Patent ID: 7700662
Filing Date: 2010-04-20
Classification: C08G,C09D

Abstract:
1. Process for preparing radiation-curing allophanate-containing prepolymers having residual monomer contents of less than 0.5% by weight and an NCO content of less than 1% by weight, wherein A) diisocyanates, B) hydroxy-functional compounds which contain groups which react, with polymerization, with ethylenically unsaturated compounds on exposure to actinic radiation, and C) polyester, polyether or polycarbonate polyols having a functionality of 1.9 to 2.1 and a number-average molecular weight (M D) optionally in the presence of a catalyst are used to form NCO-group-containing prepolymers having radiation-curing groups, which are subsequently reacted E) optionally after addition of monofunctional isocyanates in the presence F) of an allophanatization catalyst to give allophanate-containing prepolymers, the ratio of NCO groups of the compounds from A) to the OH groups of the compounds from B) and C) being 1.45:1.0 to 1.1 :1.0 and the ratio of the OH groups from B) to the OH groups from C) being 8.0:1 to 1.5:1.