EP4736674A1

EP4736674A1 - Flavor inhaler filter, method for producing same, and flavor inhaler

Info

Publication number: EP4736674A1
Application number: EP23943563.9A
Authority: EP
Inventors: Takumi AKAO; Hiroyuki Kubota; Yoko MURASAKI ABE
Original assignee: Japan Tobacco Inc
Current assignee: Japan Tobacco Inc
Priority date: 2023-06-27
Filing date: 2023-06-27
Publication date: 2026-05-06
Also published as: CN121127147A; JPWO2025004161A1; WO2025004161A1; KR20250172971A

Abstract

A filter for a flavor inhaler, that comprises cellulose fibers and that has a high phenol filtration performance, is provided. A filter for a flavor inhaler, comprising: a filter medium that comprises a cellulose fiber-containing substrate, and a coating layer provided on the filter medium, and a wrapper wrapped around the filter medium; wherein the coating layer comprises a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin.

Description

TECHNICAL FIELD

The present invention relates to a filter for a flavor inhaler, a method for producing the same, and a flavor inhaler.

BACKGROUND ART

Acetate fibers are commonly used as filter media in filters for flavor inhalers. However, cellulose fiber-containing filter media have been garnering attention because they are more biodegradable and more eco-friendly than acetate fibers. Cellulose fiber-containing filter media tend to have lower filtration performance when it comes to phenols, for example, and to result in a more acrid taste, than acetate fiber-containing filter media. Attempts have therefore been made to provide cellulose fiber-containing filter media with the capacity to filter phenols, for example, and afford better taste.
It disclosed in PTL 1, for example, that the addition of polyalkylene glycol as a filter additive results in lower phenol levels. PTL 2 discloses the addition of triacetin, for example, as an additive for lowering phenol levels. On the other hand, it is disclosed in PTL 3 that fibers containing plant pulp are bound together with a water-soluble binder during the production of a non-woven fabric filter.

CITATION LIST

PATENT LITERATURE

PTL 1: JP 2001-352963 A
PTL 2: JP 2021-515540 A
PTL 3: WO 2022/085072

SUMMARY OF INVENTION

TECHNICAL PROBLEM

An object of the present invention is to provide: a filter for a flavor inhaler, that comprises cellulose fibers and that has high phenol filtration performance; and a flavor inhaler comprising said filter.

SOLUTION TO PROBLEM

The present invention includes the following embodiments.

[1] A filter for a flavor inhaler, comprising:
- a filter medium comprising a cellulose fiber-containing substrate and a coating layer provided on the substrate; and
- a wrapper wrapped around said filter medium;
- wherein
- the coating layer comprises a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin.
[2] The filter as set forth in [1], wherein the homopolymer or copolymer having an acetate ester group in a side chain is at least one selected from the group consisting of polyvinyl acetate, vinyl acetate-acrylic copolymers, and ethylene-vinyl acetate copolymers.
[3] The filter as set forth in [1] or [2], wherein the filter further comprises a granulated substance, and the wrapper is wrapped around the filter medium and the granulated substance.
[4] The filter as set forth in [3], wherein the granulated substance is at least one selected from the group consisting of activated carbon, hydrotalcite, and cellulose granules.
[5] The filter as set forth in any of [1] through [4], wherein the filter medium further comprises hydrophobic flavoring.
[6] The filter as set forth in [5], wherein the hydrophobic flavoring is menthol.
[7] The filter as set forth in any of [1] through [6], wherein the homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin is contained in a proportion of 1 to 20% by weight per 100% by weight of filter medium.
[8] The filter as set forth in any of [1] through [7], wherein the airflow resistance is 5 to 130 mmWG/27 mm tip.
[9] The filter as set forth in any of [1] through [8], wherein the concentration of the homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin on the surface of the filter medium is higher than the concentration of the homopolymer or copolymer having an acetate ester or hydroxypropyl group in a side chain, cyclodextrin, or lecithin in the interior of the filter medium.
[10] The filter as set forth in any of [1] through [9], wherein the substrate is a cellulose fiber-containing sheet of paper or non-woven fabric.
[11] A flavor inhaler comprising: a tobacco ingredient-containing tobacco rod; and the filter as set forth in any of [1] through [10].
[12] The flavor inhaler as set forth in [11], which is a combustion-type flavor inhaler.
[13] The flavor inhaler as set forth in [12], wherein the airflow resistance of the filter is 50 to 130 mmWG/27 mm tip.
[14] The flavor inhaler as set forth in [11], which is a heat-not-burn flavor inhaler.
[15] [The flavor inhaler as set forth in [14], wherein the airflow resistance of the filter is 5 to 50 mmWG/27 mm tip.
[16] A method for producing a filter for a flavor inhaler, comprising:
- a step in which a cellulose fiber-containing substrate is prepared;
- a step in which a liquid that comprises water and a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin is applied to, and dried on, the surface of the substrate to obtain a filter medium; and
- a step in which the filter medium is wrapped with a wrapper.
[17] The method as set forth in [16], wherein the step for obtaining the filter medium is a step in which the liquid is sprayed and dried on the surface of the substrate.
[18] The method as set forth in [16] or [17], wherein the homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin is contained in a proportion of 1 to 60% by weight per 100% by weight of filter medium.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention can provide: a filter for a flavor inhaler, that comprises cellulose fibers and that has high phenol filtration performance; and a flavor inhaler comprising said filter.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 is a schematic diagram showing an example of a flavor inhaler according to the present embodiment.
Fig. 2 is a schematic diagram showing an example of a combustion-type flavor inhaler according to the present embodiment.
Fig. 3 is a schematic diagram showing an example of a heat-not-burn flavor inhaler according to the present embodiment.
Fig. 4 is a schematic diagram showing an example of a heat-not-burn flavor inhalation system of the present embodiment (a) before the heat-not-burn flavor inhaler is inserted into the heating device, and (b) while the heat-not-burn flavor inhaler is inserted into the heating device to be heated.
Fig. 5 is a graph showing the amount of phenol (per TPM) passing through filters relative to the amounts in which each phenol-trapping component was provided in the examples.
Fig. 6 is a graph showing the airflow resistance of filters relative to the amounts in which water was provided in each phenol-trapping component in the examples.

DESCRIPTION OF EMBODIMENTS

[Filter for Flavor Inhaler]

The filter for a flavor inhaler according to the present embodiment comprises: a filter medium; and a wrapper wrapped around the filter medium. Said filter medium comprises: a cellulose fiber-containing substrate; and a coating layer provided on the substrate. The coating layer comprises a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin.
In the filter for the flavor inhaler according to the present embodiment (also referred to below as the "filter"), the filter medium is composed of a cellulose fiber-containing substrate, and on the surface of the substrate there is provided a coating layer, which comprises a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in the side chain, cyclodextrin, or lecithin (also referred to below as "phenol-trapping components"). Vaporized phenol passing through the filter thus chemically interacts with the phenol-trapping components that are present on the surface of the filter substrate. The phenol is thus trapped on the surface of the filter material, resulting in better phenol filtration performance even though cellulose fibers are being used.

(Substrate)

The substrate according to the embodiment can be a substrate in the form of a sheet, but is not particularly limited, provided that cellulose fibers are included therein. The substrate is preferably a cellulose fiber-containing sheet of paper or non-woven fabric because they are more biodegradable and are more eco-friendly. The type of paper is not particularly limited; examples that can be used include gathered paper, pleated paper, crimped paper, crepe paper, and even shredded paper. The method for producing the paper or non-woven fabric may be either a wet method or a dry method, either of which can be selected, as desired.
When the substrate is in the form of a sheet, the thickness is not particularly limited, but is usually 20 µm or more, and preferably 30 µm or more, and is also usually 1.4 mm or less, and preferably 1.2 mm or less. The width of the substrate in the form of a sheet is also not particularly limited, but is usually 50 mm or more, preferably 100 mm or more, and more preferably 170 mm or more, and is also usually 300 mm or less, preferably 250 mm or less, and more preferably 230 mm or less.
When the substrate is a sheet of cellulose fiber-containing paper, the basis weight of the paper is not particularly limited, but is usually 20 g/m² or more, and preferably 25 g/m² or more, and is also usually 120 g/m² or less, preferably 80 g/m² or less, and more preferably 45 g/m² or less. A basis weight of 25 g/m² or more can ensure adequate tensile strength, and is preferable for the purposes of filter production. A basis weight of 80 g/m² or less can also ensure the flexibility of materials in the form of a sheet, making it easier to achieve suitable decreases in pressure.
The substrate may be provided with a plurality of folding lines (also referred to as crimp or crepe lines) in the axial direction of the filter, allowing the substrate to be folded accordion-wise along the folding lines. Providing such folding lines will allow the filter medium to be disposed while folded and gathered, allowing the surface area of the filter medium to be expanded, when the filter medium is disposed in the wrapper. The spacing between the folding lines can be, but is not particular limited to, 0.5 to 4.0 mm, for example.

(Coating Layer)

The coating layer according to the present embodiment is provided on the surface of the substrate, and comprises a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin. The coating layer may cover at least some of the substrate surface, and may cover the entire substrate surface. The coating layer may also consist of a homopolymer or copolymer having an acetate ester group or a hydroxypropyl group in a side chain, cyclodextrin or lecithin.
Polyvinyl acetate, vinyl acetate-acrylic copolymers, and ethylene-vinyl acetate copolymers are preferred as the homopolymers or copolymer having acetate ester groups in a side chain in the interests of higher phenol filtration performance. Hydroxypropyl cellulose and hydroxypropyl methylcellulose are preferred as the homopolymers or copolymers having hydroxypropyl groups in a side chain. α-Cyclodextrin, γ-cyclodextrin, and hydroxypropyl cyclodextrin (HP-cyclodextrin) are preferred as the cyclodextrin. These may be used alone or in combinations of two or more.
The method for forming the coating layer is not particularly limited but the layer can be formed, as described below, for example, by a method in which a liquid that comprises a homopolymer or copolymer having an acetate ester group or a hydroxypropyl group in a side chain, cyclodextrin, or lecithin, and water as a solvent (the solvent furthermore contains glycerol or propylene glycol, as needed) is sprayed and dried on the surface of the substrate.
The phenol-trapping component may also be included in the substrate. However, in order to further improve phenol-trapping performance, the phenol-trapping component concentration on the surface of the filter medium is preferably higher than the phenol-trapping component concentration in the interior of the filter medium. The following method, for example, can be used to confirm that the phenol-trapping component concentration on the surface of the filter medium is higher than the phenol-trapping component concentration in the interior of the filter medium. Laser Raman microspectroscopy can be used to image the cross-section of the target filter medium. This will allow the phenol-trapping component concentrations on the surface of, and in the interior of, the filter medium to be determined.
It is also disclosed, in PTL 3, that fibers containing plant pulp are bound together with a water-soluble binder, such as polyvinyl acetate, during the formation of non-woven fabric. However, since polyvinyl acetate, for example, is used as a binder for binding the fibers that form the non-woven fabric in PTL 3, the polyvinyl acetate, for example, is limited to the interior of the non-woven fabric, and no coating layer of polyvinyl acetate, for example, is formed on the surface of the non-woven fabric.

(Filter Medium)

The filter medium according to the present embodiment comprises the substrate and the coating layer. The content of the phenol-trapping component (homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin) in the filter medium is preferably 1 to 20% by weight, more preferably 2 to 11% by weight, and even more preferably 2 to 7% by weight per 100% by weight of the filter medium. A proportion of 1% by weight or more will enhance phenol trapping performance. A proportion of 20% by weight or less will be desirable for the purposes of suitable production in order to prevent phenol-trapping components from sticking to the machine when the filter is wrapped.
The filter medium can furthermore include hydrophobic flavoring in addition to the substrate and coating layer. In the present embodiment, the filter medium has a coating layer that includes a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin or lecithin, resulting in a high hydrophobic flavoring support capacity. Examples of hydrophobic flavoring in the present embodiment include menthol, cocoa (such as powders and extracts), esters (such as isoamyl acetate, linalyl acetate, isoamyl propionate, and linalyl butyrate), natural essential oils (plant essential oils such as vanilla extract, spearmint, peppermint, cassia, and jasmine; and animal essential oils such as musk, ambergris, civet, and castoreum), and single-component flavoring (such as anethole, limonene, linalool, eugenol, and vanillin), but menthol is preferred. The hydrophobic flavoring may be used alone or in combinations of two or more. When the filter medium does include hydrophobic flavoring, the content of the hydrophobic flavoring is preferably 10 to 50% by weight per 100% by weight of the filter medium.

(Filter Configuration, etc.)

The filter according to the present embodiment is configured by wrapping the filter medium in a wrapper. Fig. 1 shows an example of a filter according to the present embodiment. The filter 1 shown in Fig. 1 comprises: a filter medium 2 comprising the substrate and the coating layer; and a cylindrical wrapper 3 wrapped around the filter medium 2. Paper is an example of the material of the wrapper 3. The filter medium 2 has a plurality of folding lines in the axial direction of the filter 1, specifically, in the horizontal direction of Fig. 1, and is packed in the wrapper 3 while folded accordion-wise and gathered along the folding lines. The furrows formed by said gathering extend in the axial direction of the filter 1. Packing the filter medium 2 inside the filter 1 in this manner allows the surface area of the filter medium 2 to be increased while still allowing aerosol and flavor components to pass through in the axial direction of the filter 1. Phenols can thus be efficiently and selectively trapped in the filter medium 2.
The filter according to the present embodiment can furthermore comprise a granulated substance. When a granulated substance is included, the wrapper can furthermore be wrapped around the granulated substance in addition to the filter medium. Inside the cylindrical wrapper, the granulated substance can, for example, be located on the surface of the filter medium or in gaps in the filter medium. In the present embodiment, the filter medium has a coating layer that includes a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin or lecithin, resulting in high adhesion to the filter medium surface. In cases where the filter includes a granulated substance, this can ensure a higher granulated substance support capacity and can prevent the granulated substance from spilling out. Examples of granulated substances include activated carbon, hydrotalcite, and cellulose granules. These may be used alone or in combinations of two or more. Activated carbon has the effect of providing a smoother flavor. Hydrotalcite can selectively adsorb certain vapor phase components. Cellulose granules can increase the amounts in which particle phase components and semi-volatile components are transmitted. The average particle diameter of the granular substance is not particularly limited, but can be 200 to 1500 µm, for example. When the filter does include a granular substance, the content of the granular substance is preferably 1 part by weight to 50 parts by weight, and more preferably 1 part by weight to 20 parts by weight, per 100 parts by weight of the filter medium.
The airflow resistance of the filter according to the present embodiment is preferably 5 to 130 mmWG/27 mm tip, where the axial length of the filter is 27 mm. When the filter is for a combustion-type flavor inhaler, for example, the airflow resistance is preferably 50 to 130 mmWG/27 mm tip. When, on the other hand, the filter is for a heat-not-burn flavor inhaler, the airflow resistance is preferably 5 to 50 mmWG/27 mm tip. When a liquid that comprises water as well as a vinyl acetate homopolymer or copolymer, or hydroxypropyl cellulose, is provided onto, and dried on, the surface of the filter medium to form the coating layer, as described below, the airflow resistance can be adjusted, by adjusting the amount of water that is provided. It can also be adjusted based on the packing density with which the filter medium is packed in the filter. The airflow resistance can be determined using an airflow resistance measurement gauge (trade name: SODIMAX, by SODIM).
The shape of the filter according to the present embodiment is not particularly limited but can be cylindrical, for example. In cases where the filter is cylindrical, the circumferential length of the filter can be modified, as appropriate, depending on the size of the product that will be used, but is usually 14.0 mm or more, preferably 15.0 mm or more, and more preferably 16.0 mm or more, and is also usually 27.0 mm or less, preferably 26.0 mm or less, and more preferably 25.0 mm or less. The axial length of the filter can also be modified, as appropriate, depending on the size of the product, but is usually 5 mm or more, 10 mm or more, 15 mm or more, 17.5 mm or more, or 20.0 mm or more, and is 40 mm or less, 35 mm or less, 32.5 mm or less, or 30.0 mm or less. The cross-sectional shape of the filter is not particularly limited, but may be circular, elliptical, or polygonal, for example.

[Method for Producing Filter for Flavor Inhaler]

The method for producing the filter for a flavor inhaler according to the present embodiment comprises the following steps: a step in which a cellulose fiber-containing substrate is prepared; a step in which a liquid that comprises water and a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin is applied to, and dried on, the surface of the substrate to obtain a filter medium; and a step in which the filter medium is wrapped with a wrapper. This method allows the filter according to the present embodiment to be produced in an efficient and convenient manner.
The method according to the present embodiment can be carried out as follows, for example. While fed from a stock paper roll, a raw material sheet (cellulose fiber-containing substrate) is vertically creased and gathered, is wrapped with a wrapper using a filter-wrapping machine, and is made into a rod, which is cut to predetermined dimensions. Here, during the period of time from the step in which the raw material sheet is fed from the stock paper roll until the step in which it is wrapped with a wrapper, a liquid comprising water as well as a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin is applied and dried on the surface of the raw material sheet. For example, after the raw material sheet has been fed from the stock paper roll, and before it is conveyed into the filter-wrapping machine, the liquid can be applied and dried on the raw material sheet. The liquid may also be applied and dried on the raw material sheet when it is on the filter-wrapping machine before being wrapped with the wrapper.
In the step in which the liquid is applied and dried on the surface of the substrate, the distance between the fibers of the substrate shortens, resulting in shrinkage (specifically, the apparent density of the substrate decreases). This is attributed to the effect of the water that is included as solvent in the liquid. Thus, in a comparison of substrates (the amounts of which are the same), the volume of a substrate on which the liquid (water) has been applied and dried will be lower than the volume of a substrate to which no liquid is applied, resulting in less airflow resistance when the filter is formed. The amount of water that is provided when the liquid is applied can therefore be adjusted to adjust the airflow resistance of the resulting filter to the desired level. The phenol-trapping component included in the liquid is not believed to be involved in the reduction of the substrate volume.
The liquid can include, in addition to water, glycerol or propylene glycol, for example, as solvent. In cases where a homopolymer or copolymer having an acetate ester group in a side chain is used as the phenol-trapping component, the components are mixed with water (the solvent) to form an emulsion. On the other hand, in cases where a homopolymer or copolymer having a hydroxypropyl group in a side chain, or cyclodextrin or lecithin, is used as a phenol-trapping component, then glycerol or propylene glycol can be used, in addition to water, as solvent.
The step for obtaining the filter medium is preferably a step in which the liquid is sprayed and dried on the surface of the substrate in order to ensure that the liquid can be uniformly provided on the substrate surface. The content of the homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin is preferably 1 to 60% by weight, more preferably 2 to 40% by weight, and even more preferably 4 to 25% by weight per 100% by weight of the filter medium. A proportion of 1 to 60% by weight will allow the phenol-trapping component to be uniformly provided on the substrate. The liquid can be dried via heating or natural drying, for example.

[Flavor Inhaler]

The flavor inhaler according to the present embodiment comprises: a tobacco ingredient-containing tobacco rod; and the filter according to the present embodiment. The flavor inhaler according to the embodiment comprises the filter according to the present embodiment, thus allowing phenols to be adequately filtered when used and the amount of phenols to be reduced. Examples of flavor inhalers include combustion-type flavor inhalers (paper-wrapped tobacco, cigarettes), in which flavor is obtained by burning a tobacco rod, and heat-not-burn flavor inhalers, in which flavor is obtained by heating instead of burning the tobacco rod.

(Combustion-type Flavor Inhaler)

Fig. 2 shows an example of a combustion-type flavor inhaler according to the present embodiment. As shown in Fig. 2, a combustion-type flavor inhaler 11 comprises a tobacco rod 12 and the filter 13 according to the present embodiment provided adjacent to the tobacco rod 12. The airflow resistance of filter 13 is preferably 50 to 130 mmWG/27 mm tip. The tobacco rod 12 comprises: tobacco filler 14 comprising packed leaf tobacco or the like; and a wrapper 15 wrapped around the tobacco filler 14. The tobacco rod 12 and the filter 13 are connected by a tipping paper member 16, which is wrapped around the tobacco rod 12 and filter 13. The tipping paper member 16 may have ventilation holes in part of the outer circumference thereof. One or more ventilation holes, such as 10 to 40, may be formed. If there are multiple ventilation holes, the ventilation holes may, for example, be arranged in a single ring-shaped row around the outer circumference of the tipping paper member 16. Multiple ventilation holes can be arranged at roughly regular intervals. Providing ventilation holes will allow air to be drawn through the ventilation holes into the filter 13 when drawn. The mainstream smoke can be diluted with external air through the ventilation holes to design products having a desired tar level. Cigarettes are typical examples of such combustion-type flavor inhalers.
A user can enjoy the tobacco flavor by igniting the tip of the tobacco rod 12 and drawing, with the drawing end of the filter 13 held in the mouth. In particular, since the combustion-type flavor inhaler 11 comprises the filter 13 according to the present embodiment, the amount of phenols in the flavor that is provided will be reduced, resulting in milder flavor.

(Heat-not-Burn Flavor Inhaler)

Fig. 3 shows an example of a heat-not-burn flavor inhaler according to the present embodiment. The heat-not-burn flavor inhaler 20 shown in Fig. 3 comprises a tobacco rod 21 and a mouthpiece segment 22. The mouthpiece segment 22 comprises a cooling segment 23, a first filter 24 (the filter according to the present embodiment), and a second filter 25. The airflow resistance of the first filter 24 is preferably 5 to 50 mmWG/27 mm tip. When drawn, the tobacco rod 21 is heated, the components included in the tobacco filler 7 are vaporized, and are transferred, by being drawn, into the mouthpiece segment 22. The inhaler is drawn from the end of the filter 25.
The tobacco rod 21 has tobacco filler (comprising tobacco and an aerosol-generating substrate), and a cylindrical wrapper by which the tobacco filler is enclosed. Examples of aerosol-generating substrates include glycerol and propylene glycol. The tobacco filler may furthermore comprise a volatile flavor component and water, for example. The size of, and the method for producing, the tobacco that is used as filler are not particularly limited. For example, dried tobacco leaf that has been cut may be used. Dried tobacco leaf that has been ground and homogenized may also be processed into a sheet, which is then cut for use. The processed sheet may furthermore be gathered, without being cut, for use as filler. Various types of tobacco can be used as the tobacco included in the tobacco filler, whether dried leaf tobacco is used after being cut or is used in the form of a sheet of ground, homogenized tobacco. Yellow, Burley, Oriental, or native varieties, as well as other varieties of Nicotiana tabacum and Nicotiana rustica, may be blended as appropriate to achieve the intended flavor. Details on the aforementioned tobacco varieties are disclosed in the Dictionary of Tobacco, Tobacco Academic Studies Center, March 31, 2009.
The cooling segment 23 may be composed of a cylindrical member 26. The cylindrical member 26 may be a paper tube obtained by processing cardboard into a cylindrical shape, for example. The cylindrical member 26 and mouthpiece lining paper 31 described below are provided with a perforation 27 that penetrates through both. The perforation 27 allows external air to be introduced into the cooling segment 23 while drawn. As a result, the vaporized aerosol component that is generated when the tobacco rod 21 is heated will come into contact with the external air and cool off, and will thus become liquefied, forming an aerosol. There are no particular limitations as to the diameter (length across) of the perforation 27, which may, for example, be 0.5 to 1.5 mm. The number of perforations 27 is not particularly limited, and may be one or more. Multiple perforations 27 may be provided on the circumference of the cooling segment 23, for example.
The first filter 24 is the filter according to this embodiment, which includes a phenol-trapping component, and the second filter 25 is a filter that is similar to the filter according to the present embodiment, except that no phenol-trapping component is included. The first filter 24 may be the filter that is similar to the filter according to the embodiment but that contains no phenol-trapping component, and the second filter 25 may be the filter according to the present embodiment that does include a phenol-trapping component. The first filter 24 and second filter 25 may also both be filters according to the present embodiment that include phenol-trapping components. It is also possible to provide only one filter according to the present embodiment, without providing a filter that does not include a phenol-trapping component.
The first filter 24 and second filter 25 are joined by an outer plug wrapper 28. The outer plug wrapper 28 may be paper in a cylindrical shape, for example. The tobacco rod 21 and the cooling segment 23 may also be joined by the mouthpiece lining paper 29 to the already joined first filter 24 and second filter 25. These may be joined, for example, by applying glue, such as vinyl acetate-based glue, to the inside surface of the mouthpiece lining paper 29, and wrapping the lining paper around the three segments. Since the heat-not-burn flavor inhaler 20 comprises the first filter 24 according to the present embodiment, the amount of phenols in the flavor that is provided will be reduced, resulting in milder flavor.

(Heat-not-Burn Flavor Inhalation System)

The heat-not-burn flavor inhalation system according to the present embodiment comprises the heat-not-burn flavor inhaler according to the present embodiment described above and a heating device for heating the heat-not-burn flavor inhaler. The heat-not-burn flavor inhalation system according to the present embodiment may have other configurations besides the heat-not-burn flavor inhaler according to the present embodiment and the heating device.
Fig. 4 shows an example of a heat-not-burn flavor inhalation system according to the present embodiment. The heat-not-burn flavor inhalation system shown in Fig. 4 comprises the heat-not-burn flavor inhaler 40 according to the present embodiment and a heating device 41 for externally heating the tobacco rod of the heat-not-burn flavor inhaler 40. Fig. 4(a) shows the heat-not-burn flavor inhaler 40 before it is inserted into the heating device 41, and Fig. 4(b) shows the heat-not-burn flavor inhaler 40 while it is inserted into the heating device 41 to be heated. The heating device 41 shown in Fig. 4 comprises a body 42, a heater 43, a metal tube 44, a battery unit 45, and a control unit 46. The body 42 has a cylindrical recess 47, and the heater 43 and metal tube 44 are disposed on the inner side face of the recess 47 at positions facing the tobacco rod of the heat-not-burn flavor inhaler 40 which is inserted into the recess 47. The heater 43 may be a heater employing electrical resistance, with electrical power being supplied by the battery unit 45 in accordance with a command from the control unit 46 which controls the temperature, such that heating is effected by the heater 43. Heat emitted from the heater 43 is transferred through the highly thermally conductive metal tube 44 to the tobacco rod of the heat-not-burn flavor inhaler 40.
Since Fig. 4(b) is a schematic depiction, there is a gap between the outer circumference of the heat-not-burn flavor inhaler 40 and the inner circumference of the metal tube 44 therein, but in fact there is preferably no gap between the outer circumference of the heat-not-burn flavor inhaler 40 and the inner circumference of the metal tube 44, in order to ensure efficient heat transfer. Also, the tobacco rod of the heat-not-burn flavor inhaler 40 is externally heated by the heating device 41 but may be internally heated. When the tobacco rod is internally heated, a rigid plate-shaped, blade-shaped, or cylindrical heater is preferably used rather than the metal tube 44. Examples of such a heater include a ceramic heater, in which molybdenum or tungsten, for example, is applied onto a ceramic substrate.
The heating temperature of the heating device is not particularly limited, but is preferably 400°C or below, more preferably 150 to 400°C, and even more preferably 200 to 350°C. The heating temperature refers to the temperature of the heater of the heating device.

EXAMPLES

Specific examples of the present embodiment will be described below, but the present embodiment is not limited to these examples.

Example 1

A vinyl acetate-acrylic copolymer in an amount of 20% by weight was mixed with water in an amount of 80% by weight to produce an emulsion. The emulsion was sprayed (amount of vinyl acetate-acrylic copolymer applied: 26 mg) onto both sides of corrugated paper (basis weight: 40 g/m²), and was dried for 30 minutes to 1 hour at room temperature. This resulted in a filter medium, comprising a vinyl acetate-acrylic copolymer coating layer formed on the substrate surface. The proportion of the vinyl acetate-acrylic copolymer content was 10.9% by weight per 100% by weight of filter medium. The filter medium was folded so as to form a plurality of airflow channels, each of which extended from one end to the other end, and was wrapped with a paper wrapper to form a filter. The filter was joined to the tobacco rod of a commercially available paper-wrapped tobacco product (cigarette) (tradename: Winston Filter, by Japan Tobacco Inc.) to produce a cigarette. The tip of the tobacco rod of the cigarette was lit, and the product was used to assess the amount of tobacco smoke phenol that passed through the filter. The results are shown in Table 2.
Specifically, the amount of phenol passing through the filter was determined as follows. Cigarette samples were automatically smoked using an automatic smoking machine (SM410, by Cerulean) under conditions involving a smoking volume of 17.5 mL/second, a smoking time of 2 seconds/puff, a smoking frequency of 1 puff/minute, and a butt length of 35 mm, and the particulate matter (TPM) in the tobacco smoke was collected using Cambridge filters (Borgwaldt 44 mmφ). The TPM was determined based on the difference in the weight of the Cambridge filters before and after smoking. The Cambridge filters were then immersed and shaken in 10 mL of the phenol extraction solvent shown in Table 1 (contained in screw vials) to obtain samples for analysis. The resulting samples were collected in amounts of 1 µL using a microsyringe, and were analyzed by gas chromatography-mass spectrometry using a gas chromatography-mass selective detector (GC-MSD). Gas chromatography was carried out using the Agilent G7890A by Agilent Technologies Inc., and the Agilent _5795C by Agilent Technologies Inc. was used as the mass selective detector. [Table 1]

Compound Concentration

Solvent t-butyl methyl ether -

Internal standard o-chlorophenol 10.7 µg/mL
The amount of phenol passing through the filter is the amount of phenol per TPM (total particulate matter) passing through the filter, expressed as the value relative to 1, which is the amount of phenol passing through the filter in Comparative Example 1 described below (example in which no coating layer was formed).

Examples 2 through 13, and Comparative Examples 1 and 2

Filters were produced and assessed in the same manner as in Example 1, except that the components shown in Table 2 were used as phenol-trapping components, and the concentrations of the phenol-trapping components in solution as well as the amounts in which the phenol-trapping components were applied were modified as shown in Table 2. The results are shown in Table 2. In Example 7, a commercially available heat-not-burn flavor inhaler (tradename: Mevius Rich for Ploom X/Ploom S, by Japan Tobacco Inc.) was used instead of commercially available cigarettes, and a heating device (tradename: Ploom X, by Japan Tobacco Inc.) was used. The cellulose acetate fiber-containing filter and the center hole segment were removed from the heat-not-burn flavor inhaler. In their place, a filter produced in the same manner as in Example 1 was inserted into the center hole segment location, and a paper filter containing no phenol-trapping components was inserted into the filter location, resulting in a heat-not-burn flavor inhaler having the configuration shown in Fig. 3. Comparative Example 1 was assessed without any coating layer having been formed.

[Table 2]

	Coating layer		Concentration of phenol-trapping component in liquid (% by weight)	Amount of phenol-trapping component provided (mg)	Content of phenol-trapping component (% by weight) per 100% by weight of filter medium	Amount of phenol (per TPM) passing through filter
	Coating layer used	Phenol-trapping component		Amount of phenol-trapping component provided (mg)		Amount of phenol (per TPM) passing through filter
Example 1	Yes	Vinyl acetate-acrylic copolymer	20	26	10.9	0.50
Example 2	Yes	Polyvinyl acetate	10	26	10.9	0.59
Example 3	Yes	Polyvinyl acetate (50% by weight)	20	26	10.9	0.45
Example 3	Yes	Ethylene-vinyl acetate copolymer (50% by weight)	20	26	10.9	0.45
Example 4	Yes	Polyvinyl acetate (20% by weight)	20	26	10.9	0.47
Example 4	Yes	Ethylene-vinyl acetate copolymer (80% by weight)	20	26	10.9	0.47
Example 5	Yes	Ethylene-vinyl acetate copolymer	20	26	10.9	0.48
Example 6	Yes	Hydroxypropyl cellulose	4	10	4.2	0.62
Example 7	Yes	Hydroxypropyl cellulose	10	10	11.7	0.7
Example 8	Yes	Hydroxypropyl cellulose	10	26	10.9	0.55
Example 9	Yes	Hydroxypropyl methylcellulose	4	10	4.2	0.89
Example 10	Yes	α-cyclodextrin	10	25	10.5	0.66
Example 11	Yes	γ-cyclodextrin	10	25	10.5	0.7
Example 12	Yes	HP-cyclodextrin	20	25	10.5	0.66
Example 13	Yes	Lecithin	10	25	10.5	0.75
Comparative Example 1	No	-	-	0	0	1
Comparative Example 2	Yes	Polyvinyl alcohol	2	10	4.2	1.14

As shown in Table 2, in Examples 1 through 13 (use of filter media in which had been formed coating layers comprising a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin), less phenol passed through the filters than in Comparative Example 1 (use of filter media in which no coating layer had been formed). On the other hand, in Comparative Example 2 (use of filter media in which had been formed a coating layer comprising polyvinyl alcohol), the amount of phenol passing through the filter was slightly greater than in Comparative Example 1.

Examples 14 through 34

Filters were produced and assessed in the same manner as in Example 1, except that the components shown in Table 3 were used as phenol-trapping components, and the concentrations of the phenol-trapping components in solution as well as the amounts in which the phenol-trapping components and water were applied were modified as shown in Table 3. The airflow resistance of the filters of Examples 3 through 8 and Examples 14 through 34 was also determined. The results are shown in Table 3. A graph showing the amounts of phenol (per TPM) passing through filters relative to the amounts in which each phenol-trapping component was provided, as well as a graph showing the airflow resistance of the filters relative to the amounts in which water was provided in each phenol-trapping component are shown in Figs. 5 and 6, respectively. The airflow resistance of the filter in Example 7 was calculated based on a filter axial length of 27 mm.

[Table 3]

	Phenol-trapping component	Concentration of phenol-trapping component in liquid (% by weight)	Amount of phenol-trapping component provided (mg)	Content of phenol-trapping component (% by weight) per 100% by weight of filter medium	Amount of water provided (mg)	Amount of phenol (per TPM) passing through filter	Airflow resistance (mmWG/ 27 mm tip)
Example 14	Polyvinyl acetate (50% by weight) Ethylene-vinyl acetate copolymer (50% by weight)	20	5	2.1	20	0.70	109
Example 15		20	7	2.9	28	0.57	109
Example 16		20	10	4.2	40	0.53	108
Example 17		20	10	4.2	40	0.63	105
Example 18		20	13	5.5	52	0.58	99
Example 19		20	16	6.7	64	0.50	89
Example 20		20	20	8.4	80	0.58	86
Example 3		20	26	10.9	104	0.45	72
Example 21	Polyvinyl acetate (20% by weight) Ethylene-vinyl acetate copolymer (80% by weight)	20	5	2.1	20	0.69	102
Example 22		20	7	2.9	28	0.67	103
Example 23		20	10	4.2	40	0.46	98
Example 24		20	10	4.2	40	0.71	101
Example 25		20	13	5.5	52	0.68	94
Example 26		20	16	6.7	64	0.49	93
Example 27		20	20	8.4	80	0.52	83
Example 4		20	26	10.9	104	0.47	73
Example 28	Ethylene-vinyl acetate copolymer	20	5	2.1	20	0.61	109
Example 29		20	7	2.9	28	0.61	101
Example 30		20	10	4.2	40	0.50	100
Example 31		20	13	5.5	52	0.49	94
Example 32		20	16	6.7	64	0.44	92
Example 33		20	20	8.4	80	0.45	82
Example 34		20	20	8.4	80	0.47	87
Example 5		20	26	10.9	104	0.48	79
Example 6	Hydroxypropyl cellulose	4	10	4.2	90	0.62	106
Example7		10	10	11.7	234	0.7	9.4
Example 8		10	26	10.9	240	0.55	83

Table 3 shows that, in Examples 3 through 8 and 14 through 34 (use of filter media in which had been formed coating layers comprising a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin), less phenol passed through the filters than in Comparative Example 1, even when the amount in which the phenol-trapping components were provided was modified so as to modify the content of the phenol-trapping components in the filter media. Examples 3 through 6, 8, and 14 through 34 also show that the filter airflow resistance was reduced by increasing the amounts in which water was added. It can thus be seen that the amount in which water is provided when the liquid is applied can be adjusted to adjust the airflow resistance of the resulting filter to a desired level.
The present embodiment includes the following aspects.

[1] A filter for a flavor inhaler, comprising:
- a filter medium comprising a cellulose fiber-containing substrate and a coating layer provided on the substrate; and
- a wrapper wrapped around said filter medium;
- wherein
- the coating layer comprises a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin.
[2] The filter as set forth in [1], wherein the homopolymer or copolymer having an acetate ester group in a side chain is at least one selected from the group consisting of polyvinyl acetate, vinyl acetate-acrylic copolymers, and ethylene-vinyl acetate copolymers.
[3] The filter as set forth in [1] or [2], wherein the filter further comprises a granulated substance, and the wrapper is wrapped around the filter medium and the granulated substance.
[4] The filter as set forth in [3], wherein the granulated substance is at least one selected from the group consisting of activated carbon, hydrotalcite, and cellulose granules.
[5] The filter as set forth in any of [1] through [4], wherein the filter medium further comprises hydrophobic flavoring.
[6] The filter as set forth in [5], wherein the hydrophobic flavoring is menthol.
[7] The filter as set forth in any of [1] through [6], wherein the homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin is contained in a proportion of 1 to 20% by weight per 100% by weight of filter medium.
[8] The filter as set forth in any of [1] through [7], wherein the airflow resistance is 5 to 130 mmWG/27 mm tip.
[9] The filter as set forth in any of [1] through [8], wherein the concentration of the homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin on the surface of the filter medium is higher than the concentration of the homopolymer or copolymer having an acetate ester or hydroxypropyl group in a side chain, cyclodextrin, or lecithin in the interior of the filter medium.
[10] The filter as set forth in any of [1] through [9], wherein the substrate is a cellulose fiber-containing sheet of paper or non-woven fabric.
[11] A flavor inhaler comprising: a tobacco ingredient-containing tobacco rod; and the filter as set forth in any of [1] through [10].
[12] The flavor inhaler as set forth in [11], which is a combustion-type flavor inhaler.
[13] The flavor inhaler as set forth in [12], wherein the airflow resistance of the filter is 50 to 130 mmWG/27 mm tip.
[14] The flavor inhaler as set forth in [11], which is a heat-not-burn flavor inhaler.
[15] The flavor inhaler as set forth in [14], wherein the airflow resistance of the filter is 5 to 50 mmWG/27 mm tip.
[16] A method for producing a filter for a flavor inhaler, comprising:
- a step in which a cellulose fiber-containing substrate is prepared;
- a step in which a liquid that comprises water and a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin is applied to, and dried on, the surface of the substrate to obtain a filter medium; and
- a step in which the filter medium is wrapped with a wrapper.
[17] The method as set forth in [16], wherein the step for obtaining the filter medium is a step in which the liquid is sprayed and dried on the surface of the substrate.
[18] The method as set forth in [16] or [17], wherein the homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin is contained in a proportion of 1 to 60% by weight per 100% by weight of filter medium.

REFERENCE SIGNS LIST

1: Filter
2: Filter medium
3: Wrapper

Claims

A filter for a flavor inhaler, comprising:
a filter medium comprising a cellulose fiber-containing substrate and a coating layer provided on the substrate; and

a wrapper wrapped around said filter medium;

wherein

the coating layer comprises a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin.
The filter as claimed in claim 1, wherein the homopolymer or copolymer having an acetate ester group in a side chain is at least one selected from the group consisting of polyvinyl acetate, vinyl acetate-acrylic copolymers, and ethylene-vinyl acetate copolymers.
The filter as claimed in claim 1 or 2, wherein the filter further comprises a granulated substance, and the wrapper is wrapped around the filter medium and the granulated substance.
The filter as claimed in claim 3, wherein the granulated substance is at least one selected from the group consisting of activated carbon, hydrotalcite, and cellulose granules.
The filter as claimed in any one of claims 1 through 4, wherein the filter medium further comprises hydrophobic flavoring.
The filter as claimed in claim 5, wherein the hydrophobic flavoring is menthol.
The filter as claimed in any one of claims 1 through 6, wherein the homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin is contained in a proportion of 1 to 20% by weight per 100% by weight of filter medium.
The filter as claimed in any one of claims 1 through 7, wherein the airflow resistance is 5 to 130 mmWG/27 mm tip.
The filter as claimed in any one of claims 1 through 8, wherein the concentration of the homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin on the surface of the filter medium is higher than the concentration of the homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin in the interior of the filter medium.
The filter as claimed in any one of claims 1 through 9, wherein the substrate is a cellulose fiber-containing sheet of paper or non-woven fabric.
A flavor inhaler comprising: a tobacco ingredient-containing tobacco rod; and the filter as claimed in any one of claims 1 through 10.
The flavor inhaler as claimed in claim 11, which is a combustion-type flavor inhaler.
The flavor inhaler as claimed in claim 12, wherein the airflow resistance of the filter is 50 to 130 mmWG/27 mm tip.
The flavor inhaler as claimed in claim 11, which is a heat-not-burn flavor inhaler.
The flavor inhaler as claimed in claim 14, wherein the airflow resistance of the filter is 5 to 50 mmWG/27 mm tip.
A method for producing a filter for a flavor inhaler, comprising:
a step in which a cellulose fiber-containing substrate is prepared;

a step in which a liquid that comprises water and a homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin is applied to, and dried on, the surface of the substrate to obtain a filter medium; and

a step in which the filter medium is wrapped with a wrapper.
The method as claimed in claim 16, wherein the step for obtaining the filter medium is a step in which the liquid is sprayed and dried on the surface of the substrate.
The method as claimed in claim 16 or 17, wherein the homopolymer or copolymer having an acetate ester group or hydroxypropyl group in a side chain, cyclodextrin, or lecithin is contained in a proportion of 1 to 60% by weight per 100% by weight of filter medium.