| 摘要 |
1445395 Electro-deposition of gold-coppercadmium alloys SCHERING AG 3 Sept 1973 [14 Oct 1972] 41330/73 Heading C7B An alkaline aqueous electrolyte for the electrodeposition of a gold alloy contains (i) an alkali metal gold cyanide, (ii) an alkali metal copper cyanide, (iii) an alkali metal cadmium cyanide and (iv) elemental selenium and/or a selenium compound capable of forming selenocyanate ions in an alkaline cyanidic liquid. Suitable Se containing compounds are SeO 2 , alkali metal selenides, methyl selenocyanate, selenium cyanoacetic acid, dipropyl diselenide, potassium ethyl selenosulphate, sodium selenite and sodium or potassium selenocyanate. Specified conditions are a pH of 9-12, adjustment of pH with H 3 PO 4 and KOH, a temperature of 50-70‹C, a current density of 0À3-2À0 amps/sq. dm and current which is normal D.C. or reversing or modulated current. By changing the conditions used, it is possible to obtain deposits with colours from gold to red. In the Examples, the electrolytes additionally contain (1) alkyl-phenol polyglycol ether and (2) methoxy-polyethylene glycol. |
