Epoxy phenolic resins are phenolic resins modified at the phenolic hydroxyl group to include an epoxide functional group (usually a –CH2-(C2H3O) group, where -(C2H3O) is the three-membered epoxide ring). The added functionality of the phenolic resin increases the ability for the resin to crosslink, creating a stronger polymer with high resistivities. A common type of epoxy phenolic resin is epoxy phenol novolac, in which the phenolic resin is a phenolic novolac resin, consisting of short polymers between 10-20 repeating units.
These resins are often used as coatings or resistive top coats for drums, pipes, floors, tanks and automotive parts. The high chemical and solvent resistivities and temperature compatibility of epoxy phenolic resins are most useful in high-performance applications and corrosion resistance.