Two stage cure two component coating composition containing hydroxyl butyl acrylate polymers

Abstract

An acrylic oligomer useful in a two stage curing coating composition having a weight average molecular weight of 100 to 3000, a polydispersity of 1.01 to 1.7 and one or more reactive functionalities reactive with isocyanate groups and having 7.0 to 40.0 weight percent, based on the weight of the acrylic oligomer, of hydroxyl moieties wherein at least 40.0 to 70.0 weight percent of the hydroxyl moieties are provided by hydroxy butyl acrylate and the remaining hydroxyl moieties are provided by fast reacting hydroxyl constituents of hydroxy ethyl acrylate, hydroxy ethyl methacrylate or any mixtures thereof and by slow reacting hydroxyl constituents of secondary hydroxyl containing hydroxy propyl acrylate and secondary hydroxyl containing hydroxy propyl methacrylate and any mixtures thereof.

1 . An acrylic oligomer having a weight average molecular weight in the range of 100 to 3000, a polydispersity of 1.01 to 1.7 and one or more reactive functionalities reactive with isocyanate groups and having in the range of 7.0 to 40.0 weight percent, based on the weight of the acrylic oligomer, of hydroxyl moieties wherein at least 40.0 to 70.0 weight percent of the hydroxyl moieties are provided by hydroxy butyl acrylate and the remaining hydroxyl moieties are provided by fast reacting hydroxyl constituents selected from the group consisting of hydroxy ethyl acrylate, hydroxy ethyl methacrylate and any mixtures thereof and by slow reacting hydroxyl constituents selected from the group consisting of secondary hydroxyl containing hydroxy propyl acrylate and secondary hydroxyl containing hydroxy propyl methacrylate and any mixtures thereof.  
   
   
       2 . The acrylic oligomer of  claim 1  having a weight average molecular weight of 500-1500.  
   
   
       3 . The acrylic oligomer of  claim 1  wherein the oligomer is linear oligomer.  
   
   
       4 . The acrylic oligomer of  claim 1  wherein the oligomer is a branched oligomer.  
   
   
       5 . The acrylic oligomer of  claim 1  comprising in addition to the hydroxyl containing moieties polymerized monomers selected from the group consisting of styrene, alkyl styrene; vinyl toluene; acrylonitrile; alkyl (meth)acrylates having 1-18 carbon atoms in the alkyl group, cycloaliphatic (meth)acrylates, isobornyl (meth)acrylate; aryl (meth)acrylates and any mixtures thereof.  
   
   
       6 . The oligomer of  claim 1  comprising in addition to the hydroxyl containing moieties, polymerized monomers selected from the group consisting of methyl methacrylate, butyl methacrylate and isobornyl methacrylate.