Filtered Smoking Article

Abstract

A filter element suitable for use as a cigarette filter includes at least one section of fibrous tow comprising at least one plasticizer, the plasticizer including a citric acid ester, such as triethyl citrate, present in an amount of no more than about 15 weight percent based on the total weight of the filter material, and an adsorbent material, such as a granular carbonaceous material. One exemplary filter element has two or more sections of cellulose acetate tow comprising triethyl citrate in an amount of no more than about 12 weight percent based on the total weight of the filter material, and a granular carbonaceous material dispersed within at least one section of cellulose acetate tow. Cigarettes incorporating the filter element and methods of extending shelf-life of cigarettes including an adsorbent material are also provided.

1 . A filter element suitable for use as a cigarette filter, comprising at least one section of fibrous tow filter material comprising at least one plasticizer, the plasticizer comprising a citric acid ester present in an amount of no more than about 15 weight percent based on the total weight of the filter material, and an adsorbent material. 
   
   
       2 . The filter element of  claim 1 , wherein the adsorbent is a carbonaceous material. 
   
   
       3 . The filter element of  claim 2 , wherein the carbonaceous material is in granular form. 
   
   
       4 . The filter element of  claim 1 , wherein the citric acid ester comprises ester groups having C1-C10 alkyl groups. 
   
   
       5 . The filter element of  claim 4 , wherein the citric acid ester comprises ester groups having C2-C5 alkyl groups. 
   
   
       6 . The filter element of  claim 5 , wherein the citric acid ester is triethyl citrate. 
   
   
       7 . The filter element of  claim 1 , wherein the fibrous tow filter material is a cellulose acetate tow. 
   
   
       8 . The filter element of  claim 1 , comprising at least two sections of fibrous tow filter material comprising at least one plasticizer, wherein at least one section of fibrous tow filter material includes said adsorbent material dispersed therein. 
   
   
       9 . The filter element of  claim 1 , wherein the citric acid ester is present in an amount of about 5 to about 10 weight percent. 
   
   
       10 . The filter element of  claim 1 , wherein the adsorbent material is a granular carbonaceous material having a particle size between about 10 Mesh and about 400 Mesh, and wherein the carbonaceous material is present in an amount of between about 20 mg and about 500 mg. 
   
   
       11 . A filter element suitable for use as a cigarette filter, comprising two or more sections of fibrous tow filter material comprising at least one plasticizer, the plasticizer comprising a citric acid ester present in an amount of no more than about 15 weight percent based on the total weight of the filter material, and a granular carbonaceous material dispersed within at least one section of fibrous tow filter material. 
   
   
       12 . The filter element of  claim 11 , wherein the citric acid ester is present in an amount of about 5 to about 10 weight percent. 
   
   
       13 . The filter element of  claim 11 , wherein the granular carbonaceous material has a particle size between about 10 Mesh and about 400 Mesh, and wherein the carbonaceous material is present in an amount of between about 20 mg and about 500 mg. 
   
   
       14 . The filter element of  claim 11 , wherein the citric acid ester comprises ester groups having C1-C10 alkyl groups. 
   
   
       15 . The filter element of  claim 14 , wherein the citric acid ester comprises ester groups having C2-C5 alkyl groups. 
   
   
       16 . The filter element of  claim 15 , wherein the citric acid ester is triethyl citrate. 
   
   
       17 . A filter element suitable for use as a cigarette filter, comprising two or more sections of cellulose acetate tow comprising triethyl citrate in an amount of no more than about 12 weight percent based on the total weight of the filter material, and a granular carbonaceous material dispersed within at least one section of cellulose acetate tow, wherein the granular carbonaceous material has a particle size between about 10 Mesh and about 400 Mesh, and wherein the carbonaceous material is present in an amount of between about 20 mg and about 500 mg. 
   
   
       18 . A cigarette comprising a tobacco rod having a smokable filler material contained within a circumscribing wrapping material, and a filter element according to  claim 1  connected to one end of the tobacco rod. 
   
   
       19 . A cigarette comprising a tobacco rod having a smokable filler material contained within a circumscribing wrapping material, and a filter element according to  claim 11  connected to one end of the tobacco rod. 
   
   
       20 . A cigarette comprising a tobacco rod having a smokable filler material contained within a circumscribing wrapping material, and a filter element according to  claim 17  connected to one end of the tobacco rod.