Patent ID: 7473444

Claim:
A method of forming a coating film on a vehicle body comprising the steps of: (i) coating the vehicle body with a thermosetting and photocurable clear coating composition to form a wet coating film, (ii) heating the wet coating film at 70° C. to 160° C. for 10 to 20 minutes to obtain a semicured coating film having a hardness between 2B to H on the pencil hardness scale, (ii′) grinding and polishing the semicured coating film, and (iii) irradiating the semicured coating film with ultraviolet light having a wavelength of 200 to 450 nm at a dosage of 500 to 1,500 mJ/cm 2 for 3 to 60 seconds to cure the coating film; wherein the clear coating composition comprises a resin containing one or more radical-polymerizable unsaturated groups and one or more thermosetting functional groups per molecule (A), a crosslinking agent (B), a photopolymerization initiator (C), and an organic solvent (D).