol generating article to be inspected was ignited using an electric lighter and burned for 2 minutes. After 2 minutes, the aerosol-generating article was placed on the stacked Whatman paper for 10 minutes. After 10 minutes, the Whatman paper was inspected. Aerosol generating articles having a layer of ceramic paper substantially surrounding the length of the combustible heat source did not produce holes in any Whatman paper, producing a slight brown area on the top paper. I observed. The results show that having a layer of ceramic paper substantially surrounding the length of the combustible heat source reduces the surface temperature near the heat source.

A schematic diagram of a second embodiment of an aerosol generating article according to the present invention is shown in FIG. The aerosol-generating article 102 is substantially similar to the aerosol-generating article 2 shown in FIG. The aerosol-generating article 102 includes a combustible heat source 103, an aerosol-forming substrate 104, a layer of ceramic paper 105, and a layer 107 of cigarette paper, arranged similarly to the corresponding components of the aerosol-generating article 2 shown in FIG. Prepare However, the combustible heat source 103 is a non-blind heat source. The non-blind heat source 103 comprises an annular body 115 of carbonaceous material having passages 116 extending between the distal and proximal end faces. The passages 116 form a portion of the airflow path through the aerosol-generating article and also allow air to be drawn from the proximal end of the aerosol-generating article, through the combustible heat source 103, to the aerosol-forming substrate 104. The layer of ceramic paper 105 is spaced from the airflow path through the aerosol-generating article 102 so that air drawn through the airflow path does not contact the layer of ceramic paper 105.

The non-combustible, substantially air-impermeable first barrier 6 is similar to the first barrier 106 described above in connection with FIG. It is placed between the end and the end. However, unlike the first barrier 6 described above, the first barrier 106 includes an opening 120 that is aligned with the passageway 116, which allows air to pass from the passageway 116 to the aerosol-forming substrate 104.

A non-combustible, substantially impermeable second barrier 117 is coated on the inner surface of the passageway 116. The second barrier 117 separates the air passing through the passage 116 from the combustible heat source 103 and the products of combustion of the combustible heat source.

Because the combustible heat source 103 is a non-blind heat source, the aerosol-generating article 102 does not include an air inlet located in the aerosol-forming substrate 104. When a user inhales with the mouthpiece of the aerosol-generating article 102, ambient air can be drawn into the aerosol-generating article 102 through the passages 116 through the heat source 103. The air drawn into the aerosol-generating article 102 follows the airflow path of the aerosol-generating article 102, through the passageway 116, through the aerosol-forming substrate 104, the moving elements, the cooling elements and the spacer elements, and into the mouthpiece. It can flow out of the mouthpiece and out to the user for further inhalation. The general direction of the air flow through the aerosol generating article 102 is indicated by the arrows.

Of course, in some embodiments, other air inlets may also be provided in the aerosol-generating article in addition to the air passages through the combustible heat source.

The particular embodiments described above are intended to exemplify the invention. However, other embodiments may be made without departing from the scope of the invention as defined in the claims, and it will be appreciated that the particular embodiments described above are limiting. Not intended to.

Claims (13)

An aerosol-forming substrate,
A flammable heat source,
At least one layer of ceramic paper surrounding at least a portion of the length of the combustible heat source;
At least one layer of the ceramic paper comprises a cellulosic binder, the ceramic paper comprising:
Biosoluble fiber,
Low in vivo sustained fiber, and
An aerosol generating article comprising at least one of silicon dioxide, calcium oxide and a fiber comprising at least one of magnesium oxide. The aerosol-generating article of claim 1, wherein at least one layer of the ceramic paper comprises no more than about 40 weight percent cellulosic binder. An aerosol-generating article according to claim 1 or 2, wherein the ceramic paper comprises an alkaline earth silicate. 4. An aerosol-generating article according to any of claims 1 to 3, including one or more airflow paths along which air can be drawn through the aerosol-generating article for user inhalation. 5. The aerosol-generating article of any of claims 1-4, comprising one or more non-combustible, substantially impermeable barriers between the flammable heat source and the aerosol-forming substrate. The incombustible, substantially impermeable barrier between the combustible heat source and the aerosol-forming substrate is at one or both of a proximal end of the combustible heat source and a distal end of the aerosol-forming substrate. 6. The aerosol-generating article of claim 5, comprising an abutting first barrier. At least one layer of the ceramic paper is separated from the one or more airflow paths so that, in use, the air drawn through the aerosol-generating article along the one or more airflow paths is 7. The aerosol-generating article according to any of claims 1-6, which is not in direct contact with at least one layer. At least one layer of said combustible heat source, said aerosol forming substrate and said ceramic paper is arranged such that the temperature of said aerosol forming substrate does not exceed 375° C. during the combustion of said combustible heat source. The aerosol-generating article according to any one of 1 to 7. 9. The aerosol-generating article of any of claims 1-8, wherein the ceramic paper comprises at least about 50 weight percent ceramic material. 10. The aerosol-generating article of any of claims 1-9, wherein at least one layer of ceramic paper has a thickness of about 0.5 millimeters to about 5 millimeters. Arranging a flammable heat source to heat the aerosol-forming substrate;
Surrounding at least a portion of the length of the combustible heat source with at least one layer of ceramic paper comprising a cellulose derivative binder. Enclosing at least a portion of the length of the combustible heat source with at least one layer of ceramic paper,
Providing a strip of ceramic paper comprising a cellulosic binder having opposite ends;
Winding the strip around the flammable heat source such that the flammable heat source is surrounded by at least one layer of ceramic paper;
Overlapping the opposite ends of the strips,
Fixing the overlapping edges together and fixing at least one layer of the ceramic paper to the combustible heat source, the method of forming an aerosol-generating article of claim 11. Enclosing at least a portion of the length of the combustible heat source with at least one layer of ceramic paper,
Providing a strip of ceramic paper comprising a cellulosic binder having opposite ends;
Applying an adhesive layer to one of the sides of the strip at least at each of the opposite ends;
Arranging the strip so that the adhesive layer faces the combustible heat source;
Wrapping the strip around the flammable heat source such that the flammable heat source is surrounded by at least one layer of the ceramic paper;
Abutting the opposite ends of the strip without overlapping the opposite ends;
Fixing the strip to the flammable heat source using the adhesive layer. 12. A method of forming an aerosol-generating article according to claim 11.