Cigarette filter

Abstract

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 co-axially aligned in tandem.

What is claimed is:  
     
         1 . A multiple section cigarette filter comprising: 
 (a) a selective adsorbent section comprising an ion-exchange resin having a phenol-formaldehyde resin matrix that is surface-functionalized with primary and secondary amine groups, said resin being dispersed throughout a fibrous material; and    (b) 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 selective adsorbent section and said general adsorbent section being co-axially aligned in tandem.    
     
     
         2 . 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.  
     
     
         3 . The cigarette filter of  claim 2  wherein said general adsorbent section further includes a metal oxide or other metal-based complex.  
     
     
         4 . The cigarette filter of  claim 1  including a fibrous filter plug 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, said fibrous filter plug being co-axially aligned in tandem with said selective adsorbent section and said general adsorbent section.  
     
     
         5 . The cigarette filter of  claim 4  wherein said filter plug further includes a plasticizer, a liquid additive, a flavoring agent or a combination thereof.  
     
     
         6 . The cigarette filter of  claim 4  wherein said general adsorbent section is positioned between said fibrous filter plug and said selective adsorbent section.  
     
     
         7 . The cigarette filter of  claim 4  wherein said selective adsorbent section is positioned between said fibrous filter plug and said general adsorbent section.  
     
     
         8 . The cigarette filter of  claim 4  wherein said filter plug is made from cellulose acetate tow, said selective adsorbent material is an ion-exchange resin having a phenol-formaldehyde resin matrix and is surface-functionalized with primary and secondary amine groups, and said general adsorbent section comprises activated coconut charcoal dispersed throughout plasticizer-treated cellulose acetate tow.  
     
     
         9 . The cigarette filter of  claim 8  wherein said general adsorbent is positioned between said fibrous filter plug and said selective adsorbent section.  
     
     
         10 . The cigarette filter of  claim 8  wherein said selective adsorbent section is positioned between said fibrous filter plug and said general adsorbent section.  
     
     
         11 . The cigarette filter of  claim 4  wherein said filter plug is made from cellulose acetate tow, said selective adsorbent material is an ion-exchange resin having a phenol-formaldehyde resin matrix and is surface-functionalized with primary and secondary amine groups, and said general adsorbent section comprises mineral-based charcoal made from semi-anthracite coal dispersed throughout plasticizer-treated cellulose acetate tow.  
     
     
         12 . The cigarette filter of  claim 11  wherein said general adsorbent is positioned between said fibrous filter plug and said selective adsorbent section.  
     
     
         13 . The cigarette filter of  claim 11  wherein said selective adsorbent section is positioned between said fibrous filter plug and said general adsorbent section.  
     
     
         14 . The cigarette filter of  claim 4 , said fibrous filter plug being positioned between said selective adsorbent section and said general adsorbent section.  
     
     
         15 . The cigarette filter of  claim 1 , said selective absorbent material having a surface area greater than about 35 m 2 /g.  
     
     
         16 . The cigarette filter of  claim 1  including a plug wrap circumscribing said general adsorbent section and said selective adsorbent section.  
     
     
         17 . A multiple section cigarette filter comprising: 
 (a) a fibrous filter plug;    (b) a selective adsorbent section comprising an ion-exchange resin having a phenol-formaldehyde resin matrix that is surface-functionalized with primary and secondary amine groups, said resin being dispersed throughout a fibrous material; and    (c) a general adsorbent section comprising a general adsorbent material 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, said fibrous filter plug, said selective adsorbent section, and said general adsorbent section being co-axially aligned in tandem.    
     
     
         18 . The cigarette filter of  claim 17  wherein said general adsorbent section further includes an additive selected from a metal oxide or another metal-based complex.  
     
     
         19 . The cigarette filter of  claim 17  wherein said general adsorbent material is dispersed throughout a fibrous material.  
     
     
         20 . The cigarette filter of  claim 17  wherein said general adsorbent section comprises a close-packed bed of said general adsorbent material.  
     
     
         21 . The cigarette filter of  claim 17  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.  
     
     
         22 . The cigarette filter of  claim 17  wherein said filter plug further includes a plasticizer, a liquid additive, a flavoring agent or a combination thereof.  
     
     
         23 . The cigarette filter of  claim 17  wherein said general adsorbent section is positioned between said fibrous filter plug and said selective adsorbent section.  
     
     
         24 . The cigarette filter of  claim 17  wherein said selective adsorbent section is positioned between said fibrous filter plug and said general adsorbent section.  
     
     
         25 . The cigarette filter of  claim 17  wherein said filter plug is made from cellulose acetate tow, said selective adsorbent material is an ion-exchange resin having a phenol-formaldehyde resin matrix and is surface-functionalized with primary and secondary amine groups, and said general adsorbent section comprises activated coconut charcoal dispersed throughout plasticizer-treated cellulose acetate tow.  
     
     
         26 . The cigarette filter of  claim 17  wherein said filter plug is made from cellulose acetate tow, said selective adsorbent material is an ion-exchange resin having a phenol-formaldehyde resin matrix and is surface-functionalized with primary and secondary amine groups, and said general adsorbent section comprises bituminous-based charcoal made from semi-anthracite coal dispersed throughout plasticizer-treated cellulose acetate tow.  
     
     
         27 . The cigarette filter of  claim 17 , said selective absorbent material having a surface area greater than 35 m 2 /g.  
     
     
         28 . The cigarette filter of  claim 17 , said fibrous filter plug being positioned between said selective adsorbent section and said general adsorbent section.  
     
     
         29 . The cigarette filter of  claim 21  wherein said general adsorbent section is positioned between said fibrous filter plug and said selective adsorbent section.  
     
     
         30 . The cigarette filter of  claim 21  wherein said selective adsorbent section is positioned between said fibrous filter plug and said general adsorbent section.  
     
     
         31 . The cigarette filter of  claim 21 , said selective absorbent material having a surface area greater than 35 m 2 /g.  
     
     
         32 . The cigarette filter of  claim 21 , said fibrous filter plug being positioned between said selective adsorbent section and said general adsorbent section.  
     
     
         33 . The cigarette filter of  claim 21 , said filter plug, said selective adsorbent section, and said general adsorbent section being circumscribed with a plug wrap.