Acrylic synthetic lubricant

Abstract

A synthetic lubricant comprising a relatively low-molecular-weight acrylic polymer.

1 . A synthetic lubricant comprising an acrylic polymer having: 
 (a) M n  at least 1,000 and no more than 20,000;    (b) residues of at least one alkyl(meth)acrylate monomer having a C 2 -C 22  alkyl group; and    (c) a terminal reactive group derived from a radical chain transfer agent.    
   
   
       2 . The lubricant of  claim 1  in which said at least one alkyl (meth)acrylate monomer has a C 4 -C 22  alkyl group.  
   
   
       3 . The lubricant of  claim 1  in which the acrylic polymer has a T g  no greater than 40° C.  
   
   
       4 . The lubricant of  claim 1  in which the terminal reactive group is a hydroxy or thiol group.  
   
   
       5 . The lubricant of  claim 1  in which the acrylic polymer has a total of no more than 50% residues derived from among styrene monomers, methacrylamide, methacrylamide monomers, methacrylate monomers, and methacrylic acid.  
   
   
       6 . The lubricant of  claim 1  in which the acrylic polymer is substantially free of carboxylic acid groups and amino groups.  
   
   
       7 . The lubricant of  claim 1  in which the acrylic polymer has M n  at least 2000 and no more than 10,000.  
   
   
       8 . The lubricant of  claim 1  in which the acrylic polymer has at least 50% of residues derived from C 4 -C 22  alkyl(meth)acrylates.  
   
   
       9 . The lubricant of  claim 1  in which the acrylic polymer has at least 20% of residues derived from C 8 -C 22  alkyl acrylates.