Smoking articles comprising magnetic filter elements

Abstract

Disclosed is a filter element adapted to be incorporated into a filter cigarette. The filter element comprises filter material, particles of a magnetized adsorbent, and at least one magnetic substrate. During smoking of a cigarette comprising the filter element, the at least one magnetic substrate can filter (i.e., magnetically attract and trap) the magnetized adsorbent particles or fragments thereof within the filter element.

1 . A filter element adapted to be incorporated into a filter cigarette, the filter element comprising filter material, particles of a magnetized adsorbent, and at least one magnetic substrate. 
   
   
       2 . The filter element of  claim 1 , wherein the magnetized adsorbent comprises particles of a magnetic material incorporated in particles of an adsorbent material. 
   
   
       3 . The filter element of  claim 1 , wherein the magnetized adsorbent comprises particles of iron and/or an oxide of iron incorporated in particles of activated carbon. 
   
   
       4 . The filter element of  claim 1 , wherein the magnetized adsorbent has an average particle size of less than about 5 mm and the at least one magnetic substrate has at least one dimension of greater than about 1 mm or greater than about 2 mm. 
   
   
       5 . The filter element of  claim 1 , wherein the particles of the magnetized adsorbent are incorporated throughout the filter material. 
   
   
       6 . The filter element of  claim 1 , wherein the at least one magnetic substrate is selected from the group consisting of a disc, ring, cylinder, ribbon, foil, mesh or rod. 
   
   
       7 . The filter element of  claim 1 , wherein the at least one magnetic substrate consists essentially of a ferrite magnet, a neodymium iron boron magnet, a samarium cobalt magnet, an aluminum nickel cobalt magnet or an electromagnet. 
   
   
       8 . The filter element of  claim 1 , wherein the at least one magnetic substrate has a Curie temperature of at least about 300° C. and/or a magnetic field strength effective to attract and trap magnetized adsorbent particles and/or fragments of magnetized adsorbent particles within the filter element. 
   
   
       9 . The filter element of  claim 1 , wherein the filter material is wrapped in plug wrap and the at least one magnetic substrate is disposed on an inner surface of the plug wrap and/or is at least partially around the filter material. 
   
   
       10 . The filter element of  claim 1 , wherein the at least one magnetic substrate is incorporated into one or more filter parts selected from the group consisting of a shaped paper insert, a plug, a space between plugs, cigarette filter paper, a cellulose acetate sleeve, a polypropylene sleeve and a free-flow sleeve. 
   
   
       11 . A cigarette comprising the filter element of  claim 1 . 
   
   
       12 . The cigarette of  claim 11 , wherein the at least one magnetic substrate is adapted to reduce the amount of magnetized adsorbent particles or fragmented magnetized adsorbent particles entrained in the mainstream smoke of the cigarette. 
   
   
       13 . The cigarette of  claim 11 , comprising a tobacco rod attached to the filter element with tipping paper, wherein the at least one magnetic substrate is incorporated axially between the filter element and the tobacco rod. 
   
   
       14 . The cigarette of  claim 13 , wherein magnetized adsorbent particles are incorporated in the tobacco rod and/or the cigarette paper. 
   
   
       15 . The cigarette of  claim 11 , wherein the magnetized adsorbent particles and/or the at least one magnetic substrate are adapted to change the chemical composition of mainstream smoke that flows through the filter element. 
   
   
       16 . The cigarette of  claim 11 , wherein the magnetized adsorbent particles are incorporated in the filter element in an amount effective to catalyze the conversion of carbon monoxide to carbon dioxide and/or nitric oxide to nitrogen during smoking of the cigarette. 
   
   
       17 . A method of treating mainstream smoke from the cigarette of  claim 11 , the method comprising drawing the smoke through the cigarette wherein the magnetized particles and/or fragments of the magnetized particles are magnetically attracted to the at least one magnetic substrate and removed from the mainstream smoke. 
   
   
       18 . A method of making a cigarette filter element comprising filter material, magnetized adsorbent particles and at least one magnetic substrate, comprising:
 providing filter material and plug wrap material;   forming the filter material into a filter rod;   incorporating the magnetized adsorbent particles and the at least one magnetic substrate in and/or on at least one of the filter rod and the plug wrap material; and   wrapping the filter rod in the plug wrap material to form the filter element.   
   
   
       19 . The method of  claim 18 , wherein the magnetized adsorbent particles and/or the at least one magnetic substrate are incorporated in the filter material prior to forming the filter material into the filter rod. 
   
   
       20 . The method of  claim 18 , comprising forming the at least one magnetic substrate at least partially around the filter rod prior to wrapping the filter rod in the plug wrap, and/or incorporating the at least one magnetic substrate on an interior surface of the plug wrap prior to wrapping the filter rod in the plug wrap.