Methods for forming stabilized metal salt particles

Abstract

The present invention relates to a process for forming stabilized metal salt particles.

1 . A process comprising
 a. forming a first solution comprising at least one sodium iodide salt precursor;   b. forming a second solution comprising a complex formed from at least one silver acetate metal agent and a polyvinyl pyrrolidone dispersing agent in a particle size stabilizing effective amount;   c. adding said second solution to said first solution at a rate sufficient to maintain a clear solution throughout addition and to form a product solution comprising stabilized metal salt particles having a mean particle size of less than about 200 nm;   d. drying said product solution to form an antimicrobial metal salt powder comprising 0.01 to about 10 weight % metal in the antimicrobial metal salt powder.   
     
     
         2 . The process of  claim 1  wherein said second solution has a metal agent concentration of at least about 1500 ppm. 
     
     
         3 . The process of  claim 1  wherein the dispersing agent is present in said second solution in a concentration between about 20 and about 50 w/w%. 
     
     
         4 . The process of  claim 1  wherein said first solution has a salt precursor concentration of at least about 1500 ppm. 
     
     
         5 . The process of  claim 1  wherein said first solution has a salt precursor concentration of at least about 5000 ppm. 
     
     
         6 . The process of  claim 1  wherein said first solution has a salt precursor concentration of about 5000 ppm to about 50,000 ppm. 
     
     
         7 . The process of  claim 1  wherein said mean particle size is less than about 100 nm. 
     
     
         8 . The process of  claim 1  wherein said mean particle size is less than about 50 nm. 
     
     
         9 . The process of  claim 1  wherein said first and second solutions are aqueous solutions. 
     
     
         10 . The process of  claim 1  wherein said product solution has a viscosity of less than about 50 cps. 
     
     
         11 . The process of  claim 1  wherein said first solution is stirred as said second solution is added. 
     
     
         12 . The process of  claim 9  wherein said solutions are maintained at a pressure between about ambient and about 40 mbar during said adding step. 
     
     
         13 . (canceled) 
     
     
         14 . The process of  claim 1  wherein at least one of said first and second solution comprises at least one solvent and said powder comprises less than about 10 wt % of said solvent. 
     
     
         15 . The process of  claim 14  wherein said powder comprises less than about 5% of said solvent. 
     
     
         16 . The process of  claim 14  wherein said solvent comprises water. 
     
     
         17 - 18 . (canceled) 
     
     
         19 . The process of  claim 1  wherein said polyvinyl pyrrolidone and metal agent are present in said second solution in a molar ratio of at least about 1.5. 
     
     
         20 . The process of  claim 1  wherein said metal salt powder comprises at least one metal salt having a K sp  of less than about 2×10 −10  in pure water at 25° C. 
     
     
         21 . (canceled) 
     
     
         22 . The process of  claim 1  wherein said second solution has a metal agent concentration of at least about 5000 ppm. 
     
     
         23 . The process of  claim 1  wherein said second solution has a metal agent concentration of about 5000 ppm to about 50,000 ppm. 
     
     
         24 . A process comprising
 a. forming a first solution comprising Nal;   b. forming a second solution comprising a complex formed from silver acetate and polyvinyl pyrrolidone in a particle size stabilizing effective amount;   c. adding said second solution to said first solution at a rate sufficient to maintain a clear solution throughout addition and to form a product solution comprising stabilized Agl particles having a mean particle size of less than about 200 nm;   d. drying said product solution to form an antimicrobial Agl powder comprising 0.01 to about 10 weight % Ag in the antimicrobial Agl powder.