GB941139A - Improvements in or relating to electrolytic capacitors - Google Patents

Abstract

941,139. Electrolytic capacitors. DUBILIER CONDENSER CO. (1925) Ltd. March 21, 1962 [April 6, 1961], No. 12372/61. Heading H1M. In an electrolytic capacitor the electrolyte is a resinous material having crosslinked polymer molecular networks with attached ionized, or ionizable molecular groups, e.g. sulphonated polystyrene. In an example shown in Fig. 1, two inter-twined helical tantalum wire electrodes A, A<SP>1</SP> are coated with tantalum oxide in a known manner and embedded in sulphonated polystyrene B, the capacitor being provided with an encapsulation C of plastics material compatible with the electrolyte B, e.g. a styrene material. The electrolyte is applied to the electrodes in two stages by immersing them in a solution of polystyrene, each coating being hardened in a known manner, the polystyrene being subsequently sulphonate by immersion in sulphuric acid. The electrolyte may be made depolarizing by immersion in a solution containing reducable ions, e.g. a ferric chloride solution. Further examples are illustrated in Figs. 2, 3 (not shown). In another example (Fig. 4), one electrode is formed by a conducting container H<SP>1</SP> housing an oxide coated electrode H embedded in sulphanated polystyrene J, a quantity of liquid electrolyte K, e.g. lithium chloride, being provided to fill a clearance space between the electrolyte J and the container H<SP>1</SP>. A somewhat similar example is illustrated in Fig. 5 (not shown). In a still further example (Fig. 6, not shown), the resinous material is included in a capacitor of rolled construction in a known manner.