Dual cure coatings, systems

Another mode of dual curing involves the simultaneous occurrence of free radical and cationic radiation-induced cross-linking polymerization of formulations containing appropriate initiators [20, 23, 28]. This method, which is called hybrid curing, leads to coatings with imique properties. A typical hybrid-cure system contains a diacrylate and a diepoxide, the former polymerizing by a free radical and the latter by a cationic mechanism. Exposure of the system to in-... 

Recent developments in powder coatings based on epoxy include UV-curable GMA-acrylic coating for antomotive parts lower temperature cure coatings for heat-sensitive substrates such as wood (222,223) and plastics and dual cure (ther-mal/UV) systems. 

Recently, Endo and coworkers have developed novel sulfonium type initiators that can initiate polymerization either upon irradiation or upon thermal treatment. In addition, these photoinitiators are shown to be functional for both cationic and radical polymerizations. This dual activity is particularly important in hybrid curing systems for coatings and adhesions [28]. Scheme 11.6 contains the general steps for the synthesis of these photoinitiators from sulfides. 

Fabrication of simple dual-band and dual-plate junction electrodes (similar to microgap electrode systems" ) was recently demonstrated with the development of ITO-epoxy-ITO electrodes. These electrodes consist of two ITO-coated glass slides stuck together with epoxy resin (cured under pressure from a weight to minimise gap size). The end of the electrode was sliced off with a diamond blade to reveal two ITO nano-bands separated by a layer of epoxy. This type of dual-band electrode was further improved by etching out the epoxy with Piranha solution to create a dual-plate... 

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