Carbamate functional addition polymers and a method for their preparation

Abstract

A carbamate or terminal urea functional vinyl polymer is prepared by reacting a compound having an hydroxyl group and a carbamate group, terminal urea group, or a group that can be converted to a carbamate or terminal urea group, with a cyclic carboxylic acid anhydride group to form an ester bond and a free acid group from the anhydride; and reacting the free acid group with a compound having an epoxide group. The cyclic carboxylic acid anhydride group may be pendant to a vinyl polymer, or one of the compound having an hydroxyl group, a compound having the cyclic carboxylic acid anhydride group, and the compound having an epoxide group may have polymerizable ethylenic unsaturation that is polymerized, optionally with one or more copolymerizable monomers to form a vinyl polymer. When the compound having an hydroxyl group has a group that can be converted to a carbamate or terminal urea group, the group is converted to the carbamate or terminal urea group after step (a). The carbamate or terminal urea functional vinyl polymer may be included in a coating composition. The coating composition may be applied to a substrate and cured to form a cured coating on the substrate.

What is claimed is:  
     
         1 . A process for preparing a carbamate or terminal urea functional vinyl polymer, comprising steps of: 
 (a) reacting a compound having an hydroxyl group and a carbamate group, terminal urea group, or a group that can be converted to a carbamate or terminal urea group, with a cyclic carboxylic acid anhydride group to form a half-ester product with a free acid group; and    (b) reacting the free acid group with an epoxide group,    wherein either 
 (1) one of the cyclic carboxylic acid anhydride group or the epoxide group is pendant to a vinyl polymer or  
 (2) one of the compound having an hydroxyl group, a compound having the cyclic carboxylic acid anhydride group, and a compound having an epoxide group has polymerizable ethylenic unsaturation, said ethylenic unsaturation being polymerized, optionally with one or more copolymerizable monomers, to form a vinyl polymer after reaction of the compound in step (a) or step (b);  
   and further wherein, when the compound having an hydroxyl group has a group that can be converted to a carbamate or terminal urea group, the group is converted to the carbamate or terminal urea group after step (a).    
     
     
         2 . A process according to  claim 1 , wherein the cyclic carboxylic acid anhydride group is pendant to a vinyl polymer.  
     
     
         3 . A process according to  claim 2 , wherein the vinyl polymer is a copolymer of maleic anhydride.  
     
     
         4 . A process according to  claim 1 , wherein the epoxide group is pendant to a vinyl polymer.  
     
     
         5 . A process according to  claim 1 , wherein the compound having the hydroxyl group has a carbamate or carbonate group.  
     
     
         6 . A process according to  claim 1 , wherein the cyclic carboxylic acid anhydride group is provided by maleic anhydride.  
     
     
         7 . A process according to  claim 1 , wherein the cyclic carboxylic acid anhydride group is provided by a member selected from the group consisting of fumaric anhydride, itaconic anhydride, alkyl-substituted maleic anhydride, and the Diels Alder products of maleic anhydride and conjugated dienes.  
     
     
         8 . A process according to  claim 1 , wherein the compound having the hydroxyl group is an hydroxy carbamate or hydroxy carbonate compound.  
     
     
         9 . A process according to  claim 1 , wherein the vinyl polymer has residual acid groups.  
     
     
         10 . A process for preparing a carbamate or terminal urea functional vinyl polymer, comprising steps of: 
 (a) reacting a compound having an hydroxyl group and a carbamate group, terminal urea group, or a group that can be converted to a carbamate or terminal urea group, with a copolymer of maleic anhydride to form a half-ester product with a free acid group; and    (b) reacting the free acid group with a monoepoxide compound.    
     
     
         11 . A process according to  claim 10 , wherein the compound having an hydroxyl group is glycerine carbonate or an hydroxyalkyl carbamate selected from the group consisting of hydroxyethyl carbamate, hydroxypropyl carbamate, and hydroxybutyl carbamate.  
     
     
         12 . A process according to  claim 11 , wherein the hydroxyalkyl carbamate comprises up to 15% by weight of an alkylcarbonate precursor.  
     
     
         13 . A coating composition, comprising a vinyl polymer having a monomer unit selected from the group consisting of  
       
         
           
           
               
               
           
         
       
       , wherein Y is a carbamate or urea group, R 1  and R 3  are each independently alkyl groups having from 1 to 12 carbon atoms, optionally including oxygen or other heteroatoms, R 2 , R 4  and R 5  are each independently H or alkyl of 1 to 4 carbon atoms, R 6  and R 7  are each independently H or an alkyl group having from 1 to 12 carbon atoms or R 6  and R 7  together are part of a cycloaliphatic structure, optionally including oxygen or other heteroatoms in the alkyl group or cycloaliphatic structure, and R 8  is an alkynyl group having an ethylene group in the polymer backbone.  
     
     
         14 . A coating composition, comprising a carbamate or terminal urea functional vinyl polymer prepared by the process of  claim 1 .  
     
     
         15 . A coating composition according to  claim 14 , comprising a further compound, said further compound having carbamate functionality.  
     
     
         16 . A coating composition according to  claim 14 , further comprising a crosslinker reactive with active hydrogen groups.  
     
     
         17 . A composite coating on a substrate, comprising a first coating layer obtained by applying and curing the coating composition of  claim 16  and a second coating layer different from the first coating layer.  
     
     
         18 . A composite coating according to  claim 17 , wherein said first coating layer is a clearcoat layer and said second coating layer is a basecoat layer.