This invention relates to a method for forming a multi-layer coating,
comprising sequentially applying a primer surfacer, a basecoat, and a
clear coat composition on an automotive substrate in a wet-on-wet-on-wet
manner, and simultaneously curing the applied three layers together in a
single baking step, wherein the primer surfacer comprises: a film forming
binder, a volatile organic liquid carrier, and pigment(s); and the binder
contains about: (a) about 30 to 80% by weight, based on the weight of
the binder, of a hydroxyl functional polyester resin; (b) about 10 to 30%
by weight, based on the weight of the binder, of a crosslinking agent
selected from the group consisting of a melamine resin, a blocked
polyisocyanate resin, or a mixture thereof; (c) about 10 to 40% by
weight, based on the weight of the binder, of a dispersed graft polymer
comprising a non-crosslinked core of acrylic polymer which is
substantially non-soluble in non-polar organic solvent and, grafted to
the core, one end of an acrylic stabilizer in the form of a macromonomer,
said acrylic stabilizer being soluble in a non-polar organic solvent;
wherein the composition is, preferably, essentially free of crosslinked
nonaqueous dispersion resin particles or crosslinked microgel resin
particles or both, and the composition also contains at least one
non-polar organic solvent at the time of application. The resulting
multi-layered coating film has excellent aesthetic appearance, chipping
resistance, sag resistance, and film build even when formed in a three
wet layered application method.