| CPC C09D 175/16 (2013.01) [C08G 18/0823 (2013.01); C08G 18/348 (2013.01); C08G 18/5015 (2013.01); C08G 18/6692 (2013.01); C09D 7/20 (2018.01); C09D 7/65 (2018.01); C09D 175/08 (2013.01); C09D 175/14 (2013.01)] | 11 Claims |
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1. A waterborne, UV curable coating composition, comprising an aqueous dispersion of a polyurethane and at least one non-fluorinated polymer different from the polyurethane, wherein the polyurethane is present as an additive in an amount 0.1-5 wt. % based on resin solids of the coating composition, and wherein the polyurethane is a carboxyl-functional, unsaturated polyurethane containing a perfluoropolyether block, said polyurethane having a molecular weight Mn in the range from 1,000 to 5,000 determined by gel permeation chromatography with a polystyrene standard and tetrahydrofuran as the mobile phase, said polyurethane prepared by a method comprising the following steps:
a) subjecting a hydroxy-terminated perfluoropolyether A to a reaction with a molar excess of polyisocyanate B to obtain an isocyanate-functional urethane,
b) subjecting the isocyanate-functional urethane to a reaction with a carboxyl-functional polyol D to obtain an isocyanate-functional polymer,
c) subjecting the isocyanate-functional polymer obtained in step b) to a reaction with a mono-OH-functional (meth)acrylate monomer E,
d) neutralizing the reaction product of step c) with a neutralizer G to obtain a neutralized polyurethane,
e) dispersing the neutralized polyurethane obtained in step d) in water;
and wherein the method does not include chain extension with a diamine or a diol after dispersing the neutralized polyurethane in water.
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