BILAYER FILM FORMATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a bilayer film formation method yielding an excellent finish and corrosion resistance without affecting electrodeposition coatability even if a water washing process following a chemical treatment is partially or entirely dispensed with; and a coated object.SOLUTION: The provided bilayer film formation method is a bilayer film formation method including the following processes for forming a chemical treatment film and an electrodeposition coating film atop a metal-coated object: process 1: a process for forming a chemical treatment film on a metal-coated object by immersing the object within a chemical treatment liquid; and process 2: a process for forming an electrodeposition coating film by electrodeposition-coating the metal-coated object by using a cationic electrodeposition coating material while partially or entirely dispensing with a water washing process wherein the electroconductivity of the solution adhered to and/or residing on the metal-coated object at the time of electrodeposition coating during the process 2 is below 10,000 μS/cm.