WO2024079809A1 - Tobacco formulation, tobacco sheet, tobacco filling material, smoking article, tobacco formulation production method, and tobacco sheet production method - Google Patents

Abstract

The present invention addresses the problem of providing: a tobacco formulation from which it is possible to form a tobacco sheet by using a tobacco material but without externally adding other water-insoluble substance materials; and said tobacco sheet.　This tobacco formulation contains (1) a water-insoluble substance derived from a tobacco material, (2) a starch extracted from said tobacco material or from another tobacco material, and (3) a medium.

Description

Tobacco preparation, tobacco sheet, tobacco filling material, smoking article, method for manufacturing tobacco preparation, and method for manufacturing tobacco sheet

The present invention relates to tobacco preparations, tobacco sheets, tobacco fillers, smoking articles, methods for producing tobacco preparations, and methods for producing tobacco sheets.

Imitation tobacco is a tobacco material made by artificially forming tobacco leaves into a paper-like form, and is also called tobacco sheet. Known methods for manufacturing such tobacco sheets include, for example, a papermaking process, a slurry (cast) process, a rolling (rolling) process, and an extrusion molding process.

It is known that in order to obtain a tobacco sheet with a specified strength, the particle size of the tobacco raw material is set within a specified range. For example, Patent Document 1 discloses that the smaller the particle size of the tobacco, the greater the surface area that bonds the tobacco particles together, improving the strength of the tobacco sheet, and that a uniform sheet can be created by using a particle size of 60 mesh to 400 mesh (56 μm to 375 μm). Patent Documents 2 and 3 also disclose that tobacco powder with a particle size of 30 to 120 μm is used, because the strength of the tobacco web decreases when the particle size of the tobacco is 150 μm or more when homogenized. Furthermore, there is also technology for reducing the particle size of tobacco to nano size and using it as a raw material for the sheet (Patent Documents 4 and 5, and Non-Patent Document 1).

Furthermore, in order to improve the moldability and strength of tobacco sheets, water-insoluble substances such as plant fibers other than tobacco are often added. In Patent Document 6, in the mixing process before sheet molding, a cellulose material with a particle size of 200 μm to 4000 μm is added and mixed with tobacco raw material with a particle size of 30 μm to 120 μm, and in this mixture, the above two types of substances with different particle sizes become entangled, allowing the sheet structure to be stably maintained.

Furthermore, the demand for tobacco sheets for use in heated tobacco products (non-combustion heated smoking articles) is also increasing. In the manufacture of tobacco sheets for heated tobacco products, tobacco raw materials, aerosol forming agents, binders, etc. are mixed and then molded into a tobacco sheet. In the manufacture of such tobacco sheets, ingenuity has been employed to improve the moldability and strength of the sheets, such as adding water-insoluble cellulose pulp (Patent Document 7) and specifying the particle size of tobacco particles (Patent Document 8). In addition, in the manufacture of such tobacco sheets, water-insoluble metals and calcium carbonate have also been added to improve thermal conductivity during heating (Patent Documents 9 and 10).

European Patent Application Publication No. 0565360 International Publication No. 2016/050471 International Publication No. 2017/089589 U.S. Pat. No. 1,019,6778 International Publication No. 2016/013946 U.S. Patent No. 10813381 U.S. Patent No. 10,321,707 U.S. Patent No. 10813381 US Patent Application Publication No. 2017/0079325 Patent No. 4759523

“Flexible cellulose nanopaper with high wet tensile strength, high toughness and tunable ultraviolet blocking ability fabricated from tobacco stalk via a sustainable method,” Qingbo Wang, Haishun Du, Fang Zhang, Yuedong Zhang, Meiyan Wu, Guang Yu, Chao Liu, Bin Li, and Hui Penga, Journal of Material Chemistry, 2018, Vol. 6 (27), pp. 13021-13030

As disclosed in Patent Documents 6 and 7, when a poorly water-soluble substance such as plant fibers other than tobacco is added to tobacco raw materials, extra costs are incurred for preparing the poorly water-soluble substance, and the process of blending the poorly water-soluble substance requires extra work time and effort.
In view of the above circumstances, the inventors of the present application conducted intensive research and found that it is possible to prepare a tobacco sheet that is not dependent on particle size by using tobacco raw materials as plants, without externally adding raw materials of poorly water-soluble substances such as fiber materials. An object of the present invention is to provide a tobacco preparation that uses tobacco raw materials and is capable of forming a tobacco sheet without externally adding raw materials of poorly water-soluble substances, and said tobacco sheet.

The above problems are solved by the present invention described below.
[1]
(1) Poorly water-soluble substances derived from tobacco raw materials,
(2) a starch extracted from said tobacco material or from other tobacco materials; and (3) a vehicle.
[2]
A tobacco sheet comprising: (1') a poorly water-soluble substance derived from a tobacco raw material; and (2') a starch extracted from the tobacco raw material or another tobacco raw material.
[3] The tobacco sheet according to [2], wherein the starch is a starch extracted from the tobacco raw material.
[4] The tobacco sheet according to [2] or [3], wherein the starch is a soluble starch.
[5] The tobacco sheet according to any one of [2] to [4], wherein the primary particle size of the poorly water-soluble substance is 100 μm or less.
[6] The tobacco sheet according to any one of [2] to [5], wherein the starch content in the tobacco sheet is 10% by weight or less.
[7] The tobacco sheet according to any one of [2] to [6], wherein the tobacco raw material from which the poorly water-soluble substance is derived contains tobacco leaves.
[8] The tobacco sheet according to any one of [2] to [7], wherein the tobacco raw material from which the poorly water-soluble substance is derived contains an alkaloid.
[9] The tobacco sheet according to any one of [2] to [8], further comprising an aerosol generating agent.
[10] The tobacco sheet according to [9], wherein the aerosol generating agent comprises glycerin, 1,2-propanediol, 1,3-propanediol, or a mixture thereof.
[11] The tobacco sheet according to any one of [2] to [10], further comprising glucan.
[12] The tobacco sheet according to [11], wherein the glucan comprises tamarind gum, guar gum, locust bean gum, gellan gum, pullulan, or a mixture thereof.
[13] The tobacco sheet according to any one of [2] to [12], which does not contain pulp.
[14] The tobacco sheet according to any one of [2] to [13], which is a cast sheet.
[15] The tobacco sheet according to any one of [2 to [14], which is a molded product of the tobacco formulation according to [1].
[16] A tobacco filler comprising the tobacco sheet according to any one of [2] to [15].
[17] A smoking article comprising the tobacco filler described in [16].
[18] The smoking article according to [17], which is a non-combustion heating smoking article.
[19] A method for producing a tobacco formulation according to [1], comprising a step of heating the tobacco raw material in the medium to extract the starch.
[20]
A method for producing a tobacco sheet according to any one of [2] to [15], comprising: preparing the tobacco formulation by the method according to [19]; and spreading the tobacco formulation on a substrate and drying it.

The present invention provides a tobacco preparation that uses tobacco raw materials and can be used to form a tobacco sheet without the external addition of other poorly water-soluble substance raw materials, and the tobacco sheet.

FIG. 1 is a schematic cross-sectional view showing an example of a non-combustion heating smoking system. FIG. 2 is a schematic cross-sectional view showing an example of a non-combustion heat smoking article.

The present invention will be described in detail below. In this invention, "X to Y" includes the end values X and Y.

1. Tobacco formulation The tobacco formulation of the present invention comprises:
(1) Poorly water-soluble substances derived from tobacco raw materials,
(2) a starch extracted from said tobacco material or from another tobacco material; and (3) a vehicle.

(1) Poorly Water-Soluble Substances Derived from Tobacco Raw Materials The poorly water-soluble substance of the present invention is derived from tobacco raw materials. In this application, the poorly water-soluble substance refers to a substance that has a solubility in water of less than 20 μg/mL at 85° C., and can be obtained as a residue after subjecting tobacco raw materials to boiling and extraction treatments. The poorly water-soluble substance can be obtained as a residue of tobacco raw materials by subjecting tobacco raw materials to boiling and extraction treatments under specific conditions and extracting starch from the tobacco raw materials, for example, as shown in [Example 1] or [Example 2] (Preparation of tobacco formulation and tobacco sheet) described below.
Whether or not a poorly water-soluble substance is derived from a tobacco raw material can be determined, for example, by performing isotope analysis of the poorly water-soluble substance and measuring the 13C/12C ratio.
The poorly water soluble material may comprise or consist of poorly water soluble fibres.

The shape of the poorly water-soluble substance in the tobacco formulation is not limited, but it is preferably in the form of particles.
The lower limit of the primary particle diameter (D90) of the poorly water-soluble substance is not particularly limited, but from the viewpoint of maintaining the sheet structure, it is preferably 20 μm or more, more preferably 50 μm or more, and most preferably 100 μm or more. The lower limit of the primary particle diameter (D90) of the poorly water-soluble substance can be 5 μm or more or 10 μm or more. The upper limit of the primary particle diameter (D90) of the poorly water-soluble substance is not particularly limited, but from the viewpoint of uniformity of the sheet structure, it is preferably 500 μm or less, more preferably 250 μm or less, and most preferably 100 μm or less. The upper limit of the primary particle diameter (D90) of the poorly water-soluble substance can also be 80 μm or less, 50 μm or less, or 30 μm or less. The upper and lower limits of the primary particle diameter of the poorly water-soluble substance described above can be arbitrarily combined. The primary particle diameter (D90) of the poorly water-soluble substance can be measured according to the procedure and conditions described in "(1) Measurement of particle diameter of poorly water-soluble substance" in [Examples] described later.
By reducing the primary particle size of the poorly water-soluble substance, the surface area for bonding tobacco particles together increases, and the strength of the tobacco sheet can be improved.

The lower limit of the content of the poorly water-soluble substance in the tobacco formulation is not particularly limited, but from the viewpoint of functioning as a base material, it is preferably 5% by weight or more, more preferably 10% by weight or more, most preferably 15% by weight or more, and can also be 20% by weight or more, 75% by weight or more, or 90% by weight or more. The upper limit of the content of the poorly water-soluble substance in the tobacco formulation is not particularly limited, but can be 95% by weight or less, 80% by weight or less, 70% by weight or less, 50% by weight or less, or 35% by weight or less. The upper and lower limits of the content of the poorly water-soluble substance in the tobacco formulation can be combined in any manner.
The content of the poorly water-soluble substance in the tobacco formulation can be expressed as a value calculated based on the solid content excluding the medium. The content of the poorly water-soluble substance in the tobacco formulation can be measured according to the procedures and conditions described in "(3) Measurement of the content of poorly water-soluble substance" in [Examples] below, and calculated as the ratio (wt%) of the weight of the obtained dry matter to the weight of the solid content of the tobacco formulation.

The content of poorly water-soluble substances in tobacco preparations can also be calculated by the Prosky method. That is, after taking a sample of the tobacco preparation, the starch contained in the sample is randomly decomposed by heat-stable α-amylase until a small amount of glucose is linked to it. Next, the peptide bonds of the proteins contained in the sample are decomposed by protease. Finally, the sugar chains decomposed by heat-stable α-amylase are decomposed into one glucose molecule by amyloglucosidase. Then, ethanol is added to the sample to generate a precipitate, and the precipitate is collected by suction filtration and washed with ethanol and acetone. By washing with ethanol and acetone, lipids in the precipitate that were not enzymatically decomposed are washed away. The washed precipitate is dried overnight and the dry weight is measured. Meanwhile, the filtration residue obtained by the above suction filtration contains the protein derived from the sample that was not decomposed, the protein derived from the enzyme, and inorganic matter (ash). Therefore, the amount of poorly water-soluble substances is calculated by separately quantifying the protein and ash and subtracting them from the above dry weight.
The above protein content is calculated by the BSA assay method, which is based on a two-step reaction. In the first step, the divalent copper ions (Cu ²⁺ ) contained in the kit are reduced to monovalent copper ions (Cu ⁺ ) by peptide bonds in the protein solution. The amount of Cu ²⁺ reduced is proportional to the amount of protein in the solution. In the second step, two molecules of bicinchoninic acid (BCA) coordinate with Cu ⁺ to form a blue-purple complex that has strong absorption at 562 nm. This is measured with a spectrophotometer and colorimetrically quantified to calculate the protein mass. The ash content is calculated from the weight of a certain amount of the protein incinerated at a temperature of 550-600°C.

(Tobacco raw materials)
The tobacco raw materials mentioned above are raw materials derived from Nicotiana plants, and examples thereof include tobacco raw materials such as tobacco leaves, aged tobacco leaves, tobacco shreds, tobacco powder, parts other than leaves such as midribs and stems, and processed products or waste products obtained by subjecting tobacco raw materials to processing. Tobacco leaves are a general term for harvested tobacco leaves before they are aged. One form of aging includes curing. Tobacco shreds are aged tobacco leaves, etc. that have been chopped into a specified size. Tobacco powder is pulverized tobacco leaves, etc.

Various tobacco varieties can be used as the tobacco raw material. For example, examples of tobacco varieties include flue-cured, burley, orient, native, other Nicotiana tabacum varieties, and Nicotiana rustica varieties. These varieties can be used alone, but in order to obtain the desired flavor, they can also be blended during the process from tobacco leaf harvest to the processing of aged tobacco leaves into various forms (i.e., processed tobacco leaves) used in non-combustion heated tobacco products. Details of the tobacco varieties are disclosed in "Encyclopedia of Tobacco, Tobacco Research Center, March 31, 2009."

The tobacco raw material from which the poorly water-soluble substance is derived may contain alkaloids from the standpoint of palatability quality.
The type of alkaloid is not particularly limited, but nicotine, nornicotine, or a mixture thereof can be used.

(2) Starch extracted from tobacco raw materials or other tobacco raw materials In the present invention, the starch may be extracted from a tobacco raw material contained in a tobacco formulation, or may be extracted from another tobacco raw material not contained in a tobacco formulation. That is, the tobacco formulation in one embodiment contains tobacco raw material X and starch extracted from X, in another embodiment contains tobacco raw material X and starch extracted from tobacco raw material Y other than X, and in yet another embodiment contains tobacco raw material X, starch extracted from X, and starch extracted from tobacco raw material Y other than X.

The above starch is present inside the cells of the tobacco raw material. Therefore, the extraction conditions are adjusted so that the starch can be released outside the cells. The extraction conditions are described below.

In the present invention, the starch functions as a binder that bonds poorly water-soluble substances together. Therefore, among the tobacco varieties mentioned above, those that contain a large amount of starch are preferred. Thus, in one embodiment, the tobacco raw material is preferably tobacco leaves that contain 0.1 to 20% by weight of starch, and more preferably tobacco leaves that contain 0.1 to 2% by weight of starch. Examples of such tobacco leaves include flue-cured and burley varieties. The former contain about 2 to 5% by weight of starch in the tobacco leaves. The latter contain about 0.1 to 0.5% by weight of starch in the tobacco leaves.

By using starch that functions as a binder, the tobacco formulation can be made free of binders other than starch. Here, in this application, "free of" a specific component means that the component is not added intentionally, and the component may be included as an impurity. Even if a binder other than starch is included as an impurity, the content of the binder other than starch in the tobacco formulation can be 2% by weight or less, 1% by weight or less, or 0.5% by weight or less.

The type of starch is not particularly limited, but soluble starch, insoluble starch, or a mixture thereof can be used. Among these, it is preferable to use soluble starch, as its water solubility allows for uniform mixing.

The lower limit of the content of starch in the tobacco formulation is not particularly limited, but is preferably 1% by weight or more, more preferably 2% by weight or more, and most preferably 2.5% by weight or more. The upper limit of the content of starch in the tobacco formulation is not particularly limited, but is preferably 50% by weight or less, more preferably 40% by weight or less, and most preferably 25% by weight or less. The upper limit of the content of starch in the tobacco formulation can be 20% by weight or less, 15% by weight or less, 10% by weight or less, 5% by weight or less, or 4% by weight or less. The upper and lower limits of the content of starch in the tobacco formulation can be arbitrarily combined. When the content of starch is 1% by weight or more, the strength of the tobacco sheet can be increased. In addition, with regard to the upper limit of the content of starch (50% by weight or less), 50% by weight of starch, which is a viscous substance and functions as a binder, is sufficient, and even if the amount increases beyond this, the binder function is unlikely to be improved. Furthermore, by ensuring that the starch content in the tobacco formulation is within the numerical range between the above lower and upper limits, the amount of starch functioning as a binder is appropriate, and the structure of the resulting tobacco sheet can be maintained.
The starch content in the tobacco formulation can be expressed as a value calculated based on the solid content excluding the medium. The starch content in the tobacco formulation can be measured according to the procedures and conditions described in "(4) Measurement of starch content" in the [Examples] below, and calculated as the ratio (wt%) of the weight of starch to the weight of the solid content of the tobacco formulation.

(3) Medium The medium is preferably a liquid at room temperature (about 23° C.), and specific examples thereof include water or a water-soluble organic solvent. Examples of the water-soluble organic solvent include linear or branched alcohols having 1 to 3 carbon atoms, and ethers having 4 to 7 carbon atoms. These can be used alone or in combination as the medium. From the viewpoint of ease of handling, the medium is preferably water or a mixed solvent of water and a water-soluble organic solvent, and more preferably water.

The content of the medium in the tobacco formulation is not particularly limited, but from the viewpoint of thermal energy efficiency during heating, it is preferably 20 to 80% by weight, more preferably 30 to 75% by weight, and most preferably 50 to 70% by weight. The content of the medium in the tobacco formulation can be calculated based on the dry weight method using an IR moisture measuring device.

The tobacco formulation of the present invention can be produced, for example, as shown in Example 1 or Example 2 (Preparation of Tobacco Formulation and Tobacco Sheet) described below, by mixing tobacco raw materials with a medium to obtain a mixture, and then subjecting the mixture to a boiling treatment and extraction treatment to extract starch from the tobacco raw materials.

In the present invention, cellulose contained in the tobacco raw material can be used as a reinforcing material. Thus, in one embodiment, the tobacco raw material is preferably tobacco leaves containing 4 to 15% by weight of cellulose, more preferably tobacco leaves containing 5 to 13% by weight of cellulose. Examples of such varieties include flue-cured and burley varieties. The former contain about 6 to 8% by weight of cellulose in the tobacco leaves, and the latter contain about 10 to 12% by weight of cellulose in the tobacco leaves.
The poorly water-soluble substance may include the cellulose.

(Characteristics of tobacco preparations)
As described below, the tobacco preparation of the present invention is useful as a tobacco material. When starch is derived from a tobacco raw material, it has a high affinity with a poorly water-soluble substance derived from the same tobacco raw material. In particular, in an embodiment containing a poorly water-soluble substance derived from tobacco raw material X and starch extracted from the X, a poorly water-soluble substance is formed by removing part or all of the starch from tobacco raw material X, so that the medium or other components can be retained in the part of the poorly water-soluble substance from which the starch has been removed. Therefore, it is considered that the affinity between the poorly water-soluble substance and starch is particularly high. Therefore, the poorly water-soluble substance derived from the tobacco raw material has a high affinity with starch, etc., and additives added separately, etc. For this reason, the tobacco preparation of the present invention can form, for example, a tobacco sheet with excellent strength.

2. Tobacco Sheet The tobacco sheet of the present invention is
(1') a poorly water-soluble substance derived from a tobacco raw material; and (2') a starch extracted from the tobacco raw material or from other tobacco raw materials.

(1') Poorly Water-Soluble Substances Derived from Tobacco Raw Materials The type, shape, primary particle size, and other configurations of the poorly water-soluble substance contained in the tobacco sheet are not particularly limited, but may be the same as the configurations described in "(1) Poorly Water-Soluble Substances Derived from Tobacco Raw Materials" in "1. Tobacco Preparations" above.

The lower limit of the content of the poorly water-soluble substance in the tobacco sheet is not particularly limited, but from the viewpoint of functioning as a substrate, it is preferably 5% by weight or more, more preferably 10% by weight or more, most preferably 15% by weight or more, and can also be 20% by weight or more, 75% by weight or more, or 90% by weight or more. The upper limit of the content of the poorly water-soluble substance in the tobacco sheet is not particularly limited, but can be 95% by weight or less, 80% by weight or less, 70% by weight or less, 50% by weight or less, or 35% by weight or less. The upper and lower limits of the content of the poorly water-soluble substance in the tobacco sheet can be combined in any manner.
A tobacco sheet can be formed by removing the medium from the tobacco formulation. Therefore, as described in "(3) Measurement of the content of poorly water-soluble substance" in the Examples below, the content (wt%) of the poorly water-soluble substance in the tobacco formulation (converted into solid content) can be considered to be equal to the content (wt%) of the poorly water-soluble substance in the tobacco sheet.
The content of poorly water-soluble substances in a tobacco sheet can also be calculated based on the above-mentioned Prosky method.

The tobacco raw material from which the poorly water-soluble substance is derived is not particularly limited, but can be the same as the tobacco raw material described in "(Tobacco raw materials)" in "1. Tobacco preparations" above.

(2') Starch extracted from tobacco raw materials or other tobacco raw materials The types of starch and other components contained in the tobacco sheet are not particularly limited, but may be the same as the components described in "(2) Starch extracted from tobacco raw materials or other tobacco raw materials" in "1. Tobacco preparations" above.

The lower limit of the starch content in the tobacco sheet is not particularly limited, but is preferably 1% by weight or more, more preferably 2% by weight or more, and most preferably 2.5% by weight or more. The upper limit of the starch content in the tobacco sheet is not particularly limited, but is preferably 50% by weight or less, more preferably 40% by weight or less, and most preferably 25% by weight or less. The upper limit of the starch content in the tobacco sheet can be 20% by weight or less, 15% by weight or less, 10% by weight or less, 5% by weight or less, or 4% by weight or less. The upper and lower limits of the starch content in the tobacco sheet can be arbitrarily combined. When the starch content is 1% by weight or more, the strength of the tobacco sheet can be increased. In addition, with regard to the upper limit of the starch content (50% by weight or less), 50% by weight of starch, which is a viscous substance and functions as a binder, is sufficient, and even if the amount increases beyond this, the binder function is unlikely to be improved. Furthermore, by having the starch content in the tobacco sheet be within the numerical range between the above-mentioned lower and upper limits, the amount of starch functioning as a binder is appropriate, and the structure of the obtained tobacco sheet can be maintained.
A tobacco sheet can be formed by removing the medium from the tobacco formulation. Therefore, as described in "(4) Measurement of starch content" in the Examples below, the starch content (wt%) in the above-mentioned tobacco formulation (converted into solid content) can be considered to be equal to the starch content (wt%) in the tobacco sheet.

The tobacco sheet may include a component derived from a tobacco raw material. The component derived from a tobacco raw material may include a poorly water-soluble substance derived from the tobacco raw material described above, and starch extracted from the tobacco raw material described above.
The lower limit of the content of components derived from tobacco raw materials in the tobacco sheet is not particularly limited, but from the viewpoint of functioning as a base material, it is preferably 10% by weight or more, more preferably 15% by weight or more, most preferably 20% by weight or more, and can also be 75% by weight or more or 90% by weight or more. The upper limit of the content of components derived from tobacco raw materials in the tobacco sheet is not particularly limited, but can be 80% by weight or less, 70% by weight or less, or 50% by weight or less. The upper and lower limits of the content of components derived from tobacco raw materials in the tobacco sheet can be combined in any manner.
The content of components derived from the tobacco raw materials in the tobacco sheet can be calculated as the ratio of the weight of the tobacco raw materials to the total weight of the tobacco raw materials used and the externally added components.

(Other ingredients)
The tobacco sheet may further include an aerosol generating agent.
The aerosol generating agent may include, but is not limited to, glycerin, 1,2-propanediol, 1,3-propanediol, or a mixture of two or more thereof.
The content of the aerosol generating agent in the tobacco sheet is not particularly limited, but from the viewpoint of the amount of smoke produced when smoking, it is preferably 10 to 50% by weight, more preferably 15 to 45% by weight, and most preferably 20 to 25% by weight.

The tobacco sheet may further contain glucan, which is a type of binder described below.
The glucan may include, but is not limited to, tamarind gum, guar gum, locust bean gum, gellan gum, pullulan, or a mixture of two or more of these.
The glucan content in the tobacco sheet is not particularly limited, but from the viewpoint of moldability, it is preferably 0.1 to 5% by weight, more preferably 0.5 to 2% by weight, and most preferably 1.0 to 1.5% by weight.

The tobacco sheet may contain a binder. However, in the present invention, by using starch that functions as a binder, the tobacco sheet can be free of binders other than starch. Even if the tobacco sheet contains the binder as an impurity, the content of binders other than starch in the tobacco sheet can be 3% by weight or less, 1% by weight or less, or 0.5% by weight or less.

If it is desirable to have no additives, the tobacco sheet may be pulp-free. Even if the tobacco sheet contains pulp as an impurity, the pulp content in the tobacco sheet may be 3% by weight or less, 1% by weight or less, or 0.5% by weight or less.

The form of the tobacco sheet of the present invention is not particularly limited, and a paper-formed sheet, a cast sheet, or the like can be adopted. From the viewpoint of providing a low-density sheet, a cast sheet is preferable.
Details of the various types of tobacco sheets mentioned above are disclosed in "Encyclopedia of Tobacco, Tobacco Research Center, March 31, 2009."

The tobacco sheet of the present invention can be, but is not limited to, a molded product of the tobacco formulation described in the above section "1. Tobacco formulation."

3. Manufacturing method (Manufacturing method of tobacco formulation)
The tobacco formulation of the present invention is preferably produced by a method including a step of heating a tobacco raw material in a medium to extract the above-mentioned starch. The tobacco formulation may be one described in the above section "1. Tobacco formulation."

(1) Temperature The starch in the tobacco formulation is contained within the cell walls of the tobacco raw material. Therefore, a certain degree of high temperature is required to release the starch from within the cells. From this perspective, the temperature during extraction is preferably 100 to 125°C, more preferably 105 to 120°C, and most preferably 110 to 119°C. Furthermore, at this temperature, the above-mentioned cellulose can also be efficiently released outside the cells.

(2) Pressure A certain level of high pressure is required to release starch from within the cells. From this viewpoint, the average pressure during extraction is preferably 20 to 117 kPa, more preferably 50 to 110 kPa, and most preferably 85 to 95 kPa. The maximum pressure during extraction is preferably 70 to 117 kPa, more preferably 80 to 116.5 kPa, and most preferably 90 to 116.5 kPa. When the average pressure or maximum pressure is within the above numerical range, the above-mentioned cellulose can also be efficiently released outside the cells.

(3) Time A relatively long time is required to release starch from within the cells. From this viewpoint, the extraction treatment time is preferably 20 to 90 minutes, more preferably 60 to 80 minutes, and most preferably 65 to 70 minutes. Furthermore, when the extraction treatment time is within the above numerical range, the above-mentioned cellulose can also be efficiently released outside the cells.

(4) Number of times By repeating the extraction process, more starch can be released from inside the cells. From this viewpoint, the number of times of the extraction process can be 1 to 2 times, 3 to 4 times, or 5 to 10 times, and the more times the number of times, the more efficiently the starch can be released. Furthermore, when the number of times of the extraction process is within the above numerical range, the above-mentioned cellulose can also be efficiently released outside the cells.

(5) Atmosphere It is preferable to carry out the extraction of starch from tobacco raw materials in a closed system, since this can prevent a reduction in the flavor components contained in the tobacco raw materials.

(6) Grinding From the viewpoint of extraction efficiency, it is preferable that the surface area of the tobacco raw material to be extracted is large. Therefore, a step of grinding the tobacco raw material in advance may be provided, and the powdered tobacco raw material may be subjected to extraction. In this case, dry grinding is preferable. A known machine may be used for dry grinding. The particle size distribution of the powdered tobacco raw material is not limited, but it is preferable that it has a D90 of less than 500 μm, and more preferably a D90 of less than 100 μm. The lower limit of D90 is not limited, but is practically 5 μm or more.

Alternatively, the tobacco raw material may be ground simultaneously with the extraction. That is, the extraction can be carried out while the tobacco raw material is wet-ground. The wet-grinding is preferably carried out in a closed system. The particle size distribution of the wet-ground tobacco raw material is as described above.

The method for producing a tobacco formulation may further include a step of adding ingredients including an aerosol generating agent, a binder, or a combination thereof. The aerosol generating agent or binder may be those described in "(Other ingredients)" in "2. Tobacco Sheet" above.

The manufacturing method of the tobacco formulation may not include a step of adding other poorly water-soluble substances, including pulp. The other poorly water-soluble substances are poorly water-soluble substances other than the poorly water-soluble substances derived from the tobacco raw materials described above. In the present application, tobacco sheets can be formed without externally adding raw materials of other poorly water-soluble substances to the tobacco formulation.

(Production method of tobacco sheet)
The method for producing the tobacco sheet of the present invention is not particularly limited, and any known method such as a papermaking method, a casting method, etc. Of these methods, the casting method is preferred from the viewpoint of uniformity of the obtained sheet.

A method for producing a tobacco sheet of the present invention may comprise the steps of preparing a tobacco formulation by the method described above, and spreading and drying the tobacco formulation on a substrate.
When the tobacco raw material is pulverized in the step of preparing the above-mentioned tobacco formulation, the method of producing a tobacco sheet does not need to include a step of pulverizing the tobacco formulation.

<Tobacco sheet molding method (casting method)>
An example of a method for forming a tobacco sheet by a casting method (slurry method) includes a method including the following steps.
(1) A step of mixing ground aged tobacco with water, an optional pulp, and an optional binder to obtain a mixture (homogenization step).
(2) The mixture is spread (cast) into a thin sheet and dried to form a tobacco sheet.
When forming a tobacco sheet by this method, a step may be added in which a slurry of water, pulp, binder, and crushed tobacco leaves is mixed with ultraviolet light or X-rays to remove some of the components such as nitrosamines.

The shape of the tobacco sheet can be adjusted as appropriate, but in one embodiment, the thickness is 50 to 500 μm. The tobacco sheet can be chopped to produce shreds or strands. The tobacco sheet can also be pulverized to produce powder.

4. Tobacco Filler and Smoking Article The tobacco filler of the present invention comprises the tobacco sheet described above.
Furthermore, the smoking article of the present invention includes the above tobacco filler.
The smoking article of the present invention may be a non-combustion heating smoking article.

In this application, "smoking article" means an inhalation article that allows the user to enjoy a flavor by inhaling. Smoking articles can be broadly divided into combustion-type smoking articles, such as conventional cigarettes, and non-combustion heat-type smoking articles.

Examples of combustible smoking articles include cigarettes, pipes, pipes, cigars, and cigarillos.

A non-combustion heated smoking article (heated smoking article) may be heated by a heating device separate from the article, or by a heating device integrated into the article. In the former smoking article (separate type), the non-combustion heated smoking article and the heating device are collectively referred to as a "non-combustion heated smoking system." An example of a non-combustion heated smoking system is described below with reference to Figures 1 and 2.

FIG. 1 is a schematic cross-sectional view showing an example of a non-combustion heat smoking system, showing the state before a heater 12 is inserted into the smoking segment 20A of a non-combustion heat smoking article 20. When in use, the heater 12 is inserted into the smoking segment 20A. FIG. 2 is a cross-sectional view of a non-combustion heat smoking article 20.

As shown in FIG. 1, the non-combustion heat smoking system includes a non-combustion heat smoking article 20 and a heating device 10 that heats the smoking segment 20A from the inside. However, the non-combustion heat smoking system is not limited to the configuration shown in FIG. 1.

The heating device 10 shown in FIG. 1 includes a body 11 and a heater 12. Although not shown, the body 11 may include a battery unit and a control unit. The heater 12 may be an electric resistance heater, and is inserted into the smoking segment 20A to heat the smoking segment 20A.

In FIG. 1, the smoking segment 20A is heated from the inside, but the embodiment of the non-combustion heating smoking article 20 is not limited to this, and in another embodiment, the smoking segment 20A is heated from the outside.

The heating temperature by the heating device 10 is not particularly limited, but is preferably 400°C or less, more preferably 50 to 400°C, and even more preferably 150 to 350°C. The heating temperature refers to the temperature of the heater 12 of the heating device 10.

As shown in FIG. 2, the non-combustion heat smoking article 20 (hereinafter simply referred to as "smoking article 20") has a cylindrical shape. The circumferential length of the smoking article 20 is preferably 16 mm to 27 mm, more preferably 20 mm to 26 mm, and even more preferably 21 mm to 25 mm. The overall length (horizontal length) of the smoking article 20 is not particularly limited, but is preferably 40 mm to 90 mm, more preferably 50 mm to 75 mm, and even more preferably 50 mm to 60 mm.

The smoking article 20 is composed of a smoking segment 20A, a filter portion 20C that forms the mouthpiece, and a connecting portion 20B that connects these.

The smoking segment 20A is cylindrical, and its overall length (length in the axial direction) is, for example, preferably 5 to 100 mm, more preferably 10 to 50 mm, and even more preferably 10 to 25 mm. The cross-sectional shape of the smoking segment 20A is not particularly limited, but can be, for example, circular, elliptical, polygonal, etc.

The smoking segment 20A has a smoking composition sheet or material derived therefrom 21 and a wrapper 22 wrapped around it.

The filter section 20C has a cylindrical shape. The filter section 20C has a rod-shaped first segment 25 filled with cellulose acetate fiber and a rod-shaped second segment 26 similarly filled with cellulose acetate fiber. The first segment 25 is located on the smoking segment 20A side. The first segment 25 may have a hollow portion. The second segment 26 is located on the mouthpiece side. The second segment 26 is solid. The first segment 25 is composed of a first filling layer (cellulose acetate fiber) 25a and an inner plug wrapper 25b wrapped around the first filling layer 25a. The second segment 26 is composed of a second filling layer (cellulose acetate fiber) 26a and an inner plug wrapper 26b wrapped around the second filling layer 26a. The first segment 25 and the second segment 26 are connected by an outer plug wrapper 27. The outer plug wrapper 27 is adhered to the first segment 25 and the second segment 26 with a vinyl acetate emulsion adhesive or the like.

The length of the filter portion 20C can be, for example, 10 to 30 mm, the length of the connecting portion 20B can be, for example, 10 to 30 mm, the length of the first segment 25 can be, for example, 5 to 15 mm, and the length of the second segment 26 can be, for example, 5 to 15 mm. These lengths of each segment are just examples and can be changed as appropriate depending on manufacturing suitability, required quality, the length of the smoking segment 20A, etc.

For example, the first segment 25 (center hole segment) is composed of a first filling layer 25a having one or more hollow portions, and an inner plug wrapper 25b that covers the first filling layer 25a. The first segment 25 has the function of increasing the strength of the second segment 26. The first filling layer 25a of the first segment 25 is densely packed with, for example, cellulose acetate fibers. A plasticizer containing triacetin is added to the cellulose acetate fibers in an amount of, for example, 6 to 20% by mass relative to the mass of the cellulose acetate, and the fibers are hardened. The hollow portion of the first segment 25 has an inner diameter of, for example, φ1.0 to φ5.0 mm.

The first filling layer 25a of the first segment 25 may be constructed with, for example, a relatively high fiber packing density, or may be equivalent to the fiber packing density of the second filling layer 26a of the second segment 26 described below. Therefore, during inhalation, air and aerosol flow only through the hollow portion, and almost no air or aerosol flows through the first filling layer 25a. For example, if it is desired to reduce the loss of aerosol components due to filtration in the second segment 26, the length of the second segment 26 can be shortened and the first segment 25 can be lengthened accordingly.

Replacing the shortened second segment 26 with the first segment 25 is effective in increasing the amount of aerosol components delivered. Because the first filling layer 25a of the first segment 25 is a fiber-filled layer, the feel from the outside during use does not cause discomfort to the user.

The second segment 26 is composed of a second packed layer 26a and an inner plug wrapper 26b that covers the second packed layer 26a. The second segment 26 (filter segment) is packed with cellulose acetate fibers at a typical density and has typical filtering performance for filtering aerosol components.

The filtering performance for filtering the aerosol (mainstream smoke) emitted from the smoking segment 20A may be different between the first segment 25 and the second segment 26. At least one of the first segment 25 and the second segment 26 may contain a flavoring. The structure of the filter portion 20C is arbitrary, and may be a structure having multiple segments as described above, or may be composed of a single segment. The filter portion 20C may also be composed of one segment. In this case, the filter portion 20C may be composed of either the first segment or the second segment.

The connecting part 20B is cylindrical. The connecting part 20B has a cardboard tube 23 formed into a cylindrical shape, for example, from cardboard. The connecting part 20B may be filled with a cooling material for cooling the aerosol. An example of the cooling material is a sheet of a polymer such as polylactic acid, which can be folded and filled. Furthermore, a support part may be provided between the smoking segment 20A and the connecting part 20B to prevent the position of the smoking segment 20A from fluctuating. The support part may be made of a known material, such as a center hole filter like the first segment 25.

The wrapper 28 is wrapped around the outside of the smoking segment 20A, the connecting portion 20B, and the filter portion 20C in a cylindrical shape, connecting them together. One side (inner surface) of the wrapper 28 is coated entirely or almost entirely with a vinyl acetate emulsion adhesive, except for the area near the ventilation hole portion 24. The multiple ventilation hole portions 24 are formed by laser processing from the outside after the smoking segment 20A, the connecting portion 20B, and the filter portion 20C are integrated by the wrapper 28.

The ventilation hole section 24 has two or more through holes penetrating the connecting section 20B in the thickness direction. The two or more through holes are formed so as to be arranged radially when viewed from an extension of the central axis of the smoking article 20. In this embodiment, the ventilation hole section 24 is provided in the connecting section 20B, but may be provided in the filter section 20C. In addition, in this embodiment, the two or more through holes of the ventilation hole section 24 are arranged in one row at a fixed interval on one ring, but may be arranged in two rows at a fixed interval on two rings, or one or two rows of the ventilation hole section 24 may be arranged discontinuously or irregularly. When a user holds the mouthpiece in his/her mouth and inhales, outside air is taken into the mainstream smoke through the ventilation hole section 24. However, the ventilation hole section 24 does not have to be provided.

[Example 1]
(Preparation of tobacco formulations and tobacco sheets)
1000 g of flue-cured tobacco was processed in a small grinder (High Speed Mill, manufactured by LabNect Co., Ltd.) to obtain a flue-cured tobacco coarsely ground product (hereinafter referred to as "tobacco sample"). 300 g of the obtained tobacco sample and 1000 g of water were put into a switchable pressure cooker (Quick Eco, manufactured by Pearl Metal Co., Ltd.) and mixed, and the obtained mixture was then boiled under the following conditions.
Pressure: Maximum pressure 90 kPa, average pressure 80 kPa
Temperature: 119°C
Time: 30 minutes

1000 g of water was added to the mixture after the boiling treatment in the pressure cooker and mixed, and the resulting mixture was then subjected to a second boiling treatment under the following conditions.
Pressure: Maximum pressure 90 kPa, average pressure 80 kPa
Temperature: 119°C
Time: 30 minutes

The mixture after the second boiling treatment was cooled to 35°C, and the moisture content of the mixture was measured using an IR moisture meter (MB45, OHAUS) based on the IR moisture measurement method, which was 80% by weight.

After measuring the moisture content in the pressure cooker, 15 g of guar gum, 6 g of CMC (carboxymethylcellulose), and 43.5 g of glycerin were added and mixed to obtain a mixed liquid. 800 g of the resulting mixed liquid was sampled, and while adding 800 g of water, it was treated with a defibrator (high-speed dispersion high shear mixer, manufactured by Silverson) to carry out wet pulverization and extraction processing. The wet pulverization conditions were as follows.
Rotational speed: 7000 rpm
Time: 10 minutes * Slowly add 800g of water to the above mixture over a period of 10 minutes.

The above wet grinding and extraction process produced a suspension (tobacco preparation) containing poorly water-soluble substances derived from flue-cured tobacco, starch extracted from flue-cured tobacco, and water as a medium.

Next, the suspension obtained as described above was spread on a stainless steel plate and naturally dried at room temperature to produce a slurry sheet (tobacco sheet) (thickness: 1 mm).
The content of components derived from the tobacco raw materials in the tobacco sheet of Example 1 was calculated as the percentage of the weight of the tobacco raw materials to the total weight of the tobacco raw materials used (tobacco sample) and the externally added components (guar gum, CMC, and glycerin), and was found to be 82.3% by weight.

[Example 2]
(Preparation of tobacco formulations and tobacco sheets)
300 g of the tobacco sample described in [Example 1] above and 1000 g of water were mixed in a pressure cooker (Quick Eco, manufactured by Pearl Metal Co., Ltd.), and the resulting mixture was boiled under the following conditions. The boiling process was repeated twice.
Pressure: Maximum pressure 90 kPa, average pressure 80 kPa
Temperature: 119°C
Time: 30 minutes

1000 g of water was added to the mixture after the boiling treatment in the pressure cooker and mixed, and the resulting mixture was then subjected to a third boiling treatment under the following conditions.
Pressure: Maximum pressure 90 kPa, average pressure 80 kPa
Temperature: 119°C
Time: 30 minutes

The mixture after the third boiling treatment was cooled to 25°C, and the moisture content of the mixture was measured using an IR moisture meter (MB45, OHAUS) based on the IR moisture measurement method, which was 80% by weight.

After measuring the moisture content in the pressure cooker, 15 g of guar gum, 6 g of CMC (carboxymethylcellulose), and 43.5 g of glycerin were added and mixed to obtain a mixed liquid. 800 g of the resulting mixed liquid was sampled, and while adding 800 g of water, it was treated with a defibrator (high-speed dispersion high shear mixer, manufactured by Silverson) to carry out wet grinding and extraction processing. The wet grinding conditions were as follows.
Rotational speed: 4500 rpm
Time: 20 minutes * Slowly add 800g of water to the above mixture over a period of 20 minutes.

The above wet grinding and extraction process produced a suspension (tobacco preparation) containing poorly water-soluble substances derived from flue-cured tobacco, starch extracted from flue-cured tobacco, and water as a medium.

Next, the suspension obtained as described above was spread on a stainless steel plate and naturally dried at room temperature to produce a slurry sheet (tobacco sheet) (thickness: 1 mm).
The content of components derived from the tobacco raw materials in the tobacco sheet of Example 2 was calculated as the ratio of the weight of the tobacco raw materials to the total weight of the tobacco raw materials used (tobacco sample) and the externally added components (guar gum, CMC, and glycerin), and was found to be 82.3% by weight.

[Comparative Example]
(Preparation of tobacco formulations and tobacco sheets)
300 g of the tobacco sample (ground product) described in [Example 1] above and 1000 g of water were homogenized using a homogenizer (ROBOMICS, manufactured by Tokushu Kika Kogyo Co., Ltd.) to obtain a mixture. 15 g of glycerin, 15 g of pulp (particle size: 900 μm (weighted average particle size)), and 15 g of guar gum as a binder were added to 1300 g of the obtained mixture and mixed to obtain a suspension (tobacco preparation). The obtained suspension was spread on a stainless steel plate and naturally dried at room temperature to produce a slurry sheet (tobacco sheet) (thickness: 1 mm).
The content of components derived from the tobacco raw materials in the tobacco sheet of the comparative example was calculated as the percentage of the weight of the tobacco raw materials to the total weight of the tobacco raw materials used (tobacco sample) and the externally added components (glycerin, pulp, and guar gum), and was found to be 86.9% by weight.

(1) Measurement of particle size of poorly water-soluble substance 2.5 g (1 g solids weight) of the suspension obtained in Example 1 (Preparation of tobacco formulation and tobacco sheet) was weighed out and used as a sample suspension. A part of each of the slurry sheets obtained in Example 1 and Comparative Example (Preparation of tobacco formulation and tobacco sheet) was cut out to obtain 1 g of sample slurry sheets.
40 ml of water was added to 2.5 g (1 g solids weight) of the sample suspension of Example 1 and 1 g of the sample slurry sheets of Example 1 and Comparative Example, and then the mixture was heated at 80° C. for 30 minutes to obtain a mixture. The mixture was centrifuged at 5530 G for 5 minutes using a centrifuge (refrigerated centrifuge, manufactured by KUBOTA Corporation), and the supernatant was removed to obtain 0.5 g of precipitate.
To the resulting 0.5 g of precipitate, 40 ml of water was added, and the mixture was heated at 80° C. for 30 minutes to obtain a mixture. The mixture was centrifuged at 5530 G for 5 minutes using a centrifuge (refrigerated centrifuge, manufactured by KUBOTA) and the supernatant was removed to obtain 0.4 g of precipitate. The steps of adding water, heating and mixing, centrifugation, and removing the supernatant were repeated twice more in the same manner as above to obtain 0.3 g of precipitate.
40 ml of 95% ethanol aqueous solution was added to 0.3 g of the precipitate obtained, and then mixed to obtain a dispersion of the precipitate. The resulting dispersion was measured using a wet particle size measuring device (HORIBA Partica 960, Horiba, Ltd.), and the obtained particle size (D90) value was taken as the measured particle size (primary particle size) of the poorly water-soluble substance. The results are shown in Table 1.

(2) Measurement of water content The water content in the suspension (tobacco formulation) obtained in Examples 1 and 2 (Preparation of tobacco formulation and tobacco sheet) was measured using an IR moisture meter (MB45, OHAUS) based on the IR moisture measurement method. The results are shown in Table 1.

(3) Measurement of content of poorly water-soluble substances 25 g (10 g solids) of the suspension obtained by the above Examples 1 and 2 (preparation of tobacco formulation and tobacco sheet) was weighed and used as a sample suspension. 40 ml of 80°C hot water was added to 2.5 g (1 g solids) of each sample suspension of Examples 1 and 2, and the mixture was stirred for 30 minutes and centrifuged at 5530G for 5 minutes using a centrifuge (cooled centrifuge, manufactured by KUBOTA). After centrifugation, the supernatant was removed to obtain 0.5 g of precipitate. The steps of adding hot water, mixing, centrifugation, and removing the supernatant were repeated three more times for the obtained 0.5 g of precipitate in the same manner as above to obtain a precipitate, and the obtained precipitate was dried for 30 minutes at 80°C, and the weight of the obtained dried product was measured. The ratio (wt%) of the weight of the obtained dried material to the weight (1 g) of the solid content of the suspension used above was calculated, and the obtained value was taken as the content (wt%) of the poorly water-soluble substance in the suspension (converted into solid content). The results are shown in Table 1.
Since the slurry sheet is formed by removing only the water medium from the suspension, the content (wt %) of the poorly water-soluble substance in the suspension obtained as described above (converted into solids content) can be regarded as equal to the content (wt %) of the poorly water-soluble substance in the slurry sheet.

(4) Measurement of starch content The suspension obtained by the above Example 1 and Comparative Example (preparation of tobacco formulation and tobacco sheet): 2.5 g (1 g in solid weight) was weighed and used as a sample suspension. Each sample suspension: 2.5 g (1 g in solid weight) of these Example 1 and Comparative Example was homogenized and pulverized using a homogenizer (ROBOMICS, manufactured by Tokushu Kika Kogyo Co., Ltd.) to obtain a powdery product. 100 mg of the obtained powdery product was weighed and placed in a 15 ml centrifuge tube (SUMILON (registered trademark), manufactured by Sumitomo Bakelite Co., Ltd.), and 10 ml of MilliQ water at room temperature was added, and then ultrasonic waves were applied for 10 minutes at room temperature using an ultrasonic device (BRANSONIC, manufactured by Emerson Japan Co., Ltd.) to perform extraction processing, and a mixed liquid was obtained. The obtained mixed liquid was centrifuged for 5 minutes at 4 ° C. and 8000 rpm using a centrifuge (cooled centrifuge, manufactured by KUBOTA Co., Ltd.). After centrifugation, the supernatant was removed to obtain a precipitate. The precipitate was mixed with 7 ml of dimethyl sulfoxide (DMSO) and stirred with a vortex mixer to obtain a suspension. The resulting suspension was heated (extracted) at 100°C for 5 minutes to dissolve the starch in the precipitate into DMSO. The suspension after the extraction was quenched with ice water, and then centrifuged at 3000G for 5 minutes using the above-mentioned centrifuge. After centrifugation, 5 ml of the supernatant was collected and placed in a 50 ml measuring flask. The supernatant in the measuring flask was then subjected to the same process as above, including extraction at 100°C for 5 minutes, quenching with ice water, centrifugation at 3000G for 5 minutes, and collection and introduction of 5 ml of the supernatant into a 50 ml measuring flask, which were repeated three times to obtain DMSO in which starch was dissolved (in a measuring flask).
MilliQ water was added to the obtained DMSO: 20 ml, and the mixture was made up to 100 ml and stirred, and then 100 ml of the obtained sample was transferred to a glass test tube. 500 μl of 5% phenol solution was added to the sample in the test tube, and then 2.5 ml of concentrated sulfuric acid was slowly added to decompose the starch in the sample into monosaccharides. The obtained solution was then stirred with a vortex mixer and allowed to stand for 20 minutes. The absorbance of the solution in the test tube after standing was measured at a wavelength of 490 nm using a spectrophotometer (SP-300, manufactured by Optima Co., Ltd.). For the calibration curve, glucose was dissolved in 5% phenol solution, and the absorbance was analyzed in the same manner. The glucose concentrations were 0 μg/ml, 10 μg/ml, 20 μg/ml, 50 μg/ml, and 100 μg/ml, respectively. Based on the obtained absorbance measurements and the calibration curve, the ratio (wt%) of the weight of starch to the weight (1 g) of the solid content of the suspension used was calculated, and this was taken as the starch content (wt%). The results are shown in Table 1.
Since the slurry sheet is formed by removing only the water medium from the suspension, the starch content (wt %) (solid content equivalent) in the suspension obtained as described above can be considered to be equal to the starch content (wt %) in the slurry sheet.

From the results of [Example 1] and [Example 2] above, it was found that the tobacco formulations of Examples 1 and 2 can be used to produce tobacco sheets without adding other poorly water-soluble raw materials such as pulp. When obtaining the tobacco formulations of Examples 1 and 2, starch contained in the tobacco raw materials is extracted by boiling treatment, and poorly water-soluble substances are obtained as residues of the tobacco raw materials. The poorly water-soluble substances derived from the tobacco raw materials obtained in this manner improve the moldability and strength of the tobacco sheet in place of other poorly water-soluble substances, so that the tobacco sheet can be formed without adding other poorly water-soluble substances. Since the tobacco formulations of Examples 1 and 2 do not require the external addition of other poorly water-soluble raw materials such as pulp, it is possible to increase the amount of tobacco raw materials and glycerin added, which increases the freedom of design of the tobacco formulation and tobacco sheet.
In addition, as shown in Table 1, the particle size (μm) of the poorly water-soluble substance was measured to be 22.4 μm for the suspension in Example 1 and 24.2 μm for the slurry sheet, indicating that the particle size was extremely small after the grinding and extraction process. In Example 1, the particle size of the poorly water-soluble substance was thus small, which is believed to increase the surface area that bonds tobacco particles together and improve the strength of the slurry sheet.

On the other hand, the tobacco formulation of the comparative example has pulp, a poorly water-soluble substance, added to it in order to produce a tobacco sheet. If pulp were not added to the tobacco formulation of the comparative example, the sheet shape would not be able to be maintained, and tobacco sheet would not be able to be produced. In the comparative example, the particle size of the poorly water-soluble substance derived from the tobacco raw materials is large because the product does not go through the crushing and extraction process. As a result, the surface area for bonding the tobacco particles together is insufficient, and pulp must be added to improve the strength of the slurry sheet.

The results in Table 1 also show that the content of poorly water-soluble substances in the suspension of Example 2 (12% by weight) is lower than the content of poorly water-soluble substances in the suspension of Example 1 (30% by weight). In this regard, it is believed that because the boiling treatment was performed more times in Example 2 than in Example 1, more components such as starch could be extracted from the tobacco raw material, and as a result, the amount measured as poorly water-soluble substances decreased accordingly. The results of Examples 1 and 2 show that the amount of extracted components such as starch can be controlled by changing the conditions of the boiling treatment.

Furthermore, from the results in Table 1, it was confirmed that the starch content in the suspension of Example 1 was 3.04% by weight, which is higher than the starch content in the suspension of the Comparative Example, which was 2.47% by weight. This is thought to be because, compared to the suspension of the Comparative Example, which was not subjected to a boiling treatment, the suspension of Example 1 was subjected to a boiling treatment, and therefore more starch was extracted from the tobacco raw material and released into the suspension. When the suspension contains a large amount of starch, as in Example 1, the starch functions as a binder that bonds poorly water-soluble substances together, making it possible to produce a tobacco sheet with greater strength.

As described above, the tobacco formulation of the present invention uses tobacco raw materials and can produce tobacco sheets without the external addition of other poorly water-soluble substance raw materials.

10 heating device 11 body 12 heater
20 Non-combustion heating smoking article 20A Smoking segment 20B Connecting part 20C Filter part
21 Smoking composition sheet or material derived therefrom 22 Wrapper 23 Paper tube 24 Ventilation hole portion 25 First segment 25a First filling layer 25b Inner plug wrapper 26 Second segment 26a Second filling layer 26b Inner plug wrapper 27 Outer plug wrapper 28 Wrapper

Claims (20)

(1) Poorly water-soluble substances derived from tobacco raw materials,
(2) a starch extracted from said tobacco material or from other tobacco materials; and (3) a vehicle. A tobacco sheet comprising: (1') a poorly water-soluble substance derived from a tobacco raw material; and (2') a starch extracted from the tobacco raw material or another tobacco raw material. The tobacco sheet according to claim 2, wherein the starch is a starch extracted from the tobacco raw material. The tobacco sheet according to claim 2 or 3, wherein the starch is a soluble starch. The tobacco sheet according to any one of claims 2 to 4, wherein the primary particle size of the poorly water-soluble substance is 100 μm or less. The tobacco sheet according to any one of claims 2 to 5, wherein the starch content in the tobacco sheet is 10% by weight or less. The tobacco sheet according to any one of claims 2 to 6, wherein the tobacco raw material from which the poorly water-soluble substance is derived contains tobacco leaves. The tobacco sheet according to any one of claims 2 to 7, wherein the tobacco raw material from which the poorly water-soluble substance is derived contains an alkaloid. The tobacco sheet according to any one of claims 2 to 8, further comprising an aerosol generating agent. The tobacco sheet according to claim 9, wherein the aerosol generating agent comprises glycerin, 1,2-propanediol, 1,3-propanediol, or a mixture thereof. The tobacco sheet according to any one of claims 2 to 10, further comprising glucan. The tobacco sheet according to claim 11, wherein the glucan comprises tamarind gum, guar gum, locust bean gum, gellan gum, pullulan, or a mixture thereof. The tobacco sheet according to any one of claims 2 to 12, which does not contain pulp. The tobacco sheet according to any one of claims 2 to 13, which is a cast sheet. The tobacco sheet according to any one of claims 2 to 14, which is a molded product of the tobacco formulation according to claim 1. A tobacco filler comprising the tobacco sheet according to any one of claims 2 to 15. A smoking article comprising the tobacco filler according to claim 16. The smoking article according to claim 17, which is a non-combustion heat smoking article. The method for producing the tobacco formulation according to claim 1, further comprising a step of heating the tobacco raw material in the medium to extract the starch. A method for producing a tobacco sheet according to any one of claims 2 to 15, comprising the steps of: preparing the tobacco formulation by the method according to claim 19; and spreading the tobacco formulation on a substrate and drying it.