EP4721584A1

EP4721584A1 - Rolled sheet, tobacco filler, smoking product, and method for manufacturing rolled sheet

Info

Publication number: EP4721584A1
Application number: EP23939552.8A
Authority: EP
Inventors: Akihiro Koide
Original assignee: Japan Tobacco Inc
Current assignee: Japan Tobacco Inc
Priority date: 2023-05-30
Filing date: 2023-05-30
Publication date: 2026-04-08
Also published as: JPWO2024247073A1; WO2024247073A1; KR20250168662A; CN121001584A

Abstract

The present invention addresses the problem of providing a rolled sheet which can be manufactured at a low cost and has good thermal conductivity.

This rolled sheet contains calcium carbonate.

Description

TECHNICAL FIELD

The present invention relates to a rolled sheet, a tobacco filling material, a smoking article, and a method for producing a rolled sheet.

BACKGROUND ART

Synthetic tobacco, a tobacco material that has been artificially shaped into paper form using leaf tobacco as a starting material, is also called a tobacco sheet. Examples of known methods for producing tobacco sheets include a method of production via a sheet-forming (papermaking) process, a method of production via a slurry (casting) process, a method of production via a rolling (lamination) process, and a method of production via an extrusion process.

SUMMARY OF INVENTION

TECHNICAL PROBLEM

In the abovementioned sheet-forming and casting methods, the raw material composition has a high moisture content before being dried and formed into a sheet (e.g., the moisture content of the raw material composition in the casting method is approximately 80% W.B. (wet basis)). It is therefore necessary to supply a large amount of heat when the moisture content of the raw material composition is reduced to a predetermined numerical range by means of the drying process in order to form a sheet, and this increases production costs.
Meanwhile, the rolling method involves spreading and shaping a kneaded material having a low moisture content of approximately 50% W.B. or less, and the moisture content of the kneaded material before before being dried and formed into a sheet can be kept at a low level. Accordingly, it is possible to reduce the moisture content of the kneaded material to the predetermined numerical range using a small amount of heat when a sheet is formed.
Furthermore, it would be feasible to mix a substance having better thermal conductivity than the tobacco raw material with a tobacco material, for the purpose of further enhancing the functionality of a combustible smoking article or a heat-not-burn smoking article. In the case of a combustible smoking article, controlling thermal conductivity makes it possible to control static burning and burning from puffing. This can contribute to generating smoke components and controlling the number of puffs in a combustible smoking article. Furthermore, in the case of a heat-not-burn smoking article, a temperature distribution within a tobacco stick during heating can be controlled, which can contribute to generating aerosol components. The present inventors focused on calcium carbonate, which is used in the wrapping paper of combustible smoking articles, as a substance having such properties. Calcium carbonate is inexpensive and will also lead to further cost reductions.
Until now, there have been no instances of producing a tobacco sheet where the rolling method has been used and calcium carbonate has also been mixed.
As a result of thorough investigations carried out by the inventors of this application in light of the situation above, it was found that shaping is still possible when the rolling method is used and calcium carbonate is also mixed as a raw material in the production of a tobacco sheet. The problem addressed by the present invention lies in providing a rolled sheet which keeps production costs low and has good thermal conductivity.

SOLUTION TO PROBLEM

As a result of extensive research to solve the problem above, the present inventors found that the problem above can be solved by using the rolling method and also mixing calcium carbonate as a raw material, and thereby arrived at the present invention. Specific aspects of the present invention are as follows.

[1] A rolled sheet comprising calcium carbonate.
[2] The rolled sheet as disclosed in [1], wherein a particle size (D50) of the calcium carbonate is 0.07-80 µm.
[3] The rolled sheet as disclosed in [1] or [2], wherein a content of the calcium carbonate in the rolled sheet is 1-80 wt%.
[4] The rolled sheet as disclosed in any one of [1] to [3], further comprising a tobacco raw material.
[5] The rolled sheet as disclosed in any one of [1] to [4], further comprising a reinforcing material.
[6] The rolled sheet as disclosed in any one of [1] to [5], further comprising a thickener.
[7] The rolled sheet as disclosed in any one of [1] to [6], further comprising a humectant.
[8] The rolled sheet as disclosed in any one of [1] to [7], further comprising an aerosol-generating source.
[9] The rolled sheet as disclosed in any one of [1] to [8], further comprising a flavoring material, a colorant, a wetting agent, a preservative, or a combination thereof.
[10] A tobacco filling material comprising the rolled sheet as disclosed in any one of [1] to [9].
[11] A smoking article comprising the tobacco filling material as disclosed in [10].
[12] The smoking article as disclosed in [11], which is a combustible smoking article.
[13] The smoking article as disclosed in [11], which is a heat-not-burn smoking article.
[14] A method for producing the rolled sheet as disclosed in any one of [1] to [9], comprising: a step of preparing a composition comprising calcium carbonate; and a step of rolling then drying the composition.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention makes it possible to provide a rolled sheet which keeps production costs low and has good thermal conductivity.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 is a schematic view in cross section showing an example of a heat-not-burn smoking system.
Fig. 2 is a schematic view in cross section showing an example of a heat-not-burn smoking article.

DESCRIPTION OF EMBODIMENTS

The present invention will be described in detail below. As used in the present invention, the range "X-Y" includes X and Y as the end values.

1. Rolled sheet

A rolled sheet (laminated sheet) according to the present invention comprises calcium carbonate.
In the present invention, a rolled sheet which keeps production costs low and has good thermal conductivity is obtained by using the rolling method and by also mixing calcium carbonate as a raw material.
Rolled sheets are disclosed in detail in "Encyclopedia of Tobacco, Tobacco Academic Studies Center, March 31, 2009".

Calcium carbonate

There is no particular limitation as to the particle size (D50) of the calcium carbonate, but it is preferably 0.07-80 µm, more preferably 0.08-70 µm, and most preferably 0.1-50 µm. Good thermal conductivity is demonstrated as a result of the particle size (D50) of the calcium carbonate being within the numerical range above.
The particle size (D50) of the calcium carbonate can be measured based on dry laser diffractometry using a Mastersizer (manufactured by Spectris Inc., Malvern Panalytical).
There is no particular limitation as to the content of calcium carbonate in the rolled sheet, but it is preferably 1-80 wt%, more preferably 1.5-70 wt%, and most preferably 2-60 wt%.
The content of calcium carbonate in the rolled sheet may be a value based on % D.B. (dry basis) (weight percentage in terms of solids).
When the raw material composition (tobacco formulation) of the rolled sheet contains a medium such as water, the rolled sheet can be formed by removing the medium from the tobacco formulation. In this case, the content of calcium carbonate in the rolled sheet may be calculated on the basis of the content of calcium carbonate in the tobacco formulation, while taking account of the weight of medium which is removed.
Depending on the method of production, the calcium carbonate may be heavy calcium carbonate obtained by crushing and grading natural calcium carbonate, or it may be light calcium carbonate produced by chemical synthesis, but either of these may be used.

Tobacco raw material

The rolled sheet may further comprise a plant raw material, which is typically tobacco, and in particular a tobacco raw material.
A tobacco raw material is raw material derived from a tobacco plant, such as tobacco leaf, aged tobacco leaf, cut tobacco, tobacco powder, tobacco raw material parts other than leaves, such as midrib and stem waste, and processed or waste products obtained in the course of tobacco raw material processing. Tobacco leaf is a generic term for harvested tobacco leaves before they have been aged. One mode of aging includes curing. Cut tobacco is aged tobacco leaf, etc., that has been cut to a predetermined size.
Tobacco powder is tobacco leaves, etc., that have been ground. Plant raw materials other than tobacco, such as tea leaves and vegetables, may also be mixed with the tobacco raw material, or may be used alone.
A number of varieties of tobacco can be used as the tobacco raw material. Examples of tobacco varieties include yellow, Burley, orient, or native varieties, as well as Nicotiana tabacum and Nicotiana rustica varieties. These varieties can be used alone, but in order to obtain the intended flavor, they can also be blended for use over the course of the process from harvesting of tobacco leaves until the aged tobacco leaves are made into the various forms (that is, processed tobacco leaves) which are used in heat-not-burn tobacco products. Details on tobacco varieties are disclosed in "Encyclopedia of Tobacco, Tobacco Academic Studies Center, March 31, 2009".
There is no particular limitation as to the tobacco raw material, and it may comprise or consist of tobacco powder (ground whole tobacco leaf), midrib powder (midrib removed on its own and ground), or a mixture thereof. By using these components as the tobacco raw material, it is possible to sufficiently generate a tobacco aroma during use.
In terms of the size of the tobacco raw material, the cumulative 90% particle size (D90) in a volume-based particle size distribution, as measured by dry laser diffractometry, is preferably 200 µm or greater, more preferably 300 µm or greater, and even more preferably 500 µm or greater. There is no particular limitation as to the upper limit of the D90 range, but it may be 2000 µm or less, for example.
In terms of the size of the tobacco raw material, the cumulative 50% particle size (D50) in a volume-based particle size distribution, as measured by dry laser diffractometry, is preferably 40 µm or greater, more preferably 100 µm or greater, and even more preferably 200 µm or greater, from the perspective of further increasing the bulk of the tobacco sheet. There is no particular limitation as to the upper limit of the D50 range, but it may be 1000 µm or less, for example. It should be noted that in the present embodiment, the D90 and D50 can be measured by dry laser diffractometry using, for example, a Mastersizer (tradename, by Spectris Inc., Malvern Panalytical).
There is no particular limitation as to the content of the tobacco raw material in the rolled sheet, but it is preferably 0.1-80 wt%, more preferably 1.0-75 wt%, and most preferably 1.5-70 wt%. The content of the tobacco raw material being within the numerical range above allows a tobacco aroma to be imparted during use.
The content of tobacco raw material in the rolled sheet may be a value based on % D.B. (dry basis).

Reinforcing material

The rolled sheet may further comprise a reinforcing material.
There is no particular limitation as to the reinforcing material, but it may comprise or consist of pulp or a fibrous substance such as insoluble fibers/fibrous synthetic cellulose, a liquid substance such as a pectin suspension which has a surface coating function that forms a film on drying, or else a mixture of two or more of the above. Pulp is preferred among these. The physical properties of the rolled sheet can be improved by using pulp.
There is no particular limitation as to the pulp, and it may comprise or consist of fibrous pulp, cotton pulp, powder pulp, or a mixture of two or more of these. Fibrous pulp is preferred among these. The physical properties of the rolled sheet can be improved by using fibrous pulp.
There is no particular limitation as to the content of the reinforcing material in the rolled sheet, but it is preferably 1-60 wt%, more preferably 1.5-55 wt%, and most preferably 2-50 wt%. The physical properties of the rolled sheet can be improved as a result of the content of the reinforcing material being within the numerical range above.
The content of reinforcing material in the rolled sheet may be a value based on % D.B. (dry basis).

Thickener

The rolled sheet may further comprise a thickener.
There is no particular limitation as to the thickener, but polysaccharides, proteins and synthetic polymers, etc. may be cited, for example. One type thereof may be used, or two or more types may be used in combination. Examples of polysaccharides that may be cited include cellulose derivatives and naturally derived polysaccharides.
Examples of cellulose derivatives include cellulose ethers such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxymethyl ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, benzyl cellulose, trityl cellulose, cyanoethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, and aminoethyl cellulose; organic acid esters such as cellulose acetate, cellulose formate, cellulose propionate, cellulose butyrate, cellulose benzoate, cellulose phthalate, and tosyl cellulose; and inorganic acid esters such as cellulose nitrate, cellulose sulfate, cellulose phosphate, and cellulose xanthate. One type thereof may be used, or two or more types may be used in combination.
Examples of naturally derived polysaccharides that may be cited include plant-derived polysaccharides such as guar gum, tara gum, roasted bean gum, tamarind seed gum, pectin, gum arabic, tragacanth gum, gum karaya, gum ghatti, arabinogalactan, linseed gum, cassia gum, psyllium seed gum, and Artemisia sphaerocephala seed gum; algae-derived polysaccharides such as carrageenan, agar, alginic acid, propylene glycol alginate, furcelleran, and Colpomenia sinuosa extract; microbially-derived polysaccharides such as xanthan gum, gellan gum, curdlan, pullulan, Agrobacterium succinoglycan, welan gum, macrophomopsis gum, and rhamsan gum; crustacean-derived polysaccharides such as chitin, chitosan, and glucosamine; and starches such as starch, sodium starch glycolate, pregelatinized starch, corn starch, and dextrin; and polydextrin. One type thereof may be used, or two or more types may be used in combination.
Examples of proteins that may be cited include cereal proteins such as wheat gluten and rye gluten. Examples of synthetic polymers that may be cited include polyphosphoric acid, sodium polyacrylate, and polyvinylpyrrolidone. One type thereof may be used, or two or more types may be used in combination.
There is no particular limitation as to the content of the thickener in the rolled sheet, but it is preferably 0.1-15 wt%, more preferably 0.2-13 wt%, and most preferably 0.5-12 wt%. The shape of the rolled sheet is readily ensured as a result of the content of the thickener being within the numerical range above.
The content of thickener in the rolled sheet may be a value based on % D.B. (dry basis).

Humectant

The rolled sheet may further comprise a humectant.
There is no particular limitation as to the humectant, and it may comprise or consist of sorbitol, erythritol, xylitol, maltitol, lactitol, mannitol, or reduced maltose syrup, etc., or a mixture of two or more thereof.
There is no particular limitation as to the content of the humectant in the rolled sheet, but it is preferably 0.1-15 wt%, more preferably 0.2-12 wt%, and most preferably 0.5-10 wt%. The quality of the rolled sheet is readily maintained as a result of the content of the humectant being within the numerical range above.
The content of humectant in the rolled sheet may be a value based on % D.B. (dry basis).

Aerosol-generating source

The rolled sheet may further comprise an aerosol-generating source.
There is no particular limitation as to the aerosol-generating source, but it may comprise glycerol, 1,2-propanediol, 1,3-propanediol, or a mixture of two or more thereof. Glycerol is preferred among these. A good quality aerosol can be generated by using glycerol.
There is no particular limitation as to the content of the aerosol-generating source in the rolled sheet, but from the perspective of generating a sufficient amount of aerosol and achieving a good flavor, the content thereof is normally 3 wt% or greater, preferably 5 wt% or greater, and more preferably 7 wt% or greater, and is furthermore normally 50 wt% or less, preferably 40 wt% or less, and more preferably 25 wt% or less, with respect to the rolled sheet.
The content of aerosol-generating source in the rolled sheet may be a value based on % D.B. (dry basis).

Other components

The rolled sheet may further comprise, as other components, flavoring materials, colorants, wetting agents, preservatives, or combinations of two or more thereof.
The nature of these other components is not an issue, and liquids and solids may be cited, for example.
There is no particular limitation as to the type of flavoring material, and examples which may be cited include flavorings and gustatory materials from the perspective of imparting a pleasant taste.
Flavoring materials selected from among: tobacco extract and tobacco component, sugary and sugar-based flavors, licorice (glycyrrhiza), cocoa, chocolate, fruit juice and fruits, spices, liquors, herbs, vanilla, and flower-based flavors, etc., either alone or in combination, may be cited as suitable flavors of flavoring materials. Food powders or raw plant powders, such as cocoa, licorice, tea and vanilla beans may be added as flavors, either alone or in combination.
The flavoring materials may employ a wide range of types of flavoring components, such as disclosed, for example, in "Published Collection of Well-Known Prior Arts (Flavor and Fragrance)" (March 14, 2007, published by the JPO), "Saishin Koryo no Jiten [Encyclopedia of Scents - Latest Edition] (popular edition)" (February 25, 2012, edited by Soichi ARAI, Akio KOBAYASHI, Izumi YAJIMA, Michiaki KAWASAKI, Asakura Publishing Co., Ltd.), and "Tobacco Flavoring for Smoking Products" (June 1972, R.J. REYNOLDS TOBACCO COMPANY).
Flavoring materials selected from among: isothiocyanates, indole and derivatives thereof, ethers, esters, ketones, fatty acids, aliphatic higher alcohols, aliphatic higher aldehydes, aliphatic higher hydrocarbons, thioethers, thiols, terpene hydrocarbons, phenol ethers, phenols, furfural and derivatives thereof, aromatic alcohols, aromatic aldehydes, and lactones, either alone or in combination, may be cited as examples of the flavoring materials. The flavoring material may also be an ingredient producing a cooling/warming sensation.
Ingredients exhibiting sweetness, sourness, saltiness, an umami taste, bitterness, acerbity, and body, etc. may be cited as examples of gustatory materials.
Saccharides, sugar alcohols, and sweeteners, etc. may be cited as examples of ingredients exhibiting sweetness. Monosaccharides, disaccharides, oligosaccharides, and polysaccharides, etc. may be cited as examples of saccharides. Natural sweeteners and synthetic sweeteners, etc. may be cited as examples of sweeteners
Organic acids (and sodium salts thereof), etc. may be cited as examples of ingredients exhibiting sourness. Acetic acid, adipic acid, citric acid, lactic acid, malic acid, succinic acid, and tartaric acid, etc. may be cited as examples of organic acids.
Caffeine (extract), naringin, and wormwood extract, etc. may be cited as examples of ingredients exhibiting bitterness.
Sodium chloride, potassium chloride, sodium citrate, potassium citrate, sodium acetate, and potassium acetate, etc. may be cited as examples of ingredients exhibiting saltiness.
Sodium glutamate, sodium inosinate, and sodium guanylate, etc. may be cited as examples of ingredients exhibiting an umami taste.
Tannin and shibuol, etc. may be cited as examples of ingredients exhibiting acerbity.
There is no particular limitation as to the total content of these flavoring materials, and from the perspective of imparting a pleasant taste, the content is normally 10 ppm or greater, preferably 10,000 ppm or greater, and more preferably 50,000 ppm or greater, and is normally 250,000 ppm or less, preferably 200,000 ppm or less, more preferably 150,000 ppm or less, and even more preferably 100,000 ppm or less, for example.
Natural pigments and synthetic pigments, etc. may be cited as examples of colorants. Caramel, turmeric, red yeast rice, gardenia, safflower, carotene, marigold, and annatto, etc. may be cited as examples of natural pigments. Tar pigment and titanium oxide, etc. may be cited as examples of synthetic pigments.
Lipids (refined waxes, natural waxes, glycerin, medium-chain fatty acid triglycerides, and fatty acids (short-chain, medium-chain and long-chain fatty acids)), and polyols (glycerol and polyethylene glycol), etc. may be cited as examples of wetting agents. Acetic acid, benzoic acid, propionic acid, citric acid, lactic acid, malic acid, sorbic acid, tartaric acid (and salts thereof), and nisin, etc. may be cited as examples of preservatives.

Equilibrium moisture percentage

The equilibrium moisture percentage of the rolled sheet is preferably 9% or less, more preferably 7% or less, and most preferably 5% or less. The lower limit of the equilibrium moisture percentage may be set at greater than 0%, 1% or greater, or 2% or greater. The numerical ranges given above for the equilibrium moisture percentage may be combined in any way. When a rolled sheet having a low equilibrium moisture percentage is used in a tobacco filling material of a heat-not-burn smoking article in particular, it is possible to reduce the amount of heat taken up in evaporating water during heating, and an aerosol can be efficiently generated as a result.
The equilibrium moisture percentage of the rolled sheet can be measured in accordance with the procedure and method disclosed under "Equilibrium moisture percentage" in the "Evaluation of rolled sheet" section of "EXAMPLE 1" which will be described later.

2. Method for producing rolled sheet

The method for producing a rolled sheet according to the present invention is the method for producing a rolled sheet disclosed in section 1. above, which comprises: a step of preparing a composition comprising calcium carbonate, and a step of rolling then drying the composition.
The step of preparing a composition may further comprise a step of mixing calcium carbonate with components including a plant raw material such as a tobacco raw material, a reinforcing material, a thickener, a humectant, an aerosol-generating source, a flavoring material, a colorant, a wetting agent, a preservative, or a combination of two or more thereof. The calcium carbonate and the above components which are disclosed in the "1. Rolled sheet" section above may be used.
The step of preparing a composition may further comprise a step of adding a medium. There is no particular limitation as to such a medium, and it may comprise or consist of water, an alcohol, or an emulsifier, etc., or a mixture of two or more thereof. Water is preferred among these. The mixture can be homogeneously dispersed by using water.
The step of preparing a composition may further comprise a step of crushing the raw materials.
The step of preparing a composition may further comprise a step of mixing a liquid raw material into the abovementioned raw materials.
A rolling process can be adopted as the method for producing the rolled sheet of the present invention.
Method for forming rolled sheet (rolling process)
A method comprising the following steps, for example, may be cited as a method for forming a rolled sheet by means of a rolling process. The steps below may be adopted alone or in a combination of two or more.

(1) A step of mixing calcium carbonate with the crushed raw materials to obtain a mixture (homogenization step).
(2) A step of introducing the mixture between multiple rolling rollers in order to be rolled.
(3) A step of releasing the rolled shaped article from the rolling rollers with a doctor knife, feeding the article to a net conveyor, and drying the article in a dryer; or a step of feeding the rolled shaped article from one or more pairs of rolling rollers directly to a net conveyor, and drying the article in a dryer.

When a rolled sheet is formed by this method, the surface of the rolling rollers may be heated or cooled, and the speed of rotation of each rolling roller may be adjusted, depending on the intended purpose. Adjusting the intervals between rolling rollers will also allow a rolled sheet having the desired basis weight to be obtained.
The shape of the rolled sheet can be adjusted, as appropriate, but in one mode the thickness is 50-500 µm. The rolled sheet can be cut to produce shreds or strands. Furthermore, the rolled sheet can also be wound up to produce a bobbin shape. Furthermore, the rolled sheet can be crushed to produce a powder.

3. Tobacco filling material and smoking article

The tobacco filling material of the present invention comprises the rolled sheet described above.
Furthermore, the smoking article of the present invention comprises the tobacco filling material described above.
The smoking article of the present invention may be a combustible smoking article or a heat-not-burn smoking article.
The calcium carbonate content of the rolled sheet of the invention can be freely controlled between a low content and a high content while a homogeneous mixed state is maintained. A combustible smoking article may have a higher calcium carbonate content to the extent that an aerosol-generating source is not required, enabling better use of the features of the rolled sheet of the present invention.
A "smoking article" in the present application means an inhalation article with which a user experiences a flavor by means of inhalation. Smoking articles can be broadly divided into combustible smoking articles, typically conventional cigarettes, and heat-not-burn smoking articles.
Examples of combustible smoking articles which may be cited include cigarettes, pipes, oriental pipes, cigars, and cigarillos, etc.
Heat-not-burn smoking articles (heated smoking articles) may be heated by a heating device that is separate from the article, or by a heating device that is integrated with the article. In the former type of smoking article (separate heating device), the heat-not-burn smoking article and the heating device are also collectively referred to as a "heat-not-burn smoking system". An example of a heat-not-burn smoking system will be described below with reference to fig. 1 and 2.
Fig. 1 is a schematic view in cross section showing an example of a heat-not-burn smoking system, showing a state before a heater 12 is inserted into a smoking segment 20A of a heat-not-burn smoking article 20. During use, the heater 12 is inserted in the smoking segment 20A. Fig. 2 is a view in cross section of the heat-not-burn smoking article 20.
As shown in fig. 1, the heat-not-burn smoking system comprises the heat-not-burn smoking article 20, and a heating device 10 for heating the smoking segment 20A from the inside. However, the heat-not-burn smoking system is not limited to the configuration in fig. 1.
The heating device 10 shown in fig. 1 comprises a body 11 and the heater 12. The body 11 may comprise a battery unit and a control unit although these are not shown. The heater 12 may be a heater employing electrical resistance, and is inserted into the smoking segment 20A in order to heat the smoking segment 20A.
In fig. 1, the smoking segment 20A is heated from the inside, but the heat-not-burn smoking article 20 is not limited to this form, and the smoking segment 20A is heated from the outside in other forms.
There is no particular limitation as to the temperature of heating produced by the heating device 10, and it is preferably 400°C or less, more preferably 50-400°C, and even more preferably 150-350°C. The heating temperature refers to the temperature of the heater 12 of the heating device 10. There is no particular limitation as to the method of heating by the heating device, and it may also employ induction heating or microwave heating, etc., in addition to the heating produced by a heater noted above.
As shown in fig. 2, the heat-not-burn smoking article 20 (referred to below simply as the "smoking article 20") has a cylindrical shape. The circumferential length of the smoking article 20 is preferably 16 mm-27 mm, more preferably 20 mm-26 mm, and even more preferably 21 mm-25 mm. There is no particular limitation as to the total length (horizontal length) of the smoking article 20, but it is preferably 40 mm-90 mm, more preferably 50 mm-75 mm, and even more preferably 50 mm-60 mm.
The smoking article 20 comprises the smoking segment 20A, a filter portion 20C constituting a mouthpiece, and a connecting portion 20B connecting same.
The smoking segment 20A is cylindrical, and the total length (axial length) thereof is preferably 5-100 mm, more preferably 10-50 mm, and even more preferably 10-25 mm, for example. There is no particular limitation as to the cross-sectional shape of the smoking segment 20A, but it may be circular, elliptical, or polygonal, etc., for example.
The smoking segment 20A comprises a smoking segment sheet or a material 21 derived therefrom, and a wrapper 22 wrapped around the periphery thereof.
The filter portion 20C is cylindrical. The filter portion 20C has a rod-shaped first segment 25 filled with cellulose acetate fibers, and a rod-shaped second segment 26 similarly filled with cellulose acetate fibers. 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 comprises a first filling layer (cellulose acetate fibers) 25a, and an inner plug wrapper 25b wrapped around the first filling layer 25a. The second segment 26 comprises a second filling layer (cellulose acetate fibers) 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 means of an outer plug wrapper 27. The outer plug wrapper 27 is bonded to the first segment 25 and the second segment 26 by means of a vinyl acetate emulsion-based adhesive, etc.
The length of the filter portion 20C may be, for example, 10-30 mm, the length of the connecting portion 20B may be, for example, 10-30 mm, the length of the first segment 25 may be, for example, 5-15 mm, and the length of the second segment 26 may be, for example, 5-15 mm. The lengths of the individual segments are examples, and may be appropriately varied according to manufacturability, required quality, and length of the smoking segment 20A, etc.
For example, the first segment 25 (center hole segment) comprises the first filling layer 25a, which has one or more hollow portions, and the inner plug wrapper 25b which 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 filled with a high density of cellulose acetate fibers, for example. The cellulose acetate fibers are cured by adding, for example, 6-20 mass% of a triacetin-containing plasticizer to the mass of cellulose acetate. The hollow portion of the first segment 25 has an inner diameter of φ 1.0-φ 5.0 mm, for example.
The first filling layer 25a of the first segment 25 may be formed with a relatively high fiber packing density, or may have a fiber packing density comparable with that of the second filling layer 26a, for example. Therefore, when the user takes a draw, air and aerosol will flow only through the hollow portion, and virtually no air or aerosol will flow through the first filling layer 25a. If it is desirable to reduce a decrease in aerosol component caused by filtration in the second segment 26, then the second segment 26 can be shortened and the first segment 25 can also be proportionately lengthened, for example.
Replacing the shortened second segment 26 with the first segment 25 is effective for increasing the amount of aerosol component delivered. The first filling layer 25a of the first segment 25 is a fiber filled layer, and the user will therefore have little sense of incongruity when touching the outside during use.
The second segment 26 comprises the second filling layer 26a and the inner plug wrapper 26b which covers the second filling layer 26a. The second segment 26 (filter segment) is filled with cellulose acetate fibers at a typical density, and has typical aerosol component filtration performance.
The filtration performance in terms of filtering aerosol (mainstream smoke) released from the smoking segment 20A may differ between the first segment 25 and the second segment 26. The first segment 25 and/or the second segment 26 may contain a flavoring. The filter portion 20C may have any structure, and it may be a structure having multiple segments such as described above, or may consist of a single segment. The filter portion 20C may consist of one segment. In this case, the filter portion 20C may consist of either the first segment or the second segment.
The connecting portion 20B has a cylindrical shape. The connecting portion 20B comprises a paper tube 23 made of cardboard or the like, which is formed into a cylindrical shape, for example. The connecting portion 20B may be filled with a cooling member for cooling the aerosol. A sheet of a polymer such as polylactic acid may be cited as a cooling member, and this sheet can be folded before being used as a filling. A support for limiting shifts in the position of the smoking segment 20A may further be provided between the smoking segment 20A and the connecting portion 20B. The support may be formed by a well-known material such as a center hole filter, like the first segment 25.
A wrapper 28 is cylindrically wrapped around the outside of the smoking segment 20A, the connecting portion 20B, and the filter portion 20C to connect these components as a single piece. The entire surface, or substantially the entire surface, of one face (the inner face) of the wrapper 28 is coated with a vinyl acetate emulsion-based adhesive, except near a ventilation hole portion 24. After the smoking segment 20A, the connecting portion 20B, and the filter portion 20C have been formed into a single piece by the wrapper 28, a plurality of ventilation hole portions 24 are formed from the outside by means of laser processing.
The ventilation hole portions 24 comprise two or more through-holes penetrating the connecting portion 20B in the thickness direction. The two or more through-holes are formed in a radial arrangement as seen on a line of extension of the center axis of the smoking article 20. The ventilation hole portions 24 are provided in the connecting portion 20B in this embodiment, but may equally be provided in the filter portion 20C. Furthermore, the two or more through-holes constituting the ventilation hole portions 24 in this embodiment are provided in a single row at fixed intervals on one ring, but they may equally be provided in two rows at fixed intervals on two rings, or else one or two rows of ventilation hole portions 24 may be provided in a discontinuous or irregular arrangement. External air is taken into the mainstream smoke through the ventilation hole portions 24 when the user draws in while holding the mouthpiece in their mouth. However, the ventilation hole portions 24 need not be provided.

EXAMPLES

The present invention will be described experimentally through the following examples, but the following description should not be construed as limiting the scope of the present invention to those examples.

Raw materials

The raw materials used in this example are as follows.

Calcium carbonate: PCX-700 (manufactured by Shiraishi Kogyo Kaisha, Ltd., particle size (D50) 3.5 µm)
Tobacco powder: yellow variety, particle size (D50) 300 µm
Midrib powder: yellow variety, particle size (D50) 300 µm
Aerosol-generating source: glycerol
Reinforcing material: fibrous pulp (CANFOR PULP, dry fibrillated product, manufactured by Canfor Corp.)
Thickener: corn starch (Corn Alpha-Y, manufactured by Sanwa Starch Co., Ltd.), guar gum (Grindsted Guar 175, manufactured by DuPont Danisco)

Preparation of rolled sheet

EXAMPLE 1

The raw materials were introduced into a mixer (SUPER MIXER, SMV-20A, manufactured by Kawata Mfg. Co., Ltd.) to achieve the contents (% D.B. (Dry basis), weight percentage in terms of solids) of the raw materials shown in Table 1, then the raw materials were stirred for 2 minutes to obtain a mixture. The resulting mixture was kneaded with application of shear force through two pairs of metal rolls (roll pressure: 6.35 MPa, roll gap: 0.1 mm, calender rolls (manufactured by YURIROLL Co., Ltd.)), to obtain a kneaded material.
The kneaded material obtained in the manner described above was again applied to the two pairs of metal rolls and formed into a sheet which was then dried for 5 minutes at 90°C in a hot air circulation oven to produce a rolled sheet of Example 1 (thickness: 0.2 mm, width: 250 mm).

EXAMPLES 2-5 and COMPARATIVE EXAMPLE

Rolled sheets of Examples 2-5 and a comparative example (thickness: 0.2 mm, width: 250 mm) were produced in the same way as in Example 1 described above, except that the contents of the raw materials were changed as shown in Table 1.

Table 1

Table 1

[% DB]		Example 1	Example 2	Example 3	Example 4	Example 5	Comparative Example
Calcium carbonate		16	40	60	80	80
Tobacco powder		38	22	3			44
Midrib powder		26	18	2			36
Aerosol-generating source				15
Reinforcing material		12	12	12	12	12	12
Thickener	Corn starch	8	8	8		8	8
Thickener	Guar gum				8
Total		100	100	100	100	100	100

Evaluation of rolled sheet

The rolled sheets of Examples 2 and 5, and the comparative example obtained in the manner described above were evaluated as follows.

Equilibrium moisture percentage

The equilibrium moisture percentage was calculated for each rolled sheet. Specifically, the rolled sheets were cut to widths of 0.8 mm to obtain shreds. The resulting shreds were stored for 48 hours in a conditioned room at a relative humidity of 60% in order to condition the shreds, and the weight of the shreds after conditioning (before drying) was measured. The conditioned shreds were introduced into a rotary dryer at 100°C and dried for 1 hour, then the weight of the shreds after drying was measured. The equilibrium moisture percentage (% WB) was then calculated using the formula below. The results are shown in Table 2.

Equilibrium moisture percentage = (Wa-Wb)/Wa×100
Wa: Weight of shreds after conditioning (before drying)
Wb: Weight of shreds after drying

Table 2

	Example 2	Example 5	Comparative Example
Equilibrium moisture percentage [% WB]	6.0	2.5	10.1

It can be seen from Table 2 that the rolled sheets of Examples 2 and 5 which comprised calcium carbonate had a lower equilibrium moisture percentage than the rolled sheet of the comparative example which did not comprise calcium carbonate. When a rolled sheet having a low equilibrium moisture percentage is used in a tobacco filling material of a heat-not-burn smoking article in particular, it is possible to reduce the amount of heat taken up in evaporating water during heating, and an aerosol can be efficiently generated as a result. The rolled sheets of Examples 2 and 5 are superior to the rolled sheet of the comparative example in this regard.
The present invention thus enables a rolled sheet which keeps production costs low and has good thermal conductivity to be produced by using a rolling method and by also mixing calcium carbonate as a raw material.

REFERENCE SIGNS LIST

10 Heating device
11 Body
12 Heater
20 Heat-not-burn smoking article
20A Smoking segment
20B Connecting portion
20C Filter portion
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

A rolled sheet comprising calcium carbonate.
The rolled sheet as claimed in claim 1, wherein a particle size (D50) of the calcium carbonate is 0.07-80 µm.
The rolled sheet as claimed in claim 1 or 2, wherein a content of the calcium carbonate in the rolled sheet is 1-80 wt%.
The rolled sheet as claimed in any one of claims 1 to 3, further comprising a tobacco raw material.
The rolled sheet as claimed in any one of claims 1 to 4, further comprising a reinforcing material.
The rolled sheet as claimed in any one of claims 1 to 5, further comprising a thickener.
The rolled sheet as claimed in any one of claims 1 to 6, further comprising a humectant.
The rolled sheet as claimed in any one of claims 1 to 7, further comprising an aerosol-generating source.
The rolled sheet as claimed in any one of claims 1 to 8, further comprising a flavoring material, a colorant, a wetting agent, a preservative, or a combination thereof.
A tobacco filling material comprising the rolled sheet as claimed in any one of claims 1 to 9.
A smoking article comprising the tobacco filling material as claimed in claim 10.
The smoking article as claimed in claim 11, which is a combustible smoking article.
The smoking article as claimed in claim 11, which is a heat-not-burn smoking article.
A method for producing the rolled sheet as claimed in any one of claims 1 to 9, comprising: a step of preparing a composition comprising calcium carbonate; and a step of rolling then drying the composition.