| abstract |
A chemically converted Al-type plated steel plate that is good in weather resistance, water resistance and coating adhesion is described. A treating solution for a chemical conversion is coated on an Al-type alloy plated steel plate, and is dried to form a chemical conversion coating of 0.5-10 μ m thick. The treating solution contains an F-containing olefin resin, and an oxoacid salt, fluoride, hydroxide, organic acid salt, carbonate or peroxide salt of a 4A-group metal. The F-containing olefin resin has a number-averaged molecular weight of 1, 000-2, 000, 000, and contains 0.05-5 wt% of hydrophilic functional groups selected from the group consisting of carboxyl, sulfonic acid group and salts thereof, and 7-20 wt% of fluorine. In the treating solution, the metal-basis amount of the oxoacid salt, fluoride, hydroxide, organic acid salt, carbonate or peroxide salt of the 4A-group metal is 0.1-5 wt% relative to the F-containing olefin resin. |