| 摘要 |
<p>This invention provides polymer forming resin systems and high solids solvent based chain-extendable, crosslinkable coating compositions comprising same. The invention comprises a polyepoxide, preferably a diepoxide, of molecular weight between about 100 and about 1000 used generally in amounts from about 10% to about 50% by weight of total resin, and novel diblocked diisocyanate diurea oligomers of molecular weight between about 300 and about 5000. The resin components provide chain-extension polymerization during cure at elevated temperature, in situ, on the surface of a substrate. The resin system is self-crosslinking. That is, no additional crosslinking component is required. The cured coatings of the invention provide greatly improved physical properties, in particular greatly improved corrosion resistance.</p> |
