| 摘要 |
1. Electrolytic bath for the deposit of thin layers of pure gold on passive surfaces, containing from 0.5 to 20 g/l of gold under the form of a gold cyanide of alkali metal, in which gold is trivalent, and at least an acid which is present in a sufficient concentration so as the pH of this bath is at most of 0.4, characterized in that the acid is selected from the group comprising the sulfuric acid, the sulfamic acid, the pyrophosphoric acid, the mono-, di- and tri-chloroacetic acids, the malic acid, and the 1-hydroxy-1, 1-ethylidene-diphosphonic, hydroxy-methylphosphonic and amino-tris(methylene-phosphonic) acids, and the mixtures thereof. |
