Nippon Paint Compnay, Ltd.

Takanobu Ueda

Toshiharu Nakaya

Akimitsu Uenaka

Hidefumi Okuda

Aqueous coating composition comprising water insoluble resinous powder, aqueous resin, pigment and other optional additives including hardener, characterized by the fact that said water insoluble resinous powder is composed of a polymer obtained by reacting a mixture of epoxy resin and a resin having epoxy reactive functional groups, or a resin having both epoxy groups and epoxy reactive functional groups, with an amine in an amount sufficient to cause ring-opening of 10 to 50% of the total epoxy groups, or composed of carboxyl bearing resin admixed and reacted with high boiling basic compound. These compositions are excellent in storage stability, application characteristics and film performance.

Aqueous coating composition and preparation thereof

An aqueous coating composition which comprises a carboxy group-containing resin powder (I), a basic compound (II) and an aqueous resin (III), optionally with a reactive compound (IV) to at least one of the resin powder (I) and the aqueous resin (III), in an aqueous medium, the basic compound (II) being contained in an amount of 0.4 to 1.2 equivalents to the carboxy group in the resin powder (I) so as to disperse the resin powder (I) into the aqueous medium and the weight proportion of the resin powder (I) and the aqueous resin (III) being from 2:98 to 98:2. The coating composition thus obtained is excellent in storage stability and workability and can provide a coating film having good performances.

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Hirakata, Japan

Takanobu Ueda