摘要 |
<p>In order to provide a water-based coating composition for surface treatment of metallic materials having excellent chemical resistance, corrosion resistance, solvent resistance and adhesion, a cationic aqueous urethane resin (F) is prepared, which is obtained by chain-elongation of a cationic urethane prepolymer (D) using water or a polyamine compound (E), the cationic urethane prepolymer (D) being formed by neutralized a tertiary amino group by an acid or quaternarized the tertiary amino group by quaternarizing agent, the tertiary amino group being included in a urethane prepolymer comprising, as components thereof, a compound (A) having two or more active hydrogen atoms, an organic polyisocyanate (B), and a chain elongation agent (C) having the tertiary amino group.</p> |