JP2023509362A - Combustible heat sources, including ignition aids and binders - Google Patents

Abstract

A combustible heat source for an aerosol-generating article comprising carbon, an alkaline earth metal peroxide ignition aid, and a binder comprising a combination of carboxymethylcellulose and at least one additional cellulose ether heat source. Preferably, the at least one additional cellulose ether is selected from the group consisting of ethylcellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose and hydroxypropylmethylcellulose. [Selection drawing] Fig. 1

Description

The present invention relates to a combustible heat source for an aerosol-generating article and an aerosol-generating article comprising a combustible heat source and an aerosol-forming substrate downstream of the combustible heat source.

A number of aerosol-generating articles have been proposed in the art in which the tobacco material is heated rather than combusted. One purpose of such "heated" aerosol-generating articles is to reduce known noxious smoke components of the type produced by combustion and pyrolysis of tobacco in conventional cigarettes.

Heated aerosol-generating articles typically generate an aerosol by heat transfer from a heat source, such as a chemical, electrical or combustible heat source, to a physically separate aerosol-forming substrate that may be located within, around, or downstream of the heat source. is generated.

In one type of heated aerosol-generating article, the aerosol is generated by heat transfer from a combustible carbonaceous heat source to a physically separated aerosol-forming substrate comprising tobacco material located downstream of the combustible carbonaceous heat source. . During use, the volatile compounds are released from the tobacco material by heat transfer from the combustible carbonaceous heat source to the aerosol-forming substrate and become entrained in the air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol that is inhaled by the user.

Heat can be transferred from the combustible carbonaceous heat source to the aerosol-forming substrate by one or both of forced convection and conduction.

at least a rear portion of the combustible carbonaceous heat source and the aerosol of the heated aerosol-generating article to ensure sufficient conductive heat transfer from the combustible carbonaceous heat source to the aerosol-forming substrate to obtain an acceptable aerosol; It is known to include thermally conductive elements around and in direct contact with at least the forward portion of the forming substrate. For example, WO 2009/022232 A2 discloses a combustible carbonaceous heat source, an aerosol-forming substrate downstream of the combustible heat source, and a back portion of the combustible carbonaceous heat source and an adjacent front portion of the aerosol-forming substrate, around and with them. Disclosed is a smoking article comprising contacting thermally conductive elements. In use, heat generated during combustion of the combustible carbonaceous heat source is transferred to the periphery of the forward portion of the aerosol-forming substrate by conduction through the abutting downstream end of the combustible carbonaceous heat source and the thermally conductive element. be.

The combustion temperature of a combustible heat source for use in a 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 carbonaceous heat source is sufficient to release sufficient volatile compounds from the aerosol-forming substrate to generate sufficient heat to produce an acceptable aerosol, especially during inhalation. should be as high as possible.

Various combustible carbonaceous heat sources are known in the art for use in heated aerosol-generating articles.

When used in heated aerosol-generating articles, known combustible carbonaceous heat sources often do not generate enough heat to produce an acceptable aerosol after ignition and during puff initiation.

Known combustible carbonaceous heat sources are often difficult to ignite when used in heated aerosol-generating articles. Failure to properly ignite the combustible carbonaceous heat source of a heated aerosol-generating article can lead to unacceptable aerosol delivery to the user.

It has been proposed to include oxidants and other additives in combustible carbonaceous heat sources to improve their ignition and combustion characteristics. For example, WO2012/164077A1 describes metal nitrates, chlorates, peroxides, thermic materials, intermetallic materials, magnesium, zirconium, and combinations thereof having a thermal decomposition temperature of less than about 600 degrees Celsius. A combustible heat source for smoking articles is disclosed comprising carbon selected from the group and at least one ignition aid.

Some ignition aids used in known combustible carbonaceous heat sources have been found to decompose upon exposure to environmental conditions during transportation and storage of the combustible carbonaceous heat source. For example, some ignition aids used in known combustible carbonaceous heat sources have been found to degrade upon exposure to atmospheric moisture during transportation and storage of the combustible carbonaceous heat source. Degradation of ignition aids during shipping and storage can disadvantageously make it more difficult to ignite known carbonaceous combustible heat sources, including ignition aid sources.

It would be desirable to provide a combustible carbonaceous heat source that includes an ignition aid that exhibits rapid ignition and mechanical integrity even after exposure to environmental conditions.

It would be desirable to provide a combustible carbonaceous heat source containing an ignition aid that exhibits improved combustion characteristics as compared to known combustible carbonaceous heat sources containing ignition aids.

The present invention relates to combustible heat sources for aerosol-generating articles. Combustible heat sources may include carbon. Combustible heat sources may include ignition aids. The ignition aid may be an alkaline earth metal peroxide. A combustible heat source may include a binder. Binders may include carboxymethylcellulose. The binder may contain at least one additional cellulose ether. The binder may comprise a combination of carboxymethylcellulose and at least one additional cellulose ether.

SUMMARY OF THE INVENTION According to the present invention, a combustible heat source for an aerosol-generating article comprises carbon, an alkaline earth metal peroxide ignition aid, and a binder comprising at least one cellulose ether, the binder comprising A combustible heat source is provided that does not contain a non-combustible inorganic sheet silicate binder.

According to the present invention, a combustible heat source for an aerosol-generating article comprising carbon, an alkaline earth metal peroxide ignition aid, ethyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and hydroxypropyl methyl cellulose a binder comprising at least one cellulose ether selected from the group consisting of: the binder is free of non-combustible inorganic sheet silicate binders;

According to the present invention, a combustible heat source for an aerosol-generating article, the combination comprising a combination of carbon, an alkaline earth metal peroxide ignition aid, carboxymethylcellulose and at least one additional cellulose ether A combustible heat source is provided, comprising:

According to the invention there is further provided an aerosol-generating article comprising a combustible heat source according to the invention and an aerosol-forming substrate downstream of the combustible heat source.

Surprisingly, the inclusion in the combustible heat source according to the invention of a binder comprising a combination of carboxymethylcellulose and at least one additional cellulose ether advantageously results in It has been found that the decomposition of alkaline earth metal peroxide ignition aids can be reduced.

In particular, it has been surprisingly found that the inclusion in the combustible heat source according to the invention of a binder comprising a combination of carboxymethylcellulose and at least one additional cellulose ether reduces alkaline soil exposure as a result of exposure to high humidity. It has been found that the decomposition of metal peroxide ignition aids can be reduced.

While not wishing to be bound by theory, the inclusion of a binder comprising a combination of carboxymethylcellulose and at least one additional cellulose ether reduces the overall hydrophilicity and hygroscopicity of combustible heat sources according to the present invention. is thought to decrease.

By reducing the decomposition of the alkaline earth metal peroxide ignition aid, the inclusion of a binder comprising a combination of carboxymethyl cellulose and at least one additional cellulose ether is advantageous for transportation of combustible heat sources. and improve the chemical and physical stability of the combustible heat source according to the present invention during storage.

Also surprisingly, by including a binder comprising a combination of carboxymethylcellulose and at least one additional cellulose ether in combination with the alkaline earth metal peroxide ignition aid, advantageously, the It has been found that the combustion characteristics of combustible heat sources can be significantly improved.

In particular, surprisingly, the inclusion of a binder comprising a combination of carboxymethylcellulose and at least one additional cellulose ether in combination with an alkaline earth metal peroxide ignition aid advantageously results in the present invention. It has been found that the ignition propagation speed of combustible heat sources can be significantly improved.

Without wishing to be bound by theory, it is believed that a binder comprising a combination of carboxymethylcellulose and at least one additional cellulose ether provides energy during ignition of combustible heat sources according to the present invention. While not wishing to be bound by theory, it is believed that this improves the ignition propagation speed of combustible heat sources according to the present invention.

It has also been surprisingly found that the inclusion of a binder comprising a combination of carboxymethylcellulose and at least one additional cellulose ether can advantageously improve the mechanical properties of combustible heat sources according to the present invention. served.

While not wishing to be bound by theory, the inclusion of a binder comprising a combination of carboxymethyl cellulose and at least one additional cellulose ether allows the carbon and alkaline earth It is believed to modify agglomeration of group metal peroxide ignition aids. While not wishing to be bound by theory, it is believed that this affects the mechanical properties of combustible heat sources according to the present invention.

The terms "distal," "upstream," and "anterior," and "proximal," "downstream," and "posterior," as used herein in connection with embodiments of the present invention, are It is used to describe the relative positions of components, or portions of components, of an aerosol-generating article according to the invention. Aerosol-generating articles according to the present invention comprise a proximal end through which aerosol exits the aerosol-generating article for delivery to a user in use. The proximal end of the aerosol-generating article may also be referred to as the mouth end of the aerosol-generating article. In use, the user inhales on the proximal end of the aerosol-generating article to inhale the aerosol produced by the aerosol-generating article.

Aerosol-generating articles according to the present invention comprise a distal end. A combustible heat source is located at or near the distal end of the aerosol-generating article. The mouth end of the aerosol-generating article is downstream of the distal end of the aerosol-generating article. Also, the proximal end of the aerosol-generating article may be referred to as the downstream end of the aerosol-generating article, and the distal end of the aerosol-generating article may also be referred to as the upstream end of the aerosol-generating article. Components or component portions of aerosol-generating articles according to the present invention are said to be upstream or downstream of each other based on their relative positions between the proximal end of the aerosol-generating article and the distal end of the aerosol-generating article. can be described.

A combustible heat source according to the present invention has a front end face and a rear end face. The front end face of the combustible heat source is at the upstream end of the combustible heat source. The upstream end of the combustible heat source is the end of the combustible heat source furthest from the proximal end of the aerosol-generating article. The trailing end face of the combustible heat source is at the downstream end of the combustible heat source. The downstream end of the combustible heat source is the end of the combustible heat source closest to the proximal end of the aerosol-generating article.

The term "longitudinal" as used herein in connection with the present invention is to describe the direction between the upstream and downstream ends of a combustible heat source according to the invention and an aerosol-generating article according to the invention. used for

As used herein in connection with the present invention, the term "transverse" is used to describe a direction perpendicular to the longitudinal direction. That is, perpendicular to the direction between the upstream and downstream ends of the combustible heat source according to the invention and the aerosol-generating article according to the invention.

As used herein in connection with the present invention, the term "length" is used to describe the maximum longitudinal dimension of a combustible heat source according to the present invention and an aerosol-generating article according to the present invention.

As used herein in connection with the present invention, the term "diameter" is used to describe the maximum transverse dimension of combustible heat sources according to the present invention and aerosol-generating articles according to the present invention.

A combustible heat source according to the present invention is a carbonaceous heat source.

As used herein in connection with the present invention, the term "carbonaceous" is used to describe combustible heat sources containing carbon.

A combustible heat source according to the present invention contains carbon as a fuel.

The combustible heat source may contain at least about 25 weight percent carbon.

Unless otherwise specified, the weight percentages of combustible heat source components listed herein are based on the total dry weight of the combustible heat source.

The combustible heat source preferably contains at least about 30 weight percent carbon.

More preferably, the combustible heat source contains at least about 35 weight percent carbon.

The combustible heat source may contain at least about 40 weight percent carbon.

The combustible heat source may contain no more than about 60 weight percent carbon.

Preferably, the combustible heat source contains no more than about 55 weight percent carbon.

More preferably, the combustible heat source contains no more than about 50 weight percent carbon.

The combustible heat source may contain no more than about 45 weight percent carbon.

The combustible heat source is about 25 weight percent to about 60 weight percent carbon, about 25 weight percent to about 55 weight percent carbon, about 25 weight percent to about 50 weight percent carbon, or about 25 weight percent to about 45 weight percent. % carbon may be included.

The combustible heat source is from about 30 weight percent to about 60 weight percent carbon, from about 30 weight percent to about 55 weight percent carbon, from about 30 weight percent to about 50 weight percent carbon, or from about 30 weight percent to about 45 weight percent % carbon is preferred.

The combustible heat source is about 35 weight percent to about 60 weight percent carbon, about 35 weight percent to about 55 weight percent carbon, about 35 weight percent to about 50 weight percent carbon, or about 35 weight percent to about 45 weight percent % carbon is more preferred.

The combustible heat source is about 40 weight percent to about 60 weight percent carbon, about 40 weight percent to about 55 weight percent carbon, about 40 weight percent to about 50 weight percent carbon, or about 40 weight percent to about 45 weight percent % carbon may be included.

Combustible heat sources according to the present invention may be formed using one or more suitable carbon materials. Advantageously, the combustible heat source according to the invention comprises one or more carbonizing materials. Suitable carbon materials are known in the art and include, but are not limited to, carbon powder and charcoal powder.

A combustible heat source according to the present invention comprises an alkaline earth metal peroxide ignition aid.

As used herein in connection with the present invention, the term "alkaline earth metal peroxide ignition aid" means an alkaline earth metal peroxide that releases one or both of energy and oxygen during ignition of a combustible heat source. Used to describe peroxides, the rate of release of energy and/or oxygen by alkaline earth metal peroxides is not diffused to ambient oxygen. In other words, the rate of energy and/or oxygen release by the alkaline earth metal peroxide during ignition of the combustible heat source is largely independent of the rate at which ambient oxygen can reach the alkaline earth metal peroxide. be.

The amount of energy and/or oxygen released by the alkaline earth metal peroxide ignition aid during ignition of the combustible heat source is sufficient to cause the combustible heat source to undergo a two-stage combustion process. obtain.

During an initial first stage, the combustible heat source according to the invention exhibits a "boost" in temperature, and during a subsequent second stage, the combustible heat source according to the invention exhibits sustained combustion at a lower "cruising" temperature. I can receive it.

An initial "boost" in the temperature of the combustible heat source according to the present invention can occur due to the very rapid heat transfer throughout the combustible heat source that accompanies ignition of a portion thereof. Very rapid heat propagation can be the result of a chain reaction in which a portion of an ignited combustible heat source triggers the ignition of an adjacent unignited portion of the combustible heat source.

In use, in aerosol-generating articles according to the present invention, a rapid temperature increase of a combustible heat source according to the present invention to a "boost" temperature raises the temperature of the aerosol-forming substrate to a level at which volatile compounds are released from the aerosol-forming substrate. can rise rapidly. This can ensure that the aerosol-generating article according to the invention produces a perceptually acceptable aerosol during the beginning of puffing. Subsequent temperature reduction of the combustible heat source to a "cruising" temperature according to the present invention may ensure that the temperature of the aerosol-forming substrate does not reach a level where combustion or thermal decomposition of the aerosol-forming substrate occurs.

Controlling the temperature of a combustible heat source according to the present invention in the manner described above advantageously not only produces a perceptually acceptable aerosol during inhalation, but also reduces combustion or pyrolysis of the aerosol-forming substrate. It may also be possible to provide an aerosol-generating article in which contamination is substantially avoided.

The amount of alkaline earth metal peroxide ignition aid that must be included to achieve the two-step process described above will vary depending on the specific alkaline earth metal peroxide ignition aid contained in the combustible heat source. do.

Generally, the greater the amount of energy and/or oxygen released by the alkaline earth metal peroxide ignition aid per unit mass thereof, the more combustible heat source is included to achieve the two-stage combustion process described above. Less alkaline earth metal peroxide ignition aid is required.

The combustible heat source may comprise at least about 15 weight percent alkaline earth metal peroxide ignition aid.

Preferably, the combustible heat source comprises at least about 20 weight percent alkaline earth metal peroxide ignition aid.

More preferably, the combustible heat source comprises at least about 30 weight percent alkaline earth metal peroxide ignition aid.

The combustible heat source may comprise at least about 40 weight percent alkaline earth metal peroxide ignition aid.

The combustible heat source may include up to about 65 weight percent alkaline earth metal peroxide ignition aid.

Preferably, the combustible heat source comprises about 60 weight percent or less alkaline earth metal peroxide ignition aid.

More preferably, the combustible heat source comprises no more than about 55 weight percent alkaline earth metal peroxide ignition aid.

The combustible heat source may include about 50 weight percent or less alkaline earth metal peroxide ignition aid.

The combustible heat source comprises about 15 weight percent to about 65 weight percent alkaline earth metal peroxide ignition aid, about 15 weight percent to about 60 weight percent alkaline earth metal peroxide ignition aid, about 15 weight percent percent to about 55 weight percent alkaline earth metal peroxide ignition aid, or from about 15 weight percent to about 50 weight percent alkaline earth metal peroxide ignition aid.

The combustible heat source comprises about 20 weight percent to about 65 weight percent alkaline earth metal peroxide ignition aid, about 20 weight percent to about 60 weight percent alkaline earth metal peroxide ignition aid, about 20 weight percent % to about 55 weight percent alkaline earth metal peroxide ignition aid, or from about 20 weight percent to about 50 weight percent alkaline earth metal peroxide ignition aid.

The combustible heat source comprises about 30 weight percent to about 65 weight percent alkaline earth metal peroxide ignition aid, about 30 weight percent to about 60 weight percent alkaline earth metal peroxide ignition aid, about 30 weight percent More preferably, it contains from about 55 weight percent alkaline earth metal peroxide ignition aid, or from about 30 weight percent to about 50 weight percent alkaline earth metal peroxide ignition aid.

The combustible heat source comprises about 40 weight percent to about 65 weight percent alkaline earth metal peroxide ignition aid, 40 weight percent to about 60 weight percent alkaline earth metal peroxide ignition aid, about 40 weight percent From about 55 weight percent alkaline earth metal peroxide ignition aid, or from about 40 weight percent to about 50 weight percent alkaline earth metal peroxide ignition aid.

Preferably, the alkaline earth metal peroxide ignition aid is calcium peroxide.

The combustible heat source may comprise at least about 15 weight percent calcium peroxide.

Preferably, the combustible heat source comprises at least about 20 weight percent calcium peroxide.

More preferably, the combustible heat source comprises at least about 30 weight percent calcium peroxide.

The combustible heat source may comprise at least about 40 weight percent calcium peroxide.

The combustible heat source may include up to about 65 weight percent calcium peroxide.

Preferably, the combustible heat source contains no more than about 60 weight percent calcium peroxide.

More preferably, the combustible heat source comprises no more than about 55 weight percent calcium peroxide.

The combustible heat source may contain less than or equal to about 50 weight percent calcium peroxide.

The combustible heat source is about 15 weight percent to about 65 weight percent calcium peroxide, about 15 weight percent to about 60 weight percent calcium peroxide, about 15 weight percent to about 55 weight percent calcium peroxide, or about 15 weight percent to about 65 weight percent calcium peroxide. Weight percent to about 50 weight percent calcium peroxide may be included.

The combustible heat source is about 20 weight percent to about 65 weight percent calcium peroxide, about 20 weight percent to about 60 weight percent calcium peroxide, about 20 weight percent to about 55 weight percent calcium peroxide, or about 20 weight percent to about 65 weight percent calcium peroxide. It preferably contains from weight percent to about 50 weight percent calcium peroxide.

The combustible heat source is about 30 weight percent to about 65 weight percent calcium peroxide, about 30 weight percent to about 60 weight percent calcium peroxide, about 30 weight percent to about 55 weight percent calcium peroxide, or about 30 weight percent More preferably, it contains from weight percent to about 50 weight percent calcium peroxide.

The combustible heat source is about 40 weight percent to about 65 weight percent calcium peroxide, about 40 weight percent to about 60 weight percent calcium peroxide, about 40 weight percent to about 55 weight percent calcium peroxide, or about 40 weight percent Weight percent to about 50 weight percent calcium peroxide may be included.

A combustible heat source according to the present invention is a solid combustible heat source.

The combustible heat source is preferably a monolithic solid combustible heat source. That is, a piece of solid, combustible heat source.

A combustible heat source according to the present invention comprises a binder comprising a combination of carboxymethylcellulose and at least one additional cellulose.

The term "binder" as used herein in connection with the present invention means the ability to bind together the carbon and alkaline earth metal peroxide ignition aid and any other constituents of the combustible heat source. used to describe the components of a combustible heat source with

As used herein in connection with the present invention, the term "additional cellulose ethers" is used to describe cellulose ethers other than carboxymethylcellulose.

The combustible heat source may include at least about 3 weight percent binder.

Preferably, the combustible heat source comprises at least about 4 weight percent binder.

More preferably, the combustible heat source comprises at least about 5 weight percent binder.

The combustible heat source may contain up to about 20 weight percent binder.

Preferably, the combustible heat source contains no more than about 15 weight percent binder.

More preferably, the combustible heat source contains no more than about 10 weight percent binder.

The combustible heat source may comprise from about 3 weight percent to about 20 weight percent binder, from about 3 weight percent to about 15 weight percent binder, or from about 3 weight percent to about 10 weight percent binder.

Preferably, the combustible heat source comprises from about 4 weight percent to about 20 weight percent binder, from about 4 weight percent to about 15 weight percent binder, or from about 4 weight percent to about 10 weight percent binder.

More preferably, the combustible heat source comprises from about 5 weight percent to about 20 weight percent binder, from about 5 weight percent to about 15 weight percent binder, or from about 5 weight percent to about 10 weight percent binder. .

Binders include carboxymethylcellulose.

The combustible heat source may comprise at least about 1.5 weight percent carboxymethylcellulose.

Preferably, the combustible heat source comprises at least about 2 weight percent carboxymethylcellulose.

More preferably, the combustible heat source comprises at least about 3 weight percent carboxymethylcellulose.

The combustible heat source may comprise up to about 15 weight percent carboxymethyl cellulose.

Preferably, the combustible heat source comprises no more than about 12 weight percent carboxymethylcellulose.

More preferably, the combustible heat source comprises no more than about 8 weight percent carboxymethylcellulose.

The combustible heat source is from about 1.5 weight percent to about 15 weight percent carboxymethyl cellulose, from about 1.5 weight percent to about 12 weight percent carboxymethyl cellulose, or from about 1.5 weight percent to about 8 weight percent carboxymethyl cellulose. may include

Preferably, the combustible heat source comprises from about 2 weight percent to about 15 weight percent carboxymethyl cellulose, from about 2 weight percent to about 12 weight percent carboxymethyl cellulose, or from about 2 weight percent to about 8 weight percent carboxymethyl cellulose.

More preferably, the combustible heat source comprises from about 3 weight percent to about 15 weight percent carboxymethyl cellulose, from about 3 weight percent to about 12 weight percent carboxymethyl cellulose, or from about 3 weight percent to about 8 weight percent carboxymethyl cellulose. .

The binder contains at least one additional cellulose ether.

The combustible heat source may include at least about 0.2 weight percent of at least one additional cellulose ether.

The combustible heat source may comprise at least about 0.5 weight percent of at least one additional cellulose ether.

Preferably, the combustible heat source comprises at least about 0.75 weight percent of at least one additional cellulose ether.

More preferably, the combustible heat source comprises at least about 1 weight percent of at least one additional cellulose ether.

The combustible heat source may include up to about 6 weight percent of at least one additional cellulose ether.

Preferably, the combustible heat source contains about 5 weight percent or less of at least one additional cellulose ether.

More preferably, the combustible heat source includes about 4 weight percent or less of at least one additional cellulose ether.

The combustible heat source may include up to about 3 weight percent of at least one additional cellulose ether.

The combustible heat source comprises from about 0.2 weight percent to about 6 weight percent of at least one additional cellulose ether, from about 0.2 weight percent to about 5 weight percent of at least one additional cellulose ether, about 0.2 weight percent to about 5 weight percent of at least one additional cellulose ether. 5 weight percent to about 4 weight percent of at least one additional cellulose ether, or about 0.5 weight percent to about 3 weight percent of at least one additional cellulose ether.

The combustible heat source comprises from about 0.5 weight percent to about 6 weight percent at least one additional cellulose ether, from about 0.5 weight percent to about 5 weight percent of at least one additional cellulose ether, about 0.5 weight percent From about 4 weight percent to about 4 weight percent of at least one additional cellulose ether, or from about 0.5 weight percent to about 3 weight percent of at least one additional cellulose ether.

The combustible heat source comprises from about 0.75 weight percent to about 6 weight percent additional cellulose ether, from about 0.75 weight percent to about 5 weight percent additional cellulose ether, from about 0.75 weight percent to about 4 It is preferred to include weight percent additional cellulose ether, or from about 0.75 weight percent to about 3 weight percent additional cellulose ether.

The combustible heat source comprises from about 1 weight percent to about 6 weight percent additional cellulose ether, from about 1 weight percent to about 5 weight percent additional cellulose ether, from about 1 weight percent to about 4 weight percent additional More preferably, it contains a cellulose ether, or from about 1 weight percent to about 3 weight percent additional cellulose ether.

The binder comprises a combination of carboxymethylcellulose and at least one additional cellulose ether.

Preferably, the binder comprises a combination of carboxymethylcellulose and at least one additional cellulose ether selected from the group consisting of ethylcellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose and hydroxypropylmethylcellulose.

The ratio of the weight percent of carboxymethylcellulose to the weight percent of the at least one additional cellulose ether in the combustible heat source may be at least about 1:1.

Preferably, the ratio of the weight percent of carboxymethylcellulose to the weight percent of the at least one additional cellulose ether in the combustible heat source is at least about 3:2.

More preferably, the ratio of the weight percent of carboxymethylcellulose to the weight percent of the at least one additional cellulose ether in the combustible heat source can be at least about 2:1.

The ratio of the weight percent of carboxymethylcellulose to the weight percent of the at least one additional cellulose ether in the combustible heat source may be about 4:1 or less.

Preferably, the ratio of the weight percent of carboxymethylcellulose to the weight percent of the at least one additional cellulose ether in the combustible heat source can be about 7:2 or less.

More preferably, the ratio of the weight percent of carboxymethylcellulose to the weight percent of the at least one additional cellulose ether in the combustible heat source can be about 3:1 or less.

The ratio of the weight percent of carboxymethylcellulose to the weight percent of the at least one additional cellulose ether in the combustible heat source may be about 5:2 or less.

The ratio of the weight percent of carboxymethyl cellulose to the weight percent of the at least one additional cellulose ether in the combustible heat source is about 1:1 to about 4:1, about 1:1 to about 7:2, about 1:1 to about 3:1, or from about 1:1 to about 5:2.

The ratio of the weight percent of carboxymethylcellulose to the weight percent of the at least one additional cellulose ether in the combustible heat source is about 3:2 to about 4:1, about 3:2 to about 7:2, about 3:2 to about 3:1, or from about 3:2 to about 5:2.

The ratio of the weight percent of carboxymethylcellulose to the weight percent of the at least one additional cellulose ether in the combustible heat source is about 2:1 to about 4:1, about 2:1 to about 7:2, about 2:1 more preferably from about 3:1, or from about 2:1 to about 5:2.

The binder may comprise a non-combustible inorganic sheet silicate binder.

As used herein in connection with the present invention, the term "non-combustible" is used to describe components that do not burn or decompose at temperatures reached during ignition or combustion of combustible heat sources.

The term "non-combustible inorganic sheet silicate binder" as used herein in connection with the present invention is stable at the temperatures to which the binder is subjected during ignition and combustion of combustible heat sources. It is used to describe an inorganic sheet silicate binder that is stable and remains substantially intact during and after combustion of a combustible heat source.

Suitable non-combustible inorganic sheet silicate binders include, but are not limited to, clays such as bentonite, montmorillonite, and kaolinite, mica, and serpentinite.

As used herein in connection with the present invention, the term "clay" is used to describe an aluminum phyllosilicate material formed from two-dimensional sheets of silicate and aluminate ions, which form distinct layered structures within the clay.

Advantageously, the binder may be free of non-combustible inorganic sheet silicate binders.

A combustible heat source according to the present invention may comprise one or more carboxylic acid combustion salts.

As used herein in connection with the present invention, the term "carboxylic acid combustion salt" is used to describe salts of carboxylic acids other than carbonic acid. That is, the term "carboxylic acid combustion salt" as used herein in connection with the present invention does not include carbonates or bicarbonates.

One or more carboxylic acid combustion salts can advantageously facilitate combustion of combustible heat sources.

Carboxylic acid combustion salts may contain monovalent, divalent, or trivalent cations and carboxylate anions.

Carboxylic acid combustion salts may contain monovalent, divalent, or trivalent cations and acetate, citrate, or succinate anions.

The carboxylic acid combustion salt may be an alkali metal carboxylic acid combustion salt. For example, the carboxylic acid combustion salt may be a sodium carboxylic acid combustion salt or a potassium carboxylic acid combustion salt.

The carboxylic acid combustion salt may be an alkali metal acetate, alkali metal citrate, or alkali metal succinate.

Most preferably, the carboxylic acid combustion salt is potassium citrate.

A combustible heat source may include a single carboxylic acid combustion salt.

A combustible heat source may include a combination of two or more different carboxylic acid combustion salts. Two or more different carboxylic acid combustion salts may contain different carboxylic acid anions. Two or more different carboxylic acid combustion salts may contain different anions. For example, the combustible heat source may include a combination of alkali metal citrate and alkaline earth metal succinate.

The combustible heat source may comprise at least about 0.1 weight percent of one or more carboxylic acid combustion salts.

The combustible heat source may comprise at least about 0.5 weight percent of one or more carboxylic acid combustion salts.

Preferably, the combustible heat source comprises at least about 1 weight percent of one or more carboxylic acid combustion salts.

The combustible heat source may include about 4 weight percent or less of one or more carboxylic acid combustion salts.

Preferably, the combustible heat source comprises about 3 weight percent or less of one or more carboxylic acid combustion salts.

The combustible heat source may comprise from about 0.1 weight percent to about 4 weight percent of one or more carboxylic acid combustion salts, or from about 0.1 weight percent to about 3 weight percent of one or more carboxylic acid combustion salts. good.

The combustible heat source may comprise from about 0.5 weight percent to about 4 weight percent of one or more carboxylic acid combustion salts, or from about 0.5 weight percent to about 3 weight percent of one or more carboxylic acid combustion salts. good.

Preferably, the combustible heat source comprises from about 1 weight percent to about 4 weight percent of one or more carboxylic acid combustion salts, or from about 1 weight percent to about 3 weight percent of one or more carboxylic acid combustion salts.

Combustible heat sources according to the present invention are preferably substantially homogeneous in composition.

A combustible heat source according to the present invention may have any desired length.

A combustible heat source according to the present invention may have a length of about 5 millimeters to about 20 millimeters.

A combustible heat source according to the present invention preferably has a length of about 7 millimeters to about 17 millimeters.

More preferably, a combustible heat source according to the present invention has a length of about 7 millimeters to about 15 millimeters.

Most preferably, a combustible heat source according to the present invention has a length of about 7 millimeters to about 13 millimeters.

A combustible heat source according to the present invention may have any desired diameter.

A combustible heat source according to the present invention may have a diameter of about 5 millimeters to about 15 millimeters.

A combustible heat source according to the present invention preferably has a diameter of about 5 millimeters to about 10 millimeters.

More preferably, combustible heat sources according to the present invention have a diameter of about 7 millimeters to about 8 millimeters.

A combustible heat source according to the present invention may be tapered such that the diameter of the aft portion of the combustible heat source is greater than the diameter of the forward portion of the combustible heat source.

Combustible heat sources according to the present invention are preferably of substantially constant diameter.

A combustible heat source according to the invention is preferably of substantially circular cross-section.

A combustible heat source according to the present invention is preferably substantially cylindrical.

A combustible heat source according to the present invention may have a mass of about 300 milligrams to about 500 milligrams. For example, a combustible heat source according to the present invention has a mass of about 400 milligrams to about 450 milligrams.

A combustible heat source according to the present invention may have an apparent density of from about 0.6 grams/cubic centimeter to about 1.0 grams/cubic centimeter.

A combustible heat source according to the present invention may have a porosity of from about 20 percent to about 80 percent, for example, as measured by mercury porosimetry or helium pycnometry.

For example, a combustible heat source according to the present invention may be from about 20 percent to about 60 percent, from about 50 percent to about 70 percent, or from about 50 percent to about 60 percent, for example, as measured by mercury porosimetry or helium pycnometry. may have a porosity of

The desired porosity can be readily achieved during production of the combustible heat source of the present invention using conventional methods and techniques.

A combustible heat source according to the present invention is made by combining one or more carbon materials, alkaline earth metal peroxide ignition aids, binders, and any other components of the combustible heat source to form a mixture, It can be formed by forming into the desired shape.

Combustible heat sources according to the present invention combine one or more carbon materials, alkaline earth metal peroxide ignition aids, binders, and any other components of the combustible heat source to form a granular mixture. , preferably formed by forming the granular mixture into the desired shape.

Advantageously, the binder is dispersed at intergranular and intragranular locations in the granule mixture.

Combining one or more carbon materials, alkaline earth metal peroxide ignition aids, binders, and any other components of the combustible heat source, e.g., dry granulation, wet granulation, high shear Suitable known methods such as mixing, spheronizing or extrusion may be used to form the mixture.

Preferably, the one or more carbon materials, alkaline earth metal peroxide ignition aid, binder, and any other components of the combustible heat source are combined to form a granular mixture by wet granulation. .

The mixture can be formed into the desired shape using suitable known ceramic forming methods such as, for example, slip casting, extrusion, injection molding, die compression or pressing.

The mixture is preferably formed into the desired shape by pressing.

After formation, the desired shape is preferably dried to reduce its moisture content. The desired shape may be dried using suitable known methods. For example, the desired shape may be dried in an oven at a temperature of about 85 degrees Celsius to about 105 degrees Celsius.

The combustible heat source may be a non-blind combustible heat source.

The term "non-blind" as used herein in connection with the present invention includes at least one airflow channel extending along the length of a combustible heat source through which air can be drawn for inhalation by a user. Used to describe combustible heat sources.

If the combustible heat source is a non-blind combustible heat source, a non-combustible, substantially impermeable barrier may be provided between the non-blind combustible heat source and the at least one airflow channel.

The term "non-combustible barrier" as used herein in connection with the present invention describes a barrier that is substantially non-combustible at temperatures reached by combustible heat sources during its ignition and combustion. used for

By including a non-combustible, substantially impermeable barrier between the non-blind combustible heat source and the at least one airflow channel, in use, advantageously during ignition and combustion of the non-blind combustible heat source. Combustion and decomposition products formed may be substantially prevented or inhibited from entering air drawn through the at least one airflow channel.

In use, by including a non-combustible, substantially impermeable barrier between the non-blind combustible heat source and at least one airflow channel, the non-blind combustible heat source is advantageously protected during puffing by the user. combustion activation can be substantially prevented or inhibited. When used in an aerosol-generating article according to the present invention, it can advantageously substantially prevent or arrest spikes in the temperature of the aerosol-forming substrate of the aerosol-generating article during puffing by the user.

A barrier between the non-blind combustible heat source and the at least one airflow channel may have a low thermal conductivity or a high thermal conductivity.

The thickness of the barrier between the non-blind combustible heat source and the at least one airflow channel can be selected to achieve good performance.

The barrier between the non-blind combustible heat source and the at least one airflow channel is substantially thermally stable and non-combustible at temperatures achieved by the non-blind combustible heat source during ignition and combustion thereof. It may be formed from one or more suitable materials. Suitable materials are known in the art and include clays, metal oxides (such as iron oxides, alumina, titania, silica, silica-alumina, zirconia and ceria), zeolites, zirconium phosphates, and other ceramic materials and Including, but not limited to, combinations of these.

A barrier between the non-blind combustible heat source and the at least one airflow channel may be glued or otherwise affixed to the inner surface of the at least one airflow channel of the non-blind combustible heat source.

Suitable methods for adhering or affixing a barrier to the inner surface of at least one airflow channel of a non-blind combustible heat source are known in the art, see US 5,040,551 and WO 2009/074870 A2. including, but not limited to, the methods described in .

A barrier between the non-blind combustible heat source and the at least one airflow channel may comprise a liner inserted within the at least one airflow channel.

The combustible heat source is preferably a blind combustible heat source.

The term "blind" as used herein in connection with the present invention means a combustible blind that does not contain any airflow channels extending along the length of a combustible heat source through which air can be drawn for inhalation by a user. Used to describe a heat source.

Blind combustible heat sources according to the present invention and non-blind combustible heat sources according to the present invention may include one or more closed or blocked channels through which air cannot be drawn for inhalation by a user.

For example, the combustible heat source may include one or more closed channels that extend only part way along the length of the combustible heat source.

The inclusion of one or more closed channels can increase the surface area of the combustible heat source exposed to oxygen from the air. Advantageously, this can facilitate ignition and sustained combustion of combustible heat sources.

An aerosol-generating article according to the invention comprises a combustible heat source according to the invention and an aerosol-forming substrate.

The term "aerosol-forming substrate" as used herein in connection with the present invention describes a substrate comprising an aerosol-forming material capable of releasing volatile compounds capable of forming an aerosol upon heating. used for The aerosol generated from the aerosol-forming substrate of the aerosol-generating article according to the invention may or may not be visible and may be vapor (e.g., the gaseous state of substances that are normally liquid or solid at room temperature). particles of matter in the air) as well as droplets of gases and condensed vapors.

The aerosol-forming substrate may be in the form of a plug or segment containing a material capable of releasing volatile compounds upon heating, which can be surrounded by a wrapper to form an aerosol. When the aerosol-forming substrate is in the form of such a plug or segment, the entire plug or segment including the wrapper is considered an aerosol-forming substrate.

The aerosol-forming substrate is downstream of the combustible heat source. That is, the aerosol-forming substrate is between the combustible heat source and the distal end of the aerosol-generating article.

The aerosol-forming substrate may contact a combustible heat source.

The aerosol-forming substrate may be longitudinally spaced from the combustible heat source.

Advantageously, the aerosol-forming substrate comprises an aerosol-forming material comprising an aerosol former.

The aerosol former may be any suitable compound or mixture of compounds that facilitates the formation of a dense and stable aerosol in use and that is substantially resistant to thermal decomposition at the operating temperature of the aerosol-generating article. good. Suitable aerosol formers are well known in the art and include polyhydric alcohols such as triethylene glycol, propylene glycol, 1,3-butanediol and glycerin, esters of polyhydric alcohols such as glycerol mono-, di- or triacetate. etc.), and aliphatic esters of mono-, di- or polycarboxylic acids such as dodecanedioic acid and dimethyl tetradecanedioate.

Advantageously, the aerosol former comprises one or more polyhydric alcohols.

More advantageously, the aerosol former comprises glycerin.

Preferably, the aerosol-forming substrate is a solid aerosol-forming substrate. Aerosol-forming substrates may include both solid and liquid components.

Aerosol-forming substrates may include plant-derived materials. The aerosol-forming substrate may comprise homogenized plant-derived material.

The aerosol-forming substrate may contain nicotine.

The aerosol-forming substrate may comprise tobacco material.

The term "tobacco material" as used herein in connection with the present invention includes tobacco leaves, tobacco ribs, tobacco stems, tobacco stems, tobacco dust, expanded tobacco, reconstituted tobacco material, and homogenized tobacco material. is used to describe any material including tobacco, including but not limited to

Tobacco material may be in the form of, for example, powder, granules, pellets, shreds, strands, strips, sheets, or any combination thereof.

Advantageously, the aerosol-forming substrate comprises homogenized tobacco material.

As used herein in connection with the present invention, the term "homogenized tobacco material" is used to describe material formed by agglomerating particulate tobacco.

In certain embodiments, the aerosol-forming substrate advantageously comprises a plurality of strands of homogenized tobacco material.

Advantageously, the plurality of strands of homogenized tobacco material can be aligned substantially parallel to each other within the aerosol-forming substrate.

In certain embodiments, the aerosol-forming substrate advantageously comprises a collection of sheets of homogenized tobacco material.

The aerosol-forming substrate may comprise a rod comprising a collection of sheets of homogenized tobacco material.

The term "rod" as used herein in connection with the present invention is used to describe a substantially cylindrical element of substantially circular, oval or elliptical cross-section.

The term "sheet" as used herein in connection with the present invention is used to describe a laminar element having a width and length substantially greater than its thickness.

The term "aggregate" as used herein in connection with the present invention is rolled, folded or otherwise compressed substantially transversely to the longitudinal axis of the aerosol-generating article, or Used to describe a shrunken sheet.

The aerosol-forming substrate can include an aerosol-forming material and a wrapper around and in contact with the aerosol-forming material.

The wrapper may be formed from any suitable sheet material capable of being wrapped around the aerosol-forming material to form an aerosol-forming substrate.

In certain embodiments, an aerosol-forming substrate may comprise a rod comprising a collection of sheets of homogenized tobacco material and a wrapper around and in contact with the tobacco material.

In certain embodiments, the aerosol-forming substrate advantageously comprises an assembly of textured sheets of homogenized tobacco material.

As used herein in connection with the present invention, the term "textured sheet" is used to describe a sheet that has been crimped, embossed, debossed, perforated, or otherwise deformed.

The use of a textured sheet of homogenized tobacco material may advantageously facilitate assembly of the homogenized tobacco material sheet to form an aerosol-forming substrate.

The aerosol-forming substrate may comprise a collection of textured sheets of homogenized tobacco material containing a plurality of spaced apart depressions, projections, perforations or any combination thereof.

The aerosol-forming substrate may comprise an assembly of crimped sheets of homogenized tobacco material.

As used herein in connection with the present invention, the term "crimped sheet" is used to describe a sheet having a plurality of substantially parallel ridges or corrugations.

Advantageously, when the aerosol-generating article comprising the aerosol-forming substrate is assembled, the substantially parallel ridges or corrugations extend along or parallel to the longitudinal axis of the aerosol-generating article. This facilitates assembly of crimped sheets of homogenized tobacco material to form an aerosol-forming substrate.

However, crimped sheets of homogenized tobacco material for inclusion in the aerosol-forming substrate of an aerosol-generating article according to the present invention may alternatively or additionally be used in the aerosol-generating article when the aerosol-generating article is assembled. It will be appreciated that it may have a plurality of substantially parallel ridges or corrugations arranged at acute or obtuse angles to the longitudinal axis of the body.

Preferably, the aerosol-forming substrate is substantially cylindrical.

The aerosol-forming substrate may have a length of about 5 millimeters to about 20 millimeters.

The aerosol-forming substrate preferably has a length of about 6 millimeters to about 15 millimeters.

More preferably, the aerosol-forming substrate has a length of about 7 millimeters to about 12 millimeters.

Aerosol-forming substrates may have a diameter of about 5 millimeters to about 15 millimeters.

The aerosol-forming substrate preferably has a diameter of about 5 millimeters to about 10 millimeters.

More preferably, the aerosol-forming substrate has a diameter of about 7 millimeters to about 8 millimeters.

Aerosol-generating articles according to the invention may comprise a combustible heat source according to the invention, an aerosol-forming substrate downstream of the combustible heat source, and one or more other components.

The combustible heat source, aerosol-forming substrate, and, if included, one or more other components of the aerosol-generating article are assembled within one or more wrappers and are elongated having proximal and opposed distal ends. It can form rods. Therefore, an aerosol-generating article according to the present invention may resemble a conventional lit-end cigarette.

The one or more other components may include one or more of a cap, transfer or spacer element, aerosol cooling element, or heat exchanger and mouthpiece.

An aerosol-generating article according to the invention may comprise a cap configured to at least partially cover the front portion of the combustible heat source. The cap may be removable such that the front portion of the combustible heat source is exposed prior to use of the aerosol-generating article. Advantageously, the cap may protect the combustible heat source prior to use of the aerosol-generating article.

As used herein in connection with the present invention, the term "cap" is used to describe a protective cover at the distal end of the aerosol-generating article that substantially encloses the forward portion of the combustible heat source.

For example, an aerosol-generating article according to the invention may comprise a removable cap attached to the distal end of the aerosol-generating article above the line of weakness, the cap being surrounded by a wrapper, as described in WO 2014/086998 A1. It contains a cylindrical plug of material that can be

Aerosol-generating articles according to the present invention may comprise moving or spacer elements downstream of the aerosol-forming substrate. That is, the transfer element or spacer element is located between the aerosol-forming substrate and the proximal end of the aerosol-generating article.

The moving element may abut the aerosol-forming substrate. Alternatively, the moving element may be longitudinally spaced from the aerosol-forming substrate.

Inclusion of the moving element may advantageously allow cooling of the aerosol generated by heat transfer from the combustible heat source to the aerosol-forming substrate.

Including a moving element may advantageously allow the overall length of the aerosol-generating article to be adjusted to a desired value by appropriate selection of the length of the moving element. For example, including a moving element may advantageously allow the overall length of the aerosol-generating article to be adjusted to a length similar to that of a conventional cigarette.

The moving element may have a length of about 7 millimeters to about 50 millimeters. For example, the moving element may have a length of about 10 millimeters to about 45 millimeters, or a length of about 15 millimeters to about 30 millimeters.

The moving element can have other lengths depending on the desired overall length of the aerosol-generating article and the presence and length of other components within the aerosol-generating article.

The moving element may comprise an open ended tubular hollow body. In use, air drawn into the aerosol-generating article by a user will enter the open-ended tubular hollow as it passes downstream through the aerosol-generating article from the aerosol-forming substrate to the proximal end of the aerosol-generating article. can pass through the body.

The open-ended tubular hollow body may be formed from one or more materials that are substantially thermally stable at the temperature of the aerosol generated by the transfer of heat from the combustible heat source to the aerosol-forming substrate. Suitable materials are known in the art and include, but are not limited to, paper, cardboard, thermoplastics, such cellulose acetates, and ceramics.

Aerosol-generating articles according to the present invention may comprise an aerosol-cooling element or heat exchanger downstream of the aerosol-forming substrate. That is, the aerosol cooling element or heat exchanger is located between the aerosol-forming substrate and the proximal end of the aerosol-generating article.

The aerosol cooling element can advantageously cool the aerosol generated by heat transfer from the combustible heat source to the aerosol-forming substrate.

The aerosol cooling element may include a plurality of longitudinally extending channels.

The aerosol cooling element may comprise a collection of material sheets selected from the group consisting of metal foil, polymeric material and substantially non-porous paper or cardboard.

The aerosol cooling element is a material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA) and aluminum foil. It may also include a collection of sheets.

The aerosol cooling element may comprise an assembly of sheets of biodegradable polymeric material such as polylactic acid (PLA) or Mater-Bi® grades (a commercial family of starch-based copolyesters).

When an aerosol-generating article according to the invention comprises a moving element downstream of the aerosol-forming substrate and an aerosol-cooling element downstream of the aerosol-forming substrate, the aerosol-cooling element is preferably downstream of the moving element. That is, the aerosol-cooling element is preferably located between the moving element and the proximal end of the aerosol-generating article.

Aerosol-generating articles according to the present invention may comprise a mouthpiece downstream of the aerosol-forming substrate. That is, the mouthpiece is located between the aerosol aerosol formation and the proximal end of the aerosol-generating article.

Aerosol-generating articles according to the present invention preferably include a mouthpiece located at the proximal end of the aerosol-generating article.

The mouthpiece may have a low or very low filtration efficiency.

The mouthpiece may be a single segment mouthpiece.

The mouthpiece may be a multi-segment mouthpiece.

The mouthpiece may include one or more segments containing filtering material.

Suitable filtration materials are well known in the art and include, but are not limited to, cellulose acetate and paper.

The mouthpiece may include one or more segments containing absorbent material.

The mouthpiece may include one or more segments containing absorbent material.

Suitable absorbent materials and suitable absorbent materials are known in the art and include, but are not limited to, activated carbon, silica gel, and zeolites.

Aerosol-generating articles according to the present invention may include one or more aerosol modifiers downstream of the aerosol-forming substrate. For example, if included, one or more of the mouthpiece, transfer element, and aerosol cooling element of an aerosol-generating article according to the invention may include one or more aerosol modifiers.

The term "aerosol modifier" as used herein in connection with the present invention is any agent that, in use, modifies one or more characteristics or properties of the aerosol generated by the aerosol-forming substrate of the aerosol-generating article. Used to describe drugs.

Suitable aerosol modifiers include, but are not limited to, flavorants, and chemosensory agents.

The term "chemosensory agent" as used herein in connection with the present invention means that, in use, the user's Used to describe drugs that are perceived in the oral or nasal cavity. Sensation of chemosensory agents is typically via a "trigeminal response" (either trigeminal, glossopharyngeal, vagus, or some combination thereof). Chemosensors are typically perceived as pungent, savory, cooling, or soothing sensations.

Aerosol-generating articles according to the present invention may include one or more aerosol modifiers that are both flavorants and chemosensory agents downstream of the aerosol-forming substrate. For example, if included, one or more of the mouthpiece, transfer element and aerosol cooling element of an aerosol-generating article according to the invention may comprise menthol or another flavoring agent that provides a cooling chemosensory effect.

Aerosol-generating articles according to the present invention may further comprise one or more thermally conductive elements.

Preferably, an aerosol-generating article according to the present invention comprises a thermally conductive element surrounding at least a portion of the aerosol-forming substrate. The thermally conductive element can advantageously transfer heat to the periphery of the aerosol-forming substrate by conduction.

More preferably, the aerosol-generating article according to the invention comprises a thermally conductive element surrounding and in contact with at least a portion of the aerosol-forming substrate. This can advantageously facilitate conductive heat transfer to the periphery of the aerosol-forming substrate.

The thermally conductive element may be around the entire length of the aerosol-forming substrate. That is, the thermally conductive element may overlie the entire length of the aerosol-forming substrate.

Thermally conductive elements are preferably absent around the rear portion of the aerosol-forming substrate. That is, the aerosol-forming substrate advantageously extends longitudinally in a downstream direction beyond the thermally conductive element.

Preferably, the aerosol-forming substrate extends longitudinally at least about 3 millimeters in the downstream direction beyond the thermally conductive element.

Preferably, an aerosol-generating article according to the present invention includes a thermally conductive element around at least a portion of the combustible heat source and around at least a portion of the aerosol-forming substrate.

More preferably, the aerosol-generating article according to the present invention comprises a thermally conductive element around at least the rear portion of the combustible heat source and around at least the front portion of the aerosol-forming substrate.

Most preferably, the aerosol-generating article according to the present invention comprises a thermally conductive element around and in contact with at least the rear portion of the combustible heat source and around and in contact with at least the front portion of the aerosol-forming substrate. .

A thermally conductive element may provide a thermal link between the combustible heat source of the aerosol-generating article and the aerosol-forming substrate. Advantageously, this can help facilitate proper heat transfer from the combustible heat source to the aerosol-forming substrate to produce an acceptable aerosol.

The rear portion of the heat source that contacts the thermally conductive element is preferably between about 2 millimeters and about 8 millimeters long.

More preferably, the rearward portion of the heat source that contacts the thermally conductive element is between about 3 millimeters and about 5 millimeters long.

The thermally conductive elements are preferably non-combustible.

The thermally conductive element may be oxygen limiting. In other words, the thermally conductive element can impede or impede the passage of oxygen through the thermally conductive element.

The thermally conductive elements may be formed from any suitable thermally conductive material or combination of materials.

The thermally conductive element has a power output of about 10 Watts per meter per Kelvin (W/(mK )) to about 500 Watts per meter per Kelvin (W/(mK)), preferably from about 15 Watts per meter per Kelvin (W/(mK)) to about 400 Watts per meter per Kelvin ( It preferably includes one or more thermally conductive materials having a bulk thermal conductivity of W/(m·K).

Advantageously, the thermally conductive element comprises one or more metals, one or more alloys, or a combination of one or more metals and one or more alloys.

Suitable thermally conductive materials are well known in the art and include, but are not limited to, metal foils such as aluminum foil, iron foil and copper foil, and alloy foils such as steel foil.

Advantageously, the thermally conductive element comprises aluminum foil.

Aerosol-generating articles according to the present invention may comprise a non-combustible, substantially impermeable barrier between the trailing face of the combustible heat source and the aerosol-forming substrate.

By including a non-combustible, substantially impermeable barrier between the trailing face of the combustible heat source and the aerosol-forming substrate, the temperature to which the aerosol-forming substrate is exposed during ignition and combustion of the combustible heat source is can be advantageously suppressed. This can help avoid or reduce thermal decomposition or combustion of the aerosol-forming substrate during use of the aerosol-generating article.

Constituting the aerosol-forming substrate to the combustible heat source during storage and use of the aerosol-generating article by including a non-combustible, substantially impermeable barrier between the trailing face of the combustible heat source and the aerosol-forming substrate. migration can advantageously be substantially prevented or inhibited.

The barrier may be adjacent one or both of the trailing face of the combustible heat source and the aerosol-forming substrate. Alternatively, the barrier may be longitudinally spaced from one or both of the trailing face of the combustible heat source and the aerosol-forming substrate.

Advantageously, the barrier is glued or otherwise attached to the trailing face of the combustible heat source.

Suitable methods for adhering or affixing the barrier to the trailing face of the combustible heat source are known in the art and include spray painting, vapor deposition, dipping, material transfer (e.g. brushing or gluing), electrostatic deposition. or any combination thereof, including but not limited to.

A barrier between the trailing face of the combustible heat source and the aerosol-forming substrate may have a low thermal conductivity or a high thermal conductivity. For example, the barrier has a bulk thermal conductivity of about 0.1 W per meter Kelvin (W/ (m·K)) to about 200 W per meter Kelvin (W/(m·K)).

The thickness of the barrier between the trailing face of the combustible heat source and the aerosol-forming substrate can be selected to achieve good performance. For example, the barrier thickness can be from about 10 microns to about 500 microns.

The barrier between the trailing face of the combustible heat source and the aerosol-forming substrate is substantially thermally stable and non-flammable at temperatures reached by the combustible heat source during ignition and combustion. It can be formed from any material. Suitable materials are known in the art and include, but are not limited to, clays (such as bentonites and kaolinites), glasses, minerals, ceramic materials, resins, metals, or any combination thereof.

Preferably, the barrier comprises aluminum foil.

The aluminum foil barrier can be applied to the trailing face of the combustible heat source by gluing or pressing it onto the combustible heat source. The barrier may be cut or otherwise machined such that the aluminum foil covers and adheres to at least substantially the entire trailing face of the combustible heat source. Advantageously, the aluminum foil covers the entire rear end face of the combustible heat source and is adhered thereto.

An aerosol-generating article according to the invention may comprise a non-blind combustible heat source according to the invention.

When the combustible heat source is a non-blind combustible heat source, in use, air drawn through the aerosol-generating article for inhalation by the user passes through at least one airflow channel along the length of the combustible heat source.

When the combustible heat source is a non-blind combustible heat source, heating of the aerosol-forming substrate occurs by conduction and forced convection.

When an aerosol-generating article according to the invention comprises a non-blind combustible heat source according to the invention and a non-combustible, substantially impermeable barrier between the trailing face of the combustible heat source and the aerosol-forming substrate, the barrier is , should allow air drawn through at least one airflow channel extending along the length of the combustible heat source to be drawn downstream through the aerosol-generating article.

An aerosol-generating article according to the invention preferably comprises a blind combustible heat source according to the invention.

When the combustible heat source is a blind combustible heat source, in use, air drawn through the aerosol-generating article for inhalation by the user does not pass through any airflow channels along the length of the blind combustible heat source.

When the combustible heat source is a blind combustible heat source, heating of the aerosol-forming substrate occurs primarily by conduction and heating of the aerosol-forming substrate by forced convection is minimized or reduced. In such embodiments, it is particularly important to optimize conductive heat transfer between the combustible heat source and the aerosol-forming substrate.

The lack of any airflow channels extending along the length of the combustible heat source through which air can be drawn for inhalation by the user advantageously activates combustion of the blind combustible heat source during puffing by the user. can substantially prevent or inhibit This can advantageously substantially prevent or inhibit spikes in the temperature of the aerosol-forming substrate while the user smokes.

Combustion or pyrolysis of the aerosol-forming substrate under severe smoke-drawing conditions by preventing or inhibiting combustion activation of the blind combustible heat source and thus preventing or inhibiting excessive temperature rise in the aerosol-forming substrate. can be advantageously avoided. In addition, the effect of the user's smoking situation on the composition of mainstream aerosols can be advantageously minimized or reduced.

The inclusion of a blind combustible heat source advantageously allows combustion and decomposition products and other materials formed during ignition and combustion of the blind combustible heat source to be drawn through the aerosol-generating article for inhalation by the user. can substantially prevent or block entry of stray air.

Where the combustible heat source is a blind combustible heat source, the aerosol-generating article according to the present invention includes one or more air inlets in the blind combustible heat source that draw air into the aerosol-generating article for inhalation by the user. Included in downstream.

In such embodiments, air drawn through the aerosol-generating article for inhalation by the user enters the aerosol-generating article through one or more air inlets rather than through the distal end of the aerosol-generating article.

Where the combustible heat source is a non-blind combustible heat source, aerosol-generating articles according to the present invention also include one or more air inlets for drawing air into the aerosol-generating article for inhalation by a user. A blind combustible heat source may be provided downstream.

Aerosol-generating articles according to the present invention may comprise one or more primary air inlets around the perimeter of the aerosol-forming substrate.

In such embodiments, during puffing by the user, cool air is drawn into the aerosol-forming substrate of the aerosol-generating article through one or more air inlets around the perimeter of the aerosol-forming substrate. This can advantageously reduce the temperature of the aerosol-forming substrate during puffing by the user, thus substantially preventing or eliminating spikes in the temperature of the aerosol-forming substrate.

As used herein in connection with the present invention, the term "cold air" is used to describe ambient air that is not significantly heated by a combustible heat source upon puffing by a user.

By preventing or inhibiting spikes in the temperature of the aerosol-forming substrate, the inclusion of one or more air inlets around the perimeter of the aerosol-forming substrate advantageously facilitates combustion of the aerosol-forming substrate under heavy smoke conditions. or help avoid or reduce thermal decomposition.

The inclusion of one or more air inlets around the perimeter of the aerosol-forming substrate can advantageously minimize or reduce the effect of the user's smoking situation on the composition of the mainstream aerosol of the aerosol-generating article.

In certain preferred embodiments, aerosol-generating articles according to the present invention may comprise one or more air inlets located proximate the downstream end of the aerosol-forming substrate.

Aerosol-generating articles according to the present invention can have any desired length.

Aerosol-generating articles according to the present invention can preferably have an overall length of from about 65 millimeters to about 100 millimeters.

Aerosol-generating articles according to the present invention can have any desired width.

Aerosol-generating articles according to the present invention can preferably have a width of from about 5 millimeters to about 12 millimeters.

Aerosol-generating articles according to the present invention may be assembled using known methods and machines.

For the avoidance of doubt, where applicable, the features described above for combustible heat sources according to the invention may also be applied to aerosol-generating articles according to the invention, and vice versa.

The invention will be further described, by way of example only, with reference to the following accompanying drawings.

FIG. 1 shows a schematic longitudinal cross-section of an aerosol-generating article according to an embodiment of the invention. FIG. 2 shows a graph of calcium peroxide content as a function of time for a combustible heat source according to an embodiment of the invention and a comparative combustible heat source not according to the invention.

The aerosol-generating article 2 according to the embodiment of the invention shown in FIG. 1 comprises a combustible heat source 4 according to the invention and an aerosol-forming substrate 10 downstream of the combustible heat source 4 . Combustible heat source 4 is a blind combustible heat source having a front end face 6 and an opposite rear end face 8 and is located at the distal end of aerosol-generating article 2 . Aerosol-generating article 2 further comprises moving element 12 , aerosol-cooling element 14 , spacer element 16 and mouthpiece 18 . Combustible heat source 4, aerosol-forming substrate 10, moving element 12, aerosol cooling element 14, spacer element 16, and mouthpiece 18 are arranged in abutting coaxial alignment. As shown in FIG. 1, the aerosol-forming substrate 10, moving element 12, aerosol-cooling element 14, spacer element 16, and mouthpiece 18, and the rear portion of the blind combustible heat source 4 are made of, for example, a sheet of cigarette paper or the like. Wrapped in an outer wrapper 20 of material.

As shown in FIG. 1, a non-combustible, substantially impermeable barrier 22 in the form of a disc of aluminum foil is provided between the trailing end face 8 of the combustible heat source 4 and the aerosol-forming substrate 10 . The barrier 22 is applied to the trailing face 8 of the combustible carbonaceous heat source 4 by pressing a disc of aluminum foil onto the trailing face 8 of the combustible carbonaceous heat source 4 to prevent the trailing face 8 of the combustible carbonaceous heat source 4 and aerosol formation. It abuts on the base 10 .

The combustible heat source 4 is carbon, an alkaline earth metal peroxide ignition aid, and at least one additive selected from the group consisting of carboxymethylcellulose and ethylcellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose. and a binder comprising a combination of cellulose ethers.

The aerosol-forming substrate 10 is located immediately downstream of a barrier 22 applied to the trailing face 8 of the combustible heat source 4 . The aerosol-forming substrate 10 comprises a mass 24 of crimped sheets of homogenized tobacco material and a wrapper 26 surrounding and in direct contact with the mass 24 of crimped sheets of homogenized tobacco material. ,including. The assembly 24 of crimped sheets of homogenized tobacco material includes a suitable aerosol former such as, for example, glycerine.

Transfer element 12 is located immediately downstream of aerosol-forming substrate 10 and comprises a cylindrical open-ended hollow cellulose acetate tube 28 .

An aerosol cooling element 14 is located immediately downstream of the moving element 12 and comprises an assembly of sheets of biodegradable polymeric material such as polylactic acid.

Spacer element 16 is located immediately downstream of aerosol cooling element 14 and comprises a cylindrical open-ended hollow paper or cardboard tube.

Mouthpiece 18 is located immediately downstream of spacer element 16 . As shown in FIG. 1, the mouthpiece 18 is located at the proximal end of the aerosol-generating article 2 and is wrapped in a filter plug wrap 32 of suitable filtration material, such as very low filtration efficiency cellulose acetate tow. It includes a cylindrical plug 30 .

The aerosol-generating article may further include a band of tipping paper (not shown) surrounding the downstream end portion of outer wrapper 20 .

As shown in FIG. 1, the aerosol-generating article 2 surrounds and is in direct contact with the rear portion 4b of the combustible heat source 4 and the front portion 10a of the aerosol-forming substrate 10, such as, for example, aluminum foil. Further provided is a thermally conductive element 34 formed from a suitable thermally conductive material. In the aerosol-generating article 2 according to the embodiment of the invention shown in FIG. 1, the aerosol-forming substrate 10 extends downstream beyond the thermally conductive element 34 . That is, the thermally conductive element 34 is not around and in contact with the rear portion of the aerosol-forming substrate 10 . However, it should be appreciated that in other embodiments of the invention (not shown), the thermally conductive element 34 may be around the entire length of the aerosol-forming substrate 10 and may be in contact therewith. Of course, in other embodiments of the invention (not shown), one or more additional thermally conductive elements overlying thermally conductive element 34 may also be provided.

The aerosol-generating article 2 according to the embodiment of the invention shown in FIG. 1 comprises one or more air inlets 36 around the perimeter of the aerosol-forming substrate 10 . As shown in FIG. 1, a circumferential arrangement of air inlets 36 is provided in the wrapper 26 and overlying outer wrapper 20 of the aerosol-forming substrate 10 to cool air (indicated by the dashed arrows in FIG. 1). is placed within the aerosol-forming substrate 10 .

In use, the user ignites the combustible carbonaceous heat source 4 . When the combustible carbonaceous heat source 4 is ignited, the user puffs on the mouthpiece 18 of the aerosol-generating article 2 . As the user puffs on the mouthpiece 18 , cool air (indicated by the dashed arrow in FIG. 1) is drawn through the air inlet 36 and into the aerosol-forming substrate 10 of the aerosol-generating article 2 .

The periphery of the front portion 10 a of the aerosol-forming substrate 10 is heated by conduction through the rear end face 8 of the combustible heat source 4 and the barrier 22 and through the thermally conductive element 34 .

Heating of aerosol-forming substrate 10 by conduction releases aerosol formers and other volatile and semi-volatile compounds from the assembly of crimped sheets of homogenized tobacco material 24 . Compounds emitted from the aerosol-forming substrate 10 , as they flow through the aerosol-forming substrate 10 , entrain the aerosol with air drawn into the aerosol-forming substrate 10 of the aerosol-generating article 2 through the air inlet 36 . Form. Entrained air and entrained aerosols (indicated by dashed arrows in FIG. 1) pass through the cylindrical open-ended hollow cellulose acetate tube 28 of the transfer element 12, the aerosol cooling element 14, and the interior of the spacer element 16. through downstream where it cools and condenses. Cooled entrained air and entrained aerosol flow downstream through mouthpiece 18 and are delivered through the proximal end of aerosol-generating article 2 to the user. A non-combustible, substantially impermeable barrier 22 on the trailing end face 8 of the combustible carbonaceous heat source 4 prevents, in use, air drawn through the aerosol-generating article 2 from directly contacting the combustible heat source 4. As such, it isolates the combustible heat source 4 from air drawn through the aerosol-generating article 2 .

The specific embodiments and examples described above illustrate but do not limit the invention. It is understood that other embodiments of the invention may be made, and that the specific embodiments and examples described herein are not exhaustive.

A combustible heat source according to the present invention was produced having the composition shown in Table 1.

The ingredients in Table 1 were combined to form a granular mixture by wet granulation. Charcoal, calcium peroxide, and carboxymethylcellulose are mixed to form a particulate mixture. A particulate mixture of charcoal, calcium peroxide, and carboxymethylcellulose is air fluidized and sprayed with a liquid solution of potassium tricitrate hydrate and an aqueous solution of hydroxypropylcellulose to form a granular mixture.

The granular mixture is formed into a cylindrical shape by pressing. About 400 milligrams of the granular mixture was pressed into a single cavity press, a cylindrical combustible heat source having a length of about 9 millimeters, a width of about 7.7 millimeters, and a density of about 0.9 grams per cubic centimeter. to generate The cylindrical combustible heat source is removed from the single cavity press and dried in a drying oven at a temperature of about 85 degrees Celsius to about 105 degrees Celsius for about 3 hours.

Comparative combustible heat sources not according to the invention were also produced having the compositions shown in columns A, B, and C of Table 2.

The ingredients in Table 2 were combined to form a granular mixture by wet granulation. Charcoal, calcium peroxide, and carboxymethylcellulose are mixed to form a particulate mixture. A particulate mixture of charcoal, calcium peroxide, and carboxymethylcellulose is air fluidized and sprayed with a liquid solution of potassium tricitrate hydrate and an aqueous solution of bentonite to form a granular mixture.

The granular mixture is formed into a cylindrical shape by pressing. About 400 milligrams of the granular mixture was pressed into a single cavity press, a cylindrical combustible heat source having a length of about 9 millimeters, a width of about 7.7 millimeters, and a density of about 0.9 grams per cubic centimeter. to generate A cylindrical combustible heat source is removed from the single cavity press and placed in a drying oven at a temperature of about 85 degrees Celsius to about 105 degrees Celsius for about 3 hours.

To simulate the environmental conditions to which a combustible heat source may be exposed during transportation and storage, a combustible heat source according to the invention and a comparative combustible heat source not according to the invention were heated at about 30 degrees Celsius and about 75 percent Adjust to relative humidity for 7 days. The calcium peroxide content (weight percent) of a combustible heat source according to the invention and a comparative combustible heat source not according to the invention is measured as a function of time by titration with a potassium permanganate (KMnO4) solution. Results are shown in FIG. The top line labeled I in FIG. 2 shows the measured calcium peroxide content of the combustible heat source according to the invention as a function of time and is labeled A, B and C in FIG. The bottom line shows the measured calcium peroxide content of a comparative combustible heat source not according to the invention as a function of time. The values shown in Figures 2 and 3 are the average of three replicate measurements of each combustible heat source.

As shown in FIG. 2, the rate of decomposition of calcium peroxide over time in a combustible heat source according to the present invention advantageously compares favorably with the decomposition over time of calcium peroxide in a comparative combustible heat source not according to the present invention. Significantly lower than speed.

The ignition propagation velocity of ten combustible heat sources according to the invention and ten comparative combustible heat sources not according to the invention, having the compositions shown in column A of Table 2, were also measured. Results are shown in Table 3. A combustible heat source according to the invention and a comparative combustible heat source not according to the invention are conditioned at about 22 degrees Celsius and about 50 percent relative humidity for about 24 hours prior to ignition propagation velocity measurements. To measure ignition propagation velocity, a thermocouple was placed in a combustible heat source according to the invention and a comparative combustible heat source not according to the invention at a first position one millimeter from the front end face of the combustible heat source and It is inserted in two positions with the second position being 8 millimeters from the front end face of the combustible heat source. The front end face of a combustible heat source according to the invention and the front end face of a comparative combustible heat source not according to the invention are ignited using an electric lighter. A difference in the time it takes to reach about 350 degrees Celsius is measured as measured by thermocouples at the first and second positions. The ignition propagation times shown in Table 3 are the average times measured for ten combustible heat sources according to the invention and ten comparative combustible heat sources not according to the invention.

As shown in Table 3, the ignition propagation time of the combustible heat source according to the invention is advantageously significantly shorter than the ignition propagation time of the comparative combustible heat source not according to the invention.

The results in Figure 2 and Table 3 demonstrate the chemical and physical stability and combustion properties of combustible heat sources according to the present invention resulting from the inclusion of a binder comprising a combination of carboxymethylcellulose and at least one additional cellulose ether. have demonstrated improvements in

The results of Figure 2 demonstrate that the inclusion of a binder comprising a combination of carboxymethylcellulose and at least one additional cellulose ether in a combustible heat source according to the present invention advantageously results in exposure to environmental conditions. have been demonstrated to significantly reduce the decomposition of alkaline earth metal peroxide ignition aids as. In particular, the results of FIG. 2 demonstrate that including a binder comprising a combination of carboxymethylcellulose and at least one additional cellulose ether in a combustible heat source according to the present invention is beneficial when exposed to high humidity. have been demonstrated to significantly reduce the decomposition of alkaline earth metal peroxide ignition aids as a result of .

The results in Table 3 show that by including a binder comprising a combination of carboxymethylcellulose and at least one additional cellulose ether in the combustible heat source according to the invention, the combustible heat source according to the invention advantageously It has also been demonstrated to significantly improve ignition propagation velocity.

Claims (15)

A combustible heat source for an aerosol-generating article, said combustible heat source comprising:
carbon and
an alkaline earth metal peroxide ignition aid;
and a binder comprising a combination of carboxymethylcellulose and at least one additional cellulose ether. 2. The combustible heat source of claim 1, wherein said at least one additional cellulose ether is selected from the group consisting of ethylcellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose. 3. The combustible heat source of claim 1 or 2, wherein the ratio of the weight percent of carboxymethylcellulose to the weight percent of the at least one additional cellulose ether in the combustible heat source is at least about 1:1. A combustible heat source according to any preceding claim, wherein the alkaline earth metal peroxide ignition aid is calcium peroxide. The combustible heat source of any one of claims 1-4, wherein the combustible heat source comprises at least about 15 weight percent of the alkaline earth metal peroxide ignition aid. 6. The combustible heat source of any one of claims 1-5, wherein the combustible heat source comprises from about 20 weight percent to about 60 weight percent of the alkaline earth metal peroxide ignition aid. The combustible heat source of any one of claims 1-6, wherein the combustible heat source comprises at least about 3 weight percent of the binder. The combustible heat source of any preceding claim, wherein the combustible heat source comprises from about 4 weight percent to about 15 weight percent of the binder. The combustible heat source of any one of claims 1-8, wherein the combustible heat source comprises at least about 0.2 weight percent of the at least one additional cellulose ether. 10. The combustible heat source of any one of claims 1-9, wherein the combustible heat source comprises from about 0.75 dry weight percent to about 5 weight percent of the at least one additional cellulose ether. The combustible heat source of any one of claims 1-10, wherein the carboxymethyl cellulose is present in the combustible heat source in an amount of at least about 1.5 dry weight percent. A combustible heat source according to any preceding claim, wherein the combustible heat source comprises at least about 25 weight percent carbon. The combustible heat source of any one of claims 1-12, wherein the combustible heat source comprises from about 30 weight percent to about 55 weight percent carbon. 14. A combustible heat source according to any preceding claim, further comprising one or more carboxylic acid combustion salts. An aerosol-generating article,
A combustible heat source according to any one of claims 1 to 14;
an aerosol-forming substrate downstream of said combustible heat source.

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