Tobacco sheet, method for producing tobacco sheet, tobacco filler and smoking article

Abstract

The problem addressed by the present invention is to provide a tobacco sheet having improved water resistance. The tobacco sheet according to the invention comprises a carboxyalkyl cellulose onium salt.

Description

Technical Field

[0001] The present invention relates to a reconstituted tobacco, a method for producing a reconstituted tobacco, a tobacco filler, and a smoking article. Background Art

[0002] Synthetic tobacco, also known as reconstituted tobacco, is a tobacco material formed into a paper-like shape using tobacco leaves as raw materials. Examples of known methods for producing reconstituted tobacco include methods for producing reconstituted tobacco through a sheet forming (paper-making) process, a slurry (casting) process, a calendering (roll pressing) process, and an extrusion molding process.

[0003] In order to obtain a reconstituted tobacco with a predetermined strength, it is known that the particle size of the raw tobacco should be within a predetermined range. For example, PTL 1 discloses that the smaller the tobacco particle size, the larger the surface area of the combined tobacco particles, which increases the strength of the reconstituted tobacco. In particular, it is disclosed that a uniform sheet can be made by ensuring a mesh size of 60 to 400 (56 μm to 375 μm). PTL 2 and PTL 3 also describe that tobacco powder with a particle size of 30 to 120 μm should be used because when homogenized to a tobacco particle size of 150 μm or larger, the strength of the tobacco web is impaired. There is also a technique of using tobacco with a nano-scale particle size as a raw material for the sheet (PTL 4, PTL 5, and NPL 1).

[0004] Citation List

[0005] Patent Documents

[0006] PTL 1: EP 0565360

[0007] PTL 2: WO 2016 / 050471 A1

[0008] PTL 3: WO 2017 / 089589 A1

[0009] PTL 4: US 10196778 B2

[0010] PTL 5: WO 2016 / 013946 A1

[0011] Non-Patent Documents

[0012] NPL 1: “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 Summary of the invention

[0013] Technical issues

[0014] By using the tobacco particles with small particle size obtained as mentioned above and combining these tobacco particles with a certain adhesive to produce tobacco flakes with required physical properties.The tobacco flakes produced in this way are further cut into required tobacco shreds, which are then formed into, for example, tobacco rod shapes.When cutting tobacco flakes in this way, for the purpose of the intensity and moisture stability of the formed tobacco rod, water is added to the tobacco flakes before cutting the tobacco until a predetermined moisture content is reached.Yet, the inventor of the present application has found the following problem through extensive research: because the tobacco flakes have a predetermined moisture content because of adding water and the flakes are squeezed when cutting, if the water resistance of the tobacco flakes is not enough, then the tobacco shreds will stick together and make each tobacco flake difficult to spread out, and dry spots will occur when curing subsequently.

[0015] There is also a need for smoking articles to have a wider variety of flavors; for example, a sour flavor is desired. To achieve such flavors, improvements in tobacco sheets are needed.

[0016] In view of the above, an object of the present invention is to provide a tobacco sheet having improved water resistance. Another object of the present invention is to provide a tobacco sheet having a better sour flavor in addition to improved water resistance.

[0017] Solution to the problem

[0018] In order to solve the above problems, the present inventors have conducted extensive research and found that the above problems can be solved by using carboxyalkyl cellulose onium salts, thus perfecting the present invention. The specific aspects of the present invention are as follows.

[0019] [1] A tobacco sheet comprising a carboxyalkyl cellulose onium salt.

[0020] [2] The tobacco sheet according to aspect [1], wherein the content of the carboxyalkyl cellulose onium salt is 1% or more by weight.

[0021] [3] The tobacco sheet according to aspect [1] or [2], further comprising an aerosol generating agent.

[0022] [4] The tobacco sheet according to any one of aspects [1] to [3], further comprising non-pulp fibers.

[0023] [5] The tobacco sheet according to any one of aspects [1] to [4], wherein the disintegration property determined by the disintegration test is 50 seconds or longer.

[0024] [6] The tobacco sheet according to any one of aspects [1] to [5], wherein the water content of the tobacco sheet is 9% to 15% by weight.

[0025] [7] The tobacco sheet according to any one of aspects [1] to [6], wherein the tobacco sheet is a cast sheet, a sheet produced by sheet forming, or a roll-pressed sheet.

[0026] [8] A method for producing a tobacco sheet according to any one of aspects [1] to [7], the method comprising the step of obtaining a tobacco sheet by forming a composition containing tobacco leaves.

[0027] [9] The method according to aspect [8], comprising the step of heating the composition at a temperature of 130°C or higher for 10 minutes or longer.

[0028]

[10] The method according to aspect [8], comprising the step of heating the composition at a temperature of 80°C or higher for 60 minutes or longer.

[0029]

[11] A tobacco filler comprising a tobacco sheet according to any one of aspects [1] to [7].

[0030]

[12] A smoking article comprising the tobacco filler according to aspect

[11] .

[0031]

[13] The smoking article according to aspect

[12] , wherein the smoking article is a heat-not-burn type smoking article.

[0032] Advantageous Effects of the Present Invention

[0033] The tobacco sheet of the present invention has improved water resistance. In some cases, the tobacco sheet of the present invention also has a better sour flavor in addition to the improved water resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Figure 1 A cross-sectional schematic view showing an example of a heat-not-burn type smoking article.

[0035] Figure 2 Figure 2 A cross-sectional schematic view showing an example of a heat-not-burn type smoking system. DETAILED DESCRIPTION

[0036] The tobacco sheet, the method for producing the tobacco sheet, the tobacco filler, and the smoking article of the present invention are described below.

[0037] 1. Tobacco Sheet

[0038] The tobacco sheet of the present invention contains a carboxyalkylcellulose onium salt.

[0039] The alkyl group of the carboxyalkylcellulose onium salt is not particularly limited, but is preferably a C1-3 alkyl group, more preferably methyl, ethyl, or a combination thereof, and most preferably methyl.

[0040] The onium salt of the carboxymethylcellulose onium salt is not particularly limited, but an ammonium salt, a phosphonium salt, an oxonium salt, a sulfonium salt, a fluoronium salt, a chloronium salt, a bromonium salt, an iodonium salt, or a combination of two or more thereof can be used. Among them, an ammonium salt is preferred, and a quaternary ammonium salt is more preferred.

[0041] The carboxymethylcellulose onium salt may include or consist of the following: ammonium carboxymethylcellulose salt, calcium carboxymethylcellulose salt, or a combination of two or more thereof, but is not limited thereto. Among them, ammonium carboxymethylcellulose salt is preferred. Using ammonium carboxymethylcellulose salt provides a sour flavor.

[0042] The content of the carboxyalkylcellulose onium salt in the tobacco sheet is not particularly limited, but is preferably 1% or more by weight, more preferably 1% to 15% by weight, and most preferably 2% to 8% by weight. Ensuring that the content of the carboxyalkylcellulose onium salt is within the above numerical range will achieve a stronger sheet shape.

[0043] The tobacco sheet may further include an aerosol generating agent.

[0044] ​​The type of the aerosol generating agent is not particularly limited, and extracts of various types of natural products and / or their components can be selected according to the purpose of use. For example, the aerosol generating agent can include or consist of the following: polyhydric alcohols (such as glycerol, propylene glycol, sorbitol, xylitol, and erythritol); triacetin; 1,3-butanediol; or a mixture of two or more thereof. Among them, glycerol is preferred. Using glycerol can ensure a consistent amount of smoke.

[0045] The content of the aerosol generating agent in the tobacco sheet is not particularly limited, but is preferably 5% to 35% by weight, more preferably 7% to 25% by weight, and most preferably 10% to 15% by weight. Ensuring that the aerosol generating agent is within the above numerical range will produce a more consistent amount of smoke.

[0046] (non-pulp fiber)

[0047] The tobacco sheet can further include non-pulp fibers.

[0048] Non-pulp fibers are fibers other than pulp fibers. Pulp fibers are aggregates of cellulose fibers extracted from plants such as wood and are usually used as raw materials for paper. Examples of pulp fibers include recycled waste paper pulp, chemical pulp, and mechanical pulp. In the present application, non-pulp fibers are preferably of plant origin. Fibers of plant origin are biodegradable and thus cause less environmental burden.

[0049] Tobacco materials (such as traditional tobacco sheets) are based on pulp fibers, such as wood pulp, that is, bundles of plant fibers (see, for example, the specification of US 5322076). Wood pulp is usually configured in the form of bundles composed of single fibers with a fiber diameter of 20 μm, where the diameter of the wood pulp is about 100 to 200 μm and the length is about 1000 to 2000 μm. When using wood pulp to produce a tobacco sheet with a tensile strength suitable for practical use, the sheet thickness is finally 100 to 300 μm, resulting in a loss of thermal conductivity. However, using non-pulp fibers in the present application can form a sheet with better mechanical strength and achieve better thermal conductivity. From this perspective, the average fiber diameter of the non-pulp fibers is preferably 25 μm or less, more preferably 20 μm or less, and further more preferably 15 μm or less. The lower limit of the average fiber diameter is not limited, but is 2 nm or more, 10 nm or more, 100 nm or more, 1 μm or more, or 5 μm or more.

[0050] The average fiber diameter of the non-pulp fibers can be determined by obtaining an image of the fibers, determining the widths (minor axes) of multiple fibers, and averaging these values. When the fiber shape is columnar (rectangular cross-section), the width of the main surface (i.e., the longer of the main surface width and the side surface width) is defined as the fiber width. Preferably, at least 100 test samples are selected.

[0051] The non-pulped fibers are preferably single-fiber celluloses. Single-fiber cellulose refers to fine fibers obtained by treating pulped fibers through processes such as fibrillation. Single-fiber cellulose can be chemically modified such as by oxidation. The average fiber diameter of the single-fibrillated cellulose is as described above. The average fiber length of the single-fiber cellulose is not limited, but its upper limit is preferably 2000 μm or less, more preferably 1500 μm or less. Its lower limit is preferably 100 μm or more, more preferably 500 μm or more.

[0052] The non-pulped fibers are also preferably dietary fibers. Dietary fiber is a food component that cannot be digested by human digestive enzymes and is more preferably insoluble dietary fiber in the present application. The dietary fiber can be porous, i.e., sponge-like. The porous fibers can increase the surface area of the sheet of the smoking article and can improve the thermal conductivity of the sheet. For usability purposes, the fibers are preferably citrus fibers, for example. Citrus fibers mainly consist of the mesocarp of citrus fruits. The average fiber diameter of the citrus fibers is as described above. The dietary fiber can also be short fibers or columnar particles with a small aspect ratio.

[0053] In one embodiment, the single-fiber cellulose and the dietary fiber are used in combination. The combination of the two will improve the strength, water dispersibility, and smoke intensity of the tobacco sheet. For every 1 part by weight of the dietary fiber, the upper limit of the weight of the single-fiber cellulose is preferably 1.5 parts by weight or less, and more preferably 1.2 parts by weight or less, while the lower limit is preferably 0.1 part by weight or more, and more preferably 0.3 part by weight or more.

[0054] The content of the non-pulped fibers in the tobacco sheet is not particularly limited, but is preferably 30% to 50% by weight, more preferably 35% to 45% by weight, and most preferably 37.5% to 40% by weight. Ensuring that the non-pulped fiber content is within the above numerical range will result in a suitable non-pulped fiber content and thus it is easier to maintain the shape of the sheet.

[0055] In addition to the above components, the tobacco sheet may further include an antioxidant, inulin, reducing sugar, or a combination of two or more thereof. Among them, an antioxidant is preferred. Using an antioxidant will reduce the possibility of an increase in TSNA (a concerning component).

[0056] The tobacco sheet can be obtained by forming a composition containing aged tobacco leaves into a sheet form. There is no particular limitation on the aged tobacco leaves used in the tobacco sheet, but for example, aged tobacco leaves that have been de-stemmed and separated into leaves and midribs can be cited. As used herein, a "sheet" refers to a shape having a pair of substantially parallel main surfaces and side surfaces.

[0057] Multiple types of tobacco can be used for tobacco sheet. Examples include yellow tobacco varieties, burley tobacco varieties, oriental tobacco varieties or native tobacco varieties, as well as Nicotiana tabacum varieties and Nicotiana rustica varieties. These varieties can also be used alone, but in order to obtain the desired flavor, any of these varieties can also be mixed for use during the process from tobacco leaf harvesting to processing the aged tobacco leaves into multiple types (specifically processed tobacco leaves) for use in heat-not-burn tobacco products.

[0058] Details regarding tobacco varieties are disclosed in "Tobacco Dictionary, Tobacco Academic Research Center, March 31, 2009".

[0059] The tobacco sheet can be a cast sheet, a sheet made by a sheeting process, or a rolled sheet.

[0060] The method for forming the tobacco sheet is described below in "2. Method for Producing Tobacco Sheet".

[0061] (Properties of Tobacco Sheet)

[0062] There is no particular limitation on the disintegration property of the tobacco sheet, but the disintegration property determined by the disintegration test is preferably 50 seconds or longer, more preferably 55 to 600 seconds, and most preferably 55 to 300 seconds. The disintegration property of the tobacco sheet determined by the disintegration test can also be 600 seconds or less, or 600 seconds or longer. The disintegration property determined by the disintegration test indicates the water resistance of the tobacco sheet; the greater the disintegration property, the stronger the water resistance of the tobacco sheet. The method disclosed in Japanese Patent Publication No. 60,45914 is adopted as the determination method for the disintegration property determined by the disintegration test.

[0063] The above-mentioned disintegration property determined by the disintegration test can be determined based on the process and method described in "1. Water Resistance" in the (Evaluation Method) of [Examples] below. In the process and method described in "1. Water Resistance" in the (Evaluation Method) of [Examples] below, the disintegration time is the total time of the operation of shaking the sample for 5 seconds and allowing the sample to stand for 55 seconds. For example, in [Examples] below, when the water resistance level is good or excellent after repeating the operation of shaking the sample for 5 seconds and allowing the sample to stand for 55 seconds for 10 cycles, the disintegration property level can be determined to be 600 seconds or more than 600 seconds respectively.

[0064] There is no particular limitation on the water content of the tobacco sheet, but it is preferably 9% to 15% by weight, more preferably 10% to 14.5% by weight, and most preferably 10% to 14% by weight. Ensuring that the water content of the tobacco sheet is within the above numerical range, so that even if there are any changes in the ambient humidity, the change in moisture will be very small.

[0065] The moisture content of the reconstituted tobacco can be determined using an IR moisture analyzer.

[0066] 2. Method for producing reconstituted tobacco

[0067] The method for producing reconstituted tobacco in the present invention

[0068] is the method for producing reconstituted tobacco described in the above "1. Reconstituted tobacco", which method includes the step of obtaining reconstituted tobacco by shaping a composition containing tobacco leaves.

[0069] There is no particular limitation on the method for shaping the reconstituted tobacco, but for example, tobacco fine powder, nicotine, flavor development aids, and binders, and if necessary, aerosol generators and flavoring agents can be mixed, water can be added to the mixture to knead the materials, and the resulting kneaded product can be shaped by known methods (such as the sheet forming method, the casting method, or the roll pressing method). Details of various types of reconstituted tobacco shaped by such methods are disclosed in "Dictionary of Tobacco [Tobacco Dictionary], Tobacco Academic Studies Center [Tobacco Academic Research Center], March 31, 2009".

[0070] The method for producing reconstituted tobacco may include the step of heating the composition containing tobacco leaves (drying step).

[0071] There is no particular limitation on the heating temperature for heating the composition containing tobacco leaves in this step, but it is preferably a temperature of 80 °C or higher, more preferably a temperature of 100 °C or higher, and most preferably a temperature of 100 °C to 140 °C.

[0072] There is no particular limitation on the heating time for heating the composition containing tobacco leaves in this step, but it is preferably 10 minutes or longer, more preferably 30 minutes or longer, and most preferably 30 to 60 minutes.

[0073] A combination of 10 minutes or longer at a temperature of 130 °C or higher, 60 minutes or longer at a temperature of 80 °C or higher, 60 minutes or longer at a temperature of 100 °C or higher, or 30 minutes or longer at a temperature of 120 °C or higher can be used as the combination of the heating temperature and the heating time in the step of heating the composition containing tobacco leaves. Ensuring that the heating temperature and the heating time are within the above numerical ranges can be expected to cause sufficient evaporation of moisture and improve the water resistance of the resulting reconstituted tobacco.

[0074] The method for producing reconstituted tobacco may further include a multi-stage drying step, in which the drying in the above drying step is divided into multiple stages. The temperature during the drying process in the multiple stages of the multi-stage drying step may be the same as the heating temperature in the above drying step. The total time of the drying process in the multiple stages of the multi-stage drying step may be the same as the heating time in the above drying step.

[0075] 3. Tobacco filler

[0076] The tobacco filler of the present invention includes the reconstituted tobacco described in the above "1. Reconstituted tobacco".

[0077] The tobacco filler may be composed of the reconstituted tobacco described in the above "1. Reconstituted tobacco".

[0078] Tobacco filler refers to processed tobacco leaves used in a predetermined form for filling an object to be filled. The "object to be filled" is the part of a tobacco product for filling with processed tobacco leaves. Examples of the object to be filled include, but are not limited to, cylindrically wound wrapper paper, and a container having an air inlet and an air outlet.

[0079] Examples of embodiments of filling an object to be filled with processed tobacco include, but are not particularly limited to: an embodiment of completing the filling by wrapping the processed tobacco leaves in wrapper paper (hereinafter also referred to as "tobacco rod"), or an embodiment of filling the air inlet and air outlet of a container with processed tobacco leaves (hereinafter also referred to as "tobacco filter").

[0080] In the present application, the tobacco filler composed of the reconstituted tobacco for filling an object to be filled can be used as a tobacco filler.

[0081] 4. Smoking article

[0082] The smoking article of the present invention includes the tobacco filler described in the above "3. Tobacco filler".

[0083] The smoking article may be a heat-not-burn smoking article.

[0084] Examples of smoking articles include flavor inhalation articles in which a user tastes flavors by inhaling, and smokeless cigarettes (smokeless smoking articles) in which a user directly places the product in the mouth or nose to taste flavors. Flavor inhalation articles can be roughly divided into combustible smoking articles (such as traditional cigarettes) and heat-not-burn smoking articles.

[0085] Examples of combustible smoking articles include cigarettes, pipes, hookahs (Japanese pipes), cigars, and cigarillos.

[0086] A heat-not-burn smoking article (heat-type smoking article) can be heated by a heating device separated from the article or by a heating device integrated with the article. In the former type of smoking article (separated heating device), the heat-not-burn smoking article and the heating device are collectively referred to as a "heat-not-burn smoking system". The following refers to Figure 1 and Figure 2 to describe examples of heat-not-burn smoking systems.

[0087] Figure 1 is a cross-sectional view of a heat-not-burn smoking article 20. As Figure 1 shown, the heat-not-burn smoking article 20 (hereinafter simply referred to as "smoking article 20") has a cylindrical shape. In the circumferential direction, the 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 total 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.

[0088] The smoking article 20 is composed of a smoking section 20A and a filter section 20C constituting a mouthpiece, and the smoking section and the filter section are connected by a connecting section 20B.

[0089] The smoking section 20A is cylindrical, and its total length (axial length) is, for example, preferably 5 to 100 mm, more preferably 10 to 50 mm, and even more preferably 10 to 25 mm. The shape of the cross-section of the smoking section 20A is not particularly limited, but may be, for example, circular, elliptical, or polygonal.

[0090] The smoking section 20A has a smoking composition sheet 21 (or a material obtained therefrom), which is wrapped with a wrapper 22. The smoking composition sheet 21 (or a material obtained therefrom) may contain a flavoring agent.

[0091] The filter section 20C is cylindrical. The filter section 20C has a rod-shaped first section 25 made by filling with cellulose acetate fibers and a rod-shaped second section 26 also made by filling with cellulose acetate fibers. The first section 25 is located on the smoking section 20A side. The first section 25 may have a hollow portion. The second section 26 is located on the mouthpiece side. The second section 26 is solid. The first section 25 is composed of a first filling layer (cellulose acetate fibers) 25a and a core wrapper 25b wrapped around the first filling layer 25a. The second section 26 is composed of a second filling layer (cellulose acetate fibers) 26a and a core wrapper 26b wrapped around the second filling layer 26a. The first section 25 and the second section 26 are connected by an outer core wrapper 27. For example, the outer core wrapper 27 is adhered to the first section 25 and the second section 26 by an adhesive based on vinyl acetate emulsion.

[0092] For example, the length of the filter section 20C can be 10 to 30 mm. For example, the length of the connection section 20B can be 10 to 30 mm. For example, the length of the first section 25 can be 5 to 15 mm. For example, the length of the second section 26 can be 5 to 15 mm. The lengths of these individual sections are examples and can be appropriately modified according to, for example, manufacturability, required quality, and the length of the smoking section 20A.

[0093] For example, the first section 25 (central hole section) is composed of a first filling layer 25a having one or more hollow portions and a core wrapper 25b covering the first filling layer 25a. The first section 25 has the function of increasing the strength of the second section 26. The first filling layer 25a of the first section 25 is, for example, densely filled with cellulose acetate fibers. A plasticizer containing triacetin is added to and cured in the cellulose acetate fibers, and the addition amount is, for example, 6% to 20% by mass relative to the mass of the cellulose acetate. The inner diameter of the hollow portion of the first section 25 can be, for example, φ1.0 mm to φ5.0 mm.

[0094] The first filling layer 25a of the first section 25 can be, for example, configured to have a relatively high fiber filling density, or can have the same fiber filling density as the second filling layer 26a of the second section 26 described below. Therefore, when sucking, air or aerosol will only flow through the hollow portion, and almost no air or aerosol will flow through the first filling layer 25a. In the case where, for example, a relatively small reduction in aerosol components due to filtration in the second section 26 is desired, the length of the second section 26 can be shortened, for example, to allow the length of the first section 25 to be extended accordingly.

[0095] Replacing the shortened second section 26 with the first section 25 will effectively increase aerosol delivery. The first filling layer 25a of the first section 25 is a fiber filling layer, so the user will not feel any discomfort when touching the outside during use.

[0096] The second section 26 is composed of a second filling layer 26a and a core wrapper 26b covering the second filling layer 26a. The second section 26 (filter section) is filled with cellulose acetate fibers of a common density and has a common aerosol filtering ability.

[0097] The filtering ability for filtering the aerosol (mainstream smoke) released from the smoking section 20A may be different between the first section 25 and the second section 26. At least one of the first section 25 or the second section 26 may include a flavorant. The filter part 20C may have any structure and may be a structure having the above-mentioned multiple sections, or may be composed of a single section. The filter part 20C may be composed of one section. In this case, the filter part 20C may be composed of the first section or the second section.

[0098] The connecting part 20B is cylindrical. The connecting part 20B has a paper tube 23 which is formed in a cylindrical shape using, for example, cardboard. The connecting part 20B may be filled with a cooling member for cooling the aerosol. Examples of the cooling member include polymer (such as polylactic acid) sheets that can be folded and filled. A support for preventing the position of the smoking section 20A from moving around may also be provided between the smoking section 20A and the connecting part 20B. The support may be composed of a known material, such as this type of central hole filter in the first section 25.

[0099] The wrapper 28 is cylindrically wrapped around the outside of the smoking section 20A, the connecting part 20B, and the filter part 20C to integrally connect these parts. One surface (inner surface) of the wrapper 28 is coated with an adhesive based on vinyl acetate emulsion over the entire surface or substantially the entire surface except near the ventilation holes 24. After the smoking section 20A, the connecting part 20B, and the filter part 20C have been integrated by the wrapper 28, a plurality of ventilation holes 24 are formed on the outside by laser processing.

[0100] The ventilation holes 24 include two or more through holes passing through the connecting part 20B in the thickness direction. As observed along a line extending through the central axis of the smoking article 20, the two or more through holes are formed to be arranged radially. In the present embodiment, the ventilation holes 24 are provided in the connecting part 20B, but may also be provided in the filter part 20C. In this embodiment, the two or more through holes of the ventilation holes 24 are arranged in a single row in a circular pattern at a constant interval, but may also be arranged in two circular patterns at a constant interval in two rows, where one row or two rows of the ventilation holes 24 may be arranged discontinuously or irregularly. When the user holds the mouthpiece in the mouth and sucks, outside air is drawn into the mainstream smoke through the ventilation holes 24. However, it is also not necessary to provide the ventilation holes 24.

[0101] Figure 2An example of a heat-not-burn type smoking system is shown. As shown in the figure, the heat-not-burn type smoking system includes a heat-not-burn type smoking article 20 and a heating device 10 that heats the smoking section 20A from the outside.

[0102] The heating device 10 includes: a main body 11, a heater 12, a metal tube 13, a battery unit 14, and a control unit 15. The main body 11 has a tubular recess 16, where the heater 12 and the metal tube 13 are disposed at positions facing the smoking section 20A inserted therein. The heater 12 can be a heater using resistance, where the heater 12 is heated by supplying power from the battery unit 14 according to a command from the control unit 15 that controls the temperature. The heat emitted from the heater 12 is transferred to the smoking section 20A through the highly heat-conductive metal tube 13. This figure depicts an embodiment where the heating device 10 heats the smoking section 20A from the outside, but it is also possible to heat this section from the inside. The heating temperature of the heating device 10 is not particularly limited, but is preferably a temperature of 400°C or lower, more preferably 150°C to 400°C, and even more preferably 200°C to 350°C. The heating temperature refers to the temperature of the heater of the heating device 10.

[0103] Examples

[0104] The present invention will be described experimentally by the following examples, but the following description should not be construed as limiting the scope of the present invention to those examples.

[0105] (Preparation of tobacco sheet)

[0106] For the tobacco sheets used in the experiments, laminated sheets were prepared for each individual type of binder, where each tobacco sheet as a whole consists of 76% by weight of tobacco raw material, 6% by weight of binder, 12% by weight of glycerin, and 6% by weight of pulp.

[0107] Specifically, 152 g of tobacco raw material (yellow tobacco leaves), 12 g of pulp, and 12 g of any one of a variety of given types of binders were mixed in a mixer (Kenmix KM250, manufactured by AICOHSHA MFG. CO., LTD.), and 24 g of glycerin and 85 g of water were added to the resulting mixture to prepare a kneaded product. The resulting kneaded product was roll-pressed using a rolling mill (manufactured by Yuri Roll Co., Ltd.) and dried at 120°C to obtain the laminated sheets (tobacco sheets) of Example 1 and Comparative Examples 1 to 3 (length: 1000 mm; width: 250 mm; thickness: 0.25 mm).

[0108] A 1 g sample of each resulting tobacco sheet was also used to prepare a measurement sample, and the water content (% by weight) of each sheet was determined using an IR moisture analyzer (thermal drying moisture analyzer MX-50, manufactured by A&D Company, Ltd.).

[0109] The water content (% by weight) of various binders used for preparing the tobacco sheets and the water content of the tobacco sheets are shown in Table 1.

[0110] [Table 1]

[0111] Table 1

[0112]

[0113] (Evaluation method)

[0114] 1. Water resistance

[0115] The tobacco sheets of Example 1 and Comparative Examples 1 to 3 prepared using one of the binders shown in Table 1 above were respectively cut into discs with a diameter of 30 mm to obtain samples. The three samples were respectively completely immersed in warm water at 30 °C in a petri dish, and the petri dish containing the samples was shaken back and forth at a rate of 6 times every 5 seconds for 5 seconds, and then left standing for 55 seconds. The operation of shaking the samples for 5 seconds and leaving the samples standing for 55 seconds was repeated 10 times, and the water resistance was evaluated based on the difference in the disintegration of each of the three resulting samples.

[0116] The evaluation was based on the criteria described in Table 2 below. When the grade of water resistance is good or excellent, it can be considered that there are no problems with the quality of the tobacco sheet. In this case, it can be determined that the disintegration of the tobacco sheet is 600 seconds or more than 600 seconds respectively.

[0117] The results are shown in Table 2.

[0118] [Table 2]

[0119] Table 2

[0120]

[0121] 2. Evaluation of sour taste

[0122] Smoking segments were made by filling wrappers with the tobacco sheets of Example 1 and Comparative Examples 1 to 3 described above, and heating non-combustible smoking articles as shown were prepared. Then each of the resulting heating non-combustible smoking articles was installed in a heating non-combustible smoking system as shown. Figure 1 shown Figure 2 shown

[0123] Ten trained reviewers evaluated the sour flavor of the smoking articles thus prepared. In this example and the comparative examples, "sour flavor" refers to a slightly acidic, pungent taste with less off-flavor.

[0124] The sour flavor of the test smoking articles was evaluated by calculating the average of the grades given by 10 reviewers based on the five criteria in Table 3 below. In the criteria of Table 3 below, a grade of 3 means the same grade as in the comparative example. The average value with two decimal places was rounded to the first decimal place to calculate the score. The evaluation results are shown in Table 4.

[0125] [Table 3]

[0126] Table 3

[0127]

[0128] [Table 4]

[0129] Table 4

[0130]

[0131] The results in Table 4 show that the tobacco sheet containing ammonium carboxymethylcellulose (carboxyalkylcellulose onium salt) of Example 1 has excellent water resistance. The results also show that the tobacco sheet of Example 1 has excellent sour flavor in addition to excellent water resistance.

[0132] On the other hand, the results show that the tobacco sheet containing carboxyalkylcellulose instead of carboxyalkylcellulose onium salt of Comparative Example 1 has excellent water resistance, but the sour flavor is inferior to that of Example 1.

[0133] The results also show that the tobacco sheets containing potato starch of Comparative Example 2 and the tobacco sheets containing waxy corn starch of Comparative Example 3 have poor water resistance and almost no sour flavor.

[0134] The above results show that the tobacco sheet of the present application has excellent water resistance. The results also show that the tobacco sheet of the present application has excellent sour flavor in addition to excellent water resistance.

[0135] List of reference numerals

[0136] 10 Heating device

[0137] 11 Body

[0138] 12 Heater

[0139] 13 Metal tube

[0140] 14 Battery unit

[0141] 15 Control Unit

[0142] 16 Concave Portion

[0143] 17 Vent Hole

[0144] 20 Heat-not-burn Smoking Article

[0145] 20A Smoking Section

[0146] 20B Connection Portion

[0147] 20C Filter Portion

[0148] 21 Smoking Composition Sheet or Material Derived Therefrom

[0149] 22 Wrapper

[0150] 23 Paper Tube

[0151] 24 Vent Hole Portion

[0152] 25 First Segment

[0153] 25a First Filling Layer

[0154] 25b Inner Core Wrapper

[0155] 26 Second Segment

[0156] 26a Second Filling Layer

[0157] 26b Inner Core Wrapper

[0158] 27 Outer Core Wrapper

[0159] 28 Wrapper.

Claims

1. A tobacco sheet comprising a carboxyalkyl cellulose onium salt.

2. The tobacco sheet according to claim 1, wherein, The content of the carboxyalkyl cellulose onium salt is 1% or more by weight.

3. The tobacco sheet according to claim 1 or 2, further comprising an aerosol former.

4. The tobacco sheet according to any one of claims 1 to 3, further comprising non-pulp fibers.

5. The tobacco sheet according to any one of claims 1 to 4, wherein, The disintegration property determined by the disintegration test is 50 seconds or longer.

6. The tobacco sheet according to any one of claims 1 to 5, wherein the water content of the tobacco sheet is 9% to 15% by weight.

7. The tobacco sheet according to any one of claims 1 to 6, wherein the tobacco sheet is a cast sheet, a sheet produced by sheet forming, or a roll-pressed sheet.

8. A method for producing the tobacco sheet according to any one of claims 1 to 7, the method comprising the step of obtaining the tobacco sheet by forming a composition containing tobacco leaves.

9. The method according to claim 8, comprising the step of heating the composition at a temperature of 130 °C or higher for 10 minutes or longer.

10. The method according to claim 8, comprising the step of heating the composition at a temperature of 80 °C or higher for 60 minutes or longer.

11. A tobacco filler comprising the tobacco sheet according to any one of claims 1 to 7.

12. A smoking article comprising the tobacco filler according to claim 11.

13. The smoking article according to claim 12, wherein the smoking article is a heat-not-burn smoking article.

Images