Electric insulation contg. beta:keto acid ester as voltage stabiliser - in opt. crosslinked (co)polyethylene to increase breakdown strength

摘要

Electrical insulant (I) contains an ester (II) of a beta-keto acid as voltage stabiliser. (II) pref. is an acetoacetic ester of ethyl, (iso)propyl or a linear or branched fatty alcohol with max. 20C, whilst (I) is polyethylene or its copolymer with propylene, vinyl acetate or ethyl or butyl acrylate and pref. is crosslinked, e.g. with peroxides. Pref. the mixt. also contains C black or a light mineral filler (A1 silicate or CaCO3), which pref. has an organic (silane) coating. (I) is an amorphous rubber. (II) is used in conjunction with an aromatic oil. The material is suitable for high voltage applications and has improved breakdown strength. A better long term effect is obtd. with the longer chain esters.