HK1229643B - Low tar menthol cigarette - Google Patents

Description

low-tar menthol cigarettes

Technical Field

The present invention relates to a low-tar cigarette with a filter tip and added with menthol.

Background Art

In filter-tipped cigarettes, there is a known method of providing ventilation holes in the filter to adjust the amount of air flowing in for the purpose of adjusting the components in the smoke during smoking.

In general filter-tipped cigarettes, a method of adjusting the ventilation resistance of the filter according to the amount of components in the smoke is known.

Patent Document 1 discloses a filter-tipped cigarette having a filter with a ventilation resistance of 50 mmH ₂ O/100 mm (equivalent to 13.5 mmH ₂ O/27 mm) and a ventilation ratio of 20 to 80%.

Patent Document 2 describes a filter-tipped cigarette having two filter portions. The disclosure states that by adjusting the two filter portions so that one has a greater ventilation resistance than the other, and adjusting the amount of air flowing in through the tipping paper of the wrapped filter within a specified range, the concentrations of nicotine and tar in mainstream smoke can be reduced while also providing a sufficient draw.

Meanwhile, demand for menthol cigarettes is increasing year by year in the Japanese market, leading to the introduction of previously unavailable high-menthol cigarettes. Patent Document 3 describes a method for adding a flavoring agent, such as menthol, to filters. This method involves adding a flavoring liquid, prepared by dissolving and dispersing menthol in a plasticizer used in the filter manufacturing process, to acetate fiber bundles.

Patent Document 4 describes a method of retaining menthol in a flavor carrier to prevent the amount of menthol from decreasing over time.

Patent Document 5 discloses a method of preventing the decrease in menthol content over time by using a sheet having a flavor-retaining property.

Patent Document 6 also describes a filter manufacturing method in which flavoring is preliminarily added and adsorbed to prevent the amount of menthol in smoke from decreasing over time.

Prior art literature

Patent Literature

Patent Document 1: Japanese Utility Model Publication No. 62-86894

Patent Document 2: Japanese Patent Application Laid-Open No. 11-069965

Patent Document 3: Japanese Patent Publication No. 43-28077

Patent Document 4: Japanese Patent Application Laid-Open No. 2012-29637

Patent Document 5: International Publication No. 2011/118040

Patent Document 6: International Publication No. 2012/004853

Summary of the Invention

Problems to be solved by the invention

The invention described in Patent Document 1 adjusts the ventilation resistance of the filter and the ratio of air flowing in from the openings provided in the tipping paper within predetermined ranges, but the purpose thereof is not clarified.

Furthermore, the invention described in Patent Document 2 aims to provide a sufficient suck by reducing the amount of nicotine or tar as components in smoke and increasing the product ventilation resistance of the cigarette.

As for the properties of cigarette filters, generally, low ventilation resistance filters are used for filter-tipped cigarettes with low ventilation ratios and high tar content, while high ventilation resistance filters are used for filter-tipped cigarettes with high ventilation ratios and low tar content.

As mentioned above, although research has been conducted focusing on the ventilation resistance and ventilation ratio (air inflow) of filter tips, no attempt has been made to specify menthol-added filter cigarettes, especially low-tar filter cigarettes, and adjust their ventilation resistance or ventilation ratio.

On the other hand, the amount of menthol in menthol-filtered cigarettes is adjusted by the amount of menthol flavoring added to the cigarettes during smoking. However, simply increasing the amount of flavoring added to the cigarettes causes menthol, dissolved in tobacco pigment, to bleed out of the cigarette wrapping paper and adhere to the wrapping paper, resulting in an undesirable appearance. Furthermore, the amount of menthol in the smoke increases proportionally with the tar content of the cigarette. Therefore, cigarettes with a tar content of 5 mg or less, generally known as low-tar cigarettes, typically contain a low menthol content. As a solution to this problem, there is no alternative but to add the maximum amount of menthol that can be added to the cigarettes without causing bleed-out or other problems.

The method described in Patent Document 3 has the following problem: menthol added to the filter is adsorbed to the filter tow during storage of the product, and the amount of menthol in the smoke decreases significantly over time.

The method described in Patent Document 4 has the following problems: using a flavoring carrier increases costs; and when adding the carrier inside the filter, a separate carrier addition step is required, making manufacturing complicate and difficult.

The invention described in Patent Document 5, like the invention described in Patent Document 4, has concerns about increased costs and problems with cigarette manufacturing suitability caused by adding a flavor-retaining sheet to shredded cigarette tobacco.

As a method for increasing the amount of menthol in tobacco, the invention described in Patent Document 6 discloses a method for increasing the amount of menthol added to filters. However, in order to add menthol to the filter's plasticizer, a plasticizer that can dissolve menthol is required. Generally, menthol is poorly soluble in the glycerol acetate used as a plasticizer, so a solvent such as polyethylene glycol must be mixed to dissolve the menthol in order to prepare the flavoring liquid. Furthermore, if a relatively large amount of menthol is not intended to be added, a large amount of plasticizer and other menthol-soluble solvents are required, which raises concerns about the effects on the flavoring liquid's oozing out and the filter's hardness. Furthermore, if menthol is to be adsorbed into the filter, simply mixing it with the plasticizer is ineffective and time-consuming. For example, when adding the plasticizer and menthol to acetate fibers simultaneously, a high-temperature treatment is required. However, these steps require separate steps during or after filter manufacturing, making them difficult to describe as practically applicable technologies.

There are no studies that correlate the ventilation resistance of filter tips and the ventilation ratio of filter-tipped cigarettes with the menthol concentration in the smoke during smoking. Therefore, there is a need for a technology that can improve the stability of the menthol content in menthol products, particularly the stability of the menthol content in the smoke of low-tar cigarettes during smoking or after storage.

The present invention provides a low-tar menthol cigarette that not only increases the amount of menthol in smoke during smoking but also minimizes changes in the amount of menthol in the smoke after storage.

Solutions to Problems

As a result of intensive research, the present inventors have discovered a low-tar menthol cigarette that can solve the above-mentioned problems. The low-tar menthol cigarette comprises a cigarette stem and a filter wrapped with tipping paper, and has a tar yield of 5 mg or less. The filter comprises a single segment formed of cellulose acetate tow, has an airflow resistance of 25 to 80 _mmH2O /27 mm, and a ventilation ratio of inflowing air through ventilation holes formed in the tipping paper of 55% or greater. Menthol is added to the filter, leading to the completion of the present invention.

That is, the present invention is as follows.

[1] A low-tar menthol cigarette comprising a cigarette rod and a filter wrapped with tipping paper, and having a tar content of 5 mg or less, wherein the filter comprises a single segment formed of cellulose acetate tow, the filter having an air flow resistance of 25 to 80 _mmH2O /27 mm, and a ventilation ratio of inflowing air from ventilation holes formed in the tipping paper of 55% or more, and menthol is added to the filter.

[2] The low-tar menthol cigarette according to [1], wherein the amount of menthol added to the filter is 8 mg or more per low-tar menthol cigarette.

[3] The low-tar menthol cigarette according to [1] or [2], wherein the cigarette rod or filter has a resistance body.

[4] The low-tar menthol cigarette according to [3], wherein the resistance body is a capsule or a throttle hole.

[5] The low-tar menthol cigarette according to any one of [1] to [4], wherein the filter portion has a ventilation resistance of 25 to 50 mmH ₂ O/27 mm and a ventilation ratio of air inflow of 70% or more.

[6] The low-tar menthol cigarette according to any one of [1] to [5], wherein the circumference of the low-tar menthol cigarette is 20.0 to 27.0 mm.

Effects of the Invention

The low-tar menthol cigarette of the present invention increases the amount of menthol in the smoke during smoking and has little change in the amount of menthol in the smoke after storage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the relationship between the storage period of filter-tipped cigarettes and the rate of decrease in the amount of menthol in the smoke.

FIG. 2 is a graph showing the relationship between the initial menthol addition amount and the menthol release rate in stored filter-tipped cigarettes.

DETAILED DESCRIPTION

Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the following embodiments and examples, and can be implemented with arbitrary modifications without departing from the gist of the present invention.

The low-tar menthol cigarette of the present invention is a filter-tipped cigarette having a tobacco rod and a filter wrapped with tipping paper. The filter comprises a single segment formed from a single cellulose acetate tow. The filter has an airflow resistance of 25 to 80 _mmH2O /27 mm, and the ventilation ratio of inflowing air through ventilation holes formed in the tipping paper is 55% or more. Menthol is added to the filter.

The cigarette rod can be made of a known type. The type of tobacco used in the cigarette can be any known type, and the cigarette rod is formed by wrapping the tobacco in rolling paper. To adjust the ventilation resistance of low-tar menthol cigarettes (filtered cigarettes), a resistance element such as a capsule or a throttle hole can be placed inside the cigarette rod.

The filter portion of the low-tar menthol cigarette of the present invention is wrapped with tipping paper. The tipping paper that can be used in the present invention is not particularly limited, and air-impermeable paper can be used.

By providing a plurality of openings (ventilation holes) in the tipping paper along the circumference of the wrapped filter, an air inflow pattern is established. This allows for adjustment of the ventilation ratio of air flowing in through the ventilation holes in the tipping paper of a low-tar menthol cigarette. Examples of the opening pattern include providing the openings in one or more rows along the circumference of the filter.

Tipping paper having a plurality of perforated openings generally has an air permeability of 100 to 7000 C.U. Here, CU represents the flow rate (mL, (0.001 L)) of fluid passing through 1 cm ² (100 mm ² ) of tipping paper in 1 minute (60 seconds) at a differential pressure of 100 mmH ₂ O (980.665 Pa).

The low-tar menthol cigarette of the present invention has an inflow air ventilation ratio of 55% or greater. This ventilation ratio is preferably 61% or greater, and more preferably 70% or greater. At this ventilation ratio, smokers experience a stronger sense of menthol flavor. As described below, the filter's ventilation resistance at this ventilation ratio is 80 _mmH₂O /27 mm or less.

The ventilation ratio of inflow air in the present invention refers to the ratio, expressed as a percentage, of the air flow rate passing through the tipping paper (with air inflow) and entering the interior of the filter-tipped cigarette to the air flow rate at the mouth end when the filter-tipped cigarette (product) is smoked at a standard flow rate of 17.5 cm ³ /s.

The ventilation ratio of air inflow can be adjusted by, for example, changing the size, number, and number of rows of the plurality of openings, or by changing the material of the tipping paper and changing the air permeability. For example, the openings can be positioned 12 to 20 mm from the suction port.

The air flow resistance of the filter in the present invention refers to the differential pressure PD (mmH ^{2 O) of the filter when the filter is covered with air-impermeable rubber to prevent air from flowing in from the sides and inhaled from one end at a flow rate of 17.5 cm 3} _/ sec.

The filter portion of the low-tar menthol cigarette of the present invention comprises a single segment. Specifically, the filter portion of the filter-tipped cigarette of the present invention comprises a single segment made of cellulose acetate tow. Furthermore, the segment made of cellulose acetate tow may include a resistance member such as a capsule or an orifice.

Regarding the ventilation resistance of the filter of the low-tar menthol cigarette of the present invention, when a resistance member such as a capsule or an orifice is provided in the filter, the value of the filter itself without the resistance member is used as a reference.

The shape of the capsule or the orifice is not particularly limited, and known shapes can be applied.

The material constituting the individual segments of cellulose acetate tow used in the filter portion of the present invention is cellulose acetate. Examples of the cellulose acetate fibers constituting the cellulose acetate tow include, for example, those having a single-filament fineness of approximately 1.0 to 8.0 denier and a total fineness of 15,000 to 70,000 denier. Examples include those having circular, oval, Y-shaped, X-shaped, and I-shaped fiber cross-sectional shapes. For example, the interior of the filter can be uniformly filled with cellulose acetate tow.

The air flow resistance of the filter used in the low-tar menthol cigarette of the present invention is 25 to 80 mmH ₂ O/27 mm. It should be noted that the unit "27 mm" used for the air flow resistance refers to the longitudinal length of the filter.

The filter's air resistance is 25 _mmH₂O /27 mm or greater, ensuring adequate filtration of smoke during smoking. Meanwhile, a filter's air resistance is 80 _mmH₂O /27 mm or less, preventing excessive filtration of smoke during smoking and effectively reducing the filtration rate of menthol. Furthermore, the filter's low density reduces menthol adsorption during storage.

By setting the ventilation resistance of the filter within this range and the ventilation ratio of the filter-tipped cigarette within the range specified below, the menthol concentration in the smoke can be kept within a desired range. This effect is further enhanced when the ventilation resistance of the filter portion is 25-50 _mmH₂O /27 mm and the ventilation ratio of air inflow is 70% or greater.

As is known, the ventilation resistance of the filter can be adjusted by, for example, appropriately selecting the total fineness (filling amount) and the single filament fineness of the cellulose acetate tow. Specifically, increasing the single filament fineness and decreasing the total fineness of the cellulose acetate tow can reduce the ventilation resistance.

The tow weight used for the filter can be, for example, 0.100 to 0.200 g when the filter length is 27 mm. The density of the filter can be adjusted by adjusting the weight within this range.

The ventilation resistance per cigarette of the low-tar menthol cigarette of the present invention (the ventilation resistance of a single filter cigarette) is approximately 20 to 70 mmH ₂ O when no resistor is present.

Here, the ventilation resistance of a single filter-tipped cigarette refers to the differential pressure PD (mmH ₂ O) per filter-tipped cigarette, including the ventilation effect when inhaled from one end of the filter at a flow rate of 17.5 cm ³ /sec. In other words, the ventilation resistance of a single filter-tipped cigarette is the ventilation resistance measured with the cigarette body and filter connected.

The tar content of the low-tar menthol cigarette of the present invention is 5 mg or less. The tar content in the present invention refers to the amount of tar inhaled by the smoker when smoking.

In order to make the tar amount below 5 mg, that is, to make the target tar amount below 5 mg, it can be adjusted by changing the composition of the tobacco shreds contained in the cigarette rod, or changing the ventilation resistance of the filter tip, and the ventilation ratio of the low-tar menthol cigarette.

As an embodiment of a tar amount of 5 mg or less, it can be appropriately adjusted within the range of 0.5 to 5 mg, for example. The low-tar menthol cigarette of the present invention can provide smokers with a sufficient menthol flavor even with such a low-tar cigarette.

The tar content of filter-tipped cigarettes is measured according to ISO smoking conditions (ISO 4387), using, for example, 20 cigarettes as one measurement unit. The measurement is performed using gas chromatography.

The menthol in the low-tar menthol cigarette of the present invention is added to the filter. Menthol can be added to the filter, for example, by adding it to 10 to 100% by volume of the cellulose acetate tow constituting the filter. Menthol can be added to the cellulose acetate tow in advance of manufacturing the filter-tipped cigarette, or after manufacturing the filter-tipped cigarette.

As a method for adding menthol, a known method can be used without particular limitation. Menthol may be synthetic menthol or menthol derived from a natural product.

In the low-tar menthol cigarettes of the present invention, the amount of menthol added to the filter is preferably 8 mg/cigarette or more. When the amount of menthol added is 8 mg/cigarette or more, the amount of menthol in the cigarette after storage becomes more stable. The fact that the amount of menthol in the cigarette after storage becomes more stable means that, despite the storage period, the amount of menthol released from the filter portion of the cigarette after storage remains close to a certain amount when smoking. The amount of menthol added to the filter portion is more preferably 10 mg/cigarette or more, and particularly preferably 12 mg/cigarette or more. On the other hand, the upper limit of the amount of menthol can be 20 mg/cigarette or less.

The filter that can be used in the low-tar menthol cigarette of the present invention can have an axial (vertical) length of, for example, 15 to 35 mm.

The circumferential length of the low-tar menthol cigarette of the present invention can be 20.0 to 27.0 mm, more preferably 24.0 to 26.0 mm. This range is advantageous for ensuring a high menthol concentration in the smoke and maintaining a stable menthol concentration after storage.

The total length of the low-tar menthol cigarette of the present invention may be 80 to 100 mm.

<Method for producing low-tar menthol cigarettes>

The low-tar menthol cigarette of the present invention can be manufactured using a known method except that menthol is added to the filter, the ventilation resistance of the filter is within a predetermined range, and the ventilation ratio of air inflow is set within a predetermined range.

When a resistance body such as a throttle hole is provided in the cigarette rod, a known method can also be used.

As the cigarette rod portion constituting the low-tar menthol cigarette of the present invention, there can be cited a method comprising tobacco shreds forming the cigarette rod and rolling paper for wrapping the tobacco shreds. As long as the material or shape can achieve the low tar given in the present invention, known materials or shapes can be used without limitation.

The circumferential length of the cigarette stem portion can be within the same range as that of the circumferential length of the low-tar menthol cigarette of the present invention as described above.

The axial length of the cigarette rod portion can be, for example, 50 to 75 mm.

Example

The present invention will be described in more detail with reference to Examples. However, the present invention is not limited to the description of the following Examples unless the gist of the invention is exceeded.

<Example 1>

Examples 1, 2 and Comparative Examples 1, 2

To verify that cigarettes designed with filters featuring low airflow resistance and high airflow ratios can increase the amount of menthol in smoke, cigarettes with the filter airflow resistance and airflow ratio shown in Table 1 were produced, and the menthol and tar levels in the smoke of each cigarette were measured. The produced filters were stored at 22°C and 60% humidity for three weeks to allow the menthol to fully adsorb and stabilize on the cellulose acetate tow, before being used in cigarette rods. Separately, the produced cigarettes were packaged in standard aluminum packaging and stored at 22°C and 60% humidity for three weeks, and the menthol and tar levels in the smoke were measured. The tow specifications in the table indicate the single-filament fineness, cross-sectional shape, and total fineness. For example, 5.9Y35000 refers to a cellulose acetate tow with a single-filament fineness of 5.9 denier, a Y-shaped cross-sectional shape, and a total fineness of 35,000 denier.

The cigarettes used in the tests were 84 mm in total length and 27 mm in filter length. The tobacco used was an American blend, with a filler weight of 0.580 g. Menthol was added at a concentration of 12,000 ppm per weight of the tobacco. The filter resistance and ventilation ratio of each cigarette were set to achieve a tar content of 5 mg at the filter outlet.

[Table 1]

Cigarette smoking was conducted according to ISO smoking conditions. Menthol was measured twice, with 20 cigarettes as one measurement unit. Tar was measured once, with 20 cigarettes as one measurement unit. Menthol and tar levels in smoke were measured per cigarette using an Agilent GC-FID7693 (menthol and nicotine) and an Agilent GC-TCD-7890A (moisture). Ventilation ratios were measured using a SODIMAX (SODIM) instrument.

In addition, sensory evaluations of menthol were conducted on the four cigarettes listed in Table 1. The evaluation method involved using Comparative Example 1, the most common combination of conditions, as a control. Participants were asked to choose whether their menthol perception for the other three cigarettes was equal to, greater than, or less than the control. Ten participants were evaluated, and significant differences were confirmed using a one-sided cumulative binomial probability distribution at a 5% significance level.

Table 2 below shows, in addition to the menthol and tar levels in the smoke, the value obtained by dividing the menthol level by the tar level (hereinafter referred to as the M/T ratio). This serves as an indicator of the difference in menthol levels when equivalent tar levels are achieved. Generally, the menthol level in smoke increases in direct proportion to the tar level, so the values normalized by the tar level are used here to compare menthol levels. The results of the sensory evaluation are also reported, indicating whether there were significant differences.

[Table 2]

As shown in Table 2, the lower the filter's ventilation resistance and the higher the ventilation ratio of air flow into the cigarette design, the higher the menthol content and M/T ratio in the smoke. This is believed to be because the filtration rates of tar and menthol differ depending on the relationship between the filter's ventilation resistance and ventilation ratio. Specifically, when using a filter with low ventilation resistance, in addition to the physical filtration of smoke within the filter, the amount of menthol condensed/adsorbed on the filter's tow fibers is reduced due to the small total amount of tow, resulting in an increase in the menthol content and M/T ratio in the smoke. Furthermore, in designs with a high ventilation ratio, the time it takes for smoke to pass through the filter increases, generally increasing the filtration rates of tar and menthol. However, in low ventilation resistance filters with a small total amount of tow, the menthol filtration rate is less likely to increase, and the M/T ratio increases. As a result, the menthol filtration rate can be reduced compared to the tar filtration rate. In the sensory evaluation, a difference in menthol perception was also obtained, and it was confirmed that the menthol perception of Examples 1 and 2 was significantly higher than that of Comparative Example 1.

In this embodiment and the comparative example, a more preferable range is a filter airflow resistance of 80 _mmH2O /27 mm or less and an airflow ratio of 55% or greater, preferably 61% or greater. A further preferable range is 50 _mmH2O /27 mm or less and an airflow ratio of 70% or greater, as in Example 1. Considering the actual filter manufacturing process, a practical range of airflow resistance of 25 _mmH2O /27 mm or greater is considered feasible. The filter material is characterized by being composed of cellulose acetate tow.

The above demonstrates that cigarettes designed with a high ventilation ratio for air inflow increase the menthol content in the smoke. In this example, a cigarette with a filter length of 27 mm was used, but this is not limiting; similar effects can be expected with any filter length. Furthermore, while the circumferential length of the cigarette was 24.8 mm in this example, similar effects can be expected with a range close to the circumferential length of this example, specifically, 20.0 mm to 27.0 mm, with a range of 24.0 mm to 26.0 mm being more preferred.

Reference Examples 1 to 4

To verify that using a filter with low airflow resistance stabilizes the menthol content in cigarette smoke during storage of a menthol-flavored filter, tests were conducted by varying the filter storage period and the storage period in the packaged cigarette form. The airflow resistance of the filter and the amount of filter flavoring shown in Table 3 were used to measure the menthol content in the cigarette smoke as the filter and cigarette storage periods varied. To eliminate the influence of other factors, the tests were conducted without providing ventilation holes in the filter and only varying the airflow resistance of the filter.

The test was conducted in the same procedure as in Examples 1 and 2 and Comparative Examples 1 and 2 above, except for the storage conditions, ventilation resistance, and ventilation ratio of the filter.

[Table 3]

Table 4 shows the storage conditions for the filter tips and their packaging. The shortest storage period involves using the filter tips immediately after manufacture in cigarette production and not storing them in cigarette packaging (Condition A). The longest storage period involves storing the filter tips for two months after manufacture, using them to manufacture cigarettes, and then storing the cigarettes in packaging for another two months (Condition G). Menthol and tar levels were measured for each cigarette that had been subjected to Conditions A through G.

[Table 4]

Table 4

Table 5 and Figure 1 show the test results. The reduction rates shown in Table 5 represent the reduction rates of the M/T ratio under each condition, compared to the M/T ratio under Condition A, which involves storage without filters and in cigarette packaging. Figure 1 shows the reduction rates of the M/T ratio under each condition.

[Table 5]

Table 5 and Figure 1 show the following results: the longer the filter storage period and the storage period in cigarette packaging, the lower the menthol content. Furthermore, it was confirmed that the greater the airflow resistance of the filter, the greater the rate of reduction in the M/T ratio. Reference Examples 2 to 4 showed a greater rate of reduction in the M/T ratio than Reference Example 1, which met the key requirements for airflow resistance of claim 1. This is believed to be because filters with low airflow resistance have a lower tow weight, thus reducing menthol adsorption to the filter compared to filters with high airflow resistance, resulting in a higher efficiency of menthol release per unit volume.

The above results demonstrate that using a filter with low airflow resistance facilitates stable menthol content in smoke. Combining a filter with low airflow resistance and a high airflow ratio also achieves the same effect, enabling the production of cigarettes that increase the menthol content in smoke and readily maintain menthol content even after storage.

Reference Examples 5 to 8

To verify that the menthol content in the smoke is more stable when the menthol flavoring in the filter is set to 8 mg or more per cigarette, tests were conducted with varying filter airflow resistance and varying filter flavoring levels. Table 6 shows the menthol flavoring levels in the filter. As in Reference Examples 1 to 4, to eliminate the influence of other factors, the filter was tested without ventilation holes and only with varying filter airflow resistance.

[Table 6]

The filter storage environment was similar to that of Reference Examples 1-4, at a temperature of 22°C and a humidity of 60%. The tests were conducted under varying storage conditions, starting with no storage (denoted as 0) and continuing through two weeks (denoted as 2W), five weeks (denoted as 5W), and finally two months (denoted as 2M). The release rate, expressed as a percentage of the amount of menthol released from the smoke, was compared based on the amount of menthol flavoring added to the filter. Based on the previous Reference Examples 1-4, it was expected that the effects of filter storage alone would be investigated by varying the filter storage period without storing the filter in cigarette packaging. However, further storage in cigarette packaging would further reduce the release rate. Therefore, in this test, menthol flavoring was not applied to the tobacco shreds in the cigarette stem, and menthol was released only from the filter. The tests were conducted according to the same procedures as in Examples 1 and 2 and Comparative Examples 1 and 2, with the exception of the amount of menthol flavoring added to the tobacco/filter, the ventilation ratio, and the filter storage period. The test results are shown in Table 7 and FIG2 .

[Table 7]

As shown in Table 7 and Figure 2, the greater the amount of menthol flavoring added to the filter, the more stable the release rate over time. Compared to Reference Examples 5 and 6, Reference Examples 7 and 8 are more resistant to changes over time. This is because by adding a large amount of menthol, the amount of menthol added exceeds the amount adsorbed by the tow, minimizing the effects of menthol adsorption. It is conceivable that this effect is more pronounced when using filters with lower airflow resistance than Reference Examples 5-8, as the amount of menthol adsorbed by the tow itself is reduced. These results confirm that the amount of menthol in the smoke is stabilized when the amount of menthol flavoring in the filter is 8 mg or more per cigarette. A more preferred menthol flavoring amount in the filter is 10 mg or more, and even more preferably, 12 mg or more, equivalent to the conditions in Reference Example 8.

<Example 3 and Comparative Examples 3 and 4>

Examples 1 and 2 and Comparative Examples 1 and 2 were comparative tests performed at a tar content of 5 mg. To verify the effectiveness of this technology even when targeting a lower tar content of 1 mg, similar tests as those for Examples 1 and 2 and Comparative Examples 1 and 2 were conducted using the test levels shown in Table 8. Sensory evaluations were also performed in the same manner.

[Table 8]

Table 9 shows the test results, which include the M/T ratio in addition to the menthol and tar amounts in the smoke.

[Table 9]

As shown in Table 9, Example 3 has the highest menthol content, and also achieves the highest result when comparing the M/T ratio. Regarding the sensory evaluation of menthol perception, Example 3 also exhibits a significantly higher menthol perception. Similar to the evaluations of Examples 1 and 2 and Comparative Examples 1 and 2 conducted previously, the menthol content values differ significantly, indicating a significant difference. This confirms that the present technology is effective within the very low tar content range.

Claims (5)

1. A low-tar menthol cigarette, comprising a stem portion and a filter portion rolled with tipping paper, and having a tar content of 5 mg or less, wherein the filter portion comprises a single section composed of cellulose acetate tow, the air resistance of the filter portion is _25-50 mmH₂O/27 mm, and the airflow ratio from the air holes passing through the tipping paper is 70% or more, and menthol is added by adsorbing the cellulose acetate tow of the filter portion. 2. The low-tar menthol cigarette as described in claim 1, wherein the amount of menthol added to the filter portion of each low-tar menthol cigarette is 8 mg or more per cigarette. 3. The low-tar menthol cigarette as described in claim 1 or 2, wherein the stem portion or filter portion has a resistance body. 4. The low-tar menthol cigarette as described in claim 3, wherein the resistance body is a capsule or a throttling orifice. 5. The low-tar menthol cigarette as described in claim 1 or 2, wherein the circumference length of the low-tar menthol cigarette is 20.0 to 27.0 mm.