GB1323255A - Electric insulators - Google Patents

Abstract

1323255 Electrical insulator SIEMENS AG 29 June 1971 [30 June 1970] 30498/71 Heading H2C An electrical insulator comprises an electrically insulating body 1 which may be vacuum formed of casting resin having embedded control electrodes 6, 7 made of casting resin mixed with an electrically conductive additive, e.g. graphite or silicon carbide. The insulator and the control electrodes may use the same casting resin although the control electrode may be made more flexible by using the required hardener. The conductivity of the electrode should be 1-100 Áratios/cm. Threaded metal bushes 4, 5 are embedded in the electrodes. The insulator may be cycloaliphatic casting resin containing as a hardener hexahydrophthalic acid, in parts by weight of 100 : 70 respectively. The electrodes may be of 100 parts by wt. cycloaliphatic casting resin, 70 parts by wt. methylhexahydrophthalic acid anhydride and 175 parts by wt. of graphite powder or alternatively 100 parts epoxy resin based on bisphenol-A with an epoxide equivalent of 190, 250 parts by wt. of acid ester of caster oil and phthalic acid, and 1000 parts of crushed silicon carbide.