摘要 |
The present invention relates to a film forming composition, a method of forming the composition, and application of the composition to coating formulations which provide a cured coating having acid rain resistance. A film-forming polyurethane polyol composition comprises a reaction product of an n-functional isocyanate (wherein n is a number ranging from about 2 to about 5) with at least one diol or triol or mixtures thereof and a compound containing isocyanate-reactive functional groups, preferably a monofunctional alcohol or thiol. The low viscosity polyurethane polyol of the present invention is typically cross-linked/cured using a melamine to produce a cured coating which is highly acid etch resistant as well as having other desirable physical-mechanical properties. The coating compositions have improved flow characteristics compared to compositions containing polyurethane polyols prepared without the monofunctional alcohols or thiols. |