| 摘要 |
A chromium electroplating electrolyte containing trivalent chromium ions, a complexant, a buffer agent and organic compound having a -C=S group or a -C-S group within the molecule for promoting chromium deposition. The complexant is preferably selected so that the stability constant K1 of the chromium complex is in the range 10<8> < K1 < 10<1><2> M<-><1>.
<??>Complexants within this range include aspartic acid, iminodiacetic acid, nitrilotriacetic acid or 5-sulphosalicylic acid. Suitable organic compounds having a -C-S group include thiourea, N-monoallyl thiourea, N-mono-p-tolyl thiourea, thioacetamide, tetramethyl thiuram monosulphide, tetraethyl thiuram disulphide and diethyldithiocarbonate. Suitable organic compounds having a -C=S group include mercaptoacetic and/or mercaptopropianic acid. |
