JP2008523800A - Cigarette with carbon-on-toe filter - Google Patents

Abstract

The cigarette (10) comprises a tobacco rod (12) and a carbon-on-toe filter (14) comprising fiber tow (18) with flavored or unflavored carbon particles (20) distributed throughout the tow. The carbon particles have a high activity in the range of 90 to 115%, preferably 95%. As mainstream smoke is drawn through the filter (14), the vapor phase smoke component is removed and flavor is released when the particles are flavored. A vent (24) is provided to limit the amount of tobacco that burns during each smoke absorption, and the vent is located near the downstream end of the carbon-on-to-filter and is used for mainstream smoke passing through the filter. Reduce speed. The filter is a 90% or higher reduction of 1,3 butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile, benzene, and toluene, and 80% or higher reduction of acetaldehyde, and the gas phase components of mainstream smoke. A significant reduction is achieved.
[Selection] Figure 1

Description

  The present invention relates to smoking articles such as cigarettes, and more particularly, with adsorbents and fiber filter materials arranged to advantageously remove gas phase components from mainstream smoke over a long inventory storage period of cigarettes. The present invention relates to a cigarette including a filter segment.

  Smoking articles, particularly cigarettes, generally comprise a tobacco rod of shredded tobacco (usually in the form of a cut filler) surrounded by wrapping paper and a cylindrical filter aligned in an end-to-end relationship with the tobacco rod. . Typically, the filter includes a plug of cellulose acetate tow attached to the tobacco rod by tip paper. Mainstream smoke is vented by one or more rows of perforations around the location along the filter. Such aeration reduces the tar delivery by diluting the mainstream smoke sucked in with ambient air.

  When the cigarette is ignited, the smoker draws mainstream smoke from the call at the ignition end of the cigarette. The aspirated cigarette smoke first enters the upstream end portion of the filter and then passes through the downstream portion adjacent to the cheek (buccal) end of the cigarette.

  Certain cigarettes have a filter segment that incorporates an adsorbent material such as activated carbon, such examples are described in U.S. Pat. No. 2,881,770 to Tovey, U.S. Pat. No. 3,353,543, U.S. Pat. No. 3,101,723 to Seligman et al., And U.S. Pat. No. 4,481,958 to Ranier et al. Certain commercially available filters have carbon particles or granules (eg, activated carbon) dispersed alone or within cellulose acetate tow, and other commercially available filters have carbon filaments dispersed within cellulose acetate tow, Yet another commercially available filter has a so-called “plug-space-plug”, “cavity filter”, or “triple filter” design. Examples of commercially available filters include Filtrona International, Ltd. SCS IV Dual Solid Charcoal Filter and Triple Solid Charcoal Filter; Baummartner's Triple Cavity Filter; and Filtrona International, Ltd. There is ACT. Similarly, Clarke et al., World Tobacco, p. 55 (November 1992). A detailed description of cigarette and filter properties and composition can be found in US Pat. Nos. 5,404,890 and 5,568,819 to Gentry et al., The disclosures of which are hereby incorporated by reference. Embedded in the book.

  Until now, typical prior art with cigarettes called “plug-space-plug” has positioned the vent at a position along the bed of adsorbent contained within the space, from the buccal end of the filter. A sufficient space between the vent holes was obtained. At this time, the smoker's lips do not block the ventilation holes. However, such an arrangement tends to increase the speed of mainstream smoke in at least a portion of the absorbent bed and therefore tends to reduce the filtering effect of the adsorbent.

  Various annular arrangements of filters having a carbon-containing annular filter region have been disclosed in the prior art. For example, European Patent Application No. 579,410 shows several cigarette embodiments having an annular carbon-containing region surrounding either a hollow tubular cavity formed by a porous filtration material or a gas phase porous membrane. Yes. Similarly, U.S. Pat. No. 3,894,545 to Crelin et al. Describes a variety of annular carbon-containing regions surrounding a gas-phase porous membrane, or rods of carbon-containing material surrounded by a gas-phase porous membrane. The structure of is shown.

  A cigarette filter element incorporating carbon is capable of removing mainstream smoke components passing therethrough. In particular, activated carbon tends to reduce the level of certain gas phase components present in mainstream smoke, resulting in a change in the sensory properties of the smoke.

  Despite this advantage of carbon-containing filters, so far this filter has not been widely used. In previous configurations, it has been found that mainstream smoke from carbon filters tends to have flavor characteristics that are contrary to consumer preferences, and therefore their adoption in commercial cigarettes has not been popular. Similarly, plasticizers in fiber tow filters degrade certain carbon components over time, reducing the effectiveness of carbon in removing gas phase components over the long shelf life of cigarettes containing such filter configurations. Tend.

  Provided is a cigarette having a cigarette filter incorporating carbon and / or other materials capable of absorbing and / or adsorbing gas phase components present in the mainstream smoke of the cigarette and providing favorable absorption / adsorption, dilution, and suction characteristics Would be desirable.

  Furthermore, it has the desired residence time in the area containing the adsorbent / absorbent while at the same time achieving a pressure drop in the dilution area and downstream of the adsorbent / absorbent, reducing the gas phase components but allowing an acceptable flavor. It would also be desirable to provide a filter that provides acceptable suction characteristics of smoke absorption with suction resistance.

U.S. Pat. No. 2,881,770 U.S. Pat. No. 3,353,543 U.S. Pat. No. 3,101,723 U.S. Pat. No. 4,481,958 US Pat. No. 5,404,890 US Pat. No. 5,568,819 European Patent Application No. 579,410 U.S. Pat. No. 3,894,545 US Pat. No. 5,263,999 US Pat. No. 5,997,691 US Pat. No. 6,761,174 Clarke et al., World Tobacco, p. 55 (November 1992)

  According to the present invention, a smoking article such as a cigarette comprises a tobacco rod and a multi-component filter comprising a fiber tow having high activated carbon particles on the tow. In desirable embodiments, the activated carbon also contains a flavor and includes advanced activated carbon particles on the fiber tow. As mainstream smoke is drawn through the upstream portion of the filter, the vapor phase smoke component is removed and flavor is released from the activated carbon. A vent is provided to limit the amount of cigarette that burns during each smoke absorption, and this vent is located at a location downstream of most of the carbon-on-tow to reduce the speed of mainstream smoke through the adsorbent. Is done. Advanced activated carbon particles on cellulose acetate tow include 1,3 butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile, benzene, and toluene 90% or more reduction, and acetaldehyde 80% or more reduction. It is believed that a significant reduction in the gas phase component of mainstream smoke is achieved.

  Advantageously, the present invention addresses the advantage of achieving an optimal residence time for the smoke in the filter region containing the adsorbent material, while at the same time achieving a preferred dilution of the smoke with ambient air, Provides acceptable resistance to aspiration as expected by smokers.

  With regard to other advantages and features of the present invention which will become apparent from the foregoing and the following, the nature of the present invention is illustrated by the following detailed description of the invention, the appended claims, and some of the features shown in the drawings This can be understood more clearly by referring to the figure.

  In addition to the foregoing, the novel features and advantages of the present invention will become apparent to those of ordinary skill in the art by reading the following detailed description in conjunction with the accompanying drawings. In the drawings, like reference numbers indicate like elements.

  Referring to FIG. 1, a preferred embodiment of the present invention provides a cigarette 10 that includes a rod 12 of smokable material, such as shredded tobacco, and a multi-component filter 14 attached to the rod 12 by tip paper 16. . When the cigarette is ignited, mainstream smoke is generated by the tobacco rod 12 and sucked through the filter 14 from the tobacco rod.

  As used herein, the “upstream” and “downstream” relative positions between the filter segment and other features are the mainstream smoke as it is drawn from the tobacco rod 12 through the multi-component filter 14. Described in terms of direction.

  Preferably, the filter 14 comprises cellulose acetate tow 18 comprising a suitable plasticizer such as triacetin having highly activated carbon particles on granules 20 distributed throughout the tow. The labial end (cheek side) element 22 is downstream of the tow 18 and carbon 20.

  The labial end (buccal) element 22 is preferably in the form of a medium to low particle efficiency cellulose acetate plug or other suitable fiber or web material. Preferably, the particle efficiency is low and the denier and total denier are selected so that the desired overall RTD of the multi-component filter 14 is achieved.

  The carbon 20 on the tow 18 is preferably in the form of granules and the like. The carbon of the preferred embodiment is preferably a high surface area activated carbon, such as coconut shell based carbon of the typical ASTM mesh size or finer used in the cigarette industry. Activated carbon is a gas phase containing mainstream smoke components, particularly aldehydes, ketones, and other volatile organic compounds, specifically 1,3 butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile, benzene, toluene, styrene, Adsorbs acetaldehyde and hydrogen cyanide.

  In connection with the carbon particles 20, these mesh sizes are preferably 10 to 80, and more preferably 20 to 70 mesh sizes. Furthermore, as described above, the carbon particles are highly activated, with a target activity measured by the CTC (carbon tetrachloride) method of about 95%, whereas the total activity is between 90% and 110%. Is in range.

  The carbon particles 20 contain flavors or are impregnated with flavors so that these adsorbent particles not only remove one or more gas phase smoke components from the mainstream smoke, but also release the flavor into the mainstream smoke stream. Can be. Preferably, the flavor is added to the carbon granules by spraying the flavor on a bunch of activated carbon in a mixing (tumbling) drum or in a fluidized bed using nitrogen as a flow agent, in which case the flavor The material can be sprayed onto the carbon in the bed. Flavoring is done before distributing the carbon granules throughout the tow 18.

  Preferably, one or more circumferential rows of perforations 24 are formed by the tip paper 16 at locations along the downstream end of the carbon on the carbon on tows 18, 20. A preferred arrangement maximizes the distance between the buccal end of the cigarette and the perforation 24, which distance is at least 12 mm (millimeters) or more so that the smoker's lips do not obstruct the perforation 24. Is preferred.

  Preferably, the level of aeration is in the range of 40 to 60%, more preferably in the range of about 45 to 55% with 6 mg cigarette for FTC tar delivery.

  It is believed that venting not only dilutes mainstream smoke, but also results in a reduction in the amount of tobacco that is burned during each smoke when combined with the low particle efficiency filter 14. Ventilation reduces the amount of tobacco burned during smoke absorption because it reduces the suction action for the call. As a result, the absolute amount of smoking components is reduced.

  Advantageously, the perforations 24 of the present invention are located at the downstream end of the carbon-on-toe filter so that the mainstream smoke velocity through the majority of the carbon particles 20 is reduced and the mainstream between the carbons 20. Increased smoke residence time. Increased residence time improves the effectiveness of the activated carbon in reducing the mainstream smoke components of interest. The smoke is diluted by ambient air that passes through the perforations 24 and mixes with the mainstream smoke to achieve an air dilution in the range of about 45-65%. For example, at 50% air dilution, the flow through the cigarette upstream of the dilution perforations is reduced to 50%, which reduces the smoke velocity by 50%.

  Preferably, the range of carbon loading 20 on the tow 18 includes a range of at least 90 to 120 mg (milligrams) for a target loading of about 120 mg. Such carbon loading provides a flavorful cigarette, a 90% or more reduction of 1,3 butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile, benzene, and toluene, and 80% of acetaldehyde or Realize a significant reduction in the gas phase component of mainstream smoke, including further reduction. Higher carbon loading guarantees an adequate activity level sufficient to achieve such a reduction over the expected shelf life of the product (up to 6 months or more).

  With a target carbon activity in the range of 90 to 110% and about 95%, there is no significant adverse effect due to the plasticizer used on the fiber tow (eg, triacetin). If the fiber tow 18 is cellulose acetate with a triacetin plasticizer, any level of triacetin may be required (usually about 6%), which is the gas phase of mainstream smoke. Does not adversely affect the above percentage reduction of ingredients. With these carbon activity percentages, there is no significant deactivation of the carbon over the shelf life of the cigarette product, which results in a percentage reduction in the gas phase component over the entire shelf life. Cigarettes with a long shelf life of 12 months have almost the same effectiveness as cigarettes after 1 month.

  As an example, the length of the tobacco rod 12 is preferably 49 mm, and the length of the multi-component filter 14 is preferably 34 mm. The length of the carbon tow segment is preferably 20-26 mm, and the cellulose acetate plug 8 at the end of the filter 14 is preferably 8 mm. The total level of tar (FTC) is preferably in the range of 6 mg when the number of smoke absorption is 6 or more.

  The tobacco rod can be packaged with a conventional cigarette wrapper or band paper may be used for this purpose. The cigarette paper with the band places the integral cellulose bands 21 at intervals, which surrounds the finished tobacco rod of the cigarette 10 and ignites the substrate as the cigarette 10 continues to smolder on the substrate. Modify the mass burning rate of the cigarette to reduce the risk of doing so. US Pat. Nos. 5,263,999 and 5,997,691 describe banded cigarette papers, which are incorporated herein by reference in their entirety.

  In the preferred embodiment 10 of FIG. 1, 90 to 120 milligrams, preferably about 120 milligrams, of highly activated flavored carbon 20 is distributed throughout the fiber tow 18. The optional flavoring charge in carbon 20 is 3 to 6 mg, more preferably about 4 mg or 5 mg. A flavor system as high as 6 mg per 120 mg of carbon showed no adverse effects on component removal. It should be understood that references herein to 120 mg loading of flavored carbon include any flavoring. Furthermore, as described above, the carbon activity is in the range of 90 to 110% while the target value is about 95%. Despite about 6% plasticizer in the tow 18, the carbon on the tow filter element maintains the effectiveness of gas phase component removal over the long inventory storage period of the cigarette 10.

  Referring to Tables IV below, data showing the average percentage reduction of specific gas phase components in mainstream smoke obtained with the test cigarettes listed in the heading of each table relative to the commercial cigarette (control) Is provided. For a given test cigarette, the percentage in the first column indicates the average reduction obtained initially relative to the control, while the second and third columns each have about 6 months of inventory storage. FIG. 5 shows the average reduction in test cigarettes after exposure to conditions that simulate a period and a shelf life of about 12 months. The accelerated aging procedure includes repeated cigarettes under high humidity conditions and low humidity and high temperature conditions for a predetermined time period.

  As the table shows, 120 mg of carbon-on-tow significantly reduces the gas phase or smoke component even after a significant amount of simulated stock shelf life in the presence of triacetin and approximates one year of natural aging. Has been achieved.

Table I
Test cigarette: carbon on toe; 120 mg carbon / 0% triacetin / unflavored carbon / 95% activity level

Table II
Test cigarette: carbon on toe; 120 mg carbon / 3% triacetin / non-flavored carbon / 95% activity level

Table III
Test cigarette: carbon on toe; 120 mg carbon / 6% triacetin / unflavored carbon / 95% activity level

Table IV
Test cigarette: carbon-on-toe; 120 mg carbon / 0% triacetin / flavored carbon / 95% activity level

Table V
Test cigarette: carbon on toe; 120 mg carbon / 6% triacetin / flavored carbon / 95% activity level

  FIG. 2 shows a cigarette 10A having a shorter tow 18A and a smaller filling amount of carbon particles 20A distributed between the tows. The carbon loading is about 75 milligrams and the carbon is not flavored. The activity of the carbon is in the range of 90 to 115%, while the target is about 95%.

  Referring to FIGS. 3 and 4, an alternative preferred embodiment includes cigarettes 10B, 10C, which have increased activity levels from about 75 (90 to 110% versus a target level of about 95%). 120 milligrams or more of carbon loading, more preferably about 120 milligrams of such carbon in cigarette 10B and about 75 milligrams of such carbon in cigarette 10C, both of which are preferably non-flavored carbon on tow A filter plug 18 is included. About 90 mg of carbon is a suitable amount. In these embodiments, the filter further includes flavor release elements 32, 32A located downstream of the carbon-on-tow (in the sense of the direction when mainstream smoke is drawn through the cigarette) as shown in FIG. Flavor-containing spun yarn 33 (as described in commonly assigned US Pat. No. 6,761,174), or flavor release particles in or within the space of the plug-void-plug configuration in element 32 And a filter plug 32 having a bed of flavor release particles 35 as shown in FIG. 4 that can be arranged as a fiber tow plug.

  As the carbon loading and carbon activity level increase, these cigarettes 10B, 10C of FIGS. 3 and 4 provide a high degree of removal of gas phase smoke components, acceptable shelf life, and favorable organoleptic properties.

  Furthermore, the present invention can be practiced with various perimeter cigarettes, ie wide and thin cigarettes. Similarly, although the present invention is preferably practiced with a non-flavored tobacco rod, flavored tobacco materials are also contemplated.

1 is a side view of a cigarette comprising a tobacco rod and a multi-component filter containing advanced activated carbon particles on a fiber tow according to the present invention, a portion of which is cut away to show internal details. FIG. FIG. 6 is a side view of another cigarette comprising a tobacco rod and a multi-component filter containing advanced activated carbon particles on a fiber tow, with a portion cut away to show internal details. FIG. 3 is a side view of another cigarette with a tobacco rod and a multi-component filter containing advanced activated carbon particles on a fiber tow with flavor added downstream, partially in order to show internal details. Notched. FIG. 4 is a side view of yet another cigarette with a tobacco rod and a multi-component filter containing advanced activated carbon particles on a fiber tow with a flavor added downstream, in part to show internal details; Is cut out.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cigarette 12 Cigarette rod 14 Carbon filter 16 Chip paper 18 Fiber tow 20 Carbon particle 24 Ventilation part

Claims (12)

A cigarette comprising a tobacco rod and a carbon-on-tow filter comprising a fiber tow having carbon particles distributed between the tows,
The carbon-on-to-filter is constructed and arranged to substantially remove at least one smoke component from the mainstream smoke when mainstream smoke is sucked through the filter, and the activity of the carbon particles is In the range of 90 to 115%,
Cigarette characterized by that. The carbon comprises about 75 to 120 milligrams or more;
The cigarette according to claim 1. The carbon particles are flavored,
The cigarette according to claim 2. The carbon comprises about 120 milligrams;
The cigarette according to claim 1. The carbon particles are flavored,
The cigarette according to claim 4. The activity of the carbon particles is about 95%;
The cigarette according to claim 1. The filter includes a vent, the vent is in the range of 45 to 55%, and the labial end filter element is downstream of the carbon-on-toe filter element;
The cigarette according to claim 1. The vent includes at least one circumferential row of perforations through the tip paper, the tip paper attaching a carbon-on-to-filter to the tobacco rod;
The cigarette according to claim 7. The vent is disposed at a position of at least 12 mm from the cheek end of the cigarette.
The cigarette according to claim 8. The carbon-on-toe filter includes a 90% or greater reduction in at least one of 1,3 butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile, benzene, and toluene over a long inventory shelf life of at least 6 months. Achieving a significant reduction in the gas phase component of the mainstream smoke,
The cigarette according to claim 1. The carbon-on-toe filter achieves a significant reduction in the gas phase component of the mainstream smoke, including a reduction of 80% or more of acetaldehyde.
The cigarette according to claim 1.   The cigarette according to claim 1, wherein the filter includes a flavor release element disposed downstream of the carbon-on-tow.

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