Patent ID: 8362142

Claim:
An aqueous polyurethane dispersion containing polyurethane solids and a non-aqueous, organic solvent content of less than 5 weight percent wherein the polyurethane solids are obtained from a polyurethane prepolymer prepared by reacting a) a polyol comprising ai) from 92 to 99 wt % of a polyol or polyol blend having a mean average equivalent weight of 150 to 600 and a nominal average functionality of from 1.5 to 2.9 and aii) from 1 to 8 wt % of at least one polyol having a nominal functionality of 5 to 8; and an equivalent weight of 100 to 170; (b) at least one aliphatic polyisocyanate; (c) optionally additional stabilizers; and (d) optionally chain extenders wherein the prepolymer has an isocyanate (NCO) content of from 2 to 20 wt %, and wherein the solids content of the dispersion is from 30 to 60 weight percent.