Process for converting a polymeric ester to a polymeric acid

Abstract

The present invention generally relates to processes for converting an ester group to an acid group for polymers having a pendant ester of an acid group. This process is generally performed using an aqueous strong base.

1 .- 57 . (canceled) 
     
     
         58 . A process for converting an ester group of a polymer to an acid group comprising:
 forming a reaction mixture being an aqueous suspension, the reaction mixture comprising an aqueous strong base solution and a polymer having a pendant ester of an acid group which hydrolyzes to produce a polymer comprising the pendant acid group or a salt thereof and an alcohol, wherein the polymer having a pendant ester of an acid group is a hydrophobic polymer in a bead form, and wherein the aqueous strong base solution comprises an alcohol.   
     
     
         59 . The process of  claim 58 , wherein the alcohol is methanol, ethanol, propanol, or a combination thereof. 
     
     
         60 . The process of  claim 58 , wherein the alcohol comprises methanol. 
     
     
         61 . The process of  claim 60 , wherein the concentration of the alcohol in the aqueous base solution is from about 5 wt. % to about 25 wt. % of the total weight of the base solution. 
     
     
         62 . The process of  claim 60 , wherein the concentration of the alcohol in the aqueous base solution is about 10 wt. % of the total weight of the base solution. 
     
     
         63 . The process of  claim 60 , wherein the reaction mixture is allowed to react for up to about 6 hours. 
     
     
         64 . The process of  claim 60 , wherein the reaction mixture is allowed to react for up to about 5 hours. 
     
     
         65 . The process of  claim 60 , wherein the reaction mixture comprises at least 10 kg of a polymer having a pendant ester of an acid group. 
     
     
         66 . The process of  claim 58 , wherein the polymer having a pendant ester of an acid group is crosslinked. 
     
     
         67 . The process of  claim 58 , wherein the polymer having a pendant ester of an acid group comprises structural units corresponding to Formulae 1 and 2, Formulae 1 and 3, or Formulae 1, 2, and 3, wherein
 Formula 1, Formula 2, and Formula 3 are represented by the following structures:   
       
         
           
           
               
               
           
         
       
       wherein
 R 1  and R 2  are each independently hydrogen, alkyl, cycloalkyl, or aryl; 
 A 31  is an ester of a carboxylic, phosphonic, or phosphoric group; 
 X 1  is arylene; and 
 X 2  is alkylene, an ether moiety, or an amide moiety. 
 
     
     
         68 . The process of  claim 58 , wherein the polymer having a pendant ester of an acid group comprises structural units corresponding to Formulae 1A, 2A, and 3A represented by the following structures: 
       
         
           
           
               
               
           
         
       
     
     
         69 . The process of  claim 58 , wherein the polymer having a pendant ester of an acid group comprises a reaction product of a polymerization mixture comprising monomers of Formulae 11, 22, and 33, wherein
 Formula 11, Formula 22, and Formula 33 are represented by the following structures:   
       
         
           
           
               
               
           
         
       
       and wherein
 R 1  and R 2  are each independently hydrogen, alkyl, cycloalkyl, or aryl; 
 A 31  is an ester of a carboxylic, phosphonic, or phosphoric acid group; 
 X 1  is arylene; and 
 X 2  is alkylene, an ether moiety, or an amide moiety. 
 
     
     
         70 . The process of  claim 58 , wherein the polymer having a pendant ester of an acid group comprises a reaction product of a polymerization mixture comprising monomers of Formulae 11, 22, and 33 and Formulae 11, 22, and 33 are represented by the following structures: 
       
         
           
           
               
               
           
         
       
     
     
         71 . The process of  claim 70 , wherein the alkyl group of the ester is a methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, 2-pentyl, 3-pentyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 3-methyl-2-butyl, 2,2-dimethyl-1-propyl, 1,1-dimethyl-1-propyl, n-hexyl, 2-hexyl, 3-hexyl, 2-methyl-1-pentyl, 2-methyl-2-pentyl, 2-methyl-3-pentyl, 3-methyl-1-pentyl, 3-methyl-2-pentyl, 3-methyl-3-pentyl, 4-methyl-1-pentyl, 4-methyl-2-pentyl, 2,2-dimethyl-1-butyl, 2,3-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 3,3-dimethyl-2-butyl, 2,3-dimethyl-2-butyl, or 2-ethyl-1-butyl. 
     
     
         72 . The process of  claim 60 , wherein the hydrophobic polymer having a pendant ester of an acid group comprises a methyl ester of poly-α-fluoroacrylic acid, the methyl ester of poly-α-fluoroacrylic acid is crosslinked with a crosslinking monomer, and the crosslinking monomer is divinyl benzene, 1,7-octadiene, or a combination thereof 
     
     
         73 . The process of  claim 58 , wherein the polymer content of an aqueous suspension of the polymer having a pendant ester of an acid group added to the reaction mixture is about 15 wt. % to about 30 wt. %. 
     
     
         74 . The process of  claim 73 , wherein the concentration of the aqueous strong base solution added to the reaction mixture is about 15 wt. to about 50 wt. %. 
     
     
         75 . The process of  claim 58 , wherein the reaction mixture comprises a substantially oxygen-free atmosphere comprising an inert gas and the inert gas is helium, neon, nitrogen, argon, krypton, xenon, or a combination thereof. 
     
     
         76 . The process of  claim 75 , wherein the temperature of the reaction mixture is about 55° C. to about 95° C.