Metal-plastic hybrid materials with steel and/or zinc and/or alloys thereof as metal component

A method for preparing a metal-plastic hybrid material, said material comprising a substrate having at least one metallic surface and at least one thermoplastic material applied onto said metallic surface of the substrate, the method comprising at least steps 1) and 3) and optionally step 2):

• 1) applying an aqueous acidic composition at least in portion onto the at least one metallic surface of the substrate to form a film at least in portion on said surface,
• wherein the metallic surface is made at least partially of at least one kind of steel and/or zinc and/or of at least one alloy thereof, and
• wherein the acidic aqueous composition comprises, besides water, at least one water-soluble polymer having least one kind of functional group selected from the group consisting of acid groups, hydroxyl groups, amino groups, and mixtures thereof as at least one constituent a1),
• and optionally drying or curing the film to form a dried or cured layer,
• 2) optionally applying at least one thermoplastic polymeric material TM1 in form of a foil at least in portion onto the film or onto the dried or cured layer obtained after step 1), and
• 3) injecting at least one thermoplastic polymeric material TM2, which is identical to or different from the thermoplastic material TM1 optionally applied in step 2), and which is present in molten state, at least in portion onto the film or onto the dried or cured layer obtained after step 1) or onto the foil optionally obtained after step 2) to form the metal-plastic hybrid material.