Novel Moisture Curable Epoxy Resins and Epoxy/Silica Hybrids Using Latent Hardeners

摘要

Epoxy resins have widely been used as adhesives and coating compounds in the industrial field. Most of them used outside such as in the fields of civil engineering have been used as a two-part form at room temperature. Various attempts have been made to develop one-part form using moisture latent hardeners such as ketimines(Fig.1). However, no such compound has yet been developed that exhibits good balance between shelf life stability and curability. The problem is basicity of them even though their amino groups are protected by ketone. Therefore the mixture of ketimine compounds and epoxy resins suffer from gelation on storage. It has been hypothesized that steric repulsion of ketimine from epoxied could be prevented the reaction between ketimine group and epoxied, and would remain stable state on storage. In this work, six kinds of ketimines, which cause defferent steric hindrance effects, have been studied as latent hardeners. On the other hands, ketone remains inside after curing and influence to their properties of cured resin. However, there have been no papers about them. Dynamic mechanical properties and lap shear strength of their curing system have been studied. Furthermore syntheses and evaluation of cured epoxy resins using silicone oligomers having ketiminie and alkoxysilyl group are also discussed.