Abstract: The present invention is directed to improved aqueous dispersions containing polyurethane/vinyl polymers. The improved aqueous dispersions comprise polymer particles of a urethane prepolymer having carboxyl functionality therein and a vinyl monomer polymerized thereon, which are shelf stable and self crosslinkable at a low temperature. The polyurethanes have pendant carboxyl functionality in quaternary form and pendant epoxide groups provided by glycidyl acrylates and/or methacrylates. When the aqueous dispersions are cast as film and the water is removed, crosslinking between the carboxyl group and the epoxide group occurs.