ES2375106T3 - CIGARETTE FILTER. - Google Patents

Abstract

A multi-section cigarette filter, comprising: (a) a selective adsorbent section (136) comprising a selective adsorbent material (146) which is an ion exchange resin having an affinity for a predetermined class of chemical compounds dispersed through a fibrous material, said ion exchange resin being a phenol-formaldehyde resin matrix and is made surface functional with primary and secondary amine groups; (b) a general adsorbent section (134) comprising a general adsorbent material (144) that has a large surface area and that is capable of adsorbing smoke constituents without a high degree of specificity, said general adsorbent material being (144) selected from the group consisting of activated charcoal, activated coconut coal, activated coal based coal, zeolite, silica gel, sepiolite, aluminum oxide, coal based charcoal made from semi-anthracite coal, a resin carbonaceous derived from the pyrolysis of sulfonated styrene, benzene, or combination thereof; and (c) a filter plug (132), said general adsorbent section (134) being axially aligned in series between said filter plug (132) and said selective adsorbent section (136).

Description

Filter for cigarette.

BACKGROUND OF THE INVENTION

The present invention relates to a cigarette filter that includes a smoke constituent adsorbent which, when combined with a carbon-based filtration material, shows synergistic reductions in smoke vapor constituents.

Cigarettes include bars or columns of tobacco that, when burned, produce a phase of particles and a phase of vapor. About 70 years ago, filters began joining at one end of the tobacco column. Among other things, the filter suppressed several smoke components. Filters made of filamentous or fibrous material, such as bast or cellulose acetate paper, eliminate the phase of tobacco smoke particles by mechanical means. However, fibrous materials are not effective in removing volatile constituents, such as aldehydes, cyanide and hydrogen sulphides, which have been found in the vapor phase. Typically, an adsorbent or absorbent is combined with the fibrous material to improve the removal of the components of the vapor phase. For example, cigarette filters have included activated carbon, porous materials such as sepiolite, silica gel, cation exchange resins and anion exchange resins.

Charcoal has a high specific surface area and is a relatively strong adsorbent for the constituents of the vapor phase of tobacco smoke. When coated with a mixture of metal oxides, charcoal is particularly effective in removing acid gases. Sepiolite has a large adsorption area with a strong adsorption affinity for charged species, but a considerably low adsorption affinity for non-polar species. It is generally considered that silica gels are small retention adsorbents for constituents of the vapor phase of tobacco smoke. Although silica gel readily adsorbs aldehydes and hydrogen cyanide, the constituents also easily desorb from the silica gel. Cation exchange resins for nicotine removal have been proposed. Anion exchange resins for the elimination of acids from smoke have been proposed, but strongly basic anion exchangers have no effect on aldehydes of the vapor phase of the smoke. The weakly basic ion exchange resins of porous structure are suitable for the removal of acids and aldehydes from smoke, but their effectiveness decreases during the act of smoking and does so from carbon and porous minerals.

Two or more adsorbents can be used in combination in cigarette filters. For example, U.S. Patent

2,815,760 describes the use of an ion exchange material with materials that "chemically react with harmful, non-alkaline and non-acidic smoke components to form nonvolatile compounds, thereby retaining the latter in the filter." However, the aforementioned additives have not behaved satisfactorily in the selective removal of smoke phase components such as smoke aldehydes, particularly acetaldehyde and acrolein. U.S. Patent 4,300,577 discloses the use of a weakly retentive adsorbent for constituents of the vapor phase interspersed with a second component that primarily has primary amino functional groups for the removal of constituents from the vapor phase, including aldehydes and hydrogen cyanide from the smoke of the tobacco. However, the filter of patent 4,300,577 has not been shown to have adequate acceptance by the consumer or commercial possibility.

Document BE 647 803 A describes a reusable cartridge filter element for tobacco articles, comprising its filter sections in the following order: a cap with holes in it, a cellulose layer, a granulate layer of active charcoal , another layer of cellulose, a layer of a resin, another layer of cellulose and, finally, a bottom part with holes in it, in which this bottom part is arranged towards the mouth end.

US 2,815,760 discloses a filter for tobacco articles that can be made as a cartridge or can be disposed directly into a cigarette, for example. Various composite layers of this filter element are arranged in the following order: a cap with holes in it, a cation exchange granule layer, a cotton plug or plug, a layer of anion exchange granulate, another plug of cotton, a layer of active charcoal and, finally, a cap of holes in it, in which the last cap is arranged towards the mouth end of the filter element.

US 3,280,823 discloses a filter element for tobacco articles comprising a resin, which releases nicotine and flavorings into tobacco smoke. That resin may be contained in a filter base made of commercially available filter materials.

SUMMARY OF THE INVENTION

The present invention relates to a cigarette filter that includes a multi-section filter that reduces the level of predetermined constituents of smoke. The filter consists of a fibrous filter plug or plug located at the mouth end of the cigarette, a section containing a selective adsorbent material and a section containing a general adsorbent material.

The filter plug may be a filter plug known in the art, such as cellulose acetate tow. The general adsorbent material is selected from a group of relatively large surface area materials, such as activated charcoal, which are capable of absorbing a range of chemical compounds without a high degree of specificity. The selective adsorbent material is chosen on the basis of specific constituents of the smoke that are the object of its elimination. The selective adsorbent material is selected from a group of resins that have been given surface functionality, in which each resin consists of an essentially inert carrier with a surface area greater than about 35 m2 / g. In accordance with the present invention, the selective adsorbent material has a surface phenol-formaldehyde resin matrix made primarily functional with primary and secondary amine functional groups.

Structurally, the selective adsorbent material may be adjacent to a tobacco bar and the general adsorbent material located between the selective adsorbent section and the filter plug. Preliminarily, the data indicate that the orientation produces a synergistic effect in smoke constituent reductions. In addition, the selective adsorbent and the general adsorbent may be interdispersed in a traditional filter plug material, such as cellulose acetate, or the adsorbents may be packaged as a bed or thin layer sections within the filter plug material.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a perspective view of a prior art filter cigarette;

Figure 2 is a perspective view of a filter for a cigarette made in accordance with the present invention, in which the adsorbents are dispersed through a filter plug material, and the general adsorbent section is located between the cap filter and selective adsorbent section;

Figure 3 is a perspective view of a filter for a cigarette, in which the adsorbents are dispersed through a filter plug material, and the selective adsorbent section is located between the filter plug and the adsorbent section. general;

Figure 4 is a perspective view of a filter for a cigarette, in which the adsorbents are packaged as beds within a segment of a filter plug material;

Figure 5 is a cross-sectional view of a filter with the filter plug disposed between the general adsorbent section and the selective adsorbent section;

Figure 6 is a cross-sectional view of an embodiment of the present invention with the filter plug adjacent to one end of a tobacco bar;

Figure 7 is a cross-sectional view of an embodiment of the present invention, the adsorbents being arranged in sections on a single length of fibrous filter material; Y

Figure 8 is a cross-sectional view free of a filter plug section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The cigarette filter of the present invention includes a multi-section filter that reduces the levels of predetermined constituents of the smoke. The filter consists of a fibrous filter plug or plug located at the mouth end of the cigarette, a section containing a selective adsorbent material and a section containing a general adsorbent material.

As shown in Figure 1 and known in the art, a typical tipped cigarette 10 with filter has a filter 30 attached to a tobacco bar 20. The tobacco bar 20 consists of a loose mixture 22 containing tobacco, wrapped in a cigarette paper 24, and the filter 30 includes a filter cap 32 wrapped in a cap wrap 34. A tipped sheet of paper 36 attaches the filter 30 to the tobacco bar 20.

In the present invention, as shown in Figure 2, a cigarette 110 has a multi-section filter 130 attached to the tobacco bar 20. The filter 130 includes a filter plug 132, a section containing a general adsorbent 134 and a section containing the selective adsorbent 136. The filter plug 132 is adjacent to a first or mouth end 131 of the filter 130. The bed of the selective adsorbent 136 is adjacent to a second or tobacco end 137 of the filter 130. The bed of the general adsorbent 134 is located between the filter plug 132 and the bed 136 of the selective adsorbent.

The filter plug 132 is made of a filamentous or fibrous material and provides a clear and net appearance at the mouth end 131 of the cigarette. The filter cap 132 also maintains a firmness at the mouth end 131 when the cigarette 110 is consumed. As is known in the art, the filter cap 132 can be made of a variety of materials, among which the most common are Cellulose, cellulose acetate tow, paper, cotton, polypropylene tape, polypropylene tow, polyester tape, polyester tow or a combination thereof. Optionally, a plasticizer can be included.

The general adsorbent section 134 includes a general adsorbent material 144 dispersed through the filter plug material 142, such as in a "dual-dalmatian" filter, known in the art. The general adsorbent material 144 is selected from a group of relatively large surface area materials that are capable of adsorbing smoke constituents without a high degree of specificity. The general adsorbent is selected from activated charcoal, activated coconut carbon, coal-based activated carbon, zeolite, silica gel, sepiolite, aluminum oxide, or combination thereof, as well as a mineral-based charcoal, made of semi-anthracite coal with a density approximately 50% higher than coconut-based charcoal (available from Calgon Carbon, Pittsburgh, PA), Ambersorb 572 or Ambersorb 563 (a carbonaceous resin derived from the sulfonated styrene-divinylbenzene pyrolysis, available de Rohm and Haas, 5000 Richmond Street, Philadelphia, PA 19137), other materials having similar particle sizes, surface area and binding affinities, or combination thereof. To further improve the efficiency of the general adsorbent, metal oxides or other metal-based complexes can be included in the general adsorbent section.

The selective adsorbent section 136 includes a selective adsorbent material 146 dispersed through the filter plug material 142, such as "dual-dalmatian" filter, known in the art. The selective adsorbent material 146 is selected based on the specificity of the material 146 for a predetermined class of chemical compounds. The selective adsorbent material 146 is an ion exchange resin, such as Duolite A7 (available from Rohm and Haas, 5000 Richmond Street, Philadelphia, PA 19137), or a material having similar functional groups and binding affinities. Duolite A7 has a phenol-formaldehyde resin matrix and surface functionality is provided with primary and secondary amino groups, thereby improving the specificity of the resin towards aldehydes and hydrogen cyanide found in tobacco smoke.

In addition, the selective adsorbent material 146 must be selected taking into account that the contact conditions between tobacco smoke and adsorbent 146 are dependent on numerous variables, including how strongly the smoker sucks the smoke through the filter when he is being smoked. the cigarette and how much of the tobacco bar has been consumed before each puff. Thus, it is advantageous that the selective adsorbent 146 has a surface area greater than about 35 m2 / g so that the diffusion resistance is minimal and the functional locations of the surface area are easily accessible. Materials with larger surface areas also show less noticeable decrease in performance if part of the surface is covered with a plasticizer, as could happen when adsorbent 146 is dispersed in filter plug 142. '

When the cigarette is consumed, tobacco smoke is sucked by the smoker through the filter 130. The smoke initially passes over the selective adsorbent section 136 where the target constituents of the smoke are adsorbed on the surface of the selective adsorbent material 146 and is particulate matter in the smoke is retained by the filter plug material 142. The remaining smoke then passes over the general adsorbent section 134, where other constituents can be retained by the adsorbent material 144 and additional particulate matter is retained by the material of filter plug 142. Finally, the remaining smoke then passes through filter plug 132, where additional particulate matter can be removed. The filtered smoke is then supplied to the smoker.

In a first embodiment of the present invention, as shown in Figure 2, the multi-section filter 110 is made with a filter plug 132 made of cellulose acetate tow and having approximately 7 mm in length, and with a section of general adsorbent dispersed through the cellulose acetate tow 142 cut to provide a section 134 of about 10 mm in length in which the cellulose acetate tow is treated with a plasticizer, and having a section of selective adsorbent 136 consisting of 40 mg of Duolite A7 dispersed through the cellulose acetate tow 142 cut to provide a section 136 of about 10 mm in length in which the cellulose acetate tow is treated with plasticizer. When the tobacco bar is burned with a normal draft / rest cycle, the analysis of the smoke vapor existing at the mouth end 131 of cigarette 110 shows statistically significant reductions in the levels of hydrogen cyanide, furan, propionaldehyde, acetone, methyl ethyl ketone / butyraldehyde, hydrogen sulfide, 1,3_butadiene, 2-methylpropanal, isoprene, styrene, pyridine, toluene and benzene, compared to cigarettes using similar resin-only filters. When the tobacco bar is burned with a normal draft / rest cycle, the analysis of the vapor of the smoke that exists at the mouth end 131 of the cigarette 110 shows statistically significant reductions in the levels pyridine, hydrogen cyanide, hydrogen sulfide, styrene, 2-methylpropanal, benzene, propionaldehyde, furan, isoprene 1,3-butadiene crotonaldehyde, acetone, acrylonitrile, acetaldehyde, toluene, carbon disulfide, methyl ethyl ketone / butyraldehyde, propionaldehyde, acetonitrile with cigarettes, methanol in cigarettes, methanol in cigarettes charcoal filter only.

As shown in Figure 2, the multi-section filter 130 has a filter plug 132 adjacent to the mouth end 131, the selective adsorbent section 136 is adjacent to the tobacco bar end 137 and the general adsorbent section 134 is located between the filter plug 132 and the selective adsorbent section 136.

In Fig. 3, a cigarette 210 has a multi-section filter 230 in which the filter plug 132 is located at the mouth end 131, the general adsorbent section 134 is adjacent to the tobacco bar end 137 and the section of selective adsorbent 136 is sandwiched between the filter plug 132 and the general adsorbent section 134. In this embodiment, during a normal aspiration or draft, the smoke first passes through the general adsorbent section 134, then through the selective adsorbent section 136 and finally through the filter plug 132. In addition, the multi-section filter 230 is essentially identical to the filter 130 (Figure 2) of the first embodiment, except that the general adsorbent section 134 is adjacent to the tobacco bar 20 and the selective adsorbent section 136 is sandwiched between the filter plug 132 and the general adsorbent section 134. When the bar is burned of tobacco with a normal draft / rest cycle, the analysis of tobacco smoke that exists at the mouth end 131 of cigarette 210 (Figure 3) shows statistically significant reductions in levels of propionaldehyde, acetone, methyl ethyl ketone / butyraldehyde, crotonaldehyde , hydrogen sulfide, 2-methylpropanal, pyridine, acrolein, toluene, acetaldehyde, acrylonitrile, methane and benzene, compared to cigarettes using similar resin filters only. When the tobacco bar burns with a normal draft / rest cycle, the analysis of tobacco smoke that exists at the mouth end 131 of cigarette 210 shows statistically significant reductions in the levels of pyridine, hydrogen cyanide, benzene, propionitrile , crotonaldehyde, acetone, acrylonitrile, acetaldehyde, toluene, carbon disulfide, methyl ethyl ketone / butyraldehyde, propionaldehyde, acetonitrile and methanol, compared to cigarettes using charcoal filter only.

As shown in Figure 4, in a multi-section filter 330 of a cigarette 310, adsorbents 144, 146 are packaged within the filter plug material as thin-layer sections of general adsorbent 344 and selective adsorbent 346. In this embodiment, the layered adsorbents are exposed to less plasticizer than the adsorbents dispersed in bast and retain more surface area to interact with the smoke constituents. In addition, as shown in Figure 7, a multi-section filter 630 for a cigarette 610 includes the general adsorbent 344 and the selective adsorbent 346 dispersed in separate sections within a single section of fibrous filter material 342.

An advantage of the embodiment 110 of Figure 2 is that the smoke passes over the selective adsorbent material 146 before passing over the general adsorbent 144. This allows the selective adsorbent 146 to remove some specific constituents of the smoke before the general adsorbent 144 is exposed to smoke, thereby allowing general adsorbent 144 to be more effective in removing the remaining constituents of smoke. Thus, this is a synergistic effect observed for adsorbents in the cellulose acetate / general adsorbent / specific adsorbent orientation, as compared to the cellulose acetate / specific adsorbent / general adsorbent orientation.

As shown in Figures 5 and 6, in a filter 430 and 530 of multiple sections of cigarettes 410 and 510, respectively, the filter plug 132 is disposed between the general adsorbent section 134 and the selective adsorbent section 136 of the Figure 5 and is adjacent to one end of the tobacco bar 20 of Figure 6. In Figure 5 the selective adsorbent section136 is at the mouth end of the filter 430 and in Figure 6 the general adsorbent section 134 is in the mouth end of the filter 530. In addition, as shown in Figure 8, a multi-section filter 730 of a cigarette 710 includes only a general adsorbent section 134 and a selective adsorbent section 136.

The following examples are representative of the embodiments that can be prepared and the removal performance of smoke constituents of these embodiments. The presented embodiments are intended for example purposes only and are not intended to limit their scope.

Example 1: A cigarette 110 with a multi-section filter 130 is prepared as shown in Figure 2, in which the filter cap 132 is made of cellulose acetate tow and is about 7 mm in length, a section of General adsorbent 134 consists of approximately 40 mg of activated coconut charcoal 144 dispersed through plasticized cellulose acetate tow 142, cut to provide a section 134 of about 10 mm in length, and a selective adsorbent 136 consists of approximately 40 mg of Duolite A7 dispersed through cellulose acetate tow 142 treated with plasticizer, cut to provide a section 136 of about 10 mm in length. The filter is attached to a tobacco bar that is 56.5 mm long and contains approximately 617 mg of a typical mixture for non-menthol cigarettes, wrapped in 50 Coresta cigarette paper with approximately 1.8% citrate. The cigarette supplies approximately 10.3 mg of tar per cigarette.

Example 2: A cigarette 210 was prepared with a multi-section filter 230, with the section orientations as shown in Figure 3, in which the filter cap 132, the general adsorbent section 134 and the selective adsorbent section 136 are essentially identical to the filter plug 132 to the general adsorbent section 134 and to the selective adsorbent section 136 of Example 1. The filter was attached to a tobacco rod of a length of approximately 56.5 mm and containing about 617 mg of a typical non-mentholated mixture for cigarettes, wrapped in 50 Coresta cigarette paper with approximately 1.8% citrate. The cigarette supplies about 10.0 mg of tar for each cigarette.

Example 3: Cigarettes were prepared as in Example 1, except that approximately 20 mg of Duolite A7 was used in selective adsorbent section 136 instead of 40 m. The cigarette supplies about 10.2 mg of tar for each cigarette.

Example 4: Cigarettes were prepared as in Example 2, except that about 20 mg of Duolite A7 was used in selective adsorbent section 136 instead of 40 mg. The cigarette supplies approximately 10.0 mg of tar per cigarette.

Example 5: Cigarettes were prepared as in Example 1, except that about 60 mg of Duolite A7 was used in selective adsorbent section 136 instead of 40 mg. The cigarette supplies about 10.0 mg of tar per 5 cigarette.

Example 6: Cigarettes were prepared as in Example 2, except that approximately 60 mg of Duolite A7 was used in selective adsorbent section 136 instead of 40 mg. The cigarette supplies about 10.3 mg of tar per cigarette.

Example 7: Cigarettes were prepared as in Example 1, except that about 69 mg of charcoal was used

10 based on mineral, made of semi-anthracite coal in the general adsorbent section 136 instead of 40 mg of activated coconut charcoal. The cigarette supplies approximately 10.1 mg of tar per cigarette.

Example 8: Cigarettes were prepared as in Example 2, except that 69 mg of mineral-based charcoal made from semi-anthracite coal was used in general adsorbent section 136 instead of 40 mg of coal

15 activated coconut vegetable. The cigarette supplies approximately 10.2 mg of tar per cigarette.

Example 9: Representative cigarettes of Examples 1-6 were smoked to a cigarette butt length of about 4 mm from the tip using a Borgwalt RM-20 smoking machine. Following the procedures outlined by FTC, the smoke constituents existing at the mouth end of each cigarette were passed through a Cambridge filter plug, the vapor phase was collected in a bag and analyzed by GC / MS. The data is

20 standardized for about 10 mg of tar per cigarette.

Medium Steam Phase Productions (Ig / cig)

Cigarettes prepared by Example:

 1 2  3. 4 5 6

Duolite mg / cigarette

40  twenty  60

Filter Segment Order

CA / GA / CA / SA / SA GA    CA / GA / CA / SA / SA GA     CA / GA / CA / SA / SA GA

Acetaldehyde

330.9 333.7  380.7 346.2 320.3 310.9

Isoprene

231.4 240.4  252.1 246.1 227.4 227.2

Acetone

144.1 163.5 156.0 160.5 148.0 151.4

Methanol

104.9 127.6  114.5 142.8 111.7 98.5

Acetonitrile

59.8 72.0 67.0 77.4 62.8 57.3

Acrolein

29.6 31.4 33.6 32.2 28.5 29.9

Methyl ethyl ketone

29.3 35.9 30.9 38.5 30.1 31.6

Formaldehyde

23.5 25.8 25.5 25.0 22.1 24.5

Propionaldehyde

25.7 27.4 29.3 28.5 25.3 25.0

1,3-Butadiene

25.5 25.9 27.5 25.5 25.8 25.0

Toluene

22.5 25.3 22.0 27.5 23.9 22.5

Benzene

20.6 23.6 21.6 24.1 21.1 21.4

Acrylonitrile

16.8 17.7 18.0 18.0 17.0 16.5

Furan

16.2 17.0 17.3 16.4 16.4 16.2

Hydrogen cyanide

 15.1 16.4 20.7 19.6 13.6 14.8

Hydrogen sulfide

12.9 13.0 14.0 12.9 13.1 12.7

Propionitrile

12.9 15.0 13.5 15.9 13.6 12.8

2-Methylpropanal

6.4 6.7 7.0 7.0  6.6 6.4

Crotonaldehyde

5.1 5.9 5.5 6.3  5.3 5.0

Carbon disulfide

2.5 2.6 2.7 2.6  2.6 2.5

Styrene

2.0 1.8 2.2 1.9  2.1 1.7

Pyridine

1.9 1.9 1.9 1.8  1.9 1.8

CA = cellulose acetate filter plug; GA = general adsorbent section; SA = selective adsorbent section

Example 10: Representative cigarettes of Examples 7 and 8 were smoked to a cigarette butt length of about 4 mm from the tip using a Borgwalt RM-20 smoking machine. Following the procedures set forth by FTC, the smoke constituents existing at the filter end of each cigarette were passed through a Cambridge filter plug, the vapor phase being collected in a bag and analyzed by GC / MS. The data was normalized to about 10 mg of tar per cigarette.

Medium Steam Phase Productions (Ig / cig)

Cigarette prepared by Example:

 7 8

mg Duolite / cigarette

40

Filter segment order

 CA / GA / A  CA / SA / GA

Acetaldehyde

343.4 364.2

Isoprene

225.0 268.9

Acetone

138.6 162.3

Methanol

95.1 134.7

Acetonitrile

61.4 84.6

Acrolein

9.8 35.3

Methyl ethyl ketone

28.3 39.8

Propionaldehyde

26.4 30.2

1,3-Butadiene

25.4 27.7

Toluene

18.7 24.2

Benzene

21.3 27.3

Acrylonitrile

7.5    9.0

Furan

17.0 18.4

Hydrogen cyanide

16.7 19.5

Hydrogen sulfide

14.7 14.1

Propionitrile

15.7 20.3

2-Methylpropanal

13.0 14.8

Crotonaldehyde

 3.3 5.1

Carbon disulfide

2.8 2.8

Styrene

1.8 2.1

Pyridine

1.3 1.4

CA = cellulose acetate filter plug; GA = general adsorbent section; SA = selective adsorbent section

From a production perspective, there are some advantages to dispersing the selective adsorbent material 146 and the general adsorbent material 144 through the filter tow 142. Specifically, when the adsorbents 5 144, 146 are dispersed within the tow 142, the adsorbents They are easier to handle than they are as loose particles. However, when the adsorbents 144, 146 are dispersed within the tow 142, there is a risk that any plasticizer that is used in the tow 142 will affect the surface of the adsorbents 144, 146, thereby reducing the adsorption capacity. Thus, as shown in Figure 4, adsorbents 144, 146 can be packaged within the filter plug material 142 as thin-layer sections of

10 general adsorbent 344 and selective adsorbent 346. Because layered adsorbents would not be exposed to the same plasticizer level as adsorbents dispersed in bast, adsorbents would retain more available surface area to interact with smoke constituents.

From reading the foregoing, an ordinary person skilled in the art would be able to conceive variations of the inventive features. For example, the filter plug, the general adsorbent section and the

Selective adsorbent may vary in length and diameter, relative to any dimensions specified therein and one relative to another. In addition, the dimensions of the various sections can be made optimal for a particular mixture of tobacco or for particular dimensions of tobacco bars. These and other variations are considered to fall within the scope of the appended claims.

Claims (10)

1. A multi-section cigarette filter, comprising:

(to)

a section of selective adsorbent (136) comprising a selective adsorbent material (146) which is an ion exchange resin having an affinity for a predetermined class of chemical compounds dispersed through a fibrous material, said exchange resin being said of ions a phenol-formaldehyde resin matrix and is made surface functional with primary and secondary amine groups;

(b)

a general adsorbent section (134) comprising a general adsorbent material (144) that has a large surface area and that is capable of adsorbing smoke constituents without a high degree of specificity, said general adsorbent material (144) being selected from the group consisting of activated charcoal, activated coconut coal, activated coal based carbon, zeolite, silica gel, sepiolite, aluminum oxide, coal based charcoal made from semi-anthracite coal, a carbonaceous resin derived from the pyrolysis of sulfonated styrene-benzene, or combination thereof; Y

(C)

a filter plug (132), said general adsorbent section (134) being axially aligned in series between said filter plug (132) and said selective adsorbent section (136).

2.

The cigarette filter of claim 1, wherein said general adsorbent section (134) comprises said general adsorbent material (144) dispersed through a fibrous material.

3.

The cigarette filter of claim 1, wherein said general adsorbent section (134) comprises a tightly packed bed of said general adsorbent material (144).

Four.

The cigarette filter of claim 1, wherein said general adsorbent section (134) includes a metal oxide or other metal-based complex.

5.

The cigarette filter 1, said filter plug being a fibrous filter plug (132) made of cellulose, cellulose acetate tow, paper, cotton, polypropylene tape, polypropylene tow, polyester tape, polyester tow or a combination thereof.

6.

The cigarette filter of claim 5, wherein said filter plug (132) further includes a plasticizer, a liquid additive, a flavoring agent or a combination thereof.

7.

The cigarette filter of claim 1, wherein said selective adsorbent material (146) has a surface area greater than about 35 m.sup.2 / g.

8.

The cigarette filter of claim 1, comprising:

(to)

a predetermined length of fibrous material;

(b)

a selective adsorbent material (146) dispersed through a first preselected section (136) along said preselected length, said selective adsorbent material (146) having an affinity for a predetermined class of chemical compounds dispersed through the fibrous material , said selective adsorbent material (146) being an ion exchange resin, said ion exchange resin being a matrix of phenol formaldehyde resin and its surface being made functional with primary and secondary amine groups; Y

(C)

a general adsorbent material (146) selected from the group consisting of activated charcoal, activated coconut coal, activated coal based carbon, zeolite, silica gel, sepiolite, aluminum oxide, coal based charcoal, made of coal semi-anthracite, a carbonaceous resin derived from the pyrolysis of sulfonated styrene di-benzene, or a combination thereof, dispersed through a second preselected section (134) along the said preselected length, said general adsorbent material having

(144) a large surface area and being capable of adsorbing smoke constituents without a high degree of specificity, said general adsorbent section (134) being axially aligned in series between said fibrous material (132) and said adsorbent section selective (136).

9.

The cigarette filter of claim 8, wherein said general adsorbent material (144) further includes a metal oxide or other metal-based complex.

10.

The cigarette filter of claim 8, wherein said fibrous material includes a plasticizer, a liquid additive, a flavoring agent or a combination thereof.