Flame-resistantly formulated, flowable, latently reactive, phenolically curable epoxy-resin moulding compounds for the encapsulation of electronic components containing the following components:an epoxy-resin component obtained from a solvent-free reaction resin mixture of polyepoxy resin and polyisocyanate resin having a molar ratio of the epoxy groups to the isocyanate groups of 1.1 to 4 at a reaction temperature of up to 220.degree. C. in the presence of a reaction accelerator in a concentration of 0.5 to 2.5% and using triphenylphosphine oxide in a concentration of 0.05 to 10%, relative in each case to the reaction resin mixture,a hardener component containing at least two phenolic hydroxyl groups per molecule,inorganic filler,and standard additives.