RU2604020C2 - Cigarette filter and cigarette - Google Patents

Abstract

FIELD: tobacco industry.

SUBSTANCE: cigarette filter comprises filter plug (121) that includes a filter material containing cellulose acetate fibre tow (122), and filtration rate control particles (124) dispersed in tow and selected from cellulose particles, cellulose triacetate particles and a mixture thereof.

EFFECT: cigarette comprises a cigarette filter.

11 cl, 13 dwg, 24 tbl

Description

Technical field

The present invention relates to a cigarette filter and a cigarette containing such a filter.

State of the art

Many cigarettes contain filters to remove various components from inhaled cigarette smoke. As for the filter, a filter having a cellulose acetate tow is widely used as a filter material.

It is known that the acetate filter has selective filtering characteristics, such that the filtration efficiency of semi-volatile components is higher than the filtration efficiency of the resin from inhaled cigarette smoke. A semi-volatile component is a component that is present in both the particulate phase and the vapor phase of the inhaled cigarette smoke, and contains a nitrogen-containing compound, ketones and phenols. These semi-volatile components affect the taste of a cigarette and, therefore, it may be desirable that these components are not removed by the filter to a significant extent.

Patent Document 1 discloses a filter for tobacco smoke, which is essentially formed by cellulose acetate microfibers having an average diameter of from 20 to 250 microns, as a filter for tobacco smoke to remove harmful components from tobacco smoke. Patent Document 1 also discloses that microfibers are blended with a standard cellulose acetate tow. However, Patent Document 1 does not consider semi-volatile components, although it discloses that the filter is excellent in the removal efficiency of tar from tobacco smoke.

Prior art document

Patent document

Patent Document 1: Japanese Patent No. 3939823

SUMMARY OF THE INVENTION

The problem solved by the invention

An object of the invention is to provide a cigarette filter that does not substantially remove the semi-volatile component present in respirable cigarette smoke and a cigarette containing such a filter.

The solution of the problem

In order to solve the above problem, according to a first aspect of the invention, there is provided a cigarette filter comprising a filter plug that contains filter material comprising:

cellulose acetate tow and

particles to control the degree of filtration dispersed in a tow and selected from cellulose particles, cellulose triacetate particles, and mixtures thereof.

According to a second aspect of the invention, there is provided a filter cigarette comprising:

cigarette rod and

a cigarette filter according to the invention, which is attached to the end of a cigarette rod.

The technical result of the invention

The cigarette filter of the invention does not substantially remove the semi-volatile component present in respirable cigarette smoke.

Brief Description of the Drawings

FIG. 1 is a schematic view, on an enlarged scale, of a portion of a cigarette containing a filter according to an embodiment of the invention.

FIG. 2 are diagrams showing the relationship between the puff resistance of a control filter and, in each case, the permeability to tar, nicotine and typical semi-volatile components present in inhaled smoke.

FIG. 3 are diagrams showing the relationship between the drag resistance of the filter of the invention and, in each case, the permeability to resin, nicotine, and typical semi-volatile components present in inhaled smoke.

FIG. 4 is a diagram showing the relationship between the selective filter coefficient S _x and the drag resistance of the filter of the invention, together with that of the control filter.

FIG. 5 is a diagram showing the relationship between a plasticizer (triacetin) added to a filter medium and permeability for typical semi-volatile components.

FIG. 6 is a diagram showing the relationship between the drag resistance of a filter containing particles and the total area of the outer peripheral surface of the cellulose acetate fiber.

FIG. 7 is a diagram showing the relationship between the total area of the outer peripheral surface of the cellulose acetate fiber forming the filter plug and permeability for typical semi-volatile components.

FIG. 8A is a diagram showing the permeability for typical semi-volatile components for a filter, which is obtained by adding particles of cellulose triacetate to a cellulose acetate fiber having a total outer peripheral surface area of an average of 223 cm ² .

FIG. 8B is a diagram showing permeability for typical semi-volatile components for a filter, which is obtained by adding particles of cellulose triacetate to a cellulose acetate fiber having a total outer peripheral surface area of 255 cm ² on average.

FIG. 8C is a diagram showing the permeability for typical semi-volatile components for a filter, which is obtained by adding cellulose particles to a cellulose acetate fiber having a total outer peripheral surface area of an average of 206 cm ² .

FIG. 9A is a schematic view of the structure of a filter containing particles for controlling the degree of filtration used in Example 7.

FIG. 9B is a schematic view of the structure of a control filter used in Example 7.

FIG. 10 is a diagram showing the effect of introducing an additive into particles to control the degree of filtration on permeability for typical semi-volatile components for a filter.

Description of embodiments of the invention

Some embodiments of the invention are described in detail below.

The cigarette filter of the invention comprises a filter plug that contains filter material comprising a cellulose acetate tow. Particles for controlling the degree of filtration are dispersed in a cellulose acetate tow. As used herein, the term “dispersed” generally means that particles to control the degree of filtration are almost uniformly distributed throughout the interior of the cellulose acetate tow (see FIG. 1) and the distribution can be enhanced in the direction of the mouthpiece of the cigarette or in the direction of the cigarette rod. Particles for controlling the degree of filtration play a role in the control aimed at reducing the degree of filtration by the filter of semi-volatile components in inhaled cigarette smoke. Particles for controlling the degree of filtration are selected from cellulose particles, cellulose triacetate particles, and mixtures thereof.

Cellulose triacetate particles have an average degree of substitution with acetyl groups from 2.76 to 3.00, preferably an average degree of substitution with acetyl groups from 2.8 to 3.0, according to the interpretation of the Japanese Association of Chemical Fibers. The average degree of substitution with acetyl groups can be measured by the method of titration ASTM D871-96. The degree of substitution of cellulose acetate with the acetyl groups, which is determined by this measurement method, indicates a normal distribution. Accordingly, it is defined as “average degree of substitution with acetyl groups”.

Cellulose acetate fibers may be bonded to a plasticizer, such as triacetin, to form a tow. Cellulose acetate fibers extend parallel to each other along the entire length of the filter.

Cellulose acetate fibers forming a cellulose acetate tow may be cellulose acetate fibers used in conventional cigarette filters. Cellulose acetate fibers can have an individual fineness of 1.5 to 8 denier and have some cross-sectional shape, such as a circular shape, an oval shape, a Y-shape, an X-shape or an I-shape. Cellulose acetate fibers can be formed from cellulose acetate having a degree of substitution of acetyl groups from 2.4 to 2.5 (diacetate). The total fineness of the cellulose acetate tow may typically be from 15,000 to 50,000 denier. A cellulose acetate tow is marked as 1.9Y44000. This means that the individual fineness is 1.9 denier, the cross section of the fiber is Y-shaped, and the total fineness is 44000 denier, as is well known to those skilled in the art. In the present description, the unit of individual fineness “denier” represents the mass of a fiber fragment per 9000 m (g / 9000 m), and the unit of total fineness “denier” represents the mass of all fiber fragments per 9000 m (g / 9000 m).

Cellulose particles have difficulty adsorbing the semi-volatile constituents present in respirable cigarette smoke and also have difficulty adsorbing menthol (see examples 1 and 2 below). Moreover, the cellulose triacetate particles have difficulty adsorbing the volatile components present in the inhaled cigarette smoke and also have difficulty adsorbing menthol (see Examples 1 and 2 below). As described above, particles to control the degree of filtration hardly adsorb menthol. Therefore, in the case where the cigarette filter of the invention is used in a menthol cigarette, the possibility that menthol is largely adsorbed by the filter after the manufacture of the cigarette is small until the cigarette is smoked by the smoker, and the menthol content in the inhaled smoke hardly decreases when smoking a cigarette.

Particles for controlling the degree of filtration are granular in shape. The average diameter of the equivalent particle sphere for controlling the degree of filtration is preferably from 100 to 1000 microns, more preferably more than 250 microns, taking into account the filter hardness and drag, filtration characteristics and ease of manufacture of the filter. In the manufacture of a filter containing particles having an average equivalent sphere diameter of 100 to 1000 μm, a conventional carbon filter production machine can be used directly (in this case, of course, particles are used instead of coal particles to control the degree of filtration). The average diameter of the equivalent sphere can be obtained by measuring the particle size distribution using a particle size distribution measuring device and calculating a 50% median value of the diameter of the equivalent sphere, as described in the following examples. The BET specific surface area for controlling the degree of filtration is preferably less than 5 m ² / g. The specific surface area by BET can be determined in accordance with the well-known BET method.

Particles for controlling the degree of filtration can be obtained using a granulation machine of compression type. Specifically, they can be obtained using a compression type granulating machine as follows. First, the material of the cellulose particles or the cellulose triacetate particles is pulverized. The resulting crushed product and various additives are mixed using a thorough mixing mixer. The resulting mixture is then molded by compression using a dry granulator, applying pressure using a roll, and a molded product is obtained (for example, a plate-shaped product). Subsequently, the molded product is crushed using a particle sizing device. At the same time, coarse crushing of the product is carried out at this stage, and then it can be crushed to the desired particle size in the second stage. The obtained crushed product is passed through a sieving machine to sift granules having a predetermined particle size distribution. The result is particles to control the degree of filtration. Thus, the particles for controlling the degree of filtration obtained with the compression type granulating machine are excellent in terms of high yield and less problems caused by the displacement of the long fiber during winding of the filter.

As for the particles to control the degree of filtration, the cellulose triacetate particles can be obtained by grinding the cellulose triacetate flakes and sorting them. Alternatively, the cellulose triacetate particles can be obtained by granulating the cellulose triacetate flakes using a well-known granulating machine such as a drum type machine, extrusion type, fluidized bed machine, stirring type or compression type machine. In addition, cellulose particles are commercially available.

Preferably, the particles for controlling the degree of filtration comprise from 1.5 to 30% by volume of a filter containing particles for controlling the degree of filtration. Moreover, with regard to the manufacture of the filter, it should be noted that if the volume fraction of added particles increases, the manufacture is difficult. Thus, in order to obtain satisfactory results of controlling the degree of filtration and a satisfactory organoleptic perception without any effect of particles on the manufacture of the filter, it is more preferable if particles for controlling the degree of filtration account for 1.5 to 16% by volume of the volume of the filter containing regulation of the degree of filtration (see examples 3 and 4 below). Such a fraction of particles for controlling the degree of filtration can lead to a drag resistance of 35 mm H ₂ O to 180 mm H ₂ O, which is considered suitable for drag resistance of a filter having a circumference of 24.5 mm and a length of 25 mm. The volume V of the filter can be determined by the equation V = πr ² L, where r represents the radius of the filter and L represents the length of the filter (the thickness of the filter wrapping paper is small enough so that it can be neglected). The mass gain and apparent density obtained using the mercury porosimeter were used to calculate the particle volume.

If particles are added to a cellulose acetate tow to control the degree of filtration, the hardness of the resulting filter plug increases. Therefore, there is no need to add triacetin as a plasticizer. Even when triacetin is added as a plasticizer, the added amount of triacetin as a plasticizer can be reduced. For example, when particles to control the degree of filtration are added to the cellulose acetate tow in the above fraction, sufficient hardness of the filter plug is achieved by adding triacetin in an amount of 3% by weight or less based on or without cellulose acetate tow (see example 1 below). The rigidity of the filter plug can be expressed as the degree of deformation of the filter plug when the tip of the hardness tester having a diameter of 12 mm compresses the filter plug with a force of 300 g for 10 seconds. The lower the degree of deformation, the harder the filter plug.

Along with adding particles to the filter to control the degree of filtration, the added amount of plasticizer is reduced, or the plasticizer is not added to the filter. As a result, the permeability of the semi-volatile components can be further improved (see example 6 below).

Moreover, if particles to control the degree of filtration are added to the cellulose acetate tow, the total outer peripheral surface of the cellulose acetate fiber can be reduced by 10% or more (usually 30% or less) compared to the case when the particles to control the degree of filtration are not add. As a result, the permeability of the semi-volatile components is further improved (see examples 4 and 5 below).

Moreover, if a filter obtained by adding particles to control the degree of filtration to a cellulose acetate tow is used in a cigarette, the aroma of smoke can be changed compared to when a filter without particles was used in the cigarette to control the degree of filtration (see example 3 below).

To obtain a more preferred flavor of cigarette smoke, a small amount of additive may be added to the particles to control the degree of filtration. Example 7 below demonstrates that even if an additive affecting the aroma of cigarette smoke is added to the particles to control the degree of filtration, there is no effect on the selective permeability of the semi-volatile components. The additive may be a smoke aroma component (e.g., a flavor) or a component affecting smoke aroma (e.g. a humectant, amino acid, polysaccharide or dietary fiber). Both components are collectively referred to as the "component that reflects on the aroma of smoke." The added amount of the smoke-reflecting component is preferably 10% by weight or less and more preferably 5% or less by weight of the total particle weight (total particle weight to control the degree of filtration and the smoke-reflecting component). Examples of a component that affects smoke aroma include: flavors, humectants, amino acids, polysaccharides, and dietary fiber.

Flavors may be synthetic flavors, natural flavors, essential oils, and the like. Additionally, they can be used regardless of lipophilicity or hydrophilicity. Examples of lipophilic flavors include: vanillin, ethyl vanillin, guarlinalool, thymol, methyl salicylate, linalool, eugenol, menthol, cloves, anise, cinnamon, bergamot oil, geranium, lemon oil, curly mint and ginger. Examples of hydrophilic flavors include: glycerin, propylene glycol, ethyl acetate and isoamyl alcohol.

Examples of humectants include:

polyols including:

diols [eg alkanediol (eg C _2-10 alkanediol such as ethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol or hexylene glycol, preferably C _2-8 alkanediol more preferably C _2-6 alkanediol, especially C _2-4 alkanediol), polyalkylene glycol (eg diethylene glycol, dipropylene glycol, triethylene glycol or tripropylene glycol)],

triols [for example, alkanetriol (for example, C _3-10 alkanetriol, such as glycerol or 1,2,6-hexanetriol, preferably C _3-6 alkanetriol, more preferably C _3-4 alkanetriol)] and

polyols that are tetrafunctional or have higher functionality [for example, a polymer of a polyol (eg, alkantriol) that is trifunctional or has higher functionality (eg, polyglycerol, such as diglycerin or triglycerin)], and

derivatives of these polyols [eg, monoalkyl ether of dialkylene glycol (eg, methylcarbitol and ethylcarbitol), and monoacylate (poly) alkylene glycol (eg, ethylene glycol monoacetate)].

Examples of amino acids include amino acids and their salts (amino acid salts). An amino acid may be any compound of a neutral amino acid (monoaminomonocarboxylic acid, and so on), an acidic amino acid (monoaminodicarboxylic acid, and so on) and a basic amino acid (diaminomonocarboxylic acid, and so on), or it can be a sulfur-containing amino acid. The amino acid may be an α-amino acid, β-amino acid, γ-amino acid, or the like. In particular, it may be an α-amino acid. The amino acid can be either in optically active form (D-form, L-form, and so on) or in the form of a racemate. Moreover, examples include polyamino acids having a low degree of polymerization (for example, a degree of polymerization from 2 to 9, preferably a degree of polymerization from 2 to 5, more preferably a degree of polymerization from 2 to 3). The amino acid may have a substituent or may be present in the form of an amino acid derivative in which at least a portion of the carboxyl (s) group (s) or amino groups (s) are derivatized. For example, at least a portion of the carboxyl (s) group (s) in an amino acid may be a derivatized carboxyl group (e.g., an amide group).

Examples of a typical amino acid include:

an aliphatic amino acid [eg, an aliphatic monoaminocarboxylic acid such as glycine, alanine, isoleucine, leucine, valine, threonine, serine, asparagine, aminosuccinic acid, cysteine, methionine, glutamine or glutamic acid (eg amino-C _2-20 alkanecarboxylic acid preferably amino C _2-12 alkanecarboxylic acid, more preferably amino C _2-8 alkanecarboxylic acid) aliphatic polyaminocarboxylic acid such as lysine, hydroxylisine, arginine or cystine (e.g. polyamino C _2-20 alkanecarboxylic acid before respectfully polyamino-C _2-12 alkane carboxylic acid)];

an aromatic amino acid (e.g., aryl-C _2-20 alkanecarboxylic acid such as phenylalanine or tyrosine, preferably C _6-10 aryl-C _2-12 alkanecarboxylic acid);

a heterocyclic amino acid (e.g., tryptophan, histidine, proline or 4-hydroxyproline); and

a polypeptide obtained by polymerization of these amino acids with a low degree of polymerization (for example, with a degree of polymerization of 9 or less) (for example, glycylglycine, glutamylglycine, glycyl-glycyl-glycine and glycylproline). Moreover, examples of amino acid salts include: a metal salt [for example, an alkali metal salt (for example, a sodium salt such as sodium glutamate)], a hydrochloride salt (for example, arginine hydrochloride) and an amino acid salt (for example, a lysine salt with glutamic acid).

Other examples of smoke scent components include food additives such as xylitol or mannitol; polymers such as lignin; and polysaccharides or dietary fiber such as cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose, chitin, starch, glycogen, guar gum, glucomannan, sodium alginate, agarose, chitosan, pectin, carrageenan and xanthan gum.

Moreover, dye may be added to the particles to control the degree of filtration. As the colorant, for example, a natural colorant extracted from gardenia, safflower, turmeric, annatto, red pepper, paprika, red fermented rice, red cabbage, cocoa, or the like can be added. The dye can be added in an amount of from 0.1 to 5 wt.% Of the total particle weight (the sum of the particle weight to control the degree of filtration and dye). Preferably, it may be added in an amount of 1 wt.% Or less. Particles for regulating the degree of filtration containing dye may have different colors depending on the color of the dye. When a dye is added to the particles to control the degree of filtration and transparent rim paper is used to make the filter, particles to control the degree of filtration (granules) that load the filter can be recognized from the outside. It is known that color can affect a person’s sensations. Accordingly, it can be expected that a new sensation is imparted to the taste when smoking a cigarette due to the color of the dye. Moreover, when the color of the particles for regulating the degree of filtration differs from that of the filter fiber, as in the case of a carbon filter, the particles for regulating the degree of filtration can be easily distinguished from the filter fiber during quality control during the production of the filter.

The filter of the invention may be attached to one end of a cigarette rod alone or in combination with another filter plug. A final example is shown in FIG. one.

In FIG. 1 is a schematic view of a cigarette 10 comprising a filter according to an embodiment of the invention. The cigarette 10 includes a cigarette rod 110 and a filter 120, which is located at the end in the axial direction of the cigarette rod 110 so that the end surface of the filter is in contact with the end surface of the cigarette rod. The cigarette rod 110 contains tobacco filler 112, such as shredded tobacco, wrapped in cigarette paper 111. The filter 120 includes a filter plug 121 of the invention that includes a bundle 122 of a plurality of cellulose acetate fibers 123 that are located along the axial direction of the filter 120 and can be connected to a bundle with a plasticizer such as triacetin. Each of the cellulose acetate fibers 123 extends along the entire length of the filter plug 121. Particles 124 to control the degree of filtration are dispersed in the cellulose acetate tow 122. The filter plug 121 is wrapped in paper 125 to wrap the filter. The cigarette rod 110 and the filter 120 are connected by a rim paper 130, as in a conventional filter cigarette. A plurality of ventilation openings 131 may be created by perforation in the rim paper 130 in one or more rows in the circumferential direction of the filter. The so-called only acetate filter plug 140, formed from a cellulose acetate tow bundle 142 wrapped in filter wrapping paper 141, can be attached to the rear end of the filter 120 containing particles for controlling the degree of filtration (in the direction of inhalation of smoke). In this case, the filter plug 140 is also wrapped in rim paper 130.

Examples

The present invention will now be described with reference to examples.

Example 1

Particle preparation for controlling the degree of filtration

1. Particles of cellulose triacetate

Cellulose triacetate flakes (average acetyl substitution: 2.86) were purchased from Daicel Chemical Industries, Ltd. The degree of substitution of cellulose triacetate flakes with acetyl groups was determined by titration in accordance with ASTM D871-96. Thus, the aforementioned degree of substitution with acetyl groups was confirmed. After this, the cellulose triacetate flakes were ground in a coffee grinder (MK-52M manufactured by Matsushita Electric Industrial Co., Ltd.). The crushed product was sieved through a sieve using an electromagnetic sieve shaker (“AS200 control” manufactured by Retsch) to obtain particles with sizes ranging from 300 to 710 μm. Regarding the particle size distribution, the 50% median diameter of the equivalent sphere was calculated as the average particle size using a particle size distribution meter related to a digital image analysis meter (manufactured by Retsch (sold by HORIBA, Ltd.)). For the resulting particles, the average diameter of the equivalent sphere was 550 μm, the bulk density was 0.54 g / cm ³ , the apparent density obtained using a mercury porosimeter was 0.71 g / cm ³ , and the specific surface area by BET, obtained by nitrogen desorption was 4.6 m ² / g.

2. Cellulose particles

The cellulose particles were cellulose beads obtained by refining and dissolving wood and molding the resulting viscose into a granular and porous form, using cellulose particles marketed under the trademark Viscopearl from Rengo Co., Ltd. For the particles used, the average diameter of the equivalent sphere was 400 μm, the bulk density was 0.20 g / cm ³ , the apparent density obtained using a mercury porosimeter was 0.34 g / cm ³ , and the specific surface area by BET was below the limit detection.

Obtaining a filter plug

Cellulose particles or cellulose triacetate particles were added to an acetate filter containing triacetin, by analogy with the well-known method for producing a carbon filter. Additionally, only acetate filters were produced that did not contain particles to control the degree of filtration. As a wrapping paper for the filter in the case of each filter plug, one was used having a bulk of 24.0 ± 1.5 g / m ² , a thickness of 60 ± 5 μm and an air permeability of 10,000 ± 1800 Coresta units. The diameter of each filter plug was 7.7 mm and the length was 120 mm. The drag resistance of each filter was measured according to ISO6565: 2002.

The hardness of the resulting filter plugs was determined as the degree of deformation of the filter plug, when the tip of the hardness tester having a diameter of 12 mm squeezed the filter plug with a force of 300 g for 10 seconds.

The characteristics and hardness of the resulting filter plugs are shown in Tables 1A-1C below.

Table 1A Filters containing cellulose triacetate particles Filter Numbers Characteristics of cellulose acetate fiber tow The amount of triacetin (wt.%) Tightening resistance to a length of 120 mm (mm H ₂ O) Added amount of particles per filter length 10 mm (mg / 10mm) Filter hardness (mm) A-1 3,5Y / 35000 6 418 35 0.71 A-2 5.9Y / 35000 6 319 35 0.54 A-3 2,2Y / 35000 6 570 35 0.82 A-4 3,5Y / 35000 9 396 35 0.63 A-5 3,5Y / 35000 0 420 35 1,2 A-6 5.9Y / 35000 6 423 70 0.42

Table 1B Filters containing cellulose particles Filter Numbers Characteristics of cellulose acetate fiber tow The amount of triacetin (wt.%) Tightening resistance to a length of 120 mm (mm H ₂ O) Added amount of particles per filter length 10 mm (mg / 10mm) Filter hardness (mm) B-1 5.9Y / 35000 6 429 35 0.52 B-2 5.5Y / 31000 6 337 35 0.77 B-3 2,2Y / 35000 6 763 35 0.77 B-4 5.9Y / 35000 9 432 35 0.48 B-5 5.9Y / 35000 0 439 35 0.97 B-6 2,5Y / 35000 6 430 10 0.97

Table 1C Acetate filters only Filter Numbers Characteristics of cellulose acetate fiber tow The amount of triacetin (wt.%) Tightening resistance to a length of 120 mm (mm H ₂ O) Added amount of particles per filter length 10 mm (mg / 10mm) Filter hardness (mm) AF-1 2,2Y / 35000 0 470 - 1,6 AF-2 5.9Y / 35000 0 197 - 1,6 AF-3 2,2Y / 35000 6 433 - 1,0 AF-4 5.5Y / 31000 6 169 - 1,1

The hardness of A-1 through A-6 filters containing cellulose triacetate particles ranged from 0.42 to 1.2 mm. The hardness of B-1 through B-6 filters containing cellulose particles ranged from 0.48 to 0.97 mm. On the other hand, in the case of acetate filters only, the hardness of such filters (AF-1 and AF-2) not containing triacetin was 1.6 mm. Therefore, it was found that the hardness of the filters increases when particles are included in them, as illustrated by filters containing cellulose particles, and filters containing cellulose triacetate particles. When the added amount of particles increases, the hardness of the filters can be ensured regardless of the addition of triacetin.

Making a Cigarette Sample

The filter was removed from a commercially available “Mild Seven Aqua Squash Menthol” filter cigarette. The resulting cigarette rod was attached to a filter for testing, obtained by cutting the filter plug obtained in the manner described above into plugs of various lengths and placing it in a paper tube (outer diameter: 7.7 mm) with adhesive tape to obtain a cigarette sample. The length and tightening resistance of each of the cut plugs are shown below in Tables 2A-2C. A smoking test was carried out a month after the manufacture of the filters.

Table 2A Sliced filters containing cellulose triacetate particles Filter plug numbers (before cutting) Filter length after cutting (mm) Tightening Resistance (mm H ₂ O) Brands of Cigarettes Containing Cut Filters A-1 twenty 72 CA-1 A-2 twenty 53 CA-2 A-3 twenty 93 CA-3 A-4 twenty 69 CA-4 A-5 twenty 71 CA-5 A-6 twenty 70 CA-6

Table 2B Cut filters containing cellulose particles Filter plug numbers (before cutting) Filter length after cutting (mm) Tightening Resistance (mm H ₂ O) Brands of Cigarettes Containing Cut Filters B-1 twenty 72 CB-1 B-2 twenty 56 CB-2 B-3 twenty 129 CB-3 B-4 twenty 73 CB-4 B-5 twenty 75 CB-5 B-6 twenty 71 CB-6

Table 2C Cut filters containing acetate filters only Filter plug numbers (before cutting) Filter length after cutting (mm) Tightening Resistance (mm H ₂ O) Brands of Cigarettes Containing Cut Filters AF-3 10 38 CAF-3-1 AF-3 fifteen 55 CAF-3-2 AF-3 twenty 69 CAF-3-3 AF-3 thirty 104 CAF-3-4 AF-3 40 133 CAF-3-5 AF-4 10 fourteen CAF-4-1 AF-4 fifteen 22 CAF-4-2 AF-4 twenty 28 CAF-4-3 AF-4 thirty 38 CAF-4-4 AF-4 40 55 CAF-4-5

Smoking test

Ten samples of cigarettes manufactured as described above (the ventilation holes were covered with adhesive tape) were automatically smoked using an automatic smoking machine (RM20D manufactured by Borgwaldt KC Inc.) under the following conditions: puff volume: 35.0 ml / 2 sec, puff duration: 2 sec / puff, puff frequency: 1 puff / min. Suspended particles in cigarette smoke were collected using a Cambridge filter (CM-133 manufactured by Borgwaldt KC Inc.). Smoke passing through a Cambridge filter was collected on 10 ml of methanol, cooled to -70 ° C with a cooling agent of dry ice and isopropanol.

Cambridge filter containing collected suspended particles, 10 ml of methanol solution containing collected cigarette smoke, and 1 ml of internal standard solution (d-32 pentadecane: 0.05 mg / ml, d-1-ethanol: 150 ml / l, anethole: 2 ml / l, 1,3-butanediol: 4 ml / l) was added to the serum vial, which was shaken for 30 minutes. After shaking, the supernatant was taken and used as a sample for analysis. The above operation was also performed with a cigarette rod (control cigarette) obtained by removing the filter from a commercially available filter cigarette “Mild Seven Aqua Squash Menthol”.

Analysis for tar, nicotine and semi-volatile components

A sample for analysis was analyzed by gas chromatography-mass spectrometry (GC-MSD). An Agilent 7890A chromatograph (Agilent Technologies Inc.) was used for gas chromatography (GC), and an Agilent 5975C mass spectrometer (Agilent Technologies Inc.) was used for mass spectrometry (MSD).

The peak area of each component (normalized to internal standard) in the chromatogram obtained by analysis was compared with the peak area of each component in the chromatogram related to the control cigarette. The permeability “1-E _x ” for each smoke component through each filter was calculated using the following formula.

Numerical formula 1:

In the above formula, A _{x, in} and A _{x, out} represent the values obtained by normalizing according to the internal standard of the peak areas of component “x” in the smoke of the control cigarette and each sample cigarette having a filter, respectively. E _x represents the degree of filtration of the “x” component.

As for the semi-volatile components, 3-furaldehyde, 2-acetylfuran and furfural were chosen as typical semi-volatile components. The average permeability for the components was calculated and the selective filtration characteristics of the semi-volatile components were evaluated.

For cigarettes CAF-3-1 to CAF-3-5 and CAF-4-1 to CAF-4-5, the drag resistance of each filter is shown on the horizontal axis, and the logarithmic permeability values for the ability of the resin, nicotine and typical semi-volatile components are set aside on the vertical axis. The dependency data is shown in FIG. 2. In FIG. 2 (A) shows the permeability of the resin, FIG. 2 (B) shows the permeability of nicotine, and FIG. 2 (C) shows the permeability of typical semi-volatile components. In FIG. 2 (A) -2 (C) circles refer to CAF-3-1 to CAF-3-5, and triangles refer to CAF-4-1 to CAF-4-5.

For resin (Fig. 2 (A)) and nicotine (Fig. 2 (B)), permeability can be linearly approximated regardless of the type of fiber in the cellulose acetate tow. For typical semi-volatile components (Fig. 2 (C)), the permeability has a different slope depending on the type of fiber in the bundle (fiber diameter). This indicates that the permeability of the resin and nicotine is determined only by the drag resistance of each filter; however, the behavior characterizing the permeability for typical semi-volatile components varies depending on the type of tow. Since resin and nicotine are mainly components of the phase of suspended particles, filtration efficiency can be represented as a function of the drag resistance of each filter. On the other hand, semi-volatile components are distributed both in the vapor phase and in the suspended particles phase, and thus, the behavior characterizing permeability is affected by the filtration of the suspended particles phase component and the absorption of the vapor phase component by fiber. As a result, permeability is not determined solely by pull resistance.

Further, in FIG. 3 shows the results for cigarettes CA-1 to CA-5 and CB-1 to CB-5. In FIG. 3 (A) shows the permeability of the resin, FIG. 3 (B) shows the permeability of nicotine, and FIG. 3 (C) shows the permeability of typical semi-volatile components. In FIG. 3 (A) and 3 (B) line “a” refers to CAF-3-1 according to CAF-3-3 and CAF-4-4 according to CAF-4-5, line “b” refers to cigarettes with CA-1 according to CA-5, and line “c” refers to cigarettes CB-1 to CB-5. In FIG. 3 (C) line “a” refers to CAF-3-1 to CAF-3-5, and line “b” refers to CAF-4-1 to CAF-4-5.

The results presented in FIG. 3 (A) and 3 (B) show that a filter containing particles for regulating the degree of filtration according to the invention has a high permeability to resin and nicotine compared to this indicator only acetate filter, in other words, it has a low degree of resin filtration and nicotine. According to the results presented in FIG. 3 (C), it was found that a filter containing particles for controlling the degree of filtration according to the invention has a high permeability to semi-volatile components compared to only an acetate filter. That is, particles for controlling the degree of filtration according to the invention allow a significant improvement in permeability for semi-volatile components. On the other hand, the inventors have demonstrated that a filter containing cellulose diacetate particles (average substitution with acetyl groups from 2.4 to 2.5) is able to filter out the semi-volatile components and poorly passes the semi-volatile components compared to the acetate filter only.

According to the results presented in FIG. 3 (A), a filter containing particles for controlling the degree of filtration according to the invention has a different degree of filtration of the resin from that of the acetate filter alone. To identify the filtration characteristics of the semi-volatile components in comparison with the resin, the selective filtration coefficient S _{x was} calculated using the following formula as an indicator showing the selectivity for the component when filtering typical semi-volatile components.

Numerical formula 2:

In the above formula, E _TPM represents the degree of filtration of the crude resin (total suspended particles).

The selective filtration coefficient S _x calculated in this way was plotted on the diagram as a function of the drag resistance of the filter. The results are shown in FIG. 4. In FIG. 4, line “a” refers to cigarettes CAF-4-1 to CAF-4-5, and line “b” refers to CAF-3-1 to CAF-3-5. The results presented in FIG. 4 indicate the following. When comparing filters having the same individual fineness, the coefficient of selective filtration of a filter containing particles to control the degree of filtration according to the invention is reduced compared with that of only an acetate filter for any resistance to filter tightening. Even taking into account the degree of resin filtration, semi-volatile components selectively pass through the filter.

Further, in order to study the effect of plasticizer (triacetin (GTA)) added to the filter material on the permeability of typical semi-volatile components of a CA-1 cigarette (triacetin: 6 wt.%), CA-4 cigarette (triacetin: 9 wt.%) , CA-5 cigarettes (triacetin: 0%), CB-1 cigarettes (triacetin: 6 wt.%), CB-4 cigarettes (triacetin: 9 wt.%) and CB-5 cigarettes (triacetin: 0%) selective Filtration S _{x of} typical semi-volatile components was plotted against the drag. The results are shown in FIG. 5. As shown in FIG. 5, if the added amount of triacetin is small, it acts in such a direction that the semi-volatile components pass through the filter. If the added amount of triacetin is large, it acts in such a direction that the semi-volatile components are filtered. Permeability for typical semi-volatile components can also be controlled by the amount of triacetin. This is due to the fact that the vapor of semi-volatile components is absorbed (adsorbed) by triacetin on the surface of cellulose acetate fiber. It is believed that if the added amount of triacetin decreases, the adsorbed amount of semi-volatile components decreases. For a filter containing particles to control the degree of filtration according to the invention, the filter hardness can be ensured even if the added amount of triacetin is reduced. Therefore, a filter that allows greater selective permeability to semi-volatile components can be obtained by reducing the added amount of triacetin.

Summarizing the above results, it was found that a filter containing particles for controlling the degree of filtration according to the invention is effective in providing selective permeability of semi-volatile components, taking into account the structure of the filter and ease of manufacture, although the selective transmission of semi-volatile components can also be controlled by the diameter of cellulose acetate fibers forming tourniquet, and the amount of triacetin.

Example 2

When the filter according to the invention is intended for use in a menthol tobacco product, if the adsorption of menthol by particles to control the degree of filtration according to the invention continues, the amount of menthol in the inhaled smoke is reduced. Therefore, the adsorbed amount of menthol particles was evaluated to control the degree of filtration according to the invention.

Specifically, only an acetate filter (cellulose acetate tow: 1.9Y44000, weight: 30 mg, filter length: 5 mm) was attached to the end of a cigarette rod (circumference: 24.9 mm, length: 59 mm) having 640 mg of cut tobacco containing 0.59 wt.% menthol. A menthol-containing acetate filter (cellulose acetate tow: 2.5Y35000, weight: 90 mg, filter length: 15 mm) in which a menthol-containing thread was passed through the center of the filter was placed at a distance of 5 mm from the acetate filter only. The cavity between the two filters was filled with particles to control the degree of filtration according to the invention (cellulose particles or cellulose triacetate particles obtained in Example 1). The menthol content of the menthol-containing acetate filter was 1.99 wt.%. A cigarette whose cavity is filled with cellulose particles as particles to control the degree of filtration is designated as Α cigarette, and a cigarette whose cavity is filled with cellulose particles as cellulose to control the degree of filtration is designated as cigarette B.

Cigarettes made in this way were placed in a glass bottle and hermetically sealed, and then kept at 50 ° C for two weeks. Samples of cigarettes were removed from the glass bottle after being kept therein. Then, in each case, the menthol content in cut tobacco, only acetate filters, particles for controlling the degree of filtration and menthol containing acetate filters were quantified. The menthol content was quantitatively determined by methanol extraction of the samples to be analyzed (cut tobacco, only acetate filters, particles to control the degree of filtration or menthol acetate filters) and analyzing the methanol extract on a gas chromatograph (6890 series from HEWLETT PACKARD). In a preliminary test, menthol was extracted with methanol.

The menthol content of cut tobacco, acetate filters only, particles to control the degree of filtration, and menthol acetate filters, in each case, are shown in Table 3 below.

Table 3 The menthol content (unit: wt.%) Cut tobacco Acetate filter only Particles for controlling the degree of filtration Menthol Acetate Filters Before aging 0.59 0 0 1.99 After aging Cigarette a 0.56 2.03 Cellulose particles 0.20 1.97 Cigarette B 0.43 2,30 Cellulose Acetate Particles 0.22 2.23

From the results presented in Table 3, it follows that particles for controlling the degree of filtration according to the invention (cellulose particles and cellulose triacetate particles) almost do not adsorb menthol. Therefore, even if the filter according to the invention containing particles for controlling the degree of filtration is used in a menthol tobacco product, unwanted adsorption of menthol by particles to control the degree of filtration almost does not occur, and thus, the menthol taste can be sufficiently felt when smoked.

Example 3

Filter cigarettes having the structure shown in FIG. 1. A rim paper having punched ventilation holes and a filter was removed from a commercially available “Mild Seven Aqua Squash Menthol 7 Box” filter cigarette and the resulting cigarette core was used as cigarette core 110 (menthol content in cut tobacco: 0.55 weight. %). Each of the filters A-1 and A-6 shown in Table 1A, the filters B-1 and B-6 shown in Table 1B, and the AF-3 filter shown in Table 1C were cut to a length of 10 mm, so that the resistance filter tightening is 35 ± 2 mm H ₂ O in order to maintain the amount of tar, nicotine and menthol in the inhaled cigarette smoke almost constantly, and the obtained filter plugs were used as filter plug 121. Only acetate filter 140 (cellulose acetate tow: 5.0 Y35000 (containing 6.9 wt.% Triacetin); filter length: 17 mm, content entola:. 2.22 wt%) was attached to a rear end of the filter plug 121. The filter plugs 121 and 140 are attached to a cigarette rod using tipping paper. A smoking test was carried out three months after the manufacture of the filters. The characteristics of the filter plug 121 are presented for information below in Table 4.

Table 4 Chopped filters Filter plug numbers (before cutting) Filter length after cutting (mm) Tightening Resistance (mm H ₂ O) Brands of Cigarettes Containing Cut Filters A-1 10 35 ± 2 CA-1-2 A-6 10 35 ± 2 CA-6-2 B-1 10 35 ± 2 CB-1-2 B-6 10 35 ± 2 CB-6-2 AF-3 10 35 ± 2 CAF-3-1-2

Among the cigarettes containing the filters shown in Table 4, five pieces of each type of cigarette (CA-6-2 and CB-1-2) containing a large number of particles to control the degree of filtration in their filters, and five pieces of control cigarettes (CAF- 3-1-2) were smoked without closing the ventilation openings under the smoking conditions described in Example 1. The amounts of tar, nicotine and menthol in the inhaled smoke were measured, and the number of puffs was measured. The measurement results (average) of the amounts of tar, nicotine and menthol in the cigarette, as well as the number of puffs are presented below in Table 5.

Table 5 The amount of tar, nicotine and menthol in the inhaled smoke per cigarette, as well as the number of puffs Cigarette Resin (mg) Nicotine (mg) Menthol (mg) Number of puffs CAF-3-1-2 7.9 0.55 0.40 6.9 CB-1-2 8.8 0.62 0.45 6.9 CA-6-2 8.9 0.64 0.45 6.9

Then nine tasters evaluated the taste when smoking cigarettes. Tasters felt a difference in taste when smoking CB-1-2 and CA-6-2 cigarettes and CAF-3-1-2 control cigarettes. Regarding the flavor characteristics of smoking CB-1-2 and CA-6-2 cigarettes, tasters recognized a strong and distinct menthol flavor.

They also felt a difference in taste when smoking cigarettes CA-1-2 and CA-6-2 and control cigarettes CAF-3-1-2. As for the flavor characteristics when smoking CA-1-2 and CA-6-2 cigarettes, tasters recognized a strong and distinct menthol flavor. Moreover, as for the aroma when smoking CA-1-2 and CA-6-2 cigarettes, they distinctly recognized the aroma when smoking, barely detectable residual bitter taste and recognized a strong tobacco aroma. After smoking, they immediately stopped tasting cigarettes and practically did not feel a strong aftertaste.

Example 4

Only acetate filter plugs were made with different puff resistance (filter length: 10 mm; puff resistance: from 14 to 58 mm H ₂ O) and filter plugs containing particles for controlling the degree of filtration according to the invention, presented below in Table 6, and measured puff resistance. For cellulose acetate tows in the obtained filters, the total value of the areas of the outer peripheral surface of each individual fiber (the total area of the outer peripheral surface) was calculated as follows, based on the article by Kazuo Maeda “Research on Development of Tobacco Smoke Filter”, Central Research Institute, Japan Tobacco Inc ., December 1983, pp. 27-30.

The total area of the outer peripheral surface of the cellulose acetate

(1) The circular equivalent diameter of an individual fiber is calculated by the following equation:

Circular equivalent diameter = 11.91 × (individual fineness / fiber density) ^1/2

In the above equation, the fiber density is 1.32 g / cm ³ .

(2) Then, according to the following equation, the cross-sectional shape coefficient of the individual fiber is calculated.

Shape factor = actual external peripheral fiber length / (4 × π × actual cross-sectional area)

The actual external peripheral length of the fiber and the actual cross-sectional area used in the above equation are actually measured by micrographs of the cross-section of the individual fiber.

(3) Then, according to the following equation, the external peripheral length of the individual fiber is calculated.

Outer peripheral length of individual fiber = π × circular equivalent diameter × (shape factor) ^1/2

(4) Finally, the total area of the outer peripheral surface is determined from the following equation.

Total external peripheral surface area = external peripheral length of an individual fiber × number of individual fibers × fiber length

The fiber length used in the above equation is calculated by excluding the amount of triacetin from the actually measured mass of the acetate tow, obtaining the net weight of the acetate tow, and dividing only the mass of the acetate tow by the mass obtained by converting the total fineness to mass by the length of the filter.

The results are presented in Table 6.

Table 6 Filter Characteristics Particles for controlling the degree of filtration Particle size (μm) The added amount of particles per length of 10 cm (mg / 10 cm) Characteristics of cellulose acetate tow The total area of the outer peripheral surface of the cellulose acetate fiber of 10 cm length of the filter (cm ² / 10cm) The added amount of triacetin (wt.%) Filter length (mm) Fiber length (mm) Tightening Resistance (mm H ₂ O) The percentage of particles to the filter volume (vol.%) Pulp particles 400 35 5.9Y31000 80 6 10 11.5 28 22.3 400 35 5.9Y35000 87 6 10 11.8 36 22.3 400 35 2,2Y35000 123 6 10 11,4 65 22.3 400 35 5.9Y35000 87 0 10 12,2 38 22.3 400 25 5.9Y35000 87 6 10 11.9 28 15.9 400 25 5.9Y35000 87 0 10 12.0 28 15.9 400 25 5.9Y35000 87 3 10 11.9 28 15.9 700 25 5.9Y35000 87 6 10 12.1 27 15.9 Cellulose Acetate Particles 400 35 5.9Y35000 87 6 10 12.8 27 10.7 400 35 3,5Y35000 108 6 10 12,2 36 10.7 400 35 2,2Y35000 124 6 10 11.6 46 10.7 400 70 5.9Y35000 87 6 10 12.3 35 21.3 400 35 3,5Y35000 108 0 10 12.3 35 10.7 400 35 5.0Y35000 92 6 10 12.1 26 10.7 400 35 5.0Y35000 92 0 10 12.1 26 10.7 400 35 5.0Y35000 92 3 10 12.0 26 10.7

As for the results presented in Table 6, the drag resistance for each filter is plotted on the diagram depending on the total external peripheral surface area of each cellulose acetate fiber, and the results are shown in FIG. 6. In FIG. 6, black rhombuses refer only to acetate filter plugs, white triangles refer to filter plugs containing cellulose particles, and white squares refer to filter plugs containing cellulose triacetate particles. FIG. 6 shows that for any pulling resistance, filter plugs containing particles for controlling the degree of filtration according to the invention have a smaller total external peripheral surface area of cellulose acetate fiber compared to that of acetate filter plugs only. For filter plugs containing particles to control the degree of filtration according to the invention, the degree of reduction of the total area of the outer peripheral surface of the cellulose acetate fiber is from 10 to 30%. Therefore, in the case of adding particles to control the degree of filtration according to the invention, it is possible to use a cellulose acetate tow with a smaller total area of the outer peripheral surface for the manufacture of filter plugs having the same drag resistance as when these particles are not added.

Example 5

For cigarettes CA-1 to CA-6, CB-1 to CB-6, CAF-3-1 to CAF-3-5 and CAF-4-1 to CAF-4-5 (see Tables 2A-2C) and cigarettes containing filter plugs shown in Tables 7A and 7B below, calculated the total external peripheral surface area of cellulose acetate fiber, as well as the permeability and selective permeability coefficient of typical semi-volatile components. The results are shown below in Tables 8A and 8B.

Table 7A Filters containing cellulose particles (average particle size: 700 microns) Filter Numbers Characteristics of cellulose acetate tow The amount of triacetin (wt.%) Filter length (mm) Tightening Resistance (mm H ₂ O) The added amount of particles per filter length 10 mm (mg / 10 mm) Brands of cigarettes containing appropriate filters B2-1 5.9Y / 35000 6 twenty 72 35 CB2-1 B2-2 2,2Y / 35000 6 twenty 117 35 CB2-2 B2-3 5.9Y / 35000 9 twenty 71 35 CB2-3 B2-4 5.9Y / 35000 0 twenty 74 35 CB2-4 B2-5 2,5Y / 35000 6 twenty 70 10 CB2-5

Table 7B Acetate filters only Filter plug numbers (before cutting) Filter length after cutting (mm) Tightening Resistance (mm H ₂ O) Brands of Cigarettes Containing Cut Filters AF-1 10 40 CAF-1-1 AF-1 fifteen 58 CAF-1-2 AF-1 twenty 76 CAF-1-3 AF-1 thirty 112 CAF-1-4 AF-1 40 146 CAF-1-5 AF-2 10 eighteen CAF-2-1 AF-2 fifteen 26 CAF-2-2 AF-2 twenty 35 CAF-2-3 AF-2 thirty 53 CAF-2-4 AF-2 40 68 CAF-2-5

Table 8A Cigarette The total area of the outer peripheral surface of cellulose acetate fiber (cm ² ) Permeability of typical semi-volatile components The coefficient of selective permeability of typical semi-volatile components CA-1 214 0.17 3.78 CA-2 174 0.17 4,57 CA-3 247 0.10 5.60 CA-4 214 0.09 7.30 CA-5 214 0.28 2,38 CA-6 174 0.15 4.43 CB-1 174 0.21 3.42 CB-2 160 0.16 4.84 CB-3 247 0.08 6.87 CB-4 174 0.09 7.32 CB-5 174 0.47 1.51 CB-6 245 0.13 4.64 CB2-1 174 0.18 3.84 CB2-2 247 0.13 4.08 CB2-3 174 0.15 4.69 CB2-4 174 0.45 1,56 CB2-5 245 0.17 3.63

Table 8B Cigarette The total area of the outer peripheral surface of cellulose acetate fiber (cm ² ) Permeability of typical semi-volatile components The coefficient of selective permeability of typical semi-volatile components CAF-3-1 124 0.35 2.25 CAF-3-2 186 0.20 3.34 CAF-3-3 247 0.15 3.56 CAF-3-4 371 0.04 11.39 CAF-3-5 495 0,03 12.03 CAF-4-1 80 0.51 1.80 CAF-4-2 120 0.37 2,32 CAF-4-3 160 0.23 3.44 CAF-4-4 240 0.11 6.06 CAF-4-5 320 0.06 9.69 CAF-1-1 124 0.58 1.34 CAF-1-2 186 0.40 1.76 CAF-1-3 247 0.30 2.05 CAF-1-4 371 0.19 2.49 CAF-1-5 495 0.09 3.77 CAF-2-1 87 0.68 1.29 CAF-2-2 131 0.61 1.40 CAF-2-3 174 0.54 1.49 CAF-2-4 262 0.37 1.88 CAF-2-5 349 0.25 2.28

As for the results shown in Tables 8A and 8B, the permeability of typical semi-volatile components is shown in the diagram as a function of the total area of the outer peripheral surface of the cellulose acetate fiber, as shown in FIG. 7. In FIG. 7 white triangles refer to CB-5 and CB2-4 cigarettes, white squares refer to CA-5 cigarette, white circles refer to CAF-1-1 cigarettes according to CAF-1-5 and white diamonds refer to CAF-2-1 cigarettes according to CAF-2-5. The filter plugs of none of the above cigarettes contain plasticizer. In FIG. 7 black triangles refer to cigarettes CB-1, CB-2, CB-3, CB-6, CB2-1, CB2-2 and CB2-5, black squares refer to cigarettes CA-1, CA-2, CA-3 and CA-6, black circles refer to CAF-3-1 cigarettes according to CAF-3-5 and black diamonds refer to CAF-4-1 cigarettes according to CAF-4-5. The filter plugs of all the aforementioned cigarettes contain a plasticizer.

From FIG. 7 it is found that the permeability of typical semi-volatile components for each of the only acetate filter plugs is highly dependent on the amount of plasticizer added (triacetin); however, in the case of the same amount of plasticizer, the permeability of typical semi-volatile components is determined by the total external peripheral surface of the cellulose acetate fiber. Moreover, it is found that the particle size distribution of cellulose particles does not affect the filtering characteristics with respect to semi-volatile components. These facts are explained by the fact that cellulose particles and cellulose triacetate particles are difficult to dissolve in an acetone solvent and hardly adsorb menthol or triacetin and, thus, they have low adsorption ability with respect to semi-volatile components having a polarity close to that of menthol or triacetin.

In FIG. 7 shows that selective filtering characteristics for semi-volatile components can be controlled by changing the type of cellulose acetate tow or the amount of plasticizer added. However, since when specifying the amounts of tar and nicotine in the inhaled smoke, it is necessary to provide a certain level of filter hardness and it is necessary to control the puff resistance, in the case of cigarette products it is impossible to arbitrarily combine the type of cellulose acetate tow and the amount of plasticizer added. However, if particles to control the degree of filtration (cellulose particles and / or cellulose triacetate particles) are added to the filter of the invention, the filter can remain unchanged due to the presence of particles, even if the added amount of triacetin is reduced and the drag can be controlled by adding particles. to adjust the amount of tar / nicotine in the inhaled smoke to the desired level. Therefore, a cellulose acetate tow, which has been considered unsuitable by the prior art (i.e., a cellulose acetate tow, which has a small external peripheral surface area), can be used according to the invention. In other words, in general, with a decrease in the total area of the outer peripheral surface of the cellulose acetate fiber, the drag resistance of the filter plug tends to decrease. Thus, a cellulose acetate tow may be used having a pull resistance less than that of a cellulose acetate tow in a conventional cigarette filter. As a result, it is possible to develop a filter having such characteristics that the semi-volatile components pass through the filter selectively compared to the resin.

As described above, it has been found that if particles for controlling the degree of filtration (cellulose particles and / or cellulose triacetate particles) are added to the filter of the invention, the transmission control range of the semi-volatile components can be extended, which is limited in the case of traditional acetate filters only in connection with product structure or production. Thus, the present invention is effective in providing a new flavor when smoking tobacco or a new menthol flavor when smoking tobacco.

Example 6

Cellulose powder (FMC Biopolymer, trade name: Endurance MCC) and cellulose triacetate powder (Diacel Chemical Industries, Ltd., trade name: Acetate Flake DS2.9 LT-55 (TAC)) were used as raw materials. Each powder was pressed at 20 MPa for 10 minutes using a tablet machine (manufactured by Jasco Corporation) and a hydraulic hand pump (manufactured by Riken Seiki Co., Ltd.) to obtain a molded plate product. Then, the resulting plate-shaped shaped product was ground using a coffee grinder (MK-52M manufactured by Matsushita Electric Industrial Co., Ltd.). The crushed product was sieved through a sieve using an electromagnetic sieve shaker (“AS200 control” manufactured by Retsch) to obtain particles for controlling the degree of filtration with sizes ranging from 300 to 710 μm. The resulting particles to control the degree of filtration were used to make filters containing cellulose triacetate particles and filters containing cellulose particles in accordance with the same procedure as in Example 1. The drag resistance and hardness of the manufactured filters were measured in accordance with the same methodology as in example 1.

The characteristics and hardness of the resulting filter plugs are given in Tables 9A and 9B below.

Table 9A Filters containing cellulose triacetate particles Filter Numbers Characteristics of cellulose acetate tow The added amount of triacetin (wt.%) Tightening resistance to a length of 120 mm (mm H ₂ O) The added amount of particles per filter length 10 mm (mg / 10 mm) Filter hardness (mm) A-7 5.0Y35000 6 311 35 0.54 A-8 5.0Y35000 3 307 35 0.70 A-9 5.0Y35000 0 314 35 1,2 A-10 3,5Y35000 6 327 29th 0.75 A-11 3,5Y35000 3 332 29th 1,0 A-12 3,5Y35000 one 322 29th 1.3

Table 9B Filters containing cellulose particles Filter Numbers Characteristics of cellulose acetate tow The amount of triacetin (wt.%) Tightening resistance to a length of 120 mm (mm H ₂ O) Added amount of particles per filter length 10 mm Filter hardness (mm) B-7 5.9Y35000 6 339 25 0.52 B-8 5.9Y35000 3 334 25 0.7 B-9 5.9Y35000 0 331 25 1,0 B-10 5.0Y35000 6 343 21 0.65 B-11 5.0Y35000 one 321 21 1,1

In Tables 9A and 9B, the added amount of triacetin is expressed as a percentage by weight based on a cellulose acetate tow.

The hardness of A-7 through A-12 filters containing cellulose triacetate particles ranged from 0.54 to 1.3 mm. The hardness of B-7 to B-12 filters containing cellulose particles ranged from 0.52 to 1.1 mm. On the other hand, in the case of acetate filters only, the hardness of such filters (AF-1 and AF-2) not containing triacetin was 1.6 mm. Therefore, it was found that the hardness of the filters increases when particles are included in them, as illustrated by filters containing cellulose particles, and filters containing cellulose triacetate particles. When the added amount of particles increases, the hardness of the filters can be ensured even if the added amount of triacetin decreases. Specifically, it was found that sufficient hardness of the filter plugs was obtained when 3 wt.% Or less of triacetin was added, or even when triacetin was not added.

Cigarette Making

A filter was removed from a commercially available Seven Stars Solid Menthol filter cigarette. The resulting cigarette rod was attached to the filter under test, obtained by cutting the filter plug obtained in the manner described above into filter plugs of various lengths and placing the plugs in a paper tube (outer diameter: 7.7 mm) with adhesive tape to obtain a cigarette sample. A smoking test was carried out two months after the manufacture of the filters. The length and tightening resistance of each of the cut filters, as well as the total area of the outer peripheral surface of the cellulose acetate fiber, are shown in Tables 10A and 10B below.

Table 10A Sliced filters containing cellulose triacetate particles Filter plug numbers (before cutting) Filter length after cutting (mm) Tightening Resistance (mm H ₂ O) The total area of the outer peripheral surface of cellulose acetate fiber (cm ² ) Brands of Cigarettes Containing Cut Filters A-7 twenty 54 223 CA-7 A-8 twenty 53 222 CA-8 A-9 twenty 54 224 CA-9 A-10 twenty 53 255 CA-10 A-11 twenty 54 256 CA-11 A-12 twenty 56 255 CA-12

Table 10B Cut filters containing cellulose particles Filter plug numbers (before cutting) Filter length after cutting (mm) Tightening Resistance (mm H ₂ O) The total area of the outer peripheral surface of cellulose acetate fiber (cm ² ) Brands of Cigarettes Containing Cut Filters B-7 twenty 56 202 CB-7 B-8 twenty 57 202 CB-8 B-9 twenty 59 204 CB-9 B-10 twenty 62 207 CB-10 B-11 twenty 58 214 CB-11

The manufactured cigarettes CA-7 to CA-12 and CB-7 to CB-11 were subjected to a smoking test in accordance with the same procedure as in Example 1. The smoking test was also carried out on a cigarette rod (control cigarette) obtained by removing the filter from commercially available filter cigarettes “Seven Stars Solid Menthol”.

The sample for analysis obtained during the smoking test was used for analysis on resin, nicotine and semi-volatile components in accordance with the same procedure as in example 1.

Permeability (%) and selective filtration coefficient (%) were calculated using the same numerical formula as described in Example 1.

The permeability and selective filtration coefficient of typical semi-volatile components of CA-7 to CA-12 and CB-7 to CB-11 cigarettes are presented in Tables 11A to 11C below with respect to each value of the total outer peripheral surface area of cellulose acetate fiber.

Table 11A Permeability and selective filtration coefficient of typical semi-volatile components Filter CA-7 CA-8 CA-9 Permeability (%) twenty 28 32 Selective Permeability Coefficient (%) 316 244 193

Table 11B Permeability and selective filtration coefficient of typical semi-volatile components Filter CA-10 CA-11 CA-12 Permeability (%) 27 thirty 35 Selective Permeability Coefficient (%) 252 220 192

Table 11C
Permeability and selective filtration coefficient of typical semi-volatile components Filter CB-7 CB-8 CB-9 CB-10 CB-11 Permeability (%) 26 31 44 28 42 Selective Permeability Coefficient (%) 285 221 159 256 162

The permeability of typical semi-volatile components in CA-7 to CA-12 and CB-7 to CB-11 cigarettes is shown in FIG. 8A to 8C for each value of the total area of the outer peripheral surface of the cellulose acetate fiber.

In FIG. 8A shows the permeability of typical semi-volatile components for filters containing cellulose triacetate particles when the total peripheral surface area of the cellulose acetate fiber is 223 cm ² (fiber tow characteristics: 5.0Y35000). In FIG. 8B shows the permeability of typical semi-volatile components for filters containing cellulose triacetate particles when the total peripheral surface area of the cellulose acetate fiber is 255 cm ² (fiber tow characteristics: 3.5Y35000). In FIG. 8C shows the permeability of typical semi-volatile components for filters containing cellulose particles when the total peripheral surface area of the cellulose acetate fiber is 206 cm ² (fiber tow characteristics: 5.9Y35000 and 5.0Y35000).

The results presented in Tables 11A through 11C and in FIG. 8A to 8C confirm that when filters having almost the same total external peripheral surface area of cellulose acetate fiber are compared with each other, the permeability of typical semi-volatile components is high in the case of filters having a small amount of plasticizer added. This is due to the fact that the degree of adsorption of semi-volatile components on the surface of cellulose acetate fiber increases due to the plasticizer. Therefore, the transmission coefficient of the semi-volatile components through the filter can be further improved by reducing the added amount of plasticizer or not adding plasticizer while adding particles to control the degree of filtration (i.e. cellulose triacetate particles or cellulose particles) to the filter.

Example 7

To study the effect of additives on the filtering characteristics of the particles, cellulose particles and cellulose particles containing additives described in Table 12 were prepared to further control the degree of filtration. Cellulose particles were prepared using the same procedure as in Example 6. Cellulose particles containing additives were prepared by mixing additives and cellulose powder in accordance with the same procedure as in example 6. Additives were added in the amounts described in Table 12. In Table 12, “added amount” is represented by the ratio (wt.%) of additives to su Marne weight of particles for controlling the degree of filtering and additives. For comparison, particles containing no additives were also added to control the degree of filtration.

Table 12 Particles for controlling the degree of filtration with additives Particle numbers to control the degree of filtration Additives Add amount (%) A-1 - - B-1 L-arginine 5 B-2 L-alanine 5 B-3 L-glutamic acid 5 B-4 Lignin 10 B-5 Sugar powder 2 B-6 Pectin 10 B-7 Sorbitol 5

Filter plug manufacturing

To evaluate the filtering characteristics of the particles to control the degree of filtration, the particles to control the degree of filtration A-1 and B-1 according to B-7 were used for the manufacture of filter plugs F-A-1 and F-B-1 according to F-B-7. As shown in FIG. 9A, particles for controlling the degree of filtration were placed in a paper tube having a length of 25 mm. Acetate filters (5 mm) were placed in front (on the side of the tobacco rod) and back (on the side of the mouthpiece with the filter) relative to the particles to control the degree of filtration, locking the particles to control the degree of filtration. Thus, filters filled with said particles were obtained. The added amounts of particles to control the degree of filtration are shown in Table 1. As a control, they were made as shown in FIG. 9B, an F-C-1 filter plug with two acetate filters (5 mm) housed in a paper tube having a length of 25 mm. The characteristics of each filter are shown in Table 13.

Table 13 Filter Characteristics Filter Numbers Particle numbers to control the degree of filtration The added amount (mg) Filter tightening resistance (mm H ₂ O) Particle tightness to control the degree of filtration (mm H ₂ O) F-a-1 A-1 one hundred 68 54 F-b-1 B-1 one hundred 55 41 F-b-2 B-2 one hundred 53 39 F-b-3 B-3 one hundred 51 37 F-b-4 B-4 one hundred fifty 36 F-b-5 B-5 one hundred 64 fifty F-b-6 B-6 one hundred 69 55 F-b-7 B-7 one hundred 53 39 F-c-1 - - fourteen -

Test Cigarette Making

Commercially available filter cigarettes “Seven Stars Solid Menthol” were used to make test cigarettes. A filter of commercially available cigarettes was removed. The resulting cigarette rod was attached to each of the filters (F-A-1, F-B-1 to F-B-7, and F-C-1) to make cigarettes for testing. In this regard, the ventilation of the filter was set equal to 0. A cigarette made using the F-C-1 filter is a control cigarette.

Smoking test

The manufactured cigarettes were subjected to a smoking test in accordance with the same procedure as in Example 1. A sample for analysis obtained during the smoking test was used for analysis on tar, nicotine and semi-volatile components in accordance with the same procedure as in Example 1. Permeability (%) and selective filtration coefficient (%) were calculated using the same numerical formula as described in Example 1.

The permeability and selective filtration coefficient of typical semi-volatile components in cigarettes made using F-A-1 and F-B-1 filters according to F-B-7 are presented below in Table 14.

Table 14 Permeability and selective filtration coefficient of typical semi-volatile components Filter F-a-1 F-b-1 F-b-2 F-b-3 F-b-4 F-b-5 F-b-6 F-b-7 Permeability (%) 68 67 73 72 74 69 68 72 Selective Permeability Coefficient (%) 98 105 98 one hundred 101 one hundred 98 99

The permeability for typical semi-volatile components in cigarettes made using F-A-1 and F-B-1 filters according to F-B-7 is shown in FIG. 10.

The results are presented in Table 14 and in FIG. 10 confirm that the permeability of the semi-volatile components of the particles to control the degree of filtration contained in each filter is constant regardless of the presence or absence of the additive or type of additive. This result confirms the following: even if the additive that reflects on the flavor when smoking a cigarette is introduced into the particles to control the degree of filtration, its small amount does not have any effect on the filtering characteristics of the particles to control the degree of filtration.

List of Reference Items

10 - Cigarette

110 - cigarette core

111 - cigarette paper

112 - Tobacco Filler

120 - Filter

121 - Filter plug

122 - Cellulose acetate tow

123 - Cellulose acetate

124 - Particles for controlling the degree of filtration

125 - Filter wrapping paper

130 - Border paper

131 - Air vent

140 - Only acetate filter plug

141 - Filter wrapping paper

142 - Cellulose acetate tow

Claims (11)

1. A cigarette filter comprising a filter plug that contains filter material comprising:
cellulose acetate tow and
particles to control the degree of filtration dispersed in a tow and selected from cellulose particles, cellulose triacetate particles and mixtures thereof, said particles having a BET specific surface area of less than 5 m ² / g. 2. A cigarette filter according to claim 1, characterized in that the cellulose triacetate particles have an average degree of substitution with acetyl groups from 2.8 to 3.0. 3. A cigarette filter according to claim 1, characterized in that the particles for regulating the degree of filtration are from 1.5 to 30 vol. % of the total volume of the filter plug. 4. Cigarette filter according to any one of paragraphs. 1-3, characterized in that the particles to control the degree of filtration are from 1.5 to 16 vol. % of the total volume of the filter plug. 5. Cigarette filter according to any one of paragraphs. 1-3, characterized in that the total area of the outer peripheral surface of the cellulose acetate fiber forming the tow is reduced by 10% or more compared to the total area of the outer peripheral surface of the cellulose acetate fiber forming the corresponding filter plug that does not contain particles to control the degree of filtration. 6. Cigarette filter according to any one of paragraphs. 1-3, characterized in that the particles for regulating the degree of filtration are obtained using a granulation machine of compression type. 7. Cigarette filter according to any one of paragraphs. 1-3, characterized in that the particles to control the degree of filtration have an equivalent sphere diameter of from 100 microns to 1000 microns. 8. Cigarette filter according to any one of paragraphs. 1-3, characterized in that the plasticizer is added to the tow of cellulose acetate fiber in an amount of 3 weight. % or less by weight of a cellulose acetate tow or are not added. 9. Cigarette filter according to any one of paragraphs. 1-3, characterized in that the particles for regulating the degree of filtration contain a component that reflects on the aroma when smoking, and a component that reflects on the aroma when smoking, is added in an amount of 10 weight. % or less of the total particle weight. 10. Cigarette filter according to any one of paragraphs. 1-3, characterized in that the particles to control the degree of filtration contain dye. 11. A filter cigarette, comprising: a cigarette rod and a cigarette filter according to any one of paragraphs. 1-10, which is attached to the end of the cigarette rod.

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