| 摘要 |
1373712 Mixed oxide coatings C CONRADTY 11 Jan 1972 [20 March 1971] 1199/72 Heading C1A [Also in Divisions C7 and B2] An electrode comprises a main body of valve metal having a base coating and a surface coating. The valve metal may be Ti, Ta, Nb, Zr, Hf, W or Mo. The base coating may be Bi, Cd, Co, Cu, Fe, Ge, Mb, Ni, Pb, Se, Sb, the Rare Earth metals, Sn, Ag, Au, the Platinum Group metals or alloys of any of these metals and/or carbon. The surface coating is a mixture of (I) titanium dioxide or tantalum dioxide, (II) at least one oxide of Ta, Nb, W, Mo, Sb, Fe, Co, Mn, Sn, (III) an oxide of Mg, Ca, Sr, Ba, Ga, Sn, Pb, Sb, Bi, Se, Te, Cu, Cd, the Rare Earth metals, Mn, Fe, Co, or Ni. In Fig 2, the electrode comprises a main body a, abase coating b and a surface coating c. The base coating may be interrupted by scratching before the surface coating is applied. In Example I a platinum base coating is electrodeposited and the surface coating produced as follows: a 30% solution of hydrogen peroxide is added to a bath containing Ferric nitrate nonahydrate 400 gms. Manganese nitrate tetrahydrate 120 gms. Cobalt nitrate hexahydrate 150 gms. Stannous chloride dihydrate 225 gms. Titanium trichloride 150 gms. 3% Hydrochloric acid 5 litres 125 gm. of tantalum pentachloride dissolved in hydrogen peroxide is added. The solution applied to the platinum plated body for 10 min. at 300‹ C. After 20 such coatings the electrode is stored for 30 min at 400‹ C. Examples 2, 3, 4, 5 disclose similar methods for making complex oxide coatings on metal base coatings. In Examples 6-8 the base coating is carbon produced by butane pyrolysis or vapour deposition. |
