Flexible epoxy in curable tape form

In recent years developments in fusible tapes have added a new vista of convenience and quality for the motor manufacturer. These flexible tapes have made it possible to manufacture coils which are protected against moisture and dust, and in some cases eliminating the need for totally enclosed motors. Laboratory efforts by the Irvington Division of 3M have been directed toward providing this same convenience and protection with an epoxy resin. The inertness, physical properties, and electrical qualities of epoxy resins have been well established; however, these properties to date have been realized only with encapsulating resins, and rigid glass reinforced composites. A new epoxy compound which cures to give a tough permanently flexible reisn has been developed for this application, and is supplied as an uncured coating on a nonwoven polyester web tape. This flexible epoxy resin in curable tape form has extended the utility of this class of resins by providing protection equivalent to complete encapsulation in applications where encapsulation with a fluid resin is physically impractical, and where the usual glass reinforced composites are unsuited because of their rigidity.