Process for preparing thiosulfate salt polymers

Abstract

This invention relates to a method of preparing a thiosulfate salt containing polymer comprising reacting at least one thiosulfate salt with at least one halogenated styrenic monomer to form a styrenic thiosulfate salt monomer represented by Formula (1); wherein X is a cationic counter ion; R 1 is a substituent; and R 2 is a divalent linking group; and polymerizing the styrenic thiosulfate salt monomer in the presence of an initiator.

What is claimed is:  
     
         1 . A method of preparing a thiosulfate salt containing polymer comprising reacting at least one thiosulfate salt with at least one halogenated styrenic monomer to form a styrenic thiosulfate salt monomer represented by Formula (1);  
       
         
           
           
               
               
           
         
       
       wherein X is a cationic counter ion; R 1  is a substituent; and R 2  is a divalent linking group; and polymerizing the styrenic thiosulfate salt monomer in the presence of an initiator.  
     
     
         2 . The method of  claim 1  wherein X is sodium, potassium, magnesium, or ammonium.  
     
     
         3 . The method of  claim 1  wherein R 1  is either a hydrogen or halide atom, a substituted or unsubstituted alkyl group of 1 to 16 carbon atoms, a substituted or unsubstituted aryl group of 6 to 16 carbons, a substituted or unsubstituted heteroaryl group of 4 to 16 atoms, or a cyano group.  
     
     
         4 . The method of  claim 1  wherein R 2  is a substituted or unsubstituted alkylene group of 1 to 8 carbon atoms that can have one or more oxygen, nitrogen or sulfur atoms in the chain, or a substituted or unsubstituted arylenealkylene group of 7 to 16 carbons.  
     
     
         5 . The method of  claim 4  wherein R 2  is a substituted or unsubstituted alkylene group of 1 to 8 carbon atoms.  
     
     
         6 . The method of  claim 1  wherein said thiosulfate monomer is prepared in a mixture of water and at least one water miscible solvent.  
     
     
         7 . The method of  claim 6  wherein the water miscible solvent is acetone, 2-butanone, methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, tert-butanol, methyl sulfoxide, dimethyl formamide, n-methyl pyrrolidinone, ethylene glycol, methyl ethyl ketone, tetrahydrofuran, di(propylene glycol)methyl ether, or propylene glycol.  
     
     
         8 . The method of  claim 1  wherein the thiosulfate salt and the halogenated styrenic monomer are reacted at a temperature of 50° C. to 80° C.  
     
     
         9 . The method of  claim 1  wherein the styrenic thiosulfate salt monomer is polymerized in the presence of at least one additional ethylenically unsaturated monomer to produce a copolymer.  
     
     
         10 . The method of  claim 9  wherein at least one additional ethylenically unsaturated monomer is fed to the reaction mixture over a period of time.  
     
     
         11 . The method of  claim 1  wherein the polymerization step is carried out under an air or any inert atmosphere at a temperature from 10° C. to about 100° C.  
     
     
         12 . The method of  claim 1  wherein the initiator is a free radical initiator.  
     
     
         13 . The method of  claim 12  wherein the free radical initiator is a peroxide or an azo.  
     
     
         14 . The method of  claim 13  wherein the free radical initiator is 2,2′-azobis(2,4-dimethylpentanenitrile), or 2,2′-azobis(2-methylpropanenitrile).  
     
     
         15 . The method of  claim 1  wherein the polymerization step is conducted in the presence of an added surfactant.  
     
     
         16 . The method of  claim 1  wherein the styrenic thiosulfate monomer is not isolated or purified prior to the polymerization step.  
     
     
         17 . The method of  claim 1  wherein the styrenic thiosulfate monomer is polymerized with 
 (a) about 10 percent to about 99 percent, by weight, of methyl methacrylate; and,  
 (b) up to 20 percent, by weight, of a comonomer selected from the group consisting of methyl acryl ate, ethyl acryl ate, butyl acrylate, butyl methacrylate, hydroxyethyl methacrylate, acrylic acid, styrene, acrylamide, (meth)acrylonitrile, vinyl acetate, vinyl pyridine, vinylpyrrolidone, or methacrylic acid.  
 
     
     
         18 . A method of preparing a thiosulfate salt containing polymer comprising reacting at least one thiosulfate salt with at least one halogenated styrenic monomer to form a styrenic thiosulfate salt monomer represented by Formula (1)  
       
         
           
           
               
               
           
         
       
       wherein X is a cationic counter ion; R 1  is a substituent; and R 2  is a divalent linking group; wherein the styrenic thiosulfate monomer is not isolated or purified prior to the next step; 
 combining the thiosulfate monomer with at least one additional ethylenically unsaturated monomer, wherein the total additional monomer utilized is from 0 to about 99 weight percent based on the total weight of monomers;  
 diluting the monomers in an appropriate solvent;  
 adding a free radical initiator, and  
 maintaining the reaction mixture under an air or any inert atmosphere at a reaction temperature of from about 10° C. to about 100° C. during the polymerization.  
 
     
     
         19 . The method of  claim 18  wherein X is sodium, potassium, magnesium, or ammonium; R 1  is either a hydrogen or halide atom, a substituted or unsubstituted alkyl group of 1 to 16 carbon atoms, a substituted or unsubstituted aryl group of 6 to 16 carbons, a substituted or unsubstituted heteroaryl group of 4 to 16 atoms, or a cyano group; and R 2  is a substituted or unsubstituted alkylene group of 1 to 8 carbon atoms that can have one or more oxygen, nitrogen or sulfur atoms in the chain, or a substituted or unsubstituted arylenealkylene group of 7 to 16 carbons.  
     
     
         20 . The method of  claim 18  wherein the free radical initiator is a peroxide or an azo.  
     
     
         21 . The method of  claim 1  wherein an additional amount of initiator, either the same or different, is added either in a semicontinuous fashion or in one portion at the end of the reaction period.