Aqueous coating composition and method for forming metallic coating film using same

An aqueous coating composition comprising a coating film-forming resin, a curing agent, a scaly pigment, an inorganic viscosity agent, a hydrophobic associative viscosity agent, and a dispersant, wherein

• the composition contains the inorganic viscosity agent in an amount of 2 to 5 parts by mass based on 100 parts by mass of the total resin solid content of the coating film-forming resin and the curing agent,
• the inorganic viscosity agent is at least one selected from the group consisting of natural hectorite, synthetic hectorite, natural bentonite and synthetic bentonite,
• the composition contains the hydrophobic associative viscosity agent in an amount of 1 to 15 parts by mass based on 100 parts by mass of the total resin solid content of the coating film-forming resin and the curing agent,
• the hydrophobic associative viscosity agent is a urethane-based hydrophobic associative viscosity agent,
• at least one of the film-forming resin, the curing agent, the scaly pigment, the inorganic viscosity agent, and the dispersant has at least one hydrophobic group, and
• the composition has a nonvolatile content (NV) of 3% to 10%.