Patent ID: 8865832

Claim:
A tin-free, radiation-curable aqueous dispersion based on one or more polyurethane acrylates (i), wherein said one or more polyurethane acrylates (i) is prepared by reacting A) one or more compounds comprising at least one group which is reactive with isocyanate and at least one unsaturated group which can undergo free radical polymerization; B) one or more compounds which differ from A) selected from the group consisting of monomeric monols, monomeric diols, monomeric triols, oligomeric hydroxy-functional compounds, and polymeric hydroxy-functional compounds, and which comprise at least one group which is reactive with isocyanate; C) one or more compounds comprising at least one group which is reactive with isocyanate and at least one group having a hydrophilizing action; and D) one or more organic polyisocyanates; in the presence of a catalyst comprising F) one or more bismuth(III) salts; and G) an acid having a pKa of less than 2.5.