EPOXY-AMINE ADDUCT WATER SOLUBLE ACID, AND PHENOPLAST OR AMINOPLAST CROSSLINKER AQUEOUS COATING COMPOSITION

摘要

1. An aqueous coating composition which comprises (a) a dispersion in an aqueous medium of a product obtained by mixing as the sole film-forming components of the mixture and heating, (i) an epoxy-amine adduct having ionizable nitrogen-containing groups, and (ii) a crosslinking agent for the adduct which is free from carboxyl groups selected from phenol/formaldehyde and aminoplast resins, or blends of these resins to effect an increase in viscosity of the initial mixture of (i) and (ii), and (b) an acid which is capable of ionising the nitrogencontaining groups in the product defined in (a), there being present sufficient of said acid to neutralise at least 30% of the nitrogen-containing groups in and form a stable dispersion of said product in the aqueous medium. The composition has improved stability at high pH values and at elevated temperatures and is particularly suitable for cathodic deposition.