CN102458165A - Non-combustion smoking article having carbonaceous heat source - Google Patents

Abstract

There is provided a non-combustion smoking article characterized by comprising a carbonaceous heat source comprising a cylindrical outer wall and partitions disposed inside the outer wall, cross-sections of the partitions forming a grid, and having air passages defined by the partitions, and an aerosol generating section.

Description

Non-combustible smoking articles with carbonaceous heat source

technical field

The present invention relates to a non-combustion smoking article provided with a carbonaceous heat source.

Background technique

In recent years, non-combustible smoking articles that can enjoy flavor without burning tobacco have been developed instead of cigarettes. The non-combustion smoking article includes a heat source part, which is a heat radiation member provided at the front end, and a flavor generating part, which includes a flavor generating material holding flavor components in an appropriate base material. On the other hand, as the heat source part, a carbonaceous heat source is mainly used.

In conventional carbonaceous heat sources, a plurality of through holes are provided along the axial direction. These through holes function as air flow paths when the aerosol generating part is heated. The purpose of providing these through holes is to develop the initial combustion characteristics ( US Patent No. 4,881,556, US Patent No. 4,967,774, US Patent No. 4,989,619, US Patent No. 4,991,606, US Patent No. 5,067,499). In addition, an example in which the heat source portion is formed into a special structure is also included (US Patent No. 5,183,062 specification). The carbonaceous heat sources for the above-mentioned various non-combustible smoking articles are wrapped by rolling paper and heat insulating material. In addition, in conventional carbonaceous heat sources, it is desirable to contain more than 60% by weight of carbon, preferably more than 80% by weight.

Contents of the invention

Existing carbonaceous heat sources have indeed been improved in efficiently conducting heat to the aerosol generating part. However, a heat source composed of an extruded product of a heat source composition is a solid product except for a plurality of air flow paths provided, and is difficult to ignite compared with a conventional cigarette. In addition, since the amount of carbon used is large, the carbonaceous heat source may shrink during combustion and fall off from the smoking article. Furthermore, in order to efficiently conduct heat to the aerosol generating part and prevent falling off, the heat source part is basically covered with a heat insulating material or the like.

Therefore, an object of the present invention is to provide a non-combustible smoking article which has a carbonaceous heat source which has improved ignitability, does not easily come off during smoking, and does not require wrapping materials such as heat insulating materials around it.

The present invention provides a non-combustible smoking article comprising a carbonaceous heat source having a cylindrical outer wall and a partition wall having a lattice-shaped cross section provided inside the carbonaceous heat source and an aerosol generating unit, and It has an air flow path partitioned by the partition wall.

Description of drawings

[ Fig. 1 ] An end view of a carbonaceous heat source used in the non-burning smoking article of the present invention.

[ Fig. 2 ] A cross-sectional view of a non-burning smoking article of the present invention.

[ Fig. 3 ] A graph showing the relationship between the flow path circumference per unit cross-sectional area and the ignition rate of a carbonaceous heat source in a non-combustible smoking article according to an example of the present invention.

[ Fig. 4 ] A graph showing the relationship between the flow path circumference per unit cross-sectional area and the ignition rate of a carbonaceous heat source in a non-combustible smoking article in another example of the present invention.

Detailed ways

Hereinafter, the present invention will be specifically described.

The non-combustible smoking article of the present invention includes a carbonaceous heat source having a cylindrical outer wall and a partition wall having a lattice-shaped cross-section provided inside the carbonaceous heat source, and an aerosol generating portion. air flow path.

The above-mentioned grid can be in any form, for example: square grid, hexagonal grid, triangular grid. Fig. 1 shows an end face of a carbonaceous heat source having partition walls formed in the following lattices: 1 is a square lattice, 2 is a triangular lattice, 3 is a hexagonal lattice, and 4 is a radial lattice. In addition, the cross-section of the partition wall provided in the carbonaceous heat source does not have to be formed into a uniform lattice, and may be formed to include uneven lattices as shown in the carbonaceous heat source 5 in FIG. 1 .

The porosity of the carbonaceous heat source can be made 50% or more. Here, the "porosity of the carbonaceous heat source" means: in the cross section of the heat source, the ratio of the space per unit cross-sectional area of the heat source generated by partitioning. When the porosity is less than 50%, the ignitability at the time of ignition tends not to be greatly improved. The upper limit of the void ratio is limited by the die design when extruding the heat source composition. The porosity of the carbonaceous heat source is preferably 50% to 78%, more preferably 60% to 78%. The non-combustion smoking article of the present invention having such a carbonaceous heat source having a high porosity improves the ignitability.

The flow path circumference of the carbonaceous heat source is preferably 70 mm or more. If the circumference of the flow path is less than 70mm, the ignitability may decrease. The upper limit of the flow path circumference is also limited by the mold design. Here, the "peripheral length of the flow path" refers to the sum of the lengths of the latticed partition walls 10 facing the air flow path at the end surface of the heat source as shown in FIG. 1 . The flow path perimeter of the carbonaceous heat source is preferably 100 to 180 mm.

The cross-sectional area of the carbonaceous heat source is preferably 9 mm ² or more. When the cross-sectional area is less than 9 mm ² , it is not preferable in terms of product design.

The flow path circumference per unit cross-sectional area of the carbonaceous heat source is preferably 4 mm/mm ² or more. It has been confirmed that there is a certain relationship between the flow path circumference per unit cross-sectional area and the ignition rate. The details will be described below. It is known that when the flow path circumference per unit cross-sectional area is less than 4 mm/mm ² , ignitability is poor in a normal igniting method.

The heat source composition constituting the above-mentioned carbonaceous heat source preferably contains 10 to 60% by weight of carbon. When the amount of carbon is less than 10% by weight, it is not preferable because the combustibility of the heat source is insufficient. When 60% by weight of carbon is contained, both ignitability and combustibility are sufficient. There is no particular limitation on the source of the carbon used, and known carbons can be used. As described above, the heat source composition constituting the carbonaceous heat source used in the non-combustion smoking article of the present invention has a sufficient ignition rate even at a low carbon content compared with the prior art.

In addition, the heat source composition may contain calcium carbonate (particles) and other inorganic additives for lowering the maximum temperature of the carbonaceous heat source and reducing the amount of carbon monoxide generated. The compounding ratio of the inorganic additive is usually 98% by weight or less, preferably 8.0% by weight or less, and more preferably 0.100 to 3.75% by weight relative to 1% by weight of carbon.

The heat source composition of the present invention may contain a binder for binding calcium carbonate and carbon. The blending ratio of the binder is usually 0.010 to 50% by weight, preferably 0.017 to 2.0% by weight, and more preferably 0.10 to 0.75% by weight relative to 1% by weight of carbon. As the binder, alginate, carboxymethylcellulose or its salt, pectin or its salt, carrageenan or its salt, guar gum and the like can be used.

In order to facilitate the generation of aerosol during the initial smoking, the heat source composition may contain an aerosol generating substance such as polyhydric alcohol or the like. The compounding ratio of the aerosol generating substance that may be contained in the heat source composition is usually 98% by weight or less, preferably 3.0% by weight or less, and more preferably 1.5% by weight relative to 1% by weight of carbon.

In addition, pulp, tobacco dust (tabako fine powder), and the like may be contained in the heat source composition. The total compounding ratio of pulp and tobacco dust is usually 98% by weight or less, preferably 3.0% by weight or less, and more preferably 0.50% by weight relative to 1% by weight of carbon.

In addition, in the carbonaceous heat source, boron, aluminum, silicon, titanium, iron, cobalt, nickel, zinc, germanium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, tin, cerium, hafnium, tantalum Carbon monoxide reduction catalysts such as , tungsten, rhenium, osmium, iridium, platinum, gold, their oxides or mixtures of the above substances are mixed into the raw material before the carbonaceous heat source is formed.

As for the above-mentioned carbonaceous heat source, it is also possible to coat part or all of the axial surface of the air flow path with a desired substance. In particular, the carbonaceous heat source can also be made substantially air-impermeable by coating the particle layer. The ideal coating material is a material with low thermal conductivity, thermal stability, and non-combustibility at the temperature at which the carbonaceous heat source burns. Examples of preferred coating materials include clay, metal oxides such as iron oxide, alumina, titania, silica, aluminum silicate, zirconia, ceria, zeolite, zirconium phosphate, other ceramics, and combinations thereof . These coating substances preferably contain clay and iron oxide. Furthermore, these coating substances may contain catalysts which promote the oxidation reaction from carbon monoxide to carbon dioxide. Examples of the catalyst include platinum, palladium, other transition metals, and oxides thereof.

In order to coat part or all of the axial surface of the air flow path with a desired substance, various methods disclosed in the specification of US Pat. No. 5,040,551 can be used. It is also possible, for example, to spray, wet, paint solutions or suspensions of coating substances. Alternatively, a liner formed of a coating material may be inserted into part or all of the axial surface of the air flow path. For example, a substantially air-impermeable hollow tube may be inserted in the axial direction of each air flow path.

The carbonaceous heat source used in the non-combustible smoking article of the present invention burns while maintaining the shape of the partition wall whose cross section is latticed. It is considered that this is for the purpose of further suppressing the carbon content of the heat source composition as described above. In this way, even if the heat source is not covered with a heat insulating material or the like as described below, it is possible to prevent the heat source from coming off from the smoking article during smoking.

The above-mentioned carbonaceous heat source can be molded by a molding method such as extrusion molding using a mold corresponding to a desired grid. As for the carbonaceous heat source used in the present invention, there is no need to arrange heat insulating materials, roll paper, etc. around it like conventional non-combustible smoking articles, and it can fully burn in an exposed state and is not easy to fall off. Thereby, the step of providing a heat insulating material etc. around the carbonaceous heat source can be omitted, which is very advantageous in terms of cost.

In the non-combustion smoking article of the present invention, for example, the aerosol generating part may be provided in a state of being physically separated from the carbonaceous heat source. As the aerosol generating substance contained in the aerosol generating part, for example, glycerin, propylene glycol, triethylene glycol, tetraethylene glycol and other polyhydric alcohols, methyl stearate, dimethyl dodecanedioate, Aliphatic carboxylic acid esters such as dimethyl tetraalkanedate. Aerosol-generating substances are usually carried by suitable carriers. As the carrier, porous materials such as paper and activated carbon can be used. The aerosol generating material is prepared by absorbing or adsorbing the aerosol generating substance on the porous material. Alternatively, as a carrier, dextran gel such as curdlan described in Japanese Patent No. 3118462 can be used. That is, the aerosol-generating substance is added to an aqueous dispersion of thermally irreversible coagulable dextran, and the dispersion is cast into a film sheet on, for example, a stainless steel belt, and then heat-dried to generate dextran. gelling. The dextran gel holding the aerosol-generating substance can be used as an aerosol-generating material after being cut or powdered.

The aerosol generating material obtained by retaining the aerosol generating substance on the carrier can be accommodated in a cylinder to constitute an aerosol generating part. Made of non-combustible materials such as paper sheets.

In the smoking article of the present invention, in order to impart flavor to the aerosol generated by the aerosol generating part, a flavor generating part containing a flavor generating material may be attached to the rear end of the aerosol generating part. As the flavor generating material, shredded tobacco or the flavor generating medium described in Japanese Patent No. 3118462 can be used. The flavor generating material is housed in the same cylindrical body as that of the aerosol generating part.

Furthermore, the smoking article of the present invention may have a filter for conventional cigarettes at the rearmost end.

Hereinafter, an example of a non-burning smoking article using a heat source composed of a carbonaceous heat source composition according to the present invention will be described with reference to FIG. 2 .

The smoking article 100 shown in Figure 2 has: an aerosol generating part 11, a carbonaceous heat source 12 arranged at the front end of the aerosol generating part 11, a flavor generating part 36 arranged at the rear end of the aerosol generating part 11, and a The filter part 14 at the rear end of the generating part 36 .

The aerosol generating unit 11 has a cylindrical body 111 made of a non-combustible material, and in the cylindrical body 111 is accommodated, for example, a particulate aerosol generating material 112 made of a carrier carrying an aerosol generating substance.

The shape of the carbonaceous heat source 12 is circular, and it can be in various grid forms as described above.

In addition, the fragrance generating part 36 has a cylindrical body 361 formed of an incombustible material, and a fragrance generating material 362 is accommodated in the cylindrical body 361 .

The filter portion 14 is composed of a filter member 141 (for example, cellulose acetate tow) used in conventional cigarettes, and its outer periphery is wrapped with a wrapping paper 142 .

The aerosol generating part 11, the flavor generating part 36 and the filter part 14 are made of a paper sheet 20 such as a cigarette wrapping wrapping the outer periphery of the rear end part of the aerosol generating part 11 and the entire periphery of the flavor generating part 36 and the filter part 14. connect.

It should be noted that, in order to dilute the mainstream smoke components (such as carbon dioxide), the smoking article 100 may have openings for introducing air during smoking. In the filter portion 14 of the smoking article 100 shown in FIG. 2 , an opening OP that passes through the paper sheet 20 and the wrapping paper 142 is formed.

Such a non-burning smoking article 100 may have the appearance of a conventional cigarette.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1

The relationship between the void ratio of the carbonaceous heat source, the flow path perimeter of the carbonaceous heat source, the cross-sectional area of the heat source, and the flow path perimeter per unit cross-sectional area of the heat source and the ignitability were studied.

With the same composition as the heat source composition used in conventional non-combustion smoking articles (manufactured by Japan Tobacco Industry Co., Ltd.; trade name AIRS), that is, 59.6% by weight of carbon particles, 12% by weight of calcium carbonate, 8.4% by weight Graphite and 10% by weight of smoke powder were used as raw materials to prepare a heat source composition. Using various molds, the heat source composition was molded into heat sources having different wall thicknesses of partition walls and grid intervals, thereby producing carbonaceous heat source samples 1 to 6 having end surface forms shown in Table 1.

Table 1. Specifications and basic physical properties of various heat sources

＊Comparative example 1: The glass mat part is not included

Next, the heat source and the heat insulating material in which the heat source was wound were extracted from the above-mentioned AIRS product, and the carbonaceous heat source samples 1 to 6 prepared above were inserted. That is, the configuration of the smoking article other than the heat source is the same as that of the AIRS product.

Traditional Example 1

As Conventional Example 1, the aforementioned non-burning smoking article manufactured by Japan Tobacco Industry Co., Ltd. under the trade name AIRS was used.

The ignitability test was performed as follows. After preheating with an electric lighter for 3 seconds, smoking was performed at 35 ml/2 seconds. Next, smoke again after 58 seconds (that is, a 60-second puffing cycle), at this time, check with the naked eye whether the entire heat source has become red-hot, evaluate the red-hot heat source as "ignitable", and evaluate the red-hot heat source as "ignitable" and the non-red-hot The heat source is evaluated as "non-ignitable". For samples 1-6 and conventional example 1, 10 smoking articles were used to test respectively, wherein, the number of smoking articles confirmed as "ignitable" was recorded as A, and the ignition rate=A÷10×100( %)” to calculate the ignition rate.

When analyzing the ignition rate, the ignition rate was studied with respect to the flow path circumference per unit cross-sectional area of the carbonaceous heat source. The result is shown in Figure 3. The circular symbols represent the ignition rates of the carbonaceous heat source samples 1 to 6, and the triangular symbols represent the ignition rates of the carbonaceous heat source of Conventional Example 1. Under this condition, Samples 1-2 and Conventional Example 1 did not show a significant difference in the ignition rate, but the ignition rate of Sample 3 was greatly increased by about 60%. It can be seen that, in order to improve the ignitability, the design of each parameter of the carbonaceous heat source shown in Table 1 is particularly important. In addition, by using a carbonaceous heat source having an air flow path divided by a lattice-shaped partition wall in cross-section, it is possible to achieve a significant increase in porosity and flow path circumference compared to a conventional carbonaceous heat source with an opening pattern, As a result, improvement in ignitability was confirmed.

Example 2

Among the parameters shown in Table 1 above, in order to confirm only the influence of the number of grids (circumferential length of the flow channel), experiments were performed by changing the peripheral length of the flow channel while keeping the porosity and heat source cross-sectional area constant.

The same heat source compositions as samples 1 to 6 were prepared, and carbonaceous heat source samples 7 to 11 shown in Table 2 were fabricated using various molds. That is, the combination of the wall thickness and interval of the grid is changed, the circumference of the flow path is changed, and the cross-sectional area of the heat source and the porosity are kept constant.

Table 2. Specifications and basic physical properties of various heat sources

Next, the heat source and the heat insulating material around it were taken out from the AIRS product, and the produced heat source samples 7 to 11 were inserted. That is, the configuration of the non-combustible smoking article other than the heat source is the same as that of the AIRS product.

In this example, as an ignitability test, smoking was performed at 35 ml/2 seconds after preheating with an electric lighter for 2 seconds. The carbonaceous heat source in Example 2 is easy to ignite, and it is not easy to show a difference under the conditions of Example 1, so the preheating time is shortened from 3 seconds to 2 seconds to make a difference in the ignition rate.

FIG. 4 shows the relationship between the ignition rate and the flow path circumference per unit cross-sectional area of the carbonaceous heat source. Here, the cases where 2 seconds and 3 seconds are used as the preheating time are respectively shown. As can be seen from FIG. 4 , the ignition rate in the case of preheating for 3 seconds is sufficiently high at 60% or more. In addition, when the preheating time was shortened to 2 seconds, similar to samples 1 to 6, the following relationship was confirmed: the ignition rate increased as the "flow path circumference length per unit cross-sectional area of the heat source" increased. At the same time, the following results were also confirmed: under the condition that the cross-sectional area of the heat source and the porosity are basically constant, the method of increasing the number of grids by reducing the thickness of the partition wall as much as possible and narrowing the grid interval, thereby increasing the circumference of the flow path, Effective in improving ignitability.

Claims (6)

1. A non-combustible smoking article comprising a carbonaceous heat source and an aerosol generating portion, the carbonaceous heat source having a cylindrical outer wall and a partition wall having a lattice-like cross-section disposed inside the carbonaceous heat source, and comprising the The air flow path divided by the next door. 2. The non-combustion smoking article according to claim 1, wherein the carbonaceous heat source has a porosity of 50% or more. 3. The non-combustion smoking article according to claim 1, wherein, in the carbonaceous heat source, the circumference of the flow path of the partition is 70 mm or more, and the circumference of the flow path is the length of the flow path facing the partition wall. The sum of the lengths of the air flow paths described above. 4. The non-combustion smoking article according to claim 1, wherein the cross-sectional area of the carbonaceous heat source is 9 mm ² or more. 5. The non-combustion smoking article according to claim 1, wherein the flow path circumference per unit cross-sectional area of the carbonaceous heat source is 4 mm/mm ² or more. 6. The non-combustion smoking article according to claim 1, wherein the amount of carbon in the heat source composition constituting the carbonaceous heat source is 10 to 60% by weight.

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