EP4678017A1

EP4678017A1 - Aerosol-generating sheet

Info

Publication number: EP4678017A1
Application number: EP23926214.0A
Authority: EP
Inventors: Takeshi Shinkawa; Manabu Yamada; Kosuke Ota
Original assignee: Japan Tobacco Inc
Current assignee: Japan Tobacco Inc
Priority date: 2023-03-06
Filing date: 2023-03-06
Publication date: 2026-01-14
Also published as: KR20250152108A; WO2024185000A1; CN120693074A; JPWO2024185000A1

Abstract

An aerosol-generating sheet, comprising:
(A) 15 to 50% by weight of tobacco extract;
(B) non-wood fiber;
(C) a binder; and
(D) 10 to 60% by weight of an aerosol source;
wherein
the total of (B) and (C) is 23 to 50% by weight.

Description

TECHNICAL FIELD

The present invention relates to an aerosol-generating sheet.

BACKGROUND ART

Cut tobacco and tobacco extracts are known as tobacco-derived materials that are used in aerosol-generating sheets. PTL 1 and 2 disclose sheets in which a tobacco extract is used as the tobacco-derived material.

CITATION LIST

PATENT LITERATURE

[PTL 1] JP 6695359 B2
[PTL 2] JP 5248486 B2

SUMMARY OF INVENTION

TECHNICAL PROBLEM

When a sheet is produced using a tobacco extract as disclosed in PTL 1 and 2, the composition for the sheet must be concentrated. Producing a sheet without concentrating the composition for the sheet does allow the production process to be simplified, but the inventors have found that simply adjusting the moisture concentration does not allow a sheet which is easy to handle to be obtained. In view of the above circumstances, an object of the present invention is to provide an aerosol-generating sheet which is easy to handle.

SOLUTION TO PROBLEM

The inventors solved said problem by setting the total amount of non-wood fiber and binder to within a certain range.

Aspect 1

An aerosol-generating sheet, comprising:

(A) 15 to 50% by weight of tobacco extract;
(B) non-wood fiber;
(C) a binder; and
(D) 10 to 60% by weight of an aerosol source;
wherein
the total of (B) and (C) is 23 to 50% by weight.

Aspect 2

The sheet according to aspect 1, wherein (B) is dietary fiber.

Aspect 3

The sheet according to aspect 2, wherein (B) is citrus fiber.

Aspect 4

The sheet according to any of aspects 1 through 3, wherein (C) is carboxyalkyl cellulose or guar gum.

Aspect 5

A smoking article member that comprises the sheet according to any of aspects 1 through 4 and that is selected from the group consisting of flavor sources, wrappers, paper tubes, filters, and containers.

Aspect 6

A smoking article comprising the member of aspect 5.

Aspect 7

A method for producing an aerosol-generating sheet according to any of aspects 1 through 5, comprising:

a step of preparing a mixture of a tobacco extract liquid containing the tobacco extract; the non-wood fiber; the binder; and the aerosol source; and
a step of making the mixture into a sheet.

Aspect 8

The production method according to aspect 7, wherein the mixture comprises water, and the water:non-water ingredients weight ratio of the mixture is (2 to 10):1.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention allows an aerosol-generating sheet which is easy to handle to be provided.

DESCRIPTION OF EMBODIMENTS

As used in the present disclosure, the range "X-Y" includes X and Y as the end values.

1. Aerosol-Generating Sheet

An aerosol generating sheet is a sheet that is capable of generating an aerosol by being heated, for example. In one embodiment, the aerosol-generating sheet (sometimes also referred to below simply as "sheet") comprises (A) 15 to 50% by weight of tobacco extract, (B) non-wood fiber, (C) a binder, and (D) 10 to 60% by weight of an aerosol source, wherein the total of (B) and (C) is 23 to 50% by weight, based on the weight of the sheet. Unless otherwise specified, weight and percent by weight are dry weight and dry percent by weight. Dry weight is the weight excluding the weight of water.

(1) Ingredient (A): Tobacco Extract

A tobacco extract is a flavored substance or mixture that is extracted from tobacco. The tobacco extract can be prepared by known methods. The following methods are examples: 1) methods in which a tobacco raw material is extracted using a medium to obtain a tobacco extract; 2) methods in which a medium is added to a tobacco raw material, the mixture is heated, and the vapor that is generated is collected; and 3) methods in which a heat-vaporized medium is allowed to pass through a tobacco raw material, and the vapor that has passed through is collected. The medium may be water or a hydrophilic organic solvent such as an alcohol. In the methods of 1), water is preferably used as the medium in the interests of workability, for example. In the methods of 2) and 3), an alcohol such as propylene glycol, glycerol, or ethanol is preferably used as the medium in the interests of work efficiency. Acids or alkalis can also be used, as needed, for extraction. The liquid containing the tobacco extract and the medium that is obtained by the extraction is called the tobacco extract liquid.
Raw materials of the Nicotiana genus, such as Nicotiana tabacum and Nicotiana rustica, can be used as the tobacco raw material. Examples of Nicotiana tabacum that can be used include varieties such as Burley tobacco and yellow tobacco. Oriental tobacco or Burley tobacco which is an indigenous species of the Nicotiana genus may also be used.
The tobacco raw material may be a shredded or powdered tobacco raw material (also referred to below as "raw material pieces"). In such cases, the particle size of the raw material pieces is preferably 0.5 to 1.18 mm. Such raw material pieces are obtained via sifting in accordance with JIS Z 8815 using a stainless steel sieve per JIS Z 8801, for example. For example, 1) raw material pieces are sifted over a 20-minute period by means of drying and mechanical shaking using a stainless steel sieve having 1.18 mm openings to obtain raw material pieces that pass through the stainless sieve having 1.18 mm openings. 2) The raw material pieces are then sifted over a 20-minute period by means of drying and mechanical shaking using a stainless steel sieve having 0.50 mm openings to remove raw material pieces that pass through the stainless sieve having 0.50 mm openings. It is thus possible to prepare raw material pieces that pass through a stainless steel sieve of a specified upper limit (1.18 mm openings) and that do not pass through a stainless steel sieve of a specified lower limit (0.50 mm openings).
In one aspect, the tobacco raw material is treated with an alkali. Flavor components generated by way of said treatment may be collected to prepare a tobacco extract liquid comprising the tobacco extract and water. At that time, the flavor components are preferably extracted in the form of gas from the alkaline-treated tobacco raw material, and the gas is preferably introduced into water to thereby transfer the flavor components into a liquid.
The alkaline substance is preferably an alkaline liquid such as potassium carbonate aqueous solution. At that time, the alkaline substance is supplied until the pH of the tobacco raw material is within a certain range. The pH is preferably at least 8.0, and more preferably 8.9 to 9.7. The pH of the tobacco raw material is the pH of the water when the tobacco raw material is mixed with 10 times the amount of water.
The moisture content of the tobacco raw material is not limited but is preferably about 5 to 30% by weight in the interests of efficient flavor component extraction. The moisture content of the tobacco raw material can be determined by a known method; for example, the moisture content can be defined as the weight loss that has occurred at the point in time when a 1 g sample has been heated to 105°C and is heated until the rate of change in weight is no greater than 1 mg/min. This can be determined, for example, using a moisture analyzer having a halogen heat source (such as MB45, by OHAUS CORPORATION).
The sheet has a tobacco extract content of 15 to 50% by weight. The amount can be adjusted, as appropriate, to between 20 and 40% by weight, for example.

(2) Ingredient (B): Non-wood fiber

Non-wood fiber is fiber that is not derived from wood, and is preferably fiber other than tobacco fiber. Tobacco fiber is unlikely to make the sheet stronger, and may result in a harsh taste. Dietary fiber is preferred as the non-wood fiber. Dietary fiber is a dietary component that is indigestible by human digestive enzymes, and is more preferably water-insoluble dietary fiber. The dietary fiber may be porous, specifically, may be sponge-like. Porous fiber can increase the surface area of the sheet for a smoking article, and can enhance the thermal conductivity of the sheet. The fiber is preferably citrus fiber, because it is readily available, for example. Citrus fiber is primarily composed of the mesocarp of citrus fruits. Dietary fiber may also be short fiber or columnar particles that have a small aspect ratio. Citrus fiber is particularly preferred because it can be used in small amounts to make the sheet stronger. The moisture content of the non-wood fiber is determined in order to decide how much non-wood fiber should be blended so as to satisfy the above relationship. The moisture content of the non-wood fiber can be determined by a known method, and can be determined, for example, in the same manner as the moisture content of the tobacco raw material. In one aspect, the content of ingredient (B) in the sheet is 10 to 30% by weight. Wood fiber is a known fibrous material, but an advantage of using non-wood fiber is that the liquid support capacity is better than that of wood fiber. The amount of non-wood fiber that is added can thus be reduced to increase the amount of ingredients that contribute to smoking flavor and aroma.

(3) Ingredient (C): Binder

Examples of binders include carboxyalkyl cellulose and guar gum. The moisture content of the binder can be determined by a known method, and can be determined, for example, in the same manner as the moisture content of the tobacco raw material.
The total amount of ingredient (B) and ingredient (C) in the sheet is 23 to 50% by weight. An amount below this lower limit will result in poor sheet handling and insufficient sheet strength. An amount greater than this upper limit will result in less flavor or a harsher taste. Processing such as cutting or folding of the sheet will also become more difficult. In this respect, the lower limit of the total amount is preferably 24% by weight or more, and the upper limit is preferably 40% by weight or less, and more preferably 30% by weight or less. The amounts of ingredient (B) and ingredient (C) are determined so as to satisfy the total amount noted above, but in one aspect, the amount of ingredient (B) is 10 to 30% by weight or 13 to 25% by weight, and the amount of ingredient (C) is 13 to 20% by weight or 10 to 25% by weight.

(4) Ingredient (D): Aerosol source

Examples of aerosol sources include polyhydric alcohols such as glycerol or polyethylene glycol. The moisture content of the aerosol source can be determined by a known method, and can be determined, for example, in the same manner as the moisture content of the tobacco raw material. The amount of the aerosol source in the sheet is 10 to 60% by weight. An amount below this lower limit will result in insufficient smoke volume during smoking. An amount greater than this upper limit will result in poor sheet handling. In this respect, the amount is preferably 15 to 50% by weight, and more preferably 20 to 40% by weight.

(5) Other Ingredients

The sheet may contain wood fiber. Examples of wood fiber include softwood pulp, Vitacel FL400, and Vitacel L600/30 (both by J. Rettenmaier & Sohne GmbH). As described below, the mixture for producing the sheet preferably comprises water, where the water:non-water ingredients weight ratio in the mixture is preferably (2 to 10):1. The moisture content of the wood fiber is preferably determined in order to decide how much wood fiber should be blended so as to satisfy the above relationship. The moisture content of the wood fiber can be determined by a known method, and can be determined, for example, in the same manner as the moisture content of the tobacco raw material. In one aspect, the content of wood fiber in the sheet is 1 to 10% by weight.
The sheet may also contain known flavoring. Examples of flavoring include, but are not limited to, menthols, and any of the following can be used. The amount of flavoring may also be a known amount. These examples of flavoring may be used alone, or in combinations of two or more.
The following are examples of preferred flavoring: acetanisole, acetophenone, acetylpyrazine, 2-acetylthiazole, alfalfa extract, amyl alcohol, amyl butyrate, trans-anethole, star anise oil, apple juice, Peru Balsam oil, beeswax absolute, benzaldehyde, benzoin resinoid, benzyl alcohol, benzyl benzoate, benzyl phenylacetate, benzyl propionate, 2,3-butanedione, 2-butanol, butyl butyrate, butyric acid, caramel, cardamom oil, carob absolute, β-carotene, carrot juice, L-carvone, β-caryophyllene, cassia bark oil, cedar wood oil, celery seed oil, chamomile oil, cinnamaldehyde, cinnamic acid, cinnamyl alcohol, cinnamyl cinnamate, citronella oil, DL-citronellol, clary sage extract, cocoa, coffee, cognac oil, coriander oil, cuminaldehyde, davana oil, δ-decalactone, γ-decalactone, decanoic acid, dill herb oil, 3,4-dimethyl-1,2-cyclopentanedione, 4,5-dimethyl-3-hydroxy-2,5-dihydrofuran-2-one, 3,7-dimethyl-6-octenoic acid, 2,3-dimethylpyrazine, 2,5-dimethylpyrazine, 2,6-dimethylpyrazine, 2-ethyl methylbutyrate, ethyl acetate, ethyl butyrate, ethyl hexanoate, ethyl isovalerate, ethyl lactate, ethyl laurate, ethyl levulinate, ethyl maltol, ethyl octanoate, ethyl oleate, ethyl palmitate, ethyl phenylacetate, ethyl propionate, ethyl stearate, ethyl valerate, ethyl vanillin, ethyl vanillin glucoside, 2-ethyl-3,(5 or 6)-dimethylpyrazine, 5-ethyl-3-hydroxy-4-methyl-2(5H)-furanone, 2-ethyl-3-methylpyrazine, eucalyptol, fenugreek absolute, genet absolute, gentian root infusion, geraniol, geranyl acetate, grape juice, guaiacol, guava extract, γ-heptalactone, γ-hexalactone, hexanoic acid, cis-3-hexen-1-ol, hexyl acetate, hexyl alcohol, hexyl phenylacetate, honey, 4-hydroxy-3-pentenoic acid lactone, 4-hydroxy-4-(3-hydroxy-1-butenyl)-3,5,5-trimethyl-2-cyclohexen-1-one, 4-(para-hydroxyphenyl)-2-butanone, 4-hydroxyundecanoic acid sodium, immortelle absolute, β-ionone, isoamyl acetate, isoamyl butyrate, isoamyl phenylacetate, isobutyl acetate, isobutyl phenylacetate, jasmine absolute, kola nut tincture, labdanum oil, lemon terpeneless oil, glycyrrhiza extract, linalool, linalyl acetate, lovage root oil, maltol, maple syrup, menthol, menthone, acetic acid L-menthyl, paramethoxybenzaldehyde, methyl-2-pyrrolyl ketone, methyl anthranilate, methyl phenylacetate, methyl salicylate, 4'-methylacetophenone, methylcyclopentenolone, 3-methylvaleric acid, mimosa absolute, molasses, myristic acid, nerol, nerolidol, γ-nonalactone, nutmeg oil, δ-octalactone, octanal, octanoic acid, orange flower oil, orange oil, orris root oil, palmitic acid, ω-pentadecalactone, peppermint oil, petitgrain Paraguay oil, phenethyl alcohol, phenethyl phenylacetate, phenylacetic acid, piperonal, plum extract, propenyl guaethol, propyl acetate, 3-propylidene phthalide, prune juice, pyruvic acid, raisin extract, rose oil, rum, sage oil, sandalwood oil, spearmint oil, styrax absolute, marigold oil, tea distillate, α-terpineol, terpinyl acetate, 5,6,7,8-tetrahydroquinoxaline, 1,5,5,9-tetramethyl-13-oxacyclo(8.3.0.0(4.9))tridecane, 2,3,5,6-tetramethylpyrazine, thyme oil, tomato extract, 2-tridecanone, triethyl citrate, 4-(2,6,6-trimethyl-1-cyclohexenyl)-2-buten-4-one, 2,6,6-trimethyl-2-cyclohexen-1,4-dione, 4-(2,6,6-trimethyl-1,3-cyclohexadienyl)-2-buten-4-one, 2,3,5-trimethylpyrazine, γ-undecalactone, γ-valerolactone, vanilla extract, vanillin, veratraldehyde, violet leaf absolute, N-ethyl-p-menthane-3-carboamide (WS-3), and ethyl-2-(p-menthane-3-carboxamide) acetate (WS-5).

2. Member for Smoking Article

The sheet is useful as a member for smoking articles. Examples of members for smoking articles comprising the sheet include flavor sources, wrappers, paper tubes, filters, and containers. For example, the sheet can be folded or spirally shaped, or cut into strands or shredded shapes, to be used as a flavor source for smoking articles, specifically, as filler for tobacco rods. The strands have a rectangular shape, and may be disposed along the longitudinal direction of the flavor source or may be randomly arranged. Shreds are also randomly arranged in the flavor source.

3. Smoking Article

The smoking article member is useful for smoking articles. For example, a combusted smoking article or a heat-not-burn smoking article comprising the above tobacco rod and a mouthpiece member, etc., can be prepared. The mouthpiece may comprise a filter as well as a cooling portion to promote the aerosolization of the vapor that has been generated from the flavor source. The cooling portion may be composed of a paper tube. The paper tube may be filled with a material (such as a polylactic acid sheet) to facilitate cooling, and a plurality of longitudinally communicating flow paths may be provided. The circumferential surface of the cooling portion may furthermore be provided with openings through which outside air is taken in. The filter may be composed of an acetate filter, paper filter, center hole filter, or a combination thereof.
An acetate filter, paper filter, or center hole filter, for example, may be disposed as a tip plug upstream of the tobacco rod. Upstream refers to the direction opposite the mouthpiece end.

4. Production Method

The sheet of the present embodiment is preferably produced by a method comprising: a step 1 in which a mixture of a tobacco extract liquid containing ingredient (A) (tobacco extract), ingredient (B) (non-wood fiber), ingredient (C) (binder), and ingredient (D) (aerosol source) is prepared; and a step 2 in which the mixture is made into a sheet.

(1) Step 1

(1-1) Preparation of Tobacco Extract Liquid

In this step, the tobacco raw material noted above is extracted to prepare a tobacco extract liquid comprising a tobacco extract active ingredient and a medium. Water is preferably used as a medium. The extraction temperature is not limited, but is preferably 60 to 100°C, and more preferably 70 to 90°C, in the interests of smoking flavor. The extraction time is preferably 20 to 40 minutes.

(1-2) Mixing

The ingredients can be mixed by a known method; for example, the mixture can be prepared by mixing the ingredients in a mixer, for example. The mixture preferably comprises water, wherein the water:non-water ingredients weight ratio is preferably (2 to 10):1. The water may be the water included in the tobacco extract liquid or may be other water that has been added. The water content is also preferably increased, particularly when the non-wood fiber content is increased. Preferred embodiments are described below.

[When a laminate sheet is made]

The three following methods may be cited.

1) The tobacco extract liquid and binder are mixed to prepare mixture X. When water is to be added, additional water is also mixed to prepare mixture X. An aerosol source such as glycerol is mixed with other solids to prepare mixture Y. Mixture X and mixture Y are then mixed. The other solids are, specifically, ingredient (B) or the other ingredients noted above.
2) The tobacco extract liquid and an aerosol source such as glycerol are mixed. The binder is added to and mixed with this mixture. When water is to be added, the water is also mixed in at this time. Other solids are then mixed with this mixture.
3) An aerosol source such as glycerol and the binder are mixed. The tobacco extract liquid is mixed with this mixture. When water is to be added, the water is also mixed in at this time. Other solids are then mixed with this mixture.

The above methods comprise mixing a binder with a tobacco extract liquid (as well as mixing water, when water is to be added). Mixing in this manner makes it possible to prevent solids from preferentially absorbing water, and allows the binder to dissolve in the water without "clumping," thus allowing the binder function to be fully achieved. The method of first mixing the binder and the aerosol source makes it particularly unlikely that the binder will "clump." "Clumping" refers to a state in which ingredients are present in the form of clumps without being dispersed or dissolved.

[Cast Sheets]

The tobacco extract liquid is mixed with an aerosol source such as glycerol. When water is to be added, the water is also mixed in at this time. The binder is mixed with the mixture, and after it has been confirmed that the binder has been mixed to homogeneity, the other solids are mixed therein. When solids comprising the binder are mixed with each other first, the binder will "clump," a state which is difficult to resolve. In the present method, the binder and the aerosol source are mixed first, thus making it less likely that the binder will "clump."

(2) Step 2

The sheet can be made by a known method. The sheet can be made using a casting method or rolling method, for example. In casting methods, the mixture is cast onto a substrate to form a wet sheet. The wet sheet is then dried to obtain a sheet. The drying temperature is preferably 50 to 100°C. The sheet obtained by this method is also referred to as a "cast sheet."
In rolling methods, the mixture is rolled, while sandwiched between two substrate films, to a predetermined thickness (greater than 100 µm) through a pair of rollers using a calendering device (by Yuri Roll Machine Co., Ltd., for example), resulting in a laminate comprising a wet sheet present between the two substrate films. The laminate can be rolled by the rollers multiple times. The substrate films are preferably non-adhesive films such as fluoropolymer films, a specific example of which is Teflon^® film.
One of the substrate films of the laminate is then peeled off. The laminate is dried using a forced-air dryer. The drying temperature is preferably 50 to 100°C, and the drying time can be 1 to 2 minutes. The remaining substrate film is then peeled off, and the sheet is obtained after further drying under the same conditions. Drying in this manner will prevent the sheet from adhering to the other substrate.
Sheets obtained by the present method are also referred to as "laminate sheets." Laminate sheets are preferred because they have a smooth surface and can prevent cut tobacco from spilling out when in contact with other members. The present method is also suitable for producing sheets of 300 µm or less.
In rolling methods, the amount of water in the mixture obtained in step 1 is preferably adjusted to between 20 and 80% by weight, and more preferably between 20 and 40% by weight, and a moist powder (powder in a moist state) is preferably produced. The moist powder is then preferably kneaded using a single-screw or multi-screw kneading machine such as a kneader (such as the DG-1 by Dalton), before being prepared into a laminate.

EXAMPLES

EXAMPLE 1

Ground yellow and Oriental tobaccos were prepared as the tobacco raw material. The shredded tobacco leaf was extracted at room temperature using 500% by weight of water relative to the dry weight of the tobacco leaf to obtain a tobacco extract liquid.
A mixture was obtained using Herbacel AQ Plus CF-D/100 (DSP Gokyo Food & Chemical Co., Ltd.) as the non-wood fiber, carboxyalkyl cellulose (CMCF30MC, by Nippon Paper Industries Co., Ltd., ) as the binder, and glycerol as the aerosol source in the proportions shown in Table 1. The ratio of the total amount of water in the mixture:total amount of non-water ingredients was 1:4. The total amount of water here is the total weight of the water contained in each ingredient. The weight of the water of each ingredient was determined by the method noted above.
The resulting mixture was cast onto a stainless steel sheet and dried in an oven at 80°C to prepare a 0.25 mm thick cast sheet. The dried sheet was then further conditioned at least overnight at 22°C and 60% RH. At that time, assessments were made as to whether the sheet was capable of supporting liquids, whether the sheet was sticky, and whether the liquid was exuded on the surface of the sheet. The results are shown in Table 1. The weight shown in the table is the dry weight in every case. Assessment Criteria

a: Minimal sheet stickiness, without any liquid exudation
b: No liquid exudation, but substantial sheet stickiness
c: Liquid exudation

EXAMPLES 2-6

Cast sheets were prepared and assessed in the same way as Example 1, except that the formulation of the ingredients was changed as shown in Table 1.

COMPARATIVE EXAMPLES 1-7

[Table 1]

	Wood fiber		(B) Non-wood fiber	(C) Binder				(D) Glycerol	(A) Tobacco extract	Solid-liquid ratio	B+C	Assessments
	Soft wood pulp	vitacel L600/30	Herbacel	Guar gum	HPMC (4000)	CMC F30MC	CMC F350HC	(D) Glycerol	(A) Tobacco extract	Solid-liquid ratio	B+C	Assessments
Example 1			20%			5 %		35%	40%	1:4	25%	a
Comparative Example 1	20%					5%		35%	40%	1:4	-	b
Example 2			20%	5%				35%	40%	1:4	25%	b
Example 3			20%				5%	35%	40%	1:4	25%	a
Comparative Example 2			15%			5%		20%	60%	1:5	20%	c
Comparative Example 3			10%			5%		22%	63%	1:5	15%	c
Example 4			20%			5%		12%	63%	1:4	25%	a
Example 5			20%			5%		50%	25%	1:3	25%	a
Comparative Example 4	16%	-		15%				39%	30%	1:5	-	c
Comparative Example 5	16%	-			15%			39%	30%	1:5	-	c
Comparative Example 6	14%	13%		13%				34%	26%	1:5	-	a
Comparative Example 7	3%	27%				5%		15%	50%	1:4	-	a
Example 6			15%			10%		35%	40%	1:4	25%	b

The sheets obtained in the examples clearly had better handling.
Aspects of implementation are listed below.