GB1468670A - Anodes - Google Patents

Abstract

1468670 Anodes IMPERIAL CHEMICAL INDUSTRIES Ltd 19 July 1974 [2 Aug 1973] 36692/73 Heading C7B An anode assembly for an electrolytic brine cell comprises a pair of sheets 1 of a film-forming metal (Ti, Zr, Nb, Ta, W or alloy thereof e.g. Ti- Zr, Ti-Pt, Ti-Rh, Ti-Ir, Ti-Nb or Ti-Ta) and interposed between a metallic interlayer 2 having a higher electrical conductivity than that of the filmforming metal, e.g. of Cu, Al, Fe or steel, or alloys thereof, and being electrically and mechanically connected to the faces of the sheets by an electroconductive cement 3, preferably comprising an epoxy resin (e.g. condensation product of Bisphenol A with epichlorohydrin hardened with a crosslinking agent such as an amine) filled with a conductive metal powder such as Cu, Ag or Zn dust, the outer surfaces of the sheets being coated at least partly with an electro-catalytically active coating such as comprising at least one Pt group metal (Pt, Rh, Ir, Ru, Os, Pd) and/or an oxide thereof and an oxide of a film-forming metal (e.g. RuO 2 + TiO 2 ), Re, ReO 3 , magnetite, Ti nitride or a Pt group metal boride, phosphide or silicide. The interlayer 2 may be a solid sheet inserted between the outer sheets 1 to form a sandwich, or a foraminous sheet such as woven gauze or mesh, drilled plate or expanded sheet. A plurality of holes 5 may be provided for connecting to a current leadin e.g. of Cu. The assembly may be formed by applying the cement 3 to the surfaces of the sheets 1 and interlayer 2, assembling to form a sandwich and heating to effect curing whilst applying pressure. The outer plates are preferably coated by known painting, e.g. of thermally-decomposable Pt group metal compounds, and firing. Up to 50% of the Pt group metal oxide (and film-forming metal oxide) may be replaced by SnO 2 , GeO 2 and/or Sb oxides. The brine cell may be used for manufacturing chlorate or hypochlorite or (with diaphragm) chlorine. Specifications 1384996 and 1237077 are referred to.