Degradable filter element for smoking article

Abstract

A filter material configured for use as a filter element of a smoking article is provided, the filter material including at least one segment of fibrous tow having a plurality of superabsorbent objects dispersed therein, the superabsorbent objects comprising a starch material. Exemplary starch materials include naturally-occurring starch, hydroxyalkylated starch, starch esters, ionically modified starch, oxidized starch, hydrolyzed starch, plasticized starch, gelatinized starch, grafted starch, crosslinked starch, transglycosylated starch, starch ethers, and mixtures thereof, as well as blends of starch with other polymers. Filter elements and smoking articles, such as cigarettes, that contain the filter material are also provided. A method of preparing polymer fibers for use in filter elements is also provided, the method including adding the starch material to a fiber precursor solution prior to fiber extrusion or dry-blending the starch material with the polymer material to be formed into fibers.

1 . A filter material configured for use as part of a smoking article, comprising:
 at least one segment of fibrous tow   at least one degradation-enhancing object, the degradation-enhancing object configured to be activated by contact with moisture in a disposal environment.   
     
     
         2 . The filter material of  claim 1 , wherein the at least one degradation-enhancing object comprises a superabsorbent material configured to volumetrically expand upon contact with moisture and thereby to exert mechanical force against the fibrous tow. 
     
     
         3 . The filter material of  claim 2 , wherein the superabsorbent material comprises a material selected from the group consisting of sodium polyacrylate) polyacrylamide copolymer, ethylene maleic anhydride copolymer, cross-linked carboxy-methyl-cellulose, polyvinyl alcohol copolymer, cross-linked polyethylene oxide, hydrogel, starch-grafted copolymer of polyacrylonitrile, polyacrylate with poly(ethylene glycol), alginate-poly(sodium acrylate-coacrylamide), alginate-g-poly(sodium acrylate)/kaolin, carboxymethylchitosan-g-poly(acrylic acid) copolymer, copolymerizate of acrylic acid and maleic anhydride, polyvinylalcohol-phosphate, acrylic acid-polyvinyl alcohol copolymer, polyacrylamide, acrylamide/N-vinyl-pyrrolidone/3(2-hydroxyethyl carbamoyl)acrylic acid, poly(acrylamide-co-methyl methacrylate), polyacrylamide/sodium alginate, polyacrylic acid, poly(sodium acrylate) cross-linked with modified poly(ethylene glycol), sulfonated polystyrene, hydrolysed acrylonitrile sulfonated polystyrene, poly(ethylene oxide), n-vinyl-2-pyrrolidone with partially neutralized acrylic acid, poly(tartaramide)s, poly(ester-amide)s with oxyethylene segments, poly(aspartic acid), poly(aspartic acid) derivative, poly(acrylic acid)/attapulgite/sodium humate, and any combination thereof. 
     
     
         4 . The filter material of  claim 2 , wherein the superabsorbent material is configured as a selected one of a capsule, pellet, or thread. 
     
     
         5 . The filter material of  claim 2 , wherein the superabsorbent material is configured, dimensioned, and disposed such that volumetric expansion thereof will spread apart the filter material. 
     
     
         6 . The filter material of  claim 1 , further comprising at least one of plug wrap material and tipping material circumscribing the fibrous tow. 
     
     
         7 . The filter material of  claim 6 , wherein the degradation-enhancing object is disposed between the fibrous tow and the circumscribing material. 
     
     
         8 . The filter material of  claim 1 , wherein the fibrous tow comprises a plurality of individual filaments, and wherein a plurality of degradation-enhancing objects are disposed between the individual filaments. 
     
     
         9 . The filter material of  claim 1 , wherein the at least one degradation-enhancing object comprises a coating. 
     
     
         10 . The filter material of  claim 9 , wherein the coating is configured to be disruptable by moisture. 
     
     
         11 . The filter material of  claim 1 , wherein the fibrous tow comprises cellulose acetate tow, polyolefin tow, or a combination thereof. 
     
     
         12 . A filter element for a smoking article comprising one or more segments of fibrous tow filter material according to  claim 1 . 
     
     
         13 . The filter element of  claim 12 , comprising a first segment of fibrous tow filter material and a second segment of fibrous tow filter material, wherein the first segment of fibrous tow filter material comprises a superabsorbent material and the second segment is devoid of superabsorbent material. 
     
     
         14 . The filter material of  claim 1 , further comprising at least one degradability-promoting feature selected from the group consisting of microbial agents, cellulase, and fungal agents. 
     
     
         15 . A cigarette comprising:
 a tobacco rod having a smokable filler material contained within a circumscribing wrapping material and a filter element connected to the tobacco rod at one end of the tobacco rod, said filter element comprising
 at least one segment of fibrous tow having at least one degradation-enhancing object disposed therein, the degradation-enhancing object configured to be activated by contact with water. 
   
     
     
         16 . The cigarette of  claim 15 , wherein the at least one degradation-enhancing object comprises a superabsorbent material configured to volumetrically expand upon contact with moisture and thereby to exert mechanical force against the fibrous tow sufficient to disperse the fibrous tow. 
     
     
         17 . The cigarette of  claim 16 , wherein the superabsorbent material comprises a material selected from the group consisting of sodium polyacrylate) polyacrylamide copolymer, ethylene maleic anhydride copolymer, cross-linked carboxy-methyl-cellulose, polyvinyl alcohol copolymer, cross-linked polyethylene oxide, hydrogel, starch-grafted copolymer of polyacrylonitrile, polyacrylate with poly(ethylene glycol), alginate-poly(sodium acrylate-coacrylamide), alginate-g-poly(sodium acrylate)/kaolin, carboxymethylchitosan-g-poly(acrylic acid) copolymer, copolymerizate of acrylic acid and maleic anhydride, polyvinylalcohol-phosphate, acrylic acid-polyvinyl alcohol copolymer, polyacrylamide, acrylamide/N-vinyl-pyrrolidone/3(2-hydroxyethyl carbamoyl)acrylic acid, poly(acrylamide-co-methyl methacrylate), polyacrylamide/sodium alginate, polyacrylic acid, poly(sodium acrylate) cross-linked with modified poly(ethylene glycol), sulfonated polystyrene, hydrolysed acrylonitrile sulfonated polystyrene, poly(ethylene oxide), n-vinyl-2-pyrrolidone with partially neutralized acrylic acid, poly(tartaramide)s, poly(ester-amide)s with oxyethylene segments, poly(aspartic acid), poly(aspartic acid) derivative, poly(acrylic acid)/attapulgite/sodium humate, and any combination thereof. 
     
     
         18 . The cigarette of  claim 16 , wherein the superabsorbent material is configured as a selected one of a capsule, pellet, or thread. 
     
     
         19 . The cigarette of  claim 16 , further comprising at least one of plug wrap material and tipping material circumscribing the fibrous tow, and where the mechanical force is sufficient to disrupt the at least one plug wrap material and/or tipping material. 
     
     
         20 . The cigarette of  claim 15 , wherein the at least one degradation-enhancing object is disposed in a location selected from the group consisting of: between fibers of the fibrous tow, between the fibrous tow and an overlying wrapping material, between segments of fibrous tow, and any combination thereof. 
     
     
         21 . The cigarette of  claim 20 , wherein the at least one degradation-enhancing object comprises a coating. 
     
     
         22 . The cigarette of  claim 21 , wherein the coating is configured to be disruptable by moisture. 
     
     
         23 . The cigarette of  claim 21 , wherein the fibrous tow comprises cellulose acetate tow, polyolefin tow, or a combination thereof. 
     
     
         24 . A cigarette including a filter configured to degrade at an enhanced rate in a disposal environment where moisture is contacted, the cigarette comprising:
 a tobacco rod circumscribed by a wrapping material; and   a filter attached to the tobacco rod by a tipping material, the filter comprising:
 a fibrous tow material circumscribed by plug wrap material contacting the tipping material; and 
 at least one superabsorbent degradation-enhancing object contacting at least one of the tow material, the plug wrap material, and the tipping material, the object configured to volumetrically expand upon contact with moisture in a disposal environment. 
   
     
     
         25 . The cigarette of  claim 24 , wherein the volumetric expansion of the object is configured as sufficient to exert mechanical force against the fibrous tow that will disperse the fibrous tow and disrupt at least a portion of the plug wrap, the tipping material, or both the plug wrap and tipping material. 
     
     
         26 . The cigarette of  claim 24 , wherein at least one of the plug wrap and the tipping paper further comprises a biodegradable adhesive. 
     
     
         27 . A cigarette including a filter configured to degrade at an enhanced rate in a disposal environment where moisture is contacted, the cigarette comprising:
 a tobacco rod circumscribed by a wrapping material; and   a filter attached to the tobacco rod by a tipping material, the filter comprising:
 a gathered web filters made using a selected one of paper, non-woven fabric, or combination thereof, circumscribed by plug wrap material contacting the tipping material; and 
 at least one superabsorbent degradation-enhancing object contacting at least one of the tow material, the plug wrap material, and the tipping material, the object configured to volumetrically expand upon contact with moisture in a disposal environment.