| 摘要 |
A coating system for application to a substrate having a sol-gel film layer applied thereon includes a residual high acid value coating coat applied on top of the sol-gel film without an intervening adhesion layer. The residual high acid value coating composition may be a solvent borne composition that when cured, has a high level of residual free acid groups, equivalent to an acid number of greater than about 65 mgKOH/g. The residual high acid value coating may include a residual high acid value resin namely, a resin that cures having residual free acid groups, equivalent to an acid number of greater than about 65 mgKOH/g. The residual high acid value resin may be the reaction product of a polyol and a suitable crosslinker, such as a polyanhydride or polyisocyanate crosslinker or blend thereof. The residual high acid value coating composition may include opacifying pigments and condensation catalysts. |
