Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
68 words
An electrode comprising a metal substrate of a metal chosen from the group titanium and niobium with an anodically active layer, the anodically active layer having been produced by heating in an oxidising atmosphere at temperatures in excess of 350° C., there being provided a layer of tantalum or an alloy containing more than 50% of tantalum in metallic form between the anodically active layer and the substrate.
Claim 2
Dependent Claim
68 words
An electrode comprising a metal substrate of a metal chosen from the group titanium and niobium with an anodically active layer, the anodically active layer having been produced by heating in an oxidising atmosphere at temperatures in excess of 350° C., there being provided a layer of tantalum or an alloy containing more than 50% of tantalum in metallic form between the anodically active layer and the substrate.
Claim 3
Dependent Claim
24 words
An electrode as claimed in claim 1 in which the anodically active layer contains a platinum group metal or a platinum group metal oxide.
Claim 4
Dependent Claim
83 words
An electrode as claimed in claim 1 in which the anodically active layer is chosen from the group: a spinel having the general formula X 2+ Y 2 3+ O 4 where X is a bivalent metal and Y is a trivalent metal; a cobalt based spinel of the general formula M x Co.sub.(3-x) O 4 where M is a metal chosen from the group copper, magnesium or zinc; manganese dioxide or TiO x where x is in the region 1.5 to 1.9.
Claim 5
Dependent Claim
17 words
An electrode as claimed in claim 2 in which the anodically active layer contains platinum and iridium.
Claim 6
Dependent Claim
20 words
An electrode as claimed in claim 4 in which some or all of the iridium is present as iridium oxide.
Claim 7
Dependent Claim
53 words
An electrode as claimed in claim 5 in which the electrode comprises a niobium substrate having a platinum and iridium containing coating as the anodically active layer with a thin layer of tantalum in metallic form interposed between the niobium and the platinum and iridium containing layer and metallurgically bonded to the niobium.
Claim 8
Independent Claim
86 words
A method of manufacturing an electrode comprising forming on a metal substrate of a metal chosen from the group titanium and niobium a layer of tantalum or an alloy containing more than 50% of tantalum in metallic form and applying to the tantalum layer a compound which on deposition forms an anodically active layer, heating the compound and substrate in an oxidising atmosphere at temperatures in excess of 350° C. for a time sufficient to decompose the compound to form the layer of anodically active material.
Claim 9
Independent Claim
86 words
A method of manufacturing an electrode comprising forming on a metal substrate of a metal chosen from the group titanium and niobium a layer of tantalum or an alloy containing more than 50% of tantalum in metallic form and applying to the tantalum layer a compound which on deposition forms an anodically active layer, heating the compound and substrate in an oxidising atmosphere at temperatures in excess of 350° C. for a time sufficient to decompose the compound to form the layer of anodically active material.
Claim 10
Dependent Claim
35 words
A method as claimed in claim 7 in which the anodically active layer contains a platinum group metal or platinum group metal oxide, and in which the compound contains at least one platinum group metal.
Claim 11
Dependent Claim
40 words
A method as claimed in claim 8 in which the heating takes place at a temperature in the range 350° C. to 850° C., or 400° C. to 650° C., preferably further in the range 400° C. to 550° C.
Claim 12
Dependent Claim
56 words
A method as claimed in claim 9 in which the tantalum layer is applied to the metal substrate by an extrusion technique in which a billet of titanium or niobium is covered with a layer of tantalum and the billet is subsequently extruded at elevated temperatures to metallurgically bond the tantalum to the niobium or titanium.
Claim 13
Dependent Claim
99 words
An electrode as claimed in claim 1 in which the electrode is in the form of an elongate rod having a series of longitudinally extending protuberances along the length of the rod and around the circumference, there being provided the anodically active coating on the surface of the rod within some at least of the regions between the proturberances, there being provided between five and twenty protuberances, the spacing and height of the protuberances being such that a straight line connecting the peaks of two adjacent protuberances does not intersect with the body of the electrode between the protuberances.
Claim 14
Dependent Claim
13 words
An electrode as claimed in claim 11 in which there are eight protuberances.