The interest for hydroxyl-functional acrylic resins as a component in polyurethane coatings has increased not only because of improved performance through crosslinking, but also because of higher non-volatile content. Hydroxyl
This
article presents new possible approaches for alkyd resin architecture in order
to comply with market constraints related to VOC emissions. Examples and
performance of alkyd concepts are presented with regard to VOC content and
performance for “interior/exterior trim and cladding paints for wood and
metal”.
The isocyanate reaction between an isocyanate group and a hydroxyl group has been known since 1849 when Ann Wurtz obtained the first patent in this field (German Patent 71326). The polymer, containing a repetitive moiety that results from the reaction between an isocyanate group and a hydroxyl group, is a polyurethane. Its morphology depends on the structure and nature of the diol and the respective isocyanate.
