JPH0441620B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides an aerosol similar to tobacco smoke, preferably in the form of a cigarette, which has less incomplete combustion and The present invention relates to a cigarette-type smoking article in which the content of pyrolysis products is significantly reduced.

BACKGROUND OF THE INVENTION A variety of smoking articles have been proposed, particularly over the last few decades, but none have achieved commercial success.

Despite decades of interest and research, it has been found that conventional cigarettes can be produced without the significant amounts of incomplete combustion and thermal decomposition products found in conventional cigarettes. There is currently no smoking article on the market that provides a taste similar to that obtained by smoking a cigarette.

SUMMARY OF THE INVENTION The present invention provides smoking articles in the form of cigarettes that utilize small dense combustible fuel elements in conjunction with a separate aerosol generating means containing one or more aerosol generating agents.

The aerosol generating means may be in a conductive heat exchange relationship with the fuel element, and/or may include at least the fuel element in an elastic insulating jacket (also referred to as a "insulation layer" or simply "jacket") to reduce heat loss due to radiation. to enclose by When the fuel element is ignited, it generates heat, which evaporates the aerosol generating agent within the aerosol generating means. This volatile material, like the smoke from a conventional cigarette, is drawn towards the mouth end of the smoking article and into the smoker's mouth during the smoker's inhalation action.

The insulating jacket is preferably at least 0.5 mm thick and preferably surrounds at least the fuel element, preferably also the aerosol generating means, to mimic the feel of a conventional cigarette. The jacket insulation for the fuel element and the jacket insulation for the aerosol generating means may be of the same material or different materials. The material for the "insulating layer" or "insulating jacket" is tobacco material or a mixture of tobacco material and insulating fibers. The insulating fibers used in this jacket are preferably those that do not burn during use, but may contain materials that melt during use, such as slow-flammable carbon, especially low-temperature varieties of glass fibers. good. The insulation fiber is g-cal/(sec)
(cm ² ) (℃/cm) unit of about 0.05 or less, preferably about
It is preferred to have a thermal conductivity of 0.02 or less, most preferably about 0.005 or less. (See Hack's Chemistry Dictionary, 34, 4th edition, 1969, and Lang's Chemistry Handbook, 10, 272-274, 11th edition, 1973.) This jacket is made of tobacco or a mixture of tobacco and insulating fibers. This not only serves to reduce radiant heat losses, assist in retaining and directing heat from the fuel element towards the aerosol generating means, but also to suppress the flame-producing properties of the fuel. , which is highly desirable for smokers by adding to the aerosol produced by the heating action on the aerosol generating means a small amount of tobacco smoke or tobacco flavor from the tobacco material in the jacket heated by the fuel element. Provides an aerosol flavor.

The smoking article of the present invention is capable of producing a significant amount of aerosol throughout its useful life and can provide the user with a sensation similar to smoking a cigarette. The aerosol produced by this aerosol generating means is produced with almost no deterioration due to heat, and moreover, the amount of incomplete combustion and thermal decomposition products generated is considerably smaller than that of conventional cigarettes. .

The small fuel elements used in the present invention are approximately
30 mm or less, preferably about 20 mm or less, e.g. at least about 0.5 g/g as measured by mercury displacement.
cc, preferably at least about 0.7 g/cc. The fuel element can be molded or extruded from ground or reconstituted tobacco material and/or tobacco substitutes and preferably includes combustible carbon. The fuel element is also preferably provided with one or more passages, preferably from five to nine, or from five to nine, for controlling heat transfer from the burning fuel element to the aerosol generating agent in the aerosol generating means. It is further preferable to provide more passages.

The aerosol generating means comprises an aerosol generating agent support or carrier (hereinafter also simply "support" or "carrier"), preferably made of a thermally stable material, carrying one or more aerosol generating agents. It is advantageous to have a

Conductive heat exchange between the fuel element and the aerosol generating means is accomplished by a metal conductor such as a metal conductor that contacts both the fuel element and the aerosol generating means and effectively conducts heat from the burning fuel element to the aerosol generating means. It is preferable to carry out this by providing a heat conductive member. The heat conductive member preferably surrounds and contacts at least part of the outer peripheral surfaces of the fuel element and the aerosol generating means, in order to avoid interference with ignition and combustion of the fuel element, and to avoid protrusion of the heat conductive member. To achieve this, it is preferred that the thermally conductive member be spaced or retracted from the tip of the fuel element, preferably at least about 3 mm, and more preferably at least about 5 mm. More preferably, the heat conductive member surrounds at least a portion of the support of the aerosol generator. Alternatively, a separate thermally conductive container or capsule may be provided to enclose the aerosol generator and its support.

Since the fuel element is relatively short, its burning conical mass is always in close proximity to the aerosol generating means, thus maximizing heat transfer to the aerosol generating means, especially for multi-channel fuel elements, Embodiments with heat conducting members and insulating jackets maximize aerosol production. A relatively dense fuel material is used so that the small fuel element burns for approximately the same amount of time as a conventional cigarette and provides sufficient thermal energy to generate the required amount of aerosol. Since the aerosol generating means is physically separate from the fuel element, it is exposed to considerably lower temperatures than if it were placed within the burning cone, reducing the risk of thermal deterioration of the aerosol generating agent. minimized.

Smoking articles of the present invention typically include a mouthpiece including an aerosol delivery means forming a longitudinal passageway for delivering the volatile substance, or aerosol, created by the aerosol generating means to the user. . Preferably, the mouthpiece includes an elastic outer member, such as a toroid of cellulose acetate, to mimic the feel of a conventional cigarette. Advantageously, the smoking article has the same overall dimensions as a conventional cigarette, so that the mouthpiece containing the aerosol delivery means (i.e. the aerosol delivery passageway) will typically be approximately 1/2 of the total length of the smoking article. /2 or longer. Alternatively, a smoking article consisting solely of the fuel element and the aerosol generating means may be constructed without incorporating a mouthpiece containing the aerosol delivery means and combined with a separate disposable or reusable mouthpiece. You may also use it.

The smoking articles of the present invention may also be supplemented with a charge of tobacco material that can be used to add tobacco flavor to the aerosol. The tobacco material charge can be inserted between the aerosol generating means and the mouthpiece. Preferably, an annular body or jacket of tobacco material is fitted onto the outer circumferential surface of the aerosol generating means. In that case, the tobacco jacket also acts as an insulator and helps mimic the flavor and feel of a conventional cigarette. The tobacco pack may be mixed with the aerosol generating agent or may be used as a support for the aerosol generating agent. Other substances, such as flavoring agents, can also be incorporated into the smoking article to flavor or otherwise modify the aerosol.

The smoking articles of the present invention typically use significantly less fuel on a volume, and preferably weight, basis than conventional cigarettes to generate the required aerosol. Also, the aerosol that is inhaled into the user's mouth has a low content of incomplete combustion and thermal decomposition products. This is because the aerosol created from the aerosol generating means is not thermally degraded and the pyrolysis products and , or the amount of products of incomplete combustion is
Even if the fuel element is made of tobacco or other cellulosic material, it is considerably less common than in conventional jackets.

"Aerosol" as used herein refers to vapor, gas, particles, etc. created when heat from a burning fuel element acts on the aerosol generating means or on substances present in other parts of the smoking article. (visible,
(whether invisible or not), especially components that look like smoke. In addition, the term "aerosol generating agent" as used herein refers to a volatile flavoring agent and/or a pharmacologically active agent (i.e., having a pharmacological effect), regardless of whether the aerosol generated is visible or not. Or it refers to a physiologically active drug (that is, it has a chemical effect such as making you feel refreshed).

"Conductive heat exchange relationship" refers to a physical arrangement of the aerosol generating means and the fuel element arranged such that heat is transferred by conduction from the fuel element to the aerosol generating means throughout the combustion of the fuel element. The conductive heat exchange relationship involves transferring heat from the burning fuel element to the aerosol generating means by placing the aerosol generating means in contact with the fuel element and in close proximity to the combusting portion of the fuel element. It can be set by using a conductive member for. It is preferable to use the above two methods of conducting heat transfer by conduction in combination.

DESCRIPTION OF THE EMBODIMENTS The smoking article of one embodiment of the invention, shown in FIG. , aerosol generating means 12 abutted thereon, and a mouthpiece 40 defining the mouth end 15 of the article.

In this example, the fuel element 10 is extruded or molded from a mixture containing crushed or reconstituted tobacco and/or tobacco substitutes and a small amount of combustible carbon, and the fuel element 10 is extruded or molded from a mixture containing crushed or reconstituted tobacco and/or tobacco substitutes and a small amount of combustible carbon. It is preferred to have a plurality of holes or passages 16 for better performance. An example of a suitable hole arrangement is
Illustrated in FIG. 1A. These holes or passages 16, as mentioned above,
This is for controlling the heat transfer from zero to the aerosol generating agent in the aerosol generating means 12. The firing end of fuel element 10 may be tapered or otherwise reduced in diameter to facilitate ignition.

The aerosol generating means 12 comprises an aerosol generating agent support (hereinafter also simply referred to as "support") 13, such as a porous carbon body having one or more passages 17, and an impregnated solution of the support. one or more aerosol generating agents such as ethylene glycol, propylene glycol, glycerin or mixtures thereof.

Mouthpiece 40 includes a paper tube 14 (lined with foil) defining a mouthpiece end 15 . The paper tube 14 surrounds the aerosol generating means 12 and the rear non-ignition end of the fuel element, spaced approximately 15 mm from the ignition end of the fuel element 10. Paper tube 14
Also, an aerosol feeding passage 18 is formed between the aerosol generating means 12 and the suction end 15. The amount of heat transferred to the aerosol generating means is increased due to the presence of the foil-lined paper tube 14 connecting the non-igniting end of the fuel element 10 to the aerosol generating means 12. Paper tube 14
The lining foil also serves to extinguish the conical mass of the fuel element. If only a small amount of unburned fuel remains, the heat loss through the foil acts as a heat sink and thus serves to extinguish the cone. The foil used in this article is typically 0.35 mil (0.0089 mm) thick aluminum foil, but the amount of heat transfer can be virtually any desired by varying the thickness and type of conductor used. can be obtained.

The article illustrated in FIG. 1 optionally includes a tobacco plug or charge 20 for flavoring the aerosol. The tobacco material charge 20 may be disposed at the mouth end of the carbon body or aerosol generating agent support 13, as shown in FIG. It may be placed inside. For better appearance, if desired,
A low efficiency cellulose acetate filter plug 22 can be inserted at the mouth end 15.
(Here, "low efficiency" means that the efficiency as a filter for removing nicotine and tar is low.) Each embodiment of the present invention shown in FIGS. Preferably, it is provided with an elastic insulating jacket (of tobacco material or a mixture of tobacco material and insulating fibers) which also surrounds the aerosol generating means. This feature of the invention isolates heat from the fuel element from the outside to reduce radiation heat loss;
It concentrates heat within the fuel element, helps retain and direct heat from the fuel element towards the aerosol generating means, and suppresses the flame-producing characteristics of the fuel (thus reducing the conical shape of the burning fuel element). It not only works to prevent fire from spreading to other areas, but also
By adding to the aerosol produced by the heating action on the aerosol generating means a small amount of tobacco smoke or tobacco flavor from the tobacco material in the jacket heated by the fuel element, the aerosol flavor is very pleasant to the smoker. It also has the effect of making the smoking article resemble a conventional cigarette.

In the embodiment of FIG. 1, fuel element 10 has a plurality of holes 16 and is surrounded by a resilient insulating jacket 72 (FIG. 1A) approximately 0.5 mm thick.
The jacket 72 is formed of a mixture of tobacco material and insulating fibers, such as ceramic (eg, glass) fibers or non-combustible carbon or graphite fibers. Alternatively, the entire insulating jacket 72 surrounding the fuel element 10 may be replaced with loose or tightly compressed tobacco material.

Thus, the insulating jacket 72 is constructed of tobacco material or a mixture of tobacco material and insulating fibers. The use of tobacco material as a substitute for some or all of the insulation provides, in addition to its function as insulation, the additional function of adding tobacco flavor to the mainstream aerosol and generating a side stream of tobacco flavor. do.

In the embodiment of FIG. 2, an elastic insulating jacket 72 made of insulating fibers, such as glass fibers, and tobacco material is attached to the fuel element 10 and the aerosol generating means 1.
It surrounds both outer peripheral surfaces of 2. The fiberglass for the insulation jacket 72 is preferably a low temperature material that melts during use. This jacket 72 may be made of a non-porous paper jacket 72, such as P878-5 sold by Kimberly-Clark.
It is covered by 3. Preferably, the fuel element 10 is approximately 15-20 mm long and has three or more holes 16 to improve air flow. Three preferred hole arrangement modes are second A,
Illustrated in Figures 2B and 2C.

The aerosol generating means 12 has a metal container 74 surrounding a granular aerosol generating agent support 38 and/or a compressed tobacco material 76, and the aerosol generating agent is applied to either or both of the support 38 and the tobacco material 76. It is impregnated. As shown, container 7
The open end 75 of the fuel element 10 is connected to the rear end portion 3 to
It surrounds 5mm. Alternatively, open end 75 may abut the rear end of the fuel element. The opposite end of container 74 is crimped to form an end wall 78. End wall 78 has a plurality of holes 80 for passing gas, tobacco flavor, and/or aerosol generating agent to aerosol delivery passageway 18 .

The mouthpiece 40 is connected to the aerosol delivery passage 18
It consists of a plastic tube 44 defining a plastic tube, an annular member 42 of elastic high-density cellulose acetate tow surrounding the plastic tube, and a low-efficiency cellulose acetate filter plug 45 in contact with the annular member 42. . Filter plug 45 constitutes the mouth end of the smoking article. The filter plug 45 and the annular member 42 are wrapped in a conventional plug paper wrapper (wrapping paper) 85.
It is preferable to further cover the plug paper wrapper 85 with a suction paper 86. Mouthpiece paper 86
serves to connect the rear end portion of the insulating jacket 72 and the tow filter portion.

The plastic tube 44 is attached to the end wall 7 of the metal container 74.
8, or preferably surrounding the end wall 78, and is surrounded by an annular member comprised of elastic, high density cellulose acetate tow 42. Tow 42
Apply a layer of adhesive 82 or other material to seal the tow 4 and prevent air flow therethrough.
It can be applied to the fuel side end of No. 2.

As a variation of the embodiment of FIG. 2, the cellulose acetate tow 42 could be replaced by an elastic jacket. In that case, the jacket extends from the firing end to the filter plug 45. Preferably, the layer of adhesive is applied to the annular end surface of the filter plug 45 that abuts the end of the jacket, or alternatively, the layer of adhesive is applied to the opposing end surfaces of the jacket and filter plug so that the jacket and filter are bonded together. A short annular member consisting of a tow is interposed between the plugs.

FIG. 3 shows a fuel element 10 having a length of 10 to 15 mm in an elastic first tube made of a mixture of glass fiber and tobacco material.
Covered with a jacket 72, the aerosol generating means 1
2 is covered with a second jacket 88 made of tobacco material. The glass fibers used in this example should have a softening temperature below about 650° C., such as experimental fibers 6432 and 6437 manufactured by Owens Corning, Toledo, Ohio, USA, so that they will melt during use. is preferred.
First jacket 7 of glass fiber/tobacco material mixture
2 and the second jacket 88 of tobacco material, respectively.
wrapped by a plug paper wrapper 85, such as Exta 646, and joined by a cigarette paper wrapper 89, such as Kimberly-Clark 780-63-5 or P878-16-2. has been done.

Similar to the embodiment shown in FIG. 2, the aerosol generating means 12 includes a granular aerosol generating agent support and/or compressed tobacco material, a metal capsule 90 surrounding it, and any of the support and the tobacco material. It can be composed of an aerosol generating agent impregnated in one or both of them or supported in some manner.
In this embodiment, the metal capsule 90 of the aerosol generating means encloses the rear end of the fuel element 10 by 3 to 4 mm at a distance of about 6 to 12 mm from the ignition end. The rear portion of capsule 90 is crimped into a rope shape as shown in Figure 3B. A passageway 91 is formed in the center of the suction end of the capsule. Four additional passages 92 are drilled at the transition between the crimped and uncrimped portions of the capsule. Alternatively, capsule 9
The rear part of 0 may be rectangular or square in cross-section, rather than rope-shaped (for example cloverleaf-shaped in cross-section), and may or may not be provided with a peripheral passage 92. Alternatively, a simple cylindrical capsule with a crimped suction end can be used.

At the suction end of the second jacket 88 made of tobacco material,
A mouthpiece 40 is attached which includes a ring of cellulose acetate tow 42, a plastic tube 44, a low efficiency filter plug 45, and paper wrappers 85,89. The mouthpiece 40 is connected to a jacketed fuel element/aerosol generator assembly by a jacket layer of mouthpiece paper 86. As shown, the capsule end of plastic tube 44 is spaced from capsule 90.
The hot vapor (aerosol) exiting through the passageway 92 thus passes through the second jacket 88 of tobacco material, thereby vaporizing or extracting the volatile components in the tobacco material within the jacket. The aerosol flows into the passageway 18 at the point where the second jacket 88 of tobacco material and the cellulose acetate tow 42 abut.

In this type of embodiment having a low density first jacket 72, some air and gas may enter the first jacket 72.
Through the jacket 72, the tobacco material flows into the second jacket 88. Thus, capsule 90 does not necessarily need to be provided with peripheral passageway 92 to extract tobacco flavor from second jacket 88 of tobacco material.

In the embodiment of FIG. 4, the jacket 94 is comprised of tobacco material or a mixture of tobacco material and insulating fibers, such as fiberglass. In the illustrated example, the tobacco jacket 94 extends slightly beyond the suction end of the metal container 96 of the aerosol generating means 12, but it also extends over the entire length of the smoking article to the filter plug 45 at the mouth end. It may be extended to In this embodiment, it is preferred to provide one or more longitudinal slots 99 (preferably two slots 180° apart) in the outer circumferential surface of the container 96, thereby providing a means for removing the aerosol from the aerosol generating means. The vapor (aerosol) flows through the insulating jacket 94 (annular part of the tobacco material) surrounding the generating means and extracts the tobacco flavor, after which the passage 1
8.

The aerosol generating means 12 includes a granular aerosol generating agent support and/or compressed tobacco material, a metal container 96 surrounding it, and the support, as in the embodiments of FIGS. 2 and 3. and an aerosol generating agent impregnated or supported in some manner on either or both of the tobacco materials.

As shown, the tobacco material at the fuel element end of the jacket 94 is compressed to reduce air flow through the tobacco material of the jacket 94, thus preventing combustion of the tobacco material. . Further, the metal container 96 serves to extinguish the tobacco material in the jacket 94 by functioning as a heat sink. This heat dissipation effect is achieved by the capsule or container 96.
It serves to extinguish the combustion of the tobacco material in the jacket 94 surrounding the capsule 96 and evenly distributes heat to the tobacco material in the jacket 94 surrounding the capsule 96, thereby assisting in the release of tobacco flavor components.

Further, to assist in extinguishing the tobacco material in the jacket 94, a portion 93 of the cigarette paper wrapper 89 near the rear end of the fuel element is treated with a substance such as sodium silicate, so that the tobacco material in the jacket 97 is treated with a material such as sodium silicate. It is desirable to substantially prevent combustion beyond the exposed end into the interior. Alternatively, the tobacco material itself in the jacket 94 surrounding the aerosol generating means may be treated with a flammability modifier to prevent combustion of the tobacco material.

In any of the embodiments shown in FIGS. 1 to 4 described above, when the fuel element 10 is ignited, it burns and generates heat for volatilizing the aerosol generating agent present in the aerosol generating means 12. The vaporized substance, or aerosol as used herein, is drawn towards the end of the mouth when inhaled by the user, and is inhaled into the user's mouth in the same way as smoke from a conventional cigarette. .

Since the fuel element 10 is relatively short, the burning hot cone-shaped mass remains entirely within the aerosol generating means 12.
, thereby maximizing heat transfer to the metal container of the aerosol generating means and the tobacco material optionally disposed therein, thereby minimizing the aerosol and tobacco flavoring. Maximize generation. Also, because the length of the fuel element 10 is short, there is no long unburned fuel section that acts as a heat sink as in conventional thermal aerosol articles. This short fuel element also has the effect of reducing the amount of incomplete combustion products or pyrolysis products, especially in embodiments where the fuel element contains carbon and/or has multiple passages. .

The holes or passages provided in the fuel element also have the effect of increasing the heat transfer and thus the delivery rate of the aerosol by passing hot air to the aerosol generating means, especially during the inhalation action of the user.

Because the aerosol generating means is physically separate from the fuel element, it is exposed to significantly lower temperatures than if it were within the burning cone.
Therefore, the possibility of thermal deterioration of the aerosol generator and associated flavor deterioration is minimized. This configuration also generates aerosol when inhaled by the user, but minimizes aerosol generation when not inhaled (ie, while the fuel is "smoldering").

In a preferred embodiment of the invention, passageways in the jacket or insulation layer and/or the fuel element cooperate with an aerosol generating means to generate a substantial amount of aerosol and optionally Construct a system (article) that can generate flavors of choice. When the user inhales a few doses after ignition, the conical lump of the fuel element is close to the aerosol generating means, and in cooperation with the jacket and/or the multiple passages provided in the fuel element, even during the user's inhalation operation. Sufficient heat transfer can be achieved even during , and relatively long rest (smoldering) times between inhalations.

The aerosol generating means of the present invention is maintained at a relatively high temperature during the pause period between inhalations, and the additional heat, which is considerably increased by the preferred passageway provided in the fuel element during the inhalation operation, is primarily Used to evaporate aerosol generators. This increased heat transfer makes fuel energy more efficient, reduces fuel requirements, and allows for earlier delivery of the aerosol.

Furthermore, the composition of the fuel element, the number of passages in the fuel element,
It is possible to substantially control the combustion characteristics of the fuel element by appropriate selection of the size, shape and arrangement, insulating jacket, cigarette paper wrapper, and/or metal container (heat conducting means);
Thereby it is possible to control the heat transferred to the aerosol generating means and thereby vary the number of inhalations of the user and/or the amount of aerosol delivered into the user's mouth.

Generally, the length of fuel elements that can be used in the practice of the present invention is about 30 mm or less, preferably about 20 mm or less, and more preferably about 15 mm or less. Advantageously, the diameter of the fuel element is less than or equal to about 8 mm, preferably between about 3 and 7 mm, and more preferably between about 4 and 6 mm. The density of the fuel element that can be used in the present invention ranges from about 0.5 g/cc to about 1.5 g/cc, preferably 0.7 g/cc or more, more preferably 0.7 g/cc or more, as measured by mercury displacement, for example. is 0.8g/cc or more. In most cases, higher densities are desirable in order to make the fuel element's burn time comparable to that of a conventional cigarette and to provide sufficient thermal energy to generate the required amount of aerosol. .

The fuel element used in the present invention can be molded or extruded from crushed tobacco leaves, reconstituted tobacco material, or tobacco material substitutes (modified cellulose, degraded or prepyrolyzed tobacco material, etc.). It is advantageous to do so. Suitable materials include U.S. Pat.
No. 4347855, No. 3931824, No. 885574 and No.
No. 4008723 and “Tobacco Substitutes” by Shiteitsug, published by Noyce Data Corporation.
(1976). Use of other combustible materials as long as they can burn for a time comparable to that of a conventional cigarette and provide sufficient heat to generate the required amount of aerosol from the aerosol generating means. You can also do that.

Generally, it is preferred that the fuel element includes a carbon material such as that obtained by pyrolyzing or carbonizing a cellulosic material such as wood, rayon, tobacco leaf, coconut, paper, or the like. In most cases, combustible carbon is desirable because of its high heat generation capacity and low production of incomplete combustion products. Preferably, the carbon content of the fuel element is about 20-40% by weight or more.

The most preferred fuel element that may be used in the practice of the present invention is US patent application Ser.
carbonaceous fuel elements (i.e., fuel elements consisting primarily of carbon) as described in
It is. Carbonaceous fuel elements are particularly advantageous in that they have low pyrolysis and incomplete combustion products, little or no visible sidestream smoke, low ash production, and high heat capacity. Of course, the aerosol delivered into the user's mouth should have no mutagenic effects, as determined, for example, by the Ames test (Mut.Res. of Ames et al.). 31:347–364 (1976
) and Nagus et al., Mutation Research 42:335 (1977)).

Combustion additives or modifiers may also be added to the fuel element to optimize its combustion and glowing properties. If desired, fillers such as diatomaceous earth and binders such as sodium carboxymethyl cellulose (SCMC) can also be added to the fuel element. Additionally, flavoring amounts such as tobacco extract can be added to the fuel element to impart a tobacco or other flavor to the aerosol.

Preferably, the fuel element is formed with one or more longitudinal passageways. These passageways serve to control heat transfer from the fuel element to the aerosol generating means. This heat transfer control is important both in terms of transferring enough heat to generate enough aerosol and in avoiding transferring so much heat that it degrades (decomposes) the aerosol generating agent. It is also important in in general,
These passageways impart porosity to the fuel element and increase the amount of initial heat transfer to the support by increasing the amount of hot gas reaching the support of the aerosol generating means. The passages also serve to increase the combustion rate of the fuel.

Generally, when a large number of passageways, such as about 5 to 9, or more, are provided, particularly with relatively wide spacing between the passageways, as shown in FIGS. 2A and 4A, high conduction heat is achieved. A high transmission rate is obtained, resulting in a high aerosol delivery rate. or,
Having multiple passageways facilitates ignition of the fuel element.

High conductive heat transfer tends to increase the amount of CO contained in the main stream of the aerosol. To reduce the level of CO, you can reduce the number of passages or
It is possible to increase the density of the fuel element, but in that case,
Generally, the fuel element becomes difficult to ignite, reducing conductive heat transfer and thus reducing aerosol delivery rate and volume. However, the second B
If the passages are closely spaced as shown in the figure, they will coalesce into one passage due to combustion, at least at the ignition end. In comparison, it has been found that the amount of CO contained in the main combustion products is small.

The optimal arrangement, shape and number of passages in the fuel element are
It is determined to provide a stable and sufficient amount of aerosol, facilitate ignition, and reduce CO emissions. Various combinations were tested regarding the placement, shape, and/or number of passages in carbonaceous fuel elements used in each embodiment of the present invention. As a result, fuel elements having about 5 to 9 passages relatively closely spaced to combust and coalesce into one large passage are preferred fuel elements for use in the present invention, and are particularly preferred. It has been found that it best satisfies the requirements of a carbonaceous fuel element. This is believed to be true for a variety of non-carbon fuel elements that can be used in the practice of the present invention.

Variables that affect the rate at which passages in a fuel element burn and coalesce include the density and composition of the fuel element, the size, shape, and number of passages, the spacing between passages, and the pattern in which the passages are arranged. for example,
Density 0.85g/cc with 7 passages of approximately 0.5mm diameter
In the case of carbonaceous fuel elements, the passages must be within the diameter of the core, i.e., the diameter of the smallest circle circumscribing the outer edge of the passages, in order to coalesce into one passage when combusted, i.e. about 1.6 It should be placed within the range of mm to 2.5 mm. If the diameter of each of these seven passages is increased to about 0.6 mm, the diameter of the core that is coalesced by combustion will be about 2.1 mm to about 3.0 mm.
increases to

Another preferred fuel element passage arrangement that may be used in the practice of the present invention is shown in FIG. 4B. This passage arrangement has been found to be particularly advantageous in reducing CO emissions and facilitating ignition. In this preferred arrangement, a plurality of passageways 16, preferably about five to nine, are formed in a short section at the firing end of the fuel element, and the passageways merge into a large cavity 97, forming a large cavity 97 at the suction end of the fuel element. It has been extended to. The multiple passages on the lighting end provide a large surface area that is desirable for easy ignition and early delivery of the aerosol. The cavity 97 extending over approximately 30-95%, preferably over 50%, of the total length of the fuel element ensures uniform heat transfer to the aerosol generating means and directs the aerosol into the main stream.
It plays a role in reducing the amount of CO delivered.

The aerosol generating means used in the practice of the present invention is physically separate from the fuel element.
By "physically separate" is meant that the support, container, or chamber containing the aerosol generating agent does not mix with the combusting fuel element or portion thereof. As previously mentioned, this configuration serves to reduce or eliminate thermal degradation of the aerosol generator and the presence of sidestream smoke. Although the aerosol generating means is not a part of the fuel element, it is preferable that the aerosol generating means be in a conductive heat exchange relationship with the fuel element, and it is preferable that the aerosol generating means be brought into contact with or in close proximity to the fuel element. This conductive heat exchange relationship is preferably established by a heat conductive material such as a metal tube or metal foil, and the heat conductive member is preferably arranged so as to be spaced apart from and retracted from the ignition end of the fuel element. .

Preferably, the aerosol generating means comprises one or more thermally stable materials carrying one or more aerosol generating agents. A thermally stable material as used herein is one that can withstand high temperatures of, for example, 400° C. to 600° C., which occur in the vicinity of the fuel element, without decomposing or burning. Although not necessarily preferred, other means of aerosol generation, such as thermally ruptured microcapsules or solid aerosol generators, are also viable, as long as they are capable of releasing sufficient aerosol-generating vapor to resemble tobacco smoke. It is within the scope of the invention.

Thermally stable materials that can be used as supports or carriers for aerosol generators are well known to those skilled in the art. A suitable support should be porous and capable of retaining the aerosol generating agent when not in use and capable of releasing the aerosol generating vapor when heated by the fuel element. The support, especially if it is a particulate material, may be housed in a container preferably formed of a thermally conductive material such as metal.

Suitable thermostable materials include thermostable carbons such as porous carbon, graphite, activated or inert carbon. Other inorganic solids such as ceramics, glasses, alumina, vermiculite, and clays such as bentonite are also suitable. Preferred carbon materials as supports are porous carbons such as PC-25 and PG-60 manufactured by Union Carbide, and SGL carbon manufactured by Calgon. A preferred alumina for the support is SMR-14-1896, available from Davidson Chemical Division of W.R. Grace and Company. This alumina is sintered at a high temperature of approximately 1000°C or higher, for example.
It has been washed and dried.

Suitable granular supports can also be prepared in a single step from carbon, tobacco wood or a mixture of carbon and tobacco wood using a machine manufactured by Fuji Paudal Co., Ltd. of Japan and sold under the trade name "Marmerizer". It has been found that it can be formed into compressed particles. This machine is covered by German Patent No. 1294351, US Patent No.
No. 3277520 (reissued as Patent No. 27214) and Japanese Patent Publication No. 42-8684.

The aerosol generating means used in the present invention is spaced from the ignition end of the fuel element by about 40 mm, preferably by about 30 mm, and most preferably by about 20 mm. The length of the aerosol generating means is about 2 mm to about 60 mm, preferably about 5 mm to 40 mm, most preferably about 20 mm to 35 mm.
can be in the range of The diameter of the aerosol generating means is about 2 mm to about 8 mm, preferably about 3 mm to about 8 mm.
It can be between 6 mm. If a non-granular support is used, the support can be provided with one or more holes to increase the surface area of the support and to increase air flow and heat transfer. The aerosol generator used in the present invention is
It must be capable of generating an aerosol at a temperature within the aerosol generating means when heated by the combusting fuel element. The aerosol generator is preferably composed of carbon, hydrogen, and oxygen, but may contain other components.
The aerosol generator can also be in solid, semi-solid, or liquid form. The boiling point of the aerosol generator and/or mixture of aerosol generators may be up to about 500°C. Substances with such properties include polyhydric alcohols such as glycerin and propylene glycol, and fatty acid esters of mono-, di-, or polycarboxylic acids such as methyl stearate, dimethyl dodecadiate, and dimethyl dodecadiate.

Preferred aerosol generators are polyhydric alcohols or mixtures of polyhydric alcohols, particularly preferred are glycerin, propylene glycol, triethylene glycol or mixtures thereof.

The aerosol generating agent can be dispersed around or within the aerosol generating means at a concentration sufficient to penetrate or coat the support, carrier or container. For example, the aerosol generator can be applied undiluted or in the form of a diluted solution to the support by techniques such as dipping, spraying, vapor deposition, and the like. The solid aerosol-generating component can be mixed with a support and uniformly distributed within the aerosol-generating means.

The amount of aerosol generating agent charged varies depending on the type of carrier or the type of aerosol generating agent, but in the case of a liquid aerosol generating agent, the amount is generally about 20 mg to about 120 mg, preferably about 120 mg. may range from about 35 mg to about 85 mg, most preferably from about 45 mg to 65 mg. As much as possible of the aerosol generating agent carried on the aerosol generating means is
It should be sent to users as WTPM. Preferably about 2% by weight or more, more preferably about 15% by weight, most preferably about 20% by weight of the aerosol generator supported on the aerosol generating means.
is sent to the user as WTPM.

The aerosol generating means may also contain one or more flavoring agents such as menthol, artificial coffee, tobacco extract, nicotine, caffeine, liquor, and other agents that impart flavor to the aerosol; , and any other desired volatile solid or liquid substances may also be included. Alternatively, these optional agents are optionally provided in a separate support or chamber provided between the aerosol generating means and the mouth end, e.g. in a passageway leading from the aerosol generating means to the mouth end. It can also be inserted into the aforementioned tobacco inserts. If desired, these volatile agents can be
It can be used in place of some or all of the aerosol generators, in which case a non-aerosol flavor or the like is delivered to the user.

In a particularly preferred embodiment, the aerosol generating means comprises an alumina carrier;
Tobacco flavor modifiers such as spray-dried tobacco extract and levulinic acid contained in the support, 1
It consists of seeds or more flavoring agents and an aerosol generator such as glycerin. This support may be mixed with compressed tobacco particles produced, for example, in a "marmerizer", and these tobacco particles may also be impregnated with an aerosol generating agent.

The smoking articles disclosed herein can be used as pharmaceutical delivery articles to deliver volatile, pharmacologically or physiologically active substances, such as efuedrin, metaproterenol, turbitutarin, etc., as an aerosol generator. Alternatively, it can be modified for use as a pharmaceutical delivery article.

As shown in the illustrated embodiments, the smoking article of the present invention includes a tobacco charge or plug, or a tobacco-containing substance downstream of the fuel element, for imparting tobacco flavor to the aerosol. can be set. In that case, hot steam is drawn through the tobacco material, extracting and vaporizing volatile substances within the tobacco material without burning or substantially thermally decomposing them.

One preferred location for disposing the tobacco material charge is shown in FIGS. 3 and 4 in embodiments where a thermally conductive member or container is provided between the aerosol generator and the tobacco material jacket. around the outer periphery of the aerosol generating means which increases heat transfer to the tobacco material so as to increase heat transfer to the tobacco material. In these embodiments, the tobacco material also serves as a shield for the aerosol generating agent and acts to mimic the feel and aroma of conventional cigarette materials.

Another preferred location for disposing the tobacco material is within the aerosol generating means. In that case, the tobacco material may be mixed with a support for the aerosol generating agent or may be used in place of the support. The tobacco-containing material can include any available tobacco material, such as burley tobacco, hot air-cured tobacco, Turkish tobacco, reconstituted tobacco, extruded or compressed tobacco mixtures, tobacco-containing sheets, and the like. Advantageously, tobacco blends are used to provide a variety of flavours. The tobacco-containing material may also contain conventional tobacco additives such as fillers, casings, reinforcing materials such as glass fibers, humectants, and the like. Flavors and flavor modifiers may also be added to the tobacco material. Preferred thermally conductive members used in the practice of this invention should be located sufficiently recessed so as not to interfere with the firing end of the fuel element, but the It must be close to the ignition end so that conductive heat transfer can take place even during the initial and intermediate suction operations.

As shown in each of the embodiments illustrated herein, the thermally conductive member preferably contacts or overlaps the rear portion of the fuel element and at least a portion of the aerosol generating means, and extends at least approximately from the ignition end of the fuel element. Retractable by 3 mm, preferably about 5 mm or more. Preferably, the thermally conductive member extends for at most about half of the total length of the fuel element, and more preferably for at most about 5 mm of the rear end portion of the fuel element, overlapping or in some way contacting it. let In this way, since the heat conduction member is retracted from the ignition end, it does not interfere with the ignition or combustion of the fuel element, and also functions as a heat sink to reduce the contact point between the fuel element and the heat conduction member. It works to digest the combustion when it burns up to . Further, the heat conductive member does not protrude forward from the fuel element even after the fuel is consumed.

Preferably, the thermally conductive member constitutes a thermally conductive container surrounding the aerosol generating agent. Alternatively, a separate conductive container may be provided, particularly in embodiments using particulate aerosol generator supports or semi-liquid aerosol generators. The conductive container not only functions as a container for the aerosol generating agent, but also facilitates heat distribution to the aerosol generating agent and the surrounding tobacco jacket, which is provided in a preferred embodiment.
It serves to prevent the aerosol generating agent from spreading or migrating to other parts of the smoking article. The container also provides a means for controlling the pressure drop through the smoking article by varying the number, size, and/or location of passageways for delivering aerosol toward the mouth end. . Additionally, in the embodiment of FIG. 2 in which a tobacco material jacket is disposed around the outer periphery of the aerosol generating means, channels or channels are provided in the peripheral wall of the container to direct and control the flow of vapor through the tobacco material. A slot can be provided. The use of containers also has the effect of simplifying the manufacture of smoking articles by reducing the number of parts and/or manufacturing steps required.

The insulation for a jacket that can be used in the practice of the present invention is preferably formed from one or more layers of insulation in the form of a resilient insulation jacket. This insulating jacket has at least
The thickness is 0.5 mm, preferably at least about 1 mm, and more preferably about 1.5 to about 2 mm. The heat insulating jacket preferably extends over half or more of the total length of the fuel element, and more preferably covers the entire outer peripheral surface of the fuel element and all or part of the aerosol generating means. As shown in the embodiment of FIG. 3, different materials may be used to thermally isolate these two components of the smoking article (the fuel element and the aerosol generating means).

Insulating fibers that can be used in the insulating jacket of the present invention generally include, for example, glass, alumina,
Inorganic or organic fibers obtained from silica, vitreous materials, mineral wool, carbon, silicon, boron, organic polymers, cellulosic materials, etc., and mixtures thereof. The insulating material is preferably elastic, has the effect of mimicking the feel of a conventional cigarette, has a softening temperature of less than about 650-700°C so that it melts during use, and ,
It is preferable that the material does not burn during use. However, slow-flammable carbon and similar materials can be used. These materials function primarily as an insulating jacket, retaining a significant portion of the heat created by the fuel element and directing it to the aerosol generating means. Since the insulating jacket becomes hot in close proximity to the burning fuel element, it conducts some heat toward the aerosol generating means.

Preferred insulating fibers for the fuel element insulating jacket include ceramic fibers such as glass fibers. Glass fibers sold under the trade names Maniglas 1000 and Maniglas 1200 by Manning Paper Company of America are suitable. The glass fiber material for this invention is tested according to ASTM test method C338.
It is preferred to have a low softening point of about 650°C or less, measured at -73°C. Also preferred for use in the present invention are glass fibers sold by Owens Corning, USA under product numbers 6432 and 6437. This glass fiber has a softening point of about 640°C and melts during use when applied to the present invention.

Several types of inorganic fibers are commercially available that are held together by a binder (eg, PVA) that serves to maintain structural integrity. Binders that emit unpleasant odors when heated are e.g.
It should be removed before use by introducing air at about 650°C for up to about 15 minutes. If desired, about 3% by weight of pectin can be added to the fibers to provide mechanical strength to the insulating jacket without producing unpleasant odors.

As discussed in connection with each embodiment, some or all of the jacket insulation may be loosely compressed or tightly compressed tobacco material. According to the present invention, at least part or all of the insulation material of the jacket surrounding the fuel element is made of tobacco material, so that the jacket not only functions as a insulation material but also adds tobacco flavor to the mainstream aerosol. , which provides the additional function of generating a side stream of tobacco flavor.

In a preferred embodiment in which the aerosol generating means is enclosed by a jacket of tobacco material, the jacket of tobacco material serves as a non-combustible insulator and also serves to impart a tobacco flavor to the mainstream aerosol.

If the fuel element is wrapped in a jacket made of tobacco material, the tobacco material of the jacket will at most reach the area where the fuel element is combusted.
That is, it is preferable that combustion occurs only up to the point of contact between the fuel element and the aerosol generating means. Such a configuration can be accomplished by compressing the tobacco material of the jacket around the fuel element and/or by using a conductive heat sink, as in the embodiment of FIG. Alternatively, such an arrangement may include wrapping the cigarette paper wrapper and/or the tobacco material itself with a substance such as sodium silicate which has the effect of extinguishing the tobacco material in the area where the tobacco material of the jacket overlaps the aerosol generating means. obtained by processing.

In most embodiments of the invention, the fuel element/aerosol generating means assembly is attached to a mouthpiece, but the mouthpiece may also be provided separately, for example in the form of a cigarette holder. The mouthpiece provides a passageway for the vaporized aerosol generating agent to the user's mouth. The mouthpiece has a suitable length (preferably about 35-50 mm or more) to keep the hot cone away from the user's mouth and fingers, so that the hot aerosol can reach the user. Give enough time to cool before reaching the mouth.

The mouthpiece is preferably inert to the aerosol generating agent and may have a water-resistant inner layer to minimize loss of aerosol due to condensation or filtration and to protect against other components of the smoking article. It should be able to withstand high temperatures at the interface with the A preferred mouthpiece is the cellulose acetate cylinder used in the examples illustrated herein. This barrel functions as a resilient outer member and has the effect of mimicking the feel of the mouth end of a conventional cigarette. Other suitable mouthpieces will be readily apparent to those skilled in the art.

A filter tip can be used as the mouthpiece of the article of the invention to mimic the appearance of a conventional filtered cigarette. Such filters include low efficiency cellulose acetate filters and hollow or slotted filters made of plastic such as polypropylene. These filters have little interference with aerosol delivery.

The outer surface of the article of the present invention can be covered over the entire length or any part thereof with a cigarette paper wrapper (hereinafter also simply referred to as a "paper wrapper").
In that case, the paper wrapper on the fuel end side must not flare up during combustion of the fuel element. It is also preferred that the paper wrapper has certain smoldering properties, resulting in a gray, cigarette-like ash. In embodiments where an insulating jacket is provided around the fuel element and the paper wrapper is burned and peeled from the jacket, maximum heat transfer is achieved because air flow to the fuel element is unrestricted. However, the paper wrapper can also be designed to remain fully or partially unbroken when exposed to heat from the fuel element. In that case, the paper wrapper serves to restrict the air flow to the burning fuel element, thereby controlling the combustion temperature of the fuel element and the heat transfer to the aerosol generating means.

Non-porous paper treated to be slightly porous, e.g. perforated with multiple holes, to reduce the burning rate and temperature of the fuel element and thereby lower the CO/CO ₂ ratio. Non-combustible mica paper can be used as the jacket paper wrapper. Such a paper wrapper is especially suitable for intermediate suction movements (i.e. 4
The amount of heat delivered during the suction operation of the first to sixth doses is controlled.

The area from the aerosol generating means to the mouth end is non-porous to maximize aerosol delivery by preventing the aerosol from being diluted by outside air penetrating radially inward from the outside. It can be covered with high-quality paper wrapping.

These paper wrappers are well known in the cigarette industry and can be used in combination to achieve a variety of effects. Preferred paper wrappers for use in the articles of the present invention include plug paper wrapper Ecsta 01788 and 666 manufactured by Ecsta, USA;
KC-63-5, P878-5, P878-16-2 and 780
-63-5 etc.

A smoking article according to a preferred embodiment of the invention comprises:
When smoked under FTC smoking conditions, the first three puffs can deliver at least 0.6 mg of aerosol as total wet particulate matter (WTPM). (FTC smoking conditions are 2 seconds of inhalation (35 ml total volume) with 58 seconds of smoldering (pause) periods.) Smoking articles according to more preferred embodiments of the present invention are A three-dose inhalation action can deliver 1.5 mg or more of aerosol. In the most preferred embodiment,
FTC smoking conditions can deliver 3 mg or more of aerosol in the first three puffs.
Preferred embodiments also deliver an average of at least about 0.8 mg (WTPM) of aerosol per dose over at least about 6, and preferably 10, doses.

Effects of the Invention The smoking article of the present invention, which generates an aerosol similar to tobacco smoke, is characterized in that the aerosol generating means is physically separate from the fuel element, and the fuel element is configured to receive heat from the burning fuel element. and the mouth end of the smoking article, at least the fuel element is surrounded by a jacket of tobacco material or a jacket of a mixture of tobacco material and insulating fibers.

The jacket, which is an important feature of the invention, serves to reduce radiation heat loss, to help retain and direct heat from the fuel element toward the aerosol generating means, and to suppress the flame-producing properties of the fuel. do.
More importantly, this tobacco jacket,
Alternatively, a jacket of a mixture of tobacco material and insulating fibers is heated by a combusting fuel element to produce a small amount of tobacco flavor.

The aerosol created by the aerosol generating means contains virtually no incomplete combustion products and pyrolysis products such as those contained in normal cigarette smoke. The taste of the aerosol alone is felt by smokers to be soft and neutral. However, according to the present invention, the tobacco flavor produced by the heating or combustion of a very small amount of tobacco material (in the jacket) surrounding the fuel element is added to the aerosol from the aerosol generating agent, and the tobacco flavor is not present to the smoker. It was observed that the flavor of the aerosol was significantly improved. That is, in the smoking article of the present invention, most of the aerosol delivered to the smoker's mouth is generated by the heating action on the aerosol generating means; , a small amount of tobacco smoke or tobacco flavor from the tobacco material in the jacket heated by the burning fuel element is added.
This very small amount of tobacco smoke or tobacco flavor can dramatically change the flavor of the aerosol delivered to the smoker's mouth to one that is desirable to the smoker.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a smoking article according to one embodiment of the present invention. Figure 1A is the line 1A-1A in Figure 1.
FIG. FIG. 2 is a longitudinal cross-sectional view of a smoking article according to another embodiment of the present invention. Second
Figures A, 2B and 2C are end views illustrating fuel element passage arrangements suitable for use in the embodiment of Figure 2; FIG. 3 is a longitudinal cross-sectional view of a smoking article according to yet another embodiment of the present invention. FIG. 3A is an end view of the fuel element used in the embodiment of FIG. 3. Third
Figure B is an enlarged end view of the metal container used in the embodiment of Figure 3. FIG. 4 is a longitudinal cross-sectional view of a smoking article according to yet another embodiment of the present invention. FIG. 4A is an end view illustrating a fuel element passage arrangement suitable for use in the embodiment of FIG. 4. Figure 4B shows
FIG. 3 is a longitudinal cross-sectional view of a preferred fuel element passage arrangement. DESCRIPTION OF SYMBOLS 10... Fuel element, 12... Aerosol generating means, 14... Paper tube, 16... Hole or passage, 20...
... Tobacco material charging body, 22 ... Filter plug, 2
8... Support body (carrier), 72, 94... Jacket made of tobacco material or a mixture of tobacco material and insulating fibers, 88... Second jacket made of tobacco material.

Claims (1)

[Scope of Claims] 1. A combustible fuel element, the fuel element being physically separate and disposed between the fuel element and the mouth end of the smoking article so as to receive heat from the burning fuel element. an aerosol generating means containing an aerosol generating agent; and a jacket made of tobacco material or a mixture of tobacco material and heat insulating fibers, which is physically separate from the fuel element and surrounds at least the fuel element. Cigarette-type smoking articles.