Abstract: A rubber mixture is provided for direct bonding to metal surfaces, and includes a base of natural and/or synthetic rubber which contains fillers, processing aids, vulcanizing agents, a bonding agent in the form of a phenol, or derivatives thereof, which form phenolic resins with formaldehyde, a source of formaldehyde, and metallic compounds, preferably oxides of metals, the outer electron shell of which has 2s electrons. The metallic compounds are present in a measured quantity which is about 30 to 400 mMol above the conventional dosage of 40 to 60 mMol for activating the polymerization, with this measured quantity being applicable to each 100 g of rubber. The measured quantity of bonding agent ranges from two to four times the conventional quantity of 40 mMol per 100 g rubber.