JP5786038B2 - Cigarette filter and cigarette - Google Patents

Description

  The present invention relates to a cigarette filter and a cigarette including the cigarette filter.

  Many cigarettes are equipped with filters to remove various cigarette mainstream smoke components. As such a filter, a filter having cellulose acetate fiber tow as a filter medium is widely used.

  It is known that an acetate filter has selective filtration characteristics such that the filtration efficiency of semi-volatile components is higher than the filtration efficiency of tar in cigarette mainstream smoke. The semi-volatile component is a component that exists in both the particle phase and the vapor phase of cigarette mainstream smoke, and includes nitrogen-containing compounds, ketones, phenols, and the like. These semi-volatile components affect the taste of cigarette and it may be desired not to be removed significantly by the filter.

  Patent Document 1 discloses a tobacco smoke filter substantially composed of cellulose acetate microfibers having an average diameter of 20 to 250 μm as a tobacco smoke filter for removing harmful components in tobacco smoke. Patent Document 1 also discloses mixing the microfibers with normal cellulose acetate fiber tow. However, although patent document 1 shows that the filter is excellent in the removal efficiency of the tar in tobacco smoke, it does not mention a semivolatile component at all.

Japanese Patent No. 3939823

  An object of the present invention is to provide a cigarette filter that does not significantly remove semi-volatile components in cigarette mainstream smoke and a cigarette including the cigarette filter.

  In order to solve the above problems, according to the first aspect of the present invention, the cellulose acetate fiber tow was selected from cellulose particles, cellulose triacetate particles, and mixtures thereof dispersed in the tow. A cigarette filter having a filter plug comprising a filter medium containing filtration rate control particles is provided.

  According to the 2nd side surface of this invention, the cigarette provided with the cigarette rod and the filter of this invention attached to the end of the said cigarette rod is provided.

  The cigarette filter of the present invention does not significantly remove semi-volatile components in cigarette mainstream smoke.

It is an expansion schematic diagram showing a part of a cigarette provided with a filter by one mode of the present invention. It is a graph which shows the relationship between the ventilation resistance of a control filter, and the transmittance | permeability of tar, nicotine, and a typical semivolatile component in mainstream smoke. It is a graph which shows the relationship between the ventilation resistance of the filter by this invention, and the transmittance | permeability of tar, nicotine, and a typical semivolatile component in mainstream smoke. It is a graph which shows the relationship between the selective filtration coefficient _Sx of the filter by this invention, and ventilation resistance with that of a control filter. It is a figure which shows the relationship between the plasticizer (triacetin) added to a filter raw material, and the transmittance | permeability of a representative semivolatile component. It is a graph which shows the relationship between the ventilation resistance of a particle | grain addition filter, and the total outer peripheral surface area of a cellulose acetate fiber. It is a figure which shows the relationship between the total outer peripheral surface area of the cellulose acetate fiber which comprises a filter plug, and the transmittance | permeability of a typical semivolatile component. It is a graph which shows the transmittance | permeability of the representative semivolatile component of the filter which added the cellulose triacetate particle | grains to the cellulose acetate fiber which has a total outer peripheral surface area of 223 cm < ² > on average. It is a graph which shows the transmittance | permeability of the representative semivolatile component of the filter which added the cellulose triacetate particle to the cellulose acetate fiber which has a total outer peripheral surface area of 255 cm < ² > average. It is a graph which shows the transmittance | permeability of the representative semivolatile component of the filter which added the cellulose particle to the cellulose acetate fiber which has a total outer peripheral surface area of 206 cm < ² > average. FIG. 6 is a schematic view showing the structure of a filtration rate control particle-containing filter used in Example 7. FIG. 10 is a schematic diagram showing the structure of a control filter used in Example 7. It is a graph which shows the influence with respect to the transmittance | permeability of the typical semivolatile component of a filter by addition of the additive to the filtration rate control particle.

  Hereinafter, some embodiments of the present invention will be described in detail.

  The cigarette filter of the present invention includes a filter plug including a filter medium containing cellulose acetate fiber tow. Filtration rate control particles are dispersed in the cellulose acetate fiber tow. In the present specification, “dispersion” generally means that the filtration rate control particles are distributed almost uniformly throughout the interior of the cellulose acetate fiber tow (see FIG. 1), but the cigarette mouth side or cigarette It may be distributed to the rod side. The filtration rate control particles are controlled so as to reduce the filtration rate of the semivolatile components in the cigarette mainstream smoke. The filtration rate control particles are selected from cellulose particles, cellulose triacetate particles, and mixtures thereof.

  Cellulose triacetate particles have an average degree of acetyl substitution of 2.76 to 3.00, preferably an average degree of acetyl substitution of 2.8 to 3.0, according to the definition of Japan Chemical Fiber Association. The average acetyl substitution degree can be measured according to a titration method: ASTM D871-96. The degree of acetyl substitution of cellulose acetate determined by such a measurement method is defined as “average degree of acetyl substitution” in order to show a normal distribution.

  Cellulose acetate fibers can be bound by a plasticizer such as triacetin to form a tow. Each of the cellulose acetate fibers extends substantially parallel to each other over the entire length of the filter.

  The cellulose acetate fiber constituting the cellulose acetate fiber tow may be any cellulose acetate fiber that is used in a normal cigarette filter. Such a cellulose acetate fiber may have a single fineness of 1.5 to 8 denier and may have a cross-sectional shape such as a circle, an ellipse, a Y shape, an X shape, or an I shape. The cellulose acetate fiber can be composed of cellulose acetate having an acetyl substitution degree of 2.4 to 2.5 (diacetate). The total fineness of the cellulose acetate fiber tow can usually be 15000-50000 denier. The cellulose acetate fiber tow is displayed, for example, as 1.9Y44000. As is well known to those skilled in the art, this is a single fineness of 1.9 denier, the fiber cross section is Y-shaped, and the total fineness is 44000 denier. It means that. In this specification, the unit of fineness “denier” represents the weight of one fiber per 9000 m (g / 9000 m), and the unit of total fineness “denier” represents the weight of all fibers per 9000 m (g / 9000). 9000m).

  The cellulose particles hardly adsorb semi-volatile components in cigarette mainstream smoke and hardly adsorb menthol (see Examples 1 and 2 described later). Further, the cellulose triacetate particles hardly adsorb semi-volatile components in cigarette mainstream smoke, and hardly adsorb menthol (see Examples 1 and 2 described later). Thus, since the filtration rate control particles hardly adsorb menthol, when the cigarette filter of the present invention is applied to menthol cigarette, menthol is significantly adsorbed by the filter after cigarette manufacture and before smoking by the smoker. In addition, it may be difficult for the amount of menthol in mainstream smoke to decrease when smoking cigarettes.

The filtration rate control particles have a granular form. The filtration rate control particles preferably have a particle diameter of 100 μm or more and 1000 μm or less in terms of average sphere equivalent diameter from the viewpoint of filter hardness and ventilation resistance, filtration performance, and ease of manufacture of the filter. More preferably, it is larger than 250 μm. When manufacturing a filter containing particles having an average equivalent sphere diameter of 100 μm or more and 1000 μm or less, a normal charcoal filter manufacturing apparatus can be used as it is (in this case, of course, filtration is performed instead of charcoal particles). Rate control particles are used). The average sphere equivalent diameter can be obtained by measuring the particle size distribution using a particle size distribution measuring device and calculating the 50% median diameter of the sphere equivalent diameter as in the examples described later. Moreover, the BET specific surface area of the filtration rate control particles is preferably less than 5 m ² / g. The BET specific surface area can be determined according to a known BET method.

  The filtration rate control particles can be obtained by a granulation apparatus using a compression method. Specifically, it can be obtained as follows by a granulation apparatus using a compression method. First, the raw material of cellulose particles or cellulose triacetate particles is pulverized to a powder state, the obtained pulverized product and various additives are mixed in a precision mixer, and then the resulting mixture is mixed with a dry granulator And compacting while pressing with a roller to obtain a molded product (for example, a plate-like material). Next, the molded product is pulverized using a dry granulator. At this time, after coarse crushing as the first stage, it may be crushed to a desired particle size in the second stage. The obtained crushed material is passed through a sieving machine to select only granules having a predetermined particle size, thereby preparing filtration rate control particles. Thus, the filtration rate control particles obtained by the granulation apparatus using the compression method are excellent in that the yield is high and troubles during winding of the filter due to mixing of long fibers are less likely to occur.

  Among the filtration rate control particles, cellulose triacetate particles can be obtained by pulverizing and classifying cellulose triacetate flakes, or cellulose triacetate particles can be obtained by rolling cellulose triacetate flakes, extruding method, fluidized bed method, It can also be obtained by granulating with a well-known granulator such as a stirring system or a compression system. Cellulose particles are commercially available.

The filtration rate control particles preferably occupy 1.5% by volume or more and 30% by volume or less of the volume of the filter containing the filtration rate control particles. Furthermore, when considering filter production, the production tends to be difficult when the volume ratio of the added particles increases. For this reason, in order to satisfy the results of the filtration rate control and sensory evaluation without the addition of particles affecting the filter production, the filtration rate control particles have a volume of the filter containing the filtration rate control particles. More preferably, it accounts for 1.5 volume% or more and 16 volume% or less (see Examples 3 and 4 described later). The ratio of the filtration rate control particles, those circumference 24.5 mm, can be achieved airflow resistance of 35mmH ₂ O~180mmH ₂ O, which is said to be suitable as a ventilation resistance of a filter having a size of length 25mm is there. The volume V of the filter can be obtained by the equation V = πr ² L (where r is the radius of the filter and L is the length of the filter) (note that the thickness of the filter paper is small enough to be ignored). . For the calculation of the volume of the particles, the added weight and the apparent density obtained using a mercury porosimeter were used.

  By the way, when the filtration rate control particles are added to the tow of cellulose acetate fiber, the hardness of the resulting filter plug increases. Therefore, it is not necessary to add triacetin as a plasticizer, and even when triacetin is added as a plasticizer, the amount of triacetin added as a plasticizer can be reduced. For example, when the filtration rate control particles are added to the cellulose acetate fiber tow in the above ratio, the triacetin is not added, or by adding it in an amount of 3% by weight or less with respect to the cellulose acetate fiber tow, sufficient The hardness of the filter plug can be obtained (see Example 1 described later). The hardness of the filter plug can be expressed as a strain amount of the filter plug when an indenter having a diameter of 12 mm is pressed against the filter plug for 10 seconds under a load of 300 g. The smaller the strain, the harder the filter plug.

  In addition to adding the filtration rate control particles to the filter, the permeation of semivolatile components can be further improved by reducing the amount of plasticizer added or not adding a plasticizer (described later). See Example 6).

  Furthermore, when the filtration rate control particles are added to the cellulose acetate fiber tow, the total outer surface area of the cellulose acetate fibers used is 10% or more (usually 30% or less) smaller than when the filtration rate control particles are not added. As a result, the transmissivity of the semi-volatile component is further improved (see Examples 4 and 5 below).

  Moreover, when the filter which added the said filtration rate control particle to the tow | toe of a cellulose acetate fiber is used for a cigarette, compared with the case where the filter which did not add the said filtration rate control particle is used for a cigarette, a flavor is changed. (See Example 3 below).

  In order to adjust to a more desirable cigarette flavor, a small amount of an additive can be added to the filtration rate control particles. It is demonstrated in Example 7 described later that the additive contributing to the cigarette flavor does not affect the selective permeation of the semi-volatile component even when added to the filtration rate control particles. Such an additive may be a flavor component (for example, a fragrance) or a component that affects the flavor (for example, a moisturizer, an amino acid, a polysaccharide, or a dietary fiber). Also referred to as “flavoring contribution component”. The flavor contribution component is preferably added in an amount of 10% by weight or less, more preferably 5% by weight or less, based on the total weight of the particles (the total weight of the filtration rate control particles and the flavor contribution component). As a flavor contribution component, the following fragrance | flavor, a moisturizer, an amino acid, a polysaccharide, dietary fiber etc. are mentioned, for example.

  A fragrance | flavor may be a synthetic fragrance | flavor, a natural fragrance | flavor, an essential oil, etc., and can be used regardless of lipophilicity and hydrophilicity. Examples of lipophilic fragrances include vanillin, ethyl vanillin, guainalol, thymol, methyl salicylate, linalool, eugenol, menthol, clove, anise, cinnamon, bergamot oil, geranium, lemon oil, spearmint, ginger. Examples of hydrophilic fragrances include glycerin, propylene glycol, ethyl acetate, isoamyl alcohol.

Moisturizers include polyols {diols [e.g., alkanediols (ethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, hexylene glycol C _2-10 alkane diol, preferably C _2-8 alkane diol, more preferably C _2-6 alkane diol, especially C _2-4 alkane diol, etc., polyalkylene glycol (diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, etc.), etc.], triols [alkane triol (glycerol, 1,2,6-hexane _{C 3-10} alkane triols such as triol, preferably _{C 3-6} alkane triol, and Preferably C _3-4 alkane triol), etc.], the multimers of tetra- or higher-functional polyols [trifunctional or higher polyols (such as the alkane triol) (e.g., diglycerin, polyglycerin, such as triglycerol), etc.], etc.} And derivatives of these polyols [for example, dialkylene glycol monoalkyl ether (such as methyl carbitol and ethyl carbitol), (poly) alkylene glycol monoacylate (such as ethylene glycol monoacetate) and the like] and the like.

  Examples of amino acids include amino acids and salts thereof (amino acid salts). The amino acid may be a neutral amino acid (such as monoamino monocarboxylic acid), an acidic amino acid (such as monoamino dicarboxylic acid), or a basic amino acid (such as diamino monocarboxylic acid), or a sulfur-containing amino acid. Good. In addition, the amino acid may be an α-amino acid, a β-amino acid, a γ-amino acid, or the like, and particularly an α-amino acid. The amino acid may be either an optically active form (D form, L form, etc.) or a racemate. The amino acids also include polyamino acids having a low degree of polymerization (for example, a degree of polymerization of 2 to 9, preferably a degree of polymerization of 2 to 5, more preferably about a degree of polymerization of 2 to 3). The amino acid may have a substituent, and may be an amino acid derivative in which at least a part of the carboxyl group or amino group is derivatized. For example, in an amino acid, at least a part of the carboxyl group may be a derivatized carboxyl group (for example, an amide group).

Representative amino acids include aliphatic amino acids [for example, glycine, alanine, isoleucine, leucine, valine, threonine, serine, asparagine, aminosuccinic acid, cysteine, methionine, glutamine, glutamic acid, and other aliphatic monoaminocarboxylic acids (amino C _2-20 alkane carboxylic acid, preferably amino C _2-12 alkane carboxylic acid, more preferably amino C _2-8 alkane carboxylic acid), aliphatic polyamino carboxylic acid (polyamino C) such as lysine, hydroxy lysine, arginine, cystine _2-20 alkanecarboxylic acid, preferably polyamino C _2-12 alkanecarboxylic acid, etc.]], aromatic amino acids (eg, aryl C _2-20 alkanecarboxylic acid such as phenylalanine, tyrosine, preferably C _{6-6 10} aryl C _2-12 alkane carboxylic acid), heterocyclic amino acids (for example, tryptophan, histidine, proline, 4-hydroxyproline, etc.), and polyamino acids in which these amino acids are polymerized at a low degree of polymerization (for example, a degree of polymerization of 9 or less). Peptides (for example, glycylglycine, glutamylglycine, glycylglycylglycine, glycylproline, etc.) and the like can be mentioned. Examples of amino acid salts include metal salts [for example, alkali metal salts (for example, sodium salts such as sodium glutamate)], hydrochlorides (for example, arginine hydrochloride) and the like, and salts between amino acids (lysine and glutamic acid). Etc.) and the like.

  Other flavor-contributing ingredients include food additives such as xylitol and mannitol, polymers such as lignin, cellulose, carboxymethylcellulose, hydroxypropylmethylcellulose, chitin, starch, glycogen, guar gum, glucomannan, sodium alginate, agarose , Polysaccharides such as chitosan, pectin, carrageenan, xanthan gum and dietary fiber.

  Furthermore, a pigment | dye can also be added to filtration rate control particle | grains. As the pigment, for example, a natural pigment extracted from gardenia, safflower, turmeric, cypress, red pepper, paprika, red pepper, red cabbage, cacao and the like can be added. The pigment can be added in an amount of 0.1% to 5% by weight, preferably 1% by weight or less, based on the total weight of the particles (total weight of the filtration rate control particles and the pigment). be able to. The filtration rate control particles to which a dye is added can exhibit various colors depending on the color of the dye. By adding a pigment to the filtration rate control particles and producing a filter using transparent chip paper, the filtration rate control particles (granules) mounted on the filter can be confirmed from the outside. Since human sensations are known to depend on color vision, it is expected that the color of the pigment will bring a new sensation to the taste of cigarettes. Moreover, also in the quality inspection on filter manufacture, when the color of filter fiber and filtration rate control particle | grains is different like a charcoal filter, filter fiber and filtration rate control particle | grains can be distinguished easily.

  The filter of the present invention may be attached to one end of the cigarette rod alone or in combination with other filter plugs. An example of the latter is shown in FIG.

  FIG. 1 is a schematic view of a cigarette 10 with a filter according to one embodiment of the present invention. The cigarette 10 includes a cigarette rod 110 and a filter 120 provided at one end in the axial direction of the cigarette rod 110 so that the cigarette rod is in contact with the end face and the end face. The cigarette rod 110 includes a tobacco filler 112 such as a cigarette wrapped with cigarette paper 111. The filter 120 includes a filter plug 121 of the present invention that includes a tow 122 made of a large number of cellulose acetate fibers 123 that are arranged along the axial direction of the filter 120 and can be bound with a plasticizer such as triacetin. Each cellulose acetate fiber 123 extends over the entire length of the filter plug 121. The filtration rate control particles 124 are dispersed and added to the cellulose acetate fiber tow 122. The filter plug 121 is wrapped with a filter wrapping paper 125. Cigarette rod 110 and filter 120 are connected by chip paper 130 in the same manner as a normal cigarette with a filter. The chip paper 130 can be provided with a plurality of ventilation holes 131 in one or more rows in the circumferential direction of the filter. A so-called acetate plain filter plug 140 made of cellulose acetate fiber tows 142 wrapped with a filter wrapping paper 141 is attached to the downstream end (with respect to the direction of smoke suction) of the filter 120 containing filtration rate control particles. can do. In that case, the plain filter plug 140 is also wrapped by the chip paper 130.

  Hereinafter, the present invention will be described with reference to examples.

Example 1
<Preparation of filtration rate control particles>
1. Cellulose triacetate particles Cellulose triacetate flakes (average acetyl substitution degree 2.86) were obtained from Daicel Chemical Industries, Ltd. About this cellulose triacetate flake, the acetyl substitution degree was measured based on the titration method: ASTM D871-96, and it confirmed that it was the said acetyl substitution degree. Next, the cellulose triacetate flakes are pulverized by a coffee mill (MK-52M manufactured by Matsushita Electric Industrial Co., Ltd.), and classified by a sieve using an electromagnetic sieve shaker (AS200 control manufactured by Lecce Co., Ltd.), thereby separating the sieve mesh. Particles at 300-710 μm were obtained. The particle size distribution was obtained by calculating a 50% median diameter of a sphere equivalent diameter as an average particle diameter using a digital image analysis type particle size distribution measuring apparatus (manufactured by Lecce Co., Ltd. (manufactured by Horiba, Ltd.)). The average equivalent spherical diameter of the particles was 550 μm, the bulk density was 0.54 g / cc, the apparent density obtained using a mercury porosimeter was 0.71 g / cc, and the BET specific surface area by nitrogen desorption was 4 0.6 m ² / g.

2. Cellulose Particles Cellulose particles were cellulose beads obtained by refining and dissolving wood, and viscose obtained in a granular and porous form, and those sold under the Viscopearl trademark from Rengo Co., Ltd. were used. The particles used had an average sphere equivalent diameter of 400 μm, a bulk density of 0.20 g / cc, an apparent density obtained using a mercury porosimeter of 0.34 g / cc, and the BET specific surface area was below the detection limit. .

<Fabrication of filter plug>
The cellulose particles and cellulose triacetate particles were added to an acetate filter to which triacetin was added in the same manner as a generally known method for producing a charcoal filter. In addition, a plain acetate filter without addition of filtration rate control particles was also produced. As filter paper for each filter plug, a paper having a basis weight of 24.0 ± 1.5 g / m ² , a thickness of 60 ± 5 μm, and an air permeability of 10,000 ± 1,800 Cholesta unit was used. Each filter plug had a diameter of 7.7 mm and a length of 120 mm. The ventilation resistance of the filter was measured according to ISO 6565: 2002.

  The hardness of the obtained filter plug was measured as the strain amount of the filter plug when an indenter having a diameter of 12 mm was pressed against the filter plug for 10 seconds under a load of 300 g.

The specifications and hardness of the obtained filter plug are shown in Tables 1A to 1C below.

  The hardness of the cellulose triacetate particle-added filter (A-1 to A-6) is 0.42 to 1.2 (mm), and the hardness of the cellulose particle-added filter (B-1 to B-6) is 0.00. It was 48-0.97 (mm). Meanwhile, in the acetate plain filter, the hardness of the acetate plain filter (AF-1, AF-2) to which triacetin is not added is 1.6 (mm). Therefore, it has been found that the filter added with cellulose and cellulose triacetate particles exhibits the hardness of the filter by including the particles, and can increase the filter hardness regardless of the addition of triacetin if the added amount of the particles is increased.

<Preparation of cigarette sample>
The filter of the cigarette “mild seven aqua squash menthol” with a commercially available filter was removed, and the cigarette rod was cut into various lengths of the filter plug produced above and placed in a paper tube (outer diameter 7.7 mm). A cigarette sample was produced by connecting the filter with an adhesive tape. The length and ventilation resistance of each cut filter are shown in Tables 2A to 2C below. The period from filter preparation to smoking test is one month.

<Smoking test>
Using the automatic smoker (RM20D manufactured by Borgwaldt KC Inc.), smoke absorption capacity 35.0mL / 2 seconds, smoke absorption time 2 seconds for each of the 10 cigarette samples prepared above (ventilation holes were closed with adhesive tape) / Puff, smoked automatically under conditions of 1 puff / min, smoked particulate matter collected by Cambridge filter (Borgwaldt KC Inc. CM-133), and smoke passing through this Cambridge filter And 10 mL of methanol cooled to −70 ° C. with a refrigerant composed of isopropanol.

  In a serum bottle, a Cambridge filter that collected the particulate matter, 10 mL of a methanol solution that collected the tobacco smoke, and an internal standard solution (d-32 pentadecane 0.05 mg / mL, d-1-ethanol 150 mL / L, anethole 1 mL of 2 mL / L, 1,3-butanediol 4 mL / L) was added, and the mixture was shaken for 30 minutes. After shaking, the supernatant was collected and used as a sample for analysis. The above operation was also performed on a cigarette rod (control cigarette) obtained by removing a filter of a commercially available cigarette with a filter “Mild Seven Aqua Squash Mentor”.

<Analysis of tar, nicotine and semi-volatile components>
The analytical sample was analyzed by gas chromatography mass spectrometry (GC-MSD). Agilent 7890A (Agilent Technologies Inc.) was used for GC, and Agilent 5975C (Agilent Technologies Inc.) was used for MSD.

The peak area of each component in the chromatogram obtained by the above analysis (standardized by the internal standard) is compared with the peak area of each component in the chromatogram for the control cigarette. It was calculated transmittance 1-E _x of the filter.

In the above equation, A _{x, in} and A _{x, out} indicate values obtained by normalizing the peak area of the component x in the smoke of the control cigarette and each filter-attached cigarette sample with an internal standard. Ex represents the filtration rate of component x.

  In addition, as a semivolatile component, three types of 3-furaldehyde, 2-acetylfuran, and furfural are selected as representative semivolatile components, the average of the transmittance is calculated, and the selective filtration of the semivolatile components is performed. Performance was evaluated.

  For cigarettes CAF-3-1 to CAF-3-5 and CAF-4-1 to CAF-4-5, the horizontal axis represents the ventilation resistance of the filter, and the horizontal axis represents tar, nicotine, and representative semi-volatile components. The logarithmic value of the rate is plotted and shown in FIG. 2A shows the transmittance of tar, FIG. 2B shows the transmittance of nicotine, and FIG. 2C shows the transmittance of a representative semivolatile component. In FIGS. 2A to 2C, the ◯ marks relate to CAF-3-1 to CAF-3-5, and the △ marks relate to CAF-4-1 to CAF-4-5.

  For tar (FIG. 2 (A)) and nicotine (FIG. 2 (B)), a linear approximation can be made regardless of cellulose acetate tow fiber, but for representative semi-volatile components (FIG. 2 (C)), the type of tow fiber It was found that the transmittance showed different slopes depending on (fiber diameter). This indicates that the permeability of tar and nicotine is governed only by the ventilation resistance of the filter, but the representative semivolatile components have different permeation behavior depending on the type of tow. Since tar and nicotine are basically particulate phase components, filtration efficiency can be expressed as a function of filter airflow resistance, but semi-volatile components are distributed in both the vapor phase and the particulate phase. It exhibits permeation behavior that is not governed solely by ventilation resistance due to the action of filtration of the particle phase component, absorption of the vapor phase component into the fiber, and the like.

  Next, the results for cigarettes CA-1 to CA-5 and CB-1 to CB-5 are shown in FIG. 3A shows the transmittance of tar, FIG. 3B shows the transmittance of nicotine, and FIG. 3C shows the transmittance of a representative semivolatile component. 3A and 3B, line a relates to CAF-3-1 to CAF-3-3 and CAF-4-4 to CAF-4-5, and line b corresponds to cigarette CA-1. ˜CA-5, line c relates to cigarettes CB-1 to CB-5. In FIG. 3C, line a relates to CAF-3-1 to CAF-3-5, and line b relates to CAF-4-1 to CAF-4-5.

  The results shown in FIG. 3 (A) and FIG. 3 (B) show that the filter to which the filtration rate control particles of the present invention are added has a higher tar and nicotine transmittance than the acetate plain filter. It shows that the filtration rate of nicotine is low. Moreover, from the result shown in FIG. 3C, it can be seen that the filter to which the filtration rate control particles of the present invention are added transmits more semi-volatile components than the acetate plain filter. That is, the filtration rate control particles of the present invention significantly improve the permeation of semi-volatile components. On the other hand, a filter to which cellulose diacetate particles (average degree of acetyl substitution 2.4 to 2.5) are added has a function of filtering a semi-volatile component, and allows a semi-volatile component to pass through compared to an acetate plain filter. The difficulty has been demonstrated by the inventors.

Further, from the results shown in FIG. 3 (A), in the filter to which the filtration rate control particles of the present invention are added, the tar filtration rate is different from that of the acetate plain filter. In order to clarify, a selective filtration coefficient S _x was obtained from the following equation as an index representing the component selectivity in the filtration of typical semivolatile components.

Here, E _TPM indicates the filtration rate for the crude tar (whole granular material).

FIG. 4 shows a result of plotting the selective filtration coefficient _Sx thus obtained with respect to the filter ventilation resistance. In FIG. 4, line a relates to cigarettes CAF-4-1 to CAF-4-5, and line b relates to CAF-3-1 to CAF-3-5. From the results shown in FIG. 4, when compared with the same single fineness, the filter to which the filtration rate control particles of the present invention are added has a lower selective filtration coefficient in an arbitrary filter ventilation resistance than the acetate plain filter, and the tar filtration It was found that semi-volatile components were selectively permeated even when the rate was considered.

Next, in order to investigate the influence of the plasticizer (triacetin (GTA)) added to the filter material on the transmittance of the representative semivolatile component, cigarette CA-1 (triacetin 6 wt%), cigarette CA-4 (triacetin 9) %), Cigarette CA-5 (triacetin 0%), cigarette CB-1 (triacetin 6% by weight), cigarette CB-4 (triacetin 9% by weight), and cigarette CB-5 (triacetin 0%) The selective filtration coefficient S _x of volatile components was plotted against the ventilation resistance. The results are shown in FIG. As shown in FIG. 5, when the triacetin addition amount is small, it is shown that the semivolatile component permeates, and when the triacetin addition amount is large, the semivolatile component is filtered. It has been shown that the transmissivity of semi-volatile components can be controlled. This is due to the fact that the vapor content of the semivolatile component is absorbed (adsorbed) by the triacetin on the surface of the cellulose acetate fiber, and when the triacetin amount is decreased, the amount of the semivolatile component adsorbed is decreased. it is conceivable that. Therefore, in the filter to which the filtration rate control particles of the present invention are added, the filter hardness can be ensured even if the triacetin addition amount is reduced, so that the semivolatile components can be more selectively transmitted by reducing the triacetin addition amount. Can be achieved.

  Summing up the above results, the selective permeation of semi-volatile components can be controlled by the diameter of cellulose acetate fibers constituting the tow and the amount of triacetin, but in view of the ease of filter design and production, It has been found that the filter of the present invention to which filtration rate control particles are added is effective for the selective permeation of the sex component.

Example 2
When the filter of the present invention is intended for use in menthol tobacco products, the amount of menthol in mainstream smoke will decrease as menthol adsorption proceeds to the filtration rate control particles of the present invention. Therefore, the amount of menthol adsorbed on the filtration rate control particles of the present invention was examined.

  Specifically, an acetate plain filter (cellulose acetate fiber tow: 1.9Y44000) is attached to one end of a cigarette rod (circumference: 24.9 mm; length: 59 mm) having 640 mg of tobacco added with 0.59% by weight of menthol. Menthol acetate filter (cellulose acetate fiber tow: 2.5Y35000; weight) with a weight of 30 mg; filter length: 5 mm), a space of 5 mm from this acetate plain filter, and a menthol-added thread passed through the center 90 mg; filter length: 15 mm) was placed, and the filtration rate control particles of the present invention (cellulose particles or cellulose triacetate particles prepared in Example 1) were filled in the cavities between both filters. The menthol acetate filter contained 1.99% by weight menthol. A cigarette filled with cellulose particles as cavities as filtration rate control particles is designated as cigarette A, and a cigarette filled with cellulose triacetate particles as cavities as filtration rate control particles is designated as cigarette B.

  The cigarette thus obtained was sealed in a glass bottle and stored at 50 ° C. for 2 weeks. The cigarette sample after storage was taken out of the glass bottle, and the menthol content in the tobacco cut, acetate plain filter, filtration rate control particles, and menthol acetate filter was quantified. The menthol content was quantified by extracting a sample to be measured (tobacco cut, acetate plain filter, filtration rate control particles or menthol acetate filter) with methanol, and using a gas chromatograph (6890 series manufactured by HEWLETT PACKARD). In a preliminary test, it was confirmed that menthol could be extracted with methanol.

Table 3 below shows the menthol content in tobacco cuts, acetate plain filters, filtration rate control particles, and menthol acetate filters.

  From the results shown in Table 3, it can be seen that the filtration rate control particles (cellulose particles and cellulose triacetate particles) of the present invention hardly adsorb menthol. Therefore, even if the filter of the present invention to which the filtration rate control particles are added is used for a menthol tobacco product, undesirable adsorption of menthol to the filtration rate control particles hardly occurs, so that the menthol taste can be sufficiently enjoyed.

Example 3
A cigarette with a filter having the structure shown in FIG. 1 was produced. As cigarette rod 110, a cigarette with a filter “mild seven aqua squash menthol 7 box” obtained by removing the tip paper and the filter having ventilation holes (the menthol content in the chopped portion is 0. 0). 55% by weight). As the filter plug 121, filters A-1 and A- shown in Table 1A are used so that the ventilation resistance of the filter is 35 ± ₂ mmH ₂ O so that the amount of tar, nicotine and menthol in cigarette mainstream smoke is substantially constant. 6, filters B-1 and B-6 shown in Table 1B, and filter AF-3 shown in Table 1C, each cut to a length of 10 mm, were used. An acetate plain filter 140 (cellulose acetate fiber tow: 5.0Y35000 (triacetin added at 6.9 wt%); filter length: 17 mm, menthol content: 2.22 wt%) was attached to the rear end of the filter plug 121. The filter plugs 121 and 140 were connected to the cigarette rod by the chip paper. The time required from the creation of the filter to the smoking test is 3 months. As a precaution, the specifications of the filter plug 121 are shown in Table 4 below.

Among cigarettes provided with the filters shown in Table 4, cigarettes (CA-6-2 and CB-1-2) and comparative control cigarettes (CAF-3-1) having a large amount of filtration rate control particles added to the filter. -2) Each of the five was smoked under the smoking conditions described in Example 1 without closing the ventilation hole, and the amount of tar, nicotine and menthol in the mainstream smoke was measured, and the number of puffs was measured. Table 5 below shows the measurement results (average values) of the amount of tar, nicotine, and menthol and the number of puffs per cigarette.

  Next, the taste evaluation of the cigarette was performed by nine evaluation panels. About cigarette CB-1-2 and CB-6-2, the evaluation panel felt the difference in the taste with control cigarette CAF-3-1-2. As characteristics of the flavors of cigarettes CB-1-2 and CB-6-2, menthol was strongly felt and menthol was clearly felt.

  Regarding cigarettes CA-1-2 and CA-6-2, the difference in taste with the control cigarette CAF-3-1-2 was felt. As a characteristic of the cigarettes CA-1-2 and CA-6-2, menthol was strongly felt and felt clear. Furthermore, the flavors of cigarettes CA-1-2 and CA-6-2 have a sharp feeling, bitterness is unlikely to remain, and a strong tobacco-like flavor is felt. I felt that there was not much left behind.

Example 4
Acetate plain filter plugs having various ventilation resistances (filter length: 10 mm; ventilation resistance: 14 to 58 mmH ₂ O) and filtration rate control particle-added filter plugs of the present invention shown in Table 6 below were prepared, and the ventilation resistance was measured. did. In addition, regarding the cellulose acetate fiber tow in the produced filter, the total of the outer peripheral surface area (total outer surface area) of each single fiber is described in the literature (Kazuo Maeda “Development Research on Tobacco Smoke Filters” (December 1983, pages 27-30).

<Total surface area of cellulose acetate>
(1) The equivalent circle diameter of a single fiber is obtained from the following equation.
Equivalent circle diameter = 11.91 x (single fineness / fiber density) ^1/2
Here, the fiber density is 1.32 g / cm ³ .
(2) Next, the shape factor of the cross section of the single fiber is obtained from the following equation.
Shape factor = actual fiber perimeter / (4 x π x actual cross-sectional area)
Here, the actual fiber outer peripheral length and the actual cross-sectional area are measured from a micrograph of a cross section of a single fiber.
(3) Next, the outer peripheral length of the single fiber is obtained from the following equation.
Single fiber circumference = π x equivalent circle diameter x (shape factor) ^1/2
(4) Finally, the total outer peripheral surface area is obtained from the following equation.
Total outer peripheral surface area = single fiber outer peripheral length x number of single fibers x fiber length Here, the fiber length is the net acetate tow weight obtained by subtracting the triacetin amount from the measured acetate tow weight, and converted from the total fiber degree to the filter length. Find by dividing by weight.

  The results are shown in Table 6.

  Regarding the results shown in Table 6, the airflow resistance of the filter is plotted against the total peripheral surface area of the cellulose acetate fiber, and is shown in FIG. In FIG. 6, black rhombus marks relate to acetate plain filter plugs, white triangle marks relate to cellulose particle-added filter plugs, and white square marks relate to cellulose triacetate particle-added filter plugs. FIG. 6 shows that the filter plug to which the filtration rate control particles of the present invention are added has a smaller total outer surface area of cellulose acetate fiber than any acetate plain filter plug at any ventilation resistance. In the filter plug to which the filtration rate control particles of the present invention are added, the total peripheral surface area reduction rate of the cellulose acetate fiber is about 10 to 30%. Therefore, when the filtration rate control particles of the present invention are added, a cellulose acetate fiber tow having a smaller total outer peripheral surface area is used in producing a filter plug showing the same ventilation resistance as compared with the case where the particles are not added. Can do.

Example 5
Cigarettes CA-1 to CA-6, CB-1 to CB-6, CAF-3-1 to CAF-3-5 and CAF-4-1 to CAF4-5 (see Tables 2A to 2C), and Table 7A below And about the same cigarette provided with the filter plug shown to Table 7B, the total outer peripheral surface area of the cellulose acetate fiber, the transmittance | permeability of a typical semivolatile component, and the selective permeability coefficient were calculated | required. The results are shown in Table 8A and Table 8B below.

  Regarding the results shown in Table 8A and Table 8B, the transmittance of the representative semivolatile components is plotted against the total peripheral surface area of the cellulose acetate fiber and is shown in FIG. In FIG. 7, white triangle marks are for cigarettes CB-5 and CB2-4, white square marks are for cigarette CA-5, and white circle marks are for white cigarettes CAF-1-1 to CAF-1-5. Relates to cigarettes CAF-2-1 to CAF-2-5, and the filter plug of any cigarette contains no plasticizer. In FIG. 7, black triangle marks indicate cigarettes CB-1, CB-2, CB-3, CB-6, CB2-1, CB2-2, and CB2-5, and black square marks indicate cigarette CA-1, Regarding CA-2, CA-3, and CA-6, black circles indicate cigarettes CAF-3-1 to CAF-3-5, and black diamonds indicate cigarettes CAF-4-1 to CAF-4-5. Cigarette filter plugs also contain a plasticizer.

  From FIG. 7, the transmittance of the representative semivolatile component in the acetate plain filter plug largely depends on the amount of plasticizer (triacetin) added, but at the same amount of plasticizer, it is determined by the total peripheral surface area of the cellulose acetate fiber. I understand. It can also be seen that the particle size of the cellulose particles has little effect on the filtration characteristics of the semivolatile components. These facts are because cellulose particles and cellulose triacetate particles are difficult to dissolve in acetone solvent and do not adsorb menthol and triacetin so much, so they also have low adsorption ability to semi-volatile components that are close in polarity to menthol and triacetin. it is conceivable that.

  By the way, it can be seen from FIG. 7 that the selective filtration characteristics of semi-volatile components can be controlled by changing the type of cellulose acetate fiber tow and the amount of plasticizer added. Any combination of cellulose acetate fiber tow type and plasticizer amount can be freely combined with cigarette products because it must be secured and the airflow resistance must be controlled to design the amount of tar and nicotine in mainstream smoke It is impossible. However, when filtration rate control particles (cellulose particles and / or cellulose triacetate particles) are added to a filter according to the present invention, a certain hardness of the filter is maintained by the presence of the particles even if the amount of triacetin is reduced, and mainstream smoke In order to adjust the amount of tar / nicotine in the target value, the ventilation resistance can be controlled by adding filtration rate control particles, so cellulose acetate fiber tow, which is impossible with conventional technology, that is, cellulose acetate fiber with a small total outer peripheral surface area It becomes possible to use tow. In other words, in general, if the total peripheral surface area of the cellulose acetate fiber becomes smaller, the ventilation resistance of the filter plug tends to decrease, so that the cellulose acetate fiber showing lower ventilation resistance than the cellulose acetate fiber tow of the conventional cigarette filter. Since tow can be used, as a result, it is possible to develop a filter having a characteristic of selectively transmitting a semivolatile component compared to tar.

  From the above, in the filter to which filtration rate control particles (cellulose particles and / or cellulose triacetate particles) are added according to the present invention, semi-volatile components that are limited in view of product design and manufacture in conventional acetate plain filters are included. Since the transmission control width can be expanded, it has been found that it is effective to provide a new tobacco flavor taste or a menthol tobacco flavor sense.

Example 6
Cellulose powder (FMC Biopolymer, trade name: Endurance MCC) and cellulose triacetate powder (Daicel Chemical Industries, trade name: Acetate Flakes DS2.9 LT-55 (TAC)) were used as raw materials. Each powder was pressurized at 20 MPa for 10 minutes using a tablet molding machine (manufactured by JASCO) and a manual hydraulic pump (manufactured by Riken Seiki) to obtain a plate-shaped molded product. Next, the obtained plate-shaped molded product is pulverized by a coffee mill (MK-52M manufactured by Matsushita Electric Industrial Co., Ltd.) and classified by a sieve using an electromagnetic sieve shaker (AS200 control manufactured by Lecce Co., Ltd.). Thus, filtration rate control particles having a mesh interval of 300 to 710 μm were prepared. Using the obtained filtration rate control particles, a cellulose triacetate particle-added filter and a cellulose particle-added filter were produced in the same manner as in Example 1. The ventilation resistance and hardness of the produced filter were measured according to the same method as in Example 1.

The specifications and hardness of the obtained filter plug are shown in Tables 9A and 9B below.

  In Tables 9A and 9B, the addition amount of triacetin is shown in% by weight based on the tow of cellulose acetate fiber.

  The hardness of the cellulose triacetate particle-added filter (A-7 to A-12) is 0.54 to 1.3 (mm), and the hardness of the cellulose particle-added filter (B-7 to B-12) is 0.00. 52-1.1 (mm). Meanwhile, in the acetate plain filter, the hardness of the acetate plain filter (AF-1, AF-2) to which triacetin is not added is 1.6 (mm). Therefore, the cellulose particle-added filter and the cellulose triacetate particle-added filter exhibit the hardness of the filter by including the particles, and if the amount of added particles is increased, the hardness of the filter can be reduced even if the amount of triacetin is reduced. It was found that can be secured. Specifically, it was found that sufficient filter plug hardness can be obtained even when triacetin is added in an amount of 3% by weight or less or when triacetin is not added.

<Preparation of cigarette sample>
For the evaluation of the cigarette "Seven Star Solid Menthol" with a commercially available filter removed, and the cigarette rod was cut into various lengths of the filter plug produced above and placed in a paper tube (outer diameter 7.7 mm) A cigarette sample was produced by connecting the filter with an adhesive tape. The period from filter preparation to smoking test is 2 months. Tables 10A to 10B below show the length of each cut filter, the ventilation resistance, and the total peripheral surface area of the cellulose acetate fiber.

  A smoking test was performed on the produced cigarettes CA-7 to CA-12 and CB-7 to CB-11 according to the same technique as in Example 1. The smoking test was also performed on a cigarette rod (control cigarette) obtained by removing a filter of a commercially available filter cigarette “Seven Star Solid Menthol”.

  Tar, nicotine and semi-volatile components were analyzed using the analytical sample obtained in the smoking test according to the same procedure as in Example 1. According to the same calculation formula as described in Example 1, the transmittance (%) and the selective filtration coefficient (%) were obtained.

Tables 11A to 11C below show the transmittance and selective filtration coefficient of representative semivolatile components of cigarettes CA-7 to CA-12 and CB-7 to CB-11 for each total peripheral surface area of the cellulose acetate fiber.

  Moreover, the transmittance | permeability of the representative semivolatile component of cigarette CA-7-CA-12 and CB-7-CB-11 is shown to FIGS. 8A-8C for every total outer peripheral surface area of a cellulose acetate fiber.

FIG. 8A shows the transmittance of a representative semivolatile component of a cellulose triacetate particle-added filter when the total outer peripheral surface area of the cellulose acetate fiber is 223 cm ² (fiber tow specification: 5.0Y35000). FIG. 8B shows the transmittance of the representative semivolatile component of the filter added with cellulose triacetate when the total outer surface area of the cellulose acetate fiber is 255 cm ² (fiber tow specification: 3.5Y35000). FIG. 8C shows the transmittance of the representative semivolatile component of the cellulose particle-added filter when the total outer peripheral surface area of the cellulose acetate fiber is 206 cm ² (fiber tow specifications: 5.9Y35000 and 5.0Y35000).

  From the results of Tables 11A to 11C and FIGS. 8A to 8C, when filters having substantially the same total outer peripheral surface area of cellulose acetate fiber are compared with each other, a filter with a low plasticizer addition amount has a high transmittance of representative semivolatile components. Can be confirmed. This is because the plasticizer increases the amount of semivolatile components adsorbed on the surface of the cellulose acetate fiber. Therefore, in addition to adding filtration rate control particles (that is, cellulose triacetate particles and cellulose particles) to the filter, it is possible to further reduce the transmission of semi-volatile components by reducing the amount of plasticizer added or not adding a plasticizer. It is possible to improve.

Example 7
In order to investigate the influence of the additive on the filtration performance of the filtration rate control particles, cellulose particles and cellulose particles added with the additives described in Table 11 below were prepared. Cellulose particles were prepared according to the same procedure as in Example 6. Additive-added cellulose particles were prepared according to the same procedure as in Example 6 by mixing cellulose powder and each additive. The additives are added in the amounts shown in Table 11. In Table 11, the “added amount” is expressed as a ratio (% by weight) of the additive to the total weight of the filtration rate control particles and the additives. For comparison, non-added filtration rate control particles were also prepared.

<Fabrication of filter plug>
In order to evaluate the filtration performance of each filtration rate control particle, the following filter plugs FA-1 and FB-1 to F- were used using the filtration rate control particles A-1 and B-1 to B-7. B-7 was produced. As shown in FIG. 9A, each filtration rate control particle is arranged in a paper tube having a length of 25 mm, and the filtration rate control particle has a front stage (tobacco lot side) and a rear stage (filter mouthpiece) so as to cover the filtration rate control particle. An acetate filter (5 mm) was installed on the side) to prepare each filtration rate control particle-filled filter. The amount of filtration rate control particles added is shown in Table 12. As a control, a filter plug F-C-1 in which two acetate filters (5 mm) were arranged in a 25 mm long paper tube as shown in FIG. 9B was prepared. Table 12 shows the specifications of each filter.

<Preparation of test cigarette>
As a cigarette used in the test, a commercially available cigarette with a filter “Seven Star Solid Menthol” was used. The filter part of the commercially available cigarette was cut, and said filter (FA-1, FB-1 to FB-7, FC-1) was connected, and the cigarette for a test was prepared. The filter ventilation was zero. Cigarettes prepared using filter F-C-1 are control cigarettes.

<Smoking test>
About the produced cigarette, the smoking test was done according to the same method as Example 1. FIG. Tar, nicotine and semi-volatile components were analyzed using the analytical sample obtained in the smoking test according to the same procedure as in Example 1. According to the same calculation formula as described in Example 1, the transmittance (%) and the selective filtration coefficient (%) were obtained.

Table 14 below shows the transmittance and selective filtration coefficient of representative semivolatile components of cigarettes using filters F-A-1 and F-B-1 to F-B-7.

  Moreover, the transmittance | permeability of the representative semivolatile component of the cigarette using filter FA-1 and FB-1 to FB-7 is shown in FIG.

  From the results shown in Table 14 and FIG. 10, it can be confirmed that the semi-volatile component transmittance of the filtration rate control particles in each filter is constant regardless of the presence or absence of the additive and the type thereof. From this result, it was confirmed that even if an additive that contributes to the taste of cigarette was added to the filtration rate control particles, the amount of the addition would not affect the filtration characteristics of the filtration rate control particles.

  DESCRIPTION OF SYMBOLS 10 ... Cigarette, 110 ... Cigarette rod, 111 ... Cigarette wrapping paper, 112 ... Cigarette filler, 120 ... Filter, 121 ... Filter plug, 122 ... Cellulose acetate fiber tow, 123 ... Cellulose acetate fiber, 124 ... Filtration rate control particles, 125 ... Filter paper, 130 ... Chip paper, 131 ... Ventilation hole, 140 ... Acetate plain filter plug, 141 ... Filter paper, 142 ... Cellulose acetate fiber tow

Claims (11)

Tow of cellulose acetate fiber,
Filtration rate control particles selected from cellulose particles, cellulose triacetate particles and mixtures thereof dispersed in the tow, and having filtration rate control particles having a BET specific surface area of less than 5 m ² / g. A cigarette filter including a filter plug including a filter medium.   The cigarette filter according to claim 1, wherein the cellulose triacetate particles have an average degree of acetyl substitution of 2.8 to 3.0.   The cigarette filter according to claim 1 or 2, wherein the filtration rate control particles occupy 1.5 to 30% by volume of the total volume of the filter plug.   The cigarette filter according to any one of claims 1 to 3, wherein the filtration rate control particles occupy 1.5 to 16% by volume of the total volume of the filter plug.   The total outer peripheral surface area of the cellulose acetate fiber constituting the tow is reduced by 10% or more than the total outer peripheral surface area of the cellulose acetate fiber constituting the corresponding filter plug not including the filtration rate control particles. The cigarette filter as described in any one of 1-4.   The cigarette filter according to any one of claims 1 to 5, wherein the filtration rate control particles are obtained by a granulating apparatus using a compression method.   The cigarette filter according to claim 1, wherein the filtration rate control particles have a spherical equivalent diameter of 100 μm or more and 1000 μm or less.   8. A plasticizer is added to the cellulose acetate fiber tow in an amount of 3% by weight or less based on the cellulose acetate fiber tow, or a plasticizer is not added. The cigarette filter as described in any one of.   The said filtration rate control particle | grain contains a flavor contribution component, and the said flavor contribution component is added in the quantity of 10 weight% or less with respect to particle | grain total weight, The any one of Claims 1-8 characterized by the above-mentioned. The cigarette filter according to one item.   The cigarette filter according to any one of claims 1 to 8, wherein the filtration rate control particles contain a pigment.   The cigarette with a filter provided with a cigarette rod and the cigarette filter as described in any one of Claims 1-10 attached to the end of the said cigarette rod.

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