Patent ID: 6465596
Filing Date: 2002-10-15
Classification: C08G

Abstract:
A process for preparing linear oligourethanes and polyurethanes comprising:1) forming a reaction product containing both one free isocyanate group and one free isocyanate reactive group by reacting a) at least one diisocyanate with b) at least one compound having two isocyanate reactive groups in a 1:1 molar ratio, wherein the isocyanate groups of a) and/or the isocyanate reactive groups of b) have differing reactivities toward the isocyanate reactive groups or the isocyanate groups, respectively, of the other reactant and wherein the free isocyanate reactive group, the free isocyanate group, or both are the least reactive of b) and a) respectively; and 2) reacting the product of step 1) intermolecularly to form a linear oligourethane or linear polyurethane.