Metal acetylacetonates as latent accelerators for anhydridehyphen;cured epoxy resins

Abstract Twenty‐two metal acetylacetonate compounds have been evaluated as possible latent accelerators for epoxy‐anhydride solventless resins. Experimental data have revealed that titanium (IV) oxyacetylacetonate, chromium (III), zirconium (IV), cobalt (III), and cobalt (II) acetylacetonates are particularly effective with anhydride cured epoxy resins. When added to the resin at a level of 0.05–0.10% (w/w), they provide very fast gel times at 150–175°C combined with very good storage stabilities (> six months) at room temperature. The power factor values of cured resin samples, containing these preferred metal acetylacetonates, have been found to be between 2.0 and 2.5% at 150°C and 60 Hz. Correlation between the catalytic effectiveness of these metal acetylacetonates, as latent accelerators for epoxy‐anhydride resins, and their thermal stabilities suggest that decomposition products may be the active species responsible for initiating polymerization in epoxyanhydride resin systems.