Sealed electrolytic capacitor prevented from drying out and loss of function

摘要

This novel multilayer material seals the top of an electrolytic condenser can (2). The substrate is sandwiched by an outer elastomeric layer and an internal sealing layer. An additional spacer layer lies between the substrate and inner sealing layers. This is an elastomer, or other rubbery material. Preferably the same elastomer forms spacer layer and covering. The spacer layer is ethylene propylene terpolymer. The substrate is an impregnated paper multilayer and the sealing layer is polypropylene. Phenolic resin forms the impregnation. Layers are pressed together and cross-linked or vulcanised. The sealing layer may be coated-on subsequently. The spacer layer is up to 50% of the thickness of the covering layer.