Cigarette Filter

Abstract

The present invention relates to a cigarette filter that includes a multiple section filter which reduces the level of predetermined smoke constituents. The filter consists of a fibrous filter 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 selective adsorbent material, such as a phenol-formaldehyde resin matrix surface-functionalized with mainly primary and secondary amine functional groups, removes specific smoke constituents from the tobacco smoke. The general adsorbent material, such as activated charcoal, is preferably capable of adsorbing a range of chemical compounds without a high degree of specificity. Structurally, the fibrous filter plug, the selective adsorbent section, and the general adsorbent section are in tandem and are circumscribed with a plug wrap.

What is claimed is:  
     
         1 . A multiple section cigarette filter comprising: 
 (a) a fibrous filter plug;    (b) a selective adsorbent section, comprising a selective adsorbent material having an affinity for a predetermined class of chemical compounds; and    (c) a general adsorbent section, comprising a general adsorbent material having a high surface area and being capable of adsorbing smoke constituents without a high degree of specificity,    said fibrous filter plug, said selective adsorbent section, and said general adsorbent section being in tandem and circumscribed with a plug wrap.    
     
     
         2 . The cigarette filter of  claim 1  wherein said selective adsorbent material is an ion-exchange resin.  
     
     
         3 . The cigarette filter of  claim 2  wherein said selective adsorbent material has a surface area sufficient to ensure that the surface functional sites are easily accessible to a smoke constituent.  
     
     
         4 . The cigarette filter of  claim 2  wherein said ion-exchange resin has a phenol-formaldehyde resin matrix and is surface-functionalized with primary and secondary amine groups.  
     
     
         5 . The cigarette filter of  claim 2  wherein said selective adsorbent section comprises said selective adsorbent material dispersed throughout a fibrous material.  
     
     
         6 . The cigarette filter of  claim 2  wherein said selective adsorbent section comprises a close-packed bed of said selective adsorbent material.  
     
     
         7 . The cigarette filter of  claim 1  wherein said general adsorbent material is selected from the group consisting of activated charcoal, activated coconut carbon, activated coal-based carbon, zeolite, silica gel, meerschaum, aluminum oxide, a coal-based charcoal made from semi-anthracite coal, a carbonaceous resin derived from the pyrolysis of sulfonated styrene-divinylbenzene, or combinations thereof.  
     
     
         8 . The cigarette filter of  claim 7  wherein said general adsorbent section comprises said general adsorbent material dispersed throughout a fibrous material.  
     
     
         9 . The cigarette filter of  claim 8  wherein said general adsorbent section further includes an additive selected from a metal oxide or a metal-based complex.  
     
     
         10 . The cigarette filter of  claim 7  wherein said general adsorbent section comprises a close-packed bed of said general adsorbent material.  
     
     
         11 . The cigarette filter of  claim 10  wherein said general adsorbent section further includes an additive selected from a metal oxide or a metal-based complex.  
     
     
         12 . The cigarette filter of  claim 1  wherein said filter plug is made from cellulose, cellulose acetate tow, paper, cotton, polypropylene web, polypropylene tow, polyester web, polyester tow or a combination thereof.  
     
     
         13 . The cigarette filter of  claim 12  wherein said filter plug is made from cellulose acetate tow.  
     
     
         14 . The cigarette filter of  claim 12  wherein said filter plug further includes a plasticizer.  
     
     
         15 . The cigarette filter of  claim 12  wherein said filter plug further includes a liquid additive.  
     
     
         16 . The cigarette filter of  claim 15  wherein said liquid additive is a flavoring agent.  
     
     
         17 . The cigarette filter of  claim 1  wherein said general adsorbent section is sandwiched between said fibrous filter plug and said selective adsorbent section.  
     
     
         18 . The cigarette filter of  claim 1  wherein said selective adsorbent section is sandwiched between said fibrous filter plug and said general adsorbent section.  
     
     
         19 . A multiple section cigarette filter comprising: 
 (a) a fibrous filter plug;    (b) a selective adsorbent section, comprising a selective adsorbent material having an affinity for a predetermined class of chemical compounds dispersed throughout a fibrous material; and    (c) a general adsorbent section, comprising a general adsorbent material having a high surface area and being capable of adsorbing smoke constituents without a high degree of specificity,    said fibrous filter plug, said selective adsorbent section, and said general adsorbent section being in tandem and circumscribed with a plug wrap.    
     
     
         20 . The cigarette filter of  claim 19  wherein said selective adsorbent material is an ion-exchange resin.  
     
     
         21 . The cigarette filter of  claim 20  wherein said selective adsorbent material has a surface area sufficient to ensure that the surface functional sites are easily accessible to a smoke constituent.  
     
     
         22 . The cigarette filter of  claim 20  wherein said ion-exchange resin has a phenol-formaldehyde resin matrix and is surface-functionalized with primary and secondary amine groups.  
     
     
         23 . The cigarette filter of  claim 19  wherein said general adsorbent material is selected from the group consisting of activated charcoal, activated coconut carbon, activated coal-based carbon, zeolite, silica gel, meerschaum, aluminum oxide, a coal-based charcoal made from semi-anthracite coal, a carbonaceous resin derived from the pyrolysis of sulfonated styrene-divinylbenzene, or combinations thereof.  
     
     
         24 . The cigarette filter of  claim 23  wherein said general adsorbent section comprises said general adsorbent material dispersed throughout a fibrous material.  
     
     
         25 . The cigarette filter of  claim 24  wherein said general adsorbent section further includes metal oxides or other metal-based complex.  
     
     
         26 . The cigarette filter of  claim 23  wherein said general adsorbent section comprises a close-packed bed of said general adsorbent material.  
     
     
         27 . The cigarette filter of  claim 26  wherein said general adsorbent section further includes metal oxides or other metal-based complex.  
     
     
         28 . The cigarette filter of  claim 19  wherein said filter plug is made from cellulose, cellulose acetate tow, paper, cotton, polypropylene web, polypropylene tow, polyester web, polyester tow or a combination thereof.  
     
     
         29 . The cigarette filter of  claim 28  wherein said filter plug is made from cellulose acetate tow.  
     
     
         30 . The cigarette filter of  claim 28  wherein said filter plug further includes a plasticizer.  
     
     
         31 . The cigarette filter of  claim 28  wherein said filter plug further includes a liquid additive.  
     
     
         32 . The cigarette filter of  claim 31  wherein said liquid additive is a flavoring agent.  
     
     
         33 . The cigarette filter of  claim 19  wherein said general adsorbent section is sandwiched between said fibrous filter plug and said selective adsorbent section.  
     
     
         34 . The cigarette filter of  claim 19  wherein said selective adsorbent section is sandwiched between said fibrous filter plug and said general adsorbent section.  
     
     
         35 . A multiple section cigarette filter comprising: 
 (a) a fibrous filter plug;    (b) a selective adsorbent section, comprising a selective adsorbent material having an affinity for a predetermined class of chemical compounds dispersed throughout a fibrous material; and    (c) a general adsorbent section, comprising a general adsorbent material having a high surface area and being capable of adsorbing smoke constituents without a high degree of specificity dispersed throughout a fibrous material,    said fibrous filter plug, said selective adsorbent section, and said general adsorbent section being in tandem and circumscribed with a plug wrap.    
     
     
         36 . The cigarette filter of  claim 35  wherein said selective adsorbent material is an ion-exchange resin.  
     
     
         37 . The cigarette filter of  claim 36  wherein said ion-exchange resin has a phenol-formaldehyde resin matrix and is surface-functionalized with primary and secondary amine groups.  
     
     
         38 . The cigarette filter of  claim 35  wherein said general adsorbent material is selected from the group consisting of activated charcoal, activated coconut carbon, activated coal-based carbon, zeolite, silica gel, meerschaum, aluminum oxide, a coal-based charcoal made from semi-anthracite coal, a carbonaceous resin derived from the pyrolysis of sulfonated styrene-divinylbenzene, or combinations thereof.  
     
     
         39 . The cigarette filter of  claim 35  wherein said filter plug is made from cellulose, cellulose acetate tow, paper, cotton, polypropylene web, polypropylene tow, polyester web, polyester tow or a combination thereof.  
     
     
         40 . The cigarette filter of  claim 39  wherein said filter plug is made from cellulose acetate tow.  
     
     
         41 . The cigarette filter of  claim 39  wherein said filter plug further includes a plasticizer.  
     
     
         42 . The cigarette filter of  claim 39  wherein said filter plug further includes a liquid additive.  
     
     
         43 . The cigarette filter of  claim 42  wherein said liquid additive is a flavoring agent.  
     
     
         44 . The cigarette filter of  claim 35  wherein said general adsorbent section is sandwiched between said fibrous filter plug and said selective adsorbent section.  
     
     
         45 . The cigarette filter of  claim 35  wherein said selective adsorbent section is sandwiched between said fibrous filter plug and said general adsorbent section.