Лако-красочные материалы — производство

In water-reducible waterborne epoxies, acidic or basic functionali­ties are introduced into an epoxy polymer, which upon respective

neutralization with a fugitive base or acid, generates an ionic group that renders it water reducible (Figure 2.57).

Acid functionalized epoxy resins are generally prepared by este­rification of epoxy resin with an excess of acid equivalents, or by grafting of acrylic copolymers containing methacrylic acid or acry­lic acid onto the epoxy backbone. They are generally cured by an aminoplast at elevated temperature.

Base-rich epoxy resins are prepared by reaction of epoxy resins with an amine (preferably a secondary amine). These types of epoxies are commonly employed in cathodic electrodeposition coating, often cured by a blocked isocyanate and termed thermal curing.