1986 Volume 59 Issue 1 Pages 2-8
Viscosity behavior during the baking of melamine resin cured acrylic high solids coatings was measured by an oscillating plate rheometer with heating unit. Viscosity behavior was greatly influenced by molecular weight of acrylic resin, and the linear relationship between the molecular weight and the logarithmic value of amount of flow, F, which can be regarded as an index of levelling and sagging properties was observed. The influences of acrylic resin/melamine resin ratio, blocking agents for acid catalyst, setting time and the baking condition on the viscosity behavior were also studied. From these results, high solids coatings generally give larger F values than conventional type coatings, and the influences of baking conditions of high solids coatings on the F value were greater than that of conventional coatings.