| 摘要 |
<p>An improved process for forming multiple coats of finishes on a substrate by sequential (a) applying to the substrate a layer of a color basecoat composition of waterborne coating composition of an acrylic polymer latex contains pigment; (b) applying to the layer of color basecoat composition before it is fully cured a clear coat composition of an acrylic polymer having cross-linkable groups and a cross-linking agent in a volatile organic solvent and (c) subsequently simultaneously curing the basecoat composition and the clear coat composition; the improvement used therewith comprises a solvent based clear coating composition having a binder of about 40-95 % by weight of an epoxy acrylic polymer having at least one alkyl methacrylate having 2-12 carbon atoms in the alkyl group, and glycidyl methacrylate or acrylate and having a weight average molecular weight of about 3,000-10,000 and a glass transition temperature of about -20 to +50 °C; and 5-60 % by weight an organic polysiocyanate; wherein the clear coat when cured has a water vapor permeability value of about 1400-3200.</p> |
