Filter elements suitable for use in smoking articles and processes for producing the same

Abstract

A filter element suitable for use in smoking articles may include: cellulose acetate fibers bonded together using polyhydroxyalkanoate (PHA) surrounding the cellulose acetate fibers, bonded together using PHA on surfaces of the cellulose acetate fibers, and/or bonded together using PHA. A process for producing the filter element suitable for use in the smoking articles may include: embedding a bundle of the cellulose acetate fibers with an aqueous suspension of the PHA to obtain a wet bundle of the cellulose acetate fibers covered by the aqueous suspension; shaping the wet bundle into a continuous elongated element; heating the elongated element to temperature greater than or equal to 140° C. and less than or equal to 180° C. to melt the PHA and to evaporate water from the elongated element; cooling the heated elongated element to obtain crystallization of the PHA; and/or cutting the elongated element into segments.

1 . A filter element suitable for use in smoking articles, the filter element comprising:
 cellulose acetate fibers bonded together using polyhydroxyalkanoate (PHA) surrounding the cellulose acetate fibers.   
     
     
         2 . The filter element of  claim 1 , wherein the PHA is a polymer containing repeating units of formula (I):
   —O—CHR 1 —(CH 2 ) n —CO—  (I)
   where R 1  is selected from: C 1 -C 12  alkyls, C 4 -C 16  cycloalkyls, C 2 -C 12  alkenyls, optionally substituted with at least one group selected from: halogen (F, Cl, Br), —CN, —OH, —OOH, —OR, or —COOR (R═C 1 -C 4  alkyl, benzyl), and   where ‘n’ is zero or is an integer from 1 to 6.   
     
     
         3 . The filter element of  claim 2 , wherein the PHA is selected from polyhydroxybutyrate (PHB) or poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). 
     
     
         4 . The filter element of  claim 1 , wherein the PHA has a weight-average molecular weight (M w ) greater than or equal to 10,000 daltons (Da) and less than or equal to 1,000,000 Da. 
     
     
         5 . The filter element of  claim 1 , wherein the PHA is present in an amount greater than or equal to 5% by weight and less than or equal to 30% by weight with respect to a total weight of the filter element. 
     
     
         6 . The filter element of  claim 1 , wherein the cellulose acetate fibers have diameter, expressed as denier per filament (dpf), greater than or equal to 1 and less than or equal to 15. 
     
     
         7 . A process for producing the filter element suitable for use in the smoking articles of  claim 1 , the process comprising:
 embedding a bundle of the cellulose acetate fibers with an aqueous suspension of the PHA to obtain a wet bundle of the cellulose acetate fibers covered by the aqueous suspension of the PHA;   shaping the wet bundle in a form of a continuous elongated element;   heating the continuous elongated element to temperature greater than or equal to 140° C. and less than or equal to 180° C. for time sufficient to melt the PHA and to evaporate water from the continuous elongated element;   cooling the heated continuous elongated element to obtain crystallization of the PHA; and   cutting the so-obtained continuous elongated element into segments of predetermined length.   
     
     
         8 . The process of  claim 7 , wherein prior to the embedding, the bundle of cellulose acetate fibers has total denier greater than or equal to 20,000 denier and less than or equal to 80,000 denier. 
     
     
         9 . A method for quenching reactive oxygen species (ROS) in smoke produced by a smoking article, the method comprising:
 providing the filter element suitable for use in smoking articles of  claim 1 .   
     
     
         10 . The filter element of  claim 2 , where ‘n’ is 0. 
     
     
         11 . The filter element of  claim 2 , where ‘n’ is 1. 
     
     
         12 . The filter element of  claim 2 , where ‘n’ is 2. 
     
     
         13 . The filter element of  claim 1 , wherein the PHA is present in an amount greater than or equal to 10% by weight and less than or equal to 20% by weight with respect to a total weight of the filter element. 
     
     
         14 . The filter element of  claim 1 , wherein the cellulose acetate fibers have diameter, expressed as denier per filament (dpf), greater than or equal to 5 and less than or equal to 10. 
     
     
         15 . The process of  claim 7 , wherein prior to the embedding, the bundle of cellulose acetate fibers has total denier greater than or equal to 30,000 denier and less than or equal to 60,000 denier. 
     
     
         16 . The filter element of  claim 1 , wherein the PHA comprises at least one homopolymer. 
     
     
         17 . The filter element of  claim 1 , wherein the PHA comprises at least one copolymer. 
     
     
         18 . The filter element of  claim 1 , wherein the PHA comprises at least one terpolymer. 
     
     
         19 . A filter element suitable for use in smoking articles, the filter element comprising:
 cellulose acetate fibers bonded together using polyhydroxyalkanoate (PHA) on surfaces of the cellulose acetate fibers.   
     
     
         20 . A filter element suitable for use in smoking articles, the filter element comprising:
 cellulose acetate fibers bonded together using polyhydroxyalkanoate (PHA).