Patent ID: 6790329
Filing Date: 2004-09-14
Classification: C09D,Y10T

Abstract:
A method of forming a coating filmwhich comprises, sequentially, process steps of applying an electrodeposition coating [1] to an article to be coated, a driving process step, and process steps of applying an electrodeposition coating [2] thereon, followed by a baking process step, wherein said process steps of applying the electrodeposition coating [1] comprise (i) a step of immersing the article to be coated in the electrodeposition coating and (ii) a step of applying a voltage between the article to be coated and the anode, said process steps of applying the electrodeposition coating [2] thereon comprise (i) a step of immersing the article to be coated in the electrodeposition coating, (ii) a step of applying a voltage higher than the voltage applied in step [1] (ii) between the article to be coated and the anode, said electrodeposition coating [1] containing a sulfonium group-containing resin, giving a film thickness to a face B of the article to be coated of not more than one tenth of the film thickness of a face A of the article when used in the electrodeposition coating of a coating with a resin solid matter of 20% by weight by a four sheet box method at 100 V and 40Â° C. for 120 seconds following a rise time of 5 seconds to provide the face A with a 20 to 30 &mgr;m film thickness, and said electrodeposition coating [2] having a time point at which the electric resistance value per unit volume of a deposited coat increases in the process of electrodeposition under a constant current condition.