Heat-curing one-component adhesives which are based on polyurethanes derived from A) a hardener component comprising polyaddition products containing hydroxyl and uretdione groups, B) a binder component comprising 1,2-epoxide compounds having more than one 1,2-epoxide group and one or more hydroxyl groups in the molecule, optionally C) further hydroxyl-containing compounds and optionally D) auxiliaries and additives known from adhesives technology; a process for preparing these compounds and to their use as heat-curing, one-component, solvent-free, thermally stable and solvent-resistant polyurethane (PU) adhesives which do not give off elimination products.