| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an aqueous coating material composition that is superior to the conventional coating materials in low-temperature curability, is also excellent in storage stability and can be suitably applied to a painting system for forming a laminate coating film, and to provide a method that can produce a painted product such as an automotive body or the like using the aqueous coating material composition while assuring good physical properties and quality.SOLUTION: The aqueous coating material composition includes an aqueous resin (A), a melamine resin (B) and a weak acid catalyst (C). The aqueous resin (A) has a hydroxyl value of 80-200 mgKOH/g in terms of resin solid content and the melamine resin (B) has an average number of imino groups per melamine nucleus of 1.0 or more and an average number of methylol groups per melamine nucleus of 0.5 or more. The aqueous coating material composition has a mass ratio of the aqueous resin (A) to the melamine resin (B) of 90/10 to 60/40 in terms of solid content, has a content of the weak acid catalyst (C) of 0.1 to 10.0 pts.mass, provided that the total of the aqueous resin (A) and the melamine resin (B) is 100 pts.mass.</p> |
