Aq. base coat compsn. for direct application to electrophoretic primer

摘要

A multi-coat painting process for metal substrates comprises (a) applying and stoving an electrophoretic primer, (b) applying a water-based coloured and/or effect basecoat (I) directly onto the stoved primer with no other intermediate coats, and opt. (c) applying a clearcoat. Basecoat compsn. (I) contains water-dilutable binder(s) with no OH gps. or with an OH gp. content corresp. to an OH no. of less than 10 mg KOH/g (II) and di- and/or poly-isocyanate(s) contg. 4-45 g free NCO gps. per 100 g binder solids, with a ratio of (free NCO gps.): (OH gps. in the binder) of more than 5:1.