Patent ID: 7902302

Claim:
A hydroxy-functional polyester-polyurethane dispersion comprising a reaction product of: (a) at least one, at least difunctional polyol component; (b) at least one ionizable compound having at least one acid group and at least one functional group capable of reacting with isocyanate groups, the at least one functional group selected from the group consisting of mono-, di-, and trihydroxycarboxylic acids, hydroxysulfonic acids, aminosulfonic acids, and aminocarboxylic acids; (c) at least one acid anhydride; and (d) at least one, at least difunctional polyisocyanate component; wherein the at least one, at least difunctional polyol component comprises at least 75 wt. % of a first polyester polyol having a weight average molecular weight of 900 to 2500 g/mol and an average functionality of 2 to 3.5 and a secondary component selected from the group consisting of polyether polyols, polycarbonate polyols having weight average molecular weight of 800 to 6000 g/mol and a functionality of 2 to 3.5, and second polyester polyols which differ from the first polyester polyol, and wherein the secondary component is present in an amount up to 25 wt. %.