COATING WITH LEAD-FREE
ELECTRODEPOSITION COATING
Patent No. U.S. 7,294,410 B2
Honda Motor Co., Ltd. and Nippon Paint Co., Ltd. have been granted a patent for a method for coating an alloyed hot-dip galvanized steel plate with a cationic electrodeposition coating composition in which the lead content thereof is less than or equal to 10 ppm, and which includes a binder resin and a plurality of pigments. The method is comprised of electrodepositing the lead-free cationic electrodeposition coating composition onto the alloyed hot-dip galvanized steel plate, wherein the binder resin includes a cationic base resin and a crosslinking agent, and the pigments include 5- 30% by mass of pigment formed from a compound having an aluminum-containing cation and a phosphate-containing cation, and 5-30% by mass of a silicon oxide pigment having a pore volume of 0.44-1.8 ml/g and an average particle size of approximately 10 μm or less.