Abstract: Vehicles, which are water dilutable after neutralization with bases, have an acid number of 5 to 60 and are obtainable by polymerization or copolymerization of 10 to 90 parts by weight of one or several acidic, phosphoric acid-functional unsaturated monomers, which are polymerizable by a free radical mechanism and can be present in admixture with one or several ethylenically unsaturated monomers, which are also polymerizable by a free radical mechanism, with addition of a free radical initiator, in the presence of 90 to 10 parts by weight of one or several epoxide resins or modified epoxide resins, in one or several solvents. Methods of synthesizing them, aqueous coating materials containing them and their use.