Several imines were synthesized and evaluated as water-initiated hardener for epoxy resin. Imines with a lower electron density on the CϭN carbon showed a faster hydrolysis rate. Diethyl ketone-based imines were the most efficiently hydrolyzed among the imines examined, and the adhesive properties of epoxy resin with diimines used as the hardeners were evaluated. A novel diethyl ketone-based diimine, N,NЈ-di(1-ethylpropylidene)-m-xylylenediamine (10), served as an efficient latent hardener of epoxy resin. Epikote 828 containing 10, filler, and dryer increased the adhesive strength faster than Epikote 828 containing filler and dryer with methyl isobutyl ketone-based imine. The mixed system of epoxy resin and 10 showed good storage stability at room temperature.

The hydrolyses of several imines and their reactions with glycidyl phenyl ether were examined under highly humid conditions as a model study for the development of water‐initiated hardeners for epoxy resins. Diethyl ketone‐based imines were hydrolyzed more efficiently than methyl isobutyl ketone‐based imines. The reactions of glycidyl phenyl ether with the imines depended on their hydrolysis rates and the basicity of the amines generated from them. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 971–975, 2002

ABSTRACT:The curing and adhesive properties of one-component epoxy resins containing Epikote 828 and diimines, derived from N, N,, and N,NЈ-di(1,3-dimethylbutylidene)-m-xylylenediamine, which were used as water-initiated hardeners, were examined. Diethyl ketone-based imines with a lower electron density on the CAN carbon were efficiently hydrolyzed and showed curing activity. 2, a novel diethyl ketone-based diimine, served as an efficient latent hardener of the epoxy resin. A paste of the epoxy resin with 2 showed good storage stability at room temperature and good adhesive properties.

It was demonstrated that the reaction of epoxide and imine as a latent initiator under highly humid conditions was accelerated by addition of 5‐phenoxymethyl‐1,3‐oxathiolane‐2‐thione (1). When 1 was added to a mixture of glycidyl phenyl ether and an imine, the reaction of the epoxide with an amine released from the imine became faster than was the case without 1, that is, 1 worked as a promoter of the reaction. The curing rate and initial adhesive strength of epoxy resin increased compared with that without 1. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4276–4283, 2004

This article deals with curing of a one-component epoxy resin containing a bifunctional five-membered cyclic dithiocarbonate 1 with an imine 2 as a latent initiator. When 1 was added to a mixture of epoxy resin and 2, the curing rate and initial adhesive strength increased higher than that without 1. It was supposed that the reaction of 1 and an amine released from 2 was much faster than the amine-epoxide reaction, and a thiol group formed by the reaction of 1 with the amine accelerated the amineepoxide reaction. The adhesive strength of the onecomponent epoxy resin containing 10 mol % of 1 exhibited the highest value.