Humidity resistant aqueous urethane resins based on hydrophobic polyhydroxy compounds and coatings

摘要

A water reducible polyurethane resin for use in coating compositions is provided with humidity resistance at relatively low cost by employing a urethane prepolymer which is the reaction product of (i) a polyisocyanate, (ii) a polyhydroxy compound which is the reaction product of an organic acid and an epoxy compound, at least one of which includes a hydrocarbon group of at least six carbon atoms, and (iii) a monomer having an anionic group and functionality reactive with isocyanate. Preferred embodiments employ C.sub.36 dimer diacid and the propylene oxide ester of neodecanoic acid to make the polyhydroxy compound.