Epoxy resins of controlled conversion and a process for their preparation

摘要

Epoxy resins containing both terminal hydroxyl groups and epoxy or epoxy-derived groups are prepared by advancing a polyepoxide with a polyol and terminating the reaction at a point such that the epoxy resin reaction product contains both epoxy and terminal hydroxyl groups. The controlled conversion resins have improved cure rates. The epoxy groups can be further reacted to form epoxy-derived groups to improve the cure rate even further. The epoxy resins exhibit lower melt and solution viscosities than those exhibited by conventional epoxy resins having the same epoxy equivalent weight, as well as curing quickly when used. The resins are usefully employed at high solids levels in can coating formulations and other epoxy formulations wherein the resin is applied from an organic liquid solution or aqueous dispersion.