Method of forming multi-layer coating on automobile bodies without a primer bake

A method for forming a multi-layer coating, said multi-layer coating comprising sequentially applying a layer of primer coating composition, applying a layer of base coating composition and a layer of clear coating composition on a substrate;

• and simultaneously curing the applied three layers by baking, wherein the primer coating composition comprises:
• a film forming binder and an organic liquid carrier, and optionally pigment in a pigment to binder weight ratio of about 1:100-150:100;
• and the binder contains about:
• (a) 50 to 90% by weight, based on the weight of the binder, of a film-forming acrylic polymer component comprising two acrylic polymers, the first being a caprolactone-modified branched acrylic polymer and the second being a caprolactone-modified linear acrylic polymer, the polymers being provided in a relative weight ratio of from about 5:95 to 95:5;
• and.
• (b) 10 to 50% by weight, based on the weight of the binder of a crosslinking agent selected from the group consisting of aminoplast resin, blocked polyisocyanates, or mixtures thereof.