The curing characteristics

kinetics and reactivities of the diglycidyl ether

diglycidyl ester type resins and aliphatic cycloepoxy resins cured with imidazole have been studied by DSC. The results of dynamic and isothermal DSC show that thd whole curing reactions proceed in two stages

that the apparent activation energy in the first stage of various epoxy resin

except the H-71 epoxy resin

is higher than that in the second stage

and that the reactivity of the cycloaliphatic epoxy resins with imidazole is higher than those of bisphenol A type epoxy resin and diglycidyl tetrahydrophthalate resin. It was found that in the co-curing systems of the aliphatic and cycloaliphatic epoxy re-sins with imidazolem

m-phenylene diamine and anhydrides as curing agents

the former com-ponent can accelerate the reaction considerably.