Some recent developments with light-sensitive resin systems

Two general approaches in the development of light-crosslinkable resin systems with very good end-properties are summarised: (1) photoinitiation of the cationic polymerisation of epoxy resins, and (2)‘dual-functionality’ epoxies. The major known photoinitiators for epoxy cure are surveyed, and in particular various sulphonium salt types. Recent observations on sulphoxonium salts of different kinds, as new catalysts for the photo-cure of epoxy resins, are described.