Process for cross-linking an acrylic polymer or copolymer or an acrylic derivative of a copolymer and the cross-linked acrylic polymer thereby obtained

Abstract

A cross-linked acrylic polymer that is highly biocompatible is prepared from a water-soluble acrylamide monomer by preparing an aqueous polymerization solution containing an acrylamide monomer and a catalyzing agent; polymerizing the monomer present in the polymerization solution by agitating and heating the polymerization solution. The polymerization is conducted in the presence of gaseous oxygen.

1 - 12 . (Canceled)  
     
     
         13 . A cross-linked acrylic polymer, comprising: 
 in polymerized form at least one water-soluble acrylamide monomer;    wherein said cross-linked acrylic polymer is in the form of a hydrogel with imide-amide cross links.    
     
     
         14 . The cross-linked acrylic polymer according to  claim 13 , wherein said hydrogel with imide-amide cross links is represented by the following formulas  
       
         
           
           
               
               
           
         
         wherein R is an alkylene group.  
       
     
     
         15 . The cross-linked acrylic polymer according to  claim 13 , having a pH between 6.5 and 7.5.  
     
     
         16 . The cross-linked acrylic polymer according to  claim 13 , having a dry residue between 3 and 4.  
     
     
         17 . The cross-linked acrylic polymer according to  claim 13 , which is insoluble in water.  
     
     
         18 . A cross-linked chelated acrylic polymer, comprising: 
 in polymerized form at least one water-soluble acrylamide monomer; and    a chelating metal cation;    wherein said cross-linked chelated acrylic polymer is in the form of a hydrogel with imide-amide cross links.    
     
     
         19 . The cross-linked chelated acrylic polymer according to  claim 18 , wherein said hydrogel with imide-amide cross links is represented by the following formulas  
       
         
           
           
               
               
           
         
       
       wherein R is an alkylene group.  
     
     
         20 . The cross-linked chelated acrylic polymer according to  claim 18 , having a pH between 6.5 and 7.5.  
     
     
         21 . The cross-linked chelated acrylic polymer according to  claim 18 , having a dry residue between 3 and 4.  
     
     
         22 . The cross-linked chelated acrylic polymer according to  claim 18 , which is insoluble in water.  
     
     
         23 . The cross-linked chelated acrylic polymer according to  claim 18 , wherein said chelating metal cation is aluminum, zirconium or titanium.  
     
     
         24 . A cross-linked acrylic copolymer, comprising: 
 in polymerized form    at least one water-soluble acrylamide monomer; and    a comonomer selected from the group consisting of N,N′-methylene-bis-acrylamide, N,N′-ethylene-bis-acrylamide and methylolacrylamide;    wherein said cross-linked acrylic polymer is in the form of a hydrogel with imide-amide cross links.    
     
     
         25 . The cross-linked acrylic polymer according to  claim 24 , comprising N,N′-methylene-bis-acrylamide.  
     
     
         26 . The cross-linked acrylic polymer according to  claim 24 , comprising N,N′-ethylene-bis-acrylamide.  
     
     
         27 . The cross-linked acrylic polymer according to  claim 24 , comprising methylolacrylamide.  
     
     
         28 . The cross-linked acrylic polymer according to  claim 24 , wherein said hydrogel with imide-amide cross links is represented by the following formulas  
       
         
           
           
               
               
           
         
         wherein R is an alkylene group.  
       
     
     
         29 . The cross-linked acrylic polymer according to  claim 24 , having a pH between 6.5 and 7.5.  
     
     
         30 . The cross-linked acrylic polymer according to  claim 24 , having a dry residue between 3 and 4.  
     
     
         31 . The cross-linked acrylic polymer according to  claim 24 , which is insoluble in water.  
     
     
         32 . The cross-linked acrylic polymer according to  claim 24 , comprising: 
 from 2 to 7% of acrylamide;    from 0.2 to 4% of N,N′-methylene-bis-acrylamide; and    from 0.1 to 4% of N,N′-ethylene-bis-acrylamide.    
     
     
         33 . The cross-linked acrylic polymer according to  claim 13 , which is biocompatible.  
     
     
         34 . The cross-linked acrylic polymer according to  claim 18 , which is biocompatible.  
     
     
         35 . The cross-linked acrylic polymer according to  claim 24 , which is biocompatible.  
     
     
         36 . A method of implanting, comprising: 
 injecting the cross-linked acrylic polymer according to  claim 13  into a subject in need thereof, to obtain a permanent capsule which isolates the cross-linked acrylic polymer from surrounding tissue.    
     
     
         37 . A method of implanting, comprising: 
 injecting the cross-linked acrylic polymer according to  claim 18  into a subject in need thereof, to obtain a permanent capsule which isolates the cross-linked acrylic polymer from surrounding tissue.    
     
     
         38 . A method of implanting, comprising: 
 injecting the cross-linked acrylic polymer according to  claim 24  into a subject in need thereof, to obtain a permanent capsule which isolates the cross-linked acrylic polymer from surrounding tissue.