| abstract |
(57) [Problem] To be excellent in corrosion resistance, solvent resistance, alkali resistance, paint adhesion, film adhesion, bath stability, and suitable for coating steel materials such as zinc-coated steel or uncoated steel. Provided are a liquid-type water-based coating agent for steel, a method for coating steel with the coating agent, and a coated steel. SOLUTION: The aqueous dispersion resin has a solid content concentration of 5 to 30% by mass, the silica particles have a concentration of 0.1 to 20% by mass, and a urea compound, a phosphonate compound, a thiophosphonate compound, a phosphine oxide compound and a hydroxy group-containing sulfide compound. An aqueous coating agent for steel, wherein at least one selected from the group consisting of 0.01 to 5% by mass is blended. |