Encapsulated Activated Carbon and the Preparation Thereof

Abstract

The present invention relates to encapsulated activated carbon and a method of preparing the same to protect the structure of the activated carbon and preserve the odor absorbing capability of the activated carbon particles. Particularly, the present invention is directed to a method of forming a polymer substrate upon melt processing comprising providing a first master batch of activated carbon particles that are at least partially encapsulated with a non-water soluble amorphous polymer, providing a matrix polymer, mixing the first master batch with the matrix polymer to form a mixture, and extruding the mixture to form a polymer substrate.

1 . A method of forming a polymer substrate upon melt processing comprising:
 providing a first master batch of activated carbon particles, wherein the particles are at least partially encapsulated with a non-water soluble amorphous polymer;   providing a matrix polymer;   mixing the first master batch with the matrix polymer to form a mixture; and   extruding the mixture to form a polymer substrate.   
     
     
         2 . The method of forming a polymer substrate upon melt processing of  claim 1 , wherein the non-water soluble amorphous polymer is incompatible with the matrix polymer. 
     
     
         3 . The method of forming a polymer substrate upon melt processing of  claim 1 , further comprising forming microvoids or cavitations around the activated carbon particles after extrusion. 
     
     
         4 . The method of forming a polymer substrate upon melt processing of  claim 1 , further comprising cracking or crazing the non-water soluble amorphous polymer encapsulating the activated carbon. 
     
     
         5 . The method of forming a polymer substrate upon melt processing of  claim 1 , wherein the matrix polymer is linear low density polyethylene (LLDPE). 
     
     
         6 . The method of forming a polymer substrate upon melt processing of  claim 1 , wherein the non-water soluble amorphous polymer is polystyrene. 
     
     
         7 . The method of forming a polymer substrate upon melt processing of  claim 1 , wherein the non-water soluble amorphous polymer is a cyclic olefin copolymer 
     
     
         8 . The method of forming a polymer substrate upon melt processing of  claim 1 , further comprising:
 adding at least one additive to the master batch.   
     
     
         9 . The method of forming a polymer substrate upon melt processing of  claim 8 , wherein the additive is CaCO 3 . 
     
     
         10 . The method of forming a polymer substrate upon melt processing of  claim 1 , wherein the activated carbon particles are non-modified activated carbon particles. 
     
     
         11 . A polymer substrate comprising:
 a matrix polymer substrate material;   activated carbon particles; and   a non-water soluble amorphous polymer which at least partially encapsulates the activated carbon particles.   
     
     
         12 . The polymer substrate of  claim 11 , wherein the polymer substrate is an article in the form selected from a group consisting essentially of a film, web, bag sheet, wrap, or container. 
     
     
         13 . The polymer substrate of  claim 12 , wherein the article is in the form of a film and the thickness of the film is substantially between 0.5 and 10 mils. 
     
     
         14 . The polymer substrate of  claim 11 , wherein the polymer substrate is a single layer structure. 
     
     
         15 . The polymer substrate of  claim 11 , wherein the polymer substrate is a multi-layer structure. 
     
     
         16 . The polymer substrate of  claim 15 , wherein a first layer of the multi-layer structure includes the activated carbon particles. 
     
     
         17 . The polymer substrate of  claim 11 , wherein the loading of activated carbon is substantially between 0.1 and 50 wt %. 
     
     
         18 . The polymer substrate of  claim 11 , wherein the matrix polymer substrate material is linear low density polyethylene (LLDPE). 
     
     
         19 . The polymer substrate of  claim 11 , wherein the activated carbon particles are non-modified activated carbon particles. 
     
     
         20 . A master batch for use in melt processing with a matrix polymer to prepare a polymer substrate, the master batch comprising:
 activated carbon particles; and   a non-water soluble amorphous polymer which at least partially encapsulates the activated carbon particles.   
     
     
         21 . The master batch of  claim 20 , wherein the non-water soluble amorphous polymer is incompatible with the matrix polymer. 
     
     
         22 . The master batch of  claim 20 , wherein the non-water soluble amorphous polymer is a rigid, permeable polymer. 
     
     
         23 . The master batch of  claim 20 , wherein the non-water soluble amorphous polymer is polystyrene. 
     
     
         24 . The master batch of  claim 20 , wherein the non-water soluble amorphous polymer is a cyclic olefin copolymer. 
     
     
         25 . The master batch of  claim 20 , wherein the non-water soluble amorphous polymer is a brittle composition capable of being cracked. 
     
     
         26 . The master batch of  claim 20 , wherein the activated carbon particles have an average particle size of 10 microns or less. 
     
     
         27 . The master batch of  claim 20 , wherein the activated carbon particles are non-modified activated carbon particles.