| 摘要 |
<p>A copper film is formed on a non-porous siliceous substrate such as glass or ceramic by contacting it with an aqueous solution of a stannous salt such as the chloride, bromide, iodide or sulphide, then with an aqueous silver salt solution containing a reducing agent such as prepared by mixing an ammoniacal silver salt solution, e.g. containing silver nitrate, sulphate or chloride and NH4OH, with a reducing solution e.g. containing formaldehyde, dextrose or invert sugar, to deposit a "flash" silver film, and contacting the silvered substrate, e.g. by spraying, immersion, roll coating, brushing or screening, with a copper salt solution containing a reducing agent such as formaldehyde, in the presence of a nickel or cobalt salt. The copper salt solution is preferably alkaline, e.g. made by adding NaOH and contains the sulphate, nitrate, chloride, phosphate, bromide, iodide or acetate of Cu and Ni or Co ; copper formate or tartrate may also be used, and the solution may additionally contain sodium-potassium tartrate. The copper film may be thickened electrolytically and provided with a protective film of plastic or other material, e.g. quartz, alumina, MgF2, Sn/Co/Fe/Ni oxide. The method may be applied to the manufacture of solar energy reflectors, copper mirrors, insulating glass units and heat-insulating oven door units. Specifications 819,179, 894,870 and U.S.A. Specification 2,838,810 are referred to.</p> |
