A semi-finished product for electrical engineering is described, which is a composite of an aluminum sheet and a copper sheet. According to this disclosure, the semi-finished product bears an acrylate-based protective layer, which has been applied as a lacquer, which contains at least one photoinitiator and has been cured under the effect of light to form acrylate polymer, preferably acrylate copolymer. This disclosure also relates to an unfinished product produced from such a semi-finished product. A method for producing such a semi-finished product is also described.