A curable epoxy resin composition including at least an epoxy resin component and a hardener component, and optionally further additives, wherein: (a) the epoxy resin component is an epoxy resin compound or a mixture of such compounds; (b) the hardener component includes (b1) an aliphatic and cycloaliphatic or aromatic polycarbonic acid anhydride; and (b2) a polyether-amine of the general formula (I), H2N—(CnH2n—O)m—CnH2n—NH2, wherein n is an integer from 2 to 8; and m is from about 3 to about 100; (c) the polycarbonic acid anhydride [component (b1)] is present in the curable epoxy resin composition in a concentration of 0.60 Mol to 0.93 Mol; and (d) the polyether-amine of the general formula (I) [component (b2)] is present in the curable epoxy resin composition in a concentration of about 0.02 Mol to about 0.1 Mol.