Patent ID: 6548696
Filing Date: 2003-04-15
Classification: C08G

Abstract:
A 1:1-monoadduct of a diisocyanate and a hydroxy(meth)acrylate, prepared by reacting a diisocyanate with a hydroxy(meth)acrylate at a molar ratio of 5-20 moles of the diisocyanate to 1 mole of the hydroxyl(meth)acrylate, and at a temperature of 40-120Â° C. in the presence of at least one inhibitor, until the hydroxyl groups of the hydroxy(meth)acrylate are fully reacted with the diisocyanate, thereby providing a reaction product comprising the 1:1-monoadduct and unreacted diisocyanate;contacting the reaction product with air, nitrogen monoxide or oxygen or a mixture comprising (a) air, oxygen or nitrogen monoxide, and (b) 1-90% by volume of carbon dioxide, nitrogen, an inert gas or a mixture thereof while separating unreacted diisocyanate from the reaction product by short-path distillation at 80-220Â° C./0.1-10 mbar; wherein after said separation the monoadduct has a free diisocyanate content of less than 0.7% by weight and a free NCO content of 10.4-16.4% by weight.