Patent ID: 8153708
Filing Date: 2012-04-10
Classification: C08G

Abstract:
1. A process for forming a waterborne composite polyurethane/acrylic polymer dispersion, the process comprising: (a) introducing a reaction mixture to an organic solvent medium, the reaction mixture comprising: (b) allowing the reaction mixture to polymerize and yield a polyurethane polymer in the organic solvent medium, the polyurethane polymer having terminal isocyanate functional groups and pendant acid functional groups; (c) adding a monoamine to the organic solvent medium to neutralize pendant acid functional groups on the polyurethane polymer; (d) adding one or more ethylenically unsaturated monomers to the organic solvent medium; (e) inverting the organic solvent medium containing the polyurethane polymer and ethylenically unsaturated monomers into an aqueous medium containing one or more polyamines to form an aqueous dispersion; (f) adding a free radical polymerization initiator to the aqueous dispersion; (g) holding the aqueous dispersion at a temperature and for a time sufficient to polymerize the ethylenically unsaturated monomers and yield a waterborne composite polyurethane/acrylic polymer dispersion; and (h) heating the aqueous dispersion to a temperature and for a time sufficient to hydrolyze the alkyl carbonate.