A curable mixture which includes at least (a) 10 to 100 percent by weight, in relation to the sum of the components (a) and (b), of at least one bi- or polyfunctional aromatic cyanate or a prepolymer formed from at least one bi- or polyfunctional aromatic cyanate or a mixture formed from the abovementioned cyanates and/or prepolymers; (b) 0 to 90 percent by weight, in relation to the sum of the components (a) and (b), of at least one mono-, bi- or polyfunctional epoxy resin; (c) 0.5 to 30 percent by weight, in relation to the sum of the components (a) and (b), of at least one mono-, bi- or polyfunctional aromatic amine; and (d) 0 to 5 percent by weight, in relation to the sum of the components (a) and (b), of at least one catalyst from the group consisting of transition metal compounds and boron trihalides.