GB1314534A - Electropolytic capacitor - Google Patents

Abstract

1314534 Electrolytic capacitors MATSUSHITA ELECTRIC INDUSTRIAL CO Ltd 18 Sept 1970 [18 Sept 1969 26 March 1970 (3) 27 March 1970 (2) 10 April 1970] 44600/70 Heading H1M The electrolyte in an electrolytic capacitor comprises a gel with a non-aqueous organic solvent trapped within the gel structure and an ionogen in the solvent. The gel may be formed from natural polymers, e.g. agar, gelatine or synthetic cross-linkable polymers. To form the gel, the solvent, ionogen and polymer are mixed and introduced into the capacitor casing and heated in the presence of a crosslinking agent for the polymer, usually an acid and possibly the ionogen itself. Examples of polymers are polymethylolacrylamide, methoxymethyl nylon and other alkoxyalkyl nylons, optionally graft-polymerized with phenol, urethane intermediates with functional groups and the reaction product of heating a styrene-maleic anhydride copolymer with hexamethylenediamine. The cross-linked polymer may be a charge-transfer complex contributing to the electronic conductivity, e.g. polymers containing nitrogen cations. The acceptor may be 7,7,8,8-TCNQ. A photosensitive resin, e.g. polyvinyleinnamate may be used, in which case cross-linking agent and heating are unnecessary. Addition of an alcohol to the electrolyte is stated to permit higher forming voltages. Numerous examples of specific electrolytes are given, disclosing well known solvents and ionogens.