GB877637A - Acid electrolytic copper-plating baths - Google Patents

Abstract

877,637. Copper-plating baths. DEHYDAG DEUTSCHE HYDRIERWERKE G.m.b.H. March 30, 1960 [June 6, 1959], No. 11129/60. Class 41. Copper-plating baths are improved by adding a basic dyestuff which contains an ethenyl chromophore i.e. one or more groups > C = C < and nitrogen, e.g. cyanine, acridine, pyronine, quinoline, tri-phenyl methane, thiazole, and thioflavine dyes. These act as levelling agents at low current densities. There may also be present lustering agents, e.g. N mono- or disubstituted dithiocarbamic acid alkyl ester sulphonic acid, 1.3.5-triazine-2.4.6-tris-mercapto alkane sulphonic acid, thio amides and iso thio amides having a sulphonic group. In addition, to render mains water usable, there may be added amino compounds free of carboxyl groups, e.g. N: N-dimethyl bromaniline, 3-diethyl amino-1-chlorpropanol 2, and halogen salts of quaternary ammonium compounds. Wetting agents, e.g. polyethylene oxide addition products may be present. The deposition of anode mud is prevented by adding sulphonic acid salts, e.g. Na salt of azido-propane sulphonic acid. In examples, the dyestuffs added are thioflavine, p-dimethyl-amino-triphenyl carbenium chloride, 3-3<1>-diethylthiocyanine iodide thiopyronine and an indolenine dye.