Multi-coat painting, especially for cars

摘要

A process for applying several coats of paint to an electrically conductive substrate, by applying (1) an electrophoretic primer coat, stoving the primer, directly applying (2) a coloured and/or special-effect coat and then applying (3) further overcoats as required. Coating composition (2) comprises an aqueous coating material containing pigments and a binder consisting of (A) 50-85 wt% hybrid binder based on (a1) polyesters and (a2) (meth)acrylic copolymers with a hydroxyl (OH) number of 100-350 mg/KOH/g and an acid number of 20-60 mg KOH/g, (B) 0-20 wt% binder other than (A) and (C) 15-50 wt% free or blocked polyisocyanate and/or triazine-based crosslinker(s) which react with the OH groups in (A) to form ether and/or ester groups. At least 50 wt% copolymer (a2) is produced in presence of at least 20 wt% of polyester (a1).