JP7176101B2 - Method for producing carbon heat source for flavor inhaler, composite particles, carbon heat source for flavor inhaler, and flavor inhaler - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a carbon heat source for a flavor inhaler, composite particles, a carbon heat source for a flavor inhaler, and a flavor inhaler.

A flavor inhaler is known which has a carbon heat source at its tip and heats the tobacco filler by the combustion heat of the carbon heat source. The carbon heat source used in the flavor inhaler can be produced by extruding and drying a raw material slurry containing carbon particles and additives such as a binder.

Japanese Patent Application Laid-Open No. 62-224276 discloses an improved method for producing a carbon heat source with the aim of improving the combustibility of the carbon heat source. Specifically, Japanese Patent Application Laid-Open No. 62-224276, as shown in FIG. 1 of the present application, forms a raw material slurry 1 containing carbon particles 1a and an aqueous solution (dispersion medium) 1b containing a binder into a sheet. It is disclosed that the carbon heat source 5 is produced by stretching and drying, pulverizing the obtained sheet 2, adding water to the obtained pulverized material 3 and molding it, and drying the obtained molded body 4. .

WO2006/073065 discloses that a carbon heat source is produced from a composition comprising carbon particles, calcium carbonate particles and a binder, and such a carbon heat source can reduce the amount of carbon monoxide generated during combustion of the carbon heat source. Show what you can do.

When the present inventors produced a carbon heat source according to the method described in Japanese Patent Application Laid-Open No. 62-224276, they encountered the problem of difficulty in molding. Therefore, when molding was attempted by increasing the amount of water added during molding (for example, 34% by mass with respect to the pulverized product), the molding material adhered to the molding machine (Comparative Example 1 described later). ). When water is added in an amount commonly used during molding (for example, 30% by weight of the pulverized product), molding is difficult, and the resulting carbon heat source has no problem in ignitability, but strength was not sufficient (see Comparative Example 2 below).

Accordingly, an object of the present invention is to provide a technology relating to a carbon heat source for a flavor inhaler that is excellent in ease of manufacture, has high strength, and has excellent ignitability.

According to the first aspect,
forming composite particles having an average particle diameter D50 of 10 to 150 μm and a half width of 10 to 150 μm, using a slurry containing carbon particles, calcium carbonate particles, a binder, and water as raw materials;
A method for producing a carbon heat source for a flavor inhaler is provided, comprising: molding a mixture containing the composite particles and water to obtain a molded body; and drying the molded body.

A second aspect provides composite particles containing carbon particles, calcium carbonate particles and a binder, having an average particle size D50 of 10 to 150 μm and a half width of 10 to 150 μm.

According to a third aspect, there is provided a carbon heat source for flavor inhalers manufactured by the method of the first aspect.
According to a fourth aspect there is provided a flavor inhaler comprising a carbon heat source according to the third aspect.

ADVANTAGE OF THE INVENTION According to this invention, the technique regarding the carbon heat source for flavor inhalers which is excellent in manufacturability, has high intensity|strength, and has excellent ignition property can be provided.

FIG. 1 is a diagram schematically showing the method described in the prior art document. FIG. 2 is a diagram schematically showing an example of the method of the present invention. FIG. 3 is a perspective view showing an example of a carbon heat source for a flavor inhaler. FIG. 4 is a cross-sectional view showing an example of a flavor inhaler. FIG. 5 is a graph showing the particle size distribution of composite particles A1. FIG. 6 is a graph showing the particle size distribution of composite particles A2. FIG. 7 is a graph showing the particle size distribution of composite particles A3. 8 is a graph showing the particle size distribution of Composite Particle B. FIG. FIG. 9 is a micrograph of Composite Particle A2. 10 is a micrograph of Composite Particle B. FIG.

The present invention will now be described in detail, but the following description is for the purpose of illustrating the invention and is not intended to limit the invention.

<1. Method for producing carbon heat source>
In one aspect, a method for producing a carbon heat source for a flavor inhaler comprises:
forming composite particles having an average particle diameter D50 of 10 to 150 μm and a half width of 10 to 150 μm, using a slurry containing carbon particles, calcium carbonate particles, a binder, and water as raw materials;
molding a mixture containing the composite particles and water to obtain a molded body; and drying the molded body.

The carbon heat source for the flavor inhaler is a heat source that heats the flavor source in the flavor inhaler by combustion of the carbon heat source. The flavor source within the flavor inhaler is heated by the heat of combustion of the carbon heat source, but is not burned. The flavor source generates flavor when heated. In the following description, the carbon heat source for flavor inhalers is also simply referred to as "carbon heat source".

An example of the method of the present invention is schematically shown in FIG. Figure 2 shows
(1) Prepare raw material slurry 1,
(2) forming composite particles 6 from the raw material slurry 1;
(3) molding the composite particles 6 to obtain a molding 7,
(4) Dry the compact 7 to obtain the dried compact 8 .

The dried compact 8 may be used as a carbon heat source as it is, or may be used as a carbon heat source after being subjected to necessary processing. In FIG. 2, raw material slurry 1 is composed of carbon particles 1a, calcium carbonate particles 1c, and an aqueous solution (dispersion medium) 1b containing a binder.

The steps of "preparation of raw material slurry", "formation of composite particles", "molding" and "drying" are described in detail below.

(Preparation of raw material slurry)
The raw material slurry contains carbon particles, calcium carbonate particles, a binder, and water.

As the carbon particles, carbon particles that are generally used as raw materials for carbon heat sources for flavor inhalers can be used. Specifically, any carbon particles that can be combusted by ignition can be used as the carbon particles. The carbon particles are preferably activated carbon particles, more preferably activated carbon particles having a BET specific surface area of 1000-2500 m ² /g. The carbon particles preferably have an average particle size of 2-100 μm, more preferably 5-50 μm. Here, the "average particle size" refers to an average particle size D50 based on a volume-based particle size distribution measured by a laser diffraction/scattering particle size distribution measurement method.

Commercially available activated carbon particles can be used as the ^carbon particles. Y (particle diameter: 45 μm or less, BET specific surface area: 1,300 to 1,500 m ² /g, Kuraray Chemical Co., Ltd.), Kuraray Coal SA1500 (average particle diameter: 6.19 μm, BET specific surface area: 1,600 to 1,800 m ² /g). be done. One type of carbon particles may be used, or a plurality of types may be used in combination.

The carbon particles are contained in the slurry in an amount of preferably 20 to 90% by mass, more preferably 30 to 60% by mass, based on the mass of solids contained in the slurry. As used herein, "solids" refers to the remaining components (ie, non-volatiles) after the liquid is evaporated from the slurry. That is, "solids" are the components that remain when the slurry is in the form of composite particles or a carbon heat source. Therefore, the “solid content” includes not only the components present in the slurry in a solid state (carbon particles, calcium carbonate particles), but also the components dissolved in the slurry but remaining after the slurry is dried (binder ) are also included.

Calcium carbonate particles can be calcium carbonate particles that are generally used in combination with carbon particles as a raw material for a carbon heat source for flavor inhalers. Calcium carbonate particles can reduce the amount of combustion products, especially carbon monoxide.

Calcium carbonate particles having a bulk density of 0.3 to 1.0 g/cm ³ can be used, for example. Firm bulk density was measured after filling the particles into a 100 mL container in a leveled state (i.e., loose bulk density), adding an equal amount of particles, and tapping (vibrating) 180 times. refers to density. The calcium carbonate particles preferably have an average particle size of 100 μm or less, more preferably 10 μm or less. Since the smaller the average particle size of the calcium carbonate particles, the better, the lower limit is not particularly limited, but is, for example, 0.2 μm. Here, the "average particle size" refers to an average particle size D50 based on a volume-based particle size distribution measured by a laser diffraction/scattering particle size distribution measurement method.

As calcium carbonate particles, commercially available calcium carbonate particles can be used, for example, Calpine F (average particle size: 3 μm, bulk density: 0.66 g/cm ³ , Yabashi Industry Co., Ltd.). One type of calcium carbonate particles may be used, or a plurality of types may be used in combination.

The calcium carbonate particles are contained in the slurry in an amount of preferably 5 to 75% by mass, more preferably 40 to 70% by mass, based on the mass of solids contained in the slurry.

The particle size ratio of carbon particles and calcium carbonate particles can be, for example, 10:1 to 1:10. The mass ratio of carbon particles and calcium carbonate particles can be, for example, 5:1 to 1:5.

As the binder, binders commonly used as raw materials for carbon heat sources for flavor inhalers can be used. The binder binds the particles (carbon particles and calcium carbonate particles) in the slurry to each other to increase the strength of the carbon heat source. The binder is dissolved in the slurry.

Cellulose derivatives or alginates can be used as binders. Cellulose derivatives include, for example, carboxymethylcellulose, sodium carboxymethylcellulose, methylhydroxyethylcellulose, methylcellulose or hydroxypropylcellulose.

The binder is contained in the slurry in an amount of preferably 3-15% by weight, more preferably 5-10% by weight, based on the weight of solids contained in the slurry.

As will be described in the "Effect" column below, in the present invention, since the carbon heat source is produced using composite particles having a small average particle size and a sharp particle size distribution, even if the binder content is reduced, sufficient Carbon heat sources with strength can be produced. Therefore, the method of the present invention allows the binder content to be reduced as described above. Reducing the binder content increases the content ratio of the carbon particles and the calcium carbonate particles, so that the ignitability of the carbon heat source can be enhanced.

The ratio of the mass of the solid content contained in the slurry to the mass of the liquid contained in the slurry (hereinafter also referred to as solid-liquid ratio) is preferably 1:1 to 1:9, more preferably 1:2 to 1: 4. The liquid contained in the slurry is generally water.

When the raw material slurry is spread into a sheet according to the method of the prior art document described in the Background Art column (see FIG. 1), the slurry should be able to be spread into a sheet, so that the mass of the liquid relative to the mass of the solid content is ratio (solid-liquid ratio) must be increased. On the other hand, when the slurry is directly atomized to form composite particles without forming a sheet, the slurry can have a small ratio of liquid mass to solid mass (solid-liquid ratio). By reducing the solid-liquid ratio, it is possible to shorten the drying time for evaporating the water thereafter, so that the manufacturing cost can be reduced.

(Formation of composite particles)
Composite particles having an average particle size D50 of 10 to 150 μm and a half width of 10 to 150 μm are formed using the raw material slurry described above. The average particle size D50 is preferably between 10 and 120 μm.

"Average particle size D50" refers to an average particle size D50 based on a volume-based particle size distribution measured by a laser diffraction scattering particle size distribution measurement method. "Half width" refers to the half width based on the volume-based particle size distribution measured by a laser diffraction scattering particle size distribution measurement method. "Full width at half maximum" refers to full width at half maximum.

Composite particles can be formed by any method capable of forming particles having the above particle size and half width. Formation of the composite particles can be specifically performed using a technique of direct atomization of the slurry, more specifically spray drying. Preferably, forming the composite particles can be done by spray drying the slurry. Spray drying is a technique in which a liquid or slurry is atomized into a gas and dried rapidly to produce particles.

More preferably, composite particles can be formed by spraying the slurry into heated gas with an atomizer or spray nozzle and drying it instantaneously to form fine particles. The phrase "rapidly dry" or "instantaneously dried" in describing spray drying means that drying is complete while the sprayed droplets are in the air (i.e. before they fall to the ground). It means that More preferably, the composite particles are formed by spray-drying the slurry with a rotary atomizer type spray dryer, i.e., droplets of the slurry are placed in a heated gas by centrifugal force due to rotation of a disk-type atomizer (rotary atomizer). by spraying onto a surface and flash drying to form microparticles. A rotary atomizer type spray dryer is suitable for forming composite particles having a small particle size and a sharp particle size distribution.

When a rotary atomizer type spray dryer is used, composite particles having the above-described average particle size D50 and the above-described half width can be formed by setting the spraying conditions and drying conditions, for example, as follows.
Disk diameter: 60-200mm
Disk rotation speed: 8000-30000rpm
Slurry discharge speed: 15 to 160 L/h
Hot air temperature at outlet (where particles come out): 80-150°C

As described above, the composite particles have a small average particle size and a sharp particle size distribution. When such composite particles are molded, the composite particles can be molded with a uniform density and a high density throughout the molded body, thereby improving the strength of the produced carbon heat source and excellent It can provide ignitability.

The composite particles preferably have a spherical morphology. Here, the “spherical form” means that the average circularity obtained from the micrograph of the composite particles is 0 to 0.2 × D [μm] (here, D refers to the average particle diameter D50 of the composite particles). refers to a form. "Average circularity" refers to the average circularity of 20 composite particles. "Circularity" refers to the difference in radius between two concentric geometric circles when the microscopic image of the target particle is sandwiched between two concentric circles, when the distance between the two concentric circles is the minimum (JIS B 0621:1984).

As described above, when composite particles are produced by spray drying, all composite particles can generally have a spherical morphology. In this way, when composite particles having an all-spherical shape are molded, they can be molded with a higher density. Incidentally, in the prior art document described in the background art section, composite particles are produced by spreading a raw material slurry into a sheet and pulverizing the obtained sheet (see FIG. 1). Therefore, in the prior art documents, the composite particles do not have a spherical morphology.

The composite particles also preferably have smooth surfaces when viewed under a microscope. Composite particles, as described above, can generally all have smooth surfaces when produced by spray drying. Thus, when composite particles having all smooth surfaces are molded, they can be molded to a higher density. Incidentally, in the prior art document described in the background art section, composite particles are produced by spreading a raw material slurry into a sheet and pulverizing the obtained sheet (see FIG. 1). For this reason, in prior art documents, composite particles do not have smooth surfaces.

(molding)
The composite particles described above are mixed with water and the resulting mixture is molded.
The amount of water mixed with the composite particles is preferably a suitable amount for subsequent molding operations. The amount of water mixed with the composite particles is preferably 33-67% by mass, more preferably 38-57% by mass, based on the composite particles. That is, the mixture is preferably a mixture containing the composite particles and 33 to 67% by mass of water with respect to the composite particles, and the mixture contains the composite particles and 38 to 57% by mass of water with respect to the composite particles. It is more preferable that it is a mixture containing

Water dissolves the binder present on the surface of the composite particles, thereby binding the composite particles together. Therefore, it is preferable that water is uniformly present on the surface of the composite particles. Preferably, the mixture is prepared by spraying water onto the surfaces of the composite particles while the composite particles are fluidized so that the water spreads over the entire surface of the composite particles. For example, the mixture can be prepared by spraying water onto the surface of the composite particles while stirring the composite particles.

When the amount of water contained in the mixture is within the above range, it has the advantage of being easy to mold and the advantage of being able to increase the strength of the produced carbon heat source.

In the mixture, the composite particles tend to adhere to each other and may agglomerate. Therefore, before molding the mixture, the composite particles may be deaggregated, or the composite particles may be classified to select only composite particles having a predetermined size or less.

The molding can be done using molding methods commonly used in the manufacture of carbon heat sources for flavor inhalers. Molding can be done, for example, by compression molding, extrusion, or stamping. Molding can preferably be carried out by compression molding, more preferably by tableting. Molding can be carried out so as to obtain a molded body having a density of, for example, 0.6 to 1.0 g/cm ³ . The pressure during molding can be, for example, 1 to 5 kN.

The molded body preferably has a cylindrical or polygonal prism shape on the assumption that it will be incorporated into a cylindrical flavor inhaler.

(dry)
The molded body is dried to produce a dried molded body (dried molded body). Drying can be performed by heat drying. For example, the compact can be dried at 100-200° C. for 20-60 minutes. The heating temperature may be constant within the above heating temperature range over the drying period, or may be varied such that the temperature increases within the above heating temperature range. The proportion of water in the dried compact can be, for example, 10% by mass or less.

The dried compact may be used as it is as a carbon heat source. Alternatively, the dry compact can be chamfered or provided with a groove (for example, a cross groove) on the ignition surface, if necessary. A compact after such processing may be used as a carbon heat source. Chamfering contributes to making cracks and chips less likely to occur at the corners of the carbon heat source. Grooving contributes to improving ignitability.

As described above, the dry molded body has high strength because it is produced by molding the composite particles with a uniform density over the entire molded body and at a high density. For this reason, the dry compact is less likely to crack or chip even when subjected to processing such as chamfering or grooving, and is suitable for processing.

(Example of carbon heat source)
An example of a carbon heat source is shown in FIG. The carbon heat source 10 shown in FIG. 3 has a cylindrical shape. The carbon heat source 10 is incorporated into the flavor inhaler such that the tip surface 11 is positioned at the tip of the flavor inhaler.

As shown in FIG. 3, the carbon heat source 10 includes a distal end surface 11, a proximal end surface 12 facing the distal end surface 11, an air passage 13 for supplying air to the inside of the flavor inhaler main body, and an outer peripheral surface 14. , a groove portion 15 provided in the distal end surface 11, a first chamfered portion 16 formed between the distal end surface 11 and the outer peripheral surface 14, and a second chamfered portion formed between the proximal end surface 12 and the outer peripheral surface 14 and a chamfered portion 17 .

The air passage 13 is provided along the central axis C of the carbon heat source 10 so as to penetrate the carbon heat source 10 . The air passage 13 allows the distal end surface 11 and the proximal end surface 12 to communicate with each other. A portion of the air passage 13 on the side of the tip surface 11 is integrated with the groove portion 15 . The air passage 13 may be provided by forming a hollow columnar molded body having a through hole, or may be provided by drilling a through hole after forming a solid cylindrical molded body.

The groove portion 15 is formed in a “cross” shape as a whole when viewed from the distal end surface 11 side. The shape of the groove portion 15 is not limited to a "cross" shape. The number of grooves 15 is arbitrary. Further, the shape formed by the entire groove portion 15 can be any shape. For example, a plurality of grooves 15 may radially extend from the air passage 13 toward the outer peripheral surface 14 . Moreover, the groove part 15 is recessed from the front end surface 11 and the outer peripheral surface 14 so as to straddle them. Groove 15 is provided so as to communicate with air passage 13 .

The carbon heat source 10 can be formed with the following dimensions. The total length of the carbon heat source 10 (the length of the carbon heat source 10 with respect to the direction of the central axis C) is appropriately set, for example, within the range of 5 to 30 mm, preferably within the range of 8 to 18 mm. The diameter of the carbon heat source 10 (the length of the carbon heat source 10 with respect to the direction intersecting the central axis C) is appropriately set, for example, within the range of 3 to 15 mm, preferably within the range of 5 to 10 mm. The depth (length) of the groove 15 in the direction of the central axis C of the carbon heat source 10 is appropriately set, for example, within the range of 1 to 5 mm, preferably within the range of 2 to 4 mm. The width (inner diameter) of the groove portion 15 is appropriately set within a range of, for example, 0.5 to 2 mm. The inner diameter of the air passage 13 is appropriately set within a range of 0.5 to 4 mm, for example.

The carbon heat source 10 may not have the air passage 13 . In this case, it is preferable to form a plurality of small holes for ventilation in the main body of the flavor inhaler (that is, the holder). When the user inhales with the flavor inhaler, air is supplied through the small hole to the holder and to the flavor source within the holder.

(effect)
The above-described method does not have the problem of difficulty in molding the carbon heat source, and is excellent in ease of manufacture. Moreover, according to the above-described method, a carbon heat source having high strength and excellent ignitability can be produced.

In the above method, the composite particles used for producing the carbon heat source have an average particle size D50 of 10 to 150 μm, a half width of 10 to 150 μm, a small average particle size, and a sharp particle size distribution. is. When such composite particles are used to produce a carbon heat source, the composite particles can be molded with uniform density and high density throughout the molded body, thereby achieving high strength and excellent ignitability. Conceivable.

In addition, in the above-described method, the use of the above-described composite particles ensures the strength of the carbon heat source, so even if the binder content is reduced, a carbon heat source having sufficient strength can be produced. Reducing the binder content increases the content ratio of the carbon particles and the calcium carbonate particles, so that the ignitability of the carbon heat source can be enhanced.

<2. Composite particles>
According to another aspect, <1. Method for producing carbon heat source>. Specifically, composite particles containing carbon particles, calcium carbonate particles and a binder and having an average particle size D50 of 10 to 150 μm and a half width of 10 to 150 μm are provided. Preferably, composite particles are provided which contain carbon particles, calcium carbonate particles and a binder, and have an average particle size D50 of 10 to 120 μm and a half width of 10 to 150 μm.

<3. Carbon heat source>
According to another aspect, <1. A carbon heat source for a flavor inhaler is provided, which is manufactured by the method described in the section "Manufacturing method of carbon heat source". As described above, carbon heat sources have high strength and excellent ignitability. For example, the carbon heat source can have an intensity of 140-250N and a density of 0.6-1.0 g/cm ³ . Preferably, the carbon heat source can have an intensity of 140-250N and a density of 0.7-0.9 g/cm ³ .

If the carbon heat source has a strength of 140 N or more, it has sufficient strength as a carbon heat source for the flavor inhaler. The density of the carbon heat source is an index that correlates with ignitability, and the lower the density, the better the ignitability. The ignitability depends not only on the density of the carbon heat source but also on other factors such as the type of carbon particles, but when the density of the carbon heat source is within the above range, the ignitability can be improved.

<4. Flavor sucker>
According to another aspect, <1. A flavor inhaler containing a carbon heat source for a flavor inhaler manufactured by the method described in the section "Manufacturing method of carbon heat source" is provided.

An example of a flavor inhaler incorporating the carbon heat source shown in FIG. 3 is shown in FIG.
A flavor inhaler 20 shown in FIG. 22, an aluminum laminated paper 23 interposed between the flavor source 22 inside the holder 21, and a filter portion 24 provided inside the holder 21 on the side of the mouthpiece end 21A. In addition, in the flavor inhaler 20 shown in FIG. 4, the space between the flavor source 22 and the filter section 24 is hollow.

The heat generated by the combustion of the carbon heat source 10 can heat the flavor source 22 located downstream of the carbon heat source 10 to release flavor.

The holder 21 is a paper tube formed by rolling paper into a cylindrical shape. The aluminum laminated paper 23 is formed by laminating aluminum to paper, and has improved heat resistance and thermal conductivity as compared with ordinary paper. The aluminum laminated paper 23 prevents the paper tube of the holder 21 from burning even when the carbon heat source 10 is ignited. A central axis C of the holder 21 coincides with a central axis C of the carbon heat source 10 .

The flavor source 22 is provided downstream of the carbon heat source 10 at a position adjacent to the carbon heat source 10 . Flavor source 22 can be any flavor source that can release flavor when heated. For example, the flavor source 22 is formed by forming a tobacco material such as leaf tobacco into a sheet shape, forming accordion-like pleats on the tobacco sheet to form a corrugated tobacco sheet, and forming a plurality of air flow paths in the longitudinal direction of the corrugated tobacco sheet. can be prepared by gathering and forming into a cylinder to form a Also, the flavor source 22 may be granules formed from tobacco extract or leaf tobacco itself. That is, as the flavor source 22, any tobacco filler such as general cut tobacco used for cigarettes, granular tobacco used for snuff, rolled tobacco, and molded tobacco can be used. A rolled tobacco is obtained by forming a sheet-like regenerated tobacco into a roll, and has a flow path inside. Molded tobacco is obtained by molding tobacco granules with a mold. Alternatively, as the flavor source 22, a carrier made of a porous material or a non-porous material may carry tobacco flavor or flavor other than tobacco flavor. The flavor source 22 may be incorporated into the flavor inhaler 20 after being cylindrically wrapped with paper, or may be incorporated into the flavor inhaler 20 after being housed in a cup made of metal or paper.

The filter part 24 is composed of a filter commonly used in cigarettes. Filter portion 24 can be formed from various types of fillers. The filter part 24 is composed of, for example, a filler of cellulosic semi-synthetic fibers such as cellulose acetate, but the filler is not limited to this. Fillers include, for example, vegetable fibers such as cotton, hemp, manila hemp, palm and rush, animal fibers such as wool and cashmere, regenerated cellulose fibers such as rayon, synthetic fibers such as nylon, polyester, acrylic, polyethylene and polypropylene, or Combinations thereof can be used. The constituent elements of the filter part 24 may be a charcoal filter containing charcoal or a filter containing particulates other than charcoal, in addition to the filler made of cellulose acetate fiber. Moreover, the filter part 24 may have a multi-segment structure in which two or more segments of different types are connected in the axial direction.

<5. Method according to another aspect>
In another aspect, a method of manufacturing a carbon heat source for a flavor inhaler comprises:
forming composite particles by spray drying a slurry comprising carbon particles, calcium carbonate particles, a binder and water;
molding a mixture containing the composite particles and water to obtain a molded body; and drying the molded body.

The above method includes <1. Manufacturing method of carbon heat source>.

When composite particles are formed by spray drying according to the above method, composite particles having a small average particle size and a sharp particle size distribution can be formed. Preferably, composite particles having an average particle diameter D50 of 10 to 150 μm and a half width of 10 to 150 μm can be formed. When such composite particles are molded, the composite particles can be molded with a uniform density and a high density throughout the molded body, thereby improving the strength of the produced carbon heat source and excellent It can provide ignitability.

<6. Preferred embodiment>
Preferred embodiments are summarized below.
[A1] forming composite particles having an average particle diameter D50 of 10 to 150 μm and a half width of 10 to 150 μm, using a slurry containing carbon particles, calcium carbonate particles, a binder, and water as raw materials;
A method for producing a carbon heat source for a flavor inhaler, comprising molding a mixture containing the composite particles and water to obtain a molded body, and drying the molded body.

[A2] The method according to [A1], wherein the average particle size D50 is 10 to 120 μm, preferably 50 to 150 μm, more preferably 70 to 120 μm.
[A3] The method according to [A1] or [A2], wherein the half width is 30 to 150 μm, preferably 50 to 150 μm, more preferably 60 to 140 μm.
[A4] The method according to any one of [A1] to [A3], wherein the composite particles have a spherical shape.

[A5] The method according to any one of [A1] to [A4], wherein the composite particles are formed by spray-drying the slurry.
[A6] The method according to any one of [A1] to [A5], wherein the composite particles are formed by spray-drying the slurry using a rotary atomizer type spray dryer.
[A7] Any of [A1] to [A6], wherein the binder is contained in the slurry in an amount of 3 to 15% by mass, preferably 5 to 10% by mass, based on the mass of the solid content contained in the slurry. 1. The method according to 1.

[A8] Any one of [A1] to [A7], wherein the mixture contains the composite particles and 33 to 67% by mass, preferably 38 to 57% by mass of water with respect to the composite particles. 1. The method according to 1.
[A9] The ratio (A:B) of the mass (A) of the solid content contained in the slurry to the mass (B) of the liquid contained in the slurry is 1:1 to 1:9, preferably 1: The method according to any one of [A1] to [A8], wherein the ratio is 2 to 1:4.
[A10] The method according to any one of [A1] to [A9], wherein the carbon particles have an average particle size of 2 to 100 µm, preferably 5 to 50 µm.

[A11] The method according to any one of [A1] to [A10], wherein the carbon particles are activated carbon particles.
[A12] of [A1] to [A11], wherein the carbon particles are contained in the slurry in an amount of 20 to 90% by mass, preferably 30 to 60% by mass, based on the mass of the solid content contained in the slurry; 2. The method according to any one of 1.
[A13] Any one of [A1] to [A12], wherein the calcium carbonate particles have an average particle size of 100 μm or less (eg, 0.2 to 100 μm), preferably 10 μm or less (eg, 0.2 to 10 μm). 1. The method according to 1.

[A14] The calcium carbonate particles are contained in the slurry in an amount of 5 to 75% by mass, preferably 40 to 70% by mass, relative to the mass of solids contained in the slurry [A1] to [A13]. The method according to any one of .
[A15] The method according to any one of [A1] to [A14], wherein the carbon particles and the calcium carbonate particles have a particle size ratio of 10:1 to 1:10.
[A16] The method according to any one of [A1] to [A15], wherein the carbon particles and the calcium carbonate particles have a mass ratio of 5:1 to 1:5.

[A17] The method according to any one of [A1] to [A16], wherein the binder is a cellulose derivative.
[A18] The method of [A17], wherein the cellulose derivative is carboxymethylcellulose, sodium carboxymethylcellulose, methylhydroxyethylcellulose, methylcellulose, or hydroxypropylcellulose.
[A19] The method according to [A17] or [A18], wherein the cellulose derivative is carboxymethyl cellulose.

[A20] The method according to any one of [A1] to [A19], wherein the molding is performed by compression molding.
[A21] The method according to any one of [A1] to [A20], wherein the molding is performed by tableting.
[A22] The molding is carried out so as to obtain a compact having a density of 0.6 to 1.0 g/cm ³ , preferably 0.7 to 0.9 g/cm ³ [A1] to [A21] The method according to any one of .
[A23] The method according to any one of [A1] to [A22], wherein the molding is performed by applying a pressure of 1 to 5 kN.

[B1] forming composite particles by spray-drying a slurry containing carbon particles, calcium carbonate particles, a binder, and water;
A method for producing a carbon heat source for a flavor inhaler, comprising molding a mixture containing the composite particles and water to obtain a molded body, and drying the molded body.

[B2] The method according to [B1], wherein the composite particles have an average particle size D50 of 10 to 150 μm and a half width of 10 to 150 μm.
[B3] The method according to [B2], wherein the average particle diameter D50 is 10 to 120 μm, preferably 50 to 150 μm, more preferably 70 to 120 μm.
[B4] The method according to [B2] or [B3], wherein the half width is 30 to 150 μm, preferably 50 to 150 μm, more preferably 60 to 140 μm.

[B5] The method according to any one of [B1] to [B4], wherein the composite particles have a spherical shape.
[B6] The method according to any one of [B1] to [B5], wherein the composite particles are formed by spray-drying the slurry using a rotary atomizer type spray dryer.
[B7] Any of [B1] to [B6], wherein the binder is contained in the slurry in an amount of 3 to 15% by mass, preferably 5 to 10% by mass, based on the mass of the solid content contained in the slurry. 1. The method according to 1.

[B8] Any one of [B1] to [B7], wherein the mixture contains the composite particles and 33 to 67% by mass, preferably 38 to 57% by mass of water with respect to the composite particles. 1. The method according to 1.
[B9] The ratio (A:B) of the mass (A) of the solid content contained in the slurry to the mass (B) of the liquid contained in the slurry is 1:1 to 1:9, preferably 1: The method according to any one of [B1] to [B8], wherein the ratio is 2 to 1:4.
[B10] The method according to any one of [B1] to [B9], wherein the carbon particles have an average particle size of 2 to 100 μm, preferably 5 to 50 μm.

[B11] The method according to any one of [B1] to [B10], wherein the carbon particles are activated carbon particles.
[B12] of [B1] to [B11], wherein the carbon particles are contained in the slurry in an amount of 20 to 90% by mass, preferably 30 to 60% by mass, based on the mass of the solid content contained in the slurry; 2. The method according to any one of 1.
[B13] Any one of [B1] to [B12], wherein the calcium carbonate particles have an average particle size of 100 μm or less (eg, 0.2 to 100 μm), preferably 10 μm or less (eg, 0.2 to 10 μm). 1. The method according to 1.

[B14] The calcium carbonate particles are contained in the slurry in an amount of 5 to 75% by mass, preferably 40 to 70% by mass, relative to the mass of solids contained in the slurry [B1] to [B13]. The method according to any one of .
[B15] The method according to any one of [B1] to [B14], wherein the carbon particles and the calcium carbonate particles have a particle size ratio of 10:1 to 1:10.
[B16] The method according to any one of [B1] to [B15], wherein the carbon particles and the calcium carbonate particles have a mass ratio of 5:1 to 1:5.

[B17] The method according to any one of [B1] to [B16], wherein the binder is a cellulose derivative.
[B18] The method of [B17], wherein the cellulose derivative is carboxymethylcellulose, sodium carboxymethylcellulose, methylhydroxyethylcellulose, methylcellulose, or hydroxypropylcellulose.
[B19] The method of [B17] or [B18], wherein the cellulose derivative is carboxymethylcellulose.

[B20] The method according to any one of [B1] to [B19], wherein the molding is performed by compression molding.
[B21] The method according to any one of [B1] to [B20], wherein the molding is performed by tableting.
[B22] The molding is carried out so as to obtain a compact having a density of 0.6 to 1.0 g/cm ³ , preferably 0.7 to 0.9 g/cm ³ [B1] to [B21] The method according to any one of .
[B23] The method according to any one of [B1] to [B22], wherein the molding is performed by applying a pressure of 1 to 5 kN.

[C1] Composite particles containing carbon particles, calcium carbonate particles and a binder, having an average particle size D50 of 10 to 150 μm and a half width of 10 to 150 μm.
[C2] The composite particles according to [C1], wherein the average particle diameter D50 is 10 to 120 μm, preferably 50 to 150 μm, more preferably 70 to 120 μm.
[C3] The composite particles according to [C1] or [C2], wherein the half width is 30 to 150 μm, preferably 50 to 150 μm, more preferably 60 to 140 μm.

[C4] The composite particle according to any one of [C1] to [C3], which has a spherical shape.
[C5] The composite particles according to any one of [C1] to [C4], wherein the binder is contained in the composite particles in an amount of 3 to 15% by mass, preferably 5 to 10% by mass.
[C6] The composite particles according to any one of [C1] to [C5], wherein the carbon particles have an average particle size of 2 to 100 µm, preferably 5 to 50 µm.

[C7] The composite particles according to any one of [C1] to [C6], wherein the carbon particles are activated carbon particles.
[C8] The composite particles according to any one of [C1] to [C7], wherein the carbon particles are contained in the composite particles in an amount of 20 to 90% by mass, preferably 30 to 60% by mass.
[C9] Any one of [C1] to [C8], wherein the calcium carbonate particles have an average particle size of 100 μm or less (eg, 0.2 to 100 μm), preferably 10 μm or less (eg, 0.2 to 10 μm). 2. The composite particle according to 1.

[C10] The composite particles according to any one of [C1] to [C9], wherein the calcium carbonate particles are contained in the composite particles in an amount of 5 to 75% by mass, preferably 40 to 70% by mass.
[C11] The composite particles according to any one of [C1] to [C10], wherein the carbon particles and the calcium carbonate particles have a particle size ratio of 10:1 to 1:10.
[C12] The composite particles according to any one of [C1] to [C11], wherein the carbon particles and the calcium carbonate particles have a mass ratio of 5:1 to 1:5.

[C13] The composite particles according to any one of [C1] to [C12], wherein the binder is a cellulose derivative.
[C14] The composite particles of [C13], wherein the cellulose derivative is carboxymethylcellulose, sodium carboxymethylcellulose, methylhydroxyethylcellulose, methylcellulose, or hydroxypropylcellulose.
[C15] The composite particles of [C13] or [C14], wherein the cellulose derivative is carboxymethyl cellulose.

[D1] A carbon heat source for a flavor inhaler produced by the method according to any one of [A1] to [A23].
[D2] A carbon heat source for a flavor inhaler produced by the method according to any one of [B1] to [B23].
[D3] The carbon heat source for flavor inhalers according to [D1] or [D2], wherein the carbon heat source has an intensity of 140 to 250 N and a density of 0.6 to 1.0 g/cm ³ .
[D4] The carbon heat source for flavor inhalers according to any one of [D1] to [D3], wherein the carbon heat source has an intensity of 140 to 250 N and a density of 0.7 to 0.9 g/cm ³ .

[E1] A flavor inhaler comprising the carbon heat source according to any one of [D1] to [D4].
[E2] A cylindrical holder extending from the mouth end to the tip, the carbon heat source according to any one of [D1] to [D4] provided at the tip, and downstream of the carbon heat source inside the holder A flavor inhaler comprising a flavor source provided.
[E3] The flavor inhaler according to [E2], further comprising a filter portion provided inside the holder on the mouth end side.
[E4] The flavor inhaler according to [E2] or [E3], further comprising an aluminum laminated paper interposed between the holder and the flavor source.

[Test Example 1] Composite particles 1-1. Preparation of composite particles <Preparation of composite particles A1>
(1) Preparation of Slurry A1 As carbon particles, activated carbon particles, specifically Kuraray Coal SA2300 (average particle diameter: 6.6 μm, BET specific surface area: 2100 to 2400 m ² /g, Kuraray Chemical Co., Ltd.) and Kuraray Coal PW -Y (particle size: 45 μm or less, BET specific surface area: 1,300 to 1,500 m ² /g, Kuraray Chemical Co., Ltd.) was used as a mixture (2:8 mass ratio). Calpine F (average particle size: 3 μm, bulk density: 0.66 g/cm ³ , Yabashi Industry Co., Ltd.) was used as the calcium carbonate particles. As a binder, carboxymethyl cellulose, specifically Sunrose F10LC (Nippon Paper Industries Co., Ltd.) was used.

A solid content consisting of 43% by mass of carbon particles, 49.5% by mass of calcium carbonate particles, and 7.5% by mass of a binder, and water at a solid-liquid ratio (mass ratio) of 1:3.5 were mixed using a lab mixer to prepare a slurry A1.

(2) Spray-drying Slurry A1 was spray-dried to prepare composite particles. Spray-drying was carried out using a rotary atomizer type spray-drying apparatus (RDL-050CM). Specifically, the raw material slurry was sent to a disk rotating at a high speed, and droplets were dispersed in a heated gas by centrifugal force to atomize. Composite particles A1 (average particle size (D50): 76 μm) were thus prepared. The spray drying conditions were as follows.
Disk diameter: 60mm
Disk rotation speed: 8000-13000rpm
Slurry discharge speed: 15 to 30 L/hour
Outlet (where particles come out) hot air temperature: 80-120°C

<Preparation of composite particles A2>
(1) Preparation of Slurry A2 Slurry A1 was prepared with the exception that a solid content composed of carbon particles, calcium carbonate particles, and a binder was mixed with water at a solid-liquid ratio (mass ratio) of 1:3. Slurry A2 was prepared according to a similar procedure.

(2) Spray-drying Slurry A2 was spray-dried to prepare composite particles. The spray-drying was carried out using a rotary atomizer type spray-drying device (SD-6.3R type, GEA Process Engineering Co., Ltd. (formerly Niro Japan)). Specifically, the raw material slurry was sent to a disk rotating at a high speed, and droplets were dispersed in a heated gas by centrifugal force to atomize. Composite particles A2 (average particle size (D50): 94 μm) were thus prepared. The spray drying conditions were as follows.
Disk diameter: 100mm
Disk rotation speed: 10000-30000rpm
Slurry discharge speed: 20 to 40 L/hour
Outlet (where particles come out) hot air temperature: 100-150°C

<Preparation of composite particles A3>
Slurry A3 was spray-dried to prepare composite particles. Spray drying was carried out using a rotary atomizer type spray drying apparatus (SDR-27, IS Japan Co., Ltd.). Specifically, the raw material slurry was sent to a disk rotating at a high speed, and droplets were dispersed in a heated gas by centrifugal force to atomize. Composite particles A3 (average particle size (D50): 110 μm) were thus prepared. The spray drying conditions were as follows.
Disk diameter: 150mm
Disk rotation speed: 15000-25000rpm
Slurry discharge speed: 70 to 160 L/hour
Outlet (where particles come out) hot air temperature: 100-140°C

<Preparation of Composite Particle B>
(1) Preparation of Slurry B Slurry A1 was prepared by mixing a solid content consisting of carbon particles, calcium carbonate particles, and a binder with water at a solid-liquid ratio (mass ratio) of 1:4.75. Slurry B was prepared according to the same procedure as the preparation.

(2) Sheet Formation Slurry B was formed into a sheet. Sheeting was performed using a CD (compact disc) dryer (manufactured by Nishimura Iron Works). Specifically, the following procedures were performed.

In the CD dryer, the gap between the scraper and disc was adjusted to 0.2 mm. The disk was heated to 140° C. and spun at 0.8 rpm. The slurry was supplied to a circulation tank, and the slurry in the circulation tank was sprayed onto the disk using a pump. The dried product (sheet form) dried on the disk was collected with a scraper.

(3) Pulverization and classification The obtained dry product (sheet form) was pulverized and classified. Grinding was done using a tabletop mill (Wonder Blender) and classification was done using a sieve. Specifically, the following procedures were performed.

The dried product was sieved and classified into raw materials of 100 μm or more and 300 μm or less. Raw materials exceeding 300 μm were supplied to a pulverizer and pulverized. The classification and pulverization operations were repeated to obtain a pulverized material having a target particle size of 100 to 300 μm. The pulverized material thus obtained is called Composite Particles B.

1-2. Evaluation method (1) Measurement of particle size distribution The particle size distributions of Composite Particle A1, Composite Particle A2, Composite Particle A3 and Composite Particle B were measured. The particle size distribution was measured using a laser diffraction/scattering particle size distribution analyzer LMS-2000e (Seishin Enterprise Co., Ltd.).

The measurement method and measurement conditions were as follows.
Measurement method: 1. Blank measurements were made with compressed air only.
2. Appropriate amount of sample was placed in the dry unit.
Measurement conditions: Measurement range 0.20 to 20000.00μm
Compressed air pressure 0.1 MPa
Measurement method Jet-type dry measurement

The particle size distributions of Composite Particle A1, Composite Particle A2 and Composite Particle A3 are shown in FIGS. 5 to 7, respectively, and the particle size distribution of Composite Particle B is shown in FIG.

(2) Microscopic Observation Composite Particle A1, Composite Particle A2, Composite Particle A3, and Composite Particle B were observed with an optical microscope. A micrograph of Composite Particle A2 is shown in FIG. 9, and a micrograph of Composite Particle B is shown in FIG.

1-3. Evaluation Results The results of measuring the particle size distribution revealed the following. The composite particles A1 had an average particle diameter D50 of 76 μm and a half width of 62 μm (see FIG. 5). The composite particles A2 had an average particle diameter D50 of 94 μm and a half width of 103 μm (see FIG. 6). Composite particles A3 had an average particle diameter D50 of 110 μm and a half width of 137 μm (see FIG. 7). Composite particles B had an average particle diameter D50 of 221 μm and a half width of 258 μm (see FIG. 8).

Microscopic observation revealed the following. Composite particles A1, composite particles A2, and composite particles A3 had spherical morphology and smooth particle surfaces (see FIG. 9). Composite particles A2 had an average circularity of 11.5 μm (0.12×D50). On the other hand, since Composite Particle B was a pulverized product, it did not have a spherical shape and did not have a smooth surface (see FIG. 10). Composite particles B had an average circularity of 66.7 μm (0.30×D50).

[Test Example 2] Carbon heat source Using the composite particles prepared in Test Example 1, a carbon heat source was produced. Carbon heat source A1 was produced from composite particles A1, carbon heat source A2 was produced from composite particles A2, carbon heat source A3 was produced from composite particles A3, and carbon heat source B1 and carbon heat source B2 were produced from composite particles B.

Table 1 summarizes the manufacturing conditions of the carbon heat source A1, the carbon heat source A2, the carbon heat source A3, the carbon heat source B1, and the carbon heat source B2.

2-1. Production of carbon heat source <Production of carbon heat source A1>
(1) Add Water Water was added to Composite Particles A1 prepared in Test Example 1. 30 parts by mass of water was added to 70 parts by mass of composite particles A1. That is, water was added in an amount of 43% by mass with respect to Composite Particle A1. Water was added to Composite Particles A1 in a washing bottle, and the resulting mixture was mixed using a Kenmix mixer. Since the composite particles were agglomerated, the agglomerates were crushed. Crushing was performed using a tabletop mill (Wonder Blender). Thus, a mixture (base material) of mixture A1 and water was prepared. In Table 1, "moisture content" represents the ratio (% by mass) of water in the mixture.

(2) Classification A mixture (base material) of composite particles A1 and water was classified to 500 μm or less using a sieve.

(3) Molding The classified base material was tablet-molded. Tableting was performed using a tableting machine CREC (manufactured by Kikusui Seisakusho Co., Ltd.). The base material was molded into a cylindrical shape. Specifically, the following procedures were performed. The base material after classification was supplied to a metering feeder. The agitating feed shoe was rotated at 80 rpm, and the base material was supplied from the metering feeder to the agitating feed shoe. While keeping the amount of base material in the agitating feed shoe constant, tableting was carried out by rotating the tableting machine rotating disk at 15 rpm. The pressure during pressing was 1.5 to 3.0 kN.

(4) Drying The obtained tableted product was dried. Drying was performed using a constant temperature dryer OF-300S (manufactured by ASONE). Specifically, the tableted product was dried at 100°C for 8.6 minutes and then dried at 200°C for 17.3 minutes.

(5) Cutting A through hole was drilled in the dried tableted product to provide an air passage 13 as shown in FIG. In addition, the dried tableted product was chamfered and cross-shaped using a cutting device MTC (device name: carbon molded product processing tester, company name: Yamamoto Kikai Seisakusho Co., Ltd.). As shown in FIG. 3 , chamfering was performed on both the distal end surface 11 and the proximal end surface 12 , and crossing was performed only on the distal end surface 11 . After the processing, air blowing was performed on the ventilation path 13 and the groove 15 formed by the cross processing was also air blown. Thus, carbon heat source A1 was manufactured.

The manufactured carbon heat source A1 had the shape shown in FIG. 3 and had the following dimensions.
Overall length (length of carbon heat source in relation to central axis C direction): 13 mm
Diameter (length of carbon heat source in the direction intersecting central axis C): 6.49 mm
Depth (length) of groove 15 in direction of central axis C: 3.0 mm
Width (inner diameter) of groove 15: 0.6 mm
Inner diameter of air passage 13: 1.0 mm

<Production of carbon heat source A2>
Carbon heat source A2 was produced in the same manner as for carbon heat source A1, except that composite particles A2 were used instead of composite particles A1.

<Production of carbon heat source A3>
A carbon heat source A3 was manufactured according to the same procedure as the manufacturing of the carbon heat source A1, except that the composite particles A3 were used instead of the composite particles A1.

<Production of carbon heat source B1 (Comparative Example 1)>
Carbon heat source B1 was produced according to the same procedure as for producing carbon heat source A1, except that composite particles B were used instead of composite particles A1 and water was added in an amount of 34% by mass with respect to composite particles B. did.

<Production of carbon heat source B2 (Comparative Example 2)>
A carbon heat source B2 was produced in the same manner as the carbon heat source A1, except that the composite particles B were used instead of the composite particles A1.

2-2. Evaluation method (1) Strength The strength of the carbon heat source was obtained by measuring the breaking strength as follows.
Measuring device: SHIMAZU EZ-S 500N
Maximum load cell pressure: 500 N
Compression speed: 10mm/min
Compressor: Attachment with a V-shaped tip

The center of the side portion of the carbon heat source was pressurized until the attachment was broken in such a direction as to be positioned perpendicular to the carbon heat source, and the pressure at break (breaking strength) was measured. The strength was evaluated as follows based on the breaking strength value.
○: Breaking strength 140 [N] or more △: Breaking strength 80 [N] or more and less than 140 [N] ×: Breaking strength less than 80 [N]

(2) Ignition The ignitability of the carbon heat source was evaluated using a borgwalgt electric lighter with a new filament.

A lighter filament was attached directly to the carbon heat source. Directly attached so that the cross of the filament of the lighter and the cross of the groove of the carbon heat source overlap. The output of the writer was set to "strong". Evaluation was carried out by changing the time from when the switch of the lighter was turned on to the start of suction. Aspiration volume was 55 mL/2 sec. At the end of the draw, the lighter was removed from the carbon heat source. If the carbon heat source was red hot at the second puff (after 15 seconds), it was judged as ignition.

The surface (tip surface) of the carbon heat source arranged on the upper punch side of the tableting machine was evaluated. The tip surface of the carbon heat source is divided into four regions (islands) by cross-cutting (see FIG. 3). The ignitability was evaluated by the number of ignited islands.
○: When four islands are ignited
△: 2 or 3 islands ignited ×: 1 island ignited or not ignited

(3) Density The volume of the carbon heat source having a cylindrical shape was calculated from the diameter and height of the cylinder. Also, the mass of the carbon heat source was measured. The density [g/cm ³ ] of the carbon heat source was calculated from the volume and mass values. The density of the carbon heat source is an index that correlates with ignitability, and the lower the density, the better the ignitability.

2-3. Evaluation Results Table 2 shows the evaluation results.

Regarding the production of carbon heat source A1, carbon heat source A2 and carbon heat source A3, there was no problem of difficulty in molding the carbon heat source, and the ease of production was excellent. Moreover, carbon heat source A1, carbon heat source A2, and carbon heat source A3 had high strength and excellent ignitability. Composite particles A1, composite particles A2, and composite particles A3 used to produce carbon heat source A1, carbon heat source A2, and carbon heat source A3 all had a small average particle size and a sharp particle size distribution. Therefore, the composite particles can be molded with a uniform density and high density throughout the molded body, thereby improving the strength of the produced carbon heat source and providing excellent ignitability. could have been done.

On the other hand, when composite particles B were used to produce a carbon heat source, molding was difficult. Therefore, when the carbon heat source B1 was produced by increasing the amount of water added during molding, the molding material (base material) easily adhered to the tableting machine, and in particular, continuous production with the tableting machine At the beginning, it was possible to manufacture a carbon heat source, but gradually the base material adhered to the chamber and compression part of the tableting machine, making continuous production impossible. The manufactured carbon heat source B1 had high strength and excellent ignitability, but had a problem that it could not be continuously produced.

Using Composite Particles B, an amount of water generally used during molding (i.e., 30% by weight of water relative to Composite Particles B) was added to produce Carbon Heat Source B2. Heat source B2 had no problem in ignitability, but had insufficient strength.

Composite particle B had a larger average particle size and a larger half width than composite particles A1, A2 and A3. For this reason, the composite particles B cannot be molded with a uniform density and high density over the entire molded body, resulting in problems such as difficulty in molding and low strength of the produced carbon heat source. is thought to have occurred. In addition, since Composite Particle B was a pulverized product, it did not have a spherical shape, and its surface was uneven and not smooth. It is considered that such a shape of the composite particles B also affected the difficulty of molding and the decrease in the strength of the carbon heat source.

Claims (15)

forming composite particles having an average particle diameter D50 of 10 to 150 μm and a half width of 10 to 150 μm, using a slurry containing carbon particles, calcium carbonate particles, a binder, and water as raw materials;
A method for producing a carbon heat source for a flavor inhaler, comprising molding a mixture containing the composite particles and water to obtain a molded body, and drying the molded body. 2. The method of claim 1, wherein said composite particles have a spherical morphology. 3. The method of claim 1 or 2, wherein forming the composite particles is performed by spray drying the slurry. The method according to any one of claims 1 to 3, wherein the binder is contained in the slurry in an amount of 3 to 15% by weight relative to the weight of solids contained in the slurry. 5. The method according to any one of claims 1 to 4, wherein the mixture is a mixture containing the composite particles and 33 to 67% by mass of water with respect to the composite particles. The ratio (A:B) between the mass (A) of the solid content contained in the slurry and the mass (B) of the liquid contained in the slurry is 1:1 to 1:9. 10. The method of any one of clauses 1 to 1. A method according to any one of claims 1 to 6, wherein said carbon particles have an average particle size of 2 to 100 µm. The method according to any one of claims 1 to 7, wherein the carbon particles are contained in the slurry in an amount of 20-90% by mass based on the mass of solids contained in the slurry. The method according to any one of claims 1 to 8, wherein said calcium carbonate particles have an average particle size of 100 µm or less. 10. The method according to any one of claims 1 to 9, wherein the calcium carbonate particles are contained in the slurry in an amount of 5-75% by weight relative to the weight of solids contained in the slurry. The method according to any one of claims 1 to 10, wherein the binder is a cellulose derivative. A method according to any one of claims 1 to 11, wherein said molding is performed by compression molding. A carbon heat source for flavor inhalers manufactured by the method according to any one of claims 1 to 12. 14. The carbon heat source for flavor inhalers according to claim 13 , wherein said carbon heat source has a strength of 140-250 N and a density of 0.6-1.0 g/cm ³ . A flavor inhaler comprising a carbon heat source according to claim 13 or 14 .

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