Exothermic gel-forming composition

Abstract

An expandable, exothermic gel-forming compositions that are predominately useful in the consumer products and medical industries. More particularly, it relates to expandable particulate exothermic gel-forming compositions with efficient and long-lasting heat production for heating surfaces and objects without the need for electricity or combustible fuel.

What is claimed is: 
     
         1 . A method of forming an expandable exothermic gel, the method consisting of:
 combining a first galvanic particle and a second galvanic particle to form a galvanic alloy and blending the galvanic alloy with a super absorbent polymer by a blending apparatus to form a powder mixture; and   adding water and an electrolyte, separately or together in solution, to the powder mixture thereby forming the expandable exothermic gel comprised of the powdered mixture, the water, and the electrolyte and actuating an exothermic reaction.   
     
     
         2 . The method of  claim 1 , wherein the exothermic gel has an absorption capacity of greater than 400 g/g of wet weight per starting dry weight. 
     
     
         3 . The method of  claim 1 , further comprising: mixing a weight ratio of 20:1 to 5:1 galvanic alloy particles to the super absorbent polymer. 
     
     
         4 . A gel-forming composition, comprising:
 a powder mixture formed from first and second galvanic particles that are alloyed and blended with a super absorbent polymer; and   an electrolyte;   wherein, when exposed only to water, a gel composition is formed that produces an exothermic reaction and expands to a volume at least two fold (volume/volume) larger than the volume of the powder mixture and the electrolyte as the powder mixture and the electrolyte are hydrated.   
     
     
         5 . The composition according to  claim 4 , wherein the super absorbent polymer comprises an absorption capacity of at least 200 g/g of wet weight per starting dry weight. 
     
     
         6 . The composition according to  claim 4 , wherein the electrolyte comprises potassium chloride, sodium chloride or calcium chloride. 
     
     
         7 . The composition according to  claim 4 , wherein the first and second galvanic particles comprise magnesium and iron. 
     
     
         8 . The composition according to  claim 4 , further comprising a hinder. 
     
     
         9 . The composition according to  claim 8 , wherein the binder is selected from a group consisting of natural resins, synthetic resins, gelatins, rubbers, poly(vinyl alcohol)s, hydroxyethyl celluloses, cellulose acetates, cellulose acetate butylates, poly(vinylpyrrolidone)s, casein, starch, poly(acrylic acid)s, poly(methylmethacrylic acid)s, poly(vinyl chloride)s, poly(methacrylic acid)s, styrene-maleic anhydride copolymers, styrene-acrylonitrile copolymers, styrene-butadiene copolymers, poly(vinyl acetal)s (e.g., poly(vinyl formal) and poly(vinyl butyral)), poly(ester)s, poly(urethane)s, phenoxy resins, poly(vinylidene chloride)s, poly(epoxide)s, poly(carbonate)s, poly(vinyl acetate)s, poly(olefin)s, cellulose esters, and poly(amide)s. 
     
     
         10 . The composition according to  claim 4 , wherein the super absorbent polymer is sodium polyacrylamide. 
     
     
         11 . The composition according to  claim 10 , wherein the super absorbent polymer is selected from a group consisting of a polyacrylic acid salt-based polymer, a vinyl alcohol-acrylic acid salt-based polymer, a PVA based polymer or an isobutylene-maleic anhydride polymer. Other examples of SAPs include polysaccharides such as carboxymethyl starch, carboxymethyl cellulose and hydroxypropyl cellulose; nonionic types such as polyvinyl alcohol and polyvinyl ethers; cationic types such as polyvinyl pyridine, polyvinyl morpholinione, and N,N-dimethylaminoethyl or N,N-diethylaminopropyl acrylates and methacrylates; and carboxy groups which include hydrolyzed starch-acrylonitrile graft copolymers, partially neutralized hydrolyzed starch-acrylonitrile graft copolymers, hydrolyzed acrylonitrile or acrylamide copolymers and polyacrylic acids 
     
     
         12 . The composition according to  claim 4 , wherein the composition expands to a volume at least five fold (volume/volume) larger than the volume of the powder mixture and the electrolyte. 
     
     
         13 . The composition according to  claim 4 , wherein the composition expands to a volume at least ten fold (volume/volume) larger than the volume of the powder mixture and the electrolyte. 
     
     
         14 . The composition according to  claim 4 , wherein the composition has an absorption capacity of greater than 400 g/g of wet weight per starting dry weight. 
     
     
         15 . The composition according to  claim 4 , wherein the composition is housed in a bag, tea bag, or permeable sachet. 
     
     
         16 . The composition according to  claim 4 , wherein the exothermic reaction generates heat for at least an hour. 
     
     
         17 . An exothermic composition comprising:
 a galvanic alloy particle blended by a blending apparatus with a super absorbent polymer to form a powder mixture,   wherein the composition is formed by adding an aqueous solution to the composition thereby causing the composition to expand at least two fold (volume/volume) and produce an exothermic reaction.