| abstract |
A polyurethane dispersion and a method of making are provided. The polyurethane dispersion is stable in a mixture of alcohol and water. The dispersion comprises the reaction product of (a) an isocyanate terminated polyurethane prepolymer comprising the reaction product of (i) at least one oligomeric polyactive hydrogen compound insoluble in said alcohol, wherein said polyactive hydrogen compound is an alkyl, aryl, or aralkyl structure optionally substituted by N, O, and S; (ii) at least one polyisocyanate, and (iii) at least one polyactive hydrogen compound soluble in said mixture of alcohol and water; (b) a polyfunctional chain extender; and (c) a monofunctional chain terminator; wherein the equivalent ratio of difunctional chain extender to prepolymer isocyanate is 0.60 to 1.20. |