Ionic group-having hot-melt adhesive

radiation curable hot melt adhesives containing more than 30%, based on the hotmelt adhesive of at least one polyurethane polymer containing at least one radiation-polymerizable reactive group, produced by reacting a) a reactive PU prepolymer (A) having two or three NCO groups per molecule and at least one carboxyl group or a tertiary amino group, produced from i) a mixture of at least one di- or trifunctional polyol selected from polyether polyols or polyester polyols having a molecular weight between 200 to 5000 g / mol with a diol components, which still further comprises a carboxyl group or a tertiary amino group, is reacted with ii) an excess of at least one di- or triisocyanate having a molecular weight below 500 g / mol, b) 20 to 98 mol% of at least one low molecular weight compound (B) containing a radical polymerizable double bond and one reactive with an NCO group group, and c) 0 to 50 mol% of at least one compound (C) having at least one reactive towards NCO groups group, but no polymerizable group under free radical conditions, having a molecular weight of 32 to 5000 g / mol and d) 2 to 50 mol% of at least one free-radical photoinitiator (D) having a primary or secondary OH group, wherein the specifying related to the NCO groups of the PU prepolymer and is said to give% the sum of B, C, D 100 mol, and other excipients if necessary.