Method for forming coating film and coated article

A method for forming a multilayer coating film comprising:

• applying one or more base coating compositions (Y) in at least one layer to a substrate to form a base coating film in at least one layer;
• applying one or more clear coating compositions (Z) to the above uncured base coating film formed in at least one layer;
• and
• simultaneously curing the at least one layer of uncured base coating film and the above uncured clear coating film,
• wherein the one or more clear coating compositions (Z) comprises:
• a hydroxy-containing acrylic resin (A) having a hydroxy value in the range of 85 to 215 mg KOH/g,
• a polyisocyanate compound (B) having a viscosity at 25° C. in the range of 200 to 4,000 mPa·s,
• an organometallic catalyst (C) containing a metallic compound (C1) in which the metal is a member selected from the group consisting of zinc, tin, zirconium, bismuth, lead, cobalt, manganese, titanium, aluminum and molybdenum, and an amidine compound (C2), and
• an organic solvent,
• wherein the equivalent ratio (NCO/OH) of isocyanate groups in the polyisocyanate compound (B) to hydroxy groups in the hydroxy-containing acrylic resin (A) is in the range of 0.8 to 1.8.