Abstract
Polymerization of one-component epoxy resins by imines as water-initiated latent hardeners can progress through two reactions which are hydrolysis of imines and the reaction of epoxide with amines released from the imines. This one-component system has been inappropriate for practical use because of slower curing. In these reactions, the hydrolysis reaction of imines is commonly very slow, resulting in rate-determining step of curing.
It is most important, therefore to develop new imines showing faster hydrolysis. Several imines were synthesized and their hydrolysis rates were investigated. Imines with lower electron density on the C=N carbon werw found to have faster hydrolysis rates. Especially, one-component epoxy resins with imines synthesized from diethyl ketone and aliphatic amines showed faster curing rates than those with common imines. These epoxy resins showed good adhesive strength and durability as same as two-component epoxy resins. The one-component epoxy resin system with the novel diethyl ketoen-based imines was clarified to be appropriate for practical use.
