| 摘要 |
Preparation of radiation-curing allophanate-containing prepolymers comprises using diisocyanates, hydroxy-functional compounds, which contain groups, which react, with polymerization, with ethylenically unsaturated compounds on exposure to actinic radiation, and polyester, polyether, or polycarbonate polyols having a functionality of >=1.9 and a number-average molecular weight of >=1000 g/mol, in the presence of an allophanatization catalyst to give allophanate-containing prepolymers. Preparation of radiation-curing allophanate-containing prepolymers having residual monomer contents of less than 0.5 wt.% and isocyanate (NCO) content of less than 1 wt.%, comprises using (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 and a number-average molecular weight (M n) of >=1000 g/mol, (D) optionally in the presence of a catalyst, to form NCO-group-containing prepolymers having radiation-curing groups, which are subsequently reacted optionally after addition of monofunctional isocyanates, in the presence of an allophanatization catalyst to give allophanate-containing prepolymers, where the ratio of NCO groups of the compounds from (A) to the hydroxyl (OH) groups of the compounds from (B) and (C) is 1.45:1.0-1.1:1.0 and the ratio of OH groups from (B) to the OH groups from (C) is 8.0:1-1.5:1. An independent claim is included for coating compositions comprising radiation-curing allophanate-containing prepolymer(s); optionally polyisocyanate(s) containing free or blocked isocyanate groups, which are free from groups, which react, with polymerization, with ethylenically unsaturated compounds on exposure to actinic radiation; optionally other compounds, different from radiation-curing allophanate-containing prepolymer, which contain groups, which react, with polymerization, with ethylenically unsaturated compounds on exposure to actinic radiation, and optionally contain free or blocked NCO groups; optionally isocyanate-reactive compound(s) containing active hydrogen; optionally initiators; and optionally auxiliaries and additives. |
