| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an aqueous coating agent capable of forming a coating film excellent in terms of adhesiveness to a metal, in particular, and having favorable scratch resistance as well as water resistance and acid resistance under high-temperature conditions.SOLUTION: The provided aqueous coating agent is an aqueous coating agent including a polyester resin (A), a resol-type phenolic resin (B), a basic compound, and an aqueous medium. The polyester resin (A) includes at least 50 mol% of an aromatic dicarboxylic acid as a polybasic acid component and at least 20 mol% of a linear glycol possessing no side chains as a polyhydric alcohol component. The acid value is 5-40 mgKOH/g, and (A)/(B) is 95/5-30/70 (mass ratio). The polyester resin has a number-average molecular weight of at least 4,000 and a glass transition point or melting point of 40 to 100°C. The aqueous coating agent includes virtually no surfactant but includes a crosslinking agent.</p> |
