Mark Markovitz

CONTROLLABLE REACTIVITY EPOXY RESIN HARDENERS

Epoxy resin hardeners having a wide reactivity range were prepared from organometallic compounds plus a phenolic compound or a phenolic resin. It is possible to formulate epoxy resins with these hardeners having a working life stability of months at room temperature to resins which gel instantly by varying the phenolic compound or its content. The organometallic compounds used were organic titanates, metal acetylacetonates and bis(trialkyltin) oxides. While many epoxy resins are only reactive toward certain classes of hardeners, every epoxy resin tested was cured by these controllable reactivity hardeners. The cured resins were hard solids with excellent electrical properties at 25 to at least 170°C. High heat distortion temperatures were also obtained with many of these compositions.