New polymers by emulsion polymerization

A process for protecting metallic substrates against corrosion, comprising

• I) preparing by emulsion polymerization a polymer comprising as synthesis components in copolymerized form
• (A) at least one vinylaromatic compound,
• (B) at least one compound having two conjugated ethylenically unsaturated double bonds,
• (C) at least one ethylenically unsaturated compound selected from the group consisting of compounds having at least one amide function and hydroxyalkyl (meth)acrylates,
• (D) optionally at least one compound, other than the compounds (A) and (C), having an ethylenically unsaturated double bond, and
• (E) optionally at least one compound, other than compounds (B), having at least two ethylenically unsaturated double bonds,
• at least a portion of the monomers being metered into the reaction mixture during the polymerization over a certain time period or metering period,
• and less than half the total amount of the monomer (C) being metered into the reaction mixture in the first half of the metering period,
• II) optionally mixing the resultant polymer with at least one auxiliary selected from the group consisting of flow control agents, thickeners, defoamers, fillers, pigments, pigment dispersing assistants, corrosion inhibitors, and active anti-corrosion pigments,
• III) applying the coating material to the metallic substrate, and
• IV) drying the coating at a temperature from ambient temperature up to 100° C. over a period from a few minutes up to several days.