| 摘要 |
1365111 Coated surface ALLEGHENY LUDLUM INDUSTRIES Inc 1 Sept 1971 [1 Sept 1970] 40845/71 Heading B2E [Also in Division C7] A metal surface, e.g. steel, brass, Al, Ag, Zn, Cu, Pb, Cr, Ni, Au, Pt or alloys of these metals is coated with a composition comprisping phosphate, chromium, and ammonium ions in a concentration between 0.01 and 1.00 moles per 100 ml. of water in the proportion of 27 to 73 mole % phosphate ion, 5 to 39% mole % chromate ion, and 0.5 to 35 mole % ammonium ions, in which silicate ions, e.g. alkali metal silicate, are present in a concentration of 0.01 to 33% of the molar concentration of phosphate, chromate, and ammonium ions. The composition may also contain 0 to 23 mole % Mg. The phosphate ion may be supplied as orthophospheric acid, magnesium, ammonium or magnesium-ammonium phosphate. The chromate may be chromium trioxide or the chromate or dichromate of magnesium or ammonium. Magnesium may be the oxide, hydroxide, carbonate, bicarbonate, phosphate or chromate. Wetting agents may be added to the solution. |
